Ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer

Abstract

The invention provides an ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer, and relates to the technical field of water vapor barrier materials, the ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer comprises a base layer, the base layer is composed of nano montmorillonite and an ethylene-vinyl acetate copolymer (EVA) matrix, the surface of an aluminum foil layer is coated with a functional layer composed of a chitosan quaternary ammonium salt solution, and the surface of the aluminum foil layer is coated with a water vapor barrier layer. The packaging film has strong inhibition and killing effects on common bacteria, molds and other microorganisms, has the bacteriostasis rate of more than 99% on escherichia coli and staphylococcus aureus, provides a lasting health protection barrier for packaging contents, comprehensively meets the hygienic standard of food and medicine packaging, and meanwhile, can be used as a packaging film for packaging food and medicines. Part of raw materials such as chitosan quaternary ammonium salt have certain biodegradability, a road is opened up for green development of packaging materials, and the problems that an ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier material is single in function, and an existing product only has a basic barrier function and cannot be used for packaging materials are solved. The emerging requirements of antibiosis, self-repairing, degradability and the like cannot be met.

Description

Technical Field

[0001] The present invention relates to the technical field of water vapor barrier materials, and particularly to an ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer. Background Art

[0002] Traditional aluminum foil composite packaging materials usually use ethylene-vinyl acetate copolymer (EVA) as the adhesive layer, and laminate the aluminum foil and the plastic substrate through a lamination process. They have been widely used in the fields of food, medicine, electronic components, etc. Although the traditional ethylene-vinyl acetate copolymer (EVA) composite aluminum foil materials are widely used, they have many drawbacks:

[0003] First, the functional singleness of the ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier material. Existing products only have basic barrier functions and cannot meet emerging requirements such as antibacterial, self-repairing, and degradable.

[0004] Second, the traditional process directly laminates EVA and aluminum foil, and the interfacial bonding force is poor (the existing interfacial bonding strength ≤ 1.2 MPa), and defects such as microcracks and bubbles are likely to occur, resulting in only the situation of water vapor penetration.

[0005] Third, the surface of the aluminum foil is easily oxidized, and the barrier rate drops by 30% after 24H of oxidation, affecting its normal use. Summary of the Invention

[0006] Aiming at the above problems, an object of the present application is to make up for these shortcomings. More specifically, it provides an ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer, which can avoid enriching the functionality of the product, prevent defects such as microcracks and bubbles during lamination, and effectively alleviate the easy oxidation of the aluminum foil surface.

[0007] In the first aspect of the present disclosure, there is provided an ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer, which specifically includes: a base layer, the base layer is composed of nano-montmorillonite and an ethylene-vinyl acetate copolymer (EVA) matrix; an adhesive layer is provided on the base layer; the adhesive layer is connected to a modified barrier layer, and the adhesive layer is located between the base layer and the modified barrier layer; an antioxidant layer, a repair isolation layer, and a functional layer are sequentially provided outside the modified barrier layer.

[0008] Preferably, the adhesive layer is composed of an acrylic adhesive modified by a silane coupling agent.

[0009] Preferably, the modified barrier layer includes an aluminum foil layer and an interface strengthening layer. The aluminum foil layer is mainly composed of a combination of aluminum elements and alloy elements; the interface strengthening layer is formed by treating the surface of the aluminum foil layer by grafting acrylate monomers through plasma.

[0010] Preferably, the antioxidant layer is composed of graphene coated after nano-scale grooves are etched on the surface of the aluminum foil layer by low-temperature plasma.

[0011] Preferably, the repair and isolation layer is composed of microencapsulated polysiloxane doped with an EVA matrix. The microcapsule shell layer is polyurea formaldehyde resin, and the core material is hydroxyl-terminated polydimethylsiloxane.

[0012] Preferably, the functional layer is formed by drying a chitosan quaternary ammonium salt solution coated on the surface of the aluminum foil layer.

