A high-brightness high-hiding composite optical film

Abstract

This invention discloses a high-brightness, high-coverage composite optical film, relating to the field of composite optical film technology. The high-brightness, high-coverage composite optical film comprises the following raw materials in parts by weight: 65-80 parts modified polycarbonate, 6-12 parts modified nano-titanium dioxide, 5-10 parts polymethyl methacrylate, 2-6 parts zirconium oxide, 1-3 parts calcium stearate, 0.2-0.8 parts antioxidant 1010, 0.3-0.5 parts antioxidant 168, 0.2-0.4 parts ultraviolet absorber UV-531, and 0.1-0.2 parts... The composite optical film contains the following components: 1 part UV absorber UV-400, 2-4 parts dioctyl terephthalate, 0.5-1.2 parts silane coupling agent KH-550, 0.3-1.0 parts modified nano-barium sulfate, 1-3 parts polyvinyl butyral, 1.5-3.0 parts propylene glycol monomethyl ether, 5-8 parts acrylic resin, 0.2-0.3 parts silane coupling agent KH-570, and 10-15 parts propyl acetate / propylene glycol methyl ether mixed solvent. The raw materials are scientifically formulated, including modified polycarbonate, resulting in both high brightness and high opacity. The key raw materials are modified, exhibiting excellent dispersibility and compatibility. The preparation process is standardized, with precise temperature control, stable performance, and suitability for the needs of the optical field.

Description

Technical Field

[0001] This invention relates to the field of composite optical film technology, specifically to a high-brightness, high-coverage composite optical film. Background Technology

[0002] In fields such as display technology, lighting equipment, and optical instruments, composite optical films are core optical components. Their brightness and opacity performance directly determine the visual effect and user experience of end products. The market demand for composite optical films that combine high brightness, high opacity, and stable performance is becoming increasingly urgent.

[0003] Currently available composite optical films mostly achieve their optical properties through a single substrate or by simply adding inorganic fillers, which presents significant technical shortcomings. On the one hand, traditional optical films often use ordinary polycarbonate or polymethyl methacrylate as substrates. These substrates have limited light transmittance and refractive index, and their compatibility with functional fillers such as titanium dioxide and zirconium oxide is poor, easily leading to filler agglomeration. This results in insufficient film brightness, making it difficult to meet the high brightness requirements of high-definition display devices. On the other hand, to improve opacity, some products increase the amount of filler added. However, excessive filler can disrupt the uniformity of the film structure, causing problems such as decreased film surface flatness and weakened mechanical properties. At the same time, traditional fillers have not undergone targeted modification treatment, resulting in poor dispersion stability, which further exacerbates the fluctuations in the film's optical performance.

[0004] Furthermore, there is room for improvement in the existing manufacturing processes for composite optical films. For example, in the raw material pretreatment stage, there is a lack of precise standards for controlling the drying temperature and particle size of different components, which can easily leave trace amounts of moisture or coarse particle impurities, affecting the stability of subsequent extrusion and stretching processes. In the coating and shaping process, improper control of parameters such as temperature and rotation speed can lead to insufficient coating curing and large deviations in film thickness uniformity, ultimately reducing the optical consistency and service life of the product.

[0005] Meanwhile, as end products develop towards lightweight and high durability, composite optical films need to improve their comprehensive performance, such as weather resistance and anti-aging properties, while ensuring optical performance. However, existing products mostly focus on optimizing a single optical index, making it difficult to achieve synergistic improvement of multiple performances and failing to fully meet the high-end application needs in fields such as display and lighting. Therefore, developing a composite optical film with reasonable raw material compatibility, precise preparation process, high brightness and high opacity, and excellent comprehensive performance has become a key direction for industry development. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a high-brightness, high-coverage composite optical film, which solves the problems of insufficient brightness, poor coverage, and unstable performance.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A high-brightness, high-coverage composite optical film comprises the following raw materials in parts by weight: 65-80 parts modified polycarbonate, 6-12 parts modified nano-titanium dioxide, 5-10 parts polymethyl methacrylate, 2-6 parts zirconium oxide, 1-3 parts calcium stearate, 0.2-0.8 parts antioxidant 1010, 0.3-0.5 parts antioxidant 168, 0.2-0.4 parts ultraviolet absorber UV-531, and 0.1-0. 2 parts UV absorber UV-400, 2-4 parts dioctyl terephthalate, 0.5-1.2 parts silane coupling agent KH-550, 0.3-1.0 parts modified nano barium sulfate, 1-3 parts polyvinyl butyral, 1.5-3.0 parts propylene glycol monomethyl ether, 5-8 parts acrylic resin, 0.2-0.3 parts silane coupling agent KH-570, and 10-15 parts propyl acetate / propylene glycol monomethyl ether mixed solvent.

[0008] Furthermore, the acrylic resin has a solid content of 35%-40%, which ensures that the coating film has both adhesion and optical transparency after formation, avoiding the coating being too thin or insufficiently opaque due to too low a solid content, or the coating being brittle due to too high a solid content; the volume ratio of propyl acetate to propylene glycol methyl ether in the mixed solvent is 7:3, which can fully dissolve the acrylic resin and control the coating drying rate, preventing coating bubbles from forming due to excessively fast solvent evaporation or affecting production efficiency due to excessively slow solvent evaporation, and ensuring coating uniformity and film surface gloss.

[0009] Furthermore, the modified nano-barium sulfate has a particle size of 20-40 nm and a secondary agglomerate D50 < 150 nm, which can reduce particle agglomeration and ensure optical dispersion. It is modified with silane coupling agent KH-570, specifically as follows: 100 g of nano-barium sulfate powder is added to a high-speed mixer and premixed at 900 r / min for 5 min at room temperature. Then, a mixed solution of 2 g of silane coupling agent KH-570 and 4 mL of anhydrous ethanol is added dropwise. The mixture is heated to 90 °C and stirred at 1200 r / min for 20 min to obtain the modified nano-barium sulfate. The modified nano-barium sulfate exhibits significantly improved compatibility with organic substrates, can be uniformly dispersed, and enhances light scattering effects, synergistically improving the film's hiding power while avoiding abnormal increases in haze caused by agglomeration.

[0010] The modification process of nano-barium sulfate first involves breaking up the initial agglomeration of nano-barium sulfate through mechanical stirring to increase the specific surface area; then, the silane coupling agent KH-570 is diluted with anhydrous ethanol to ensure uniform contact with the particle surface, and the alkoxy groups of the coupling agent undergo hydrolysis and condensation reaction with the hydroxyl groups on the particle surface; finally, the reaction is accelerated by heating and high-speed stirring is used to ensure uniform grafting, allowing organic groups to be grafted onto the particle surface, improving compatibility with organic substrates and reducing agglomeration.

