Flexible patch type packaging film and preparation method and packaging method thereof

Abstract

The invention relates to the field of packaging materials, in particular to a flexible patch type packaging film and a preparation method and a packaging method thereof. According to the packaging film, single-layer graphene serves as a core water and oxygen blocking layer, a polymer protection layer is arranged on the outer side of the graphene, and multiple layers of polymers with the surface energy sequentially reduced are arranged on the inner side of the graphene, so that the graphene and the multiple layers of polymers are of a gradient surface energy structure, the multiple layers of polymers are stacked from the graphene to the innermost layer according to the sequence that the surface energy is from high to low, a gradient water and oxygen blocking and water absorbing structure is obtained, a barrier for blocking water and oxygen layer by layer is formed, and meanwhile water is adsorbed and diffused outwards layer by layer. The patch type packaging film can be rolled into a roll, can be directly attached to the area, needing to be packaged, of the device like a conventional adhesive tape, and is simple and efficient. According to the invention, the defects of the traditional packaging material in the aspects of flexibility, operation convenience and protection performance are overcome, and the packaging material has a wide application prospect in the packaging field of electronic devices, optoelectronic devices and other sensitive equipment.

Description

Technical Field

[0001] The present invention relates to the field of packaging materials, and specifically to a flexible patch-type packaging film and a preparation method and packaging method thereof. The packaging film uses a single-layer graphene as a core barrier material, and is combined with a multi-layer polymer material. Through reasonable surface energy design, it has a gradient water-proof and oxygen-proof and water-absorbing structure, thereby achieving an efficient waterproof and oxygen-proof effect. In addition, the patch-type packaging film can be rolled into a roll, similar to the form of a conventional tape, which is easy to use and is suitable for waterproofing and oxygen-proofing electronic devices, optoelectronic devices and other sensitive devices of different shapes and sizes. Background Art

[0002] With the continuous development of electronic and optoelectronic devices, the requirements for the performance of packaging materials are becoming higher and higher. Traditional packaging materials such as glass, metal and polymer films have many limitations in terms of waterproof, oxygen-proof and operation. Although glass has excellent waterproof and oxygen-proof properties, it is brittle and easy to break during operation, resulting in packaging failure. At the same time, the weight and thickness of glass are large, which is not suitable for the packaging of devices that require lightness and flexibility. Although metal materials have good barrier properties, they are easily corroded in humid or corrosive environments, affecting the packaging effect, and the conductivity of metal materials may cause short circuits or interference in some applications, increasing the complexity of use. The waterproof and oxygen-proof effect of polymer films is poor, and it is difficult to have efficient water barrier and oxygen isolation at the same time, and it is easy to be affected by environmental factors and performance degradation occurs. The sandwich structure of polymers and inorganic materials combines the advantages of both, bringing new opportunities for flexible packaging. However, the inherent brittleness of inorganic thin film materials and the elastic mismatch between the polymer layer and the inorganic layer make the flexible packaging effect still poor and the packaging process complicated. Therefore, there is an urgent need to develop new packaging materials and technologies that can maintain good water-proof and oxygen-proof properties while also being light, flexible and easy to operate.

[0003] As an emerging two-dimensional material, graphene has excellent physical barrier properties, good flexibility, and strong elastic deformation ability. It is an ideal flexible packaging material. However, a single graphene film is very easy to break in practical applications, which affects its barrier effect and is not easy to operate. To this end, researchers have proposed a method of compounding graphene with polymers in order to enhance its barrier properties and operability. In the prior art, the sandwich structure film of multilayer graphene and polymer has made certain progress in waterproof and oxygen-proof properties, but the preparation of multilayer graphene films is difficult and costly. Moreover, in practical applications, how to design the stacking structure of graphene and polymer packaging films to obtain better waterproof and oxygen-proof properties, and how to increase interlayer interactions to avoid stratification and shedding are still urgent problems to be solved. In addition, how to prepare it in a form that is easy to use is also the core key, especially in some occasions that require fast and efficient packaging, the ease of use and operating efficiency of existing materials need to be further improved. Summary of the invention

