‘ the material.

Patented Oct.’ 24, 1944 , 2,360,844

UNITED‘ STATES PATENT ‘OFFICE 2,360,844

PREPARATION OF DETERGENTS

George Burt Bradshaw, Wilmington, Del., and Walter. C. Meuly, New Brunswick, N. J., assign ors to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware

N 0 Drawing. Application November 26, 1941, ‘ Serial No. 420,590

(Cl. 260—410.9) 15 Claims.

This invention relates to methods forthe prep aration of soaps and soap compositions. More particularly it relates to a novel process of mak ing soaps from glycerides. Still more particu larly it relates to a process of making soap from the glycerides of higher open chain aliphatic car boxylic acids. In one of its aspects it relates to an improved method of producing dry soap and/or controlling the water content thereof. It further relates to novel spraying procedures for obtaining sponge-like small particles of soap. The invention also pertains to the separation of glycerine from natural glycerides to produce a re?ned base. vThis invention also relates to oil or fat re?ning and to saponifying methods amen able to continuous processes and to such continu ous processes and to novel improvements in the soap making arts. In the usual process for manufacturing soap

naturally occurring oils and fats are ?rst refined or puri?ed and then saponi?ed. In common re ?ning processes caustic soda is added to crude liquid fat so that free fatty acids in the fat are precipitated as soaps. During precipitation, col oring matter, mucilagenous and protein material is precipitated along with the soap. There are many disadvantages connected with this proce dure among which are (1) waste of fats since the foots obtained are difficult to utilize and (2) the reactions are slow and tie up processing equip ment for long periods of time. In the usual proc ess for manufacture of soap from the re?ned fats or oils these materials are treated step-wise with dilute caustic soda or potash solutions and then with salt solutions to effect (a) separation of the glycerine, (b) conversion of the fatty material to ,soap as complete as possible and (c) isolation of the soap in a condition as free from water and as pure as possible. By this procedure there is incompletely recovered a very impure glycerine of from 5 to 10% strength containing both im purities from the original oils and‘ dissolved salt and lye. The soap resulting contains about 35% of water and salt, free caustic and unsaponi?ed fat, depending on the skill with which the opera tion has been carried out and also the economics of the situation. The dilute glycerine is puri?ed and recovered by intricate processes and when sold, often represents the only net return in the whole soap operation. Often the saponi?cation operation lasts from 4 to 6 days. The soap must generally be dried so as-to be marketable. This is di?icult because of the gelatinous nature of

A really dry soap for making special powdered soaps may be dried for a year.

in

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Spray drying and drum drying operations are used to a considerable extent.

In the conventional spray drying operation, a I soap» which has been saponl?ed as completely as possible and from which the glycerine has been removed is brought into a molten or liquid con dition by a combination of factors including heat and moisture. It is then sprayed into a zone which is so arranged that most of the water present will escape as steam and be carried away from the soap particles. The water escapes from the small droplets of soap by bursting through the walls thereof. High temperatures necessi tating special heating facilities are required by such procedures. This invention has for an object the provision

of a rational process for producing soap and soap compositions which can be carried out in an economical manner. Another object is to over come the difficulties of the prior art procedures. A further object is to provide a novel process for making soaps which is applicable to any natural glyceride. A further object is to provide a proc ess for making soap in which the glycerine may be recovered in a substantially anhydrous and concentrated “condition. A further object is to furnish a process for making hard soap from oils which have hitherto yielded soft soap. A still further object is to provide a low temperature process for making soap. Another object is to furnish a process for making hard potash soaps. Another object is to furnish a process for mak ing high melting-point wax-like material. An other object is to furnish a process for making lighter colored and more brilliant soaps than formerly possible from a given grade of oil or fat. A further object is to furnish a process for a soap containing a new superfatting agent. A further object is to provide a re?ned fatty acid mono ester from a natural glyceride which can be easily, quickly, and completely saponi?ed to form either a pure dry soap or modi?ed at will. Yet another object is to control the water content of dried soaps within narrow limits. A related object is to prepare particles of soap which have minute pores and do not dust readily. A further

} object is to provide a process amenable to con

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tinuous operation. A still further object is to furnish a process for a new composition of matter consisting of dry crystalline sodium and/or po tassium salts of mixed natural fatty acids. Many efforts have been made to simplify and

rationalize the usual procedures. The merely simplified methods so far result in a poor quality of soap. Some of the better methods are scien

2 ti?cally more rational than the usual process, but are too expensive. The commonest of these processes is to separate the glycerine by a fat splitting process not involving the use of caustic soda or potash. The free fatty acid is then neu- . tralized with soda to produce a soap. In one proc ess this involves producing a lime soap which is double decomposed with soda to form a soda soap, All these processes have been in existence for many years, but can only compete under very specialized conditions against the usual saponifl cation procedure first described above.

