Heat-curable and solvent-soluble ester group-containing polymer compositions and process for their preparation

摘要

A heat-curable and solvent-soluble ester group-containing polymer composition is prepared by the steps of: (1) either (i) reacting a highly polymerized linear aromatic polyester with a diaryl carbonate to depolymerize it to a solvent-soluble low-molecular-weight polyester (component A) containing terminal aryl carboxylate groups, or (ii) effecting the above depolymerization in the presence of a compound containing at least two specified functional groups thereby to form a modified solvent-soluble low-molecular-weight polyester (component A') containing terminal aryl carboxylate groups; and (2) either (i) mixing the resulting component A or A' with a monomeric or solvent-soluble polymeric, polyfunctional compound (component B) containing at least two hydroxyl and/or primary or secondary amino groups or (ii) partially reacting the resulting component A or A' with the component B. The composition has superior workability in molding and curing, and gives cured molded products of high utilitarian value. It is especially suitable for use in wire enamelling varnishes.