Edge sealing structure and edge sealing method of PDLC light control film

Abstract

The application discloses an edge sealing structure and method of a PDLC light modulation film. The edge sealing structure comprises a PDLC film piece, double-sided adhesive and an edge sealing film. The double-sided adhesive is arranged at a distance of 0.5mm-30mm from the edge of the PDLC film piece or from the half-cut position, and first and second cutting routes are sequentially laser-cut on the protective film on the surface of the PDLC film piece along the edge contour of the PDLC film piece from the outside to the inside, wherein the first protruding structure is arranged on the second cutting route. The edge sealing film is distributed along the length direction of the edge of the PDLC film piece and is attached to the double-sided adhesive, and the edge sealing film is provided with the second protruding structure which is embedded and matched with the first protruding structure, and the limit is formed by mutual embedding to resist various external forces. The application can be adapted to PDLC film materials of multiple specifications, thicknesses and special shapes, and effectively solves the problems of edge sealing deviation, warping and delamination.

Description

Technical Field

[0001] This application relates to the field of PDLC dimming film technology, and in particular to a sealing structure and sealing method for a PDLC dimming film. Background Technology

[0002] Polymer Dispersed Liquid Crystal (PDLC) dimming film is a functional film material that achieves light transmission / blocking switching based on changes in the orientation of liquid crystal molecules. Its typical structure includes upper and lower substrate layers, upper and lower conductive layers, and a polymer dispersed liquid crystal layer in the middle. It is currently widely used in various intelligent dimming scenarios.

[0003] When fabricating PDLC dimming films into dimming glass, a PVB (polyvinyl butyral) film is typically used for lamination. During lamination, PVB melts and flows under high temperature and pressure, covering the entire PDLC dimming film. However, once the small plasticizer molecules in PVB come into contact with the exposed polymer-dispersed liquid crystal layer at the edge of the PDLC dimming film, a similarity-of-mix effect occurs, causing the liquid crystal molecules to lose their orientation ability, thus rendering the dimming function ineffective. Therefore, edge sealing of the PDLC dimming film is a key technical aspect to ensure its service life and dimming performance. If the edge sealing is not tight, in addition to plasticizer penetration, external moisture may also seep into the film, leading to oxidation of the PET substrate, deterioration of the liquid crystal layer, and consequently, problems such as abnormal dimming, film yellowing, and interlayer delamination.

[0004] The existing edge-sealing technology for PDLC dimming films has the following main drawbacks: Traditional sealing methods are difficult to adapt to PDLC dimming films of varying thicknesses. Especially for ultra-thin PDLC films with a thickness of 100μm to 120μm, the adhesive layer formed by traditional sealing methods typically reaches a thickness of 150μm to 200μm, far exceeding the thickness of the ultra-thin PDLC film itself. Under the high temperature and pressure of lamination, this significant thickness difference can easily lead to film bending and deformation, and even cause the dimming function to fail.

[0005] Existing edge sealing tapes mostly use a one-step direct bonding process, which requires extremely high bonding and alignment accuracy. Once a deviation occurs, rework is required, making it difficult to guarantee that the bonding is straight, without skewing or air bubbles. The overall error tolerance is low, which cannot meet the needs of efficient automated production line operations.

[0006] With increasing demands for weather resistance in applications such as automobiles, PDLC dimming films need to maintain stable edge-sealing performance in harsh environments such as extreme cold and high temperatures. Existing solid adhesive edge-sealing methods are prone to embrittlement and cracking under extreme temperature conditions; other types of edge-sealing tapes, due to insufficient treatment at the overlap, have local weak points in the seal, allowing plasticizers to quickly penetrate into the film, leading to edge-sealing failure.

[0007] When using PET film for edge sealing, full-coverage edge sealing is difficult to achieve due to limitations in film size and processing conditions. If multi-segment edge sealing is used, gaps will exist in areas without overlap, and gaps will also occur in overlapping areas due to the added thickness. Both of these situations will create sealing defects at local overlaps, allowing plasticizers to quickly penetrate into the film and causing edge sealing failure.

[0008] In summary, existing edge sealing technologies for PDLC dimming films have significant shortcomings in terms of adaptability, precision control, reliability, and weather resistance, and there is an urgent need to develop a new edge sealing structure that can overcome these defects. Summary of the Invention

[0009] This application addresses the shortcomings of existing PDLC dimming film edge sealing technologies in terms of thickness adaptability, alignment accuracy, extreme environment adaptability, and overlap sealing reliability by providing an edge sealing structure and method. The edge sealing structure includes a first cutting path and a second cutting path sequentially formed on the protective films of the upper and lower surfaces of the PDLC film along the edge contour. A first protrusion structure is provided on the second cutting path. Both the first and second sealing films have second protrusion structures that interlock with the first protrusion structures. Third protrusion structures protruding outwards are provided at both ends of the first sealing film, and the end of the second sealing film overlaps the end of the first sealing film, forming an overlap. Through this structure, this application can effectively resist tensile and warping forces, extend the penetration path of plasticizers, and reduce alignment difficulty through the guiding effect of the interlocking structure. Therefore, while improving thickness adaptability and edge sealing reliability in extreme environments, it also improves the overall edge sealing performance and service life of the PDLC dimming film. The technical solution provided by this application is as follows: On the one hand, this application provides a sealing structure for a PDLC dimming film, including: PDLC membrane; Double-sided adhesive is applied at a distance of 0.5mm to 30mm from the edge of the PDLC film or from the edge of the half-cut position; wherein, the half-cut position is the boundary of the half-cut area facing the center of the PDLC film, and the half-cut area is formed by a half-cut process, removing the local protective film and the PET substrate layer and conductive layer below it from the half-cut position; Along the edge contour of the PDLC film, a first cutting path and a second cutting path are sequentially laser-cut on the protective film on the surface of the PDLC film from the outside to the inside; a plurality of first protrusion structures are spaced apart on the second cutting path, and the first protrusion structures protrude toward the center of the PDLC film; At least one sealing film is attached to the double-sided adhesive, and the sealing film is provided with a second protruding structure that fits and matches the first protruding structure.

[0010] In some preferred embodiments, the distance between the first cutting path and the side of the double-sided adhesive near the edge of the PDLC film is 0mm to 5mm, and the distance between the second cutting path and the side of the double-sided adhesive near the center of the PDLC film is 0.3mm to 5mm.

[0011] In some preferred embodiments, the sealing film includes at least a first sealing film and a second sealing film arranged sequentially along the length of the edge of the PDLC film; The first sealing film and the second sealing film are respectively provided with the second protrusion structure; The first sealing film has a third protrusion structure protruding outward at each of its two ends along its length; The end of the second sealing film overlaps the end of the first sealing film to form an overlap; The overlapping portion is provided with single-sided adhesive, which is used to fix the end of the second sealing film to the first sealing film and cover the third protruding structure.

[0012] In some preferred embodiments, the thickness of the protective film is 20μm to 150μm, and the thickness of the protective film is greater than the sum of the thickness of the double-sided adhesive and the thickness of the sealing film.

[0013] In some preferred embodiments, the double-sided adhesive has a thickness of 10μm to 60μm and a width of 0.1mm to 1.9mm; In some preferred embodiments, the thickness of the sealing film is 10 μm to 80 μm.

