DE1469718C - Process for coloring fiber materials with water-soluble ester salts of leukocupene dyes - Google Patents

Description

In the known processes for dyeing fiber materials with ester salts of leuco vat dyes the fiber materials with the leuco vat esters are used to develop the color, possibly at elevated temperature, in the presence of acids, the action of an oxidizing agent, such as B. alkali metal nitrite, chromate or chlorate exposed. The development can either by aftertreatment with a bath of the oxidizing agent containing acid or acid-releasing agents be made; mostly, however, the oxidizing agent as well as an acid-releasing agent is used Means already added to the solution of the Leukoküpenester, so that the development in the downstream Steaming or dry heating takes place. A disadvantage of this known mode of operation is that hereafter on blended fabrics made of synthetic fibers, such as. B. polyester fibers and cellulose fibers, only allow dyeings with the same fibers and uneven levels to be achieved.

It has now been found that fiber materials with water-soluble ester salts of leuco vat dyes can be dyed in a simple way, even without the use of oxidizing agents and acids, if one uses leuco vat ester from an aqueous, optionally thickening agent on the fiber materials applies the preparation containing, dries and then briefly at high temperatures (thermosetting conditions) heated. The aqueous preparations can be printing pastes or, preferably Act Klotzfiotten.

The conversion of the leuco vat ester to the dye pigment takes place under the heat setting conditions customary in practice for the individual fiber types, ie by dry heating to temperatures in the range from about 170 to 240 ^° C. for about 5 seconds to 4 minutes. This apparently results in thermal cleavage of the ester group from the ester salt of the leuco vat dye and oxidation to the vat dye by the oxygen in the air. In general, the higher the fixing temperature, the greater the dye yield. In the case of mixed fabrics, the dye is fixed on both the synthetic fibers and the natural fibers at the same time.

As fiber materials that can be dyed by the method of the present invention, come Fiber strands, woven fabrics, knitted fabrics, nonwovens and the like made from natural fibers, such as. B. Cotton or other cellulose fibers, wool, silk and especially synthetic fibers made from linear polyesters, Polyamides, polyacrylonitrile and the like, as well as mixtures of »natural and synthetic fibers in Ask. Fiber materials made of linear polyesters and, above all, mixtures of polyester and cellulose fibers.

ίο One advantage of the procedure is that it is very simple Working method that is important in practice with the increasing use of unskilled workers. Because of the very simple dyeing recipe, good reproducibility is guaranteed when dyeing large quantities.

Application of the method of the present invention to fiber blends of polyester and Cellulose fibers are particularly advantageous because, surprisingly, dyeings with very good levelness, tone uniformity and uniformity of color depth can be obtained with good fastness properties at the same time. This Fiber mixtures offer dyeing with ester salts of leuco vat dyes according to the known processes with the use of oxidizing agents particular difficulties because of the stronger staining of the Cellulose fibers easily have a tone and color depth disparity the coloration occurs.

When dyeing cellulose fibers, it can help prevent hue shifts, as occurs when Dyeing of large quantities easily occur, it is appropriate to use the ester salts of leuco vat dyes Adding addition compounds of ethylene oxide to alkylphenols in the pad bath. Preferably addition compounds come from 7 to

10 moles of ethylene oxide and 1 mole of nonylphenol are used. This means that even when using Mixtures of leuco vat esters with different substantivity, color shifts are balanced and colorations with the same ends are obtained. Through The addition of these oxyethylation products is used when dyeing synthetic fibers or synthetic fibers Fibers containing blended fabrics in many cases also increase the color yield on the synthetic Fiber material causes.

example 1

A 1 g / l of the dye CI 69526 (Color Index, Vol. 3, 1956) containing liquor at 20 ⁰ C on a mixed fabric made of polyethylene terephthalate fibers and cotton (67/33) having a squeezing effect of

about 65% padded out. Subsequently, "is dried at 130 ⁰ C, fixed for 60 seconds at 210 ⁰ C and then soaped at the boil, as usual, and finished. This gives a gray coloration, stained tongleich wherein both types of fibers.

Example 2

A fabric made of polyethylene terephthalate fibers is padded with a squeeze effect of about 45 ° / ₀ with a liquor at 20 ° C which contains 1 g of the dye CI 73 361 (Color Index, Vol. 2, 1956) per liter. It is then ^{dried at 120 °} C., ^{heated dry to 210 °} C. for 60 seconds and soaped at the boil. A pink color is obtained.

3 4

Example 3 a polyamide fabric padded at 20 ° C. The goods will

continuously intermediate dried at 100 ⁰ C, for

With an aqueous liquor, which heats 1 g of the dye-fixture per liter at 180 ° C. for 60 seconds and then soaped off the boiling point CI 59 106 (Color Index, Vol. 3, 1956). It is ⁷ receives a] Gold yellowing, is it with a pick of about 45%. 5

Claims (1)

Claim: Process for dyeing fiber materials made of natural and / or synthetic fibers, preferably mixtures of polyester and cellulose fibers with ester salts of leuco vat dyes, characterized in that aqueous preparations containing the leuco vat esters are applied to the fiber materials, then dried and for fixation without use of oxidizing agents or acids to dry heating at about 170 to 240 ⁰ C for a short time.