| 摘要 |
PURPOSE:To continuously produce the methacrylate polymer extruded sheet with excellent resistance to heat decomposition and uniform quality by a method wherein mixture of radical polymerization initiator and monomers containing mercaptan is continuously bulk-polymerized and, after volatile matters therein being removed by separation, molded by extrusion and rolling. CONSTITUTION:The monomer mixture containing methyl methacrylate, alkyl acrylate or alkyl methacrylate (excluding methyl methacrylate), 0.01-10wt% mercaptan, and the radical polymerization initiator, the amount of which satisfies the formulae described here, is continuously fed to a reactor. Polymerization is performed while the reaction mixture being uniformly mixed by stirring at a temperature in the range of 130-200 deg.C and at the same time the viscosity of the reaction mixture being maintained at a fixed value in the range of 10-500 poises. After that, the reaction mixture is continuously taken out of the reactor and yet the polymer and the unreacted monomer are separated from each other at a volatile eliminating extruder. Finally, the separated polymer is extruded from the extruder die in order to be formed in a sheet. Di-tert-butyl peroxide or the like is employed as the radical polymerization initiator. |