[0014] In some preferred embodiments, the first protrusion structure and the second protrusion structure are spaced at the same interval; the interval is determined based on the thickness of the double-sided adhesive and the length of the side of the PDLC film to which the interval is applied, specifically satisfying the following conditions: When the thickness of the double-sided adhesive is 10μm~30μm: When the length of the side of the PDLC film to which the spacing is applied is ≤100mm, the spacing is 20mm~25mm; When the length of the side of the PDLC film to which the spacing is applied is greater than 100 mm and less than or equal to 500 mm, the spacing is 30 mm to 65 mm. When the length of the side of the PDLC film to which the spacing is applied is >500mm and ≤1000mm, the spacing is 80mm~120mm; When the length of the side of the PDLC film to which the interval is applied is greater than 1000 mm and less than or equal to 2000 mm, the interval is 135 mm to 160 mm. When the length of the side of the PDLC film to which the interval is applied is greater than 2000 mm and less than or equal to 5000 mm, the interval is 190 mm to 210 mm. When the thickness of the double-sided adhesive is 31μm~45μm: When the length of the side of the PDLC film to which the spacing is applied is ≤100mm, the spacing is 30mm~35mm; When the length of the side of the PDLC film to which the spacing is applied is greater than 100 mm and less than or equal to 500 mm, the spacing is 50 mm to 90 mm. When the length of the side of the PDLC film to which the interval is applied is >500mm and ≤1000mm, the interval is 110mm~140mm; When the length of the side of the PDLC film to which the interval is applied is greater than 1000 mm and less than or equal to 2000 mm, the interval is 160 mm to 190 mm. When the length of the side of the PDLC film to which the interval is applied is greater than 2000 mm and less than or equal to 5000 mm, the interval is 230 mm to 260 mm. When the thickness of the double-sided adhesive is 46μm~60μm: When the length of the side of the PDLC film to which the spacing is applied is ≤100mm, the spacing is 40mm~45mm; When the length of the side of the PDLC film to which the spacing is applied is greater than 100 mm and less than or equal to 500 mm, the spacing is 80 mm to 90 mm. When the length of the side of the PDLC film to which the spacing is applied is >500mm and ≤1000mm, the spacing is 170mm~220mm; When the length of the side of the PDLC film to which the interval is applied is greater than 1000 mm and less than or equal to 2000 mm, the interval is 250 mm to 280 mm. When the length of the side of the PDLC film to which the interval is applied is greater than 2000 mm and less than or equal to 5000 mm, the interval is 300 mm to 320 mm.

[0015] In some preferred embodiments, the extension length L1 of the third protrusion structure extending outward from the first sealing film body satisfies: 3mm≤L1≤50mm.

[0016] In some preferred embodiments, the edge of the PDLC membrane is provided with a half-cut region, and the width D1 of the half-cut region satisfies: 0 <D1≤10mm; The distance D2 between the edge of the third protrusion structure away from the center of the PDLC film and the half-cut position satisfies: D1 <D2; The distance D5 between the edge of the third protrusion structure near the center of the PDLC film and the half-cut position satisfies: 2mm≤D5≤8mm.

[0017] In some preferred embodiments, the distance D2 further satisfies: 3mm+D1≤D2≤8mm+D1.

[0018] In some preferred embodiments, the distance between the edge boundary of the sealing film away from the center of the PDLC film and the half-cut position is D3, and the ratio of D3 to the distance D2 satisfies: 1.3≤D3 / D2≤1.8; The distance D6 between the edge of the third protrusion structure near the center of the PDLC film and the first cutting path satisfies: 2mm≤D6≤8mm.

[0019] In some preferred embodiments, the shapes of the first protrusion structure and the second protrusion structure are selected from any one of a semicircle, triangle, trapezoid, or rectangle.

[0020] On the other hand, this application also provides a method for sealing the edge of a PDLC dimming film, employing the sealing structure described in any of the above claims, comprising the following steps: Along the edge contour of the PDLC film, a first cutting line, a second cutting line, and multiple first protrusion structures located on the second cutting line are laser-cut on the protective film; Double-sided adhesive is applied 0.5mm to 30mm from the edge of the PDLC film or from the edge of the half-cut position; A second protrusion structure matching the first protrusion structure is formed on the sealing film; The sealing film is attached to the double-sided adhesive so that the second raised structure and the first raised structure fit together.

[0021] In some preferred embodiments, the upper and lower surfaces of the PDLC film are sealed, specifically including the following steps: a) Along the edge contour of the PDLC film, a first cutting path and a second cutting path are sequentially laser-cut from the outside to the inside on the protective film on the upper and lower surfaces of the PDLC film, and a plurality of first protrusion structures are cut on the second cutting path. b) Apply double-sided adhesive at a distance of 0.5 mm to 30 mm from the edge of the PDLC film or from the edge of the half-cut position; c) Provide at least two sealing films, including a first sealing film and at least one second sealing film; by laser cutting, a second protrusion structure matching the first protrusion structure is formed on each sealing film, and a third protrusion structure protruding outward is provided at the end of the first sealing film in the length direction; d) Each sealing film is sequentially attached to the double-sided adhesive along the second cutting line, so that the second protrusion structure of each film is fitted into the first protrusion structure; and the end of the next attached sealing film is overlapped on the end of the previous attached sealing film to form an overlap. e) Apply single-sided adhesive to the overlapping part, fix the end of the second sealing film to the first sealing film, and cover the third protruding structure; f) Flip the PDLC film over and repeat steps d) to e) to complete the sealing of the other side surface.

[0022] In some preferred embodiments, for PDLC films with electrodes or grooves on all four sides, the edge is sealed only on the side directly above the electrodes or grooves, while no edge sealing structure is provided on the back side of the electrodes or grooves.

[0023] By adopting the above technical solution, the edge sealing structure and method of the PDLC dimming film provided in this application have the following beneficial effects: 1. The sealing structure of this application includes a first cutting path and a second cutting path sequentially formed on the protective film on the upper and lower surfaces of the PDLC film along the edge contour of the PDLC film. A first protrusion structure is provided on the second cutting path. A second protrusion structure is provided on the sealing film to interlock with the first protrusion structure, forming an interlocking structure. This effectively ensures the accuracy of the sealing assembly position. Simultaneously, this interlocking structure can resist external forces in subsequent processes, preventing displacement or warping of the sealing film. Furthermore, the cutting path can be arbitrarily adjusted according to the edge contour of the film, without being limited by rectangular, circular, or polygonal shapes, thus adapting to the sealing requirements of PDLC films of different shapes and thicknesses, covering multiple application scenarios.

[0024] 2. Further, the sealing film includes at least a first sealing film and a second sealing film arranged sequentially along the length of the PDLC film edge; the first sealing film has a third protruding structure protruding outward at each of its two ends along its length; the end of the second sealing film overlaps the end of the first sealing film to form an overlap; a single-sided adhesive is provided on the overlap, which is used to fix the end of the second sealing film to the first sealing film and cover the third protruding structure. During the lamination process, the PVB film melts and flows under high temperature and pressure, which can make the area firmly compressed during lamination; however, in harsh environments, intense thermal molecular movement may still cause the plasticizer to penetrate into the PDLC film along the microchannels formed by the height difference or the micro-gap at the overlap interface, thereby causing sealing failure. This application adopts the above-mentioned third protrusion structure design. Even if a tiny gap is formed under extreme conditions, the plasticizer cannot enter the interior of the PDLC film in a short time because the inward penetration path is significantly extended. This ensures that the polymer-dispersed liquid crystal layer is not eroded under extreme conditions, blocks water vapor and plasticizer from invading the film, and improves the sealing performance, structural weather resistance and service life of the dimming film. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of the sealing structure of the PDLC dimming film provided in the embodiments of this application. Figure 1 ; Figure 2 Schematic diagram of the edge-sealing film provided in the embodiments of this application Figure 1 ; Figure 3 This is a cross-sectional schematic diagram of the sealing structure of the PDLC dimming film provided in the embodiments of this application; Figure 4 This is a structural schematic diagram of the half-cut position provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of the edge sealing alignment area provided in the embodiments of this application; Figure 6 Provided for the embodiments of this application Figure 5 A magnified schematic diagram of part A; Figure 7 Schematic diagram of the edge-sealing film provided in the embodiments of this application Figure 2 ; Figure 8A schematic diagram of the sealing structure of the PDLC dimming film provided in the embodiments of this application. Figure 2 ; Figure 9 A schematic diagram of the sealing structure of the PDLC dimming film provided in the embodiments of this application. Figure 3 ; Figure 10 This is a schematic diagram of the single-layer sealing structure of the PDLC dimming film provided in the embodiments of this application.

[0027] The following is supplementary explanation of the attached figures: 100 - PDLC film; 101 - Half-cut position; 200 - Sealing alignment area; 201 - First cutting path; 202 - Second cutting path; 203 - First raised structure; 300 - Double-sided adhesive; 400 - Sealing film; 401 - First sealing film; 402 - Second sealing film; 403 - Second raised structure; 404 - Third raised structure; 500 - Single-sided adhesive; 600 - PVB film; 701 - Corner module; 702 - Edge module. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0029] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. In the description of this application, it should be understood that the terms "upper," "lower," "top," "bottom," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0030] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included. For example, a specified range from “1 to 10” should be considered to include any and all subranges between the minimum value 1 and the maximum value 10. Exemplary subranges of the range 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0031] like Figures 1 to 4 As shown, this application provides a sealing structure for a PDLC dimming film, including a PDLC film 100, double-sided adhesive 300, and at least one sealing film 400.

