US2859135A

US2859135A - Treatment of textile fibers

Info

Publication number: US2859135A
Application number: US513910A
Authority: US
Inventors: Elmer H Rossin
Original assignee: Monsanto Chemicals Ltd
Current assignee: Monsanto Chemicals Ltd; Monsanto Chemical Co
Priority date: 1949-12-01
Filing date: 1955-06-07
Publication date: 1958-11-04
Anticipated expiration: 1975-11-04

Description

United States Patent TREATMENT OF TEXTILE FIBERS Elmer Rossin, Springfield, Mass., assignor to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. On'ginal application December 1, 1949, Serial No. 130,603, now Patent No. 2,730,790, dated January 17, 1956. Divided and this application June 7, 1955, Serial No. 513,910

6 Claims. (Cl. 117-139.5)

The present invention relates to the treatment of textile fibers prior to spinning for the purposes, among others, of improving the inter-fiber friction of such fibers and increasing the tensile strength of the yarn resulting from the further processing and the eventual spinning of the fibers.

It is one object of the present invention to provide an improved method of treating textile fibers prior to spinning to produce fibers having increased inter-fiber friction and other improved properties and which are readily spun into yarns of high tensile strength and at the same time avoid the formation of sticky fibers or the generation of excessive amounts of fly during the manipulation of such fibers prior to and during spinning.

Still further objects and advantages of this invention will appear from the following description and the appended claims.

This invention is carried out, in general, by applying to textile fibers at some stage of their processing prior to spinning, an aqueous dispersion of fine, discrete, unagglomerated particles of a hard, non-plasticized, waterinsoluble, polymerized thermoplastic resin which is substantially resistant to plasticization with water and is nonfilm-forming at temperatures below 150 F. The dispersion is supplied to the fibers in an amount suflicient to deposit from 0.1 to 3% by Weight of the resin and not more than 40% by weight of water, both based on the weight of the fibers. The fibers are then allowed to dry while they are further processed and without heating the fibers.

The dispersion may contain anionic surface active agents since the dispersions employed in this invention are prepared in most instances by the emulsion polymerization of suitable unsaturated organic compounds in the presence of anionic surface active agents. The dispersions should, however, be free of cationic surface active agents which cause the resin to exhaust onto the fibers since the resin first agglomerates and then exhausts on the fibers resulting in the deposition of large, nonuniform particles on the fibers. The dispersions should also be free of multivalent metals which also render the resin substantive, and should also be free of agents which agglomerate or coagulate the resin particles. Anionic surface active agents are preferably used in the dispersion to assist the penetration of the dispersion through the fiber mass.

As examples of textile fibers which are treated in accordance with the methods of the present invention may be mentioned wool fibers, cotton fibers, mixtures of wool and cotton fibers, synthetic staple fibers such as staple fibers prepared from regenerated cellulose, cellulose esters, cellulose ethers, synthetic linear polyamides, polyacrylonitrile, copolymers of vinyl chloride and vinyl acetate and the like or mixtures of such synthetic staple fibers withcotton and/or wool; or such natural fibers as linen, flax and the like. The preferred fibers are wool or cotton or mixtures thereof.

The aqueous dispersions employed in accordance with.

Patented Nov. 4, 1958 2. A this invention may be prepared in a variety of ways provided the dispersion is sufliciently stable to permit its application to the fibers without settling or agglomeration of the resin particles therein and providing also that it is substantially free of cationic surface active agents, multivalent metals and resin agglomerating agents. Such dispersions are known in the resin art and are commercially available. A satisfactory method for preparing dispersions or suspensions in the case of resins which cannot be prepared by emulsion polymerization involves dispersing extremely finely divided resin particles in water with the aid of an anionic surface active agent by mixing in a high speed stirrer, a colloid mill or a homogenizer. This result may also be achieved by mixing such ingredients in a ball mill until the resin particles remain suspended.

A preferred method for forming the aqueous dispersions is to polymerize in an aqueous emulsion suitable gaseous or liquid monomeric unsaturated organic compounds which when sufiiciently polymerized are'hard and Water-insoluble materials and are also non-filmfo ing when dried at room temperature. Polymerization of such monomericcompounds in an aqueous emulsionis generally carried out by first dispersing the monomers n water with an anionic surface active agent to form an aqueous emulsion and then heating the resulting emulsion either in the presence or absence of a polymerization catalyst. The polymerization may also be carried out at room temperature or even lower temperatures in the presence of actinic radiation and/or a polymerization catalyst. Gaseous monomers can be emulsion polymerized in a low pressure autoclave.

