US3291560A - Method of forming polymers on fibrous substrates through high velocity impingement with solutions containing unsaturated monomers and chemical catalysts - Google Patents

Description

Dec. 13, 1966 G. MACHELL ETAL METHOD OF FORMING POLYMERS ON FIBROUS SUBSTRATES THROUGH HIGH VELOCITY IMPINGEMENT WITH SOLUTIONS CONTAINING UNSATURATED MONOMERS AND CHEMICAL CATALYSTS Filed Dec. 10, 1962 INVENTORQ REV/LLE lMC/IELL ATTORNEY x THOM S United States Patent .0

METHOD OF FORMING P DLYMERS ON FIBROUS SUBSTRATES THROUGH HIGH VELOCITY IM- PIN-GEMENT WITH SOLUTIONS CONTAINING UNSATURATEI) MQNOMERS AND CHEMICAL CATALYSTS Greville Machell and Manuel A. Thomas, Spartanhurg,

S.C., assignors to Deering Milliken Research Corporation, Spartanhurg, S.C., a corporation of Delaware Filed Dec. 10, 1962, Ser. No. 243,671 6 Claims. (Cl. 8116) This invention relates to a novel process for modifying the characteristics of keratin fibers with compounds containing the group more particularly to a process for modifying wool fibers.

Compounds containing the group have been used to treat fabrics containing wool fibers in the past, generally to impart increased resistance to shrinking in aqueous media. Although the desired shrinkproofing has been accomplished by these techniques, the aesthetic properties of the fabric have been diminished to the point that such fabrics have not been acceptable commercially. The same ditficulty arises when such compounds are applied to wool fabrics for other purposes, e.g., to modify the dyeing characteristics thereof. This diificulty has been partially overcome by conducting the reaction on loose fibers in accordance with the inventions described in copending and coassigned US. patent application, Serial Number 242,6l0, filed December 6, 1962, and preparing a fabric from the treated fibers.

In attempting to treat loose fibers (i.e., fibers not in the form of yarn or fabric), it was soon realized that some of the problems associated with treatment of fabric were still present. More particularly, surface deposits of polymer, i.e., polymer which had not reacted with the fibers were still being formed, so that the handle of the fibers, though improved, was still not entirely satisfactory for many end uses.

In addition, it was found to be diflicult to treat loose fibers by techniques suitable for treating fabrics without extensive modification of apparatus normally used for modifying fabrics with compounds containing the group. For example, wool top can be quite readily pulled apart and, consequently, its not amenable to processes suitable for treating fabrics.

Prior processes for modifying fabrics with compounds containing the CHz=(- group were found to present at least two basic ditficulties, in addition to the heretofore insurmountable problem of boardy, coarse handle. Firstly, it was discovered that the monomer available for reaction in the solutions utilized was being inefficiently converted to reacted material. Secondly, and more importantly, it was discovered that in many instances, substantial amounts of the compound which was converted to reacted material were not permanently attached to the fibers, i.e., the reacted material could be readily stripped from the fibers by a solvent for the material. Since one of the reasons for using a compound of the formula to treat wool fibers is to effect a reaction between the fibers and the compound, or at least to induce such a relationship that the reacted material could not be stripped readily from the fibers, this discovery was most disturbing.

While difficulties presented by treating fabrics could be solved, at least partially, by treating loose fibers and processing them into fabrics, additional improvement can be made by modifying radically the processes utilized in treating the fibers.

It is an object of this invention to modify the characteristics of keratin fibers in a process characterized by highly efficient conversion of the group-containing compounds to reacted material.

Another object of this invention is to increase substantially the proportion of said compound which reacts with the keratin fibers to total reacted material.

Yet another object of this invention is to provide such a process wherein said compounds are applied uniformly to the keratin fibers being treated.

These and other objects are accomplished in accordance with this invention by repeatedly forcing through a mass of loose keratin fibers a solution of a compound containing the group in the presence of the desired catalyst system. Preferably, the solution is repeatedly forced back and forth through the mass of fibers at a sufficiently rapid rate that the supply of monomer at the surfaces of the fibers is constantly being replenished in an amount considerably in excess of that which, at least initially, the fibers can have exhausted thereon. This procedure is continued until the monomer in the solution is substantially exhausted onto and into the fibers.

Despite the more rapid and more complete conversion of the available monomer to reacted material, the reacted material, quite unexpectedly, is nearly completely-unextractable with a solvent for the polymeric form of the compound. One might reasonably expect that a compound being absorbed by a fiber more rapidly and in greater abundance would tend to react not only with the fibers but also with itself to a greater extent. Keratin fibers treated in accordance with this invention, however, are characterized by far less extractable reacted material than fibers treated by prior art immersion techniques. Furthermore, compounds containing the groups are reacted with the mass of fibers more uniformly than in the prior art processes. If, however, it is desired to utilize the process of this invention to place reacted material which is ionically bound within the fibers, and hence extractable to a greater degree, many advantages will accrue even in this type process.

