| 摘要 |
PURPOSE:To improve transparency, chemical reactivity, cross-linkability, etc., by randomly copolymerizing propylene, butene-1, and a nonconjugated diene in such a way that the resulting copolymer is given a ratio of components, an intrinsic viscosity, a crystallinity, a max. endothermic point, etc., each in a specified range. CONSTITUTION:Propylene, butene-1, and a nonconjugated diene of the formula (wherein R<1> is 1-4C alkyl; and R<2> and R<3> are each H or R<1> provided that at least one of them is R<1>) are randomly copolymerized in the presence of a catalyst comprising a Ti catalyst component contg. Mg, Ti, a halogen, and an electron donor, an organoaluminum compd. as a catalyst component, and an electron donor catalyst component, giving a propylene copolymer having a molar ratio of the propylene units to the butene-1 units of (90:10)-(60:40), a content of the diene units of 0.05-10mol%, an intrinsic viscosity (135 deg.C, in decalin) of 0.5-6.0dl/g, a crystallinity (by X-ray diffraction) of 50% or lower, a max. endothermic point (by differential scanning calorimetry) of 30-140 deg.C, and a content of boiling r-heptane insolubles of 5wt.% or lower. |
