CYCLOOLEFIN COPOLYMER FORMED BY RING-OPENING POLYMERIZATION, PROCESS FOR PRODUCING THE SAME, AND OPTICAL MATERIAL

摘要

A cycloolefin copolymer formed by ring-opening polymerization which is excellent in optical properties including transparency, is reduced in water (moisture) absorption, has high affinity for other materials, has satisfactory suitability for bonding, printing, and other processings after molding, and is excellent in heat resistance and mechanical strength. The cycloolefin copolymer formed by ring-opening polymerization comprises structural units (A) represented by the general formulae (1-1) to (1-3) and structural units (B) derived from a specific cycloolefin having an ester group, in a proportion of from 10/90 to 50/50 by mole. The monomers for obtaining the structural units (A) are tricyclomonoolefin compounds at least 80 mol% of which are accounted for by one or more endo compounds. The copolymer has a glass transition temperature of 120 to 250°C. General formula (1-1) General formula (1-2) General formula (1-3) [In the general formulae (1-1) to (1-3), R<1> to R<13> each represents hydrogen, halogeno, or a group selected among C1-4 alkyls and halogenated alkyls; and X<1> to X<3> each represents ethylene or vinylene.]