Waxes for - DIEL ENTERPRISE · 2 WAxES FOR PVC LuBRICATION CONTeNTs Theory of lubrication PVC 4...

Waxes forPVC LUBRICATION

waxes for PVC lubriCation2

CONTeNTs

Theory of lubrication PVC 4

Action mode of lubricants 6

Requirements of the final articles 10

Lubricants for PVC 11

Product description 12

Product characteristics 14

Overview of PVC applications 15

Waxes for calendering films 16

Waxes for PVC extrusion 20

Basic formulations 24

PVC foam extrusion 26

PVC injection molding 28

Flexible PVC 29

Semi-rigit PVC 30

Technical information 31

Waxes for PVC LUBRICATION

3

Many plastics are not chemically stable enough at the necessary processing temperatures. The results are oxidation, cross-linking, chain scission, etc. The thermal sensitivity of PVC is well known. Hydrogen chloride already begins to split off above 120 °C and is associated with dramatic losses in the optical, mechanical, and rheological characteristics of the polymer. The rapid discoloration (»charring«) and the formation of corrosive fragmentation products (HCl) are the main problems in this context.

Thermostabilizers make it possible to eliminate or reduce substantially the splitting off of hydrogen chloride. In addition to the thermal stress, the plastic melt is also subject to strong mechanical stress (shear and friction) during processing. Depending on the processing method, 80 % of the heat energy is brought into the polymer via friction and only about 20 % through direct heating.

Additives that have a favorable effect on the flow behavior of the polymer melt are therefore indispensable for troublefree processing. They are called lubricants or waxes.

These lubricants are added to the PVC to fulfill the following requirements:

· Improvement of the flow behavior of the melt, i. e., reduction of internal and external friction, which means less damage to the material

· Achievement of certain characteristics in the end product (e. g. gloss, smoothness, anti-blocking) · Extrernal lubrication like anti-sticking and die-lubrication

For these requirements Clariant offers a variety of different waxes. Furthermore, Clariant has a wide assortment of additives such as light stabilizers and antistatic agents for PVC. Additional details on these products are available in the respective leaflets.

For consulting and for development of tailor-made customer solutions, our experienced team of technical service consultants is available to you.


Theory of lubrication ImPACT ON PVC

ChemICAL sTRUCTURe ANd POLARITyThe structure and above all the polarity of the lubricant are decisive for the effect during PVC processing. External lubricants, which are less compatible with the plastic matrix, act as a »lubricating film« between the polymer melt and the hot metal parts of the process-ing machine. Internal lubricants take effect primarily between the particles (polymer chains). However, very few lubricants can be classified purely in the one group or the other. Their effects usually overlap and also depend on the dosage (solubility limit).

The mode of action of the waxes in PVC can be illustrated using their chemical structure and the morphology of PVC:

5

mORPhOLOgICAL sTRUCTURe Of PVCThe PVC particle (secondary particle) is made up of so-called primary particles or globules, which are about 1 μm in size. They consist of nodules about 10 nm in size. At processing temperatures up to 190 °C the secondary particles break down into globules, a process normally referred to as plasticization. After about 190 °C these in turn break down into nodules, which is called gelation (fig.1). Thus there is not a pure melt during PVC processing. Instead one speaks of particle flow. Suitable lubricants are able to delay or accelerate this process.

VOLATILITyIn plastics processing, the volatility of lubricants plays an important role. The formation of vapors and condenses on machines and equipment parts not only impairs production, but also working conditions for the personnel. In extrusion processes the effect is seen in the form of deposits on the nozzles. In calendering films, with their large open melt surfaces, formation of vapors is especially critical. In injection molding too, deposits on the tools are undesirable. Low-molecular products like fatty acid esters are viewed as particularly critical in this context.

fIgURe 1: Morphological structure of PVC

seCONdARy PARTICLe(Particles)

100 µm

gLOBULes(Microparticles)

1 µm

NOdULes(Submicroparticles)

10 nm

Plasticization, up to approx. 190 °C

Gelation, after approx. 180 °C


Action mode of LUBRICANTs

VIsCOsITy RedUCTIONLubricants with high polarity and short C-chains have a relatively high ability to penetrate the PVC particle. The extreme case is represented by plasticizers, which permeate the entire particle and thus change not only the viscosity, but also the hardness of the final product. However, internal lubricants penetrate the particle to only a limited extent and reduce friction between the globules. The characteristics of the final particles are not affected by the quantities that are normally used. Typical representatives are internal lubricants, such as glycerol monooleate (GMO), glycerol monostearate (GMS), and stearyl stearate.

INfLUeNCINg geLATION BehAVIOR ANd ReLeAse effeCT Gelation of PVC is delayed primarily by the reduction of wall adhesion. As the non-polar remnants of the lubricant molecules become longer, they are less able to penetrate the PVC particle, and the external proportion of the lubrication effect increases. The polyolefine and paraffin waxes represent an extreme case. They do not dissolve in PVC, are displaced from the melt, and are deposited between the metal and the melt. As a result, however, they are also susceptible to incompatibility reactions, such as plateout.

Between the two extremes mentioned, polar/internal and non- polar/external lubricants, there is a wide range (fig. 3). Oxidation of polyethylene waxes can produce polar wax oxidates. Ester waxes made up of long-chain nonpolar chains also provide an external lubrication effect and form a lubricating film.

fIgURe 2: Action mode of lubricants

PLAsTICIzATION sheAR dePeNdeNT VIsCOsITy CONTROL

RedUCTION Of fRICTION

VIsCOsITy RedUCTION ReLeAse effeCT sLIP effeCT

7

Lubricants with long hydrocarbon backbone protect the globules and prevent degradation into nodules. However, viscosity is lower when there are fewer nodules. Experience has shown that ester lubricants with long (C26 – C32) non-polar chains, such as montanic acid esters, allow a wide processing range and are less susceptible to variations in shear speeds (fig. 4). In practice the use of montan waxes is said to provide a »wider processing window« (shear de-pendent viscosity control).

