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View Prior Art for Claim 00019

The method of Claim 18, wherein the cyclic monomer has the general structure (14):

wherein Y independently represents O, S, NH or NR″; X′ represents O, S, NH, or NR″; each R′ independently represents a hydrogen, a halide, an alkyl group comprising 1 to 20 carbons, an ester group comprising 1 to 20 carbons, an amide groups comprising 1 to 20 carbons, an aryl group comprising 1 to 20 carbons, or an alkoxy group comprising 1 to 20 carbons; each R″ in Y and X′ independently represents an alkyl group comprising 1 to 20 carbons or an aryl group comprising 1 to 20 carbons; R′″ represents an alkyl group comprising 1 to 20 carbons, or an aryl group comprising 1 to 20 carbons; and z is 0 or 1.

#693Cyclic polycarbonate oligomers and methods for their preparation and use

Applies to Claims 1,13,14,15,18,19,3,4,5

Submitted by: Shaojun YaoLast updated: over 2 years ago

Patent/Application # 4644053

Description

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 alkaili 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.

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