[0004] The object of the present invention is to provide a flexible patch type packaging film and its preparation method and packaging method, aiming to solve the deficiencies of traditional packaging materials in terms of waterproof and oxygen-proof protective performance, flexibility and ease of operation and use. The flexible patch type packaging film uses a single layer of graphene as the core barrier material, and forms a gradient surface energy structure with a polymer material. The inner layer is a multilayer polymer material, and a multilayer polymer material is deposited on the surface of the graphene layer. Through surface energy design, it is stacked from graphene to the innermost layer in the order of high to low surface energy to form a barrier that blocks water and oxygen layer by layer. At the same time, the gradient surface energy polymer layer can absorb moisture in the device or equipment to be packaged, so that the moisture diffuses outward layer by layer, thereby achieving a more efficient waterproof and oxygen-proof effect. In addition, the bonding force between the layers of material is stronger, ensuring the stability and durability of the packaging film. The packaging film can be rolled into a roll, similar to the conventional tape form, which is easy to use and suitable for electronic devices, optoelectronic devices and other sensitive devices of various shapes that require efficient packaging.

[0005] The technical solution of the present invention is:

[0006] A flexible patch-type packaging film, which uses a single-layer graphene as a core water and oxygen barrier layer, a polymer protective layer on the outside of the graphene, and a multilayer polymer with a surface energy decreasing successively on the inside of the graphene, so that the graphene and the multilayer polymer form a gradient surface energy structure, and the multilayer polymers are stacked in order from high to low surface energy from the graphene to the innermost layer to obtain a gradient water and oxygen barrier and water absorption structure, forming a barrier that blocks water and oxygen layer by layer, and at the same time absorbs water to diffuse it outward layer by layer.

[0007] In the flexible patch type packaging film, the graphene is prepared on the polymer protective layer by chemical vapor deposition growth and transfer technology, and the graphene is a single layer.

[0008] The polymer protective layer of the flexible patch packaging film is a flexible polymer, including one or more layers of polyethylene terephthalate, polyimide, polyethylene naphthalate, and flexible glass, and has a thickness of 30 to 200 μm.

[0009] The flexible patch packaging film has a multilayer polymer with a lower surface energy than graphene on the inner side of the graphene, including polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, polyethylene terephthalate, polyamide, polyvinyl alcohol, polycarbonate, polyimide, ultraviolet light curing adhesive, biaxially oriented polypropylene film, polyvinylidene fluoride, and acrylate. The materials selected for the multilayer polymer are stacked on the graphene surface in order of surface energy from high to low, with a layer number of 2 to 7 and a thickness of 50nm to 50μm.

[0010] The preparation method of the flexible patch type packaging film is as follows: first, graphene is grown by chemical vapor deposition and transferred to a polymer protective layer to form a composite structure of a polymer protective layer and a core water and oxygen barrier layer; then, multilayer polymers with different surface energies are coated layer by layer on the graphene surface by centrifugal coating, spin coating or scraping technology to form multilayer polymers with successively decreasing surface energies, and heat pressing is performed to form a final flexible patch type packaging film.

[0011] In the method for preparing the flexible patch type packaging film, the temperature of the hot pressing treatment is 60-100° C. and the pressure is 0.3-10 MPa.

[0012] The method for preparing the flexible patch type packaging film has a multi-layer structure with a total number of 4 to 9 layers. From the graphene layer to the innermost layer, the surface energy decreases step by step, ranging from 15 to 65 mN / m.

[0013] In the packaging method of the flexible patch type packaging film, the flexible patch type packaging film is rolled into a roll, and when in use, it is directly attached to the area of ​​the device or equipment that needs to be packaged.

[0014] The packaging method of the flexible patch type packaging film further performs heat pressing treatment on the edge of the packaging film, the heat pressing temperature is 110-140° C., and the pressure is 0.5-2 MPa.

[0015] The packaging method of the flexible patch type packaging film is that the flexible patch type packaging film is flexible as a whole, and the flexible design enables the packaging film to be better attached to irregular surfaces, and is suitable for waterproofing and oxygen-proofing electronic devices, optoelectronic devices and other sensitive equipment of different shapes and sizes.

