| 摘要 |
PURPOSE:To obtain the titled novel copolymer having specific composition, intrinsic viscosity and crystallinity, high dynamic modulus and loss tangent, useful as a vibration damping material, and composed of propylene, 1-butene and an alpha-olefin having higher carbon number than the above. CONSTITUTION:A monomer mixture composed of (A) 10-85mol% propylene, (B) 3-60mol% 1-butene and (C) 10-85mol% 5-12C alpha-olefin (e.g. 4-methyl-1-pentene) is polymerized in the presence of a catalyst composed of e.g. TiCl4 supported on anhydrous magnesium chloride, etc. to obtain a copolymer having an intrinsic viscosity [eta] of 0.5-6.0dl/g measured at 135 deg.C in decalin, crystallinith of <=20% measured by X-ray diffraction, dynamic modulus [E'] of 5X10<7>-5X10<9>dyn/cm<2> at 25 deg.C, loss tangent [tandelta] of <=0.4, content of boiling n-heptane-insoluble fraction of <=5.0% and content of acetone-soluble fraction of <=3.0wt%. |