[0032] The double-sided adhesive 300 is positioned 0.5mm to 30mm from the edge of the PDLC film 100 or the edge of the half-cut position 101. If the distance is less than 0.3mm, the double-sided adhesive 300 is too close to the edge of the PDLC film 100 or the edge of the half-cut position 101, and may even directly adhere to the edge of the PDLC film 100, reducing the adhesion stability and sealing reliability of the sealing film 400. If the distance is greater than 30mm, on the one hand, the safety margin is too redundant, and the width of the sealing film 400 will also increase, increasing costs; on the other hand, an excessively wide sealing area will encroach on the viewing area of ​​the dimming glass, and many customers prefer a larger viewing area. A balance needs to be struck between ensuring sealing reliability and the viewing area. The half-cut position 101 is the boundary of the half-cut area facing the center of the PDLC film 100; the half-cut area is formed by a half-cut process, removing a portion of the protective film and the underlying PET substrate layer and conductive layer starting from the half-cut position 101. Preferably, the double-sided adhesive 300 is made of at least one of acrylic adhesive, water-based adhesive, or silicone adhesive. It should be noted that the edge of the PDLC membrane 100 may or may not have a half-cut area, depending on actual needs: if no half-cut area is provided, the double-sided adhesive 300 is positioned 0.5mm to 30mm from the edge of the PDLC membrane 100; if a half-cut area is provided, the double-sided adhesive 300 is positioned 0.5mm to 30mm from the edge of the half-cut position 101. The specific distance can be determined according to actual usage.

[0033] Along the edge contour of the PDLC film 100, a first cutting line 201 and a second cutting line 202 are sequentially laser-cut from the outside to the inside on the protective film surface of the PDLC film 100. Multiple first protrusion structures 203 are spaced apart on the second cutting line 202, protruding towards the center of the PDLC film 100. The first protrusion structures 203 are uniformly or non-uniformly distributed along the length of the second cutting line 202, and their spacing is determined by the thickness of the double-sided adhesive 300 and the length of the long or short side of the PDLC film 100 to ensure effective fitting and positioning and process compatibility.

[0034] At least one sealing film 400 is distributed along the length of the edge of the PDLC film 100 and attached to the double-sided adhesive 300. The sealing film 400 has a second protruding structure 403 that fits and matches the first protruding structure 203. The material of the sealing film 400 can be PET (polyethylene terephthalate), PI (polyimide), COP (cyclic olefin polymer), CPI (colorless polyimide), etc. The shape, size, and distribution of the second protruding structure 403 are consistent with the first protruding structure 203. After attachment, the first protruding structure 203 and the second protruding structure 403 fit and match each other, forming a mating structure, thereby effectively ensuring the accuracy of the sealing assembly position. Simultaneously, this mating structure can resist external forces in subsequent processes, preventing the sealing film 400 from shifting or warping. Specifically, this is demonstrated as follows: When preparing smart glass, a high-temperature and high-pressure lamination process using PVB film 600 is typically employed. During the melting, flow, curing, and shrinkage process, PVB film 600 generates a lateral pulling force. Under the action of this lateral pulling force, the first protruding structure 203 and the second protruding structure 403 form a reverse resistance, preventing the sealing film 400 from shifting left or right along the cutting path.

[0035] During the PDLC film 100 flipping and material handling operations, the overall structure is easily subjected to warping torque. The first protrusion structure 203 and the second protrusion structure 403 can fix the attachment posture of the sealing film 400 and avoid overlapping gaps that may be caused by warping.

[0036] The second protruding structure 403 and the sealing film 400 are integrally cut and formed structures, and both have the same deformation toughness. When the sealing film 400 is subjected to external force, the stress is preferentially transferred to the second protruding structure 403. The stress is absorbed and dispersed by the slight elastic deformation of the second protruding structure 403, so that the main body area of ​​the sealing film 400 remains flat and attached, thereby reducing the probability of defects such as edge wrinkles and gaps from the source.

[0037] Especially under the high temperature and high pressure environment of the lamination process, the PVB film 600 melts upon heating and flows towards the semi-cut area around the PDLC film 100. The semi-cut area, due to the removal of the protective film and PET substrate, forms a stepped thickness difference. Molten PVB readily diffuses towards the lower thickness area, thus applying a lateral tensile force to the sealing area. At this time, the second protruding structure 403 preferentially bears this lateral tensile force and absorbs stress through its own deformation, effectively protecting the main sealing area and avoiding problems such as sealing wrinkles, bonding gaps, and tensile cracking, ensuring the overall sealing performance and structural reliability of the PDLC film 100 edge sealing.

[0038] In some preferred embodiments, the distance between the first cutting line 201 and the side of the double-sided adhesive 300 near the edge of the PDLC film 100 is 0mm to 5mm. A distance greater than 5mm would increase the width of the outer protective film, requiring a longer distance for the peeling force during tearing, potentially causing microscopic separation or lifting at the interface between the double-sided adhesive and the protective film, reducing adhesive integrity. Furthermore, 5mm is sufficient for edge sealing reliability; an unnecessary increase in width would encroach on the PVB film 600's edge-patching area, potentially affecting the uniformity of PVB film 600's melt flow during lamination, and entering the visible area in narrow-bezel dimming glass applications. The distance between the second cutting line 202 and the side of the double-sided adhesive 300 near the center of the PDLC film 100 is 0.3mm to 5mm. When the gap is less than 0.3mm, the double-sided adhesive 300 is too close to the second cutting path 202, and the double-sided adhesive 300 is prone to overflowing into the raised structure area, interfering with the precise fitting of the first raised structure 203 and the second raised structure 403. Too close a gap in the double-sided adhesive 300 will interfere with the laser cutting energy, resulting in incomplete cutting of the second cutting path 202, which is detrimental to subsequent film peeling and alignment. When the gap is greater than 5mm, the second cutting path 202 is too far from the inner edge of the double-sided adhesive 300, increasing the distance between the retained protective film stop step and the inner edge of the sealing film. When the sealing film 400 is subjected to a pushing force towards the center of the film, the raised structure cannot function in time, potentially causing the film to shift inward. Simultaneously, an excessively wide gap will result in an excessively wide sealing edge, compressing the visible area of ​​the dimming product.

[0039] In some preferred embodiments, the sealing film 400 includes at least a first sealing film 401 and a second sealing film 402 arranged sequentially along the length of the edge of the PDLC film 100, both of which are attached to the double-sided adhesive 300. The first sealing film 401 and the second sealing film 402 are respectively provided with a second protruding structure 403 that fits and matches the first protruding structure 203, and the first sealing film 401 is provided with a third protruding structure 404 protruding outward at each of its two ends along its length. The end of the second sealing film 402 overlaps the end of the first sealing film 401, forming an overlap.

[0040] Specifically, on each side surface of the PDLC film 100, there are at least a first sealing film 401 and a second sealing film 402 arranged sequentially along the edge length direction, and the sealing operation is performed in sequence. Since the two sealing films with a certain thickness are stacked on each other, a smooth transition height difference is formed at the overlap. During the lamination process, the PVB film melts and flows under high temperature and pressure, which can make the area firmly squeezed during bonding; however, in harsh environments, intense thermal molecular movement may still cause the plasticizer to penetrate into the interior of the PDLC film 100 along the microchannels formed by the height difference or the micro gaps at the overlap interface, thereby causing sealing failure. This application adopts the above-mentioned third protrusion structure 404 design. Even if a micro gap is formed in extreme cases, the inward penetration path is significantly extended, and the plasticizer cannot enter the interior of the PDLC film 100 in a short time. This ensures that the polymer-dispersed liquid crystal layer is not eroded under extreme conditions, blocks moisture and plasticizer from penetrating into the film, and improves the sealing performance, structural weather resistance, and service life of the dimming film.

[0041] A single-sided adhesive 500 is provided on the overlap portion. The single-sided adhesive 500 is used to fix the end of the second sealing film 402 to the first sealing film 401 and cover the third protruding structure 404. It should be noted that the second sealing film 402 only needs to overlap its end and cover the third protruding structure 404; it does not need to overlap the entire surface. Since there is a part below the overlap end of the second sealing film 402 without double-sided adhesive 300 for fixation, this area is prone to bending or tearing due to stress during handling and subsequent processes, thus affecting the sealing effect. Therefore, the single-sided adhesive 500 is attached to the overlap portion to provide auxiliary fixation to this part of the area, ensuring that the end of the second sealing film 402 always remains flat and attached, thereby avoiding sealing failure due to bending or tearing.

