US3466136A - Shrinkproofing of wool - Google Patents

Description

United States Patent 3,466,136 SHRINKPROOFING OF WOOL William L. Wasley, Berkeley, Robert E. Whitfield, Pleasant Hill, and Lowell A. Miller, Walnut Creek, Calif., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Filed Mar. 17, 1964, Ser. No. 352,700

Int. Cl. D06m 3/06 US. Cl. 8127.5 12 Claims A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to and has among its objects the provision of novel methods for treating textile materials, particularly wool, to achieve shrinkproofing and other desirable effects. Further objects and advantages of the invention will be evident from the following description wherein parts and percentages are by weight, unless other wise specified.

In the patent of Miller, Whitfield, and Wasley (3,078- 138, granted Feb. 19, 1963) there are disclosed processes combined therewith. In a typical embodiment of their process, a wool fabric is serially impregnatedwith two solutions--the first being a solution of a'diarnine in water, the second being a solution of a diacid chloride in a waterimmiscible, volatile, inert solvent. By such treatment the fibers are coated with superposed layers of the mutually} insoluble solutions: an inner layer of diamine in water and an outer layer of diacid chloride in water-immiscible solvent. Under these conditions the diamine and diacid chloride react almost instantaneously at the interface between the phases, producing in situ on the fibers a highmolecular weight, resinous polyamide which coats the fibers and renders the fabric shrinkproof without detriment to the hand, porosity, and other valuable properties of, the fabric. Moreover, the polyamide is chemically .hdnded to the wool so that the shrinkproofing effect is highly durable, i.e., the polyamide deposit is not removed by repeated washing of the treated fabric in conventional soap and water or detergent and water laundering formulations, or in conventional dry-cleaning formulations. From a procedural standpoint, the process has the advantage of simplicity and rapidity in that the basic operation is simply a serial impregnation of the fabric in the two solutions. Another point is that the process does not re- 3,466,136 Patented Sept. 9, 1969 ice attained without any degradation or weakening of the fibers. Moreover, such important characteristics of the fiber as hand, porosity, resiliency, etc. are not harmed. On the other hand, in conventional setting procedures involving the application of reducing agents per se to wool textiles, a weakening of the fibers is an invariable sideeffect. A further advantage of the process of the invention is that the setting is attained Without detriment to the desired shrinkproofing effect. As a matter of fact, our investigations have shown that a better shrinkproofing elfect is attained for a given amount of polymer formed on the wool fibers. It is thus evident that the use of a reducing agent in conjunction with the aforesaid interfacial polymerization system unexpectedly provides a synergistic effect.

For use in the process of the invention, a preferred class of reducing agents comprises the inorganic salts which provide sulphide ions in aqueous: solution. Typical of this class are the alkali metal, alkaline earth metal, ammonium, etc. sulphides and hydrosulphides. Another very useful class of reducing agents comprises the organic compounds containing a thiol group, as, for example,

thioglycollic acid, or its salts such as the alkali metal or ammonium salts; beta-mercapto ethanol; monthio glyt cerol; .dithio-glycerol; butyl mercaptan; thiornalic acid or its, salts; .thio-lactic acid or its salts; thiophenol; thiocresol;

" .jetrijother reducing agents which may be used are listed below by way of illustration: Formamidine sulphinic acid, also known as iminoaminomethane sulphinic acid betaine. Formaldehyde sulphoxylates, generally used in the form of their alkali metal, zinc, or ammonium salts. Alkali metal or ammonium sulphites, bisulphites and hydrosulphites. Aldehyde or ketone addition products with sulphites or bisulphites, e.g., sodium formaldehyde bisulphite, sodium acetone bisulphite, etc. Generically, the reducing agents used in accordance with the invention may be defined as sulphur-containing, reductive, disulphidesplitting agents because of the fact that they all contain sulphur in their structures and because they have the ability to open the disulphide (cystine) linkage in the wool molecule, generally converting a single disulphide (SS) bond into'two thiol (-SH groups.

The amount of reducing agent is not critical and may be varied depending on such circumstances as the efficacy of the agent selected, the durability of set desired in the product, the character of the fibers being treated, etc. Even minute amounts of the reducing agent will provide some degree of improvement over the known techniques.

- Usually, the reducing agent is used in an amount from quire any heat curing of the treated fabric as is commonly necessary in most resin shrinkproofing procedures.

In accordance with the present invention, the basic principles of the aforesaid processes are applied in conjunction with the use of certain additives (to the treatment solutions) whereby to achieve advantageous results over and above those attained by the patented procedures.

