High-transmittance screen protection film with ultra-clear layered structure and preparation method of high-transmittance screen protection film

Abstract

The invention discloses an ultra-clear layered structure high-light-transmittance screen protection film and a preparation method thereof, and relates to the technical field of screen protection films, the ultra-clear layered structure high-light-transmittance screen protection film comprises an anti-scraping layer, an optical compensation layer, a substrate layer and a pressure-sensitive adhesive layer which are sequentially arranged from outside to inside; the anti-scraping layer is prepared from the following raw materials in parts by weight: 75 to 85 parts of UV acrylic resin, 10 to 20 parts of nano SiO2, 1 to 3 parts of UV initiator and 0.1 to 0.3 part of fluorosilane modified resin. According to the invention, the SiO2 and TiO2 films are alternately deposited, light reflection is reduced by using a multilayer film interference principle, the light transmittance of the protective film is remarkably improved, visual interference caused by ambient light reflection is reduced, the display definition and color rendition degree of a screen are improved, and by using the characteristics of extremely high transparency and low birefringence of COP, the light transmittance of the protective film is improved. Scattering or polarization distortion generated when light passes through is avoided, and the optical performance is further optimized in cooperation with the optical compensation layer.

Description

Technical Field

[0001] The present invention relates to the technical field of screen protectors, and specifically to a super-clear laminated structure high-transmittance screen protector and a preparation method thereof. Background Art

[0002] Screen protectors are mainly simple plastic films, which can only play a basic physical protection role, preventing the screen from being scratched and contaminated with dust. When the device accidentally drops or is impacted, the screen protector can play a certain buffering role, reducing the direct impact of external force on the screen and lowering the risk of screen breakage. With the development of consumer electronics and display technologies, users' performance requirements for screen protectors are increasing day by day. They not only need basic scratch and wear resistance functions, but also pay more attention to high transmittance, low haze, precise optical compensation, and excellent adhesion performance.

[0003] However, in the prior art, traditional protective film substrates such as PET films have a birefringence effect, resulting in a phase difference when light passes through, causing display image distortion, and generally having a low transmittance, affecting the color reproduction and clarity of the screen. Moreover, traditional single-layer films or simple composite films cannot achieve precise optical modulation, easily leading to problems such as reflection and rainbow patterns. Summary of the Invention

[0004] The purpose of the present invention is to provide a super-clear laminated structure high-transmittance screen protector and a preparation method thereof, so as to solve the problems in the above background art that traditional protective film substrates such as PET films have a birefringence effect, resulting in a phase difference when light passes through, causing display image distortion, and generally having a low transmittance, affecting the color reproduction and clarity of the screen, and traditional single-layer films or simple composite films cannot achieve precise optical modulation, easily leading to problems such as reflection and rainbow patterns.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A super-clear laminated structure high-transmittance screen protector, comprising a scratch-resistant layer, an optical compensation layer, a substrate layer, and a pressure-sensitive adhesive layer arranged in sequence from outside to inside; the scratch-resistant layer contains the following raw materials in parts by weight: 75 - 85 parts of UV acrylic resin, 10 - 20 parts of nano-SiO2, 1 - 3 parts of UV initiator, and 0.1 - 0.3 parts of fluorosilane-modified resin; the optical compensation layer is an alternating stack of 5 - 7 layers of SiO2 film and TiO2 film; the substrate layer contains the following raw materials in parts by weight: 90 - 95 parts of cycloolefin polymer COP and 3 - 10 parts of toughening agent; the pressure-sensitive adhesive layer contains the following raw materials in parts by weight: 1 - 5 parts of modified polydimethylsiloxane, 60 - 70 parts of acrylate pressure-sensitive adhesive, and 1 - 3 parts of crosslinking agent.

[0006] Preferably, the thickness of the scratch-resistant layer is 5 - 8 μm, and the thickness of the optical compensation layer is 550 - 650 nm.

[0007] Preferably, the thickness of the substrate layer is 50 - 100 μm, and the thickness of the pressure-sensitive adhesive layer is 20 - 30 μm.

