| 摘要 |
Spinnable solutions of acrylonitrile polymers are prepared by polymerizing a monomeric material containing 50-100% by weight of acrylonitrile and up to 50% by weight of one or more copolymerisable compounds in an organic solvent for the polymer and in the presence of a catalyst mixture containing (a) a sulphinic acid amide and (b) an organic or inorganic acid and/or an organic peroxy compound. (The term "organic acid" is used herein to include both carboxylic and sulphonic acids and, also, aromatic disulphonimides of the formula R-SO2-NH-SO2-R1 in which R and R1 each represent an aromatic radical.) Suitable comonomers include methacrylonitrile, acrylic and methacrylic esters and amides, vinyl esters, styrene and its derivatives, and vinyl and vinylidene chloride, as well as dye-receptive monomers such as styrene sulphonic acid, methacrylamidobenzene-benzene -disulphimide and vinyl pyridine. The acid comonomers may also serve as the acid component of the catalyst system. Solvents specified are dimethyl formamide, dimethyl acetamide and dimethylsulphoxide. Many examples of the sulphinic amide and acid catalyst components are listed; suitable organic peroxy compounds include hydroperoxides, keto-peroxides, acyl peroxides and peresters. Accelerators such as taurine, N-methyltaurine, sulphanilic acid or N-methyl sulphanilic acid may also be present; so too may small quantities of water. The monomers can contain stabilizers such as thiosemicarbazide, ammonia, hydroquinone and its derivatives. When the desired conversion has been reached, polymerization can be stopped by the addition of a known inhibitor and/or a concentrated acid. Filaments and fibres spun from the polymer solutions have a high degree of whiteness. |