Montanic acid esters in particular are typical examples of such ester waxes. They delay slightly the gelation of the PVC mass, but thanks to their polar groups, they are anchored to the globules adequately enough that no plateout occurs. This provides optimal prevention of adhesion to the hot machine parts. In addition, there is almost no negative effect upon melt strength and Vicat softening temperature.

INfLUeNCe ON INTRINsIC VIsCOsITy ANd meLT sTReNgTh Of PVCIntrinsic viscosity is understood as the drop in viscosity of a melt with increasing shear. For example, lubricants that increase the intrinsic viscosity of PVC are especially useful in extrusion processes, in which there are areas of different shear speed. In especially shear-intensive zones in the extruder, a less viscous melt exerts less resistance, thus lessening the danger of local thermal overload (i. e., charring). In zones of reduced shear, the melt is thicker, and it is easier to introduce heat energy. In addition, the melt displays higher firmness where there is low shear, e. g., in the shaping area (nozzle) or when drawing a calender film.

fIgURe 3: Classification of various lubricants by their effect in tin-stabilized PVC

LUBRICATION effeCT IN PVC

Internal External

Fatty acid ester

Fatty acid amide (Licowax C)

Montanic acid diol ester (Licowax E)

Montanic acid diol ester, partially saponified (Licowax OP)

Montanic acid triol ester (Licolub WE 4)

Montanic acid complex ester (Licolub WE 40)

Oxidized polyethylene wax (Licowax PED 191)

Polypropylene wax (Licocene PP 6102)

Polyethylene wax (Licowax PE 520)

fIgURe 4: Viscosity in relation to modulus of shear deformation

Ap

par

ent

visc

osi

ty [

log

η*]

Apparent shear speed [log γ*]

Newtonian behavior PVC with viscosity-reducing lubricant (fatty acid ester)PVC without lubricant PVC with shear dependent viscosity control lubricant (montan wax)

internal method


fORmATION Of fLOw LINe ANd dIe sweLL IN PVCIn the calendering process in particular, the formation of flow lines is undesirable. The quality of the film depends decisively on the running behavior of the kneading mass and therefore must always be viewed in conjunction with lubricants. In addition, however, the viscoelastic characteristics of plastic melts must also be taken into consideration. In addition to flow (non-Newtonian flow), every plastic melt also displays elastic behavior, i. e., it can be compressed. The spring-damper model (fig. 5) describes the phenomenon well. The spring effect ensures that the melt returns to its original state after short-term stress, once that stress has been released. The damper effect ensures flow, i. e., the mass evades long-term stress.

Action mode of LUBRICANTs

fIgURe 5: Viscosity in relation to modulus of shear deformation

mOdeL

sPRINg

dAmPeR

meLT

eLAsTICITy

VIsCOsITy

9

Put simply the plastic melt has a memory: if the material is com-pressed for only a short time (e. g., in a very short nozzle), it tends to relax and resume its original form immediately after leaving the pressure zone. If the kneading mass does not run optimally through the roll gap and displays waves and deformation, these waves will also appear again as flow lines on the other side of the gap. This behavior can also be quantified via the die swell, which, for examplein injection molding, represents an undesirable effect (fig. 6).

BAsICALLy TheRe ARe TwO wAys TO INfLUeNCe VIsCOeLAsTIC BehAVIORFirst: Improve the flowability of the melt by adding internal lubricants or by selecting a suitable type of PVC. However, the former have the disadvantage of lowering melt strength.

Second: Control swelling behavior through suitable additives. While PMMA copolymers (processing aids, high-molecular release agents) have a great influence on swelling, lubricants with release properties have practically no such effect.

PLATeOUT, fORmATION Of CONdeNsed PReCIPITATesPrecipitates on calender rolls or cold machine parts are an unpleasant phenomenon in continuous production. Many components in the formulation of the PVC compound can cause this phenomenon. An analysis of such precipitates usually detects all the components of the formulation. In addition to the quality of the PVC, the compatibility of the additives plays an important role. For example, the individual additives can be very compatible, but in a formulation the additives can displace each other, react with each other, or lead to plateout. Very incompatible lubricants with low affinity to PVC, such as polyethylene waxes, have a strong tendency toward plateout.

Oxidized polyethylene waxes also have a strong tendency toward cross-linking upon contact with oxygen and thus to formation of deposits on the rolls that are difficult to remove. As already mentioned, the volatility of internal lubricants plays a role, and lubricants that contain metallic soaps are suspected of promoting the formation of deposits. It is a very complex topic, which generally cannot be reduced to a particular component of the formulation. Solving the problem or improving the situation requires that the PVC formulation is examined precisely.

Certain non-polar PO waxes however seem to be more sensitive than others. Especially Licocene PP 6102 has a beneficial behaviour showing less plate out than standard PE waxes.

fIgURe 6: Die swell in PVC through various additives

Die

sw

ell ø

[ %

]

50

40

30

20+ 0.5 phr*Licowax E

+ 0.5 phr Licolub WE 4

+ 0.5 phrFatty acid

complex ester

+ 0.5 phrHigh-molecularrelease agent

+ 1.0 phrHigh-molecularrelease agent

internal method

formulation (phr)*: S-PVC, k-value 60 100.0Sn stabilizer 1.5Glycerol dioleate 0.5

Conditions: Extrusiometer screw 4:2; 20 rpmTemp.: 150/170/185/195/195 °CNozzle: ø 4 mm

* Parts per hundred resin


Requirements ofThe fINAL ARTICLes

TheRmOsTABILITy is an important parameter for many appli-cations. The end product must not deform or soften at its service temperature or any possible temperature peaks (e. g., inside automobiles). A suitable measurement for this characteristic is the Vicat (softening) templerature or heat distortion temperature (HDT). The more polar, i. e. more compatible a lubricant (internal lubricant), the more it is able to penetrate the PVC particle and to soften the polymer. The Vicat temperature decreases. On the other hand, in a deep-drawing sheet, this effect can be quite desirable. Unlike internal lubricants, external lubricants do not lower the Vicat temperature.