As examples of monomeric substances whichare useful in the preparation of the aqueous dispersions by emulsion polymerization techniques may be mentioned styrene; vinyl chloride; nuclear substituted chloro-styrene; acrylonitrile; vinylidene chloride; or combinations of one or more of these monomers with divinylbenzene; mixtures of styrene, vinyl chloride or vinylidene chloride and fumaro-nitrile or acrylonitrile; mixtures of from to 99% by weight of styrene or chloro-styrene and from 20 to 1% by weight of butadiene or isoprene; mixtures of from 80 to 99% by weight of styrene, chloro-styrene, vinyl chloride or vinylidene chlorideand from 20 to 1% by weight of alkyl acrylates .containing from 1 to 4 carbon atoms in the alkyl group, alkyl methacrylates containing from 1 to 4 carbon atoms in the alkyl'group or mono or dialkyl esters of maleic or fuman'c acid containing-from 1 to 6 carbon atoms in the alkyl group;

mixtures of from to 99% by weight of vinyl chloride and from 15 to 1% by weight of vinyl acetate; and mixtures of from 65 to 99% by weight of styrene, chlorostyrene, vinyl chloride or vinylidene chloride and from 35 to 1% by weight of methyl acrylate, methyl methacrylate or dimethyl maleate. Improvedhardness and resistance to plasticization by water can be obtained by using a cross-linking agent such as divinyl benzene. The above list is not exhaustive since any gaseous or liquid monomeric unsaturated compounds which polymerize in an aqueous emulsion to form aqueous dispersions of fine, discrete, unagglomerated particles of a hard, waterinsoluble, non-plasticized thermoplastic resinwhi'ch is non-film-forming and non-plasticizable by wateninay also be used.

Aqueous dispersions prepared by the emulsion polymerization of styrene are preferred for use in the'methods of this invention because they give excellent results and are cheap and readily available. These dispersions and the dispersions prepared from the monomeric unsaturated compounds described above should be substantially free of monomers, however, since the monomers tend .to plas- V ably'between 10 and 55% by Weight. largely dependent on the nature of the textile fiber being or even'film-forming. Such monomers can be kept at a minimum by carrying the polymerization to substantial completion, forexample, by increasing the polymerization"'time or" by distilling off the monomers.

Polymers or'copolymers' produced fromany ofthe combinations of unsaturated compounds mentioned above may'be polymerizediin other ways or coagulated after emulsion polymerization and then ground up into extremely fine particles and dispersed mechanically in the manner'hereinb'efore described to form suitable aqueous dispersions. I

' As examples of anionic surface active agents which are "useful. in preparing emulsion polymers of the type described above or which are useful for dispersing finely divided thermoplastic resins suitable for the preparation of thaqueous dispersions may be mentioned water-soluble alkalirmetal salts of saturated and unsaturated fatty acids'containing 10 or more carbon atoms, water-soluble alkali metal salts of alkylated naphthalene sulfonic acids iorqof alkylated benzene sulfonic acids, water-soluble alkali metal salts of sulfated or sulfonated fatty alcohols containing" 10 or more carbon atoms or the like.

i The aqueous dispersions employed in this invention ,generally'have 'a pH between about '5 and 8 depending upon" the materials used in their preparation and the conditions under which they are prepared. However, it is alsopossible to use dispersions having a higher pH than 8 *o'r a'lower pH than 5; For example, wool may be ftreated without'appreciable loss in tensile strength with Taeidic or mildly alkaline dispersions while cotton and other cellulosic materials do not show any appreciable :loss in strength when alkaline or mildly acidic dispersions 'are employed. Some synthetic staple fibers, for example,

cellulose acetate or'polyamides. may require treatment with neutral or substantially neutral dispersions. "The resin concentration of the aqueous dispersions is "generally between 0.5 and 70% by weight and prefer- This factor is treated. For example, in the case of cellulosic fibers .such as cotton'fibers and regenerated cellulose fibers best .results are obtained when a minimum of water is added to thefibers with the resins. In such instances when 0.1

153% by weight, based on the weight of the fibers, of

resin is applied,v the amount of water applied is not in -excess .of 6% by weight on the weight of the fibers. This -.means, normally, that the aqueous dispersions should not contain less than about 33% .by weight of resin for the application of 3 by weight of resin on the fibers and not 'less'than 2% by weight resin for the application of 0.1%

by weight resin on the fibers.

