GB583428A - Process for imparting to cellulosic textile fabrics an increased resistance to shrinkage - Google Patents

Abstract

A process for imparting to cellulosic textile fabrics an increased resistance to shrinkage when washed comprises treating such fabrics with an aqueous solution of an etherified melamine-formaldehyde condensation product, containing at least one formaldehyde-reactive hydrogen, and formaldehyde which is present in an amount of at least one third of the weight of the etherified melamine-formaldehyde condensation product and thereafter heating the fabric in order to produce a water-insoluble resin thereon. The melamine-formaldehyde condensation product may be a methylolmelamine in which resinification has not proceeded to any considerable extent, i.e. one made from one molecular proportion of melamine and substantially three molecular parts of formaldehyde. In an example the methyl ether of a methylol-melamine is prepared by mixing 200 parts melamine, 400 parts of a 40 per cent aqueous formaldehyde solution and 5 parts by weight of disodium hydrogen phosphate for 15 minutes at 75 DEG C. The cooled mixture is stirred into 972 parts by weight of methanol. Aqueous hydrogen chloride is then added and the whole allowed to stand for 30 mins. before the solution is neutralized with an excess of sodium bicarbonate. The solution is concentrated by evaporation of water under reduced pressure at 40 DEG C. The impregnating solution may contain 5-50 per cent by weight of the etherified melamineformaldehyde condensation product. Amounts greater than 15 per cent by weight lead to crease-resistant finishes. After impregnation, the fabric may be dried and then heated or dried and heated, in a single operation, the heating preferably being carried out above 100 DEG C. The impregnating solution may contain an acid catalyst such as ammonium dihydrogen phosphate, ammonium chloride or tartaric acid. In an example, cotton fabric is steeped in a neutral aqueous solution of an etherified melamine-formaldehyde condensation product to which is added ammonium dihydrogen phosphate and aqueous formaldehyde. The fabric is removed and squeezed to retain its own weight of liquor, stentored at the required dimensions, dried and finally heated at 150 DEG C.