DE741053C - Process for the preparation of water-soluble leucoesters of anthraquinone dyes - Google Patents

Description

Process for the preparation of water-soluble leuco esters of anthraquinone vat dyes It has been found that there are stable, water-soluble leuco esters of anthraquinone vat dyes obtained when one on aqueous vats of anthraquinone @ vat dyes in the presence of reaction products of naphthalenesulfonic acids with formaldehyde acylating agent, which contain at least one substituent, which, if appropriate, after suitable Conversion, water solubility conditional, allows to act.

Examples of acylating agents of the type mentioned are halides of aromatic sulfocarboxylic acids, i.e. about. of the dichloride of benzene-i-tarboxylic acid-a-sulfonic acid or corresponding halides derived from phosphoric acid, e.g. B. Monokrssylphosphorsäuredichlori% d or mononaphthyl phosphoric acid, dichloride. Also acid halides of polycarboxylic acids can be used e.g. B. the dichloride of 4-carboxylphenylacetic acid, or also anhydrides of sulfocarboxylic acids, such as the anhydride of benzene-i-carboxylic acid-a-sulfonic acid.

The term anthraquinone vat dyes is intended to be used in the work of Kunz in the Bulletin de la Societe Industrielle de Mulhouse, 1934 to have. For example, the vat dyes of the dibenzanthrone, Dibenzpyrenquinone, antbrachinone acridone, anthanthrone, pyranthrone, indanthrone and Fl.avanthron row. Of course, vat dyes that derive from actual® anthraquinones, use for the procedure how for example i-benzoyl-amino-4-chloranthraquino.

Proceeds for the production of the leucoester one example so that the dye with the required amount of alkali and sodium hydroxide vat in the usual way, and the vat obtained in this way after the addition of a reaction product of naphthalenesulfonic acids with formaldehyde as a distribution agent with the acylating agent treated. But you can also add the distribution agent at the point of vatting. Depending on the ability of the acylating agent to react, there are more or more less large proportions and, if necessary, with cooling. If the implementation doesn't runs very quickly, it is advisable to work with the exclusion of air. This measure is particularly indicated when the reaction mixture is stirred vigorously or shakes. In general, it is beneficial or even advisable to have either one Excess of alkali waste liquor or other acid-binding agents such as alkali carbonates or pyridine, to be added. The resulting leuco compounds are then separated, e.g. B. by salting out. They can be used in dough, depending on the desired use. or put in powder form.

The leuco ester salts obtained are on. constant to the air. You let saponify themselves in acidic and usually also in alkaline liquid and go in Presence of oxidizing agents in the vat dyes on which they are based above. They can therefore be used for dyeing and printing a wide variety of fibers use.

It is already known to use ester salts of leuco compounds of vat dyes in dyes by reacting benzoic acid-m-sulfohalides with the dry ones Leuco compounds of anthraquinone vats in the presence of a dry tertiary base to win. However, the present method is much simpler because it is one separate, usually laborious production of the dry leuco compounds of There is no need for vat dyes and also expensive solvents such as dry tertiary ones Bases, not needed.

The parts given in the examples below are parts by weight. Example i 4. Parts of a 23% paste of Dibrotn-Bz 2, Bz 2 -dimethoxydibenzanthrone are made with the addition of 2 parts of the sodium salt of the reaction product Naphthalene-2-sulfonic acid with formaldehyde and 1 part of 35% sodium hydroxide solution and 0.75 Parts of sodium hydrosulfite in 75 parts of water at 60 ° vat. To that at about 5 ° The cooled vat solution is then given in small portions of 2 parts with the exclusion of air of the mixture of benzene-i-carboxylic acid-2-sulfonic acid and the reaction mixture is stirred until the resulting red solution is no longer oxidized in air. It is advantageous to add sodium carbonate solution to the reaction mixture always to be kept alkaline. The resulting leucoester is then used in the usual way separated by the addition of sodium chloride. It dissolves in water with a brownish red color Color and can be treated with acid or caustic alkali in the presence of an oxidizing agent split again to the green starting dye. Example e 4.2 parts of Bz2, Bz2'-diethoxydibenzanthrone are suspended in 17o parts of water and, after the addition of 7 parts, 35% Sodium hydroxide solution and 3.5 parts of sodium hydrosulfite at 60 ° v. The vat solution is in 800 parts of water at room temperature, in which 10 parts of the sodium salt of the reaction product of naphthalene-2-sulfonic acid are dissolved with formaldehyde, and that by adding i part 35 "/, i" -er sodium hydroxide solution and i part sodium hydrosulfite has been made oxygen-free, entered. At a temperature of about 30 ° then 15 parts of the dichloride of benzene-i-carboxylic acid-2-sulfonic acid are added with stirring admitted; the solution becomes weakly alkaline by adding sodium bicarbonate solution held and stirred until its red color persists in the air. Then 300 parts of potassium chloride are added, the precipitated potassium salt is sucked Leucoesters off and dry it. It dissolves in water with a reddish brown color and can be in the presence of an oxidizing agent in both acidic and alkaline Split the solution again into the blue-green starting material.