One phase of the invention involves the addition of a reducing agent to one of the complementary treating solutions, preferably to the diamine solution. A primary advantage obtained thereby is that when the Product is subsequently subjected to a conventional setting treatment (heating while constrained in a predetermined shape), it acquires a permanent set. Accordingly, when the fabric or garments made therefrom are subjected to such stresses as crushing, folding, or use in the rain or other humid conditions, they remain essentially free from wrinkles or creases. Moreover, this set is maintained even when the material is subjected to repeated washing or dry cleaning. Another advantage is that such desirable setting effect is about 0.1 to 5 parts per part of diamine in the treating solution. To avoid possibility of degradation of the textile material when it is contacted with the treating solution, it is generally preferred to limit the maximum concentration of the reducing agent to less than 0.5 molar, preferably not more than about 0.2 molar. For best results it is preferred to use the reducing agents in. conjunction with an alkaline agent to raise the pH of the solution of reducing agent plus diamine to a level of about 12 to 13. With some of the reducing agents, such as the alkali metal sulphides, additional alkaline material will not usually be necessary because of the strongly basic character of the sulphides. With other reducing agents such as )8- mercaptoethanol, thioglycollic acid etc, one may addadditional alkaline material such as an alkali metal hydroxide, carbonate, or, more preferably, an alkali metal metasilicate or dithiocarbamate. The advantages to be gained from such compounds are explained hereinbelow in connection with another phase of the present inven- O and (2) diacid chloride in water-immiscible solvent, a polyamide resin is formed and this resin is chemically bonded (grafted) to the Wool, to a greater or lesser extent, depending on the conditions of reaction. It is postulated that when a reducing agent is present in the environment, reactive sites are opened up in the wool molecules-fr example, through splitting of disulphide linkages. The resulting free thiol groups are then available for combination with acid chloride or other reactive groups. Since the said reactive sites are added to those already present, it is believed that the resin is grafted to the wool to a greater extentthe resin is more tightly locked to the wool fibers and thus the shrinkage protection is more effective and more resistant to removal by repeated washing.

In a typical practice of the present invention, the procedure of Patent 3,078,138 is employed with, of course, the change that the reducing agent is added. Thus the textilein the form of garments, fabris, yarn, roving, top, etc.-is entered into an aqueous solution containing a diamine plus the reducing agent. After the textile has been impregnated with this solution it is pressed to remove excess liquid. Then, it is impregnated with the second solution, for example, a solution of a diacid chloride in a volatile, inert, Water-immiscible solvent. After another pressing to remove excess liquid, the textile is washed in warm water containing a small proportion of a soap or synthetic detergent and rinsed in order to remove unreacted materials and particles of resinous reaction product which are not firmly attached to the textile fibers. Following this, the textile is dried and then treated to establish the permanent set. This is done in conventional manner and simply involves arranging the material in a desired pattern and applying heat while constraining it in such pattern. For example, if a fiat set is desired (as in the case with ordinary yardage) the product is subjected to a standard semi-decating procedure. This involves winding the fabric, sandwiched between smooth cotton cloth, onto the hollow, perforated shaft of the semi-decater device. Steam is then caused to flow into the shaft, through the perforations, and through the layers of wound-up fabric. After such steaming for a few minutes, the supply of steam is cut off and the hollow shaft is connected to a source of vacuum to draw air through the fabric layers and so cool them. It is obvious that if-it is desired to set the fabric in a pattern other than a fiat one, one can apply other conventional setting techniques. For example, to form the material into pleats it may be folded into the desired arrangement of pleats and the resulting package of pleated material tied into a bundle and placed in a chamber where it is steamed to set the fabric in the pleated arrangement. It is obvious from the above that one can use any of the conventional systems which involve arranging the material in a predetermined physical configuration and, while holding in such state, subjecting it to heat applied by the use of live steam, hot platens or rollers etc. Such systems are, of course, well known in the art and the inventors herein claim no novelty in such procedures, per se. Moreover, since the invention provides useful advantages, e.g., improved shrinkproofing, whether or not a setting treatment is applied, it is within the ambit of the invention to apply reducing agents as described hereinabove in a tool system where no setting treatment is applied.

In accordance with another phase of the present invention, the basic principles of the aforesaid Miller et al. process (3,078,138) are applied in conjunction with certain additives-a silicate or a dithiocarbamate-whereby to achieve advantageous results over and above those obtained by the patented procedures. Thus, it has been obserbed that by addition of a silicate or a dithiocarbamate to the treating solutionspreferably to the diamine solution-an enhanced shrinkproofing effect is attained. For a given amount of polymer formed on the fibers a greater degree of shrinkage protection is obtained. Also, it has been found that the additives yield products with a better hand. Moreover, these valuable advantages are attained without any detriment to the fibersthere is no degradation or weakening of the fibers nor reduction in porosity or resilience of the treated material. As the silicate, sodium metasilicate is preferred. However, other alkali metal silicates may be used, for example, alkali metal metasilicates, ortho silicates, or any of the molecularlydehydrated silicates, or polysilicates as they may be termed, such as Na Si O Na Si O Na Si O etc. As the dithiocarbamate, we prefer to use ethylene bis-(sodium dithiocarbamate) which has the formula s s NaSi 1N H-CHz-CHz-NH-iL-S-N a As well known in the art, dithiocarbamates are prepared by reacting a primary or secondary amine with carbon bisulphide in the presence of a base such as sodium hydroxide whereby a hydrogen atom attached to nitrogen is replaced by the radical In the process of the invention one can use any of such compounds, derived, for example, from aliphatic, aromatic, or heterocyclic amines, wherein at least one hydrogen atom attached to nitrogen is replaced by the group (wherein M is a metal such as an alkali metal). Typical of the compounds which may be used are propylene bis- (sodium dithiocarbamate), tetramethylene bis-(sodium dithiocarbamate), paraphenylene bis-(sodium dithiocarbamate), piperazine bis-(sodium dithiocarbamate), sodium ethyl dithiocarbamate, sodium phenyl dithiocarbamate, sodium piperidyl dithiocarbamate, etc.

