Acrylonitrile (co)polymerization while regulating temperature of vapor phase

摘要

A process for the (co)polymerization of a monomer material, which includes at least an acrylonitrile monomer as an essential component, at a temperature of 80 DEG C. or higher by bulk or solution polymerization while allowing said monomer material to evaporate. The (co)polymerization is conducted while providing a vapor phase over a polymerization mixture in a reaction tank. During the (co)polymerization, the temperature of the vapor phase is maintained in a range of from 30 DEG C. to 65 DEG C. so that the polymerization is conducted without substantially releasing vapor, which is evaporated from the polymerization mixture, to outside of the reaction tank. By cooling the vapor phase of the reaction tank and maintaining its temperature in the above specific range in accordance with the present invention, it is possible to avoid mixing of a gelled polymer in a product and also to effectively remove reaction heat at the time of the (co)polymerization.