Flexible compositions based on propylene polymers

• Main Authors: Mikielski, Raymond, Costa, Jean-Louis
• Format: Patent
• Language: English
• Published: 12.10.2004

The present invention relates to flexible compositions based on propylene polymers. More particularly, it concerns flexible compositions based on random copolymers of propylene and on plastomers having no elastomeric fractions. The flexible compositions having no elastomeric fractions comprise:A) from 10 to 90 parts by weight of random copolymer of propylene and at least one comonomer selected from ethylene and C-Calpha-olefins having a melting point of at least 100° C. and not exceeding 140° C. and a flow index measured at 230° C. under a weight of 2.16 kg (ASTM standard D1238, 1986) of from 0.5 to 15 g/10 min, andB) from 90 to 10 parts by weight of plastomer prepared with participation of a metallocene catalyst and consisting of a random copolymer of ethylene and at least one C-Calpha-olefin having a density of from 0.860 to 0.920 g/cm, a melt flow index measured at 190° C. under a weight of 2.16 kg (ASTM standard D1238, 1986) of from 0.5 to 30 g/10 min, and a molecular mass distribution M/Mof at most 4.These compositions provide an excellent compromise between flexibility and low-temperature impact resistance and heat resistance. They are suitable for producing flexible mouldings and very particularly for the manufacture by extrusion of films, of flexible sheeting, and of cables.