GB924452A - Metalliferous azo-dyestuffs and process for their manufacture - Google Patents

Abstract

The invention comprises metalliferous azodyestuffs which contain one atom of chromium bound in complex union to two molecules of two dyestuffs, one of which is an ortho-hydroxy-ortho1-amino-monoazo-dyestuff containing a primary amino group in the ortho1-position and the other is an azomethine or monoazo dyestuff free from secondary amino groups and both of which dyestuffs are free from carboxylic groups not present in ortho-position to the azo linkage and from sulphonic groups, and a process for the manufacture of metalliferous azo-dyestuffs which contain one atom of chromium bound in complex union to two molecules of monoazo dyestuffs or to one molecule of a monoazo dyestuff and one molecule of an azomethine dyestuff wherein a metal-free metallizable mono-azo dyestuff or azomethine dyestuff and a complex chromium compound of an ortho-hydroxy-ortho1-amino-monoazo dyestuff which contains one atom of chromium bound in complex union to one molecule of dyestuff are reacted together in a molecular ratio of about 1:1 and the starting materials are free from carboxylic acid groups not in ortho position to the azo linkage and from sulphonic acid groups. The 1:1-chromium complex compounds may contain non-ionic substituents such as chlorine atoms, nitro, alkyl, alkoxy, alkylsulphonide, alkyl sulphone, cyclic alkanesulphonyl, sulphonamido and acylamino groups. Azo dyes free from heavy metal for use in the process may be prepared by coupling o-hydroxyamines or o-carboxyamines of the naphthalene or benzene series with hydroxybenzenes, hydroxynaphthalenes, 2, 4-dihydroxyquinolines, pyrazolones and acetoacetylaminobenzenes capable of coupling in a position vicinal to a hydroxyl group or an enolisable keto group. Metal-free azomethine dyes for use in the process are prepared by reacting aromatic aldehydes which contain a hydroxyl group in a position vicinal to the aldehyde group and amines which contain in a position vicinal to the amino group a complex forming group. The chromium containing starting materials may be prepared by chroming the appropriate metal free dyes by conventional methods. The complexes are suitable for dyeing and printing silk, leather, wool and polyamide and polyurethane fibres. Examples are furnished.