[0016] The design concept of the present invention is:

[0017] In order to solve the needs of waterproof, anti-oxygen, flexibility and ease of use faced by current electronic devices and optoelectronic devices in the packaging process, the present invention provides a new type of flexible patch packaging film and packaging technology, which combines the excellent barrier properties of graphene and the design flexibility and functional diversity of polymer materials, and realizes efficient packaging effect and ease of use through multi-layer structure and surface energy gradient design. As a core barrier material, single-layer graphene can effectively block the penetration of water molecules and oxygen molecules by virtue of its excellent physical barrier properties. Flexible polymers serve as polymer protective layers of the packaging film to protect graphene from physical damage. On this basis, multi-layer polymer materials are coated on the surface of graphene, and the surface energy and hydrophilicity from graphene to the innermost layer (i.e., the contact layer between the packaging film and the area to be packaged) are gradually reduced to form a gradient surface energy structure, which blocks the penetration of water molecules layer by layer, and further enhances the overall waterproof oxygen effect. At the same time, the residual water molecules in the device will diffuse outward layer by layer from the polymer layer with low hydrophilicity, so this gradient surface energy structure can also play a role in adsorbing water molecules in the device to be packaged. In addition, the surface energies of adjacent polymer layers are similar, resulting in better interface bonding. The final flexible patch-type packaging film formed by hot pressing technology has stronger interlayer adhesion, thus avoiding the possibility of delamination and falling off.

[0018] The patch-type packaging film is flexible as a whole and can be rolled into a roll, so it can be directly attached to the area where the device or equipment needs to be packaged, similar to conventional tape, to achieve simple, convenient and efficient packaging operations, greatly improving the efficiency of use and the convenience of operation. Through the above design ideas, the present invention provides a new type of flexible patch-type packaging film, which can not only meet the needs of efficient waterproof and oxygen-proof, but also has excellent flexibility and ease of use, can adapt to the protection needs of electronic devices of different shapes and sizes, and has broad application prospects.

[0019] The advantages and beneficial effects of the present invention are:

[0020] 1. The present invention uses a single-layer graphene as the core barrier material, which is prepared by chemical vapor deposition (CVD) technology and transferred to a flexible substrate to ensure the integrity and high-efficiency barrier performance of the graphene layer. Only a single atomic layer of graphene can effectively block the penetration of water molecules and oxygen molecules, so that the packaging film has excellent waterproof and oxygen-proof properties. At the same time, the single-layer graphene has a strong elastic deformation ability, and the combination with the polymer to form a flexible patch-type packaging film avoids the performance degradation caused by elastic mismatch.

[0021] 2. The multilayer polymer material of the present invention forms a gradient surface energy structure, and the surface energy decreases layer by layer from graphene to the innermost layer. This multilayer gradient surface energy structure design not only provides multiple protection barriers, but also allows water molecules in the device to be packaged to diffuse out layer by layer, forming a more comprehensive and efficient protection system. In addition, the surface energies of adjacent polymer layers are similar, with better interface bonding. The final flexible patch-type packaging film formed by hot pressing technology has stronger interlayer adhesion, avoiding the possibility of stratification and shedding, ensuring the mechanical strength, stability and durability of the packaging film, and extending the service life of the packaging film.

[0022] 3. The packaging film of the present invention is designed as a flexible structure. The flexible design enables the packaging film to be better attached to irregular surfaces, and can adapt to the protection requirements of electronic devices of different shapes and sizes, thereby improving the sealing and reliability of the packaging. In addition, the patch packaging film can be rolled into a roll, which is in the form of a conventional tape and can be directly torn off and attached to the area that needs to be packaged, thus achieving a simple and efficient packaging operation. Users can complete the packaging process without the aid of complex tools or equipment, which greatly improves the operating efficiency, and is particularly suitable for application scenarios that require fast and efficient packaging, such as the packaging of flexible electronic devices and optoelectronic devices.

[0023] In summary, the present invention provides a packaging material with excellent performance and easy operation by improving comprehensive performance such as efficient water and oxygen barrier properties, flexibility and ease of use, solves related problems in the prior art, and meets the needs of modern electronic devices and optoelectronic devices for efficient protection and convenient application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The structure of the flexible patch type packaging film of the present invention is shown in the figure. In the figure, 1 is a polymer protective layer; 2 is a core water and oxygen barrier layer; 3 is a multilayer polymer with successively decreasing surface energy, which still has good adhesion after hot pressing.

[0025] Figure 2 This is the surface energy ranking diagram of some materials in the packaging film structure.

[0026] Figure 3 Schematic diagram of the principle of water vapor movement within a gradient surface energy structure.

