MULTIMODAL POLYETHYLENE FILM Russian patent published in 2021 - IPC C08L23/04 C08L23/06 C08J5/18 

FIELD: chemical industry.

SUBSTANCE: invention relates to a multimodal polyethylene composition for molding, in particular for films or geomembranes. The composition includes: (A) from 40 to 65% by weight of low molecular weight polyethylene having weighted average molecular weight (Mw) from 20,000 to 90,000 g/mol, wherein low molecular weight polyethylene has a MI₂ value from 500 to 1000 g/10 min according to ASTM D 1238 standard, (B) from 5 to 17% by weight of ultra-high molecular weight polyethylene having weighted average molecular weight (Mw) from more than 1,000,000 to 5,000,000 g/mol, and (C) from 30 to 50% by weight of high molecular weight polyethylene, having weighted average molecular weight (Mw) from more than 150,000 to 1,000,000 g/mol. The density of ultra-high molecular weight polyethylene and high molecular weight polyethylene is in the same range, and both densities are in the range from 0.910 to 0.940 g/cm³. The molecular weight distribution of the multimodal polyethylene composition is from 22 to 24 as measured by gel-penetrating chromatography, and the multimodal polyethylene composition has a MI₂ value from 0.03 to 0.10 g/10 min. Film including a multimodal polyethylene composition, where film is characterized by thickness from 40 to 120 mcm, and the use of film as a product selected from a group consisting of an industrial bag and geomembrane are also described.

EFFECT: improvement in performance and mechanical properties, including the piercing strength by dropping a piercing object and the tensile strength for industrial film and geomembrane.

9 cl, 2 tbl, 4 ex