A magnetron forming sealant, a forming process, a sealant strip and a display panel

Abstract

This invention discloses a magnetron sputtering sealant and its molding process, a sealant strip, and a display panel. The sealant comprises: a UV-curable resin, a PUR moisture-curable resin, a non-electromagnetically responsive filler, a non-conductive opaque pigment, and a non-conductive elastically modified filler. The sealant can form a rounded triangular cross-section under a vertical magnetic field and is fixed through UV-PUR dual curing. The sealant is a non-silicone system and non-conductive, exhibiting high elastic recovery characteristics after curing. This invention, through the synergy of UV-PUR dual curing and magnetron sputtering rounded triangular molding technology, provides a sealant that can be rapidly molded on-site, is non-conductive, opaque, and has high elastic stress dispersion function, effectively replacing foam tape and fundamentally solving the problem of light leakage due to pressure on the display panel frame.

Description

Technical Field

[0001] This invention relates to the field of sealing materials technology, and in particular to a magnetron sputtering sealant and its molding process, a sealing strip, and a display panel. Background Technology

[0002] Display panels (such as LCD and OLED) typically require a sealing structure at the panel bezel during production and use to achieve functions such as waterproofing, dustproofing, light blocking, and stress buffering. Traditional bezel sealing solutions mainly use pre-fabricated foam tape for bonding. The foam tape absorbs assembly tolerances and buffers external impacts through the physical compression deformation of its microporous structure, while the black foam tape can also provide some edge light blocking.

[0003] However, existing foam tape solutions have the following significant technical drawbacks: (1) Elasticity decay and compressive light leakage. The buffering function of foam tape relies on the compressibility of its microporous structure. However, under long-term use or high temperature and humidity conditions, foam materials are prone to aging, creep, and plastic deformation, resulting in a significant decrease in elastic recovery ability. When the elasticity of the foam decays, it cannot effectively disperse the concentrated stress generated by the panel during assembly and thermal expansion and contraction. Excessive local stress can lead to panel deformation or gap changes, which in turn causes compressive light leakage, seriously affecting display quality. Existing literature indicates that the compression ratio and thickness of the foam have a significant impact on module light leakage. Increasing the compression ratio and thickness of the foam can improve the light leakage phenomenon to a certain extent, but this is only a passive improvement measure and cannot fundamentally solve the problem of elasticity decay.

[0004] (2) Poor adaptability, unable to adapt to narrow bezels and irregular structures. Foam tape is a prefabricated part, which needs to be pre-made into a specific shape through die-cutting process. For narrow bezels, curved surfaces or irregular bezel structures, the die-cutting accuracy is limited and the fitting and alignment are difficult, which can easily cause misalignment, wrinkles or air bubbles, affecting the consistency of sealing. In addition, the aspect ratio of foam tape is uncontrollable, making it difficult to accurately adapt to the design requirements of different bezel gaps.

[0005] (3) Limited light-blocking function. Although some black foam tapes can block light to a certain extent, their light-blocking effect depends on the physical light-blocking ability of the foam substrate. With long-term use, as the foam deforms and ages, the light-blocking performance will also decrease, and it cannot provide a long-term stable opaque seal.

[0006] Besides foam tape, another existing technology for sealing display panel bezels is Form-In-Place (FIP) dispensing. This process uses automated equipment to directly apply fluid sealant to the workpiece surface, which cures to form a sealing gasket, avoiding compatibility issues with prefabricated parts. In the field of FIP sealants, the Trishield® series from Nolato Silikonteknik AB of Sweden is a typical example. This technology uses a two-component silicone conductive adhesive system, forming a tall and narrow triangular cross-section gasket through the FIP dispensing process. It is mainly used for electromagnetic interference (EMI) shielding and sealing of electronic equipment. The adhesive is a two-component thermosetting conductive silicone, requiring a curing temperature of 100-150℃; the gasket cross-section is triangular, with an aspect ratio of up to 2:1, featuring low compressive force and high material utilization. Norland has filed several patents related to this technology, such as patent application WO / 2024 / 058705, which discloses a method for manufacturing a pad for electromagnetic shielding by a specific method, including the step of providing a composition containing adhesive material and conductive particles and curing it.

