Water vapor barrier film

Abstract

The utility model relates to a water vapor barrier film with comprehensive functional characteristics, the film specifically comprises a barrier function layer, a bonding layer and an anti-dazzle function layer, the barrier function layer is composed of a water vapor barrier layer made of a high-performance material and a first base material layer, an efficient water vapor barrier effect is achieved, the thickness of the first base material layer is 25-100 micrometers, and the anti-dazzle function layer is arranged between the bonding layer and the first base material layer. The stiffness and stability of the base material are ensured, the barrier function layer is arranged on the cutting starting side, the cutting position is optimized, and therefore defects are avoided. The anti-dazzle function layer is composed of an anti-dazzle layer with a special optical design and a second base material layer, and light reflection and scattering are effectively reduced. An ultraviolet blocking layer can be added to effectively block ultraviolet radiation, and a first protection film and a second protection film are arranged on the two sides of the water vapor blocking film respectively to form an all-directional protection structure. In addition, an indication mark is further arranged in the water vapor barrier film, the cutting starting side is clearly marked, the production efficiency is improved, and the risks of mistaken cutting and product damage are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of optical films, and in particular to a water vapor barrier film. Background Art

[0002] With the continuous advancement of display technology, flexible electronic paper displays (e-paper displays), with their superior properties such as lightness, bendability, and impact resistance, are gradually replacing traditional glass-based e-paper displays, bringing revolutionary changes to e-readers, wearable devices, and mobile communications. These displays use transparent plastic films as a flexible substrate, significantly reducing weight and allowing for greater design freedom. However, moisture poses a serious threat to the display performance of the e-paper ink layer, necessitating that the transparent plastic front panel possess excellent moisture vapor barrier properties.

[0003] In order to deal with the problem of water vapor erosion and improve the user's reading experience, the industry generally adopts a multi-layer composite film structure as a transparent plastic front panel. Figure 1 From top to bottom, this structure consists of an AG layer (Anti-Glare), a first substrate layer, an adhesive layer (OCA layer, Optical Clear Adhesive), a vapor barrier layer, and a second substrate layer. The AG layer scatters light through its microstructure, effectively reducing glare and improving reading comfort. The vapor barrier layer protects the interior of the e-paper from moisture, ensuring long-term stable display performance. This structure exhibits excellent anti-glare and water-repellent properties when the substrate layer is approximately 125 microns thick.

[0004] In recent years, with the growing market demand for thinner and lighter e-paper display modules, the thickness of the substrate layer has been continuously reduced, with the current common thickness range after thinning being between 25 and 100 microns. This change not only further reduces the weight of the device, but also improves its portability and aesthetics. However, the thinning of the substrate layer also brings new problems. Due to the reduction in material rigidity, the stiffness of the composite film layer is significantly reduced, resulting in cracks in the film layer near the cut line during subsequent punching and processing. These cracks not only affect the appearance quality of the film layer, but more importantly, they may damage the integrity of the water vapor barrier layer, allowing water vapor to penetrate into the e-paper interior, resulting in reduced display performance or even failure.

[0005] While current technologies have achieved some success in anti-glare and water vapor barrier performance, the reduced stiffness and cracking associated with thinning the substrate layer remain pressing challenges. Therefore, developing a new technology that maintains the advantages of thin and lightweight composite films while effectively preventing cracking and ensuring a complete water vapor barrier is crucial for the further development of flexible e-paper displays. Utility Model Content

[0006] The purpose of the present application is to provide a water vapor barrier film, the water vapor barrier layer of which is not easily invalidated due to the punching process, and specifically includes a barrier function layer, an adhesive layer, and an anti-glare function layer;

[0007] The barrier function layer includes a water vapor barrier layer and a first substrate layer, and the anti-glare function layer includes an anti-glare layer and a second substrate layer;

[0008] The barrier function layer and the anti-glare function layer are bonded together via the adhesive layer;

[0009] The thickness of the first substrate layer and the second substrate layer is in the range of 25 μm-100 μm, the thickness of the water vapor barrier layer is less than 100 nm, and the barrier functional layer is arranged on the cutting starting side of the water vapor barrier film.

