DE1032865B - Process for the production of cobalt-containing monoazo dyes - Google Patents

Description

Process for the preparation of cobalt-containing monoazo dyes It has been found that valuable cobalt-containing monoazo dyes can be prepared in an advantageous manner by using diazotized aminobenzenes of the general formula in which V and Z are hydrogen, alkyl or aryl groups and R and R 'are identical or different low molecular weight alkyl groups, are coupled with 2-oxynaphthalene or its alkyl, halogen and / or alkoxy derivatives and the o-oxy-o'- alkoxymonoazo dyes converted by processes known per se into cobalt complex compounds of the corresponding o, o'-dioxyazo dyes which contain about 1 cobalt atom for every 2 azo dye molecules.

Suitable azo components are, for. B. 2-oxynaphthalene, 4,8-dichloro-2-oxynaphthalene, 2-oxy-6-bromonaphthalene, 3- or 6-methyl-2-oxynaphthalene or 2-oxy-6-methoxynaphthalene.

The conversion into the cobalt complex compounds can e.g. B. after the in German patents 715 082 or 715 948 or in French Patent 836 257 described method can be made.

The cobalt-containing dyes obtainable in this way are distinguished by high fastness properties and good leveling properties and are particularly useful for dyeing Suitable for wool and polyamide fibers from neutral or slightly acidic baths.

The cobalt complex compound of the azo dye 1,4-dimethoxy-2-aminobenzene-5-sulfonic acid amide - 2-oxynaphthalene prepared according to the invention is, when dyed on wool, better lightfast than the corresponding chromium complex compound known from the example of British patent 681653. The same wool dyeing of the same dye according to the invention is also better than that of the cobalt complex compound of the azo dye 1-oxy-2-amino-4-methylbenzene-5-sulfonic acid amide - @ 2-oxynaphthalene, which is listed in the table of German patent 937 367 as no. 14 is mentioned.

The parts mentioned in the example are parts by weight. Example 23.2 Parts of 1,4-dimethoxy-2-aminobenzene-5-sulfonic acid amide are dianotized in the usual way and coupled with an alkaline solution of 14.4 parts of 2-oxynaphthalene.

20 parts. of the monoazo dye thus obtained are mixed with a solution of 6 parts of cobalt (II) chloride (Co C12. 6 H2 O) in 200 parts of acetamide for 5 hours heated to 130 ° C. Then the mixture is introduced into 2000 parts of water, the falls cobalt-containing dye with 200 parts of sodium chloride, filtered off with suction, washed with some water and dry at 80 ° C.

The cobalt-containing dye produced in this way dyes wool and polyamide fibers from a weakly acidic bath in bluish violet shades of very good fastness properties.

In a corresponding manner, cobalt-containing dyes can be prepared from the following components Coloring of the cobalt Diazo component Azo component complex compound on wool 1,4-dimethoxy-2- 2-oxy-6-bromo-blue-violet aminobenzene-5-naphthalene sulfonic acid amide 1,4-diethoxy-2-oxy-6-methoxy blue aminobenzene-5-naphthalene sulfonic acid amide

Claims (1)

PATENT CLAIM: Process for the preparation of cobalt-containing monoazo dyes, characterized in that diazotized aminobenzenes of the general formula in which V and Z are hydrogen, alkyl or aryl groups and R and R 'are identical or different low molecular weight alkyl groups, are coupled with 2-oxynaphthalene or its alkyl, halogen and / or alkoxy derivatives and the o-oxy-o'- alkoxy monoazo dyes converted into cobalt complex compounds of the corresponding o, o'-dioxyazo dyes, which contain about 1 cobalt atom for every 2 azo dye molecules. Considered publications: German patent application C 6261 IVb, 122a (published on 5th B. 1954), British patent specification No. 681653. When the application was published, two color tables were laid out with explanations.