| 摘要 |
1426524 Crystallizing polycarbonates UNIBRA SA 26 Feb 1973 [28 Feb 1972 27 July 1972] 9386/73 Heading C3R A process for crystallizing a polycarbonate comprises adding a finely divided nucleating agent selected from salts of carbonic or carboxylic acids to the polycarbonate together with a plasticizing agent compatible with the polycarbonate and crystallizing the mixture thus obtained at a temperature higher than the vitreous transition temperature, i.e. the minimum temperature at which the polymer will crystallize from the mixture. Preferably from 0À01 to 20% by weight of the nucleating agent and from 1 to 50% by weight of the plasticizer are used, the percentages based on the total weight of the composition. The examples describe crystallizing polycarbonates derived from bisphenol A. bis(hydroxyphenyl)methane or bis(hydroxyphenyl)sulphide using various nucleating agents (e.g. CaCO 3 , Na 2 CO 3 or sodium benzoate) and plasticizing agents (e.g. esters of trimellitic acid, tritolylphosphate or n-butylbenzylphthalate). Glass fibres may also be present. |
