Method for producing crystalline methacrylic resin and plastic foam

Abstract

Provided are a method for producing a crystalline methacrylic resin, the method comprising a step of bringing a mixture of an isotactic methyl methacrylate-type polymer and a syndiotactic methyl methacrylate-type polymer into contact with high pressure gas and a method for producing a plastic foam of the crystalline methacrylic resin, the method comprising a step of foaming the mixture. According to the method of the present invention, a crystalline methacrylic resin which is not limited in a form applicable to molded articles thereof and has high crystallinity and excellent solvent resistance can be obtained in a simple method and a plastic foam of the crystalline methacrylic resin can be obtained, the plastic foam embracing fine cells having an average cell diameter of about 10 μm or less and a cell number density of 109 to 1015 cells/cm3. Such a plastic foam is superior in the solvent resistance and in the mechanical properties such as impact resistance and bending strength.

Dependencies are inferred from the claim text.