US2737434A - Process for treating wool textile products and resulting products - Google Patents

Description

March 6, 1956 e. w. PIERCE 3 PROCESS FOR TREATING WOOL TEXTILE PRODUCTS AND RESULTING PRODUCTS 5 Sheets-Sheei 1 Filed April 9, 1949 RIO 3mm Ge orje W P/erce ATTORNEY PROCESS FOR TREATING WOOL TEXTILE PRODUCTS AND RESULTING PRODUCTS Filed April 9, 1949 March 6, 1956 e. w. PIERCE 3 Sheets-Sheet 2 m 6-.- F W 1.3 9

o 6eorgc W/ /rce ATTOR N EY March 6, 1956 G. w. PIERCE PROCESS FOR TREATING WOOL TEXTILE PRODUCTS AND RESULTING PRODUCTS 3 Sheets-Sheei 3 Filed April 9. 1949 QUSvQ Q uukuq 1 7 W Z i r w 6 P 6 5 W n r w 6 N m a u 7 C 0 P m 3 w m a P v N 2 e U C 0 I w m L c a 3 a b 2 m M 4 0 ATTOR N EY United States Patent (3 PROCESS FOR TREATING WOOL TEXTILE PROD- UCTS AND RESULTING PRGDUCTS George W. Pierce, Bethlehem, Pa.

Application April 9, 1949, Serial N 0. 86,454

11 Claims. (tCl. 8-115.6)

My invention relates to improvements in the art of treating textile products with a polymeric substance, more particularly the art of treating wool products with such a substance to provide a treated wool product having improved physical characteristics such as improved shrink resistance, increased solvent resistance and improvedaging qualities.

It is known to treat textile products with aqueous dispersions of various kinds for various purposes and is in fact known to treat wool products with an aqueous dispersion of a polymeric substance for the purpose of coating the fibers thereof with such substance to impart an improved shrink resistance characteristic thereto. The limitations of such previously known methods of treatment have, however, restricted their utilization in the field of treating wool products with polymeric substances in that only a restricted number of such substances evidenced any substantial capahility of being used in such treatment to effect an improvement in the shrink resistance characteristic, many of them were unsuitable as a practical matter because of accompanying loss of hand, drape or feel of the goods resulting from one or more of the characteristics of harshness, boardiness, oiliness of tackiuess, and others displayed a lack of resistance to aging. Moreover, all of these known methods have the manifest disadvantage that the coated textile fibers display a solvent susceptibility which makes it improssible to use any polymeric substance having per se a low solvent resistance and undesirable to use others having a high solvent resistance by themselves, but nevertheless susceptible to extraction from the textile product when subjected to treatment with organic solvents.

I have found that the hithertofore supposed limiting factors which handicap the utilization of an aqueous dispersion for the purpose of treating a Wool product with a polymeric substance to effect an improved shrink resistance characteristic can be substantially avoided by practicing my novel process of applying such substances as hereinafter described. As a matter of fact, my novel process can be utilized not only to obtain a further improved shrink resistance characteristic with polymeric substances heretofore used for treating wool products and to permit usage of polymeric substances heretofore considered unsuitable for such purpose, but also to obtain more uniform and thorough treatment of textile products generally with any polymeric substance capable of forming an aqueous dispersion.

I have also found that wool products treated with a particularly class of polymeric substances, namely sulphur vulcanizable unsaturated polymeric substances, particularly when such substances are applied in accordance with my novel process, can be given a novel additional treatment to yield either an improvement, or a further improve ment, in the shrink resistance characteristic of the product and/ or to improve other physical characteristics such as solvent resistance, aging resistance, hand, drape and feel.

It is, accordingly, an object of my invention to provide a simplified and direct process for the impregnation of textile products with an aqueous dispersion of a polymeric substance to yield even and uniform distribution of such substance on the textile fibers.

A further object is to provide such a process which can be operated as a continuous process for progressive treatment of a continuous length of such a textile prodnot.

A still further object is to provide such a process for treating wool products with a polymeric substance to enhance the shrink resistance characteristic of such products.

Another object is to provide a process for treating a wool product whose fibers have been uniformly and evenly coated with a sulphur vulcanizable unsaturated polymeric substance, to bond such substance to said fibers.

Another object is to provide a Wool product whose fibers are coated with a sulphur vulcanizable unsaturated polymeric substance bonded thereon.

Still another object is to provide such a wool product having a enhanced shrink resistance characteristic as compared to a similar product in which the polymeric substance is not bonded to said fibers.

Another and further object is to provide such a wool product having an increased solvent resistance as compared to a similar product in which the polymeric substance is not bonded to said fibers.

A still further object is to provide such a wool product having an improved hand, improved resistance to creasing, scorching, attack by moths, discoloration by light or air oxidation and which when dyed, has improved dye fastness to washing. I

Other and further objects and advantages of the present invention will appear from the detailed description hereinafter set forth, it being understood that such detailed description is given by way of illustration and not by way of limitation since various changes which may be made within the scope and spirit of my invention will readily occur to those skilled in the art.

In the drawings Figure 1 is a diagrammatic illustration of a padding machine for use in applying a polymeric substance to the fabric in accordance with may invention. Figure 2 is a diagrammatic illustration of an irradiation chamber for use in irradiating fabric treated in accordance with my invention. Figure 3 is a series of curves showing the results obtained by twenty-hour wash tests on various fabrics. Figure 4 is a series of curves showing the shrink resistance characteristics of various fabrics treated with various amounts of a polymeric substance.

Broadly speaking, my invention relates to methods of treating textile products with an aqueous dispersion of a polymeric substance by an impregnation or padding technique. The process of padding, well known in the textile art, consists essentially in immersing the product in the dispersion and alternately squeezing and relaxing the same to cause the dispersion to become entrained in the product. The impregnation technique differs substantially from those known techniques of effecting deposition of a dispersed solid on a textile product by promoting instability of the dispersion while in contact with the goods as, for example, by the introduction of an electrolyte or coagulant or by treating either the goods or the dispersion to produce opposite electrical charges as between the goods and the dispersed solid. Where evenness, thoroughness and uniformity of coating of textile fibers with a dispersed solid is of paramount importance, the deposition technique leaves something to be desired in that the deposition on the fibers in nonuniform due to the inherent randomness of the deposition and excess deposition normally occurs on the sur- 3 face fibers of the textile product being treated. Moreover, such a technique is not generally adapted to continuous processing by progressive treatment of a continuous length of a textile product due to the fact that the textile product to be treated and the treating bath must be handled as a batch.

I have found that in using the impregnation or padding technique certain criteria should be observed if one is to realize the full advantages of such technique by way of permitting one to obtain a maximum degree of evenness, thoroughness and uniformity of coating of the textile fibers with the dispersed solid. These criteria are that deposition resulting from instability of the dispersion in the presence of the textile product, or from mechanical manipulation of the textile product and the dispersion during impregnation, or destabilization or coagulation of the dispersed solid on the surface fibers due to dehydration of the dispersion should be avoided.

In accordance with my invention, 1 have found that these criteria can be satisfied in treating a textile product with an aqueous dispersion of a polymeric substance in accordance with the impregnation or padding technique by insuring that complete impregnation of the textile product with the dispersion is effected before any influence tending to fix or set the polymeric substance on the fibers is permitted to act. According to the present invention the controlling consideration may be realized by fully stabilizing the aqueous dispersion both chemically and mechanically prior to impregnation in the manner hereinafter described so that the dispersion is able to maintain itself against any material aggregation, agglomeration, gelation or coagulation either in the bath or in the presence of the textile product to be impregnated and under the mechanical action incident to such impregnation. Preferably the dispersion is so treated that the dispersed solid possesses a similar or neutral electrical charge with respect to the fibers of the product. In the case of a neutral or alkaline wool product, the dispersion of a polymeric substance would be stabilized on the alkaline side at a pH of 7 or about and preferably above 10. However, it is also possible to carry out the process with an aqueous dispersion on the acid side where the charge of the wool product has been reversed by treating it with a strong acid, but the use of alkaline or neutral wool and an alkaline dispersion is preferred in order to avoid handling and corrosion problems. As a matter of fact, the dispersion may even be neutral in the case of either alkaline or acid wool or the wool may be neutral in the case of a dispersion on the alkaline or the acid side, however, care should be exercised to avoid the use of a wool and an aqueous dispersion in which the dispersed solid possesses a charge dissimilar to that of the wool.

l have further found it to be of particular advantage to thoroughly wet out the textile product to be treated before impregnation with the dispersion. In such case, the padding technique causes the aqueous dispersion to displace the water entrained in the wetted product. This avoids premature deposition of the dispersed solid on the surface fibers of the product by dehydration of the dispersion at such points. I have also found it to be of particular advantage in the case of a textile product such as a wool product which is difiicult to wet, to include a wetting agent in the aqueous dispersion or in the wool product particularly where the product has not been thoroughly wetted out with water prior to impregnation with the dispersion. The water used for prewetting the textile product may contain a wetting agent and may be in a neutral range with respect to pH, however I prefer to use water with approximately the same pH as the dispersion used for impregnation. Further advantages accrue by incorporating added stabilizer in the water used for preliminarily wetting out the product.

At this point in my improved process of treating a textile product with a stabilized aqueous dispersion all or substantially all of the dispersed solid can be washed out with water which in itself contains no destabilizer or coagulating agent, thus demonstrating that there has been no or substantially no deposition of the dispersed solid on the textile fibers. Thus, the next step in my process is to fix the dispersed solid on the fibers in its uniformly and evenly distributed state. This fixing step may be accomplished by various means. For example, the impregnated product may be immersed in a coagulant for the dispersion such as an acid bath and subsequently dried or the product may be immediately dried without such treatment in an acid bath. Where the impregnated product is treated with the acid bath, the solid phase of the dispersion is fixed on the fibers in the sense that it cannot be easily washed out. Where the impregnated product is dried without such treatment in an acid bath or is dried after such treatment, the solid phase is set on the fibers in such a Way that it cannot be removed by ordinary washing although it may be largely removed by extraction with an organic solvent.

