The use of stable mixtures of polyacrylamide and aqueous dispersions of water-repellent agents for finishing textiles

摘要

Stable compositions suitable for finishing textiles comprise a mixture of polyacrylamide and an aqueous dispersion of a water-repelling agent based on a zirconium salt, an aluminium salt and/or a solid paraffin, the polyacrylamide having been prepared by polymerizing acrylamide, optionally together with not more than 1% by weight (based on the polymer) of a comonomer such as a carboxylic monomer, in the presence of a free radical catalyst and a mercaptan having an O-containing group adjacent to the -SH group. Salts specified are zirconium acetate and aluminium oxychloride. The compositions may also contain additives such as white oil, bone glue, buffers, acetic acid, and condensation products of formaldehyde with ureas, melamine, dicyanodiamide and etherified derivatives thereof. The polyacrylamide is preferably prepared in aqueous solution at a pH of from 3.5 to 6 using a catalyst such as hydrogen peroxide, acetyl peroxide or azodiisobutyronitrile, or less preferably a persulphate or perborate, and an oxygen-containing mercaptan such as 2-mercapto-ethanol, 1 - thio - glycerine or thioglycollic acid. The reaction mixture may also include a small amount of K2FeCl4. Textiles treated with the compositions are finished by heating the impregnation, optionally in the presence of a curing catalyst such as ammonium chloride.ALSO:Textiles are finished by impregnating with a composition comprising polyacrylamide and an aqueous dispersion of a water-repelling agent based on a zirconium salt (e.g. the acetate), an aluminium salt (e.g. the oxychloride and/or a solid paraffin, the polyacrylamide having been prepared by polymerising the monomer in the presence of a free radical catalyst and a mercaptan having an O-containing group adjacent to the -SH group. The compositions may optionally include additives such as white oil, bone glue, buffers, acetic acid, ammonium chloride (curing catalyst) and aminoplast condensation products. The impregnated textiles are dried and heated to obtain water-repellent and, optionally, crease-proof, swelling-proof and shrink-resistant finishes. The compositions can be applied to woollen, cotton and synthetic-fibre fabrics.