POLYMER MULTILAYER

Abstract

A multilayer comprises at least one first layer and at least one second layer is provided. The first layer includes a water-soluble polymer, wherein the first layer has an oxygen barrier. Furthermore, the first layer comprises a salt. The salt can act as a lubricant. The second layer has a water vapor and/or humidity barrier. The multilayer can offer a high barrier-performance with respect to oxygen permeation and permeation of water/humidity. This enables for a broad applicability of the multilayer in various areas as e.g., in packing, in particular, for food packing, in particular for packing coffee.

Claims

1. A multilayer comprising: at least one first layer comprising at least 20 wt %, water-soluble polymer wherein the first layer has an oxygen transmission barrier, wherein the first layer comprises a salt; at least one second layer wherein second layer has a water vapor and/or humidity barrier.

2. The multilayer according to claim 1, wherein the multilayer comprises an oxygen transmission rate of a maximum of 3 cm.sup.3/m.sup.2 per day at 23 C. and a relative humidity of 50%.

3. The multilayer according to claim 1, wherein the water-soluble polymer is at least one of poly(vinyl alcohol), cellulose-ether polymer, Butenediol-Vinylalcohol-Copolymer, and Ethylene-Vinylalcohol-Copolymers.

4. The multilayer according to claim 1, wherein the first layer fulfils at least one of the following conditions: the salt comprises a salt of alkaline metals, earth alkaline metals, aluminum comprising salt and/or a mixture thereof, including NaCl, Na-citrate, and the respective potassium analogues; the first layer comprises at least 1 wt %, of the salts; the first layer comprises 1-40 wt %, of the salt; the first layer comprises a vinyl-alcohol copolymer comprising 1 to 20 mol % of a non-OH group comprising comonomer; the first layer comprises an inorganic filler; the first layer comprises an organic filler; the first layer comprises a minimum of 35 wt % of one or more respective vinyl alcohol rich copolymers.

5. The multilayer according to claim 1, wherein the first layer further comprises an additive, including at least one of a plasticizer and a stabilizer.

6. The multilayer according to claim 1, wherein the second layer fulfils at least one of the following conditions: the second layer comprises at least one of the following components: polyester aliphatic polyester poly(hydroxy alkanoates) (PHAs) polylactic acid (PLA) polybutylene succinate (PBS), and poly(hydroxy butyrates) (PHB), including Poly(3-hydroxy butyrate); the second layer comprises polyester, wherein homo- and/or copolyester comprise at least to an extent of 80 wt. % of aliphatic units. the second layer comprises an additive, wherein the additive is selected from at least a plasticizer, a stabilizer and a nucleating agent.

7. The multilayer according to claim 1, wherein at least one of the first layer and the second layer is at least one of bio-degradable and compostable, or home compostable.

8. The multilayer can have a water vapor and/or humidity barrier of a maximum of 15 g/m.sup.2 per day at 23 C. and a relative humidity of 85%.

9. The multilayer according to claim 1, wherein the multilayer comprises a sealing layer; wherein the sealing layer is essentially identical or similar to the second layer and/or first layer wherein the sealing layer comprises at least one of the following components: polyester polyurethane(s) or polycarbonate(s). aliphatic polyester poly(hydroxy alkanoates) (PHAs), and vinyl alcohol rich copolymer and/or homopolymer.

10. The multilayer according to claim 1, wherein the multilayer comprises a tie layer for promoting adhesion between the first layer and the second layer.

11. The multilayer according to claim 1, wherein the layers of the multilayer are separable from each other.

12. The multilayer according to claim 1, wherein the salt in the first layer is present as solid material.

13. A method for producing a multilayer according to claim 1, wherein the multilayer is produced at least as one of a blown film, a cast film and by an extrusion-coating-method, wherein the multilayer is produced by at least one of: co-extrusion of the first layer 1 and the second layer 2; thermoforming; co-injection moulding; and compression moulding.

14. A method comprising utilizing a multilayer according to claim 1 for packing, including for food packing, for packing coffee.

15. Packaging comprising a multilayer according to claim 1.

16. The multilayer of claim 1 wherein: the at least one first layer comprising at least 35 wt %, water-soluble polymer.

Description

BRIEF DESCRIPTION

[0166] Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

[0167] FIG. 1 shows a multilayer;

[0168] FIG. 2 shows a multilayer with an additional tie layer; and,

[0169] FIG. 3 shows a multilayer with tie layers and a sealing layer;

[0170] FIG. 4 shows a multilayer in an integrated tie layer;

[0171] FIG. 5 shows a multilayer with a second layer as middle layer; and

[0172] FIG. 6 shows a multilayer with a first layer covered by two second layers.

DETAILED DESCRIPTION

[0173] FIG. 1 shows a multilayer 5 comprising a first layer 1 and a second layer 2. The first layer 1 comprises a water-soluble polymer and a salt. The first layer 1 has an oxygen transmission barrier.

[0174] The multilayer 5, in particular the first layer 1 has an oxygen transmission rate of a maximum of 3 cm.sup.3/m.sup.2 per day at room temperature (RT, room temperature=23 C.) and a relative humidity of 50% (rel. H), in particular the oxygen transmission rate can be maximal 1 cm.sup.3/m.sup.2 per day at room temperature and a relative humidity of 50%, in particular maximal 0.2 cm.sup.3/m.sup.2 per day at room temperature (23 C.) and a relative humidity of 50%.

[0175] The second layer 2 has a water vapor barrier and/or a humidity barrier.

[0176] The multilayer, in particular the second layer, has a water vapor and/or humidity barrier of a maximum of 15 g/m.sup.2 per day at 23 C. and a relative humidity of 85%, in particular a maximum of 10 g/m.sup.2 per day at 23 C. and a relative humidity of 85%, in particular 3/m.sup.2 per day at 23 C. and a relative humidity of 85%.

[0177] FIG. 2 shows a similar multilayer 5 with the first layer 1 and the second layer 2. Additionally, a tie layer 4 is arranged between the first layer 1 and the second layer 2. The tie layer 4 can be designed as an additional layer. Furthermore, the tie layer 4 can be designed to be integrated in the first layer 1 and/or second layer 2 as shown in FIG. 4.

[0178] FIG. 3 shows multilayer 5 with an additional sealing layer 3 which is arranged adjacent to the second layer 2. The second layer 2 and the sealing layer 3 are connected by a tie layer 4. As described above the tie layer 4 can be also integrated into the second layer 2 and/or sealing layer 3.

[0179] The sealing layer 3 can be designed such that the multilayer 5 can be sealed to a further multilayer 5, in particular to a sealing layer 3 of the multilayer 5.

[0180] In embodiments, the further multilayer 5 is identical to the first multilayer 5. This enables to seal the multilayer 5 to its own and producing a pouch of packing from one piece of multilayer 5. In another embodiment the first multilayer 5 and the further multilayer 5 are separate multilayers and can also be sealed together as a pouch of packing.

[0181] FIG. 5 shows a multilayer 5 with two first layer 1 arranged next to one second layer 2. The second layer 2 is arranged in the middle between two first layer 1.

[0182] FIG. 6 shows an alternative of a at least tree layered multilayer 5, with two layers being a second layer 2 and one first layer 1. The two second layer 2 cover both sides of the first layer 1. The first layer 1 is arranged in the middle of two second layer.

[0183] Although the present invention has been disclosed in the form of embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0184] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements. The mention of a unit or a module does not preclude the use of more than one unit or module.