| 摘要 |
PURPOSE:To enable high-yield production of the title copolymer which has a homogeneous composition and is suitably used as an optical material such as optical memory disks by liquid-phase copolymerization of ethylene with a specific cyclic olefin in the presence of a specific catalyst. CONSTITUTION:In the presence of a catalyst prepared from (A) a soluble vanadium compound having a tert.-alkoxy or beta-diketone as a ligand and (B) an organoaluminum compound of the formula: (i-Bu)nAlCl3-n (n is 1 to 2.5), the liquid-phase copolymerization of ethylene and a cyclic olefin of formula I (R<1> to R<18>, R<a>, R<b> are H, halogen, or the like; n, q are 0 or 1; m is 0 or a positive integer) or II (R<1> to R<19> are H, alkoxy; p, q are 0, 1 or higher positive integer; m, n are 0 to 2), when needed, additionally an alpha-olefin of 3 to 20 carbon atoms, is carried out to give the objective copolymer including 40 to 97 mole % of ethylene-originating units, 3 to 60 mole % of cyclic olefin-originating units and 0 to 20 mole % of the units originating from the alpha-olefin. |