The amount of the agent (silicate or dithiocarbamate) is not critical and may be varied depending on such circumstances as the efiicacy of the agent selected, the character of the fibers being treated, the degree of improvement in shrinkproofing desired, etc. Even small amounts of the agents will provide some degree of improvement over the known techniques. The agents in question are strongly alkaline and are usually used in such amount as to raise the pH of the diamine solution to above 12. At this point it may be mentioned that Miller et al. (3,078,138) advocate addition of an alkaline agent-such as alkali metal hydroxide or carbonate-to the diamine solut1on to act as an HCl-acceptor, that is, to take up the hydrogen chloride formed in subsequent reaction of the diamine with the diacid chloride. However, in accordance with the present invention, it is not just a matter of HCl-acceptance. Although the agents used herein are alkaline substances, they provide results over and above anything which could be attributed to their mere alkalinity. For example, addition of sodium carbonate in amount adequate for HCl-acceptance does not yield the results obtained as described herein when, for example, sodium metasllicate or ethylene bis-(sodium dithiocarbamate) is added to the diamine solutionnote Examples 2 and 3, below. Moreover, although the alkali metal hydroxides suggested by Miller et al. are useful as HCl-acceptors, they exert such a corrosive action that the wool fibers being treated are damaged-they develop a harsh hand totally unlike the smooth hand attained When wool fabrics are treated in accordance with the present invention, using silicates or dithiocarbamates as the additive. Thus, although alkali metal hydroxides are useful additives for HCl-acceptance, they cannot provide the combination of desirable results-improved shrinkage control plus retention of the hand of the textileobtained with the additives used in accordance with the present invention.

The effectiveness of silicates and dithiocarbamates is believed to involve the following mechanism: In the known practice, there is a likelihood that the diamine in the treating solution will react with CO from the atmosphere, yielding reaction products such as carbamates and carbonates which interfere with proper amine-diacid chloride condensation. However, it is postulated that the added silicate (or dithiocarbamate) prevents or minimizes this diamine-CO reaction with the net result that the diamine is utilized fully in the desired condensation with the diacid chloride. Another point is that it is believed that the silicate (or dithiocarbamate) has the effect of opening up reactive sites on the wool molecules. Since these reactive sites are added to those already present, it is believed that thereby the resin (subsequently formed by condensation of the diamine and diacid chloride) is grafted to the wool to a greater extent, i.e., the resin is more tightly locked to the wool fibers and thus the shrinkage protection is more effective and more resistant to removal by repeated washings.

In a typical practice of the present invention, the procedure of Patent 3,078,138 is employed with, of course, the change that the silicate or dithiocarbamate is added. Thus the textile material-in the form of garments, fabrics, yarn, roving, top, etc.is entered into an aqueous solution containing a diamine plus the added silicate or dithiocarbamate. After the textile has been impregnated with this solution, it is pressed to remove excess liquid. Then, it is impregnated with the second solution, for example, a solution of a diacid chloride in a volatile, inert, water-immiscible solvent. After another pressing to remove excess liquid, the textile is wased in Warm water containing a small proportion of a soap or synthetic detergent and rinsed, thus to remove unreacted materials, particles of resin not firmly bonded to the fibers, ect. Following this, the textile is dried. Other conventional treatments such as dyeing, shearing, pressing, semi-decating, etc. may be applied as desired.

In the above description we have stressed application of the invention to a system Where the polymer formed in situ in the textile material is produced by the interfacial reaction of a diamine and a diacid chloride. In its broad aspect, the invention encompases the utilization of any of the reaction systems -disclosed in Patents 3,078,138, 3,084,0l8, 3,084,019 and 3,093,441-where one of the reactants is a diamine and the other is a bifunctional compound capable of forming polymers with the diamine. Typical of these bifunctional compounds are diacid, chlorides, bischloroformates, diisocyanates, and mixtures thereof. In cases where a diacid chloride is used, the polymer formed is a polyamide; where a bischloroformate is used, the polymer is a polyurethane; where a disocyanate is used, the polymer is a polyurea. By using mixtures of bifunctional compounds, interpolymers may be produced. Typical of the last is the use of a diamine in conjunction with a mixture of a diacid chloride and a bischloroformate to produce a type of interpolynter which may be termed a copoly amide-urethane. Accordingly, in its broad aspect the invention encompasses application of the critical factors described above in connection with any system for shrinkproofin'g which involves serial impregnation of a wool textile with (1) an aqueous diamine solution and then with (2) a solution of a bifunction-al compound capable of forming a polymer with the diamine, said second solution having as its solvent an inert, essentially 'waterdmmiscible solvent. As noted above, typical of the bifunctional compounds which can be employed in the second solution are acid chlorides, bischloroformates, diisocyanates, and mixtures thereof. By applying these types of compounds in serial manner and in essentially mutually-immiscible phases, various types of polymers may be formed in situ on the wool fibers, rendering the textile shrinkproof. Typical examples of compounds which can be employed in a practice of the invention are described below.

