| abstract |
A single- or multilayer film is disclosed, the film made on the basis of a blend of (co)polyamide and polyvinyl alcohol, soluble in at least one solvent A, comprising more than 50% water, at that said film comprising polyvinyl alcohol—PVAs, soluble in the same solvent A, and bonded polyvinyl alcohol—PVAB, which (i) is virtually insoluble in the same solvent A at temperatures from 18° C. to the initial boiling point at normal pressure, (ii) is soluble in at least one of the solvents, capable of dissolving (co)polyamide, (iii) gives the typical for PVA color reaction with iodine, and (iv) reacts with at least one primary amine, with formation of water-soluble PVA, wherein the CB/CS ratio, where CB is the film content for PVAB, that becomes water-soluble after its treatment with said primary amine, and Cs is the content of PVAs in the film, is not less than 0.05. When this condition is satisfied, there is noticeable improvement in the stability of the technological process of production, and in the mechanical strength of the film. The claimed film can be used, specifically, for sausage casings. 2 independent and 30 dependent claims, 6 tables. |