ANTISTATS FOR HIGH TEMPERATURE SHORT HEATER TEXTURING

Abstract: A process for inhibiting the build-up of static electricity on polymeric fibers during their texturing in a fiber texturing heating apparatus involving contacting the polymeric fibers, prior to their being textured, with a finish composition containing: (a) an antistat agent selected from the group consisting of an alkoxylated ethylene diamine, a pelargonic diethanolamide, a copolymer of alpha-olefins and dicarboxylic acids esterified with short or medium carbon chain length alcohols, tetra-functional block copolymers, 1-hydroxyethyl-2-alkylimidazolines, and mixtures thereof; (b) a lubricant component; and (c) water.

Description: TITLE OF THE INVENTION: ANTISTATS FOR HIGH TEMPERATURE SHORT HEATER TEXTURING BACKGROUND OF THE INVENTION: The present invention generally relates to antistat compositions used to treat polymeric materials. More particularly, the invention relates to the incorporation of a specific antistatic agent into fiber finish compositions, prior to thermal treatment of the polymeric materials. It is oftentimes desirable to manufacture polymeric textile fibers having elastic properties. Certain articles of clothing such as, for example, pantyhose, which are made from nylon fibers are expected to have a certain amount of stretch or elasticity. In order to impart this property onto the polymeric fibers, they must first be textured. One method of texturing polymeric fibers is known as "draw-texturing", whereby partially oriented yarn is drawn between two sets of nip rolls and simultaneously false twisted. The process involves first twisting the yarn, while passing it through a heat source in order to plasticize the yarn, followed by untwisting the yarn as it cools down. The twisting and untwisting of the yarn transforms it from a flat yarn into a bulky, elastic yarn. These types of yarns have a natural appearance and texture than flat, untextured yarns. One problem associated with such texturing processes involves the unwanted build-up of static electricity. The build-up of static electricity is caused by the friction between: yarn/guides, yarn/twisting aggregate, and internal capillary/capillary friction. Unless the build-up static electricity is controlled, via build-up prevention or rapid static dissipation, the yarn may start to vibrate, particularly in the secondary or setting heater. Such vibration results in unstable yarn tension and uneven texturing properties. Another disadvantage associated with static electricity build-up is that it has a tendency to discharge onto workers handling the yarn. In order to prevent the build-up of static electricity on the polymeric fibers (yarn), the fibers, prior to being textured, are first treated/coated with a finishing composition containing a lubricant component and an antistat agent. Known antistats include organic salts such as phosphonates, phosphates and quaternary compounds. Although finish compositions containing these compounds provide excellent antistatic properties, upon exposure to heat, they have a tendency to volatilize, i.e., thermally decompose. While this type of volatilization is inevitable, it is imperative that the volatilized finish composition not redeposit itself onto any part of the texturing apparatus. Redeposition of the vaporized finishing composition onto the texturing apparatus will cause uneven heat transfer to the yarn, resulting in yarn breakage. With the advent of high speed texturing machines enabling the texturing of up to 1200 meters of yarn per minute, classic long contact heaters have been progressively replaced by high temperature short heaters, which are only 1 meter in length and reach temperatures of over 600°C. These heaters have a number of contact points with the yarn being textured in order to stabilize it and prevent it from breaking. These high temperature short heaters have rendered known antistatic compounds ineffective due to their use of such high temperatures. Thus, whereas the previously used long contact heaters employed temperatures of up to about 230°C, the temperatures employed in the new short heaters is almost three times as high. Consequently, there is now a need for antistatic finish compositions capable of withstanding the kinds of high temperatures employed in texturing processes, which do not leave residues upon thermal decomposition. BRIEF SUMMARY OF THE INVENTION: It has been surprisingly discovered that by employing certain antistat agents in the textile finish compositions used to coat and protect polymeric fibers from the high temperatures of heating units used to texture polymeric fibers, the finish composition remains on the fiber after passing over the first heating element, thereby precluding the accumulation of static electricity on the fiber prior to its passage over the second element. Also, by employing these specific antistat agents it has also been found that the finish composition, once volatilized, will not redeposit itself, in the form of ash, onto any part of the texturing apparatus. The present invention is thus directed to a process for inhibiting the buildup of static electricity on polymeric fibers during texturing of the fibers in a heat texturing apparatus involving contacting the polymeric