Wool'fibers and similar animal fibers, on the other lhan'd, can be wetted with larger amounts of water than cotton and regenerated cellulose fibers without interfering with the manipulative characteristics of the fibers.

Thus animal fibers which are processed in the Woolen system or in the Bradford or French systems can tolerate the addition of up to about 35% by weight and in f'some'instances up to 40% 'by weight of water, based on the weight of fibers. with from 15 to 20% by weight of water and with from "5 to 10% by weight of oil, both percentages being based on the'fiber weight, during the processing of such fibers.

Normally, wool fibers are treated 'In accordance with the present invention the water normally applied with the wool oil is supplied to the fibers by using the aqueous dispersion of the resin per se or by using such dispersion and additional quantities of water, if such additional quantities of water are necessary. In those instances when 0.1 to 3% by weight of .resin, based on the weight of the wool fibers, is applied, Ithe amount of water applied is, preferably, in the range of from 5 to 20% by weight based on the weight of the fibers, although larger amounts as high as 40% by weight may be used. This means, normally, that the aqueous dispersion preferably contains not less than about weight resin and 5% by weight water on the fibers, the

aqueous dispersion preferably contains not less than 2% by weight resin, or when it is desired to apply 0.1% by weight resin and 20% by weight of water, the aqueous dispersion preferably contains not less than 0.5% by Weight resin.

The amount of water which can be applied with the resin to other fibers, for example, synthetic staple 'fibers such as linear polyamide staple fibers, cellulose ester staple fibers, cellulose ether staple fibers or the like is generally the same as in the case of cotton fibers or is intermediate between the amount applied to cotton fibers and wool'fibers.

It is thus seen that the resin is applied to the textile fibers in amounts of 0.1 to 3% by weight, based onthe weight of 'the fibers, and that the amount of water applied with the resin is'up to 40% by weight, based on the weight of the fibers, depending upon the particular fiber which is being processed. Again, the resin concentration of the aqueous dispersions varies between 0.5 and 60% by weight depending onthe amount of resin ap plied to the fibers and the particular fiber being treated.

The aqueous dispersions hereinbefore defined may 'be applied to textile fibers at any stage'of their processing prior to spinning. .In the case of wool and other animal fibers which are processed according to the wool system it is preferred to apply the aqueous dispersions to the wool fibers just prior to the blending box. Application is generally made by spraying or sprinkling the dispersion on the fibers until the desired amount of resin and water has been applied. Since oil is normally added to the wool fibers, the oil may be incorporated in the dispersion and applied therewith or it maybe added separately. The aqueous dispersion is "preferably applied to wool fibers or other animal fibers, which are being processed in the Bradford or French systems, at the gill box where the fibers are formed into a sliver. Here the dispersions are applied, for example, by dripping the dispersion on' the fibers or by means of the normal squirrel cage applicator the dispersions on the fibersuntilthe desired amount of In those instances resin and water has been applied. y when the fibers are treated after carding but before the formation of the fully condensed sliver, the dispersions may be applied in various ways. For example, one mode of procedure consists in first forming a partiallycondensed web of the carded fibers as they move from the card, which Web is thin and' generally rectangular in cross section, and then spraying the dispersion in finely dividedform on opposite sides'and to the same part of the web as itmoves in a vertical plane.

Another mode -of procedure is to apply the dispersion to the interior portion'of the sliver by means of an applicator device as the web or'car ded fibers is condensed in a customary trumpet, *Thisjapplicator device includes a hollow tube which is positioned in the trumpet in such a manner that it is substantially coincident with the center' of the trumpet and parallel tothe'direction of movement of the fibers passingthrough thetnnnpet, the orifice of the hollow tube terminating insidethetrumpet and closely adjacent to theorifice of the trumpet; and also" includes At the first three of the above-named locameans for supplying a liquid to the hollow tube. The aqueous dispersion is supplied to the hollow tube by gravity flow and the dispersion is wiped from the orifice of the tube, as it drips therefrom, by the fibers as they move past the tube on their way through the orifice of the trumpet. The dispersion is thus deposited in the center portion of the sliver as the sliver is formed in the trumpet. The amount of resin and water deposited is regulated by the rate at which the sliver is formed, the rate of flow of the dispersion through the hollow tube, and the resin concentration of the. dispersion. The procedure and apparatus used in this mode of operation are described in greater detail in the patent to Siever, No. 2,115,218.

