GB704231A - Improvements in and relating to vat dyestuffs - Google Patents

Abstract

Vat dyeings are obtained by treating the material in an alkaline vat with a cobalt phthalocyanine and a water-soluble reducing agent; the phthalocyanine may be substituted with sulphonic acid, sulphonamide, sulphinic acid, carboxylic acid, carboxylic amide, cyano, hydroxy, alkoxy, mercapto, alkylthio, nitro, amino, alkylamino or acylamino groups. There may be used a mixture of a hydrophilic-substituted phthalocyanine and cobalt phthalocyanine itself or a non-hydrophilic substituted compound. A preferred mixture is one containing 15-40 per cent of cobalt phthalocyanine sulphonic acids, calculated as monosulphonic acid. Examples are given of the dyeing of cotton with cobalt phthalocyanines vatted with sodium hydrosulphite and caustic soda; after dyeing, the cotton is hung in the air to develop the colour. A further example shows the similar treatment of wool, the dyestuff containing as substituent the trimethylamino-acetamido (quaternary chloride) group. Other suitable dyestuffs are mentioned. Pyridine and bis- (hydroxyethyl) sulphide are specified as vat auxiliaries. The phthalocyanines may be obtained as described in Specification 704,310. The Provisional Specification includes the subject-matter of the above specification and in addition contains further examples of the preparation of substituted cobalt phthalocyanines: (1) 4-nitrophthalic acid is heated with cobalt sulphate and the usual additions; the nitro groups are reduced to amino during vatting and the dyeings can be diazotized and coupled on the fibre; (2) 4-acetylaminophthalic acid and (3) 4-methoxyphthalic acid are heated with cobalt sulphate and the usual additions; (4) cobalt phthalocyanine is treated with sulphur chloride and aluminium chloride; (5) mononitro cobalt phthalocyanine is obtained by heating phthalic anhydride, 4-nitrophthalic acid and cobalt sulphate with the usual additions; the product is reduced to amino, diazotized, treated with potassium thiocyanate and hydrolysed to give monomercapto cobalt phthalocyanine; the di-, tri- and tetra-mercapto compounds are obtained similarly; (6) 4-phenylphthalic acid is heated with phthalimide - 4 - sulphomethylamide, cobalt sulphate and the usual additions; 4-methoxyphthalic acid may be used in place of the second reactant; (7) a mixture of anthraquinone-2-carboxylic 3\sv : 4\sv - dicyano - p - xenylamide, benzophenone, phthalonitrile and cobalt chloride is heated; (8) the chloride of 4-(trimethylamino-acetylamino)-phthalimide is heated with urea, benzamide, cobalt sulphate and ammonium salts. Specification 322,169, [Class 15(ii)], also is referred to.