[0010] In one embodiment, the thickness of the adhesive layer is in the range of 5 μm-30 μm.

[0011] In one embodiment, the thickness of the first substrate layer and the second substrate layer is in the range of 45 μm-55 μm, and the thickness of the adhesive layer is in the range of 10 μm-20 μm.

[0012] In one embodiment, the first substrate layer in the barrier function layer and the second substrate layer in the anti-glare function layer are in contact with the adhesive layer.

[0013] In one embodiment, the water vapor barrier layer, the first substrate layer, the adhesive layer, the second substrate layer and the anti-glare layer are stacked in sequence from top to bottom.

[0014] In one embodiment, the present invention further includes a first protective film and a second protective film, wherein the first protective film and the second protective film are respectively formed on both sides of the water vapor barrier film.

[0015] In one embodiment, a hardening layer is further included, and the hardening layer is adjacent to the water vapor barrier layer.

[0016] In one embodiment, the thickness of the hardened layer is greater than the thickness of the water vapor barrier layer.

[0017] In one embodiment, the barrier function layer further includes a UV blocking layer, and the UV blocking layer is disposed on a side of the first substrate layer opposite to the water vapor barrier layer.

[0018] In one embodiment, an indicator mark is further included. The indicator mark is provided in the first substrate layer, the second substrate layer or the adhesive layer to mark the cutting start side of the water vapor barrier film.

[0019] Compared with the prior art, the present application has the following beneficial effects: the water vapor barrier film provided by the present application improves the stability and reliability of the water vapor barrier layer in the punching process, effectively solves the problems of decreased film stiffness and cracking caused by thinning of the substrate layer, and ensures the integrity and long-term effectiveness of the water vapor barrier function. The water vapor barrier film mainly includes a barrier function layer, an adhesive layer and an anti-glare function layer. Among them, the barrier function layer is composed of a water vapor barrier layer and a first substrate layer, and the anti-glare function layer is composed of an anti-glare layer and a second substrate layer. The two functional layers are tightly bonded by the adhesive layer to form a composite structure that has both water vapor barrier capability and anti-glare effect. While ensuring the thinness of the film layer, it also ensures sufficient structural strength, reduces the generation of cracks during the punching process, and further improves the stiffness and crack resistance of the film layer. The vapor barrier layer is arranged on the cutting starting side of the water vapor barrier film, which effectively avoids direct damage to the water vapor barrier layer during the punching process. Through a series of innovative designs and technical features, the stability and reliability of the water vapor barrier layer are improved, and the overall performance and processing convenience of the film layer are optimized, providing strong support for the widespread application of flexible electronic paper displays. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of a water vapor barrier membrane in the prior art;

[0021] Figure 2 is a schematic structural diagram of a water vapor barrier membrane in one embodiment of the present application;

[0022] Figure 3 is a schematic structural diagram of a water vapor barrier film including a protective film in one embodiment of the present application;

[0023] Figure 4 Schematic diagram of the structure of a water vapor barrier film including a hardened layer in one embodiment of the present application.

[0024] Explanation of the accompanying drawings: 100, barrier functional layer; 110, water vapor barrier layer; 120, first substrate layer; 200, adhesive layer; 300, anti-glare functional layer; 310, anti-glare layer; 320, second substrate layer; 400, hardening layer; 510, first protective film; 520, second protective film. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some, rather than all, structures related to the present application are shown in the accompanying drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] As used herein, the terms "comprise," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0027] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] In the field of flexible electronic paper displays, which pursue lightweight, high reliability and excellent display performance, moisture barrier films play a vital role. With the continuous development of electronic paper technology and the growing market demand for lightweight and portable displays, traditional glass substrates are gradually being replaced by transparent plastic films. This change not only gives electronic paper displays more design freedom, but the erosion of the electronic paper ink layer by water vapor has become one of the key factors restricting its stable performance. Therefore, the development of a moisture barrier film that can effectively block moisture and has a good anti-glare effect has become a hot topic of current research. The following will introduce a new moisture barrier film design in detail. This design solves the problems of reduced film stiffness and cracking caused by thinning the substrate layer by optimizing the material selection, thickness control and structural layout of each layer, and achieves high stability and reliability of the moisture barrier layer in the punching process. At the same time, the moisture barrier film also has an excellent anti-glare effect, further enhancing the user's reading experience. Please refer to Figure 2 , Figure 2 1 is a schematic structural diagram of a water vapor barrier film in one embodiment of the present application. The water vapor barrier film of the present application specifically includes a barrier function layer 100, an adhesive layer 200, and an anti-glare function layer 300;

