| abstract |
The present invention relates to a method of (co) polymerizing a monomer containing at least an acrylonitrile-based monomer as an essential component at a temperature of 80 ° C or higher while evaporating the monomer by bulk or solution polymerization, wherein When the gas phase portion is formed on the upper side, the temperature of the gas phase is maintained at 30 ° C. to 65 ° C., and the polymerization of the (co) polymer is carried out substantially without evaporating vapor from the lower polymerization solution to the reaction tank. By providing the manufacturing method, by the method of the present invention, by cooling the gas phase part of the reaction tank and maintaining at a specific temperature, polymerization of the unreacted monomer in the gas phase part is suppressed, and the gelled polymer is not incorporated into the product. Moreover, the heat of reaction at the time of superposition | polymerization can be removed efficiently. |