GB980504A - Improvements in and relating to the colouration of polyester fibres - Google Patents

Abstract

Mono- and dis-azo dyes of formula <FORM:0980504/C4-C5/1> or <FORM:0980504/C4-C5/2> wherein A is a benzene or azobenzene radical are used to dye polyester fibres (see Division D1). The dyes are prepared by coupling a diazotized aminobenzene or aminoazobenzene with a 2-hydroxy-carbazole or -diphenylene oxide. The dyes give yellow-brown to violet-brown shades on polyester fibres. In examples, the following diazo components are specified: 4 - aminoazobenzene, 4 - amino - 3,21 - dimethylazobenzene, 4 - amino - 41 - nitroazobenzene, 4 - amino - 3,6,41 - trimethoxy - azobenzene, 4 - amino - 41 - methoxy - 3,6 - diethoxy - azobenzene and 4 - N - diethyl-sulphonamido - 2 - amino - anisole.ALSO:Polyester fibres are dyed in yellow-brown to violet-brown shades by applying thereto a dye of formula <FORM:0980504/D1-D2/1> wherein A is a benzene or azobenzene radical. The dyes are prepared by the usual coupling procedure (see Division C4) and are applied to the fibre in the presence of carriers at ordinary pressure or under pressure with or without carriers. The dyes may also be used to colour cellulose triacetate, polyamide, polyvinyl and polyacrylic fibres. The dyes are preferably admixed with dispersing agents such as alkaryl sulphonates and methylene-dinaphthyl sulphonates. In examples: 1 the diazo dye 4-aminoazobenzene --> 2-hydroxycarbazole is prepared and dried in the presence of a dispersing agent and used to dye polyester fibres under elevated temperature and pressure followed by a treatment in an alkaline reducing bath; II polyester fabric is printed with an aqueous paste of the dye specified in I containing sodium methylenedinaphthyl sulphonate, ethylene glycol monoethyl ether, sodium chlorate and industrial gum and otherwise proceeding as in I. Further dyeings are listed.