METHOD FOR PRODUCING A MULTILAYER COMPOSITE FILM, MULTILAYER COMPOSITE FILM AND APPLICATION THEREOF Russian patent published in 2022 - IPC B32B27/08 B29C48/21 C08L27/08 B65D37/00 B65D65/40 

FIELD: films.

SUBSTANCE: invention relates to the field of polymer materials and pertains to a method for producing a multilayer composite film for food packaging. The method includes the stage of coextrusion of at least three layers (a), (b), and (c), wherein layer (a) forms the outward-facing surface of the composite film, layer (c) forms the surface of the composite film facing or coming in contact with the packaged product, and layer (b) is located between the layers (a) and (c). The method also includes the stage of biaxial pulling of the coextruded composite film. Herewith, layer (a) contains or consists of a thermoplastic resin constituting a polylactic acid (PLA) or a polyamide (PA). Layer (b) contains or consists of polyvinylidene chloride resin (PVdC resin). Layer (c) contains or consists of a resin, preferably casting resin, in particular, heat-sealable resin. Any type of crosslinking of the composite film by radioactive emission in the process of producing the composite film and after the production is herein avoided.

EFFECT: creation of a composite film with high setting properties, good processability, high puncture resistance and heat resistance, good optical properties with respect to low opacity and/or weak colour tone, stable oxygen impermeability and recycling capacity.

20 cl, 10 tbl