Non-catalyzed interfacial polycondensation polycarbonate process
AssigneeGeneral Electric Company
InventorSubhas K. Sikdar
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Abstract
This invention relates to a non-catalyzed equilibrated interfacial polycondensation aromatic polycarbonate process comprising forming an equilibrated substantially uniform agitated two-phase admixture containing an organic phase containing an inert solvent, and an aqueous phase containing a solution of an aromatic dihydroxy compound and a strong base, adding and reacting a carbonyl halide with the aromatic dihydroxy compound to form an aromatic polycarbonate, and separating and recovering the solid aromatic polycarbonate particulate from the liquid aqueous phase.
Claims10
An improved interfacial polycondensation polycarbonate process wherein at least one dihydric phenol is reacted with a carbonyl halide the improvement comprising performing the process in the absence of a polycondensation catalyst and in accordance with the following process sequence and parameters:
- (1) forming an equilibrated substantially uniform agitated two-phase admixture containing
- (i) an organic phase containing an inert solvent,
- (ii) an aqueous phase containing dissolved therein an aromatic dihydroxy compound, a strong base, and having a pH of at least about 11, subject to the proviso that,
- (a) the volume ratio of inert organic solvent phase to aqueous phase is within the range of from 0.04:1 to 0.20:1, and
- (b) the mol ratio of base to aromatic dihydroxy compound is at least about 0.25:1,
- (2) adding and reacting a carbonyl halide with the aromatic dihydroxy compound to form an aromatic polycarbonate having a M.sub.w of at least about 2000 as determined by gel permeation chromatography and an M.sub.w /M.sub.n of less than about 6.0,
- and
- (3) separating and recovering the solid aromatic polycarbonate particulate from the liquid aqueous phase.
Dependencies are inferred from the claim text.