Flushable multilayer film
Multilayer film, comprising an at least flushable, thermoplastic layer composite made of at least one layer which is at least comminutable via exposure to water and is resistant to cold water or can only be dissolved slowly therein, formed of at least one at least partially saponified polyvinyl acetate having a layer thickness of <10 μm, and at least one layer soluble in cold water comprised of at least one at least partially saponified polyvinyl acetate and at least one substance that increases the water solubility, selected from the group consisting of biodegradable polymers, surfactants, inorganic pigments and fillers, and flushable packages produced therefrom.
1. A multilayer film comprising an at least flushable, thermoplastic layer composite made of
A) at least one layer which is at least comminutable via exposure to water and which does not dissolve in water having a temperature of at most 25° C. until at least two minutes have passed, or which is resistant to cold water, and which is formed of at least one at least partially hydrolyzed polyvinyl acetate with layer thickness <10 μm, and which does not comprise any solubility promoting agent, and is adjacent to layer B)
B) at least one cold-water-soluble layer of at least one at least partially hydrolyzed polyvinyl acetate and at least one substance that promotes solubility in water, selected from the group consisting of biodegradable polymers, surfactants, inorganic pigments and fillers, said biodegradable polymers being selected from the group consisting of lactic acid (ester) homo- or copolymers, polyhydroxyalkanoates, starch, cellulose, cellulose derivates, polycaprolactones, polyesters, polyethers, ethylene-vinyl alcohol copolymers and mixtures thereof, wherein said at least one substance that promotes solubility in water includes at least one of said biodegradable polymers.
2. The multilayer film as claimed in claim 1 , wherein layer A) is formed of at least one fully hydrolyzed polyvinyl acetate, at least one partially hydrolyzed polyvinyl acetate, a mixture made of at least two differently partially hydrolyzed polyvinyl acetates, or a mixture made of at least one partially hydrolyzed polyvinyl acetate and of at least one fully hydrolyzed polyvinyl acetate.
3. The multilayer film as claimed in claim 1 wherein the cold-water-soluble layer B) is formed of at least one partially hydrolyzed, cold-water-soluble polyvinyl acetate, or of a mixture made of at least two differently partially hydrolyzed, cold-water-soluble polyvinyl acetates.
4. The multilayer film as claimed in claim 1 , wherein the degree of hydrolysis of the partially hydrolyzed polyvinyl acetates of the layer A) is from 85 to 98 mol %.
5. The multilayer film as claimed in claim 1 , wherein the degree of hydrolysis of the partially hydrolyzed polyvinyl acetates of layer B) is from 70 to 95 mol %.
6. The multilayer film as claimed in claim 1 , wherein layer B) comprises at least 50% by weight, based on the total weight of the layer B), of at least one partially hydrolyzed polyvinyl acetate.
7. The multilayer film as claimed in claim 1 , wherein layer B) comprises from 0.1 to 50% by weight, based on the total weight of the layer B), of at least one substance that promotes solubility in water.
8. The multilayer film as claimed in claim 1 , wherein said substance that promotes solubility in water is an inorganic pigment or filler and the inorganic pigments or filler is selected from the group consisting of silicates, carbonates and oxides.
9. The multilayer film as claimed in claim 1 , wherein said substance that promotes solubility in water is a surfactant, and said surfactant is selected from the group consisting of cationic, anionic, nonionic, and amphoteric surfactants.
10. The multilayer film as claimed in claim 1 , wherein layer A), also, comprises at least one substance that promotes solubility in water, selected from the group consisting of biodegradable polymers, surfactants, inorganic pigments and fillers, in an amount of from 5 to 35% by weight, based on the total weight of the layer A).
11. The multilayer film as claimed in claim 1 , wherein layer A) and optionally layer B), in contact with water, can at least be comminuted to particles, where the particles at least have a size <10 mm.
12. The multilayer film as claimed in claim 1 , wherein the modulus of elasticity of the flushable layer composite is at most 3000 N/mm 2 .
13. The multilayer film as claimed in claim 1 , wherein the thickness of the layer A) is from 1 μm to 9 μm.
14. The multilayer film as claimed in claim 1 , wherein layer A) or layers A) represent(s) (a) surface layer(s) of the multilayer film.
15. The multilayer film as claimed in claim 1 , wherein the multilayer film is a printed film and/or transparent film and/or colored film and/or siliconized film.
16. The multilayer film as claimed in claim 1 , wherein the multilayer film is composed of the layer composite of the layer A) and of the layer B), or said layer composite has a further layer A) which is immediately adjacent to layer B), so that the layer B) has a layer A) at each of its surfaces, or the layer composite has a further layer B) which is immediately adjacent to layer B), so that the layer B) has, at its surfaces, a layer A) and a layer B).
17. A method for producing flushable packaging, which comprises producing said flushable packaging with the multilayer film of claim 1 .
18. A flushable packaging made of the multilayer film of claim 1 .
19. Tampons, diapers, or sanitary napkins packaged in the flushable packaging of claim 18 .
20. A flushable protective covering for adhesive areas on hygiene items, made of the multilayer film of claim 1 .