US2931695A

US2931695A - Halogen substituted mono-aromatic phenolic reserving agents for acrylonitrile polymer base fibers

Info

Publication number: US2931695A
Application number: US751652A
Authority: US
Inventors: William M Blankenship; Allan R Wirth
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1958-07-29
Filing date: 1958-07-29
Publication date: 1960-04-05
Anticipated expiration: 1977-04-05

Description

linited States Patent HALOGEN SUBSTITUTED MONO-AROMATIC Pm:- NOLIC RESERVING AGENTS FoR ACRYLONI- TRILE POLYNIER BASE FIBERS William M. Blankenship, Williamsburg, and Allan R. Wirth, Newport News,Va., assignors to TheiDow Chemical Company, Midland, Mich., a corporation of Delaware No Drawing. pplication July 29, 1958 Serial No. 751,652

21 Claims. (Cl. 8-21) A valuable and significant contribution to the synthetic fiber art has been the development and provision of the nitrile alloy class of fibers. Such man-made fibers are comprised essentially of an acrylonitrile polymer base which contains in the polymer molecule at least about 80 weight percent of acrylonitrile, advantageously polyacrylonitrile, which has been beneficially modified without sacrifice of or compromise in its basic fiber properties by alloying the acrylonitrile polymer base, as it were, with beneficial additaments or constituents that are adapted to achieve one or more ameliorative ends for the fiber product. Primarily, and of exceptional benefit, the nitrile alloy fibers contain appropriate functional components that render the fiber product remarkably and permanently receptive of many of a Wide variety of dyestuffs. Because of this, nitrile alloy" fibers are readily dyeable to deep and level shades of lasting coloration by practice of ordinary dyeing techniques and procedures, using the usual materials and operations for the purpose. By their superior attributes in these as'well as other particulars, the nitrile alloy fibers are clearly and easily distinguishable from the conventional prototype acrylonitrile polymer fibers (including the usual and well known copolymeric varieties) with which the art is familiar and which are oftentimes referred to and known as being acrylic fibers.

As paradoxal as it may seem, there are instances wherein the exceptional and capacious receptivity to dyestuffs of nitrile alloy fibers might advantageously be restrained or partially or completely diminished, in order that such characteristics of the fiber product might be basically altered so as to provide it with a partial or complete degree of resistance to becoming stained or colored with dyestuffs.

For example, if a stain-free, white fiber product is desired from a nitrile alloy material, such as a cloth or fabric article, it would be advantageous for the nitrile alloy to be provided in such a form as to be capable of complete resistance to becoming stained or colored by dyes or other color-imparting substances with which the nitrile alloy may come in contact.

Of at least commensurate practical significance is the problem of producing white or two-toned effects on nitrile alloy fibers when they are dyed in the presence of other fibers, such as cellulosics or wool and other proteinous fibers (both natural and artificial or synthetic in origin) with which the nitrile alloy fibers may be blended as well as that of achieving union-dyeing or t advantages, may be achieved pursuant to the compre- 2 of the fibers in the blend) to the same or sequentially the same uniform and balanced blend of coloration of each of the fibers in the blend. For purposes of achieving the immediately above-mentioned ends, it would be advantageous, as is apparent, for nitrile alloy fibers to be provided in such a form that they would have only a partial resistance to or reserving action against dye stuffs and coloring agents, depending on whether diverse or equal tones of coloration are desired in the dyed blend in which the nitrile alloy fiber is contained. 7

Thus, it would be advantageous, and it is the aim andconcern of the present invention, to provide nitrile alloy fibers, altered or modified with respect .to their receptivity for dyestuffs over a range extending fromthe capability of such altered forms of nitrile alloy fibers.

were, from slightly to considerable in inverse proportion to their altered degree of dye-receptivity.

It is the principal object of the present invention to.

provide and make available highly efficacious reserving (or dye-resisting) agents specific in their limiting effect or action from the dye-receptivity of nitrile alloy fibers so as to be useful for the several indicated and related purposes upon and in conjunction with nitrile alloy fibers, particularly those comprising polymerized N-vinyl lactam (especially N-vinyl pyrrolidone or N-vinyl caprolactam) or polymerized N-vinyl-Z-oxazolidinone (including especially the unsubstituted and methyl and ethyl ring-substituted species) constituents as dye-receptive adjuvants for the fiber, including unmixed nitrile alloy fibers as well as blends of nitrile alloy" fibers with cellulosic or proteinous fibers and yarn, thread, cord and the like and cloth or fabric constructed from such fibers or fiber blends.

Another object of the invention is to provide, as new and improved articles of manufacture, nitrile alloy" fibers, including such fibers in unmixed as well as in blended forms and textile articles constructed therefrom, having their degree of dye-receptivity or susceptibility to coloration or staining by dyes and the like controlled by modification or alteration of their normal characteristics in such regards by means of certain dye-resisting agents, as herein more fully delineated, applied to the fibers.

Still an additional object of the invention is to furnish a method or means for controlling the dye-receptivity of nitrile alloy fibers in unmixed or blended masses or in various constructed or fabricated textile articles or, as might be otherwise expressed, a new and improved method for dyeing or controlling the dye receptivity of nitrile alloy fibers, especially when they are in blended cellulose or proteinous fiber-containing masses, so as to achieve and possibilitate tw0-tone or union-dyeing effects.

