A method for manufacturing an edge structure of a multi-layer light control film

Abstract

This application provides a method for preparing the edge structure of a multilayer dimming film. The method involves plasma activation treatment of the cut end face of the film to form an activation layer, coating its surface with an interface anchoring liquid to form a flexible anchoring layer, and then applying an edge-sealing agent followed by a three-stage gradient curing process. This achieves high strength, durability, and self-healing capabilities at the film edge. Through the synergistic effect of the interface anchoring liquid and the edge-sealing agent, this method significantly improves the adhesion, protection, and mechanical stability of the film edge, while also exhibiting resistance to environmental aging and self-healing properties. It solves the problems of easy peeling, water seepage, and performance degradation at the edges of traditional dimming films, and has high industrial application value.

Description

Technical Field

[0001] This invention relates to the field of transparent conductive thin film materials for flexible display technology, and in particular to a method for preparing the edge structure of a multilayer dimming thin film. Background Technology

[0002] Multilayer dimming films have attracted widespread attention due to their important applications in smart windows, displays, and flexible electronic devices. Their performance depends not only on the optical modulation capability and electrical response characteristics of the film itself, but also on the reliability and durability of the film's edge structure. Existing multilayer dimming films are typically manufactured by mechanically cutting to the required dimensions. However, the cut surfaces often contain microscopic defects, burrs, or microcracks. These defects can easily lead to film delamination, peeling, or water seepage during long-term use, severely impacting product performance and lifespan.

[0003] Traditional edge-sealing technologies, such as hot pressing, single-component edge sealing agent coating, or simple UV curing, often struggle to simultaneously ensure film edge adhesion, flexible protection, and long-term environmental stability. Furthermore, existing technologies largely rely on chemical coupling agents or single surface treatments to improve interfacial bonding, lacking multifunctional synergistic mechanisms and offering limited support for self-healing capabilities in complex environments. This results in films being prone to cracking and peeling under temperature and humidity cycling, UV exposure, or mechanical stress. Therefore, this application is submitted. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a method for preparing the edge structure of a multilayer dimming film. By performing plasma activation treatment on the cut end face of the film to form a highly active surface, and coating it with an interface anchoring liquid containing biomimetic adhesion monomers and nano-reinforcing materials to form a flexible anchoring layer, a multifunctional edge sealing agent is applied and cured through a three-stage gradient process. This enables the film edge to acquire excellent mechanical strength, flexible protection, waterproofness, and self-healing ability, thereby significantly improving the environmental tolerance and service life of the film and solving the technical problem of performance degradation of existing dimming films during long-term use.

[0005] In order to achieve the objective of this invention, the following technical solution is adopted: This invention provides a method for preparing the edge structure of a multilayer dimming film, comprising the following steps: S1: The cut end face of the thin film is subjected to plasma activation treatment to form an activation layer; S2: Coat the surface of the activated layer with an interface anchoring liquid and let it stand to form a flexible anchoring layer; S3: Apply an edge sealant to the surface of the flexible anchoring layer and cure the edges of the film after applying the edge sealant.

[0006] Furthermore, in S1, the plasma activation treatment uses atmospheric pressure low-temperature plasma, the treatment atmosphere is a mixture of argon, oxygen and carbon tetrafluoride, the volume mixing ratio is Ar:O2:CF4=5:2:1, the treatment power is 800-1200W, and the distance between the treatment nozzle and the cutting end face is 5-10mm.

[0007] Furthermore, in step S2, the settling time is 60-180 seconds, the temperature is 25-35℃, and the relative humidity is 40-60%.

[0008] Furthermore, in S3, the sealing agent is applied using a micro-jet dispensing process, with a jetting pressure of 0.2-0.5 MPa, a nozzle diameter of 0.1-0.3 mm, and a jetting angle of 45-60° to the edge of the film.

[0009] Furthermore, in step S3, the curing process is a three-stage gradient curing process. The first stage is infrared thermal curing, heating to 50-70℃ and holding for 5-10 minutes; the second stage is ultraviolet curing, with ultraviolet light energy of 1500-2500 mJ / cm². 2 The third stage involves post-heat curing, which is performed in an oven at 80-100℃ for 20-40 minutes.

