Preparation method of modified light diffusion particles and optical diffusion film

Abstract

PMMAxPBMA1-x modified light diffusion particles containing nanoscale inorganic particle components are prepared through a simple solvothermal synthesis method, and the nanoscale inorganic particles are cross-linked to the surfaces of the light diffusion particles through the action of a coupling agent. The modified light diffusion particle has a high refractive index, and is beneficial to widening the visual angle range and maintaining the brightness at a high level.

Description

Technical Field

[0001] This invention relates to the field of optical thin film technology, and in particular to a method for preparing modified light-diffusing particles and an optical diffusion film. Background Technology

[0002] In modern flat panel display technology, liquid crystal displays (LCDs) have secured a mainstream market position due to their stable performance and relatively low price. They are widely used in various display devices such as tablets, laptops, mobile phones, e-readers, advertising display boards, LCD TVs, imaging systems, and touch panels. Optical diffusion films, as a key component in LCD optical systems, function to uniformly distribute the light emitted from the light guide plate, improve the surface uniformity of the backlight module, and prevent uneven brightness in the displayed image. They also effectively shield the dot matrix of the light guide plate. With the diversification of office and entertainment scenarios, people have increasingly higher demands for the image quality of displays. High brightness makes the image clearer under strong sunlight or artificial light. However, at high brightness, the film layer may experience glare or color shift due to excessive light, especially at wider viewing angles where brightness decays more rapidly. Wide viewing angles ensure that users receive a relatively consistent visual experience when viewing the screen from different angles, avoiding problems such as color deviation and image distortion.

[0003] CN202510518932.3 discloses a modified light-diffusing particle, its preparation method, and a diffusion film. The modified light-diffusing particle is prepared by refluxing, stirring, filtering, drying, and pulverizing PMMA spherical diffusion particles and water-based aluminum paste at a certain temperature. The modified light-diffusing particles are then coated onto the light-diffusing layer of a diffusion film to improve the film's brightness. However, this preparation process is relatively cumbersome and not conducive to large-scale production. Furthermore, the water-based aluminum paste on the PMMA surface is primarily physically bonded, lacking strong chemical bonds. When subjected to external forces such as friction and vibration, the weak physical bond structure is easily damaged. From an environmental perspective, the aluminum powder particles in the water-based aluminum paste are typically micron-sized, easily suspended in the air to form dust, which can cause harm to the human body with prolonged exposure.

[0004] CN201610651708.2 discloses a novel multifunctional light diffusing agent. Specifically, it involves reacting cerium nitrate hexahydrate with triethanolamine in an ethanol solution to obtain a triethanolamine complex. This complex is then reacted with PMMA, ammonium persulfate, and vinyltrimethoxysilane (VTMS) to ultimately yield a core-shell type light-diffusing hybrid microsphere. This light diffusing agent exhibits high temperature resistance, high transmittance, and excellent mechanical properties. A diffusing plate prepared using this agent was tested for transmittance and haze; however, the paper does not mention the high-temperature resistance and mechanical properties of the light diffusing agent.

[0005] To address the aforementioned problems, this invention provides a modified light-diffusing particle with a simple and environmentally friendly preparation process, as well as an optical diffusion film prepared from the modified diffusion particle. This optical diffusion film exhibits high brightness and low total cost of ownership (TCO). By designing a modified light-diffusing particle, this invention effectively widens the viewing angle of the display while maintaining its brightness compared to ordinary diffusion particles, thus possessing significant application value. Summary of the Invention

[0006] To alleviate the conflict between brightness and viewing angle, this invention provides a method for preparing modified light-diffusing particles and a diffusion film with high brightness and wide viewing angle.

[0007] To address the aforementioned technical problems, the present invention adopts the following technical solution.

[0008] The present invention includes a method for preparing modified light-diffusing particles and an optical diffusion film containing modified light-diffusing particles.

