BLOWN FILMS WITH IMPROVED PROPERTY PROFILE Russian patent published in 2023 - IPC B29C48/08 C08J5/18 C08F210/06 B32B27/06 C08F4/659 C08L23/14 

FIELD: packaging materials.

SUBSTANCE: blown film containing a C₂C₃ random copolymer and an ethylene-based plastomer is provided. The proposed film has a dart impact strength of 60-1700 g and an Elmendorf tear strength of 5-50 N/mm in the machine direction and 80-300 N/mm in the transverse direction. The random copolymer is obtained using a catalyst with one active site and consists of polymer fraction A-1, having an ethylene content of 1.5-5.0 wt.%, and polymer fraction A-2, having an ethylene content of 4.0-10.0 wt.%. At the same time, the ethylene content in polymer fraction A-2 is higher than the ethylene content in polymer fraction A-1, and the melt flow index (MFI₂) in polymer fraction A-2 is lower than that in polymer fraction A-1. The random copolymer has a total ethylene content of 1.0-7.0 wt.%, MFR₂ at 230°C under a load of 2.16 kg 0.5-4.0 g/10 min and a melting point of 110°C to 140°C. The ethylene-based plastomer comprises a comonomer selected from С₄-С₈ alpha-olefin, has a density of 860-900 kg/m³ and an MFI₂ at 190°C under load 2.16 kg 0.1-50.0 g/10 min. Applications for blown film are also proposed.

EFFECT: group of inventions makes it possible to reduce the film sealing start temperature, increase its tear resistance and impact strength while maintaining low haze.

15 cl, 3 tbl