| 摘要 |
1,177,199. Copolymers. E.I. DU PONT DE NEMOURS & CO. 30 Aug., 1968 [30 Aug., 1967], No. 41634/68. Heading C3P. [Also in Division D1] An interpolymer containing (a) 50-97À8% copolymerized vinyl acetate, (b) 2-49À8% copolymerized ethylene and (c) 0À2-15% copolymerized unsaturated N-methylol amine or an alkyl ether thereof and having an inherent viscosity of 0À5-2 dl/g. is used as a binder for polypropylene fibres. The amide can be the N-methylol derivatives of acrylic, itaconic, citraconic or maleic acids or their methyl, ethyl, propyl, isopropyl or butyl ether derivatives. The interpolymer can be made by polymerizing about 10% of the vinyl acetate under an ethylene pressure in an emulsion in the presence of specified catalysts stabilizers, buffering agents (pH 5-7), protective colloids, polymerization modifiers and emulsifying agents. The remaining vinyl acetate and N-methylol amide is added continuously. The reaction is conducted at 40-80‹ C. under 100-2000 p.s.i. |