The PRINTABILITy of a finished product depends mainly upon its surface tension. Here the migration of additives can play an important role. Additives that are not very compatible and also have a low molecular weight, are inclined, especially at higher temperatures, to migrate to the surface and can thus decrease printability. In this context, mainly metallic soaps and amide waxes based on fatty acids are suspected of having a negative effect. However, print technology and printing ink quality are certainly of higher importance.

The gLOss of finished parts is determined substantially by the type of processing. With calender films, for example, the last two calender rolls, the embossing rolls, if present, and the draw-off rolls play the decisive role. External lubricants have hardly any effect.In injection molding too, the tool and its surface are extremely im-portant. However, in this case, external lubricants do have an effect.

In profile extrusion, however, the gloss is created primarily in the nozzle / die by by the slippage of the melt along the wall. External lubricants are predestined for this application. Primarily hydro-carbon waxes with high softening points are used like Licowax PE 520 or Licocene PP 6102.

The TRANsPAReNCy of an end product is often used as a measure of the compatibility of the additives used. Internal lubri-cants usually have very little effect on transparency. As the effect of external lubricants increases, transparency is impaired more. Of course the presence of other additives that affect transparency also plays an important role. When impact modifiers are present, primarily methacrylic styrene-butadiene copolymer (MBS), the influence of the lubricant on transparency is very slight.

PIgmeNT dIsPeRsION, especially organic colored pigments in thin-walled PVC applications, can be improved markedly by pre-dispersion of the pigments with montan wax, e. g. Licowax OP. When rubbed off on a triple roll mill, the pigment-wax prepara-tion is produced as a dust-free powder that is optimal for further processing.

11

Lubricants forPVC

Lubricants are present in formulations in only small quantities, but they have a decisive effect on the rheology and, in part, on the characteristics of the PVC.

Based on the customer’s requirements profile and the equipment conditions, an optimal formulation must be developed, which, as a rule, cannot be finalized until a production test is done. An important parameter in the selection of the components of the formulation is price, which also applies to the lubricant. However, price means the effective price, i. e. the price/performance ratio. The following information will show that high-quality lubricants based on montan wax can have a positive influence on many characteristics, help avoid problems, and thus have an optimal price/performance ratio.


ProductdesCRIPTION

Based on their chemical structure, Licowax®, Licolub®, Licocene® and Licocare® can be divided into 6 groups:

mONTAN wAxesThe montan wax esters Licowax E, Licowax OP, Licolub WE 4, Licolub WM 31 and Licolub WE 40 are secondary products of the oxidative refinement of raw montan wax.

The montanic acids contained in raw montan wax are unbranched, even-numbered monocarboxilic acids with chain lengths in the range of C26-C32. These long-chain montanic acids result in low volatility for these products.

Licowax e, Licolub we 4, and Licolub we 40 are esters of montanic acids with ethylene glycol and glycerol, in which the latter are complex esters. Licowax OP differs from these products in that the montanic acids are only partially esterified with butanediol and that the rest is saponified with calcium hydroxide. Licowax OP thus contains not only montanic acid esters but also calcium mon-tanate, and it thus displays additional effects (binds acid).

Licolub wm 31 is an ester based on montanic acids and other long chain aliphatic acids.

Due to its polar centers and the long, non-polar hydrocarbon chains, the montanic acid esters combine internal and primarily external lubrication effects in PVC:

· Maintenance of transparency· Low volatility· Low migration tendency· Intrinsic viscosity· Melt strength· High processing safety

POLyeThyLeNe wAxesThe low molecular weight PE waxes from Clariant are waxes polymerized using the Ziegler and the Metallocene process, with especially high thermostability. They thus differ from decomposition waxes, which are usually produced through thermal decomposition of polyethylenes.

Licowax Pe 520 is a medium-molecular, slightly branched polyethylene wax with low density and is marked by high resistance to oxidation and thus high color and viscosity stability. Licowax PE 520 and Licowax PE 190 have a strong external lubricating effect in PVC.

Licowax Pe 190 is a high-molecular, linear PE wax with high density and is used preferably in the production of transparent PVC articles.

Licocene Pe 4201 is a medium-molecular, low branched metal-locene polyethylene wax with even stronger external lubricating effect in PVC than Licowax PE 520 and Licowax PE 190.

Licowax Ped 191 is a high-molecular, oxidated, and thus polar PE waxes, which is used primarily in tin-stabilized rigid PVC due to its strong nonstick effect and high transparency for sheet extrusion and the production of blow molded parts. In addition it promotes gelation in calcium/zinc stabilized or lead-stabilized PVC.

Licolub h 12, a polar PE wax based on Licowax PE 520, also has a strong antisticking effect. Important areas of applications are pipe and profile extrusion and extrusion blow molding, especially when the final product does not require high transparency.

13

POLyPROPyLeNe wAxLicocene PP 6102 is an isotactic metallocene polypropylene wax and has a strong external lubricating effect in PVC. It is suitable for regulation of gelation behavior of Pb-stabilized and Ca/Zn- stabilized PVC mixtures and provides a lower buildup of pressure in the extruder in comparison to Licowax PE 520. Especially in the field of pipe extrusion it can be used as FT-paraffin replacement.

hydROCARBON wAxLicolub h 4 is a modified hydrocarbon wax with an external lubricating effect, which is used primarily in extrusion of opaque PVC products.

AmIde wAxLicowax C and Licolub fA 1 vegetable based are amide waxes of type N,N-bis-stearyl ethylenediamine with particularly good thermostability. They provide PVC film with slip (rigid sheets) and anti-blocking characteristics (flexible films) as well as good release properties in injection molding applications (flexible PVC). During processing they act predominantly as an internal lubricant to improve flow.

