Idemitsu Kosan Company, Limited

Hirosi Yamada

Sanae Tagami

Hideo Konuma

Yoshihiro Narita

A process is provided for preparing a polycarbonate composition with excellent weatherproof properties. The process comprises adding an ultraviolet absorbing compound having a hydroxy group which contributes at least partially to the molecular weight modifier to an oligomeric polycarbonate which is obtained by the reaction of a dioxy compound with phosgene, and then condensing said oligomeric polycarbonate to polymerize the same. The invention also concerns a process for preparing a polycarbonate with excellent weatherproof properties which process comprises introducing a dioxy compound in alkaline solution and an organic solvent for the polycarbonate into a tubular reactor continuously to form a turbulent flow, feeding phosgene concurrently to the reactor with cooling outside of the reactor to produce an oligomeric polycarbonate as the solution of organic solvent, adding an aqueous alkaline solution of dioxy compound, molecular weight modifier, which is contained at least in part ultraviolet absorbing compound having an hydroxy group, and catalyst selected from the group consisting of tertiary amine and quaternary ammonium salt and, if desired, antioxidant to said oligomeric polycarbonate solution and condensing said oligomeric polycarbonate to polymerize the same.

Growing community of inventors

Tokuyama, Japan

Hirosi Yamada