| 摘要 |
PURPOSE: To efficiently manufacture acrylic polymer having high molecular weight, narrow molecular weight distribution and highly cohesive force by heating acrylic monomer in a screw extruder, bulk polymerizing it, and removing the residual monomer while holding the temperature of the polymer at a specific temperature. CONSTITUTION: Heat polymerizable composition to be used includes acrylic monomer and pyrolytic radical polymerization initiator. Acrylic polymer is obtained by the steps of heating in a screw extruder (A) to bulk polymerize it to obtain polymer having 90wt.% or less of monomer conversion rate, introducing the polymer to a plurality of screw extruders (B) each having vacuum venting function, holding the temperature of the polymer in the extruders (B) to the temperature (TA) of the polymer immediately after the discharge from the extruder (A) at (TA-30)-(TA+40) deg.C, and removing the residual acrylic monomer. |