[0029] The barrier functional layer 100 includes a water vapor barrier layer 110 and a first substrate layer 120, and the anti-glare functional layer 300 includes an anti-glare layer 310 and a second substrate layer 320. The barrier functional layer 100 and the anti-glare functional layer 300 are bonded to each other via the adhesive layer 200. The thickness of the first substrate layer 120 and the second substrate layer 320 is in the range of 25 μm to 100 μm, the thickness of the water vapor barrier layer 110 is less than 100 nm, and the barrier functional layer 100 is arranged on the cutting starting side of the water vapor barrier film.

[0030] The barrier layer 100, as one of the foundations of the vapor barrier film, primarily consists of a vapor barrier layer 110 and a first substrate layer 120. The vapor barrier layer 110 utilizes a high-performance barrier material, with its thickness precisely controlled to less than 100 nanometers. This design minimizes material consumption while ensuring vapor barrier performance. The first substrate layer 120, serving as support for the vapor barrier layer 110, has a thickness ranging from 25 to 100 microns. This thickness ensures substrate stiffness and stability while avoiding the added weight and decreased flexibility associated with excessive thickness. Specifically, the barrier layer 100 is positioned at the cutting start side of the vapor barrier film. This layout optimizes the cutting process, reduces the risk of damage to the vapor barrier layer 110 during the cutting process, and thus enhances product reliability and stability. The water vapor barrier film is selected from any one of a silicon oxide coating layer, a silicon nitride coating layer, and a metal oxide coating layer, and the water vapor barrier coating layer is formed on the substrate by vacuum sputtering, and the selected water / vapor barrier ratio is less than 8*10 -3 g / ㎡*day.

[0031] The anti-glare layer 310 is achieved by coating a hardened resin containing inorganic or organic particles onto a PET substrate. It reduces ambient light reflection and improves display clarity. The adhesive layer 200 is required to have sufficient bonding strength to ensure a secure bond between the layers. It also requires good flexibility and weather resistance to accommodate the flexible e-paper display's diverse operating environments. The anti-glare functional layer 300 primarily consists of the anti-glare layer 310 and a second substrate layer 320. Through its specialized optical design, the anti-glare layer 310 effectively reduces light reflection and scattering on the e-paper display's surface, thereby minimizing glare. The second substrate layer 320, also with a thickness ranging from 25 to 100 microns, provides support for the anti-glare layer 310. The substrate layer is made of polyethylene terephthalate (PET), preferably with a thickness of 50 microns.

[0032] Specifically, the thickness of the adhesive layer 200 ranges from 5μm to 30μm. Precise control of the thickness of the adhesive layer 200 ensures its full bonding effect, tightly bonding the barrier layer 100 to the anti-glare layer 300 and preventing performance degradation or failure due to interlayer separation during use. This optimal thickness ensures that the vapor barrier film maintains excellent vapor barrier and anti-glare properties while also possessing good flexibility, ensuring stable performance in complex display applications such as bending and folding. The adhesive layer 200 can be selected from adhesives such as OCA, POE, and EVA.

