US3377412A - Polyvinyl pyrrolidone in viscose and method of producing dye-receptive filaments - Google Patents

Description

April 9, 1968 N. E. FRANKS POLYVINYL PYRROLIDONE IN VISCOSE AND METHOD OF PRODUCING DYE-RECEPTIVE FILAMENTS Filed-Aug. 14, 1967 vIsCoSE POLYVINYLPYRROLIDONE VISCOSE SUPPLY SUPPLY SUPPLY h MIXING APPARATUS I SPINNERETTE SPINNERETTE APPARATUS APPARATUS REGENERATING RECENERATINC BATH BATH I I STRETCHING STRETCHING APPARATUS APPARATUS l l PLYING AND I COLLECTING MEANS PURIFICATION a DRYING I I w CoNvERSIoN YAR INTo FABRIC DYEING DYEING I TONE ON TONE TWO COLOR FABRICS INVENTOR. NEAL E. FRAN KTS 3,377,412 POLYVINYL PYRROLIDONE IN VISCOSE AND METHOD OF PRODUCING DYE-RECEPTIVE FILAMENTS Neal E. Franks, Cincinnati, Ohio, assignor to American Enka Corporation, Enka, N.C., a corporation of Delaware Continuation-impart of application Ser. No. 371,840, June 1, 1964. This application Aug. 14, 1967, Ser. No. 660,250

2 Claims. (Cl. 264-78) ABSTRACT OF THE DISCLOSURE A process for the production of regenerated cellulose in the form of textile structures such as filaments, fibers and yarns, the combination including incorporating into a viscose, prior to extrusion thereof, an amount of polyvinyl pyrrolidone having an average molecular weight of about 360,000 and a K-value between 80-100 in order to permit dyeing with acid or premetallized dyestuffs. The thus modified structures can then be combined with unmodified structures that are only susceptible to those dyestuffs normally used in dyeing regenerated cellulose in order to obtain a composite textile article of manufacture consisting of polyvinyl pyrrolidone modified textile structures and unmodified structures that are especially suitable for multicolored effect dyeing when utilizing a single dyebath and containing at least two distinct classes of dyestuffs, i.e., the above-mentioned acid or premetallized dyes and direct or substantive dyes.

SPECIFICATION This invention relates to the production of textile structures consisting of regenerated cellulose such as yarns, filaments, fibers or the like as well as fabrics made therefrom which have remarkable dyeing properties with respect to the acid and/or premetallized dyestuffs. This application is a continuation-in-part of application Ser. No. 371,840 filed June 1, 1964, commonly assigned herewith now abandoned.

It is known that the various kinds of cellulose-containing textile structures such as filaments, fibers, yarns, ribbons and/ or tow are generally non-receptive to the acid and premetallized dyestuffs commonly used to dye nitrogen-containing woolen, synthetic nylon, or acrylic filaments, fibers and yarns as well as ultimate textile fabric products made therefrom. It is also known that numerous processes have been proposed in an effort to increase the affinity of such structures for the dyestuffs and many generally embrace treatments with various chemical agents after they are shaped or converted into end products such as fabrics and the like. It has also been proposed to include various organic compounds in a spinning solution to produce uniformly modified structures that are readily susceptible to dyeing with acid or premetallized dyes throughout a given cross-section. Compounds which the prior art teaches that can be uniformly incorporated in spinnable solutions or compositions include, for example, the polyalkylene amines, polyalkylene imines, various urea derivatives, basic condensation products from phenol, formaldehyde, aliphatic monoor diamines, reaction products of halogenated aliphatic or aromatic hydrocarbons, esters, ketones, polymerizates, etc. The compounds, when added to spinnable compositions such as viscose or the like, increase the affinity of the structures for acid and/or premetallized dyestuffs in some degree although, with most, serious practical disadvantages exist.

In using the known compounds it is found that they States Patent cause either fabric stiffness or the acid or premetallized dyestuffs are not sufficiently stable to the effects of wet treatments, for example, to the effects of washing, bleaching, mercerizing, dry cleaning, perspiration and the like. The acid and/ or premetallized dyestuffs are easily leached out and, in general, textile fabrics containing such dyes lack the wash or light fastness required to compete commercially with a material which, for example, has been printed or dyed with a more stable but less brilliant direct or substantive type dye.

In the case wherein known dye improving additives are merely impregnated on the fabric, a time consuming and expensive post-treatment of the material has been found necessary to increase the retention of the additives and consequently the dye in final products. Uniformity of additive impregnation with a resulting uniformity in dyeing of the products throughout their crosssection is difficult to accomplish when additives are incorporated with textiles in this way and, additionally, many inhibitors or improvers are unsatisfactory in that they also impair the chemical and physical properties of the yarns and finished textile products containing the yarns. Fabrics treated by post-treatment and the like also lose strength and tend to fade quickly when exposed to ultraviolet light.

