Water-blocking composite film, heat exchange module, electronic device, and packaging film material

Abstract

A water-blocking composite film, a heat exchange module, an electronic device, and a packaging film material. The water-blocking composite film comprises a water-blocking layer and a protective layer that are stacked; the water-blocking layer is formed of a three-dimensional material having a layered crystal structure and / or at least two layers of stacked two-dimensional sheet-structured materials; the water vapor transmission rate of the water-blocking layer at the temperature of 25°C±5°C and the RH of 50±5% is less than 0.05 g / m2·day. The water-blocking composite film has good water-blocking performance and good flexibility, thereby improving the reliability of the operation of the heat exchange module.

Description

Water-blocking composite membranes, heat exchange modules, electronic devices, and packaging films

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411849140.6, filed on December 14, 2024, with the title “Water-blocking composite membrane, heat exchange module and electronic equipment and packaging film material”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of packaging materials, specifically to a water-blocking composite film, a heat exchange module, electronic equipment, and packaging film. Background Technology

[0004] With the increasing power, integration, and multifunctionality of electronic devices, the heat generated by their internal components has also increased dramatically. Taking mobile terminals such as foldable phones, computers, watches, and glasses as examples, 5G terminal devices use MIMO antenna technology, requiring more antennas to be built into the phone. Each antenna has its own power amplifier, leading to increased power consumption and heat generation. Besides antennas and related components, the performance of processors, batteries, and display components in 5G electronic products is constantly improving to meet the demands of high-speed networks. Their power consumption is significantly higher than in the 4G era, and heat generation has also increased dramatically. For example, processors generate a large amount of Joule heat when performing complex data calculations and signal processing. Current electronic products are constantly pursuing extreme thinness and lightness. Within a limited body space, more high-performance heat-generating components must be accommodated, leaving less and less space for traditional heat dissipation methods. This places higher demands on heat dissipation solutions, requiring efficient heat dissipation without occupying too much space.

[0005] Existing heat dissipation methods involve incorporating a heat exchange module within the electronic device. This module contains a heat exchange medium that circulates within it. When configuring the heat exchange module, one part can be placed in the high-temperature region of the electronic device, while the other part can be placed in the low-temperature region. This transfers heat from the high-temperature region to the low-temperature region, achieving uniform heat distribution within the device. However, because the heat exchange module is located inside the device, leakage of the heat exchange medium within the module directly affects the normal operation of the electronic device, and such leaks are difficult to detect. Furthermore, for applications requiring bending, such as foldable phones and tablets, the water-resistant membrane in existing heat exchange modules is prone to cracking, increasing the probability of heat exchange medium leakage, reducing the reliability of the heat exchange module, and ultimately lowering the safety of the electronic device. Summary of the Invention

[0006] This application provides a water-blocking composite membrane, a heat exchange module, an electronic device, and a packaging film. The water-blocking composite membrane has high water-blocking performance and good flexibility to improve the reliability of the heat exchange module operation.

[0007] In a first aspect, this application provides a water-blocking composite membrane, comprising a water-blocking layer and a protective layer stacked together; the water vapor permeability of the water-blocking layer is lower than that of the protective layer. The water-blocking layer is formed from a three-dimensional material having a layered crystalline structure, and / or at least two layers of a two-dimensional sheet structure material stacked together. The water vapor permeability of the water-blocking layer at 25℃±5℃ and 50±5%RH is <0.05g / m³. 2 ·day.

[0008] The water-blocking composite membrane of this application has a low water vapor permeability of less than 0.05 g / m³ at 25℃±5℃ and 50±5% relative humidity (RH). 2 • Day, used to achieve high water and gas barrier performance. The water-blocking layer is mainly formed of three-dimensional materials with a layered crystal structure or mainly of stacked two-dimensional sheet-like materials. When subjected to external forces, the water-blocking layer can effectively disperse pressure to various layers, thereby improving its resistance to breakage and enhancing its own deformation capacity, thus improving its stability. The protective layer can encapsulate the water-blocking layer to prevent it from detaching.

[0009] In one implementation, the elongation at break of the protective layer is greater than that of the water-blocking layer. The higher elongation at break of the protective layer provides better flexibility to the water-blocking composite membrane, enabling it to maintain high integrity even during repeated bending and reducing the likelihood of cracking in the water-blocking layer. This allows the water-blocking composite membrane to achieve both high water-blocking properties and crack resistance and bending resistance.

[0010] In one implementation, the three-dimensional material with a layered crystal structure may include at least one of a first carbon material, mica, boron nitride, carbon nitride, silicon nitride, and montmorillonite. In another implementation, the two-dimensional layered structure material includes at least one of a second carbon material, transition metal dichalcogenide, two-dimensional black scale, and Mxene material. The water-blocking layer, formed using the above materials, can achieve both high water-blocking performance and a certain degree of crack resistance, thereby improving the overall performance of the water-blocking composite membrane.

[0011] In one implementation, the first carbon material is a three-dimensional carbon material with a layered crystal structure, such as graphite. In another implementation, the second carbon material is a carbon material with a two-dimensional sheet structure, such as at least one of graphene, graphene oxide, graphene selenide, and graphene sulfide. In one implementation, the water-blocking layer can be formed from carbon-based materials such as the first or second carbon material. Carbon-based materials such as graphite and graphene have high thermal diffusivity, thermal conductivity, excellent stability, and corrosion resistance, which can improve the thermal conductivity of the water-blocking composite film. Furthermore, these carbon-based materials can be easily formed into large-area thin films, thus facilitating the fabrication of the water-blocking composite film.

[0012] In one implementation, the elongation at break of the water-blocking layer is greater than 3%, for example, greater than or equal to 5%, or greater than or equal to 7%. Increasing the elongation at break of the water-blocking layer helps improve the flexibility of the entire water-blocking composite membrane. Water-blocking composite membranes formed using water-blocking layers with high elongation at break can meet the requirement of being able to withstand 200,000 repeated bends without cracking at a bending radius of ≤5mm, and further at ≤2mm, making them suitable for use in foldable electronic devices.

[0013] In one implementation, the water vapor permeability of the water-blocking layer at 25℃±5℃ and 50±5%RH is <0.03g / m. 2 ·day, for example, <0.01g / m 2 The lower the water vapor permeability of the water-blocking layer, the better the water-blocking properties of the resulting water-blocking composite membrane. In this application, a water vapor permeability of less than 0.03 g / m is achieved by using carbon-based materials. 2 The water-blocking layer of day can greatly improve the overall performance of the water-blocking layer.

[0014] In one implementation, the domain size La in the material forming the water-blocking layer is greater than 10 μm, for example, greater than or equal to 20 μm, or for example, greater than or equal to 50 μm. When the water-blocking layer includes carbon-based materials such as a first carbon material or a second carbon material, increasing the domain size in the carbon-based material can help reduce internal defects and interlayer spacing, thereby effectively reducing the water vapor permeability of the carbon-based material and improving its water-blocking performance.

[0015] In one implementation, the density of the water-blocking layer is greater than 2 g / cm³. 3 For example, it can be greater than or equal to 2.1 g / cm³. 3 For example, it can be greater than or equal to 2.15 g / cm³. 3 The water-blocking layer in this application has a high density, indicating a small interlayer gap, which effectively blocks the transport of water vapor within the water-blocking layer and prevents water vapor from seeping out along the interlayer gaps. Therefore, when the density of the water-blocking layer is greater than 2 g / cm³... 3This indicates that the water-blocking layer has few internal pores, and experimental verification shows that when the density of the water-blocking layer is greater than 2 g / cm³... 3 At this time, its water vapor permeability can be significantly reduced.