[0011] Furthermore, the modified nano-titanium dioxide is prepared using the following specific steps: A1. Add nano-titanium dioxide to a 95% ethanol solution and ultrasonically disperse at 400W for 30-40 min to form a uniform suspension; add a mixture of silane coupling agent KH-570 and deionized water dropwise, and stir at 70-80℃ at 300-400 r / min for 2-3 h; after the reaction is complete, centrifuge to separate the product, wash with ethanol 3-4 times, and vacuum dry at 80-90℃ for 4-5 h to obtain the first modified nano-titanium dioxide; In A1, the ethoxy group of the silane coupling agent KH-570 hydrolyzes in an ethanol-water system to generate silanol. The silanol condenses with the hydroxyl groups on the surface of titanium dioxide particles to form Si-O-Ti covalent bonds, which effectively inhibits the photocatalytic active center of titanium dioxide and suppresses the ultraviolet degradation of polycarbonate. At the same time, it introduces polymerizable double bonds, providing an "anchor point" for subsequent coating and improving the interfacial compatibility between particles and resin.

[0012] A2. Add the first-modified nano-titanium dioxide and sodium dodecyl sulfate to an ethanol-water mixture with a volume ratio of 1:1, and stir at 250-350 r / min for 10-15 min; then simultaneously add 0.20 mol·L⁻¹ dropwise at a rate of 2 mL / min. -1 Aqueous solution of cerium nitrate hexahydrate and 0.20 mol·L⁻¹ -1 After the aqueous solution of lanthanum nitrate hexahydrate is stirred evenly, 1.0 mol·L⁻¹ is slowly added dropwise. -1 The pH of the solution was adjusted to 9-10 with ammonia water, and the reaction was stirred at 350-450 r / min at 60-70℃ for 1.5-2.5 h. After standing and aging for 1.5 h, the precipitate was collected by suction filtration, washed with deionized water until the filtrate was neutral, and the precipitate was dried at 100-110℃ for 5-6 h, and then calcined at 450℃ for 2 h to obtain the second modified nano titanium dioxide. In A2, sodium dodecyl sulfate first forms a negatively charged micelle network, ensuring uniform dispersion of the first-modified nano-titanium dioxide particles. With the addition of ammonia, the system becomes alkaline, causing Ce³⁺, La³⁺, and OH⁻ to co-precipitate at the micelle-particle interface, forming Ce-La hydroxides that uniformly coat the surface of the first-modified nano-titanium dioxide. After drying and calcination, the hydroxides dehydrate and transform into high-refractive-index cerium oxide-lanthanum oxide nano-islands, which reflect and scatter visible light, enhancing film brightness and inhibiting photocatalytic reactions, thus reducing the risk of substrate aging.

[0013] A3. Add the second modified nano-titanium dioxide to toluene, ultrasonically disperse at 400W for 30-40 min, add sodium dodecylbenzenesulfonate and stir at 250-350 r / min for 10-15 min; then add methyl methacrylate and azobisisobutyronitrile, and react under nitrogen protection at 65-75℃ with stirring at 400-500 r / min for 3-4 h; after the reaction is completed, centrifuge, wash with toluene 2-3 times, and vacuum dry at 70-80℃ for 6-7 h to obtain modified nano-titanium dioxide.

[0014] In A3, azobisisobutyronitrile initiates the graft polymerization of methyl methacrylate on the particle surface to form a polymethyl methacrylate shell, which simultaneously improves optical transparency and mechanical properties.

[0015] Furthermore, the ratio of nano-titanium dioxide, ethanol solution, silane coupling agent KH-570, and deionized water in A1 is 10g: 80-120mL: 0.8-1.5g: 3-5mL.

[0016] Furthermore, the ratio of the first modified nano-titanium dioxide, ethanol-water mixture, sodium dodecyl sulfate, cerium nitrate hexahydrate aqueous solution, and lanthanum nitrate hexahydrate aqueous solution in A2 is 10g: 200-300mL: 0.3-0.6g: 6.0-11.5mL: 3.5-7.0mL.

[0017] Furthermore, the ratio of the amount of the second modified nano-titanium dioxide, toluene, sodium dodecylbenzenesulfonate, methyl methacrylate, and azobisisobutyronitrile in A3 is 10g: 100-150mL: 0.4-0.8g: 2.0-3.5g: 0.08-0.15g.

[0018] Furthermore, the modified polycarbonate is prepared using the following specific steps: B1. Add polycarbonate powder, epoxy resin E-44, dicumyl peroxide, triethylamine, and phosphite to a high-speed mixer and premix for 20-30 min at 80-90℃ and 800-1000 r / min. Add the premix to a twin-screw extruder and control the temperature of each zone as follows: Zone 1 160-180℃, Zone 2 220-240℃, Zone 3 240-250℃, Zone 4 230-240℃, screw speed 250-350 r / min, residence time 35 s for reactive extrusion grafting. The extrudate is water-cooled and pelletized, and then vacuum-dried at 90-100℃ for 5-6 h to obtain the first modified polycarbonate. Under high temperature conditions, dicumyl peroxide undergoes a cracking reaction to generate free radicals. Under the action of free radicals and catalysts, epoxy resin undergoes ring-opening reaction with the active sites on the polycarbonate chain, or forms an interpenetrating network structure, thereby improving the polarity and compatibility of polycarbonate.

[0019] B2. The first modified polycarbonate was added to xylene and dissolved by stirring at 350-450 r / min at 110-120℃. Then maleic anhydride, dicumyl peroxide and antioxidant 168 were added and reacted by stirring at 400-500 r / min for 2-3 h under nitrogen protection. After the reaction was completed, the product was cooled to room temperature and poured into isopropanol at 20-30℃. The product was stirred at 150-250 r / min to precipitate. After filtration, the product was washed 2-3 times with isopropanol and dried under vacuum at 80-90℃ for 4-5 h to obtain the second modified polycarbonate. Dicumyl peroxide is used again to generate free radicals, which initiate an olefin addition reaction between maleic anhydride and polycarbonate molecular chains, forming a polycarbonate-grafted maleic anhydride comb structure. The anhydride groups introduced by maleic anhydride have high reactivity and can undergo ring-opening reactions with the hydroxyl and amino groups of other substances. This not only increases the surface polarity of polycarbonate, making the coating spread more evenly on its surface and significantly reducing the pinhole rate, but also provides secondary crosslinking sites for subsequent organosilicon modification.

[0020] B3. Add the second modified polycarbonate to tetrahydrofuran and stir at 300-400 r / min at 50-60℃ until completely dissolved; then add organosilicon resin, adjust the pH to 4-5 with 37% hydrochloric acid, add dibutyltin dilaurate, and stir at 350-450 r / min at 70-80℃ for 2.5-3.5 h; after the reaction is completed, remove part of the solvent by vacuum distillation at -0.09 MPa and 40-50℃, retaining 60%-70% solid content to obtain modified polycarbonate resin.

