PRODUCT BASED ON POLYPROPYLENE WITH INCREASED RETENTION OF SURFACE TENSION Russian patent published in 2024 - IPC C08J5/18 C08F210/06 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing a polypropylene-based film having surface tension retention. Proposed method comprises the following stages: A) providing a propylene-ethylene random copolymer (RACO) obtained using a metallocene catalyst and having a) an ethylene content of 1.8 to 4.0 wt.% based on the total weight of the propylene-ethylene random copolymer; b) melt flow index MFI2 (230 °C/2.16 kg), measured in accordance with ISO 1133, from 3.0 to 12.0 g/10 min; c) melting point Tm, determined by DSC in accordance with ISO 11357, from 120 to 145 °C; d) fraction of substances soluble in cold xylene (SSCX; ISO 16152, 2005; 25 °C) from 0.5 to 4.0 wt.%; and e) content of 2.1-regiodefects from 0.10 to 1.2 mol.%, determined by ¹³C-NMR spectroscopy; B) forming a film from a propylene-ethylene random copolymer (RACO) obtained using a metallocene catalyst with thickness of 1.0 to 1000 mcm; and C) processing one or more surfaces of said film, increasing surface tension, to obtain a film based on polypropylene, having retention of surface tension, wherein the treatment increasing surface tension at step C) is corona discharge treatment or flame treatment. Propylene-ethylene random copolymer (RACO) obtained using a metallocene catalyst is the only polymer used for forming a film, and wherein the propylene-ethylene random copolymer (RACO) is produced in the presence of a metallocene catalyst. Invention also relates to a film obtained by a method of producing a film based on polypropylene, having retention of surface tension.

EFFECT: obtaining articles using a specific propylene-ethylene random copolymer (RACO) and a metallocene catalyst, which have higher surface tension immediately after surface treatment and improved retention of surface tension.

17 cl, 5 tbl, 3 ex