[0016] In one implementation, the thickness of the water-blocking layer is 0.1–100 μm, for example, 0.1–10 μm, or 0.1–1 μm. The thickness of the water-blocking layer can be reduced to meet the needs of the integration of electronic devices. In addition, when the thickness of the water-blocking layer is small, it can exhibit a light-transmitting effect, thereby allowing observation of the operation of other components through the water-blocking layer.

[0017] The thickness of the water-blocking layer can be controlled by adjusting the thickness of the coating slurry, or it can be thinned by mechanical peeling. For example, for a carbon-based water-blocking layer, mechanical thinning can be achieved by roll-to-roll adhesive peeling.

[0018] In one implementation, the water-blocking layer is obtained by graphitizing multiple layers of graphene. After graphitization, the atomic orientation of the multilayer graphene increases, the size of the crystal domains increases, the interlayer distance decreases, the interlayer structure becomes denser, and there are fewer defects within the layers. This avoids delamination of the graphene during bending, thus obtaining a water-blocking layer with better stability and lower water vapor permeability.

[0019] In one implementation, the surface roughness of the water-blocking layer is 0.1–5 μm, or for example, 0.1–1 μm. By adjusting the surface roughness of the water-blocking layer, the bonding force between the water-blocking layer and other layers can be improved, thereby increasing the interlayer bonding strength and density and preventing water vapor from penetrating between the water-blocking layer and other layers. For example, the surface roughness of the water-blocking layer can be achieved by adjusting the roughness of the coating substrate during coating.

[0020] In one implementation, the water-blocking composite membrane further includes an adhesive layer disposed on the side of the water-blocking layer opposite to the protective layer and bonded to the water-blocking layer. By providing the adhesive layer, connections with other substrates, heat exchange plates, or heat exchange components can be achieved.

[0021] In one implementation, the thickness of the adhesive layer is greater than or equal to 0.5 μm, or for example, greater than or equal to 1 μm. If the thickness of the adhesive layer is too small, the reliability of the adhesive force provided will decrease. Therefore, in the implementation of this application, the thickness of the adhesive layer is greater than 0.5 μm, which can provide higher adhesive strength for the water-blocking composite membrane, thereby preventing delamination of the water-blocking composite membrane during bending and improving the water-blocking rate of the water-blocking composite membrane after bending.

[0022] In one implementation, the thickness of the adhesive layer is less than or equal to 20 μm, or even less than or equal to 10 μm. If the adhesive layer is too thick, it will increase the overall thickness of the water-blocking composite membrane. Furthermore, if the adhesive layer is too thick, water vapor will be transported within the adhesive layer, which will be detrimental to improving the water-blocking performance of the water-blocking composite membrane.

[0023] In one implementation, the basis weight of the adhesive layer is greater than or equal to 300 g / m². 2 For example, it can be greater than or equal to 500g / m 2 By increasing the basis weight of the adhesive layer, the adhesion of the adhesive layer is improved, thereby increasing the water-blocking rate of the water-blocking composite film after dynamic bending. This avoids delamination after connection with other substrates or after bending, which would cause the water-blocking performance to fail.

[0024] In one implementation, the thermal diffusivity of the water-blocking composite membrane is greater than or equal to 600 mm². 2 / s, or for example, greater than or equal to 700mm 2 / s, or for example, greater than or equal to 800mm 2 / s. The thermal diffusion system of the water-blocking composite membrane is greater than or equal to 600mm. 2 At a temperature of / s, the water-blocking composite membrane can simultaneously possess excellent heat dissipation performance, enabling the heat gained by the water-blocking composite membrane to be rapidly conducted, thus achieving a uniform temperature effect.

[0025] Secondly, this application provides a heat exchange module, which includes a heat exchange pipeline, and the surface of the heat exchange pipeline is provided with the water-blocking composite membrane of this application.

[0026] The heat exchange module of this application can be filled with a heat exchange medium, which can be a liquid heat exchange medium or a gaseous heat exchange medium. The water-blocking composite membrane of this application is set on the surface of the heat exchange pipeline, which can effectively prevent the leakage of the heat exchange medium and maintain the normal operation of the heat exchange pipeline.

[0027] In one implementation, the heat exchange module further includes a pump, which is connected to the heat exchange pipeline to form a closed heat exchange path; the heat exchange pipeline includes a pipeline body and a water-blocking composite membrane, with the water-blocking composite membrane disposed on the outer surface of the pipeline body.

[0028] The heat exchange module also includes a pump that is in closed-loop connection with the heat exchange pipeline. The heat exchange medium within the pipeline circulates under the action of the pump, thereby achieving heat transfer. A water-blocking composite membrane is installed on the outer surface of the pipeline body to prevent leakage of the heat exchange medium.

[0029] The heat exchange pipeline with the water-blocking composite membrane of this application can be used for cooling and heat exchange in various electronic devices, such as foldable phones and foldable tablets. The heat exchange pipeline may have a bent section and extensions on both sides of the bent section, with the bent section used to achieve bending. The bent section can be positioned to correspond to the hinge area of ​​a foldable phone. In foldable devices, the bent section needs to withstand repeated bending. Using the heat exchange pipeline of this application, because the water-blocking composite membrane itself has high water-blocking performance and flexibility, the heat exchange module of this application can maintain structural integrity during 100,000 to 400,000 bending tests at a small-angle bending radius ≤5mm, avoiding cracks or breakage, and consistently maintaining high water-blocking performance, thus improving the stability of the heat exchange module.

[0030] In one implementation, the water-blocking composite membrane is bonded to the pipe body. Bonding achieves the connection between the water-blocking composite membrane and the pipe body, facilitating separate fabrication of the membrane and the pipe body, and simplifying assembly.

[0031] Thirdly, this application provides an electronic device including a heat-generating device and a heat exchange module as described in this application, wherein at least a portion of the heat exchange module is connected to the heat-generating device and at least a portion of the heat exchange module is connected to the heat dissipation area of ​​the electronic device.

[0032] The electronic devices covered by this application may include foldable or non-foldable electronic devices, as well as other electronic devices with heat-generating components. As long as a heat-generating component exists within the electronic device, such as a circuit board or power module, the heat exchange module of this application can be used for heat dissipation. Foldable electronic devices may include foldable phones, foldable tablets, foldable glasses, etc. In non-foldable electronic devices, such as non-foldable phones, the heat exchange module of this application can also be installed internally. A portion of the heat exchange pipelines in the heat exchange module can be located in the high-temperature zone, and another portion can be located in the low-temperature zone, thereby achieving uniform temperature within the electronic device. Furthermore, in other electronic devices, such as power devices, a portion of the heat exchange module can be connected to the heat-generating element of the power device, and another portion can be connected to the heat dissipation zone of the power device, thereby transferring heat from the heat-generating element to other areas and preventing heat concentration that could lead to device failure.

[0033] In one implementation, the electronic device may be a foldable phone, comprising a display screen, a mid-frame, a back cover, and a circuit board. The mid-frame supports the circuit board and the display screen, and is located between the display screen and the back cover. A heat exchange module is located between the back cover and the mid-frame, and / or between the display screen and the mid-frame. By placing the heat exchange module between the back cover and the mid-frame, and / or between the display screen and the mid-frame, rapid heat conduction can be achieved.

[0034] In one implementation, the electronic device has multiple temperature zones, and heat exchange modules can be segmented within different temperature zones. The heat exchange modules of this application can be installed between the various heat-generating and non-heat-generating zones in the electronic device to facilitate heat transfer between them. For example, this electronic device can be a robot, a power module, a drone, or other electronic equipment.