As the diamine one may employ any of the aromatic,

aliphatic, or heterocyclic compounds containing two primary or secondary amine groups, preferably separated by at least two carbon atoms. The dliamines may be substituted if desired with various non-interferring (nonfunctional) substituents such as ether radicals, thioether radicals, tertiary amino groups, sulphone groups, fluorine atoms, etc, Typical compounds in this category are listed below merely by way of illustration and not by way of limitation: ethylene diamine; trimethylene diamine; tetramethylene diamine; hexamethylene diamine; octamethylene diamine; decamethylene diamine; N, N'-dimethyl-l, 3-propanediamine; l,2-diamino2-methylpropane; 2,7-diamino 2,6 dimethyloctane; N,N-dirnethyl-l,6-hexanediamine; 1,4-diamino cyclohexane; 1,4-bis-(aminomethyl) cyclohexane; 2,2-diaminodiethyl ether; 2,2-diaminodiethyl sulphide; bis-(4-aminocyclohexyl) methane; N,N- dimethyl-2,2,3,3,4,4-hexafiuoropentane 1,5 diamine; ortho-, meta-, or para-phenylene diamine; benzidine; xylylene diamine; m-toluylene diamine; orthotolidine; piperazine, and the like. If desired, mixtures of different dia'mines may be used. It is generally preferred to use aliphatic alpha, omega diamines, particularly of the type wherein n has a value of 2 to 12, preferably 6 to 10. Particularly preferred in hexamethylene diamine, i.e., the compound of the above formula wherein 11:6.

As the diacid chloride one may employ any of the aliphatic, aromatic, or heterocyclic compounds containing two carbonylchloride (-COCl) groups, preferably separated by at least two carbon atoms. The diacid chlorides may be substituted if desired with non-interfering (non-functional) substituents such as ether groups, thioether groups, sulphone groups, etc. Typical examples of compounds in this category are listed below merely by way of illustration and not limitation: oxalyl chloride, maleyl chloride, fumaryl chloride, malonyl chloride, succiny chloride, glutaryl chloride, adipyl chloride, pirneyl chloride, suberyl chloride, azelayl chloride, sebacyl chloride, cyclohexane-1,4-biscarbonyl chloride, phtha'lyl chloride, isophthalyl chloride, terephthalyl chloride, 4,4'-biphenyl-dicarbonyl chloride, ,B-hydromucony'l chloride,

ClCOCH CI-I=CHCH COCl diglycollic acid chloride, i.e.

O(CH -COCl) higher homologues of this compound as dithiodigycollic acid chloride, diphenylolpropanediacetic acid chloride, i.e.

(CH C(C H OCH COCl) 2 and the like. If desired, mixtures of different diacid chlorides may be used. It is also evident that the sulphur analogues of these compounds may be used and are included Within the spirit of the invention. Thus, instead of using compounds containing two COC1 groups one may use compounds containing one CSCl and one --COC1 group or compounds containing two CSCl groups. Moreover, although the diacid chlorides are preferred as they are reactive and relatively inexpensive, the corresponding bromides and iodies may be used.

As the diacid chloride, it is generally preferred to use the aliphatic compounds containing two carbonylchloride groups in alpha, omega positions, particularly those of the type:

wherein n has a value from 2 to 12. Another preferred category includes the compounds of the formula ClCOA-COC1 '(Where A is the benzene or cyclohexane radical), especially para-substituted compounds such as terephthalyl and hexahydroterephthalyl chlorides.

