Patent ID: 6291631
Filing Date: 2001-09-18
Classification: C08G

Abstract:
A method for preparing polycarbonates, which comprises contacting a diaryloxy compound with a dihydric phenol compound in the presence of at least one compound of Formula (I) or (II): ##STR12##wherein A represents alkali metals selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium; B contains a charge balancing sulfonate, carboxylate, or phosphonate group; and Tm represents a transition metal, x is an integer of from 1 to 4 and y is an integer of from 1 to 4; optionally in the presence of a co-catalyst selected from tetraalkyl ammonium and tetraalkyl phosphonium salts;under polycarbonate melt polymerization conditions.