In the same way, Bz 2, Bz 2'-dimethoxydibenzanthrone in transfer the red-brown leuco ester, which is also in the presence of oxidizing agents can split in acidic or alkaline solution to the green starting dye. example 3 5.5 parts of an aqueous dough of flavanthrone are divided into 250 parts Water with the help of 2.5 parts of 35% sodium hydroxide solution and 1 part of sodium hydrosulfite tilted at 60 °. The vat solution, cooled to 20 °, is after addition of 5 parts of the sodium salt of the reaction product of naphthalene-2-sulfonic acid with formaldehyde mixed with 5 parts of the anhydride of benzolecarboxylic acid - 2-sulfonic acid and that Mixture by adding sodium carbonate Solution kept alkaline. After the reaction has ended, the blue-black colored leuco ester is separated Addition of sodium chloride. The leucoester is difficult to dissolve in water, but it works he with the addition of alkali with deep blue color in solution and draws from this Solution on cotton. By treating with sulfuric acid and alkali nitrite or with Caustic soda and an 'oxidizing agent, such as hydrogen peroxide, become the dye split back into the starting dye in substance or on the fiber. example 4 An from ro parts of a 9% aqueous suspension of anthraquinone z. (N) 2-naphthacridone, 5 parts of the reaction product of naphthalene-2-sulfonic acid with formaldehyde, 2.5 parts of 35% sodium hydroxide solution, z part of sodium hydrosulfite and 250 parts of water produced at 45 ° are added to the vat after cooling to room temperature with 5 parts of the finely powdered anhydride of benzene-r-carboxylic acid-2-sulfonic acid. The color of the solution changes from Bordo to yellow-brown. The solution that keep it alkaline by adding sodium bicarbonate, keep stirring until until a sample no longer changes in air. Then m.an part by adding from sodium chloride the sodium salt of this leuco ester formed. It dissolves in water with a yellow-brown color and is made by treating in acidic or alkaline Solution converted back into the red starting dye with oxidizing agents. The leucoester can be used in the usual way for dyeing and printing natural and serve artificial fibers.

In a similar way, one also obtains from dibenipyrenequinone, dibromodibenzpyrenquinone, r-Benzoylamino.-4-chloroanthraquinone, pyranthrone, dibenzanthrone and dibromoanthanthrone stable, water-soluble ester salts. Example 5 For one of z2 parts Bz 2, Bz 2'-dimethoxydibenzane, throne, 65o parts of water; in the 2o parts of the conversion product are dissolved from naphthalene-2-sulfonic acid with formaldehyde, 20 parts of 38% sodium hydroxide solution and to parts of sodium hydrosulfite at 45 ° are prepared under good vat Stir 40 parts of the dichloride of monocresylphosphoric acid and stir the mixture in the absence of air until a sample no longer oxidizes in air. The red leuco compound is then separated off by adding sodium chloride. It easily pulls out of the aqueous solution on cotton or other fibers and can by- treating with dilute sulfuric acid and sodium nitrate in the original green starting dye can be cleaved back.

Example 6 For one of r part of anthraquinone-z (N) -2, 2 '(N), z'-naphthacri, don, 2 parts of the reaction product of naphth @ aline-2-sulfonic acid with formaldehyde, 2.5 parts 35% Sodium hydroxide solution, 1 part sodium hydrosulfite and 250 parts water at 45 ° are added to the vat after cooling to 10 ' : 2.5 parts of the dichloride of 4-carboxyphenylacetic acid and the mixture is heated with stirring to about 30 ° until the color of Bordo turned yellowish brown. The solution, which is kept alkaline by adding sodium carbonate, is stirred for a further 2 hours and finally the potassium chloride is precipitated by adding potassium chloride or sodium chloride. Sodium salt of the resulting leuco compound. This is yellow-brown and draws the same color from the aqueous solution onto the fiber, e.g. B. cotton. By treating in an acidic solution with sodium nitrite or in an alkaline solution with hydrogen peroxide or similar oxidizing agents, the red starting dye can be recovered.

Also with the dichlorides of isophthalic acid, terephthalic acid or Phthalic acid gives you water-soluble leuco compounds that can easily be reintegrated into the Starting dyes can be split.

Claims (1)

PATENT CLAIM: Process for the production of water-soluble leuco esters of anthraquinone vat dyes, characterized in that one is based on aqueous Vat of anthraquinone vat dyes in the presence of reaction products of Naphthalenesulfonic acids with formaldehyde acylating agents that have at least one substituent contain, which, if necessary after suitable conversion, causes water solubility, can act.