As the bischloroformate one may use any of the aliphatic, aromatic, or heterocyclic compounds containing two chloroformate groups preferably separated by at least two carbon atoms. The bischlorofor-mates may be substituted if desired with non-interfering (non-functional) substituents such as sulphone groups, ether groups, thioether groups, etc. Typical examples of compounds in this category are listed below merely by way of illustration and not limitation: ethylene glycol bischloroformate, diethylene glycol bischloroformate, 2,2-dimethyl propane 1,3-diol bischloroformate, propane-1,3-diol bischloroformate, butane-1,4-diol bischloroformate, hexane 1,6 diol bisch'loroformate, octane-1,8-diol bischloroformate, decane 1,10-di0l bischloroformate, butane-1,2-dio1 bischloroformate, hexane-1,2-di0l bischloroformate, Z-methoxyglycerol-1,3-bischloroformate, glycerol 1,2 bischloroformate, glycerol-1,3-bischloroformate, diglycerol bischloroformate, hexanetriol bischloroformate, pentaerythritol bischloroformate, cyclohexane-lA-diol bischloroformate, hydroquinone bischloroformate, resorcinol bischloroformate, catechol bischloroformate, bischloroformate of 2,2-bis(parahydroxyphenyl) propane, bischloroformate of 2,2-bis(parahydroxyphenyl) butane, bischloroformate of 4,4-dihydroxybenzophenone, bischlorofor mate of 1,2-bis(parahydroxyphenyl) ethane, naphthalene- 1,5-diol bischloroformate, biphenyl-4,4-diol bischloroformate, etc. If desired, mixtures of different bischloroformates may be used.

Among the preferred compounds are the aliphatic bischloroformates, for example, those of the type:

II CICO' (CHZ)L1 OPJCI wherein n has a value from 2 to 12. Another preferred category of compounds are the bis-chloroformates derived from polyethylene glycols, e.g.

it ClCOCH;-OH -[O OH ClI2]uO oIr2o1I2-o C-Cl wherein n has a value from zero to 10. A useful category of aromatic bischloroformates are the bisphenol chloroformates, that is, compounds of the type:

wherein RC-R represents an aliphatic hydrocarbon group containing 1 to 12 carbon atoms and R is hydrogen or a low alkyl radical.

It is also evident that the sulphur analogues of the bischloroformates may be used and such are included within the spirit of the invention. Thus, instead of using the compounds containing two group one may use any of the compounds containing the sulphur analoges of these groups, for example, the compounds containing two groups of the formula it XCCl wherein one X is sulphur and the other is oxygen or wherein both Xs are sulphur. Moreover, although the bischloroformates are preferred because they are reactive and relatively inexpensive, it is not essential that they contain chlorine and one may use the corresponding bisbromoformates or bisiodoformates.

As the diisocyanate one may employ any of the aliphatic, aromatic, or heterocyclic compounds containing two isocyanate (-NCO) groups, prefer-ably separated by at least two carbon atoms. The diisocyanates may be substituted if desired with non-interfering (nonfunctional) substituents such as ether groups, thioether groups, sulphone groups, etc, Typical examples of compounds in this category are listed below merely by way of illustration and not limitation: ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, haxamethylene diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, cyclohexylene diisocyanate, bis(2-isocyanatoethyl) ether, bis(2-isocyanatoethyl) ether of ethylene glycol, o-phenylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, tolylene-2,4-diisocyanate, tolylene-Z,6-diisocyanate, 3,3-bitolylene-4,4'-diisocyanate,

diphenyl ether-4,4'-diisocyanate, i.e.

3,5,3',5 -bixy1ylene-4,4-diisocyanate, i.e.

I I R R diphenylmethane-4,4'-diisocyanate, i.e.

biphenylene diisocyanate, 3,3 dimethoxy-biphenylene- 4,4-diisocyanate, naphthalene diisocyanates, polymethyl polyphenyl isocyanates, etc. It is also evident that the sulphur analogues of these compounds may be used and such are included within the spirit of the invention. Thus for example, instead of using the compounds containing two NCO groups one may use their analogues containing either two NCS groups or one -NCO group and one NCS group. Another point to be made is that it is within the spirit of the invention to utilize the derivatives which yield the same products with compounds containing active hydrogen as do the isocyanates. Particular reference is made to the biscarbamyl chlorides which may be used in place of the diisocyanates, Thus one may use any of the above-designated compounds which contain carbamyl chloride groups (R is CH3) or their sulphur analogues i (-NCCl) in place of the isocyanate groups. Among the preferred compounds are the aliphatic diisocyanates, for example, those of the type OCH( CH -NCO wherein n has a value from 2 to 12. Other preferred compounds are the tolune diisocyanates, xylyene diisocyanates, and diphenylmethane-4,4'-diisocyanate which may also be termed methylene-bis(p-phenylisocyanate).

Since the process of the invention makes use of an interfacial polymerization (formation of a polymer at the interface between mutually-immiscible phases of the individual rectants), it is evident that the polymer-forming agents need be applied in solutions wherein the solvents are substantially mutually immiscible. Thus the diamine reactant is applied in aqueous solution while the complementary reactant (diacid chloride, bischloroformate, or

diisocyanate is applied as a solution in an inert, essentially water-immiscible solvent, preferably one which is volatile, for example, benzene, carbon tetrachloride, toluene, xylene, ethylene dichloride, chloroform, hexane, octane, petroleum ether, or other volatile petroleum hydrocarbon mixture. It is generally preferred that the solution of the complementary reactant be dilute; that is, it should contain about /2 to preferably /2 to 2%, of the reactant. Generally, the conditions of treatment, such as the rate of traversal of the fabric, concentration of the reactants, degree of pressing, etc., are so correlated that the product contains about 0.25 to 3% of polymer.

