US3563685A - Dyeing polyamide fibers with a yellow monazo acid dye - Google Patents

Abstract

DYEING POLYAMIDE FIBERS WITH A DYEBATH CONTAINING DISODIUM DODECYLIDIPHENYLETHER DISULFONATE AND THE YELLOW ACID DYE OF THE FOLLOWING STRUCTURE

1-(4-CL-PHENYL),3-CH3,4-((2-CL,5-(M-O3S-)PHENYL)-N=N-)-

PYRAZOLE

WHERE M IS H, AMMONIUM RADICAL OR ALKALI METAL.

Description

United States Patent 01 lice 3,563,635 Patented Feb. 16, 1971 US. Cl. 8-41 2 Claims ABSTRACT OF THE DISCLOSURE Dyeing polyamide fibers with a dyebath containing disodium dodecyldiphenylether disulfonate and the yellow acid dye of the following structure I CH3 y 1| N SOJIVI H N where M is H, ammonium radical or alkali metal BACKGROUND OF THE INVENTION This invention is directed to a process for dyeing polyamide fibers, particularly in nylon carpet.

Because of the wide acceptance and use of nylon, the dyeing of polyamide fibers in their various forms has become a very large and competitive business. Several classes of dyes are used for dyeing polyamide fibers, each class having generally some advantages and some disadvantages. Disperse dyes were the first type to be recommended. They are believed to dye by dissolving in the polyamide fiber, without chemical reaction. They therefore give level dyeings on all types of polyamide fibers, the dyeings being unaffected by chemical differences. Disperse dyes have not met all the needs of the carpet dyer. Very bright dyes and dyes of maximum light and fume fastness are not found among the disperse dyes. These qualities are more often found among the acid dyes. The reason that acid dyes, with these generally superior qualities, have not been adapted for nylon carpet dyeing is the problem of lack of uniformity.

Acid dye molecules are assumed to associate With polyamide molecules at cationic ammonium end groups in the polymer chain. Thus, any lack of uniformity in am monium end groups among the fibers used in making a textile product will be reflected in the lack of uniformity of dyeing in acid dyed material. In carpeting made from continuous filament polyamide fibers, such lack of uniformity is evidenced as a streaky dyeing. This is particularly noticeable in open width dyeing of polyamide carpets where 15 foot by 100 foot loops are dyed in large kettles, called becks. Unassisted acid dyes will expose lack of uniformity in the fibers as well defined streaks, lighter or darker than the surrounding area.

A second major difficulty in dyeing large carpets in becks is the problem of lack of levelness, or uniformity of the shade depth from side to center to side. This problem exists with any type of dye, but is greater with acid dyes or any site-dyeing dyes which associate chemically with the fiber molecules. The problem is minimized by careful addition of the dye to the bath and by efficient agitation, but practical experience has shown that such expedients are not sufiicient to solve the problem.

Over the years a number of methods for overcoming the above-listed difficulties have been tried. Three general methods will be mentioned:

The first of these is the use of swelling agents or high temperature to open up the fiber. This concept suggests that if the dye could move more rapidly into and within the fiber, dye transfer would be facilitated, physical differences between yarns would be less significant, and dyes which perform poorly under normal conditions might produce more uniform dyeings.

A second method for obtaining improved level dyeing with acid dyes involves complexing the dye in the dyebath with a cationic material before application of the dye to the fiber. The dye complex is formed at a low temperature and at a low pH, then, under the influence of the higher dyeing temperature, the complex gradually dissociates and the dye ion becomes available to diffuse into the fiber. Since at any given time the actual concentration of free dye ion is very low, level dyeing is obtained as it would be from a very dilute dyebath.

A third method for promoting levelness uses anionic dyeing assistants. The mode of operation is within the nylon fiber, not in the dyebath as was the case with the cationic approach. This method depends on the competition of certain colorless anions in the dyebath with the dye for the positively charged dyeing sites in the fiber. Thus it becomes more difficult for the dye molecule to find a point of attachment during the initial stages of dyeing. As dyeing progresses, the anionic dye competes more successfully with the colorless anionic assistant for dye sites, resulting in improved levelness of dyeing.

The process of this invention provides level dyeing of polyamide fibers with a monazo acid type dye without streakiness.

SUMMARY OF THE INVENTION The process of dyeing fibers which comprises contacting the fibers with an aqueous dyebath which contains disodium dodecyldiphenylether disulfonate and the dye of the following structure l N S 03M H O N/ where M is H, ammonium radical or alkali metal.

DESCRIPTION OF THE INVENTION The dyeing process of this invention may be carried out using 20 to parts of water per part of textile material without effect on the process efficiency.

