GB739172A - Improvements in or relating to process of treating cotton gray goods - Google Patents

Abstract

In a process of bleaching cotton grey goods in which the goods are conditioned prior to bleaching, the goods are treated, prior to bleaching, with a dilute solution of a predominantly hydrophilic wetting agent having a high molecular weight organic hydrophobic group, the solution containing no oxidizing agents and having a pH of above 7.0, and an oils and waxes content in the goods of at least 0.4 per cent by weight being maintained in the pre-bleaching treatment. The wetting agent may be incorporated in or may be applied after a hot aqueous caustic alkali treatment or may be applied in a separate aqueous solution following or in place of a preliminary sulphuric acid desizing step preceding a caustic alkali treatment. Alternatively, following an acid desize, the aqueous solution of the wetting agent may be applied in place of the customary caustic alkali treatment. The wetting agent may be present in a concentration of 0.01 to 0.5 per cent by weight, and in the caustic alkali solution a concentration of caustic soda between 1.0 and 3.0 per cent by weight may be used. The solution of wetting agent and/or caustic alkali may be at a temperature of 140 DEG to 210 DEG F. The wetting agent may be sodium di-(2-ethylhexyl) phosphate, castile soap, the sulphate of lauryl alcohol, a sulphated ester of a long-chain fatty acid and an aliphatic alcohol, sorbitan mono-oleate, sorbitan mono-laurate, a high molecular weight polyoxyethylene ether, a high molecular weight alkylated aryl polyether alcohol, a high molecular weight alkyl polyoxyethylene alcohol, an alkyl (12 to 20 carbon atoms) trimethyl ammonium chloride or di-(isobutyl-phenoxy-ethoxy) ethyl dimethyl benzyl ammonium chloride. The bleaching may be effected with sodium hypochlorite, sodium chlorite or hydrogen peroxide. The acid desize step and an antichlor treatment which may follow the bleaching may be effected with sulphuric acid.