* GB784618 (A)

Description: GB784618 (A) ? 1957-10-09

Improvements in or relating to the production the antibiotic griseofulvin

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j PATENT SPECIFICATION Inventors: ALAN RHODES, RODGER CROSSE, THOMAS PRIMROSE FERGUSON and DEREK LAWRENCE FLETCHER 784,618 Date of fling Complete Specification (under Section 3 ( 3) of the Patents Act, 1949): March 14, 1956. Application Date: March 28, 1955. Application Date: March 28, 1955. Complete Specification Published: Oct 9, 1957. No 9012/55. No 9013/55. Index at acceptance: -Class 2 ( 3), AA 1 (B: CIB: CID 1), AA 2 C 2. International Classification: C 12 d. COMPLETE SPECIFICATION Improvements in or relating to the Production of the Antibiotic Griseofulvin A ERRATA SPECIFICATION No 784,618 Page 4, line 22, for "When" read "Where" Page 4, line 36, for "quantitatively" read "qualitatively" Page 7, line 18, for "of" read "or" Page 8, line 25, for "used" read "use" Page 11, line 101, for "taken" read "take" Page 15, in the Table, line 10, for" 5 59 "read " 6.59 " Page 16, in the Table, line 1, for " 465 " read " 475 " Page 16, in the Table, line 6, for " 6 85 " read " 6.84 " Page 16, in the

Table, line 13, for " 8/07 " read " 8 07 " Page 16, in the' Table, line 15, for " 8 13 " read " 9 13 " Page 18, line 65, for "source" read "course" Page 20, line 99, for "is" read "in" Page 21, line 39, for "asd" read "and" THE PATENT OFFICE, 29th October, 1957. etd-a (t'cci k); and Mac Millan, Chem, & in August 25th 1951, p 719) it appears di griseofulvin has been produced in surfa, cultures only from iat least three species mould namely P griseofultum, P jcwczews A and P putulum. The antibiotic griseofulvin possesses valuab antifungal properties, and inter alia is very sui I tu L ort-ne antibiotic contained in the whole d broth In general, a griseofulvin producing at organism should be used in the fermentation ce which produces, under deep culture conditions, of at least 150 micrograms (,ug) of griseofulvin per ml, of broth, it being understood that the culture is carried out under the condile tions specified herein, and for a period t until mycelial break-down just commences A d 4 i i 1 I ?.PATENT SPECIFICATION Inventors: ALAN RHODES, RODGER CROSSE, THOMAS PRIMROSE FERGUSON and DEREK LAWRENCE FLETCHER 784618 Date of filing Complete Specification (under Section 3 ( 3) of the Patents Act, 1949): March 14, 1956. Application Date: March 28, 1955. Application Date: March 28, 1955. Complete Specification Published: Oct 9, 1957. No 9012/55. No 9013155. Index at acceptance:-Class 2 ( 3), AA 1 (B: CI 1 B: C 1 D 1), AA 2 C 2. International Classification:-C 12 d. COMPLETE SPECIFICATIC Improvements in or relating to the Produi Griseofulvin We, GLAXO LABORATORIES LIMITED, a British Company of Greenford, Middlesex, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention is concerned with improvements in or relating to antibiotics, and in particular relates to a process for the production of griseofulvin under deep culture conditions. Griseofulvin is a known antibiotic, which has been shown to possess important antifungal properties Its structure was first established by Grove et dat (Chem & Ind 17th March 1951, page 219) and the following structure was assigned by them to the antibiotic:o.ca 3 O O %C 5 CH 3O A li l = Uy Q OCH 5 The production and isolation of griseofulvin on a large scale has hitherto proved difficult. Thus from the literature (see Oxford et al, 7 Biocnhem XXXIII ( 2),

240, ( 1939); Brian et al Trans Brit Mycot Soc 29, 173 ( 1946); Grove et al, Nature 160, 574 ( 1947); Grove et al (toc cit); and Mac Millan, Chem & Ind. August 25th 1951, p 719) it appears that griseofulvin has been produced in surface cultures only from at least three species of mould namely P griseofulvum, P janczewskii and P pahtltm. The antibiotic griseofulvin possesses valuable antifungal properties, and inter alia is very suitthe Antibiotic able for use as an antifungal agent, particularly in agriculture for use for example in fruit and other sprays or as a seed dressing. The use of an antibiotic, particularly on a large scale, such as for agricultural purposes, requires that it can be cheaply produced in large quantities The methods of producing griseofulvin hitherto proposed have all involved the surface culture of various moulds, a technique which is by no means suited to large scale production. We have however now found that it is possible to obtain griseofulvin on a large scale, and more conveniently than hitherto, by culturing suitable organisms under submerged aerobic culture conditions, and by paying careful attention to various factors governing the culture. As is known, various species of the genus Penicillium produce griseofulvin in differing quantities when grown on suitable media It is difficult to specify exactly which species are suitable for the production of griseofulvin by submerged fermentation, and indeed there is considerable variation amongst stains of a particular species Perhaps the simplest method of determining which strains may be used for satisfactory deep fermentation is by carrying out trial fermentations, according to, the method of this invention, and selecting such strains as produce a reasonable level of the antibiotic The antibiotic is found mainly in the mycelium, and in determining the amount produced reference is made to Ithe amount of the antibiotic contained in the whole broth In general, a griseofulvin producing organism should be used in the fermentation which produces, under deep culture conditions, at least 150 micrograms (jug) of griseofulvin per ml, of broth, it being understood that the culture is carried out under the conditions specified herein, and for a period until mycelial break-down just commences A strain which produces at least 200 micrograms (j/g) per ml should desirably be used, and we prefer to use a strain producing at least 500 micrograms (jug) per ml. One strain that we have found to be particularly suitable for the process according to the invention is that known as Penicillitumn patulum &inier T 7 rom ( 4640,455) C M I. 39,809 lNRRL ( 989) as P urticce Bain (A)I 0 G Smith 1949 l This strain and mutants thereof is at present preferred since it has been found to give a high yield of griseofulvin under different submerged

culture conditions. Moreover, this strain and mutants thereof has shown no substantial tendency to produce dechlorogriseofulvin when grown under the conditions specified herein, even applying tests sensitive to one microgram/ml As is known, the dechoro compound has markedly less antifungal activity than griseofulvin itself, and is of little value. Other strains which have been tested and which have been found more or less suitable are the following: Asymmetrica Fasciculata (P urticcae series):Penicillium patulumn CMI 28,808 Bainier Coll-Thom ( 4640-454). NCTC ( 1722) 1932-NRRL 994, ATCC 9260 Penicillium lrtice Bain, (Rg 8 g) (P griseoftivzrm) C B S Baarn Asymmentriaa Disaricata (P nigricans series): Pekiciittin nigrt'cancs (Bain) (Zaleski). C.B S Baarn. Penici 1 imil jarczewskii Zal. C.M I 29,100 (Soil, Lakenheath Warren Suffolk 1947-J H Warcup B 25) Penicillium albdum Sopp C M I. 40,219 Peniciliutnm, aciborskii Zal C M I. 40,568 (?T) Peniciliumn melinii Trnom C M I 40,216 It has been found that in order to achieve the relatively high yields of griseofulvin which are afforded by the present invention under deep culture conditions, the fermentation should take place under certain either essential or preferable conditions. In general terms, the media to be used in the process according to this invention should include a source of nitrogen, a source of carbon anid energy, and nutrient salts Purely synthetic media (wherein, for example, the nitrogen is present as sodium nitrate) may be used; however, we prefer to use media wherein the nitrogen is provided by complex organic materials, since as is known-such materials frequently have the advantage of supplying growth factors often desirable to support good growth of micro-organisms Suitable complex nitrogenous materials include, for example, corn steep liquor (CSL) milk products such as whey powder, buttermilk, liquid whey, cottonseed meal, oatmeal and soya bean meal The choice of these materials wvill depend largely on availability and cost, but is also influenced by other factors in the fermentation technique employed, for example ease of control of p H 70 The final choice must depend on the balance of advantage in any given circumstances. Good results can also be obtained by the use of two or more different nitrogen sources together, as for example a mixture of corn steep 75 liquor and whey powder or liquid whey. The source of carbon and energy is preferably a carbohydrate such as lactose, glucose, sucrose or starch For economy, these may preferably be supplied in impure forms as 80 waste products from other processes,

for example in the form of milk products media, molasses, or sulphite waste liquor Fats may be used for this purpose, but carbohydrates are preferable As with the nitrogen source, 85 the final choice will depend on the balance of advantage in any given circumstances. The nutrient salts which should be present particularly include phosphates A source of chloride ions and magnesium ions is also pre 90 ferable, especially if the other nutrients used are deficient in available chlorine and magnesium. We have found that the most fundamentally important factor in successfully carrying out 95 the invention is to control the level of available nitrogen in the medium Although it has been found possible to produce griseofulvin within a wide range of available nitrogen levels in the medium, we have found that this 103 level markedly influences the yield of griseofulvin, and for commercially satisfactory yields must be carefully controlled at rather lower levels than might be expected. According to this invention therefore we 105 provide a process for the production of griseofulvin under submerged aerobic conditions which includes the step of culturing a griseofulvin-producing organism in a culture nedium which will support the growth of said or 110 ganisi, for the production of griseofulvin, said mrediutrincluding an assimilable source of nitrogen at a level of O 04 % 5 to 0 30 % of N, a scurce of carbon and energy, and nutrient salts. For optimum results we find that the avail 115 able nitrogen level is preferably between about 0.075 % and 0 25 %, We find that the optimum nitrogen level shows some variation with type of inoculum and type of fermenter For example, in 250 ml shake 120 flasks the nitrogen level of the medium is optimal around 0 2 %, when a spore suspension is used as inoculum, but around 0 10.15 % when a 5 % vegetative inoculum is employed In 150-gal fermenters we have ob 125 tained very satisfactory yields of griseofulvin with a nitrogen level of 0 2 % in the medium and a vegetative inoculum This variation of the optimum nitrogen level can be seen from the following table 130 784,618 TABLE A Treatments 7 days 8 days 9 days 10 days 11 days Nitrogen Inocula Carbohydrate Level p H Assay p H Assay p H Assay p H Assay p H Assay Lactose 0 24 % 6 43 593 6 29 973 6 61 1080 7 07 1455 6 89 1230 , 0 17 % 6 40 664 6 20 902 6 45 952 6 71 1173 6 65 1318 , 0 10 % 6 45 840 6 31 1730 6 37 1564 6 68 1292 6 55 2625 Glucose 0 24 % 7 20 656 7 21 700 7 72 772 7 66 772 7 83 872 , 0 17 %o 7 20 532 7 20 810 7 51 861 7 66 933 7 68 1108 Veg,, 0 10 % 6 24 930 6 39 1220 6 88 726 7 06 884 6 83 1176 Inoc. Sucrose 0 24 % 6 85 641 7 62 620 8 03 536 8 25 582 , 0 17 % 7 36 541 7 63 618 7 71 678 7 95 700 7 78 804 , 0 10 % 6 57 1070 6 51 1162 6 87 842 7 13 933 7 32 836 Starch 0 24 % 8 18 517 7 86 532 7 94 535 8 25

602 8 47 470 , 0 17 % 7 97 397 7 63 535 7 77 702 8 02 604 8 33 612 , 0 10 % 6 86 1055 6 65 733 7 18 568 7 46 731 7 68 798 Lactose 0 24 % 6 63 302 6 19 308 6 18 287 6 58 332 7 03 570 , 0 17 % 6 71 339 6 26 301 6 69 333 7 01 400 7 28 682 , 0 10 % 6 60 259 6 09 300 6 23 342 6 38 386 6 41 360 Glucose 0 24 % 7 56 586 7 25 638 7 57 653 7 80 892 7 77 802 , 0 17 % 7 39 764 7 05 730 7 51 572 7 73 602 7 73 725 Spores,, 0 10 % 6 44 640 6 78 604 7 76 659 7 08 596 Direct Sucrose 0 24 % 7 37 376 7 53 642 7 74 589 8 05 823 , 0 17 % 7 59 495 7 35 598 7 52 777 7 83 720 8 08 930 , 0 10 % 7 01 496 6 61 472 6 65 372 6 99 456 7 06 532 Starch 0 24 % 7 51 561 7 33 570 7 55 612 7 83 618 8 11 602 , 0 17 % 7 40 578 7 01 443 7 61 574 8 01 575 8 27 573 , 0 10 % 7 20 303 6 31 238 7 39 471 7 47 381 7 57 475 Veg Lactose 0 17 % 6 72 698 6 87 855 6 29 884 6 65 800 6 16 1016 Inoc (Chalk) 00 a O cl, The media employed to carry out the fermentations whose results Jare tabulated above were as follows:C.S L solids to give 0 1 %, 0 17 % lor 0 24 % N. Lactose, Glucose, Sucrose or Starch 7 % K Hl PO 4 O 4 % KC 1 O 1 i% Limestone 0 8 % (or in one case precipitated chalk) The following factors are also important in the successful practice of the invention to obtain the best results:(a) As stated above it is preferred that the source of carbon and energy should be a carbohydrate The carbohydrate level should preferably be rather higher than might be expected. The level of carbohydrate can be as low as 3.5,%, or even lower, but we prefer that it should be above 51 % The upper limit is not critical, but will not normally exceed about 12 % When the carbohydrate is supplied in impure form, e g as molasses, it will of course be understood that these percentages refer to the carbohydrate content of ithe final medium, and will require correspondingly higher perTABLE B centage additions of the impure carbohydratecontaining material At stated above, sources of carbohydrate conventionally used in fermentation procedures are all available for use in the present process, including glucose, brown sugar and starch, but at present we prefer to use lactose We find: however, that the beneficial effect of lactose only becomes apparent when a vegetative inoculum is used, as can also be seen quantitatively from ithe above Table A. The beneficial results to be obtained from high levels of carbohydrate can be seen quantitatively from the following Table B. Source and 7 days 8 days 9 days 10 days 11 days 12 days Quantity of Carbohydrate p H Assay p H Assay p H Assay p H Assay p H Assay p H Assay 7 % Lactose 6 11 552 6 13 734 6,91 1300 6 41 1352 6 60 1135 3.5 % Lactose 6 74 510 6 84 636 6 51 772 6 65 604 7 28 534 7 79 600 7 % Glucose 7 07 613 7 02 775 7 85 778 7 45 754 7 64 837 7 85 862 3.5 % Glucose 7 89 473 7 91 471 8 47 500 8 43 470 8 40 514 8 71 498 7 % Sucrose 7 37 625 7 53 555 8 15 583 7 85 544 7 87 634 7 83 675 3.5 % Sucrose 8 10 388 8 08 448 8