[0009] On the one hand, the present invention first provides a modified light-diffusing particle, the preparation method of which is as follows:

[0010] The first step involves mixing light-diffusing particles, an organic solvent, and a silane coupling agent to obtain a mixed solution of diffusion microspheres. The diffusion particles are at least one of PMMA and PBMA particles. PMMA is used... x PBMA 1-x This indicates that x = 0 to 1;

[0011] The second step is to add the precursor solution of nano-titanium dioxide to the mixed solution and stir until homogeneous.

[0012] The third step involves transferring the mixed solution into a stainless steel reactor lined with polytetrafluoroethylene and heating it at 120–200°C for 1–24 hours to obtain modified light-diffusing particles.

[0013] Furthermore, the particle size range of the modified light-diffusing particles is 0.1–30 μm, or 0.1–10 μm, 0.1–15 μm, 0.1–20 μm, or 0.1–25 μm.

[0014] Furthermore, the refractive index of the modified light-diffusing particles is 1.5 to 1.7, or 1.55, 1.57, 1.59, 1.61, 1.63, 1.65, 1.67, or 1.69.

[0015] Furthermore, the particle size of the light-diffusing particles is 0.1–30 μm, or 0.1–10 μm, 0.1–15 μm, 0.1–20 μm, or 0.1–25 μm.

[0016] Furthermore, the light-diffusing particles are made of PMMA.x PBMA 1-x Let x represent x, where x is 0, 0.1, 0.2, 0.3, 0.5, 0.7, 0.8, 0.9, 1.0.

[0017] Furthermore, the silane coupling agent is at least one of vinyltriethoxysilane (KH151), vinyltrimethoxysilane (KH171), γ-aminopropyltriethoxysilane (KH550), γ-glycidoxypropyltrimethoxysilane (KH560), γ-methacryloyloxypropyltrimethoxysilane (KH570), γ-mercaptopropyltriethoxysilane (KH580), γ-mercaptopropyltrimethoxysilane (KH590), N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane (KH602), and γ-aminopropylmethyldiethoxysilane (KH902).

[0018] Furthermore, the precursor solution of the nano-titanium dioxide is a titanate compound solution.

[0019] Furthermore, the titanate is at least one of tetraethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate.

[0020] Furthermore, the precursor solution of the nano-titanium dioxide contains hydroxycarboxylic acid.

[0021] Furthermore, the hydroxycarboxylic acid is at least one of glycolic acid, citric acid, lactic acid, and salicylic acid.

[0022] Furthermore, the titanate, hydroxycarboxylic acid, and PMMA x PBMA 1-x The mass ratio is 3:1:(5~100).

[0023] Furthermore, the mixed solution is heated in a reactor and then cooled, filtered, and dried to obtain modified light-diffusing particles.

[0024] Further, the mixed solution is transferred to a reaction vessel and heated in an oven at 120-200°C for 1-24 hours, then cooled to room temperature to obtain a modified suspension. The modified suspension is then vacuum filtered, and the filter cake is washed with ethyl acetate solvent for 60 minutes. The washed filter cake is then placed in a drying oven and heated at 60°C for 12 hours. The block material is then crushed and ground to obtain modified light-diffusing particles.

[0025] Furthermore, the oven temperature is 130°C, 140°C, 150°C, 160°C, 180°C, or 190°C.

[0026] Furthermore, the heating time of the oven is 2h, 5h, 10h, 15h, 18h, or 20h.

[0027] On the other hand, the present invention provides a method for preparing modified light-diffusing particles as follows:

[0028] The first step involves mixing light-diffusing particles, an organic solvent, and a silane coupling agent to obtain a mixed solution of diffusion microspheres. The diffusion particles are at least one of PMMA and PBMA particles. PMMA is used... x PBMA 1-x This indicates that x = 0 to 1;

[0029] The second step is to add the precursor solution of nano-titanium dioxide to the mixed solution and stir until homogeneous.