Generally, it is believed that in the presence of a suitable catalyst system, compounds containing the group react with keratin fibers to produce polymeric compounds permanently chemically attached, or grafted, to the wool fibers so as to be unextractable with a solvent for the polymeric form of the. monomer or low polymer utilized. Under these same conditions, in some instances, some of the monomer or low polymer can react with itself rather than with the wool fibers to produce a homopolymer which can be readily extracted from the wool fibers.

the fiber mass per minute.

This latter condition is a great deal less prevalent, if not in fact eliminated, by the process of this invention.

It is realized, of course, that some homopolymer may form Within the fibers being treated by the process of this invention and that this material, though homopolymeric in nature and not reacted with the fibers, would not be readily extractable. At any rate, even though this condition may existand it is not known in fact that it does the fact still remains that less reacted material can be removed from wool fibers treated in accordance with this invention than from fibers treated in accordance with immersion techniques using the same monomer or low polymer system.

There is no readily apparent explanation for the improvements provided by this invention and none will be attempted here. It is known, however, that when the monomer system is forced, preferably back and forth, through the mass of fibers in accordance with this invention, little or no reacted material is removed during extraction techniques.

In general, excellent improvement is provided when the monomer is forced through the mass of fibers, most preferably in the form of loose fibers as set forth above, at a rate in excess of about 5 pounds of monomer/pound of fibers/minute. Generally, this amount constitutes an excess of at least about 1000 times that amount of monomer which can theoretically exhaust initially on Under these conditions, the monomer exhausts onto and into the fibers themselves at an average rate in excess of about 0.005 pound of monomer/ pound of fibers/ minute.

These conditions are most readily obtained in equipment which is normally used in the package dyeing of yarn. Generally, however, the flow rate of the system through this apparatus must be adjusted to a level whereby the monomer or low polymer system is forced through the mass of fibers at a sufficiently rapid rate that the supply of monomer at the surface of the fiber is constantly being replenished in an amount considerably in excess of that which, at least initially, the fiber can have exhausted thereon. In most package dyeing machines, this condition is readily obtainable. If sufficient flow is not provided by the selected equipment, this difficulty can generally be overcome by selecting a higher capacity pump or by decreasing the load of wool fibers in the equipment. These latter expedients are suggested should a large amount of extractable reacted material be noticed after a few runs using the equipment.

Wool fibers are generally treated with an aqueous solution of the desired monomer or low polymer in the presence of a catalyst system capable of inducing polymerization thereof. The catalyst system most generally used is a redox catalyst system composed of a reducing agent and an oxidizing agent. The prior art teaches that wool fibers should be impregnated with one of these catalyst components and then contacted with the monomer and the other catalyst component, in the belief that the monomer will polymerize in a solution containing both catalyst components. This in fact does occur in many of the prior art immersion baths. For some reason, again unexplainable, the expected polymerization does not occur when a single system containing the desired monomer and all catalyst components is applied to wool fibers under the conditions of flow utilized in accordance with this invention. This characteristic of the invention, therefore, constitutes a distinct advantage of this invention over the prior art immersion techniques in that far superior control of the process is possible when all components can be added from a single bath.

The reducing agent and/or the oxidizing agent, however, may be applied to the fibers prior to the application of the monomer, or vice versa.

The preferred redox catalyst system is composed of a reducing agent and an oxidizing agent initiator, the interaction of which provides free radicals which cause polymerization of the monomeric or low polymeric material with the keratin substrate.

The reducing agent may be an iron compound, such as the ferrous salts including the sulfates, acetates, phosphates, ethylenediamine tetra-acetates and the like; metallic formaledhyde sulfoxylates, such as zinc formaldehyde sulfoxylate; alkali-metal sulfoxylates, such as sodium formaldehyde sulfoxylate; alkali-metal sulfites, such as sodium and potassium bisulfite, sulfite, metabisnlfite or hydrosulfite; mercaptan acids, such as thioglycollic acid and its water-soluble salts, such as sodium, potassium or ammonium thioglycollate; mercaptans, such as hydrogen sulfide and sodium or potassium hydrosulfide; valkyl mercaptans, such as butyl or ethyl mercaptans and mercaptan glycols, such as beta-mercaptoethanol; alkanolamine sulfites, such as monoethanolamine sulfite and monoisopropanolamine sulfite; manganous and chromous salts, ammonium bisulfite, sodium sulfide, sodium hydrosulfide, cysteine hydrochloride, sodium hypophosphite, sodium thiosulfate, sodium dicyanate, titanous chloride, sulfur dioxide, sulfurous acid and the like, as well as mixtures of these reducing agents. In addition, a salt of hydrozine may be used as the reducing agent, the acid moiety of the salt being derived from any acid such as hydrochloric, hydrobromic, sulfuric, sulfurous, phosphoric, benzoic, acetic and the like.