[0007] However, Norland's Trishield® technology also cannot meet the special requirements for sealing the display panel bezel: First, conductivity is incompatible with the safety of display panels. This adhesive contains conductive metal fillers, making it conductive for EMI shielding. Applying it directly to the display panel bezel poses a short-circuit risk and fails to meet the safety requirements of display panels for non-conductive sealants.

[0008] Secondly, high-temperature curing can damage heat-sensitive components. The thermal curing process (100-150℃) may cause thermal damage to heat-sensitive components such as polarizers and optical films in the display panel. Although Norland has launched a room temperature vulcanization (RTV) version of its Trishield product in recent years, its conductive system and silicone matrix remain unchanged, and EMI shielding remains its core function.

[0009] Third, the silicone system has poor compatibility with subsequent processes. Silicone materials have low surface energy, making them difficult to coat or bond, and they are prone to producing silicon precipitates that contaminate optical components.

[0010] Fourth, the elasticity of the adhesive strip is insufficient to disperse stress. Trishield adhesive strips are mainly made of rigid conductive silicone, and their design goal is to maintain stable conductivity and low compressive force, rather than to provide high elastic recovery to disperse concentrated stress, thus failing to solve the problem of compressive light leakage.

[0011] Fifth, it lacks light-blocking functionality. Existing Trishield products are light-colored or transparent and do not have light-blocking capabilities.

[0012] Therefore, it is evident that existing display panel bezel sealing technologies suffer from several drawbacks: foam tape exhibits elasticity degradation, poor adaptability, and limited light-shielding performance; while FIP dispensing sealing technologies such as Norland Trishield® can achieve high-precision triangular gasket molding, their conductivity, high-temperature curing, and silicone-based approach fundamentally conflict with the display panel's requirements for non-conductivity, light-shielding, high elasticity, and room-temperature processing. Neither of these existing technologies can simultaneously meet the comprehensive requirements of display panel bezel sealing for "non-conductivity, opacity, high elasticity stress dispersion, rapid room-temperature curing, and high-precision molding."

[0013] Therefore, developing a display panel bezel sealing solution that can take into account the above-mentioned performance, replace existing foam tape, and avoid compressive light leakage is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0014] To address the aforementioned technical problems, the present invention aims to provide a magnetron sputtering sealant, its molding process, a sealing strip, and a display panel. This invention, through the synergy of UV-PUR dual curing and magnetron sputtering rounded corner triangular molding technology, provides a sealant that can be rapidly molded on-site, is non-conductive, opaque, and possesses high elasticity and stress dispersion capabilities. It can effectively replace foam tape and fundamentally solve the problem of light leakage due to pressure on the display panel frame.

[0015] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution: The present invention provides a magnetron-cured sealant comprising: a UV-curable resin, a PUR moisture-curable resin, a non-electromagnetic responsive filler, a non-conductive opaque pigment, and a non-conductive elastic modified filler. The sealant can form a rounded triangular cross section under the action of a vertical magnetic field and is shaped by UV-PUR dual curing; the sealant is a non-organosilicon system and is non-conductive, and has high elastic recovery characteristics after curing.

[0016] Further, by weight, the sealant comprises: 15-45 parts of UV-curable resin, 25-55 parts of PUR moisture-curable resin, 3-20 parts of non-electromagnetic responsive filler, 0.5-12 parts of non-conductive opaque pigment, and 3-15 parts of non-conductive elastic modified filler.

[0017] Preferably, the UV-curable resin is selected from one or more of epoxy acrylate, polyurethane acrylate, polyester acrylate, and polyether acrylate; The PUR moisture-curing resin is a polyurethane prepolymer with isocyanate-terminated groups. The non-electromagnetic response filler is selected from one or more of carbonyl iron powder, iron-silicon-chromium alloy powder, amorphous soft magnetic powder, and ferrite powder, and the surface of the non-electromagnetic response filler has an insulating coating layer. The non-conductive, opaque pigment is selected from one or more of carbon black, aniline black, titanium black, and iron oxide black; The non-conductive elastic modified filler is selected from one or more of the following: core-shell structured rubber microspheres, nitrile rubber powder, polyurethane elastic microspheres, and acrylate elastic microspheres.