68 432 8 56 409 8 52 491 8 79 467 7 % Starch 7 08 503 7 59 684 7 92 606 7 57 813 7 62 826 8 09 917 3.5 % Starch 7 98 272 8 27 302 8 64 298 8 53 285 8 45 310 8 71 294 In the above table the results were obtained using a vegetative inoculum in the following media:C.S L solids to give 0 17 % N. Lactose, Glucose, Sucrose and Starch 7 % or 3 5 % KHIPO 04 O% KCI 0 1 %/ Limestone 0 8 % (b) the p H of the medium is not critical, but should preferably be adjusted to between 4.5 and 5 5 before the fermentation commences During the course of ithe fermentation the p H rises, and when complete is frequently of the order of 6 5 to 8 Griseofulvin itself is stable within the p H range of from 3 0 to 8 8. In order to make any necessary initial adjustment of the p H, and in order to buffer the fermentation, we have found it advantageous to add to the medium between 0 4 and 1 2 % of phosphate and/or O 4-1 2 c% of limestone or chalk It is at present preferred to employ 0 4 % to 0 8 % of KHIPO, or K HPO, and 0.8 % of limestone It may be noted that these substances also act as nutrient salts land that the phosphate in particular has a very beneficial effect on the yield of griseofulvin The 4. 00 o 00 on presence of limestone greatly diminishes pig the effects of phosphate and of limestone we mentation of the broth In order to illustrate now give the following two tables C and D. TABLE C p H of Medium and Level of Limestone in Lactose-C S L Medium Treatments 6 days 8 days 11 days Limestone Phosphate Level Level p H Assay p H Assay p H Assay Nil Nil 6 20 197 6 32 362 7 20 452 ,,, 6 06 180 6 20 300 6 97 326 , O 4 % 5 84 248 6 03 289 6 84 655 ,,,, 5 84 325 6 00 250 6 73 624 , O O 8 % 5 84 270 6 07 380 6 64 515 ,,,, 5 84 280 6 00 442 0.4 % Nil 6 63 139 6 74 7 47 423 ,,,, 7 27 165 6 75 250 7 38 410 ,, 0 4 % 6 54 227 6 75 340 7 71 568 ,,,, 6 51 248 6 59 370 7 71 652 , 0 8 % 6 42 229 6 73 325 7 43 830 ,,, 6 49 227 6 81 325 7 58 798 0.8 % Nil 6 70 133 6 82 152 7 93 304 ,,, 6 89 133 7 12 200 8 08 312 , O 4 % 6 63 257 6 68 315 7 45 532 ,,, 6 62 253 6 58 312 7 48 631 , 0 8 % 6 61 248 6 81 315 7 59 672 ,,, 6 60 253 6 68 289 7 43 684 1.2 % Nil 6 78 152 7 03 252 7 97 307 ,,,, 6 93 148 7 31 277 7 99 381 ,, O 4 % 6 55 270 6 85 320 516 ,,,, 6 52 293 6 67 350 7 37 521 , O 8 % 6 61 238 6 76 292 7 37 611 ,,, 6 60 227 6 65 334 7 27 582 These results were obtained using the lactose-C S L medium I described below, and from them it will be seen that where the carbohydrate source is lactose the ititres respond very favourably to the presence of phosphate, but only slightly to limestone However, 784,618 784,618 undesirable brown pigmentation occurred in the absence of the latter The next table shows that using an otherwise similar medium, in which, however, glucose replaced lactose, and with two different sources of phosphate at a level of 0 4 % in each case, the beneficial effects of limestone

on the titre are much more marked Here again the presence of limestone also reduced pigmentation. TABLE D p H of Medium and Level of Limestone in Glucose -C S L Medium Treatments 6 days 8 days 9 days Limestone Level Phosphate p H Assay p H Assay p H Assay Nil KHIPO 4 6 05 475 6 76 535 7 i 1 570 ,,, 6 18 518 6 85 525 7 11 448 0.4 %,, 6 38 448 7 40 608 8 80 400 ,,, 6 36 485 8 39 626 8 06 620 0.8 %,, 6 85 473 7 44 740 8 88 633 ,,, 6 85 450 7 45 672 8 97 550 1.2 %, 6 88 525 7 30 584 8 13 592 ,, 6 84 535 7 41 760 8 02 522 Nil K 2 HPO, 6 42 480 7 24 670 7 83 512 ,, 6 40 450 7 27 658 7 83 510 0.4 %, 6 85 608 7 56 678 7 95 648 ,,, 6 94 606 7 51 708 8 08 681 0.8 %,, 7 28 625 7 50 735 8 07 634 ,,, 7 36 612 9 06 548 1.2 %, 7 21 602 7 58 740 9 13 736 ,,, '6 94 545 9 13 623 (c) The degree of aeration should be good. It appears in general that, within limits, the greater the aeration the higher will be the yield of griseofulvin, and this is particularly the case the higher the level of nitrogen in the medium It is however impossible to quote precise values for the aeration, for as is well known the degree of aeration depends not only on the actual rate of air supply but also on the efficiency with which it is used, which in turn depends on many other variables too numerous to detail, including the size and shape of the fermentation vessels and the manner in which ithe air is introduced. The effect of increased aeration is illustrated in the following table E, in which results are given for a series of fermentations carriel out employing media in which the nitrogen level was in each case 0 15 % but in which the carbohydrate sources varied Volumes of mls, 60 mls and 80 mls respectively of broth were in every case shaken in 250 ml flasks It will be understood that the lower the broth volume the greater was the aeration. Except las regards the carbohydrate source the medium employed in each case was similar to the C S L lactose medium I described below, inoculated with 1 ml, 1 5 mls and 2 mls respectively of a submerged spore suspension. 784,618 TABLE E Treatments 6 days 7 days 8 days Broth Carbohydrate Volume p H Assay p H Assay p H Assay mls 6 47 255 6 41 300 318 6.47 137 6 41 256 Lactose 60 mls 6 34 140 6 12 6 33 110 6.56 218 6 18 6 33 380 mls 6 67 187 6 56 270 6 41 208 7.03 158 6 41 218 6 47 205 mls 7 74 475 7 81 652 8 08 655 7.74 443 7 81 500 8 08 655 Brown Sugar 60 mls 7 75 441 7 57 515 7 59 606 7.61 395 7 74 505 7 84 593 mls 7 63 505 7 24 537 7 73 500 7.64 386 7 34 430 7 62 453 mls 7 47 585 7 57 675 932 7.47 554 7 57 727 Glucose 60 mls 7 52 562 7 50 615 7 70 708 7.52 546 mls 6 68 418 7 05 573 7 57 650 6.35 368 7 12 537 (d) The medium must contain a proportion of available chlorine in order to avoid formation of dechloro

griseofulvin Provided that sufficient chlorine is present, the level does not appear to be critical If complex organic materials are used as the nitrogen source, these usually contain some proportion of chlorine We have however found that it is usually convenient to ensure satisfactory results by making additions of at least 0 1 % and preferably of between O 1 and 0 25 % of suitable soluble chlorides and we prefer at present to employ approximately O 1 % of KC 1. (e) The inoculum employed can be either a spore suspension of a freely-growing vegetative inoculum, but the latter is to be preferred. Where a spore suspension is used to inoculate a 150 litre seed-stage vessel we have found it satisfactory to employ 150 mls of suspension having a count of approximately 18 x 100 spores per ml When well-grown this vegetative inoculum is used at a level between 1 and % for inoculation of the fermentation medium. We now give, by way of illustration only, three examples of media which have proved satisfactory for the production stage of the process. a) Medium for subme'rgetd fermentation (I) C.S L solids Lactose KC 1 K Ho PO, Limestone Natural p H 2.85 % (= O 15 % N) 7.0 % 0.1 % 0.4 % 0.8 % b) Medium for submerged fermentation (II) Whey 5 73 8 % _ 3 5 % lactose Lactose 3 5 % 60 1 % nitrogent KH 2 PO 4 0 4 % KC 1 0 1,% C.S L solids 0 38 % (givingapprox. Natural p H 0 035 % N) c) Medium for submerged fermentation (III) C.S L solids 2 85 % ( 0 15 % N) Starch 7 O % K Cl 0 1 % K Hm PO 4 Limestone Natural p H 0.4 % 0.8 % is The temperature at which the fermentation is effected is not apparently critical, but we at present prefer to employ a temperature of approximately 250 C It is also often desirable to /add an antifoam agent to the fermentation, such as white mineral oil, conveniently in an amount in the medium of from 0 25 to 0 75 %. It has been found that in order to bring about sporulation of the griseofulvin-producing mould for the purpose of preparing a spore suspension suitable for used as an inoculum, either for a development or production stage, particularly in the case of the preferred strain Peunicillium patiulum Bainier-Thom, it is not in general satisfactory to employ the normal production medium We have however found that spore suspensions can be produced in a submerged medium provided certain requirements are met In particular it is desirable that the total available nitrogen level of the media used for the production of spore suspensions should be below 0 25 %, and preferably lie between 0 05 and 0 1 %, and also that good aeration should be maintained, the latter factor being perhaps the more important The optimum values of these factors vary slightly from strain to strain of the organism. We have found that there is a marked interaction between the nitrogen

level and the aeration which is necessary, the lower the aeration the lower being the level of nitrogen that is required As lan illustration, we -have found that 600 mls of a medium in which whey is used as the nitrogen source to give a nitrogen level of about 0 05 %, and which includes suitable proportions of lactose, phosphate, chloride and corn steep liquor, when strongly shaken in a 2 litre flask at 250 C for six days gave prolific sporulation We will now give, by way of illustration, an example of a medium that has been found suitable for the sporulation stage of the process. Medium for submerged sporulation of P patulum Bainier Thomn (IV) Whey Powder approx 2 84 % to give 0 05 % 1 N 1.725 % lactose Lactose KH 2 PO, K I C.S L solids Natural p H 1.775 % 0.4 % 0.05 % 0.38 %, to give approx. 0.04 % O N. As previously mentioned, the spore suspension obtained from the sporulation stage can either be used for direct inoculation of the fermentation stage proper, or it can be subjected to development in any suitable medium 70 to yield a vegetative inoculum for the fermentation stage This latter course is at present preferred, particularly where the carbohydrate source in the fermentation stage is to be lactose; where glucose is used in the fermenta 75 tion stage the advantage derived from a vegetative inoculum is not so apparent The conditions governing the development stage of the process are in general not unlike those in the final fermentation stage, and we have found 80 that satisfactory results can be obtained with various development media, including either of the media I or II described above for the fermentation stage of the process. We have found that griseofulvin produced 85 by the fermentation remains to a major extent, e.g 90 %, in the mycelium itself rather than passing into 'the broth, unless the fermentation is allowed to proceed too far, in which case the mycelium breaks down and the griseo 90 fulvin may become distributed throughout the broth The extraction of griseofulvin from the broth itself presents difficulties We therefore prefer to take advantage of the retention of the griseofulvin in the mycelium, and to stop the 95 fermentation before break-down of the mycelium occurs to any substantial extent. The extraction of the antibiotic can be carried out in any convenient manner Methods for performing this extraction have been pre 100 viously proposed for surface cultures, and in general such methods are suitable for use in the process of this invention. We now give by way of example a general description of our preferred methods of 105 extraction. The mycelium is separated from the broth, preferably by filtration at a p H which should be lower than 8 0 The filtrate, which contains