Suitable oxidizing agents initiators for use in the redox catalyst system include inorganic peroxides, e.g., hydrogen peroxide, barium peroxide, magnesium peroxide, etc., and the various organic peroxy catalysts, illustrative examples of which are the dialkyl peroxides, e.g., diethyl peroxide, dipropyl peroxide, dilauryl peroxide, dioleyl peroxide, distearyl peroxide, di-(tert.-butyl) peroxide and di-(tert.-amyl) peroxide, such peroxides often being designated as ethyl, propyl, lauryl, oleyl, stearyl, tert.-butyl tert.-amyl peroxides; the alkyl hydrogen peroxides, e.g., tert.-butyl hydrogen peroxide (tert.-butyl hydroperoxide), etc.; symmetrical diacyl peroxides, for instance peroxides which commonly are known under such names as acetyl peroxide, propionyl peroxide, lauroyl peroxide, stearoyl peroxide, malonyl peroxide, succinyl peroxide, phthaloyl peroxide, benzoyl peroxide, etc.; fatty oil acid peroxides, e.g., coconut oil acid peroxides, etc.; unsymmetrical or mixed diacyl peroxides, e.g., acetyl benzoyl peroxide, propionyl benzoyl peroxide, etc.; terpene oxides, e.g., ascaridole, etc.; and salts of inorganic peracids, e.g., ammonium persulfate, potassium persulfate, sodium percarbonate, potassium percarbonate, sodium perborate, potassium perborate, sodium perphosphate, potassium perphosphate, etc.

Other examples of organic peroxide initiators that can be employed are the following: tetralin hydroperoxide, tert.-butyl diperphthalate, cumene hydroperoxide, tert.- butyl perbenzoate, 2,4-dichlorobenzoyl peroxide, urea peroxide, caprylyl peroxide, p-chlorobenzoyl peroxide, 2,2-bis(tert.-butyl peroxy) butane, hydroxyheptyl peroxide, diperoxide of benzaldehyde.

The above oxidizing agents, particularly the salts of inorganic peracids, may be utilized alone to initiate the graft polymerization process, although faster reactions at lower temperatures may be conducted when the oxidizing agent is combined with a reducing agent to form a redox catalyst system. Also, ferric salts can be used as oxidizing agents and form a redox catalyst system with hydrogen peroxide, in which case the peroxide functions as a reducing agent.

Other suitable catalysts or initiators for the polymerization process include azo catalysts, such as azobisisobutyronitrile, as well as irradiation under the influence of high energy fields, including the various actinic radiations, such as ultra-violet, X-ray, and gamma radiations, as well as radiation from radioactive materials, such as cobalt-60.

The processes of this invention may be utilized to apply to keratin fibers any compound which will react with the fibers and polymerize thereon. The most satisfactory compounds are characterized by the group and include both the monomeric and low polymeric (readily polymerizable) forms of these compounds. Included within this class of compounds are N-dialkyl acrylamides, e.g., N,N'-dimethyl, -diethy1, -dipropyl, -dibutyl, -diamyl, -dihexyl, -dioctyl, etc., acrylamides, N-(panisyl)methacrylamide, N (p chl0ropheny1)methacrylamide, N-phenyl methacrylamide, N-ethylmethylrnethacrylamide, N-methylmethacrylamide, N-(p-tolyDmethacrylamide and the like; the acrylic, alpha-alkyl acrylic and alpha-haloacrylic esters of saturated monohydric alcohols, for instance saturated aliphatic monohydric a1- cohols, e.g., the methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, etc., esters of acrylic, methacrylic, ethacrylic, propacrylic, chloroacrylic, bromoacrylic, aconitic, itaconic, maleic, crotonic, fumaric etc., acids; these latter acids and anhydries thereof; the phenyl, benzyl, phenylethyl, etc., esters of the aforementioned acids; vinyl aromatic compounds, e.g., styrene; methylstyrenes, such as 0-, m-, p-methylstyrene; dirnethylstyrenes, such as 2,5-dimethylstyrene; halogenated styrenes, such as -bromostyrene, p-bromostyrene, p-iodostyrene, pentachlorostyrene, dichlorostyrene, a,,8,,8-trifiuorostyrene, 2,5 bis(trifluoromethyl)styrene, 3-trifluoromethylstyrene and the like; the various cyanostyrenes; the various methoxysty-renes, such as p-methoxystyrene, vinyl naphthalcnes, such as 4-chlorol-vinylnaphthalene, 6-chloro 2 vinylnaphthalene, etc.; vinyl and vinylidene halides, e.g., vinyl and vinylidene chlorides, bromides, etc.; alkyl vinyl ketones, e.g., methyl vinyl ketone, ethyl vinyl ketone, methyl isopropenyl ketone, etc.; itaconic and maleic diesters containing a single group e.g., the dimethyl, diethyl, di-B-chloroethyl, diethylchloro, dipropyl, disopropyl, dibutyl and other saturated aliphatic monohydric alcohol diesters of itaconic and maleic acid, diphenyl itaconate and maleate, dibenzyl itaconate and maleate, di-(phenylethyl) itaconate and maleate, etc.; vinyl allyl and metallyl esters of saturated aliphatic monocarboxylic acids, e.g., vinyl, allyl and metallyl acetates, vinyl, allyl and metallyl propionates, vinyl, allyl and methallyl valerates, etc.; vinyl thiophene; vinyl pyridine, vinyl pyrrole; nitriles containing a single 7 OH2=C|3 group, e.g., acrylonitrile, methacrylonitrile, etc.