[0030] The third step involves transferring the mixed solution into a stainless steel reactor lined with polytetrafluoroethylene and heating it at 120–200°C for 1–24 hours to obtain modified light-diffusing particles.

[0031] Furthermore, a method for preparing modified light-diffusing particles is as follows:

[0032] The first step involves mixing 10-100 parts by weight of light-diffusing particles, 100 parts by weight of a mixed solvent of ethyl acetate and butanone (volume ratio 1:1), and 0.5-2 parts by weight of silane coupling agent, and ultrasonically dispersing the mixture for 60 minutes to obtain a mixed solution of diffusion microspheres.

[0033] The light-diffusing particles are at least one of PMMA and PBMA particles with a particle size of 0.1–30 μm and a refractive index of 1.49, using PMMA. x PBMA 1-x (where x = 0 to 1);

[0034] The silane coupling agent is at least one of vinyltriethoxysilane (KH151), vinyltrimethoxysilane (KH171), γ-aminopropyltriethoxysilane (KH550), γ-glycidoxypropyltrimethoxysilane (KH560), γ-methacryloyloxypropyltrimethoxysilane (KH570), γ-mercaptopropyltriethoxysilane (KH580), γ-mercaptopropyltrimethoxysilane (KH590), N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane (KH602), and γ-aminopropylmethyldiethoxysilane (KH902);

[0035] The second step is to place the PMMA x PBMA 1-x Add the precursor titanium ester compound of nano-titanium dioxide to the mixed solution, then slowly add hydroxycarboxylic acid, and stir at a constant speed for 60 min;

[0036] The third step is to transfer the mixed solution to a reaction vessel with a polytetrafluoroethylene liner, place it in an oven at 120-200°C for 1-24 hours, and cool it to room temperature to obtain a modified suspension.

[0037] The modified suspension was vacuum filtered, and the filter cake was washed with ethyl acetate solvent for 60 min.

[0038] The cleaned filter cake was placed in a drying oven and heated at 60°C for 12 hours. The block material was then crushed and ground to obtain modified light-diffusing particles.

[0039] Furthermore, the titanate, hydroxycarboxylic acid, and PMMA x PBMA 1-x The mass ratio is 3:1:(5~100).

[0040] Furthermore, the titanate is at least one of tetraethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate;

[0041] Furthermore, the hydroxycarboxylic acid is at least one of glycolic acid, citric acid, lactic acid, and salicylic acid;

[0042] Furthermore, the modified light-diffusing particles have a particle size of 0.1–30 μm and a refractive index of 1.5–1.7.

[0043] On the other hand, the present invention provides an optical diffusion film comprising a transparent substrate made of optical material, wherein a light diffusion layer is disposed on the upper surface of the transparent substrate, the diffusion layer comprising a resin film-forming material, the modified light diffusion particles of the present invention, and an additive, and an anti-adhesion layer is disposed on the lower surface of the transparent substrate, the anti-adhesion layer comprising a resin film-forming material, light diffusion particles, and an additive.

[0044] Furthermore, the substrate is selected from at least one of polyethylene terephthalate, polycarbonate, cellulose triacetate, polyamide, polyimide, polyethylene, polypropylene, or polystyrene.

[0045] Furthermore, the coating liquid of the diffusion layer includes acrylic resin oligomers, acrylic resin monomers, curing agents, dispersants, leveling agents, defoamers, modified diffusion particles, and organic solvents.

[0046] Furthermore, the coating liquid of the anti-adhesion layer includes acrylic resin oligomers, acrylic resin monomers, curing agents, light diffusing particles, dispersants, defoamers, antistatic agents, and organic solvents.

[0047] Furthermore, the acrylic resin oligomer is a heptafunctional acrylic resin oligomer, an octafunctional acrylic resin oligomer, a nonafunctional acrylic resin oligomer, or a decafunctional acrylic resin oligomer.

