| 摘要 |
Compositions comprise a polymer containing in polymerized form at least 80% by weight of acrylonitrile and up to 20% by weight of at least one mono-olefinically unsaturated monomer and, as light stabilizing agent 0,05 to 5,0% by weight of the polymer of an alkyl substituted pyridine or aromatic substituted pyridine. Specified pyridines are 2-methyl-5-ethyl, 3-ethyl-4methyl, 2,6-dimethyl-4-ethyl, 2-butyl, 2-benzyl, 3-benzyl, dimethyl, 2-ethyl, 3-ethyl, 2-ethyl3,5-dimethyl, 5-methyl-2-ethyl, 2-phenyl, 2-propyl and 2,4,6-trimethyl pyridines. Many suitable comonomers are listed including unsaturated acids and the esters, nitriles and amides thereof, vinyl and vinylidene halides, vinyl esters, vinyl ketones, vinyl ethers, vinyl aromatic compounds, unsaturated sulphonic acids and un-saturated hetero cyclic compounds. Terpolymers, e.g. of acrylonitrile, a vinyl pyridine or 1-vinyl imidazole and vinyl acetate, methyl methacrylate, methacrylonitrile, vinyl chloride or vinylidene chloride; or mixtures of polymers, e.g. of polyacrylonitrile or an acrylonitrilevinyl acetate copolymer with a copolymer of a vinyl pyridine, 1-vinyl imidazole or vinyl lactam and acrylonitrile. The polymers are particularly suitable for spinning fibres, and the stabilizer may be incorporated therein by adding to a spinning solution of the polymer, e.g. in N,N-dimethyl formamide, N,N-dimethyl acetamide, ethylene carbonate, dimethyl sulphoxide, nitromethane, gamma-butyrolactone, aqueous zinc chloride, aqueous sodium thiocyanate, sulphuric acid or aqueous nitric acid; or by adding to a finishing bath in which the spun fibre is immersed for further processing. In the examples 2-methyl-5-ethyl pyridine is added to solutions of acrylonitrile-vinyl acetate copolymers in N,N-dimethyl acetamide containing titanium dioxide, and the resulting solutions wet spun into fibres. |