[0013] The present invention provides an ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer, which has the following beneficial effects:

[0014] 1. By setting an adhesive layer in the present invention, an acrylic adhesive modified by a silane coupling agent is coated between the base layer and the aluminum foil layer, so that the acrylic adhesive penetrates and fills the micropores on the surface of the aluminum foil, and the bonding effect between the base layer and the aluminum foil layer can be better realized;

[0015] 2. By setting a repair and isolation layer in the present invention, a repair and isolation layer composed of microencapsulated polysiloxane doped with an EVA matrix is coated on the surface of the aluminum foil layer. When cracks appear due to physical damage, the microcapsules can be triggered to rupture by near-infrared light irradiation for 10 minutes, and the repair agent is released to fill the cracks, which can extend the service life of the material and reduce the generation of waste;

[0016] 3. By setting a functional layer in the present invention, a functional layer composed of a chitosan quaternary ammonium salt solution is coated on the surface of the aluminum foil layer, which can strongly inhibit and kill common microorganisms such as bacteria and molds. The antibacterial rates against Escherichia coli and Staphylococcus aureus are both > 99%, providing a lasting sanitary protection barrier for the packaged contents and fully meeting the sanitary standards for food and pharmaceutical packaging. At the same time, some raw materials such as chitosan quaternary ammonium salt have certain biodegradability, opening up a way for the green development of packaging materials;

[0017] 4. By setting an antioxidant layer in the present invention, the surface of the aluminum foil layer is treated with low-temperature plasma to etch nano-scale grooves on the surface of the aluminum foil layer, and then graphene is coated to form an antioxidant layer, which can effectively alleviate the oxidation of the aluminum foil layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Those skilled in the art will have a better understanding of the present disclosure through the following drawings, and the advantages of the present disclosure will be more clearly reflected. The drawings described here are only for the purpose of illustrating the selected embodiments, rather than all possible embodiments and are not intended to limit the scope of the present disclosure.

[0019] In the drawings:

[0020] Figure 1Shows a schematic diagram of the hierarchical structure according to an embodiment of the present invention.

[0021] List of reference numerals

[0022] 1. Base layer; 2. Adhesive layer; 3. Modified barrier layer; 301. Aluminum foil layer; 302. Interface strengthening layer; 4. Antioxidant layer; 5. Repair isolation layer; 6. Functional layer. Detailed implementation manners

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0024] Embodiment 1: Please refer to Figure 1 as shown:

[0025] The present invention provides an ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer, including: a base layer 1, which is composed of nano-montmorillonite and ethylene-vinyl acetate copolymer (EVA matrix); an adhesive layer 2 is provided on the base layer 1; the adhesive layer 2 is connected to a modified barrier layer 3, and the adhesive layer 2 is located between the base layer 1 and the modified barrier layer 3; an antioxidant layer 4, a repair isolation layer 5, and a functional layer 6 are sequentially provided outside the modified barrier layer 3.

[0026] In this application, by setting an EVA matrix added with nano-montmorillonite, the combined base layer 1 can have better water vapor barrier performance.

[0027] As the second embodiment of this application, on the basis of Embodiment 1, as Figure 1 shown, the adhesive layer 2 is composed of an acrylic adhesive modified by a silane coupling agent.

[0028] In this application, by using the adhesive layer 2, the acrylic adhesive can penetrate and fill the micropores on the surface of the aluminum foil layer 301, and thus better realize the fixation of the aluminum foil layer 301 and the base layer 1.

[0029] As the third embodiment of this application, on the basis of Embodiment 1, as Figure 1 shown, the modified barrier layer 3 includes an aluminum foil layer 301 and an interface strengthening layer 302. The aluminum foil layer 301 is mainly composed of a combination of aluminum elements and alloy elements; the interface strengthening layer 302 is formed by treating the surface of the aluminum foil layer 301 through plasma grafting of acrylate monomers.

[0030] In this application, by setting the aluminum foil layer 301, the effect of blocking water vapor can be achieved through the characteristics of the aluminum foil layer 301; by setting the interface strengthening layer 302, the interfacial shear strength of the aluminum foil layer 301 can be ≥8 Mpa, thereby increasing the service strength.

[0031] As the 4th embodiment of this application, on the basis of the first embodiment, as Figure 1 shown, the antioxidant layer 4 is composed of graphene coated after nano-scale grooves are etched on the surface of the aluminum foil layer 301 by low-temperature plasma.