Yet another object of the invention is to provide reserving agents for nitrile alloy fibers having excellent resistance to caustic solutions so as to provide fiber compositions comprised of the nitrile alloy fibers treated with the agents that are capable of demonstrating unusual resistance to staining after dyeing and to discoloration of the fiber when it is subjected to highly basic solutions, such as those which are frequently encountered in scouring operations and in some types of dyeing procedures.

The above indicated objects, and corollary benefits and Patented Apr. 5, 1960 lrension andpractice ofthepresent invention by treating a"nitrile alloy fiber' (particularly one of the herein indicated highly desirable varieties) with a minor proportion of from about 0.1 ,to about -25 weight percent, biased on the weight of the resulting composition and depending upon the extent of dye-resistance or degree of control desired, of a certain variety of halogen substituted mono-aromatic phenolic materials, as herein more fully illustrated, as a dye-reserving or dye-resisting agent that is applied to and is in intimate physical contact with the fiber at least during the treatment. As might be anticipated, the degree of control or resistance to dyeing or the extent of modification of the dye-receptivity of the nitrile alloy fiberthat may be achieved is in proportion to the quantity of thedye reserving or resisting agent that isapplied thereto or employed for the treatment.

ln' this connection, not all of the presently contemplated halogen substituted mono-aromatic phenolic reserving agent initially applied to or employed for treatment of the nitrile alloy fiber is generally or necessarily aflixed in a permanent and wash-resistant manner to the fiber. The reserving agents are not without exception permanently adsorbed by the nitrile alloy in quantitative proportion to the relative amount in which they are applied to or used for initial treatment of the fiber. A good proportion (frequently 60 weight percent or more) may frequently be washed, leached or extracted out of the fiber after (or even during) the initial treatment by cold water or other solvent liquid washes. It is diflficult to predict in all instances precisely and exactly how much of the presently contemplated reserving agent is permanently and with positive substantivity affixed to the niti'ile alloy fiber in the practice of the present invention. Generally at least about 0.01 weight percent on the weight ofthe dry fiber (o.w.f.) and frequently in the neighborhood of at least 0.05 percent is permanently adsorbed, incorporated in and retained by the nitrile alloy after thetreatment and despite the extractive influence of water and most other solvent washes. The mechanism of the presently contemplated reserving agents apparently is independent of a quantitative, physically permanent adsorption but is thought to involve more of a blockingout efliect of the dycstuff from the nitrile alloy comp sition. In any event, minor proportions of permanently and substantively retained reserving agent of the aboveindicated order of magnitude are, surprisingly enough, adequate to produce the described anti-staining characteristics in the treated nitrile alloy article. And, even more remarkably, the degree of anti-staining efiect achieved (despite the relatively minute quantities of re serving agent that may be retained with true permanence inthe nitrile alloy article) is dependent upon and a function of the relative quantity of agent initially applied to andused to treat the fiber.

vThus, complete or practically complete resistance to dyeing and coloration are generally afforded by heavier applications of or treatments with the agent, such as those in the neighborhood of from about 10 to weight percent o.w.f. which, as indicated, is not necessarily or even probably all permanently retained by the fiber. A partial or appreciably enhanced resistance to dyeing (or decrease in dye-receptivity) of the nitrile alloy fiber blends may be secured by using a reserving quantity of the agent on and in the initial treatment of the fiber that is between about 1 or 2 to about 10 percent by weight o.w.f., with the specific ultimate effect (notwithstanding permanent retention) of the agent again being proportional to the quantity employed. Union-dyeing effects in blends of nitrile alloy fibers of the cellulosic or proteinous fibers may ordinarily be facilitated by utilizing application of or treatment with a balancing quantity of the agent between about 0.1 and 1.5 or 2 percent by weight o.w.f. (not necessarily and probably not actually all permanently retained) in order to promote excellent shade balancing of all the diverse filamentary 4 components during the dyeing of the blend, especially when'the dyestuffs employed have a propensity to" build up upon or disproportionately'color the nitrile alloy fiber in the blend, as is often the case with certain direct or after-treated types of dyestuffs when used to dye cellulosic blends of the nitrile alloy fibers and certain aciddyestuffs with proteinous blends. In any case, the precise quantity of the reserving agent that is necessary to be applied or used in the treatment for any particular purpose can be quickly and readily determined by relatively simple and straightforward control testing techniques.

The treated nitrile alloy fiber products prepared in I accordance with the present invention have the same physical properties as their untreated counter-parts and have the added features of controlled dye shades, of resistance to caustic discoloration and of stain resistance after dyeing. In this connection, an amount of the reserving agent used in the treatment (and not necessarily permanently retained) that is between about 0.5 and 2 percent by weight, based on the weight of the resulting fiber product, is generally preferred to secure optimum caustic stability in the treated nitrile alloy fiber products.

