POLYOLEFIN COMPOSITION WITH IMPROVED IMPACT STRENGTH AND BLUSHING RESISTANCE Russian patent published in 2022 - IPC C08L23/12 C08L23/16 

FIELD: polymers.

SUBSTANCE: present invention relates to polyolefin compositions with high impact strength and fine blushing resistance. Invention relates to the following group of inventions: a polymer composition for use in packaging and an article. The polymer composition includes 95.0 to 70.0 wt.% heterophase propylene copolymer (HPPC) and 5.0 to 30.0 wt.% bi- or multimodal polyethylene (mPE). The heterophase propylene copolymer includes 70.0 to 90.0 wt.% polypropylene matrix (M) and 10.0 to 30.0 wt.% elastomeric propylene copolymer (EPC) dispersed in said matrix (M). The content of an ethylene comonomer in the polypropylene matrix (M) is within 0.0 to 5.0 wt.%. The content of a xylene-soluble fraction of the polypropylene matrix (M) is 1.0 wt.% to 3.0 wt.%. The melt flow index MFI₂ (2.16 kg, 230°C) of the polypropylene matrix (M) is 0.3 to 30.0 g/10 min. The HPPC has a melt flow index MFI₂ (2.16 kg, 230°C) of 0.5 to 20.0 g/10 min. The bi- or multimodal polyethylene (mPE) constitutes a terpolymer of ethylene and two different comonomers selected from alpha olefins with 4 to 10 carbon atoms, synthesised using a metallocene catalyst. The mPE has an MFI₂ (2.16 kg, 190°C) of 0.5 to 10.0 g/10 min, a molecular weight distribution MWD (Mw/Mn) of 2.0 to 7.0, and a density of 890 to 925 kg/m³. The bi- or multimodal polyethylene (mPE) includes at least a first ethylene polymer component (A) and a second ethylene polymer component (B). The first ethylene polymer component (A) has a melt flow index MFI₂ (2.16 kg, 190°C) of 1.0 to 10.0 g/10 min. The second ethylene polymer component (B) has a melt flow index MFI₂ (2.16 kg, 190°C) of 0.2 to 1.0 g/10 min. The article includes the polymer composition.

EFFECT: creation of a polyolefin composition with good impact strength and good optical properties (low turbidity and lower blushing under load).

13 cl, 2 dwg, 1 tbl, 6 ex