The. disodium dodecyldiphenylether disulfonate dye assistant may be prepared according to the disclosure of US. Pat. 2,081,876. The amount used may vary from 0.5 to 4.0 weight percent of the fibers, the preferred amount is from 0.5% to 2%. Lesser amounts are insufficient to insure satisfactory leveling and streak coverage. Amounts greater than 4% may lead to poor exhaust from the dyebath and consequent economic loss. Excessive amounts have also caused a diminution of lightfastness.

The dyeing process may be carried out in any convenient manner. In the dyeing of carpets, the preferred manner is to use a beck or large kettle in which to 100 foot loops are dyed. This process is particularly suited for full width, in the range of from 12 ft. to 15 ft., carpet dyeings.

Dyeing may be carried out at any pH in the range of from 3 to 7, with the preferred range being from a pH of 6 to 7. Higher pHs tend to cause poor exhaust. Acetic acid or tetrasodium pyrophosphate may be used to adjust the pH of the dyebath.

The optimum temperature for the dyeing process is at the range of from 95 to 100 C. Lower temperatures extend the time required and also give poor exhaust.

The acid dye of this process was developed for dyeing bulked continuous filament polycarbonamide fibers. It has successfully solved the uniformity problem in an economic manner. This dye also gives good levelness on flatwoven and knit fabrics. This dye is unusual among acid dyesin having good transfer properties. The dyeing assistant, disodium dodecyldiphenylether disulfonate helps promote their transfer and is much superior in this respect to other anionic leveling agents.

As shown under Example 1 below, the yellow acid dye of this invention can be prepared by diazotizing 3- amino4-chlorobenzene sulfonic acid; coupling to l-pchlorophenyl-3-methyl-5-pyrazolone; isolating by filtration; and drying.

The process of this invention, while related to the anionic dyeing system, does not depend on retarding the striking rate of the dye by either a cationic or anionic agent, but is based on the interdependence of the special anionic material together with the selected dye which has the ability to transfer well. The transfer principle, or ready mobility of the dye, is the direct means of obtaining levelness. The anionic agent used, disodium dodecyldiphenylether disulfonate, aids this transfer in a unique way and, at the same time, competes with the dye for the cationic sites within the fiber. When the dyeing problem is extremely difficult as in the open width dyeing of very wide nylon carpeting, dye transfer can be further facilitated by the use of a nonionic agent such as the condensation product of moles of ethylene oxide with one mole of C alcohol along with the adjuvant of the invention. As in older procedures, there is a competition for the dye sites. The novel feature of the present process is the ready movement of the dye and agent in and out of the fiber. This allows correction of unlevelness by transfer, rather than requiring a controlled initial strike.

The complete mechanism by which the adjuvant and the dye of this invention compete to provide improved level dyeing action on polycarbonamide articles is not known in firm detail. The results, however, are clear. This dye is much less prone to develop a streaky pattern in a fabric that is faulty in this respect. The exceptional transfer performance that takes place in the dyebath accounts for the improved levelness of dyeing.

It is well known in the art that there are wide variations in level-dyeing properties among the many acid dyes available; but in addition to this, other factors such as color fastness, draw rate, solubility, etc., must be considered. Above all, maximum lightfastness was a major criterion of acceptability. In its shade class, the dye of this invention was found, surprisingly, to offer technical advantages ever known dyes of somewhat similar structure, when used with the recommended adjuvant for dyeing polyamide fibers.

4 The following examples are representative of the process of this invention. All parts are by weight unless otherwise specified.

EXAMPLE 1 The yellow acid dye of this invention was prepared in the following manner. A solution was prepared containing 11.5 grams of 3-amino-4-chlorobenzene sulfonic acid sodium salt, 25 ml. of 37% hydrochloric acid and ml. of water. Ice was added to cool to 10 C. and 10 ml. of 5 N sodium nitrite was added over 5 minutes. A small amount of sulfamic acid was added to destroy the excess nitrite.

A coupler solution was prepared at 25 C. containing 125 gram of l-p-chlorophenyl-3-methyl-5-pyraz0lone in ml. of water and 2.1 grams of sodium hydroxide. To the coupler solution was added a solution of 12 grams of anhydrous sodium carbonate in ml. of water, and the entire solution cooled to 8 to 10 C.

The diazo solution was added to the coupler solution, maintaining the temperature at 8 to 10 C. The solution was heated to 50 C. to complete the reaction. The slurry was stirred over night, then filtered. The wet product was dissolved in dilute caustic soda solution, filtered, and the product reprecipitated with hydrochloric acid,

' then filtered, washed and dried. The yield was 17.5 grams of dry product. The finished product was used in the following examples.