[0042] In some preferred embodiments, such as Figure 7 and Figure 8As shown, for ultra-wide PDLC dimming films (e.g., width > 1600mm, length > 2500mm), using a two-piece sealing film 400 (i.e., only the first sealing film 401 and the second sealing film 402 arranged sequentially along the edge length direction) will result in extremely low material utilization, high cost, and inconvenient transportation and storage. To solve the above problems, this application also proposes a modular sealing film structure, which decomposes the sealing film 400 into multiple standardized independent modules, specifically including L-shaped or right-angled corner modules 701 set at the four corners, and elongated edge modules 702 set in the middle area of ​​each side. The corner module 701 covers the corner area of ​​two adjacent sides, and each end of it is provided with a third protruding structure 404 to form an extended plasticizer penetration channel at the corner, and to overlap with the adjacent side module 702. The side module 702 connects the two corner modules 701 and is used to overlap and fix with the corresponding ends of the corner module 701 to form a complete edge sealing ring. The standardized corner module 701 and side module 702 can achieve a high material utilization rate and reduce costs through optimized layout; at the same time, the modular structure forms multiple overlaps between the corner and the side, which can effectively disperse thermal stress and mechanical stress, and avoid warping or wrinkling caused by accumulated stress in ultra-long continuous edge sealing strips. In terms of overlap and sealing design, the corner module 701 and the edge module 702 are overlapped at their ends and fixed with single-sided adhesive 500, while covering their respective third protrusion structures 404. The third protrusion structures 404 of each module are staggered to avoid excessive thickness and stress concentration caused by multi-layer stacking. Through the above modular overlap design, the entire sealing ring forms a continuous and complete multi-extended permeation channel, achieving economical and efficient sealing of the large-size PDLC membrane 100 while ensuring sealing reliability.

[0043] In some preferred embodiments, the thickness of the protective film is 20μm~150μm, and the thickness of the protective film is greater than the sum of the thickness of the double-sided adhesive 300 and the thickness of the sealing film 400. After being attached, the protective film protrudes from the surface of the sealing film 400, forming a physical stop structure, which effectively prevents the sealing film 400 from lateral displacement. The protective film is removed before lamination to ensure that the PDLC film 100 enters the lamination assembly with a clean and intact appearance.

[0044] In some preferred embodiments, the double-sided adhesive 300 has a thickness of 10μm to 60μm and a width of 0.1mm to 1.9mm. When the thickness is less than 10μm, the adhesive force is insufficient, and the sealing film 400 is easily peeled off or shifted in subsequent processes (such as flipping, handling, and lamination). When the thickness is greater than 60μm, the double-sided adhesive 300 is too thick, and it is easy to overflow into non-target areas during the sealing operation, contaminating the first / second raised structure or the edge of the protective film, affecting the fitting accuracy and film tearing operation. During the lamination process, the excessively thick double-sided adhesive 300 may flow excessively under high temperature and pressure, causing the sealing film 400 to drift or have uneven thickness, thereby affecting the sealing reliability.

[0045] When the width is less than 0.1mm, the adhesive width is too narrow, resulting in insufficient contact area with the sealing film 400 and low adhesive strength. Under lateral pulling or warping torque, the sealing film 400 is prone to detaching from the adhesive edge. The alignment tolerance is extremely small; even slight deviations can lead to partial non-adhesion, easily causing sealing failure. When the width is greater than 1.9mm, the excessively wide adhesive increases the overall rigidity of the sealing edge, reducing the flexibility of the sealing film 400. This makes it difficult to adhere to irregular edges or corners, easily causing wrinkles or bubbles. A double-sided adhesive 300 of 0.1mm to 1.9mm is sufficient for reliable adhesion; excessive width wastes material and increases the risk of adhesive overflow.

[0046] In some preferred embodiments, the thickness of the sealing film 400 is 10μm to 80μm. This thickness range forms a suitable thickness relationship with the protective film and the double-sided adhesive 300 to ensure that the physical stop structure of the protective film protruding from the surface of the sealing film 400 is effectively formed. If the thickness of the sealing film 400 is too thin, the sum of its thickness and that of the double-sided adhesive 300 may be less than the thickness of the protective film. Although the stop condition is still met, the tensile strength and puncture resistance of the sealing film 400 are insufficient, and it is prone to tensile deformation or breakage during high temperature and high pressure lamination and subsequent processes, resulting in sealing failure. If the thickness of the sealing film 400 is too thick, the sum of its thickness and that of the double-sided adhesive 300 may exceed the thickness of the protective film, causing the protective film to be unable to protrude from the surface of the sealing film 400. The physical stop structure fails, and it cannot prevent lateral displacement. Moreover, it forms a significant step difference with the PDLC film 100 body, which hinders the PVB melt flow during lamination and easily generates bubbles or uneven bonding in the sealing area.

[0047] In some preferred embodiments, the first protrusion structure 203 and the second protrusion structure 403 are spaced at the same interval, which is determined by the thickness of the double-sided adhesive 300 and the length of the side of the PDLC film 100 to which the interval is applied.

[0048] Taking a rectangular shape for the PDLC film 100 as an example, the lengths of its long and short sides are different. Therefore, the number and distribution density of the protrusions can be adjusted adaptively according to the side lengths. Specifically, when the sealing film 400 is located on the short side of the PDLC film 100 (e.g....), Figure 9 As shown in the blue area ①, its length extending along the edge of the PDLC film is relatively short, and correspondingly, fewer protrusions are arranged; when the sealing film is set on the long side of the PDLC film 100 (such as... Figure 9 As shown in the red area ②, the length extending along the edge of the PDLC film is relatively long, and correspondingly, a larger number of protrusions are arranged. In other words, the number of protrusions arranged along the long side is greater than the number of protrusions arranged along the short side, thereby ensuring the effectiveness of the fitting and positioning while taking into account process adaptability and production efficiency.

[0049] The thicker the double-sided adhesive 300, the stronger its buffering and stress dispersion capabilities for the adhesive layer of the sealing film 400, and the better the overall resistance of the interlocking structure to external forces. Therefore, it allows for a larger spacing without significantly affecting the reliability of the limit. When the thickness of the double-sided adhesive 300 is small (e.g., 10μm~30μm), the interlocking structure is more sensitive to external forces, and a denser spacing of raised structures is required to enhance local constraints and prevent the sealing film 400 from local dislocation or warping when subjected to lateral tensile or torsional loads.

[0050] The longer the sealing film 400 is, the greater the risk of cumulative stress and deformation during lamination and handling. In particular, long films are more prone to overall stretching or warping under high temperature and pressure conditions. To effectively suppress this stress transmission, the spacing of the protrusions needs to be appropriately increased with the length, so that the protrusions can evenly distribute the stress within each length segment, avoiding insufficient constraint in the middle area of ​​the long film due to excessively long spacing.

[0051] If the interval is too small, the laser cutting path will be too dense, increasing processing time and equipment wear. It may also cause stress concentration in local areas of the sealing film, which will reduce its flexibility under bending conditions. If the interval is too large, the film area between two adjacent interlocking structures will lack effective constraint. When subjected to lateral pulling force or warping torque, this area is prone to local bulging, lateral slippage or the formation of micro gaps, which will cause plasticizers or moisture to penetrate into the PDLC film 100 along this weak link, damaging the sealing performance.