[0018] Furthermore, the top of the rounded triangular cross-section has a smooth arc transition, and its height-to-width ratio is 0.8:1 to 1.2:1; the sealant is black or dark-colored and opaque, with a visible light transmittance of ≤1%.

[0019] Furthermore, the elastic recovery rate of the sealant after curing is ≥85%; the elastic recovery rate is achieved synergistically through the polyurethane elastomer segments in the resin molecular structure and the non-conductive elastic modified filler.

[0020] Another aspect of the present invention provides a molding process for a magnetron-molded sealant, which includes the following steps: (1) Apply the sealant according to any one of claims 1-4 to the surface of the substrate; (2) While the adhesive is in a flowing state, a vertical magnetic field is applied to pull the adhesive to form a rounded triangular cross section, thus obtaining a pre-formed adhesive strip; (3) Perform UV pre-curing and shaping to ensure that the adhesive strip maintains the rounded triangular cross-section and has preliminary elasticity; (4) Perform deep curing of PUR moisture to achieve the final high elasticity and sealing performance of the adhesive strip.

[0021] Furthermore, the sealant is black or dark opaque. In step (3), UV or UV-LED irradiation parameters suitable for the opaque sealant are selected so that UV light can penetrate the surface of the sealant strip to achieve effective pre-curing. Moreover, the non-conductive opaque pigment and non-conductive elastic modified filler do not interfere with the moisture penetration and deep curing process in step (4).

[0022] Furthermore, the width of the rounded triangular cross section is 0.8-1.2mm, the height is 0.8-1.2mm, and the height-to-width ratio is 0.8:1 to 1.2:1.

[0023] The present invention also provides a sealing strip, which is made using the sealant or molding process described above. The sealing strip has a rounded triangular cross section with a smooth arc transition at the top. The sealing strip has opaque properties and high elastic recovery properties.

[0024] Furthermore, the sealing strip can be used to seal the frame of the display panel; the sealing strip has an elastic recovery rate of ≥85%, which can be used to disperse the concentrated stress generated during the assembly and use of the display panel; and the visible light transmittance of the sealing strip is ≤1%, which can be used to block light leakage from the edge of the display panel.

[0025] The present invention further provides a display panel, which includes two substrates disposed opposite to each other, and a frame sealing structure disposed between the two substrates; the frame sealing structure includes the sealant or sealing strip described above.

[0026] The beneficial effects of this invention are as follows: (1) The sealant of the present invention can achieve synergistic effects through dual curing: UV pre-curing enables the sealant strip to quickly set within seconds, effectively maintaining the molded shape and preventing collapse; PUR moisture deep curing further enhances adhesion, toughness and weather resistance. The combination of the two takes into account both operational efficiency and final performance, overcoming the inherent defects of a single curing system.

[0027] (2) The present invention can achieve the effect of magnetically controlled rounded triangle forming: through precise guidance by a vertical magnetic field, a rounded triangle cross section can be stably formed with a smooth transition at the top and no sharp corners, and the aspect ratio can be controlled. This structure is conducive to adapting to narrow bezel sealing gaps, and the rounded corner design can avoid local stress concentration; unlike the existing sharp triangle cross section (which is prone to stress singularity), the arc transition of the present invention, combined with highly elastic adhesive, can more evenly distribute the compressive load and reduce local pressure on the display panel.

[0028] (3) The sealant of the present invention has a non-conductive safety effect: the sealant is non-conductive as a whole, which meets the insulation requirements of display panels and precision electronic devices, and there is no risk of short circuit. It is fundamentally different from the existing conductive magnetic sealant.

[0029] (4) The sealant of the present invention can achieve the effect of opaque light blocking: the sealant strip is black or dark in color and has low visible light transmittance, which can effectively block light leakage at the edge of the display panel and meet the light blocking requirements of the frame.

