[1]Unioted States Patent Office 3@466PI36 3,466,136 SHRINKPROOFING OF WOOL William L. Wasley, Berkeley, Robert E. WhitfieId, Pleasant Hill, and Lowell A. Miller, Walnut Creek, CaUf., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Filed Mar. 17, 1964, Ser. No. 352,700 U.S. Cl. 8- 127.5 Int. Cl. D06m 3106 12 CIaims A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughotit 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 treatin.- textile materials, particularly wool, to achieve shrinkproofing and other desirable effects. Further objects and advantages of the invention will be evident from the following descripti-on wherein parts and percenta-es are by weight, unless otherwise specified. In the patent of Miller, Whitfield, and Wasley (@,@078' 138, granted Feb. 19, 1963) there are disclosed procosse s for shrink-proofing wool wherein a condensation@ pol[y mer-typically a polyamide-is f ormed in situ on the wool fibers and grafted to the wool, that is, chemically combined therewith. In a typical embodiment of theit process, a wool fabric is serially impre,-nated with tw6 s,olutions-the first being a solution -of @ Idiamine, iin wateir, the second bein- a solution of a diacid chl6@ide in a waterimmiscible, volatile, inert solvent. By such treatment the fibers are coated with superposed layers of the mutuallyinsoluble solutions: an inner layer of diamine in water and an outer layer of diacid chloride in water-immisclblp 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 hig,hmolecular weight, resinous polyamide which cohts the fibers and renders the fabric shrinkproof without detriment to the hand, porosity, and other valuable prbperties 6f, the fabric. Moreover, the polyamide is chemically ,p6nded to the wool so that the shrinkproofing effect is highly durable, i.e., the polyamide deposit is not remove@ by repeated wasbing of the treated fabric in conventional soap and water or detergent and water laundering formulations, or in conventional dry-cleaning formulations. Fr,om a procedural standpoint, the process has the advantage of simplicity and rapidity in that the basic operation is simply a serialimpregnation of the fabric in the two solutions. Another point is that the process does not require any heat curin- of the treated fabric as is commonly necessary in most resin shrinkproofing procedures. In d@lcordance with the present invention, the basic principles of the aforesaid processes are applied in conj Linction with the us,- of certain additives (to the treatment solutions) whereby to achieve advantageoiis resiilts over a,id above those attained by the patented procedures. One phas-- of the invention involves the addition of a reducing agent to -one of the complementary treating solutions, preferably to the diamine solution. A primary adva-ntage obtained thereby is that when the product is subs@quently subjected to a conventional setting treatment (heating while constrained in a predetermined sbape), it acquires a permanent set. Accordingly, when the fabric or garments made th@-refrom 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 stich desirable setting effect is Patented Sept. 9, 1969 2 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 weakenina, 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 in10 vestigations have sbown that a better shrinkproofing effect 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 unex@pectedly provides a synergistic effect. 15 For use in the process of the invention, a preferred class of reduc'ng aaents 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 20 very Liseful class of reducing agcnts comprises the organic compounds containing a thiol group, as, for example, thi,ogiycollic acid, or its salts such as the alkali metal or ammonium salts; beta-mereapto ethanol; monthio glycerol;.dithio-glycerol; butyl mercaptan; thiomalic acid or its @alts- thi6-lactic acid or its salts; thiophenol; thiocresol; 25 I et6. Olth6r -reducing agents which may be used are listed @elow by'.way of illustration: Formamidine sulphinic acid, als6 known as iminoaminomethane sulphinic acid betaine. Formaldehyde sulphoxylates, generally used in 30 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 fbrmaldehyde bisulphite, sodium acetone bisulphite, etc. Generically, the 35 reducing agents used in accordance miith the invention may be defined as sulphur-containing, reductive, disulphidesplittin.- a.-ents because of the fact that they all contain sulphur in their structures and because they have th.- ability to open the disulphide (eystine) linkage in the 40 wool molecule, generally converting a single disulphide (-S-S) 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 a.