approximately 10 %,% of the griseofulvin pro 110 duced, is generally then discarded, although if desired the antibiotic may be recovered therefrom by separate extraction techniques. The mycelial solid is extracted with an organic solvent, for example, ethyl acetate, 115 n-butanol, amyl acetate or preferably butyl acetate The extraction is conveniently carried 784,618 The air-flow was about 3 cubic feet per minute, (cf/m) for the first twentyfour hours and was then increased gradually to 8 cf/m. as growth developed and foaming subsided. The temperature was 250 C with stirring at 350 revolutions per minute (rpm) The seedstage was transferred to the fermentation medium at 28 hours. Fermntation stage 450 litres of the following medium were used: CSL solids, to give Nitrogen 0 2 % Lactose 7 % Limestone 0 8 i% KH 2 PO 4 0 4 % KC 1 0 1 % No p H adjustment Sterilised 20 mins at C. The fermentation medium was inoculated with 10 % vegetative inoculum from the seedstage fermenter. Air-flow was maintained as near to 10 cf/m. as possible for the first eight hours, and was thereafter approximately 20 cf/m The temperature was 25 C and the stirring rate was 350 rpm. White mineral oil was used as antifoam as required. Details of the fermentation were as follows:out by mixing the mycelium and solvent together, preferably at an equal weight/volume. for a period of approximately 15 minutes, and then separating them by sedimentation and S Recantation This extraction procedure should preferably be repeated two or more times The decanted solution is then preferably clarified by centrifugation or by filtration, and concentrated, preferably under vacuum so that the 'temperature does not exceed 50 C The concentrat Ion is carried out to the fullest extent practicable, and the concentrate is then allowed to cool to 20 C or thereabouts, and the solid filtered off If, as is commonly the case, some oily liquid has been extracted from the mycelium at the same time as the griseofulvin, any oil adhering to the solid is washed off by mixing it with some suitable solvent, for example butyl acetate, in equal weight/volume ratio and refiltering The washed solid is dried, preferably under vacuum, for example over phosphorous pentoxide at room temperature The crude griseofulvin thus obtained may be purified by dissolving it in an organic solvent such as acetone, filtering, and precipitation by the addition of water, in which griseofulvin is not soluble to any extent. This procedure can if necessary be repeated, and the product is then dried yielding pure crystalline griseofulvin. In order that the invention may be well understood, we shall now give,

by way of illustration only, an example of a small scale production process for griseofulvin:Precparation of Spord suspension 600 mls. of the following medium were autoclaved in a 2-litre conical flask:Lf'actose 3 5 % Whey powder, to give t 'Nitrogen 0 05 % KH 2 PO, 0 4 % KCI 0 05 % C.S L solids 0 38 % (to give approx. 0.04 % N) The flask was inoculated with 'a suspension of spores from a well sporulated Czapek-Dox agar culture of Perdicillium patulum Bainier Thom ( 4640,455) C M I 39,809, and incubated on a shaker at 25 C for seven days By this time the culture had produced abundant submerged spores. Vegetativse seed-stage 150 litres of the following medium, contained in a stirred fermenter, were inoculated with 150 mls of the suspension of submerged spores containing approximately 18 x 106 spores/ml: Whey powder} Lactose 3 5 % Lactose 5 to give Nitrogen O 11 % KH 2 PO 4 O 4 % K Ci 0 1 % C S L solids 0 38 % (to give approx 0 04 % N) No p H adjustment Sterilised 20 minutes at C. Log hrs. 0 56 114 138 162 Titre 530 910 1355 1675 The batch on solvent extraction by the pro 100 cedure previously described gave 150 gins of % pure griseofulvin.

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* GB784619 (A)

Description: GB784619 (A) ? 1957-10-09

Improvements in or relating to cold shaping of steel

Description of GB784619 (A)

PATENT SPECIFICATION 784619 Date of Application and filing Complete Specification May 26,

1955. No 15185/55. Application made in United States of America on May 27, 1954. Complete Specification Published Oct 9, 1957. Index at Acceptance:-Classes 83 ( 2), A( 40: 123); and 83 ( 4), Q 1 (B Q), Q 2 (A 3: A 5 AX: B: H), V 2, Z. International Classification: -B 21 d B 23 d, p. COMPLETE SPECIFICATION Improvements in or relating to Cold Shaping of Steel We, AMERICAN RADIATOR AND STANDARD SANITARY CORPORATION, a corporation organized under the laws of the State of Delaware, United States of America, of 40, West 40th Street, City of New York, State of New York, United States of America, (Assignees of BEN KAUL), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to cold shaping steel and has more particularly to do with the cold working of a tubular steel article to very accurate dimensions and by such cold working, providing one or more surfaces of the article with an extremely smooth finish. In many articles of manufacture, such as hydraulic or pneumatic pistons and cylinders, it is necessary to form the work pieces with very accurately dimensioned mating surfaces having an extremely smooth finish in order to prevent leakage of fluid between these surfaces when in use For example, in the case of accumulators it has heretofore been the practice to finish the ir(er surface of the accumulator cylinder by a honing operation in order to obtain the degree of accuracy and smoothness required of such surfaces The operation of honing such cylinders is not only costly and time consuming, but does not always result in a surface having the dimensional accuracy and smoothness desired. The present invention contemplates a method and apparatus for forming such smooth and accurately dimensioned surfaces on tubular work pieces without the necessity of a honing operation, and it is accordingly an object of the present invention to form such surfaces solely by cold working operations. According to one feature of the present invention a method of producing elongate hollow articles which are provided with very smooth, axially extending surfaces and which are extremely straight in an axial direction comprises, cold extruding a hollow blank to lPricsubstantially the same size and shape as required of the finished hollow article and thereafter axially straightening said cold extru 50 ded blank and smoothing out the irregularities on the axially extending surfaces thereof by a series of cold working operations

comprising relatively moving into contacting relation one surface of the side wall of the blank and an 55 axially straight metal flowing tool so that the blank assumes the axial alignment of the tool and thereafter ironing out the opposite surface of the blank side wall by applying pressure thereto in excess of the elastic limit of the 60 metal while the first surface is temporarily deformed by said tool to thereby bring said wall into permanent axial alignment with said tool and to permanently smooth out the irregularities in the surface thereof 65 According to a further feature of the present invention a method of producing elongate hollow articles which are provided with very smooth, axially extending surfaces and which are extremely straight in an axial direction 70 comprises, cold extruding a hollow blank to substantially the same size and shape as required of the finished hollow article and thereafter axially straightening said cold extruded blank and smoothing out the irregularities 75 on the axially extending surfaces thereof by a series of cold working operations comprising inserting into said hollow article an axially straight, smooth walled punch which is dimensioned to deform the blank into at least tem 80 porary axial alignment with the punch and at the same time elastically deform the irregularities on the inner surface of the blank so as to conform to the smooth walls of the punch and while said blank is so temporarily and 85 elastically deformed, relatively moving the punch supported blank axially through an annular die dimensioned to cold work the outer surface of the blank beyond the elastic limit of the metal of the blank 90 Thus the invention contemplates an arrrangement of a punch and a die arranged to successively operate on a tubular work piece, first to flow metal in one direction to 784,619 smooth out any imperfections and roughness on the surfaces desired to have the extremely smooth finish and then to flow the metal in the wall of the work piece to produce a permanent deformation of such metal so that the surface of the work piece originally worked upon is substantially permanently set in the condition resulting from its contact with the first die or punch with which it is engaged. In practicing the present invention it is preferred to dimension the first die or punch that is brought into contact with the work piece only sufficiently different from the dimension of the work piece worked upon to smooth out any irregularities or out-of-roundness on the surface on which the extremely smooth finish is to be provided The second punch or die is dimensioned to engage another surface of the work piece while the work piece is still mounted on the first punch or die to compress the wall of the work piece against the first punch or die and thereby permanently iron out such irregularities or roughness in the surface of the work piece. It is appreciated that such work pieces cannot be heat treated

subsequent to the surface finishing operation if they are to maintain their dimensional accuracy, and the present invention therefore also contemplates the development of the hardness required in the finished work piece solely by such cold working operations. Thus, when necessary, the tubular article worked upon is, prior to the surface finishing operation given a stress relief, for example at 900 to 950 F for a S A E 1010 or 1012 steel, so that the subsequent cold working will raise the hardness to that required of the finished article. The invention wil be further described by way cf example with reference to the accompanying drawings which illustrate one embodiment of ithe invention and in which:Fig 1, 2, 3, 4 and 5 are somewhat diagrammatic view S taken along the line x-x in Fig. 6 showing the successive operations of the apparatus employed in accordance with the invention for producing the smooth surface referred to on a cylindrical work piece. Fig 6 is a view taken generally along the line 6-6 in Fig 1, Fig 7 is a view taken along the line 7-7 in Fig 1, Fig 8 is an enlarged fragmentary view showing in an exaggerated manner the operation of the punch on the work piece, and Fig 9 is a view similar to Fig 8 and showing the manner in which the die operates on the work piece. The process of the present invention is adapted for finishing tubular work pieces of most any type Such a work piece is shown generally at 10 The work piece 10 is in the form of a cylinder having a side wall 12 of substantially uniform thickness and a bottom wall 14 which may be of irregular or regular shape The work piece 10 is preferably formed of a low carbon or mild steel Such a work piece lends itself admirably to being formed by a cold extrusion process such as disclosed in our prior British Patents Nos 718,506 and 70 718,590 Normnally, when a tubular work piece such as show %n at 10 is formed by a series of cold extrusion operations as disclosed in said co-pending patents, the work piece possesses a substantially uniform hardness throughout 75 wvhich is developed solely by cold working If the hardness of the blank 10 is at or substantially at the hardness required of the finished article, then the blank is subject to a stress relief treatment to reduce the hardness a 80 desired amount so that the subsequent cold working operations again raise the hardness of the article to that desired of the finished work piece In our process, the extent of hardening by cold working the blank to produce the 85 finished articles can be calculated or estimated; and therefore, if the blank is not of the correct pre-hardness,, it is a simple matter to stress relieve the blank to an extent necessary to obtain the hardness desired in the subsequent 90 cold vworking The temperature at which the blank is stress relieved should be maintained

within a prescribed range depending on the carbon content of the steel and its hardness created by prior cold working operations For 95 example, in the case of having cold worked S.A E 1010 or 1012 steel to a hardness of 95 Rockwell B, than a stress relief of 925 F. + 25 is preferred so that the hardness can be reduced to 85 to 90 Rockwvell B so that the 100 final hardness after working the metal as set forth herein is raised to 98 to 100 Rockwell B. The higher the ultimate strength produced by cold working, the higher the yield strength, the less the elongation, and the higher 105 the spring back If the stress relief anneal is too low, the elastic limit may be exceeded during subsequent cold working causing cracking and galling If the strees relief is to high, the elongation is greater and although the metal 110 stays where it has been displaced, it would not have the required final strength or hardness. A hardness of 90 Rockwell B is the critical point above which subsequent cold working may cause trouble The thickness of the wall 115 also limits the amounts of cold working A thin wall will stand less cold working than a thick wall to obtain the same hardness and ultimate strength. The blank 10 is initially formed slightly 120 less than the nominal dimensions required of the finished work piece The blank, whether it be formed by cold extrusion, drawing, etc, necessarily has at least a slight degree of out-of-roundness depending upon the length and 125 the diameter of the blank In addition, there will be slight irregularities on the inner and outer surfaces of the blank walls as shown at 11 and 13 in Figs 8 and 9. Assuming that the blank 10 is of a hard 130 size of the punch with respect to the inner diameter of the blank will depend upon several factors; primarily, upon the diameter of the blank and the out-of-roundness of the blank. The extent of oversize of the punch is pre 70 ferably just sufficient to smooth out the inperfections and roughness on the inner surface of the blank wall and to eliminate any out-ofroundness of the blank. Considering for the moment only the opera 75 tion of the punch 24 shown at the left of Fig. 1, when the punch assembly is moved downwardly to the position shown in Fig 2, the punch will engage within the bore of the blank seated in ring 30 and will slightly expand Su the blank as it moves progressively downwardly into the blank. Referring now to Fig 8 wherein the out-ofroundness of the surface irregularities on the blank 10 are shown in a somewhat exagger 85 ated form it will be observed that as the punch 24 travels downwardly into blank 10, it smooths out the irregularities 11 on the inner surface of the blank and displaces the metal in such irregularities in a

direction outwardly 90 Thus, when the punch has progressed down-wardly to the position shown in Fig 3, the inner surface of blank wall 12 has been smoothed out and the blank tightly grips the punch The extent to which the blank is 95 expanded by introducing the punch 24 therein is preferably such that if the blank is removed from the punch at this point, the wall of the blank will spring back to its original condition In other words during the step of 100 inserting the punch into the blank, the blank wall is subjected to a stress preferably below the elastic limit of the steel. After the punch has been Sully inserted in the blank 10, the punch assembly is raised, 105 the blank clinging to the punch, and the ram plate is rotated 90 to bring the punch with the blank thereon into a position in vertical alignment with the die ring 40 in the adjacent die holder 34 A second pair of blanks are 110 then positioned in the two locating rings 30 from which blanks have just been lifted by the punch The punch assembly is then caused to move downwardly again as shown in Fig. 2 The blank 10 which had previously grippcd 115 the punch 24 is thereby driven downwardly through the die ring 40 Die ring 40 has a diameter less than the outer diameter of the expanded blank 10 and preferably less than the outer diameter of the blank prior to its expan 120 sion by the punch 24 Thus, the wall of the blank is squeezed laterally by the die ring 40 and is caused to flow slightly axially The cold working of the outer surface of the blank wall in this manner irons out the irregularities on 125 the outer surface of the blank and compresses the inner surface of the blank wall against the surface of the punch thereby welieving the stresses set up by the elastic deformation of the blank wall by the punch and more or less 130 ness such that subsequent cold working thereof will produce the desired hardness in the finished article, the first step of the present process is to subject the blank to a pickling operation to remove any foreign particles in the inner or outer surface of the blank If a stress relief of the blank is required, such stress relief of course precedes the pickling operation Any conventional acid pickling operation may be employed Thereafter, the blank is washed free of acid and given a conventional phosphate treatment After being coated with a lubricant, the blank is ready for sizing and finishing in accordance with the present invention. Referring now to Fig 1, there is illustrated in a general way the apparatus employed for producing such sizing and surface finishing operation The apparatus illustrated is designed to be mounted in a press not shown and includes a punch shoe 16 on which is rotatably supported a ram plate 18 Ram plate 18 is rotatably supported on shoe 16 by means of a central bearing assembly 20 and a series of gibs 22

