GB485372A - Improvements in the treatment of artificial yarns, fabrics, films and the like - Google Patents

Abstract

Yarns, fabrics, films and the like of organic derivatives of cellulose are rendered creaseresisting by causing the material to absorb from a non-aqueous solution in a liquid having a swelling action on the material, synthetic resin components or an intermediate condensation product of such components, and forming a water-insoluble resin on the material. The material is preferably dried at room temperature after impregnation and before heating to condense the resin, the impregnation and drying may be repeated several times. Impregnation is preferably effected under acid conditions. All reagents used are free from water, and the material to be treated is preferably subjected to a preliminary treatment to remove water, e.g. an extraction with anhydrous alcohol, or by heating. Formation of a resin film on the material is prevented by subjecting to mechanical treatment as described in Specification 485,199 or by scouring with a mildly alkaline solution. In an example, urea and formaldehyde dissolved in methanol are pre-condensed in the presence of caustic potash, acetic anhydride added and the solution allowed to stand; the solution is acidified with conc. sulphuric acid and a cellulose acetate fabric immersed therein, air-dried and heated to 180-200 DEG C. for about 5 mins. Instead of methanol there may be employed ethyl acetate, methyl formate or methyl acetate; liquids such as ethyl acetate which are solvents should be be diluted with non-aqueous diluents, e.g. ether or benzene. Instead of urea there may be used thiourea, dicyandiamide, biuret, guanidine, phenols, aromatic aromatic amines, e.g. aniline, and sulphonamides, e.g. p-toluene sulphonamide. Materials so treated also have an increased affinity for acid dyestuffs, retain mechanical effects such as crimping in yarns or embossing, and have an increased resistance to water. Local effects may be produced by effecting the polymerization or condensation locally. According to the first Provisional Specification other suitable resins are the polybasic acid polyhydric alcohol type. Polyvinyl and poly-acrylic compounds may also be used. It is stated that instead of resins, substances such as ester resins, rubber, guttapercha and balata may be employed. Other suitable swelling agents are acetone, diacetone alcohol, dioxane and ethyl acetate.