[0008] A preparation method of a super-clear layered structure high-transparency screen protector, comprising the following steps: Ⅰ. Accurately weigh cycloolefin polymer COP and a toughening agent, add them into a high-speed mixer, stir at 60 - 80 °C for 30 - 60 minutes until evenly mixed, and melt-mold the mixed material through a casting machine or an extruder to obtain a substrate COP film; Ⅱ. Fix the substrate COP film in a vacuum coating device, and alternately deposit SiO2 film and TiO2 film on the surface of the COP film by magnetron sputtering. After coating, keep the vacuum state for 30 minutes, slowly introduce dry nitrogen, and take out the film for standby; Ⅲ. Add UV acrylic resin, nano-SiO2, UV initiator, and fluorosilane-modified resin into a reaction kettle, stir at room temperature for 1 - 2 hours to form a uniform coating solution, coat it on the surface of the optical compensation layer, and perform UV curing after pre-drying treatment; Ⅳ. Place modified polydimethylsiloxane, acrylate pressure-sensitive adhesive, and a cross-linking agent in a blender, stir at low speed at room temperature for 30 - 60 minutes until completely dissolved and mixed to obtain a glue solution. Coat the glue solution evenly on one side of the substrate layer without the optical compensation layer coated, and dry at 80 - 100 °C for 10 - 15 minutes to remove the solvent; Ⅴ. After drying, perform thermal cross-linking at 100 - 120 °C for 30 - 60 minutes to form a pressure-sensitive adhesive layer with a thickness of 15 - 25 μm; Ⅵ. Place the composite film material at 40 - 50 °C for 24 - 48 hours for curing treatment to obtain a finished high-transparency screen protector; Ⅶ. Cut the finished protector according to a preset size, and store it in packages after passing the inspection.

[0009] Preferably, in step Ⅱ, the alternate deposition of SiO2 film and TiO2 film comprises the following steps: A1. SiO2 film: Using electron beam evaporation or magnetron sputtering method, with a high-purity silicon target or SiO2 target as the raw material, deposit the first layer of SiO2 on the substrate surface, with a thickness of 50 - 100 nm and a deposition rate of 0.5 - 1 nm / s; A2. TiO2 film: Switch to a titanium target or TiO2 target, introduce oxygen as a reaction gas, deposit the second layer of TiO2, with a thickness of 30 - 80 nm and a deposition rate of 0.3 - 0.8 nm / s; A3. Repeat the above steps to alternately deposit SiO2 and TiO2 films, with a total number of layers of 5 - 7, and finally form an optical compensation layer.

[0010] Preferably, in step III, the wet film formed by coating the coating solution has a thickness of 20-30 μm. The UV curing after the pre-drying treatment includes the following steps: B1. Place the film material with the coated wet film in a drying device, pre-dry it at 60-80 °C for 5-10 minutes to remove the solvent; B2. Use a medium-pressure mercury lamp UV curing device, with an irradiation energy of 800-1200 mJ / cm² and a curing time of 10-20 seconds; B3. Take it out after UV curing to form an anti-scratch layer with a thickness of 5-10 μm.

[0011] Preferably, in step IV, the wet film thickness of the uniformly coated adhesive solution is 30-50 μm.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the present invention, by alternately depositing 5-7 layers of SiO2 and TiO2 thin films, the multi-layer film interference principle is used to reduce light reflection, significantly improving the light transmittance of the protective film, while reducing the visual interference caused by ambient light reflection, improving the screen display clarity and color restoration. Utilizing the extremely high transparency and low birefringence characteristics of COP itself, scattering or polarization distortion during light passing is avoided, and the optical performance is further optimized with the cooperation of the optical compensation layer; 2. In the present invention, with UV acrylic resin as the matrix, adding nano-SiO2 particles and fluorosilane-modified resin, a wear-resistant coating with a hardness of 4H-6H is formed after curing, which can effectively resist scratches from hard objects such as keys and pen tips during daily use. At the same time, the fluorosilane component endows the surface with hydrophobicity, reducing the attachment of fingerprints and oil stains and keeping the screen clean. Through tight binding by UV curing, the substrate layer provides flexible support to avoid cracking or peeling of the coating, and the surface integrity is still maintained after long-term use; 3. In the present invention, with acrylate pressure-sensitive adhesive as the main body, compounding modified polydimethylsiloxane and cross-linking agent to form an adhesive layer with a thickness of 20-30 μm, which has both high initial adhesion for quick positioning and fitting, and low residual glue characteristics so that there is no glue residue after peeling. At the same time, the heat cross-linking process improves the temperature resistance of the adhesive layer to adapt to different usage scenarios; 4. In the present invention, after adding a toughening agent to the substrate layer, the flexibility of the film is improved, which can absorb the external impact energy, reducing the risk of screen breakage caused by dropping or squeezing, while maintaining the thin and light characteristics. The fluorosilane-modified resin of the anti-scratch layer and the COP of the substrate layer both have excellent UV aging resistance. With the cross-linked structure of the adhesive layer, the protective film is not prone to yellowing, delamination or failure in high-temperature, high-humidity or UV irradiation environments, and the service life is extended. Specific embodiments

[0013] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0014] The present invention will be further described below in conjunction with embodiments.