It has now been found that the above disad vantages can be obviated, the above vobjects at tained and that natural fats can be refined and made into soaps by first subjecting the dried fat to an alcoholysis with a volatile monohydric ali phatic alcohol of 1 to 4 carbon atoms using caus tic soda or its equivalent as a catalyst plus enough alkali to neutralize any present acidity, separat ing the glycerine by its difference in specific grav ity after decomposition with acid of soaps if present, washing with water. mixing the mono hydric esters with a saponifying quantity of al kali and completing the reaction and separation of the monohydric alcohol under controlled con tions. To obtain all the bene?ts of the invention, it is

desirable to use all the novel steps herein de scribed. However, some of the bene?ts are ob tainable by using only one or two steps of the complete invention. The invention will ?rst be exempli?ed in one of its more complete aspects by a typical procedure with a vegetable glyceride. Coconut oil, which in its usual commercial state, contains a certain amount of water, free fatty acids, mucilaginous matter, protein, coloring mat ter and sugars, is ?rst selected. The water which will separate by gravity when the oil is in the liquid state is removed. If the oil still contains more than about 1% of water it is then dried by one of the well known means e. g. direct heat ing of the oil, to less than 1% water content. The free acidity and ester value is determined by the usual method. The oil is heated to a moder ate temperature e. g. 25° C. to 100° C. more or less depending on the time the apparatus can be occupied. If a closed system or a re?ux is used the temperature and consequently speed of the reaction may be increased. There is then mixed into the oil a substantially water-free solution of commercial anhydrous methanol containing a small amount of caustic soda or potash. The total amount of the methanol used in a one step process preferably should be about 1.6 equivalents of that required for ester interchange. The amount of caustic alkali used in this case should be about 25% greater than that calculated as requisite for neutralization of the free fatty acid content of the oil. In general amounts of caustic alkali in excess of that necessary to maintain alkalinity to Clayton yellow should be avoided. Upon the addition and admixture of this meth anol solution the batch should test alkaline to Clayton yellow and continue to do so. If it does not more alkali must be added preferably in methanol solution to maintain this degree of al

2,800,844 ating power than the acids of the slycerides treated, such as acetic acid is added and mixed in until the formed soap has all been decom posed. Now upon standing the glycerine rapidly separates carrying down with it most of the im purities of the original oil.‘ The fatty acid thus set free remains with the newly formed ester. The conversion of the glyceride to methyl ester

. is about 98% complete. The lower layer of nearly

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kalinity. If the acidity of the oil being subjected ' to re?ning and alcoholysis is low the glycerine will begin to settle to the bottom almost imme diately. If the process is being carried out at 80° C. then about ?fteen minutes after the addi tion and admixture of the methanol and caustic, the batch still being alkaline to Clayton yellow, a mild acid having an appreciably greater dissoci

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anhydrous glycerine which is ?rst developed or formed consists of at least about 95% of the glycerine content of the original oil and will contain a small amount of. methanol as well as color and impurities from the crude oil. The glycerine because of its high degree of purity may be used directly in many chemical processes, for example, in the manufacture of glyptal resins. The glycerine and methanol, still retained in the formed esters can be removed by two or three washes with a small amount of water each time. After settling, the wash can be drawn off each time from the bottom. This operation also puri fies and lightens the color of the esters. The washing may be eliminated if the esters are to be distilled in accordance with the following pro cedure. The oily layer formed consisting of the methyl '

ester of the coconut oil acids is now fractionally distilled. With the heating up of the oil the small content of fatty acids is rendered non corrosive. The monoesters distill on an average of 30 to 50° lower than the free acids and can be readily separated therefrom. The distillation of vthe esters is much simpler than the distilla tion of fatty acids and has many advantages. The distillation may be effectively conducted un der reduced pressure, e. g. 3 min. pressure and with 110 lbs. of steam in the heating coils, ?rst the Ca and then the C10 methyl ester is driven or topped off through a packed column e. g. ?lled with Raschig rings. The residue in the still con sisting of methyl esters of C12, C14, C18 and sat urated and unsaturated Cm acids can be drawn off and worked up to soap, or can be further separated by distillation or hydrogenated and separated by crystallization and other known processes. To make substantially anhydrous soaps, there is

added to the mixed monoalkyl esters, e. g. methyl esters which are preferably still warm, a solution and/or suspension of the equivalent quantity of caustic soda or potash in a commercially anhy drous alcohol, e. g. methyl alcohol. This should be mixed in quickly so that it is uniformly ad mixed before the mass thickens due to soap formation. This mixture may be made into soap ?akes by one of the usual procedures and allowed to stand until the neutral soap is formed and most of the evolved methyl alcohol dissipated by evaporation, or the still fluid that is, unreacted, mixture is sprayed into the top of a tower in which there is a current of hot air, and recovered at the bottom as neutral soap powder. The alco hol can be recovered if desired and reused. By using very ?nely ground or dispersed caustic alkali and suitable mixing device, all or nearly all of the alcohol solvent for the saponifying alkali can be dispensed with especially if some alcohol is added to the esters previous to adding the caustic. The soap so produced by the process just described is an anhydrous pure alkali salt of mixed natural fatty acids. It is crystalline in nature and much harder, brighter, more trans parent, and of higher melting point than soaps ~made by any of the known processes from the

2,300,844 same materials and is apparently a new product. It is also more stable. This is probably because no incipient rancidity has been caused by exces sive or prolonged heating as in the usual soap processes. ‘ -