The improved impregnation, and fixing or setting technique of the present invention is particularly useful in effecting the coating of the wool fibers of a wool product with a polymeric substance to impart to such wool product an improved shrink resistance characteristic. 1 have found that the evenness, thoroughness and uniformity of treatment of the fibers obtained by using the impregnation or padding technique of my invention enables one to obtain an unexpected and surprising improvement in the shrink resistance characteristic \vtih respect to various polymeric substances heretofore known to be useful for such purpose and further enables one to utilize other polymeric substances heretofore believed to be unsatisfactory either because they failed to promote any substantial improvement in shrink resistance or because even though an improvement in shrink resistance was attained, the treated wool product proved unsatisfactory because of resulting poor hand, drape or feel. Moreover, the decided improvement in shrink resistance obtained with polymeric substances previously known to be suitable can be obtained even though the total quantity of such substance fixed on the fibers of the Wool product is substantially reduced over what has heretofore been considered necessary to obtain any substantial shrink proofing effect.

in the case of a wool product which has been impregnated with a stabilized aqueous dispersion of a polymeric substance in accordance with my invention, I have found that when the dispersed solid has been set on the wool fibers it is more or less permanently attached thereto in such a way that if the product is subsequently deformed as, for example, by stretching, it has a tendency to return to its original dimensions and substantially resists any inherent tendency to shrink beyond that point. On the other hand, when the dispersed solid has merely been fixed on the fibers, it is only loosely attached thereto and it is possible to deform the product within reasonable limits as by stretching and to then set the solid while the product is in such stretched condition so that it has dimensional stability in the sense that it will substantially resist any tendency to shrink from its newly attained dimensions. Accordingly, the terms fixed and set as used hereinafter shall be taken to describe coatings of dispersed solid on fibers having the respective distinctive characteristics herein set forth.

By the term textile product as used herein I mean raw or processed natural or synthetic fibers and spun, woven, knitted, felted or other manufactured products made from such fibers; and by the term wool product I mean a textile product comprising wool fibers including protein fibers such as Angora and Cashmere having shrink or felting characteristics similar to wool.

Broadly speaking, any polymeric substance which can be incorporated in an aqueous dispersion can be applied to a textile product in accordance with the technique of my invention to obtain a treated product the individual fibers of which have been more thoroughly and uniform- 1y coated throughout the product than has heretofore been possible.

I have found the process to be particularly suitable for the impregnation of wool products with natural or synthetic elastomeric substances such as natural rubber and synthetic polymers which are capable of imparting to a wool product an improved characteristic or characteristics such as hereinafter described.

While my improved method of obtaining a uniform and thorough impregnation of a textile product with a stable aqueous dispersion of a polymeric substance of the class hereinafter described brings about a substantial improve ment in the shrink resistance of a wool product, I have found as an additional aspect of my invention that such a wool product can be rendered much more resistant to wash shrinkage and felting and/or can be given an improved solvent resistance, an improved resistance to aging, and an improved hand, drape or feel especially with respect to oiliness and tackiness by a further uniform treatment of the coating of such substance in contact with the wool fibers, with a cystine linkage splitting agency. Such agencies have the capacity to effect a splitting of the disulfide group in the cystine linkage of the wool and comprise oxidizing and reducing agents, light and alkalies e. g., water, salt or acid solutions at elevated temperatures, irradiation with sunlight, ultra violet or infra red rays, dry heat, mildly oxidative conditions or mildly reducing conditions. Of these agencies, the preferred treatment is with ultra violet irradiation or sunlight, which as is well known, promotes a photochemical decomposition of the wool fibers by splitting the cystine linkage. Such treatment with a cystine linkage splitting agency when applied to a wool product having a coating of a sulphur vulcanizable unsaturated polymeric substance in contact with the fibers brings about a bond between such polymeric substance and the wool fiber which is unique and unexpected and which imparts to such product various new physical characteristics.

I believe that the explanation of this phase of my invention is the following: wool contains a characteristic which in the presence of a cystine linkage splitting agency each having a free sulphur terminus. These residues, when in contact with a sulphur vulcanizable unsaturated polymeric hydrocarbon, or substituted hydrocarbon, apparently form a sulphurdinked-wool-residue-polymcrcomplex which is much more insoluble than the original polymeric substance.

Whether this be the true explanation or not, I know as a fact that all sulphur vulcanizable unsaturated polymeric substances which I have so far tested cannot be totally extracted from the wool after boiling a sample for 16 hours in trichlorethylene following the Soxhlet method. On the other hand even highly cross linked and substantially insoluble polymeric substances can be largely extracted by such treatment if the cystine linkage splitting agency treating step is omitted.

In addition to this uniform characteristic exhibited by all sulphur vulcanizable unsaturated polymeric substances which I have tested namely the marked increase in solvent resistance as determined by the above extraction test, even where highly cross linked and so called difiicultly soluble polymeric substances are used, I have found that a considerable number of such substances leave the hand, drape and feel of the wool unaffected after treatment. Others make the wool product boardy and some give it a poor drape, an oily feel or a greasy hand, hence one as a practical matter might not wish to use every polymeric substance of the class in the anti-shrink treatment of wool despite the uniform characteristic of a marked increase in solvent resistance after the polymeric substance has been coated on the Wool fibers and after the coated wool has undergone the above described treatment with a cystine linkage splitting agency.

Accordingly, by the term bonded as used herein, it is meant, therefore, that the sulphur vulcanizable unsaturated polymeric substance has been united with the fibers in some physical or chemical manner by treatment with a cystine linkage splitting agency in such a way that the resultant coating is less susceptible to extraction in a sixteen hour Soxhlet extraction in trichlorethylene than when fixed or set upon the fibers without such treatment.

As has been explained, the hereinbefore defined terms fixed and set may represent discreet stages in the character of the polymer-wool system, but may also be effected concurrently by a single treatment. Similarly, it will be understood that although the term bonded likewise represents a discreet stage, it will in practice be possible to combine treatments in such a way that the stages overlap or that two or more of the consecutive stages of fixing, setting and bonding may be attained simultaneously by a single treatment.

It is of special interest to note that although I may impregnate'wool products with an aqueous dispersion as above described and even fix, set or bond the dispersed solid at an early stage in the process of manufacture, the treatment surprisingly does not interfere with subsequent stages of normal manufacture. Thus, wool products treated in accordance with my process will carbonize and dry mill in essentially the same manner as unimpregnated products whereas one would expect that such treatment would serve to protect the cellulose particles against attack by carbonization and would only bind them into the goods preventing successful dry milling.

It is likewise completely unexpected that such impregnated goods would dye normally and evenly, yet such is the case and it has been further found in wash fastness tests that such dyed wool products will retain their shade better against bleeding than will equivalent untreated wool products.

Any sulphur vulcanizable unsaturated polymeric substance may be used for the impregnation of wool prodnets to be treated with a cystine linkage splitting agency in accordance with my invention. I have found the following to be particularly suitable, specific examples being included hereinafter by way of illustration, and not by way of limitation: natural rubber and synthetic polymers such as polymers of butadiene, polymerized derivatives and polymerized lower homologues of butadiene, copolymers of butadiene with any of its derivatives or lower homologues, and copolymers of butadiene or its derivatives or lower homologues with one or more vinyl compunds of the formula *1 CHFC-X where X represents halogen, --CN, COOR, phenyl or halogenated phenyl (R being alkyl or aryl), and A represents H, halogen, or alkyl. Accordingly, by the term polymeric substance as used herein I mean to include not only homopolymers as such but copolymers, interpolymers and heteropolymers.

Example 1 A quantity of neutral or slightly alkaline scoured and fulled, but uncarbonized, woven woolen fabric was thoroughly wetted out with water at about 80 F., pH 8.5-10, containing 0.1% by weight of Tergitol #4 (Carbide and Carbon Chemical Corp.) a wetting agent which is the sodium sulphate derivative of 7-ethyl-Z-methyl-undecanol- 4 and the excess removed by passing the fabric through squeeze rolls in such a manner that the fabric retained about 50% of the water based on its dry weight. The wetted out fabric was immersed in a fully stabilized aqueous dispersion of polymerized butadiene i. e. a synthetic latex, completely stable in the presence of such fabric and under mechanical treatment such as hereinafter described. Such latex, produced as hereinafter described, was diluted to a solids content of 11.5% and adjusted to a pH of 9.5 and the immersion was continued for a period of time sufficient to permit the woolen fabric to become thoroughly impregnated. In order to insure complete impregnation the fabric was alternately squeezed and relaxed under the surface of the aqueous dispersion after which it was run through squeeze rolls to remove the excess latex and dried to an extent sufficient to set the polymer in the fabric; whereupon it was found to have retained 6.2% of its dry weight of polymer.

After drying, the fabric was given a carbonization treatment which in this case consisted of running the fabric through a 2% (by weight) sulphuric acid and 0.1% Tergitol #4 carbonizing bath, subjecting the same to an increasingly higher temperature ranging from approximately 190 F. to 208 F. for a period of approximately 5 minutes in a carbonizing oven and finally passing it under a bank of infra red lights to complete the carbonization of foreign vegetable matter in the fabric in order to permit its ready removal. Following the carbonization treatment, the fabric was dry milled in the usual way to remove the carbonized burrs and foreign vegetable material whereupon it was uniformly exposed to the direct rays of the sun for one hour on each side and from there on was processed, dyed with an acid textile dye in the manner well known in the textile art and finished to produce a finished piece of woolen goods in which the fibers have been uniformly coated and impregnated with the polymer which has in turn been set and bonded to the fibers by exposure to sunlight and the acid treatment and heat incident to carbonizing, dyeing and finishing.

As an alternative procedure to setting the polymer in the fabric directly after impregnation, I have at times found it of advantage to simply fix the polymer in the fabric in order to prevent migration or washing out of the otherwise stable latex, postponing the final setting of the polymer in the fabric to a later stage in the process. This may be accomplished by the use of various gelling or coagulating agents not adversely affecting the properties of the fabric. For example, in the present instance I may fix the polymer in the fabric by passing the impreg nated goods, from which the excess latex has been expressed by squeezing, directly into the 2% sulfuric acid carbonizing bath. The polymer is thus fixed, set and partially bonded as a result of the cystine linkage splitting effect of the carbonizing operation and finally bonded in the irradiation and dyeing operation.

Samples of the fabric, taken at various stages of the treatment as indicated, were then measured before and after washing for comparative shrinkage on a relaxed basis in the following manner: First, the fabric was relaxed by immersing the samples in water at a temperature of 80 F. with a wetting out agent such as sodium lauryl sulphate for a period of two hours. The samples were not manipulated at this stage, but were simply allowed to soak in the water so as to assume a completely relaxed state. The samples were then removed and placed. in an extractor to remove the major portion of absorbed water whereupon they were laid out to dry on a screen with no tension and at room temperature.

