| 摘要 |
Compositions suitable for making yarns, films and shaped articles comprise a solution of polyacrylonitrile or of a copolymer in which at least 85 per cent by weight is acrylonitrile, in a solvent comprising a compound from a specified class of organic sulphoxy compounds. The compositions are clear mobile solutions at elevated temperatures, e.g. 100 DEG C., and may gel at room temperature. The preferred compounds are dimethyl sulphoxide, hydroxyethylmethyl sulphone and dimethyl sulphone, but others specified are substituted with N.N-dimethyl carbamyl, halogen, oxygen, bivalent sulphur, hydroxyl, thiol, cyano, thiocyano and/or sulphoxy groups, e.g. chloromethane disulphonic acid dimethyl ester, methyl ethane sulphinate, bis - (methylsulphonylmethylsulphonylmethyl) sulphone, 1-bromo-2-thiocyanoethane sulphonic acid methyl ester, bis-(methyl sulphonyl) butyronitrile, N.N-dimethyl (ethyl sulphonyl) acetamide, 1.3-dithiolane-1-oxide, 2-bromo-2-methyl-1.3-dithiane tetraoxide and N.N-dimethyl-a -cyano-b -ethylsulphinyl propionamide. Specified compounds with which the acrylonitrile may be copolymerized are vinyl acetate and chloride, acrylic acid and its esters and homologues, styrene, isobutylene and butadiene (see Group V). Optionally, the compositions may contain other plasticisers (non-solvents for the polymer), e.g. glycerol, solvents for the polymer of lower b.p., e.g. dimethyl sulphoxide and dyes, linear polyamides, cellulose ethers and esters, polyvinyl chloride and acetate and polyacrylic acid. The solutions may be shaped to form filaments, yarns, films, tubes and other articles, e.g. by moulding, casting or extrusion into an evaporative atmosphere or a bath of coagulant miscible with the solvent, but an inert non-solvent for the polymer, e.g. water, glycerol, alcohol, ether and aqueous solutions of salts, alkalies and acids. The properties of the products can be improved by subjecting them to a stretching operation. The compositions are also suited for use as adhesives for attaching films of polyacrylonitrile together and particularly for making laminated structures from polyacrylonitrile films. The solutions are also suited for use as lacquers and coating compositions, e.g. as coatings for wires. The dry and wet spinning of yarn and the casting of films from the compositions is described. The yarn is drawn by the method of Specification 585,368 and is suitable for clothing, e.g. hosiery and flat and pile fabrics, e.g. velvets, plushes, upholstery, carpeting. The yarns are useful for the manufacture of tents, sails, acid-proof filter cloths, protective clothing and liners and separators for storage batteries. Specifications 404,504, 594,999, 595,043 and 595,045 and U.S.A. Specifications 2,117,210, 2,140,921 and 2,167,537 also are referred to.ALSO:Compositions suitable for making yarns, films and shaped articles comprise a solution of polycrylonitrile or of a copolymer in which at least 85 per cent. by weight is acrylonitrile in a solvent comprising a compound from a specified class of organic sulphoxy compounds (see Group IV]. The compositions are clear mobile solutions at elevated temperatures, e.g., 100 DEG C., and may gel at room temperature. The preferred compounds are dimethyl sulphoxide, hydroxyethylmethyl sulphone and dimethyl sulphone but others specified are substituted with N.N-dimethyl carbamyl, halogen, oxygen, bivalent sulphur, hydroxyl, thiol, cyano, thiocyano and/or sulphoxy groups, e.g., chloromethane disulphonic acid dimethyl ester, methyl ethane sulphinate, bis (methylsulphonylmethylsulphonylmethyl) sulphone, 1-bromo-2-thiocyanoethane sulphonic acid methyl ester, bis (methyl sulphonyl) butyronitrile, N.N-dimethyl (ethyl sulphonyl) acetamide, 1.3-dithiolane-1-oxide, 2-bromo-2-methyl-1.3-dithiane tetraoxide and N.N-dimethyl a -cyano-b -ethylsulphinyl propionamide. The acrylonitrile may be copolymerised with diolefines, e.g., butadiene. Optionally, the compositions may contain other plasticisers (non-solvents for the polymer), e.g., glycerol, solvents for the polymer of lower b.p., e.g., dimethyl sulphoxide, and dyes, linear polyamides, cellulose ethers and esters, polyvinyl chloride and acetate and polyacrylic acid. The solutions may be shaped to form filaments, yarns, films, tubes and other articles, e.g., by moulding, casting or extrusion into an evaporative atmosphere or a bath of coagulant miscible with the solvent but an inert non-solvent for the polymer, e.g., water, glycerol, alcohol, ether and aqueous solutions of salts, alkalies and acids. The properties of the products can be improved by subjecting them to a stretching operation. The compositions are also suited for use as adhesives for attaching films of polyacrylonitrile together and particularly for making laminated structures from polyacrylonitrile films. The solutions are also suited for use as lacquers and coating compositions, e.g., as coatings for wires. The dry and wet spinning of yarn and the casting of films from the compositions is described. The yarn is drawn by the method claimed in Specification 585,368, [Group IV], and is suitable for clothing, e.g., hosiery and flat and pile fabrics, e.g., velvets, plushes, upholstery, carpeting. The yarns are useful for the manufacture of tents, sails, acid-proof filter cloths, protective clothing and liners and separators for storage batteries. Specifications 404,504, 594,999, [both in Group IV], 595,043 and 595,045 and U.S.A. Specifications 2,117,210, 2,140,921 and 2,167,537 also are referred to. |
