US3383160A

US3383160A - Method for dyeing polyester fibers with monoazo dyestuffs

Info

Publication number: US3383160A
Application number: US356068A
Authority: US
Inventors: Lester N Stanley; William H Armento
Original assignee: General Aniline and Film Corp
Current assignee: GAF Chemicals Corp
Priority date: 1964-03-31
Filing date: 1964-03-31
Publication date: 1968-05-14
Anticipated expiration: 1985-05-14

Description

United States Patent ABSTRACT OF THE DISCLOSURE Polyester fiber is dyed by padding with a dye of the formula:

at a temperature of from 140 F. to 180 F., then drying and heating the dried material to a temperature of from 390 F. to 440 F. for one-half to two minutes.

The present invention relates, in general, to the art of dyeing synthetic materials and, in particular, to an improved method of dyeing a polyester fiber utilizing an azo dye of the formula:

With the advent of synthetic fibers as textile materials and particularly polyester-type materials the demand for improved dyeing processes'for these materials has increased. Similarly, conventional dyes, of the type previously found suitable for dyeing other synthetic fibers such as polyamides and acetates, when employed in the dyeing of polyester-type materials, have been found unsatisfactory since these dyes lack sufiicient wash and dry cleaning fastness and are not sufficiently resistant to fading and sublimation. Etforts to overcome these drawbacks have led to the development of processes employing a type of dye wherein diazotiza-tion and coupling occur directly upon the fiber. While this expedient has offered some irnprovements, such processes are quite diificult and lengthy. Additionally, many new dyes have been olfered on the market which have been particularly tailored for use in dyeing polyester fibers, however, many of these dyes when applied to polyester fibers result in products of poor light fastness and when the dyes are of sufficient light fastness they are usually subject to the disadvantage of insufi'icient resistance to sublimation at high temperatures thus preventing their use in high temperature dyeing processes which are presently commercially advantageous in producing especially fast, bright dyeings in an economical and practical manner.

Accordingly, it is a primary object of this invention to overcome the aforementioned and other difficulties by means of an improved method for dyeing a polyester material.

Another object of this invention resides in the provision of a method which provides improved dyeings characterized by superior light, wash and dry-cleaning fastness.

Still another object of this invention resides in the provision of an improved process for dyeing a polyester fiber at high temperatures wherein the dye employed is characterized by good resistance to sublimation under the dyeing conditions.

Yet another object of this invention resides in the provision of means for dyeing a polyester fiber a strong bright orange color of good build-up with fastness to light, washing, dry cleaning, crocking and sublimation.

These and other objects, features and advantages of the present invention will become further apparent as the detailed description of the invention proceeds.

The achievement of the aforesaid objects of the invention is readily accomplished by the method which comprises impregnating a polyester fiber at a first elevated temperature with an aqueous dispersion of an azo dye of the formula:

drying said dyed polyester fiber and subsequently subjecting said dried fiber to a second elevated temperature higher than said first elevated temperature for a period of time sufiicient to develop the full color of said dyed polyester fiber.

The term a polyester fiber as used herein is intended to include the fibers obtained by the polyester condensation products of dicarboxylic acids and polyols and in particular those polyesters obtained by the condensation of terephthalic acid and ethylene glycol as well as mixed polyesters and blends thereof with other synthetic and/or naturally derived fibers such as cotton. The invention is also applicable to polyester fibers which have been modified or plasticized by the addition of other materials such as glycols or plasticizers which are mixed with the polyethylene terephthalate.

The azo dyestufi' represented by .the above formula is readily prepared by diazotization of 6-chloro-alpha, alpha, alpha-trifiuoro-meta-toluidine and subsequently coupled with a Naphthol AS compound of the formula:

OH CH3 condensation of sulphonated aromatic derivatives with aldehydes, such as the methylene-dinaphthylsulphonates, are particularly valuable auxiliary substances since they allow the preparation of a good dispersion of the dyestuffs and facilitate the taking up of the latter on the polyester fibers. On the other hand, carriers, such as monoor poly-chlorinated derivatives of the benzene series or diphenyl, can be added to the dye bath or to the printing pastes. These substances exert a swelling action on the polyester fibers and are capable of improving the t-inctorial yield.

'In carrying out the dyeing procedure of the present invention weight percent active dispersed paste of the dyestutf is dissolved in water at concentrations of from about 1.0 to 15.0 ounces per gallon. The solution is thickened to suitable padding consistency by the addition of conventional thickeners such as gum traga-canth in quantities normally about twice that of the water employed.