[0010] Furthermore, by mass, the interface anchoring liquid comprises: 20-40 parts of hyperbranched polyester acrylate, 10-25 parts of mussel biomimetic adhesion monomer containing catechol groups, 5-15 parts of boron nitride nanotubes, 3-10 parts of sulfonated calixarene, 4-8 parts of free radical-cationic hybrid photoinitiator, and 1-3 parts of fluorinated surfactant.

[0011] Furthermore, the mussel biomimetic adhesion monomer containing catechol groups is dopamine methacrylamide; the boron nitride nanotubes are aminated boron nitride nanotubes with a diameter of 3-8 nm and an aspect ratio greater than 50:1.

[0012] Furthermore, by weight, the edge sealing agent comprises: 40-60 parts of isocyanate-terminated polydimethylsiloxane prepolymer, 20-35 parts of acrylated cyclodextrin, 5-15 parts of liquid polybutadiene, 3-8 parts of photoinitiator, 2-6 parts of latent moisture-curing catalyst, and 1-4 parts of molecular sieve dehydrating agent.

[0013] Furthermore, the edge sealing agent also contains 1-5 wt% of a metal-organic framework material, wherein the metal-organic framework material is ZIF-8.

[0014] Furthermore, the interface anchoring solution also contains 2-4 parts of self-healing microcapsules, wherein the capsule wall of the self-healing microcapsules is polyurea formaldehyde resin, the capsule core is hexamethylene diisocyanate trimer, and the microcapsule particle size is 10-30 μm.

[0015] The present invention has the following technical effects: (1) This application utilizes atmospheric pressure low-temperature plasma activation treatment on the cut end face of the film to form a flexible anchoring layer containing biomimetic adhesion monomers and nano-reinforcing materials, which significantly enhances the surface energy and chemical activity of the film edge, enabling the interface anchoring liquid to firmly adhere and form a continuous flexible protective layer. This multi-layered structure effectively enhances the mechanical strength and fatigue resistance of the film edge, preventing the cut end face from peeling or cracking due to external force, vibration, or bending during long-term use, thus achieving long-term reliable structural stability of the film edge.

[0016] (2) This application applies a multifunctional edge-sealing agent containing isocyanate-terminated polydimethylsiloxane, cyclodextrin, and liquid polybutadiene to the flexible anchoring layer, and employs a three-stage gradient curing process of infrared, ultraviolet, and post-thermal to obtain a protective layer at the film edge. This structure not only provides excellent waterproof and impermeable properties, but also enhances the stability against high and low temperatures, ultraviolet light, and humid heat cycling, thereby effectively preventing performance degradation at the film edge in complex environments and significantly improving the long-term reliability of multilayer dimming films. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0018] In a first aspect, this application provides 1. a method for preparing the edge structure of a multilayer dimming film, comprising the following steps: S1: The cut end face of the thin film is subjected to plasma activation treatment to form an activation layer; S2: Coat the surface of the activated layer with an interface anchoring liquid and let it stand to form a flexible anchoring layer; S3: Apply an edge sealant to the surface of the flexible anchoring layer and cure the edges of the film after applying the edge sealant.

[0019] This application proposes a method for preparing the edge structure of a multilayer dimming film, aiming to solve the problems of easy peeling, performance degradation, and poor environmental adaptability of film edges in existing technologies. The method involves a triple treatment process of plasma activation, interface anchoring liquid coating, and edge sealing agent curing, which comprehensively optimizes and protects the film edges, significantly improving the adhesion, mechanical strength, protective properties, and self-healing ability of the film edges.

[0020] First, the method's initial step involves plasma activation treatment of the cut film surface using atmospheric pressure low-temperature plasma technology to form an activation layer. This process effectively enhances the surface energy of the film edges, providing a good adhesion foundation for subsequent coating of the interface anchoring liquid. Plasma activation generates a large number of active groups on the film surface, significantly improving the adhesion between the film surface and the coating material, thus laying a solid foundation for subsequent processes. The plasma atmosphere used is a mixture of argon, oxygen, and carbon tetrafluoride. By precisely controlling the gas ratio and processing power, the type and quantity of active groups on the film surface are optimized, further enhancing the adhesion of the interface layer.

