WATER SOLUBLE POLYVINYL ALCOHOL FILM, RELATED METHODS AND RELATED PRODUCTS Russian patent published in 2023 - IPC C08J5/18 C08L29/04 B65D65/46 C11D17/04 C08K5/00 

FIELD: polymer materials.

SUBSTANCE: group of inventions is related to a water-soluble film used for manufacturing of packaging, and to a product for storing a liquid composition containing said film in form of a bag. The proposed film has a crystallinity of at least 15% and contains a mixture of polyvinyl alcohol (PVA) resins, including a first PVA copolymer, in which the first anionic monomer unit selected from maleic anhydride and an alkali metal salt of maleic anhydride is present in an amount of 1-3 mol.%; a second PVA copolymer, in which the second anionic monomer unit selected from maleic anhydride and the alkali metal salt of maleic anhydride is present in an amount of 3-8 mol.%, these quantities differ from each other, and the amount of the first PVA copolymer in the specified mixture is 10-70 wt.%, wherein the first and second PVA copolymers contain side groups, the first PVA copolymer has a first level of side groups (a1) derived from the first anionic monomer unit, and the second PVA copolymer has a second level of side groups (a2) obtained from the second anionic monomer unit, and the difference between a1 and a2 is 4-10 mol.%.

EFFECT: group of inventions ensures the preservation of the rigidity, elasticity and acceptable transparency of the film without compromising its final solubility during use.

24 cl, 2 dwg, 23 tbl, 127 ex