Process for producing cycloolefin random copolymer

摘要

A process for producing a cycloolefin random copolymer, which comprises (1) copolymerizing (a) ethylene or both ethylene and an alpha-olefin having at least 3 carbon atoms with (b) a cycloolefin such as octahydronaphthalenes and bicyclo[2,2,1]hept-2-ene in the presence of (c) a catalyst formed from a soluble vanadium compound and an organoaluminum compound at least one of which has halogen, in (d) a liquid phase composed of a hydrocarbon medium to form a solution of a cycloolefin random copolymer, and (2) contacting the resulting copolymer solution with (e) an adsorbent containing a metal cation.