[0048] Furthermore, the acrylic resin oligomer is one or a combination of at least two of the following: polyurethane acrylic resin, epoxy acrylic resin, polyester acrylic resin, polyether acrylic resin, urea acrylic resin, and amino acrylic resin.

[0049] Furthermore, the acrylic resin monomer is one or a combination of at least two of the following: dipropylene glycol diacrylate resin, tripropylene glycol diacrylate resin, ethylene glycol diacrylate resin, 1,6-hexanediol diacrylate resin, neopentyl glycol diacrylate resin, trimethylolpropane triacrylate resin, pentaerythritol triacrylate resin, polymethylolpropane triacrylate resin, pentaerythritol tetraacrylate resin, dimethylolpropane tetraacrylate resin, dipentaerythritol pentaacrylate resin, and dipentaerythritol hexaacrylate resin.

[0050] Furthermore, the curing agent is one or a combination of at least two of the following curing agents: isophorone diisocyanate, hexamethylene diisocyanate, and dicyclohexylmethane diisocyanate.

[0051] Furthermore, the dispersant is one or a combination of at least two of sodium polyacrylate, polyacrylate, stearic acid, or sodium stearate.

[0052] Furthermore, the leveling agent is one or a combination of at least two of the following: acrylate leveling agents, silicone leveling agents, or fluorocarbon leveling agents.

[0053] Furthermore, the defoamer is one or a combination of at least two of the following: silicone defoamer, polyether defoamer, or mineral oil defoamer.

[0054] Furthermore, the antistatic agent is one or a combination of at least two of the following: quaternary ammonium salts, ammonium salts, alkyl sulfonates, phosphates, fatty acid esters, polyol esters, alkanolamides, alanine salts, and polyacrylic acid derivatives.

[0055] Furthermore, the diffusing particles of the anti-adhesion layer are selected from one or a combination of at least two of the light-diffusing particles in the anti-adhesion layer, namely polymethyl methacrylate, polybutyl methacrylate, polyamide, polyurethane or polystyrene.

[0056] Furthermore, the thickness of the light diffusion layer is 10–30 μm; the thickness of the anti-adhesion layer is 2–15 μm.

[0057] This invention also provides a method for preparing a light diffusion film, comprising:

[0058] Step D1: Mix the acrylic resin oligomer, acrylic resin monomer, isocyanate curing agent, dispersant, leveling agent, defoamer, diffusion particles and organic solvent evenly to prepare a diffusion coating liquid;

[0059] Step D2: Apply the diffusion coating liquid to the substrate surface, remove the solvent through a drying system, and then transfer it to an aging chamber to cure the diffusion layer;

[0060] Step D3: Thoroughly mix acrylic resin oligomer, acrylic resin monomer, isocyanate curing agent, antistatic agent, diffusion particles and organic solvent to prepare an anti-blocking coating liquid.

[0061] Step D4: Apply the anti-blocking coating liquid to the substrate surface of the semi-finished product after aging treatment, remove the solvent through the drying system, and then transfer it to the aging chamber for curing.

[0062] Compared with the prior art, the present invention has the following advantages:

[0063] PMMA containing nanoscale inorganic particles was prepared by solvothermal synthesis. x PBMA 1-x Modified light-diffusing particles are formed by cross-linking nano-sized inorganic particles onto the surface of light-diffusing particles through a coupling agent. These modified light-diffusing particles have a high refractive index, which is beneficial for widening the viewing angle range and maintaining a high level of luminance, thus possessing significant practical application value. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the preparation process for modified light-diffusing particles;

[0065] Figure 2 A schematic cross-sectional view of the diffusion membrane provided in this application;

[0066] Figure 3 Fourier infrared spectra of light-diffusing particles before and after modification in Example 1;

[0067] Figure 4 The particle size distribution diagrams of the light-diffusing particles before and after modification in Example 1, as well as the particle size comparison data of D06-D100, are shown.

