A process for the preparation of vådægte dyeings on cellulose materials by dyeing, padding or printing.

摘要

Water-insoluble dyes containing mercapto groups are prepared by heating a water-soluble azo or phthalocyanine dye which contains two or more thiosulphuric acid groups but is free from other water-solubilizing groups, in an aqueous solution at a temperature between about 40 DEG and 110 DEG C., if desired in the presence of an organic compound promoting solubility, with a non-oxidizing inorganic or organic acid or a mixture thereof. The starting materials are used in the form of their alkali metal or ammonium salts. Specified acids are hydrobromic, phosphoric, sulphuric, acetic, trichloroacetic, formic and, preferably, hydrochloric acid. Specified organic compounds which promote solubility are methanol, ethanol and isopropanol. The dyes may be used as pigment dyes but are preferably used to dye and print cellulose materials in alkaline medium (see Division D1). In examples the preparation of mono- and dis-azo and copper phthalocyanine dyes is described. Specification 949,956 and 953,428 are referred to.ALSO:Cellulose material is dyed padded or printed by applying thereto a water-soluble azo or phthalocyanine dye containing mercapto groups (see Division C4) in the presence of an inorganic or organic base or of a substance capable of developing alkali when heated and, if desired, heating the material during or after application of the dye. The dyes are preferably applied from alkaline liquors in which they are soluble. The material may be dyed by a long liquor process or by continuous padding-steaming or padding-drying processes. Urea is preferably added to the padding-liquors and pastes. Specified bases are sodium and potassium hydroxides, sodium carbonate, sodium bicarbonate, tertiary sodium phosphate, pyridine and quinoline. In examples the dyeing and printing of cotton is described. Specifications 949,956 and 953,428 are referred to.