Patent GB-560787-A (GB)
Title: Process for chroming mordant dyestuffs, the resulting products, their use, and materials dyed therewith
IPC: C09B45/38
Filed: 1942-10-14
Abstract: Water-soluble chromium complexes of o : o1-dihydroxy - azo, o - hydroxy - o1 - carboxy - azo and o-hydroxycarboxy dyestuffs, free from sulphonic acid groups, are obtained by treating such dyestuffs in aqueous solution or suspension at raised temperature and, if desired, under pressure, with a complex chromium compound of an aromatic o-hydroxycarboxylic acid, with the use of at least one atom of chromium for each mordant grouping of the dyestuff.  A mordant grouping is defined as (a) an o : o1-dihydroxy azo grouping or (b) an o-hydroxy-o1-carboxy-azo grouping or (c) an o-hydroxy-carboxy grouping.  Specified aromatic o-hydroxycarboxylic acids are salicylic acid and its homologues and substitution products, mono-and di-sulpho-salicylic acids, e.g. 2-hydroxy-5-sulphobenzoic acid, sulphocresolinic acids and o - hydroxynaphthoic acids, e.g. 6 - sulpho - 2 - hydroxy-3-naphthoic acid, and their sulphonic acids, and the complex chromium compounds thereof used include the diammine complexes.  The products from the o : o1-dihydroxy-azo and o-hydroxy-o1-carboxy-azo dyestuffs are suitable for application from a weak acid bath to cotton and animal fibres, including leather and those from the o-hydroxycarboxy dyestuffs are suitable for similar application to cotton, paper, silk and leather.  In examples: (1) an aqueous solution containing Eriochromazurol B (1 mol.) and ammonium chromium salicylate (containing more than 2 atoms Cr) is heated for 20 minutes at 90-100 DEG  C. and the product is salted out; (2) an aqueous solution containing Eriochromeflavin A (1 mol.) and sodium chromium salicylate (containing more than 2 atoms Cr) is boiled under reflux and the product is salted out; (3) an aqueous solution containing soda lye, the dyestuff, 4-nitro-2-aminophenol --> 1-phenyl-3-methyl-5-pyrazolone (1 mol.) and sodium chromium sulpho salicylate (containing more than 1 atom Cr) is boiled under reflux and, after filtering off some water-insoluble complex, the desired water-soluble complex is salted out from the filtrate.  A table is also given showing the shades obtainable on various fibres, viz: wool, silk, leather or cellulose fibres, with the water-soluble chromium complexes obtainable by chroming, in some cases with sodium or ammonium chromium salicylate, in others with the corresponding sulphosalicylate, the following dyestuff, viz: Eriochromazurol B and G, Naphthochrome green G, the condensation product from 2-(41-diethylamino-21-hdyroxy)-benzoylbenzoic acid and b -resorcylic acid, the oxidised condensation product from methylene-di-o-cresotinic acid hydrol and 1-phenyl-3-methyl-5-pyrazolone (cf. Specification 26677/10, [Class 2 (iii)]), the oxidised condensation product from 4-dimethylamino-2-chlorobenzaldehyde and o-cresotinic acid, Eriochromeflavin A, anthranilic acid or 4-nitro-2-aminophenol --> 1-phenyl-3-methyl-5-pyrazolone, 2 : 4-dihydroxyquinoline or p-cresol, 6-methyl-4 - nitro - 2 - aminophenol --> 1 - phenyl - 3 - methyl - 5 - pyrazolone and 4 - chloro - 2 - aminophenol --> 2 : 4 - dihydroxyquinoline.  Sodium chromium salicylate is obtained in aqueous solution by boiling an aqueous solution containing chromium acetate (1 atom Cr) and sodium salicylate (2 mols.) while neutralising with sodium carbonate.  Ammonium chromium salicylate is obtained in aqueous solution by heating at 90-100 DEG  C. an aqueous solution containing chromium acetate (1 mol.) and ammonium salicylate (2 mols.) while neutralising with ammonia.  Sodium and ammonium chromium sulphosalicylates are obtained in aqueous solution by dissolving chromium hydroxide (1 mol.) in an aqueous solution of sulphosalicylic acid (2 mols.) and neutralising with sodium carbonate and ammonia respectively.  Diamine compounds of complex chromium compounds of aromatic o-hydroxycarboxylic acids are obtained by treating alkali chromium salicylates or sulphosalicylates with excess of ammonia, alkylamines, ethylene diamine, pyridine or piperidine.