POLYETHYLENE COMPOSITION WITH HIGH RESISTANCE TO STRESS CRACKING Russian patent published in 2018 - IPC C08L23/04 C08L23/08 C08F210/02 

FIELD: chemistry.

SUBSTANCE: invention relates to a polyethylene composition for manufacturing of geomembranes by means of cast extrusion, extrusion with blowing or lamination, and to the the method for its production. Composition is characterized by the density from 0.930 up to 0.945 g/cm³, the MIF/MIP ratio from 10 up to less than 30, and the MIF value from 3 up to 25 g/10 min, where MIF is the melt flow index at 190 °C with the cargo weight of 21.60 kg, the MIP is the melt flow index at 190 °C with the cargo weight of 5 kg. In this case, the composition has the value of the z-average molecular weight (Mz) of not less than 1,500,000 g/mol and the long chain branching index (PCR) not exceeding 0.50 at the molecular weight M, which equals to 1,000,000 g/mol.

EFFECT: resulting composition has good manufacturability during processing and resistance to cracking under the environmental influence.

10 cl, 1 dwg, 1 tbl, 2 ex