GB431201A - Improvements in the manufacture and production of azo dyestuffs - Google Patents

Abstract

Azo dyes capable of being chromed in substance or on the fibre are prepared by coupling a diazotized o-aminophenol or o-aminonaphthol containing at least one nitro group and/or halogen atom with a condensation product derived from one molar proportion of a ketone and two molar proportions of a phenol or with a sulphonic acid derivative of such product, the said condensation product being a tetra-substituted methane wherein two substituting radicles are p-oxyphenyl radicles. Specified diazo components are 1-oxy-2-amino-4-nitro- (and 4-chloro-) benzene 6-sulphonic acid, 1-oxy-2-amino-4-nitro-6-chlorbenzene and 1-oxy-2-amino-4.6-dinitrobenzene: specified coupling components are b .b -di-(4-oxyphenyl)-propane, -butane, -cyclohexane, and -b -phenylethane, b .b -di-(4-oxy-3-sulphophenyl-) - propane, b .b -di - (4-oxy - 3 - methylphenyl) -propane. In some cases disazo dyes may be prepared. In examples: (1) diazotized 1 - oxy - 2 - amino - 4 - nitrobenzene - 6 - sulphonic acid is coupled with b .b - di - (4-oxyphenyl-) - propane, 1 - di - (4 - oxyphenyl -)-cyclohexane, b .b - di - (4 - oxy - 3 - methylphenyl-) - propane, and b .b - di - (4-oxyphenyl-)-butane; the products either as their chromium compounds or on after-chroming on the fibre, dye wool brown shades; (2) diazotized 1 - oxy-2 - amino - 4 - chlorbenzene - 6 - sulphonic acid is coupled with b .b - di (4 - oxyphenyl-) - propane; the product after-chromed on the fibre gives brown-violet shades; (3) diazotized 1 - oxy - 2 - amino - 4 - nitro - 6 - chlorbenzene is coupled with b .b - di - (4 - oxy - 3 - sulphophenyl) - propane; the product, after-chromed on the fibre, dyes wool brown shades; (4) diazotized 1 - oxy - 2 - amino - 4.6 - dinitrobenzene is coupled with b .b - di - (4 - oxyphenyl) propane; the product applied to wool in the single bath chroming process gives olive-brown shades. Specification 325,208, [Class 2 (iii)], is referred to.