[0021] Under the catalysis of hydrochloric acid, hydroxyl-terminated silicone resins mainly undergo ring-opening addition reactions with anhydride groups on the surface of polycarbonate. Through condensation reactions, the hydroxyl groups between silicone resin molecules ultimately graft silicone side chains containing Si-OC and Si-O-Si structures onto the polycarbonate molecular chain, forming a stable modified resin. This enhances the structural stability of polycarbonate and significantly reduces the thermal shrinkage rate of the film.

[0022] Furthermore, the ratio of polycarbonate powder, epoxy resin E-44, dicumyl peroxide, triethylamine, and phosphite in B1 is 100g: 5-10g: 0.3-0.6g: 0.5-1.0mL: 0.2-0.5g.

[0023] Furthermore, the ratio of the first modified polycarbonate, xylene, maleic anhydride, dicumyl peroxide, and antioxidant 168 in B2 is 100g: 300-500mL: 3-6g: 0.2-0.4g: 0.1-0.3g.

[0024] Furthermore, the ratio of the second modified polycarbonate, tetrahydrofuran, organosilicon resin, hydrochloric acid, and dibutyltin dilaurate in B3 is 100g: 150-250mL: 8-15g: 0.3-0.6mL: 0.1-0.3g.

[0025] Furthermore, the silicone resin is hydroxyl-terminated, with a viscosity of 500-1500 mPa·s at 25°C and a solid content ≥98%. The hydroxyl-terminated silicone resin can form a stable cross-linked structure with modified polycarbonate; the 500-1500 mPa·s viscosity ensures uniform mixing and cross-linking, avoiding excessively high viscosity that makes dispersion difficult or excessively low viscosity that leads to insufficient cross-linking; this characteristic of the silicone resin effectively improves the weather resistance and anti-aging properties of polycarbonate without compromising the optical transparency of the film.

[0026] A method for preparing a high-brightness, high-coverage composite optical film specifically includes the following steps: S1. Polymethyl methacrylate, zirconium oxide, calcium stearate, antioxidant 1010, antioxidant 168, UV absorber UV-531, UV absorber UV-400, modified nano barium sulfate, and polyvinyl butyral are vacuum dried at 60-70℃ for 2-3 hours, and then pulverized to 80-100 mesh. Modified nano titanium dioxide and modified polycarbonate are vacuum dried at 80-90℃ for 4-5 hours, and then pulverized to 80-100 mesh. Dioctyl terephthalate and propylene glycol monomethyl ether are stirred at 40-50℃ at 200-300 r / min for 10-15 minutes to remove trace amounts of moisture. This pretreatment provides high-quality raw materials for subsequent mixing and film formation, and reduces performance defects. S2. Add the pretreated and pulverized polymethyl methacrylate, zirconium oxide, calcium stearate, antioxidant 1010, antioxidant 168, UV absorber UV-531, UV absorber UV-400, modified nano barium sulfate, polyvinyl butyral, modified nano titanium dioxide, and modified polycarbonate to a high-speed mixer. First, premix at room temperature at 600-800 rpm for 10 minutes. While maintaining the mixer, add the pretreated dioctyl terephthalate and propylene glycol monomethyl ether dropwise at a rate of 5-10 mL / min, while simultaneously adding silane coupling agent KH-550. After the dropwise addition is complete, raise the temperature to 80-90℃, increase the speed to 1200-1500 rpm, and continue stirring for 25-30 minutes to obtain a paste-like premix. The improved uniformity of the premix ensures stable film-forming performance. S3. Add the paste-like premix to the main feed port of the twin-screw extruder, and control the temperature of each section of the extruder: Zone 1 160-180℃, Zone 2 220-240℃, Zone 3 240-250℃, Zone 4 230-240℃, die head temperature 220-240℃, screw speed 300-400r / min, extrude and granulate, and vacuum dry the extruded masterbatch at 110-120℃ for 6-7h; the granulation process provides uniform particles for casting and film formation, and reduces film thickness deviation; S4. Add the dried masterbatch to the casting film machine, and control the barrel temperature: Zone 1 230-250℃, Zone 2 250-270℃, Zone 3 260-280℃, and the die temperature 250-270℃. The gradient temperature of the casting machine ensures that the masterbatch is completely melted and does not degrade, and the die temperature ensures the fluidity of the melt and avoids the appearance of streaks in the film. After the melt is extruded through the die, it is cooled and shaped by a 30-40℃ cooling roller to form a primary film with a thickness of 50-100μm. S5. The primary film is fed into a biaxial stretching machine. First, longitudinal stretching is performed at a temperature of 140-150℃ and a stretching ratio of 2.5-3 times. Then, transverse stretching is performed at a temperature of 145-155℃ and a stretching ratio of 2-2.5 times. After transverse stretching, the film is immediately placed in the tempering section and held at 140-150℃ for 8-12 minutes. This process slowly releases internal stress to reduce subsequent shrinkage. The biaxial stretching process described above can significantly enhance the strength and brightness of the film and optimize its optical performance. S6. The stretched film is placed in a heat-setting oven and heat-set at 150-160℃ for 30-40 minutes to further stabilize the film structure; then cooled to room temperature; acrylic resin, propyl acetate / propylene glycol methyl ether mixed solvent, and silane coupling agent KH-570 are added to a mixing tank and stirred at 300-400 r / min for 20-30 minutes at 25-30℃, adjusting the viscosity to 150-200 mPa·s to obtain a coating liquid; a microgravure coating method is used at a coating speed of 5-8 m / min to coat the surface of the film, with a coating thickness of 5-10 μm, and dried at 120-130℃ for 20-30 minutes; finally, the edges are trimmed and the film is spun to obtain the high-brightness, high-opacity composite optical film.

[0027] This invention provides a high-brightness, high-coverage composite optical film with the following advantages: 1. This invention utilizes a scientifically formulated blend of modified polycarbonate, modified nano-titanium dioxide, and zirconium oxide, along with multi-step modification of key raw materials. For example, the modified nano-titanium dioxide undergoes a three-layer modification process involving silane coupling agent grafting, rare earth element coating, and polymer coating. The modified polycarbonate is grafted with epoxy resin, modified with maleic anhydride, and composited with organosilicon resin. This significantly improves the compatibility and dispersibility of the raw materials, preventing optical performance loss due to filler agglomeration. Simultaneously, the synergistic effect of modified nano-titanium dioxide and nano-barium sulfate enhances light reflection and scattering, while zirconium oxide optimizes the film's refractive index. Ultimately, the composite optical film possesses both high brightness, meeting the brightness requirements of high-definition display devices, and high opacity, effectively shielding substrate defects or background stray light, thus solving the problem of traditional optical films struggling to balance brightness and opacity.