At this stage the samples were found to be in a completely relaxed state andby measuring the samples, com

puting the area, and comparing the results thus obtained with the original areas, the percentage decrease in area for each sample was readily determined. This percentage decrease in area then represents the relaxation shrinkage of the material.

The relaxed samples were washed for 5 hours in an agitator type washing machine such as an Easy domestic washer using 16 gallons of a 0.5% aqueous soap solution at 110 F. and a total loading in the washer of 3.5 pounds of goods dry weight. A free running suds was maintained by the addition of ammonia to compensate for free or combined acid in the goods. The samples were then given two rinses of 5 minutes and 1 minute respectively in fresh water at F. after which they were run through a roll wringer and air dried fiat on a piece of wire screen. *"apcrience has shown that such treatment is equivalent to 20 washes of 15 minutes each. The percentage decrease in area of the washed and dried samples based on the area of the relaxed samples represents the shrinkage on a relaxed basis.

The results obtained by computing the shrinkage in this manner on the samples taken at various stages of the treatment described in this example showed the following results:

dyed.

in addition to the excellent shrink resistant quality produced by the above described treatment, it was found that the fabric presented a good hand and was neither sticky nor hard and boardy. The fact that the fabric had been treated would hardly be discerna-ble to anyone but an expert, there having been formed on the fibers what is apparently a reaction product of the wool and the butadiene polymer and which is not visible to the naked eye or even under an ordinary microscope and which has a greatly increased solvent resistance as compared to the original butadiene polymer. Moreover, the aging properties of the treated fabric proved to be excellent in that it exhibited no change in physical characteristics even after several months.

in respect to the reference hereinbefore made to the use of wetting agents to accelerate and insure uniformity and completeness of wetting out of the fabric prior to impregnation, it will be understood that the amount of wetting agent used is not critical, i. e., an increased quantity could be used if it is desired to further accelerate this step. in this case, the Tergitol #4 is not only a wetting agent, but acts as an added stabilizer during impregnation. Also other wetting agents may be used such as Decersol O. T. (American Cyanamid) which is dioctyl sodium sulfosuccinate. It will be understood, of course, that the use of a wetting agent to facilitate wetting out the fabric prior to impregnation may be dispensed with entirely where a thorough wetting may be obtained Without resort to such an agent or Where the latex used for impregnation is stabilized to such an extent that prewet-ting is unnecessary.

In preparing the polymer dispersion used in this example, the following components Water 200 were loaded into a jacketed, pressure vessel equipped with a suitable agitator and reacted while being agitated for 20 hours at 60 C. at which time the rate of polymerization had decreased and the solids content was about 31% representing about 89% conversion of the monomeric butadiene into the polymerized form. The latex was then deodorized by steam stripping to remove unreacted monomer, diamers and other volatile components. The resulting polymer was found to have a plasticity value of approximately 120 when measured on the Mooney plastometer. In this and subsequent examples, the Mooney plastometer measurements were taken at 212 F. using the full rotor.

In order to further prepare the aqueous dispersion of polymerized butadiene for use in carrying out the above described treatment of the fabric the following additions were made based on one hundred parts of polymer content in the latex:

2 parts of an emulsion containing 50% of Agerite Stalite (heptylated diphenyl amine) 50 parts of an aqueous solution containing 10% of sodium oleate and 2% of DAXAD #11 (the sodium salt of a formaldehyde condensed and polymerized naphthalene sulphonic acid) The Agerite Stalite acts in the capacity of an antioxidant while the sodium oleate and DAXAD #11 serve to stabilize the latex during the course of its use in carrying out the fabric treatment. .It will be understood, of course, that these stabilizing additions may, if desired, be added to the polymerization mixture or system at an earlier stage the important consideration being that the stabilizing effect is sufiicient to preserve both the chemical and mechanical stability of the aqueous dispersion when the latex is brought into the presence of neutral or alkaline wool.

The stabilized latex at this point had a pH of about 9.5 and a solids content of about 28.5%.

Example 2 The following example illustrates the manner of applying the teaching of my invention in a woolen mill as a continuous process.

A continuous web of neutral, or slightly alkaline, scoured, fulled plain woven 10 /2 ounce wool flannel fabric thoroughly wetted out with water as in Example 1 and retaining approximately 50% of such water based on its dry weight was passed through a padder containing an aqueous dispersion of polymerized butadiene prepared in a manner similar to that described in Example 1, but having a Mooney plastometer value of 85. In this example the polybutadiene latex was diluted to a solids content of 12.5% and adjusted to a pH of about 10.5.

The padder used in this case to accomplish the impregnation of the fabric is a piece of apparatus well known in the textile art. As shown diagrammatically in Figure 1, it consists of a tank 1 which contains the polybutadiene latex the level of which is indicated at 2. The fabric 3 is fed into the tank over roll 4 and passes between the squeeze rollers 5 and 5'. It is then led over a guide roller 6 above the surface of the latex and again under the surface over roller 7, out of the latex over roller 8 and again under the surface and through squeeze rollers 9. After passing through this last set of squeeze rollers, it is led over a guide roller 10 and to the, final set of rubber squeeze rolls 11 and 11'. The drip tray 12 is so arranged as to extend along underneath the fabric as it is conveyed from the guide roll 10 through the final squeeze rolls so as to catch the excess latex expressed by the squeeze rolls and return it through conduit 13 to the tank 1. The squeeze rolls 5 and 5' and 9 and 9' which may be made of rubber need only be loaded to an extent suflicient to squeeze the fabric sufficiently to effect displacement of the water in the fabric and allow its replacement by the polybutadiene latex. The final ,ited to the 3,650 mercury resonance line.

10 squeezerolls 11 and 11 which are made of semi-soft rubber are loaded to the extent necessary to express the excess latex so as to obtain the desired pick-up of polymer on the goods.

After passing through the last set of rubber squeeze rolls the impregnated fabric, which at this point may contain 40% or more moisture, was dried at an elevated temperature to an extent sufficient to set the polymer in the goods. This can be done by various textile mill techniques such as by passing the goods over one or more internally heated rotary drying cans, through an infrared drier, or through a tenter frame drier. I prefer to use a tenteri frame drier which can be operated to dry the goods while holding the same in a relaxed or in a stretched condition as desired.

At this point the goods which showed a pick-up of 4.6% of polymer, and may contain in the neighborhood of 14% moisture (both based on the dry weight of the goods), were given a carbonization treatment similar to Example 1 by passing the same through a 2% sulphuric acid bath followed by heating to a degree and for a period of time sufficient to cause carbonization of foreign matter.

As an alternative carbonizing procedure, I have found it effective to run the impregnated goods in rope form through an aluminum chloride solution of 5 degrees Twaddell at room temperature, extract the excess solution and dry the goods at a temperature approaching 220 F. followed by a bake at about 240 F. for a period of time sufiicient to carbonize the extraneous vegetable matter present.

After carbonization, the fabric was led through an irradiation chamber containing an ultra violet source so located as to exposethe fabric uniformly on both sides. Referring to Figure 2, the irradiation chamber is illustrated diagrammatically as having an external housing 15 with slots 16 and 16 through which the fabric is led into and out of the chamber respectively. Upon entering the chamber, the fabric passes over guide rolls 17, 17' through 21, 21' which guide the same in alternate up and down passes through the chamber. A series of ultra violet light sources comprising tubes 22, 23, 24', and 25 are positioned in sockets 26 through 33 in such a way that one side of the fabric on one up and down pass is exposed to the radiation from tubes 22 and 23 and the other side of the fabric on a succeeding down and up pass is exposed to the radiation from tubes 24 and 25. It will be understood that the tubes are energized through the sockets by any suitable source of electrical energy not shown. While only four ultra violet tubes are shown in the diagrammatic illustration, it will be understood that those shown represent a series of tubes positioned therebehind, uniformly spaced and sufficient in number to uniformly irradiate the fabric over its full width.

While any suitable source of ultra violet may be used, in this case a number of Westinghouse BH-9, 3,000 watt mercury vapor tubes were used. These tubes were positioned at a distance of 12 inches from the fabric and were spaced 8 inches apart center to center across the width of the fabric.

According to the manufacturer this BH-9 lamp radiates approximately 117 watts of energy in the ultra violet wave lengths between the cut-off point of the glass at 3,000 Angstroms and the upper ultra violet limit of 3,800 Angstroms with about 60% of this irradiation being lim- Part of the remainder of the irradiated energy amounting to approximately 338 watts manifests itself in the visible wave lengths between 3,600 and 3,800 Angstroms and the rest of the irradiated energy appears as infra red.

The length of each pass of the fabric through the chamber was so designed with respect to the speed of the traveling fabric that the total exposure time on each side of the fabric in passing through the chamber amounted to 22 seconds.

Inasmuch as it is a characteristic of these ultra violet light sources that after starting they must be energized for some time before they reach their uniform and normal ultra violet output it has been found desirable to so construct the irradiation chamber that sliding doors or removable shields can be interposed between the tubes and the fabric while the tubes are being warmed up and before the fabric is started through the chamber. Such protecting doors or shields have also been found desirable as a safety device in case anything happens to the mill machinery so that it is necessary to shut down while the fabric is still traveling through the irradiation chamber. In such an event, it is desirable to introduce the shields between the tubes and the fabric to protect the fabric from overexposure particularly overexposure to the heat energy radiated by the tubes. These shields have been illustrated diagrammatically in Figure 2 by the dotted lines 34, 35, 36 and 37. Suitable mechanism, not shown, is provided for withdrawing the shields when the irradiation chamber is operating. If desired, the operating mechanism for the shields may be interlocked with the controls for the textile mill machinery in such a way that the mill cannot be operated to feed the fabric to the irradiation chamber until the tubes have warmed up to their normal output and the shields have been withdrawn. Similarly these controls may be interlocked in such a way that in the event of a shutdown of the feed of the fabric to the chamber, the shields will automatically be inserted to protect the fabric.