fibers, prior to their being textured, with a finish composition containing: (a) an antistat agent selected from the group consisting of an alkoxylated ethylene diamine, an alkanolamide, copolymers of alpha-olefins and dicarboxylic acids esterified with short or medium carbon chain length alcohols, tetra- functional block copolymers, 1 -hydroxyethyl-2 alkylimidazolines, and mixtures thereof; (b) a lubricant component; and (c) water. DETAILED DESCRIPTION OF THE INVENTION: Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions, are to be understood as being modified in all instances by the term "about". The antistat agents found to be effective at controlling the build-up of static electricity on polymeric fibers during texturing of the fibers in high temperature short heaters are those selected from the group consisting of alkoxylated ethylene diamine, a pelargonic diethanolamide, copolymers of alpha- olefins and dicarboxylic acids esterified with short or medium carbon chain length alcohols, tetra-functional block copolymers, 1-hydroxyethyl-2- alkylimidazolines, non-halogenated quaternary amines, octylphosphonate ethylesters and their salts, and mixtures thereof. Suitable alkoxylated ethylene diamines include both random and block copolymers thereof. The random alkoxylated ethylene diamines may contain a random distribution of ethylene and propylene oxide moieties ranging from about 50/50 to about 90/10 and have a theoretical molecular weight ranging from about 2000 to about 20,000. The preferred random alkoxylated ethylene diamine is a 50/50 by weight EO-PO copolymer having a molecular weight of about 6000 and having a kinematic viscosity of 600 cSt at 40°C. Block copolymers of alkoxylated ethylene diamine may contain an EO/PO block distribution ranging from about 60/40 to about 40/60, with a theoretical molecular weight ranging from about 6700 to about 7200. The random and block alkoxylated diamine copolymers can be made by methods known to those skilled in the art. Alkanolamides corresponding to the formula: wherein R T is a monovalent organic radical having from 6 to 22 carbon atoms, and x is a number from 1 to 3, may also be used as effective antistats in the present invention. Particularly preferred alkanolamides are diethanolamides of pelargonic acid such as those commercially available from Henkel Corporation, Emery Division, under the tradename EMID® 6542. The copolymers of alpha-olefins and dicarboxylic acids esterified with short or medium carbon chain length alcohols are characterized by their having a "double-comb" structure in which the ester and hydrocarbon groups are present in the side chains of the copolymer with the main polymer chain, i.e., polymer backbone, consisting of carbon atoms only. Suitable alcohols for use in esterifying alpha-olefins and dicarboxylic acids have a chain length ranging from about C 4 to about C 12 . 14 . These copolymers have a viscosity ranging from about 450 to about 1200 mm 2 /s, and an average molecular weight of from about 600 to about 7000. The 1-hydroxyethyl-2 alkylimidazolines useful as antistats in the present invention are oil soluble and water dispersible. These compounds contain no solvents and are classified as cationic surface active agents. They correspond to the formula: N — CH, R-C CH 2 \ / NCH 9 CH 9 0H wherein R is an alkyl group having from about 7 to about 17 carbon atoms. The lubricant component employed in the process of the present invention is a copolymer of butanol containing a random distribution of EO/PO ranging from about 5/20 to about 20/5, and a viscosity ranging from about 30 to about 250 cps. A particularly preferred EO/PO distribution is 50/50. A typical formulation for the finish composition to be applied onto the polymeric fibers, prior to their texturing in a high temperature short heater contains: (a) from about 1 to about 20% by weight, preferably from about 3 to about 15% by weight, and most preferably from about 4 to about 10% by weight, of an antistat agent; (b) from about 30 to about 95% by weight, preferably from about 50 to about 90% by weight, and most preferably from about 60 to about 85% by weight, of a lubricant; and (c) remainder, water, all weights based on the weight of the finish composition. Additional fiber finish additives may also be incorporated into the formulation, if desired. Examples thereof include, but are not limited to, additional lubricants such as boundary lubricants, emulsifiers, antioxidants, and the like. The finish composition may be applied onto the polymeric fibers according to a variety of known procedures. For example, in the melt spinning process used for polypropylene manufacture, the polymer is melted and extruded through spinnerette holes into filaments which are cooled and solidified in an air stream or water bath. Shortly thereafter, they contact a finish composition applicator which can be in the form of a kiss roll rotating in a trough. The amount of finish composition applied to the fibers can be controlled by the concentration of finish composition in the solution or emulsion and the total wet pick-up. Alternatively, positive metering systems may be used which pump the finish composition to a ceramic slot which allows the finish composition to contact the moving fibers. In