[0028] 2. During the preparation process, this invention ensures that the raw materials are fully melted and mixed to form a uniform and stable film substrate by precisely controlling the process parameters at each stage—such as the temperature of each section of the twin-screw extruder and the screw speed. In the biaxial stretching process, reasonable longitudinal and transverse stretching parameters are set, combined with tempering and heat setting treatment, to eliminate internal stress in the film and improve the crystallinity and structural density of the film. In addition, the synergistic effect of the modified polycarbonate and acrylic resin coating further enhances the tensile strength and bending resistance of the film, reduces damage and deformation caused by external forces during use, significantly extends the service life of the composite optical film, and meets the requirements of long-term stable use of end products.

[0029] 3. This invention constructs a synergistic protection system by adding antioxidants 1010 and 168, and ultraviolet absorbers UV-531 and UV-400. The antioxidants inhibit the oxidative degradation of the film during processing and use, preventing yellowing and performance degradation caused by oxidation. The ultraviolet absorbers efficiently absorb ultraviolet rays, reducing the damage of ultraviolet rays to the molecular structure of the film and slowing down the aging rate. At the same time, the modified raw material has a more stable molecular structure and stronger adhesion to the substrate, which can reduce the impact of environmental factors such as temperature changes and humidity fluctuations on the film performance. This allows the composite optical film to maintain stable optical performance and structural integrity under different usage environments, broadening its application range in display, lighting, optical instruments and other fields.

[0030] 4. This invention standardizes the entire process of composite optical film preparation, from raw material pretreatment and premix preparation to extrusion granulation, casting and shaping, biaxial stretching and coating processing, clearly defining the specific process parameter ranges to reduce human error. At the same time, the modification process of key raw materials is standardized to ensure stable and controllable raw material performance, avoid fluctuations in finished product performance due to batch differences in raw materials, make the production process easier to control, and significantly improve the consistency of finished products in terms of brightness, opacity, thickness uniformity, etc., providing a reliable guarantee for the large-scale mass production of composite optical films and reducing the defect rate in the mass production process. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0032] Example 1: Preparation of a high-brightness, high-coverage composite optical film. The specific preparation steps are as follows: S1. Polymethyl methacrylate, zirconium oxide, calcium stearate, antioxidant 1010, antioxidant 168, UV absorber UV-531, UV absorber UV-400, modified nano barium sulfate, and polyvinyl butyral were vacuum dried at 60℃ for 2 hours, and then pulverized to 80 mesh. Nano titanium dioxide and polycarbonate were vacuum dried at 80℃ for 4 hours, and then pulverized to 80 mesh. Dioctyl terephthalate and propylene glycol monomethyl ether were stirred at 200 r / min for 10 minutes at 40℃ to remove trace amounts of moisture. S2. Add 5 parts of pretreated and pulverized polymethyl methacrylate, 2 parts of zirconium oxide, 1 part of calcium stearate, 0.2 parts of antioxidant 1010, 0.3 parts of antioxidant 168, 0.2 parts of UV absorber UV-531, 0.1 parts of UV absorber UV-400, 0.3 parts of modified nano barium sulfate, 1 part of polyvinyl butyral, 6 parts of nano titanium dioxide, and 65 parts of polycarbonate to a high-speed mixer. First, premix at room temperature at 600 r / min for 10 min. While running, add 2 parts of pretreated dioctyl terephthalate and 1.5 parts of propylene glycol monomethyl ether dropwise at a rate of 5 mL / min, and simultaneously add 0.5 parts of silane coupling agent KH-550. After the dropwise addition is completed, raise the temperature to 80℃, increase the speed to 1200 r / min, and continue stirring for 25 min to obtain a paste-like premix. S3. Add the paste-like premix to the main feed port of the twin-screw extruder, and control the temperature of each section of the extruder: Zone 1 160℃, Zone 2 220℃, Zone 3 240℃, Zone 4 230℃, Die head temperature 220℃, screw speed 300r / min, extrude and granulate, and vacuum dry the extruded masterbatch at 110℃ for 6h. S4. Add the dried masterbatch into the casting film machine and control the barrel temperature: Zone 1 230℃, Zone 2 250℃, Zone 3 260℃, and die head temperature 250℃. After the melt is extruded through the die head, it is cooled and shaped by a 30℃ cooling roller to form a primary film with a thickness of 50μm. S5. Feed the primary film into the biaxial stretching machine, first perform longitudinal stretching at a temperature of 140℃ and a stretching ratio of 2.5 times; then perform transverse stretching at a temperature of 145℃ and a stretching ratio of 2 times; after the transverse stretching is completed, immediately enter the tempering section and hold at 140℃ for 8 minutes. S6. The stretched film is placed in a heat-setting oven and heat-set at 150°C for 30 minutes, then cooled to room temperature. 5 parts acrylic resin, 10 parts propyl acetate / propylene glycol methyl ether mixed solvent, and 0.2 parts silane coupling agent KH-570 are added to a mixing tank and stirred at 300 r / min for 20 minutes at 25°C. The viscosity is adjusted to 150 mPa·s to obtain the coating liquid. A microgravure coating method is used at a coating speed of 5 m / min to coat the surface of the film, with a coating thickness of 5 μm. The coating is then dried at 120°C for 20 minutes. Finally, the edges are trimmed and the film is spun to obtain the high-brightness, high-opacity composite optical film.

