GB1140300A - Process for the production of novel thermoplastic polycarbonates of high molecular weight - Google Patents

Abstract

1,140,300. Polycarbonates. FARBENFABRIKEN BAYER A.G. 1 June, 1967 [4 June, 1966], No. 25372/67. Heading C3R. Polycarbonates are made by reacting an esterforming derivative of carbonic acid with a dihydric phenol of formula wherein Ar is a divalent aromatic radical both of the free valencies of which are directly attached to nuclear carbon atoms. The radical Ar may be one of the radicals Up to 80 mol. per cent of the above sulphone dihydric phenol may be replaced by another dihydric phenol, e.g. hydroquinone, resorcinol, a dihydroxydiphenyl, a dihydroxynaphthalene or a bis (hydroxyaryl)-alkane, -cycloalkane, -ether, -sulphide, -sulphoxide or -sulphone or by a dihydric alcohol, e.g. 1: 4-butanediol, 1: 6-hexanediol, neopentyl glycol or 1:4-bis-(hydroxymethyl)-cyclohexane. Molecular weight regulators, e.g. phenol or p-tert-butylphenol may be included. The ester-forming derivative of carbonic acid may be phosgene, a bischloroformate or a diester of carbonic acid. In examples polycarbonates are made by reacting phosgene with one of the above sulphone dihydric phenols or a mixture thereof with bisphenol A using the interfacial process.