The processes just described might be outlined as follows: A natural glyceride is ?rst reacted with a substantially anhydrous alcohol, prefer ably a lower saturated volatile, aliphatic primary alcohol, e. g. methyl or ethyl alcohol in small ex cess in the presence of a small amount of a dry alkali metal hydroxide above that necessary to neutralize the acidity of the glyceride, any formed soaps are decomposed with an acid such as acetic or hydrochloric acid, the resulting alkyl esters are separated from the glycerine and then subjected to fractional distillation to remove the lower boil ing esters; the mixture of higher esters is then reacted with an alkali metal hydroxide, preferably in the substantial absence of water to form soaps. The amount of alcohol required for the libera

tion of the glycerine as will be apparent from the above description may be varied somewhat. Furthermore, the amount can be reduced substan tially by working in steps. For instance, if the theoretical quantity of methyl alcohol is used for the alcoholysis of a previously re?ned oil, the con version will be about 80%. The glycerine can then be removed and more alcohol and catalyst added. If the alcohol is added in small'portions, e. g. in three or four substantially equal portions, the amount required can be reduced, for instance, from one and six tenths times theory to one and one tenth times theory. With a previously refined dry neutral oil the ?rst addition should not be less than four tenths of an equivalent. The preferable amount for the ?rst addition is six tenths of an equivalent. Amounts of methyl alcohol above 1.75 equiva

lents tend to prevent the gravity separation of ' the glycerine thus adding useless expense to the separation. Also the more alcohol used the more goes into the glycerine layer. Amounts of alco hol from 1.10 to 1.75 equivalents represent a practical range. If a previously re?ned neutral oil is used the amount of alkali required is only that necessary to maintain alkalinity to Clayton yel low during the alcoholysis. With anhydrous caustic soda this is 0.1 to 0.5% by weight based on the oil. .It should be added as a solution in the alcoholysis alcohol. Any alkali metal compound or mixture of such compounds that will give the equivalent alkalinity can be used, e. g‘. sodium or potassium methylate. At ordinary tempera tures and with dry neutral materials the glycerine separates almost immediately. Higher tempera tures increase the speed of this reaction so that it is practicable to run it in a continuous process with continuous feed of proportioned ingredients and separation of glycerine and washes by con tinuous centrifuging. When the step-wise alcoholysis or ester inter

change is applied to unre?ned oil, certain pre cautions must be observed. In this case the ?rst addition of esterifi'ing alcoholland catalyst should be somewhat nearer the theoretical equivalency than when working with re?ned oil. The dis solved caustic of this addition must be enough to neutralize all free acidity plus a catalytic excess, so as to show continued alkalinity to Clayton yellow. After the reaction and decomposition of the formed soap by the addition of acid and sepa ration of the ?rst portion of glycerine another portion of alcohol containing catalyst in solution

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3 is added and the next portion of glycerine sepa rated. Various kinds of acids may be used for decom-

posing the soap or soaps formed during the alco ,holysis step. In general, a mild acid having an appreciably greater dissociating power than the acids contained in the glycerides treated should be used. Acids which do not form gelatinous pre cipitates and do not have a carbonizing or other deleterious effect on the glycerides used have obvious advantages. Organic acids having a rela tively high dissociation constant and which can .be economically obtained in a substantially water free or anhydrous form are preferred. Suitable acids include formic, acetic, propionic, hydro chloric, sulfuric, sulfamic, phosphoric, etc. acids. In general, the mineral acids should be used in diluted condition. '

If a concentrated caustic soda solution, e. g. 50% strength is used, as the saponifying agent, it preferably is emulsi?ed with the’methyl esters to a homogeneous emulsion before the reaction causes much thickening. The emulsion may be treated as described above, and will produce a neutral soap containing about 12% water which is the usual amount in ?ne soaps. However, if more concentrated solutions of caustic alkali are used, soaps with a lower Water content may be obtained. If sodium carbonate is used, high heat ing Or autoclaving will be necessary to effect the reaction. If a de?ciency of saponifying alkali is employed the v?nished soap will still be neutral and will contain a valuable superfatting material that is the mono ester or esters of the fatty acids from the glycerides with the alcohol used. A somewhat narrower but important use of the

invention is involved in making valuable prod ucts including soaps, from cotton seed and similar unsatrrated oils. Re?ned oils when employed re sult in a saving of chemicals but crude oils can be used'by adding extra alkali to compensate for the free acids as explained above. The ester value and acidity are determined and 1.6 equivalents of methyl alcohol containing about 25% of caus tic soda in excess of that needed to neutralize free acids is admixed. The mixture is warmed to 1 about 25° to 100° C. and the formed soaps de composed With acetic acid, the glycerine is drawn off and the oil washed free of glycerine and alco hol. The methyl esters of the cotton seed oil acids are treated with saponifying agent to pro duce an anhydrous soap. The soap is found to be hard like the ordinary soap made from satu rated fats and has the above described proper-v ties. The mixed esters of the unsaturated acids, e. g.

