Process for preparing vinyl chloride polymer under specified vapor pressure

摘要

A vinyl chloride polymer is prepared through suspension polymerization of a vinyl chloride monomer in the presence of a polymerization initiator in a reactor. The reactor is charged with up to +E,fra 4/5+EE of the overall monomer charge to initiate polymerization. Polymerization is carried out under a certain saturated vapor pressure of P1 kgf/cm2 at a preset polymerization temperature. When the internal pressure of the reactor declines to P2 kgf/cm2, the remainder of the overall monomer charge is continuously fed to the reactor so as to maintain the internal pressure within the range of (P1- DELTA P) wherein DELTA P=P1-P2 ranges from 0.1 to 2.0 kgf/cm2. A vinyl chloride polymer having a high degree of polymerization is efficiently produced while alleviating the load of heat removal.