[0015] Embodiment 1: This embodiment provides a super-clear layered structure high-transparency screen protector, which includes a scratch-resistant layer, an optical compensation layer, a substrate layer, and a pressure-sensitive adhesive layer arranged in sequence from outside to inside; The scratch-resistant layer has a thickness of 7 μm and contains the following raw materials in parts by weight: 80 parts of UV acrylic resin, 15 parts of nano-SiO2, 2 parts of UV initiator, and 0.2 part of fluorosilane-modified resin; The optical compensation layer has a thickness of 650 nm and contains SiO2 thin films and TiO2 thin films alternately stacked and deposited in 5 layers; The substrate layer has a thickness of 80 μm and contains the following raw materials in parts by weight: 93 parts of cycloolefin polymer COP and 7 parts of toughening agent; The pressure-sensitive adhesive layer has a thickness of 22 μm and contains the following raw materials in parts by weight: 3 parts of modified polydimethylsiloxane, 65 parts of acrylate pressure-sensitive adhesive, and 2 parts of cross-linking agent; A preparation method of a super-clear layered structure high-transparency screen protector includes the following steps: Step 1: Accurately weigh cycloolefin polymer COP and toughening agent, add them to a high-speed mixer, stir at 70 °C for 45 minutes until evenly mixed, and melt-mold the mixed material through a casting machine or an extruder to obtain a substrate COP film; Step 2: Fix the substrate COP film in a vacuum coating device, and alternately deposit SiO2 thin films and TiO2 thin films on the surface of the COP film by magnetron sputtering. After coating, maintain the vacuum state for 30 minutes, slowly introduce dry nitrogen, and take out the film for standby; among them, the alternate deposition of SiO2 thin films and TiO2 thin films includes the following steps: A1. SiO2 thin film: Using electron beam evaporation or magnetron sputtering method, with high-purity silicon target or SiO2 target as raw material, deposit the first layer of SiO2 on the substrate surface, with a thickness of 80 nm and a deposition rate of 0.5 - 1 nm / s; A2. TiO2 thin film: Switch to titanium target or TiO2 target, introduce oxygen as a reaction gas, deposit the second layer of TiO2, with a thickness of 50 nm and a deposition rate of 0.3 - 0.8 nm / s; A3. Repeat the above steps to alternately deposit SiO2 and TiO2 thin films, with a total of 5 layers, and finally form an optical compensation layer; Step 3: Add UV acrylic resin, nano-SiO2, UV initiator, and fluorosilane-modified resin into a reaction kettle, stir at room temperature for 1 - 2 hours to form a uniform coating solution, coat it on the surface of the optical compensation layer, and perform UV curing after pre-drying treatment; among them, the wet film thickness formed by coating the coating solution is 25 μm, and the UV curing after pre-drying treatment includes the following steps: B1. Place the film material with the wet film coated in a drying device, pre-dry it at 60 - 80 °C for 5 - 10 minutes to remove the solvent; B2. Use a medium-pressure mercury lamp UV curing device with an irradiation energy of 1000 mJ / cm² and a curing time of 10 - 20 seconds; B3. Take it out after UV curing to form an anti-scratch layer with a thickness of 5 - 10 μm; Step 4: Place modified polydimethylsiloxane, acrylate pressure-sensitive adhesive, and cross-linking agent in a blender, stir at low speed at room temperature for 30 - 60 minutes until completely dissolved and mixed to obtain an adhesive solution, coat the adhesive solution evenly on one side of the substrate layer without the optical compensation layer coated, with a wet film thickness of 40 μm, and dry it at 90 °C for 12 minutes to remove the solvent; Step 5: After drying, perform thermal cross-linking at 110 °C for 45 minutes to form a pressure-sensitive adhesive layer with a thickness of 15 - 25 μm; Step 6: Place the composite film material at 45 °C for 36 hours for aging treatment to obtain a finished high-transparency screen protection film; Step 7: Cut the finished protection film according to the preset size, and store it in packages after passing the inspection.