I have found it to be important in giving the fabric the irradiation treatment just described that the irradiation chamber be so constructed, the light sources so positioned and the speed of travel of the fabric be such that the fabric is given the necessary uniform minimum exposure. For the purpose of my invention, the minimum exposure is the amount necessary to achieve the desired improvement in the shrink resistance characteristic. In the present example, the 22 seconds exposure on each side was sufficient to yield the desired shrink resistance characteristic. As hereinafter pointed out, the desired uniform minimum exposure may be exceeded to a very substantial extent without adversely affecting the shrink resistance characteristic of the fabric so long as it is not carried to the point where it is harmful to the wool fibers or to the polymer itself.

Following this irradiation treatment, the fabric was dry milled to remove the carbonized matter and dyed as in the case of Example 1. In this particular case, the dyeing operation was one commonly used in the textile industry for the dyeing of Woolen materials and comprised treatment with an acid dyestutf Fast Light Orange 2G, British color index No. 27. This treatment took place in a dye beck in the well known manner and the dyeing bath comprised:

Parts Water 4,000 Glauber salt (anhydrous) I3 Dyestuff 2 all based on 100 parts by dry weight of the fabric treated. This bath was maintained at a temperature of 100 F. at the time of introducing the goods and was then slowly raised to boiling temperature over a period of minutes and maintained at boiling temperature for 1 hour. The bath and the goods were then cooled by running in water until the temperature had been lowered to 120 P. whereupon the goods were thoroughly rinsed at this temperature and finally cooled to approximately 85 F. by running in additional cold water.

Where aluminum chloride is used as the carbonizing agent the dyeing procedure isslightly modified to the extent that the goods are first neutralized with ammonia and rinsed after which the bath is dropped in pH to about 4 with sulphuric acid while circulating the goods. The goods are removed and a fresh bath made up and adjusted for dyeing as above.

In the particular dyeing procedure the amount of. dyestuff in the above described bath might be varied from 0.2 part to 4 parts depending on the color desired and. additional dyestuff might even be added during the boiling stage along with an appropriate amount of sulphuric or acetic acid. It should be understood that since this whole procedure is carried out in a dye beck the goods are subjected to a considerable amount of mechanical manipulation as well as to the high temperature of the boiling dye bath. Normally such treatment promotes further shrinking and fulling of the goods, whereas in the present case such tendency was not only avoided, but actually the dyeing treatment acted to improve the shrink resistance characteristic of the goods. The procedure described is given only as an illustration of a suitable dyeing process and whereas an acid dyestuff is used in the illustration, it is also possible to use other dyes or other dyeing techniques so long as they are suitable for dyeing woolen goods. For example, vat dyes, metallized dyes such as Neolan dyes (Ciba) and Palatine dyes (General Dyestufi Corp.) may be used, but in such cases care should be exercised to be sure that the aging propertiesof the polymer treated fabric are not injured by. the metallic content of the dye or by the mordanting, as hereinafter explained.

The resulting dye application was uniform and even and showed an improved fastness to light, washing, etc., over the case of the same dye applied under the same conditions to an unimpregnated piece of the same fabric. Furthermore, as in the case of Example 1, the hand and appearance of the impregnated goods was in all apparentrespects the same as the hand and appearance of the unimpregnated goods which hadotherwise been given the same treatment. The impregnated goods yielded no evidence to the naked eye that-they had been given the special polymer treatment and the bonded coating on the fibers showed a substantial increase in solubility as compared to the solubility of the polymer by itself.

Test pieces taken from the fabric at various stages of the treatment described in this example and given a five hour wash test as described in Example 1 and measured for comparative shrinkage on a relaxed basis gave the following results:

After pressing no change of hand, felting, or loss of definition was apparent in the fully-treated and washed fabric. The unimpregnated control sample of fabric was very badly felted as borne out by the shrinkage figures.

The other control sample which although impregnated was not irradiated but was otherwise given the same treatment illustrates what I have found to be the case, namely, that even without irradiation the impregnation and drying treatment which itself reduces the latent shrinkage will, with the additional steps of carbonizing, dyeing and finishing. further materially reduce such latent shrinkage. The effectiveness of the combined carbonizing, dyeing and finishing operation as divorced from the irradiation, in addition to varying with the amount of polymer in the fabric and the nature of the fabric itself varies also with the apparent etfectivenessof these treating steps as cystine linkage splitting agencies; In this case, the reduction in latent shrinkage was from 20% after impregnation and setting thepolymer by drying-to 11% after bonding the polymer to the fibers by thefurther steps of carbonizing,

13 dyeing and finishing. in other cases the effectiveness may be less or under favorable conditions even greater as is illustrated in Example 3. A further reduction of latent shrinkage to 4% is effected by the additional bonding due to the use of irradiation as a cystine linkage splitting agency.

The above data clearly illustrates the increased shrinkage and felting tendency of the unimpregnated fabric normally promoted by the usual carbonizing, dyeing and finishing steps, whereas in the case of the impregnated fabric these steps not only failed to promote an increase in the shrinkage and felting tendency but, contrary to what might be expected, actually operated to improve the shrink resistant quality very materially.

Of the three operations, carbonizing, dyeing and finishing, I have found that dyeing and carbonizing have the greatest effect as the cystine linkage splitting agencies and that the former may in turn be substituted by heating the impregnated goods, in which the polymer has first been set, at or about the boiling point in water or preferably dilute solutions of acids or salts not injurious to the fibers; thus, alkali chlorides, sulphates, acid sulphates, acid phosphates, di-acid phosphates, disodium phosphate, borax, acetic acid, phosphoric acid, etc., may be used. A 0.1-0.25 solution of sulphuric acid kept at a boil for one-half hour or longer is particularly effective.

Example 3 The treatment described in Example 2 was repeated with a thoroughly wetted out neutral or slightly alkaline scoured 12 /2 ounce twill flannel fabric which had been more highly fulled than the /2 ounce plain woven flannel. Test pieces taken from the fabric at various stages in the same manner as in Example 2 and given the same wash test were measured for comparative shrinkage on a relaxed basis and gave the following results:

Here again the washed, fully treated, fabric, after pressing, showed no apparent change of hand, felting, or loss of definition due to the impregnation treatment whereas the unimpregnated control sample was badly felted. The same phenomenon demonstrated in Example 2. by which the carbonizing, dyeing and finishing steps act to bond the polymer to the fiber and enhance the shrink resistance quality of the fabric treatedin accordance with my invention is also illustrated here.

I have found that not only is the latent shrinkage and felting of woolen goods during, or due to, mill processing controlled by my process, but that in addition two further entirely unanticipated and economically important advantages accrue.

A. The relaxation shrinkage of normally finished woolen goods treated in accordance with my invention is materially less than that of corresponding untreated goods. This difference in relaxation shrinkage resolves itself into a substantially lowered shrinkage loss during the sponging operation and therefore a greater yardage yield or lowered net cost per yard to the ultimate consumer. In fact, by slight modifications in the finishing steps, most of the relaxation shrinkage of the treated goods can be taken care of and the expensive sponging operation may be eliminated.

B. Woolen goods stretched, or otherwise deformed, during or after impregnation and maintained under the deforming force while setting the polymer in the goods 14 will, for practical purposes, maintain their dimensions during the remainder of the processing and finishing operations in accordance with my invention and will not relax or shrink above that of normally impregnated and processed goods in subsequent wash tests.

Thus, in addition to the already described advantages of goods treated in accordance with my invention it is obvious to one skilled in the art of spinning, knitting, weaving or otherwise fabricating wool that by controlling fulling before impregnation and the stretch during the setting of the polymer, my invention olfers a novel method of controlling weight, quality, and dimensional stability in the goods during manufacture without recourse, as for example in woven goods, to the usual costly procedure of changing the thread count, weight and width of goods woven.

It is likewise obvious, and as will be made further apparent by the following example, that by maintaining the impregnated goods under tension while setting the polymer and by eliminating, or using only a slight tension during the drying incident to the finishing operations, that the desired dimensions can be attained and at the same time the relaxation shrinkage can be controlled in such a manner as to eliminate it or retain a residual 3-5 as desired by the garment trade. As an alternate procedure, I have accomplished the same objective by running at normal tension during the drying incident to the finishing operations followed by steaming to reduce the relaxation shinkage to 3-5%.

Example 4 The following is an example of the utilization of the foregoing variation of my process.

A 12 /2 ounce scoured and fulled but uncarbonized woolen flannel was thoroughly wetted out, impregnated and processed in a manner similar to Example 2. The goods, however, were kept under a longitudinal stretching tension while passing through the padder and while drying at normal width in the tenter frame drier to set the polymer. In this manner the length of a unit yard of the goods fed into the padder was increased to 38.1 inches as it came out of the drier. Comparative tests were made on untreated goods with the tension set to give dried goods of 38.1 inches and on impregnated fabric to give dried goods of only 37 inches per unit yard of feed stock.

The polymer pick-up on the impregnated goods was 2.5% based on the dry weight.

After impregnation and drying the goods were processed, dyed, and finished to the above dimensions as described in Example #2. The finished goods, which were of excellent hand, were then relaxed and washed for 5 hours as described in Example #1.

The following table clearly illustrates the dimensional stability of the so treated and stretched goods by a comparison of relaxation shrinkages and wash shrinkages on a relaxed basis:

Dimensions Shrinkage Processing Finished, Relaxed, f 5 Hour in m on, Wash,

' percent percent I have found that by following the procedure described in Examples 1-4, the somewhat oily and slightly sticky hand which results from the impregnation of the fabric, especially with the lower Mooney value polymers, is eliminated. Thus goods which are oily after impregnation and drying and still of the same nature, but to a much lesser degree after carbonizing and irradiation are completely free of objectionable oilyness after dyeing, drying andpressing. This improvement is believed to be mainly brought about by the bonding of the polymer to the fibers produced by the cystine linkage splitting agency treatment namely, the acid treatment and irradiation as well as the prolonged exposure to high temperatures which take place during carbonizing, drying and finishing. In any event, the combined dry and wet treatment at elevated temperatures results in the complete removal of the objectionable oilyness or surface tack.

The procedures of Examples l4, in addition to fitting in well with the normal operation of a woolen mill and removing the surface tack which would otherwise tend to result from impregnation especially with lower Mooney value polymers, brings about a further surprising phenomenon namely, a considerable improvement in the aging properties of the treated fabric (even though the polymer contains a relatively low amount of anti-oxidant) over a fabric in which the impregnation with the aqueous dispersion of the polymer takes place after carbonizing or after carbonizing and dyeing and where the adsorbed or combined acid would have been all. or essentially all neutralized by the alkalinity of the latex dispersion. Thus, for example, a sample of woolen fabric which had been treated after carbonizing in such a manner as to take up 12% its weight of a polymer prepared in a manner similar to Example 1, although having excellent shrink resistance, started to show stiffening after one months exposure to sunlight whereas the same fabric treated before carbonizing as in Examples 14, was unaffected under the exposure conditions.