[0033] Example 2: Preparation of a high-brightness, high-coverage composite optical film. The specific preparation steps are as follows: S1. Polymethyl methacrylate, zirconium oxide, calcium stearate, antioxidant 1010, antioxidant 168, UV absorber UV-531, UV absorber UV-400, modified nano barium sulfate, and polyvinyl butyral were vacuum dried at 70℃ for 3 hours, and then pulverized to 100 mesh. Nano titanium dioxide and polycarbonate were vacuum dried at 90℃ for 5 hours, and then pulverized to 100 mesh. Dioctyl terephthalate and propylene glycol monomethyl ether were stirred at 300 r / min for 15 minutes at 50℃ to remove trace amounts of moisture. S2. Add 10 parts of pretreated and pulverized polymethyl methacrylate, 6 parts of zirconium oxide, 3 parts of calcium stearate, 0.8 parts of antioxidant 1010, 0.5 parts of antioxidant 168, 0.4 parts of UV absorber UV-531, 0.2 parts of UV absorber UV-400, 1.0 part of modified nano barium sulfate, 3 parts of polyvinyl butyral, 12 parts of nano titanium dioxide, and 80 parts of polycarbonate to a high-speed mixer. First, premix at room temperature at 800 r / min for 10 min. While running, add 4 parts of pretreated dioctyl terephthalate and 3.0 parts of propylene glycol monomethyl ether dropwise at a rate of 10 mL / min, and simultaneously add 1.2 parts of silane coupling agent KH-550. After the dropwise addition is completed, raise the temperature to 90℃, increase the speed to 1500 r / min, and continue stirring for 30 min to obtain a paste-like premix. S3. Add the paste-like premix to the main feed port of the twin-screw extruder, and control the temperature of each section of the extruder: Zone 1 180℃, Zone 2 240℃, Zone 3 250℃, Zone 4 240℃, Die head temperature 240℃, screw speed 400r / min, extrude and granulate, and vacuum dry the extruded masterbatch at 120℃ for 7h. S4. Add the dried masterbatch into the casting film machine and control the barrel temperature: Zone 1 250℃, Zone 2 270℃, Zone 3 280℃, and die head temperature 270℃. After the melt is extruded through the die head, it is cooled and shaped by a 40℃ cooling roller to form a primary film with a thickness of 100μm. S5. Feed the primary film into the biaxial stretching machine, first perform longitudinal stretching at a temperature of 150℃ and a stretching ratio of 3; then perform transverse stretching at a temperature of 155℃ and a stretching ratio of 2.5; after the transverse stretching is completed, immediately enter the tempering section and hold at 150℃ for 12 minutes. S6. The stretched film is placed in a heat-setting oven and heat-set at 160℃ for 40 min, then cooled to room temperature. 8 parts acrylic resin, 15 parts propyl acetate / propylene glycol methyl ether mixed solvent, and 0.3 parts silane coupling agent KH-570 are added to a mixing tank and stirred at 400 r / min for 30 min at 30℃. The viscosity is adjusted to 200 mPa·s to obtain the coating liquid. A microgravure coating method is used at a coating speed of 8 m / min to coat the surface of the film, with a coating thickness of 10 μm. The coating is then dried at 130℃ for 30 min. Finally, the edges are trimmed and the film is spun to obtain the high-brightness, high-opacity composite optical film.

[0034] Example 3: Preparation of a high-brightness, high-coverage composite optical film. The specific preparation steps are as follows: S1. Polymethyl methacrylate, zirconium oxide, calcium stearate, antioxidant 1010, antioxidant 168, UV absorber UV-531, UV absorber UV-400, modified nano barium sulfate, and polyvinyl butyral were vacuum dried at 65℃ for 2.5h, and then pulverized to 90 mesh. Nano titanium dioxide and polycarbonate were vacuum dried at 85℃ for 4.5h, and then pulverized to 90 mesh. Dioctyl terephthalate and propylene glycol monomethyl ether were stirred at 250r / min for 13min at 45℃ to remove trace amounts of moisture. S2. Add 7 parts of pretreated and pulverized polymethyl methacrylate, 4 parts of zirconium oxide, 2 parts of calcium stearate, 0.5 parts of antioxidant 1010, 0.4 parts of antioxidant 168, 0.3 parts of UV absorber UV-531, 0.15 parts of UV absorber UV-400, 0.7 parts of modified nano barium sulfate, 2 parts of polyvinyl butyral, 9 parts of nano titanium dioxide, and 72 parts of polycarbonate to a high-speed mixer. First, premix at room temperature at 700 r / min for 10 min. While running, add 3 parts of pretreated dioctyl terephthalate and 2 parts of propylene glycol monomethyl ether dropwise at a rate of 7 mL / min, and simultaneously add 0.8 parts of silane coupling agent KH-550. After the dropwise addition is completed, raise the temperature to 85℃, increase the speed to 1300 r / min, and continue stirring for 27 min to obtain a paste-like premix. S3. Add the paste-like premix to the main feed port of the twin-screw extruder, and control the temperature of each section of the extruder: Zone 1 170℃, Zone 2 230℃, Zone 3 245℃, Zone 4 235℃, Die head temperature 230℃, screw speed 350r / min, extrude and granulate, and vacuum dry the extruded masterbatch at 115℃ for 6.5h. S4. Add the dried masterbatch into the casting film machine and control the barrel temperature: Zone 1 240℃, Zone 2 260℃, Zone 3 270℃, and die head temperature 260℃. After the melt is extruded through the die head, it is cooled and shaped by a 35℃ cooling roller to form a primary film with a thickness of 75μm. S5. Feed the primary film into the biaxial stretching machine, first perform longitudinal stretching at a temperature of 145℃ and a stretching ratio of 2.7 times; then perform transverse stretching at a temperature of 150℃ and a stretching ratio of 2.2 times; after the transverse stretching is completed, immediately enter the tempering section and hold at 145℃ for 10 minutes. S6. The stretched film is placed in a heat-setting oven and heat-set at 155°C for 35 min, then cooled to room temperature. 7 parts acrylic resin, 12 parts propyl acetate / propylene glycol methyl ether mixed solvent, and 0.25 parts silane coupling agent KH-570 are added to a mixing tank and stirred at 350 r / min for 25 min at 27°C. The viscosity is adjusted to 170 mPa·s to obtain the coating liquid. A microgravure coating method is used at a coating speed of 7 m / min to coat the surface of the film, with a coating thickness of 7 μm. The coating is then dried at 125°C for 25 min. Finally, the edges are trimmed and the film is spun to obtain the high-brightness, high-opacity composite optical film.

[0035] Example 4: Preparation of modified nano-titanium dioxide. The specific preparation steps are as follows: A1. Add 10g of nano-titanium dioxide to 80mL of 95% ethanol solution and disperse by ultrasonication at 400W for 30min to form a uniform suspension; add dropwise a mixture of 0.8g of silane coupling agent KH-570 and 3mL of deionized water, and stir at 300r / min at 70℃ for 2h; after the reaction is completed, centrifuge to separate the product, wash it 3 times with ethanol, and vacuum dry it at 80℃ for 4h to obtain the first modified nano-titanium dioxide. A2. Add 10g of the first-modified nano-titanium dioxide and 0.3g of sodium dodecyl sulfate to 200mL of an ethanol-water mixture with a volume ratio of 1:1, and stir at 250r / min for 10min; then simultaneously add 6.0mL of 0.20mol·L⁻¹ solution dropwise at a rate of 2mL / min. -1 Aqueous solution of cerium nitrate hexahydrate and 3.5 mL of 0.20 mol·L⁻¹ -1 After the aqueous solution of lanthanum nitrate hexahydrate is stirred evenly, 1.0 mol·L⁻¹ is slowly added dropwise. -1 The pH of the solution was adjusted to 9 with ammonia water, and the reaction was stirred at 350 r / min at 60℃ for 1.5 h. After standing and aging for 1.5 h, the precipitate was collected by filtration, washed with deionized water until the filtrate was neutral, dried at 100℃ for 5 h, and then calcined at 450℃ for 2 h to obtain the second modified nano titanium dioxide. A3. Add 10g of the second modified nano-titanium dioxide to 100mL of toluene, and sonicate at 400W for 30min. Add 0.4g of sodium dodecylbenzenesulfonate and stir at 250r / min for 10min. Then add 2.0g of methyl methacrylate and 0.08g of azobisisobutyronitrile, and stir at 400r / min for 3h under nitrogen protection at 65℃. After the reaction is completed, centrifuge, wash twice with toluene, and vacuum dry at 70℃ for 6h to obtain modified nano-titanium dioxide.

