摘要:
According to this invention, the prior art problem that relatively many steps and a long time are required for obtaining a high quality polycarbonate of a high molecular weight by a solid phase polymerization method has been solved by subjecting a polycarbonate oligomer to swollen solid phase polymerization under an atmosphere containing a swelling solvent gas or subjecting a polycarbonate oligomer to poor solvent solid phase polymerization under a stream of a poor solvent gas.
摘要:
Provided is a method for producing a granular polycarbonate prepolymer for solid-phase polymerization, comprising dissolving a polycarbonate prepolymer in a solvent under heat, then crystallizing it by cooling, and shaping it. The grains of the granular prepolymer hardly fuse together in polymerization, and the granular prepolymer is suitable for high-speed solid-phase polymerization to give polycarbonate.