[0016] Example 2: This example provides a super-clear laminated structure high-transparency screen protection film, which includes an anti-scratch layer, an optical compensation layer, a substrate layer, and a pressure-sensitive adhesive layer arranged in sequence from outside to inside; The anti-scratch layer has a thickness of 8 μm and contains the following parts by weight of raw materials: 75 parts of UV acrylic resin, 20 parts of nano-SiO2, 3 parts of UV initiator, and 0.2 parts of fluorosilane-modified resin; The optical compensation layer has a thickness of 550 nm and is an alternating stack of 5 layers of SiO2 thin films and TiO2 thin films; The substrate layer has a thickness of 100 μm and contains the following parts by weight of raw materials: 90 parts of cycloolefin polymer COP and 10 parts of toughening agent; The pressure-sensitive adhesive layer has a thickness of 20 μm and contains the following parts by weight of raw materials: 3 parts of modified polydimethylsiloxane, 65 parts of acrylate pressure-sensitive adhesive, and 2 parts of cross-linking agent; A preparation method of a super-clear laminated structure high-transparency screen protection film includes the following steps: Step 1. Accurately weigh the cycloolefin polymer COP and the toughening agent, add them to a high-speed mixer, stir at 70 °C for 45 minutes until evenly mixed, and melt-mold the mixed material through a casting machine or an extruder to obtain a base COP film; Step 2. Fix the base COP film in a vacuum coating equipment, and alternately deposit SiO2 film and TiO2 film on the surface of the COP film by magnetron sputtering method. After coating, maintain the vacuum state for 30 minutes, slowly introduce dry nitrogen, and take out the film for standby; Among them, the alternate deposition of SiO2 film and TiO2 film includes the following steps: A1. SiO2 film: Adopt electron beam evaporation or magnetron sputtering method, use high-purity silicon target or SiO2 target as raw material, deposit the first layer of SiO2 on the surface of the base material, with a thickness of 70 nm and a deposition rate of 0.5 - 1 nm / s; A2. TiO2 film: Switch to titanium target or TiO2 target, introduce oxygen as the reaction gas, deposit the second layer of TiO2, with a thickness of 40 nm and a deposition rate of 0.3 - 0.8 nm / s; A3. Repeat the above steps to alternately deposit SiO2 and TiO2 films, with a total of 5 layers, and finally form an optical compensation layer; Step 3. Add UV acrylic resin, nano-SiO2, UV initiator and fluorosilane-modified resin to a reaction kettle, stir at room temperature for 1 - 2 hours to form a uniform coating solution, coat it on the surface of the optical compensation layer, and perform UV curing after pre-drying treatment; Among them, the wet film thickness formed by coating the coating solution is 25 μm, and the UV curing after pre-drying treatment includes the following steps: B1. Place the film material coated with the wet film in a drying equipment, pre-dry at 60 - 80 °C for 5 - 10 minutes to remove the solvent; B2. Use a medium-pressure mercury lamp UV curing equipment, with an irradiation energy of 1200 mJ / cm² and a curing time of 20 seconds; B3. Take out after UV curing to form an anti-scratch layer with a thickness of 5 - 10 μm; Step 4. Place the modified polydimethylsiloxane, acrylate pressure-sensitive adhesive and cross-linking agent in a blender, stir at low speed at room temperature for 30 - 60 minutes until completely dissolved and mixed to obtain a glue solution, evenly coat the glue solution on one side of the base material layer without the optical compensation layer, with a wet film thickness of 40 μm, and dry at 90 °C for 12 minutes to remove the solvent; Step 5. After drying, perform thermal cross-linking at 110 °C for 45 minutes to form a pressure-sensitive adhesive layer with a thickness of 15 - 25 μm; Step 6. Place the composite film material at 45 °C for 36 hours for aging treatment to obtain a finished high-transparency screen protection film; Step 7. Cut the finished protection film according to the preset size, and store it in packages after passing the inspection.

