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AssigneeGeneral Electric Company
InventorsSwaminathan Sivaram, Sukhendu Bikash Hait
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This invention involves a novel process for preparing branched polycarbonates employing a solid state polycondensation process; specifically, subjecting a linear crystallized oligomer derived from dihydroxydiaryl compound and a diaryl carbonate to solid state polycondensation process by heating the said oligomer at a temperature which is higher than the glass transition temperature but below its melting point in the presence of a multifunctional phenol and an alkali or alkaline metal salt or bisphenol or tetraalkylammonium hydroxide, carboxylate or bicarboxylate catalyst, the reaction being effected under inert atmosphere.
A process for the preparation of branched polycarbonates which comprises subjecting a linear crystallised polycarbonate oligomer prepared by reaction of a dihydroxydiaryl compound with a diaryl carbonate to solid state polycondensation by heating said oligomer at a temperature higher than its glass transition temperature but below its melting point, in the presence of a multifunctional phenol and an alkali or alkaline metal salt of a bisphenol or a tetraalkylammonium hydroxide, carboxylate or bicarboxylate as catalyst, said polycondensation being effected in an inert atmosphere.
Dependencies are inferred from the claim text.