The reserving agents for the present invention are, as

indicated, at least partially and to a detectable degree ad-.

herescent upon and substantiative to the nitrile alloy" fibers and, once applied, remain in at least minute quantities on the fiber in a generally permanent manner throughout the normal usages and exposures to which the fiber may be put. In general, the permanently retained quantities of the dye reserving or resisting agents have no excessive deleterious effect or intolerable influence on the physical or aesthetic characteristics and properties of the fibers on which they are applied and may ordinarily be employed for many of a wide variety of uses with relative impunity in this regard. Of course, certain of the properties of the treated fiber may vary with the employment of particular treating agents and the quantity of the agent utilized in and permanently retained by the fiber from any given treatment.

j In addition to using'the agents for purposes of stabilizing or augmenting the resistance to staining by dyestuffs and the like of uncolored nitrile alloy" fibers, the agents may be frequently employed with considerable benefit upon already dyed or colored articles of the fiber to increase or establish their resistance to undesired staining or additional coloration from various sources. Such stain-proofing treatment, incidentally, may also be made on dyed or otherwise colored nitrile alloy fibers that have been pretreated, prior to dyeing, with lesser, dyeaccepting, modifying or mere color reserving" or balancing applications or doses of the agent in quantities insufiicient to achieve a total or absolute (or practically so) dyeing or coloration-resisting effect. In addition, as is apparent, the reserving agents may also be used with great advantage for producing white effects in fiber mixtures in piece dyeing, such as may be accomplished by depositing or printing the reserving agents on the nitrile alloy cloth or fabric goods being dyed, followed by the piece dyeing operation.

The reserving or dye-resisting agents of the present invention, as has been indicated, are capable of achieving excellent results with many dyestuffs, especially with direct types of dyes and certain acid dyes, on nitrile alloy fibers.

The halogen-substituted mono-aromatic phenolic reserving agents that'are so advantageously employed in combination with the nitrile alloy fibers in the practice of the present invention are of'the structural formula whereineach-X is independently chlorine or bromineand R is chlorine; bromine; fluorine; hydroxy; (-OH); methyl '(-CH ethyl (-C H and other alkyl substituents containing up to about 4 carbon atoms; 1 to 4 carbon atom alkoxy radicals such as methoxy (--OCH and partly or completely halogen substituted alkyl substituents containing halogens of atomic number from 9 to 35 and from 1 to about 4 carbon atoms such as trifluoromethyl (-CF trichloromethyl (CCl etc.; and the like. Advantageously, such compounds as tetra bromo-o-cresol, tetra-chloro pyrocatechol, pentachloro phenol, penta-bromo-phenol, 3,5-dibromo-2,4,6- trichloro phenol, and the like are utilized as reserving agents in the practice of the present invention.

It is advantageous for the applicating formulation or composition of the dye-resisting agent that is utilized for deposition of the latter upon the nitrile alloy fibers to contain between about 0.1 and 20 percent by weight, based on the weight of the fiber, of the dissolved or dispersed dye-resisting agent, depending on the precise quantity of the agent that may be desired to be deposited in or. at least employed for treatment of the fiber. The actual concentration of the agent with respect to the liquid medium in which it is applied may be much less :than the above indicated values. highly effective in their result on the nitrile alloy fibers, their precise concentration with respect to the liquid vehicle in the applicating formulation is relatively immaterial. Generally, the precise concentration of the reserving agent in the liquid vehicle therefor contained in the applicating formulation is not an essential criticality in the practice of the present invention. In most instances, however, it is unnecessary for the applicating formulations to contain more than about 5 percent of the dye-resisting agent, based on the weight of the dry fiber used and depending on the type of dyeing procedure to be employed. Suitable application of the dye-resisting agent may be made when the liquor-to-fiber ratio of the applicating formulation to the nitrile alloy fiber being treated is between about 1 and 100 parts by weight of the former to .eachpart by weight of the fiber. More often, it is advantageous for such liquor-to-fiber ratio to be betweenabout 2:1 and 50:1, respectively.

'Various techniques may be utilized for preparing suitable applicating formulations of the dye-reserving or resisting agent. Usually, as is apparent, it is advantageous to apply it from an aqueous liquid dispersion or solution,

particularly a basic solution containing minor propor-. tions of sodium hydroxide or other caustic ingredients.

Such a dispersion may be prepared by making preliminary or preparatory solution of the dye-resisting agent in a liquid in which it is soluble (such as aqueous sodium hydroxide or other caustic solution or lower aliphatic alcohols or ketones) and then diluting the initially prepared solution with the desired quantity of the water to prepare the final formulation. Most advantageously, especially when the reserving agents are used in conjunction with dyeingtreatments on the fiber, the applicating formulation may be prepared and employed directly as part of the liquid vehicle or bath in which the fibers are contained during the dyeing. Thus, if it is intended to apply the resisting agent prior to dyeing, the applicating formulation may be prepared and used for treatment with the resisting agent as well as to constitute the body of the dye bath in which the dyeing treatment is accomplished.

In an analogous manner, the dye-resisting agents may be added to dyed fibers in intermediate stages or after completion of dyeing by incorporating them in the dye bath during the dyeing treatment or after the dyeing has been accomplished, depending upon the particular purpose for which the agent is being employed. When aqueous caustic solutions, such as aqueous sodium hydroxide solutions, are used as the dispersing vehicle for the agent, it is generally of benefit for the strength of the solution to be such. that its pH is between about 8 and 13.