[0027] Figure 4 The figure is a schematic diagram of the production and use of flexible patch packaging film and packaging technology. In the figure, 1 is a polymer protective layer; 2 is a core water and oxygen barrier layer; 3 is a multi-layer polymer with decreasing surface energy; 4 is a roll of patch packaging film tape; 5 is a substrate in actual application; 6 is a target material, product or device that needs to be packaged and protected; 7 is a patch packaging film that has been packaged.

[0028] Figure 5This is a physical picture of the flexible patch-type packaging film prepared in Example 1. DETAILED DESCRIPTION

[0029] In the specific implementation process, the present invention uses CVD growth and transfers to one or more polymer protective layers 1 of polyethylene terephthalate (PET), polyimide (PI), polyethylene naphthalate (PEN), and flexible glass with a thickness of 30 to 200 μm to form a graphene such as Figure 1 The polymer protective layer 1 and the core water and oxygen barrier layer 2 shown in the figure are only a single layer of graphene. Then, by centrifugal coating, spin coating or scraping technology, two or more polymer materials with different surface energies such as polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyamide (PA), polyvinyl alcohol (PVA), polycarbonate (PC), polyimide (PI), ultraviolet curing glue (UV glue), biaxially oriented polypropylene film (BOPP), polyvinylidene fluoride (PVDF), acrylate, etc. are coated on the graphene surface layer by layer to form a Figure 1 The multilayer polymer 3 has a decreasing surface energy, a number of layers of 2 to 7, and a thickness of 50 nm to 50 μm.

[0030] according to Figure 2 As shown, the coating sequence is adjusted from high to low according to the surface energy. From the graphene layer to the innermost layer, the surface energy decreases step by step, covering a range of 15 to 65 mN / m. This multi-layer gradient surface energy structure design not only provides multiple protection barriers, but also allows water molecules in the device to be encapsulated to diffuse out layer by layer, forming a more comprehensive and efficient protection system. Finally, after hot pressing treatment at 60 to 100 ° C and 0.3 to 10 MPa, a flexible water and oxygen barrier packaging film based on a multilayer structure of graphene and polymer was obtained. The total number of layers is 4 to 9. After hot pressing treatment, it still has good adhesion, and the adhesion between adjacent layers is strong, avoiding the possibility of stratification and shedding.

[0031] like Figure 3 As shown in the figure, the movement mechanism of water vapor in the gradient surface energy structure is based on the driving force caused by the surface energy gradient, which enables water molecules to move between multilayer films. This phenomenon is called capillary transport effect. In the multilayer film structure, due to the difference in surface energy between different layers, water molecules are subject to different interfacial attractions, which promotes the migration of water from the functional layer A with low surface energy to the functional layer B with high surface energy. Specifically, the surface energy gradient drives the water molecules to move in the direction of decreasing contact angle, that is, from the receding contact angle (θ a ) Advancing contact angle (θ b ) direction.

[0032] like Figure 1 and Figure 4 As shown, the specific implementation process of the packaging technology based on the flexible patch packaging film in the present invention is as follows: First, since the patch packaging film has good flexibility, a roll packaging film (i.e., a roll of the patch packaging film tape 4) can be obtained by rolling, which has the ease of use similar to that of conventional tapes, and can be packaged by pulling out and cutting, so as to realize the immediate use of the flexible patch packaging film. During packaging, the patch packaging film is cut off and tightly attached to the outer surface of the target material, product or device 6 that needs to be packaged and protected. The packaged patch packaging film 7 that has been packaged will cover the target material, product or device 6 that needs to be packaged and protected on the substrate 5 in actual application. The edge of the patch packaging film can also be further subjected to a hot pressing treatment at a temperature of 110 to 140°C and a pressure of 0.5 to 2MPa to enhance the sealing performance of the packaging film, thereby providing more effective waterproof and oxygen-proof protection.

[0033] The present invention is further described in detail below with reference to embodiments.