[0068] Figure 5a and 5b The images show the EDS energy spectra before and after modification with light-diffusing particles in Example 1, respectively.

[0069] Figure 6 This is a high-powered microscope image of the diffusion film of Example 1 (the surface contains modified light-diffusing particles). Detailed Implementation

[0070] To better understand the structure, functional features, and advantages of the present invention, preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings:

[0071] like Figure 1As shown, the present invention provides a method for preparing modified light-diffusing particles, comprising the following steps:

[0072] Step S1: Mix 10-100 parts by weight of light-diffusing particles, 100 parts by weight of a mixed solvent of ethyl acetate and butanone (volume ratio 1:1), and 0.5-2 parts by weight of silane coupling agent, and ultrasonically disperse for 60 min to obtain a mixed solution of diffusion microspheres.

[0073] The silane coupling agent is at least one of KH151, KH171, KH550, KH560, KH570, KH580, KH590, KH602, and KH902;

[0074] Furthermore, the diffused particles are a mixture of PMMA and PBMA particles, using PMMA x PBMA 1-x Indicated by (where x = 0 to 1). The diffused particle size is 0.1 to 30 μm, and the refractive index is 1.49.

[0075] Step S2: Place the PMMA x PBMA 1-x Add the precursor titanate of nano-titanium dioxide to the mixed solution, then slowly add hydroxycarboxylic acid, and stir at a constant speed for 60 min;

[0076] Furthermore, the titanate, hydroxycarboxylic acid, and PMMA x PBMA 1-x The mass ratio is 3:1:(5~100).

[0077] Step S3: Transfer the above solution to a reaction vessel with a polytetrafluoroethylene liner, place it in an oven and heat at 120-200°C for 1-24 hours, then cool to room temperature to obtain a modified suspension;

[0078] Step S4: Vacuum filter the modified suspension and wash the solid filter cake with ethyl acetate solvent for 60 min;

[0079] Step S5: Place the cleaned filter cake into a vacuum drying oven and heat it at 60°C for 12 hours. Then crush and grind the dried material to obtain modified light-diffusing particles.

[0080] like Figure 2 As shown, the high-brightness wide-viewing-angle optical diffusion film provided by the present invention includes an upper diffusion layer 1, which contains resin 101 and modified light diffusion particles 102, a substrate layer 2 and an anti-adhesion coating 3, and the anti-adhesion layer contains resin 301 and light diffusion particles 302.

[0081] The method for preparing a high-brightness, wide-viewing-angle light diffusion film provided by this invention includes the following steps:

[0082] Step D1: Mix the acrylic resin oligomer, acrylic resin monomer, isocyanate curing agent, dispersant, leveling agent, defoamer, diffusion particles and organic solvent evenly to prepare a diffusion coating liquid;

[0083] Step D2: Apply the diffusion coating liquid to the substrate surface, remove the solvent through a drying system, and then transfer it to an aging chamber to cure the diffusion layer;

[0084] Step D3: Thoroughly mix acrylic resin oligomer, acrylic resin monomer, isocyanate curing agent, antistatic agent, diffusion particles and organic solvent to prepare an anti-blocking coating liquid.

[0085] Step D4: Apply the anti-blocking coating liquid to the substrate surface of the semi-finished product after aging treatment, remove the solvent through the drying system, and then transfer it to the aging chamber for curing.

[0086] The following are the specific implementation methods of the examples and comparative examples:

[0087] Example 1: Nano-titanium dioxide modified PMMA x PBMA 1-x Particles and their optical diffusion films

[0088] Nano-titanium dioxide modified PMMA x PBMA 1-x The particle preparation process is as follows:

[0089] Step S1: Mix 15 parts by weight of PMMA and 15 parts by weight of PBMA diffusion particles together, denoted as PMMA. 0.5 PBMA 0.5 A mixed solution of diffusion particles (the particle size range of the diffusion particles in Example 1 is 0.1-15 μm and the refractive index is 1.49), 100 parts by weight of a mixed solvent of ethyl acetate and butanone (volume ratio 1:1), and 0.5 parts by weight of KH570 silane coupling agent are mixed to obtain a mixed solution of diffusion particles.

