Patent ID: 6831147
Filing Date: 2004-12-14
Classification: C08G

Abstract:
A process for producing aromatic polycarbonates with UV-absorber terminal groups and average molecular weights {overscore (M)}w (weight average, determined by light scattering) of between 1,500 and 150,000 from diphenols by melt transesterification, which comprises chain-terminating the polycarbonates with chain terminators of the formula (II): in whichR1 is H, C1-C18 alkyl, C3-C6 cycloalkyl or C6-C10 aryl, R2 is H, Cl or C1-C12 alkyl, X is a single bond, C1-C12 alkylene, C5-C6 cyclo-alkylene or C6-C10 arylene, and Y is a biphenolate residue of the formula (III): â€”Oâ€”Arâ€”Oâ€”â€ƒâ€ƒ(III), in whichâ€”Arâ€” is an arylene with from 6 to 30 carbon atoms and is monocyclic or polycyclic, wherein the chain terminator condenses with the polycarbonate at the carboxyl group of the chain terminator.