POLYETHYLENE COMPOSITIONS, PRODUCTION METHODS THEREOF AND ARTICLES MADE THEREFROM Russian patent published in 2012 - IPC C08L23/08 C08J5/00 C08F2/00 C08F210/02 F16L9/12 

FIELD: chemistry.

SUBSTANCE: composition contains a mixture of a high-molecular weight ethylene-based interpolymer and a low-molecular weight ethylene-based interpolymer. The high-molecular weight ethylene-based interpolymer is a heterogeneously branched linear or homogeneously branched linear interpolymer of ethylene and C3-C20 α-olefins and has density from 0.922 g/cm³ to 0.929 g/cm³ and flow melt index at high load I₂₁ from 0.2 g/10 min to 1.0 g/10 min. The low-molecular weight ethylene-based interpolymer is a heterogeneously branched linear or homogeneously branched linear interpolymer of ethylene and C3-C20 α-olefins and has density from 0.940 g/cm³ to 0.955 g/cm³ and flow melt index I₂ from 6 g/10 min to 50 g/10 min. The mixture has a single peak on the ATREF curve during elution at higher than 30°C and has viscosity average molecular weight coefficient (CMν) less than -0.0032 in log(calculated Mν) - elution temperature coordinates, where said CMν is calculated at elution temperature from 70°C to 90°C, and where Mν is the viscosity average molecular weight.

EFFECT: disclosed composition enables to obtain articles having a combination of high ESCR, SCG and lasting breaking strength during action of constant internal pressure at high temperature.

69 cl, 33 dwg, 64 tbl