[0052] Based on the above considerations, and through extensive experiments and process verification, the specific spacing between the first protrusion structure and the second protrusion structure satisfies the following conditions: When the thickness of the double-sided adhesive is 10μm~30μm: When the length of the side of the PDLC membrane 100 with the applied gap is ≤100mm, the gap is 20mm~25mm; When the length of the side of the PDLC membrane 100 with the applied gap is greater than 100 mm and less than or equal to 500 mm, the gap is 30 mm to 65 mm. When the length of the side of the PDLC membrane 100 with the applied gap is >500mm and ≤1000mm, the gap is 80mm~120mm; When the length of the side of the PDLC membrane 100 with the applied gap is >1000mm and ≤2000mm, the gap is 135mm~160mm; When the length of the side of the PDLC membrane 100 with the applied gap is greater than 2000 mm and less than or equal to 5000 mm, the gap is 190 mm to 210 mm. When the thickness of the double-sided adhesive is 31μm~45μm: When the length of the side of the PDLC membrane 100 with the applied gap is ≤100mm, the gap is 30mm~35mm; When the length of the side of the PDLC membrane 100 with the applied gap is greater than 100 mm and less than or equal to 500 mm, the gap is 50 mm to 90 mm. When the length of the side of the PDLC membrane 100 with the applied gap is >500mm and ≤1000mm, the gap is 110mm~140mm; When the length of the side of the PDLC membrane 100 with the applied gap is greater than 1000 mm and less than or equal to 2000 mm, the gap is 160 mm to 190 mm. When the length of the side of the PDLC membrane 100 with the applied gap is >2000mm and ≤5000mm, the gap is 230mm~260mm; When the thickness of the double-sided adhesive is 46μm~60μm: When the length of the side of the PDLC membrane 100 with the applied gap is ≤100mm, the gap is 40mm~45mm; When the length of the side of the PDLC membrane 100 with the applied gap is greater than 100 mm and less than or equal to 500 mm, the gap is 80 mm to 90 mm. When the length of the side of the PDLC membrane 100 with the applied gap is >500mm and ≤1000mm, the gap is 170mm~220mm; When the length of the side of the PDLC membrane 100 with the applied gap is greater than 1000 mm and less than or equal to 2000 mm, the gap is 250 mm to 280 mm. When the length of the side of the PDLC membrane 100 to which the spacing is applied is greater than 2000 mm and less than or equal to 5000 mm, the spacing is 300 mm to 320 mm.

[0053] In some preferred embodiments, the extension length L1 of the third protruding structure 404 extending outward from the main body of the first edge-sealing film 401 satisfies: 3 mm ≤ L1 ≤ 50 mm. The third protruding structure 404 can be understood as a cantilever beam extending outward from the main body of the edge-sealing film 400, and the extension length L1 is the extension length of the cantilever beam. Since the edge-sealing film 400 itself has high flexibility and low rigidity, it has a long cantilever beam effect, that is, the longer the cantilever, the worse the structural rigidity and the lower the deformation resistance. Controlling L1 within the range of 3 mm to 50 mm, on the one hand, enables the PET cantilever beam to maintain sufficient rigidity, can resist the stress transmitted in the width direction, may avoid uncontrollable deformation in the length direction, and at the same time ensures that the third protrusion forms a sufficiently long plasticizer penetration channel to achieve reliable sealing protection. If L1 < 3 mm, the extension length of the third protruding structure 404 is insufficient, and an effective extended penetration channel cannot be formed. Plasticizer and water vapor may pass through the structure and enter the interior of the PDLC film 100, thereby causing its core sealing function to fail; if L1 > 50 mm, the extension length is too long, the long cantilever beam effect is significantly enhanced, the rigidity of the edge-sealing film 400 cannot support the structural stability in the length direction, which is very likely to cause warping and tensile deformation, resulting in edge-sealing gaps, subsequent gap expansion and possible penetration failure.

[0054] In some preferred embodiments, as Figure 5 and Figure 6 shown, a half-cut area is provided at the edge of the PDLC film 100, and the width D1 of the half-cut area satisfies: 0 < D1 ≤ 10 mm. It should be noted that the value of D1 can be flexibly adjusted according to actual application scenarios: when electrodes need to be fabricated or grooves need to be processed, corresponding half-cut widths can be set; in some scenarios where half-cutting is not required, the original shape can be maintained, that is, D1 is 0. The specific width of the half-cut area can be adapted according to different electrode fabrication requirements or application scenarios.

[0055] The distance D2 between the edge of the third protruding structure 404 away from the center of the PDLC film 100 and the half-cut position 101 satisfies: D1 < D2. If D2 is too short, the edge of the third protruding structure 404 away from the center of the PDLC film 100 may overlap within the half-cut area, or be too close to the half-cut area, which is very likely to cause gaps and affect the sealing effect; if D2 is too wide, the overall edge-sealing structure will occupy too much of the outer PVB edge-complementary area, which is not conducive to space utilization and structural compactness.

[0056] The distance D5 between the edge of the third protrusion structure 404 near the center of the PDLC film 100 and the half-cut position 101 satisfies the following condition: 2mm ≤ D5 ≤ 8mm. D5 constitutes an extended channel that prevents plasticizer inside the PDLC film 100 from entering the half-cut area. This channel extends longitudinally and, together with the channel of D3, forms a double-layer long channel structure, thereby improving the barrier effect against plasticizers. If D5 is too narrow, it cannot provide a sufficiently safe extended channel; if D5 is too long, it will encroach on the width space required for the overall sealing edge. Therefore, controlling D5 between 2mm and 8mm can reasonably meet the overall requirements for sealing edge width while ensuring effective barrier against plasticizers.

[0057] In some preferred embodiments, the distance D2 further satisfies: 3mm + D1 ≤ D2 ≤ 8mm + D1. By limiting D2 within this range, it is possible to ensure that the edge of the third protrusion structure 404 away from the center of the PDLC membrane 100 does not fall into the half-cut area and to avoid the generation of gaps, while preventing the sealing structure from excessively occupying the outer PVB patching area. Thus, a reasonable balance between space utilization and sealing performance is achieved while ensuring the reliability of the sealing.

[0058] In some preferred embodiments, the distance between the boundary of the first sealing film 401 away from the center of the PDLC membrane 100 and the half-cut position 101 is D3, and the ratio of D3 to distance D2 satisfies: 1.3≤D3 / D2≤1.8. If the value of D3 is too small and the width is insufficient, a sufficiently long tortuous barrier path cannot be formed, making it difficult to form an effectively extended plasticizer permeation channel. If the widths of D3 and D2 are too close, during the overlapping assembly of the second sealing film 402, the two sealing films 400 are difficult to fit tightly and compact due to the step structure formed in the half-cut area, easily forming through-type micro gaps between layers and in the L1 extension direction. Such interconnected channels will significantly reduce the small molecule barrier capacity, allowing plasticizers, water vapor, and other media in PVB to penetrate into the interior of the PDLC membrane 100 along the gaps, which may lead to sealing failure. By limiting the reasonable ratio of D3 to D2, the length of the transverse seepage prevention channel can be ensured, while optimizing the overlapping and bonding state of the two layers of PET sealing, eliminating gaps between layers, and improving the overall seepage prevention and barrier effect and the stability of the sealing structure.

[0059] The distance between the edge of the third protrusion structure 404 away from the center of the PDLC film 100 and the boundary of the first sealing film 401 away from the center of the PDLC film 100 is D4, and D4 is defined by the ratio of D3 to D2. The distance D6 between the edge of the third protrusion structure 404 near the center of the PDLC membrane 100 and the first cutting line 201 satisfies the following condition: 2mm ≤ D6 ≤ 8mm. The specific width of D6 can be selected differently depending on the type of sealing adhesive: For polyethylene and polypropylene pressure-sensitive adhesives, their molecular chains are less regular and the intermolecular distance is larger. Under high-temperature conditions, the small molecules of plasticizer undergo vigorous thermal motion, making it easier for them to pass through the sealing adhesive and enter the protrusion structure. Therefore, a wider D6 is needed to enhance the barrier effect, with a preferred range of 5mm ≤ D6 ≤ 8mm. For epoxy and phenolic resin adhesives, their molecular chains are tightly arranged and the intermolecular distance is smaller. Even under high-temperature conditions, plasticizers are not easily able to pass through the sealing adhesive. Therefore, the width of D6 can be appropriately narrowed, with a preferred range of 2mm ≤ D6 ≤ 5mm. By rationally selecting the D6 width according to the characteristics of the adhesive system, the sealing structure design can be optimized while ensuring the barrier effect.

[0060] In some preferred embodiments, the shapes of the first protrusion structure 203 and the second protrusion structure 403 are selected from any one of semicircle, triangle, trapezoid, or rectangle. By flexibly selecting the protrusion shape according to specific working conditions, a balance is achieved between fitting reliability, processing convenience, and stress dispersion effect.

[0061] This application also provides a method for sealing the edge of a PDLC dimming film, using the PDLC dimming film edge sealing structure of any of the above embodiments for the edge sealing operation. The method includes the following steps: Along the edge contour of the PDLC film, a first cutting line, a second cutting line, and multiple first protrusion structures located on the second cutting line are laser-cut on the protective film; Apply double-sided adhesive at a distance of 0.5mm to 30mm from the edge of the PDLC membrane or from the edge of the half-cut position 101; A second protrusion structure matching the first protrusion structure is formed on the sealing film; The sealing film is attached to the double-sided adhesive so that the second raised structure and the first raised structure fit together.