[0090] Step S2: Place the PMMA 0.5 PBMA 0.5 Add 3 parts by weight of tetraisopropyl titanate to the mixed solution, then slowly add 1 part by weight of glycolic acid, and stir at a constant speed for 60 minutes.

[0091] Step S3: Transfer the above solution to a reaction vessel with a polytetrafluoroethylene liner, place it in an oven and heat at 180°C for 3 hours, then cool to room temperature to obtain a modified suspension;

[0092] Step S4: Vacuum filter the modified suspension and wash the solid filter cake with ethyl acetate solvent for 60 min;

[0093] Step S5: Place the cleaned filter cake in a drying oven and heat it at 60°C for 12 hours. Crush and grind the block material to obtain modified light-diffusing particles.

[0094] The modified light-diffusing particles prepared in Example 1 have a particle size of 0.1–15 μm and a refractive index of 1.59. The preparation method of the optical diffusion film is as follows:

[0095] Step D1: Mix 45 parts by weight of acrylic resin oligomer, 25 parts by weight of acrylic resin monomer, 5 parts by weight of isocyanate curing agent, 1 part by weight of dispersant, 0.5 parts by weight of leveling agent, 0.5 parts by weight of defoamer, 10 parts by weight of modified light diffusion particles and 90 parts by weight of organic solvent evenly to prepare a diffusion coating liquid.

[0096] Step D2: Apply the diffusion coating liquid to the substrate surface, remove the solvent through a drying system, and then transfer it to an aging chamber to cure the diffusion layer;

[0097] Step D3: Thoroughly mix 35 parts by weight of acrylic resin oligomer, 25 parts by weight of acrylic resin monomer, 5 parts by weight of isocyanate curing agent, 1 part by weight of antistatic agent, 0.5 parts by weight of light diffusing particles, and 100 parts by weight of organic solvent to prepare an anti-blocking coating liquid.

[0098] Step D4: Apply the anti-blocking coating liquid to the substrate surface of the semi-finished product after aging treatment, remove the solvent through the drying system, and then transfer it to the aging chamber for curing.

[0099] Example 2

[0100] Compared to Example 1, Example 2 has 7 parts by weight of modified light-diffusing particles and 3 parts by weight of unmodified light-diffusing particles. The modified light-diffusing particles prepared in Example 2 are the same as those in Example 1.

[0101] Example 3

[0102] Compared to Example 1, Example 3 had 3 parts by weight of modified light-diffusing particles and 7 parts by weight of unmodified light-diffusing particles. The modified light-diffusing particles prepared in Example 4 were the same as those in Example 1.

[0103] Example 4

[0104] Compared to Example 1, the light-diffusing particles in Example 4 have a particle size range of 0.1–30 μm. The modified light-diffusing particles prepared in Example 4 have a particle size range of 0.1–30 μm and a refractive index of 1.59.

[0105] Example 5

[0106] Compared to Example 1, in Example 5, 3 parts by weight of tetrabutyl titanate and 1 part by weight of salicylic acid were added to the mixed solution in step S2. The modified light-diffusing particles prepared in Example 5 had a particle size of 0.1–15 μm and a refractive index of 1.58.

[0107] Example 6

[0108] Compared to Example 1, Example 6 uses pure PMMA particles. The modified light-diffusing particles prepared in Example 6 have a particle size of 0.1–15 μm and a refractive index of 1.59.

[0109] Example 7

[0110] Compared to Example 1, Example 7 used pure PBMA particles. The modified light-diffusing particles prepared in Example 7 had a particle size of 0.1–15 μm and a refractive index of 1.59.

