A process for preparing readily dyeable polypropylene fibers

摘要

Polypropylene fibres of enhanced dyeability are made by ultra-violet irradiation of the fibres in the presence of a sensitizer, followed by graft polymerization with monomeric vinyl compound having epoxy groups, and treating the fibres with a solution of a substance selected from the group consisting of water-soluble hydroxyamines and water-soluble salts of amino acids in a mixture of dimethyl formamide and water. Irradiation may be effected in air or in vacuo for from 30 mins. to 2 hours, and the fibres may be treated with a solution of the sensitizer, or fibres made from a melt or spinning solution in which a sensitizer is incorporated may be used. Specified sensitizers include acetophenone, benzophenone, and products sold under the Registered Trade Mark "Nvinul". Specified monomeric vinyl compounds having epoxy groups include glycidyl acrylate, glycidyl methacrylate and glycidylvinylurethane. Graft polymerization may also be effected with a mixture of monomeric vinyl compounds having epoxy groups with other vinyl compounds, e.g. vinyl acetate, methyl methacrylate and acrylonitrile. The weight increase of the fibres after graft polymerization is desirably 20-30%. Specified hydroxyamines include diethanolamine, and specified amino acid salts include the sodium salts of monoamino monocarboxylic acids, e.g. glycine and alanine, of monoaminodicarboxylic acids, e.g. glutamic acid, and of diaminomonocarboxylic acids, e.g. lysine. A preferred treating solution is a 30-50% by weight solution of the hydroxyamine or amino-acid salt in a mixture of 30-70% by weight water and 70-30% by weight dimethylformamide.