[0033] When in Figure 1 When the structure is , the water vapor barrier layer 110 (which can generally be a coating) is subjected to an extrusion force during the punching process, and is therefore easily peeled off and adhered to the adhesive layer 200 (for example, an OCA film), resulting in the water vapor barrier layer 110 being broken and its function being impaired. In the technical solution of the present application, when Figure 2 During the punching process, the water vapor barrier layer 110 (coating) is subjected to tensile force, so the film layer is not easy to break or peel off, ensuring the integrity of the edge of the film surface after punching. Figure 3 In the technical solution, the force direction of the water vapor barrier layer 110 (coating) is the same as Figure 2 The technical solution is consistent with that in the previous section and it has an outer layer of protection, so the edge integrity during the punching process is better guaranteed.

[0034] Specifically, the thickness of the first substrate layer 120 and the second substrate layer 320 ranges from 45 μm to 55 μm, and the thickness of the adhesive layer 200 ranges from 10 μm to 20 μm. Precise control of the thickness of the first substrate layer 120 and the second substrate layer 320 ensures that the multi-layer composite structure maintains a thin and lightweight structure while also maintaining good structural stability. Within the aforementioned range, the overall strength of the multi-layer composite structure is enhanced, thereby improving structural stability, bonding performance, and cost-effectiveness.

[0035] Specifically, the first substrate layer 120 in the barrier layer 100 and the second substrate layer 320 in the anti-glare layer 300 are bonded to the adhesive layer 200. Lamination technology achieves a close bond with the adhesive layer 200, ensuring structural stability between the various layers of the vapor barrier film and improving its overall performance. Regarding the barrier layer 100, the first substrate layer 120 serves as a support layer for the vapor barrier layer 110. Its material is typically selected from materials with high barrier properties, such as multi-layer co-extruded PET (polyethylene terephthalate) or EVOH (ethylene vinyl alcohol copolymer). Through its close bond with the adhesive layer 200, the vapor barrier layer 110 effectively blocks external water vapor penetration, protecting the interior from water vapor erosion, thereby extending the lifespan of the flexible e-paper display. This close bond also reduces water vapor accumulation at the interlayer interface, preventing its adverse effects on film performance. Regarding the anti-glare functional layer 300, the second substrate layer 320 serves as a carrier for the anti-glare treatment. Its surface is typically treated with special treatments, such as a micro-concave-convex structure or an anti-reflective coating, to reduce light scattering and reflection, thereby reducing visual fatigue. By closely adhering to the adhesive layer 200, the second substrate layer 320 ensures a smooth transition between the anti-glare layer 310 and the barrier functional layer 100, avoiding the negative impact of interlayer interface irregularities on visual effects. This tight connection also enhances the overall strength of the water vapor barrier film, improving its tear and puncture resistance. Furthermore, the design of the first substrate layer 120 and the second substrate layer 320 being closely adhering to each other via the adhesive layer 200 facilitates processing and assembly. This structural design simplifies the production process, reduces production costs, and improves the assembly efficiency and yield rate of the water vapor barrier film.

[0036] Specifically, the water vapor barrier layer 110 , the first substrate layer 120 , the adhesive layer 200 , the second substrate layer 320 and the anti-glare layer 310 are stacked in sequence from top to bottom.

[0037] See also Figure 4 , Figure 4This is a schematic diagram of the structure of a vapor barrier film including a protective film in one embodiment of the present application. The film also includes a first protective film 510 and a second protective film 520, each formed on either side of the vapor barrier film. These two protective films, attached to either side of the vapor barrier film, form a comprehensive protective structure, enhancing the durability and protective performance of the vapor barrier film while also further improving its stability and reliability in various applications. The first protective film 510, tightly attached to one side of the vapor barrier film, primarily provides physical protection. This protective film is typically made of highly transparent, wear-resistant materials such as PET (polyethylene terephthalate) or PP (polypropylene), effectively protecting the vapor barrier film from scratches, abrasion, and contamination during normal storage. The presence of the first protective film 510 protects the integrity of the vapor barrier film and ensures the continued effectiveness of its vapor barrier properties. As for the second protective film 520, it is also tightly attached to the other side of the water vapor barrier film, but it focuses more on chemical protection or protection under specific environmental conditions. Materials with special functions, such as UV resistance, aging resistance, or acid and alkali resistance, can be used to cope with chemical erosion or physical damage that the water vapor barrier film may encounter in different application environments.

