US2683647A - Fugitive coloration of textiles - Google Patents

Description

Patented July 13, 1954 FUGITIVE COLORATION OF TEXTILES Lamont Hagan, Clemson, S. 0., assignor to Deering Milliken Research Trust, Pendleton, S. 0., a nonprofit trust of Maine No Drawing. Application December 6, 1950, Serial No. 199,547

6 Claims.

This invention relates to the fugitive tinting or coloration of textiles, more particularly those based on wool, nylon, and other synthetic fibers, including those which are wholly or partly acrylic polymers, or esters, but excluding the cellulosic textile materials containing cellulose or cellulose derivatives. The invention is also applicable to textile yarns based on blends of wool with such non-cellulosic synthetic fibers.

Fugitive coloration of nylon, in particular, pre sents special problems since the tinted yarn, or fabric woven or knitted therefrom, is subjected to a heat-setting treatment, usually with steam. This heat-setting treatment tends to fix the tinting dye more or less permanently in the fibers so that the yarns remain stained or colored, and the tint cannot be removed readily in later finishing operations, e. g., the scouring bath. Special reducing or oxidizing treatments to remove the tint are accordingly required. The above, as well as other factors, affect the fugitivity of dyes or tints on nylon or other yarn subjected to heatsetting. Accordingly, it cannot be predicted with certainty which dyes will be suitable for the fugitive tinting of such fibers.

In accordance with the present invention, it has been found that alkaline aqueous solutions of p-nitrophenol are highly suitable for fugitive tinting of wool, of non-ce11ulosic synthetic fibers such as nylon, polyacrylonitrile (Orlon), terephthalic acid ethylene glycol polymer (Fiber V) and. partially acrylic fibers (Dynel and Chemstrand) and of blends of wool with such synthetic fibers. Thus, for example, a solution such as is obtained by dissolving p-nitrophenol in an aqueous sodium hydroxide solution, whereby the p-nitrophenol is converted into the sodium salt thereof, will fugitively color nylon a bright yellow, which, even after a steam-setting of the tinted yarn spun therefrom, can be removed by simply scouring in a soap and water bath. Any color which does not come out in the scouring bath, does so upon treatment of the tinted material with an acidic solution, such as dilute sulfuric acid, hydrochloric acid or acetic acid. The acid media convert the yellow p-nitrophenol sodium salt to p-nitrophenol which is colorless.

A separate acid treatment to remove residual color is not required in the case of mixtures containing wool which are to be passed through a carbonizing apparatus since the acid employed in the carbonizing processing renders any residual tint colorless.

Instead of preparing an alkaline solution of the p-nitrophenol by dissolving p-nitrophenol in sodium hydroxide solution, the sodium salt of the p-nitrophenol can be dissolved in water, and the resulting yellow colored aqueous solution applied to fugitively tint the non-cellulosic fiber alone or in mixture with Wool.

Among the advantages of p-nitrophenol as a tint is its extreme stability; the color does not fade on exposure to air. Yet the tint is readily removed from the fiber by simply scouring with soap and water, or an acid souring treatment, even if the yarn has been heat-set. The sodium p-nitrophenolate thus has the advantage of not becoming fixed in the synthetic fiber, and the further advantage of being readily removable, or converted into a colorless compound on treatment with an acid.

A further advantage is that only small amounts of the sodium salt of p-nitrophenol are required in the tinting solutions to impart sufficient tinctorial properties to clearly stain the synthetic fiber. Thus, for example, about a 0.3 per cent solution of sodium p-phenolate is suihcient to fugitively color nylon, or other non-cellulosic fibers or mixtures thereof with wool or wool.

- When loose fibers are to be tinted they are merely dipped in or sprayed with the solution of sodium p-nitrophenolate, the excess squeezed out and the fiber permitted to dry. Yarns can be passed through a bath of the tinting fluid or passed over a wick applicator. Any other suitable methods may be employed in applying the sodium p-nitrophenolate solution.

After the tinted fibers or yarns have been processed, the tint is simply removed by scouring with soap and water. Any residual stain may be removed or cleared up by using an acid sour, or in the case of wool blends is removed in the carbonizing treatment to which the tinted wool synthetic fiber mixtures are usually subjected in the finishing of such textiles.