[0035] Fourthly, this application provides a packaging film material, which includes a substrate and a water-blocking composite film of this application disposed on the surface of the substrate.

[0036] The packaging film material of this application, due to its water-blocking composite film, achieves high water-blocking performance. Using this packaging film material, moisture penetration can be prevented, extending the protection time of the stored items.

[0037] In this application, the data in the various possible implementations mentioned above, such as water vapor transmission rate, thickness, temperature, elongation at break, density, basis weight, surface roughness, etc., should be understood as being within the range defined in this application, provided that the values ​​are within the engineering measurement error range. Attached Figure Description

[0038] Figure 1 is a schematic diagram of the internal structure of a foldable mobile phone according to an embodiment of this application;

[0039] Figure 2 is a schematic diagram of the structure of a water-blocking composite membrane according to an embodiment of this application;

[0040] Figure 3 is a schematic diagram of the structure of a water-blocking composite membrane according to another embodiment of this application;

[0041] Figure 4 is a schematic cross-sectional view of a heat exchange pipeline.

[0042] Reference numerals: 001-Folding phone; 01-Hinge; 02-Screen area; 021-First screen area; 022-Second screen area; 03-Heat exchange module; 10-Pump; 20-Heat exchange pipeline; 21-Bend; 22-Extension; 221-First extension; 222-Second extension; 23-Pipe body; 230-Heat exchange channel; 231-First cover plate; 232-Second cover plate; 233-Support column; 24-Water-blocking composite membrane; 241-Adhesive layer; 242-Water-blocking layer; 243-Protective layer. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0044] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise.

[0045] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0046] In fields such as heat exchange and packaging, the water-blocking performance of materials directly affects the reliability of heat exchange modules and packaging films. Taking the heat exchange module of electronic devices as an example, the heat exchange module is usually filled with a heat exchange medium, and heat is conducted by the flow of the heat exchange medium. However, the water-blocking layer of existing heat exchange modules is usually an inorganic material layer with high rigidity and an elongation at break of less than 3%. It is only suitable for non-bending applications such as candybar mobile phones and candybar tablets. For flexible applications that require multiple bends, the above-mentioned water-blocking layer is not suitable, and after multiple bends, the water-blocking layer will partially peel off or even fall off. This leads to a rapid deterioration of the water-blocking performance of the water-blocking layer, and the dynamic water loss rate will increase by more than 100 times.

[0047] In view of this, embodiments of this application provide a water-blocking composite film. The following uses a foldable mobile phone as an example to illustrate the application scenarios of the water-blocking composite film of this application.

[0048] Figure 1 is a schematic diagram of the internal structure of a foldable phone according to an embodiment. As shown in Figure 1, the foldable phone 001 includes at least two screen areas 02, and a hinge 01 is provided between two adjacent screen areas 02. Since the heat-generating components are usually concentrated below one screen area 02, the temperature of that part of the screen area 02 will be higher than the temperature of other screen areas 02. In existing heat dissipation methods, a self-driven heat exchange module 03 can be set inside the electronic device. This heat exchange module 03 can be set across the hinge 01, that is, it extends from one screen area 02 across the hinge 01 to another screen area 02, thereby conducting heat from the high-temperature screen area to the low-temperature screen area, achieving heat dissipation and temperature equalization.

[0049] Specifically, as shown in Figure 1, taking a bi-folding folding phone as an example, the folding phone includes a hinge 01 and two screen areas 02 located on both sides of the hinge, namely a first screen area 021 and a second screen area 022. Heating elements can be integrated into the first screen area 021, for example. During the operation of the folding phone, the temperature of the first screen area 021 will be higher than the temperature of the second screen area 022. The first screen area 021 can be a high-temperature screen area, and the second screen area 022 can be a low-temperature screen area. In the structure shown in Figure 2, the heat exchange module 03 needs to be set across the screen areas, thereby using the heat exchange module 03 to conduct heat from the high-temperature screen area to the low-temperature screen area, realizing heat transfer within the electronic device.

[0050] It is understandable that electronic devices can be not only bi-fold devices, but also tri-fold, quad-fold, or more fold devices. Taking a tri-fold electronic device as an example, the number of hinges can be two, and the corresponding number of screen areas can be three. And so on, which will not be elaborated here.

[0051] As shown in Figure 1, the heat exchange module 03 includes a pump 10 and a heat exchange pipeline 20 connected to the pump 10. The heat exchange pipeline 20 can be filled with a heat exchange medium. The heat exchange medium is used for heat conduction.

[0052] Pump 10 can be installed in a screen area 02 of the electronic device, for example, in the first screen area 021 or the second screen area 022. Pump 10 can be a micro pump, mainly used to provide circulating flow for the cooling medium in the heat exchange module 03.

[0053] Pump 10 and heat exchange pipeline 20 are connected to form a closed heat exchange path. Specifically, pump 10 may be provided with a first inlet (not shown in the figure) and a first outlet (not shown in the figure). Heat exchange pipeline 20 may be provided with a second inlet (not shown in the figure) and a second outlet (not shown in the figure), the second outlet being connected to the first inlet, and the first outlet being connected to the second inlet. The connection between pump 10 and heat exchange pipeline 20 needs to be sealed to prevent the heat exchange medium from flowing out.

[0054] As shown in Figure 1, pump 10 can be installed at one end of heat exchange pipeline 20. Exemplarily, pump 10 can be fixed to the surface of heat exchange pipeline 20 by thermoforming. It is understood that a sealed connection is required when pump 10 is connected to heat exchange pipeline 20. For example, the first inlet of pump 10 is sealed to the second outlet of heat exchange pipeline 20, and the first outlet of pump 10 is sealed to the second inlet of heat exchange pipeline 20.

[0055] The heat exchange medium can circulate in the heat exchange path formed by the pump and heat exchange pipelines to transfer heat from the high-temperature shield area to the low-temperature shield area. The heat exchange medium can be a liquid or a gaseous medium. Liquid heat exchange media can be, for example, one or a combination of at least two of water, heat transfer oil, silicone oil, and fluorinated liquid. Gaseous heat exchange media can be, for example, carbon dioxide, nitrogen, and inert gases or non-flammable and non-explosive organic gases. To prevent short circuits caused by heat exchange medium leakage, in one embodiment, the heat exchange medium can be selected from heat transfer oil, silicone oil, or a gaseous heat exchange medium.

[0056] Referring again to Figure 1, in a foldable phone, the heat exchange pipe 20 may include at least one bend 21 and at least two extensions 22. Taking the heat exchange module 03 shown in Figure 1 as an example, the heat exchange pipe 20 includes one bend 21 and two extensions 22. The bend 21 is located between the two extensions 22. The bend 21 may be configured to correspond to the pivot. The two extensions 22 are each configured to correspond to a screen area. The two extensions 22 are respectively denoted as the first extension 221 and the second extension 222. The first extension 221 is configured to correspond to the first screen area 021, and the second extension 222 is configured to correspond to the second screen area 022. When the foldable phone is folded, the bend 21 bends along with the pivot, while the two extensions 22 do not bend. During the operation of the foldable phone, the heat of the first screen area 021 is conducted to the second screen area 022 through the first extension part 221, the bending part 21, and the second extension part 222, thereby dissipating heat from the first screen area 021.

[0057] To prevent the heat exchange medium from flowing out of the heat exchange pipe, the heat exchange pipe in this embodiment includes a pipe body and a water-blocking composite membrane disposed on the surface of the pipe body. Since the bends in the heat exchange pipe need to be repeatedly bent following the rotation of the shaft, the water-blocking composite membrane corresponding to the bends must not only have excellent water-blocking performance, but also meet the requirement of not cracking after 100,000 to 400,000 bends at small bending angles.

