OBTAINING POLYOLEFIN PRODUCTS Russian patent published in 2022 - IPC C08F210/16 C08F4/6592 

FIELD: chemical or physical processes.

SUBSTANCE: invention relates to methods of producing polyolefins and used catalyst systems. Disclosed is a method for polymerising olefins to obtain a polyolefin polymer with a multimodal composition distribution, involving contacting ethylene and a comonomer, which is C₃-C₁₆ alpha-olefin, with a catalyst system in a gas-phase or suspension polymerisation reactor. Catalyst system comprises a first catalyst compound and a second catalyst compound, which are deposited on a common substrate to form a catalyst system on a common substrate. First catalytic compound contains a compound of general formula (C₅H_aR¹_b)(C₅H_cR²_d)HfX₂, where each R¹ or R² is independently H or a hydrocarbon group, at least one R¹ and at least one R² is a hydrocarbon group, a and c≥3; a+b = c+d = 5 and each X independently represents a hydrocarbon group. Second catalytic compound contains a compound of formula (1), where each R³ or R⁴ independently represents H or a hydrocarbon group, where each R³ or R⁴ can be the same or different, and each X is a hydrocarbon group. (1).

EFFECT: disclosed method enables to obtain polyolefins with improved physical characteristics, such as strength and resistance to environmental cracking.

16 cl, 4 dwg, 11 tbl