Formaldehyde modification of cellulose catalyzed by a lewis acid salt and formic acid generated in situ by a peroxide

摘要

A composition suitable for use as a catalyst in the methylenation of cellulosic fibres with formaldehyde or other aldehydes at temperatures of 240-300 DEG F. comprises an aqueous solution containing hydrogen peroxide or an alkali metal persulphate and a polyvalent metal salt of a Lewis acid, e.g. magnesium, calcium, barium, zinc or strontium nitrate or chloride, chromium acetate, chromic chloride, nickel chloride, aluminium chloride, zirconium oxychloride or magnesium sulphate.ALSO:Cellulosic textile materials, e.g. cotton and regenerated cellulose fibres alone or in admixture with synthetic fibres such as cellulose acetate, acrylic, methacrylic, nylon, polyolefin or polyester fibres, are crease-proofed by methylenation by a process comprising impregnating them with an aqueous solution containing formaldehyde or another aldehyde such as glyoxal, a -hydroxy-adipaldehyde or glutaraldehyde and then curing them by heating in the presence of a catalytic composition comprising an aqueous solution containing hydrogen peroxide or an alkali metal persulphate and a polyvalent metal salt of a Lewis acid, at a temperature of 240 DEG -300 DEG F. for 3-7 minutes. The aldehyde may be produced from a compound which upon heating liberates an aldehyde, e.g. methylol ketones, paraformaldehyde and trioxane. The polyvalent metal salt of the Lewis acid may be magnesium, calcium, barium, zinc or strontium nitrate or chloride, chromium acetate, chronic chloride, nickel chloride, magnesium sulphate, aluminium chloride or zirconium oxychloride. The aqueous solution of the catalyst may be present in the aqueous solution of the aldehyde which may also contain methylol ethylene ureas, p methlolacetylene diureas, methylol dihydroxyethylene ureas or methylol triazones, acrylic emulsions and wetting agents, e.g. alkaryl polyether alcohols. The process may comprise mechanically treating fabrics to alter the shape and relative disposition of the yarns, e.g. by calendering, pleating or ruffling.