the methyl esters from the cotton seed oil may be hydrogenated and distilled to form fractions of nearly pure methyl palmitate and methyl stear ate. If the methyl stearate, for instance, is con verted into an anhydrous soap as sodium stearate, there is obtained’ a crystalline waxy material melting at about 260° C. It is useful as an in— gredient of waxy coatings, for instance, of use in coating paper, producing paper from which later printing ink can be easily removed. The use of a spraying device for completing

the manufacti're of soap from the monohydric alcoholic esters of fatty acids presents a number of new aspects. The actual conversion from a mixture of ester and alkali to soap can be delayed, say by temperature control, until the moment when the spray forms. As this conversion is exothermic‘ and as the mixture or emulsion of ester and alkali plus the controlled quantity of

4 water and/or alcohol is ?uid and not viscous as it enters the sprayer, the amount of heat required is small. Consequently, also the spray device can be operated merely as a remover of alcohol as it is formed to produce a new type of sprayed soap 5 material still containing the small amount of water desired in the ?nished product. The form of the product is different from any form previ ously made though it can be made to simulate previous forms. A main characteristic of the 10 novel product is its porous, sponge-like structure and dust free nature. Another characteristic is light gravity. This is in part due to the fact that the material is produced by the evolution of al cohol or alcohol plus water rather than water. An important aspect of the invention is that

it can be carried out continuously. This can be done without the use of high temperatures and pressures or corrosive conditions. The-glycerine and wash waters can be separated by continuous 20 centrifuges. The monohydric alcohol ester of fatty acids, as it issues-from the centrifuge, can be mixed with a proportioned amount of caustic alkali continuously, for instance with the help of a homogenizer. and the reaction can then be made 25 to occur almost instantaneously by the applica tion of a very little heat as the product is being sprayed or drum flaked. *\ The invention will be further illustrated, but is

not intended to be limited by the following ex- 30 amples:

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Example I

One thousand pounds of unre?ned cocoanut oil, on testing, is found to contain 1.1% water. It is heated to about 100° in a kettle under a 35 vacuum corresponding to a pressure of 30 mm. When the water content has been reduced to 0.5%, the oil is tested for acidity and ester value. It is found to have an acid value of 7 and to be 96.7% glyceride of M. W. 640.v The amount of 40 92% purity anhydrous caustic soda required to neutralize the oil calculates as

9.94X .50 .92

The amount of 99.8% purity methanol required for equivalency to the glycerine is

The ?rst treatment of the oil is with 0.7 of an equivalent or 0.7 of 145.3 lbs.'—_-101.7 lbs. methanol. In, this methanol is dissolved 1.25x5.4=6 lbs. 12 ozs. of 92% NaOH. To the dried cocoanut oil now at a temperature of about 80° C., is 55 added under stirring this solution of 6 lbs. 12 ozs. caustic soda in 101.7 lbs. methanol. The tem

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I perature is held up so as to increase the solu bility of the impurities in the glycerine. On testing the batch is found to be alkaline to so Clayton yellow, After ?fteen minutes, the agi tator is started again and 10 lbs. 5 ozs. glacial acetic acid added. The agitator is stopped and at the end of one half hour the glycerine layer which has meanwhile settled out is drawn off. For the second treatment 0.2 equivalent of such

substantially anhydrous methanol or 29 lbs. is used containing 2 lbs. caustic soda. , This is mixed in for a few minutes and allowed to stand. On testing the batch is found to be alkaline to Clay- 70 ton yellow. At the end of 20 minutes the glyc erine layer is drawn off and another treatment is made with 29 lbs. methanol containing 2 lbs. caustic in solution.‘ Upon'analyzing, it is now found that the glycerine layers when combined 76

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2,860,844 amount to about 169 lbs. of this following com position: I

Glycerine __________________ __ 128 lbs.— 75.7%

Methanol ______-____-________ 12lbs.—- 7.1% Esters and soaps ___________ __ 5lbs.-- 3.0% Sodium acetate ____________ __ 121bs.—- 7.1% Water, NaOH and impurities--- 12lbs.— 7.1%

169 lbs. 100.0%

The oil or ester layer is found to amount to about 1006 lbs. containing:

Methyl esters ___________ __ 941 ' lbs.—' 93.5%

Methanol _______________ __ 6 .9 lbs.— .7 % Glycerides _______________ __ 29 lbs.— 2.9%

Free fatty acids _________ __ 25.5 lbs.— 2.5% Sodium acetate __________ __ 1.5 lbs.— .2% Glycerine ________________ _ . 1.7 lbs.— .2 %

1005.6 lbs. 100.0%

The undesirable impurities in the ester layer are water soluble and can be washed out, but as for the purpose in mind in this example, the gain in quality does not compensate for the ex pense involved, this ester layer is used as is. There is now quickly admixed in this ester layer to a homogenous emulsion 310 lbs. of a 60% NaOH solution. The mixed liquid amounting to 1316 lbs. contains:

Pounds Methyl esters ________________________ __

Glycerides ___________________________ __ 995.5

Free fatty‘acids ______________________ _.

Caustic soda _________________________ __ 186

Water ________________________________ __ 124

Methanol free and in combination _____ __ 148

This homogenous liquid is now worked in a mixer while the soap reaction occurs. The tempera ture rises spontaneously and a portion of the alcohol vaporizes off along with a portion of the water. The material is now formed into soap cake by the usual methods. The cakes of soap totalling about 1150 lbs. contain about 7% water and 3% methanol and are completely saponi?ed that is less than 0.1% free alkali content.

