Nano-zirconia dispersion, its preparation method, and resulting monomer dispersion and optical film

Abstract

The present application provides a nano-zirconia dispersion in the fine chemical field, a method for preparing the same, and a monomer dispersion and an optical film obtained thereby. The nano-zirconia dispersion provided herein contains nano-zirconia particles in an amount of 45-75 wt % and has a refractive index of 1.420-1.565. Here, when the nano-zirconia particles were characterized by infrared spectroscopy, the following functional groups in the peak-out range were found on the surface of the nano-zirconia particles: hydroxyl group: 3200 cm -1 ~3600cm -1 , Zr-O-Zr: 480 cm -1 ~850cm -1 , saturated carbon-hydrogen bond: 2850 cm -1 ~2960cm -1 , ester carbonyl group: 1700cm -1 ~1750cm -1 , delocalized conjugated ester group: 1460cm -1 ~1580cm -1 , Si-O-Zr: 800 cm -1 ~1200cm -1 and CO ether bond: 1000 cm -1 ~1200cm -1 It has been found that the nano-zirconia dispersion provided in the present application has a high dispersion content, and the dispersion content of the nano-zirconia monomer dispersion obtained thereon can reach 55-85wt%, and the refractive index can reach 1.620-1.720, which can then greatly improve the refractive index of the high refractive coating layer in the process of producing, for example, a brightness enhancement film or an anti-reflection film, thereby improving the performance of the film.

Description

[Technical Field]

[0001] <Related Applications> This application claims priority to a Chinese patent application filed with the China Patent Office on September 13, 2021, bearing application number 202111067304.6 and entitled "Nanozirconia dispersion, its preparation method, and resulting monomer dispersion and optical film," the entire contents of which are incorporated herein by reference.

[0002] The present application is in the field of fine chemicals, and in particular relates to nano-zirconia dispersions, methods for their preparation, and the resulting monomer dispersions and optical films. [Background technology]

[0003] In recent years, zirconia particle dispersions have been increasingly used in the optical field by combining them with transparent resins and thin films, taking advantage of their high refractive index. For example, high-refractive-index zirconia dispersions are used in the manufacture of optical films such as brightness enhancement films and anti-reflection films, which can increase the brightness and clarity of LCD display screens. They can also improve the refractive index of LED encapsulation resins, further increasing the brightness of LEDs. In conclusion, their high refractive index properties can be used in high-refractive-index coating layers, which are used in a variety of fields.

[0004] Conventionally, the above-mentioned zirconia particle dispersions have used dispersions in which the dispersion medium is water, and in many applications of optical materials, such as the production of optical thin films, it has been common to mix an aqueous dispersion with a resin composition for use. However, because aqueous dispersions have particularly poor kneadability with water-insoluble resin compositions, there has been a strong demand in recent years for dispersions in which the dispersion medium is an organic solvent. Zirconia particles are usually fairly well dispersed in aqueous solvents, but their dispersibility in organic solvents is usually poor.

[0005] The performance of a zirconia dispersion is closely related to the crystalline structure of nanozirconia in the system, the particle dispersion state, and the dispersion preparation process. CN107001066B discloses a method for preparing highly dispersed zirconia nanoparticles and their transparent dispersions. In this preparation method, zirconia particles are directly prepared by reacting a zirconium salt with an alkali at 170°C. The water in the dispersion medium of the zirconia particles is then replaced with at least one alcohol solvent selected from methanol and ethanol. The zirconia particles in the alcohol dispersion are then surface-treated with a silane coupling agent and a 12-hydroxystearic acid surface treatment agent. Finally, the alcohol solvent of the zirconia particle alcohol dispersion is replaced with the desired organic solvent by distillation or ultrafiltration. The organic solvent dispersion of zirconia prepared by this method has a transmittance of 10% or more at a wavelength of 400 nm and 80% or more at a wavelength of 800 nm, and a viscosity of 10 mPa·s or less immediately after preparation at 25°C. However, this process requires an alcohol solvent as an intermediate phase to obtain the desired phase dispersion, which makes the preparation process complicated and expensive. In addition, the low boiling point of the alcohol solvent limits the modification temperature, causing the problem of insufficient modification.

[0006] Therefore, how to prepare a zirconia dispersion that is stable, uniformly dispersed, and has a high refractive index is particularly important to better meet the performance needs of transparent organic-inorganic composites. Summary of the Invention [Problem to be solved by the invention]

[0007] The present application provides a nano-zirconia dispersion, a method for preparing the same, and the resulting monomer dispersion and optical film, and the resulting nano-zirconia dispersion has characteristics such as good dispersion uniformity and a high refractive index. [Means for solving the problem]

[0008] To achieve the above objectives, the present application adopts the following technical solutions: A first aspect of the present invention provides a nano-zirconia dispersion, wherein the amount of nano-zirconia particles contained in the nano-zirconia dispersion is 45 to 75 wt %, and the refractive index of the nano-zirconia dispersion is 1.420 to 1.565, and when the nano-zirconia particles are characterized by infrared spectroscopy, functional groups in the following peak-out range are present on the surface of the nano-zirconia particles: Hydroxy group: 3200cm -1 ~3600cm -1 , Zr-O-Zr: 480 cm -1 ~850cm -1 , saturated carbon-hydrogen bond: 2850 cm -1 ~2960cm -1 , ester carbonyl group: 1700cm -1 ~1750cm -1 , delocalized conjugated ester group: 1460cm -1 ~1580cm -1 , Si-O-Zr: 800 cm -1 ~1200cm -1 and CO ether bond: 1000 cm -1 ~1200cm -1 was found to be grafted.

