Method of polycarbonate preparation
AssigneeGeneral Electric Company
InventorsDaniel Joseph Brunelle, Patrick Joseph McCloskey, Paul Michael Smigelski, Jr., Timothy Brydon Burnell, Ganesh Kailasam
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Abstract
Polycarbonates containing low or undetectable levels of Fries rearrangement product may be prepared by the melt reaction of a dihydroxy aromatic compound such as bisphenol A with an ester-substituted diaryl carbonate such as the diaryl carbonate of methyl salicylate, bis-methyl salicyl carbonate. Low levels of Fries product are obtained as the combined result of a highly effective catalyst system which suppresses the Fries reaction and the use of lower melt polymerization temperatures relative to temperatures required for the analogous polymerization reaction using diphenyl carbonate.
Claims38
A method of preparing polycarbonate comprising heating a mixture comprising a catalyst;
- at least one diaryl carbonate having structure I
- wherein R1 and R2 are independently C1-C20 alkyl radicals, C4-C20 cycloalkyl radicals, or C4-C20 aromatic radicals, R3 and R4 are 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, or C1-C20 acylamino radical;
- and b and c are independently integers 0-4;
- and at least one dihydroxy aromatic compound;
- 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 10−5 and about 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.
A method of preparing bisphenol A polycarbonate comprising heating a mixture of bisphenol A with from about 0.8 to about 1.10 molar equivalents of bis-methyl salicyl carbonate at a temperature in a range between about 140° C. and about 240° C., and a pressure in a range between about 0.01 mmHg and about 760 mmHg, in the presence of a catalyst comprising sodium hydroxide and a quaternary ammonium compound or quaternary phosphonium compound, said sodium hydroxide being present in an amount in a range between about 1×10−5 and about 1×10−8 moles sodium hydroxide per mole starting bisphenol A, said quaternary ammonium compound or quaternary phosphonium compound being present in an amount between about 2.5×10−3 and about 2.5×10−6 moles per mole starting bisphenol A.
A method of preparing bisphenol A polycarbonate comprising heating a mixture of bisphenol A with from about 0.8 to about 1.10 molar equivalents, based on moles of bisphenol A, of bis-methyl salicyl carbonate, and about 0.1 mole percent to 10 mole percent based upon the number of moles of bisphenol A employed, of a monofunctional phenol, at a temperature in a range between about 140° C. and about 240° C., and a pressure in a range between about 0.01 mmHg and about 760 mmHg, in the presence of a catalyst comprising sodium hydroxide and a quaternary ammonium compound or quaternary phosphonium compound, said sodium hydroxide being present in an amount in a range between about 1×10−5 and about 1×10−8 moles sodium hydroxide per mole starting bisphenol A, said quaternary ammonium compound or quaternary phosphonium compound being present in an amount between about 2.5×10−3 and about 2.5×10−6 moles per mole starting bisphenol A.
Dependencies are inferred from the claim text.