| abstract |
PURPOSE: To obtain the titled copolymer narrow in an MW distribution and a composition distribution and excellent in heat resistance, transparency, chemical resistance, etc., by copolymerizing ethylene with a specified cycloolefin. n CONSTITUTION: While the concentration of a soluble vanadium compound (a) fed to the polymerization system is kept at a value which is at least ten times the concentration of component (a) in the polymerization system and the ratio of Al to V (Al/V) in the polymerization system is kept at 2 or larger, the component (a) and an organoaluminum component (b) are fed continuously to the system and 1W99mol% ethylene is copolymerized with 99W1mol% cycloolefin of formula I or II (wherein R 1W10 are each H, a halogen, a hydrocarbon group, n and m are positive integers, and l≥3) to obtain a cycloolefin random copolymer consisting of 40W97mol% ethylene-derived repeating units and 60W3mol% cycloolefin-derived repeating units of formula III or IV and having an intrinsic viscosity of 0.01W20dl/g when measured in decalin at 135°C, an MW distribution ≤4 when measured by gel permeation chromatography, a glass transition temperature of 10W24°C and a crystallinity of 0W10% when measured by X-ray diffractometry. n COPYRIGHT: (C)1987,JPO&Japio |