Additional suitable ethylincally unsaturated compounds include:

l-acetoxy-l,3-butadieneacrolein; allyltriethoxysilane; N-benzylidene-4-methacryloxyaniline; bis (trimethylsiloxy) vinylmethylsilane; S-bromovinyl ethyl ether; 1,3-butadiene; Z-butenyltriethoxysilane;

n-butyl cinnamate;

n-butyl crotonate;

N-butyl crotonate;

N-butyl maleirnide;

n-butyl vinyl ether;

tert-butyl vinyl ether, 11 butyl vinylsulfonate; 2-chloroallyl acetate;

2-chloroallyl alcohol; u-chlorovinyltriethoxysilane; citraconic anhydn'de; crotonaldehyde, crotonic acid; 1-cyano-l,3-butadiene;

diallyl phthalate; 4,6-diamino-Z-vinyl-s-triazine; 2,3-dichloro-1,3-butadiene;

diethoxyethylvinylsilane;

diethoxymethylvinylsilane;

diethoxyphenylvinylsilane;

diethylaminoethyl methacryl-ate;

diethyleneglycol monovinyl ether;

diethyl fumarate;

diethylvinylphosphonate;

l,l-dihydroperfluorobutyl acrylate;

N-( l, l-dihydroperfiuorobutyl -N-ethyl acrylamide;

dimethallyl oxalate;

2,4-dimethoXy-6- fi-itaconylhydrazino) -s-triazine;

2- N, N- dimethyl amino -4-vinyl pyrimidine;

2,3-dimethyl-1,3-butadiene;

dimethyl 'dithiolfumarate;

dimethyl fumarate;

dimethyl methacrylyliminodiacetate;

dinonyl fumarate;

m-divinyl-benzene;

divinyl sulfide;

1,4-diviny1-2,3,5,6-tetrachlorobenzene;

ethyl a-acetoxyacrylate;

ethyl acid fumarate;

ethyl acid maleate;

ethyleneglycol dimethacrylate;

ethyl ,G-ethoxyacrylate;

ethyl methacrylylaminoacetate;

ethyl vinyl ether;

5-ethyl-2-vinylpyridine;

ethyl vinyl sulfide;

N-ethyl-N'-vinylurea;

fumaronitrile;

fumaryl chloride;

glycidyl methacrylate;

hydronopyl acrylate;

p-iodostyrene;

isobutyl vinyl ether;

isopropyl vinyl ether;

maleonitrile;

methacrolein;

4-methacryloXybenzylideneaniline;

4-methacryloxybenzylidene-4'-chloroaniline;

methacryloxymethylpentamethyldisiloxane;

N-methacryloyl-e-caprolactam;

methallyl acetate;

methallyl chloride;

p-methoxystyrene;

methyl acid maleate;

methyl a-chloroacrylate;

methyl thiolacrylate;

methyl vinyl ketone;

Z-methyl-S-vinylpyridine;

methyl vinyl sulfide;

methyl vinyl sulfone;

methyl vinyl sulfoxide;

N-methyl-N-vinyl-p-toluenesulfonamide;

pentachlorophenyl vinyl sulfide;

phenyl vinyl sulfide;

phenyl vinyl sulfone;

poly( 1,3-butyleneglycol fumarate);

poly(ethyleneglycol fumarate);

p-potassium styrenesulfonate;

n-propyl crotonate;

sodium acrylate;

sodium methacrylate;

sodium styrenesulfonate;

sodium vinylsulfonate;

triethoxyvinylsilane;

triethyl aconitate;