[0058] The water-blocking composite membrane of the present application embodiment will be explained below with reference to Figures 2 and 3.

[0059] Figure 2 is a schematic diagram of the structure of a water-blocking composite membrane according to an embodiment. As shown in Figure 2, the water-blocking composite membrane may include a water-blocking layer 242 and a protective layer 243. The water-blocking layer 242 and the protective layer 243 are stacked. The number of water-blocking layers 242 is at least one. The number of protective layers 243 is at least one. In the structure shown in Figure 2, the water-blocking layer 242 is one layer, and the protective layer 243 is one layer.

[0060] The protective layer 243 has a higher elongation at break than the water-blocking layer 242. The higher elongation at break of the protective layer 243 provides better flexibility to the water-blocking composite membrane 24, allowing it to maintain high integrity even during repeated bending and reducing the likelihood of cracking in the water-blocking layer 242. This enables the water-blocking composite membrane 24 to achieve both high water-blocking properties and crack resistance and bending resistance. Simultaneously, the protective layer 243 acts as a coating for the water-blocking layer 242, protecting it from scratches and preventing debris from falling off should the water-blocking layer 242 crack.

[0061] Referring to Figure 2, the protective layer 243 of this embodiment has a certain elongation at break, such as >3%, or >5%, or >10%. The protective layer 243 needs to have a certain thickness to achieve the protective function. However, in order to achieve the requirement of thinner and lighter water-blocking composite membrane, in one embodiment, the thickness of the protective layer 243 can be less than 50μm, or for example, less than 10μm, or for example, less than 5μm.

[0062] The protective layer 243 structure needs to have a certain degree of integrity and can be a thin film or coating that is not easy to shed, so as to prevent the protective layer 243 itself from generating contaminants and impurities.

[0063] The film can be a polymer film. Considering both density and thinness, the protective layer 243 can be a parylene film. It can be formed by room temperature vacuum deposition. To reduce bending friction during application, the protective layer can be made from a fluoropolymer film, such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF). It can be achieved through an adhesive application method.

[0064] When the protective layer 243 is a plating layer, it can be a highly dense metallic plating layer, such as a copper plating layer, an aluminum plating layer, or an inorganic plating layer. Inorganic plating layers include silicon dioxide plating layers, aluminum oxide plating layers, etc.

[0065] Referring again to Figure 2, in this embodiment, the water vapor permeability of the water-blocking layer 242 is lower than that of the protective layer 243. The water-blocking layer 242 has a low water vapor permeability, with a water vapor transmission rate of <0.05 g / m³ at 25℃±5℃ and 50±5% RH. 2 ·day, used to achieve high water and gas barrier performance.

[0066] The water-blocking layer 242 is formed by a three-dimensional material having a layered crystal structure, and / or a two-dimensional sheet structure material with at least two layers stacked together.

[0067] Among them, a three-dimensional material with a layered structure has a three-dimensional atomic arrangement, but has a layered structure in the two-dimensional direction, with no gaps between the layers. For example, a three-dimensional material with a layered structure includes at least one of a first carbon material, mica, boron nitride, carbon nitride, silicon nitride, and montmorillonite. The first carbon material may be, for example, graphite.

[0068] Two-dimensional sheet-like materials are materials in which the atoms are arranged in a two-dimensional direction and have no three-dimensional arrangement. Monolayer two-dimensional sheet-like materials have a thickness equal to the thickness of a single atom. For example, two-dimensional sheet-like materials include at least one of a second carbon material, a transition metal dichalcogenide, a two-dimensional black scale material, or a Mxene material.

[0069] The second carbon material can be selected from at least one of graphene, graphene oxide, graphene selenide, graphene sulfide, etc.

[0070] Transition metal disulfides can be, for example, molybdenum disulfide, tungsten disulfide, etc.

[0071] Mxene, short for two-dimensional transition metal carbides, nitrides, or carbonitrides, is mainly composed of transition metal carbides, nitrides, or carbonitrides. Its chemical formula can be represented as Mn+1XnTx, where M represents a transition metal (such as Sc, Ti, V, etc.), X represents C or N, and Tx represents surface end groups (such as -O, -OH, -F, etc.). MXene materials possess a unique two-dimensional layered structure and are a class of two-dimensional nanomaterials obtained by etching away the alumina (A) element from the MAX phase of layered ceramic materials.

[0072] When subjected to external forces, the water-blocking layer formed from the above materials can effectively distribute pressure to various layers, thereby improving its resistance to rupture and enhancing its own deformation capacity, thus improving its stability. The use of these materials in the water-blocking layer not only provides high water-blocking performance but also gives it a certain degree of crack resistance, thereby improving the overall performance of the water-blocking composite membrane.

[0073] Referring again to Figure 2, in one embodiment, the water-blocking layer 242 may be formed of a carbon-based material. The carbon-based material may include, for example, at least one of graphite, graphene, graphene oxide, graphene selenide, and graphene sulfide. Carbon-based materials such as graphite and graphene have high thermal diffusivity, thermal conductivity, excellent stability, and corrosion resistance, which can improve the thermal conductivity of the water-blocking composite film layer 24. Furthermore, these carbon-based materials can be easily formed into large-area films, thus facilitating the fabrication of the water-blocking composite film 24.

[0074] Traditional three-dimensional materials with layered structures and two-dimensional sheet-like structures typically have a static intrinsic water vapor permeability greater than 0.1 g / m³. 2• day, dynamic water vapor transmission rate is greater than 1 g / m 2 The material, being of poor quality, cannot be used as a water-blocking material in electronic devices. However, in this embodiment, by improving the material, the water-blocking layer formed by it has a water vapor permeability of <0.05 g / m at 25℃±5℃ and 50±5%RH. 2 ·day.

[0075] Water vapor transmission rate is a physical quantity used to characterize the water vapor blocking effect of a membrane material; it refers to the amount of water vapor passing through the membrane material per unit area per unit time. In the embodiments of this application, the static intrinsic water vapor transmission rate is the static water loss mass of the membrane material. The dynamic water vapor transmission rate is the water loss mass of the membrane material after repeated bending.

[0076] For example, the following description uses a water-blocking layer made of graphene as an example.

[0077] In one embodiment of this application, the water-blocking layer 242 is obtained by graphitizing multiple layers (such as at least two layers) of graphene. Graphene has two-dimensional structural characteristics. By subjecting the multi-layered graphene to high-temperature graphitization, the carbon atoms of the graphene are oriented, reducing intralayer defects and increasing the crystal domain size of the graphene, thereby improving the water-blocking performance of the graphene water-blocking layer.

[0078] In graphene, after graphitization, the domain size La is greater than 10 μm, for example, greater than or equal to 20 μm, or greater than or equal to 50 μm. As an example, the minimum value of the domain size La can be, for example, 11 μm, 15 μm, 17 μm, 18 μm, 20 μm, 22 μm, 25 μm, 28 μm, 30 μm, 32 μm, 35 μm, 37 μm, 40 μm, 43 μm, 45 μm, 48 μm, 50 μm, 52 μm, 55 μm, 58 μm, or larger. These will not be listed exhaustively here. Increasing the domain size in graphene helps reduce intralayer defects and improves the interlayer bonding strength, reducing the internal interlayer distance of carbon-based materials. This effectively reduces the water vapor permeability of graphene and improves its water-blocking properties.

