GB224681A - Improvements in or relating to the dyeing, printing or stencilling of cellulose acetate - Google Patents

Abstract

Pyrazolone dyes containing no sulphur groups, particularly pyrazolone-azo dyes, are dissolved in aqueous caustic alkali, or dissolved in an organic solvent miscible with water and poured into water, or dispersed in sulphoricinoleic acid or other of the solubilizing-agents described in Specification 219,349, and employed for dyeing or printing cellulose acetate goods.ALSO:Pyrazolone dyes prepared by coupling non-sulphonated diazo compounds with 1-phenyl-3-methyl-5-pyrazolone, 1 : 3-dimethyl-5-pyrazolone, or other non-sulphonated pyrazolone, are employed for dyeing or printing cellulose acetate goods; the monoazo dyes from diazotized aniline or o-anisidine and 1-phenyl-3-methyl-5-pyrazolone, and the disazo dye from diazotized p-aminobenzene-azo-dimethylaniline and 1-phenyl-3-methyl-5-pyrazolone, are specified. The dyes may be employed dissolved in aqueous caustic alkali, or they may be dissolved in an organic solvent miscible with water and poured into water, or they may be dispersed in sulphoricinoleic acid or other of the solubilizing-agents described in Specification 219,349.ALSO:Cellulose acetate goods (yarns, threads, filaments, fabrics, films, &c.) are dyed, printed, or stencilled with pyrazolone dyestuffs containing no sulpho groups; azo dyes prepared by coupling non-sulphonated diazo compounds with 1-phenyl-3-methyl-5-pyrazolone, 1 : 3-dimethyl-5-pyrazolone, &c. are particularly suitable; the monoazo dyes from diazotized aniline or p-anisidine and 1-phenyl-3-methyl-5-pyrazolone, and the disazo dye from diazotized p-aminobenzene-azo-dimethylaniline and 1-phenyl-3-methyl-5-pyrazolone, are specified. The dyes may be employed in solution in a limited amount of caustic alkali, or they may be dissolved in an organic solvent miscible with water and the solution poured into water, or they may be dispersed in sulphoricinoleic acid or other of the solubilizing-agents described in Specification 219,349. Protective colloids may be added to the dye-bath if desired. When the dye employed contains a diazotizable amino group, the shades may be developed in the usual manner. Uniform or contrasting shades may be produced on mixed goods containing cellulose acetate associated with cotton or other cellulose fibre, cellulose artificial silks, silk, wool, &c. by employing the pyrazolone dyes for the acetate portion and suitable dyes for the non-acetate portion.