Flexible packaging film based on two-dimensional material

Abstract

The utility model relates to the field of optical / electronic packaging, in particular to a flexible packaging film based on a two-dimensional material. The packaging film structure is composed of a first protection layer, a two-dimensional material layer, a transfer supporting layer, a heat-resistant supporting layer, an adhesion layer and a second protection layer which are stacked in sequence. Firstly, a two-dimensional material layer grows on a metal foil substrate, then a transfer supporting layer is manufactured on the surface of the two-dimensional material layer, after the metal foil substrate is removed, the two-dimensional material layer / the transfer supporting layer is transferred to the surface of a first protection layer, and finally a heat-resistant supporting layer, an adhesion layer and a second protection layer are manufactured on the surface of the transfer supporting layer. And gas between layers is eliminated and interaction between the layers is increased through a mold pressing method. According to the utility model, the two-dimensional material layer is kept complete in structure, the packaging film can have high water vapor and oxygen barrier characteristics only through 1-3 layers of two-dimensional materials, has good flexibility, is convenient to use, can be used for packaging a device through simple pasting and covering, and can meet the bending property and winding property of the device.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of light / electronic packaging, concretely is a kind of flexible packaging film based on two-dimensional material. BACKGROUND

[0002] Flexible light / electronic devices, including organic transistors, organic solar cells, organic light-emitting diodes, etc., have become an important trend in the development of future devices due to their unique flexibility, portability and lightness, etc., and have broad application prospects. However, the stability and life of the device are one of the biggest challenges to its development. Among them, the invasion of water vapor and oxygen in the environment is the main factor causing the rapid decline of device performance, so using a packaging layer that blocks the diffusion of water and oxygen and other gases to package the device is the key to extending the service life of flexible light / electronic devices and maintaining long-term stability of the device to achieve industrialization.

[0003] The traditional packaging method is to use resin glue to attach a rigid glass cover plate to the target area to block water and oxygen. However, this rigid packaging cannot meet the packaging needs of flexible light / electronics. Currently, a protective layer with inorganic and organic mixed structure replaces the cover plate packaging, bringing a breakthrough in flexible light / electronic technology. However, the process used is complex, the inorganic thin film material has inherent brittleness, and the elastic mismatch between the organic layer and the inorganic layer causes the thin film to delaminate when subjected to external stress and strain, making the flexible packaging effect still unsatisfactory.

[0004] Graphene, boron nitride and other two-dimensional material structures are dense, which are ideal physical barrier layers, with strong covalent bond connection within the layer and good elasticity, so that a sandwich structure with an organic layer is expected to achieve excellent flexible packaging effect. Currently, large-area, high-quality two-dimensional material thin films are mainly grown on metal foil substrates by chemical vapor deposition (CVD) and other methods, and the metal foil substrate often needs to be removed and the two-dimensional material thin film needs to be transferred to the corresponding protective layer, and then the transfer support layer is removed. This process is complex and costly. More importantly, because the support layer often interacts strongly with the two-dimensional material, it is easy to cause defects, cracks and other defects in the two-dimensional material thin film during the removal process, which will greatly affect the barrier properties of the packaging film. In addition, traditional cover plate packaging often uses edge sealing technology, which uses epoxy resin ultraviolet curing glue to bond the cover plate and the substrate, but the epoxy resin ultraviolet curing glue is the main channel for water and oxygen and other gases to pass through, affecting the barrier properties of the packaging film. UTILITY MODEL CONTENTS

[0005] The utility model discloses a flexible packaging film based on two-dimensional material, utilize two-dimensional material film excellent barrier property, and the excellent adhesion of polydimethylsiloxane, phenolic resin, polyurethane etc. adhesive solution solidification, designed the flexible packaging film of structure for first protective layer / two-dimensional material layer / transfer support layer / heat -resistant support layer / adhesion layer / second protective layer, it is simple in structure, has good flexibility, can satisfy the bending and winding of device.

[0006] The utility model discloses a flexible packaging film based on two-dimensional material, utilize two-dimensional material film excellent barrier property, and the excellent adhesion of polydimethylsiloxane, phenolic resin, polyurethane etc. adhesive solution solidification, designed the flexible packaging film of structure for first protective layer / two-dimensional material layer / transfer support layer / heat -resistant support layer / adhesion layer / second protective layer, it is simple in structure, has good flexibility, can satisfy the bending and winding of device.

[0007] A flexible packaging film based on two-dimensional material, the packaging film structure is first protective layer, two-dimensional material layer, transfer support layer, heat -resistant support layer, adhesion layer, second protective layer constitute in turn.