[0062] In some preferred embodiments, the upper and lower surfaces of the PDLC film are sealed, specifically including the following steps: a) Select a complete PDLC film 100 after cutting and shaping, ensuring the original peelable protective film is intact on both the upper and lower surfaces. Using a precision laser cutting process, precisely form a first cutting line 201 and a second cutting line 202 sequentially on the upper and lower protective film surfaces, moving from the outside of the PDLC film 100 towards its center. Simultaneously, along the length of the second cutting line 202, create several first protruding structures 203 that protrude towards the center of the PDLC film 100. It should be noted that the laser cutting depth only penetrates the protective film, without damaging the underlying PET substrate layer and conductive functional layer.

[0063] b) Apply double-sided adhesive 300 at a distance of 0.5mm to 30mm from the edge of the PDLC membrane or from the edge of the half-cut position 101. Specifically, if the edge of the PDLC membrane 100 does not have a half-cut area, the double-sided adhesive 300 is applied at a distance of 0.5mm to 30mm from the edge of the PDLC membrane 100; if a half-cut area is provided, the double-sided adhesive 300 is applied at a distance of 0.5mm to 30mm from the edge of the half-cut position 101.

[0064] c) Provide at least two sealing films 400, including a first sealing film 401 and at least one second sealing film 402. A second protruding structure matching the first protruding structure 203 is formed on each sealing film by laser cutting, and a third protruding structure 404 protruding outwards is provided at the end of the first sealing film 401 along its length. The shape, size, and distribution of the second protruding structures are consistent with the first protruding structure 203 to ensure the accuracy of subsequent fitting and assembly.

[0065] d) Each sealing film is sequentially attached to the double-sided adhesive 300 along the second cutting line 202, so that the second raised structure of each film is fitted into the first raised structure 203. Simultaneously, the end of the subsequently attached sealing film is overlapped over the end of the previously attached sealing film to form an overlap, covering the third raised structure 404. The design of the third raised structure 404 effectively extends the penetration path of the plasticizer, blocking the continuous flow of microchannels and micro-gaps, thereby improving the reliability of the sealing.

[0066] e) Apply single-sided adhesive 500 to the outer surface of the overlap. The single-sided adhesive 500 only reinforces and locks the suspended overlap end of the second sealing film 402 at a fixed point, preventing the end of the second sealing film 402 from lifting, bending, tearing or shifting during transportation, flipping and assembly, thereby ensuring that the overlap area is tightly fitted and without gaps.

[0067] f) Smoothly flip the PDLC membrane 100, which has been sealed on one side, to keep it flat, without creases or stretching deformation. Repeat steps d to e above to symmetrically complete the sealing of the other side of the PDLC membrane 100, and finally obtain a finished edge-sealed PDLC dimming membrane with complete edge sealing, high alignment accuracy, excellent anti-seepage performance, and suitable for subsequent lamination processes.

[0068] In some preferred embodiments, such as Figure 10 As shown, for PDLC membranes with electrodes or grooves on all four sides, the sealing is only applied directly above the electrodes or grooves, without any sealing structure on the back of the electrodes or grooves. While retaining core functions such as interlocking and extending the permeation path, this reduces the amount of sealing material and process steps by approximately 50%, thus lowering costs. This single-sided sealing structure is suitable for cost-sensitive applications, applications with moderate weather resistance requirements, or applications requiring reserved operating space on the back of the electrodes / grooves.

[0069] The following detailed description of examples of the present invention is exemplary and is used only to explain the present invention, and should not be construed as limiting the present invention.

[0070] Example 1 This embodiment provides a sealing structure and sealing method for a PDLC dimming film, as detailed below: 1. PDLC membrane preparation A PDLC film measuring 1200mm × 800mm was selected. The upper and lower surfaces of the PDLC film were covered with a PET protective film with a thickness of 80μm. A half-cut area was set at the edge of the PDLC film. This half-cut area was formed by removing a portion of the PET protective film and the underlying PET substrate layer and conductive layer through a half-cutting process. The width of the half-cut area D1 = 3mm, and double-layer sealing was used.

[0071] 2. Laser cutting process Along the edge contour of the PDLC film, a first cutting line and a second cutting line are sequentially laser-cut from the outside to the inside on the PET protective film on the upper and lower surfaces of the PDLC film. The first cutting line is 3.5 mm away from the side of the double-sided adhesive near the edge of the PDLC film, and the second cutting line is 2.0 mm away from the side of the double-sided adhesive near the center of the PDLC film. Multiple first protrusions, each in a semi-circular shape, are spaced apart along the second cutting line.

[0072] 3. Double-sided adhesive tape The double-sided adhesive is applied 8 mm from the edge of the half-cut position 101, with a thickness of 40 μm and a width of 1.5 mm.

[0073] 4. Preparation of sealing film The first and second sealing films were prepared by laser cutting. Both films had a thickness of 25 μm and were made of PET material.

[0074] Second protrusion structures, matching the first protrusion structure, are formed on the first and second sealing films, respectively, and are also semi-circular in shape. Specifically, the second protrusion structures corresponding to the sealing films on the long side (1200mm) of the PDLC film are spaced 175mm apart, while the second protrusion structures corresponding to the sealing films on the short side (800mm) are spaced 120mm apart.

[0075] The first sealing film has outwardly protruding third protrusions at both ends along its length, with an extension length L1 = 15 mm from the main body of the first sealing film. The third protrusions on the upper and lower surfaces of the same side of the PDLC film are staggered. The positional parameters are set as follows: The distance between the edge of the third protrusion structure furthest from the center of the PDLC membrane and the half-cut position 101 is: D2 = 8 mm; The distance between the edge of the first sealing film away from the center of the PDLC film and the half-cut position 101: D3=12mm; The distance between the edge of the third protrusion structure furthest from the center of the PDLC film and the edge of the first sealing film furthest from the center of the PDLC film is: D4 = D3 - D2 = 12mm - 8mm = 4mm; The distance between the edge of the third protrusion structure near the center of the PDLC membrane and the half-cut position 101 is: D5 = 5mm; The distance between the edge of the third protrusion structure near the center of the PDLC film and the first cutting path is: D6 = 5mm.

[0076] 5. Applying edge sealing film The first and second sealing films are sequentially attached to the double-sided adhesive along the second cutting line, so that their respective second protruding structures interlock with the first protruding structures. At the same time, the end of the second sealing film is overlapped on top of the end of the first sealing film to form an overlap.

[0077] 6. Single-sided adhesive fixing A single-sided adhesive is applied to the overlap to fix the end of the second sealing film to the first sealing film and cover the third raised structure. The single-sided adhesive has a thickness of 30 μm and a width of 10 mm.

[0078] 7. Double-sided edge sealing completed Flip the PDLC film over and repeat steps 5 to 6 to seal the other side of the surface, finally obtaining the sealed PDLC dimming film.

[0079] Example 2 Referring to the sealing structure and sealing method of Embodiment 1, the difference is that the two ends of the first sealing film in the length direction do not have a third protruding structure protruding outward.

[0080] Example 3 Referring to the sealing structure and sealing method of Example 1, the difference is that the sealing film is a continuous strip, rather than a first sealing film and a second sealing film arranged sequentially along the length of the PDLC film edge; and, the two ends of the continuous sealing film do not have a third protruding structure protruding outward.

[0081] Example 4 Referring to the sealing structure and sealing method of Embodiment 1, the difference is that the ends of the first sealing film and the second sealing film are butted together instead of overlapped.

[0082] Example 5 Referring to the sealing structure and sealing method of Embodiment 1, the difference is that the end of the second sealing film is only superimposed on the end of the first sealing film, and no single-sided adhesive is applied for fixation.

[0083] Example 6 Referring to the sealing structure and sealing method of Embodiment 1, the difference is that the overlapping direction is opposite, and the end of the second sealing film is overlapped below the end of the first sealing film.

[0084] Example 7 Referring to the sealing structure and sealing method of Example 1, the difference is that the distance between the first cutting path and the side of the double-sided adhesive near the edge of the PDLC film is 7mm.

[0085] Example 8 Referring to the sealing structure and sealing method of Example 1, the difference is that the distance between the second cutting path and the side of the double-sided adhesive near the center of the PDLC film is 0.1 mm.

[0086] Example 9 Referring to the sealing structure and sealing method of Example 1, the difference is that the thickness of the PET protective film is 50μm, the thickness of the double-sided adhesive is 30μm, and the thickness of the sealing film is 30μm.