[0038] See also Figure 3 , Figure 3 FIG4 is a schematic diagram of the structure of a water vapor barrier film including a hardening layer 400 in one embodiment of the present application. The hardening layer 400 is also included and is adjacent to the water vapor barrier layer 110. The hardening layer 400 is formed by coating. Selecting different hardening adhesives based on the characteristics of the object being adhered can improve the bonding performance between the object being adhered and the barrier film, further enhancing the stability of the entire system.

[0039] Specifically, the thickness of the hardened layer 400 is greater than the thickness of the water vapor barrier layer 110 .

[0040] Specifically, the barrier layer 100 also includes a UV barrier layer, which is disposed on the side of the first substrate layer 120 opposite the moisture barrier layer 110. As a crucial component of the barrier layer 100, the UV barrier layer's primary function is to effectively block and absorb UV radiation, thereby comprehensively protecting the moisture barrier film and its attached electronic components from UV damage. The UV barrier layer is typically composed of materials with high UV absorption capabilities, such as polymer films containing UV absorbers, titanium dioxide (TiO2) coatings, or UV-absorbing nanoparticles. These materials effectively absorb or reflect UV radiation, reducing UV penetration through the moisture barrier film, thereby protecting internal components from UV damage. Positioning the UV barrier layer on the opposite side of the first substrate layer 120 from the moisture barrier layer 110 ensures dual protection of moisture and UV barrier functions, while also achieving structural optimization and complementary performance. On the one hand, the moisture barrier layer 110 effectively isolates moisture, preventing internal components from getting wet. On the other hand, the UV barrier layer blocks ultraviolet rays, preventing aging, fading, and performance degradation of electronic components caused by long-term exposure to UV rays. This design also improves the durability and long-term stability of the moisture barrier film. In outdoor environments or those with high UV intensity, the UV barrier layer significantly extends the life of the moisture barrier film, reducing replacement and maintenance costs caused by UV damage. This makes the moisture barrier film more suitable for various high-end applications, such as outdoor displays and automotive electronic equipment, which often have higher requirements for product weather resistance and stability.

[0041] Specifically, an indicator mark is provided in the first substrate layer 120, the second substrate layer 320, or the adhesive layer 200 to identify the cutting start point of the vapor barrier film. This mark clearly identifies the cutting start point of the vapor barrier film, greatly facilitating subsequent processing, cutting, or assembly. The indicator mark is designed with practicality and easy recognition in mind and can take a variety of forms, such as color coding, numerical or alphanumeric codes, or specific geometric shapes. These marks are not only easily visible to the naked eye but can also be automatically detected and located by machine vision systems, significantly improving production efficiency and accuracy. Placing the indicator mark in the first substrate layer 120, the second substrate layer 320, or the adhesive layer 200 takes into account the overall structure and processing requirements of the vapor barrier film. Regardless of the layer in which the indicator mark is provided, it ensures that operators or machines can quickly and accurately locate the cutting start point during the cutting, cutting, or assembly process, thereby avoiding problems such as miscutting, material waste, and product damage.