[0008] The two-dimensional material layer is one or more than two stacking structures of graphene, boron nitride, transition metal chalcogenide, MoSi2N4 and WSi2N4 with a layered structure, and the number of layers is 1-3.

[0009] The first protective layer or the second protective layer is polyethylene terephthalate, polyethylene naphthalate, polycarbonate or polypropylene.

[0010] The thickness of the first protective layer is 20-300 microns, and the thickness of the second protective layer is 10-50 microns.

[0011] The transfer support layer is one or more than two layers of polymethyl methacrylate, rosin, paraffin, polycarbonate, polypropylene carbonate and polyimide, and the thickness is 20-300 nanometers.

[0012] The heat -resistant support layer is one or more than two layers of polyimide, polyphenylene sulfide and polyether ether ketone, and the thickness is 100-40 microns.

[0013] The adhesion layer is polydimethylsiloxane, phenolic resin or polyurethane, and the thickness is 100-40 microns.

[0014] The design idea of the utility model is:

[0015] The two-dimensional material structure such as graphene, boron nitride, transition metal chalcogenide, MoSi2N4, WSi2N4 and the like is dense, is an ideal physical barrier layer, the layer is connected by strong covalent bond, has good elasticity, and the interlayer structure formed by the two-dimensional material layer and the organic layer can avoid the problem of elastic mismatch. Therefore, the interlayer structure formed by the two-dimensional material layer and the organic layer can obtain a flexible encapsulation film with excellent water and oxygen barrier properties. On this basis, by using the excellent adhesion of polydimethylsiloxane, phenolic resin, polyurethane and the like, the encapsulation film can be directly attached to the area to be encapsulated of the optical / electronic device to play a water and oxygen barrier role, the operation is convenient, and the complex edge sealing process of the traditional cover plate encapsulation can be avoided and the problem of water and oxygen gas permeating through the ultraviolet curing glue of the epoxy resin can be solved.

[0016] The key to prepare the two-dimensional material encapsulation film is to sandwich the two-dimensional material film between the organic films. At present, the large-area and high-quality two-dimensional material film is mainly grown on a metal foil substrate by a CVD method and the like, and needs to be transferred to the organic layer. In the transfer process, a transfer support layer needs to be made on the surface and then the metal foil substrate is removed, and after being transferred to the corresponding organic layer, the transfer support layer also needs to be removed. This process is complex, high in cost and difficult to scale. More importantly, the process is prone to cause defects and cracks of the two-dimensional material film. Especially, the transfer support layer interacts with the two-dimensional material strongly, and the removal process can tear the two-dimensional material film and cause defects, greatly affecting the barrier properties of the encapsulation film. The utility model directly uses the transfer support layer as one support layer of the encapsulation film, avoids the removal process of the transfer support layer, ensures the structural integrity of the two-dimensional material film, and only 1-3 layers of two-dimensional material are needed to make the encapsulation film have high water vapor and oxygen barrier properties.

[0017] The utility model has the advantages and beneficial effects that:

[0018] 1. The utility model uses the high water and oxygen barrier properties and good elasticity of the two-dimensional material layer such as graphene, forms an interlayer structure with the organic material, and uses the excellent adhesion of polydimethylsiloxane, phenolic resin and polyurethane, designs the flexible encapsulation film with the structure of first protective layer / two-dimensional material layer / transfer support layer / heat-resistant support layer / adhesion layer / second protective layer, the structure is simple, has good flexibility, solves the problem of elastic mismatch of the interlayer structure formed by the inorganic layer and the organic layer in the bending and winding process, and can meet the bending and winding properties of the device.

[0019] 2. The utility model directly uses the transfer support layer as one support layer of the encapsulation film, avoids the removal process of the transfer support layer, ensures the integrity of the two-dimensional material film, and thus only 1-3 layers of two-dimensional material are needed to have high water vapor and oxygen barrier properties.

[0020] 3. The encapsulation film of this utility model is easy to use. After peeling off the second protective layer, it can be directly applied to the surface of optoelectronic devices for encapsulation. This avoids the complexity of traditional cover sealing processes and prevents the penetration of gases such as water and oxygen through the epoxy resin UV curing adhesive. It can also achieve roll-to-roll encapsulation, is easy to scale up, and has good market application scenarios. Attached Figure Description

[0021] Figure 1 This is the structure of the encapsulation film based on two-dimensional materials according to this utility model. In the figure, 1 is the first protective layer; 2 is the two-dimensional material layer; 3 is the transfer support layer; 4 is the heat-resistant support layer; 5 is the adhesion layer; and 6 is the second protective layer. Detailed Implementation

[0022] like Figure 1 As shown, the encapsulation film structure of this utility model consists of a first protective layer 1, a two-dimensional material layer 2, a transfer support layer 3, a heat-resistant support layer 4, an adhesion layer 5, and a second protective layer 6 stacked sequentially.

