| abstract |
A process is provided for making high molecular weight halosubstituted aromatic polycarbonates in a phase boundary reaction in which an o,o,o'',o''-tetrahalogenobisphenol and phosgene are reacted in an aqueous medium at a pH of 7 to 9 in the presence of from 2 mol% to 20 mol% catalyst in a first step and the resulting product is polycondensed at a pH of at least about 13 in a second step. |