| 摘要 |
Olefin polymer composition comprising (by weight, unless otherwise specified): A) 60-95% of a propylene homopolymer or copoloymer having a Polydispersity Index (P.I.) value of from 4.6 to 10 and a content of isotactic pentads (mmmm), measured by 13C NMR on the fraction insoluble in xylene at 25° C., higher than 98 molar, B) 5-40% of a copolymer of ethylene containing from 40% to 70% of propylene or C4-C10 alpha-olefins) or of combinations thereof, and optionally minor proportions of a diene; said composition having a Temperature Rising Elution Fractionation (TREF) profile, obtained by fractionation in xylene and collection of fractions at temperatures of 40° C., 80° C. and 90° C., in which the ethylene content Y of the fraction collected at 90° C. satisfies the following relation (1): Y<=-0.8+0.035X+0.0091X2 wherein X is the ethylene content of the fraction collected at 40° C. and both X and Y are expressed in percent by weight, and a value of intrinsic viscosity [eta] of the fraction soluble in xylene at 25° C. of from 1.8 to 4.2 dl/g. |