I have also found that as to three samples of woolen fabric which have been impregnated in accordance with my invention with an aqueous dispersion of the polymer and dried to set the polymer coating, one having been subsequently treated with a 2% sulphuric acid solution at ordinary room temperature and then rinsed, and one having been treated with a 0.2% sulphuric acid solution and boiled for a period of one hour, and rinsed, and the third not having been treated with any acid, it is quite surprising to find that the sample which was treated with the low concentration of acid and boiled in the solution broke down more rapidly under artificial aging conditions than did the sample which was untreated with acid, and the latter broke down more rapidly than did the sample which was treated with the higher concentration of acid at room temperature.

The artificial aging conditions used in making this test included the subjecting of the fabric samples to a temperature of 240 F. with circulating hot air until such time as the fabrics began to show definite signs of aging as evienced by stififenin g.

Example 5 A quantity of 12 /2 ounce neutral scoured but uncarbonized twill woven flannel was wetted out, impregnated and dried as in Example 1. It was found that the fabric retained 6% by weight on the wool of the polymer. A number of samples of the treated material were then exposed for "arious periods of time to sunlight and to the output of a single Westinghouse BH-9 lamp located 17 inches from the fabric. Following exposure the samples were relaxed and washed as described in Example 1 except that in this case the samples were given eight washes of 2 /2 hours each. After each wash the pieces were rinsed in water at 110 F. for five minutes, run through the wringer, air dried at room temperature on a wire screen and the shrinkage on a relaxed basis computed in accordance with Example 1. In each succeeding wash, a new 0.5% aqueous soap solution at 110 F. was used. The results shown in Figure 3 indicate the shrinkage on a relaxed basis plotted graphically against the hours of washing for the untreated goods, the goods which had been impregnated and dried, but not exposed to a cystine linkage splitting agency, the goods which had been exposed to sunlight, and the goods which had been exposed to the irradiation of the BH-9 lamp for varying periods of time. In Figure 3, the identification of the curves is givenv by the following table.

Curve Treatment Exposure None None. Impregnated and dried Sunlight-1 hour each side. o BH-9-15 seconds each side.

BH-Q-l minute each side. BH920 minutes each side.

None.

These curves given in Figure 3 demonstrate what has been found to be the case namely, that once the fabric has been given the uniform minimum exposure necessary to effect the bonding of the polymer to the fibers and to attain the desired shrink resistance characteristic, excess irradiation operates to give only a minor further improvement and does not interfere with the retention of the desired shrink resistance characteristic so long as it is not carried to the point where it may be harmful to the goods or to the polymer. The curves further demonstrate the fact that the shrink resistance characteristic attained on the basis of the five-hour wash test is representative of the characteristic which may be expected to persist even with extended washing. As a matter of practice, I have found that each S-hour wash test is equivalent to twenty ordinary washings of fifteen minutes each. Accordingly, the 20-hour wash test described in this example represents the results which may be expected in actual consumer usage of the fabric with eighty washmgs.

Example 6 As a modification of the impregnation method described in the preceding examples, the following example ,illustrates a variation in which a highly stabilized emulsion is used to treat a fabric which has been pretreated with acid and thoroughly rinsed to remove all uncombined acid.

184 grams of neutral scoured and fulled but uncarbonized and undyed woolen flannel was treated with 5.5 grams of 66 Baume H2804 dissolved in 5,520 cc. of water for 15 minutes at 200 F., after which it was rinsed twice with water at F. to remove any excess acid and to insure that only such acid as was chemically associated with the fiber would remain. Following this treatment, the excess Water was removed by passing the goods through wringer rollers. The acid treated flannel was then immersed in an impregnating bath comprising 37 grams of the fully stabilized polymer dispersion prepared as described in Example 1, diluted with 5,460 cc. of water, which bath was then heated to 180 F. The aqueous dispersion thus formed contained approximately 1.9% solids and had av pH of 9.5. The goods were then stirred in the impregnating bath for about 45 minutes while maintaining the temperature at this value.

At the end of this period, the bath was essentially clear, indicating that substantially all of the polymer had been dyed on, and had begun fixing to, the fibers of the fabric. The pH of the bath had at this time dropped to approximately 4.5. The impregnated goods were then given two rinses of five minutes at 130 F. and dried at room temperature to set the polymer. At this point it was determined that the goods had increased in weight by 5.7%.

The impregnated and treated fabric was then exposed uniformly to the direct rays of the sun for one hour on both sides as in Example 1. The finished goods appeared normal in all respects and were possessed of a soft although somewhat oily and tacky hand. Samples taken from the material at various stages and washed as described in Example 1 showed a shrinkage on a relaxed basis as follows:

Shrinkage Stage percent I Acid treated and impregnated 28 Acid treated, impregnated and exposed 5. 6 Control sample, untreated 36 In place of the sulphuric acid used to treat the goods prior to impregnation, it will be understood that I might use appropriate quantities of other strong polyvalent acids such as phosphoric, but for economic reasons sulphuric acid is preferred. Care should be exercised in carrying out the acid treatment to make sure that all excess acid is removed from the goods and further, the latex should be fully stabilized and on the alkaline side as indicated by the pH stated above. .Such precautions insure that no excess acid will be present to cause flocculation of the polymer with consequent uneven deposition chemically on the surface of the fabric as contrasted to the result obtained in the foregoing treatment whereby the fabric is actually impregnated and the polymer is deposited evenly on the individual fibers where the acid combined with the wool operates to cause such deposition as may be present in situ and uniformly throughout the fabric.

I have found that if these precautions are not taken so that excess acid is left in the fabric, the polymer deposits unevenly and is largely plated on the surface of the fabric resulting in a rubbery hand and interfering seriously with uniform dyeing as well as other finishing operations to which the fabric may be subjected. Furthermore, the shrink resistance characteristic of such material is greatly inferior to the results obtained by following the procedure described in this example. However, if these precautions are taken the impregnated fabric after drying, in contradistinction to previously known deposition processes, has a soft hand and has a comparatively good shrinkresistance characteristic.

As hereinafter indicated, the deposition method of this example may be used with other polymeric substances and while the shrink resistance characteristic of wool fabrics treated by the deposition method and merely dried is normally not as good as is obtainable by simple impregnation with a stabilized latex as described in the preceding examples nevertheless when combined with the subse quent uniform treatment with a cystine linkage splitting agency such as sunlight or an appropriate artificial source of ultraviolet or the other after treatments hereinbefore and hereinafter described, the final shrink resistance characteristic is improved to such an extent that it is in some cases equal to that obtainable when the polymer is applied by my preferred impregnation process. There is always the objection, however, that the deposition type of process does not lend itself to the processing of the fabric on a continuous basis.

Example 7 v The following is an example of the application of my process to a quantity of acid dyed and finished Botany Worsted Saxony knitting yarn thoroughly wetted out with water and the excess removed so as to leave an amount equivalent to the dry weight of the wool. The yarn was then immersed and impregnated in an aqueous polymerized butadiene dispersion prepared according to Example 1, diluted to a solids content of and having a pH of 9 to 10, after which the excess polymer was removed to yield a pick-up of 6.5% by running the yarn through squeeze rolls. In this case the acidity of the wool resulting from the dyeing operation was neutralized by the alkalinity of the excess latex, but in cases where such acidity is higher than may be desired, the wool may be fully or partially neutralized by treatment with a solution of a soluble alkali such as ammonia. The yarn was 18 then dried and uniformly exposed for one hour to direct sunlight. A sweater knit from the yarn and subjected to the 5-hour wash test of Example 1 showed a total shrinkage of only 4% including relaxation.

Example 8 I have found that my invention is equally effective with heavier woolen goods as is demonstrated by its application to acid dyed and finished 5 pound woolen blanket stock. A quantity of such goods was thoroughly wettedout and treated in accordance with the technique of Example 7 to yield a pick-up of 8.2% polymer. Part of the treated goods was ironed on both sides with an iron heated to 410 F. and part was given a l-hour uniform exposure to direct sunlight on each side "with the following results in shrinkage after a 5-hour wash test as described in Example 1: A

In the preceding examples I have defined the degree of polymer pick-up in relation to the dry weight of the fabric. In the impregnation or padding technique the amount of polymer taken up by the goods is a function of the amount of moisture in the goods at the time of introduction into the impregnating bath, the per cent of polymer solids in the impregnating bath, the efficiency of displacement of the original moisture in the goods by the latex from the bath and the amount of excess latex removed by the final squeeze after final removal from the impregnating bath. Of these controlling factors it is preferred to maintain the efiiciency of displacement of the original moisture as close as possible to since this means, for an impregnating bath containing a given per cent of polymer solids, thoroughness of impregnation is insured and the ultimate pick-up can be easily controlled by the final squeeze prior to drying. Experience has shown that while the upper limit of the amount of polymer used in treating woolen fabrics is a matter of individual preference depending upon the type of hand and appearance desired, the lower limit required to achieve good shrink resistance assuming even and uniform coating and impregnation of the fibers by the polymer dispersion is primarily a function of the type of wool being treated and the amount and kind of processing that may have preceded the application of the polymer. For example, on the same type of woven fabric, a sample of goods which had been treated before dyeing was found to require less polymer in order to achieve a good shrink resistance characteristic than was required by a corresponding sample which had been dyed before treating. In

one case, it was found that where felting normally occurred in the dyeing operation this comparison was 6% polymer required for the undyed goods as compared to 10% polymer required by the dyed goods in order to yield a corresponding shrink resistance characteristic. On the other hand, it wasfound that the samefabric when treated with up to 18.6% polymer yielded an equally good shrink resistance characteristic but evidenced a slightly rubbery hand. 4

In Figure 4, curve A illustrates the relatively sharp break in the shrink resistance characteristic with decreasing amounts of polymer pick-up for a sample of Botany worsted flannel treated in a manner similar to Example 6 i. e. acid treated, the uncombined acid thoroughly rinsed out, impregnated and exposed to sunlight for one hour on each side, but not dyed, after having been submitted to the 5-hour wash tests described in that example. Curve B shows the corresponding result for a 16 /2 ounce fulled plain woven wool flannel when wetted out, impregnated dried and carbonized with sulphuric acid in accordance with Example 1+2, but not dyed. Following the carbonizing operation, the treated fabric was exposed uniformly to sunlight for 1 hour on each side, rinsed twice, dried, boiled for 1 hour in 612% sulphuric acid, rinsed and dried. Curve C shows the corresponding shrinkage results for a fabric identical with, and which has received the same treatment as, the fabric described in connection with curve B except that the original fabric in this instance was unfulled. Curve D gives a graphical representation of the shrinkage results on a worsted gabardine treated in the same manner as the fabrics described in connection with curves B and C.