Ordinarily, no reaction promoters are required in the reactive solutions. However, one may add such agents as tertiary amines to the aqueous diamine solution. Other typesof agents which may be added to the diamine solution or to the solution of the complementary reactant are tributyl tin chloride, stannous tartrate, ferric chloride, titanium tetrachloride, boron trifluoride-diethyl ether complex, or tin salts of fat acids such as tin laurate, myristate, etc.

To aid the diamine solution in penetrating into the textile, it is generally preferred to incorporate a minor proportion of a surface-active agent into this solution. For this purpose one may use such agents as sodium alkyl (C -C sulphates, the sodium alkane (C C sulphonates, the sodium alkyl (C C benzene sulphonates, esters or sulphosuccinic acid such as sodium dioctylsulphosuccinate, and soaps, typically sodium salts of fat acids. Surface-active agents of the non-ionic type may also be used and they have the desirable property of being non-substantive; that is, they are not preferentially absorbed by the wool. Typical examples of nonionic agents are the reaction products of ethylene oxide with fatty acids, with polyhydric alcohols, with partial esters of fatty acids and polyhydric alcohols or with alkyl phenols, etc. Typical of such agents are a polyoxyethylene stearate containing about oxyethylene groups per mole, a polyoxyethylene ether of sorbit-an monolaurate containing about 16 oxyethylene groups per mole, a distearate of polyoxyethylene ether of sorbitol containing about 40 oxyethylene groups per mole, iso-octyl phenyl ether of polyethylene glycol, etc. A useful class of non-ionic agents are the nonylphenoxy polyethyleneoxy ethanols, containing 9 to 12 moles of ethylene oxide per mole of nonylphenol, as these compounds are readily soluble in the diamine solution even in the presence of relatively high concentrations of sodium carbonate. Generally, only a small proportion of surfaceactive agents is used, on the order of 0.05 to 0.5%, based on the weight of the solution. In addition to, or in place of the surface-active agent, a supplementary solvent may be added to the primary solvent (water) in quantity suflicient to disperse the active reactant. For such purpose one may employ acetone, or other iner-t, volatile solvent, particularly one that is at least partially miscible with water.

In the foregooing description we have emphasized the utilization of our invention in connection with the shrinkproofing of wool. However, Wool is by no means the only substrate which can be treated. In its broad aspect, the invention can be utilized in the treatment of any fibrous material. Typical examples of such materials are animal hides; leather; animal hair; cotton; hemp; jute; ramie; linen; wood; paper; synthetic cellulosic fibers such as viscose, cellulose acetate, cellulose acetatebutyrate; casein fibers; polyvinyl alcohol-protein fibers; alginic fibers; glass fibers; asbestos; and organic noncellulosic fibers such as Poly (ethylene glycol terephthalate), polyacrylonitrile, polyethylene, polyvinyl chloride, polyvinylidene chloride, etc. Such applications of the teachings of the invention may be for the purpose of obtaining functional or decorative effects such as sizing, finishing, increasing gloss or transparency, increasing water-repellency, increasing adhesionor bonding-characteristics of the substrates with rubber, polyester resins, etc. The process of the invention is of special advantage as applied to hydrogen-donor textiles, for example, protein and cellulosic fibers, because these are especially adapted for chemical bonding of the resin to the fiber molecules.

In utilizing the present invention for the shrinkproofing of long lengths of wool textiles on a continuous basis, it is preferred to include in the total system the features disclosed in the copending application of Fong, Brown, Wasley, Whitfield and Miller, Ser. No. 174,315, filed Feb. 19, 1962 and in the copending application of Miller and Pong, Ser. No. 325,195, filed Nov. 20, 1963. Although these features form no part of the present invention, they are explained herein to provide a complete description of the preferred environment in which to practice the present invention. The features in question are described in the following paragraphs, numbered 1 to 6:

1) Condition of wool.-The wool prior to entering the first (diamine) solution should be in a neutral or alkaline state. If for any reason it is in an acid state, it is preferably to soak it in an aqueous solution of an alkaline agent, such as sodium carbonate, to remove the acidity.

(2) Temperature of the diamine solution.To attain rapid penetration of the solution into the textile and to enhance exhaustion of the diamine onto the fibers, it is preferred to have the solution at an elevated temperature, e.g., at about IUD-150 F.

(3) Time of contact between wool and diamine solution.-The textile should be maintained in the diamine solution for a period long enough for the solution to thoroughly penetrate into the material and for the diamine to exhaust out onto the fibers. In continuous operation this can be ensured with slowing down the production rate by threading the material back and forth in the solution.

(4) Removal of excess diamine solution.--After leaving the diamine solution, the textile is treated-as by efficient pressing or application of vacuum-to remove all the excess solution which is loosely associated with the material as in the form of surface deposits or collected in interstices between individual fibers.