Four punches 24 spaced 90 apart are mounted on ram plate 18 by means of punch holders 26 Punches 24 are all the same size as described more fully hereinafter The punch assembly mounted on die shoe 16 is arranged to move vertically toward and away from a die assembly mounted on the press by means of a lower die shoe 28 It will be appreciated, of course, that a punch and die assembly constructed for relative movement in a horizontal plane may be employed if desired. It will also be appreciated that although four punches are shown, a greater or lesser number may be employed. On die shoe 28, there is arranged a pair of diametrically spaced locating rings 30 provided with a cavity 32 shaped to receive the lower end of blank 10 Die rings 30 are in juxtaposed relation to a pair of diametrically opposed punches 24 on the upper shoe 16. There is also arranged on die shoe 28 a pair of diametrically opposed upright die supports 34 which are provided with an axial openng 36 therethrough Die shoe 28 is also provided with openings 38 which register with the openings 36 in supports 34 A die ring 40 is mounted on each support 34 by means of the die holder 42 and a clamping ring 44 The assembly also includes conventional stripper heads 46 Mechanism not shown is also provided for rotatably indexing ram plate 18 to successively position the punches 24 first over a locating ring 30 and then over the adjacently positioned die support 34. Punch 24 is very accurately machined so that its shank is formed by a truly cylindrical surface of very accurate diameter The diameter of punch 24 is only slightly larger than the inner diameter of blank 10 For example, the diameter of punch 24 may be on the order of 005 " to 025 " greater than nominal inner diameter of the blank 10 The degree of over784,619 784,619 permanently setting or fixing the inner surface of the blank in the condition resulting from its contact with the cylindrical wall of the punch. The extent of cold working of the blank wall as the blank is driven through the die ring 40 causes a permanent deformation of the metal. Therefore, when the punch assembly has moved downwaardly to a position such as shown in Fig 3, the imperfections, roughness and irregularities on the inner and outer surfaces of the blank wall have been permanently ironed out and the stresses in the blank wall due to expansion have been substantially reduced so that the blank is readily stripped from the punch by the stripper leaves 46 when the punch assembly is elevated as shown in Figs 4 and 5. When stripped from the punch as shown in Fig 5, the work piece shrinks only very slightly but substantially uniformly so that the diameter of the final article generally designated 48 w-ill not vary from top to bottom more than 002 " in a cylinder 42 " long and having a diamter of 4 " By determining the extent which the work piece shrinks after being

stripped from the punch, the size of the punch and the die can be readily controlled to produce a very accurately sized work piece For example, by mieans of the present invention, a tolerance of + 001 " has been held on a work piece having a diameter of 5 " and work pieces of about 1 " or less in diameter may be held within a tolerance of + 0005 ". In order to illustrate typical relationships between the diameters of the punch and die in relation to the blank before and after being subjected to the operations illustrated in Figs. 1 through 5, reference may be had to the table set forth below wherein such dimensionsfor four work pieces of different diameters are gilvenil:Blank as extruded Punch Die Finished articie 0 D I D Dia Dia O D I D. A 5 398 " 4 726 " 4 758 " 5 355 " 5 370 " 4 750 " to to 4.745 " 4 752 " B 910 " 746 " 751 " 906 " 907 " 750 " to to 912 " 7515 " C 2 760 " 2 002 " 2 0255 " 2 743 " 2 752 " 2 020 " D 3 524 " 2 498 " 2 521 " 3 490 " 3 501 " 2 519 " to 3.502 " It will be observed that since the punch 24 slightly expands the blank by slidably engaging the inner surface of the blank wall, a burnishing action is produced This burnishing action coupled with the burnishing and ironing out of the irregularities on the outer surface of the blank wall by driving the expanded blank while on the punch through the die ring 40 produces an extremely smooth finish on the inner and outer surface of the blank wall Articles have been produced in this manner having a surface the smoothness of which eliminates any necessity for honing Work pieces have been consistently produced having a smoothness of about 30 RMS With reference to cylinders, the present invention is especially suited since any working marks that are produced lie in an axial direction rather than a circular direction as is the case with honing. In carrying out the present invention as described herein, it is preferred to reduce the cross sectional area of the blank to the extent of about 4 to 5 % The hardness and physical properties of the blank are preferably increased up to about 20 %, depending upon the physical properties of the blanks as compared with the physical properties desired of the finished work piece. In the arrangement illustrated and described herein an extremely smooth finish is formed 85 on the inside and on the outside of the finished article There has been some argument as to which of the two surfaces is the smoothest and tests seem to indicate that the outer surface is ihe smoother Regardless of on e,hich surface 90 the smoother finish is obtained, it will be appreciated that the sequence of operations may also Dbe reversed For example, the oversized blank may be first driven into a die having an undersized cavity in which the blank 95 is adapted to be received and thereafter an oversized

punch driven into the blank In this method of operation, the die and the punch would be dimensioned in relation to the blank so that the metal is stressed to an extent pre 100 ferably less than its elastic limit when the blank is driven into the die and to an extent in excess of its elastic limit when the punch is driven into the blank In using the method of the present invention, past experience has 105 shown that when the dimensional difference betveen the work piece and the tool is too great, galling of the surface being worked upon results. It will also be appreciated that although the 110 invention is described with reference to an article of circular cross section, articles having 784,619 a cross section other than circular may also be worked in accordance with the method and the apparatus of the present invention It is merely necessary to provide punches and dies of the same shape as the article to be worked upon Likewise, the invention may be utilized for forming a smooth finish on an article having tapered side walls rather than straight side walls as illustrated. Thus it will be seen that we have provided a novel punch and die arrangement and a novel and efficacious method of cold working a tubular blank to produce a finished tubular article having a cross section maintained within a very narrow dimensional tolerance and having a surface which is exceedingly smooth.

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* GB784620 (A)

Description: GB784620 (A) ? 1957-10-09

Manufacture of aliphatic chloroepoxides

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

PATENT SPECIFICATION Date of Application and filing Complete Specification: June 8, 19 No 16537/55. Application made in United States of America on June 28, 1954. Complete Specification Published: Oct 9, 1957. Index at acceptance:-Class 2 ( 3), C 1 G( 1 A 2: IE; 513; 6 A 1; 6 811), C 3 A 15. International Classification:-C 07 c, d. COMPLETE SPECIFICATION Manufacture of Aliphatic Chloroepoxides We, UNION CARBIDE CORPORATION (formerly Union Carbide and Carbon Corporation), of 30, East 42nd Street, New York, State of New York, United States of America, a Corporation organised under the laws of the State of New York, United States of America, (assignee of BENJAMIN PHILLIPS jointly with PAUL SPENCER STARCHER), doi hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a process for the production of aliphatic chloroepoxides,, and more particularly to a process for the productibn of aliphatic chloroepoxides by the reaction of an aliphatic chloroalkene with peracetic acid or perpropionic acid. According to the present invention a process is provided for the production of aliphatic clo roepoxides which comprises; reacting an allylic chlorohydrocarbon having the group: I I l -C =C-C-C 1 I i. with peracetic or perpropionic acid substantially free from hydrogen peroxide, water, mineral acids and salts, ro form the corresponding dhloroepoxy compoaund. Examples of starting materials to which the process; of this invention is applicable are those aliphatic chloroalkenes containing from three to ten carbon atomsl in the skeletal chain which may be represented by the general formnula: R 2,3 R 4 RI -C-C-C-Ct R 5 ii. wherein R,, R, R,, R, arnd R, represent hydrogen, allo or chloroalkyl radicals.

As may be readily observed from the general formula ii set forth aboave, these starting materials, that is the aliphatic chloroalkenes, possess in common, at least one chlorine atom in the allyliie position and no, chlorine atoms joined directly to either of the olefinic carbon atoms. The tern "allylic position" as, used herein is intended to refer to the position of the chlorine atoms with respect to the position of the clefinic double bond of the basic carbon chain Expressed in terms; of a molecular illustration, the characteristics; grouping referred to as the allylie position can, be represented by the structure: I l I 1 -C = C-C-Cl l These starting materials are further limited by the fact that there are never more than, two chlorine atoms in allylic positions which means that in any given compound only one of the radicals, R, R 2 or R may contain an allylic chlorine atom Thus, for the purposes of illustration, suh a compound may be depicted as follows,: when R 1 represents a chloroalkyl radical, the mlecule will contain two allylic chlorine atoms: a 6 R 2 ',3 q 4 Ct C C = C C Cl R 7 R 5 Wherein R,, R,, R 4, RS, RG and R, represent alkyl radicals or hydrogen atoms In the same manner Ro or R, can contain the allylic chlorine atom and although more than one allylie position may be present in the starting material only two chlorine atoms may occupy the allylic positions. Existing processes for the preparation of chloroepoxides employ the halohydrin route for the synthesis of these compounds The p 784,620 955. commercial process for the preparation of epichlkrhydrin is an example of the halohydrin route and involves the addition of hypochlorous acid to, allyl chloride and subsequent dehydrohalogenation with sodium hydroxide to produce epichlorhydrin, salt and water This process suffers from, the serious disadvantage that it requires the consumption of one mel of hypochlomrus acid and one mnol of base to produce epichloihydrin from allyl chloride. In existing process there is also the recovery or waste problem of the co-product sodium chloride Furthermore, problems; of corrosion are encountered in handling aqueous sodium chloride, and the use cf special, more expensive, equipment is necessary to avoid this corrosion. An advantage of the process of this invention is the production of a single product of known structure Frequently the halohydrin route fails to yield a pure compound This problem is especially true when one attempts to prepare the epoxide cf a dihaloalkene For example, the addition of hypoel-orous acid to 1,4-dichloro-2-butene yields a compound: Cl-CHG -CH = CH-CH- -C 1 H I OH Cl which en d-hydrohalogenation a

mixture of: with base gives CH.-GCH-CH-CH 2 and Cl-CH -CH-CH-CHLC' O I I 0 Gl C 1 O The problem is also encountered with many monohaloalkenes, such as for example, crotyl chloride Addition of hypochlorous acid to crotyl chloride gives a mixture of: CH,-CH-CH-GH Cl and CHI,-CH-CH-G-H C 1 r r I f OH C 1 C 1 OH which on dehydrohalogenation with base yield a mixture of: CH 3,-CH-CH-CH 2,C 1 and CH 3-CH-CH-CH 2 0 C 1 O The synthesis of epichlorhydrin mentioned hereinbefore is one of the few cases where a single product is obtained since when either chlorine atom of glycerol dichlorhydrin is removed by dehydrohalcgenaton the same product results. Normally, compounds having at least one chlorine in the allylic position are not epoxidized readily and much difficulty is encountered in converting these compounds to epoxid-s Particularly, allyl chloride, the parent olefin (i e, material for the synthesis) cf epichlorhydrin, is extremely difficult to epoxidize since it is very unreactive towards peracids, no doubt due to the fact that there are no alkyl groups to activate the double bond. Because of this unreactivity, high temperatures and a long reaction period are necessary in order to effect appreciable reaction The use oef high temperatures increases the opportunity for side reactions to cocur with consequent losses of desired product. The reaction illustrating the process of this invention may be depicted as follows For the purpose of convenience, only the characteristic allylic grouping and specific oxidizing agents, such as peracetic acid, will be shown: PERACETIC ACID METHOD 0 -C=C-C-Ct CCHC-0 OH- -c-ct CE' Prior to this time, reactions of the types of compounds disclosed herein as starting materials with peracetic acid resulted in the production of mixtures of dihydroxy and hydroxyacetoxy derivatives of the starting materials This undoubtedly was due to lack of purity of the peracetic acid Thus, the use of improved oxidizing agents provides results which were never heretofore obtainable. Existing processes for the manufacture of lower aliphatic peracids, and particularly peracetic acid, involve the addition of hydrogen peroxide to acetic acid to give an, equilibrium mixture of peracetic acid, acetic acid, hydrogen peroxide and water In the absence of added catalyst, the rate at which the equilibriumi is reached is impractically slow at temperatures up to about 40 C, but, on the other hand, at higher temperatures it is difficult tom prevent excessive loss of active oxygen. 784,620 784,620 When sulfuric acid is used as a catalyst, the phuric acid and sa equilibrium is attained much sooner However, process ef