Since the agents are In addition to the procedures mentioned in the fore going, the dye-resisting agents may also be applied toy or used for treating the fibers from their applicating formulations by distributing the formulation, somewhat in the manner of conventional textile finish application, directly to a running strand of the nitrile alloy fiber being treated, using a liquid jet or spray of the formulation. If desired, applicating rollers and equivalent devices may be utilized for such purpose. When the dyeresisting agents are being applied to or for treating nitrile alloy articles, including articles prepared from fiber blends that are in the form of cloth or fabric, the applica-' tion may be made during any stage of manufacture or dyeing of such article, using procedures analogous to those herein described and demonstrated. When cloth and fabric are being treated, it may frequently be most convenient for the application to be made in a manner analogous to conventional padding treatments.

In order to further illustrate the invention, but without being limited thereto or restricted thereby, the following examples are given wherein, unless otherwise indicated, all parts and percentages are to be taken on a weight basis.

EXAMPLE 1 A uniform blend of about parts of viscose rayon fibers and 100 parts of nitrile alloy" fibers was prepared, spun into yarn and made into knit cloth from which several individual five gram samples were obtained. The nitrile alloy synthetic fibers in the blend were about 3 denier fibers in staple lengths of about 1% inches. They were comprised of polyacrylonitrile in which there was uniformly incorporated about 8 percent, on the weight of the fiber (o.w.f.), of poly-N-vinyl-2-pyrrolidone (PVP), having a Fikentscher K-value of about 55. The

viscose rayon yarn was a dull yarn having a staple length of about 1% inches and a denier of about 3.

The reserving action of tetra-bromo-o-cresol, tetrachloro-pyrocatechol and penta-chloro-phenol on the cloth samples of the blend were tested by first dissolving 0.4 gram of each of the halogen substituted mono-aromatic phenolic compounds in 1 cc. of 40 percent aqueous sodium hydroxide, then diluting the resulting solution to a volume of 100 ccs. with water. Separate samples of the knit blend were then impregnated with and treated by means of each of the solutions for 30 minutes at about 40 C. The fibers were then dyed in the conventional manner with 2 percent Cibanone Blue GF, a vat dyestufi (Colour Index 1113 or Vat Blue 6). The nitrile alloy" fibers in the blend remained essentially white while the viscose component dyed to a distinct blue shade of coloration.

In contrast, when the foregoing was repeated, excepting to eliminate the preliminary applications of the reserving agents the full depth dyeing of both types of fibers in each of the blended samples was obtained.

EXAMPLE 2 Two separate five gram samples of the same knit blends of the nitrile alloy fiber and viscose rayon employed in the first example were scoured for 30 minutes at 70 C. in a 1 percent aqueous solution of Igepon T (an anionic detergent obtained from General Aniline and Film Corporation which is sodium N-methyl-N-oleoyl taurate). The samples were then placed in a Laundrometer (a commercial wash-fastness testing apparatus consisting of a set of jars in which textile samples are placed with a solution of a detergent, the jars being rotated so they are immersed in hot water for at least half of the rotating cycle) wherein one of the samples was impregnated with a 0.25 gram solution of penta-bromophenol prepared as in the first example and the other with a similar strength solution of 3,5-dibromo-2,4,6-trichloro-phenol for 15 minutes at F. At the end of this time, about 1.5 grams of Cibanone Green BF, a vat dyestufi, (Colour Index 1101 or Vat Green 1) was added assassto each solution and the resulting" so utions maintained at the' s'a me temperature for an additional 45 minutes. The samples" were then removed from the dye b'ath's', rinsed thoroughly with water, treated with one ml of 30 percent aqueous hydrogen peroxide and 2 ml. of 10 percent acetic acid (while the samples were contained in a water bath having a volume of about 150 ccs.), dried at 80 C., scoured with 1 percent o.w.f. of Igepon T in aqueous solution-and again rinsed and dried. Again, the dye-receptivity of the nitrile alloy fiber component in each of the; knit blends was quite beneficially altered in a readily apparent and visually discernible manner while the viscose rayon components were dyed to deep and level shades of coloration.

EXAMPLE 3 One molar solutions of various phenolic compounds in alcohol were prepared, vTen ml. of each of the resulting solutions were then mixed with 10 ml. of one molar NaOH and the resulting solutions diluted to 100 ml. with water. A caustic test solution was prepared by adding about 80 ml. of 40 percent aqueous NaOH to 41 ml. of water. To separate 100 ml. volumes of caustic test solution, there was added separate 10-, 25-, and 50- volumes of each of the phenolic solutions that had been prepared. The pH of the resulting solutions ranged from about 12.6 to 12.9. Five gram samples of the same unblended nitrile alloy fiber as employed in the first example were then added to each solution and maintained at 160 C. for one hour. The samples were rinsed, dried and then observed for discoloration using a Beckman spectrophotometer. The results are given in Table 1 wherein each of the phenolic materials employed is also identified. Thepercent color is a measure of the discoloration caused bythe basic solutions using a reference of 100 percent discoloration of the fiber when no' reservingagent was employed to lend its stabilizing effect against caustic'thereto.

About. 0.2 gram of penta-chloro phenol was dissolved in an alkaline solution of caustic in water (pH 9) and heated to 70 C. A two gram sample of a blend of 50 percent by weight of the nitrile alloy fiber employed in the first example and 50 percent by weight of middling cotton staple was dyed with Calcodur Pink 2BL, a direct dyestufi (Colour Index 353), water-washed and dried. The cotton dyed a bright pink but the nitrile alloy fiber remained white, being neither dyed or discolored by the caustic solution.