(5 Final padding.--After the textile leaves the second (diacid chloride) solution, it is pressed at high pressure, for example, at at least lbs. per linear inch, to enhance the shrinkproofing effect.

(6) In continued operation of the system, material from the first (diamine) solution will be detached from the textile and mixed with the second (diacid chloride) solution. This causes problems such as evolution of corrosive HCl fumes, excessive consumption of diacid chloride, etc. The problems are readily obviated by continuously pumping the second solution through a molecular sieve, such as a natural or synthetic zeolite, which adsorbs water and HCl from the solution and also filters out any particles of suspended matter or sludge.

The invention is further demonstrated by the following illustrative examples:

Standard wash procedure for shrinkage test.The tests for shrinkage referred to below were conducted in the following manner: The wool samples were washed in a reversing agitator-type household washing machine, using a three-pound load, a water temperature of F., and a low-sudsing detergent in a concentration of 0.1% in the wash liquor. The wash cycle itself was for 75 minutes, followed by the usual rinses and spin-drying. In most cases this washing program was repeated several times. The damp material was then tumble-dried in a householdtype clothes dryer. The samples were then measured to determine their length and width and the shrinkage calculated from the original dimensions.

Fabric breaking strength.-ASTM Method D 39-40, cut strip method, 6-inch x 1 inch samples, 3-inch gauge, 20 seconds to break.

1 1 EXAMPLE 1 Solution A.Aqueous solution containing hexamethylene diamine, sodium carbonate, and a reducing agent, in concentrations specified below.

Solution B.-3% sebacoyl chloride in a petroleum distillate (Stoddard solvent).

An all-wool worsted fabric was treated, in continuous operation, in the following manner: Immersion in solu- Area shrinkage, percent Fabric breaking After 4th After 6th strength, lbs.

75-min. 75-min. Run Additive wash wash Warp Fill Blank 50 30. 9 23. 5 a.. Nazsiog 0.2 1.3 32.5 29.4 Ethylene bis-(sodium 0. l 34. 27. 5

Dithiocarbamate. 0 Na CO 27.8 33.8

tion A for 5 seconds, pressing to remove excess liquid, immersion in solution B for 5 seconds, pressing to remove excess liquid, washing in warm water containing a small amount of detergent, rinsing in plain water, air drying, semi-decating to give a flat set.

Samples of the products were tested for shrinkage, using the standard wash procedure described above. Also, to measure their flat set character, the samples, after such standard wash procedure and while still damp, were placed flat on a table and observed under oblique lighting conditions (to highlight wrinkles, etc.). Samples of the products were tested also for breaking strength. The results obtained are tabulated below:

Having thus described the invention, what is claimed is:

1. In the process wherein fibrous textile material having disulphide bonds is subjected to serial impregnation with (I) a solution of a diamine in water and with (II) a solution of a bifunctional organic compound capable of forming a polymer with said diamine, the said compound being dissolved in an inert, volatile, water-immiscible solvent, the improvement which comprises incorporating in said solution (I) a sulphur-containing, reductive, disulphide-splitting agent.

2. In the process wherein wool is subjected to serial impregnation with (I) a solution of a diamine in water and with (II) a solution of a bifunctional organic com- Conc. of Area shrinkage Fabric breaking Cone. of sodium after [our strength, lbs. HMDA, carbonate, Reducing agent and 75-min. washes, Flat setting Run percent percent concentration thereof percent Warp Fill rating 1 1 (blank) None None None 1 42. 2 30. 9 23. 5 1 2 (control).. 2 4 o 32. 8 34. 3 28. t) 2 3 2 4 Na2S.9H O, 0.6%. 20. 7 33. 5 25. 8 3 4... 2 4 NflzS.9Hg0, 1.2%... 14. 0 34. 5 28.5 4 5... 2 4 Na2S.9H20, 2.4%... 4. 5 34. 6 26. 5 5 6... 1 None NazS.9HgO, 4.8% 0.8 31. 7 26. 3 5 7 2 4 B-Mercaptoethanol, 0.4%. 0 35. 4 26. 7 4 8. 2 4 B-Mercaptocthanol, 1.6%....- 6. 9 30. 3 27. 6 5 9 2 4 Na thioglycollatc, 1'7 0. 8 33. 5 27. 0 4 1 2 None Na thioglycollate, 5% 1. 2 32. 2 .24. S 4

1 In this case, the shrinkage stated (42.2%) was after the first 75-min. wash. 2 Flat setting character of the samples was rated on the basis: l=poor to 5=excellcnt.

EXAMPLE 2 Comparison of sodium metasilicate and sodium carbonate Solution A.--Aqueous solution containing 2% hexamethylene diamine and 2% sodium metasilicate. Solution A .-Aqueous solution containing 2% hexaunethylene diamine and 2% sodium carbonate. Solution B.3% Sebacoyl chloride in a petroleum distillate (Stoddard solvent).

