Patent GB-237739-A (GB)
Title: Improvements in dyeing acetyl silk
IPC: D06P3/40
Filed: 1924-08-22
Abstract: The Specification describes the use in dyeing cellulose acetate of sulphato compounds of monoazo dyes and specifies the following pairs of components: p-nitraniline and ethylsulphatoethylaniline, the compound produced may be reduced to the corresponding amino compound with sodium sulphide; m-nitraniline and sulphatoethylaniline, the Provisional Specification refers also to the reduction of this compound; m-nitraniline, 4-nitro-1-naphthylamine, 3 : 5-dinitro-1-toluidine, o-chlor-p-nitraniline, and 2 : 4-dinitraniline, all with ethylsulphatoethylaniline; 1-nitro-2-naphthylamine with methylsulphatoethylaniline; p-nitraniline with sulphatoethylaniline, sulphatoethyl-o-toluidine, and sulphato-ethyl-b -naphthylamine; 2 : 4-dinitraniline with benzylsulphatoethylaniline; and p-nitraniline, o-chlor-p-nitraniline, 2 : 4-dinitraniline, and 2 : 4-dinitro-1-naphthylamine, all with sulphatoethyl-a -naphthylamine.  Specification 181,750 is referred to.ALSO:Acetyl silk is dyed in a neutral, acid, or alkaline dyebath or printed with "sulphato" compounds of monazo dyes, and particularly of nitrated monazo dyes.  If the dye contains in addition an amino group, it may be diazotized on the fibre and developed in the usual way.  In dyeing mixed fabrics of cellulose acetate and cotton the silk alone is dyed with the above dyestuffs and a substantive cotton dyestuff may be added to the same dyebath.  Examples are given of dyeing acetyl silk yarn in a bath containing the dyestuff from diazotized p-nitraniline and the sodium salt of ethyl sulphatoethylaniline with or without sulphuric acid to produce a scarlet; of dyeing to a bronze-brown with the corresponding amino compound obtained by reduction with sodium sulphide of the above dyestuff and also of diazotizing this dyestuff on the fibre and developing with resorcin, m-phenylenediamine, ethyl-b -naphthylamine, b -naphthol, a -naphthylamine ether, or b -oxynaphthoic acid to obtain red to bluish to black shades.  A further example shows the dyeing of mixed acetyl silk and cotton in a bath containing the disazo dye from benzidine and H acid, the p-nitrobenzeneazoethylsulphatoethylaniline used in the first example, salt and soda ash to obtain blue on the cotton and scarlet on the acetyl silk.  In addition the azo dyes from the following pairs of components are specified as suitable for the process and yield shades varying from yellowish-red to bluish-red and greenish-blue:-m-nitraniline and sulphatoethylaniline, m-nitraniline and ethylsulphatoethylaniline, 1-nitro-2-naphthylamine and methylsulphatoethylaniline, p-nitraniline and sulphatoethylaniline, p-nitraniline and sulphatoethyl-o-toluidine, 4-nitro-1-naphthylamine and ethylsulphatoethylaniline, 3 : 5-dinitro-1-toluidine and ethylsulphatoethylaniline, o-chlor-p-nitraniline and ethylsulphatoethylaniline, 2 : 4-dinitraniline and benzylsulphatoethylaniline, p-nitraniline and sulphatoethyl-b -naphthylamine, 2 : 4-dinitraniline and ethylsulphatoethylaniline, p-nitraniline and sulphatoethyl-a -naphthylamine, o-chlor-p-pitraniline and sulphatoethyl-a-naphamine, 2 : 4-dinitraniline and sulphatoethyl-a-naphthylamine, and 2 : 4-dinitro-1-naphthylamine p  and sulphatoethyl-a-naphthylamine.  The Provisional Specification refers also to the use of the dyestuff obtained by reducing the compound from m-nitraniline and sulphatoethylaniline. Specification 181,750, [Class 2 (iii), Dyes &c.], is referred to.