ReNewABLe wAxLicocare sBw 11 TP* is a natural based, chemically modified wax, which is produced by metathesis of soya bean oil. Due to the good external lubrication effect and excellent color behavior, this test product is perfectly suitable for rigid PVC processing.

TP * = Test product


ProductChARACTeRIsTICs

PROdUCT NAme ChemICAL ChARACTeRIsTICs PhysICAL ANd ChemICAL PROPeRTIes

Drop point [ °C ]

Acid value[ mg KOH/g ]

Density 23 °C [ g/cm3 ]

Viscosity at 100°C [ mPa·s ]

Color

LICOwAx e Montan wax-based ester wax

~ 81 ~ 18 ~ 1.02 ~ 20 Pale yellowish

LICOwAx OP Partially saponified, montan wax-based ester wax

Ca2+

~ 99 ~ 12 ~ 1.02 ~ 300 (120 °C) Yellowish

LICOLUB wm 31 Montan wax and long chain aliphatic acid based ester wax

~ 74 ~ 12 ~ 1.00 ~ 26 Pale yellowish

LICOLUB we 4 Montan wax-based ester wax ~ 80 ~ 26 ~ 1.01 ~ 60 Yellowish

LICOLUB we 40 Complex ester of montanic acids

n

~ 76 ~ 20 ~ 1.02 ~ 150 Yellowish

LICOwAx C Amide wax ~ 142 < 8 ~ 1.00 – White

LICOLUB fA 1 VegeTABLe BAsed

Amide wax ~ 142 < 8 ~ 1.00 – White

LICOLUB h 12 Polar polyethylene wax ~ 104 ~ 17 ~ 0.95 ~ 350 Almost white

LICOwAx Ped 191 Polar polyethylene wax ~ 123 ~ 17 ~ 0.98 ~ 1800 (140 °C) Almost white

LICOwAx Pe 190 Non-polar polyethylene wax ~ 135 – ~ 0.96 ~ 25000 (140 °C) White

LICOwAx Pe 520 Non-polar polyethylene wax ~ 120 – ~ 0.93 ~ 650 (140 °C) White

LICOLUB h 4 Modified hydrocarbon wax ~ 111 – ~ 0.92 max. 10 (120 °C) White

LICOCeNe PP 6102 Non-polar polypropylene wax ~ 145±± – ~ 0.90 ~ 60 (170 °C) White

LICOCeNe Pe 4201 Non-polar polyethylene wax ~ 128 – ~ 0.97 ~ 60 (140 °C)

LICOCARe sBw 11 TP* Modified soya bean wax ~ 55 Typical 0 – – Off-white

TP* Test product ** Softening point according to DIN 51920, ASTM D 3104Test methods: Drop point [ °C ] ISO 2176, Acid value [ mg KOH/g ] ISO 2114, Density (23 °C) [ g/cm3 ] ISO 1183, Viscosity [ mPa · s ] DIN 53018

15

Overview ofPVC APPLICATIONs

PROdUCT NAme CALeNdeRINg exTRUsION INjeCTION mOLdINg

fOAm APPLICATIONs

fLexIBLe APPLICATIONs

LICOwAx C

LICOLUB fA 1 VegeTABLe BAsed

LICOwAx e

LICOwAx OP

LICOwAx Pe 190

LICOwAx Pe 520

LICOCeNe Pe 4201

LICOwAx Ped 191

LICOCeNe PP 6102

LICOLUB h 4

LICOLUB h 12

LICOLUB we 4

LICOLUB we 40

LICOLUB wm 31

LICOCARe sBw 11 TP*

TP* Test product Recommended Applicable

TP * = Test product


Waxes forCALeNdeRINg fILms

TIN sTABILIzATIONAs already mentioned, lubricants serve many purposes in PVC during various processing steps.

mIxINg· Homogenization· Phase compatibilizing· Dispersion

exTRUdeR· Viscosity reduction· Regulation of gelation time· Increasing intrinsic viscosity

CALeNdeR· Good bank behavior· (Viscosity)· Release effect

fINIshed ARTICLe PROPeRTIes· Anti-blocking effect· Printability· Gloss Transparency· Thermostability

Waxes from Clariant, Licowax, Licolub and Licocare, fulfill above mentioned requirements. The montanic acid esters in particular provide a high degree of processing safety and result in good product characteristics:

LICOLUB we 4LICOLUB we 40*LICOLUB wm 31*LICOwAx OPLICOwAx e

LICOwAx CLICOLUB fA 1 VegeTABLe BAsed

LICOCARe sBw 11 TP* * For technical applications

From a technical point of view, these are the highest-quality additives for the production of PVC calender films.

AdVANTAges ANd effeCTs of the montan waxes in PVC

AdVANTAges effeCTs

Comprehensive lubricant effect (internal and external)

Improved flowDispersionRelease effectDemolding properties

High melt strength Dimensional stability

Low volatility Less mold depositsLess condensation

Universal compatibility Surface properties (smoothness)TransparencyNo plateout

TP * = Test product

17

The ReLeAse effeCT of various lubricants is usually determined on the two-roll mill by measuring the time it takes for the melt to stick to the roll. The longer the tack-free time, the better the release effect. The following test (fig. 7) shows that high-molecular release agents have a corresponding effect, but only at much higher dosages and without an additional lubricating effect.