[0030] (5) The sealant of the present invention has a high elastic stress dispersion effect: after curing, the sealant strip has a stable high elastic recovery ability, which can adapt to slight deformation of the panel, disperse the concentrated stress during assembly and use, thereby reducing the oppressive light leakage caused by local pressure.

[0031] (6) The sealing strip of the present invention can replace foam tape and has better overall effect: on-site dispensing and molding does not require pre-drilling and can be flexibly adapted to various irregular frame shapes; compared with foam tape, the elastic recovery ability of this sealant is more durable, avoiding the light leakage problem caused by foam aging and permanent deformation due to compression during long-term use, and improving the long-term reliability of the sealing structure. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] This invention provides a magnetron sputtering sealant comprising a UV-curable resin, a PUR moisture-curable resin, a non-electromagnetic responsive filler, a non-conductive opaque pigment, and a non-conductive elastic modified filler. The sealant is a non-silicone system and is non-conductive. It can form a rounded triangular cross-section under the action of a vertical magnetic field and be cured by UV-PUR dual curing. After curing, it has high elastic recovery characteristics.

[0034] Specifically, regarding the base resin, the UV-curing resin is selected from one or more of epoxy acrylate, polyurethane acrylate, polyester acrylate, and polyether acrylate. Preferably, to improve the elastic recovery performance of the cured adhesive strip, polyurethane acrylate can be used as the UV-curing resin, as the polyurethane segments in its molecular structure can impart good flexibility to the cured product. The PUR moisture-curing resin is a polyurethane prepolymer with isocyanate-terminated groups. By weight, the amount of UV-curing resin is 15-45 parts, and the amount of PUR moisture-curing resin is 25-55 parts, with a preferred weight ratio of 1:2-2:1, more preferably 1:1.5-1.5:1. Through this compound system, the UV component can achieve second-level setting under light irradiation to prevent the adhesive strip from collapsing, while the PUR component absorbs moisture in the subsequent process to complete deep curing, thus balancing rapid operation efficiency with final high adhesion, high toughness, and weather resistance, overcoming the technical defects of single UV adhesives being brittle and single PUR adhesives being slow to cure.

[0035] Furthermore, to achieve magnetic field-assisted shaping and ensure that the sealant is entirely non-conductive, the non-electromagnetically responsive filler is selected from one or more of carbonyl iron powder, iron-silicon-chromium alloy powder, amorphous soft magnetic powder, and ferrite powder. It should be noted that the filler has an insulating coating layer on its surface, which can be formed using conventional surface treatment techniques in the art. For example, the filler particles can be dispersed in a solution containing an insulating precursor, and a silica layer can be deposited on its surface using a sol-gel method; or a resin insulating layer can be coated by mechanical fusion. For ferrite materials, which inherently possess high resistivity, a dense oxide insulating layer can be formed on their surface through high-temperature oxidation treatment. The function of this insulating coating layer is twofold: firstly, the insulating coating layer does not shield the magnetic field, allowing the filler to still be magnetically attracted, thereby driving the adhesive to flow and form a predetermined cross-sectional shape under the action of a perpendicular magnetic field; secondly, the insulating coating layer blocks the electrical contact between the filler particles, keeping the sealant in a non-conductive state, meeting the insulation safety requirements of precision electronic devices such as display panels. The amount of this non-conductive electromagnetic responsive filler is 3 to 20 parts. It is only used for magnetic field-assisted shaping and does not have conductive or electromagnetic shielding functions.

[0036] To address the specific requirements of display panel bezels for light shielding and light leakage prevention, this invention incorporates a non-conductive, opaque pigment into the sealant. This pigment is selected from one or more of carbon black, aniline black, titanium black, and iron oxide black, and is used in amounts ranging from 0.5 to 12 parts, giving the sealant a black or dark opaque appearance. Within this dosage range, the visible light transmittance of the cured sealant is ≤1%, effectively blocking light leakage from the edges of the display panel. It is important to emphasize that the addition of this opaque pigment does not interfere with the sealant's dual-curing effect or magnetic response properties.