The textile fibers which have been treated with resin and water in the amounts hereinbefore descibed, are further processed in the normal manner and without being dried. This is an important advantage in that no extra equipment, outside of the spraying equipment or other application equipment used in applying the dispersions, is required. Also, by dispensing with the drying of the fibers it is possible to process the fibers at lower cost and without the danger of softening the resin which softening often results in the formation of neps or other lumps which interfere with the processing of the fibers and cause an increased number of ends down. By using fine, discrete, unagglomerated particles of a hard, non-plasticized, water-insoluble, polymerized resin which is non-film-forming and hydrophobic, it is possible to obtain improved slip resistance, spin the fibers into yarn at a lower twist multiple or to speed up the rate of production without the formation of appreciable amounts of neps or other lumps of fibers and without appreciably increasing the normal number of ends down.

The yarns produced in accordance with the methods of the present invention contain from 0.1 to 3% by weight of fine, discrete, substantially unagglomerated particles of a hard, non-plasticized, water-insoluble, polymerized thermoplastic resin. The resin particles are distributed throughout the length of the yarn. These yarns are characterized by increased tensile strength at normal twist multiples or by normal tensile strength at lower twist multiples than can normally be used and in the latter case are softer and fuller than yarns prepared without the addition of such resin. They are further characterized in that they are relatively free of neps and by the fact that the fibers therein are not bound together by the resin and are free of resin film.

A further understanding of the present invention will be obtained from the following specific examples which are intended to be illustrative of the invention but not limitative of the scope thereof, parts and percentages being by weight unless otherwise specified.

Example I An aqueous dispersion of polystyrene resin was first prepared as follows:

Forty parts of monomeric styrene, 0.1 part of K S O as a catalyst, 12 parts of the sodium salt of dodecyl benzene sulfonic acid as an emulsifying agent, 0.07 part of sodium dihydrogen phosphate and 0.28 part of disodiurn hydrogen phosphate as buffering agents, and 58.2 parts of water were first agitated to form an emulsion. The emulsion was then heated at a temperature between 90 and 95 C. for 2 hours under a reflux condenser and :then cooled'rapidly to room temperature. The resulting dispersion contained 40% by weight of fine discrete, un- :agglomerated particles of hard, water-insoluble and nonplasticized polystyrene resin which was non-film-forming when placed on a watch glass and allowed to dry at room temperature. The dispersion also contained about 0.3% by weight of free monomer. The pH of the dispersion was between 7.0 and 7.5 as measured by indicator paper.

The above dispersion was diluted with water until it contained polystyrene solids. This dispersion was then applied to a webof 1%; inch regenerated cellulose (viscose) staple fibers, as the web was being condensed into a sliver, by means of a hollow tube which was in serted into the central portion of the sliver as it was formed in such a way that the dispersion was taken up by the fibers by a wiping action as the sliver passed by the tube. The type of apparatus and the method of application employed are described in detail in U. S. Patent No. 2,115,218, hereinbefore referred to. The dispersion was supplied to the hollow tube in an amount suflicient to provide 0.25% polystyrene resin and 2.5% water, both based on the weight of the fibers in the sliver, and throughout the entire length of the sliver. i

The resulting sliver was drawn twice and then made into a roving in the normal manner. .During the drawing the sliver exhibited a considerably increased resistance to slippage, indicating that the inter-fiber friction had been increased by the resin treatment. To compensate for this increased resistance to slippage the drawing was conducted by opening up the drawing roll settings.

A control roving was prepared from 1% inch regenerated cellulose (viscose) staple fiber in the normal manner and without the resin treatment.

The treated roving and control rovings were then tested for break factor with the following results:

The treated roving gave no difiiculty during spinning and enabled the spinning of a yarn having good tensile strength at reduced twist multiple.

Example 11 An aqueous dispersion of polystyrene resin was first prepared as described in Example I and was then diluted with water until it contained 5% polystyrene solids. This dispersion was then mixed with a self-emulsifiable wool oil, the wool oil being added in amounts sufficient to equal the weight of polystyrene in the dispersion. The resulting dispersion was sprayed in the form of finely divided droplets on clothing wool fibers in the blending box in an amount suflicient to deposit 0.5% of polystyrene particles, 0.5% of the wool oil and 10% of water, all percentages being based on the weight of the fibers. The fibers were then processed into wool yarns according to the wool system of processing and spinning. The fibers were processed without difiiculty, but did exhibit an increased drag or resistance to slippage during the processing operations. The resulting yarn was relatively free of neps or lumps of fibers and the processing machinery showed no evidence of resin accumulation.

Control yarns were prepared from clothing wool in the same manner except that no polystyrene resin was used.