The dyeing method of the invention comprises essentially impregnating the polyester fiber by padding or printing with an aqueous suspension or solution of the dye corresponding to Formula 1 above at a temperature of about 140 F. to 180 F., drying the impregnated fiber and subsequently subjecting said impregnated fiber to a heat treatment at a temperature of from about 390 F. to about 440 F. for a period of time sufficient to develop the full color.

The aforesaid procedure results in polyester dyeings of a strong, bright orange color of excellent build-up with an unexpected fastness to light, washing and dry cleaning, crocking and sublimation.

That such results are obtained is indeed surprising since inferior results are obtained by dyeing other synthetic tfibers with the dyestuti of the invention and, on the other hand, equally inferior results are obtained by dyeing polyester fiber with dye compounds of a structure similar to the dyestuff of this invention. Thus, it appears that the unexpected results obtained are primarily due to the unique combination of the polyester fiber and the dyestutf of the invention.

The commercial significance of the instant invention resides, in part, in the fact that the Thermosol dyeing of polyester fibers has proven to be a persistent problem particularly with respect to producing dyed fibers in the yellow and orange shade ranges because most yellow and orange dyes heretofore employed in the Thermosol process sublimed or volatilized during processing thus smearing not only the goods but the equipment.

The following example will serve to illustrate the practice of the invention:

Example 1 To 268 pounds of hydrochloric acid 20 B. there were added 44.1 pounds of 6-chloro-alpha, alpha, alpha-tritfiuoro-m-toluidine. After stirring Well, 150 pounds of ice was added followed by the addition of 17.1 pounds of a 31.5% sodium nitrite solution and the mixture stirred for one hour. It was then treated with 2 pounds of diatomaceous earth and 0.5 pound of activated carbon and 'rfiltered. Before coupling an additional 250 pounds of ice was added and excess nitrite removed with sulfamic :acid.

To 600 pounds of water there were added 63.5 pounds of 3-hydroxy-2-naphth-o-toluidide and 16 pounds of sodium hydroxide by weight). The mixture was warmed to about 75 C. and stirred to solution, then cooled to C.

To the diazo solution there was added 2.5 pounds of a polyoxyethylated fatty alcohol known as Emulphor ON.

The coupler solution was then added to the diazo solu- 4 tion, with stirring, while maintaining the temperature below 20 C. After the coupling reaction was complete the product was filtered, washed with water and dried. The dye product has the formula:

on CONH Gate Five ounces of the dye was dissolved in 1 gallon of water and then thickened to a padding consistency with 0.2 ounce of Keltex gum (gum tragacanth) and 0.1 ounce of Leonil SA (anionic naphthalenesulfonate dispersing agent). A 5 /2 x 18 inch piece of Dacron polyester fiber (poly-condensate of terephthalic acid with ethylene glycol) was padded with the above dye at F., dried, and .then subjected to 425 F. for 1 /2 minutes. The material was soaped for 5 minutes at the boil, rinsed and dried. A strong bright orange dyeing of good build-up, and exceptional light fastness, sublimation, dry cleaning and crock fastness was obtained.

Thus having described the invention it is manifest that obvious modifications and variations thereof will occur to those skilled in the art without departing from the spirit and scope of the invention. Therefore, it is intended that all such modifications and variations be included within the scope of the appended claims insofar as the state of the art permits.

1. A method for coloring a polyester fiber a strong, bright orange color to produce a dyeing characterized by fastness to light, Washing and dry cleaning, crocking and sublimation which comprises impregnating at a temperature of from 140 F. to 180 F. a polyester fiber with an aqueous composition containing a dyestuff of the formula:

drying the fiber and subjecting the fiber to heat at a temperature of from 390 F. to 440 F. for 'a period of time sufiicient to develop full color.

2. The method according to claim 1 further characterized in that the dried, impregnated fiber is subjected to heat at a temperature of from 390 F. to 440 F. for a period of from one-half to two minutes.

References Cited UNITED STATES PATENTS 2,663,613 12/1953 Gibson 8-4 X 3,238,189 3/ 1966 May et a1. 8-55 X FOREIGN PATENTS 809,221 2/-1959 Great Britain.

NORMAN G. TOHCHIN, Primary Examiner.

T. J. HERBERT, Assistant Examiner.