GB1347571A - Thermally stable polycarbonate - Google Patents

Abstract

1347571 Polycarbonate compositions GENERAL ELECTRIC CO 19 April 1971 [13 April 1970] 26231/71 Heading C3R A thermal oxidatively stable aromatic polycarbonate composition is produced by mixing with the polycarbonate 0À005-1À0% by weight of a phosphonite of the formula in which R 1 , R 2 and R 3 are unsubstituted or halogen substituted alkyl, aryl, cycloalkyl, aralkyl or alkaryl radicals containing 1-25 carbon atoms. The composition may also contain 0À01- 0À5% by weight of an epoxy compound preferably of the formula in which R 4 , R 5 , R 6 and R, are hydrogen, alkyl, cycloalkyl, substituted cycloalkyl, aryl, substituted aryl or heterocyolic radicals containing 1-24 carbon atoms, and in which two of the radicals R4 to R; may, together with the radical form a cycloalkyl ring. The phosphonite may be added to the polycarbonate during its preparation or may be blended with dry polycarbonate powder. The composition which may be used in moulding may also contain sized or unsized glass fibres, pigments or mineral fillers, e.g. quartz or silica. In Examples (a) diphenyl benzene phosphonite, dinonylphenyl benzene phosphonite or diisodecyl benzene phosphonite and di - 3,4 - epoxy - 6 - methylcyclohexyl methyl adipate are mixed with a polycarbonate powder prepared by the reaction of bisphenol-A with phosgene and the composition formed into pellets using a screw extruder or (b) diphenyl benzene phosphonite, dinonyl phenyl benzene phosphonite or di-isodecyl benzene phosphonite is added to a mixture of methylene chloride, 2,2-bis-(4-hydroxyphenyl)propane, calcium hydroxide, p-tertiary butyl phenol and triethylamine which is reacted with phosgene to produce a polycarbonate.