Preconditioning and processing crude cellulose fibres - with polyhydroxy carboxylic acid, monosaccharide and wetting agent, in aq. alkali

摘要

Cellulose fibres are preconditioned nd processed by treating with (a) >=1 polyhydroxy carboxylic acid (e.g. glycolic acid) and/or salt; (b) >=1 monosaccharide (e.g. lactose); and (c) >=1 wetting agent, pref. a surfactant; in an aq. alkaline medium. The amt. of (a) used is 0.01-10 (pref. 0.1-3) wt.%; of (b) is 0.01-10 (pref. 0.1-3) wt.%; and of (c) is 0.01-2 (pref. 0.1-1.5) wt.%, (based on fibres). Treatment is at 80-150 (pref. 95-135) degrees C. for 30 sec. - 5 hr. Method gives optimal purification and brightening of fibres: (a) are better complexing agents for alkaline earths than the conventionally used polyamino carboxylic acids, and use of (b) facilitates removal of coloured impurities and prevents oxidn. of the cellulose by air. The removal of seed husks is easier, and whiteness and wetting ability of the fibres are increased. In an example, crude unbleached cotton treated with a soln. contg. 50 g./l. NaOH, 1 g./l. polyglycolether, 3.0 g./l. fructose and 3.0 g./l. Na-gluconate had a degree of whiteness 74.4% cf. that of the untreated cloth 55.4%.