| 摘要 |
1,198,877. Cross-linked olefin-vinyl ester copolymers. LEUNA-WERKE " WALTER ULBRICHT " VEB. 18 Nov., 1968, No. 54611/68. Heading C3P. Copolymers of an olefin and a vinyl ester are cross-linked by mixing and heating with an alkali metal alcoholate at 60-250‹ C. The preferred cross-linking agent is a methanolic solution of sodium methylate. The copolymer may be in admixture with an olefin homopolymer and the copolymer of this mixture may be cross-linked. The copolymer may be crosslinked first with a peroxide and subsequently or simultaneously with the alcoholate. A filler, such as glass fibres, may be admixed with the copolymer prior to cross linking. In the examples, a copolymer of ethylene and vinyl acetate, stabilized with a phenolic antioxidant, is cross linked by heating with a methanolic solution of sodium methylate, or with sodium palmitylate, dicumyl peroxide and potassium methylate or lithium octylate. In further examples, a mixture of an ethylene homopolymer and an ethylene-vinyl acetate copolymer are cross linked by first heating with dicumyl peroxide and then heating with either a methanolic solution of sodium methylate or sodium palmitylate. |