EXAMPLE 2 The following example illustrates the dyeing of nylon carpeting using the yellow acid dye of Example 1. The carpeting is made by tufting polycarbonamide yarn onto a jute or polypropylene backing. The continuous filament polycarbonamide yarn used for this is 3700-denier, 204- continuous filaments, trilobal, jet-bulked yarn, melt-spun from poly (hexarnethylene adipamide) flake. The yarn is jet-bulked with the jet taught by Hallden et al. in US. Pat. 3,005,251.

Thirty parts of said carpeting are installed in dyebath equipment. First, the carpet is scoured at 82 C. for 20-30 minutes in a hath made up of 1000 parts water, 0.2 part of a nonionic surfactant (the condensation product of 20 moles of ethylene oxide with one mole of C alcohol), 0.6 part concentrated ammonium hydroxide and 0.15 part sodium hydroxide. The bath is dropped and the carpet is rinsed with clean water. A dyebath is then made up of 1000 parts water, 0.3 part of dodecyldiphenylether disulfonic acid, disodium salt according to the disclosure of US. Pat. 2,081,876, 0.03 part of the yellow acid dye of Example 1 and 0.6 part of monosodium phosphate. The pH is adjusted to 6.0 by addition of acetic acid or disodium phosphate. The bath temperature is raised to 99 C. over a 45-1ninute period and the dyeing is continued for one hour. The bath is dropped and the carpet is given a warm water rinse.

When the pH of the dyebath is adjusted to 6.5, instead of 6.0 as in the present example, similar results are obtained.

The dye of the present invention may be applied in this manner to give shades having excellent levelness and lightfastness. Potential streakiness is effectively restrained. Wool and silk may also be dyed in fast shades by the proress of this example.

EXAMPLE 3 A number of dyes of structure similar to the yellow acid dye of Example 1 were synthesized and compared with regard to color transfer and lightfastness.

The test for transfer is carried out by exposing a piece of undyed carpeting and a piece of previously dyed carpeting in a bath containing all the regular materials as in Example 2 except the dye itself. After the standard dyeing time, the samples are removed, dried and compared. With perfect transfer, 50% of the dye will be on each sample, and both will have the same shade. If none of the dye transferred from the dyed to the undyed sample, percent transfer would be 0. Gradings are made by visual comparison. Dyes with satisfactory transfer properties will give level dyeings on full width carpets by piecedyeing when the process of this invention is used. Satisfactory streak coverage is also obtained, this quality depending on the efficiency of the adjuvant in masking fibers containing higher or lower concentration of amine end groups.

The lightfastness test was performed according to the American Association of Textile Chemists and Colorists procedure titled Color Pastness to Light, Tentative Test method 16 E-1964, using a Xenon Lamp for 80 hours. Lightfastness was evaluated according to the following scale:

5-Negligible or no change 4-Slightly changed 3Noticeably changed Z--Considerably changed 1Much changed It will be noted from the results which appear in Table I that relatively slight changes in the chemical make up of the dye cause profound changes in the dye properties.

TABLE I.YELLOW ACID TYPE DYES Percent The yellow acid dye of this invention was used to dye duplicate pieces of nylon carpet with and without the EXAMPLE 4 Much, to considerably weaker.

additive disodium dodecyldiphenylether disulfonate. Similar dyeings were made with another representative A Comparison was made of the transfer qualities of the 7 acid yellow dye at the same time. The results presented yellow acid dye of this invention and a representative yellow acid dye. The dyeings were carried out as in Example 2. It will be seen from the results presented in Table II that the yellow acid dye of this invention compares favorably with the other representative acid dye.

in Table III illustrate the eifect of the dyeing assistant disodium dodecyldiphenylether disulfonate in promoting transfer and shows the possible variations to be expected in the transfer properties of acid dyes, and that the dye of the present invention is superior in this property.

TABLE IILEFFEC'1 O1" DYElNG ASSISTANT Percent; Dye Assistant transfer Yes 40 -N=N lcH, No 35 N SOzNfl HO N C. I. acid yellow 40 1350s o It is to be understood that the preceding examples are representative and that said examples may be varied within the scope of the total specification, as understood by one skilled in the art, to produce essentially the same results.

As many widely difi'erent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that this invention is not limited to the specific embodiments thereof.

I claim:

1. The process of dyeing polycarbonamide fibers which comprises contacting said fibers with an aqueous dyebath containing disodium dodecyldiphenylether disulfonate and the dye of the following structure i Ii SOiM

UNITED STATES PATENTS 20 1,962,226 6/1934 Woodward. 2,081,876 5/1937 Prahl.

FOREIGN PATENTS 25 966,677 8/1964 Great Britain.

988,829 4/1965 Great Britain.

GEORGE F. LESMES, Primary Examiner B. BETTIS, Assistant Examiner US Cl. X.R. 8-179, 89