POLYPROPYLENE COMPOSITION Russian patent published in 2021 - IPC C08L23/12 C08L23/16 C08J5/18 C08F110/06 C08F210/06 B32B27/00 

FIELD: polymers.

SUBSTANCE: invention relates to a polypropylene composition for producing sterilisable products. The composition contains a component (A) and optionally a component (B) in an amount from 0.0 to 5.0% wt. relative to the total weight of the composition of one or more additives selected from the group consisting of friction-reducing agents, anti-blocking agents, UV stabilisers, alpha- and/or beta-nucleating agents, antistatic agents, antioxidants. The component (A) constitutes a mixture of: (a) 75.0 to 92.0% wt. of a propylene terpolymer relative to the total weight of the mixture, containing (i) units produced from ethylene comonomers in an amount of 1.0 to 2.5% wt. and (ii) units produced from 1-butene in an amount of 6.0 to 10.0% wt., wherein the propylene terpolymer has an MFR₂ measured according to ISO 1133 at 230°C and a load of 2.16 kg, within 1.5 to 5.0 g/10 minutes, a melting point Tm, as measured using DSC according to ISO 11357, from 132°C to 140°C, and the content of the fraction soluble in cold xylene (XCS) within 5.0 to 12.0% wt., as measured according to ISO 16152, 2005, at 25°C, and (b) 8.0 to 25.0% wt. relative to the total weight of the mixture of an ethylene-based plastomer constituting a copolymer of ethylene and 1-octene, with a density according to ISO 1183 of 0.860 g/cm³ to 0.880 g/cm³ and an MFR₂, measured according to ISO 1133 at 190°C and a load of 2.16 kg, within 0.3 to 2.0 g/10 minutes. Also described are a method for producing a polypropylene composition for producing sterilisable products, an application of the composition for producing sterilisable products, a sterilisable product, in particular a cast or blown film, and an application of the product as a heat-sealable layer in a multi-layered film.

EFFECT: provided are polypropylene composition for producing sterilisable products, in particular films, combining a low seal initiation temperature (SIT), high strength of the welded joint in a hot state, good optical properties, such as low turbidity, and an improved stiffness/impact strength balance.

12 cl, 3 tbl, 6 ex