Example 9 The eifect caused by the use of sunlight exposure as in Example 1 or by the use of an artificial ultraviolet source of radiation as in Example 2, as cystine linkage splitting agencies to effect bonding of the polymer to the fibers is not fully understood, but its efi'tect in bringing about a remarkable increase in the shrink resistance characteristic of the treated woolen goods and a remarkable decrease in solvent susceptibility is readily apparent from the examples heretofore and hereafter given.

I have found that other treating agencies which are known to have the capacity of splitting the disuifide group in the cystine linkage will bring about to a similar or lesser degree a corresponding increase in the shrink resistance and decrease in solvent susceptibility of polymer treated goods. For example, oxidizing agents of which i prefer water soluble peroxides, e. g. hydrogen eroxide, potassium persulphate, sodium perborate, etc, are suitable. A similar action in increasing the shrink resistance and decreasing the solvent susceptibility be obtained by treating the goods with ozone or air containing a reasonable concentration of ozone. in such cases the action is accelerated if the goods are in a moist in shrink resistance and decrease in solvent susceptibility and to a lesser degree ironing'with hot iron will yield the same effect. Exposure under infrared radiation is also eifective and need be only of short duration.

Some of these treatments which have been hereinbefore collectively referred to as treatment with a cystinc linkage splitting agency have been used alone or in combination in the preceding examples. in each case as demonstrated by the data given, the wash shrinkage resistance and the resistance to felting is surprisingly and unexpectedly increased even though the treatments were in many cases accompanied by agitation in high temperature baths and mechanical manipulation which would normally cause shrinking and felting to a substantial degree. Other advantages and rather remarkable results already noted have been the decreased solvent susceptibility and the increased aging resistance of the polymer treated goods as will further appear from examples given hereinafter.

In describing the treatment with ultraviolet light in the previous examples reference was made to the use of Westinghouse 31-1-9 ercury vapor tubes as an ultraviolet source. I have found also that the Hanovia Alpine Lamp having a spectral output from 1850 to 4080 Angstroms is very effective.

In order to illustrate the comparative results obtainable on a shrink resistance basis between exposure to sunlight or ultraviolet light as illustrated in Examples 1 to 8 and some of the other cystine linkage splitting agencies just discussed, an impregnated specimen of Botany worsted flannel was prepared in accordance with the padding technique of Example 2. The flannel was first wetted and the excess water removed so as to leave the goods carrying their own weight of water after which they were padded in an aqueous dispersion of polymer prepared in accordance with Example 1, diluted to a l0% solids content and having a pH of 9.5, the poly mer pick-up being so controlled that it amounted to 6% of the dry weight of the fabric. After drying, the fabric was cut into sections and treated as shown in the following table. The results of a Shout wash test (conducted in Example 1) on the treated specimens are shown opposite the respective samples.

Shrink go i l x d Treatment i H c percent.

Car No impregnation" 5t impre nated and dried only. as. 5 "mated, dried, and l-hont .nllhif,

std. l. lmpreg lamp xposnre on oaci side 2. 3 l and [r0 d 4.0 .d 5 minutes Infrared e at 1 hour in 10 V lllI'LltI F. for to h' Solo.

in order to illustrate the effect on the solvent susceptibility of the cystine linkage splitting agency treatment of the polymer treated fabric the following procedure was carried out using in one case a highly crossed linked insoluble butadiene polymer and in the other a highly soluble butadiene-styrene copolymer.

A quantity of uncarbonized ltfl/z ounce slightly alkaline, scoured and fulled wool was freed fro i solvent soluble matter by extraction three tin es with low boiling naphtha and dried. Following the cedure of Example 1, the fabric was wetied out and impregnated with a fully stabilize-d latex of polymerized butadienc having a Mooney plasticity valu of i013 and diluted to a solids content of 10% of which 9% was polymer solids. The latex solids pickup on the fabric was determined by calculation to be 4.9 and the polymer picl' .ip to be 4.4%. The fabric was dried at 75 C. to set the polymer and different samples from the piece were given the treatment indicated below after which they Jere extracted for 16 hours continuously in a modified Soxhlet extractor with trichlorethylene and the percent of polymer remaining in the fabric calculated from the extract. in each case the polymer remaining on the fabric in the extractor thimbles was in the form of a swelled gel.

As a comparison, a thin film of the same polymer latex was spread on each of two supporting pieces of aluminum foil and dried at 75 C. Gne ample was then exposed to the same intensity of ultraviolet irradiation as in the case of the fabric sample #3 below, i. e., 20 minutes, and the other sample was left unexposed. The films were then stripped off the supporting pieces of foil and extracted for 16 hours continuously in the same modified Soxhlet extractor with trichlorethylene. in both cases the extraction thimbles were full of swelled gel although the exposed gel was somewhat less swelled than in the case of the unexposed. The less swelled condition of the gel for the exposed sample is as would be anticipated, in view of the known fact that continued exposure of rubber to ultraviolet radiation causes degradation followed by crosslinking.

Percent Sample Treatment Polymer Dissolved Polymer Latex Film 0 Do n O 1gelrcent II;1ercent o ymer crease 5,2 3 Treatment Remaindue to ing on Bonding Fabric 1 Action 1 #1 Impregnated and dried 41 #2 Impregnated and dried plus 1 hour 58 17 boil in 0.2% H2804 solution, dried. #3 Impregnated and dried plus 10 min- 70 29 uties ultraviolet radiation on each s1 e. #4 Impregnated and dried plus carboni- 77 36 zation with 2% H2804 solution follnved by a bake of 30 min. at 125 #5 Impregnated and dried plus carboni- 84 43 zation and irradiation. #6 Impregnated and dried plus carboni- 86 45 zation, irradiation and acid boil in 0.2% H2804, dried.

1 Based on original percent of polymer on fabric.

The insolubility of the unexposed and exposed polymer films supported on the aluminum foil shows that this particular polymer was essentially all cross linked during polymerization. The extract value obtained in the case of wool sample #1 also demonstrates the surprising phenomenon which I have discovered namely that even in the case of highly cross-linked and so called insoluble polymers which are simply set on the wool fibers, the polymer is largely extractable with an active organic solvent due to its lack of any bond on the fibers. On the other hand, the low extract values for the wool fabric samples which have been fully treated with the cystine linkage splitting agencies heretofore described illustrate the low solvent susceptibility and bonding effect caused by treatment with such agencies.

A similar experiment was carried out using a highly soluble copolymer of 73% butadiene and 27% styrene which was less highly cross-linked than the above 100% butadiene polymer and which had a Mooney plasticity value of 52. The latex was fully stabilized by the addition of 1.5% Agerite stalite and 5% sodium oleate based on the solids, the final solids content being 21.1%. This was diluted to a solids content of 10.5% and further stabilized by raising the pH to 10.5 for impregnating the wool fabric with a calculated pick up of 6%. By preparing the same samples both of polymer impregnated wool and of simple films and extracting as above, the following results were obtained:

Percent Sample Treatment Polymer Dissolved Copolymer Latex Film None 89 Do Irradiated 20 minutes... 91

IIjelrcent IPercent o ymer ncrease 5 2 Treatment Remaindue to p ing on Bonding Fabric 1 Action 1 #1 impregnated and dried 0 #2 Impregnated and dried plus carboni- 26 26 zation in a 2% H2804 solution folliwed by a bake of 30 min. at 125 Impregnated and dried plus 1 hour 43 43 boil in 0.2% H2304 solution, dried. Impregnated and dried plus 10 min- 58 58 ujgzs ultraviolet irradiation on each si e. Impregnated and dried plus carboni- 58 58 zation, irradiation and acid boil (0.2% H2804), dried.

1 Based on original percent of polymer on fabric.

This experiment demonstrates that a highly soluble polymer undergoes the same bonding effect noted above.

I have found it to be a fact that in all cases where the polymeric substance used to impregnate the wool fabric is a sulphur vulcanizable unsaturated polymer, the solvent resistance of the polymer coating on the fibers is substantially increased. This is not only true of the butadiene polymers referred to in Examples 1-8 inclusive, but is also true with respect to natural rubber, various other polymers and copolymers of butadiene as well as polymerized derivatives and polymerized homologues of butadiene, copolymers of butadiene with its derivatives or homologues and copolymers of butadiene or its derivatives or homologues with vinyl compounds. As examples of the improved solvent resistance in respect to some other illustrative sulphur vulcanizable unsaturated polymers and copolymers including natural rubber, the polymeric substances listed in the following table have been tested in accordance with the procedure described immediately above in this example, the only difference being that the latex baths used were diluted to a somewhat diflerent degree to give a calculated pick-up of 2.5 to 3.5% latex solids. The increase in solvent susceptibility (bonding effect) due to treatment with a cystine linkage splitting agency was as indicated in the table.

1 Based on original percentage of polymeric substance on fabric: 16 hour Soxhlet extraction in trichlorethylenc.

The foregoing illustrates the great improvement in bonding effect (increased solvent resistance) resulting from treatment with the cystine linkage splitting agency. A further advantage by way of an improved physical characteristic is the greatly increased aging resistance which accrues as a result of the treatment to bond the polymer to the fiber. This is demonstrated by the following simple tests.

The technique and the latex dispersion of Example 1 was used except that the latex was further stabilized by addition of 2% by weight of Santo White (Monsanto) in the form of an emulsion. This is a dialkyl phenol sulphide, a non-discoloring antioxidant. A 10 /2 ounce, scoured, fulled, slightly alkaline and wetted flannel was used with a pick-up of 5% of polymer on the goods. After drying, carbonization, irradiation for 10 minutes on each side, and a one hour boil in 0.2% sulphuric acid solution a sample was artifically aged in a circulated air oven at 240 F.

