GB583115A - Process for printing staple fibre of regenerated cellulose with leuco ester salts of vat dyestuffs - Google Patents

Abstract

In the printing of staple fibre of regenerated cellulose with ester salts of leuco vat dyes by the process wherein the ester salt is printed on the fibre in conjunction with a chlorate as oxidising agent and an oxidation catalyst, and the colour is developed by steaming, the catalyst used is one which causes the oxidation to proceed more slowly than does ammonium vanadate. Specified catalysts are hydroxides of manganese, iron and cobalt and ferrocyanides, ferricyanides and nitroprussides of the alkali metals. In examples: (1) a fabric of regenerated cellulose staple fibre is printed with an aqueous preparation containing the sodium salt of the acid sulphuric acid ester of leuco-dibromodibenzpyrenequinone, thiodiglycol, starch-tragacanth thickening, ammonium chlorate and sodium ferrocyanide and the print is steamed, soaped at the boil, rinsed and dried; (2) a similar fabric is similarly printed with the use as dyestuff of the sodium salt of the acid sulphuric acid ester of leuco-dibromoanthanthrone and with an addition of urea to the printing preparation; (3) a similar fabric is printed as in (1) with the use as dyestuff of the sodium salt of the acid sulphuric acid ester of leuco-dichloroisodibenzanthrone; (4) to (6) a similar fabric is printed as in (2) with the use as dyestuffs of the sodium salts of the acid sulphuric acid esters of (4) leuco-a -anthraquinonyl - Bzl - aminobenzanthrone; (5) leuco - dimethoxydibenzanthrone; (6) leuco - dibromo - pyranthrone; (7) a similar fabric is printed with an aqueous preparation containing the sodium salt of the acid sulphuric acid ester of leuco - a - anthraquinonyl - Bzl - aminobenz - anthrone, thiodiglycol, urea, starch-tragacanth thickening, ammonium chlorate and sodium nitroprusside and the print is steamed, soaped at the boil, rinsed and dried; (8) a similar fabric is printed with an aqueous preparation containing the sodium salt of the acid sulphuric acid ester of leuco-dimethoxydibenzanthrone, thiodiglycol, urea, starch-tragacanth thickening, sodium chlorate, ammonium sulphate, ammonia and ferrous ammonium sulphate, manganese sulphate or cobalt sulphate and the print is steamed, soaped at the boil, rinsed and dried. Samples have been furnished under Sect. 2 (5) of prints obtained by means of printing compositions containing thiodiglycol, urea, starchtragacanth thickening, ammonium chlorate, sodium ferrocyanide and (I) the sodium salt of the sulphuric acid ester of leuco-dibromodimethoxy-dibenzanthrone; (II) the sodium salt of the sulphuric acid ester of leuco-4-methyl - 6 - chloro - 61 - methoxy - thioindigo; and (III) the sodium salt of the sulphuric acid ester of leuco-8-chloro-1,2-naphththio-51-bromindol-indigo. Specifications 24604/08, [Class 2], 205,304, [Class 2 (iii)], 220,964, [Class 15 (ii)], 222,094, 260,998 and 327,756, [all in Class 2 (iii)], are referred to.