An all-wool worsted fabric was treated, in continuous operation, in the following manner: Immersion in solution A or A for 5 seconds, pressing to remove excess liquid, immersion in solution B for 5 seconds, pressing to remove excess liquid, washing in warm water containing a small amount of a detergent, rinsing in plain water, and drying in air.

Samples of the products were tested for shrinkage, using the standard wash procedure described above. The results are tabulated below:

pound capable of forming a polymer with said diamine, the said compound being dissolved in an inert, volatile, water-immiscible solvent, the improvement which comprises incorporating in said solution (I) a sulphur-containing, reductive, disulphide-splitting agent.

3. In the process wherein wool is subjected to serial impregnation with (I) a solution of a diamine in water and with (II) a solution of a diacid chloride dissolved in an inert, volatile, water-immiscible solvent, the improvement which comprises incorporating in said solution (I) a sulphur-containing, reductive, disulphide-splitting agent.

4. The process of claim 3 wherein said sulphur-containing, reductive, disulphide-splitting agent is an alkali metal sulphide.

5. The process of claim 3 wherein said sulphur-conraining, reductive, disulphide-splitting agent is an alkali metal thioglycollate.

Area shrhikage, percent After 1st After 2nd After 3rd After 4th After 6th -min. 75-min. 75-min. 75-min. 75-min. Run Additive wash wash wash wash wash 1 Sodium metasilicate 0. 3 0. 8 1. 0 1. 2 1. 3 2 Sodium carbonate 1v 8 4. 2 7. 8 11. 2 N.D.

N.D.Not determined.

EXAMPLE 3 6. The process of claim 3 wherein said sulphur-contain- Solution A.An aqueous solution containing 0.2 molar ing, reductive, disulphide-splitting agent is ,B-mercaptohcxamethylene diamine plus one of the following ad- 75 ethanol.

7. In the process wherein fibrous textile material is subjected to serial impregnation with (I) a solution of a diamine and (II) a solution of a bifunctional organic compound capable of forming a polymer with said diamine, the said compound being dissolved in an inert, volatile, water'immiscible solvent, the improvement which comprises incorporating in said solution (I) an alkali-metal silicate.

8. In the process wherein wool is subjected to serial impregnation with (I) a solution of a diamine and (II) a solution of a bifunctional organic compound capable of forming a polymer with said diamine, the said compound being dissolved in an inert, volatile, water-immiscible solvent, the improvement which comprises incorporating into said solution (I) an alkali metal silicate.

9. In the process wherein wool is subjected to serial impregnation with (I) a solution of a diamine and (II) a solution of a diacid chloride dissolved in an inert, volatile, water-immiscible solvent, the improvement which comprises incorporating into said solution (I) an alkali metal metasilicate.

10. In the process wherein fibrous textile material is subjected to serial impregnation with (I) a solution of a diamine in Water and ('II) a solution of a bifunctional organic compound capable of forming a polymer with said diamine, the said compound being dissolved in an inert, volatile, water-immiscible solvent, the improvement which comprises incorporating in said solution (I) a dithiocarbamate.

11.1In the process wherein wool is subjected to serial impregnation with (I) a solution of a diamine in water and (II) a solution of a bifunctional organic compound capable of forming a polymer with said diamine, the said compound being dissolved in an inert, volatile, water-immiscible solvent, the improvement which comprises incorporating in said solution (I) a dithiocarbamate.

12. In the process wherein wool is subjected to serial impregnation with (I) a solution of a diamine in water and (II) a solution of a diacid chloride dissolved in an inert, volatile, water-immiscible solvent, the improvement which comprises incorporating in said solution (I) ethylene bis-(sodium dithiocarbamate).

References Cited UNITED STATES PATENTS 2,508,713 5/1950 Harris et a1 8l27.6 2,955,016 10/1960 Moore 8128 3,049,445 8/1962 Lundgren et a1. 8-l28 X 3,051,544 8/1962 Wolf et a1 8l28 3,078,138 2/1963 Miller et a1 8128 NORMAN G. TORCHIN, Primary Examiner I CANNON, Assistant Examiner US. Cl. X.R.

Claims (1)

1. IN THE PROCESS WHEREIN FIBROUS TEXTILE MATERIAL HAVING DISULPHIDE BONDS IS SUBJECTED TO SERIAL IMPREGNATION WITH (I) A SOLUTION OF A DIAMINE IN WATER AND WITH (II) A SOLUTION OF A BIFUNCTIONAL ORGANIC COMPOUND CAPABLE OF FORMING A POLYMER WITH SAID DIAMINE, THE SAID COMPOUND BEING DISSOLVED IN AN INERT, VOLATILE, WATER-IMMISCIBLE SOLVENT, THE IMPROVEMENT WHICH COMPRISES INCORPORATING IN SAID SOLUTION (I) A SULPHUR-CONTAINING, REDUCTIVE, DISULPHIDE-SPLITTING AGENT.