Aromatic polycarbonate polymers with uniform constant soln. viscosity - prepd. by 2-phase boundary surface method operated continuously, providing long prodn. runs

摘要

In continuous process for prodn. of polycarbonates (I) from diphenols, phosgene, opt. chain-terminating agents, catalyst, and opt. branching agents in mixt. of aq.-alkaline and organic solvent phases, effects of changes in amt. and concn. of materials charged on relative viscosity of (I) are detected and are used to regulate charging in of the materials, taking into account the time delay between charging and the effect of that charging on the relative viscosity. ADVANTAGE - (I) with uniform constant soln. viscosity are obtd. over long prodn. runs, even at start up and termination of reaction and with change of prod. typ