-ent selected, the durability of set desired in the 45 product, the character of the fibers being treated, etc. Even minute amounts of the reducing agent will provide some degree bf improvement over the, known techniques. Usually, the reducing agent is used in an amount from about 0.1 to 5 parts per part of diamine in the treating 5o solution. To avoid possibility of degradation of the textile material when it is contacted with the treating solution, it is - encrally 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 5,5 preferred to use the reducing agents in. conjunction with an alkaline agent to raise the pH of the solution of reducin.- agent plus diamine to a level of about 12 to 13. With some of the reducing ag--nts, such as the alkali metal sulphides, additional alkaline material will not usually ro be necessary because of the strongly basic character of the sulphides. With other reducing agents such as 6mercaptoethanol, thioglycollic acid etc., one may add additional alkaline material such as an alkali metal hydroxide, carbonate, or, more preferably, an alkali metal 6,5 metasilicate or dithiocarbamate. The advantages to be gained from such compounds are explained hereinbelow in connection with another phase of the present invention. The mechanism involved in the improvement of a 70 shrinkproofing effect by addition of a reducing agent is believed to involve the following: When wool fibers are successively treated with (1) aqueous diamine solution
[2]3 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-for example, through splitting of disulphide linka,-es. 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 -rafted to the wool to a greater extent-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 washing. In a typical practice of the present invention, the procedure of Patent 3,078,138 is employed with, of course, the chan-e that the reducing agent is added. Thus the textile-in the form of -arments, fabris, yarn, roving, top, etc.-is entered into an aqueous soltition containing a dianiine plus the reducing a,-ent. 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 containin-, 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 flat 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 clofh, 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 w6und-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 obv'ous that if it is desired to set the fabric in a pattern other than a flat 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 shrinkproofin.-I whether or not a setting treatinent is applied, it is within the ambit of the invention to apply reducing agents as described hereinabove in a tool system whe re 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 3,466,136 4 been found that the additives yield products with a better hand. Moreover, these valuable advantages are attained without any detriment to the fibers-there 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 10 termed, such as Na2Si2O5, Na2Si3O7, Na2Si4O9, etc. As the dithiocarbamate, we prefer to use ethylene bis-(sodium dithiocarbamate) which has the formula s s 11 11 15 Na-S-C-NH-CH2- CI12--NH-C-S--Na 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 20 is replaced by the radical s 11 U-115 In the process of the invention one can use any of such 25 compounds, derived, for example, from aliphatic, aromatic, or heterocyclic amines, wherein at least one hydrogen atom attached to nitro,-en is replaced by the .@roup 0 30 (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 dithiocar35 bamate), 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 cir40 cumstances as the efficacy of the agent selected, the character of the fibers beina 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 4@o 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 50 solution to act as an HCI-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 HCI-acceptance. Although the agents used herein are 55 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 HCI-acceptance does not yield the results obtained as described herein when, for example, sodium 60 metasilicate or ethylene bis-(sodium dithiocarbamate) is added to the diamine solution-note Examples 2 and 3, below. Moreover, although the alkali metal hydroxides suggested by Miller et al. are useful as HCI-acceptors, they exert such a corrosive action that the wool fibers 65 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 70 HCI-acceptance, they cannot provide the combination of desirable resultsimproved shrinka,-e control Plus retention of the hand of the textile-obtained with the additives used in accordance with the present invention. The effectiveness of silicates and dithiocarbamates is 75 believed to involve the following mechanism: In the
