| abstract |
Flame resistant acrylic fibers are produced by, in a solution polymerization of a mixture consisting of 30-80% by weight of acrylonitrile, 20-70% by weight of vinyl chloride or vinylidene chloride and 0-15% by weight of the other unsaturated monomer in a solvent of dimethylformamide, adding a polymer (referred to as blendmer) consisting of acrylonitrile, vinyl chloride or vinylidene chloride and an anionic monomer and zinc salt of an aromatic sulfonic acid prior to starting of the polymerization, subjecting the resulting mixture to the solution polymerization, removing unreacted monomers from the formed polymer solution, adding sulfur dioxide and adding water to adjust water content, spinning the thus formed spinning solution into an aqueous solution of dimethylformamide. |