In contrast, when the untreated nitrile alloy fiber isdyed with the same dyestuif, deep and level shades of coloration are readily obtained therein.

EXAMPLE A five gram sample of the same nitrile alloy fiber as employed in the first example was treated, in an unblended condition, with an alkaline solution containing about 0.5 gram of penta-chloro phenol dissolved ina mixture of 0.2 gram NaOH and 50 ml. of water. After the sample was washed and dried, it was immersed in a solution of Food Drug and Cosmetic No. 1 (a food dye). The fiber was initially colored by the dyestutf but'the eoloration was "easily washed out of'the treated fiberso as tollave, after washing, a whiteand unstained-fiber product;

' V EXAMPLE 6 The procedures of each of the five preceding examples is repeated excepting to use a nitrile alloy fiber comprised of polyacrylonitrile containing normally solid poly- N-vinyl-2-caprolactam as the dye-assisting adjuvant in place of the PVP. Identical results are achieved. Likewise, identical results are achieved with nitrile alloy aromatic phenolic reserving agents indicated to be withinthe scope of the invention are utilized in place of those specifically illustrated. Excellent results may also be achieved when the resistingagents are applied on unmixed or unblended nitrile alloy fibers for purposes and applications where such technique and manner of treatment is desirable and indicated. Commensurate results may likewise be achieved when other blends of the nitrile alloy fibers, including blends with cellulosics other than cottonor viscose rayon yarn (such as cuprommonium rayon yarn, cellulose acetate and the like cellulose esters and other cellulose fibers of natural or synthetic or artificial origin) as well as blends of the nitrile alloy fibers with various proteinous fibers of natural or synthetic origin, including wool, silk fibers, zein-protein fibers (such as those that are commercially available under the trade name Vicara) feather-keratin, casein fibers, protein fibers and the like proteinous or so-called Azlon fibers of natural, artificial, regenerated or reconstituted origin.

As has been indicated in the foregoing, the nitrile alloy" fibers are comprised essentially of the mentioned acrylonitrile polymer base which has been modified or alloyed with beneficial additaments or constituents which are adapted and calculated to provide the fiber product with its peculiar and unusually advantageous properties. Variousbeneficial additaments or constituents that are capable of securing the desirable characteristics of which the nitrile alloy fiber is possessed may be of any of several diverse types. For example, the beneficial constituent may be derived from and originate with a monomer or mixture of monomers, capable of being converted 'to a dye-receptive and possibly otherwise functional polymer product, which is graft or block copolymerized to and upon the already formed (and, with advantage, already fabricated) acrylonitrile polymer base. Alternatively, and witl1 equal advantage, the beneficial constituent may be a dye-receptive and possibly otherwise functional; polymeric product with which the essential acrylonitrile base is graft or block copolymerized by graft copolymeriz'ation of acrylonitrile or an acrylonitrile monomer mixture on or with the already formed functional polymer in order to furnish the fiber-forming polymer product of which the nitrile alloy fiber is composed. Or, as a suitable and frequently quite satisfactory alternative, the already formed beneficial additaments or constituents in the ,nitrile alloy fiber may be in the nature of polymeric adjuvants that are physically blended and intimately incorporated by any of several suitable procedures with the essential acrylonitrile polymer base. Such adjuvants may be homopolymeric, copoiymeric or graft copolymeric substances which serve to augment at least the dyeability of the normally difiicult (if not impossible) to dye acryloni' 'trile polymer base.

Amongst the most beneficial and advantageous of the nitrilealloy fibers are those that are comprised of the essential acrylonitrile polymer base, particularly polyacrylonitrile, in which there has been'intimately and permanently" or substantially permanently incorporatedminor proportions of from 1 'or so up to about 20 or so percent by weight, based on the weight of the nitrile alloy composition, of any of the beneficial additaments or constituents adapted to serve the desired purpose and provide the beneficial result. Generally, such beneficial additaments are employed primarily as dye-assisting adjuvants or components. Advantageously, they may be the polymerized products of such azotic monomers, or mixtures thereof, as the several N-vinyl lactams including such broadly related products as the N-vinyl-3,-morpholinones; the N- vinyl-2-oxazolidinones; and certain of the N-vinyl-N- methyl-alkylsulfonamides. Thus, the nitrile alloy may be comprised of the acrylonitrile polymer base that is prepared by graft or block copolymerization of acrylonitrile or an acrylonitrile-containing monomer mixture upon a minor proportion of an already formed polymer derived from any of the indicated varieties of azotic monomers or their mixtures. Or, as mentioned, it may consist of a graft copolymer product of any of the indicated varieties of azotic monomers on an already formed and preferably already fabricated acrylonitrile polymer base. Advantageously, and frequently with consumate suitability, the nitrile alloy fiber may be comprised of the acrylonitrile polymer base in which there is permanently incorporated by physical blending a minor porportion of any of the polymer products from the specified azotic monomers or mixtures thereof, primarily as dyeassisting adjuvants.

