Continuous polymerization of polycarbonates and removal of low-boiling by-products therefrom

Claim 1

IN THE METHOD OF CONTINUOUSLY PREPARING A POLYCARBONATE RESIN BY REACTION OF A DIHYDROXY AROMATIC ORGANIC COMPOUND WITH A MONOMERIC BIS(CARBONATE ESTER OF A DIHYDROXY COMPOUND AT A TEMPERATURE OF FROM ABOUT 200* C. TO ABOUT 325*C. AND A PRESSURE ABOVE 100 MILLIMETERS OF MERCURY IN A SUCCESSION OF ZONES, THE IMPROVEMENT WHICH COMPRISES (A) CONTINUOUSLY FEEDING A FLUID MIXTURE OF SAID REACTANTS INTO A FIRST REACTION ZONE WHEREIN SAID REACTANTS ARE CONVERTED INTO A REACTION MASS COMPOSED OF THE RESULTING MOLTEN POLYCARBONATE RESIN, LOWBOILING BY-PRODUCTS AND UNREACTED REACTANTS, (B) MAINTAINING SAID REACTANTS AND SAID POLYCARBONATE RESIN IN SAID REACTION MASS MOLTEN IN SAID FIRST REACTION ZONE AND AT A PRESSURE OF AT LEAST 100 MILLIMETERS TO SUPPRESS VOLATILIZATION OF SAID MONOMERIC BISCARBONATE ESTER;