[0021] Next, an interface anchoring solution is coated onto the activated film end face, and allowed to stand for a certain period of time to form a flexible anchoring layer. This anchoring solution contains key components such as hyperbranched polyester acrylate, a mussel-inspired adhesion monomer containing catechol groups, and boron nitride nanotubes. The hyperbranched polyester acrylate enhances adhesion while ensuring the flexibility and durability of the coating. The mussel-inspired adhesion monomer containing catechol groups mimics the strong adhesion mechanism of mussels in nature, further enhancing the adhesion of the film edges. These functional molecules not only provide better mechanical stability to the film but also improve its durability in complex environments. The addition of boron nitride nanotubes enhances the material's thermal stability and compressive strength, while also providing additional nanoscale reinforcement.

[0022] After the anchoring layer is completed, an edge sealant is applied to the film edges. This edge sealant is uniformly applied to the film edges using a micro-spraying dispensing process, ensuring the uniformity and density of the edge seal layer. The edge sealant contains isocyanate-terminated polydimethylsiloxane prepolymer, acrylated cyclodextrin, and liquid polybutadiene, effectively providing edge protection. Its chemical structure not only ensures the film edges' water resistance, chemical corrosion resistance, and UV resistance, but also provides a certain degree of flexibility, adapting to film deformation and bending, preventing cracks or peeling caused by external forces. The photoinitiator contained in the edge sealant promotes cross-linking reactions under UV light irradiation, improving the mechanical strength of the edge seal layer.

[0023] To ensure the durability and reliability of the edge sealing layer, this application adopts a three-stage gradient curing process. Through this multi-stage curing process, the film edge not only receives strong protection, but also maintains the flexibility and durability required during use.

[0024] Furthermore, metal-organic frameworks (MOFs) can be added to the sealing agent. These materials enhance the barrier properties of the film, enabling it to maintain excellent performance even in high-humidity or highly corrosive environments. MOFs possess high porosity and surface area, effectively preventing the penetration of moisture and harmful gases, providing an additional protective barrier for the film, thereby significantly improving its adaptability to harsh environments.

[0025] Finally, this application also introduces self-healing microcapsule technology. The capsule walls are made of polyurea-formaldehyde resin, and the core contains hexamethylene diisocyanate trimer. These microcapsules can self-repair when microcracks or scratches appear at the film edges. The addition of self-healing technology solves the problem of performance degradation at film edges due to external force damage during long-term use, further extending the service life of the film.

[0026] In some embodiments, in step S1, the plasma activation treatment uses atmospheric pressure low-temperature plasma, the treatment atmosphere is a mixture of argon, oxygen and carbon tetrafluoride, the volume mixing ratio is Ar:O2:CF4=5:2:1, the treatment power is 800-1200W, and the distance between the treatment nozzle and the cutting end face is 5-10mm.

[0027] In some embodiments, in step S2, the settling time is 60-180 seconds, the temperature is 25-35°C, and the relative humidity is 40-60%.

[0028] In some embodiments, in step S3, the sealing agent is applied using a micro-jet dispensing process with a jetting pressure of 0.2-0.5 MPa, a nozzle diameter of 0.1-0.3 mm, and a jetting angle of 45-60° to the edge of the film.

[0029] In some embodiments, in step S3, the curing process is a three-stage gradient curing process, wherein the first stage is infrared thermal curing, heating to 50-70℃ and holding for 5-10 minutes; the second stage is ultraviolet light curing, with ultraviolet light energy of 1500-2500 mJ / cm². 2 The third stage involves post-heat curing, which is performed in an oven at 80-100℃ for 20-40 minutes.

[0030] In some embodiments, the interface anchoring liquid comprises, by weight, 20-40 parts of hyperbranched polyester acrylate, 10-25 parts of mussel biomimetic adhesion monomer containing catechol groups, 5-15 parts of boron nitride nanotubes, 3-10 parts of sulfonated calixarene, 4-8 parts of free radical-cationic hybrid photoinitiator, and 1-3 parts of fluorinated surfactant.

[0031] In some embodiments, the mussel biomimetic adhesion monomer containing catechol groups is dopamine methacrylamide; the boron nitride nanotubes are aminated boron nitride nanotubes with a diameter of 3-8 nm and an aspect ratio greater than 50:1.

[0032] In some embodiments, the edge sealing agent comprises, by weight parts: 40-60 parts of isocyanate-terminated polydimethylsiloxane prepolymer, 20-35 parts of acrylated cyclodextrin, 5-15 parts of liquid polybutadiene, 3-8 parts of photoinitiator, 2-6 parts of latent moisture-curing catalyst, and 1-4 parts of molecular sieve dehydrating agent.

