DUAL CATALYTIC SYSTEM FOR PRODUCING LONG CHAIN BRANCHED HIGH-DENSITY POLYETHYLENES Russian patent published in 2023 - IPC C08F10/02 C08F210/16 C08F4/652 C08J5/18 

FIELD: polymers.

SUBSTANCE: invention relates to copolymers of ethylene with an alpha-olefin, where the alpha-olefin is selected from 1-butene, 1-hexene, 1-octene, or a combination thereof, as well as to industrial products containing such a copolymer. At the same time, the ethylene copolymer has: a melt flow index of 1 g/10 min or less, a density in the range from 0.93 to 0.965 g/cm³, the parameter CY-a at 190°C that is 0.2 or less, the average number of short chain branches (SCB) per 1000 atoms of all carbon atoms in an ethylene copolymer with a molecular weight in the range of 400,000 to 600,000 g/mol, which exceeds their number in a molecular weight in the range of 40,000 up to 60,000 g/mol, and the average number of long chain branches (LCB) per 1,000 atoms of all carbon atoms in an ethylene copolymer with a molecular weight in the range from 400,000 to 600,000 g/mol, which exceeds their number at a molecular weight in the range from 4,000,000 to 6,000,000 g/mol. Moreover, the specified ethylene copolymer has an average number of LCB in the range from 0.015 to 0.085 LCB per 1000 atoms of all carbon atoms at a molecular weight in the range from 400,000 to 600,000 g/mol. The average number of LCB in an ethylene copolymer can be from 0.01 to 0.06 long chain branches per 1000 atoms of all carbon atoms. The ethylene copolymer can be characterized by M_n in the range from 10,000 to 40,000 g/mol, M_w in the range from 100,000 to 300,000 g/mol, M_z in the range from 750,000 to 1,500,000 g/mol.

EFFECT: provision of ethylene copolymers characterized by improved dilution characteristics shear strength, melt strength and sleeve stability suitable for end applications such as pipe extrusion, blow moulding and blown film.

20 cl, 8 dwg, 5 tbl, 61 ex