CH353477A - Process for the production of copper-containing trisazo dyes - Google Patents

Description

  

  Process for the preparation of copper-containing trisazo dyes It has been found that valuable copper-containing azo dyes are obtained when treating trisazo dyes of the following composition A-N = N-B-N = N-C-N = N D in an acid medium at temperatures above 100 with copper-releasing agents.

   In the formula, A denotes a radical of the benzene or naphthalene series, B a radical of the benzene series, C the radical of a 1-amino-2-alkoxy-naphthalene coupled in the p-position to the amino group or

   a sulfonic acid derivative thereof and D the remainder of a 1-amino-8-oxynaphthalenesulfonic acid which is coupled in the o-position to the oxy group and optionally acylated on the amino group.



  The metal-free trisazo dyes of the composition given above are known from German Patent No. 481642. They are converted into the copper complexes by the action of copper-releasing agents in an acidic, preferably acidic, medium at temperatures above 100. In this case, 1 atom of copper is bonded to the radicals C and D, with the alkyl group of the amino naphthol ether component being split off.



  The copper dyes obtainable in this way dye cotton and regenerated cellulose in lightfast, etchable, green tones. Compared to the metal-free dyes of analogous composition known from German patent specification 481642, the dyes obtainable according to the invention are distinguished by a considerably improved lightfastness while maintaining the etchability of the dyeings on cotton.



  <I> Example 1 </I> 95.7 parts by weight of the trisazo dye obtained by coupling 2-amino-naphthalene-8-sulfonic acid with 1-amino-3,5-dimethyl-benzene, according to the method of DRP No. 481642, Further diazotization and coupling with 1-amino-2-ethoxy-naphthalene-6-sulfonic acid, further diazotization and coupling with 1-acetylamino-8-oxy-naphthalene-3,6-disulfonic acid is produced in 700 parts by weight of water solved and,

   with 25 parts by weight of crystallized copper sulfate and 25 parts by weight of sodium acetate ver sets.



  The reaction mixture is then heated to 115 ° C. in a stirred autoclave for 4 hours and the resulting dye is isolated with 70-80 parts by weight of salt. A dark powder is obtained which dissolves in water with green and in sulfuric acid with brownish-red color and dyes cotton in lightfast green tones that can be etched in pure white.



  Dyestuffs with similar properties are obtained if the dyestuffs in the table below are coppered by the process given in Example 1: 2. 1-Amino-benzene-4-sulphonic acid -> 1-Amino-2-methyl-benzene -> . 1-Amino-2-ethoxy-naphthalene-6-sulphonic acid -> 1-benzoylamino-8-oxy-naphthalene-3,6-disulphonic acid.



  3. 1-Amino-benzene-4-sulphonic acid -> 1-amino-2-methyl-benzene -> 1-amino-2-ethoxy-naphthalene-6-sulphonic acid-> 1- (2'-chloro-benzoylamino ) -8-oxy-naphthalene-3,6-disulfonic acid.



  4. 2-Amino-naphthalene-8-sulfonic acid -> Amino benzene -> 1-Amino-2-ethoxy-naphthalene 6-sulfonic acid <B>--> </B> 1- (2'-chlorine- benzoylamino) - 8 - oxy-naphthalene-3,6-disulfonic acid.

 

Claims (1)

PATENT CLAIM Process for the production of copper-containing azo dyes, characterized in that trisazo dyes of the following composition A - N = N-B-N = N-C-N = N-D wherein A is a residue of the benzene or naphth.alin series, B a residue of the benzene series, C is the remainder of a 1-amino-2-alkoxy-naphthalene coupled in the p-position to the amino group or a sulfonic acid derivative thereof and D is the remainder of a 1-amino-2-alkoxy-naphthalene coupled in the p-position to the amino group and D the remainder of a one coupled in the o-position to the oxy group and optionally acylated on the amino group. 1-Amino-8-oxy-naphthalene-sulfonic acid mean treated in an acidic medium at temperatures above 100 C with copper-releasing agents.