[0033] In some embodiments, the sealing agent also contains 1-5 wt% of a metal-organic framework material, wherein the metal-organic framework material is ZIF-8.

[0034] In some embodiments, the interface anchoring fluid further contains 2-4 parts of self-healing microcapsules, wherein the capsule wall of the self-healing microcapsule is polyurea-formaldehyde resin, the core is hexamethylene diisocyanate trimer, and the microcapsule particle size is 10-30 μm.

[0035] The following is a detailed explanation using specific embodiments: Example 1: I. Preparation of Interface Anchoring Solution Under conditions protected from light, add the following components to a 250 mL three-necked flask: Hyperbranched polyester acrylate (functionality 12, number average molecular weight 2800) 20g; Dopamine methacrylamide (purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) 25g; Aminated boron nitride nanotubes (purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., tube diameter 5nm, aspect ratio 60:1, amino grafting rate approximately 2.5%) 10g; 3g of sulfonated calixarene; The free radical-cation hybrid photoinitiator is composed of 1-hydroxycyclohexylphenyl ketone and diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate in a mass ratio of 1:1 (8g). 2g of fluorinated surfactant (nonionic, fluorine content approximately 32%).

[0036] Add a magnetic stir bar and mechanically stir at 800 rpm in a 40°C water bath in the dark for 2.5 hours until the boron nitride nanotubes are uniformly dispersed and the system is a homogeneous black viscous liquid, thus obtaining the interface anchoring liquid. Degas the liquid by sonication for 10 minutes before use.

[0037] II. Preparation of Edge Sealing Agent First, self-healing microcapsules were prepared: 10g of hexamethylene diisocyanate trimer was dissolved in 30ml of cyclohexane as the oil phase; 80g of polyurea-formaldehyde prepolymer aqueous solution (purchased from Shandong Yousuo Chemical Technology Co., Ltd.) was mixed with 0.5g of sodium dodecylbenzenesulfonate as the aqueous phase. After emulsification at 1000rpm for 10 minutes, dilute hydrochloric acid was slowly added to adjust the pH to 2.5, and the mixture was heated to 60℃ and reacted for 3 hours. After filtration, washing, and drying, microcapsules with a particle size of approximately 20μm were obtained.

[0038] Under a dry nitrogen atmosphere, add the following components to a 100 mL three-necked flask: Isocyanate-terminated polydimethylsiloxane prepolymer (isocyanate group content 3.2%, number average molecular weight approximately 2800) 40g; Acrylated β-cyclodextrin (purchased from Shandong Binzhou Zhiyuan Biotechnology Co., Ltd., degree of substitution 2.5) 35g; 10g of liquid polybutadiene; Photoinitiator (2-hydroxy-2-methyl-1-phenylpropanone) 3g; Latent moisture-curing catalyst (amine latent curing agent) 6g; Molecular sieve dehydrating agent (Type 3A powder, pore size 0.3nm, particle size 2-4μm) 2.5g; 1.5g of metal-organic framework material ZIF-8 (purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., particle size 100nm); Self-repairing microcapsules 4g.

[0039] Add all components to the reaction flask and mechanically stir at 500 rpm for 40 minutes under nitrogen protection, avoiding air bubbles, to obtain a homogeneous sealing agent. Store in a sealed container at room temperature away from light before use.

[0040] III. Fabrication of the Edge Structure of the Multilayer Dimming Film The film substrate used is a multilayer dimming film.

[0041] S1: Plasma activation treatment The multilayer dimming film was cut into 200mm × 300mm samples, exposing the cut ends. An atmospheric pressure low-temperature plasma treatment device was used, and the process parameters were set as follows: The volume ratio of the mixed gases in the atmosphere is argon:oxygen:carbon tetrafluoride = 5:2:1. Processing power 800W; The distance between the nozzle and the cutting end face should be 10mm. The scanning speed is 10 mm / s, and the scan is performed twice.

[0042] An activation layer is formed after treatment.

[0043] S2: Coating the interface anchoring liquid and forming a flexible anchoring layer The interface anchoring solution prepared in step one was uniformly coated onto the activated end face using a precision microneedle (0.2 mm inner diameter), with a coating thickness of approximately 20 μm. The film was then placed in a constant temperature and humidity chamber and allowed to stand for 60 seconds. Temperature 35℃; Relative humidity 50%.

[0044] After standing, a continuous, transparent, and viscoelastic flexible anchoring layer is formed on the end face, with a thickness of approximately 10 μm.

