Patent ID: 6583258
Filing Date: 2003-06-24
Classification: C08G

Abstract:
A method for the preparation of polycarbonate, said method comprising contacting at least one diaryl carbonate with at least one dihydroxy aromatic compound in the presence of a transesterification catalyst and optionally a co-catalyst, under melt polymerization conditions to afford a polycarbonate, said transesterification catalyst comprising at least one alkali metal or alkaline earth metal salt of an organic phosphate; said alkali metal or alkaline earth metal salt of an organic phosphate being selected from the group consisting of salts of adenosine 5â€²-monophosphate having structure III and salts of 2-deoxy-6-phosphogluconic acid having structure IV wherein A is independently at each occurrence an alkali metal ion or an alkaline earth metal ion; p is an integer having a value of 1 or 2, and X+ is a charge balancing species.