[0036] Example 5: Preparation of modified nano-titanium dioxide. The specific preparation steps are as follows: A1. Add 10g of nano-titanium dioxide to 120mL of 95% ethanol solution and disperse by ultrasonication at 400W for 40min to form a uniform suspension; add dropwise a mixture of 1.5g of silane coupling agent KH-570 and 5mL of deionized water, and stir at 80℃ and 400r / min for 3h; after the reaction is completed, centrifuge to separate the product, wash with ethanol 4 times, and vacuum dry at 90℃ for 5h to obtain the first modified nano-titanium dioxide. A2. Add 10g of the first-modified nano-titanium dioxide and 0.6g of sodium dodecyl sulfate to 300mL of an ethanol-water mixture with a volume ratio of 1:1, and stir at 350r / min for 15min; then simultaneously add 11.5mL of 0.20mol·L⁻¹ solution dropwise at a rate of 2mL / min. -1 Aqueous solution of cerium nitrate hexahydrate and 7.0 mL of 0.20 mol·L⁻¹ -1 After the aqueous solution of lanthanum nitrate hexahydrate is stirred evenly, 1.0 mol·L⁻¹ is slowly added dropwise. -1 The pH of the solution was adjusted to 10 with ammonia water, and the reaction was stirred at 450 r / min at 70℃ for 2.5 h. After standing and aging for 1.5 h, the precipitate was collected by filtration, washed with deionized water until the filtrate was neutral, dried at 110℃ for 6 h, and then calcined at 450℃ for 2 h to obtain the second modified nano titanium dioxide. A3. Add 10g of the second modified nano-titanium dioxide to 150mL of toluene, sonicate at 400W for 40min, add 0.8g of sodium dodecylbenzenesulfonate and stir at 350r / min for 15min; then add 3.5g of methyl methacrylate and 0.15g of azobisisobutyronitrile, and stir at 500r / min for 4h under nitrogen protection at 75℃. After the reaction is completed, centrifuge, wash three times with toluene, and vacuum dry at 80℃ for 7h to obtain modified nano-titanium dioxide.

[0037] Example 6: Preparation of modified polycarbonate. The specific preparation steps are as follows: B1. Add 100g of polycarbonate powder, 5g of epoxy resin E-44, 0.3g of dicumyl peroxide, 0.5mL of triethylamine, and 0.2g of phosphite to a high-speed mixer and premix for 20min at 80℃ and 800r / min. Add the premix to a twin-screw extruder and control the temperature of each section as follows: Zone 1 160℃, Zone 2 220℃, Zone 3 240℃, Zone 4 230℃, screw speed 250r / min, residence time 35s for reactive extrusion grafting. The extrudate is water-cooled and pelletized, and then vacuum dried at 90℃ for 5h to obtain the first modified polycarbonate. B2. 100g of the first-modified polycarbonate was added to 300mL of xylene and stirred at 350r / min at 110℃ to dissolve. Then, 3g of maleic anhydride, 0.2g of dicumyl peroxide and 0.1g of antioxidant 168 were added, and the mixture was stirred at 400r / min for 2h under nitrogen protection. After the reaction was completed, the product was cooled to room temperature and poured into isopropanol at 20℃. The mixture was stirred at 150r / min to precipitate the product. After filtration, the product was washed twice with isopropanol and dried under vacuum at 80℃ for 4h to obtain the second-modified polycarbonate. B3. Add 100g of the second modified polycarbonate to 150mL of tetrahydrofuran and stir at 300r / min at 50℃ until completely dissolved; then add 8g of organosilicon resin, adjust the pH to 4 with 37% hydrochloric acid, add 0.1g of dibutyltin dilaurate, and stir at 350r / min at 70℃ for 2.5h; after the reaction is completed, remove part of the solvent by vacuum distillation at -0.09MPa and 40℃, retaining 60% solid content to obtain the modified polycarbonate.

[0038] Example 7: Preparation of modified polycarbonate. The specific preparation steps are as follows: B1. Add 100g of polycarbonate powder, 10g of epoxy resin E-44, 0.6g of dicumyl peroxide, 1.0mL of triethylamine, and 0.5g of phosphite to a high-speed mixer and premix for 30min at 90℃ and 1000r / min. Add the premix to a twin-screw extruder and control the temperature of each section as follows: Zone 1 180℃, Zone 2 240℃, Zone 3 250℃, Zone 4 240℃, screw speed 350r / min, residence time 35s for reactive extrusion grafting. The extrudate is water-cooled and pelletized, and then vacuum-dried at 100℃ for 6h to obtain the first modified polycarbonate. B2. 100g of the first-modified polycarbonate was added to 500mL of xylene and stirred at 450r / min at 120℃ to dissolve. Then, 6g of maleic anhydride, 0.4g of dicumyl peroxide and 0.3g of antioxidant 168 were added, and the mixture was stirred at 500r / min for 3h under nitrogen protection. After the reaction was completed, the product was cooled to room temperature and poured into isopropanol at 30℃. The mixture was stirred at 250r / min to precipitate the product. After filtration, the product was washed three times with isopropanol and dried under vacuum at 90℃ for 5h to obtain the second-modified polycarbonate. B3. Add 100g of the second modified polycarbonate to 250mL of tetrahydrofuran and stir at 400r / min at 60℃ until completely dissolved; then add 15g of organosilicon resin, adjust the pH value to 5 with 37% hydrochloric acid, add 0.3g of dibutyltin dilaurate, and stir at 450r / min at 80℃ for 3.5h; after the reaction is completed, remove part of the solvent by vacuum distillation at -0.09MPa and 50℃, retaining 70% solid content to obtain modified polycarbonate.

[0039] Comparative Example 1: A high-brightness, high-coverage composite optical film was prepared. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the nano-titanium dioxide in Example 3 is replaced with the modified nano-titanium dioxide prepared in Example 4, to prepare a high-brightness, high-coverage composite optical film.

