| 摘要 |
Process for the preparation of polymers, characterized in that a mixture of carbon monoxide with one or more olefinically unsaturated compounds is polymerized by contacting the mixture at an elevated temperature and pressure with a solution of a catalyst composition in a diluent in which the polymers are insoluble or virtually insoluble, and which catalyst composition is based upon a) a palladium compound, b) an acid with a pKa of less than 2, and c) a diphosphine of the general formula R<1>R<2>P-R-PR<3>R<4>, wherein R<1>-R<4> represent the same or different optionally polar-substituted hydrocarbyl groups and R is a bivalent organic bridging group containing at least two carbon atoms in the bridge, in which process the catalyst composition that is used at the outset of polymerization comprises a halogen monocarboxylic acid as component b) in a concentration of less than 6 equivalents per mol of palladium and in which process the acid concentration of the catalyst composition is increased after the polymer concentration has reached a value of at least 0.2 g per 100 g of polymer suspension, the latter increase being effected either by adding a halogen monocarboxylic acid in such a quantity that the overall concentration of halogen monocarboxylic acid is at least 7 equivalents per mol of palladium or by adding an acid other than a halogen monocarboxylic acid in a quantity of at least 1 equivalent per mol of palladium. |
