COMPOSITION OF HETEROPHASE POLYOLEFIN WITH ENHANCED OPTICAL PROPERTIES Russian patent published in 2022 - IPC C08F210/06 C08L23/10 C08L23/12 C08F2/00 

FIELD: polymers.

SUBSTANCE: invention relates to a heterophase copolymer of propylene for producing films with improved optical properties, in particular, low turbidity. The heterophase copolymer of propylene (HECO) for producing films comprises 82.0 to 93.0 wt.%, from the total mass of the heterophase copolymer of propylene, of a matrix (M) constituting a homopolymer of propylene (H-PP), and 7.0 to 18.0 wt.%, from the total mass of the heterophase copolymer of propylene, of an elastomeric propylene copolymer (EPC) dispersed in said matrix (M). The heterophase copolymer of propylene (HECO) has: a) a melt flow rate MFR₂ (2.16 kg, 230°C), as measured according to ISO 1133, within the range from 0.2 to 8.0 g/10 min, (b) a content of a xylene cold soluble (XCS) fraction, as determined according to ISO 16152 (25°C), within the range from 10.0 to 20.0 wt.%, and (c) a total content of an ethylene comonomer within the range from 2.5 to 8.0 wt.%, wherein optionally (d) the melt flow rate MFR₂ (2.16 kg, 230°C), as measured according to ISO 1133, of the matrix (M) is within the range from 0.2 to 4.0 g/10 min, (e) the content of an ethylene co-monomer of the xylene cold soluble (XCS) fraction of the heterophase copolymer of polypropylene is within the range from 25.0 to 40.0 wt.%, (f) the intrinsic viscosity (IV), as determined according to DIN ISO 1628/1 (in decalin at 135°C), of the xylene cold soluble (XCS) fraction of the heterophase copolymer of polypropylene is within the range from greater than 1.0 to less than 2.9 dl/g, and (g) the relative content of the isolated sequences of ethylene relative to the block sequences (I(E)) of the XCS fraction satisfies the inequality wherein C2(XCS) is the content of the comonomer, wt.% of the XCS fraction, and wherein the content of I(E) is determined using the equation wherein I(E) is the relative content of the isolated sequences of ethylene relative to the block sequences of the XCS fraction, fPEP is the mole fraction of propylene/ethylene/propylene (PEP) sequences of the XCS fraction, fPEE is the mole fraction of propylene/ethylene/ethylene (PEE) sequences and ethylene/ethylene/propylene (EEP) sequences of the XCS fraction, fEEE is the mole fraction of ethylene/ethylene/ethylene (EEE) sequences of the XCS fraction, wherein all concentrations of sequences are based on data from the statistical analysis of 13C-NMR triads of the XCS fraction of the heterophase copolymer. Also described is a cast film containing the heterophase copolymer of propylene (HECO), preferably with a thickness from 10 to 1,000 mcm.

EFFECT: provided heterophase copolymers of propylene, constituting polypropylene materials with enhanced optical properties and essentially with a low turbidity.

9 cl, 1 dwg, 4 tbl, 10 ex