POLYPROPYLENE COMPOSITION Russian patent published in 2020 - IPC C08L23/12 C08L23/14 C08L23/16 C08J5/18 B65D65/40 

FIELD: chemistry.

SUBSTANCE: present invention relates to a polypropylene composition, a method of producing a polypropylene composition, use of the polypropylene composition, an article and use of the article. Polypropylene composition contains mixture (A) from ternary propylene copolymer (a) from 80.0 to 97.0 wt%, including comonomer links formed from ethylene, in amount of 0.3 to 4.0 wt% and comonomer links formed from C₄-C₁₀ α-olefin, in amount of 4.0 to 16.0 wt%, and ethylene-based plastomer (b) with density of 0.850 g/cm³ to 0.915 g/cm³ in accordance ISO 1183 and MFI₂ of 3.0 to 20.0 wt.; and (B) optionally one or more additives in total amount of 0.0 to 5.0 wt%, based on a composition selected from a group comprising friction-reducing agents, antistick agents, UV stabilizers, alpha- and/or beta-nucleating agents, antistatic agents, antioxidants. Triple copolymer has a melt flow index (MFI₂), measured according to ISO1133 at 230 °C, 2.16 kg, 0.5 to 20.0 g/10 min and a melting point T_m as measured by differential scanning calorimetry (DSC) according to ISO 11357, 130 °C to 145 °C. Method comprises steps of: (i) obtaining component (a) by polymerization of propylene, ethylene and C₄-C₁₀ α-olefin in presence of Ziegler–Natta catalyst, (ii) mixing component (a) with plastomer (b) based on ethylene, optionally in the presence of one or more additives to obtain a mixed weight of components (a) and (b), and (iii) extruding said mixed mass to obtain a polypropylene composition comprising a mixture of (A) components (a) and (b). Polypropylene composition is used to produce sterilized articles. Articles are used as a solder layer in a multilayer film.

EFFECT: obtained polypropylene composition has optimized or improved welding properties, id est low temperature of the beginning of welding (TBW) and high adhesion in a hot state, combined with preferential optical properties and high melting point.

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