Process for preparing heat-resistant resins

摘要

A polymer produced through ring opening of a 5-norbornene-2-carboxylate ester or a derivative thereof is dissolved in an organic solvent miscible with water and is subjected to hydrolysis by addition thereto of an alkali substance until at least a portion of the polymer is separated out. Then, water is added to the reaction mixture to dissolve the separated-out polymer, and the resulting solution is again subjected to hydrolysis treatment, which is followed by addition thereto of an acid to neutralize the resulting hydrolyzate. Thus, a polymer resin having excellent thermal resistance or a polymer resin of improved color shade or transparency can be obtained.