In assessing lubricants, however, one must always consider the entire formulation. It is known that various additives can influence each other. Thus, as a rule, higher amounts of release agents have to be used in formulations with impact modifiers. There can be two different causes for this situation. The addition of MBS impact modifiers (methacrylic styrene-butadiene copolymers) can increase tackiness. It is also possible that the lubricants will dissolve preferably in the MBS phase and thus no longer be available to reduce tackiness on the surface of the PVC.

fIgURe 7: Influence of release-effective lubricants in comparison to high-molecular release agents

Tack

-fre

e ti

me

[ min

]

30

20

10

0Licowax E

0.5 phrLicolub WE 4

0.5 phrHigh-molecularrelease agents

0.5 phr

High-molecularrelease agents

1.0 phr

internal method

formulation (phr): S-PVC, k-value 60 100Sn-stabilizer 1.5MBS impact modifier 8.0PMMA processing aid 1.0Glycerol dioleate 0.5

Conditions: Two-roll mill, 190 °C 25/30 rpm


Waxes forCALeNdeRINg fILms

With the help of a measuring rolling mill, it is possible to quantify not only the tack-free time but also the adhesive force. In addition, it is possible to track the tackiness of a formulation relative to time, which can produce interesting results (fig. 8).

Here the advantage of Licolub WE 4 compared to fatty acid complex ester (FACE) is obvious too. After longer processing time, the FACE deviates from Licolub WE 4, i. e., the adhesive force of WE 4 remains at the desired level throughout the duration of processing.

When using mixtures of fatty acid complex esters and fatty acid esters (FACE/FAE) it is common to use 0.5 – 1.0 phr high-molecular-weight, release agent, too in order to improve tack-free time. By replacing FACE/FAE with Licolub WE 4 this release agent can be significantly reduced (fig. 9), wich leads to cost minimization.

formulation (phr): S-PVC, k-value 60 100.0Octyltin mercaptide 1.5MBS impact modifier 8.0PMMA processing aid 1.0Glycerol dioleate 0.6Test product 0.5

fIgURe 8: Differentiation of lubricants on a measuring rolling mill

Ad

hes

ive

forc

e [ %

]60

50

40

30

20

10

00 200 400 600 800 1000 1200 1400

internal method

Time [ sec ]

Licolub WE 4 Fatty acid complex ester

formulation (phr): S-PVC, k-value 60 100.0Octyltin stabilizer 1.2Glycerol dioleate 0.5MBS impact modifier 6.0Processing aid 0.5Lubricant 0.3

fIgURe 9: Release effect of Licolub WE 4 in comparison to fatty acid complex ester/fatty acid ester (FACE/FAE) mixture

Tack

-fre

e ti

me

[ min

]

40

30

20

10

0Mixture ofFACE/FAE

Licolub WE 4 Mixture ofFACE/FAE

Licolub WE 4

internal method

0.5 phr high-molecular-weight Release agent

Without high-molecular-weight Release agent

19

In comparison to Licowax E, Licolub WE 4 has a better release effect under slight loss of transparency, although Licolub WE 4 is still better than the fatty acid complex ester. Licowax OP is used primarily for film formulations that contain acetate copolymers,since the calcium montanate it contains has a co-stabilizing effect. Here too the advantages of the montan waxes compared to fatty acid complex ester mixtures are seen.

If slip effects are needed for rigid PVC films, then amide waxes are used, i. e., Licowax C (dosage 0.1 – 0.3 phr). However, in case these films are to be further processed (e. g., printed, metalized, etc.), the strong migration tendency of this type of wax to the film surface should be taken into consideration and the dosage adjusted accordingly.

fIgURe 10: Sticking power (Collin Two Roll Mill, 220 g, 195 °C, 15/20 rpm)

30

25

20

15

10

5

00 200 400 600 800 1000 1200 1400

internal method

Time [ sec ]

Fatty acid complex ester Licowax E Licocare SBW 11 TP

Sti

ckin

g p

ow

er

fIgURe 11: Sticking behavior of Licolub WM 31 vs. Fatty Acid Complex Ester Mixture (GL 2), (Collin two roll mill, 195 °C, friction 25 %)

30

25

20

15

10

5

00 50 100 200

internal method

Time [ sec ]

Mixture of fatty acid complex esters Licolub WM 31

Sti

ckin

g p

ow

er

formulation (phr):S-PVC, k60 100Octyl tin stabilizer 1.2MBS impact modifier 8.0PMMA Processing aid 1.2Glycerol dioleate 0.3Test product 0.3


Waxes forPVC exTRUsION

As already mentioned, the slip of the melt along the walls plays a decisive role in the processability and the characteristics of the final products in extrusion. External lubricants, especially PE waxes and hydrocarbon waxes are used here.

In more demanding applications, such as extruded profiles for windows, the use of montanic acid esters has a very positive effect on processing and performance. Depending on the type of stabilization and the end product, different waxes are used.

TP * = Test product

21

Calcium/zinc stabilization

In Ca/Zn-stabilized systems the stabilizer has hardly any self-lub-ricating effect. Therefore somewhat higher quantities of lubricants and processing aid are needed compared to Pb-stabilized systems. To reduce friction internal lubrications like fatty acid esters are used. In profile applications, the use of montanic acid esters or the renewable wax, Licocare SBW 11 TP*, is recommended.

In these compounds too the non-polar and thus incompatible waxes Licowax PE 520, Licocene PP 6102, Licocene PE 4201 and Licolub H4 act as external lubricants, which regulate gelation behavior. In comparison to Licowax PE 520, the Licocene waxes causes a later and lower build-up of pressure in the extruder as well as stronger nozzle lubrication. Especially the metallocene wax Licocene PP 6102 shows a beneficial behavior regarding less mold deposits.