this inve the presence of sulfuric acid in the peracetic cracking of an alipi acid mixture is not benaficial for the obtain tion product to lit ing of satisfactory conversions of olefines to therefrom The lit epoxides for the sulfuric acid in a peracid arated forthwith fr acetic acid solution catalyses the ring opening of the cracking ste of epoxides by acetic acid yielding hydroxy peracid can react acetates appreciable extent Although the conversion of olefines to epox aldehyde addition ides can be improved by the replacement in the oxidation of tr whole, or in part, of the acetic acid with oxygen, at a low te acetic anhydride, the use of anhydride may The reaction wh lead to, the conversion of the peracetic acid to, tially free from in the highly explosive diacetyl peroxide prepared may be i Peracids substantially free from hydrogen general equation in paroxide, water, mineral acids such as sul0;110 2 Cb CHOO O H 2 C&CHO, 02 low teny Peritare CH 3 i \CHCH 3 \ O 0 / (Acetatdch yde onoperacetate) /- % O CH 3 C / CHC 3 crackiog eaa&t e CC-0-H CH 3 CHO \ O 0/ In preparing acetaldehyde monoperacetate, oxygen is diffused into acetaldehyde at a temperature below 15 C A temperature of about 5 C to O C is preferred If desired, the oxygen can be in admixture with non-teactive gases, suchi as, for example, air. The oxidation of acetaldehyde to acetaldehyde monoperacetate is best carried out in the presence of a catalyst Salts of the heavy nmetals, such as salts; of cobalt, of copper and iron, are powerful catalysts for this reaction At the same time, the presence of metal salts decreases the stability of the peroxide that is formed and often causes side. reactions during subsequent use of the peroxide For good results when a metal salt is used as the catalyst, the amount of such salt should not exceed 5 O per cent based on the acetaldehyde inclusive of any amount of acetaldehyde present as solvent On the other hand, an amiount, less than 0 0001 per cent ona the same aldehyde basis has nrot been found to be effective as a catalyst An amount which is about O 01 per cent is preferred. The reaction can also be catalysed by irradiating the acetaldehyde with ultraviolet light or by a small amount of ozone in the oxygen. Before converting the acetaldehyde mlonoperacetate to peracetic it is usually desirable, when other solvent is; present, first to distill off free or unreacted aldehyde. The removal of acetaidehyde by distillation is carried out under reduced pressure, and either a batchwise or a contirnuous distillation procedure can be employed. The 'succeeding step in the productions of peracetic acid from acetaldehyde monoaperacetate, can be carried cut catalytically, or altsi which are used in the ention, are produced by the Iatic

peracid-aldehyde addierate the aliphatic peracid b.erated peiacid' is then svpIm I the aldehyde co-product ip before the aldehyde and with one another to an The aliphatic peracidproduct can be made by he aldehyde with molecular mperature. ereby the peracids, substanorganic impurities, can be illustrated by the following the case of acetaldehyde: (I) (II) non-catalytically In D either case, provision should be made for the rapid remdoval of the acetaldehyde co-product in order to minin-mize 75 the formation of acetic acid from interaction of the aldehyde with the, peracetic acid. The cracking reaction is carried out by feeding the acetaldehyde monoperacetate into a still kettle which; contains an inert solvent 80 under reflux; the solvent having a boiling point above the boiling point of peracetic acid or being capable of forming an azeotrope therewith The condenser at the still head isl mainrained at a temperature such that per 85 acetic acid and the solvent are condensed, while the aldehyde that is liberated is allowed to goi past the still head and is recovered in a cold trap, There is continuously removed from the still head the peracetic acid in the 90 form of a solution in the particular solvent chosen. By another procedure, the solution of acetaidehyde mlonoperacetate is completely vaporized in a heated zone and heated to a tem 95 perature in the range of 50 C to 250 C, approximately The vapors are then passed to a condenser or dephlegmator maintained at a temperature which will permit the peracetic acid to be condensed while allowing the acer 100 aldehyde to pass through along with any other low boiling material that might be present. If desired, the vapors emerging fromn the heated zonee may be diluted withan inert solvent before entry intoi the dephliegxiator and the 105 condensate recovered from the dephlegmator will thenl be a solution of peracetic acid in the inert solvent This procedure permits a wider choice of solvents and can be operated with solvents boiling lower than peracetic acid 110 as well as solvents boiling higher than peracetic acid Solvents; whi chi can be used include acetone, ethyl acetate, acetic acid, butyl acetate and dibutyl ether. This process provides paracids and particularly peracetic acid which are free of impurities commonly present in peracids made by prior metheds Solutions of peracids and particularly peracetic acid made by this process are substantially free of water, hydrogen peroxide, mineral acids and salts; and the concentration of any carboxylio acids present can be, if desired, far lower than in the case of peracids made by other methods. In carrying out the epoxidation reaction, the allylic chlorohydrocarbon is charged to a reaction vessel and heated under

reflux at atmospheric pressure The oxidizing agent is then added gradually to, the starting material either alone or in admixture with acetaldehyde and/ or acetone In general, the reaction can be carried cut at any convenient temperature desired depending on the nature of the starting material and the nature and concentration of the oxidizing agent employed Suitable tmnperatures at which these epoxidation reactions can be carried out are those in the range of C to, 200 C The reaction conditions are maintained until arn analysis for the oxidizing agent indicates that substantially all of the oxidizing agent has been consumed. As pointed out earlier, the presence of heavy metal ions in the reaction mixture is undesirable, since these ions can catalyze decomposition of the peroxide, thereby causng a low perc xide efficiency Furthermore, this same decomposition produces free radicals which are capable of causing the allylic chlorides to undergo undesirable side reactions such as dimcrization and polymerization The, great ease with which dimlerization and poclymerization occur was shownr by Frank and Blackham (J A C S 72, 3283, 1950) for allyl chloride and methallyl chloride It is not always easy, ho wever, to avoid the presence of heavy metal ions, particularly since large-scale manufacturirg processes are usually conducted in nmetal equipment We have fcund that it is possible to overcome this difficulty by the addition of a small amount of a sequestering agent which inactivates the heavy m:etal ions by forming complexes with threm Very effective sequestering agents are the alkali nmetal salts cf polyphosphates, including partially esterified polyphosphates Examples are sodium pyrophosphate, sodium hexametaphosphat disodium dimethyl pyrophosphate, and the "Victawet" anionic wetting agents such as "Victaw vet B", Na ( 2-ethylhexyl)-(P,01 o)2 Other types of sequestering agents, for exampll, gluccnic acid, ethylenediaminetetracetic acid, sodium silicate, and the commercially available "Perma Kleers", manufactured by Refined Products Corporation, may also b used. Small amounts of compounds which inhibit the decomposition of the peracid due to the presence of metal ions may also be added. Examples of such inhibitors are pyregallol, trinitrobenzenz and sedium pyrophosphate. After the reaction period is over the reaction 70 mixture can be worked up in any convenient manner and the epoxide recovered by any convenient nmeans, such as distillation or extraction. In the examples, the analysis for the epoxide 75 group is based upon its reaction with pyridine hlydrochloride to, form the chlorhydrin and pyridine Into a pressure bottle containing 23 milliliters of l N pyridine hydrochloride in chloroform was intreduced a sample of 80

epcxide calculated to use about 50 per cent of the pyridin: hydrochloride The bottle was then closed and the contents heated in a steam bath for a period of one hocur At the end of that time, the bttle and contents were cooled, 85 drops of phenolphthalein indicator ( 1 0 gram per 100 milliliters of 60 per cent ethanol) added, and the mixture titrated to a permanmnt red endpoint with standard 0 2 N alcoholic potassiuml hydroxide solution A blank 90 was also run in precisely the same fashion except that the sample was omitted The preparation of the, oxidizing agents is illustrated below: PREPARATION I 95 PREPARATION OF PERACETIC ACID An acetone solution containing 202 grams of acztaldehyde moncperacetate in a total of 422 grams of solution was mixed with 300 grams of cold dibutyl ether' and the whole fed 100 dropwise ever a period of 2 1 hours into a steam-heated (temperature 980 C to 98 50 C) flask of two liters capacity The flask was fitted with a steam-heated tube leading to a water-cooled condenser having at its discharge 105 end a receiver surrounded by ice water The pressure inside the equipment was maintained at 48 to 55 millimiters of mercury, absolute There was collected 417 grams of distillate having a peroxide content corres 110 peonding to, 81 grams of peracetic acid This distillate which still contained a small amount cf acetaldehyde m onoperacetate was then again fed dropwise through the same apparatus over a period of eighty minutes under 115 the same, conditions From the second pass there was obtained 388 grams of solution containing 75 gramns of peracetic acid The overall yield of peracetic acid from acetaldehyde mrncperaceta te was 60 per cent 120 PREPARATION II PREPARATION OF PERPROPIONIC ACID A solution of 270 grams of propionaldehyde and 90 grams of isopropyl acetate was charged to, a cylindrical glass oxidizer and cooled to 125 -4 C The solution was irradiated with ultraviolet light, and oxygen, was introduced through a diffuser near the bettom of the oxidizer for a period of two hours At the end of that time there was obtained 398 130 784,620 584,6201 grams of solution which was found upon analysis to contain 43 6 per cent by weight of propionaldehyde monoperpropionate This solution was mixed with, 0 3 liter of isopropyl acetate cooled to a temperature of 5 C to which had previously been added 0 4 gram of Nai( 2-ethylhexyl),(PO 00), (Victor Stabilizer No 53) dissolved in 4 milliliters; of propionic acid Unreacted propionaldehyde was removed from the solution under a reduced pressure of 10 millimeters of mercury, absolute, with the kettle contents maintained at a temperature of about -5 C to O C The resulting solution, weighing 427 grams and analyzing 39 per cent propionaldehyde monoperpropionate, was fed through a stainless steel, steam-heated vaporizer to the mid-section of a three-foot stainless steel-packed column at the rate of 0 1 to 0 2 liters per hour The column was

operated at an absolute pressure of 50 millimletersl of mercury and with a head temperature of 18 C to 21 C. Isopropyl acetate was fed through a steamheated vapuorizer into the column near the bottom at the rate of 0 16 to} 0 22 liter per hour An isopropyl acetate solution taken from the bottom of the column continuously during the run weighed 443 grams and contained 17 5 per cent by weight of perpropionic acid by analysis The yield based on the propionaldehyde maonoperpropionate obtained from the oxidizer was 76 per cent. The invention will be illustrated by reference to the following Examples: EXAMPLE I. PREPARATION OF CHLOROISOBUTYLENE OXIDE FROM METHALLYL CHLORIDE AND PERACETIC ACID Methallyl chloride ( 543 grams) containing 0 2 per cent of pyrcgallol inhibitor was heated under reflux at atmospheric pressure (kettle temperature 72 C) irn a kettle equipped with a 3-foot column packed with glass helices. Over a period of 2 hours and 20 minutes, 503 grams of a 30 2 per cent solution of peracetic acid in acetone was added to, the kettle The kettle temperature remained at 72 C throughout the addition After am additional 2 5-hour reaction, period the reaction mixture was allowed to stand overnight at room temperature The reaction mixture was then fractionally distilled A 70 per cent yield of chioroisobutylene oxide was obtained in a cut boiling at 40 C to, 50 C at 50 min pressure which contained about equal weights of acetic acid and the oxide A portion of this mixture was ste;am distilled under 200 mmn pressure. The chloroisobutylene oxide came over at 58 C and separated out as a lower layer which was continuously removed After drying, the oil layer (n,'0 1 4280) analyzed 99 5 per cent as chloroisobutylene oxide, using pyridine hydrochloride in chloroform as the analytical reagent. EXAMPLE II 65 PREPARATION OF 3-CHLORO-1,2-EPOXYBUTANE FROM 3-CHLORO-1-BUTENE AND PERACETIC ACID A solution of peracetic acid ( 1460 grams of a 20 7 per cent solution) in acetone was added 70 dropwise over a period of 4 hours to'1448 grams of 3-chloro-1-butene containing 2 8 grams of trinitrobenzene as an inhibitor The temperature was maintained at 58 C to 60 C throughout the addition An additional 8 75 hour reaction period at this same temperature was required before the peracetic acid was substantially all reacted ( 91 per cent) The reaction mixture was stripped of excess chloroalkene and acetone under reduced pressure 80 The residue was diluted with 500 grams of carbon tetrachloride and washed three times with water to' remove acetic acid The washed oil layer was then distilled under reduced pressure The cuts boiling

