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 low-density polyethylene, a method for producing linear bimodal low-density polyethylene, a product, a method for coating substance, and a method for coating a product. This composition contains a polyethylene component with lower molecular weight (hereinafter – LMW) and a polyethylene component with higher molecular weight (hereinafter – HMW), while each of LMW and HMW polyethylene components contains monomeric links derived from ethylene and comonomeric links formed of alpha-olefins (C₃-C₂₀). This method includes bringing into contact 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 of activator molecules, a non-metallocene complex of a ligand with group 4 metal and a metallocene complex of a ligand with group 4 metal, 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 linear bimodal low-density polyethylene that is easier to process and has improved rigidity.

14 cl, 3 dwg, 3 tbl, 2 ex