[0037] Furthermore, to enhance the elastic recovery and stress dispersion effect of the adhesive strip, a non-conductive elastic modified filler is added to the sealant of this invention. This filler is selected from one or more of core-shell structured rubber microspheres, nitrile rubber powder, polyurethane elastic microspheres, and acrylate elastic microspheres, and is used in an amount of 3 to 15 parts. This elastic modified filler can synergistically work with the polyurethane elastomer segments in the resin matrix to jointly construct a highly elastic network structure for the adhesive strip, resulting in an elastic recovery rate of ≥85% after curing. This allows the sealant to adaptively adjust to slight deformations of the display panel, effectively dispersing concentrated stress generated during assembly and use.

[0038] In addition, it is understood that other additives known in the art, such as photoinitiators, silane coupling agents, rheology modifiers, antioxidants, dispersants, and defoamers, may be added to the sealant of the present invention as needed.

[0039] The present invention also provides a molding process suitable for the above-mentioned sealant. The process includes the following steps in sequence: (1) Dispensing Step: The sealant is precisely applied to the surface of the product structure to be sealed using an FIP on-site dispensing device. This sealant contains non-conductive and opaque pigments, giving it a black or dark opaque appearance, and can be directly applied to the sealing area at the edge of the display panel. This step does not require pre-fabrication of die-cut parts, allowing for flexible adaptation to various irregular frame structures and improving assembly efficiency.

[0040] (2) Vertical magnetic field shaping step: When the adhesive is in a flowing state, a vertical magnetic field is applied to pull the non-conductive electromagnetic response filler in the adhesive, thereby driving the overall adhesive to flow and forming a stable rounded triangular cross section to obtain a pre-formed adhesive strip; the top of the cross section is a smooth arc transition without sharp corners, the width is 0.8 to 1.2 mm, the height is 0.8 to 1.2 mm, and the height-to-width ratio is 0.8:1 to 1.2:1.

[0041] (3) UV pre-curing and shaping steps: The adhesive strip is pre-cured and shaped by UV or UV-LED irradiation. For this opaque sealant, appropriate UV irradiation parameters should be selected (such as appropriately extending the irradiation time, increasing the irradiation intensity, or selecting a wavelength with better penetration) to ensure that the UV light can penetrate the surface of the adhesive strip to achieve effective pre-curing, thereby locking the rounded triangular shape and giving the adhesive strip initial elasticity, so that it can initially buffer slight stress during subsequent assembly. (4) PUR moisture deep curing step: Allow the adhesive strip to absorb moisture from the air at room temperature to complete the final curing, achieving high elasticity and sealing performance. It should be noted that the addition of the non-conductive opaque pigment and elastic modified filler does not interfere with the moisture penetration and deep curing process.

[0042] In particular, in terms of cross-sectional shape design, this invention adopts a rounded triangular cross-section with a smooth, rounded transition at the top, unlike the sharp triangular cross-section of existing technologies (such as Norland Trishield®). The sharp triangular cross-section has a significant geometric abrupt change at its apex, which can lead to stress concentration under compressive stress. Combined with its rigid conductive silicone system, this can easily create localized high-pressure pressure on the display panel. In contrast, the rounded triangle of this invention eliminates the geometric abrupt change point through its rounded transition, uniformly distributing compressive stress along the arc surface and avoiding stress peak concentration. Furthermore, this rounded corner structure works synergistically with the highly elastic adhesive of this invention to form a dual stress dispersion mechanism of "structure + material," thereby effectively reducing localized pressure on the display panel and preventing compressive light leakage.

[0043] This invention also provides a sealing strip made using the above-mentioned sealant or molding process. The sealing strip has a rounded triangular cross-section with a smooth, rounded top transition, exhibiting opacity and high elastic recovery. Specifically, the sealing strip has an elastic recovery rate ≥85% and a visible light transmittance ≤1%. This sealing strip is particularly suitable for sealing the bezels of display panels: its high elastic recovery can disperse concentrated stress generated during assembly and use, preventing compressive light leakage; its opacity can block light leakage from the edges of the display panel. Compared to existing foam tapes, the sealing strip of this invention has the following advantages: on-site dispensing and molding eliminates the need for pre-die-cutting, allowing for flexible adaptation to various irregularly shaped bezels; its elastic recovery is more durable, avoiding light leakage problems caused by foam aging and permanent compression deformation during long-term use; and its aspect ratio is precisely controllable, resulting in good sealing consistency.