Many of the compounds included in spinnable rayon compositions also deleteriously affect the chemical and physical properties of structural products formed therefrom, notwithstanding the fact that many of those which are known are not sufficiently soluble in the composition and therefore are not readily and uniformly intermixed throughout the products.

In accordance with the invention, it surprisingly has been discovered that by physically admixing or treating cellulosic spinning compositions with a certain readily available polymeric material of extremely high molecular weight heretofore thought impractical because of the materials inherent water solubility characteristics, textile structures can be formed which not only have a high affinity for acid dyes and premetallized dyes closely resembling that possessed by wool and the nitrogen-containing synthetics but also avoid the disadvantages noted above. Equally surprising, it has been found that by modifying the cellulosics with the novel compound (identified hereafter) an affinity for those dyestuffs normally used in dyeing such materials, e.g., the direct or substantive dyes, is noticeably improved.

It is, therefore, an object of this invention to provide deeper and more uniformly dyed viscose fibers and yarns not having the aforementioned disadvantages.

Another object of this invention is to provide a process for increasing the afiinity of viscose fibers and yarns for dyes, more specifically the acid and premetallized type dyes.

Still another object of this invention is to provide a modified fiber-forming viscose solution that will increase the action of conventional viscose treating dyestuffs and easily accept acid and premetallized dyes.

An additional object of this invention is to provide a process for obtaining a uniform dispersion and retention of the dye-influencing additive throughout the viscose fibers and yarns.

These and other objects will become apparent from the following detailed description.

In accordance with one embodiment of the invention and in its broadest aspect, regenerated cellulose fibers and filaments can be modified to possess an increased afiinity for certain dyes by incorporating into a regenerated cellulose solution, such as viscose, prior to filament or fiber formation a small amount of high molecular weight polyvinyl pyrrolidone (hereinafter referred to as PVP). Now,

for the first time, regenerated cellulose textile structures can be produced that have a remarkable increased and lasting aflinity for those dyestuffs normally used in dyeing the nitrogen-containing natural or synthetic filaments, fibers and yarns. Furthermore, the dyestuffs, i.e., acid and premetallized dyes, do not migrate or wash out when subjected to severe wash tests and evaluations.

While not wishing to be bound by theory, it is believed that the addition of the PVP to the viscose stream increases the number of dye sites available in the extruded filament for the attachment of the premetallized or acid dye molecules and the PVP is held in the regenerated cellulose by an attraction or bonding between the PVP molecule and hydroxyl hydrogen atoms of the cellulose molecules although a positive cross-linking or chemical reaction does not appear to take place to any appreciable extent between the polymer molecules. In any event, when the PVP is homogeneously mixed in the viscose solution, resulting shaped products are found to be quite stable to the etfects of washing, caustic treatments, etc., and will not be decomposed under the normal uses to which such regenerated cellulosics are subjected. Dyed textile products containing PVP in particular are similarly stable when subjected to such treatments and, perhaps even more surprising in view of that which is known, the PVP containing products dyed with direct or substantive dyes also show improvements in relation to depth of color and stability.

The high molecular weight PVP is a readily available material and may be incorporated into the viscose solution in a number of ways. For example, it may be mixed batch-wise or it may be added directly to the flowing stream prior to spinning by a method such as that shown by Patent No. 2,934,448 to T. E. Patton. The exact method used to effectively mix the solutions is not critical, as long as a homogeneous dispersion of the PVP in the viscose is accomplished. By addition prior to spinning, a high degree of retention of the PVP in. the final fiber is believed accomplished due to the unusual hydrogen bonding previously mentioned which prevents subsequent loss of the dye in normal washings of the dyed fabric. Further, the addition prior to spinning also allows a more uniform distribution of the PVP throughout the entire fiber product, thus in effect creating a more uniform coloring in the textile material.

The amount of the high molecular weight PVP added to the fiber-forming viscose solution can be varied, depending on the results desired. Amounts less than about 2% by weight PVP based on the weight of the cellulose in the viscose solution (CIV) are not generally sufficient to produce the degree of effect desired. It is preferred that amounts below 6% be used since greater amounts have been found to cause difficulties in spinning and processing of the viscose solution prior to fiber or filament formation. Preferably, amounts of PVP ranging from 2% to are employed in the process. In general, the molecular weight of the polymeric vinyl pyrrolidone to be employed may range from about 200,000 to 400,000 or higher. Optimumly,,it is preferred that the average molecular weight be approximately 360,000 as determined by appropriate viscosity measurement techniques.