Such species of nitrile alloy" fibers are capable of being accurately described as synergetic and anisotropic clathrates that are composed of a hydrophobic polymer in combination with a hydrophilic polymer. ties of the nitrile alloy fibers (as well as in other of the forms in which they may be obtained) there is a mutually enhancing cooperative union of a highly crystalline polymer which provides strength, durability, wrinkle recovery and high melting point in the fibers with an unusually non-ionic polychelate that provides dye-receptivity as well as moisture regaining powers for the fiber and other aesthetic' characteristics that lend to the wearing comfort oftextile goods manufactured from the fiber. The nitrile alloy fibers have been described by G. W. Stanton in an article entitled Zefran appearing in the Textile Research Journal, volume XXVII, No. 9, for September 1957, pp. 703-712. They have also been recognized as a distinct class of man-made synthetic textile fibers in Textil Organon, September 1956, at pages 129-130.

As indicated, the adjuvant or beneficial constituent in the nitrile alloy fiber may be homopolymeric in nature or it may be a straight copolymer of any of the azotic monomers specified with other monoand polyfunctional monomers. Adjuvants of this variety are ordinarily physically blended with the essential acrylonitrile polymer base in order to secure the desired intimate incorporation of the beneficial constituent and the resulting alloying effect in the fiber. Likewise, there may be similarly utilized for physical blending purposes adjuvants or additaments that are graft copolymeric in nature and which consist of various monomers that are graft copolymerized on substrates consisting of polymers of any In such variecent by weight, based on the weight of the nitrile alloy: composition. It is frequently quite desirable to employ a homopolymeric N-vinyl lactam' polymer, such aspoly- N-vinylpyrrolidone (which may also be identified as poly N-vinyl-Z-pyrrolidone or, with varied terminology, poly- N-vinyl-Z-pyrrolidinone), poly-N-vinyl caprolactam, or somewhat related thereto, a poly-N-vinyl-3-morpholinone;

. or a homopolymeric N-vinyl-Z-oxazolidinone or poly-N- of the indicated azotic monomers, such as poly-N-vinylcomponent in nitrile alloy fibers in an amount that is in the neighborhood or range of from about 5 to 15 pervinyl-5-methyl-2-oxazolidinone; or a homopolymeric N- vinylmethylalkylsulfonamide polymer such as homopolymeric Nv-vinyl-N-methyl-methylsulfonamide; as the polymeric adjuvant that is blended with the essential acrylo-, nitrile polymer base in the nitrile alloy composition. When physically blended nitrile alloy products are prepared that utilize, as the beneficial additament or constituent, copolymeric or graft copolymeric products of the indicated azotic monomers, it is usually beneficial for the polymeric adjuvants that are employed to be' those which are comprised of at least about 50 percent or even as much as or more percent by weight of the products of the indicated constituents derived from the azotic monomers.

In addition to products of N-vinyl-pyrrolidone or N- vinyl caprolactam, other of the N-vinyl (or l-vinyl) lactams which may be utilized include any of those (ortheir mixtures) that have been described or which are involved in US. Patents Nos. 2,265,450; 2,355,454 and 2,371,804. Particular mention may also be made of N- vinyl-5 methyl-pyrrolidone; N-vinyl-3,3-dimethyl gamma valerolactam; and N-vinyl piperidone. Particular mention may also be made of somewhat related products derived in any of the ways described from N-vinyl-3- morpholinones of the structure:

wherein each substituent R unit is independently selected from the group consisting of hydrogen, 1 to about 4 carbon alkyl radicals, 6 to about 10 carbon aryl radicals and equivalents thereof.

Similarly, besides unsubstituted N-vinyl-Z-oxazolidinone, other N-vinyl (or 3-vinyl)-2-oxazolidinone products which may be used as polymeric adjuvants include those derived from monomers represented by the formula:

HC=CH2 in which at least one of the substituent R R R or K; groups, when it is not hydrogen, may be a 1 to about 4 carbon atom alkyl. radical or a 6.to about 10 carbon atom aryl radical or their equivalents. Typicals of such monomers may be mentioned N-vinyl-S-methyl-2-oxazolidinone; N-vinyl-5-chloromethyl-Z-oxazolidinone; N-vinyl-4,5-dimethyl-Z-oxazolidinone, N-vinyl-5-ethyl-2-ox azolidinone; N-vinyl-5-phenyl-2-oxazolidinone; and the like.

The N-vinyl-N-methyl-alkylsulfonamide 7 monomers whose polymeric products may be advantageously utilized for the, nitrile alloys include those represented by the.- formula:

wherein Ris hydrogen, a 1 to about 4 carbonv alkyb radical, a" 6 to about 10 carbon-aryl radical or some equivalent thereof.

Suitable nitrile alloy" products may also be manufa'c tured from other beneficial additaments or components that are more or'less equivalent to those derived from the azotic monomers indicated in the foregoing. Thus, other varieties of N-heterocyclic monomers more or less similar or related to the specified N-2-propenyl types and analogous related azotic compounds may'freque 'ntly be employed in combination with or to' replace the several beneficial additaments or constituents th'at have been delineated.