Example II

One thousand pounds re?ned Cochin type co coanut oil is warmed to aobut 30° C. Five pounds dry caustic soda is dissolved in 240 lbs. of commercial anhydrous methanol. For this type of oil 240 lbs. of methanol is 1.6 equivalents. The solution is stirred into the oil for a few minutes and the agitation stopped. Within thirty minutes the glycerine has separated. It amounts to about 200 lbs. and tests alkaline to Clyaton yellow. The composition of this layer is found by analysis to be:

Glycerine ________________ __ 134 lbs.—- 67%

Methanol ________________ __ 40 lbs.—- 20%

Esters and soap.v __________ __ 24.51bs.—— 12.3% NaOH ____________________ _- 1.5lbs.—— .7%

200.0 lbs. 100.0%

The oil or ester layer amounts to 1045 lbs. and analyzes:

Methyl esters _______________ __ 971lbs.-— 92.9%

Methanol __________________ __ 40 lbs.— 3.8% Glycerides _________________ __ 30 lbs.— 2.9 % Glycerine __________________ __ 4 lbs.— .4%

1045 lbs. 100.0%

2,860,844 The esters are washed with two washes, one of 15 gals. and one of 8 gals. of water of 50—60° temperature agitating each time l/g hour and allowed to settle each time and the wash waters drawn o?. ‘ -

The ester layer now amounts to 1,000 lbs. and contains about: . "

, Pounds

Methyl esters _________________________ __ 97 _0 Glycerides ‘ 30

1000 This oil is submitted to fractional distillation to top off or remove the methanol and the lower esters that is the Ca, Ca, and part of C10 esters. The mixture, remaining in the still amounting to 830 lbs. is found by analysis to require;140 lbs. NaOH to saponify it. Two hundred-forty pounds of caustic soda solution containing 140 lbs. NaOH and being at a temperature of about 60° C. is mixed with the 830 lbs. of topped esters. The topped esters are at a temperature of about 70° C. when introduced to the mixing device. The mixing is done by feeding continuously the two materials by proportioning pumps to an homog enizer. The outlet of the homogenizer feeds by a short steam jacketed connection, the spraying device of a spray tower similar to that commonly used for spray drying soap. However’, the tem perature of the carrier gases in the spray tower are only about one-half that usually employed. This is because there is heat liberated from the saponification reaction. The ‘temperatures of these carrier gases, is controlled so that the ?n ished product is completely saponi?ed and ana lyzes about 5% water and only traces of'metha nol. The product is porous, sponge-like discrete particles free from dust and has an apparent density such that it easily dissipates in water.

Example III

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One thousand pounds of re?ned Cochin type . cocoanut oil is treated as described in Example II so as to produce 830 lbs. of topped methyl esters. There is then prepared a dispersion of po. tassium hydroxide containing 196 lbs. KOI-I. This dispersion is prepared by removing the water from a solution of potassium hydroxide by adding a light petroleum fraction e. g. kerosene and dis tilling. The ?nely dispersed potassium hydroxide obtained is mixed with 830 lbs. of topped methyl esters. The temperature of the methyl esters at the start is about 20° C. As soon as the mixture is homogeneous, it is worked in. a jacketed mixer with a small amount of heat in the jacket. The reaction occurs and the material passes through a plastic stage to a powdery one. There is ob tained an anhydrous potassium soap which can be ground to as ?ne a powder as desired. This powder is not hydroscoplc and is suitable for dis pensing from a can with a perforated top, say for shaving soap.

Example IV

Seven hundred and ?fty pounds of re?ned cot ton seed oil ‘and 250 lbs. of a neutral hardened fat whose fatty acids have a titer of about 55° C. are melted together and brought to a. temperature of 80° C. The composition is:

Per cent Glyceride, unsaturated Cm, one double bond- 30 Glyceride, unsaturated C18, two double bond_ 33 Glyceride, saturated _____________________ __‘ 37

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5 The ester value is such that theoretically 1,000 lbs. require 111 lbs. pure methanol for alcoholysis. 1.2 equivalents methanol, therefore, equals about 133 lbs. In 133 lbs. of commercial anhydrous methanol is dissolved ?ve pounds of anhydrous 96% caustic soda. One-half this solution is stirred into the warm oil for ?ve minutes and the agitation stopped. During this admixture the batch is ?rst cloudy and then clears up. As the reaction proceeds, it again becomes cloudy due to separated glycerine. At this stage a sample is taken and tested in a Gerber milk testing centri fuge. If the glycerine layer amounts to 1/20 of the total volume, the reaction mass is ready for centrifuging.‘ If not, more time is needed for the reaction to occur. When reacted, the batch is run through a centrifuge and separated into two por tions, one of about 1009*lbs. and another of about 60 lbs. which contains the separated glycerine. To the 1009 lbs. is added the second half of the methanol solution and the procedure again fol lowed as just detailed. The combined portions of separated glycerine amount to about 129 lbs. and contain: '