[0045] S3: Apply edge sealing agent and cure. The sealing agent prepared in step two was applied to the surface of the flexible anchoring layer using a micro-jet dispensing system. Injection pressure: 0.2 MPa; Nozzle diameter 0.3mm; The spray angle is 45° to the edge of the film; The nozzle moves at a constant speed along the end face, and the sealing agent covers the surface of the anchoring layer. The coating width is about 1.2 mm and the thickness is about 50 μm.

[0046] The curing process employs a three-stage gradient process: Infrared thermosetting: Use an infrared heating lamp to heat to 70℃ and hold for 5 minutes; UV curing: High-pressure mercury lamp (light intensity 80mW / cm²), cumulative energy 1500 mJ / cm², nitrogen protection; Post-heat curing: Place in a 100℃ oven for 20 minutes.

[0047] After curing, the sealing layer and the anchoring layer form an integrated and dense structure, which is firmly bonded to the end face of the film without bubbles or delamination.

[0048] Comparative Example 1 Preparation of edge sealing adhesive At room temperature, add the following components to a 500 mL three-necked flask: 100g polyester polyurethane resin, 200g ethyl acetate, 100g butanone, 15g isocyanate curing agent, and 0.2g dibutyltin dilaurate catalyst.

[0049] Polyester-type polyurethane resin was added to a mixed solvent and mechanically stirred at 500 rpm for 2 hours to dissolve it. After the resin was completely dissolved, isocyanate curing agent and dibutyltin dilaurate catalyst were added, and stirring was continued for 30 minutes to obtain a uniform sealing adhesive. Before use, it was allowed to stand at room temperature for 15 minutes to defoam.

[0050] Fabrication of multilayer dimming film edge structure The thin film substrate used is the same as in the example, which is a multilayer dimming film.

[0051] S1: End face processing Cut the multilayer dimming film into 200mm×300mm samples, exposing the cut end face. Use anhydrous ethanol to moisten a lint-free cloth and wipe the cut end face to remove surface dust and oil, then let it air dry at room temperature for 5 minutes.

[0052] S2: Edge sealing adhesive coating Using a brush, apply the sealing adhesive prepared in step two manually to the cut end face of the film, to a thickness of approximately 100 micrometers. During the application process, some degree of inward shrinkage and sagging of the adhesive is observed on the end face. After application, hang the film vertically and let it stand at room temperature for 10 minutes to allow excess adhesive to flow naturally.

[0053] S3: Curing process Place the film coated with edge-sealing adhesive in a forced-air drying oven, set the temperature to 60℃, and cure for 120 minutes. After curing, remove it and allow it to cool naturally at room temperature.

[0054] The cured edge sealing layer is semi-transparent in appearance, with a small number of shrinkage marks visible at the edges. There are no obvious bubbles at the junction with the end face, but the thickness of the edge sealing layer is uneven, and there are fine cracks in some areas.

[0055] Experiment Example 1: Performance Comparison Test of Multilayer Dimming Film Edge Structure in Smart Car Window Applications I. Experimental Objective In this experiment, the multilayer dimming film edge structure products prepared in Example 1 and Comparative Example 1 were installed in a real smart car window demonstration system to simulate the actual use environment of a car window. Through a comprehensive performance test lasting 90 days, the reliability, durability and optical performance retention of the two edge sealing processes in the actual application scenario were evaluated.

[0056] II. Preparation of Experimental Samples 2.1 Sample Preparation 2.2 Sample Installation Samples from groups A and B were installed in two identical smart window demonstration systems. Each system included: Aluminum alloy window frame (350mm×450mm); 48V AC drive power supply and dimming controller; Temperature and humidity sensors, light sensors, and data loggers; The glass interlayer installation structure seals and fixes the film to the window frame.

[0057] During installation, ensure that the edge sealing area of ​​the film is completely embedded in the window frame sealing strip to simulate the actual installation state of a car window.

[0058] Three test conditions 3.1 Test Cycle and Conditions The total experimental period was 90 days, divided into three phases of testing, each lasting 30 days, simulating different seasonal usage environments, as detailed in Table 1 below: Table 1 Test Conditions 3.2 Working Status During the experiment, all samples underwent six dimming cycles daily (each dimming cycle consisted of 30 minutes in the powered-on atomized state and 30 minutes in the powered-off transparent state) to simulate daily usage frequency. A data logger continuously recorded the thin film's operating current, temperature, and environmental parameters.

