PIPES MADE OF PROPYLENE-BASED POLYMERS FOR PIPELINES Russian patent published in 2006 - IPC C08L23/10 C08F110/06 C08F297/08 F16L9/12 C08K5/20 C08K5/09 C08K5/3415 C08K5/3417 C08K5/3437 F16L9/127 F16L9/133 B32B1/08 B32B37/04 

FIELD: polymer chemistry.

SUBSTANCE: invention relates to mono- or multilayered pipes and parts thereof made of propylene-based polymers for pipelines comprising propylene homopolymer having flow melt index from 0.05-8 g/10 min at 230°C/2.16 kg or propylene block-copolymer containing 90.0-99.9 mass % of propylene units and 0.1-10.0 mass % of C₂- or C₄-C₁₈ α-olefin units having flow melt index from 0.05-8 g/10 min at 230°C/2.16 kg or mixtures thereof, wherein propylene polymers or propylene block-copolymers represent propylene polymers with crystal-nucleating agents in β-form hawing IRτ >=0.97. Pipelines made of propylene homopolymers with crystal-nucleating agents in β-form have fast crack spreading with critical temperature from -25 to 0°C and critical pressure of >=3 bar below critical temperature; and pipelines made of propylene block-copolymers with crystal-nucleating agents in β-form have fast crack spreading with critical temperature from -5 to +40°C and critical pressure of >=3 bar below critical temperature. Also disclosed is method for pipe production from propylene homopolymers or propylene block-copolymers by extrusion or injection molding. Pipelined of present invention are useful in conveyance of fluid media and fluid media under pressure.

EFFECT: pipes of improved cracking resistance.

4 ex, 3 cl