N,N,N-triethyl-N-(Z-methacryloxyethyl)-ammonium iodide;

trimethoxyvinylsilane;

trimethyl aconitate;

trimethylsiloxyvinyldimethylsilane;

trimethylvinylsilane;

triisopropoxyvinylsilane;

7 tris(trimethylsiloxyl)vinylsilane; vinyl acetylene; vinyl benzoate; vinyl butyrate; vinyl caprate; vinyl caproate; vinyl isocaproate; vinyl caprylate; 9-vinylcarbazole; vinyl chloroacetate; vinylcyclohexene; vinyl dichloroacetate; vinylene carbonate; vinyl Z-ethylhexanoate; vinyl formate; vinyl isocyanate; vinyl isothiocyanate; vinyl laurate; vinyl levulinate; 2-vinylmercaptobenzothiazole; l-vinyln-aphthalene; 2-vinylnaphthalene; N-vinyl-Z-oxazolidinone; vinyl palmitate; vinyl pelargonate', vinyl perfluorobutyrate; 2-vinylphenanthrene; 3-vinylphenanthrene; m-vinylphenol; vinyl pinonate; 2-vinylpyridine; 4-vinylpyridine; 4-vinylpyrimidine; N-vinylpyr-rolidone; Z-vinylquinoline; vinyl; vinyl stearate; N-vinylsuccinimide; vinylsulfonic acid; vinyl thiolacetate; 2-vinylthiophene; vinyl trifluoroacetate; vinyl undecylenate; N-vinylurethane; and the like.

The treatment of keratin fibers in accordance with this invention may be conducted at any desired temperature, although temperatures between about 40 and about 60 C. are generally preferred. A temperature in eX- cess of about 100 C. is generally not preferred when a redox catalyst system is used since some of the components of these systems degrade at elevated temperatures.

In general, such conditions as concentrations of the reagents, pH time and temperature of reaction may be modified to suit the individual circumstances and equip ment selected, while still providing the desired conversion at low homopolymer levels.

Reaction between the keratin fibers and the ethylenically unsaturated compounds most readily takes place in the presence of water. This generally presents no problem since the catalyst components or monomer are preferably applied to the substrate in an aqueous medium. If the substrate is dry, however, during exposure to the monomer or low polymer, the ensuing reaction will be slower. Consequently, it is preferred that the substrate fibers be moistened with water when the reaction takes place. Ionic or non-ionic surface active agents may be utilized in any aqueous medium used in applying any of the reagents.

Improved results may be obtained when the keratin fiber substrate is in a swollen condition during reaction. This condition is most readily obtained by conducting the reaction in the presence of a-swelling agent for keratin fibers, such as urea, thiourea, lithium salts, such as the chloride, bromide and iodide; guanidine compounds, such 8 as the hydrochlorides; amides, such as formamide, N,N'- dimethylformamide, acetamide, N,N'-dimethylacetamide and the like.

The wool fibers are exposed to the monomer in a most highly preferred embodiment of this invention as a solution in that package dye machinery is readily available and particularly adaptable to the application of such systems to wool fibers. Other liquid systems, such as dispersions and emulsion, however, may be utilized if desired.

In the preferred embodiment of this invention, the readily polymerizable ethylenically unsaturated com pounds are applied to keratin fibers in a substantially free form, such as in the form of top, tow, roving, sliver or the like. In these forms, the fibers are freer to uncrimp during treatment than are the fibers of yarn or fabric. This is. generally true even though the fibers are wound quite tightly into package form during treatment, although the difference in uncrimping freedom is less Under this condition. Substantial improvement is obtained, however, even when such compounds are applied to yarns and fabrics under the required flow conditions.

Cellulosic fibers, such as cotton, cellulose acetate, viscose rayon and the like also may be treated in accordance with this invention. When treating a cotton substrate, it is generally preferred to conduct the reaction on yarn or fabric. In addition to the above initiating systems, ceric ions also may be used, e.g., in the form of ceric salts, such as ceric nitrate, ceric sulfate, ceric ammonium nitrate, ceric ammonium sulfate, ceric ammonium pyrophosphate, ceric iodate and the like.

A typical apparatus for conducting the processes of this invention is shown in the drawing. The conventional package dye machine shown therein is a closed system comprising the dye chamber 1, recirculating conduits 2, 3 and 15 and pump 4. Feed lines 5, 6, and 7 are used to feed the desired reagents into the recirculating system. The dye chamber 1 is partially surrounded by a jacket 8 into which may be fed either steam for heating or water for cooling. Located within the dye chamber in circulating relationship with conduit 3 is a perforated spindle 9.

