Patent ID: 6518391
Filing Date: 2003-02-11
Classification: C08G

Abstract:
A method of preparing polycarbonate by solid state polymerization, said method comprising heating to a temperature between about 120Â° C. and about 280Â° C. under solid state polymerization conditions a partially crystalline precursor polycarbonate comprising structural units derived from at least one dihydroxy aromatic compound, and endgroups having structure I wherein R1 is a C1-C20 alkyl radical, C4-C20 cycloalkyl radical or C4-C20 aromatic radical, R2 is independently at each occurrence a halogen atom, cyano group, nitro group, C1-C20 alkyl radical, C4-C20 cycloalkyl radical, C4-C20 aromatic radical, C1-C20 alkoxy radical, C4-C20 cycloalkoxy radical, C4-C20 aryloxy radical, C1-C20 alkylthio radical, C4-C20 cycloalkylthio radical, C4-C20 arylthio radical, C1-C20 alkylsulfinyl radical, C4-C20 cycloalkylsulfinyl radical, C4-C20 arylsulfinyl radical, C1-C20 alkylsulfonyl radical, C4-C20 cycloalkylsulfonyl radical, C4-C20 arylsulfonyl radical, C1-C20 alkoxycarbonyl radical, C4-C20 cycloalkoxycarbonyl radical, C4-C20 aryloxycarbonyl radical, C2-C60 alkylamino radical, C6-C60 cycloalkylamino radical, C5-C60 arylamino radical, C1-C40 alkylaminocarbonyl radical, C4-C40 cycloalkylaminocarbonyl radical, C4-C40 arylaminocarbonyl radical, and C1-C20 acylamino radical; and b is an integer 0-4.