COMPOSITION OF MULTIMODAL POLYPROPYLENE FOR APPLICATION IN PIPES Russian patent published in 2017 - IPC C08L23/14 C08F210/06 F16L9/12 

FIELD: chemistry.

SUBSTANCE: composition contains a multimodal copolymer of propylene (U), which comprises 75 to 98 wt % of a random propylene copolymer composition (X) and 2 to 25 wt % of a propylene copolymer (Y). Moreover, the composition of multimodal polypropylene (U) has a melt flow rate MFR2 (2.16 kg, 230°C) of 0.25 to 1.00 g/10 min, determined in accordance with ISO 1133, the content of soluble in cold xylene substances (XCS) of 4.0 to 17.0 wt % determined at 25°C in accordance with ISO 16152, and the polydispersity coefficient PI of 2.5 to 4.0 Pa^-1 determined by means of rheological measurements in accordance with ISO 6721-1 and ISO 6721-10.

EFFECT: resulting multimodal polypropylene alpha-olefin composition exhibits good impact resistance, stiffness, creep resistance and slow cracking properties and a long-term resistance to pressure.

25 cl, 1 dwg, 3 tbl