[0040] Comparative Example 2: A high-brightness, high-coverage composite optical film was prepared. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the polycarbonate in Example 3 is replaced with the modified polycarbonate prepared in Example 7 to prepare a high-brightness, high-opacity composite optical film.

[0041] Comparative Example 3: A high-brightness, high-coverage composite optical film was prepared. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the nano-titanium dioxide in Example 3 is replaced with the modified nano-titanium dioxide prepared in Example 4, and the polycarbonate is replaced with the modified polycarbonate prepared in Example 7, to prepare a high-brightness, high-coverage composite optical film.

[0042] Performance testing Test Project Test Standards Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 <![CDATA[ Luminance (cd / m 2 ).]]> ASTME811 2850 3120 3380 3860 3920 4550 Coverage (contrast ratio) ASTMD2805-11 0.88 0.90 0.92 0.95 0.96 0.98 Haze (%) GB / T2410-2008 3.2 2.8 2.5 1.8 1.6 1.1 Tensile strength (MPa) GB / T1040.3-2006 45.2 48.6 51.3 56.8 58.2 63.5 UV aging resistance (brightness retention, %) GB / T16422.3-2022 78.5 81.2 83.8 88.6 89.3 94.2 Heat shrinkage rate (120℃×2h, %) GB / T13541-2009 2.1 1.8 1.5 1.2 1.0 0.6 Performance test results show that with the optimization of raw material formulation and modification of key raw materials, the overall performance of the product gradually improves. Among them, the luminance of the composite optical film of unmodified nano-titanium dioxide and modified polycarbonate in Example 3 is 3380 cd / m. 2 The properties of Comparative Example 1 (using only modified nano-titanium dioxide) and Comparative Example 2 (using only modified polycarbonate) are superior to those of Example 3. Comparative Example 3, using both modified nano-titanium dioxide and modified polycarbonate, exhibits the best performance, achieving a luminance of 4550 cd / m². The opacity (comparative ratio) is 0.92, haze is 2.5%, tensile strength is 51.3 MPa, UV aging resistance and luminance retention is 83.8%, and heat shrinkage is 1.5%. 2 The results, including a contrast ratio of 0.98 for opacity, 1.1% for haze, 63.5 MPa for tensile strength, 94.2% for UV aging resistance and 0.6% for luminance retention, and 0.6% for thermal shrinkage, fully demonstrate that the synergistic effect of modified nano-titanium dioxide and modified polycarbonate can significantly improve the luminance, opacity, mechanical properties, UV aging resistance and dimensional stability of the composite optical film.

[0043] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A high-brightness, high-coverage composite optical film, characterized in that: It contains the following raw materials in parts by weight: 65-80 parts modified polycarbonate, 6-12 parts modified nano titanium dioxide, 5-10 parts polymethyl methacrylate, 2-6 parts zirconium oxide, 1-3 parts calcium stearate, 0.2-0.8 parts antioxidant 1010, 0.3-0.5 parts antioxidant 168, 0.2-0.4 parts ultraviolet absorber UV-531, 0.1-0.2 parts ultraviolet absorber UV-400, 2-4 parts dioctyl terephthalate, 0.5-1.2 parts silane coupling agent KH-550, 0.3-1.0 parts modified nano barium sulfate, 1-3 parts polyvinyl butyral, 1.5-3.0 parts propylene glycol monomethyl ether, 5-8 parts acrylic resin, 0.2-0.3 parts silane coupling agent KH-570, and 10-15 parts propyl acetate / propylene glycol methyl ether mixed solvent.

2. The high-brightness, high-coverage composite optical film according to claim 1, characterized in that: The acrylic resin has a solid content of 35%-40%; the volume ratio of propyl acetate to propylene glycol methyl ether in the propyl acetate / propylene glycol methyl ether mixed solvent is 7:

3.

3. The high-brightness, high-coverage composite optical film according to claim 1, characterized in that: The modified nano-barium sulfate has a particle size of 20-40 nm and a secondary agglomerate D50 < 150 nm. It is modified with silane coupling agent KH-570. The specific method is as follows: 100 g of nano-barium sulfate powder is added to a high-speed mixer and premixed at 900 r / min for 5 min at room temperature. Then, a mixed solution of 2 g of silane coupling agent KH-570 and 4 mL of anhydrous ethanol is added dropwise. The temperature is raised to 90 °C and stirred at 1200 r / min for 20 min to obtain modified nano-barium sulfate.

4. The high-brightness, high-coverage composite optical film according to claim 1, characterized in that: The modified nano-titanium dioxide is prepared using the following specific steps: A1. Add nano-titanium dioxide to a 95% ethanol solution and ultrasonically disperse at 400W for 30-40 min to form a uniform suspension; add a mixture of silane coupling agent KH-570 and deionized water dropwise, and stir at 70-80℃ at 300-400 r / min for 2-3 h; after the reaction is complete, centrifuge to separate the product, wash with ethanol 3-4 times, and vacuum dry at 80-90℃ for 4-5 h to obtain the first modified nano-titanium dioxide; A2. Add the first-modified nano-titanium dioxide and sodium dodecyl sulfate to an ethanol-water mixture with a volume ratio of 1:1, and stir at 250-350 r / min for 10-15 min; then simultaneously add 0.20 mol·L⁻¹ dropwise at a rate of 2 mL / min. -1 Aqueous solution of cerium nitrate hexahydrate and 0.20 mol·L⁻¹ -1 After the aqueous solution of lanthanum nitrate hexahydrate is stirred evenly, 1.0 mol·L⁻¹ is slowly added dropwise. -1 The pH of the solution was adjusted to 9-10 with ammonia water, and the reaction was stirred at 350-450 r / min at 60-70℃ for 1.5-2.5 h. After standing and aging for 1.5 h, the precipitate was collected by suction filtration, washed with deionized water until the filtrate was neutral, and the precipitate was dried at 100-110℃ for 5-6 h, and then calcined at 450℃ for 2 h to obtain the second modified nano titanium dioxide. A3. Add the second modified nano-titanium dioxide to toluene, ultrasonically disperse at 400W for 30-40 min, add sodium dodecylbenzenesulfonate and stir at 250-350 r / min for 10-15 min; then add methyl methacrylate and azobisisobutyronitrile, and react under nitrogen protection at 65-75℃ with stirring at 400-500 r / min for 3-4 h; after the reaction is completed, centrifuge, wash with toluene 2-3 times, and vacuum dry at 70-80℃ for 6-7 h to obtain modified nano-titanium dioxide.