[0034] Example 1

[0035] In this embodiment, the graphene on the polymer protective layer PET with a thickness of 125 μm is first prepared by CVD growth and transfer technology. The number of graphene layers is 1, the thickness is 0.5 nm, and it has excellent flexibility. Then, the PI layer, PVC layer, PMMA layer and acrylate layer are deposited on the graphene surface in sequence by centrifugal coating technology. The surface energy is reduced layer by layer, and the thickness of each layer is 100 nm, forming a multi-level, efficient barrier structure packaging film. After that, the packaging film is subjected to hot pressing treatment, and the hot pressing conditions are set to a temperature of 80 ° C and a pressure of 10 MPa to ensure the close combination of each layer of material and the mechanical strength of the overall structure. Finally, a multi-layer structure flexible patch packaging film with a structure of PET layer / single-layer graphene / PI layer / PVC layer / PMMA layer / acrylate layer is obtained, which has excellent flexibility and a total number of layers of 6 layers. Due to its good viscosity, the innermost acrylate layer enables the entire packaging film to be closely attached to the target material or device surface when in use.

[0036] like Figure 5As shown, the flexible patch packaging film is rolled into a roll-shaped patch packaging film finished product similar to a tape. In a specific application, the patch packaging film is cut and attached to the surface of the perovskite solar cell device, and the edge of the packaging film is further subjected to a hot pressing treatment at a temperature of 110°C and a pressure of 2MPa to enhance the sealing performance of the packaging film. The encapsulated device is then placed in a hydrobromic acid solution with a pH of 1 and a temperature of 85°C for durability testing. After 7 days, the photoelectric conversion efficiency of the device only decreased by 10%, and the characteristic peak of the absorption spectrum of the internal perovskite material still did not show significant changes, verifying the effective protection ability of the packaging film for electronic devices in extreme environments. Finally, the encapsulated device was mechanically shaken in boiling pure water for 1 hour, with an amplitude of 40 mm and an oscillation frequency of 150 times / minute. The packaging film still fits tightly to the surface of the device, and no delamination or detachment occurs.

[0037] Example 2

[0038] The difference from Example 1 is that in this embodiment, the structure of the obtained flexible patch-type packaging film is: PET layer, graphene layer, PMMA layer and acrylate layer, with a total number of 4 layers. The PMMA layer and acrylate layer are sequentially deposited on the graphene surface by centrifugal coating technology, and the thickness of the PMMA layer is 300nm and the thickness of the acrylate layer is 100nm. The packaging film is subjected to hot pressing treatment, and the hot pressing conditions are temperature 70°C and pressure 6MPa to form a multi-layer high-efficiency barrier structure flexible patch-type packaging film.

[0039] This embodiment has the simplest packaging structure. In a specific application, the patch packaging film is cut and attached to the surface of the perovskite solar cell device, and the packaged device is placed in a hydrobromic acid solution with a pH of 1 and a temperature of 85°C for durability testing. After 7 days, the photoelectric conversion efficiency of the device decreased by 20%, and the characteristic peak of the absorption spectrum of the internal perovskite material remained unchanged, verifying the effective protection ability of the packaging film for electronic devices in extreme environments; finally, the packaged device was mechanically shaken in boiling pure water for 2 hours, and the packaging film still fit tightly to the surface of the device without obvious stratification or shedding.

[0040] Example 3

[0041] The difference from Example 1 is that in this example, the structure of the obtained flexible patch type packaging film is: flexible glass layer, PET layer, graphene layer, PI layer, PVC layer, PMMA layer and acrylate layer in sequence; in the specific preparation process, the graphene is transferred to the composite polymer protective layer of the PET layer with a thickness of 50 μm and the flexible glass layer with a thickness of 150 μm. The packaging film is subjected to hot pressing treatment, and the hot pressing conditions are a temperature of 80°C and a pressure of 0.5 MPa to form a multi-layer high-efficiency barrier structure flexible patch type packaging film.

[0042] In specific applications, the patch-type packaging film is cut and attached to the surface of the flat perovskite material, and the edge of the packaging film is further subjected to a heat pressing treatment at a temperature of 140°C and a pressure of 0.5MPa to enhance the sealing performance of the packaging film, and then placed in a hydrobromic acid solution with a pH of 1 and a temperature of 85°C for durability testing. After 14 days, the characteristic peak of the absorption spectrum of the perovskite material did not change significantly, indicating that the packaging film played an effective protective role and could provide reliable protection in extremely acidic environments.

[0043] Example 4

[0044] The difference from Example 1 is that in this embodiment, a PC layer and a PMMA layer with a thickness of 100 nm are sequentially coated on the graphene surface using a scraping technique. The resulting flexible patch-type packaging film structure is a PET layer, a graphene layer, a PC layer and a PMMA layer. The packaging film is subjected to a hot pressing treatment, and the hot pressing conditions are a temperature of 100°C and a pressure of 10 MPa to form a multi-layer, high-efficiency barrier structure flexible patch-type packaging film. The innermost PMMA layer has good adhesion, so that the entire packaging film can be closely attached to the target material or device surface when in use.