The sample showed no particular aging after 160 hours of such treatment whereas a control sample which was the same in all respects, but received no after treatment, i. e., carbonization, irradiation and acid boil, failed completely (became hard and stiff) after thirty hours.

The foregoing procedure, when repeated without the addition of the 2% of Santo White, yielded a sample which showed no appreciable aging after hours in the-240 F. circulated air oven whereas the control sample which had received no after treatment failed at 22 hours.

Example 10 The following example illustrates the fact that for the purpose of controlling the shrinkage of wool products treated in accordance with my process, the after treatment with the various cystine linkage splitting agencies above carbonization, irradiation and acid boil treatments (1 hour boil in 0.12% aqueous solution of sulphuric acid followed by a rinse) in various order as indicated in the following table, one set being irradiated by exposure to direct sunlight for 1 hour on each side and the other set being irradiated by exposure to the output of the Hanovia Alpine lamp for 5 seconds on each side. The relatively minor variation in the shrink resistance characteristic of the two sets of samples is also given in the following table.

A B C D E F Order of treatment:

Impregnation 1 1 1 1 1 1 Drying 2 2 2 3 2 Carbonization 3 4 3 4 3 4 Exposure 4 3 6 2 2 5 Acid boil and rinse 5 5 4 5 4 3 Dry 6 6 5 6 5 Shrinks In the following Examples 11 and 12, i will refer to specific polymer formulations suitable for use in carrying out the process of my invention. As heretofore pointed out, the increased shrinl; resistance characteristic of wool products resulting from the use of my improved method of treating wool products with a fully stabilized emulsion, and the further improvement in shrink resistance, solvent resistance or aging resistance resulting from the use of my preferred treatment with a cystine linkage splitting agency is not always fully determinative of the choice of polymeric substance to be used. While the characteristics of stickiness, oiliness, harshness, and boardiness may be unobjectionable in some cases insofar as utility of the treated woolen fabric is concerned, a good shrink resistance characteristic without loss of hand is much to be preferred and, accordingly, for most purposes and particularl for fabrics intended for apparel I prefer to avoid excessively soft or plastic polymers or polymer systems which give rise to an oily or tacky hand or conversely excessively hard polymers which tend to give a harsh boardy hand. Where there is likelihood that the final trea ed and finished fabric may be submitted to dry cleaning as practiced in ordinary commercial dry cleaning establishments, I prefer to use a polymer which in itself has a low solvent susceptibility. This property can readily be obtained by cross linking during the polymerization, a procedure which is well understood in the synthetic rubber art. However, as heretofore indicated, it has been found that where the irradiation and alternative treatments with a cystine linkage splitting agent are used they operate in any event to lower the solvent susceptibility of the polymer in the fabric to a point where ordinary dry cleaning with organic solvents has no undesirable effect even though the original polymer may have had a substantial solvent susceptibility.

The use of various emulsifying agents, modifiers, pI-l adjusters, buffers and catalysts in the preparation of polymers suitable for use in carrying out my invention being generally well known, it is believed that the illustrative preparation described in Example 1 together with the following additional formulations will serve to fully demonstrate the principles involved. As a general mat ter, it will be understood that the variables just mentioned are so controlled along with the temperature and time of reaction as to promote the formation of fully stabilized emulsions in which the polymer is neither excessively soft or plastic nor excessively hard. After completion of polymerization, a suitable quantity of antioxidant dispersion is added. In addition to the heptylated diphenyl amine used in Example 1, I have found other antioxidants such as the monobenzyl ether of hydroquinone, phenyl e naphthyl amine and the low temperature condensation product of acetone and diphenyl amine to be suitable. It is preferred to use a non-discoloring antioxidant such as the heptylated diphenyl amine or monobenzyl ether of hydroquinone just mentioned. In this connection I have found it to be advisable to exercise precautions to avoid the incorporation or contamination with products which may act as oxygen carriers and thus permit a catalytic eifect in bringing about a continuing oxidation of the polymer leading eventually to polymer resinification as manifested by stiffening or hardening of the treated fabric or alternatively polymer degradation as manifested by the development of a tacky hand. This phenomenon is well understood in the rubber art. Among products to be avoided as materials which tend to promote such undesirable changes are polymer soluble compounds of copper, iron, manganese and chromium. Such products may exert a seriously detrimental effect even when present in concentrations as low as 25 parts or less of metallic content per million of polymer. As a specific precaution to be observed, it is desirable when working with metalized dyes or chrome mordanting procedures to determine on a small scale whether or not such dyes or mordanting procedures act to cause the detrimental effect here described.

if necessary, and as already described, in order to fully stabilize the latex chemically and mechanically against material aggregation, agglomeration, flocculation or coagulation in the bath or in the goods during impregnation, I may add in addition to the antioxidant a suitable quantity of a suitable stabilizer or stabilizers such as the sodium oleate or Daxad 11 which were added to the emulsion following completion of the polymerization in Example 1. As a further variant the stabilizer might be added to the fabric by itself or along with the wetting out bath as heretofore indicated.

The need for such additional stabilizer. may be empirically determined in each case the only requirement being that the latex dispersion should be completely stable both chemically and mechanically in the presence of the woolen fabric to be treated and under the conditions of treatment in order to obtain the uniform and thorough impregnation which I have found to be important in carrying out my invention; and in the case where the wool to be treated carries combined but no free acid, as in Example 6, the stability should be such that deposition will take place only in situ on the fibers carrying such combined acid. I have found that the amount of stabilizer needed to thus fully stabilize the is substantially in excess of the amount that would be needed to produce and maintain such a latex dispersion stable in the absence of the wool or the mechanical action incident to impregnation. As a variation of Example 1, l have found that either the sodium oleate or the Daxad ll may be used alone or in combination and in fact any compatible natural or synthetic protective colloid will serve the purpose. As examples of alternative stabilizers, the water soluble salts of such compounds as alkylated naphthalene sulphonic acids, long chain aliphatic alcohol sulphates, casein, rosin, disproportionated rosin, or hydrogenated rosin may be mentioned.

In certain cases where desired, I may further stabilize the latex by the addition of an alkali to adjust the pH to a desired value which I have found may range from slightly above where the latex dispersion becomes unstable under the conditions of application to the point at which the alkalinity of the treating bath gives rise to tenderization of the wool and consequent loss of strength.

Example 11 As a further illustration of specific polymer formula- 25 tions which I have found to be suited for use in carrying out my invention, reference may be had to the following: Using a jacketed, pressure vessel equipped with a suitable agitator as in Example 1, the following charge was loaded and reacted at 50 C. with constant agitation.

The reaction was permitted to proceed until there had been a 77% conversion of the monomeric butadiene into the polymerized form (about 15 hours) whereupon a quantity of a short stopper such as hydroquinone (0.08 part based on the latex solids) was added to stop the reaction short of completion. After steam stripping to remove the unreacted monomer the resulting polymer which was less highly cross linked than in Example 1, was found to have a Mooney plastometer value of 71. An antioxidant, 1.5 parts (based on latex solids) of Agerite Stalite was then added and the resulting aqueous dispersion was adjusted to a pH of 10.5 and used to impregnate a quantity of thoroughly wetted-out, slightly alkaline woven woolen fabric as in Example 1. In this case, the aqueous dispersion as above prepared was found to be completely stable in the presence of the woolen fabric without the addition of any further stabilizing agents. After drying, it was found that the fabric had retained 7.4% of its dry weight of polymer. After immersing the fabric in a 2% sulphuric acid solution at 90 F. for 15 minutes it was rinsed, run through squeeze rolls, dried and exposed to the direct rays of the sun for one hour on each side, as in Example 1, samples taken from the quantity of fabric at various stages showed the following results:

Wash Test As In Stage Example 1 Hand Original fabric Shrinkage 34.8% Impregnated and dried Not tested Soft and sticky. Impregnated, dried, acidified, 3.8% Good.

rinsed, dried and exposed.

The same latex dispersion having a pH of 10.5 except with the further addition of 5 parts (based on latex solids) of sodium oleate as a stabilizing agent, was used to impregnate a quantity of a wetted-out slightly alkaline woolen fabric in the same manner and with a polymer pick-up on the fabric of 8.7% of its dry weight, gave the following results:

Wash Test As In Stage Example 1 Hand Original fabric Shrinkage 34.8% impregnated and dried Not tested Sofs, ksomewhat s y. Impregnated, dried, acidified, 2.5% Good.

rinsed, dried and exposed.

Example 12 Using the same apparatus and reaction temperature as in the immediately preceding example, the following 26 charge was reacted to the point of 77% conversion (about 13 hours.)

Parts Butadiene 1-3 (freed from inhibitor) Styrene 5 Potassium soap of disproportionated rosin 4.6 Dodecyl mercaptan 1.05 Potassium persulphate 0.5 Sodium hydroxide 0.11 Water Wash Test As In Stage Example 1 Hand Original fabric Shrinkage 34.87 Impregnated and dried Not tested. Soft, very sticky. Impregnated, dried, acidified, 1.8% Good.

rinsed, dried and exposed.

The same latex dispersion having a pH of 10, except with the further addition of 5. parts of sodium oleate as a stabilizing agent, when used to impregnate a quantity of a wetted-out slightly alkaline woolen fabric in the same manner and with a polymer pick-up of 7.5% of the dry weightof the fabric, gave the following results:

Wash Test As In Stage Example 1 Hand Original fabric Shrinkage 34.8%... Impregnated and dried Not tested Soft, k slightly stic y. Impregnated, dried, acidified, 1.25% Good.

rinsed, dried and exposed.

Here, as in the preceding example, the addition of the sodium oleate makes it unnecessary to prewet the fabric unless desired.

Example 13 Where desirable, I may replace the soap type emulsifying systems used in the polymerization formulations by other protective colloids giving rise to latices which have improved stability toward chemical coagulation. Thus for example, I have replaced the 6 parts of sodium oleate in the formula of Example 1 with a combination of 4 parts of Daxad 11 and 0.75 part of sodium lauryl sulphate. No addition of stabilizer was made to the finished latex. After addition of the anti-oxidant emulsion the latex had a pH of 6.2. The Mooney value of the dry polymer was 84.

