| abstract |
A cyclic olefin ring-opening polymer having a high refractive index and Abbe number, having solubility in a solvent, and useful for optical materials, and capable of dispersing a hydrogenated body thereof and a compounding agent represented by a rubbery polymer, the cyclic olefin The ring-opening polymer is obtained by ring-opening copolymerization of a cyclic olefin monomer mixture comprising 3 to 5 monomers of cyclopentadiene, wherein 3 to 5 monomers of cyclopentadiene are the geometric isomers (2) in each case of n = 1 to 3 It contains 55% or more of the compound. |