[0079] Because the interlayer bonding of stacked graphene is relatively weak, it is prone to delamination under stress. To address this issue, in this embodiment of the application, the stacked multilayer graphene is subjected to calendering, which increases the density of the graphene under high pressure, reduces the gaps between the layers, and improves the interlayer bonding.

[0080] In one embodiment, the density of the water-blocking layer obtained by calendering and graphitizing graphene as a raw material can be greater than 2 g / cm³.3 For example, it can be greater than or equal to 2.1 g / cm³. 3 For example, it can be greater than or equal to 2.15 g / cm³. 3 The graphene material in this application has a high density, indicating small interlayer gaps, which effectively blocks the transport of water vapor within the graphene and prevents water vapor from permeating through the interlayer gaps. Therefore, when the density of the water-blocking layer is greater than 2 g / cm³, 3 This indicates that the water-blocking layer has few internal pores, and experimental verification shows that when the density of the water-blocking layer, that is, the density of graphene, is greater than 2 g / cm³, the water-blocking layer exhibits good performance. 3 At this time, its water vapor permeability can be significantly reduced.

[0081] For example, the minimum density of the water-blocking layer can be 2.01 g / cm³. 3 2.02 g / cm 3 2.03 g / cm 3 2.04 g / cm 3 2.05g / cm 3 2.06 g / cm 3 2.07 g / cm 3 2.08 g / cm 3 2.09 g / cm 3 2.10 g / cm 3 2.11 g / cm 3 2.12 g / cm 3 2.13 g / cm 3 2.14 g / cm 3 2.15g / cm 3 2.16 g / cm 3 2.17 g / cm 3 2.18 g / cm 3 2.19 g / cm 3 or 2.20 g / cm 3 Or even higher values. These will not be listed individually here.

[0082] By utilizing a water-blocking layer formed from large crystal domains and high-density graphene, the water vapor permeability can reach <0.03 g / m² at 25℃±5℃ and 50±5%RH. 2 ·day, for example, <0.03g / m 2 ·day, for example, <0.01g / m 2 The lower the water vapor permeability of the water-blocking layer, the better the water-blocking properties of the resulting water-blocking composite membrane. In this application, a water vapor permeability of less than 0.05 g / m is achieved by using carbon-based materials. 2 The water-blocking layer of day, compared to existing layers with a strength greater than 1.0 g / m², has a lower water resistance. 2For the graphene water-blocking layer of day, the overall performance of the water-blocking layer can be greatly improved.

[0083] For example, the highest water vapor transmission rate of the water-blocking layer in this embodiment of the application at 25℃±5℃ and 50±5%RH can be, for example, 0.049g / m³. 2 ·day, 0.048g / m 2 ·day, 0.047g / m 2 ·day, 0.046g / m 2 ·day, 0.045g / m 2 ·day, 0.044g / m 2 ·day, 0.043g / m 2 ·day, 0.042g / m 2 ·day, 0.041g / m 2 ·day, 0.040g / m 2 ·day, 0.039g / m 2 ·day, 0.038g / m 2 ·day, 0.037g / m 2 ·day, 0.036g / m 2 ·day, 0.035g / m 2 ·day, 0.034g / m 2 ·day, 0.033g / m 2 ·day, 0.032g / m 2 ·day, 0.031g / m 2 ·day, 0.030g / m 2 ·day, 0.029g / m 2 ·day, 0.028g / m 2 ·day, 0.027g / m 2 ·day, 0.026g / m 2 ·day, 0.025g / m 2 ·day, 0.024g / m 2 ·day, 0.023g / m 2 ·day, 0.022g / m 2 ·day, 0.021g / m 2 ·day, 0.020g / m 2 ·day, 0.019g / m 2 ·day, 0.018g / m 2 ·day, 0.017g / m 2 ·day, 0.016g / m 2 ·day, 0.015g / m2 ·day, 0.014g / m 2 ·day, 0.013g / m 2 ·day, 0.012g / m 2 ·day, 0.011g / m 2 ·day, 0.010g / m 2 ·day, 0.009g / m 2 ·day, 0.008g / m 2 ·day, 0.007g / m 2 ·day, 0.006g / m 2 ·day, or 0.005g / m 2 • Day, or lower values, will not be listed here.

[0084] In this embodiment, the material forming the water-blocking layer possesses a certain degree of flexibility due to its specific layered structure. Furthermore, specific processing methods such as graphitization or calendering can further improve the interlayer bonding performance of the material. Taking graphene as an example, by improving its crystal domains and density, and increasing the interlayer bonding force, the flexibility of the water-blocking layer itself is increased, giving it flexible water-blocking properties. Through the above improvements, in one embodiment of this application, the elongation at break of the water-blocking layer can be greater than 3%, for example, greater than or equal to 5%, or greater than or equal to 7%. Increasing the elongation at break of the water-blocking layer helps to improve the flexibility of the entire water-blocking composite film. This allows the water-blocking composite film containing the water-blocking layer to meet the requirement of bending radius ≤5mm, and further, bending repeatedly 100,000-400,000 times without cracking at a bending radius ≤2mm, for use in foldable electronic devices.

[0085] For example, the elongation at break of the water-blocking layer may be 3.1%, 3.2%, 3.5%, 3.7%, 3.9%, 4.0%, 4.2%, 4.4%, 4.6%, 4.8%, 5.0%, 5.2%, 5.4%, 5.6%, 5.8%, 6.0%, 6.2%, 6.4%, 6.6%, 6.8%, 7.0%, 7.2%, 7.4%, 7.6%, or 7.8%, or higher, etc., and will not be listed here.

[0086] Based on the trend towards thinner and lighter electronic devices, to reduce the overall thickness of the water-blocking composite film, in one embodiment, the thickness of the water-blocking layer is 0.1–100 μm, for example, 0.1–10 μm, or 0.1–1 μm. Controlling the water-blocking layer within this range ensures sufficient water-blocking effect while meeting the needs of centralized and thinner electronic devices such as mobile terminals. Furthermore, when the thickness of the water-blocking layer is small, it can exhibit light transmission, allowing observation of the heat exchange pipeline body. For example, with a graphene-based water-blocking layer, when the thickness is controlled at around 1 μm, the light transmittance can be increased to over 50%. When this water-blocking layer is applied to the surface of the heat exchange pipeline, the processing of the pipeline body can be observed through the water-blocking layer. Moreover, when the pipeline body is also transparent, the flow of the heat exchange medium can be observed.

[0087] The thickness of the water-blocking layer can be controlled by adjusting the thickness of the coating slurry. However, even after high-temperature sintering and calendering, the thinnest graphene film prepared by existing coating methods is still over 10 μm. In foldable phones, due to the inherent thickness limitations of the foldable phone itself, the graphene film needs to be extremely thinned. Thinning of the water-blocking layer can be achieved through mechanical peeling. For example, mechanical thinning can be performed via roll-to-roll adhesive peeling. Mechanical thinning can improve light transmittance. After thinning, the graphene water-blocking layer can be used in ultra-thin module structures.

[0088] For example, the thickness of the water-blocking layer may be 0.1μm, 0.2μm, 0.4μm, 0.5μm, 0.7μm, 0.8μm, 1.0μm, 1.5μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm, or any value between two of these values.

[0089] To achieve the connection between the water-blocking composite membrane and the pipeline body in the heat exchange pipeline, the water-blocking composite membrane in this application embodiment also includes an adhesive layer.

