PROCESS FOR THE PREPARATION OF HIGH MOLECULAR WEIGHT COPOLYCARBONATES BY SOLID STATE POLYMERIZATION

摘要

A preparation process of a high molecular weight polycarbonate copolymer is provided to prevent the discoloration of color due to a short crystallization process and to obtain a high molecular weight polycarbonate having excellent optical characteristic. A preparation process of a high molecular weight polycarbonate copolymer comprises (a) a step for manufacturing a low molecular weight amorphous poly carbonate prepolymer having the number average molecular weight of 1,000-10,000 g/mol by melt-polymerizing a dihydroxy aromatic compound and diarylcarbonate through the use of a mixed catalyst of a tetra ammonium compound and tetra aryl phosphonium compound; (b) a step for manufacturing a low molecular weight polycarbonate prepolymer having a semi-crystalline structure by dissolving the amorphous poly carbonate prepolymer in a solvent, injecting not-solvent in the solution and crystallizing it; and (c) a step for manufacturing a high molecular weight polycarbonate copolymer having the average molecular weight of 25,000-200,000 g/mol by using a solid phase polymerization method of the low molecular weight polycarbonate prepolymer having a semi-crystalline structure.