WATER-SOLUBLE PLASTIC ARTICLE

Abstract

A plastic product has a plastic body injection-moulded or deep-drawn from water-soluble polyvinyl alcohol (PVOH). The surface of the plastic body, which is exposed to ambient moisture or a water-containing substance from completion of the plastic product up to and during the intended use of the plastic product is completely coated with a continuous, water-impermeable and water-resistant protective layer and the plastic body can be completely dissolved in water after the intended use of the plastic product when a non-coated surface is exposed or after the continuous protective layer is destroyed. The protective layer is applied so thinly that it disintegrates or can be separated out of the water after the dissolution of the plastic body, and/or the protective layer (3) has a melting temperature between 50° C. and 90° C., preferably 60° C. to 85° C.

Claims

1-16. (canceled)

17. A plastic product having a plastic body injection-moulded or deep-drawn from water-soluble polyvinyl alcohol (PVOH), wherein a surface of the plastic body which is exposed to ambient moisture or a water-containing substance from completion of the plastic product until and during the intended use of the plastic product, is coated completely with a continuous water-impermeable and water-resistant protective layer, wherein after the intended use of the plastic product, the plastic body is, upon exposure of a non-coated surface or after destruction of the continuous protective layer, completely soluble in water; wherein the protective layer is applied with a thickness such that the protective layer disintegrates or is separable from the water after the dissolution of the plastic body, and/or wherein the protective layer has a melting temperature between 50° and 90° Celsius.

18. The plastic product according to claim 17, wherein the protective layer comprises parylenes or an inorganic-organic hybrid polymer.

19. The plastic product according to claim 17, wherein the protective layer comprises a material selected from shellac, wax, or combinations thereof.

20. The plastic product according to claim 17, wherein the protective layer is built in a multi-layered manner from various materials.

21. The plastic product according to claim 20, wherein the protective layer has a first inner layer made from wax and a second outer layer made from shellac.

22. The plastic product according to claim 17, wherein the PVOH is dissoluble at room temperature within 2 hours.

23. The plastic product according to claim 17, wherein the PVOH is only dissoluble in water from a temperature of at least 40° C., within 2 hours.

24. The plastic product according to claim 17, wherein the plastic product is a packaging container.

25. The plastic product according to claim 24, wherein the inner surface of the closed packaging container is not provided with the protective layer.

26. The plastic product according to claim 24, wherein the packaging container is only provided with the protective layer on the outside or externally and internally.

27. The plastic product according to claim 24, wherein the packaging container is closed with a closure means.

28. The plastic product according to claim 27, wherein the closure means is in the form of a sealing film or a plastic cap.

29. The plastic product according to claim 17, wherein the plastic product is a catering product.

30. The plastic product according to claim 17, wherein the plastic product is dimensionally stable and self-supporting.

31. The plastic product claim 17, wherein the protective layer is 0.01 to 500 μm (micrometres) thick.

32. The plastic product according to claim 17, wherein the protective layer is applied by vacuum coating methods, spray or dipping methods.

33. The plastic product according to claim 17, wherein the protective layer has a melting temperature between 60° to 85° Celsius.

34. A plastic product having a plastic body injection-moulded or deep-drawn from cold-water-soluble polyvinyl alcohol (PVOH), wherein a surface of the plastic body, which is exposed to ambient moisture or a water-containing substance from completion of the plastic product until and during the intended use of the plastic product, is coated completely with a continuous protective layer made from warm-water-soluble polyvinyl alcohol (PVOH), and after the intended use of the plastic product, the plastic body is completely soluble in water having a water temperature above 40° C. upon dissolution or after destruction of the continuous protective layer.

35. The plastic product according to claim 34, wherein the water temperature is above 50° C.

Description

SHORT DESCRIPTION OF THE FIGURES

[0041] The invention shall be explained in more detail in the following on the basis of exemplary embodiments in connection with the drawing(s). In the figures:

[0042] FIG. 1 shows a sectional illustration of a plastic product in the form of a plate;

[0043] FIG. 2 shows a sectional illustration of a plastic product in the form of a packaging container closed with a sealing film; and

[0044] FIG. 3 shows a sectional illustration of a plastic product in the form of a packaging container closed with a plastic cap.

WAYS OF REALIZING THE INVENTION

[0045] FIG. 1 shows a plastic product 1 in the form of a plate. The plate has a plastic body 2 made from water-soluble polyvinyl alcohol (PVOH). In order to protect the plate from water and thus its decomposition or dissolution until and during the intended use, it is completely provided with a water-vapour-impermeable protective layer 3. The protective layer 3 comprises e.g. parylenes or an inorganic-organic hybrid polymer. In this manner, the plastic body 2 made from PVOH is protected from decomposition or dissolution by water, until the PVOH located below the protective layer is at least partially exposed, e.g. by breaking or cutting of the plastic product 1. Good results were also achieved using a multi-layered protective layer made from a first inner layer made from wax, preferably carnauba wax, and a second outer layer made from shellac. A protective layer of this type may have a melting temperature of more than 65° C., so that the plastic product is also suitable for warm beverages and/or meals.

[0046] FIGS. 2 and 3 each show a closed plastic packaging container 4. The plastic packaging container 4 comprises a container body 6 and a closure means 5, which closes the container body 6 in a sealing manner. Analogously to the previously described plastic product from FIG. 1, the container body 6 has a plastic body made from water-soluble PVOH and a protective layer 3.

[0047] In the embodiment shown in FIG. 2, the container body 6 is designed to be cup-shaped and has a sealing flange 7, onto which a closure means 4 is adhesively bonded or welded in the form of a sealing film. Depending on the type of sealing, the sealing flange 7 may have a sealing zone which is not provided with the protective layer 3, i.e. is protective-layer-free. The sealing film may be a conventional sealing film made from aluminium, which is disposed of separately after removal. Alternatively, the sealing film may likewise have a plastic body made from PVOH, which is provided with a previously described protective layer 3. If the container 6 is provided for dry substances, then it is possible to dispense with a coating of the interior. In the case of coating with a first inner layer made from wax, preferably carnauba wax, and a second outer layer made from shellac, it is possible to dispense with the shellac layer in the interior of the container.

[0048] In the embodiment shown in FIG. 3, the container body 6 is designed to be bottle-shaped. The closure means 5 in the form of a plastic cap can in this case be attached on the neck of the bottle in a sealing manner. In this case, the plastic cap generally has a plastic body 2 made from PVOH, which is provided with a previously described protective layer 3.

LIST OF REFERENCE NUMBERS

[0049] 1 Plastic product [0050] 2 Plastic body [0051] 3 Protective layer [0052] 4 Plastic packaging container [0053] 5 Closure means [0054] 6 Container body