HYDROGENATED RING-OPENING POLYMER

摘要

A thermoplastic norbornene resin having the number-average molecular weight (Mn) of at least 12,000 (in terms of polyisoprene) as measured by gel permeation chromatography and being lowly birefrigent and excellent in the resistance to oils and greases is obtained by subjecting polycyclic norbornene monomers containing at least 70 % by weight of a norbornene monomer represented by general formula (I) (for example, 1,4-methano-1,4,4a, 9a-tetrahydrofluorene) to ring-opening polymerization and then hydrogenating the obtained polymer in such a manner as to give the hydrogenation ratio of the double bond in the main chain of at least 98 % and the hydrogenation ratio of the six-membered ring structure of at least 90 %, wherein the lowermost 6-membered ring may have a double bond.