[0090] Figure 3 is a schematic diagram of the structure of a water-blocking composite membrane according to another embodiment of this application. As shown in Figure 3, the water-blocking composite membrane 24 includes an adhesive layer 241, a water-blocking layer 242, and a protective layer 243. The adhesive layer 241 is disposed on the side of the water-blocking layer 242 opposite to the protective layer 243 and is bonded to the water-blocking layer 242. That is, the water-blocking layer 242 is disposed between the adhesive layer 241 and the protective layer 243. The adhesive layer 241 is used for connection to the pipeline body. In other fields, such as in packaging materials, the adhesive layer is used for connection to the substrate of the packaging material. Exemplarily, the material forming the adhesive layer may include polymer materials such as acrylic resin, epoxy resin, polyurethane resin, and hot-melt copolyester.

[0091] The thickness of the adhesive layer 241 is greater than or equal to 0.5 μm, and for example, greater than or equal to 1 μm. The thickness of the adhesive layer 241 is less than or equal to 20 μm, and for example, less than or equal to 10 μm. If the thickness of the adhesive layer 241 is too small, the reliability of the adhesive force provided will decrease. Therefore, in this implementation, the thickness of the adhesive layer 241 is greater than 0.5 μm, which can provide higher adhesive strength for the water-blocking composite membrane 24, thereby preventing delamination of the water-blocking composite membrane 24 during bending and improving the water-blocking rate of the water-blocking composite membrane 24 after bending. If the thickness of the adhesive layer 241 is too thick, it will increase the overall thickness of the water-blocking composite membrane 24, and if the thickness of the adhesive layer 241 is too thick, water vapor will be transported within the adhesive layer 241, which is detrimental to improving the water-blocking performance of the water-blocking composite membrane 24.

[0092] For example, the thickness of the adhesive layer may be 0.1 μm, 0.2 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.0 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2.0 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm, 2.5 μm, 2.6 μm, 2.7 μm, 2.8 μm, 2.9 μm, 3.0 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, or any two of these values.

[0093] To improve the adhesion between the adhesive layer 241 and the water-blocking layer 242 and prevent delamination or separation between them, the adhesion between the two can be improved by increasing the roughness of the water-blocking layer 242 and increasing the basis weight of the adhesive layer 241.

[0094] The surface roughness of the water-blocking layer 242 is 0.1–5 μm, or for example, 0.1–1 μm. By adjusting the surface roughness of the water-blocking layer 242, the bonding force between the water-blocking layer 242 and the adhesive layer 241 can be improved, thereby increasing the interlayer bonding strength and density and preventing moisture from seeping through between the water-blocking layer 242 and the adhesive layer 241. For example, the surface roughness of the water-blocking layer can be achieved by adjusting the roughness of the coating substrate during coating.

[0095] For example, the surface roughness of the water-blocking layer is 0.1μm, 0.2μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1.0μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2.0μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2. A value between any two values ​​of 6μm, 2.7μm, 2.8μm, 2.9μm, 3.0μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, 3.6μm, 3.7μm, 3.8μm, 3.9μm, 4.0μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm, 4.8μm, 4.9μm, or 5.0μm or higher.

[0096] Referring to Figure 3, the basis weight of adhesive layer 241 can be greater than or equal to 300 g / m². 2 For example, it can be greater than or equal to 500g / m 2 By increasing the basis weight of the adhesive layer 241, the bonding force between the adhesive layer 241 and the water-blocking layer 242 and the bonding force between the adhesive layer 241 and the pipe body are improved, thereby increasing the water-blocking rate of the water-blocking composite membrane 24 after dynamic bending. This avoids delamination between the adhesive layer 241 and the water-blocking layer 242 or between the adhesive layer 241 and the pipe body due to insufficient bonding force of the adhesive layer 241, which would cause the water-blocking performance to fail.

[0097] For example, the basis weight of the adhesive layer may be 300 g / m³. 2 350g / m 2 400g / m 2 450g / m 2 500g / m 2 550g / m 2 or 600g / m 2 or higher values, etc.

[0098] When the water-blocking composite film of this application embodiment is applied to the heat dissipation field, in order to achieve rapid heat transfer, in one embodiment, the thermal diffusivity of the water-blocking composite film is greater than or equal to 600 mm². 2 / s, or for example, greater than or equal to 700mm 2 / s, or for example, greater than or equal to 800mm 2 / s. The thermal diffusion system of the water-blocking composite membrane is greater than 600mm. 2 At a speed of / s, the water-blocking composite membrane can simultaneously possess excellent heat dissipation performance, enabling the heat gained by the water-blocking composite membrane to be quickly conducted, achieving a uniform temperature effect, and thus improving the heat dissipation effect of the entire heat exchange module.

[0099] The performance of the water-blocking layer described above is illustrated using graphene as an example. When other materials are used to form the water-blocking layer, the same technical characteristics can be achieved. Further details will not be provided here.

[0100] The following will describe in detail the placement of the composite water-blocking membrane in the heat exchange module of the embodiments shown in Figures 2 and 3 in this application, with reference to Figure 4.

[0101] Figure 4 is a schematic cross-sectional view of a heat exchange pipeline. As shown in Figure 4, the heat exchange pipeline 20 includes a pipeline body 23 and a water-blocking composite membrane 24 disposed on the surface of the pipeline body 23.

[0102] Referring to Figure 4, the pipeline body 23 includes a first cover plate 231 and a second cover plate 232 spaced apart. A support column 233 is provided between the first cover plate 231 and the second cover plate 232. The first cover plate 231, the second cover plate 232, and the support column 233 enclose a heat exchange channel 230. When a heat exchange module is installed inside an electronic device, the first cover plate 231 can be the upper cover plate of the heat exchange pipeline 20, and the second cover plate 232 can be the lower cover plate of the heat exchange pipeline 20. In the thickness direction of the heat exchange pipeline 20, as shown in the z-direction, the lower cover plate is located closer to the axis of rotation, and the upper cover plate is located away from the axis of rotation. The support column 233 is provided between the first cover plate 231 and the second cover plate 232 to provide support and separation for the first cover plate 231 and the second cover plate 232 in the height direction of the heat exchange pipeline 20. There can be multiple support columns 233. One end of each support column 233 is sealed to the first cover plate 231, and the other end is sealed to the second cover plate 232. Thus, multiple heat exchange channels 230 can be formed between the first cover plate 231, the second cover plate 232 and the support column 233.

[0103] The first cover plate 231, the second cover plate 232, and the support column 233 can each be independently formed using thermoplastic materials. Thermoplastic materials include, but are not limited to, polyethylene glycol terephthalate (PET), polyethylene naphthalate dimethyl methacrylate (PEN), thermoplastic polyurethane (TPU), thermoplastic polyolefin (TPO), and polystyrene (PST). The glass transition temperature (Tg) of the thermoplastic material can be in the range of 60–200°C, or for example, in the range of 65–140°C. The materials used to make the first cover plate 231, the second cover plate 232, and the support column 233 can be the same or different; no specific limitations are imposed here.

[0104] The first cover plate 231, the second cover plate 232, and the support column 233 can be shaped using methods such as etching or laser processing. During manufacturing, the first cover plate 231, the second cover plate 232, and the support column 233 can be integrally formed using thermoplastic molding, or they can be manufactured separately and then sealed using hot pressing. The first cover plate 231 and the second cover plate 232 can be made from the same material and have the same thickness to ensure symmetrical material mechanical parameters on both sides of the pipeline body 23, preventing the first cover plate 231 or the second cover plate 232 from curling or warping at high temperatures, which could affect the reliability of the heat exchange module 03.

[0105] The water-blocking composite membrane 24 can be disposed on the entire outer surface of the first cover plate 231 and the second cover plate 232, or it can be disposed on the inner surface of the first cover plate 231 and the second cover plate 232. When the water-blocking composite membrane 24 is disposed on the inner surface of the first cover plate 231 and the second cover plate 232, its placement position must correspond to the position of the heat exchange channel. The water-blocking composite membrane does not need to be disposed at the position corresponding to the support column 233.