The treated and control yarns were tested for tensile strength with the following results:

Example III An aqueous dispersion containing 15% by weight of fine, discrete, unagglomerated particles of a hard, nonplasticized, water-insoluble, polyvinyl chloride which is substantially resistant to plasticization with water and non-'film-forming at temperatures below 150 F., prepared by the emulsion polymerization of vinyl chloride, and about 1.5% of decyl benzene sodium sulfonate as a dispersing agent was sprayed in the form of fine droplets on 1 inch Strict Middling cotton at the cotton picker hopper. The dispersion was supplied in an amount suificient to deposit 0.75% polyvinyl chloride particles and 5.0% water, both percentages based on the Weight of the fibers. The treated fibers were made into laps, and then carded, drawn and roved on regular mill equipment. In order to spin the roving into yarn it was necessary to reduce the normal roving twist by 20%.

The roving was spun into s, 20s and 30s yarns which had appreciably more tensile strength than similar yarns prepared from the same cotton fibers but which were not treated with resin.

The aqueous dispersions employed in accordance with the present invention may be modified by the addition of textile conditioning agents other than the anionic surface active agentsor oils heretofore described. Thus it is possible to add small amounts, i. e., 0.1 to 5% by weight of softening agents, humectants, hygroscopic agents, lubricants, non-ionic surface active agents and the like providing, of course, that such agents are not cationic surface agents or agglomerating agents or do not plasticize the thermoplastic resin particles.

This is a division of my .co-pending application Serial No. 130,603, filed December 1, 1949, now U. S. Patent No. 2,730,790, granted January 17, 1956.

What is claimed is: g

1. A spun textile yarn containing wool fibers and from 0.1% to 3% by weight, based on the weight of fibers in the yarn, of fine, discrete, substantially unagglomerated particles of a'hard non-plasticized water-insoluble polymerized thermoplastic resin derived from monomeric unsaturated organic compounds, said resin being substantially free of monomers, said yarn being further characterized in that the fibers therein are not bound together by the resin and are free of resin film.

.2. A spun textile yarn containing from 0.1 to 3% by Weight, based on the weight of fibers in the yarn, of fine, discrete, substantially unagglomerated particles of a'hard, non-plasticized, water-insoluble polymerized thermoplastic resin derived from monomeric, unsaturated organic compounds, said resin being substantially free of monomers, said yarn being further characterized in that the fibers therein are not bound together by the resin and are free of resin film.

3. A spun textile yarn as in claim 2, but further char acterized in that said resin is polystyrene.

4. A spun textile yarn as in claim 2, but further characterized in that said resin is polyvinyl chloride.

5. A spun textile yarn as in claim 2, but further characterized in that said resin is a copolymer of a mixture of from to 99% styrene and 20' to 1% of an alkyl maleate containing from 1 to 6 carbon atoms in the alkyl group.

6. Unspun textile fibers containing from 0.1 to 3% by weight, based on the weight of fibers, of fine, discrete,

substantially unagglomerated particles of a hard, nonplasticized, water-insoluble polymerized thermoplastic resin derived from monomeric, unsaturated organic compounds, said resin being substantially free of monomers, said fibers being further characterized in that they are not bound together by the resin and are free of resin film.

References Cited in the file of this patent UNITED STATES PATENTS 1,983,349 Dreyfus Dec. 4, 1934 2,054,131 Kollek Sept. 15, 1936 2,350,032 Hager May 30, 1944 2,436,614 Sparks et al Feb. 24, 1948 2,511,593 Lightfoot -3 June 13, 1950 2,534,315 Swanson l Dec. 19, 1950 2,534,318 Swanson Dec. 19, 1950 2,570,750 Bauer Oct. 9, 1951 2,610,927 Foulds Sept. 16, 1952

Claims

2. A SPUN TEXTILE YARN CONTAINING FROM 0.1 TO 3% BY WEIGHT, BASED ON THE WEIGHT OF FIBERS IN THE YARN, OF FINE, DISCRETE, SUBSTANTIALLY UNAGGLOMERATED PARTICLES OF A HARD, NON-PLASTICIZED, WATER-INSOLUBLE POLYMERIZED THERMOPLASTIC RESIN DERIVED FROM MONOMERIC, UNSATURATED ORGANIC COMPOUNDS, SAID RESIN BEING SUBSTANTIALLY FREE OF MONOMERS, SAID YARN BEING FURTHER CHARACTERIZED IN THAT THE FIBERS THEREIN ARE NOT BOUND TOGETHER BY THE RESIN AND ARE FREE OF RESIN FILM.