| 摘要 |
1441986 Alcoholysis of ethylene/vinyl ester copolymers NATIONAL DISTILLERS & CHEMICAL CORP 25 Sept 1973 [25 Sept 1972] 44902/73 Heading C3P Alcoholysis of ethylene/vinyl ester copolymers, especially ethylene/vinyl acetate copolymers, is effected in the solid phase in a reaction medium containing (1) a C 1-4 monohydric alcohol, e.g. methanol, (2) an alkaline or acidic catalyst, e.g. sodium methoxide, (3) an aprotic dipolar solvent, e.g. dimethyl formamide, dimethyl sulphoxide or tetrahydrothiophene-1,1-dioxide, and optionally, and preferably, (4) a hydrocarbon solvent, e.g. toluene. In examples, the copolymer is in the form of film, sheeting, pellets or powder. |