between 45 C and 85 C at 50 mm pressure had a purity of 90.5 per cent as judged by an analysis for epoxide by the pyridine-hydrochloride in chloroform, method Distillation of the water wash material gave additional epoxide The 90 combined yield, based on peracetic acid, was 68 per cent of the theoretical. EXAMPLE III. PREPARATION OF 1,4-DICHLORO-2,3-EPOXYBUTANE FROM 1,4-DICHLORO-2-BUTENE 95 AND PERACETIG ACID A solution of peracetic acid in acetone ( 708 grams of a 21 5 per cent solution) was fed dropwise with stirring to a flask containing 1000 grams of 1,4-dichloro-2-butene at 60 C 100 After adding approximately one-half of the peracetic acid an analysis indicated that the reaction was proceeding slowly The temperature was raised ta 800 C to 88 C and the addition continued A total of 4 hours was 105 required for the addition to be completed. The reaction was; continued for an additional 2 hours at 80 C to, 88 C After standing overnight at ronrr teamperature the reaction mixture was fractionally distilled The pro 110 duct was a colourless liquid boiling at 66 C. to 68 C and 5 mmlin pressure and was obtained in a yield of 82 per cent (based on peracetic acid) It was identified as 1,4dichloro-2,3-epo xybutane by the following: 115 n D 30 = 1 4743 Sp, Grav - C = 1 3112 Calc. Molecular Refraction Oxygen Analysis Epoxide Analysis (morpholine mnethod) 30.55 11.35 % % Found 30.20 11.64:11 70 % 120 93.5 % The infra-red spectrum had a characteristic absorption peak at 7 85 microns, the same as epichlorohydrin and ethylene oxide The material also showed absorption at two other points (though these are less characteristic) commonly attributed to the epoxide group. EXAMPLE IV. PREPARATION OF EPICHLOROHYDRIN FROM ALLYL CHLORIDE AND PERACETIC 9 ACID A solution ( 256 grams) of peracetic acid ( 32 7 per cent) in acetone containing O 5 grams cf sodium: pyrophlo sphatre was added dr;cpwise over a period cf 1 hour to a boiling ksttle of allyl chloride ( 430 grams) The reaction mixture was heated under reflux (temperature 500 C to 53 C) for an additional 6 hours, at which time an analysis for peracetic acid indicated that 89 per cent of it had reacted The excess allyl chloride and acetone were removed from the reaction mixture by distillatiorn at 170 mi pressure The pressure was reduced and the product, epichlorohydrin, was distilled as a mixture with acetic acid. The epichlorohydrin and acetic acid were separated by steam distillation under reduced pressure ( 120 nmn) The lower layer was reml.ved continuously from the distillate, dried over sodium sulfate and distilled on, a Vigreux column to give a 50 per cent yield of

epichlorchydrin: having a boiling point of 52 C. at 74 mm pressure. Per Cent Run Reaction Sequestering No Time Agent EXAMPLE V. PREPARATION OF EPICHLOROHYDRIN A method of analysis for epichlorohydrin in the presence of acetic acid and allyl chloride was, developed and checked against synthetic mixtures The method involved the reaction of pyridinium chloride in chloroform solution with epichlorohydrin with a correction made for the acetic acid present This method gave accurate values for known compositions of acetic acid, epichlorohydrin, and allyl chloride. A series of runs was, made in a stainless steel bomb to chck the effect of a sequestering agent and various inhibitors cn the reaction between Fpracetic acid and allyl chloride At the end of the reaction the reaction mixtures were distilled and were analyzed by the above meathod This gave an accurate value of the yield of epichlcrohydrin The losses and the time involved in separating epichlorohydrin fromt acetic acid on a small scale were thus elimlinated In each of these runs the molar ratio cf allyl chloride to peracetic was to 1, and the reaction temperature was 60 C The sequestering agent was Na,( 2-Ethylhexyl),,(PO,,)2 "Victawet 35 B". A suirnary of these runs is given in the following table: %' Inhibitor Yield of Epichlorohydrin ( 1) 7 5 hrs. ( 2) 7 hrs. ( 3) 10 hrs. ( 4) 8 hrs. ( 5) 9 hrs. ( 6) 8 5 hrs. 0.05 %, 0.1 % 0.1 % r 0.1 % 1 0.1 % 0 1 % None None 0.1 %, trinitrobenzene 0.1 %'o 2,4-dinitro-6chlorophenol 0.1 ',' 2-nitro-4-chloroaniline 0.1 %' phenyl-betanaphthylamine EXAMPLE VI CONTINUOUS PREPARATION OF EPICHLOROHYDRIN AT 100 %C. Epichlorchydrin was prepared continuously by passage of al mixture of allyl chloride and Allyl chloride % solution of Victawet 35 B in acetic acid Peracetic acid solution in acetone ( 24 7 '%) and put under 75 pounds per square inch nitrogen pressure and passed through a coil made of 1/8-inch stainless steel tubing having a volume of 67 cc The tube effluent was peracetic acid solution through a stainless steel coil under pressure and heated to 100 ' C. with steam' The following charge stock was made up: 530 grams 0.95 cc. 451 grams analyzed for Feracntic acid and for epichloro 80 hydrin as described in Example IX The results are recorded in the following table: 66 ' 76 %', 84.1 %, 84.9 %' %,, 61 ',, 784,62 o 784,620 Rul No.

Fe-d rate Temp Pressure cc/hr. ( 1) 100 C 75 psi 230 ( 2) 100 C 75 psi 110 EXIMPLE VII. PREPARATION OF 3,4-DICHLORO-1,2EPOXYBUTANE Twenty In O os ( 2500 grams) of 3,4-dichloro1-butene was placed in a three-necked 5-liter flask equipped with a stirrer, thermometer, and dropping funnel A weight cf 2 5 grams ( 0.1 % by weight of the olefin) of Nas( 2-Ethylhexyl),(PO 00)2, "Victawet 35 B", was added as a stabilizer Then, with stirring at 75 , five mols of 25 O per cent peracetic acid in acetone was; added over a three-hour period After heating for an additional one and one-half hours, analysis for peracetic acid showed that a conversion of 89 per cent had been achieved. The reaction mixture was charged to, a distillation kettle attacked to a packed 24 " glass column Then, at 50 , the acetic acid and acetone were removed by flash distillation It was; observed that the last amounts of acetic acid distilled as, an azeotrope with unreacted 3,4-dichloro-1-butenr The remaining material was carefully fractionated to obtain pure unareacted chloro:olefin and the desired epoxide. A total cf 471 grams ( 75 per cent) of 3,4dichroro-1,2-ep:oxybutane was obtained The epoxide distilled at 43 at 2 mm pressure. Arn index of refraction of N O = 1 4740 was observed for this compound Arn analysis for epoxide by the "pyridine hydrochloride in chloroform" method indicated a purity of 93 3 per cent However, no foreign groups such as olefin, carbonyl, or hydroxyl, were found to be present by an infrared absorption examination Redistillation gave material of the same physical proper;ties, indicative of the presence of a single compound. EXAMPLE VIII PREPARATION OF 2,3-EPOXY-2-ETHYLHEXYL CHLORIDE (a) Preparation of the unsaturated halide To a mixture of 256 grams of 2-ethyl-2hexenol and 167 grams of pyridine was added, over a period of 2 3 hours, 319 grams of thionyl chloride at a temperature of approxi-mately O C The reaction mixture was then held at 5 C for 1 hour and then heated to 70 C for an additional 3 hours The reaction mixture was cooled, diluted with 600 cc of hexane, and poured into 1500 grams of ice and water with vigorous agitation The organic layer was separated and washed twice with dilute sodium carbonate solution Distillation gave a 49 per cent yield of 2-ethyl-2Contact minutes mnuntes 17.4 36.5 01 Peracetic Consumed 89 96.2 % Yield of Epichlorohydrin 81.5 % 86 % hexenyl chloride having a boiling point of 52 C tot 54 C at 10 mm pressure and a refractive index range of 1 4449-1 4485 (n a 0). The refractive index range is probably due to the product's being a mixture of cis and trams isomers Analysis for allylic chlorine by saponification and determination of chloride ion by the Volhard method

indicated a purity of 92 per cent Quantitative bromination analysis indicated a purity of 96 per cent. (b) Preparation of the epoxide A solution of peracetic acid in acetone ( 390 grams of a 22 per cent solution) was added over a period of 1 5 hours to'110 ' grams of 2-ethyl-2-hexewnyl chloriderat a temperature of C The temperature was raised to 50 C. and the reaction allowed to continue for an additional 4 hours Toluene ( 300 cc) was added, and the acetone was removed by distillaticn under reduced pressure The residue was washed with water to remove acetic acid and then fractionated under reduced pressure. A 67 per cent yield of 2,3-epoxy-2-thylhexyl chloride, a colourless liquid boiling at 70 C. to 71 C at 10 mm pressure and having a refractive index of 1 4420 (n,)0) was cbtained. An analysis by the pyridinium-chloride-inchloroform method for e Foxide indicated a purity of 94 %. EXAMPLE IX "PREPARATION OF 1-CHLORO-2,3-EPOXYBUTANE FROM CROTYL CHLORIDE AND PERPROPIONIC ACID " A solution ( 614 g) of 28 3 % perpropionic 90 acid ( 1 93 mols) in' ethyl propionate was added dropwisei over a period of one hour to 177 g cf crotyl chloride ( 1 96 mols) with stirring at a temperature of 40 C The reaction mixture was then heated an additional 95 7 hours at 40 C after which time approximately 90 % of the peracid had been consumed The reaction mixture was cooled and diluted with 500 ml of chleoroeform and washed with sodium bicarbonate solution 100 until substantially free of acid Rapid distillation of the washed solution under reduced pressure ( 100-70 ramin) gave 183 g of crude 1-chloroe-2,3-epoxybutane contaminated with ethyl propionate and somea propionic acid 105 Redistillation at 40 mm gave 115 g ( 56 % yield based en peracid) of 1-chloro-2,3-epaxybutane, a colourless liquid having a boiling point of 49 C at 50 mm and, a refractive index of 1 4286 (n O ) 110

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* GB784621 (A)

Description: GB784621 (A) ? 1957-10-09

Improvements in or relating to conductive elastomeric compositions andmethod of making

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

COMPLETE SPECIFICATION Improvements in or relating to Conductive Elastomeric Compositions and method of making We, THE CONNECTICUT HARD RUBBER COMPANY, a corporation organized under the laws of the State of Connecticut, one of the United States of America, of 407, East Street, New Haven, State of Connecticut, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to conductive rubber compositions and more particularly to rubber compositions capable of retaining a high degree of electrical conductivity under flexure. Electrically conductive rubbers are useful, for example, in shoe soles for preventing build-up of static charges by providing a leakage path to ground. Other uses include heating blankets or coverings, radiant heaters, conducting gaskets, electric potential distributors and various other applications. In the prior art, carbon black modified rubber compositions have displayed some degree of conductivity. The electrical conductiveness of these compositions, however, depends on the maintenance of continuous chains of carbon particles within the body of the material which become ruptured through continual fiexure and distortion resulting in partial or total loss of electrical conductance.

A primary object of the present invention is to provide elastomeric rubber compositions wherein the rubber is modified in such a manner as to provide an electrolytic medium for the transfer of current through the body of material and which is substantially unaffected by flexure and distortion of the rubber for an indefinite period of time. By virtue of being electrolytic conductors, the compositions described herewith are electrically conductive throughout every element of volume of the materials which contain both positive and negative ions, rather than being conductive only through chains of electronically conducting carbon particles interspersed in a continuous non-conducting medium. The inherent difference between our conducting compositions and those of the prior art is therefore two-fold: electrolytic versus electronic, and continuous throughout volume versus discontinuous end dependent on continuous threads or chains of filler. The electrically conducting elastomers formed in accordance with the present invention are primarily characterized by two principal fields of use or application. The first application is in the antistatic field, wherein the ability of the rubber to conduct permits static charges to leak to ground, thereby preventing the build-up of high and often dangerous potentials. Practical examples are conducting gaskets, shoe soles and tires. The second application is in the heating field, wherein the ability of the rubber to conduct causes the rubber to produce heat when an external voltage is applied to a block or sheet of the material. Examples of the latter class of applications include airplane de-icers, radiant heaters, and heating blankets, tapes, and coverings. Elastomers in general, as defined by Harry S. Fisher, in Industrial and Engineering Chemistry, Vol. 31, No. 8, pp. 941-945, of August, 1939, have properties which resemble those of natural rubber including very high electrical resistance, elasticity, elongation, tensile strength and the like. Such elastomeric compositions are especially characterized as possessing to a high degree physical strength, abrasive resistance and insulating properties relative to the passage of electrical current. Electrolyte solutions, on the other hand, are liquids characterized by a high electrical conductivity without physical strength. An important aspect of the invention is to provide a composition which in a novel manner combines the conductivity of electrolyte solutions with the physical strength, flexibility and abrasive resistance of the synthetic elastomers. The conductance of an electrolyte in a solvent depends on the chemical composition of the electrolyte and its concentration and especially on

the viscosity and dielectric constant of the solvent. For a given concentration of a particular electrolyte, the conductance is higher, the lower the viscosity of the solvent medium and the higher its dielectric constant. Elastomers such as natural rubber and styrene-butadiene copolymers, while elastic solids from the macroscopic point of view, are liquid-like from the microscopic point of view of molecular motion. The local viscosity of many elastomers is high, but can be markedly reduced by the incorporation of certain liquids of low vapor pressure, known to those skilled in the art as plasticizers. Electrolytes in general are not soluble in organic liquids, but certain special classes of electrolytes such as quaternary ammonium compounds, sulfonium compounds, phosphonium compounds, and iodonium compounds, are soluble, and, in accordance with the invention, it has been discovered that the solubility in general of these soluble electrolytes increases with the dielectric constant of the solvent. The invention described herein depends on a novel combination of properties achieved by compounding an elastomer which contains polar comonomers such as acrylonitrile with a polar plasticizer such as dimethyl-sulfolane to give a medium of high enough dielectric constant to dissolve quaternary and similar electrolytes. By adding a polar plasticizer, the dielectric constant is further increased, and simultaneously the local viscosity is decreased. The effect of the high dielectric constant plasticizer is to insure solubility of the electrolytic solute and especially to increase the degree of ionization of the electrolyte. The effect of the lowered viscosity is to increase the mobility of the ions of the electrolytes. These effects combine to produce an elastomer which, in addition to the normal mechanical properties of a similar elastomer which contains no electrolyte, possesses an electrical resistance many powers of ten lower. This unique and novel combination of properties is obtained by a conductive rubber composition comprising a polar synthetic elastomer having a dielectric constant of at least 5.0, a polar plasticizer having a dielectric constant of at least 10.0 which is compatible with the elastomer and an electrolyte which is soluble in the plasticizer. The three types of materials referred to, namely, the polar elastomer, polar plasticizer and electrolyte, reinforce their own several properties in a unique and distinctive manner and impart conductive properties to the elastomer never before achieved. Certain of the currently recognized elastomers have polar characteristics which render them particularly amenable to the practice of the invention. For example, "Hycar" (Registered Trade Mark), an acrylonitrile-butadiene copolymer and " Neoprene," a