[0111] Example 8

[0112] Compared to Example 1, the reaction conditions in step S3 of Example 8 were 150°C for 6 hours. The modified light-diffusing particles prepared in Example 8 had a particle size of 0.1–15 μm and a refractive index of 1.57.

[0113] Comparative Example 1

[0114] Compared with Example 1, Comparative Example 1 did not add any modified light-diffusing particles, and the amount of unmodified light-diffusing particles was 10 parts by weight.

[0115] Comparative Example 2

[0116] Compared with Example 1, Comparative Example 1 did not add any modified light-diffusing particles, and the amount of unmodified light-diffusing particles was 15 parts by weight.

[0117] Comparative Example 3 is CH152FNS product manufactured by SKC.

[0118] The testing method for diffusion particles and diffusion films provided by this invention is as follows:

[0119] 1. Particle size: The Bettersize 2600 particle size analyzer was used, and the test was performed in accordance with the GB / T 19077-2024 standard.

[0120] 2. Infrared spectroscopy: Tested using a Thermo Nicolet iS5 Fourier transform infrared spectrometer.

[0121] 3. Microscopic morphology: Tested using a KEYENCE VK-X3000 laser microscope.

[0122] 4. Elemental composition: Measured using a Regulus-8230EDS energy dispersive spectrometer.

[0123] 5. Refractive index: Tested using a WYA-2S digital Abbe refractometer.

[0124] 6. Transmittance / Haze: The NIPPON NDH7000 haze meter was used, and the test was performed in accordance with the ASTM D1003 standard.

[0125] 7. Luminance: Tested using a KONICAMINOLTA CA410 handheld luminance meter.

[0126] 8. TCO: The TCO in the horizontal and vertical directions is tested using the Fostec SMS-1000 screen tester, and is represented as TCO-H (horizontal direction) and TCO-V (vertical direction) respectively.

[0127] 9. The transmittance, haze, brightness, and TCO of the diffusion film were tested. The optical structure for testing, from bottom to top, consisted of the reflective film, light guide plate, diffusion film, lower brightness enhancement film, upper brightness enhancement film, and LCD screen. The brightness enhancement film was an optical film manufactured by Ningbo Jizhi Technology Co., Ltd. The brightness and TCO tests were conducted using a 27-inch BOE MNT module. The optical performance test data are shown in Table 1 below:

[0128] Table 1. Test data of optical performance of diffusion film

[0129]

[0130] As can be seen from the test results of the examples and comparative examples in Table 1, the TCO of Example 1 and the SKC CH152FNS product of Comparative Example 3 are closest in luminance and TCO, and the luminance is slightly higher than that of CH152FNS. The luminance of the examples is higher than that of Comparative Examples 1 and 2, and the TCO of the examples is better than that of Comparative Examples 1 and 2. In the above examples and comparative examples, as the proportion of modified light diffusing particles increases, the haze of the diffusion film gradually increases, and the TCO level improves. The diffusion film using modified light diffusing particles has higher luminance and lower TCO level. In Comparative Examples 1 and 2, increasing the proportion of light diffusing particles is beneficial to reducing TCO; however, compared with the examples, modified light diffusing particles have a better effect on reducing TCO than unmodified light diffusing particles.

[0131] In practical applications, modified light-diffusing particles are obtained through a simple solvothermal reaction. After modification, the light-diffusing particles have a higher refractive index, which can more fully diffuse light, resulting in better light homogenization, thereby reducing TCO and widening the viewing angle range.

[0132] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. All equivalent variations and modifications made based on the content of the present invention are covered within the patent scope of the present invention.

Claims

1. A modified light diffusion particle, wherein the modified light diffusion particle is prepared by the following steps: First, light diffusion particles, an organic solvent and a silane coupling agent are mixed to obtain a mixed solution of diffusion particles, the diffusion particles being at least one of PMMA and PBMA particles, with PMMA x PBMA 1-x denotes, wherein x = 0 to 1; Step 2: adding a precursor solution of nano-titanium dioxide into the mixed solution and stirring uniformly; Step 3: moving the mixed solution into a stainless steel reaction kettle with a polytetrafluoroethylene lining, heating at 120-200℃ for 1-24h to obtain the modified light diffusion particle.