Spinning procedures and equipment customarily used in production of viscose fibers, including conventional spinbath, can be used with the PVP-modified viscose and the fiber product may be processed into yarn by any known means. The attached figure shows a schematic representation of one particularly suitable procedure for forming composite yarns of the invention. Modified and unmodified filament bundles can either be combined immediately after precipitation of the viscose in spinbath or they can be combined immediately before collection in a suitable package (spool or cake). Combining immediately after spinning results in a heather coloring effect in the yarns, i.e., a random blending of one color into another, caused by filament placement, while combining the yarns immediately before collecting into a package results in a distinct contrasting two-color effect when two distinct color producing dyestuffs are used, or, alternatively, a contrasting two-tone effect when a one-color producing direct dyestuff is used.

It should be understood that the modified yarn can be crosswoven with untreated viscose yarns into fabrics or tufted into carpets and, when dyed with a direct dyestuff of a single color using standard procedures, a striking two-tone wash fast color effect is achieved in the finished product. Dyeing with dyes of two distinct color, i.e., one acid or premetallized and one direct, will give a two-color effect in the fabrics or carpets.

It also should be understood that several yarn bundles containing the PVP can be combined with like yarn bundles which do not contain the additive to form a composite tow which facilitates composite staple fiber manufacture. The tow can be cut into fibers of preselected length according to known practices. It will be appreciated that the staple fibers can be manufactured from solely PVP-containing yarns and thereafter spun with synthetic staple, e.g., nylon, polyester or acrylic, to produce yarns having distinct multicolored characteristics when woven into fabrics; or, composite regenerated cellulose fibers (PVP modified and unmodified) can also be spun with synthetic staple fibers to produce fabrics having an even further increased multicoloring capacity.

For purposes of illustration, the following examples are given, However, the invention is not intended to be limited thereby. Unless otherwise indicated, percentages are given in percentages by weight.

Example I A fiber-forming viscose solution, prepared by conventional xanthation of alkali cellulose, followed by the usual treatment with dilute sodium hydroxide, was combined with a 20% aqueous solution of PVP (a clear viscous aqueous solution of polyvinyl pyrrolidone sold by General Aniline & Film Corporation, New York, N.Y., under the name K- and having an average molecular weight of about 360,000) at 49 F. to produce a resulting batch mixture containing 2.5% PVP-CIV (cellulose in viscose). The mixture was agitated for one-half hour to disperse and dissolve the PVP throughout the viscose. The result- 5 ing mixture was deaerated overnight at 63 F. and spun into an acid spinbath containing 4.6% sulfuric acid, 11.9% sodium sulfate, and 3.75% zinc sulfate (percentages by weight of the spinbath). The temperature of this spinbath was held at 108 F. The resultant filaments were washed and given normal post-treatment.

Example II A viscose solution prepared as in Example I was injected with a 5.0% aqueous solution of PVP. The injection was made directly into the viscose stream and mixed according to the process defined by the aforementioned Patent No. 2,934,448. The final composition spun contained 2.5% by weight PVP to the CW. The composition was spun into a spinbath containing 11.2% sulfuric acid, 5.1% magnesium sulfate, 17.45% sodium sulfate, and 1.0% zinc sulfate, and the extruded filament was then conventionally purified and dyed.

Example III A skein composed of the viscose prepared by the process of Example II and an untreated viscose skein were scoured with Rohm & Haas Triton CF 10, 0.2% (a benzyl ether of an acetylphenol-ethylene oxide adduct) and 0.5% tetrasodium pyrophosphate at 180 F. for 20 minutes. After rinsing, the skeins were placed in a 1.0% Triton CF 10 bath at F. for ten minutes. The temperature of the bath was raised to 200 F. and 0.5% of Du Ponts Alkanol HCS (a non-ionic surfactant) and 0.3% ammo- V. A unique two-color effect was produced in the material.

TABLE IMODIFICATION DATA carpet Polymer Identification, Proper- Spinbath ties and Concentration in Viscose Examples (Sample) K- Avg. Temp. Ident. Value gives. Con. Composition F.)

VII K- 15-21 10,000 2.5 Aqueous solution containing: 108

4.6% H2804, 11.9% NazSO-l, 3.75% Z11S04. VIII K 26-35 40,000 2.5 do 108 I K430... 5062 160, 000 2. 5 108 X K90 80-100 360,000 2. 5 108 Aftertreatment Dyeing Examples Percent Temp. Remarks (Sample) Wash- Bleach- Polymer Type 2 of Dye- Time ing ing Remainbath (min.)

ing 1 F.) VII Yes Yes 0. 01-0. 10 AB 200 45 Fabric only stained. VIII Yes Yes 0.01-0.10 AB 200 45 Do. IX Yes Yes. 0.01-0.10 AB 200 45 Do. X Yes Yes. 2. 5 AB 200 45 Excellent color (i0. 10. 2) quality.