[3]known practice, there is a likelihood that the diamine in the treating solution will react with C02 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 diamineCO2 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 openin@ 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 shrinl@lage protection is more effective and more resistant to removal by repeated washings. In a typical practice of the present invention, the procedure of Patent 3,07,8,138 is employed with, of course, the change that the silicate or dithiocarbamate is iadded. Tbus 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 deter.-ent and rinsed, -thus to remove unreacted materials, particl,es 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, 3,084,018, 3,084,019 and 3,093,441-where one of the reactants is a diamine and the other is a bifunctional compotind capable of formin.- polymers with the diamine. Typical of these bifunctional compounds are diacid, chlorides, bischloroformates, diisocyanates, ai-id mixtures thereof. In cases where a diacid chloride is used, th-. polymer formed is a polyamide; wbere a bischloroformate is used, the polymer is a polyurethane; where a disocyanate is used, the polymer is a polylirea. By using ,niixtures 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 interpolyn-ter 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 shrinkproofing which involves serial im pregnation of a wool textile with (1) an aqueous diamine solution and then with (2) a solution of a bifunctional compound capable of forming a polymer with the diamine, said second solution having as its solvent an inert, essentially water-immiscible -solvent. As noted above, typical of the bifunctional compounds which can be employed in the second solution are acid chlorides, bisehloroformates, diisocyanates, and mixtures thereof. By applying these types of compounds in serial manner and in essentially mutually-immiscible phases, varioiis 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, 3@466,136 6 aliphatic, or heterocyclic compounds containing two 'primary or secondary amine groups, preferably septrated by at least two carbon atoms. The diamines may be substituted f desired with various non-iri@terferring (nonfunctional) substituents such as ether radicals, thioether radicals, tertiary amino grolips, sulphone groups, fluorine atoms, etc. Typical compounds in this cate.-Ory are listed b,Iow m--rely by way of illustration an-d not by way of limitation: ethylene diamine; trimethylene diamine; tetra10 methylene diamine; hexamethylene diamine; octamethylene diamine; decamethylene diamine; N, N'-dimethyl-1, 3-propanediamine; 1,2-diamino-2- methylpropane; 2,7-diamino - 2,6 - dimethyloctane; N,N'-dimethyl-1,6- hexanediamine; 1,4-diamino cyclohexane; 1,4-bis-(aminomethyl) 15 cyclohp-xane; 2,2'-diaminodiethyl ether.; 2,2'-diaminodiehyl sulphide; bis(4- aminocyclohexyl) methane; N,N'dimethyl-2,2,3,3,4,4- hexafitioropentane - 1,5 - diamine; ortho-, meta-, or para-phenylen-- diamine; benzidinexylyiene diamine; mtoluylene diamine; orthotolidine; 20 piperazine, and the like. If desired, mixttires of different diamin--s may be used. It is gen-,rally preferred to use aliphatic alpha, oniega diamines, particularly of the typ.- H,N-(CH,)=NH2 25 wherein 7i ha-s a value of 2 to 12, preferably 6 to 10. Partictilarly preferr,-d in li,- xan-iethylene diamine, i.e., the compound of the above formula wherein n = 6. As the diacid chloride one may employ any of the aliphatic, aromatic, or h,- terocyclic compounds contain30 ing two carbonylchloride (-COCI) -groups, preferably separated by at least two carbon atoms. The diacid chlorid-,s may be substituted if desired with noninterfering (non-functional) substituents such as etber groups, thioether groups, sulphone groups, etc. Typical examples 35 of compounds in ithis category are list:ed below merely by way of illustration and not limitation: oxalyl chloride, maleyl chloride, fumaryl chlorid 6, maloayl chloride, sueeiny chloride, glutaryl chloride, adipyl chloride, pimeyl 40 chloride, suberyl chloride, azelayl chloride, sebacyl chloride, cyclohexane-1,4- biscarbonyl chloride, phthalyl chloride, isophthalyl chloride, terephthalyl chloiide, 4,4'-biphenyl-dicarbonyl chloride, 3-bydromuconyl chloride, i.e. 45 CICO-CH,-CH=CH-CH2-COC1 diglycollic acid chloride, i.e. O(CH,-COCI), higher hoi-nologues of this compound as 150 O(CH2-CH2--COCI)2 dithiodigycollic acid chloride, diphenylolpropanediacetic acid chloride, i.e. 55 (CH,),C(C,H,OCH,COCI), and th-. like. If desired, mix-tures 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 inven'lion. 'fhus, instead of 60 11SIng compounds cantaining two -COCI -grotips one may use compounds containing one -CSCI and one -COCI group or compounds containing two -CSCI groups. Moreov@-r, al-though the diacid chlorides are preferred as they are reactive and relatively inexpensive, the cor65 responding bromides and iodies may be used. As the diacid chloride, it is generally preferred to use the aliphatic compounds containing two carbonylehloride groups in alpha, omega positions, particularly those of the type: 70 CICO-(CH,),,COCI wherein ii has a value from 2 to 12. Ajiother preferred category includes the compounds of the formula CICO-A-COCI (where A is the benzene or cyclo75 hexane radical), especially para-substituted compounds