Glycerine _________________ __ 102 lbs.- 79.0% Methanol ________________ -1- 18 lbs.-—- 14.0% Esters and soaps ____________ __ '7 lbs.— 5.4% Causticsoda ________________ __ 2 lbs.-— 1.6%

129 lbs. ,100.0% The oil or ester layer amounts to about 1009 lbs. and contains:

Methyl esters _____________ __ ‘981 lbs.- 97.2% Glycerides ________________ __ 20 lbs.- 2.0% Methanol ________________ __ 6 lbs.- .6% ‘Glycerine ________________ __ 2 lbs.— .2%

1009 lbs. 100.0% From the composition it is calculated the 1009 lbs. of methyl esters would require 140 lbs. NaOH to saponify them. They are charged into a jack eted mixer with tight cover of the Werner and P?eiderer type. Thereis also charged in 150 lbs. commercial anhydrous methanol and when this is uniformly intermixed there is quickly admixed 145 lbs. ?nely dispersed caustic soda containing 140 lbs. NaOI-I. There is now admixed 15 lbs. of ?nely ground sodium salt of trimethylamine tri carboxylic acid, 60% purity. The agitation is run with a closed cover until the mass has become‘ discrete. Heat and vacuum are then turned on with slow agitation until 220 lbs. of methanol have been evaporated off. ‘The ?nished product is a bulky powder of marked detergent properties even in hard water. It is anhydrous and non~ hygroscopic and remarkably stable. The com

_ bined fatty acids contained in it are over 55% 60

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unsaturated Cm and of them over half have dou ble unsaturation. A similar product is made by omitting the addition of the sodium salt of tri methylamine tricarboxyli'c acid and making up the ?nished material to contain 10 to 25% of sodium phosphates or poly phosphates. These phosphates should not introduce more than 5% water from their water of crystallization.

Emample V

Bleached, dried and ?ltered neutral soap stock is brought to a uniform molten or liquid condi tion and analyzed. It is found to have an aver age molecular weight of 863 which means that 1,000 lbs. of it theoretically requires 111 lbs. of pure methanol for alcoholysis or 139 lbs. pure

6 caustic soda for saponi?cation. An apparatus ‘is provided which is special as to certain features. It may be made of iron. For a production of 8,000 lbs. per hour of soap this apparatus in eludes:

A. A continuous mixer of about 20 gals. ca- pacity so that average hold up of material passing through it is one minute.

B. A continuous gravity separator of about 350 gals. capacity so that average time of passage is about 20 minutes.

C. Another mixer but of about 1'75 gals. ca pacity so that average passage time is 10 minutes.

D. A continuous centrifuge planned for remov ing continuously the heavier component of about 5%.

E. A continuous mixer and homogenizer for oil and caustic soda solution. Time of passage, brief.

F. A spray tower. ' A solution of caustic soda in methanol is made

containing 21/270 caustic soda. The melted fat is maintained at a temperature or about 80° C. and is fed continuously to mixer A at the rate of 8,000 lbs. per hour. Simultaneously, the methanol solution is fed to the same mixture in the pro portion of 7.9 lbs. methanol solution to 100 lbs. oil by means of proportioning pumps. The ef fluent from mixer A ?ows continuously to sepa rator B which may be lagged to prevent loss of heat. About 6% is continuously drawn from the bottom‘ of a glycerine fraction. The continuous over?ow goes to mixer C to which is also fed continuously a stream of the above methanol solution in the proportion of 5.6 lbs. methanol solution to 100 lbs. of oil. From this mixer a con tinuous stream is red to the centrifuge D. The continuous stream of oil at about temperature 70° C. from D is fed to mixer E and at the same time by a proportioning pump is fed to E a stream of warm 60% caustic soda in the ratio of 23 lbs. ofthissolutionto 100 lbs. of the oil. The discharge from this machine is by a steam jacketed pipe direct to the spray nozzle of tower F. The time of ?ow in this last step is such that the mixture ‘ is just beginning to gelatinize evidencing the in itiation of the saponi?cation, as it leaves the spray nozzle. As the material is sprayed and falls down the tower, the combined alcohol evolves and is carried away from the soap by the hot carrier gases. These gases are not hot enough to dry the last five per cent of water from the soap. The range of glycerides available for producing

soap directly by this process is greater than that available for the old processes because harder soaps can be made from liquid glycerides. In place of the speci?c glycerides described above may be substituted other animal and vegetable fats and oils which have been used for the pro duction of soap. As examples of additional suit able materials, mention is made of olive oil, palm oil, sardine oil, castor oil, whale oil, linseed oil, stearin, tallow, cocoa butter, etc. The preparation of the esters of the fatty acids

preparatory to making soap from them as taught ' herein is not limited to the speci?c alcohols above named, but other alcohols may be used. Thus, saturated aliphatic alcohols or alkanols having from 1 to 4: carbon atoms have utility. The pre ferred alcohols are saturated aliphatic monohy dric alcohols boiling below about 100° C. and es pecially below about 85° C. As examples of ad ditional suitable alcohols, mention is made of propanol, isopropanol and the butanols. Of these,

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those which are water miscible and most volatile 75

2,360,844 are preferred. An amount of alcohol above 1.75 equivalents or use of an alcohol with great inter solubility powers with glycerine such as methyl propylcarbinol will tend to prevent or prevent the glycerine from settling to the bottom and separating as an easily removable phase. One important embodiment of the invention I

is concerned with the use of caustic potash as the saponifying agent in above procedures, where by hard potash soaps are formed. These soaps are believed to be new mixtures and have greater utility in the arts. The invention has a number of decided ad

vantages, among which are: (1) The starting material may be any glyc

eride, (2) The glycerine may be removed me. very

pure and highly concentrated form, (3) There are very small amounts of by

products formed, for instance, the small amount of lower alcohols does not require recovery to make the process economical.