12 /2 ounce thoroughly wetted-out slightly alkaline woolen flannel which had been scoured and fulled was impregnated with the diluted latex as in Example 1 to yield a pick-up of 8.2%. The dried fabric was uniformly exposed to the direct rays of the sun for 3 hours on one side and 1 hour on the other after which it was washed as in Example 1, but for a period of 7.5 hours.

The comparative shrinkage results on the relaxed basis were:

Example I 4 The following table gives a number of illustrations of sulphur vulcanizable unsaturated polymeric substances which I have found to be suitable for use in my improved treating process. Polymerization of the monomer systems listed were carried out in a manner analogous to that described in Examples 11 and 12 and the Mooney value for the polymer or copolymer is indicated in the table.

Monomer System gigg butadiene 100%, styrene 110 butadiene 90%, styrene 135 butadiene 80%, styrene 85 butadiene 73%, styrene 27%. 50 butadiene 70%, styrene 30%. 10 butadiene styrene 50 54 butadiene 50%, styrene 50%. 20 butadiene 30%, styrene 200 butadiene 30%, styrene 70%..... 46 butadiene 85%, Cl. styrene 15%-.. butadiene aerylenitrile 15% 54 butadiene 85%, vinyl chloride 15%-.." butadiene 85%, methyl pentadiene 15%. 87 butadiene 20%, methyl peutadiene 80%.- 2 butadiene 85%, isoprene 15% 128 butadieue 80%, styrene 10%, methyl methacrylate 10%... 60 butadiene 85%, methyl methaerylate 5% 146 butadiene 80%, styrene 10%, acrylonitrile 10% 200 butadiene 0%, isoprcne 81 All of these formulations, when used in the form of an aqueous dispersion and applied in accordance with the technique described in Example 1 to impregnate various woolen fabrics ranging from Botany worsted fiannel to 10 /2 oz. plain woven flannel and 12 /2 oz. twill flannel Were found to give excellent results by way of a greatly improved shrink resistance characteristic after the fabric had been impregnated in accordance with the padding technique and subsequently dried to set the polymeric substance on the fibers. In all cases, this improved shn'nk resistance characteristic was further improved by treatment with a cystine linkage splitting agency such as irradiation with sunlight or ultraviolet light with or without a preceding or subsequent treatment at an elevated temperature in a sulphuric acid solution. In many cases, the hand of the fabric was entirely satisfactory from the standpoint of stickiness, oiliness, tackiness or boardiness after the simple treatment in which the polymeric substance was simply set on the fibers by drying. In other cases, where the hand of the fabric was slightly sticky, or slightly stiff, after the simple treatment just mentioned, this undesirable hand had substantially or entirely disappeared after further treatment with a cystine linkage splitting agency or agencies.

While I have illustrated the utilization of my improved method for treating textile products with particular reference to wool products composed entirely or substantially entirely of wool fibers, it will be understood that the process is equally applicable to wool products composed of a mixture of wool fibers and other fibers such as cotton or synthetic fibers. In such case, the choice of procedure must, of course, be governed by the fiber makeup of the goods, for example, where vegetable fibers are iixed with Wool fibers, one would naturally avoid the use of the carbonization procedure or other acid treatments which might tenderize such vegetable fibers. It will also be understood that where the preferred embodiment of my invention in which the polymeric substance is bonded to the fibers, is not utilizable because of the fibers being unresponsive to treatment with a cystine linkage splitting agency, nevertheless the treatment utilizing a fully stabilized aqueous dispersion to obtain even, thorough, and uniform impregnation of a textile product with a polymeric substance is applicable to produce a treated textile product having improved characteristics growing out of such even, thorough and uniform impregnatien.

28 I claim:

1. The method of treating a wool product which comprises impregnating said product uniformly and throughout with an aqueous dispersion of a sulphur vulcanizable unsaturated polymeric substance, then setting said polymerie substance on the fibers of said product by drying, and bonding said polymer to said fibers by uniform treatment with a cystine linkage splitting agency.

2. The method of treating a wool product which comprises impregnating said product uniformly and throughout with an aqueous dispersion of a sulphur vulcanizable unsaturated polymeric substance, treating said impregnated product with an aqueous solution of an acid at an elevated temperature, drying, and bonding said polymer to the wool fibers by uniform treatment with a cystine linkage splitting agency.

3. The method of treating a wool product which comprises impregnating said product uniformly and throughout with an aqueous dispersion of a sulphur vulcanizable unsaturated polymeric substance, and bonding said polymer to the wool fibers by uniform treatment with ultra violet irradiation.

4. The method of treating a wool product which comprises impregnating said product uniformly and throughout with an aqueous dispersion of a sulphur vulcanizable unsaturated polymeric substance, treating said impregnated product with an aqueous solution of an acid at an elevated temperature, drying, and bonding said polymeric substance to the wool fibers by uniform treatment with ultra violet irradiation.

5. The method of treating a wool product which comprises immersing the wool product in a bath of an aqueous dispersion of a sulphur vulcanizable unsaturated polymeric substance, which dispersion is stable in the presence of said product to an extent sufficient to permit uniform impregnation throughout the product without any substantial fixing of said polymeric substance on the fibers of said product, removing the impregnated product from said bath, expressing any excess of the aqueous dispersion from said impregnated product, then drying said impregnated product to set said polymeric substance on the fibers of said product, and then bonding said poly meric substance in the impregnated product to the wool fibers by a uniform treatment with a cystine linkage splitting agency.

6. The method of treating a wool product which comprises immersing the wool product in a bath of an aqueous dispersion of a sulphur vulcanizable unsaturated polymeric substance, which dispersion is stable in the presence of said product to an extent sufficient to permit uniform impregnation throughout the product without any substantial fixing of said polymeric substance on the fibers of said product, removing the impregnated product from said bath, expressing any excess of the aqueous dispersion from said impregnated product, then fixing said polymeric substance on the fibers of said product and then bonding said polymeric substance in the impregnated product to the wool fibers by a uniform treatment with a cystine linkage splitting agency.

7. The method of treating a wool product which comprises immersing the wool product in a bath of an aqueous dispersion of a sulphur vulcanizable unsaturated polymeric substance, which dispersion is stable in the presence of said product to an extent sufficient to permit uniform impregnation throughout the product without any substantial fixing of said polymeric substance on the fibers of said product, removing the impregnated product from said bath, expressing any excess of the aqueous dispersion from said impregnated product, then fixing said polymeric substance on the fibers of said product and then bending said polymeric substance in the impregnated product to the wool fibers by a uniform treatment with a cystine linkage splitting agency, said treatment with said, agency being continued until the shrink resistance imparted to said product is increased to such a value that further treatment with said agency will not cause 29 I more than a substantially inconsequential increase in shrink resistance of said product.

8. The method of treating a wool product which comprises impregnating said product uniformly and throughout with an aqueous dispersion of a sulphur vulcanizable unsaturated polymeric substance, which dispersion is stable in the presence of the product to an extent sufficient to permit such impregnation uniformly and throughout without any substantial fixing of said polymeric substance on the fibers of said product, then drying said impregnated product to set said polymeric substance on the fibers of said product, and bonding said polymeric substance to the wool fibers by uniform treatment with an aqueous solution of an acid at an elevated temperature.

9. The method of treating a wool product which comprises impregnating said product uniformly and throughout with an aqueous dispersion of a sulphur vulcanizable unsaturated polymeric substance, which dispersion is stable in the presence of the product to an extent sufficient to permit such impregnation uniformly and throughout without any substantial fixing of said polymeric substance on the fibers of said product, then drying said impregnated product to set said polymeric substance on the fibers of said product, and bonding said polymeric substance to the wool fibers by uniform treatment with a 0.1 to 25% aqueous solution of sulphuric acid.

10. The method of treating a wool product which comprises impregnating said product uniformly and through out with an aqueous dispersion of a sulphur vulcanizable unsaturated polymeric substance, which dispersion is stable in the presence of the product to an extent sufficient to permit such impregnation uniformly and throughout without any substantial fixing of said polymeric substance on the fibers of said product, then drying said impregnated product to set said polymeric substance on the fibers of said product, and bonding said polymeric substance to the wool fibers by uniform treatment with infrared irradiation.

11. A wool product comprising wool fibers uniformly coated with a sulphur vulcanizable unsaturated polymeric substance bonded to said fibers by a uniform treatment with a cystine linkage splitting agency, the bond between said polymeric substance and the wool fibers being of such nature that a substantially greater proportion of said polymeric substance is retained on said wool product after a sixteen hour Soxhlet extraction with a solvent for said polymeric substance than upon a similar wool product having said polymeric substance set upon the fibers thereof by a process consisting of impregnating the wool product with an aqueous dispersion of said polymeric substance and drying the impregnated product, said wool product having a marked increase to shrinkage resistance over a similar wool product having said polymeric substance set upon the fibers thereof by a process consisting of impregnating the wool product with an aqueous dispersion of said polymeric substance and drying the impregnated product.

References Cited in the file of this patent UNITED STATES PATENTS 1,240,116 Bernstein Sept. 11, 1917 1,242,586 Ostromislensky Oct. 9, 1917 1,958,821 Haarburger May 15, 1934 1,967,275 Williams July 24, 1934 1,967,863 Collins July 24, 1934 2,050,595 Wolfe Aug. 11, 1936 2,447,539 Rust Aug. 24, 1948 2,447,540 Rust Aug. 24, 1948 2,447,772 Rust Aug. 24, 1948 2,499,653 Kropa Mar. 7, 1950 2,622,996 Cohen Dec. 23, 1952 2,642,332 Cohen June 16, 1953 FOREIGN PATENTS 727,359 Germany Nov. 2, 1942 OTHER REFERENCES Hattinger: Textile Chemistry of Sulfites, Am. Dyestufit' Reporter, Nov. 16, 1936, pp. 609-612.

Claims (1)

1. THE METHOD OF TREATING A WOOL PRODUCT WHICH COMPRISES IMPREGNATING SAID PRODUCT UNIFORMLY AND THROUGHOUT WITH AN AQUEOUS DISPERSION OF A SULPHUR VULCANIZABLE UNSATURATED POLYMERIC SUBSTANCE, THEN SETTING SAID POLYMERIC SUBSTANCE ON THE FIBERS OF SAID PRODUCT BY DRYING, AND BONDING SAID POLYMER TO SAID FIBERS BY UNIFORM TREATMENT WITH A CYSTINE LINKAGE SPLITTING AGENCY.

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