POLYETHYLENE COMPOSITION FOR OUTER COATING LAYER OF STEEL PIPES Russian patent published in 2016 - IPC C08L23/06 C08L23/08 C08L23/16 C08L23/20 C08L9/00 C09D123/00 

FIELD: chemistry.

SUBSTANCE: invention relates to a polyethylene composition for external layer of coating of steel pipes. Composition contains HDPE, which is an ethylene homopolymer and/or copolymer of ethylene with alpha-olefin with density of 0.940 to 0.964 g/cm³, LDPE, which is a branched high-pressure polyethylene with density of 0.91 to 0.925 g/cm³, or a copolymer of ethylene with alpha-olefin with density of 0.904 to 0.935 g/cm³, or a copolymer of ethylene with vinyl acetate containing from 5 to 30 wt% vinyl acetate groups and having density of 0.925-0.955 g/cm³. Furthermore, composition contains a synthetic elastomer and/or synthetic rubber.

EFFECT: use of such composition enables to obtain coatings on steel pipes with cold-resistant properties at temperatures lower than -45 °C and improved physical and mechanical properties, such as strength properties, and resistance to cracking in aggressive environment, as well as high resistance to indentation.

1 cl, 5 tbl, 56 ex