[0059] IV. Test Items and Methods 4.1 Optical performance testing Testing instrument: Spectrophotometer Test method: Visible light transmittance (380-780nm) and haze were tested in the central and edge areas (5mm from the edge of the seal) of each group of samples every month (on the 30th, 60th and 90th days). Five tablets were taken from each group of samples, and each tablet was tested three times and the average value was taken. The transmittance retention rate was calculated, and the final test results are shown in Table 2.

[0060] Table 2 Optical Test Results Results analysis: After 90 days of testing, the transmittance of Group A samples remained at 98.2% in the central area and 97.5% in the edge area, with only a slight increase in haze, indicating that the edge sealing structure effectively blocked water vapor and oxygen from penetrating from the edges. In Group B samples, the transmittance in the edge area decreased significantly, and the haze increased to 15.3%, with water vapor intrusion at the edges causing local failure of the PDLC layer and oxidation of the ITO layer.

[0061] 4.2 Edge appearance inspection Inspection method: The sealed area was observed monthly using a 20x optical microscope. Record the bonding status between the sealing layer and the film end face, including phenomena such as delamination, bubbles, cracks, whitening, discoloration, and powdering; Photos were taken and archived, and scores were given according to defect level (Level 0: No defects; Level 1: Minor defects, area <5%; Level 2: Moderate defects, area 5-20%; Level 3: Severe defects, area >20%). The final test results are shown in Table 3 below.

[0062] Table 3. Results of edge appearance inspection Microscopic observation: Group A showed clear and complete sealing boundary, with no obvious interface separation between the anchoring layer and the sealing layer in an integrated structure; Group B showed obvious separation at the interface between the sealing layer and the film end face, with some areas of the sealing adhesive shrinking to form gaps, which became channels for water vapor intrusion.

[0063] 4.3 Water vapor infiltration Test method: After the 90th day of the experiment, the sample was removed from the window frame; Samples were cut and taken at distances of 0mm, 5mm, 10mm, and 20mm from the edge of the sealing film, and the interlayer moisture content of the film was determined using a Karl Fischer moisture analyzer.

[0064] Table 4 Water Vapor Permeability 4.4 Electrical Performance Testing Test instrument: LCR bridge Test method: On day 90, the capacitance and dielectric loss of each sample group were tested in the transparent and atomized states. Test frequency 1kHz, test voltage 1V; The changes in drive current were recorded, and the final test results are shown in Table 5 below.

[0065] Table 5 Electrical Performance Test Results Results analysis: Group A's electrical performance remained stable, with a slight decrease in capacitance and a slight increase in driving current, all within the normal range. Group B showed a significant decrease in capacitance and a significant increase in driving current, indicating that moisture intrusion at the edges led to a reduction in the effective electrode area and a decrease in the dielectric constant.

[0066] 4.5 Overall Weather Resistance Score Each test metric is scored from 0 to 10 (10 being the highest), and the overall performance score is calculated using a weighted average. Weighting is as follows: Optical performance retention rate: 30% Edge appearance integrity: 25% Water vapor barrier: 25% Electrical performance stability: 20%; The scoring and evaluation levels are shown in Table 6 below.

[0067] Table 6 Score Level Evaluation The final results are shown in Table 7 below.

[0068] Table 7 Overall Performance Score Through a 90-day simulation test of smart car window application scenarios, the following conclusions were drawn: Optical performance retention: In Example 1, the transmittance of the central region of the sample was maintained at 98.2% and that of the edge region was maintained at 97.5% under harsh conditions such as high temperature and humidity, temperature shock, and ultraviolet irradiation, and the haze increased by only 0.4-0.8 percentage points. In contrast, the transmittance of the edge region of the sample of Comparative Example 1 decreased to 78.6% and the haze increased to 15.3%, and the water vapor intrusion at the edge caused the PDLC layer to fail.

[0069] Edge sealing structure integrity: In Example 1, the edge sealing layer was firmly bonded to the end face of the film, and there was no delamination, no bubbles, and no cracks after 90 days. Only a few samples showed very slight discoloration. In Comparative Example 1, whitening and cracks appeared after 30 days, and about 35% of the samples showed edge sealing layer detachment after 90 days, with severe interface corrosion.

