METHOD FOR PRODUCTION OF MULTILAYERED COMPOSITE FILM, MULTILAYERED COMPOSITE FILM AND ITS USE Russian patent published in 2023 - IPC B32B27/08 B29C48/16 B65D37/00 B65D65/40 

FIELD: polymer materials.

SUBSTANCE: invention relates to the field of polymer materials for packaging items, preferably food products or food-flavored products, and concerns a method for the production of multilayered composite film. The method includes a stage of coextrusion of at least three layers (a), (b), and (c), of which the layer (a) forms a surface of composite film, facing outwards, the layer (c) forms a surface of composite film, facing the packed good or contacting it, and the layer (b) is between the layer (a) and the layer (c). In addition, the method also includes a stage of two-axes extraction of coextruded composite film. At the same time, the layer (a) contains thermoplastic resin or consists of it. The layer (b) contains polyvinylidenchloride resin (PVDC resin) or consists of it. The layer (c) contains resin, preferably sealed, in particular thermally welded resin, or consists of it. At the same time, any crosslinking of composite film with radioactive radiation, in particular beta-, gamma-, X-ray, and/or electronic radiation, during the production of composite film and/or after it is excluded.

EFFECT: invention provides creation of composite film having properties such as high shrinkage, resistance to piercing, thermal resistance, good processability, good optical properties relatively to low dullness and/or weak color shade, possibility of recycling, and long-term unaffected, i.e., stable, oxygen impermeability.

16 cl, 10 tbl