[0042] As can be seen from the above, the water vapor barrier film of the present application specifically includes a barrier functional layer, an adhesive layer, and an anti-glare functional layer. The barrier functional layer is composed of a water vapor barrier layer and a first substrate layer. The water vapor barrier layer uses high-performance materials and its thickness is precisely controlled to be less than 100 nanometers to achieve an efficient water vapor barrier effect while reducing material consumption. The first substrate layer serves as a support and has a thickness ranging from 25 microns to 100 microns, ensuring the stiffness and stability of the substrate. In particular, the barrier functional layer is arranged on the cutting starting side of the water vapor barrier film, which optimizes the cutting process and improves the reliability and stability of the product. The anti-glare functional layer is mainly composed of an anti-glare layer and a second substrate layer. The anti-glare layer reduces light reflection and scattering through a special optical design. The second substrate layer also has an appropriate thickness range to provide stable support for the anti-glare layer. The adhesive layer is the key to connecting the barrier functional layer and the anti-glare functional layer. Its thickness is between 5 microns and 30 microns, ensuring a firm bond between the layers and giving the water vapor barrier film good flexibility and weather resistance. In addition, the present application may also add an ultraviolet barrier layer, which is arranged on the other side of the first substrate layer relative to the water vapor barrier layer to effectively block ultraviolet radiation and protect the internal electronic components from damage. At the same time, a first protective film and a second protective film are respectively provided on both sides of the water vapor barrier film to form an all-round protective structure to enhance the durability and protective performance of the water vapor barrier film. The present application also provides an indicator mark in the water vapor barrier film to clearly identify the starting side of the cutting, which provides great convenience for subsequent processing, cutting or assembly processes. This design not only improves production efficiency, but also reduces the risk of miscutting and damaging the product. In summary, the water vapor barrier film of the present application, with its exquisite structural design and comprehensive functional characteristics, provides a more reliable and efficient water vapor barrier and anti-glare solution for high-end application fields such as flexible electronic paper displays.

[0043] The above is only a specific implementation of the present application. Any other improvements made based on the concept of the present application are considered to be within the scope of protection of the present application.

Claims

1. A water vapor barrier film, characterized in that: It comprises a barrier function layer (100), an adhesive layer (200), and an anti-glare function layer (300); The barrier function layer (100) comprises a water vapor barrier layer (110) and a first substrate layer (120); the anti-glare function layer (300) comprises an anti-glare layer (310) and a second substrate layer (320); The barrier function layer (100) and the anti-glare function layer (300) are bonded via the adhesive layer (200); The thickness of the first substrate layer (120) and the second substrate layer (320) is in the range of 25 μm-100 μm, the thickness of the water vapor barrier layer (110) is less than 100 nm, and the barrier functional layer (100) is arranged on the cutting starting side of the water vapor barrier film.

2. The water vapor barrier film according to claim 1, characterized in that The thickness of the bonding layer (200) is in the range of 5 μm to 30 μm.

3. The water vapor barrier film according to claim 2, characterized in that The thickness of the first substrate layer (120) and the second substrate layer (320) is in the range of 45 μm to 55 μm, and the thickness of the bonding layer (200) is in the range of 10 μm to 20 μm.

4. The water vapor barrier film according to claim 1, characterized in that The first substrate layer (120) in the barrier function layer (100) and the second substrate layer (320) in the anti-glare function layer (300) are in contact with the adhesive layer (200).

5. The water vapor barrier film according to claim 4, characterized in that The water vapor barrier layer (110), the first substrate layer (120), the adhesive layer (200), the second substrate layer (320), and the anti-glare layer (310) are stacked in sequence from top to bottom.

6. The water vapor barrier film according to claim 1, characterized in that It also includes a first protective film (510) and a second protective film (520), wherein the first protective film (510) and the second protective film (520) are respectively formed on both sides of the water vapor barrier film.

7. The water vapor barrier film according to any one of claims 1 to 6, characterized in that: It also includes a hardening layer (400), wherein the hardening layer (400) is adjacent to the water vapor barrier layer (110).

8. The water vapor barrier film according to claim 7, characterized in that The thickness of the hardened layer (400) is greater than the thickness of the water vapor barrier layer (110).

9. The water vapor barrier film according to claim 1, characterized in that The barrier function layer (100) further comprises an ultraviolet barrier layer, and the ultraviolet barrier layer is arranged on a side of the first substrate layer (120) opposite to the water vapor barrier layer (110).

10. The water vapor barrier film according to claim 1, characterized in that It also includes an indicator mark, which is arranged in the first substrate layer (120), the second substrate layer (320) or the adhesive layer (200) to mark the cutting starting side of the water vapor barrier film.

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