| 摘要 |
1484438 Flame retardant polycarbonates BAYER AG 31 Oct 1975 [19 Dec 1974] 45320/75 Heading C3R A thermoplastic aromatic polycarbonate is prepared by reacting the melt of an aromatic polycarbonate prepared by the solvent or interfacial method with from 0À001 to 0À1% by weight, based on the polycarbonates, of an alkali metal salt of an organic compound, the salt being soluble in the polycarbonate melt, at 250-400‹ C. for 1 to 30 minutes, until the resulting polycarbonate has a Standinger Index which is from 3 to 30 cm.<SP>2</SP>/g. higher than the original polycarbonate. Glass fibres in an amount of from 10-40% by weight, based on the total composition, may be added. The examples describe reacting polycarbonates derived from (a) bisphenol A and (b) bisphenol A and 1,1-bis(4- hydroxyphenyl) cyclohexane with various alkali metal salts, e.g. disodium bisphenolate A, potassium acetate and sodium stearate. |
