POLYETHYLENE COMPOSITION Russian patent published in 2021 - IPC C08L23/08 C08F210/02 C08F210/16 C08F10/02 

FIELD: chemistry.

SUBSTANCE: present invention relates to a composition of linear bimodal polyethylene of medium density for the manufacture of products, a method for obtaining a composition of linear bimodal polyethylene of medium density from 0.930 to 0.950 g/cm³ and a product. This composition is obtained by copolymerization of ethylene (monomer) and at least one alpha-olefin (C₃-C₂₀) (comonomer) with a mixture of a bimodal catalytic system and a trimming solution in the presence of molecular gaseous hydrogen and an inert condensing agent (ICA) in one, two or more polymerization reactors under (co)polymerization conditions. Before mixing, the trimming solution consists of a complex of (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium and an inert liquid solvent. The bimodal catalytic system consists essentially of activator molecules, a complex of bis(2-pentamethylphenylamido)ethyl)amine zirconium and a complex of (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium, all of which are located on a solid carrier. The reaction temperature is from 80°C to 110°C. The molar ratio of gaseous molecular hydrogen to ethylene is from 0.001 to 0.050. The molar ratio of comonomer to ethylene is from 0.005 to 0.10.

EFFECT: development of an easier-to-process linear bimodal medium-density polyethylene with improved rigidity; the resulting film has high instant impact strength and high tensile strength.

13 cl, 2 dwg, 3 tbl, 2 ex