POLYPROPYLENE COMPOSITION WITH IMPROVED SHOCK STRENGTH FOR APPLICATION IN PIPES Russian patent published in 2017 - IPC C08L23/14 C08F210/06 F16L9/12 

FIELD: chemistry.

SUBSTANCE: composition comprises a random copolymer of propylene with, at least, one comonomer selected from alpha-olefins with 2 or 4-8 carbon atoms. The random copolymer of propylene consists of, at least, a low molecular weight of propylene copolymer (low molecular weight (LMW) fraction) and a high molecular weight of propylene random copolymer (high molecular weight (HMW) fraction), wherein the weight average molecular weight of the low molecular weight fraction is lower than the weight average molecular weight of the high molecular weight fraction. The polypropylene composition has a melt flow rate (MFR₂) (2.16 kg, 230°C) of 0.05 to 1.0 g/10 min determined in accordance with ISO 1133, a polydispersity (PI) ratio of 2.0 to 7.0, and a Charlie impact toughness with a notched cut at 0°C of, at least, 6.5 kJ/m², determined in accordance with ISO 179/1eA: 2000.

EFFECT: polypropylene composition of the invention has an improved balance of mechanical properties and impact resistance.

16 cl, 2 tbl