Multimodal polymer of propylene, composition containing the same and a process for manufacturing the same

摘要

The present invention aims to provide a multimodal polymer of propylene comprising a matrix of semicrystalline polymer and a rubber (D) dispersed in said matrix, the multimodal polymer comprising units derived from propylene of from 85 to 99 % by weight and units derived from ethylene or C 4 to C 10 alpha-olefins of from 1 to 15 % by weight. The multimodal polymer has a fraction soluble in xylene XS at a temperature of 25 °C of from 7 to 16 % by weight, a melt flow rate MFR2 of from 0.05 to 5 g/10 min, a polydispersity index Pl of from 3.5 to 30, and a tensile modulus TM and XS meeting the relationship TM ‰¥ 2375 - 46.2.XS. Furthermore, the present invention aims to produce the above-mentioned multimodal polymer in a process comprising several reaction steps or zones. The compositions comprising the multimodal polymer of propylene have excellent stiffness combined with good impact strength at a low temperature.