[0044] The present invention further provides a display panel. The display panel includes two substrates disposed opposite to each other (e.g., an array substrate and a color filter substrate, or a display substrate and a cover plate), and a bezel sealing structure disposed between the two substrates. The bezel sealing structure includes the aforementioned sealant or sealing strip. By employing the sealing technology of the present invention, the display panel can achieve waterproof and dustproof sealing of the bezel area, while simultaneously meeting the requirements for edge light shielding (preventing light leakage) and stress buffering. This avoids the compressive light leakage problem caused by the elastic decay of traditional foam tape, thereby improving the long-term reliability and display quality of the display panel.

[0045] The present invention will be further described below through specific embodiments.

[0046] The raw materials used in each embodiment and comparative example are as follows: UV-curable resin: polyurethane acrylate; PUR moisture-curing resin: isocyanate-terminated polyurethane prepolymer; Non-conductive electromagnetic response filler: carbonyl iron powder, with an insulating layer (particle size 5-10μm) coated on the surface by silica sol-gel method. Non-conductive, opaque pigments: insulating grade carbon black; Non-conductive elastic modified filler: core-shell structured rubber microspheres; Photoinitiator: 2-hydroxy-2-methyl-1-phenyl-1-propanone; Coupling agent: γ-glycidoxypropyltrimethoxysilane. Example 1

[0047] Weigh the following components by weight: 30 parts UV-curable resin, 40 parts PUR moisture-curable resin, 10 parts non-electromagnetic responsive filler, 3 parts non-conductive opaque pigment, 5 parts non-conductive elastic modified filler, 2 parts photoinitiator, and 1 part coupling agent.

[0048] Preparation method: UV curing resin and PUR moisture curing resin are mixed evenly in a vacuum mixer. Then, non-electromagnetic responsive filler, opaque pigment, elastic modified filler, photoinitiator and coupling agent are added in sequence. Stirring is continued until the mixture is evenly dispersed to obtain the sealant. Example 2

[0049] Weigh the following components by weight: 20 parts UV-curable resin, 50 parts PUR moisture-curable resin, 15 parts non-electromagnetic responsive filler, 5 parts non-conductive opaque pigment, 10 parts non-conductive elastic modified filler, 2 parts photoinitiator, and 1 part coupling agent. The preparation method is the same as in Example 1. Example 3

[0050] Weigh the following components by weight: 40 parts UV-curable resin, 30 parts PUR moisture-curable resin, 5 parts non-electromagnetic responsive filler, 8 parts non-conductive opaque pigment, 12 parts non-conductive elastic modified filler, 2 parts photoinitiator, and 1 part coupling agent. The preparation method is the same as in Example 1.

[0051] Comparative Example 1 The difference from Example 1 is that no non-conductive elastic modified filler is added, while the remaining components and amounts are the same.

[0052] Comparative Example 2 The difference from Example 1 is that no UV-curing resin was added, the PUR moisture-curing resin was adjusted to 70 parts, and the remaining components and amounts were the same. This comparative example cannot be UV pre-cured and relies solely on moisture curing.

[0053] Comparative Example 3 The difference from Example 1 is that no PUR moisture-curing resin was added, the UV-curing resin was adjusted to 70 parts, and the remaining components and amounts were the same. This comparative example relies solely on UV curing and does not involve deep moisture curing.

[0054] Comparative Example 4 A commercially available black foam tape (1.0mm thick, 1.0mm wide) for display panel bezels was selected as a control. This foam tape consists of a polyurethane foam substrate and a double-sided pressure-sensitive adhesive layer.

[0055] Comparative Example 5 Norland Trishield® series two-component high-temperature curing conductive adhesive was selected as a control. This product is packaged in two components, with metal or metal-plated particles as the conductive filler and a silicone base. It requires high-temperature curing at 100-150℃ and is suitable for FIP (Fixed In-Place Molding) processes. When guided by a magnetic field, it can form sharp triangular EMI conductive pads. This product features excellent conductivity. High-temperature curing can be performed according to the product instructions.