[0017] Example 3: This example provides a super-clear hierarchical structure high-transparency screen protector, which includes a scratch-resistant layer, an optical compensation layer, a substrate layer, and a pressure-sensitive adhesive layer arranged in sequence from outside to inside; The thickness of the scratch-resistant layer is 5μm, and it contains the following raw materials in parts by weight: 85 parts of UV acrylic resin, 10 parts of nano-SiO2, 1 part of UV initiator, and 0.1 part of fluorosilane-modified resin; The thickness of the optical compensation layer is 560nm, and it is a SiO2 thin film and a TiO2 thin film alternately stacked and deposited in 7 layers; The thickness of the substrate layer is 50μm, and it contains the following raw materials in parts by weight: 95 parts of cyclic olefin polymer COP and 3 parts of toughening agent; The thickness of the pressure-sensitive adhesive layer is 20μm, and it contains the following raw materials in parts by weight: 1 part of modified polydimethylsiloxane, 60 parts of acrylate pressure-sensitive adhesive, and 1 part of crosslinking agent; A preparation method of a super-clear hierarchical structure high-transparency screen protector includes the following steps: Step 1: Accurately weigh cyclic olefin polymer COP and toughening agent, add them to a high-speed mixer, stir at 60 - 80°C for 30 - 60 minutes until evenly mixed, and melt-mold the mixed material through a casting machine or an extruder to obtain a substrate COP film; Step 2: Fix the substrate COP film in a vacuum coating equipment, and alternately deposit SiO2 thin film and TiO2 thin film on the surface of the COP film by magnetron sputtering method. After coating, keep the vacuum state for 30 minutes, slowly introduce dry nitrogen, and take out the film for standby; among them, the alternate deposition of SiO2 thin film and TiO2 thin film includes the following steps: A1. SiO2 thin film: Adopt electron beam evaporation or magnetron sputtering method, use high-purity silicon target or SiO2 target as raw material, deposit the first layer of SiO2 on the substrate surface with a thickness of 50nm and a deposition rate of 0.5 - 1nm / s; A2. TiO2 thin film: Switch to titanium target or TiO2 target, introduce oxygen as reaction gas, deposit the second layer of TiO2 with a thickness of 30nm and a deposition rate of 0.3 - 0.8nm / s; A3. Repeat the above steps to alternately deposit SiO2 and TiO2 thin films with a total of 7 layers, and finally form an optical compensation layer; Step 3: Add UV acrylic resin, nano-SiO2, UV initiator, and fluorosilane-modified resin to a reaction kettle, stir at room temperature for 1 - 2 hours to form a uniform coating solution, coat it on the surface of the optical compensation layer, and perform UV curing after pre-drying treatment; among them, the wet film thickness formed by coating the coating solution is 20μm, and the UV curing after pre-drying treatment includes the following steps: B1. Place the film material after coating the wet film in a drying equipment, pre-dry it at 60 - 80 °C for 5 - 10 minutes to remove the solvent; B2. Use a medium-pressure mercury lamp UV curing equipment with an irradiation energy of 1200 mJ / cm² and a curing time of 20 seconds; B3. Take it out after UV curing to form an anti-scratch layer with a thickness of 5 - 10 μm; Step Four. Place the modified polydimethylsiloxane, acrylate pressure-sensitive adhesive, and cross-linking agent in a blender, stir at low speed at room temperature for 30 - 60 minutes until completely dissolved and mixed to obtain a glue solution. Coat the glue solution evenly on one side of the substrate layer without the coated optical compensation layer, with a wet film thickness of 40 μm, and dry it at 90 °C for 12 minutes to remove the solvent; Step Five. After drying, conduct thermal cross-linking at 110 °C for 45 minutes to form a pressure-sensitive adhesive layer with a thickness of 15 - 25 μm; Step Six. Place the composite film material at 45 °C for 36 hours for curing treatment to obtain a finished high-transparency screen protection film; Step Seven. Cut the finished protection film according to the preset size, and store it in packages after passing the inspection.

[0018] Example 4: This example provides a super-clear laminated structure high-transparency screen protection film, which includes an anti-scratch layer, an optical compensation layer, a substrate layer, and a pressure-sensitive adhesive layer arranged in sequence from outside to inside; The anti-scratch layer has a thickness of 6 μm and contains the following parts by weight of raw materials: 80 parts of UV acrylic resin, 15 parts of nano-SiO₂, 2 parts of UV initiator, and 0.2 parts of fluorosilane-modified resin; The optical compensation layer has a thickness of 600 nm and is an alternately stacked and deposited 6-layer SiO₂ thin film and TiO₂ thin film; The substrate layer has a thickness of 90 μm and contains the following parts by weight of raw materials: 92 parts of cycloolefin polymer COP and 8 parts of toughening agent; The pressure-sensitive adhesive layer has a thickness of 25 μm and contains the following parts by weight of raw materials: 5 parts of modified polydimethylsiloxane, 60 parts of acrylate pressure-sensitive adhesive, and 3 parts of cross-linking agent; A preparation method of a super-clear laminated structure high-transparency screen protection film includes the following steps: Step One. Accurately weigh cycloolefin polymer COP and toughening agent, add them to a high-speed mixer, stir at 70 °C for 45 minutes until evenly mixed, and conduct melt molding of the mixed material through a casting machine or an extruder to obtain a substrate COP film; Step 2: Fix the COP film substrate in a vacuum coating equipment. Use the magnetron sputtering method to alternately deposit SiO2 film and TiO2 film on the surface of the COP film. After coating, maintain the vacuum state for 30 minutes, slowly introduce dry nitrogen, and take out the film for standby. Among them, the steps of alternately depositing SiO2 film and TiO2 film include the following steps: A1. SiO2 film: Use the electron beam evaporation or magnetron sputtering method. Take high-purity silicon target or SiO2 target as raw material to deposit the first layer of SiO2 on the substrate surface with a thickness of 60 nm and a deposition rate of 0.5 - 1 nm / s. A2. TiO2 film: Switch to titanium target or TiO2 target, introduce oxygen as the reaction gas, deposit the second layer of TiO2 with a thickness of 40 nm and a deposition rate of 0.3 - 0.8 nm / s. A3. Repeat the above steps to alternately deposit SiO2 and TiO2 films with a total of 5 layers, and finally form an optical compensation layer. Step 3: Add UV acrylic resin, nano-SiO2, UV initiator, and fluorosilane modified resin into a reaction kettle, stir at room temperature for 1 - 2 hours to form a uniform coating solution, coat it on the surface of the optical compensation layer, and perform UV curing after pre-drying treatment. Among them, the wet film thickness formed by coating the coating solution is 25 μm, and the steps of performing UV curing after pre-drying treatment include the following steps: B1. Place the film material with the wet film coated in a drying equipment, pre-dry it at 60 - 80 °C for 5 - 10 minutes to remove the solvent. B2. Use a medium-pressure mercury lamp UV curing equipment with an irradiation energy of 1000 mJ / cm² and a curing time of 10 - 20 seconds. B3. Take out the film after UV curing to form an anti-scratch layer with a thickness of 5 - 10 μm. Step 4: Place the modified polydimethylsiloxane, acrylate pressure-sensitive adhesive, and cross-linking agent in a blender, stir at low speed at room temperature for 30 - 60 minutes until completely dissolved and mixed to obtain a glue solution. Coat the glue solution evenly on one side of the substrate layer without the optical compensation layer, with a wet film thickness of 50 μm, and dry it at 100 °C for 10 minutes to remove the solvent. Step 5: After drying, perform thermal cross-linking at 120 °C for 30 minutes to form a pressure-sensitive adhesive layer with a thickness of 15 - 25 μm. Step 6: Place the composite film material at 50 °C for 48 hours for curing treatment to obtain a finished high-transparency screen protection film. Step 7: Cut the finished protection film according to the preset size, and store it in packages after passing the inspection.

