Patent ID: 7799889

Claim:
A polycarbonate resin produced by the continuous interfacial process characterized in that after alkaline hydrolysis with sodium hydroxide, the polycarbonate resin contains an amount of 0.01 to 150 ppm of carbamate compounds according to formula (1) said amount measured by high pressure liquid chromatography wherein R 1 and R 2 independently of one another denote hydrogen or C 1 -C 12 -alkyl, or together denote C 4 -C 12 -alkylidene, and R 3 and R 4 independently of one another denote hydrogen, C 1 -C 12 -alkyl or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, said process comprising phosgene reacting with at least one bisphenol at 8 to 17% molar excess of phosgene relative to said bisphenol.