GB696282A - Process for the dimensional stabilisation of cellulose fabrics - Google Patents

Abstract

Natural and regenerated cellulose fabrics are impregnated with epichlorhydrin or a substance which may be hydrolysed by aqueous caustic alkali to release epichlorhydrin, and then treated with aqueous caustic alkali at a temperature above 70 DEG C. whilst under tension. Cross linkages are produced between neighbouring cellulose chains. Suitable reagents which give rise to epichlorhydrin on hydrolysis include glycerol-1,3-dichlorhydrin, glycerol-1,2-dichlorhydrin, 1-chloro-2-bromopropanol-(3) and mixtures of these, particularly a mixture of the glycerol-dichlorhydrins which is commercially available. The selected reagent may be used in solution in water, benzene, acetone, carbon tetrachloride or diethyl ether. Sodium or potassium hydroxide may be used as the alkali, and it is advantageous to have present in the solution one or more alkali metal salts, such as the chloride, bromide, nitrate, carbonate or acetate of sodium or potassium. The conditions for treatment of regenerated cellulose fabrics may be 8.2-15.5 g. of glycerol 1,3 dichlorhydrin or up to 18 g. if the solution is warmed, 0.8-7.5 g. (preferably 2-4 g.) of caustic soda, 1.0-28.2 g. of alkali metal salt, say sodium chloride (preferably 20-25 g.), all per 100 ml. of aqueous treating liquids, reaction temperature 70-107 DEG C. (preferably about 90 DEG C.) and time of treatment 10 seconds to 30 minutes. The conditions for natural cellulose may be 2.1-15.5 g. of glycerol 1 : 3 dichlorhydrin, 0.8-25.2 g. (preferably 10-20 g.) of caustic soda, 1.0-28.2 g. (preferably 15-25 g.) of alkali metal salt, say sodium chloride, all per 100 ml. of aqueous treating liquids, reaction temperature 70-110 DEG C. (preferably about 90 DEG C.) and time of treatment 5 seconds to 60 minutes. Lower concentrations of reagents may be used with higher temperatures and longer reaction times. The treated fabric is proofed against laundry shrinkage and ironing extensions, is insoluble in cuprammonium solutions, and possesses low swelling properties. In an example a plain weave spun viscose rayon fabric is impregnated at room temperature with an aqueous solution containing 15 g. of glycerol-1,3-dichlorhydrin per 100 ml. Excess solution is squeezed out and the fabric passed under tension into a solution containing 3.0 g. of sodium hydroxide and 25 g. of sodium chloride per 100 ml. at 90 DEG C. for 2 minutes. It is washed, soured with 0.5 per cent sulphuric acid, washed again, soaped and dried. The Provisional Specification is not limited to the use of epichlorhydrin and compounds which give rise to it, but p refers to the use of any halogenated compound of the aliphatic or alicyclic series containing at least two halogen atoms, at least two of which are not situated on the same carbon atom and are capable of forming epoxide rings with at least one hydroxyl group which also must be present in the molecule, or alternatively containing at least one halogen atom and at least one epoxide ring either adjacent to it or, if not adjacent, with the additional presence of one or more hydroxyl groups, at least one of which is capable of forming a second epoxide ring with at least one halogen atom. Compounds falling within this definition include, in addition to those listed in the Complete Specification, glycerol - 1,2 - dibromhydrin, glycerol - 1,3-dibromhydrin, 1 - bromo - 3 - chloropropanol - (2), 1 - bromo - 2 - chloropropanol - (3), and epibromhydrin. Natural cellulose may be treated at any temperature between 20 DEG and 110 DEG C. and regenerated cellulose at any temperature between 60 DEG and 107 DEG C.