Patent ID: 7589165

Claim:
A polycarbonate resin produced by a continuous interfacial process wherein the resin contains 0.2 to 300 ppm of one or more compounds conforming structurally to formula (I) 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, R 3 and R 4 independently of one another represent hydrogen or C 1 -C 12 -alkyl, or phenyl, or together with carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, and R 5 denotes hydrogen, C 1 -C 12 -alkyl, C 5 C 12 -cycloalkyl, phenyl or cumyl, wherein the content is measured in acetone extract by chromatography by means of HPLC wherein the process comprises reacting at least one bisphenol with an excess of 5 to 17 mol % of phosgene (based on the total of bisphenols employed) wherein the reaction has a pH is in the alkaline range and a temperature of 0 to 40° C.