polychloropreys, "Thiokol" (Registered Trade Mark), a polyethylene sulfide and other highly polar polymers are especially suitable and in general any high dielectric constant elastomer having at least 15 7o of a polar comonomer may be employed to produce an effectively conductive composition. In accordance with the invention, it has been found that the properties of relatively high dielectric constant elastomers having polar characteristics may be suitably modified to form a medium having remarkably low resistance to current flow. It has further been found that current transfer in such a medium is drastically increased by the presence of small quantities of electrolytes which appear to function through ionic movement as in electrolyte solutions. In order to provide a medium which will allow the proper functioning of the electrolyte, the internal viscosity of the elastomer is modified by a plasticizer having a relatively high dielectric constant which is compatible with the elastomer and which also contains polar groups. For purposes of this description, by dielectric constant, we mean the value of the constant measured at relatively low frequencies, e.g., 1,000 cycles and room temperature. All elastomers do not provide an appropriate solvent medium for the conductive electrolyte salts. Appropriate elastomers for purposes of the invention are those having a content of at least 15 -o of a highly polar comonomer such as acrylonitrile or chloroprene, and, further, have a dielectric constant of at least 5.0 and preferably over 7. With this is combined a highly polar plasticizer having the property of modifying the internal viscosity, dielectric constant, and resistivity of the polar elastomer. The conventional plasticizers such as tricresyl phosphate, dibutyl phthalate and dioctyl phthalate do not have the dielectric and other properties for purposes of the invention. The suitability of a polar plasticizer for purposes of the invention is in general measured by the dielectric constant of the material. For example, tricresyl phosphate having a dielectric constant of 7.0 at 25 C., dibutyl phthalate having a dielectric constant of 6.4 at 30 C., and dioctyl phthalate having a dielectric constant of 5.1 at 25 C., are found to not have the polarity and solvent requirements suitably to modify the electric conductiveness of the elastomer. The addition of a selectively polar plasticizer to the polar elastomer has the property of substantially increasing the dielectric constant of the elastomeric conductive medium. This increase in dielectric constant by the plasticizer is primarily the consequence of a reduction of the internal or local viscosity of the elastomer. For a given dipole content (measured as number of polar groups per unit volume), the dielectric constant at a given

temperature and frequency is higher the lower the viscosity. Furthermore, the dipoles of the plasticizer molecules also contribute substantially to the dielectric constant of the aggregate. Among the suitable polar plasticizers for purposes of the invention may be mentioned the cyclic and aromatic sulfones, alkyl and aryl nitriles, nitro-compounds, and the alkoxy esters of dibasic carboxylic acids. In order to favorably affect the conductive properties of the elastomeric medium, the plasticizer should have a dielectric constant of at least 10 and preferably 20 or above. When incorporated into the elastomeric conductive medium in proportions of from 35 to 85 parts of plasticizer to each 100 parts of elastomer, the effect on the conductivity of the elastomeric medium increases as an exponential factor when the dielectric constant of the plasticizer is 20 or above. The plasticizer must further be entirely compatible and miscible within the indicated ranges with the elastomeric medium and furthermore be a solvent for the electrolyte. For example, the plasticizers, when incompatible with the elastomeric conductive medium, cause the composition to break down and crumble when mixed in a rubber mixing mill or, in certain cases, although appearing initially to be miscible, will later form a "bloom" on the surface of the product after aging. Suitable electrolytes for purposes of the invention may be the sulfonium, phosphonium and iodonium salts, salts of carboxylic acids and other electrolyte salts which are soluble and miscible with the plasticized elastomeric conductive medium. The quaternary ammonium salts have been found to be particularly suitable. Referring again to the elastomeric medium, the dielectric constant of elastomers (a) having suitable characteristics for the practice of the invention are compared with the dielectric constants of (b) ordinary rubber and of a low dielectric constant elastomer in the following table: TABLE I Dielectric Loss Factor D.C. Volume Constant 1 kcps at Resistivity No. Gum 1 kcps at RT RT (XlO9ohm-cm) E263 Hypalon S--2 7.70 1.02 400. E264 Neoprene 6.40 0.567 268. E265 Thiokol & T 7.35 0.544 39.4 E266 Hycar 1014 10.0 1.56 3.44 E267 Hycar 1013 11.9 1.30 4.57 E268 Hycar 1002 13.5 1.69 2.92 E269 Hycar 1001 16.5 2.94 1.12 E261 Smoked sheet 2.58 0.161 400 E262 GR-S 2.44 0.146 400

An elastomeric composition having the required characteristics is suitably incorporated with a high dielectric constant plasticizer having the property of raising the dielectric constant, reducing the internal viscosity and/or lowering resistivity of the conductive medium. Suitable polar plasticizers and their effect on reducing the DC volume resistivity of Hycar 1001 are illustrated in the following table: TABLE II DC Volume Compound Parts Resistivity No. Parts Polar Compound TEAB (megohm-cm) 550a - - - 470. 570 - - 5.0 73. 559 50.0 ss,ssl-Oxydipropionitrile - 1.1 560 50.0 ,, 5.0 0.12 543 50.0 Dimethylsulfolane - 21. 571 50.0 " 5.0 0.59 572 50.0 2-Nitro-p-cymene 5.0 3.6 574 50.0 Anisonitrile 5.0 1.1 575 50.0 Benzonitrile 5.0 1.8 576 50.0 o-Nitroanisole 5.0 0.51 577 50.0 Methyl-o-nitrobenzoate 5.0 1.7 It will be appreciated from the foregoing Table II that while the unplasticized Hycar containing the electrolyte TEAB (Tetraethylammonium bromide) had a DC volume resistivity of 73, the addition of 50 parts of beta, beta'-oxydipropionitrile to 100 parts of the elastomer reduced the DC volume resistivity of the composition to approximately 0.12. In other words, the addition of the plasticizer reduced the resistivity by a factor of over 600. The addition of other plasticizers of the type listed in the Table had a corresponding effect upon the DC volume of resistivity of the elastomeric conductive medium. As ordinarily manufactured in standard commercial practice, plasticizers contain small amounts of electrolytic materials arising from the reagents used in the synthesis, either as byproducts or impurities. It is not necessary to state the chemical composition of these electrolytic substances; it is well known to all who have worked with organic liquids that electrolyte is often present in these liquids as received, because purification methods invariably increase their electrical resistance. In the practice of the present invention, it is planned that this purification will not be carried out, so that the normally present electrolyte in the plasticizer will lower the resistance of the elastomer to which it is added by the contribution

to conductance from the electrolyte content of the plasticizer. In the above Tables, it will be observed that a substantial conductivity was achieved through the mere addition of the polar plasticizer to the elastomer indicating the presence of electrolyte substances in the plasticizer. It will be appreciated that in many cases the presence of electrolytic material in the polar plasticizer imparts sufficient conductivity to the resulting elastomer so that further addition of quaternary salts or other electrolytes can be dispensed with. The following Examples are illustrative of elastomer compositions prepared according to the teachings of the invention and displaying unusual conductive properties in accordance therewith: EXAMPLE 1 A copolymer was prepared consisting of substantially 39 parts by weight of acrylonitrile and 61 parts by weight of butadiene. The copolymeric elastomer was found to have a dielectric constant of 16.5, which contrasted greatly with the dielectric constant of 2.04 of a copolymer of butadiene and styrene, or the dielectric constant of 2.58 of natural rubber. The high dielectric constant of the nitrile rubber was believed to be attributable to the presence of the nitrile group, providing polar groups within the elastomer, thereby raising the dielectric constant. A sample of dimethyl sulfolane (2,5-dimethyl tetramethylene sulfone) was tested and found to have a dielectric constant of 29. Elastomeric mixtures consisting of essentially 50 parts of dimethylsulfolane and 100 parts of the copolymer of acrylonitrile and butadiene were found to have dielectric constants of the neighborhood of 19. A composition was prepared consisting of: Elastomer Copolymer 100 parts Modifier 64 parts The modifier consisted of: Plasticizer Dimethylsulfolane 50 Salt Phenyltrimethylammonium iodide 5 Filler Zinc oxide 5 Softener Stearic acid 1 Curing agent Tetramethylthiuramdisulfide 3 64

The composition was compounded by incorporating the elastomer with the plasticizer in a conventional rubber mill. This was milled for 15 minutes, during which time the filler was periodically added in small quantities, followed by the incorporation of the quaternary salts and other ingredients. The composition was then milled an additional 15 minutes, placed in a mold and press-cured for a period of 30 minutes at 300 F. The resulting rubber article had a direct current volume resistivity of 0.58 megohm per centimeter cube and an alternating current volume resistivity of 0.54 megohm per centimeter cube. The electrical conductivity remained unchanged after severe flexing tests. EXAMPLE 2 A rubber article was prepared using the modifier of Example 1 but employing Hycar 1001 as the elastomer. Hycar 1001 is a copolymer of acrylonitrile and butadiene, containing approximately 39% acrylonitrile, and is sold by the B. F. Goodrich Company of Akron, Ohio. The article resulting from the curing of the composition had electrical conductivity characteristics substantially the same as the article of Example 1. EXAMPLE 3 A rubber article was prepared essentially according to Example 1, and utilizing the curing agents of Example 1 in an elastomeric mixture consisting essentially of 100 parts of a polychloroprene, 50 parts dimethyl sulfolane and 5 parts of laurylisoquinolinium bromide. The cured product had a DC resistivity of 2.1 megohm per centimeter cube. The higher resistivity of the neoprene product was believed to be attributable to the fact that the chloro group was not as effective as the nitrile group in increasing the dielectric constant of the elastomeric material. EXAMPLE 4 A cured article was prepared essentially as in Example 3, with laurylisoquinolinium bromide as the salt but with dimethoxyethoxyethyl adipate as the plasticizer. The product had a direct current resistivity of 5.8 megehms per centimeter cube. EXAMPLE 5 By substituting 50 parts of octadecylnitrile as the plasticizer in the composition of Example 4, a cured article was prepared having a direct current resistivity of 9.3 megohms per centimeter cube. EXAMPLE 6 A cured rubber article was prepared from a composition consisting essentially of 100 parts of Thiokol (a polyethylene-polysulfide sold by the Thiokol Corporation), 50 parts of dimethyl sulfolane and 5 parts of phenyltrimethyl ammonium iodide and the curing agents outlined in Example 1. The cured rubber article had a DC volume resistivity of 0.71 megohm per centimeter cube and an AC volume

resistivity of 0.59 megohm per centimeter cube. EXAMPLE 7 A mixture was prepared consisting of equal parts of dimethylsulfolane, octadecylnitrile, tetramethylene sulfone, dimethoxyethoxyethyladipate and several similar plasticizers, each having a dielectric constant significantly above 15, plus about 10 to 40 per cent of equal parts of tetraethylammonium bromide, laurylisoquinolinium bromide, phenyltrimethylammonium iodide, phenyltrimethylammonium bromide, triethylmethylammonium p-toluene sulfonate, methyl pyridinium p-toluene sulfonate and several other quaternary salts having anions of strong acids, and this mixture or an equivalent mixture of a single high dielectric plasticizer and a single quaternary salt, was used to impart improved electrical conductivity to an elastomeric mixture comprising Hycar 1001, neoprene, Thiokol, and/or other elastomers having a dielectric constant significantly greater than that of the hydrocarbon rubbers, for example, a dielectric constant greater than 7. EXAMPLE 8 An article was prepared from a composition comprising: Elastomeric material Elastomer Hycar 1001 100 parts Plasticizer Dimethylsulfolane 50 Quaternary salt Salt having strong anion Laurylisoquinolinium bromide 5 Supplementary materials Curing agent Tetramethylthiuramdisulfide 3 Filler Vulcan S C carbon black 50 The article was cured at 310 F. to produce a rubber having both excellent mechanical and excellent electrical properties. Tests showed that the cured article had: Hardness (Shore A) 45 Elongation 500 % Tensile strength 1987 psi. Megohm per centimeter cube 0.0028 Abrasion tests demonstrated that carbonfilled elastomers of the present invention were well suited as shoe soles, and in actual wearing tests, the conductive rubber shoe soles of the present invention proved superior to those previously available. EXAMPLE 9

A rubber composition was prepared essentially in accordance with the method of the preceding Examples, including the following components: Hycar 1001 100 parts Tetraethylammonium bromide 5 ss,ssl-Oxydipropionitrile 50 Silene EF (filler) 125 Age Rite Alba (antioxidant) 0.4 Stearic acid (processing agent or activator) 2 Altax (Registered Trade Mark) 1 Methyl Zimate (accelerator) 0.16 Zine Oxide (accelerator) 5 Sulfur (curing agent) 3 A composition prepared in accordance with the teachings of the previous Examples demonstrated a direct current resistivity of 0.088 megohms per centimeter cube, hardness of 71 by the Shore method, tensile strength 788 psi., elongation 175,n, tear strength 123 lbs. per inch. The following Table illustrates the effect on volume resistivity of incorporating polar plasticizers having dielectric constants of between 10 and 40 in various synthetic elastomers: EFFECT OF COMPOUNDING DIMETHYLSULFOLANE PLASTICIZER IN VARIOUS RUBBERS <img class="EMIRef" id="026700845-00060001" /> I Parts of Volume Resistivity No. Gum Essential Ingredients DC (x 106 ohm-cm) 377 Hycar 1001 None 1,000. 378 " 5.0 LIQB 250. 379 " 50.0 DMS 21. 380 " 5.0 LIQB + 50.0 DMS 5.0 396 " 5.0 LIQB + 50.0 TCP 210. 381 Neoprene GN None 47,000. 382 5.0 LIQB 2,000. 383 " 50.0 DMS 2.3 384 " 5.0 LIQB + 50.0 DMS 2.1 397 " 5.0 LIQB + 50.0 TCP 110. 385 Thiokol ST None 10,000. 386 " 5.0 LIQB 1,500. 388 " 5.0 LIQB + 50.0 DMS 1.6 389 GRS None 390 " 5.0 LIQB 391 50.0 DIS 50,000.

