Patent ID: 6610814
Filing Date: 2003-08-26
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 antimony or germanium said salt having structure I(MOn)m(A)p(R1)qâ€ƒâ€ƒI wherein M is antimony or germanium, n is an integer in a range from 0 to 4, m is an integer in a range from 1 to 2, A is independently at each occurrence an alkali metal ion or an alkaline earth metal ion, p is an integer in a range from 1 to 4, R1 is an organic ligand having structure III and q is an integer in range from 1 to 2.