CH261840A - Process for the preparation of a metallizable o-oxymonoazo dye. - Google Patents

Description

  

  Additional patent to main patent no. 255966. Process for the production of a metallizable o # oxymonoazo dye. The present patent relates to a process for the preparation of a metallizable azo dye, which is characterized by

   that in metal complexes of the monoazo dye made from dianotized 1-oxy-2-amino-4-chlorobenzene-6-sulfonic acid and resorcinol the hydroxyl group in the azo bond is esterified with benzenesulfonic acid chloride and the reaction products are demetallized with acids or salts.



  In the following examples, parts mean parts by weight. <I> Example 1: </I> The copper complex of the monoazo dye from 22.4 parts of 1-oxy-2-amino-4-chlorobenzene-6-sulfonic acid and 11 parts of resorcinol is slowly mixed with 19 to 24 parts of benzenesulfonyl chloride are added and the mixture is stirred until all of the starting dye has disappeared.

   The resulting sulfonic acid ester of the dye is filtered off after the addition of salt. In order to split off the complex-bound copper, this is stirred at 0 to 100 parts with 100 parts of concentrated hydrochloric acid for one hour and filtered off. If necessary, the dye can be cleaned by boiling it with water.



  He dyes wool from an acid bath in brownish-yellow tones. Chromium plating gives it a Bordeaux red with excellent fastness properties. The dye is also very suitable for the neutral single bath chrome process. <I> Example 2: </I> The iron complex of the monoazo dye from 22.4 parts of 1-oxy-2-amino-4-chlorobenzene-6-sulfonic acid and 11 parts of resorcinol is slowly mixed in an alkaline solution at 70 to 750 with 19 to 24 parts of benzenesulfonyl chloride are set and stirred until all the starting dye has disappeared.

   The resulting sulfonic acid ester of the dye is stirred in Congo acid medium with 20 parts of oxalic acid at about 700 for half an hour to split off the complexly bound iron. After adding salt, it is filtered off and washed thoroughly with dilute sodium chloride solution. If necessary, the dye can be cleaned by boiling it with water. It is identical to the dye described in the first example.

      <I> Example 3: </I> The monoazo dye made from 22.4 parts of 1-oxy-2-amino-4-chlorobenzene-6-sulfonic acid and 11 parts of resorcinol is boiled with 6 parts of magnesium oxide and then at 70 to 750 slowly ver in alkaline solution with 19 to 24 parts of benzenesulfonyl chloride and stirred until all the starting color has disappeared. Hydrochloric acid is then added until the reaction is clearly Congo acid and, after the addition of salt, it is filtered off. If necessary, the dye can be cleaned by boiling it with water.

   It is identical to the dye described in the first example.

 

Claims (1)

PATENT CLAIM: Process for the preparation of a metallizable azo dye, characterized in that in metal complexes of the monoazo dye from diazotized 1-oxy-2-amino-4-chlorobenzene-6-sulfonic acid and resorcinol, the p-position hydroxyl group esterified with benzenesulfonic acid chloride and demetallizing the reaction products with acids or salts. The new dye is a dark powder. It dyes wool from an acid bath in brownish-yellow tones. Chromium plating gives a Bordeaux red with excellent fastness properties. The dye is also very suitable for the neutral one-bath chrome process.