Heretofore, in the case of synthetic fiber wool mixtures, where the wool alone was tinted, during scouring the dye would bleed from the wool onto the synthetic fiber from which it could not be removed during scouring. When using sodium p-nitrophenolate as the tinctorial agent, any bleeding of this tint from the wool onto the nylon or other synthetic fiber blended with the wool is readily removed in the scouring bath.

The following examples will serve to illustrate the invention:

Example 1 A solution is made up of the following:

3.55 grams of p-nitrophenol 1.02 grams of sodium hydroxide 5.92 grams of Triton X-100 (an alkylarylpolyether wetting agent) 1172.51 grams of water.

The solution has a pH of about 11 and is sufficient to tint 50 pounds of nylon staple. It is applied to the nylon staple by spraying. In the case of nylon yarn, the solution is applied by passing the yarn therethrough or over a wick applicator.

Example 2 A solution is made up of:

3.55 grams of sodium p-nitrophenolate 5.92 grams of Triton X-IOO, and 1173.53 grams of water.

The tinting solution has a pH of about 11 and is applied in the same manner as described in Example 1.

Example 3 In the case of tinting non-cellulosic snythetic fiber-blends or all wool stock, the pH of the tinting solution should not be over about 8 to avoid the possibility of alkaline damage to the wool. Such tinting solutions are prepared from the solutions described in Examples 1 and 2 by adding thereto sufficient sodium bicarbonate to reduce the pH to about 8. In the case of wool-snythetic fiber blends, the tinting solutions of about pH 8 are applied dropwise onto a roving of the blends, conveniently at the pin drafter. In the case of 100 per cent wool stock, tinting solutions are applied preferably by spraying.

It will be understood that the usual penetrants, lubricants, and sizes may be included in the tinting bath. The concentration of the sodium p-nitrophenolate may be varied over wide limits. Usually about a 0.3 per cent solution is sufficient to provide suflicient tinting coloration.

The following is claimed:

1. A process for the fugitive tinting of organic non-cellulosic textile materials for purposes of identification during textile operations wherein the tint is capable by scouring of complete removal without residual staining, which process comprises subjecting the textile materials to an aqueous solution containing sodium p-nitrophenolate.

2. A process as in claim 1 wherein nylon is tinted.

3. A process as in claim 1 wherein a mixed nylon-wool textile is tinted.

4. A process in accordance with claim 1 in which the concentration of the sodium p-nitrophenolate in the solution is about at least 0.3%.

5. A process for fugitive tinting of textile materials for purposes of identification during textile operations wherein the tint is capable by scouring of complete removal Without residual staining which process comprises dissolving pnitrophenol in an aqueous solvent containing sodium hydroxide, and tinting an organic noncellulosic textile material with the resulting yellow colored solution.

6. A process as in claim 5 wherein nylon is tinted.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,341,423 Catlin Feb. 8, 1944 FOREIGN PATENTS Number Country Date 553,442 Great Britain May 21, 1943 OTHER REFERENCES Rowes Colour Index, published by Society Dyers & Colorists, London, 1st ed, 1924, pages 1, 1, 2, 2.

Organic Dyestuffs, by A. Wahl, translated by Atack, published in London, 1914, by G. Bell & Sons, pages 85, 86, 87.

Amer. Dyestuff Reporter for July 30, 1945, page 304.

Silk Jour. and Rayon World for August 1945, p. 33.

Claims (1)

1. A PROCESS FOR THE FUGITIVE TINTING OF ORGANIC NON-CELLULOSIC TEXTILE MATERIALS FOR PURPOSES OF IDENTIFICATION DURING TEXTILE OPERATIONS WHEREIN THE TINT IS CAPABLE BY SCOURING OF COMPLETE REMOVAL WITHOUT RESIDUAL STAINING, WHICH PROCESS COMPRISES SUBJECTING THE TEXTILE MATERIALS TO AN AQUEOUSL SOLUTION CONTAINING SODIUM P-NITROPHENOLATE.