[0056] Test methods (1) Elastic recovery rate: Refer to GB / T 1681-2009 "Determination of resilience of vulcanized rubber". For the sealant or conductive adhesive samples of Examples 1-3 and Comparative Examples 5, they were injected into cylindrical molds (12 mm in diameter and 6 mm in depth), and after complete curing under their respective curing conditions, they were demolded to obtain cylindrical solid samples. For the foam tape of Comparative Example 4, samples of the same size were prepared by directly stacking. After all samples were kept at 23℃±2℃ for 24 hours, the rebound rate was tested using a rebound hammer. Each sample was tested 5 times and the average value was taken.

[0057] (2) Visible light transmittance: For the sealant or conductive adhesive samples of Examples 1-3 and Comparative Examples 5, they were coated onto a transparent PET film and fully cured under their respective curing conditions to form an adhesive layer with a thickness of 1 mm. The transmittance was tested using a UV-Vis spectrophotometer in the wavelength range of 400-700 nm, and the average value was taken. For the foam tape of Comparative Example 4, the transmittance of its substrate layer was directly tested.

[0058] (3) Volume resistivity: Refer to GB / T 1410-2006 "Test Methods for Volume Resistivity and Surface Resistivity of Solid Insulating Materials". For the sealant or conductive adhesive samples of Examples 1-3 and Comparative Examples 5, they were injected into a circular mold (50 mm in diameter and 2 mm in depth), and after complete curing under their respective curing conditions, they were demolded to obtain circular sample pieces. For the foam tape of Comparative Example 4, circular sample pieces of the same size were directly cut. The volume resistivity of each sample was tested using a high-resistivity meter.

[0059] (4) Compression stress dispersion test (simulating the risk of light leakage under pressure): For the sealant or conductive adhesive samples of Examples 1-3, the sealant was applied to the glass substrate using a magnetron sputtering process to form a rounded triangular strip with a width of 1 mm and a height of 1 mm. After complete curing according to their respective curing conditions, another glass substrate was covered, and a vertical compression load of 5 N was applied. The maximum stress peak value at the contact surface between the adhesive strip and the glass was tested using a pressure distribution measurement film. For the foam tape of Comparative Example 4, it was directly adhered to the glass substrate, and after covering it with another glass substrate, a vertical compression load of 5 N was applied to test its maximum stress peak value. For the Norland product of Comparative Example 5, a sharp triangular cross-section sample was prepared using the same process, and after complete curing under the high temperature conditions required by the product instructions, it was tested.

[0060] (5) Elastic recovery rate after high temperature and high humidity aging: The samples prepared for testing the elastic recovery rate (the cured samples of Examples 1-3 and Comparative Examples 5, and the foam tape sample of Comparative Example 4) were placed in a constant temperature and humidity chamber at 85℃ and 85%RH for 500 hours and then the elastic recovery rate was tested.

[0061] The test results are shown in Table 1.

[0062] Table 1 The test results show that the elastic recovery rates of Examples 1-3 are significantly higher than those of all comparative examples, and remain at a high level even after aging. This indicates that the synergistic effect of the non-conductive elastic modified filler and the dual-curing system of the present invention endows the adhesive strip with excellent and durable elastic recovery capabilities. The visible light transmittance of Examples 1-3 is extremely low, meeting the requirements for opacity and light blocking; comparative examples 4 (foam tape) and 5 (Nolant) have significantly higher transmittance, indicating insufficient light blocking. The volume resistivity of Examples 1-3 is high, indicating they are non-conductive materials; comparative example 5 has a lower volume resistivity. The maximum stress peak values ​​of Examples 1-3 are lower than those of all comparative examples, indicating that the rounded triangular cross-section combined with the highly elastic adhesive can more evenly distribute the compressive load and reduce localized pressure. Regarding the elastic recovery rate after aging, the decrease in elastic recovery rate of the present invention is the smallest, and the elastic recovery rate remains good after aging, while the comparative examples all show significant attenuation, indicating that the present invention has superior long-term elastic stability.

