Improvements in bleaching and scouring treatments for unfinished textiles

摘要

535,107. Bleaching textiles. MATHIESON ALKALI WORKS. Nov. 6, 1939, No. 29496. Convention date, Dec. 24, 1938. [Class 15 (ii)] Unfinished cellulosic fabrics, e.g. greige cloth or similar unfinished fabrics containing cotton, flax, hemp, jute or rayon, are bleached and scoured by subjecting them to the action of an acid aqueous solution containing sodium chlorite and a detergent which is effective in acid solution and is not reactive with the chlorite. Specified detergents are sodium lauryl sulphate, sodium 2-methylpentane-4- sulphate, sodium N-sulphoethyl-N-methyllauramide, sodium sulphoethylmyristate, sodium diamylsulphosuccinate, sodium decylbenzenesulphonate and sodium hexadecylsulphonate. The acid present may be, for example, acetic, lactic, formic or phosphoric acid. In an example, a cotton greige cloth is treated for 4 hours with an aqueous solution at 180‹ F. containing sodium chlorite, acetic acid and sodium lauryl sulphate, washed and dried to obtain a good bleach with removal of sizing, wax, pectins, and motes. With a preliminary padding in a cold aqueous solution of caustic soda and allowing to stand overnight the duration of the bleaching teatment may be reduced. Specification 380,488 is referred to.