[4]3,466,136 7 such as terephthalyl and hexahydroterephthalyl chlorides. As the bischloroformate one may use any of the aliphatic, aromatic, or heterocyclic compounds containing two chloroformate @roups 0 5 preferably separated by at least two carbon atoms. The bischloroformates may be substituted if desired with non-interferin.- f(non-functional) substituents such as 10 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 bis15 chloroformate, propane-1,3-diol bischloroformate, butane-1,4-diol bischloroforn-iate, hexane - 1,6 - diol bischloroformate, octane-1,8-diol bischloroformate, decane1,10-diol bischloroformate, butane-1,2-diol bischloroformate, hexane-1,2-diol bischloroformate, 2-methoxy20 ,-lycerol-1,3-bischloroformate, glycerol - 1,2 - bischloroformate, glycerol-1,3-bischloroformate, diglycerol bischloroformate, hexanetriol bischloroformate, pentaerythritol bischloroformate, cyclohexane-1,4-diol bischloroformate, hydroquinone bischloroformate, resoreinol bis25 cbloroformate, catechol bischloroformate, bischloroformate of 2,2-bis(parahydroxyphenyl) propane, bischloroformate of 2,2-bis(parahydroxyphenyl) butane, bischloroformate of 4,4'-dihydroxybenzophenone, bischloroformate of 1,2-bis(parahydroxyphenyl) ethane, naphthalene30 1,5-diol bischloroformale, 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: 35 0 0 11 11 CIC 0-(CH2).-O C Cl wherein ii has a value from 2 to 12. Another preferred category of compounds are the bis-chloroformates de- 40 rived from polyethylene glycols, e.,-- 0 0 11 11 Cl-C-0-CI12-CI12-[O CH2-CI12I.-OClf2-CII2-0 C-Cl wherein it has a value from zero to 10. A useful categoFY 4-0 of aromatic bischloroformates are the bisphenol chloroformates, that is, compounds of the type: R' R R' 0 @@- C, 0 11 I - 50 ci-co R 08-Cl wh-.rein R-C-R represents an aliphatic hydrocarbon oup containing 1 to 12 carbon atoms and R' is hydrogen or a low alkyl radical. it is also evident -that the sulphur analoglies of the 55 bischloroformates may be used and such are included within the spirit of the invention. Thus, instead of usin.the compounds cgntaining two 0 60 grolip one may use any of the compounds containing the sulphur analoges of these groups, for exaniple, the compounds containing -two groups of the formula x 65 11 -X-C-Cl wherein one X is sulphur and the other is oxy.-en or wherein both X's are sulphur. Moreover, althou,ah the bischloroformates are preferred because they are reactive 70 an,cl relatively inexpensive, it is not essential that they contain chlorine iand one may Lise the correspondin.- bisbromoformates or bisiodoformates. As the diisocyanate one may employ aiiy of the aliphatic, aromatic, or heterocyclic COMPOLinds coiitaining 75 8 two isocyanate (-NCO) groups, preferably separated by at least two carbon atoms. The diisocyanates may be substituted if desired with non-interferin.- (non-f unctional) 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 diiso:cyanate, decamethylene diisocyanate, cyclohexylene diisocyanate, bis(2-isocyanatoethyl) e,her, bis(2-isocyanatoethyl) ether of ethylene -lycol, o-phenylen@ diisocyanate, m-phedylene diisocyanate, p-phenylene diisocyanate, tolylene-2,4- diisocyanate, tolylene-2,6-diisocyanate, 3,3'-bitol ylene-4,4'-diisocyanate, i.e. CH3 CH3 0 C N-@@-e--,@-Nco diphenyl ether-4,4'-diisocyanate, i.e. 0 CN-e---\\\>-O-e---,@- NCO 3,5,3',5'-bixylylene-4,4'-diisocyanate, i.e. R R 0 C C 0 I (R is -CH3) diphenylmethane-4,4'-diisocyanate, i.e. C H@-C--\\>-N C 0 biphenylene diisocyanate, 3,3' - dimethoxy-biphenyl ene4,4'-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 usin.- the compounds containing two @NCO -roups 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 containin.@ active hydrogen as do the isocyanates. Particular reference is made to the biscarbamyl chlorides which may be tised in place of the diisocyanates. Thus one may use anY of the above-designated com ounds which contain p carbamyl chloride groups 0 (-I\T-C-Cl) or their sulphur analogues s 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 tolun,- diisocyanates, xylyene diisocyanates, and diphenylm ethane-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 soltitions wherein the solvents are substantially mutually immiscible. Thus the diamine i-e@ietant is applied in aqueotis solution -while the complementary reactant (diacid chloride, bischloroformate, or