[0063] In summary, this invention achieves comprehensive performance with non-conductive, opaque, highly elastic, and low stress concentration properties, and can effectively replace foam tape for sealing display panel bezels, solving the problem of pressure-induced light leakage.

[0064] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0065] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A magnetron sputtering sealant, characterized in that, Includes: UV-curable resin, PUR moisture-curable resin, non-electromagnetic responsive filler, non-conductive opaque pigment, and non-conductive elastic modified filler. The sealant can form a rounded triangular cross-section under the action of a vertical magnetic field and is cured and set by UV-PUR dual curing. The sealant is a non-silicone system and is non-conductive, exhibiting high elastic recovery properties after curing.

2. The magnetron sputtering sealant according to claim 1, characterized in that, By weight, the sealant comprises: 15-45 parts of UV-curable resin, 25-55 parts of PUR moisture-curable resin, 3-20 parts of non-electromagnetic responsive filler, 0.5-12 parts of non-conductive opaque pigment, and 3-15 parts of non-conductive elastic modified filler.

3. The magnetron sputtering sealant according to claim 1, characterized in that, The UV-curable resin is selected from one or more of epoxy acrylate, polyurethane acrylate, polyester acrylate, and polyether acrylate; The PUR moisture-curing resin is a polyurethane prepolymer with isocyanate-terminated groups. The non-electromagnetic response filler is selected from one or more of carbonyl iron powder, iron-silicon-chromium alloy powder, amorphous soft magnetic powder, and ferrite powder, and the surface of the non-electromagnetic response filler has an insulating coating layer. The non-conductive, opaque pigment is selected from one or more of carbon black, aniline black, titanium black, and iron oxide black; The non-conductive elastic modified filler is selected from one or more of the following: core-shell structured rubber microspheres, nitrile rubber powder, polyurethane elastic microspheres, and acrylate elastic microspheres.

4. The magnetron sputtering sealant according to claim 1, characterized in that, The top of the rounded triangular cross section has a smooth arc transition, and its height-to-width ratio is 0.8:1 to 1.2:1; the sealant is black or dark-colored and opaque, with a visible light transmittance of ≤1%.

5. A molding process for a magnetron sputtering sealant, characterized in that, Includes the following steps: (1) Apply the sealant according to any one of claims 1-4 to the surface of the substrate; (2) While the adhesive is in a flowing state, a vertical magnetic field is applied to pull the adhesive to form a rounded triangular cross section, thus obtaining a pre-formed adhesive strip; (3) Perform UV pre-curing and shaping to ensure that the adhesive strip maintains the rounded triangular cross-section and has preliminary elasticity; (4) Perform deep curing of PUR moisture to achieve the final high elasticity and sealing performance of the adhesive strip.

6. The molding process according to claim 5, characterized in that, The sealant is black or dark opaque. In step (3), UV or UV-LED irradiation parameters suitable for the opaque sealant are selected so that UV light can penetrate the surface of the sealant strip to achieve effective pre-curing. The non-conductive opaque pigment and non-conductive elastic modified filler do not interfere with the moisture penetration and deep curing process in step (4).

7. The molding process according to claim 5, characterized in that, The width of the rounded triangular cross section is 0.8-1.2mm, the height is 0.8-1.2mm, and the height-to-width ratio is 0.8:1 to 1.2:

1.

8. A sealing strip, characterized in that, The sealant strip is made using the sealant according to any one of claims 1-4 or the molding process according to any one of claims 5-7. The cross-section of the sealant strip is a rounded triangle with a smooth arc transition at the top. The sealant strip has opaque properties and high elastic recovery properties.

9. The sealing strip according to claim 8, characterized in that, The sealing strip can be used to seal the frame of the display panel; the sealing strip has an elastic recovery rate of ≥85%, which can be used to disperse the concentrated stress generated during the assembly and use of the display panel; and the visible light transmittance of the sealing strip is ≤1%, which can be used to block light leakage at the edge of the display panel.

10. A display panel, characterized in that, It includes two substrates arranged opposite to each other, and a frame sealing structure disposed between the two substrates; the frame sealing structure includes the sealant according to any one of claims 1-4 or the sealing strip according to any one of claims 8-9.

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