[0106] Since the first cover plate 231, the second cover plate 232, and the support column 233 in the heat exchange module of this application are typically assembled by laser thermofusion welding, from the perspective of process convenience, the water-blocking composite membrane can be applied to the surfaces of the first cover plate 231 and the second cover plate 232 before assembly. If the water-blocking composite membrane is applied to the first cover plate 231 and the second cover plate 232 before assembling the heat exchange pipeline, certain requirements are placed on the light transmittance of the water-blocking composite membrane. To achieve the desired light transmittance of the water-blocking composite membrane, the mechanical thinning method mentioned in the embodiments of this application can be used, controlling the thickness of the water-blocking layer to 1 μm or less.

[0107] Based on the same technical objective, embodiments of this application provide an electronic device, which may include a heating element and a heat exchange module according to embodiments of this application. The heat exchange module in the electronic device of this application embodiment may be the heat exchange module shown in Figure 1. In one embodiment, the heating element may be an electrical device such as a circuit board or a power module, or a power-powered heating element such as a battery. The electronic device may be a non-bending electronic device or a bending electronic device. The water-blocking composite film in the electronic device may be in a flat state or a bent state.

[0108] When the electronic device in the embodiments of this application is a foldable electronic device, such as a foldable mobile phone, the electronic device may include a display screen, a mid-frame, a back cover, and a circuit board. The mid-frame is used to support the circuit board and the display screen. The mid-frame is disposed between the display screen and the back cover. The heat exchange module is disposed between the back cover and the mid-frame, and / or the heat exchange module is disposed between the display screen and the mid-frame.

[0109] Due to the uneven placement of heat-generating components within electronic devices, at least two temperature zones exist inside: a low-temperature zone and a high-temperature zone. The low-temperature zone represents a temperature below a certain threshold, while the high-temperature zone is a temperature above that threshold. Electronic devices may have multiple temperature zones, for example, at least two. Heat exchange modules are segmented and located within these different temperature zones. For instance, one part of a heat exchange module may be located in the high-temperature zone, while another part is located in the low-temperature zone.

[0110] It is understood that the above heat exchange module is merely a specific application example of the water-blocking composite membrane in this application embodiment. The application of the water-blocking composite membrane in this application embodiment is not limited to this. In addition to being used in bendable electronic devices, the water-blocking composite membrane in this application embodiment can also be used in non-bendable electronic devices, such as tablet computers, outdoor displays, robots, etc., and can also be used in electronic devices with heat-generating devices such as battery modules and outdoor power devices to achieve heat conduction.

[0111] As explained above, the water-blocking composite film of this application embodiment can be used in various application scenarios. Besides electronic devices, it can also be used in the packaging field. Based on this, this application embodiment also provides a packaging film material. The packaging film material of this application embodiment may include a substrate and a water-blocking composite film disposed on the surface of the substrate. The structure of the water-blocking composite film can adopt the structure shown in Figures 2 and 3 of this application embodiment.

[0112] Packaging film materials made using the water-blocking composite film of the present application embodiment can have better water-blocking performance and can improve the shelf life of the packaged products.

[0113] The water-blocking performance of the water-blocking composite membrane of this application will be described below with reference to specific embodiments.

[0114] Examples 1-9 and Comparative Examples 1-2

[0115] Examples 1-9 and Comparative Examples 1-2 are heat exchange modules. Their structures can be seen in Figures 1 and 4. The pipeline body 23 is formed by a first cover plate 231, a second cover plate 232, and a support column 233. A water-blocking composite membrane 24 is provided on the outer surface of both the first cover plate 231 and the second cover plate 232. The water-blocking composite membrane 24 includes an adhesive layer 241, a water-blocking layer 242, and a protective layer 243 stacked sequentially. The adhesive layer 241 is made of epoxy resin. The water-blocking layer 242 is formed of graphitized graphene. The protective layer 243 is a pyrene film.

[0116] The heat exchange modules in all embodiments and comparative examples have the same structure. The difference lies in the characteristics of the adhesive layer and the water-blocking layer in the water-blocking composite membrane. The parameters of each layer in the water-blocking composite membrane 24 are listed in Table 1.

[0117] The static water loss mass and dynamic water loss mass after 50,000 bends were tested for the heat exchange pipelines of each embodiment and comparative example. The test results are listed in Table 1.

[0118] The test methods for various performance parameters of the water-blocking composite membrane and heat exchange pipeline in the embodiments and comparative examples of this application are as follows.

[0119] 1. Elongation at break test: Place a dumbbell-shaped specimen on a tensile testing machine and stretch it continuously at a certain rate until it breaks. Record the maximum values ​​of force and elongation. This can be obtained by referring to GB 13022-91 (Plastics—Films—Test Method for Tensile Properties) using a mechanical testing machine. Specifically, carbon fiber can be cut into standard samples, and stress-strain curves can be obtained using a mechanical testing machine. Analysis of the stress-strain curves reveals the elongation at break and the breaking strength.

[0120] 2. Thickness test: Measured using equipment such as a micrometer and thickness gauge.

[0121] 3. Surface roughness test: Using the principle of optical wave interference (see flat crystal and laser length measurement technology), the shape error of the surface to be measured is displayed as an interference fringe pattern. The microscopic part of these interference fringes is magnified by a microscope with high magnification (up to 500 times) and then measured to obtain the surface roughness.

[0122] 4. Density test: It can be measured by a true density meter, water displacement method, etc. For the density measurement of graphene water-blocking layer, the true density meter method can be used.

[0123] 5. Test of La (μm) of crystal domains of carbon-based materials: The size of single crystals in microscopic characterization is measured by X-ray powder diffraction (XRD) and calculated by the half-width of the signal peak on the (001) plane.

[0124] 6. Water loss rate reliability test: 800mg of deionized water was injected into the heat exchange module and sealed. The heat exchange module was placed in an environmental oven at 65℃ and 50%RH. The daily mass change of the heat exchange module was measured using an electronic balance.

[0125] 7. Dynamic water loss after 50,000 bends: 800 mg of deionized water was injected into the heat exchange module and sealed. The heat exchange module was then placed in a bending tester and subjected to 50,000 cycles of bending at an R1.5 mm angle. Both the bending tester and the heat exchange module were placed in an environmental oven at 65℃ and 50% RH. The mass change of the heat exchange module after 50,000 cycles of bending was measured using an electronic balance.

[0126] Table 1

[0127] Table 1 (continued)

[0128] In this application, the elongation at break of the water-blocking composite membrane is greater than 3%. The elongation at break of the protective layer is greater than that of the water-blocking layer.

[0129] As shown in Table 1, the heat exchange pipelines with the water-blocking composite membrane of this application have static water loss of less than 1 mg / day and dynamic water loss of less than 3 mg / day after 50,000 bends. Specifically, the static water loss in Examples 1-4 is less than 0.5 mg / day and the dynamic water loss after 50,000 bends is less than 1 mg / day.

[0130] In Comparative Example 1, the heat exchange pipeline, having only a water-blocking layer and no protective layer, exhibited a lower static water loss, but a dynamic water loss exceeding 12 mg / day after 50,000 bends. In Comparative Example 2, lacking both a water-blocking and protective layer, the heat exchange pipeline experienced a static water loss exceeding 20 mg / day and a dynamic water loss exceeding 30 mg / day after 50,000 bends. This demonstrates that the water-blocking composite membrane of this application can effectively improve the dynamic water-blocking effect of heat exchange pipelines under bending conditions.

