Patent ID: 6870025

Claim:
A method of preparing a polycarbonate, said method comprising heating a mixture comprising a catalyst, at least one diaryl carbonate having structure I wherein R 1 and R 2 are independently C 1 -C 20 alkyl radicals, C 4 -C 20 cycloalkyl radicals, or C 4 -C 20 aromatic radicals, R 3 and R 4 are independently at each occurrence a halogen atom, cyano group, nitro group, C 1 -C 20 alkyl radical, C 4 -C 20 cycloalkyl radical, C 4 -C 20 aromatic radical, C 1 -C 20 alkoxy radical, C 4 -C 20 cycloalkoxy radical, C 4 -C 20 aryloxy radical, C 1 -C 20 alkylthio radical, C 4 -C 20 cycloalkylthio radical, C 4 -C 20 arylthio radical, C 1 -C 20 alkylsulfinyl radical, C 4 -C 20 cycloalkylsulfinyl radical, C 4 -C 20 arylsulfinyl radical, C 1 -C 20 alkylsulfonyl radical, C 4 -C 20 cycloalkylsulfonyl radical, C 4 -C 20 arylsulfonyl radical, C 1 -C 20 alkoxycarbonyl radical, C 4 -C 20 cycloalkoxycarbonyl radical, C 4 -C 20 aryloxycarbonyl radical, C 2 -C 60 alkylamino radical, C 6 -C 60 cycloalkylamino radical, C 5 -C 60 arylamino radical, C 1 -C 40 alkylaminocarbonyl radical, C 4 -C 40 cycloalkylaminocarbonyl radical, C 4 -C 40 arylaminocarbonyl radical, or C 1 -C 20 acylamino radical, and b and c are independently integers 0-4; and at least one dihydroxy aromatic compound selected from the group consisting of resorcinol, methylresorcinol, hydroquinone, and methylhydroquinone, said catalyst comprising at least one source of alkaline earth ions or alkali metal ions, and at least one quaternary ammonium compound, quaternary phosphonium compound, or a mixture thereof, said source of alkaline earth ions or alkali metal ions being present in an amount such that between about 1×10 −5 and about 1×10 −8 moles of alkaline earth metal ions or alkali metal ions are present in the mixture per mole of dihydroxy aromatic compound employed, said quaternary ammonium compound, quaternary phosphonium compound, or mixture thereof being present in an amount between about 2.5×10 −3 and about 1×10 −6 moles per mole of dihydroxy aromatic compound employed, to provide a product polycarbonate, said product polycarbonate comprising repeat units derived from at least one member of the group consisting of resorcinol, methylresorcinol, hydroquinone, and methylhydroquinone.