The fiber package 10, composed of wool top supported on a cage-like bobbin 11, is mounted on perforated spindle 9. A 4-way reverse valve 12 is provided Within the recirculation system for changing the direction of flow of the system or systems utilized, valves 13 and 14 being provided for flow rate control.

In operation, an aqueous solution containing the desired ethylenically unsaturated compounds and the catalyst components is added through feed line 5 into recirculating conduit 15. This system is then pumped past the reverse valve 12 (shown here in outside-in position) into the dye chamber 1, where it is forced nnidirectionally through the fiber package from the outside thereof into the spindles and conduit 3, and then recirculated. The reverse valve 12 is periodically switched to the position shown by dotted lines at 12' in order to reverse the flow of fluid from the inside of the spindle to the outside of the package, again unidirectionally. This procedure is repeated until the monomer is substantially exhausted onto and into the Wool fibers.

Besides package dyeing machinery, other fluid flow machinery adjusted to provide the desired flow, can be utilized. For example, the pressure-beam dyeing equipment of Burlington Engineering Sales Company and Gaston County Dyeing Machine Company may be modified for operation in accordance with this invention.

In the following examples, except where noted, each wool sample treated is scoured by immersing in or having passed therethrough in the package dye machine, an aqueous solution containing 0.5% on the weight of wool of surfonic N-95, anon-ionic surface active agent and 1.5% onthe weight of wool of glacial acetic acid. After scouring for 20 minutes at 140 F. the sample is rinsed in water at F. for 10-15 minutes. Deionized water is used in preparing all aqueous media.

9. Example 1 Into a two-pound Gaston County package dye machine, are mounted 800 grams of wool top, 400 grams being mounted on each of two bobbins which are placed on the single perforated spindle of the dye machine. After scouring and rinsing the wool top, an aqueous solution made up from 7400 cc. of H containing 1.74 gms. Fe(No -9H O (0.03% Fe+++ based on wool wt.), 12.2 cc. of a 50% solution of H 0 (50/1 molar ratio of peroxide based onFe+++) and 40 cc. of concentrated H SO is circulated through the machine and wool top. After 10 minutes, 960 gms. of acrylonitrile (enough for 120% pickup) is added into the recirculating catalyst system. The resulting system has a pH of 1.3 and provides a liquor/Wool ratio of 11/1. This system is then held at 7585 F. and forced back and forth through the fibers at a flow rate of about 34 gallons per minute for 15 minutes at a cycle of 3 minutes outside/in and 2 minutes inside/out, after which the temperature is increased to 120 F. by passing steam through the heat jacket of the package dye machine. The reaction is continued at this temperature for an additional 105 minutes.

The wool top is then removed from the machine and found to have increased in weight uniformly by 95.5%.

When this same process is conducted with constant stirring in a one-liter flask, the wool top increases in weight by only 10%. Among other things, this shows that processes considered inoperable in a flask are rendered operable by conducting the process in a package dye machine adjusted to deliver the above flow conditions.

A plain weave fabric is produced from the above fibers and compared with a similar fabric reacted as such with the same acrylonit rile system to about 95% pickup. This latter fabric has lost all fabricproperties, being boardy and coarse in handle, while the fabric produced from the above wool top is far superior in handle.

The fibers treated in the package dye machine have an uncrimping extension of 0.79%, an uncrimping energy of 0.0003 gm. cm./cm. grex, tenacity at extension of 0.64 gm./grex, tenacity at the break of 0.85 gm./grex and an extension to break of 35.52%, s

.' Example IIv The procedure of Example I is repeated, except that the discharge pressure is adjusted to various levels and the acrylonitrile is added to the recirculating catalyst system prior to impregnation of the fibers therewith. At a discharge pressure corresponding to a flow rate at the dis charge side'of the pump of 10 gallons per minute from the package dyeing machine into the recirculating system, the wool top so. treated increases in weight by 94% but contains a large'amount'(from 1020% across the wool top) of extractible homopolymer. At this discharge pressure and the various concentrations involved, it is computed that the wool is initially contacted by 5.2 lbs. of acrylonitrile/lb. of wool/minute.

The flow rate is then adjusted to 34 gallons/minute and the wool top so treated is found to increase in weight by 93%. Atthis increased level of flow, however, little or no homopolymer is deposited upon the wool top. The concentration of acrylonitrile which initially contacts the wool at this flow rate is calculated to be 17.7 lbs. acrylonitrile/ lb. of wool/minute.