[0019] Example 5: This example provides a super-clear laminated structure high-transparency screen protection film, which includes an anti-scratch layer, an optical compensation layer, a substrate layer, and a pressure-sensitive adhesive layer arranged in sequence from outside to inside. The thickness of the scratch-resistant layer is 7 μm, and it contains the following raw materials in parts by weight: 80 parts of UV acrylic resin, 15 parts of nano-SiO₂, 2 parts of UV initiator, and 0.2 part of fluorosilane-modified resin; The thickness of the optical compensation layer is 650 nm, which is composed of 5 layers of SiO₂ thin films and TiO₂ thin films alternately stacked and deposited. The thickness of the substrate layer is 80 μm, and it contains the following raw materials in parts by weight: 93 parts of cycloolefin polymer COP and 7 parts of toughening agent; The thickness of the pressure-sensitive adhesive layer is 28 μm, and it contains the following raw materials in parts by weight: 1 part of modified polydimethylsiloxane, 65 parts of acrylate pressure-sensitive adhesive, and 3 parts of cross-linking agent; A preparation method of a super-clear laminated structure high-transparency screen protector includes the following steps: Step 1: Accurately weigh cycloolefin polymer COP and toughening agent, add them into a high-speed mixer, stir at 70 °C for 45 minutes until evenly mixed, and melt-mold the mixed material through a casting machine or an extruder to obtain a substrate COP film; Step 2: Fix the substrate COP film in a vacuum coating equipment, and alternately deposit SiO₂ thin film and TiO₂ thin film on the surface of the COP film by magnetron sputtering method. After coating, keep the vacuum state for 30 minutes, slowly introduce dry nitrogen, and take out the film for standby; Among them, the alternate deposition of SiO₂ thin film and TiO₂ thin film includes the following steps: A1. SiO₂ thin film: Using electron beam evaporation or magnetron sputtering method, with high-purity silicon target or SiO₂ target as raw material, deposit the first layer of SiO₂ on the substrate surface with a thickness of 80 nm and a deposition rate of 0.5 - 1 nm / s; A2. TiO₂ thin film: Switch to titanium target or TiO₂ target, introduce oxygen as reaction gas, deposit the second layer of TiO₂ with a thickness of 50 nm and a deposition rate of 0.3 - 0.8 nm / s; A3. Repeat the above steps to alternately deposit SiO₂ and TiO₂ thin films with a total of 5 layers, and finally form an optical compensation layer; Step 3: Add UV acrylic resin, nano-SiO₂, UV initiator, and fluorosilane-modified resin into a reaction kettle, stir at room temperature for 1 - 2 hours to form a uniform coating solution, coat it on the surface of the optical compensation layer, and perform UV curing after pre-drying treatment; Among them, the wet film thickness formed by coating the coating solution is 25 μm, and the UV curing after pre-drying treatment includes the following steps: B1. Place the film material coated with the wet film in a drying equipment, pre-dry at 60 - 80 °C for 5 - 10 minutes to remove the solvent; B2. Use a medium-pressure mercury lamp UV curing equipment, with an irradiation energy of 1000 mJ / cm² and a curing time of 10 - 20 seconds; Take it out after UV curing to form a scratch-resistant layer with a thickness of 5 - 10 μm; Step 4: Place the modified polydimethylsiloxane, acrylate pressure-sensitive adhesive, and cross-linking agent in a blender and stir at low speed for 30 - 60 minutes at room temperature until completely dissolved and mixed to obtain a glue solution. Coat the glue solution evenly on one side of the substrate layer without the optical compensation layer, with a wet film thickness of 40 μm, and dry it at 90°C for 12 minutes to remove the solvent; Step 5: After drying, conduct thermal cross-linking at 120°C for 30 minutes to form a pressure-sensitive adhesive layer with a thickness of 15 - 25 μm; Step 6: Place the composite film material at 45°C for 36 hours for curing treatment to obtain a finished high-transparency screen protection film; Step 7: Cut the finished protection film according to the preset size, and after passing the inspection, package and store it.

