Abstract: Modacrylic fibers having high retraction, reduced inflammability and high glossiness, prepared by wet spinning a solution, in an organic spinning solvent miscible with water, of a mixture of copolymers from acrylonitrile, vinylidene chloride, at least a vinyl ester and at least an unsaturated monomer containing at least a sulphonic group, the acrylonitrile units being from 50% to 85% by weight and the vinyl ester units from 3% to 6% by weight; hot drawing the coagulated fiber in a mixture of water and spinning solvent; drying the fiber in hot air while leaving it free concurrently to contract; and subsequently further hot drawing it in air.

Abstract: Textile fibers having reduced inflammability and high luster, constituted copolymers of acrylonitrile, vinylidene chloride and a significantly homopolymerizable sulphonic comonomer are described. Significantly homopolymerizable comonomers are defined as monomers which homopolymerize with a conversion above 30.degree.-40.degree. under standard conditions set forth in the specification. A preferred class of such comonomers are the derivatives of acrylamidoalkanesulphonic acids, e.g. 2-acrylamido-2-methylpropane-sodium sulphonate. The fibers are spun from spinning dopes containing said copolymers in solution in organic solvent miscible with water and less than 4% of water. Said spinning dopes can be obtained by preparing a binary copolymer of acrylonitrile and the sulphonic monomer, in solution in the solvent, mixing the solution with a solution of acrylonitrile and vinylidene monomers in the same solvent, and subjecting the mixture to copolymerization.