[0023] The specific preparation process of the encapsulation film based on two-dimensional materials in this invention is as follows:

[0024] First, one to three layers of two-dimensional materials with layered structures, such as graphene, boron nitride, transition metal chalcogenides, MoSi₂N₄, or WSi₂N₄, are grown on a metal foil substrate of Cu, Ni, Au, Pt, or their alloys, with a thickness of 10–50 μm. Then, one or more layers of polymethyl methacrylate (PMMA), rosin, paraffin wax, polycarbonate (PC), polypropylene carbonate (PPC), or polyimide (PI) are fabricated on the surface of the two-dimensional material layer as a transfer support layer, with a thickness of 20 nm–300 nm. Subsequently, the metal foil substrate is removed by chemical etching or electrochemical stripping. If necessary, a single-layer two-dimensional material / transfer support layer can be further deposited as a composite transfer support layer on the surface of the two-dimensional material layer grown on the metal foil substrate. Repeating the metal foil substrate removal step yields two to three layers of two-dimensional material / transfer support layer structures with one or more stacked structures. Finally, the two-dimensional material / transfer support layer is transferred to the surface of a first protective layer with a thickness of 20–300 μm. Next, one or more layers of polyimide (PI), polyphenylene sulfide (PPS), or polyetheretherketone (PEEK) are fabricated on the surface of the transfer support layer as a heat-resistant support layer, with a thickness of 100 nm to 40 μm. Further, an adhesion layer with a thickness of 100 nm to 40 μm and a second protective layer with a thickness of 10 μm to 50 μm are sequentially fabricated on the surface of the heat-resistant support layer. Finally, moisture and gas between the layers are removed by molding, and interlayer interactions are increased.

[0025] The adhesion layer is polydimethylsiloxane (PDMS), phenolic resin or polyurethane, and has the characteristics of stability in high temperature, acidic and alkaline environments.

[0026] The obtained encapsulation film has high flexibility and is convenient to use.

[0027] The results of implementation show that the two-dimensional material flexible encapsulation film maintains the integrity of the two-dimensional material layer structure during preparation, and only 1-3 layers of two-dimensional material can effectively block water vapor and oxygen. The first protective layer is used on the outermost side to protect the two-dimensional material layer and other functional layers; the transfer support layer ensures the integrity of the two-dimensional material transfer process; the heat-resistant support layer further enhances the support effect and has a heat insulation effect; the adhesion layer maintains stability in high temperature, acidic and alkaline environments; and the second protective layer prevents the surface of the adhesion layer from being contaminated, and is torn off when used. At the same time, the encapsulation film has good flexibility and is convenient to use, and can encapsulate the device by simple pasting, and can meet the bending and winding properties of the device.

Claims

1. A flexible encapsulation film based on a two-dimensional material, characterized by The encapsulation film structure is sequentially stacked with a first protective layer, a two-dimensional material layer, a transfer support layer, a heat-resistant support layer, an adhesive layer, and a second protective layer.

2. The flexible encapsulation film based on two-dimensional materials according to claim 1, characterized in that, The two-dimensional material layer is one or more than two stacked structures of graphene, boron nitride, transition metal chalcogenide, MoSi2N4, and WSi2N4 with a layered structure, and the number of layers is 1-3. 3.The flexible encapsulation film based on two-dimensional materials according to claim 1, characterized in that, The first protective layer or the second protective layer is polyethylene terephthalate, polyethylene naphthalate, polycarbonate, or polypropylene. 4.The flexible encapsulation film based on two-dimensional materials according to claim 1, characterized in that, The thickness of the first protective layer is 20-300 μm, and the thickness of the second protective layer is 10-50 μm. 5.The flexible encapsulation film based on two-dimensional materials according to claim 1, wherein, The transfer support layer is one or more than two layers of polymethyl methacrylate, rosin, paraffin, polycarbonate, polypropylene carbonate, or polyimide, and the thickness is 20 nm-300 nm. 6.The flexible encapsulation film based on two-dimensional materials according to claim 1, wherein, The heat-resistant support layer is one or more than two layers of polyimide, polyphenylene sulfide, or polyether ether ketone, and the thickness is 100 nm-40 μm. 7.The flexible encapsulation film based on two-dimensional materials according to claim 1, wherein, The adhesive layer is polydimethylsiloxane, phenolic resin, or polyurethane, and the thickness is 100 nm-40 μm.

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