| abstract |
PURPOSE: To obtain the titled copolymer narrow in an MW distribution and a composition distribution and excellent in transparency, heat resistance, chemical resistance, etc., by polymerizing ethylene with a cycloolefin monomer in the presence of a specified catalyst. 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 1W6 are each H, a halogen or a hydrocarbyl and n is 3W4) to obtain a cycloolefin random copolymer consisting of 40W90mol% ethylene-derived repeating nits and 60W10mol% 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 10W130°C and a crystallinity of 0W10% when measured by X-ray diffractometry. n COPYRIGHT: (C)1987,JPO&Japio |