What is claimed is:

l. A synthetic textile fiber which is characterized in having its normally receptivity to dyestuffs modified so" as to have dye-resisting characteristics, said fiber being selected from the class of synthetictextile fibers consist ing of (A) intimate polymer blends comprised essentially of (A1) between about 80 and about 99 weight percent, based on dry fiber weight, of a fiber-forming acrylonitrile addition polymerwith (A2) between about 20 and about 1 weight percent, based on dry fiber weight, of an azotic' polymeric dye-assisting adjuvant selected from the group consisting of addition polymers of at least about 50 weight percent, based on the weight of the azotic polymer, of (A2a) N-vinyl lactam monomers; (A2b) n-vinyl-3- morpholinone monomers of the structure:

uo Eon RCH 0:0

acme, wherein each substituent R unit is independently selected from the group consisting of hydrogen, 1 to about 4 carbon atom alkyl substituents and 6 to about 10 carbon atom aryl substituents; (A2c) N-vinyl-2-oxazolidinone monomers of the structure:

11 -0%? Ra-C 0=0 H(I]=CH: in which R R R and R are independently selected from the group consisting of hydrogen, 1 to about 4 carbon atom alkyl substituents and 6 to about 10 carbon atom aryl substituents; (A2d) N-vinyl-N-methyl-alkylsulfonamide monomers of the structure:

wherein R is selected from the group consisting ofhydrogen, l to about 4 carbon atom alkyl substituents and 6 to about 10 carbon atom aryl'substituents; and (A2e) mixtures thereof; (B) fiber-forming graft copolymers comprised essentially of (B1) between about 80 and about 99 weight percent, based on dry fiber weight,- of a pre-formed fiber-forming acrylonitrile addition polymer; substrate with graft copolymerized substituents thereon of (B2) between about 20 and about 1 weight percent, based on dry fiber weight, of addition polymerized'azo'tic monomer substituents of at least about 50 weight percent, based on the weight of graft .copolymerized subs't'ituerit', of (B2a) N-vinyl lactam monomers; (B2b) said N-vinyl- 3-tnorpholinone monomers; (820) said N-vinyl-2-oxazolidinone monomers; (B2d) said N-vinyl-N-methyl-alkylsulfonamide monomers; and (B2e) mixtures thereof; and (C) fiber-forming graft copolymers comprised essentially of (C1) between about 80 and 99 weight percent, based on dry fiber weight, of acrylonitrile graft copoly 7 merize'd on (C2) between about 20 and about 1 weight percent, based on dry fiber weight, of a pre-formed, dyemssisting, azotic addition polymer substrate of at least about'50 weight percent, based on' the weight of said substrate, of (C2a) N-vinyl lactam monomers; (C2b) said N-vinyl-3-morpholinone monomers; (C2a) said N- vinyl-2-oxazolidinone monomers; (C2d) said N-vinyl-N- methylalkylsulfonarnide monomers; and (C2e) mixtures thereof, said fiber containing as a dye-reserving and resisting agent effective against direct, acid and vat dyestuffs between about 0.1 and25 weight percent, based on the weight of the fiber, of which at least about 0.01 weight percent is permanently and substantiatively retained by said fiber, of a compound having the structure:

wherein each X is independently selected from the group consisting'of chlorine and bromine and R is selected from the group consisting of chlorine, bromine, fluorine, hydroxy, alkyl radicals containing from 1 to about 4 carbon atoms, halogen substituted alkyl radicals containing halogens of atomic number from 9 to 35 and from 1 to about 4 carbon atoms, and alkoxy radicals containing from 1 to about 4 carbon atoms.

2. The treated fiber of claim 1, having from about 0.1 toabout 1.5 percent by weight of said reserving agent initially applied thereon and characterized in having relatively slight resistance to becoming stained upon contact with dyestuffs.

3. The treated fiber of claim 1 having from about 1.5 to 10 percent by'weight of said reserving agent initially applied thereto and characterized in having a moderate reserving action to becoming stained upon being contacted with dyestuffs.

4. The treated fiber of claim 1, having from about 10 to 25 percent by weight of said reserving agent initially applied thereon and characterized in having a substantially complete resistance to become stained upon contact with dyestuffs.

5. The treated fiber of claim 1 contained in a blend of fibers with cellulose fibers.

6. A blend of fibers in accordance with the blend set forth in claim 5, wherein said cellulosic fibers are cotton.

7. A blend of fibers in accordance with the blend set forth in claim 5, wherein said cellulosic fibers are viscose rayon;

8. The treated fiber ofclaim 1 contained in a blend of fibers with proteinous fibers.

9. A blend of fibers in accordance with the blend set forth in claim 7, wherein said proteinous fibers are wool.

10. The treated fiber of claim 1, wherein said synthetic fiber contains from about 1 to about 20 percent by weight, based on the weight of the fiber, of polymerized N-vinyl lactam monomer.

11. The treated fiber of claim 1, wherein said synthetic fiber contains from about 1 to about 20 percent by weight, based on the weight of the fiber, of polymerized N-vifiyl-Z-oxazolidinone monomer.

I 12. The treated fiber of claim 1, wherein said synthetic fiber contains from about 1 to about 20 percent by weight, based on the weight of the fiber, of polymerized N-vinyl- 3-morpholinone monomer.

13. The treated fiber of claim 1, wherein said synthetic fiber consists of an intimate polymer blend of polyacrylonitrile and from about 1 to about 20 percent by weight, based on the weight of the fiber, of poly-N-vinyl-2-pyrrolidone as a dye-assisting adjuvant.

14. The treated fiber of claim 1, wherein said synthetic fiber consists of an intimate polymer blendof polyacrylonitrile and from about 1 to about 20 percent by weight,

based on the weight of the fiber, of poly-'N-vinylcaprolactam as a dye-assisting adjuvant.