general, the amount of finish composition to be applied onto the fiber prior to texturing will range from about 0.25 to about 0.6%, based on the weight of the fiber. However, the precise amount of finish composition to be applied will depend on a number of varying factors including the specific fibers to be textured and the specific heat texturing apparatus used. That amount, however, can easily be determined by those skilled in the art of heat texturing of fibers. From this point the fibers, which now have a coating of finish composition, are then introduced into a heat texturing apparatus such as a high temperature short heater for texturing. The polymeric fibers to be textured are transported through the heat texturing apparatus via rollers/guides. It is imperative that the polymeric fibers maintain an even on-line-tension during the texturing process. The precise on-line-tension to be maintained during a texturing process will depend on the specific type of fiber being textured. Variations in denier, cross- section, etc. all influence the fiber's on-line-tension. These values, however, are known to those skilled in the art of fiber texturing. Since the build-up of static electricity on polymeric fibers during the texturing process results in an increase in on-line-tension, the fibers are then more susceptible to breaking, resulting in unwanted waste of fibers, and possible damage to the heating apparatus. Therefore, regardless of the particular on-line-tension employed, the critical aspect for purposes of the present invention is that it be evenly maintained, without any significant fluctuations, during the texturing process. Briefly stated, the heat texturing process involves applying a finish composition onto yarn/fibers to be textured, followed by their introduction into the high temperature short heater. The yarn/fibers (hereinafter referred to as "the substrate") are introduced into the apparatus via feed rollers which transport the substrate over the first heater. As the substrate exits the first heater it is then cooled by a cooling plate. The cooled substrate then comes in contact with a frictional surface such as friction disks which impart a texture to the substrate. The textured substrate is then transported over a second heater which heat sets the texture in the substrate. The thus textured substrate is then packaged for further processing. By employing the finish composition of the present invention prior to heat texturing, both the build-up of static electricity on the fibers being textured and the complete volatilization of the finish composition on the fibers is inhibited, thereby resulting in less damage to both the fibers and the heat texturing equipment. It should be noted, however, that the present invention is in no way limited to texturing processes only, but rather, may be used in any fiber treating process employing high temperatures such as, for example, draw-twisting, cabling, spin- drawing, draw-warping, and the like. The present invention will be better understood from the examples which follow, all of which are intended for illustrative purposes only, and are not meant to unduly limit the scope of the invention in any way. EXAMPLES Texturing was performed in a high temperature short heater Model No. RPR 3SDS, made in Italy by RPR. The texturing machine consists of two heating zones operating at a temperature of 540°C each. The production speed at which the machine was operated was 900 m/min, and a draw ratio of 1.58. The apparatus was operated under the following parameters: Over feed 3rd(%) 2.5 Over feed 4th(%) -0.3 Over feed take-up(%) 1.0 Crossing angle (deg.) 26 Ratio Spindles (D/Y) 2 Oiling (rpm) 0.5 PU disk 53.5 mm Set of 6 Tension During Texturing (cN): Position 4 = 42-46 Position 5 = 38-42 Position 6 = 34-37 Various finish compositions were evaluated to determine their effectiveness at preventing the build-up of static electricity during a texturing process. Each of the finish compositions contained equal amounts of an alkoxylated polymer, an ethoxylated alcohol, an antistat and water. The only variable in all of these finish compositions was the specific type of antistat used. The fibers were then tested and evaluated, using the evaluation scale identified below, to determine the composition's effectiveness at inhibiting the build-up of static electricity during processing in the high temperature short heater. Static Value kVm/m @ 60 min Very effective ± 1.9 Moderately effective ± 2.0 - 4.7 Least effective + 5.0 - 9.2 The specific antistats tested, along with static electricity data obtained, are found in Table 1 below. Table 1 Ex. 1 = a random alkoxylated ethylene diamine is a 50/50 by weight EO-PO copolymer having a molecular weight of about 6000 and having a kinematic viscosity of 600 cSt at 40°C. Ex. 2 = a copolymer of alpha-olefins and dicarboxylic acids esterified with short or medium chain length alcohols having a molecular weight of about 2500. Ex. 3 = a copolymer of alpha-olefins and dicarboxylic acids esterified with short or medium chain length alcohols having a molecular weight of about 20,000. Comp. 1 = a potassium salt of octylphosphonate ethylester. Comp. 2 = a non-halogenated quaternary amine. Ex. 4 = pelargonic diethanolamide. Ex. 5 = coco imidazoline.