[0070] Moisture barrier capability: In Example 1, the moisture content of the sealing surface was 285 ppm, which dropped to 72 ppm 20 mm from the edge, effectively preventing moisture from entering along the edge; in Comparative Example 1, the moisture content of the sealing surface was as high as 1240 ppm, which was still 320 ppm 20 mm from the edge, indicating that the barrier effect was significantly insufficient.

[0071] Electrical performance stability: In Example 1, the capacitance value decreased by 3.5%, the driving current increased by 3.5%, and the electrical performance remained stable; in Comparative Example 1, the capacitance value decreased significantly, and the driving current increased significantly.

[0072] Overall Performance Evaluation: Example 1 scored 9.38 points, while Comparative Example 1 scored only 5.45 points. The plasma activation, flexible anchoring layer, functionalized edge sealant, and three-stage gradient curing process employed in Example 1 demonstrate excellent edge sealing reliability, environmental durability, and optical performance retention in practical applications, fully meeting the long-term reliability requirements of multi-layer dimming film edge structures in high-end applications such as smart car windows. The existing conventional edge sealing process represented by Comparative Example 1 cannot meet the usage requirements of the aforementioned demanding application scenarios.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing the edge structure of a multilayer dimming film, characterized in that, Includes the following steps: S1: The cut end face of the thin film is subjected to plasma activation treatment to form an activation layer; S2: Coat the surface of the activated layer with an interface anchoring liquid and let it stand to form a flexible anchoring layer; S3: Apply an edge sealant to the surface of the flexible anchoring layer and cure the edges of the film after applying the edge sealant.

2. The production method according to claim 1, characterized by, In S1, the plasma activation treatment uses atmospheric pressure low-temperature plasma, the treatment atmosphere is a mixture of argon, oxygen and carbon tetrafluoride, the volume mixing ratio is Ar:O2:CF4=5:2:1, the treatment power is 800-1200W, and the distance between the treatment nozzle and the cutting end face is 5-10mm.

3. The preparation method according to claim 1, characterized in that, In step S2, the settling time is 60-180 seconds, the temperature is 25-35℃, and the relative humidity is 40-60%.

4. The preparation method according to claim 1, characterized in that, In step S3, the sealing agent is applied using a micro-jet dispensing process with a spraying pressure of 0.2-0.5 MPa, a nozzle diameter of 0.1-0.3 mm, and a spraying angle of 45-60° to the edge of the film.

5. The preparation method according to claim 1, characterized in that, In S3, the curing process is a three-stage gradient curing process, wherein the first stage is infrared thermal curing, which involves heating to 50-70°C and holding for 5-10 minutes; The second segment is UV-cured with UV energy of 1500-2500 mJ / cm 2 The third segment is post-thermally cured by placing in an oven at 80-100 °C for 20-40 minutes.

6. The preparation method according to claim 1, characterized in that, By weight, the interface anchoring liquid comprises: 20-40 parts of hyperbranched polyester acrylate, 10-25 parts of mussel biomimetic adhesion monomer containing catechol groups, 5-15 parts of boron nitride nanotubes, 3-10 parts of sulfonated calixarene, 4-8 parts of free radical-cationic hybrid photoinitiator, and 1-3 parts of fluorinated surfactant.

7. The preparation method according to claim 6, characterized in that, The mussel biomimetic adhesion monomer containing catechol groups is dopamine methacrylamide; the boron nitride nanotubes are aminated boron nitride nanotubes with a diameter of 3-8 nm and an aspect ratio greater than 50:

1.

8. The preparation method according to claim 1, characterized in that, By weight, the edge sealing agent comprises: 40-60 parts of isocyanate-terminated polydimethylsiloxane prepolymer, 20-35 parts of acrylated cyclodextrin, 5-15 parts of liquid polybutadiene, 3-8 parts of photoinitiator, 2-6 parts of latent moisture-curing catalyst, and 1-4 parts of molecular sieve dehydrating agent.

9. The preparation method according to claim 8, characterized in that, The edge sealing agent also contains 1-5 wt% of a metal-organic framework material, wherein the metal-organic framework material is ZIF-8.

10. The preparation method according to claim 8, characterized in that, The interface anchoring solution also contains 2-4 parts of self-healing microcapsules, the capsule wall of which is polyurea-formaldehyde resin, the core of which is hexamethylene diisocyanate trimer, and the microcapsule particle size is 10-30 μm.

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