392 5.0 LIQB 3- 50.0 DMS 51,000. 399 5.0 LIQB 3- 50.0 TCP 58,000. 415 Smoked sheet None > 400,000. 416 5.0 LIQB > 404000. 417 50.0 DIS > 404000. 418 v 5.0 LIQB + 50.0 DMS > 400,000. 419 " 5.0 LIQB + 50.0 TCP > 400,000. DMS = Dimethylsulfolane, LIQB = Laurylisoquinolinium bromide, TCP = Tricresylphosphate. From the above reported experimental work, it will be observed that the incorporation of the highly polar dimethylsulfolane plasticizers reduced the DC volume resistivity from 1,000 to approximately 21.0, in the case of Hycar 1001 from 2,000 to approximately 2.3, in the case of Neoprene GN and with Thiokol ST from 10,000 to approximately 1.6 with the addition of a small quantity of electrolyte. In the case of Neoprene GN, the presence of electrolyte in the plasticizer was sufficient after the addition of the plasticizer to reduce the DC volume resistivity from 47,000 to approximately 2.3. The further addition of electrolyte, it will be observed, had little effect in securing a further reduction of the resistivity. What we claim is: - 1. A conductive rubber composition comprising a polar synthetic elastomer having a dielectric constant of at least 5.0, a polar plasticizer having a dielectric constant of at least 10.0 which is compatible with the elastomer and an electrolyte which is soluble in the plasticizer. 2. A composition as set forth in claim 1 in which the elastomer has a dielectric constant over 7.0. 3. A composition as set forth in claim 1 or 2 in which the plasticizer has a dielectric constant of at least 20.0. 4. A composition as set forth in any of the preceding claims, in which the plasticizer is selected from cyclic and aromatic sulfones, alkyl and aryl nitriles, nitro compounds, and alkoxy esters of dibasic carboxylic acids. 5. A composition as set forth in claim 4 in which the plasticizer is dimethylsulfolane, ss,2-oxydipropionitrile, octadecylnitrile, tetramethylene sulfone, or dimethoxyethoxyethyl adipate. 6. The method of forming a conductive rubber composition which comprises mixing a polar synthetic elastomer having a dielectric constant of at least 5.0, a polar plasticizer having a dielectric constant of at least 10.0 which is compatible with the elastomer and an electrolyte which is soluble in the plasticizer. 7. The method set forth in claim 6 in which the composition is

vulcanized. 8. A conductive rubber composition substantially as hereinbefore described. 9. The method of forming a conductive rubber composition substantially as hereinbefore described particularly with reference to any of Examples 1 to 9.

* GB784622 (A)

Description: GB784622 (A) ? 1957-10-09

Tetrakisazo dyestuffs and process of making the same

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i 7 w , 5 >->nY yh,; PATENT SPECIFICATION K- 784,622 Date of Application and filing Complete Specification: Aug 9, 1955. No 22972/55. Application made in Germany on Aug 25, 1954. Complete Specification Published: Oct 9, 1957. Index at acceptance:-Class 2 ( 4), P 2 G( 2 A: 5 A), P 2 H( 5: 10: 20: 21), P( 4 X: 9 A 7 C). International Classification:-C 09 b. COMPLETE SPECIFICATION SPECIFICATI Oi NO 784, 622 The inventor of this invention in the sense of being the actual deviser thereof within the meaning of Section 16 of the Patents Act, 1949, is Klaus Bocimaann, of Koln-Sta nheimr,

C-erstenkamp, 8, Gennany, of German nationality. THE PATENT OFFICE, 29th October, 1957 DB OO 058/1 ( 8)/3591 100 10/57 R L. 0 Jr In this formula, R stands for hydrogen, alkyl, hydroxy alkyl or aryl and R 1 and R,, mean a radical of the benzene or naphthalene series, and R, stands for a radical of the benzene series carrying the NH-C-NHR-group in II o-position to the azo bridge and the -NHgroup in p-position to the azo bridge. The new tetrakisazo dyestuffs can be obtained by coupling diazotized amino dyestuffs of the benzene or naphthalene series with a 3-amino- 11-phenyl urea of the general formula: N H 2 NH-C-NHR To wherein R has the same meaning as above and the benzene nucleus A may be further substituted except for the coupling position, and converting the aminodisazo dyestuffs thus obtained-e g by treating them with phosgeneinto their ureas. The 3-amino-phenyl ureas used as coupling components can be obtained by reacting 1disulphonic acid are diazotized in usual manner and coupled with 151 parts of 3-aminophenyl urea in acetic acid solution The resulting amino-disazo dyestuff is converted into the corresponding urea by reacting it with phosgene When the amino disazo dyestuff has completely reacted, the resulting tetrakisazo dyestuff of the formula: lHo 35-Oiw 4 K 2}-NN 44 HI-rnt CO _q 03 W NW-C-Nllz o 2 is filtered and dried It represents a brown powder which is readily soluble in water The new dyestuff dyes cotton and regenerated cellulose in orange-red shades of very good fastness to light and very good dischargeability. EXAMPLE 2. 357 Parts of 4-amino-azo-benzene-3,41-sulphonic acid are diazotized as described in Example 1 and then combined with 195 parts of N ( 3 amrnino)- 11 phenyl-Nl-hydroxyethyl urea The formed amino cdisazo dyestuff is converted into its urea with phosgene After 1 c, I-,O,,, 9, PATENT SPECIFICATION 784,622 d Date of Application and filing Complete Specification: Aug 9, 1955. No 22972/55. Application made in Germany on Aug 25, 1954. Complete Specification Published: Oct 9, 1957. Index at acceptance:-Class 2 ( 4), P 2 G( 2 A: 5 A), P 2 H( 5: 10: 20: 21), P( 4 X: 9 A 7 C). International Classification:-CO 9 b. COMPLETE SPECIFICATION Tetrakisazo Dyestuffs and process of making the same We, FARBENFABRIKEN BAYER AKTIENGESELLSCHAFT, a body corporate organised

under the laws of Germany, of Leverlkusen, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to tetrakisazo dyestuffs and to a process of making the same; more particularly, it relates to dyestuffs corresponding to the general formula: Ro-N-N-R 2-N-N-R 3 -NH-1 CO L fl N -C-N Hr12 a -12 In this formula, R stands for hydrogen, alkyl, hydroxy alkyl or aryl and R 1 and R 2 mean a radical of the benzene or naphthalene series, and R, stands for a radical of the benzene series carrying the NH-C-NHR group in 0 o-position to the azo bridge and the -NIHgroup in p-position to the azo bridge. The new tetrakisazo dyestuffs can be obtained by coupling diazotized amino dyestuffs of the benzene or naphthalene series with a 3-amino- 11-phenyl urea of the general formula: >-IH 2 NH-C-NHR II wherein R has the same meaning as above and the benzene nucleus A may be further substimtuted except for the coupling position, and converting the aminodisazo dyestuffs thus obtained e g by treating them with phosgeneinto their ureas. The 3-amino-phenyl ureas used as coupling components can be obtained by reacting 1amino 3 acylamino benzene with chloroformic acid phenyl ester in aqueous acetic 35 solution, treating the urethane thus obtained with ammonia or an amine in neutral to alkaline medium The 3-acylamino-l-phenyl urea, which is formed while phenol is split off, is hydrolised in acid solution to form 3-amino 40 1-phenyl urea. The new tetralisazoi dyestuffs dye cotton and regenerated cellulose essentially orangered to reddish brown shades of very good fastness to light and improved dischargeability 45 The following examples illustrate the invention, the parts being by weight: EXAMPLE 1. 357 Parts of 4-aminoe-azo-benzene-3,41disulphonic acid are diazotized in usual manner and coupled with 151 parts of 3-aminophenyl urea in acetic acid solution The resulting amino-disazo dyestuff is converted into the corresponding urea by reacting it with phosgene When the amino disazo dyestuff has completely reacted, the resulting tetrakisazo dyestuff of the formula: CO o 2 is filtered and dried It represents a brown powder which is readily soluble in water The 60 new dyestuff dyes cotton and regenerated cellulose in orange-red shades of very good fastness to light and very good dischargeability. EXAMPLE 2. 357 Parts of 4-amino-azo-benzene-3,4 '-sulphonic acid are diazotized as described in Example 1 and then combined with 195 parts of N ( 3 amino)-1,phenyl-Nl-hydroxyethyl urea The formed amino disazo dyestuff

is converted into its urea with phosgene After drying the resulting azo dyestuff corresponding to the formula: 6,8-disulphonic acid with 107 parts of lamino-3-methylbenzene is diazotized in usual manner and coupled with 151 parts of 3amino-phenyl urea in acetic acid solution 45 After converting the amino dyestuff into the urea with phosgene the tetrakisazo dyestuff of the formula: H 0.35-0 N=N-4 <N:N-G}NH 503 N NH-C-NN-Ci CH 2-OH 0 is a brownish red powder which is readily soluble in water; it dyes cotton and regenerated cellulose in scarlet red shades of very good fastness to light and good dischargeability. EXAMPLE 3. The amino azo dyestuff which can be obtained by coupling 253 parts of diazotized 1aminobenzene-2,4-disulphonic acid and 121 parts of 1-amino-2,5-dirterhylbenzene is diazotized in usual manner and combined with 151 parts of 3-amino-phenyl-urea in acetic acid solution The formed amino disazo dyestuff is converted into the urea with phosgene. The dyestuff thus obtained corresponds to the formula: Ns" 9 "yt H CO f"J-C-NH 2 0-2 is isolated and dried It represents a brown powder which is readily soluble in water; it dyes cotton and regenerated cellulose in brown shades of good fastness to light and good dischargeability. EXAMPLE 6. The amino azo dyestuff, obtained by coupling 253 parts of diazotized 1-aminobenzene2,5-disulphonic acid with 121 parts of 1amino-2,5-dimethylbenzene, is diazotized in acetic acid solution and combined with 165 parts of 3-amino-4-methyl-l-phenyl urea The formed amino disazo dyestuff is converted into the urea with phosgene After drying the resulting azo dyestuff of the general formula: CH 3 HOBS Q-N=N N=fi NH CO 503 H CH 3 RNH-C-NH 1 2 2 _ After drying it represents a brown powder which is readily soluble in water; it dyes cotton and regenerated cellulose in red-brown shades of good fastness to light and good dischargeability. EXAMPLE 4. 357 Parts of 4-aminoazobenzene-3,4-disulphonic acid are diazotized as described in Example 1, coupled with 308 parts of N-( 3amino)-l-phenyl-Nl-3-sulphophenyl urea and the formed amino disazo dyestuff is converted into the urea with phosgene After drying the resufiting azo dyestuff of the formula: CO w 355 C> ' C c- 4 "H) CO so 3 II NH-C-Hl _ Sop; -2 represents a brown powder which is soluble in water; it dyes cotton and regenerated cellulose in orange-red shades of good fastness to light and good dischargeabiity. EXAMPLE 5.

The monoazo dyestuff obtained by coupling 303 parts of diazotized 2-amino-naphthaleneCO 65 represents a brown powder which is soluble in water; it dyes cotton and regenerated cellulose in reddish-brown shades of good fastness to light and good dischargeability. EXAMPLE 7. The amino azo dyestuff which can be obtained by coupling 173 parts of diazotized 1aminobenzene-3-sulphonic acid and 223 parts of 1 -aminonaphthalene 7 sulphonic acid is diazotized in usual manner and combined with 165 parts of N-3-aminophenyl-N 1-methylurea in acetic acid solution The formed amino disazo dyestuff is converted into the urea with phosgene The dry dyestuff represents a brown powder which is readily soluble in water; it dyes cotton and regenerated cellulose in red-brown shades of good fastness to light

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