[0045] In specific applications, the flexible patch packaging film is cut and attached to the surface of the flexible organic solar cell, and the edge of the packaging film is further subjected to hot pressing at a temperature of 110°C and a pressure of 1MPa. Then, a number of reliability tests were carried out. In the 0.5-meter drop test, the packaging film showed excellent mechanical stability and adhesion performance. After the test, there was no peeling, breakage or cracking of the packaging film. Next, the organic solar cell was placed in an accelerated aging environment with a humidity of 90% and a temperature of 85°C for 72 hours. The results showed that the packaging film can still effectively block the intrusion of moisture and oxygen in a humid environment, and the photoelectric conversion efficiency of the organic solar cell remains stable. This shows that the packaging film not only has excellent mechanical protection functions, but also can provide long-term and stable waterproof and oxygen protection in high humidity and harsh environments, ensuring the performance and life of organic solar cells.

[0046] Example 5

[0047] The difference from Example 1 is that in this embodiment, a single layer of graphene transferred to a PI layer with a thickness of 100 μm is used to form the core barrier layer of the packaging film. Subsequently, a PVDF layer and an acrylate layer with thicknesses of 600 nm and 50 nm, respectively, are coated on the graphene surface by spin coating technology. The resulting flexible patch-type packaging film structure is a PI layer, a graphene layer, a PVDF layer and an acrylic layer, in sequence. The packaging film is subjected to hot pressing treatment at a temperature of 70°C and a pressure of 5 MPa to form a multi-layer, high-efficiency barrier structure flexible patch-type packaging film.

[0048] In specific applications, the flexible patch packaging film was cut into suitable sizes for packaging 6×6 small solar cell arrays of 0.2cm×0.2cm in size. The edges of the packaging film were further subjected to a heat pressing treatment at a temperature of 90°C and a pressure of 1.5MPa to enhance the sealing performance of the packaging film. Next, the packaged battery array was subjected to an accelerated aging test for 10 days in a high temperature and high humidity environment (85°C, 90% humidity). The results showed that the photoelectric conversion efficiency of the solar cell was maintained at a high level, and the packaging film did not show delamination or peeling.

[0049] Example 6

[0050] The difference from Example 1 is that in this embodiment, the core barrier material of the flexible patch-type packaging film is transferred to a single-layer graphene on a PEN layer with a thickness of 150 μm. The scraping technology is used to coat the graphene surface with a PTFE layer, a PP layer, and a PA layer with thicknesses of 1 μm, 500 nm, and 100 nm, respectively. The resulting flexible patch-type packaging film structure is a PEN layer, a graphene layer, a PTFE layer, a PP layer, and a PA layer, in sequence. The packaging film is subjected to hot pressing treatment at a temperature of 90°C and a pressure of 8 MPa to form a multi-layer, high-efficiency barrier structure flexible patch-type packaging film.

[0051] The flexible patch packaging film was cut and attached to the outer surface of the metal electrode of the organic light-emitting diode (OLED) display device, and an accelerated aging test was carried out at a temperature of 70°C and a humidity of 90%. The results showed that the packaging film can effectively prevent moisture from intruding, and after 100 hours, the brightness of the OLED display decayed by less than 5%.

[0052] Example 7

[0053] The difference from Example 1 is that in this embodiment, a single layer of graphene transferred to a PI layer with a thickness of 150 μm is used. PA, PET, PI, UV glue, PVC, PMMA and acrylate layers with a thickness of 100 nm are coated on the graphene surface by centrifugal coating technology. The resulting flexible patch-type packaging film structure is a PI layer, a graphene layer, PA, PET, PI, UV glue, PVC, PMMA and an acrylate layer in sequence. The packaging film is subjected to hot pressing treatment, and the hot pressing conditions are a temperature of 85°C and a pressure of 8MPa to form a multi-layer, high-efficiency barrier structure flexible patch-type packaging film.

[0054] In a specific application, the flexible patch packaging film was cut and used to package 64×64 100μm×200μm flexible active matrix OLED display arrays. The packaged OLED array was subjected to an accelerated aging test for 10 days in a high temperature and high humidity environment (85°C, 90% humidity). The results showed that the efficiency of the OLED display array was only reduced by 5%, and the packaging film had no delamination or peeling.