[0087] Example 10 Referring to the sealing structure and sealing method of Example 1, the difference is that the thickness of both the first sealing film and the second sealing film is 5 μm.

[0088] Example 11 Referring to the sealing structure and sealing method of Example 1, the difference is that the thickness of both the first sealing film and the second sealing film is 100 μm.

[0089] Example 12 Referring to the edge sealing structure and method of Embodiment 1, the difference is that the spacing between the first protrusion structure and the second protrusion structure is 100mm.

[0090] Example 13 Referring to the sealing structure and sealing method of Example 1, the difference is that the extension length L1 of the third protrusion structure extending outward from the first sealing film body is 1mm.

[0091] Example 14 Referring to the sealing structure and sealing method of Example 1, the difference is that the extension length L1 of the third protrusion structure extending outward from the first sealing film body is 60mm.

[0092] Example 15 Referring to the sealing structure and sealing method of Example 1, the difference is that the distance D5 between the edge of the third protrusion structure near the center of the PDLC film and the half-cut position 101 is 1mm.

[0093] Example 16 Referring to the sealing structure and sealing method of Example 1, the difference is that the distance D3 between the edge boundary of the first sealing film away from the center of the PDLC film and the half-cut position 101 is 20mm.

[0094] Comparative Example 1 Referring to the sealing structure and sealing method of Embodiment 1, the difference is that the first protrusion structure is not provided on the second cutting path, the second protrusion structure is not provided on the first sealing film and the second sealing film, and the two ends of the first sealing film in the length direction are not provided with the third protrusion structure protruding outward.

[0095] Test case The following tests were performed on the sealing structures of Examples 1-16 and Comparative Example 1: High-temperature and high-pressure lamination followed by sealing displacement test: The sealed PDLC dimming film was placed under simulated lamination conditions (temperature 120-150℃, pressure 1.0-1.5MPa, heat and pressure holding for 60 minutes), and the offset of the sealing film edge relative to the first cutting path was measured to evaluate the ability of the interlocking structure to resist the lateral pulling force generated by the PVB melt flow; Warp and torsion environment adhesion posture test: Simulating film flipping and handling operations, repeated bending and torsional loads were applied to the sealed film, with a torsion angle of ±15° and 50 cycles. The sealing film was visually inspected for warping, displacement, or overlapping gaps to evaluate the fixing effect of the interlocking structure on the sealing posture; Plasticizer penetration aging test (plasticizer is present in PVB; the sample used in this experiment was dimming glass after lamination of the sealed PDLC film), the sealed PDLC dimming glass was placed at 85℃ / 85%... The PDLC films were aged for 1000 hours in a high-temperature and high-humidity (RH) environment. Periodic sampling and observation using infrared spectroscopy or microscopy were performed to observe whether plasticizer penetration caused turbidity, delamination, or functional layer failure at the edges. This aimed to evaluate the sealing and protective effect of the extended channel of the third protrusion structure and the barrier capability of the overlap. Additionally, the warping and wrinkling rate of the sealing area were statistically analyzed. After lamination, all samples were optically scanned or microscopically observed, and the proportion of obvious wrinkles, gaps, or voids in the sealing area was statistically analyzed. This aimed to evaluate the influence of parameters such as the protrusion spacing, D5 width, and D3 / D2 ratio on the flatness and tightness of the sealing. Specific characterization results are shown in Table 1.

[0096] Table 1

[0097] Based on the above tests, Example 1, due to its simultaneous integration of interlocking and limiting, third protrusion structure extending the channel, overlapping and single-sided adhesive fixing, and optimized dimensional matching, achieved the best overall edge sealing reliability. After high-temperature and high-pressure lamination, the offset was only 0.4mm, the warpage torque test showed no abnormalities, the functional layer failure width after plasticizer penetration and aging was 0%, and the wrinkle / void rate in the sealing area was 0%. In contrast, Example 2 lacked the third protrusion structure, the extended channel disappeared, and the plasticizer penetrated directly along the overlapping interface, significantly increasing the failure width to 6.6mm. However, because the interlocking structure still existed, the offset (0.6mm) and wrinkle rate (0.3%) were less affected. Example 3 used a single sealing film without the third protrusion structure. Stress concentration at the corners led to slight gaps, and the lack of a third protrusion structure covering the closed end created a through-penetration channel, resulting in a failure width of 11.8mm. The gaps also increased the wrinkle rate to 1.1%. Example 4 used butt joints instead of overlapping, exposing the third protrusion structure to the butt joint gap. In Example 5, the area could not be effectively covered, and the plasticizer penetrated directly, resulting in a failure width of 11.5 mm. In Example 6, the suspended end was not fixed with single-sided adhesive, and the end of the second sealing film slipped significantly during the lamination process, with an offset of up to 6.5 mm. Simultaneously, the end curled up, resulting in a wrinkle rate of 5.3%. In Example 7, the overlap direction was reversed, and the third protruding structure was not effectively pressed and covered by the upper sealing film, extending the channel and making it easier for plasticizer to penetrate, increasing the failure width to 4.9 mm. In Example 8, the distance from the first cutting path to the outer side of the double-sided adhesive increased to 7 mm. The outer protective film was too wide, and the peeling force was transmitted over a long distance during film removal, causing damage to the double-sided adhesive. Microscopic separation occurs at the interface with the protective film, reducing adhesive integrity, increasing offset to 0.8 mm, and causing slight warping. In Example 8, the distance between the second cutting path and the inner side of the double-sided adhesive is only 0.1 mm. The double-sided adhesive is too close to the second cutting path, causing slight adhesive overflow, interfering with the precise fitting of the first and second raised structures, increasing offset to 1.1 mm, and causing slight warping. In Example 9, the thickness of the protective film (50 μm) is less than the sum of the thicknesses of the double-sided adhesive (30 μm) and the sealing film (30 μm) (60 μm). The protective film cannot protrude to form a physical stop structure, weakening lateral constraint, and increasing offset to 1.3 mm. In Example 10, the sealing film thickness was only 5 μm, resulting in insufficient tensile strength and puncture resistance. During the lamination process, it was prone to tensile deformation, with an offset of 1.2 mm. Furthermore, its thinness caused wrinkling during bonding, resulting in a wrinkle rate of 4.7%. In Example 11, the sealing film thickness reached 100 μm, leading to excessive stiffness, decreased flexibility, and loose bonding. The offset increased to 2.1 mm, with slight displacement and a wrinkle rate of 5.3%. In Example 12, the raised structure was spaced 100 mm apart, which was relatively too close. Although this enhanced local limiting ability and kept the offset at 0, it was not ideal.However, the small spacing of 6mm reduces the flexibility of the sealing film under bending conditions, leading to stress concentration, local warping, and a wrinkle rate of 6.6%. In Example 13, the extension length of the third protrusion structure L1 = 1mm is insufficient, and the plasticizer can easily pass through the third protrusion structure into the film, increasing the failure width to 4.2mm. In Example 14, the extension length of the third protrusion structure L1 = 60mm is significant, resulting in a long cantilever beam effect, reduced rigidity, and easy warping and tensile deformation of the sealing film, with an offset as high as 5.1mm. In Example 15, the distance D5 between the inner edge of the third protrusion structure and the half-cut position 101 is 1mm, indicating a severe deficiency in the inner extension channel, resulting in a failure width of 5.7mm. In Example 16, the distance D3 between the outer boundary of the first sealing film and the half-cut position 101 is 20mm, indicating an excessively long transverse seepage prevention channel. This makes it difficult for the two films to be tightly bonded and compacted when the second sealing film overlaps, resulting in a through-hole between the layers. Plasticizer intrusion leads to a failure width of 3.4mm, while poor bonding results in an offset of 1.4mm and a wrinkle rate of 1.9%. Comparative Example 1 completely lacks the interlocking structure of the first and second protrusion structures and also lacks the extension channel of the third protrusion structure. Under high temperature and pressure, the sealing film is unrestrained laterally, resulting in an offset as high as 10.6mm. The plasticizer penetrates directly along the straight interface, resulting in a failure width of 4.7mm. The alignment and bonding are poor, with a wrinkle rate of 8.5%. All performance aspects are significantly inferior to those of the examples. The above results demonstrate that this application optimizes edge-sealing performance by using interlocking and limiting mechanisms, extending the penetration channel, and combining this with experimentally verified optimal parameter range. Exceeding or falling short of this optimal range will lead to performance degradation. Therefore, this application can effectively extend the plasticizer's penetration path while ensuring mechanical reliability, thereby improving the sealing performance, weather resistance, and service life of the edge seal.