The polar and thus partially compatible lubricants Licolub H 12 (oxidized PE wax) and Licolub WE 40 (montanic acid complex ester) fulfill the same functions already described for the lead- stabilized compounds. As a rule, the additive quantities are from 0.2 – 0.4 phr.

fIgURe 12: Metallocene wax in Ca/Zn-stabilized PVC window profiles – Pressure formation along the single screw extruder

Pre

ssur

e [b

ar]

internal method300

200

100

0p1 p2 p3 p4 p5

0.3 phr standard PE wax 0.2 phr PP 6102 0.3 phr PP 6102

formulation (phr): S-PVC k-value 68, Ca/Zn-Stabilizer compound: 100, Impact modifier: 2.4, Processing aid: 7, TiO2: 1

■ F

usi

on

tim

e [ m

in ]

fIgURe 13: Waxes in Ca/Zn stabilized PVC window profiles – FACE versus Licolub WE 40

internal method250

200

150

100

50

0

20

16

12

8

4

0

■ O

utp

ut

[ g/m

in ]

0.3 phr FACE +0.2 phr Licowax PE 520

0.3 phr Licolub WE 40 + 0.2 phr Licowax PE 520

formulation (phr): S-PVC, k value 64, impact mod, Ca-Stearate: 100.0, Zn-Stearate: 0.5, Hydrotalcit: 1.0, ß-Diketone: 1.0, Di-Trimethylol Propane: 0.6, Phenolic Antioxidant: 0.5

0.3/0.05 phr C80/H1 0.35 phr Licocene PE 4201 0.35 phr Licocene PP 6102

formulation (phr): S-PVC k-value 68: 100, CaCO3 (90T): 15.0, Ca/Zn Core stabilizer: 1.18, Test products: 0.35

Licocene PE 4201, Licocene PP 6102, Licolub H 4, Licolub H 12, Licowax PE 520, Licolub WE 40, Licocare SBW 11 TP*

E-v

alue

[ K

Wh/

kg ]

0.105

0.100

0.095

0.090

0.085

0.080

0.075

fIgURe 14: Waxes in Ca/Zn stabilized PVC pipes - Energy consumption at different screw speeds

internal method

50 60 70 80 90 100Screw speed [ l/min ]


Tin stabilization

PVC compounds produced with tin stabilizers tend to stick to hot metal parts on the processing equipment. Therefore the use of external and internal lubricants is indispensable. Calcium stearate is normally used in large quantities, acts as a co-stabilizer, and supports gelation. The build-up of pressure in the extruder and the lubricating effect are controlled by non-polar hydrocarbon and PE waxes (Licolub H 4, Licowax PE 520 and Licocene PE 4201).

For higher requirements concerning anti-sticking, oxidized PE waxes (Licolub H 12, Licocene PE 4201 and Licowax PED 191) are preferred. Furthermore, the use of montan waxes (Licolub WE 4 and Licolub WM 31), e. g., in the production of high-quality profiles, offers a large number of technical (and economical) advantages, which have already been described in detail in the preceding sections.

Licocene PE 4201, Licocene PP 6102, Licowax PE 520, Licolub H 4, Licolub H 12, Licowax PED 191, Licolub WE 4, Licolub WM 31

fIgURe 15: meTALLOCeNe wAxes IN sn-sTABILIzed PVC

Pre

ssur

e [b

ar]

internal method300

200

100

0

p1 p2 p3 p4 p5

1.0 phr Hydrocarbon wax 0.7 phr mPP 6102 1.0 phr mPE 4201 1.0 phr mPP 6102

formulation (phr): S-PVC, k-value 57 100.00 Sn-butyl-stabilizer 1.3 TiO2 8.0 Chalk 6.0 Impact modifier 5.0 Processing aid 1.0 Ox. PE-wax 0.5 Test products 1.25 – 0.7 Conditions: Extrusiometer E 30 M: D = 30 mm, 25 L/D, n = 30 rpm, 180-185-190-200-210 °C, round-section die: 215 °C

23

Due to the relatively strong lubricating effect of lead stabilizers, the addition of a certain amount of external lubricants is usually sufficient in these systems. The lead salts are combined with neutral and/or dibasic lead stearate and calcium stearate. The lead salts provide acceptable flowability, and stearic acid (which reacts on the surface of the lead oxides) and hydrocarbon waxes can be added in order to delay gelation. These provide also good slippage along the walls in the extruder head and nozzle. However, if the dosage is too high, there is a danger that deposits will form on the nozzles.

Licowax PE 520 (PE wax) and even more Licocene PE 4201 / Licocene PP 6102 are used to regulate gelation behavior, i. e., they delay gelation and improve the surface, especially the gloss of Pb-stabilized PVC compounds. The amounts added range from 0.05 to 0.2 phr.

The metallocene waxes, Licocene PE 4201 and Licocene PP 6102 as well as the hydrocarbon wax Licolub H 4 act as strong external lubricants. They are used predominantly in the production of pipes in the dosage 0.1 – 0.4 phr.

Oxidized PE waxes, such as Licolub H 12, increase energy input in the extruder and thus provide optimal, early gelation. Its positive influence on gelation can be strengthened through the use of high-molecular, oxidized PE waxes, i. e. Licowax PED 191 (fig. 10). As a result of the even faster gelation, the better homogeneity of the melt leads to improved physical characteristics and higher surface gloss. Dosage: 0.1 – 0.4 phr.

For high-quality profiles, e. g., profiles for windows, combination with the partially saponified montan wax ester Licowax OP or the montan wax ester Licowax E and Licolub WM 31 (0.3 – 0.5 phr wax) is recommended. The profiles then have a smooth surface even at high pigment and filler contents, without impairing weldability or thermostability.

fIgURe 16: eNeRgy INPUT of oxidized PE waxes in the PVC extrusion (Pb-stabilized)

Tack

-fre

e ti

me

[ min

]

60

55

50

45

40Licolub H 12 Licowax PED 191

internal method

formulation (phr): S-PVC, k-value 60 100.00PMMA processing aid 2.00CaCO3 5.00Lead stabilizer mixture 4.75Hydrostearic acid 0.20Distearyl phthalate 0.60Lubricant combination 0.35Test product 0.20

Conditions: Weber CE 3; 20 1/min screw speedMaterial direct from dosing hopperCylinder temperature: 175/185/190 °CTool temperature: 185/185/190/200 °C

Lead stabilization

Licocene PE 4201, Licocene PP 6102, Licolub H 4, Licowax PE 520, Licolub H 12, Licowax PED 191, Licolub WM 31, Licowax E, Licowax OP


Basic formulationsPIPes/PROfILes

Ca/zn PIPe fORmULATIONphr

S-PVC, k-value 65 – 68 100.0

Ca/Zn stabilizer compound 2.2

Phosphite (e. g. TNPP) 0.4

PMMA impact modifier 1.0

Distearyl phthalate 0.4

Hydroxystearic acid 0.2

Licocene PE 4201 / Licocene PP 6102 / Licolub H 4 0.5

Licowax PE 520 0.2

Ca/zn wINdOw PROfILe fORmULATIONphr

PVC copolymer, impact mod.

