Patent ID: 7057004
Filing Date: 2006-06-06
Classification: C08G

Abstract:
1. A method of producing a copolycarbonate with improved color wherein the method comprises the steps of, i. preparing a molten reaction mixture comprising a first dihydroxy aromatic compound comprising monomer residue (a), a second dihydroxy aromatic compound comprising monomer residue (b), and a carbonate source, ii. selecting a catalyst introduction strategy sufficient to result in a product copolycarbonate with improved color, wherein the catalyst introduction strategy is selected from the group consisting of, iii. introducing the catalyst according to the selected catalyst introduction strategy, iv. introducing the reaction mixture to a series of process units, and v. allowing the reaction mixture to polymerize in the series of process units thereby forming copolycarbonate, wherein the copolycarbonate has improved color as compared to a copolycarbonate formed in a melt process without the steps of selecting a catalyst introduction strategy and introducing catalyst according to the selected strategy.