Abstract: The present invention provides 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 R1 and R2 independently of one another denote hydrogen or C1-C12-alkyl, or together denote C4-C12-alkylidene, and R3 and R4 independently of one another denote hydrogen. C1-C12-alkyl or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, the process comprising phosgene reacting with at least one bisphenol at 8 to 17% molar excess of phosgene relative to the bisphenol.

Abstract: An improvement to the phase interface process of preparing aromatic polycarbonate is disclosed. The process is characterized in that the phosgenation is carried out at 0 to 40° C., and in that the temperature of the reaction mixture at the time of addition of the catalyst at 10 to 40° C., and in that the molar ratio of aromatic dihydroxy compounds to phosgene at 1:1.05 to 1:1.20. The polycarbonate thus produced is characterized in its low content of carbamates, making it particularly suitable for the preparation of optical storage media.

Abstract: An improvement to the phase interface process of preparing aromatic polycarbonate is disclosed. The process is characterized in that the phosgenation is carried out at 0 to 40° C., and in that the temperature of the reaction mixture at the time of addition of the catalyst at 10 to 40° C., and in that the molar ratio of aromatic dihydroxy compounds to phosgene at 1:1.05 to 1:1.20. The polycarbonate thus produced is characterized in its low content of carbamates, making it particularly suitable for the preparation of optical storage media.

Abstract: A polycarbonate resin that after alkaline hydrolysis with sodium hydroxide contain an amount of 0.01 to 150 ppm of carbamate compounds according to formula (1) wherein R1 and R2 independently of one another denote hydrogen or C1-C12-alkyl, or together denote C4-C12-alkylidene, and R3 and R4 independently of one another denote hydrogen, C1-C12-alkyl or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, said amount measured after alkaline hydrolysis with sodium hydroxide by high pressure liquid chromatography.