PIPES WITH COATING HAVING IMPROVED MECHANICAL PROPERTIES AND METHOD OF THEIR MANUFACTURING Russian patent published in 2012 - IPC C09D123/06 C09D123/08 F16L58/10 

FIELD: construction.

SUBSTANCE: pipe comprises an inner surface, an outer surface layer (A) and a coating layer (B), coating the above outer surface layer (A). The coating layer (B) contains a coating composition (B-2), with a wear resistance ratio of 30 at the highest, and including a multimodal ethylene copolymer (B-1). The multimodal copolymer of ethylene (B-1) is a copolymer of ethylene and one or more alpha-olefin comonomers containing from 6 to 10 atoms of carbon and has an average weighted molecular mass from 70000 g/mole to 250000 g/mole, the melt index MFR2 determined in compliance with ISO 1133 at 190 °C and the load of 2.16 kg, from 0.05 g/10 min to 5 g/10 min, melt index MFR₅, determined in accordance with ISO 1133 at 190 °C and the load of 5 kg, from 0.5 to 10 g/min, density from 930 kg/m³ to 950 kg/m³ and the ratio of the average weighted molecular mass to the number average molecular weight, Mw/Mn, from 15 to 50.

EFFECT: coated pipes have improved mechanical properties, for instance, very high resistance to cracking under stress, pipes may be coated with high efficiency and good cost-effectiveness of production.

28 cl, 1 dwg, 2 tbl