PRESSURE PIPES AND POLYOLEFIN COMPOUNDS FOR THEIR PRODUCTION Russian patent published in 2014 - IPC B29C47/00 

FIELD: oil-and-gas industry.

SUBSTANCE: proposed pipe comprises heterophase polyolefin composition. This composition contains: 70-90 wt % of static copolymer of propylene with 0.5-6 wt % of 1-hexene and 10-30 wt % ethylene polymer with C₃-C₁₀ α-olefin and, optionally, diene. Note here that propylene polymer features the content of ethylene of 55-80 wt % and characteristic viscosity [η] of 3-5 dl/g. Note here that said characteristic viscosity [η] corresponds to the following expression: [η] < A*C, where C is the content of ethylene in wt % in its polymer while A is constant making 0.060.

EFFECT: higher strength, hardness and impact resistance at low temperatures.

6 cl, 4 tbl, 1 ex