GB382466A - Process for the production of fast colour reserves under aniline black - Google Patents

Abstract

Fast colour reserves under aniline black are obtained by printing the white material with an ester salt of a leuco vat dye, together with a usual reserve for aniline black, steaming if required, producing the aniline black ground colour in known manner, and finally producing the reserve effect by a short passage through an acid bichromate bath. In examples, the material is printed with a paste containing the sulphuric ester salt of the leuco compound of 6 : 6<1>-dichlor-7 : 7<1>-dimethylthioindigo, 3 : 4 : 8 : 9-dibenzpyrene-5 : 10-quinone, 2 : 1 : 2<1> : 1<1>-naphthioindigo or 6-ethoxy-4<1>-methyl-6<1>-chlorthioindigo, gum, zinc acetate, and one or more of the following: diethyltartrate, urea, diethylenethioglycol, diethyleneglycol diethylether, or sodium benzylsulphanilate; the material is then dried, steamed, padded in the manner usual in the production of aniline black, dried and steamed to develop the ground colour, and finally passed through a bath containing sulphuric acid and sodium or potassium bichromate. Ester salts of the leuco compounds of 5 : 7 : 5<1> : 7<1>-tetrabromindigo, 6 : 5<1> : 7<1>-trichlorindigo, 5 : 5<1>-dichlor-7 : 7<1>-dimethylthioindigo, 6 : 6<1>-dichlor-4 : 4<1>-dimethylthioindigo, the dyestuff from a -isatinanilide and 1-methyl-7 : 8-oxybenzocarbazole, the dyestuff from bromo - 1 - chlor - 2 : 3 - naphthisatin and 4-methoxy-1-naphthol (Specification 289,154, [Class 2 (iii), Dyes &c.]), Bz2 : Bz2<1>-dimethoxy-dibenzanthrone, and di-p-chloranilidobenzoquinone. Specification 186,057, [Class 15 (ii), Dyeing, Processes &c. for], also is referred to.