FIELD: polymer coatings. SUBSTANCE: coating is accomplished by wrapping pipes by polyolefin composition in the form of film, tape or strip, optionally placing hot-melt adhesive, and heating thus obtained layer of polyolefin material: (i) 10-60 wt parts of polypropylene with isotacticity index above 90 or crystalline copolymer of propylene with ethylene and/or C4-C8-alpha-olefin containing more than 85 wt % propylene, or their mixtures, intrinsic viscosity of this component ranging from 0.5 to 3 dl/g in tetrahydrofuran at 135 C; (ii) 10-40 wt parts of ethylene-containing polypropylene fraction insoluble in xylene at room temperature (intrinsic viscosity 2-8 dl/g in tetrahydrofuran at 135 C); (iii) 30-60 wt parts of amorphous fraction of ethylene-propylene copolymer containing 1 to 10 wt % diene (1,4-hexadiene, 1,5-hexadiene, ethylidenenorbornen) soluble in xylene at room temperature and 40 to 70 wt % ethylene (intrinsic viscosity 2-8 dl/g in tetrahydrofuran at 135 C); total content of ethylene polymerized in composition varying between 20 and 60 wt %. Polyolefin composition is cross-linked by grafting, to main polyolefin chain, 1-3 wt % of alkenyl-substituted alkoxysilanes of general formula SiRn(OR′)4-n, wherein R is vinyl or allyl, R' C1-C8-alkyl, and n = 1,2 or 3, followed by interaction with water to achieve shrinkage of film less than 175% at 200 C and less than 15% at 23 C. EFFECT: increased mechanical and corrosive resistance and facilitated coating operation. 5 cl, 1 tbl, 5 ex