2. The modified light diffusing particle of claim 1, wherein, The particle size of the modified light diffusion particle is 0.1-30μm.

3. The modified light diffusing particle of claim 1, wherein, The refractive index of the modified light diffusion particle is 1.5-1.

7.

4. The modified light diffusing particle of claim 1, wherein, The diffusion particles are made of PMMA x PBMA 1-x wherein x is 0, 0.1, 0.2, 0.3, 0.5, 0.7, 0.8, 0.9, 1.

0.

5. A method for preparing a modified light diffusion particle, comprising the following steps: First, light diffusion particles, an organic solvent and a silane coupling agent are mixed to obtain a mixed solution of the diffusion particles, the diffusion particles being at least one of PMMA and PBMA particles, PMMA x PBMA 1-x wherein x = 0 to 1. Step 2: adding a precursor solution of nano-titanium dioxide into the mixed solution and stirring uniformly; Step 3: moving the mixed solution into a reaction kettle with a polytetrafluoroethylene lining, heating at 120-200℃ for 1-24h to obtain the modified light diffusion particle.

6. The method for preparing modified light-diffusing particles according to claim 5, characterized in that, The silane coupling agent is at least one of vinyltriethoxysilane (KH151), vinyltrimethoxysilane (KH171), γ-aminopropyltriethoxysilane (KH550), γ-glycidoxypropyltrimethoxysilane (KH560), γ-methacryloxypropyltrimethoxysilane (KH570), γ-mercaptopropyltriethoxysilane (KH580), γ-mercaptopropyltrimethoxysilane (KH590), N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane (KH602), and γ-aminopropylmethyldiethoxysilane (KH902).

7. The method for preparing modified light-diffusing particles according to claim 5, characterized in that, The precursor of nano-titanium dioxide is a titanate compound.

8. The method for preparing modified light-diffusing particles according to claim 5, characterized in that, The mixed solution is cooled, filtered and dried after heating in the reaction kettle to obtain the modified light diffusion particle.

9. An optical diffusion film, comprising a transparent substrate made of an optical material, wherein the upper surface of the transparent substrate is provided with a light diffusion layer, the diffusion layer comprises a resin film-forming material, the modified light diffusion particle of any one of claims 1-4 and an auxiliary agent, the lower surface of the transparent substrate is provided with an anti-blocking layer, and the anti-blocking layer comprises a resin film-forming material, light diffusion particles and an auxiliary agent.

10. The optical diffusion film according to claim 9, wherein The substrate is at least one of polyethylene terephthalate, polycarbonate, cellulose triacetate, polyamide, polyimide, polyethylene, polypropylene or polystyrene.

11. The optical diffusion film according to claim 9, wherein The thickness of the light diffusion layer is 10-30μm, and the thickness of the anti-blocking layer is 2-15μm.

12. A method for preparing the optical diffusion film of claims 9-11, comprising: Step D1: mixing acrylic resin oligomer, acrylic resin monomer, isocyanate curing agent, dispersant, leveling agent, defoaming agent, diffusion particles and organic solvent uniformly to prepare a diffusion coating solution; Step D2: coating the diffusion coating solution on the surface of the substrate, removing the solvent through a drying system, and then transferring to an aging oven to cure the diffusion layer; Step D3: mixing acrylic resin oligomer, acrylic resin monomer, isocyanate curing agent, antistatic agent, diffusion particles and organic solvent to prepare an anti-blocking coating solution; Step D4: coating the anti-blocking coating solution on the surface of the substrate of the semi-finished product after aging treatment, removing the solvent through a drying system, and then transferring to an aging oven for curing.

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