[0055] The implementation results show that the present invention transfers a single layer of graphene on a flexible substrate such as PET, and then uses centrifugal coating and other technologies to coat polymer materials with different surface energies layer by layer, so that the surface energy is reduced in sequence, thereby realizing a multi-level efficient barrier structure. The encapsulation film finally obtained by hot pressing technology has excellent mechanical strength, flexibility, and water-proof and oxygen-proof properties. The flexible patch-type encapsulation film of the present invention is also convenient and easy to use. By rolling the encapsulation film into a form similar to a tape, it can be easily pulled out, cut and used immediately. This design not only improves the practicality of the encapsulation film, but also greatly simplifies the encapsulation process and improves work efficiency. In the encapsulation applications of various devices such as perovskite solar cells, organic solar cells and organic light-emitting diodes, the encapsulation film of the present invention has shown excellent performance and demonstrated broad application prospects.

Claims

1. A flexible patch packaging film, characterized in that: The packaging film uses a single-layer graphene as the core water and oxygen barrier layer, a polymer protective layer on the outside of the graphene, and a multilayer polymer with decreasing surface energy on the inside of the graphene, so that the graphene and the multilayer polymer have a gradient surface energy structure. The multilayer polymers are stacked in order from high to low surface energy from graphene to the innermost layer to obtain a gradient water and oxygen barrier and water absorption structure, forming a barrier that blocks water and oxygen layer by layer, while adsorbing water to diffuse outward layer by layer.

2. The flexible patch packaging film according to claim 1, characterized in that: The graphene is prepared on the polymer protective layer by chemical vapor deposition growth and transfer technology, and the graphene is a single layer.

3. The flexible patch packaging film according to claim 1, characterized in that: The polymer protective layer is a flexible polymer, including one or more layers of polyethylene terephthalate, polyimide, polyethylene naphthalate, and flexible glass, and has a thickness of 30 to 200 μm.

4. The flexible patch packaging film according to claim 1, characterized in that: The inner side of the graphene is a multilayer polymer with a lower surface energy than the graphene, including polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, polyethylene terephthalate, polyamide, polyvinyl alcohol, polycarbonate, polyimide, UV-curing adhesive, biaxially oriented polypropylene film, polyvinylidene fluoride, and acrylate. The materials selected for the multilayer polymer are stacked on the graphene surface in order of surface energy from high to low, with a layer number of 2 to 7 and a thickness of 50nm to 50μm.

5. A method for preparing the flexible patch type packaging film according to any one of claims 1 to 4, characterized in that: First, graphene is grown by chemical vapor deposition and transferred to a polymer protective layer to form a composite structure of a polymer protective layer and a core water and oxygen barrier layer; then, multilayer polymers with different surface energies are coated layer by layer on the graphene surface by centrifugal coating, spin coating or scraping technology to form multilayer polymers with successively decreasing surface energies, and then hot pressing is performed to form the final flexible patch-type packaging film.

6. The method for preparing the flexible patch type packaging film according to claim 5, characterized in that: The temperature of the hot pressing treatment is 60 to 100° C., and the pressure is 0.3 to 10 MPa.

7. The method for preparing the flexible patch type packaging film according to claim 5, characterized in that: The packaging film has a multi-layer structure with a total number of 4 to 9 layers. From the graphene layer to the innermost layer, the surface energy decreases step by step, ranging from 15 to 65 mN / m.

8. A packaging method for the flexible patch type packaging film according to any one of claims 1 to 4, characterized in that: The flexible patch packaging film roll is wound into a roll and is directly applied to the area where the device or equipment needs to be packaged when used.

9. The packaging method of the flexible patch type packaging film according to claim 8, characterized in that: The edge of the packaging film is further subjected to heat pressing treatment, with the heat pressing temperature being 110 to 140° C. and the pressure being 0.5 to 2 MPa.

10. The packaging method of the flexible patch packaging film according to claim 8, characterized in that: The flexible patch packaging film is flexible as a whole. The flexible design enables the packaging film to be better attached to irregular surfaces. It is suitable for waterproofing and oxygen-proofing of electronic devices, optoelectronic devices and other sensitive equipment of different shapes and sizes.

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