[0020] Comparative Example 1: A super-clear layered structure high-transparency screen protection film and its preparation method provided in this example are generally the same as those in Example 3. The main difference is that the COP in the substrate layer raw material is replaced with PET resin and there is no optical compensation layer.

[0021] Comparative Example 2: A super-clear layered structure high-transparency screen protection film and its preparation method provided in this example are generally the same as those in Example 3. The main difference is that there is no nano-SiO2 and fluorosilane-modified resin in the scratch-resistant layer raw material.

[0022] Comparative Example 3: A super-clear layered structure high-transparency screen protection film and its preparation method provided in this example are generally the same as those in Example 3. The main difference is that there is no modified polydimethylsiloxane in the pressure-sensitive adhesive layer raw material.

[0023] Performance Test and Result Analysis Conduct performance tests on the products prepared in Examples 1 - 5 and Comparative Examples 1 - 3 respectively. The detection contents include light transmittance, haze, hardness, adhesion, bending resistance, and fingerprint-proof performance, and record the relevant data in Table 1.

[0024]

[0025] As can be seen from Table 1, compared with the comparative examples, the screen protectors prepared in Examples 1-5 have significant advantages in optical properties, mechanical properties, fitting reliability and functional synergy. The low birefringence characteristics of the COP substrate cooperate with the phase difference adjustment of the optical compensation layer, making the birefringence of the COP far lower than that of PET, eliminating polarized light interference, improving the clarity of 3D display content, having less light scattering, and the light transmittance reaching 95% - 97%. Through 5-7 layers of alternating SiO2 / TiO2 films, the reflectivity is ≤1%, eliminating ambient light reflection, and through optical path difference compensation, the common "rainbow pattern" problem of OLED screens is solved. The nano-SiO2 in the scratch-resistant layer provides hardness support, and fluorosilane reduces the surface roughness. On this basis, the fingerprint-proof layer further reduces the surface energy, forming a "hard support + low adsorption" composite protection, and the fingerprint resistance performance is improved compared with the single functional layer.

[0026] In the present invention, by using the principle of multi-layer film interference to reduce light reflection, the light transmittance of the protective film is significantly improved, while reducing the visual interference caused by ambient light reflection, and improving the screen display clarity and color restoration. The substrate layer is made of a blend of cycloolefin polymer and toughening agent. The COP itself has extremely high transparency and low birefringence characteristics, avoiding light scattering or polarization distortion when light passes through. Cooperating with the optical compensation layer further optimizes the optical properties. By using UV acrylic resin as the matrix, adding nano-SiO2 particles (10-20 parts by weight) and fluorosilane-modified resin, a wear-resistant coating with a hardness of 4H - 6H (thickness 5-8μm) is formed after curing, which can effectively resist scratches from hard objects such as keys and pen tips during daily use. At the same time, the fluorosilane component imparts surface hydrophobicity, reducing the attachment of fingerprints and oil stains and keeping the screen clean. The adhesive layer is mainly composed of acrylate pressure-sensitive adhesive, compounded with modified polydimethylsiloxane and cross-linking agent, forming an adhesive layer with a thickness of 20-30μm, having both high initial adhesion (facilitating quick positioning and fitting) and low residual glue characteristics (no glue residue after peeling). At the same time, the thermal cross-linking process improves the temperature resistance of the adhesive layer (can withstand an environment of 60-80°C), adapting to different usage scenarios.