5. The high-brightness, high-coverage composite optical film according to claim 4, characterized in that: The ratio of nano-titanium dioxide, ethanol solution, silane coupling agent KH-570, and deionized water in A1 is 10g: 80-120mL: 0.8-1.5g: 3-5mL; The ratio of the amounts of the first modified nano-titanium dioxide, ethanol-water mixture, sodium dodecyl sulfate, cerium nitrate hexahydrate aqueous solution, and lanthanum nitrate hexahydrate aqueous solution in A2 is 10g: 200-300mL: 0.3-0.6g: 6.0-11.5mL: 3.5-7.0mL; The ratio of the amount of the second modified nano-titanium dioxide, toluene, sodium dodecylbenzenesulfonate, methyl methacrylate, and azobisisobutyronitrile in A3 is 10g: 100-150mL: 0.4-0.8g: 2.0-3.5g: 0.08-0.15g.

6. The high-brightness, high-coverage composite optical film according to claim 1, characterized in that: The modified polycarbonate is prepared using the following specific steps: B1. Add polycarbonate powder, epoxy resin E-44, dicumyl peroxide, triethylamine, and phosphite to a high-speed mixer and premix for 20-30 min at 80-90℃ and 800-1000 r / min. Add the premix to a twin-screw extruder and control the temperature of each zone as follows: Zone 1 160-180℃, Zone 2 220-240℃, Zone 3 240-250℃, Zone 4 230-240℃, screw speed 250-350 r / min, residence time 35 s for reactive extrusion grafting. The extrudate is water-cooled and pelletized, and then vacuum-dried at 90-100℃ for 5-6 h to obtain the first modified polycarbonate. B2. The first modified polycarbonate was added to xylene and dissolved by stirring at 350-450 r / min at 110-120℃. Then maleic anhydride, dicumyl peroxide and antioxidant 168 were added and reacted by stirring at 400-500 r / min for 2-3 h under nitrogen protection. After the reaction was completed, the product was cooled to room temperature and poured into isopropanol at 20-30℃. The product was stirred at 150-250 r / min to precipitate. After filtration, the product was washed 2-3 times with isopropanol and dried under vacuum at 80-90℃ for 4-5 h to obtain the second modified polycarbonate. B3. Add the second modified polycarbonate to tetrahydrofuran and stir at 300-400 r / min at 50-60℃ until completely dissolved; then add organosilicon resin, adjust the pH to 4-5 with 37% hydrochloric acid, add dibutyltin dilaurate, and stir at 350-450 r / min at 70-80℃ for 2.5-3.5 h; after the reaction is completed, remove part of the solvent by vacuum distillation at -0.09 MPa and 40-50℃, retaining 60%-70% solid content to obtain modified polycarbonate resin.

7. The high-brightness, high-coverage composite optical film according to claim 6, characterized in that: The ratio of polycarbonate powder, epoxy resin E-44, dicumyl peroxide, triethylamine, and phosphite in B1 is 100g: 5-10g: 0.3-0.6g: 0.5-1.0mL: 0.2-0.5g; The ratio of the first modified polycarbonate, xylene, maleic anhydride, dicumyl peroxide, and antioxidant 168 in B2 is 100g: 300-500mL: 3-6g: 0.2-0.4g: 0.1-0.3g; The ratio of the second modified polycarbonate, tetrahydrofuran, organosilicon resin, hydrochloric acid, and dibutyltin dilaurate in B3 is 100g: 150-250mL: 8-15g: 0.3-0.6mL: 0.1-0.3g.

8. The high-brightness, high-coverage composite optical film according to claim 6, characterized in that: The silicone resin is hydroxyl-terminated, with a viscosity of 500-1500 mPa·s at 25°C and a solid content of ≥98%.

9. A method for preparing a high-brightness, high-coverage composite optical film, characterized in that: Specifically, it includes the following steps: S1. Polymethyl methacrylate, zirconium oxide, calcium stearate, antioxidant 1010, antioxidant 168, UV absorber UV-531, UV absorber UV-400, modified nano barium sulfate, and polyvinyl butyral are vacuum dried at 60-70℃ for 2-3 hours, and then pulverized to 80-100 mesh. Modified nano titanium dioxide and modified polycarbonate are vacuum dried at 80-90℃ for 4-5 hours, and then pulverized to 80-100 mesh. Dioctyl terephthalate and propylene glycol monomethyl ether are stirred at 40-50℃ at 200-300 r / min for 10-15 minutes to remove trace amounts of moisture. S2. Add the pretreated and pulverized polymethyl methacrylate, zirconium oxide, calcium stearate, antioxidant 1010, antioxidant 168, UV absorber UV-531, UV absorber UV-400, modified nano barium sulfate, polyvinyl butyral, modified nano titanium dioxide, and modified polycarbonate to a high-speed mixer. First, premix at room temperature at 600-800 r / min for 10 min. While running the mixer, add the pretreated dioctyl terephthalate and propylene glycol monomethyl ether dropwise at a rate of 5-10 mL / min, and simultaneously add silane coupling agent KH-550. After the dropwise addition is complete, raise the temperature to 80-90℃, increase the speed to 1200-1500 r / min, and continue stirring for 25-30 min to obtain a paste-like premix. S3. Add the paste-like premix to the main feed port of the twin-screw extruder, and control the temperature of each section of the extruder: Zone 1 160-180℃, Zone 2 220-240℃, Zone 3 240-250℃, Zone 4 230-240℃, Die head temperature 220-240℃, screw speed 300-400r / min, extrude and granulate, and vacuum dry the extruded masterbatch at 110-120℃ for 6-7h. S4. Add the dried masterbatch into the casting film machine and control the barrel temperature: Zone 1 230-250℃, Zone 2 250-270℃, Zone 3 260-280℃, and the die head temperature 250-270℃. After the melt is extruded through the die head, it is cooled and shaped by a 30-40℃ cooling roller to form a primary film with a thickness of 50-100μm. S5. Feed the primary film into the biaxial stretching machine and first perform longitudinal stretching at a temperature of 140-150℃ and a stretching ratio of 2.5-3 times. Then perform transverse stretching at a temperature of 145-155℃ and a stretching ratio of 2-2.5 times. After transverse stretching is completed, immediately enter the tempering section and hold at 140-150℃ for 8-12 minutes. S6. Place the stretched film into a heat-setting oven and heat-set it at 150-160℃ for 30-40 min, then cool it to room temperature; add acrylic resin, propyl acetate / propylene glycol methyl ether mixed solvent, and silane coupling agent KH-570 into a mixing tank, stir at 300-400 r / min at 25-30℃ for 20-30 min, and adjust the viscosity to 150-200 mPa·s to obtain the coating liquid; A microgravure coating method is used at a coating speed of 5-8 m / min to coat the surface of the film with a coating thickness of 5-10 μm. The film is then dried at 120-130℃ for 20-30 min. Finally, the film is trimmed and spun to obtain the high-brightness, high-opacity composite optical film.