(e. g. k-value 64; 7 % acrylate copolymer) 100.0


Phosphite (e. g. TNPP) 0.4

PMMA processing aid 2.0


Licolub WE 40 0.3

Licocene PP 6102 / Licowax PE 520 0.2

TiO2 7.0

CaCO3 4.0

sn sIdINg PROfILe (TwIN sCRew)phr

S-PVC, k-value 67 100.0

Sn stabilizer (containing sulfur) 1.2

MBS impact modifier 5.0


Calcium stearate 1.2


Licolub H 12 0.2

TiO2 10.0

sn wINdOw PROfILe (TwIN sCRew)phr

PVC copolymer, impact mod.(e. g. k-value 64; 7 % acrylate copolymer) 100.0




Glycerol monostearate 0.5


Licolub WE 4 0.4

Licowax PE 520 0.1

TiO2 8.0

CaCO3 3.0

sn PIPe fORmULATION (TwIN sCRew)phr

S-PVC, k-value 65 – 68 100.0




Licocene PE 4201 / Licocene PP 6102 / Licolub H 4 0.7 – 1.2

Licolub H 12 0.2

TiO2 1.0

CaCO3 5.0

25

Basic formulationssheeTs/BLOw mOLded PARTs/ BLOwN fILms

sn sheeT fORmULATIONphr

S-PVC, k-value 58 – 62 100.0


Impact modifier 8.0


Epoxidized soya bean oil 1.0

Lauryl stearate 0.6

Licolub WE 40 0.5

Licowax PED 191 0.1

sn shRINk-wRAPPINg fILmphr





Glycerol dioleate 0.8

Licolub H 12 0.3

sn BOTTLe fORmULATIONphr



Impact modifier 10.0



Licolub WE 4 / Licolub WM 31 0.3

Licowax PED 191 0.2


Foamed PVC places special requirements upon rheological behavior (melt strength) and makes the selection of suitable lubricants especially important. Improper selection or an increased dosage can lead to undesired effects.

These include formation of bubbles, resulting in a higher volumet-ric weight; delay of the necessary fast gelation and thus impairment of welding of the individual filaments of the melt after passing the mandrel, the strainer plate, or the torpedo carriers.

PVCfOAm exTRUsION

ReqUIRemeNTs:

· Improvement in lubrication between the surface of the metal and the expandable melt (containing a foaming agent)

· Prevention of plateout

27

Calcium/zinc stabilization

Tin stabilization

Licocene PE 4201, Licocene PP 6102, Licolub H 4, Licowax OP

Licocene PE 4201, Licocene PP 6102, Licolub H 4, Licolub H 12, Licowax E, Licolub WM 31

Licowax PED 191, Licowax ELicolub WM 31

Ca/zn sheeT, fRee-fOAmedphr



Phosphite (e. g., TNPP) 0.4






Licowax OP 0.2

Foaming agent (e. g., azodicarbonamide) 1.0

TiO2 4.0

CaCO3 2.0

Pb sheeT, fRee-fOAmedphr


Tribasic lead sulfate 2.2

Dibasic lead stearate 0.7





Licowax E / Licolub WM 31 0.2

Licolub H 12 0.2

Foaming agent (e. g., azodicarbonamide) 1.0

TiO2 4.0

CaCO3 3.0

Pb sheeT, CeLUkA PROCessphr






Stearyl stearate 0.6


Licolub H 12 0.5

Foaming agent (e. g., azodicarbonamide, hydrogen carbonate) 2.0

TiO2 5.0

CaCO3 3.0

Ca/zn sheeT, fRee-fOAmedphr








Licowax PED 191 0.6

Foaming agent (e. g., azodicarbonamide, hydrogen carbonate) 1.0

TiO2 4.0

CaCO3 2.0

Lead stabilization


PVCINjeCTION mOLdINg

Usually in injection molding, S-PVC or M-PVC with k-values between 55 and 65 are used, with k-values of 58 to 60 being most frequent. Flowability and mechanical stability are the most important criteria in injection molding. Therefore in this case, the montanic acid esters are particularly suitable as lubricants; here Licowax E, Licolub WM 31, Licowax OP and Licocare SBW 11 TP*.

LICOwAx eLICOwAx OPLICOLUB wm 31LICOCARe sBw 11 TP*

· High heat distortion temperature· High flowability· High mold filling· Less charring due to shear

Ca/zn – sTABILIzATIONphr


Ca/Zn-stabilizer compound 2.8


Licowax E / Licocare SBW 11 TP 0.9

TIN sTABILIzATIONphr



Impact modifier 2.0



Licowax E / Licolub WM 31 / Licocare SBW 11 TP* 0.5

LeAd sTABILIzATIONphr




Neutral lead stearate 0.1




TP * = Test product

29

Flexible PVC hOses, wIRe ANd CABLe sheAThINg,CALeNdeR ANd BLOwN fILms

Ca/zn CABLe sheAThINgphr


Plasticizer (e. g. DIDP) 50.0

Ca/Zn-stabilizer compound 3.7

CaCO3 60.0

Ester waxes 0.3

Pigment x

Licowax ELicolub WM 31

Licolub WE 4, Licolub WM 31, Licowax C, Licolub FA 1 vegetable based

These profiles are usually produced on linear, horizontal extrusionequipment. The k-values preferred lie between 65 and 70, with S-PVC and also E-PVC being used, depending on the application. Phthalate plasticizers are used. The stabilization system depends on the application. Lead stabilizers have been widely used. Now it is Calcium/Zinc or Barium/Zinc and tin. For cost reasons one often incorporates natural or precipitated calcium carbonate as fillers in dosages of up to 80 phr (coating mixtures). The resulting impairment of processing characteristics is not inconsiderable. Therefore in this area too, montanic acid esters, i. e., Licowax E, Licolub WM 31, have proven useful especially for small cross-sections.