(4) The catalysts used are very cheap and do not have to be recovered,

(5) The lower alkyl esters of the fatty acids from the glycerides readily mix with the saponify ing agent and allow the saponi?cation to pro ceed rapidly,

(6) ‘The reaction starts and completes at low temperatures,

(7) The soaps are not subjected to prolonged or excessive temperatures at any stage,

(8) The initial and final products are non corrosive to metals,

(9) Large amounts of caustic soda do not have to be recovered,

(10) Glycerides which were hitherto not uti lized for making soaps because they yielded soft soaps by the conventional method can be con verted by this process into hard soaps without the necessity of ?rst hydrogenating.

It is possible to produce soaps di?erent from those of the prior art. For example, they can be made lighter in color, non-irritating, and con taining a neutral superfatting agent. They may be obtained in a pure anhydrous form having less than 1/;% of electrolyte content. However, vari ous amounts of water may be contained in the ?nal products. Fats and inorganic or organic diluents, as soap

builders and cake formers, solubility modifying agents, preservatives, bleaching agents, may be compounded with the soaps, as lanolin, stearyl alcohol, methyl stearate, sodium carbonate, so dium silicate, sodium phosphate, sodium pyro phosphate, alkali metal salts of polybasic phos phorous acids, e. g. sodium polyphosphate, poly carboxylic tertiary amines, including those of U. S. P. 2,240,957, sodium perborate, cyclohexa none, glyceryl acetals, e. g. methyl cyclohexanone glyceryl acetal, cyclohexanone glyceryl acetals, etc. glue, glyceryl monooleate, glyceryl mono stearate, bentonite, perfume, etc. The anhydrous pure soap which consists of a

mixture of salts of higher fatty acids have great utility and may be substituted in a great many arts in the same way that-soap and the newer soap-substitutes have been used. The properties of these soaps described above

make them suitable for use in a large number of processes. The following uses are suggested as being indicative of the manner in which the products may be employed: scouring raw wool, fulling, sizing, desizing, impregnating, bleaching, mordanting, lime soap dispersing, mercerizing,

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improvement of absorption, delustering, degum _ming, kier boiling, felting, oiling and lubricating, - dyeing cellulose acetate ?bers with insoluble dyes, dyeing of leather, dye printing pastesrpastes of dyes or dye components, preparation of lakes, preparation of inorganic pigments, emulsiflcation and dispersion, treatment of oil wells, air foam and chemical foam ?re extinguishers,’ cooking wood pulp, radiator cleaners, stripping? dyeing in neutral, or alkaline dye baths, dyeing of animal fibers with vat dyes, cleansing agents, fat‘ liquor ing, washing paper mill felts, improving absorb ency of paper products, household dye prepara tions, metal cleaning, removal of fibrous layers from surfaces, shampoos, insecticides and agri cultural sprays, scouring rayon, ?otation, break ing petroleum emulsions, food preparations, crep ing assistant, ?ooding oil bearing sands, ceramic assistant, polishing, abrasive and bu?ing com positions, dentri?ces, agents to prevent rubber

. and other plastics from sticking to‘molds, in ad hesives such as starch, glue and casein and in compositions containing degraded proteins, wash ing of discharge prints, softening finishing and reducing static charges on textile materials espe cially from cellulose derivatives such as cellulose acetate. I

Thus, the herein described sodium and potas sium soaps may be substituted in equal amounts for the alkyl betaines in Examples 16, 18 to 31, inclusive, 34, 36 to 53 inclusive, 55 to 59 inclusive, and 61 to 66 inclusive, of French Patent No. 849,393. The soaps may be mixed with soaps produced by other processes or with soap sub stitutes such as alkyl naphthalene sulfonic acids, Turkey red oil, higher aliphatic alcohol sulfates, higher alkyl betaines both of they C— and N— type, mineral oil sulfonates, etc. 7 - .

As many apparently widely different embodi ments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that we do not limit ourselves to the speci?c embodiments herein except as de ?ned by the appended claims.

This application is a c'ontinuation-in-part of application Serial No. 268,820, ?led April 19, 1939,' now Patent No. 2,271,619. We claim: - .

l. The process which comprises reacting a crude glyceride with an alkanol of not more than 4 carbon atoms under substantially anhydrous conditions in the presence of su?lcient alkali metal base to neutralize the free acids in said glyceride and to maintain the solution alkaline to Clayton yellow, adding an acid in su?icient amount to decompose the soaps formed, separat ing the glycerine and recovering monoalkyl esters of the fatty acids contained in said glycerides.

