POLYOLEFIN POLYMER COMPOSITION AND METHOD FOR PRODUCTION THEREOF Russian patent published in 2021 - IPC C08F210/16 C08F2/01 C08F2/38 C08F4/659 C08F4/6592 

FIELD: polymers.

SUBSTANCE: present invention relates to a polyolefin polymer and a method for producing a polyolefin polymer. The polyolefin polymer exhibits the following properties: the melt flow index is from 0.1 to 1.5 g/10 min; the density is from 0.91 to 0.93 g/cm³; the polydispersity index is from 3 to 7; Mz/Mw is from 2.3 to 4.5; the COI value is from 5 to 12; when restoring the TREF curve of multimodal distribution from a convolution, the area under the TREF curve with a peak at a temperature from 60°C to 70°C is from 40% to 65% of the total area under the TREF curve of multimodal distribution. The method includes the stages of: introducing a metallocene hafnium-based catalyst on a carrier, ethylene, and alpha-olefin into a reactor selected from the group consisting of a reactor for conducting polymerisation in suspension and a gas phase polymerisation reactor, and then conducting polymerisation for the purpose of obtaining a first polymer with an Ml of 4 to 15 and density of 0.925 to 0.940 g/cm³; introducing the metallocene hafnium-based catalyst on a carrier, ethylene and alpha-olefin into another reactor selected from the group consisting of a reactor for conducting polymerisation in suspension and a gas phase polymerisation reactor, and then conducting polymerisation for the purpose of obtaining a second polymer with an Ml of 0.1 to 0.5 and density of 0.900 to 0.915 g/cm³; and mixing the polymerised first polymer component and second polymer component in a melt to obtain a polyolefin polymer.

EFFECT: production of a stretchable film, overlapping film, high-strength film, etc., which must exhibit high impact strength, by applying a polyolefin polymer with a suitable molecular weight distribution and a new structural composition with BOCD.

7 cl, 6 dwg, 2 tbl, 20 ex