Glass-clear flexible PVC films are usually produced using a suspension PVC (but M-PVC is also used) with k-values between 65 and 75. Depending on the requirements, however, k-values of 55 to 80 are applied. For pigmented films E-PVC is preferred (higher filler capacity, better antistatic behavior). The phthalate plasticizer content is between 20 and 100 phr.

For processing flexible PVC on the calender or in extrusion blow molding, external lubricants are needed in order to prevent sticking to the hot machine parts. Here the montanic acid ester Licolub WE 4 or Licolub WM 31 displays optimal performance with regard to antisticking effect, processing window, and final product characteristics (dosage: 0.3 – 0.5 phr). Here also the renewable wax, Licocare SBW 11 TP* can be successfully used. There is less need for internal lubricants, primarily for semi-rigid settings.


Semi-rigit PVC CALCIUm/zINC sTABILIzATION

Ca/zn shRINk-wRAPPINg fILm fORmULATION, CALeNdeRed phr



Phthalate plasticizer 8 – 11.0



Impact modifier 6.0


Licowax OP / Licolub WM 31 / Licocare SBW 11 TP* 0.2

Ca/zn BLOOd BAg fORmULATIONphr

S-PVC, k-value 70 > 55.0

Calcium stearate + zinc stearate ≤ 1.0

Plasticizer, here DOP ≤ 40.0

Epoxidized soya bean oil ≤ 10.0

Licowax C / Licolub FA 1 vegetable based ≤ 1.0

Ca/zn shRINk-wRAPPINg fILm fORmULATION, BLOwN fILm exTRUsION phr



Phthalate plasticizer 8 – 11.0



Impact modifier 6.0

Glycerol monostearate (or GDO) 0.2

Licowax OP 0.3

RefeReNCes· Plastics Additives Handbook, 5th Edition,

Hanser Publishers, Munich· Kunststoff Handbuch (Becker/Braun)

Polyvinylchlorid, Carl Hanser Verlag, Munich· Gleitmittel für die Folienherstellung,

Dr. Eric Richter/Clariant Gersthofen, Lecture at the meeting »PVC Folien und Alternativen«, SKZ/Würzburg (07/1999)

· Various technical wax brochures for plastics processing, Clariant

TP * = Test product

31

TeChNICAL dATAFor further information on the physical and chemical properties, detailed application and packaging of our products please refer to our product data sheets, our various application brochures and product flyers.

sAfeTy INfORmATIONThe usual precautions to be taken when handling chemicals should be observed. A safety data sheet will be supplied for each individual product upon request. When handling organic powders, the domestic regulations must be observed in order to prevent dust fires and dust explosions.

Toxicological and ecological propertiesFor data on the toxicological and ecological properties of the product groups mentioned, please refer to the relevant safety data sheet or the corresponding product data sheet.

status according to the european chemicals law ( ReACh )The products mentioned in this leaflet or the monomers are either pre-registered, registered, or exempt from registration as polymers ( EC 1907/2006 ).

sTORAgeThe products described in this leaflet have a minimum shelf life of two years from date of delivery when stored in a dry place at room temperature.

TechnicalINfORmATION

DA

829

3 E

| 0

9.2

013

CLARIANT INTERNATIONAL LTD

Rothausstrasse 614132 MuttenzSwitzerland

BuSINESS uNIT ADDITIVES

BuSINESS LINE WAxES

Phone + 41 (0) 61 469 79 12 Fax + 41 (0) 61 469 75 50

WWW.ADDITIVES.CLARIANT.COM

WWW.CLARIANT.COM

This information corresponds to the present state of our knowledge and is intended as a general description of our products and their possible applications. Clariant makes no warranties, express or implied, as to the information’s accuracy, adequacy, sufficiency or freedom from defect and assumes no liability in connection with any use of this information. Any user of this product is responsible for determining the suitability of Clariant’s products for its particular application. * Nothing included in this information waives any of Clariant’s General Terms and Conditions of Sale, which control unless it agrees otherwise in writing. Any existing intellectual/industrial property rights must be observed. Due to possible changes in our products and applicable national and international regulations and laws, the status of our products could change. Material Safety Data Sheets providing safety precautions, that should be observed when handling or storing Clariant products, are available upon request and are provided in compliance with applicable law. You should obtain and review the applicable Material Safety Data Sheet information before handling any of these products. For additional information, please contact Clariant.

* For sales to customers located within the United States and Canada the following applies in addition: NO EXPRESS OR IMPLIED WARRANTY IS MADE OF THE MERCHANTABILITY, SUITABILITY, FITNESS FOR A PARTICULAR PURPOSE OR OTHERWISE OF ANY PRODUCT OR SERVICE.

® Trademark of Clariant registered in many countries.© 2013 Clariant International Ltd

http://www.additives.clariant.com

http://www.clariant.com

Waxes for - DIEL ENTERPRISE · 2 WAxES FOR PVC LuBRICATION CONTeNTs Theory of lubrication PVC 4...

Documents

Transcript of Waxes for - DIEL ENTERPRISE · 2 WAxES FOR PVC LuBRICATION CONTeNTs Theory of lubrication PVC 4...