Preparation of poly(ester carbonate) by interfacial method

Claim 1

An interfacial process of producing a substantially amorphous, melt processible poly(ester carbonate) which comprises: (1) mixing with an aqueous bisphenolate solution having a pH of at least about 8, (a) phosgene and (b) an organic solution of an acid halide which solution is immiscible with the aqueous bisphenolate solution, at a temperature and for a sufficient time and under sufficient agitation to react said phosgene and said acid halide with said bisphenolate to form an amorphous polymer, said aqueous bisphenolate being an alkali metal or alkaline earth metal salt of at least one bisphenol of the formula ##STR4## where R is alkylene of 1-4 carbons, --O--, --S--, --SO 2 --, --CO-- or a single bond, and R' is independently at each occurrence, H, Cl, Br, F, alkyl, phenyl or halogenated alkyl; said acid halide being at least one compound of the formula ##STR5## with X being Cl or Br, the acid halides being meta or para or 2,6 or 2,7 and R" being independently at each occurrence, H, Cl, Br, F, alkyl, phenyl or halogenated alkyl; the overall molar ratio of phosgene to acid halide being between about 0.2:1 and about 20:1; the molar ratio of bisphenolate to acid halide plus phosgene being between about 1:1 and about 1.0:1.2; and at least about 20% of phosgene as a mole percentage of the acid halide being mixed with the aqueous bisphenolate no later than the mixing of the acid halide with the bisphenolate; (2) separating the aqueous phase and the organic phase; (3) washing the organic phase with aqueous liquid; and (4) recovering the substantially amorphous, melt processable poly(ester carbonate) polymer from the washed organic phase.