Patent GB-535935-A (GB)
Title: Dyeing cellulosic fibres
IPC: D06P1/12
Filed: 1939-09-25
Abstract: 535,935. Dyeing textiles. BLACKSHAW, H., HADDOCK, N. H., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. Sept. 25, 1939, No. 26602. [Classes 2 (iii) and 15 (ii)] Cellulosic fibres, e.g. of cotton or regenerated cellulose, are dyed violet to green or grey shades, specially fast to washing, by impregnation with a solution of a tetradiazonium salt derived from a tetra-(4)- or tetra-(3)-aminophthalocyanine or a nuclear substitution product thereof, cf. Specification 529,847, followed by treatment with (a) an azoic coupling component or (b) a reagent capable of removing the diazonium nitrogen atoms. The phthalocyanines may be metal-free or may contain metals such as copper, nickel, cobalt, magnesium, lead or aluminium. Specified coupling components are 1- and 2- naphthols, the anilide, 2<SP>1</SP>-toluidide and 4<SP>1</SP>- anisidide of 2:3-hydroxynaphthoic acid, the 4<SP>1</SP>-chloroanilide of 2:3-hydroxycarbazolecarboxylic acid, diacetoacetyltolidine, 1-phenyl-3- methyl-5-pyrazolone and resorcinol. Specified reagents for removing the nitrogen atoms are boiling water, alcohol, sodium oleyl sulphate, sodium or potassium ethyl xanthate, sodium. stannite, sulphite, sulphide, thiosulphate, formate, hypophosphite, thiocyanate or cuprocyanide, potassium bromide, iodide, cyanate or ferrocyanide, ammonia, formic acid, benzoquinone, pyridine, hydrazine sulphate and alkaline formaldehyde. In examples : (1) cotton yarn is immersed for 1 hour in an aqueous solution at 10‹C. of tetradiazotized copper tetra-4-aminophthalocyanine, squeezed, rinsed, placed for 10 minutes in boiling water, squeezed and dried to obtain a greenish-blue dyeing, fast to washing and to light; (2) cotton yarn is similarly treated with an addition to the boiling water of potassium bromide to obtain a bright greenish-blue dyeing, fast to washing; the potassium bromide may be replaced by sodium ethyl xanthate, potassium iodide, sodium stannite, alcohol or pyridine to obtain specified shades ; the tetradiazo solution may be replaced by one of the zinc chloride double salt of the tetradiazo compound ; (3) cotton yarn, impregnated as in (1) with the tetradiazo compound or the corresponding compounds containing nickel or cobalt, in place of copper, is developed with 2-naphthol, the anilide, 2<SP>1</SP>-toluidide or 4<SP>1</SP>-anisidide of 2:3-hydroxynaphthoic acid or the 4<SP>1</SP>- chloranilide of 2:3-hydroxycarbazolecarboxylic acid to obtain specified shades ; (4) cotton yarn, impregnated with a tetradiazo compound as in (3), is developed with diacetoacetyltolidine resorcinol or 1-phenyl-3-methyl-5-pyrazolone to obtain specified shades ; (5) hanks of cotton are immersed for ¢ hour in an aqueous solution at 17-19‹C. containing copper tetra-(4)-aminophthalocyanine, hydrochloric acid and sodium nitrite, with additions of sodium chloride during the immersion, squeezed and placed in a boiling aqueous solution containing . sodium thiosulphate, benzoquinone, hydrazine sulphate, potassium cyanate, sodium formate, hypophosphite, thiocyanate or cuprocyanide, or formaldehyde and sodium hydroxide to obtain specified shades.