Patent GB-998522-A (GB)
Title: Metalliferous water-insoluble benzimidazole bis-azo dyestuffs and processes for their manufacture
IPC: D06P1/12
Filed: 1962-01-12
Abstract: The invention comprises complex metal compounds of water-insoluble azo dyes of the general formula <FORM:0998522/C4-C5/1> in which A represents aromatic or heterocyclic radical, R1 represents a hydrogen atom or an alkyl group, R2 and R3 represent hydrogen atoms, alkyl or alkoxy groups, 2 represents the radical of an arylamide of an aromatic or heterocyclic ortho-hydroxy carboxylic acid or of an acylacetic acid, the acyl group being derived from a carboxylic acid and n stands for one of the integers 1 and 2 and a process for the preparation thereof wherein a diazonium compound of an amine of the formula <FORM:0998522/C4-C5/2> in which A, R1, R2 and R3 have the meanings given above is coupled with an appropriate arylamide and the dye obtained is treated with an agent yielding metal.  The treatment with agents yielding metal may be carried out by known methods during or after the coupling in substance or on the fibre (see Division D1). In Example (3) 7-amino-5-methyl-4-(21-methoxyphenyl - 11 - azo) - benzimidazole is diazotized and coupled with 2,3-hydroxynaphthoyl-aminobenzene and an aqueous copper sulphate solution containing triethanolamine is added and the mixture heated to obtain a dye. Additional diazo components are specified and among the many coupling components specified are terephthaloyl - bis - (1 - acetylamino - 2,4 -dimethoxy-5-chlorobenzene); 1-(31-hydroxy-diphenylene oxide - 21 - carboylamino - 2 - ethoxybenzene) 2 - acetoacetylamino - 6 - ethoxy - benzthiazole and 2,3 - hydroxynaphthoyl aminobenzene.  Metals specified include copper, cobalt, nickel, iron and zinc and these may be employed in the form of inorganic or organic salts or complexes, e.g. with hydroxy alkylamines. Many of the products are black dies and they are suitable for dyeing or printing vegetable fibres and regenerated cellulose fibres and for dyeing animal fibres such as wool or silk.ALSO:In a process for forming metalliferous water insoluble azo dyes on animal or vegetable fibres a diazonium compound of an amine of the general formula <FORM:0998522/D1-D2/1> in which A represents an aromatic or heterocyclic radical, R, represents a hydrogen atom or an alkyl group and R2 and R3 represent hydrogen atoms, alkyl or alkoxy groups is coupled on the fibre with an arylamide of an aromatic or heterocyclic ortho-hydroxy carboxylic acid or of an acylocetic acid, the acyl group being derived from a carboxylic acid, the components being selected so that they are free from groups imparting solubility in water and the dyestuff obtained is treated with an agent yielding metal.  The dyes may be produced on vegetable fibres, regenerated cellulose fibres and wool and silk by the usual methods.  In examples (1) cotton yarn is treated in an impregnation bath containing 1-(21, 31-hydroxynaphthoylamino)-2.4-dimethoxy-5-chlorobenzene and subsequently in a developing bath containing diazotised 7-amino-5-methyl-4-(31-methyl phenyl-11-azo)-benyimidazole and nickel sulphate to obtain a black dyeing; and (2) cotton yarn is treated in an impregnation bath containing 2-(21, 31-hydroxynaphthoylamino)-naphtholene, then in a developing bath containing diazotised 7-amino-5-methyl-4-(21-mechoxy-51-introphenyl-11 -azo)-benzimidazole and the dyed yarn is metallised in a bath containing nickel sulphate.