1 Percent polymer weight based on CIV.

2 Dye Ty e and the skeins allowed to remain for 45 minutes. The skeins were then removed, rinsed and dried. A slight staining of the untreated skein was accomplished which immediately washed out, while the treated skein showed a deep blue color.

Example IV Skeins of treated and untreated viscose yarns were prepared and scoured in the same manner as Example III. The skeins were then added to a solution containing 0.5% Triton CF 10 and Geigy Chemicals Erional NW 2.0% (a mixed condensate of naphthalene mono-sulfonic acid with dihydroxy diphenylsulfones and formaldehyde) at 115 F. and allowed to remain for 10 minutes. The treating bath was then heated to 200 F., 15% sodium chloride was added, and a premetallized dye consisting of 0.5% CI Acid Red 182 was added. After 45 minutes, the skeins were removed, rinsed and dried. A slight staining was observed on the nontreated skein while the treated skein was a deep red.

Standard wash fastness tests were performed on the dyed skeins with favorable results and light fastness tests showed no appreciable loss in the treated skein under prolonged exposure. Secondary swelling values and strengths of the treated and untreated skeins showed no appreciable change.

Example V A knitted fabric composed of treated and untreated yarns was scoured and pretreated with Triton CF 10 and Erional NW as in Example IV. To the resulting solution was added a mixture of premetallized and direct dyestuffs consisting of Ciba Chemical & Dye Companys Cibalan Brilliant Blue RL 5.0%, Organic Chemical Corporations Orcolite Fast Yellow EFL 0.3%, and General Dyestuff Companys Fastusol Blue FL 3 GL 0.6%. After 45 minutes at 200 F. the knitted fabric was removed and rinsed. The resulting treated fabric produced a two-color efiect consisting of deep blue and green. Standard light fastness and wash fastness tests showed no significant loss in the treated yarn portions compared to the untreated yarn portions of the fabric.

Example VI A tufted carpet material produced by combination of the regenerated cellulosic fibers treated with PVP and such nontreated fibers was dyed according to Example Examples VIIX The above samples in the table clearly show that the K-90 modified yarns will not solubilize in any appreciable amounts when used according to the invention and, moreover, will have a much improved dye affinity over the standard viscose yarns when treated with lower molecular weight polymer under identical conditions.

The Kvalue (Fikentscher) of any particular mixture of polymers is calculated from viscosity data and is useful as an indication of the average molecular weight of such mixture. Its determination is fully described in Modern Plastics, 23, No. 3, 157-61, 212, 214, 216, 218 (1945) and is defined as 1000 times k in the empirical relative viscosity equation:

ic "reel 75102 C l+1.5kC'

wherein C is the concentration in grams per hundred cc. of polymer solution and a is the ratio of the viscosity coefficient in order to avoid the use of decimals. For the purpose of the present invention there may be employed polymeric N-vinyl pyrrolidone having a K-value of 200, preferably of 80 to 100, and having an average molecular weight of about 360,000.

What is claimed is:

1. A fiber-forming composition of matter comprising a major amount of viscose including a wash-fast and lightfast dye improving quantity of at least about 2% by weight of polyvinyl pyrrolidone based on the weight of cellulose in said viscose, said polyvinyl pyrrolidone being of average molecular weight of about 360,000 and having a K-value of approximately 8090.

2. A process for the preparation of multifilament yarns of regenerated cellulose having a wash-fast and light-fast afiinity for acid and/ or premetallized dyestuffs comprising in combination:

(a) homogeneously including into a viscose solution prior to extrusion, at least about 2% polyvinyl pyrrolidone based on the weight of cellulose therein, said polyvinyl pyrrolidone being of average molecular weight of about 360,000 and having a K-value of approximately 8090,

(b) extruding the thus modified viscose through a spinneret to form a plurality of continuous filaments in at least one acid coagulating and regenerating bath,

References Cited UNITED STATES PATENTS Watson 8-15 Bock et a1 815 Geigy 8-85 Benneville et a1. 26017 Stoner et a1. 260-17 Howsrnon 264194 Mautner 885 Walles et a1. 260--17 OTHER REFERENCES Schildknecht Vinyl and Related Polymers, 1952, TP986 V4853, pp. 676 and 677.

JAMES A. SEIDLECK, Primary Examiner.

A. KOECKERT, Assistant Examiner.

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