15. The treated fiber of claim 1, wherein said syn thetic fiber consists of an intimate polymer blend of polyacrylonitrile and from about 1 to about 20 percent by weight, based on the weight of the fiber, of poly-N- yinyl-S-methyl-Z-oxazolidinone as a dye-assisting aduvant.

16. The treated fiber of claim 1, wherein said synthetic fiber consists of an intimate polymer blend of polyacrylonitrile and from about 1 to about 20 percent by Weight, based on the weight of the fiber, of poly-N- vinyl-3-morpholinone as a dye-assisting adjuvant.

17. The treated article of claim 1, wherein said dyereserving agent is tetra-bromo-o-cresol.

18. The treated article of claim 1, wherein said dyereserving agent is tetra-chloro-pyrocatechol.

19. The treated article of claim 1, wherein said dyereserving agent is penta-chloro-phenol.

20. The treated article of claim 1, wherein said dyereserving agent is penta-bromo-phenol.

21. Treatment for a synthetic fiber to reduce its receptivity to dyestutfs, said fiber being selected from the class of synthetic textile fibers consisting of (A) intimate polymer blends comprised essentially of (A1) between about 80 and about 99 weight percent, based on dry fiber weight, of a fiber-forming acrylonitrile addition polymer with (A2) between about 20 and about 1 weight percent, based on dry fiber weight, of an azotic polymeric dye-assisting adjuvant selected from the group consisting of addition polymers of at least about 50 weight percent, based on the weight of the azotic polymer, of (A2a) N-vinyl lactam monomers; (A2b) N-vinyl-3-morpholinone monomers of the structure:

me sort Ros 0=o HO=CH2 wherein each substituent R unit is independently selected from the group consisting of hydrogen, 1 to about 4 carbon atom alkyl substituents and 6 to about 10 carbon atom aryl substituents; (A2c) N-vinyl-2-oxazolidi none monomers of the structure:

Ego- 0 14 in which R R R and R are independently selected from the group consisting of hydrogen, 1 to about 4 carbon atom alkyl substituents and 6 to about 10 carbon atom aryl substituents; (A2d) N-vinyl-N-methyl-alkylsulfonamide monomers of the structure:

0 ll R?=O NCHa HC=OH2 wherein R is selected from the group consisting of hydrogen, 1 to about 4 carbon atom alkyl substituents and 6 to about 10 carbon atom aryl substituents; and (A2e) mixtures thereof; (B) fiber-forming graft copolymers comprised essentially of (B1) between about 80 and about 99 weight percent, based on dry fiber weight, of a pre-formed fiber-forming acrylonitrile addition polymer substrate with graft copolymerized substituents thereon of (B2) between about 20 and about 1 weight percent, based on dry fiber weight, of addition polymerized azotic monomer substituents of at least about weight percent, based on the weight of graft copolymerized substituent, of (132a) N-vinyl lactam monomers; (B2b) said N-vinyl-3-morpholinone monomers; (B20) said N- vinyl-2-oxazolidinone monomers; (B2d)' said N-vinyl-N- methyl-alkylsulfonamide monomers; and (B2e) mixtures thereof; and (C) fiber-forming graft copolymers comprised essentially of (C1) between about and 99 weight percent, based on dry fiber weight, of acrylonitrile graft copolymerized on (C2) between about 20 and about 1 weight percent, based on dry fiber weight, of a pre-formed, dye-assisting, azotic addition polymer substrate of at least about 50 weight percent, based on the weight of said substrate, of (02a) N-vinyl lactam monomers; (C2b) said N-vinyl-3-morpholinone monomers; (C2c) said N-vinyl-2-oxazolidinone monomers; (C2d) said N-vinyl-N-methyl-alkylsulfonamide monomers; and (C29) mixtures thereof, which treatment comprises initially applying to the fiber between about 0.1 and 25 weight percent, based on the weight of the fiber, of a dye-reserving agent efiective against direct, and vat dyestufis as defined by Formula I in claim 1.

References Cited in the file of this patent OTHER REFERENCES Sandoz: J.S.D.C., vol. 66, October 1950, p. 564.

Claims

1. A SYNTHETIC TEXTILE FIBER WHICH IS CHARACTERIZED IN HAVING ITS NORMALLY RECEPTIVITY TO DYESTUFFS MODIFIED SO AS TO HAVE DYE-RESISTING CHARACTERISTICS, SAID FIBER BEING SELECTED FROM THE CLASS OF SYNTHETIC TEXTILE FIBERS CONSISTING OF (A) INTIMATE POLYMER BLENDS COMPRISED ESSENTIALLY OF (A1) BETWEEN ABOUT 80 AND ABOUT 99 WEIGHT PERCENT, BASED ON DRY FIBER WEIGHT, OF A FIBER-FORMING ACRYLONITRILE ADDITION POLYMER WITH (A2) BETWEEN ABOUT 20 AND ABOUT 1 WEIGHT PERCENT, BASED ON DRY FIBER WEIGHT, OF AN AZOTIC POLYMERIC DYE-ASSISTING ADJUVANT SELECTED FROM THE GROUP CONSISTING OF ADDITION POLYMERS OF AT LEAST ABOUT 50 WEIGHT PERCENT, BASED ON THE WEIGHT OF THE AZOTIC POLYMER, OF (A2A) N-VINYL LACTAM MONOMERS, (A2B) N-VINYL-3MORPHOLINONE MONOMERS OF THE STRUCTURE: