GB1032881A - Improvements in and relating to the modification of cellulose fibres - Google Patents

Abstract

Cellulosic fibres are crease proofed by impregnating and reacting them with an aqueous solution of dialdehyde, e.g. glyoxal, glutaraldehyde, succinaldehyde and hydroxyadipaldehyde, at a pH of 3-8, preferably in an amount such that they contain 4-10% by weight of the dialdehyde, to form a cellulose/dialdehyde adduct containing hemiacetal groups and reacting the adduct with an aqueous solution of a reactant having 1 or 2 functional groups capable of converting hemiacetal groups to acetal groups, e.g. formaldehyde, acetaldehyde, acrolein, a ketone, monohydric alcohol or a glycol, in the ratio of at least 1 equivalent proportion by weight of the reactant per molar proportion of reacted dialdehyde, at pH of 3-8 and in the presence of a catalyst which is a metal salt soluble to the extent of at least 0.3 gram mole per litre in water at 20 DEG C. at pH 5 and is zinc sulphate or a slat of a metal of Group II of the Mendeleef Periodic Table with a monobasic acid which is ionised to the extent of at least 50% if in the normal aqueous solution at 10 DEG C., and drying and heating the fibres to a temperature above 100 DEG C. The dialdehyde and the compound capable of forming an acetal may be applied to the fibres sumultaneously from the same solution but it is preferred to treat the fibres with the dialdehyde, dry them and then treat them with the acetal forming compound. The catalyst may be magnesium benzene sulphonate or a salt of magnesium, calcium, barium, strontium, cadmium or zinc with hydrochloric, hydrobomic, hydriodic, nitric, perchloric or thiocyanic acid. Glyoxal solutions containing less than 5% by weight of impurities are preferably used. Fibres, yarns or woven, knitted or non-woven fabrics comprising cotton, sisal, flax, hemp, jute, ramie, regenerated cellulose or cellulose ester fibres alone or in admixture with other fibres may be treated.