2. The process which comprises reacting a crude glyceride with an alkanol of not more than 4 carbon atoms under substantially anhydrous conditions in the presence ‘of sufhcient alkali metal base to neutralize the freeacids in said glyceride and to maintain the solution alkaline to Clayton yellow, adding an acid to the mixture of alkyl esters in su?icient amount to decompose the soaps formed, separating the glycerine and recovering monoalkyl esters of the fatty acids contained in said glycerides and saponifying said esters.

3. The process which comprises reacting a crude glyceride with an alkanol of not more than 4 carbon atoms in the liquid phase at moderate temperatures under substantially anhydrous con

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ditions in the presence of su?icient alkali metal 15

7 base to neutralize the free acids in said glyceride and to maintain the solution alkaline to Clayton yellow, adding an acid in sufficient amount to decompose the soaps formed, separating the alkyl esters'from the glycerine and distilling said esters.

4. The process which comprises reacting a crude glyceride with an alkanol of not more than - 4 carbon atoms in the liquid phase under sub stantially anhydrous conditions, in the presence of su?lcient alkali metal hydroxide to neutralize the free acids in said glyceride and to maintain the solution alkaline to Clayton yellow, adding an acid in sll?lcient amount to decompose the soaps formed and separating the alkyl esters from the glycerine, distilling said esters and sa ponifying at least one fraction of latter.

5. The process which comprises reacting a crude glyceride with an alkanol of not more than 4 carbon atoms under substantiallyanhydrous conditions, in the presence of suflicient alkali metal hydroxide to neutralize the free acids .in said glyceride and to maintain the solution al kaline to Clayton yellow, adding an acid in suf ?cient amount to decompose the soaps formed; the amount of alkanol employed being not more than 1.75 equivalents of the glyceride.

6. The process which comprises admixing alkyl esters of higher fatty acids and an alkanol of 1 to 4 carbon atoms-in the liquid state with a solution of caustic soda of at least 40% strength in an amount suf?cient to saponify said esters, and spray drying the resulting solution.

7. The process which comprises admixing alkyl esters of higher fatty acids and an alkanol of 1 to 4 carbon atoms in the liquid state, with an aqueous solution of caustic soda of at least 40% strength in an amount suiiicient to saponify the said esters, and spraying the resulting solution into a gaseous medium maintained at a tem perature su?lcient to vaporize the said alkanol.

8. A continuous process which comprises ad mixing alkyl esters of higher fatty acids where in the alkyl groups contain from 1 to 4 carbon atoms in the liquid state with an aqueous solu tion of caustic alkali of at least 50% strength and spraying the same into a chamber contain ing a gaseous medium at a temperature su?icient to carry oil the vapor phase of the alcohol set free. .

. 9. A continuous process which comprises ad mixing alkyl esters of higher fatty acids where in the alkyl groups contain from 1 to 4 carbon atoms in the liquid state with an aqueous solu tion of caustic alkali of at least 50% strength, heating said mixture to a temperature whereby saponiflcation is initiated and spraying the same into a chamber containing a gaseous medium at a temperature suiiicient to carry off the vapor phase of the alcohol set free.

10. A continuous process which comprises ad mixing alkyl esters of higher fatty acids wherein the alkyl groups contain from 1 to 4 carbon atoms in the liquid state with an aqueous solution of caustic alkali of at least 50% strength, heating said mixture to a temperature whereby saponifi cation is initiated and spraying the same into a chamber containing a gaseous medium at a tem perature suf?cient to carry off the vapor phase of the alcohol set free, but insu?icent to vaporize all the water. . '

11. A continuous process which comprises ad mixing alkyl esters of higher fatty acids wherein the alkyl groups contain from 1 to 4 carbon atoms in the liquid state with an aqueous solu tion of caustic alkali of at least 50% strength

8 heating said mixture to a temperature whereby saponi?cation is‘ initiated and spraying the same into a chamber containing a gaseous medium at. a temperature su?lcient to carry off the vapor phase of the alcohol set free but insu?icient to completely dry any substantial amount of the soap.

12. The process which comprises reacting a crude glyceride with successive portions of an alkanol of not more than 4 carbon atoms in the liquid phase under substantially anhydrous con ditions, in the presence of sufficient alkali metal hydroxide to neutralize the free acids in said glyceride and to maintain the solution alkaline to Clayton yellow, the first portion being at least 0.4 of a chemical equivalent and not more than 1375 equivalents, adding after the first addition an acid in suf?cient amount to decompose the soap formed, settling after each admixture and

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9,360,844 drawing of! each resulting glycerine layer until the total alcohol added is equal to the chemical equivalent of the glyceride plus the alcohol con tained in the glycerine layers, the whole process being carried out at moderate temperatures.

13. A process as set forth in claim 2 wherein the esters are heated prior to the addition of said acid.

14. The process which comprises admixing alkyl esters of higher fatty acids and an alkanol or 1 to 4 carbon atoms in the liquid state, with a small amount of an alkanol of 1 to 4 carbon atoms and saponifying the mixture with a dis persion of a solid alkali metal hydroxide.

155. The process of claim 12 wherein the reac tion and steps are carried out in a continuous manner.

GEORGE BURT BRADSHAW. WALTER C. MEULY.