Even though the wool top samples contain essentially the same amount of reacted acrylonitrile, the handle of the sample differs radically. The wool top which was treated at a discharge pressure of 10 gallons/minute feels harsher than the sample treated at the increased flow rate. In addition, the latter wool top is readily processable into yarn, while the Wool top treated at the lower flow rate fails to process into yarn because of tackiness caused by the large amounts of homopolymer present.

Example 111 Onto the beam of a 100-lb. capacity Gaston County package dye machine, are wound 63 lbs. of wool top.

The beam is then mounted over the perforated spindle, the machine is closed and the wool is scoured for 30 minutes at 140 F. with gallons of water containing 149 gms. of synfac 905, a non-ionic wetting agent containing a nonylphenol-ethylene oxide (1 to 9 to 1 to 2 molar ratio) condensation product, and 429 gms. of acetic acid. During the scouring operation, as in all succeeding operations in this example, the liquids are forced back and forth through the wool at a cycle of 4 minutes outside-to-inside, 6 minutes inside-to-outside.

After scouring, a redox catalyst system maintained at F. and composed of 63 gms. of Fe(NO and 429 gms. of 50% H 0 in.75 gallons of water, adjusted to a pH of 1.35 with 12 lbs. of H 80 is passed through the wool for 20 minutes. The flow rate of the system through the wool is measured as'about gallons/minute.

Four-teen lbs. of butyl acrylate and 5 lbs. of styrene are then added to the recirculating catalyst solution and the resulting system is run for 20 minutes at 120 F. The remaining monomers (43 lbs. butyl acrylate, 14 lbs. styrene) are added to the system continuously until expended-about 1% hours. The reaction is continued for an additional 3 hours, after which the machine is drained and the wool is washed with water at 75 F. for 20 minutes' As afinishing operation, the wool is then impregnated with 80 gallons of water containing 4% arquad 1650, hexadecyltrimethylammonium chloride lubricant, and 1% synfac 905 for 30 minutes at F.

The wool top treated in this manner is found to have increased in weight by 100.6%.

Example IV (Run 33) Example V A package wound from one pound of 1/34s yarn is mounted onto the spindle of a package dye machine as used in Example I. The package is scoured at F. by circulating therethrough 10 liters of tap water containing 0.5% by weight of surfonic N-95. The machine is then drained and 10 liters of a 0.2% ferrous ammonium sulfate solution containing 10 milliliters of 1 N H SO is placed in the machine and circulated for 2 hours, during which time the temperature rises to 104? F.

After draining the machine and rinsing the yarn, a solution made up of 500 milliliters acrylic acid, 28 milliliters l N H SO and 12 milliliters of 35% hydrogen peroxide in 10 liters of water containing 0.02% methylethyl hydroquinine is introduced into the machine. This solution is circulated through the yarn package at F. for four hours.

After completion of the reaction, the machine is drained and the package rinsed with water, then again with a 10 liter solution containing 0.5% surfonic N95 and 10 milliliters hydrochloric acid. After Washing with this solution for 30 minutes at 140 F., the package is rinsed and dried. Upon weighing, the yarn is found to have increased in weight by an average of 35 This yarn is then dyed, along with an untreated control yarn, in 10 liters of water containing 0.188 gm. sulphon acid blue, 7.5 gms. sodium sulfate, 1.5 gms. surfonic N-95 and 2.25 milliliters acetic acid. After boiling in this dye formulation for one hour, the yarn which has been reacted with acrylic acid is found to have picked up substantially less dye than the untreated control, so

that a fabric produced from both yarns could be dyed to a two-tone effect with a single dyestuff.

Example VI The procedure of Example III is repeated, except that a monomer system composed of 37.8 lbs. of Z-ethylhexyl acrylate, 37.8 lbs. of styrene and 15 lbs. of dibutyl maleate is used. In three separate tests, the flow rate of the system through the beam of fibers is adjusted to 40 gallons per minute, 80 gallons per minute and 120 gallons per minute, respectively.

After drying, the three fiber samples are measured for percent pickup, uniformity of pickup from inside to outside of the beam and percent extractible material. Since the same amount of monomers is used in each test, the pickup of polymeric material on the fibers is essentially the same in each test.

The outstanding difference between the three samples is the uniformity of pickup across the beam of reacted wool top. At a flow rate of 40 gallons per minute, there is an average variation in'pickup across the beam of 41% (from 108% in some areas to 67% in others), while at a flow rate of 80 gallons per minute the average variation is even greater at 51% (from 121.5% to 70.5%). At a flow rate of 120 gallons per minute, however, the variation is only 14.5% (from 73% to 57.5%), a remarkable improvement in uniformity of the product.

In extraction tests, wherein the fibers are basted in dirnethylformamide for 6 hours, less material is removed from the'fibers treated at 120 gallons per minute than from those produced at the lower flow rates.

