| 摘要 |
Using a catalyst comprising (1) a solid substance which contains magnesium and titanium, (2) an organometallic compound and (3) an electron donor, there are polymerized ethylene, propylene and 1-butene to obtain a soft or semi-hard terpolymer of low crystallinity containing 75.2 to 91.5 mol % propylene, 7.5 to 14.9 mol % ethylene and 1.0 to 9.9 mol % 1-butene. |