[5]3,466,136 9 diisocyanate is applied as a soludon 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 (>f the complementary reactant be dilute; that is, it should contain about I/z to 10%, preferably 1/2 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 terti ! ary amines to the aqueous diamine solution. Other types'o.f agents which may be added to the diamine solution or to the solution of the complementary reactant are tributyl tin chloride, stannous tartrate, ferric eblor,ide, 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 (Cg--C,8) sulphates, the sodium alkane (C8 -C,8) sulphonates, the sodium alkyl (C8-C20) benzene sulphonates, esters or sulphosuccinic acid such as sodium dioetylsulphosuccinate, 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-substantivc; 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 20 oxyethylene groups per mole, a polyoxyethylene etber of sorbitan mono_ laurate containing abotit 16 oxyethylene groups per mole, a distearate of polyoxyethylene ether of sorbitol containing about 40 oxyethylene grotips per mole, iso-octyl phenyl ether ofpolyethylene glycol, etc. A useful class of non-ionic agents are the nonylphenoxy polyetbyleneoxy ethanols, containing 9 to 12 moles of etbylene 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 quantitysufficient to disperse the active reactant. For such purpose one may employ acetone, or other inert, 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 anialal hides; leather; animal hair; cotton; hemil), jtite; ramie; linen; wood; paper; synthetic cellulosic fibei.s such as viscose, cellulose acetate, cellulose acetatebutyrate; casein fibers; polyvinyl alcohol-protein fibers; alginic fibers; glass fibers; asbestos; and organic noncelli.ilosic fibers such as poly (ethylene glycol terephthalate), polyacrylonitrile, polyethylene, polyvinyl chloride polyvinylidene chloride, etc. Such applications of the tealings of the invention may be for the purpose of obtaining functional or decorative effects such as sizing, finishing, increasing gloss or transparency, increasing waterrepellency, increasing adhesion- or bonding-charac10 teristics 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 len.aths of wool textiles on a continuous basis, it is preferred to include in the total system the 10 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 Fong, Ser. No. 325,195, filed Nov. 20, 1963. Although these features form no part of the present in15 vention, they are explained herein to provide a complete description of the preferred environment in which to practice the present invention. The features in qtiestion are described in the following paragraphs, numbered 1 to 6: 20 (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 soditim carbonate, to remove the 25 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, 30 e.g., at about 100-150' 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 35 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 effi. 40 cient 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 45 (diacid chloride) solution, it is pressed at high pressure, for example, at at least 100 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 50 the textile and mixed with the second (diacid chloride) solution. This causes problems such as evolution of corrosive HCI ftimes, excessive consumption of diacid chloride, etc. The problems are readily obviated by continuously pumping the second solution through a molecular sieve, 55 such as a natural or synthetic zeolite, which adsorbs water and HCI from the solution and also filters out any particles of suspended matter or sludge. The invention is ftirther demonstrated by the followingillustrative examples: (30 Standard wash procedure for shrinkage test.-The testq for shrinkage refer@red 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 105' F., and 65 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 spindrying. In most cases this washing pro,-ram was repeated several times. The damp material was then tumble-dried in a household70 type 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 I inch samples, 3-inch galige, 20 75 seconds to break.
[6]3,466,136 12 EXAMPLE 1 ditives: (a) 0.4 molar sodium metasilicate, (b) 0.2 Solution A.-Aqueous solution containing hexamethylene molar ethylene bis-(sodium dithiocarbamate), or (c) diamine, sodium carbonate, and a reducing agent, in 0.4 molar sodium carbonate. ,concentrations specified below. Solution B.-3% Sebacoyl chloride in a petroleum distilSolution B.-3% sebacoyl chloride in a petroleum distil5 late (Stoddard solvent). late (Stoddard solvent). An all-wool worsted flannel was treated with the above solutions as described in Example 2. The products were An all-wool worsted fabric was treated, in continuous then tested for shrinkage and for tear strength. The reoperation, in the following manner: Immersion in solusults -are tabulated below: A r e a s h r i l - @ k a g e , p e r c e n t F a b r i c b r e a k i i i g Aft er 4th Aft er 6th strei jgth, lbs. 75- min. 75- min. Ruii Add itive was h was h Wa rp Fill Blaiik -------------------------------- - 50 -------------- 30. 9 23.5 a -- -------- Na@sio @ ------------ ------- 0. 2 1.3 3 2.5 29.4 b ---------- Etliylene bis(sodium 0 0. 1 34.5 2 7. 5 Dithiocarbamate. c---------- Na2CO3 --------------- ---- 27. 8 -------------- 33. 8 29.0 tion A for 5 seconds, pressing to remove excess liquid, 20 Having thus described the invention, what is