A plain weave fabric produced from yarns made up from the fibers treated at 120 gallons per minute has a soft, pleasant hand, whereas a similar fabric treated to about 60% pickup by immersion first in the Fe(NO then in the peroxide and monomer system of this example, has a tacky handle far inferior to the above fabric produced from reacted wool top.

Example VII Cotton fabric (162.6 g.) is wound on the spool of a /2 lb. package dyeing machine with a flow rate of 6.5 liters/min. After scouring and rinsing the cotton as in Example I an emulsion of methyl acrylate (180 g.) and Arquad 18 (15 g.) in water (1300 ml.) is added and circulated while flushing With nitrogen at a temperature of 77 F. A solution of 0.1 M ceric ammonium nitrate/ N-nitric acid (50 ml.) is then added dropwise over 75 min. with circulation at 77 F., and the liquid then discarded.

The resultant product is then rinsed with water, neutralized with a 1% solution of sodium bicarbonate and rinsed again to a final pH of 6. After air-drying, the treated sample is found to weigh 295 g., the weight increase being 82%.

It has been shown above that fabrics of improved handle can be provided by treating fibers in generally lose form and processing them into fabrics. This process can be greatly improved by conducting the process under certain conditions of forced flow. The small amounts, or absence, of homopolymer when these processes are conducted under certain conditions of flow eliminates the necessity for conducting extraction techniques,

In addition, the forced'flow process provides a technique whereby the amount of homopolymer formed may be controlled, from the point of elimination to controlled low levels. In addition, less time is required to get efficient conversion of available monomer. Furthermore, the products prepared in accordance with this invention are much whiter than fibers of prior art processes, which often are substantially darkened during treatment. This greatly increases the uses of such fibers in providing fibers suitable for use in fabrics dyed to light pastel shades.

()ne of the outstanding advantages of the forced flow rate system provided by this invention is that wool fibers may be treated with a single system containing both the catalyst Components and the monomer without forming appreciable amounts of homopolymer.

That which is claimed is:

1. A process for modifying the characteristics of continuous lengths of loose, non-woven textile fibers which are confined in a given configuration throughout the modification comprising providing a solution of a compound containing the group and a fibrous substrate; forcing said solution at a rate substantially greater than that possible as a result of merely refluxing said fibers in said solution through said fibrous substrate unidirectionally, intermittently back and forth throughout the process, said process being conducted in the presence of a chemical catalyst for the polymerization of said compound.

2. The process of claim 1 'wherein keratin fibers are treated, said fibers being in a condition whereby they are substantially free to uncrimp from their natural crimp level while said solution is being forced therethrough.

3. The process of claim 1 wherein the solution is forced at a sufliciently rapid rate that the supply of compound at the surface of the fibers is constantly being replenished in an amount, at least initially, considerably in excess of that which the fibers can have exhausted therein.

4. The process of claim 1 wherein the compound is supplied to the fiber surfaces at a rate in excess of about 5 lbs/lb. of fibers/minute.

5. The process of claim 1 wherein said solution is forced past the fibers at a rate so as to provide an excess of at least about 1000 times that which theoreti cally, initially, exhausts per minute.

6. The process of claim 1 wherein the chemical catalyst comprises a redox catalyst system.

References Cited by the Examiner Lipson et al.: Nature, vol. 157, p. 590 (1946).

Lipson et al.: Nature, vol. 157, p. 736 (1946).

Lipson: Nature, vol. 164, p. 576 (1949).

Speakman et al.: Journal of the Society of Dyers and Colorists, vol. 70, pp. 112-116 (1954).

Valentine: Journal of the Textile Institute, T27 0-T283,

Claims (1)

1. A PROCESS FOR MODIFYING THE CHARACTERISTICS OF CONTINUOUS LENGTHS OF LOOSE, NON-WOVEN TEXTILE FIBERS WHICH ARE CONFIRMED IN A GIVEN CONFIGURATION THROUGHOUT THE MODIFICATION COMPRISING PROVIDING A SOLUTION OF A COMPOUND CONTAINING THE GROUP CH2=C< AND A FIBROUS SUBSTRATE; FORCING SAID SOLUTION AT A RATE SUBSTANTIALLY GREATER THAN THAT POSSIBLE AS A RESULT OF MERELY REFFLUXING SAID FIBERS IN SAID SOLUTION THROUGH SAID FIBROUS SUBSTRATE UNIDIRECTIONALLY, INTERMITTENTLY BACK AND FORTH THROUGHOUT THE PROCESS, SAID PROCESS BEING CONDUCTED IN THE PRESENCE OF A CHEMICAL CATALYST FOR THE POOLYMERIZATION OF SAID COMPOUND.

Images