Cyclic polycarbonate oligomers and methods for their preparation and use
AssigneeGeneral Electric Company
InventorsDaniel J. Brunelle, Thomas L. Evans, Thomas G. Shannon, David A. Williams
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Abstract
Cyclic polycarbonate (or thiol analog) oligomer mixtures are prepared by the reaction of bishaloformates or their thio analogs or mixtures thereof with dihydroxy or dimercapto compounds, with alkali metal hydroxides and various amines. The oligomer mixtures may be converted to polycarbonates or their thiol analogs by a method which is particularly adaptable to integration with polycarbonate processing operations.
Claims13
A composition consisting essentially of a mixture of cyclic oligomers having varying degrees of polymerization from 2 to about 30, the structural units in said oligomers having the formula ##STR4## at least about 60% of the total number of R values in said composition being aromatic and the balance of the R values being aliphatic, alicyclic or aromatic.
Dependencies are inferred from the claim text.