A process for producing vinyl chloride resin.

摘要

The present invention provides a process for producing vinyl chloride resin in suspension polymerization of vinyl chloride monomer by the use of a polymerization reactor equipped with a reflux condenser wherein a nonionic surface active agent having HLB value of 6-14 is added upon initial charging of reactants, polymerization is started in a range of 0.8 to 1.0 of the water/monomer ratio, polymerization temperature is raised 3 to 10 °C at polymer conversion being not more than 50 weight percent, with water being added in the course of polymerization not more than making up for the volumetrical contraction resulting from the progress of polymerization so that upon completion of polymerization the water/monomer ratio is controlled in a range of 1.0 to 1.4. The polyvinyl chloride resin obtained by the present process is superior in quality such as high bulk density and little fish eye with high productivity.