[0131] In Comparative Examples 3 and 4, the water vapor permeability of the water-blocking layer was higher than 0.05 g / m. 2 ·day, respectively 0.06g / m 2 ·day and 0.079g / m 2 The static water loss mass of the heat exchange module corresponding to Example 1 is greater than that of Example 1. Furthermore, the dynamic water loss mass of Comparative Examples 3 and 4 is also greater than that of Example 1. A comparison of Example 1 with Comparative Examples 3 and 4 shows that the water-blocking performance of the water-blocking layer decreases when the density and size of the crystal domains decrease. Data in Table 1 shows that the static water loss mass of Comparative Examples 3 and 4 tends to increase compared to Example 1. This indicates that the density and crystal domain size of graphene in the water-blocking layer affect its water-blocking performance.

[0132] As shown in the comparison between Examples 1-4 and Comparative Example 2, the water vapor transmission rate of the water-blocking layer can be altered by changing its thickness. The water vapor transmission rate decreases as the thickness of the water-blocking layer increases. When the thickness exceeds 0.5 μm, the decreasing trend in water vapor transmission rate slows down. In other words, when the thickness of the water-blocking layer is controlled above 0.5 μm, its water-blocking performance is sufficient to achieve high performance. When the thickness of the water-blocking layer is in the range of 1-10 μm, the static water loss mass and the dynamic water loss mass after 50,000 bends of the corresponding heat exchange pipeline are both within 1 mg / day.

[0133] Comparative data from Examples 1, 5, and 6 show that changes in the surface roughness of the water-blocking layer affect both the static and dynamic water loss of the heat exchange pipeline. Specifically, when the surface roughness of the water-blocking layer is 0.05 μm, the static water loss of the corresponding heat exchange pipeline does not change significantly compared to Example 1, while the dynamic water loss after 5W bending cycles increases from 0.4 mg / day in Example 1 to 2.7 mg / day. This indicates that changes in the surface roughness of the water-blocking layer have a certain impact on the interlayer bonding force between the adhesive layer and the water-blocking layer. In this case, delamination is likely to occur between the water-blocking layer and the adhesive layer after repeated bending, thus affecting the water-blocking performance of the heat exchange pipeline.

[0134] Furthermore, in the comparison data between Example 1 and Example 6, when the surface roughness of the water-blocking layer is 2 μm, the static water loss mass and the dynamic water loss mass after 5W bends of the corresponding heat exchange pipeline are both increased compared to Example 1. This indicates that excessively high roughness of the water-blocking layer can easily lead to a lower degree of wetting between the adhesive layer and the water-blocking layer, more interlayer voids, and enhanced water vapor evaporation effect.

[0135] A comparison between Examples 1 and 7 shows that as the thickness and weight of the adhesive layer decrease, the dynamic water-blocking weight of the corresponding heat exchange module increases, and the dynamic water-blocking performance decreases. This indicates that the thickness and weight of the adhesive layer affect its bonding performance, thereby affecting the dynamic water-blocking performance of the heat exchange module.

[0136] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A water-blocking composite membrane, characterized in that, It includes a water-blocking layer and a protective layer stacked together; the water vapor permeability of the water-blocking layer is less than that of the protective layer. The water-blocking layer is formed by a three-dimensional material having a layered crystal structure, and / or a two-dimensional sheet structure material with at least two layers stacked together. The water-blocking layer has a water vapor permeability of <0.05 g / m at 25℃±5℃ and 50±5%RH. 2 ·day.

2. The water-blocking composite membrane according to claim 1, characterized in that, The three-dimensional material having a layered crystal structure includes at least one of the following: a first carbon material, mica, boron nitride, carbon nitride, silicon nitride, and montmorillonite.

3. The water-blocking composite membrane according to claim 2, characterized in that, The first carbon material includes graphite.

4. The water-blocking composite membrane according to claim 1, characterized in that, The two-dimensional sheet structure material includes at least one of the following: second carbon material, transition metal dichalcogenide, two-dimensional black scale, and Mxene material.

5. The water-blocking composite membrane according to claim 4, characterized in that, The second carbon material includes at least one of graphene, graphene oxide, graphene selenide, and graphene sulfide.

6. The water-blocking composite membrane according to any one of claims 1-5, characterized in that, The elongation at break of the water-blocking layer is greater than 3%.

7. The water-blocking composite membrane according to any one of claims 1-6, characterized in that, The water-blocking layer has a water vapor permeability of <0.03 g / m at 25℃±5℃ and 50±5%RH. 2 ·day.

8. The water-blocking composite membrane according to any one of claims 1-7, characterized in that, In the material forming the water-blocking layer, the domain size La is greater than 10 μm.

9. The water-blocking composite membrane according to any one of claims 1-8, characterized in that, The density of the water-blocking layer is greater than 2 g / cm³. 3 .

10. The water-blocking composite membrane according to any one of claims 1-9, characterized in that, The surface roughness of the water-blocking layer is 0.1–5 μm.

11. The water-blocking composite membrane according to any one of claims 1-10, characterized in that, The thickness of the water-blocking layer is 0.1–100 μm.

12. The water-blocking composite membrane according to any one of claims 1-11, characterized in that, The water-blocking layer is obtained by graphitizing multiple layers of graphene.

13. The water-blocking composite membrane according to any one of claims 1-12, characterized in that, The water-blocking composite membrane further includes an adhesive layer, which is disposed on the side of the water-blocking layer opposite to the protective layer and is bonded to the water-blocking layer.

14. The water-blocking composite membrane according to claim 13, characterized in that, The thickness of the adhesive layer is greater than or equal to 0.5 μm.

15. The water-blocking composite membrane according to claim 13 or 14, characterized in that, The thickness of the adhesive layer is less than or equal to 20 μm.

16. The water-blocking composite membrane according to any one of claims 13-15, characterized in that, The basis weight of the adhesive layer is greater than or equal to 300 g / m³. 2 .

17. The water-blocking composite membrane according to any one of claims 1-16, characterized in that, The thermal diffusivity of the water-blocking composite membrane is greater than or equal to 600 mm. 2 / s.

18. A heat exchange module, characterized in that, It includes a heat exchange pipeline, the surface of which is provided with a water-blocking composite membrane as described in any one of claims 1-17.

19. The heat exchange module according to claim 18, characterized in that, The heat exchange module also includes a pump, which is connected to the heat exchange pipeline to form a closed heat exchange path; the heat exchange pipeline includes a pipeline body and the water-blocking composite membrane, which is disposed on the outer surface of the pipeline body.

20. The heat exchange module according to claim 18 or 19, characterized in that, The water-blocking composite membrane is bonded to the pipeline body.

21. An electronic device, characterized in that, It includes a heat-generating device and a heat exchange module as described in any one of claims 18-20, wherein at least a portion of the heat exchange module is connected to the heat-generating device and at least a portion of the heat exchange module is connected to the heat dissipation area of ​​the electronic device.

22. The electronic device according to claim 21, characterized in that, The electronic device includes a display screen, a mid-frame, a back cover, and a circuit board. The mid-frame is used to support the circuit board and the display screen. The mid-frame is disposed between the display screen and the back cover. The heat exchange module is disposed between the back cover and the mid-frame, and / or the heat exchange module is disposed between the display screen and the mid-frame.

23. The electronic device according to claim 21, characterized in that, The electronic device has multiple temperature zones, and the heat exchange module is segmented and located in different temperature zones within the electronic device.

24. A packaging film material, characterized in that, It includes a substrate and a water-blocking composite membrane as described in any one of claims 1-17 disposed on the surface of the substrate.

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