Claims: WHAT IS CLAIMED IS: 1. A process for inhibiting the build-up of static electricity on polymeric fibers during their texturing in a fiber texturing heating apparatus comprising contacting the polymeric fibers, prior to their being textured, with a finish composition containing: (a) an antistat agent selected from the group consisting of an alkoxylated ethylene diamine, an alkanolamide, a copolymer of alpha-olefins and dicarboxylic acids esterified with short or medium carbon chain length alcohols, tetra-functional block copolymers, 1-hydroxyethyl-2-alkylimidazolines, and mixtures thereof; (b) a lubricant component; and (c) water. 2. The process of claim 1 wherein the antistat agent is an alkoxylated ethylene diamine. 3. The process of claim 1 wherein the antistat agent is an alkanolamide. 4. The process of claim 1 wherein the antistat agent is a copolymer of alpha- olefins and dicarboxylic acids esterifed with alcohols having a carbon chain length ranging from about C 4 to about C 12-14 . 5. The process of claim 1 wherein the antistat agent is a 1-hydroxyethyl-2- alkylimidazoline. 6. The process of claim 1 wherein the antistat agent is a tetra-functional block copolymer. 7. The process of claim 3 wherein the antistat agent is a diethanolamide of pelargonic acid. 8. The process of claim 1 wherein the antistat agent is present in the finish composition in an amount of from about 1 to about 20% by weight, based on the weight of the composition. 9. The process of claim 1 wherein the lubricant component is a random alkoxylated copolymer of butanol. 10. The process of claim 1 wherein the lubricant component is present in the finish composition in an amount of from about 30 to about 95% by weight, based on the weight of the composition. 11. The process of claim 1 wherein the fiber texturing heating apparatus is a high temperature short heater. 12. The process of claim 1 wherein the finish composition further contains an additive selected from the group consisting of a boundary lubricant, an emulsifier, an antioxidant, and mixtures thereof. 13. The process of claim 1 wherein the finish composition is applied onto the fibers in an amount ranging from about 0.25 to about 0.6%, based on the weight of the fibers. 14. The product of the process of claim 1. 15. The product of the process of claim 2. 16. The product of the process of claim 3. 17. The product of the process of claim 4. 18. The product of the process of claim 5. 19. The product of the process of claim 6. 20. The product of the process of claim 7. 21. The product of the process of claim 8. 22. The product of the process of claim 9. 23. The product of the process of claim 10. 24. The product of the process of claim 11. 25. The product of the process of claim 12. 26. The product of the process of claim 13.

Inventors: CHILDERS JOHN, KLEIN RALF, MATHIS RAYMOND E, MUDGE ELBERT H, YOUNG RODNEY E, CHILDERS, JOHN, KLEIN, RALF, MATHIS, RAYMOND, E., MUDGE, ELBERT, H., YOUNG, RODNEY, E.
Applicants: HENKEL CORP, HENKEL CORPORATION
Application year: 1999
Main classification: D06M13
IPC codes: D06M13, D06M15