[0027] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A super-clear layered structure high-transparency screen protector, characterized in that, It includes a scratch-resistant layer, an optical compensation layer, a substrate layer, and a pressure-sensitive adhesive layer arranged from outside to inside in sequence; The scratch-resistant layer contains the following raw materials in parts by weight: 75-85 parts of UV acrylic resin, 10-20 parts of nano-SiO2, 1-3 parts of UV initiator, and 0.1-0.3 parts of fluorosilane-modified resin; The optical compensation layer is composed of 5-7 layers of SiO2 thin films and TiO2 thin films alternately stacked and deposited; The substrate layer contains the following raw materials in parts by weight: 90-95 parts of cycloolefin polymer COP and 3-10 parts of toughening agent; The pressure-sensitive adhesive layer contains the following raw materials in parts by weight: 1-5 parts of modified polydimethylsiloxane, 60-70 parts of acrylate pressure-sensitive adhesive, and 1-3 parts of crosslinking agent.

2. The super-clear layered structure high-transparency screen protector according to claim 1, characterized in that: The thickness of the scratch-resistant layer is 5-8μm, and the thickness of the optical compensation layer is 550-650nm.

3. The super-clear layered structure high-transparency screen protector according to claim 1, characterized in that: The thickness of the substrate layer is 50-100μm, and the thickness of the pressure-sensitive adhesive layer is 20-30μm.

4. A preparation method of a super-clear layered structure high-transparency screen protector, characterized in that, Using a super-clear laminated high-transparency screen protector according to any one of claims 1-3, it includes the following steps: Ⅰ. Accurately weigh cycloolefin polymer COP and toughening agent and add them to a high-speed mixer, stir at 60-80°C for 30-60 minutes until evenly mixed, and melt-mold the mixed material through a casting machine or an extruder to obtain a substrate COP film; Ⅱ. Fix the substrate COP film in a vacuum coating equipment, and alternately deposit SiO2 thin film and TiO2 thin film on the surface of the COP film by magnetron sputtering method. Keep the vacuum state for 30 minutes after coating, slowly introduce dry nitrogen, and take out the film for standby; Ⅲ. Add UV acrylic resin, nano-SiO2, UV initiator, and fluorosilane-modified resin to a reaction kettle, stir at room temperature for 1-2 hours to form a uniform coating solution, coat it on the surface of the optical compensation layer, and perform UV curing after pre-drying treatment; Ⅳ. Place modified polydimethylsiloxane, acrylate pressure-sensitive adhesive, and crosslinking agent in a blender, stir at low speed at room temperature for 30-60 minutes until completely dissolved and mixed to obtain a glue solution, evenly coat the glue solution on the side of the substrate layer without the optical compensation layer coated, and dry at 80-100°C for 10-15 minutes to remove the solvent; Ⅴ. After drying, perform thermal crosslinking at 100-120°C for 30-60 minutes to form a pressure-sensitive adhesive layer with a thickness of 15-25μm; Ⅵ. Place the composite film material at 40-50°C for 24-48 hours for aging treatment to obtain a finished high-transparency screen protector; Ⅶ. Cut the finished protector according to the preset size, and store it in packages after passing the inspection.

5. The preparation method of a super-clear layered structure high-transparency screen protector according to claim 4, characterized in that, In step Ⅱ, the alternate deposition of SiO2 thin film and TiO2 thin film includes the following steps: A1. SiO2 thin film: Using electron beam evaporation or magnetron sputtering method, with high-purity silicon target or SiO2 target as raw material, deposit the first layer of SiO2 on the substrate surface, with a thickness of 50-100nm and a deposition rate of 0.5-1nm / s; A2. TiO2 thin film: Switch to titanium target or TiO2 target, introduce oxygen as reaction gas, deposit the second layer of TiO2, with a thickness of 30-80nm and a deposition rate of 0.3-0.8nm / s; A3. Repeat the above steps to alternately deposit SiO2 and TiO2 thin films with a total number of layers of 5 - 7, and finally form an optical compensation layer.

6. The preparation method of a super-clear layered structure high-transparency screen protector according to claim 4, characterized in that, In Step III, the wet film formed by coating the coating solution has a thickness of 20 - 30 μm. The UV curing after the pre-drying treatment includes the following steps: B1. Place the film material with the coated wet film in a drying device and pre-dry it at 60 - 80 °C for 5 - 10 minutes to remove the solvent. B2. Use a medium-pressure mercury lamp UV curing device with an irradiation energy of 800 - 1200 mJ / cm² and a curing time of 10 - 20 seconds. B3. Take it out after UV curing to form an anti-scratch layer with a thickness of 5 - 10 μm.

7. The preparation method of a super-clear layered structure high-transparency screen protector according to claim 4, characterized in that, In Step IV, the wet film thickness of the uniformly coated adhesive solution is 30 - 50 μm.

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