[0032] In this application, by setting the antioxidant layer 4 composed of graphene, the antioxidant property of the surface of the aluminum foil layer 301 can be greatly improved.

[0033] As the 5th embodiment of this application, on the basis of the first embodiment, as Figure 1 shown, the repair isolation layer 5 is composed of microencapsulated polysiloxane doped with an EVA matrix, the microcapsule shell layer is polyurea formaldehyde resin, and the core material is hydroxyl-terminated polydimethylsiloxane.

[0034] In this application, by setting the repair isolation layer 5, the microcapsules can be triggered to rupture after being irradiated with near-infrared light (808 nm) for 10 minutes, releasing the repair agent and filling the cracks caused by physical damage.

[0035] As the 6th embodiment of this application, on the basis of the first embodiment, as Figure 1 shown, the functional layer 6 is formed after the chitosan quaternary ammonium salt solution coated on the surface of the aluminum foil layer 301 is dried.

[0036] In this application, by setting the functional layer 6, by coating the antibacterial chitosan quaternary ammonium salt on the outer side of the aluminum foil layer 301, it can have a strong inhibitory and killing effect on common microorganisms such as bacteria and molds.

[0037] The specific usage and functions of this embodiment:

[0038] In the present invention, as Figure 1As shown, the aluminum foil layer 301 is treated by plasma grafting acrylate monomer to form an interface strengthening layer 302 on the outside of the aluminum foil layer 301, the base layer 1 is fixed to the aluminum foil layer 301 through the adhesive layer 2, and treated with low-temperature plasma (Ar gas, power 200-300W, treatment time 30-60s) to etch nano-scale grooves (depth 50-100nm) on the surface of the aluminum foil, and then coated with graphene to form an antioxidant layer 4, and then covered with a repair isolation layer 5 formed by microencapsulated polysiloxane on the aluminum foil layer 301, and finally a chitosan quaternary ammonium salt solution with a concentration of 1.5% is prepared, and the solution is evenly coated on the surface of the composite film by a coating machine, and the coating thickness is controlled to be 2μm. After coating, it is dried in an oven at 60°C to obtain the final ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer product.

[0039] In this article, there are a few points to note:

[0040] 1. The drawings of the embodiments of the present disclosure only involve structures related to the embodiments of the present disclosure, and other structures may refer to general designs.

[0041] 2. In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to obtain new embodiments.

[0042] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. Ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer, including: A base layer (1), the base layer (1) being composed of nano-montmorillonite and ethylene-vinyl acetate copolymer (EVA matrix); characterized in that an adhesive layer (2) is provided on the base layer (1); the adhesive layer (2) is connected to a modified barrier layer (3), and the adhesive layer (2) is located between the base layer (1) and the modified barrier layer (3); an anti-oxidation layer (4), a repair isolation layer (5) and a functional layer (6) are provided in sequence on the outside of the modified barrier layer (3).

2. The ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer according to claim 1, characterized in that: The adhesive layer (2) is composed of an acrylic adhesive modified by a silane coupling agent.

3. The ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer according to claim 1, characterized in that: The modified barrier layer (3) is composed of an aluminum foil layer (301) and an interface strengthening layer (302); the aluminum foil layer (301) is mainly composed of a combination of aluminum elements and alloy elements; and the interface strengthening layer (302) is formed by treating the surface of the aluminum foil layer (301) with ion-grafted acrylic acid monomers.

4. The ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer according to claim 3, characterized in that: The anti-oxidation layer (4) is composed of graphene coated on the surface of the aluminum foil layer (301) after nanoscale grooves are etched on the surface by low-temperature plasma.

5. The ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer according to claim 1, characterized in that: The repair isolation layer (5) is composed of a microencapsulated polysiloxane doped with an EVA matrix, the microcapsule shell layer is a polyurea-formaldehyde resin, and the core material is a hydroxyl-terminated polydimethylsiloxane.

6. The ethylene-vinyl acetate copolymer composite aluminum foil water vapor barrier veneer according to claim 3, characterized in that: The functional layer (6) is formed by drying the chitosan quaternary ammonium salt solution coated on the surface of the aluminum foil layer (301).

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