Claims

1. An edge seal structure for a PDLC light modulating film, characterized by, include: PDLC membrane; Double-sided adhesive is applied at a distance of 0.5mm to 30mm from the edge of the PDLC film or from the edge of the half-cut position; wherein, the half-cut position is the boundary of the half-cut area facing the center of the PDLC film, and the half-cut area is formed by a half-cut process, removing the local protective film and the PET substrate layer and conductive layer below it from the half-cut position; Along the edge contour of the PDLC film, a first cutting path and a second cutting path are sequentially laser-cut on the protective film on the surface of the PDLC film from the outside to the inside; a plurality of first protrusion structures are spaced apart on the second cutting path, and the first protrusion structures protrude toward the center of the PDLC film; At least one sealing film is attached to the double-sided adhesive, and the sealing film is provided with a second protruding structure that fits and matches the first protruding structure; The first cutting path is 0mm to 5mm away from the side of the double-sided adhesive near the edge of the PDLC film to prevent the width of the outer protective film from increasing; the second cutting path is 0.3mm to 5mm away from the side of the double-sided adhesive near the center of the PDLC film to prevent the double-sided adhesive from overflowing into the raised structure area.

2. The sealing structure of the PDLC dimming film according to claim 1, characterized in that, The sealing film includes at least a first sealing film and a second sealing film arranged sequentially along the length of the edge of the PDLC film, and the first sealing film and the second sealing film are respectively provided with the second protrusion structure; The first sealing film has a third protrusion structure protruding outward at each of its two ends along its length; The end of the second sealing film overlaps the end of the first sealing film to form an overlap; The overlapping portion is provided with single-sided adhesive, which is used to fix the end of the second sealing film to the first sealing film and cover the third protruding structure.

3. The sealing structure of the PDLC dimming film according to claim 1, characterized in that, The thickness of the protective film is 20μm to 150μm, and the thickness of the protective film is greater than the sum of the thickness of the double-sided adhesive and the thickness of the sealing film.

4. The sealing structure of the PDLC dimming film according to claim 1, characterized in that, The thickness of the double-sided adhesive is 10μm~60μm, and the width is 0.1mm~1.9mm.

5. The sealing structure of the PDLC dimming film according to claim 1, characterized in that, The thickness of the sealing film is 10μm~80μm.

6. The sealing structure of the PDLC dimming film according to claim 1, characterized in that, The first protrusion structure and the second protrusion structure are spaced at the same interval; the interval is determined based on the thickness of the double-sided adhesive and the length of the side of the PDLC film to which the interval is applied, specifically satisfying the following conditions: When the thickness of the double-sided adhesive is 10μm~30μm: When the length of the side of the PDLC film to which the spacing is applied is ≤100mm, the spacing is 20mm~25mm; When the length of the side of the PDLC film to which the spacing is applied is greater than 100 mm and less than or equal to 500 mm, the spacing is 30 mm to 65 mm. When the length of the side of the PDLC film to which the spacing is applied is >500mm and ≤1000mm, the spacing is 80mm~120mm; When the length of the side of the PDLC film to which the interval is applied is greater than 1000 mm and less than or equal to 2000 mm, the interval is 135 mm to 160 mm. When the length of the side of the PDLC film to which the interval is applied is greater than 2000 mm and less than or equal to 5000 mm, the interval is 190 mm to 210 mm. When the thickness of the double-sided adhesive is 31μm~45μm: When the length of the side of the PDLC film to which the spacing is applied is ≤100mm, the spacing is 30mm~35mm; When the length of the side of the PDLC film to which the spacing is applied is greater than 100 mm and less than or equal to 500 mm, the spacing is 50 mm to 90 mm. When the length of the side of the PDLC film to which the interval is applied is >500mm and ≤1000mm, the interval is 110mm~140mm; When the length of the side of the PDLC film to which the interval is applied is greater than 1000 mm and less than or equal to 2000 mm, the interval is 160 mm to 190 mm. When the length of the side of the PDLC film to which the interval is applied is greater than 2000 mm and less than or equal to 5000 mm, the interval is 230 mm to 260 mm. When the thickness of the double-sided adhesive is 46μm~60μm: When the length of the side of the PDLC film to which the spacing is applied is ≤100mm, the spacing is 40mm~45mm; When the length of the side of the PDLC film to which the spacing is applied is greater than 100 mm and less than or equal to 500 mm, the spacing is 80 mm to 90 mm. When the length of the side of the PDLC film to which the spacing is applied is >500mm and ≤1000mm, the spacing is 170mm~220mm; When the length of the side of the PDLC film to which the interval is applied is greater than 1000 mm and less than or equal to 2000 mm, the interval is 250 mm to 280 mm. When the length of the side of the PDLC film to which the interval is applied is greater than 2000 mm and less than or equal to 5000 mm, the interval is 300 mm to 320 mm.

7. The sealing structure of the PDLC dimming film according to claim 2, characterized in that, The extension length L1 of the third protrusion structure extending outward from the first sealing film body satisfies: 3mm≤L1≤50mm.

8. The sealing structure of the PDLC dimming film according to claim 2, characterized in that, The edge of the PDLC membrane has a semi-cut region, and the width D1 of the semi-cut region satisfies: 0 <D1≤10mm; The distance D2 between the edge of the third protrusion structure away from the center of the PDLC film and the half-cut position satisfies: D1 <D2; The distance D5 between the edge of the third protrusion structure near the center of the PDLC film and the half-cut position satisfies: 2mm≤D5≤8mm.

9. The sealing structure of the PDLC dimming film according to claim 8, characterized in that, The distance D2 further satisfies: 3mm+D1≤D2≤8mm+D1.

10. The sealing structure of the PDLC dimming film according to claim 8 or 9, characterized in that, The distance between the edge of the sealing film away from the center of the PDLC film and the half-cut position is D3, and the ratio of D3 to the distance D2 satisfies: 1.3≤D3 / D2≤1.8; The distance D6 between the edge of the third protrusion structure near the center of the PDLC film and the first cutting path satisfies: 2mm≤D6≤8mm.

11. The sealing structure of the PDLC dimming film according to claim 1, characterized in that, The shapes of the first protrusion structure and the second protrusion structure are selected from any one of semicircle, triangle, trapezoid or rectangle.

12. A method for sealing the edge of a PDLC dimming film, employing the sealing structure described in any one of claims 1 to 11, characterized in that, Includes the following steps: Along the edge contour of the PDLC film, a first cutting line, a second cutting line, and multiple first protrusion structures located on the second cutting line are laser-cut on the protective film; Double-sided adhesive is applied 0.5mm to 30mm from the edge of the PDLC film or from the edge of the half-cut position; A second protrusion structure matching the first protrusion structure is formed on the sealing film; The sealing film is attached to the double-sided adhesive so that the second raised structure and the first raised structure fit together.

13. The edge-sealing method according to claim 12, characterized in that, The upper and lower surfaces of the PDLC film are sealed, specifically including the following steps: a) Along the edge contour of the PDLC film, a first cutting path and a second cutting path are sequentially laser-cut from the outside to the inside on the protective film on the upper and lower surfaces of the PDLC film, and a plurality of first protrusion structures are cut on the second cutting path. b) Apply double-sided adhesive at a distance of 0.5 mm to 30 mm from the edge of the PDLC film or from the edge of the half-cut position; c) Provide at least two sealing films, including a first sealing film and at least one second sealing film; by laser cutting, a second protrusion structure matching the first protrusion structure is formed on each sealing film, and a third protrusion structure protruding outward is provided at the end of the first sealing film in the length direction; d) Each sealing film is sequentially attached to the double-sided adhesive along the second cutting line, so that the second protrusion structure of each film is fitted into the first protrusion structure; and the end of the next attached sealing film is overlapped on the end of the previous attached sealing film to form an overlap. e) Apply single-sided adhesive to the overlapping part, fix the end of the second sealing film to the first sealing film, and cover the third protruding structure; f) Flip the PDLC film over and repeat steps d) to e) to complete the sealing of the other side surface.

14. The edge-sealing method according to claim 12, characterized in that, For PDLC films with electrodes or grooves on all four sides, the sealing is performed only on the side directly above the electrodes or grooves, while no sealing structure is provided on the back side of the electrodes or grooves.

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