GB443222A - The manufacture of azodyestuffs and dyeing and printing preparations - Google Patents

Abstract

Azo dyes; lakes; dye preparations; azo dyes, forming upon the material; printing.--Azo dyes are manufactured in substance or on a substratum, particularly vegetable fibres, by splitting up by the action of an acid medium a triazene compound obtained by condensing cyanamide, cyanamide-carboxylic acid or a salt thereof with a diazo compound of a base suitable for preparing water-insoluble azo dyes, in the presence of a coupling component free from solubilizing groups. Preparations for dyeing and printing purposes comprise a mixture of the said triazene compounds and coupling components, if desired with the addition of wetting or dispersing agents. The dyeing may be developed by treatment in an acid medium, or in some cases by merely hanging in the air. In examples: (1) cotton tissue is printed with an aqueous mixture of the condensation product from diazotized 5-nitro-2-amino-1-methoxybenzene and sodium cyanamide, 2 : 3-hydroxynaphthoic acid a -naphthylamide, highly sulphonated castor oil, caustic soda and starch tragacanth thickener, and a full Bordeaux is developed by exposure to superheated steam containing formic and acetic acid vapours or by treatment in an aqueous formic or acetic acid solution; (2) a similar printing colour containing the condensation product from diazotized 5-nitro-2-amino-1 methylbenzene and sodium cyanamide, and 2 : 3-hydroxynaphthoic acid o-toluidide yields a full reddish-Bordeaux; (3) a similar printing colour containing the condensation product from diazotized 4-chloro-2-anisidine and sodium cyanamide, and 2 : 3-hydroxynaphthoic acid o-anisidide yields a full clear red; (4) a similar printing colour containing the condensation product from diazotized 2-nitro-4-chloraniline and sodium cyanamide, and 2 : 3-hydroxynaphthoic acid anilide yields a full yellowish-red; there may similarly be employed the condensation products from sodium cyanamide and diazotized 4-nitro-2-toluidine, 2-nitro-4-toluidine, 4-chloro-2-toluidine, 2 : 5-dichloraniline, 5 - benzoylamino - 2 - amino - 1 : 4-diethoxybenzene, 4-amino-4<1>-nitro-3-methoxy-6-methylazobenzene, 2-aminocarbazole or 1-aminoanthraquinone; (5) a similar printing colour containing the condensation product from diazotized 5-nitro-2-amino-1-methoxy-benzene and the sodium salt of cyanamide-carboxylic acid, and 2 : 3-hydroxynaphthoic acid a -naphthylamide yields a full Bordeaux. The Specification as open to inspection under Sect. 91 comprises also the manufacture of the triazene compounds employed above. Additional examples describe the manufacture of the triazene compounds employed in (1), (2) and (5) above, and also of the condensation products of sodium cyanamide with diazotized 2 : 5 - dichloraniline or 4 - amino - 4<1> - nitro - 3-methoxy - 6 - methylazobenzene, and of the sodium salt of cyanamide-carboxylic acid with diazotized 5 - nitro - 2 - amino - 1 - methylbenzene. This subject-matter does not appear in the Specification as accepted.