[0009] In some embodiments of the present application, the refractive index of the nano-zirconia dispersion is 1.420 to 1.535 when the zirconia content is 45% to 65%, and 1.498 to 1.565 when the zirconia content is 65% to 75%.

[0010] In some embodiments of the present application, the refractive index of the nano-zirconia particles in the nano-zirconia dispersion is 2.20 to 2.60, and the proportion of the tetragonal phase crystal grain structure in the nano-zirconia particles is 60 to 95%.

[0011] A second aspect of the present invention provides a method for preparing a nano-zirconia dispersion, the method comprising: The method includes the steps of adding an organic solvent to an aqueous zirconia solution, mixing them uniformly, adding an organic acid and a modifier to the system to modify the zirconia particles, then adding an oil-based dispersion aid, and removing water by rotary evaporation to obtain a nano-zirconia dispersion; Here, the organic acid is added in an amount of 3 to 20 wt% based on the content of nano-zirconia, the modifier is added in an amount of 5 to 20 wt% based on the content of nano-zirconia, and the oil-based dispersion aid is added in an amount of 5 to 20 wt% based on the content of nano-zirconia.

[0012] In some embodiments of the present application, modifying the zirconia particles by adding an organic acid and a modifier to the system specifically includes: Adding an organic acid and a modifier to the system at atmospheric pressure and 50 to 150°C to modify the zirconia particles; or The organic acid and the modifier are dissolved in the organic solvent, and the solution is added to a dispersion liquid obtained by mixing an aqueous zirconia solution and an organic solvent under atmospheric pressure and a temperature of 50 to 150° C., thereby modifying the zirconia particles.

[0013] In some embodiments of the present application, the organic solvent is at least one of butanone, methyl isobutyl ketone, propylene glycol methyl ether, and ethylene glycol methyl ether, and the volume ratio of the added organic solvent to the aqueous zirconia solution is (3-5):1.

[0014] In some embodiments of the present application, the organic acid is selected from at least one of saturated or unsaturated monocarboxylic acids, polycarboxylic acids, and hydroxycarboxylic acids.

[0015] In some embodiments of the present application, the monocarboxylic acid is selected from at least one of formic acid, acetic acid, propionic acid, butyric acid, isooctanoic acid, acrylic acid, and methacrylic acid; the polycarboxylic acid is selected from at least one of oxalic acid, malonic acid, succinic acid, phthalic acid, fumaric acid, and maleic acid; and the hydroxycarboxylic acid is selected from at least one of lactic acid, malic acid, tartaric acid, and citric acid.

[0016] In some embodiments of the present application, the modifier is at least one of 3-(methacryloyl oxy)propyl trimethoxy silane and 3-glycidyl ether oxypropyl trimethoxy silane.

[0017] In some embodiments of the present application, the oil-based dispersing aid is selected from at least one of an anionic dispersant, a cationic dispersant, a non-ionic dispersant, and a polymeric dispersant.

[0018] In some embodiments of the present application, the oil-based dispersing aid is selected from BYK-9076 or BYK-9077.

[0019] A third aspect of the present invention provides a nano-zirconia monomer dispersion, which is prepared by adding a photocurable resin to any one of the nano-zirconia dispersions described above, and then removing the organic solvent from the dispersion by vacuum distillation.

[0020] In some embodiments of the present application, the nano-zirconia content in the nano-zirconia monomer dispersion is 55 to 85 wt %, and the refractive index of the nano-zirconia monomer dispersion is 1.620 to 1.720.

[0021] In some embodiments of the present application, the photocurable resin is selected from acrylic or methacrylic acid monomers or oligomers thereof containing ester, urethane, ether, silicon, halogen, and / or phosphorus-containing groups, and the photocurable resin is added in an amount of 15 to 45 wt % based on the total mass of the zirconia and the photocurable resin.

[0022] In some embodiments of the present application, the photocurable resin is at least one of phenoxybenzyl acrylate, methyl acrylate, and methyl methacrylate.

[0023] A fourth aspect of the present application provides an optical film prepared using any one of the nano-zirconia dispersions described above or any one of the nano-zirconia monomer dispersions described above. [Effects of the Invention]

[0024] Compared with the prior art, the present application has the following advantages and positive effects: 1. The method for preparing nano-zirconia dispersion provided in at least one embodiment of the present application is simple in operation. The simplest method, distillation substitution, can be used directly to obtain an organic solvent dispersion by phase inversion of an aqueous zirconia dispersion, and the organic solvent dispersion can be further substituted to obtain a monomer dispersion, without the need for an intermediate phase. 2. The method for preparing nano-zirconia dispersion provided in at least one embodiment of the present application uses an organic acid, a modifier, and an oil-based dispersion aid to simultaneously act on zirconia particles, fully utilizing their synergistic effect to achieve the best dispersion effect and effectively improve the compatibility of the subsequent organic solvent dispersion with the photocurable monomer. 3. In the method for preparing nano-zirconia dispersion provided in at least one embodiment of the present application, when adding raw materials, the organic acid and modifier must be added to the dispersion system before adding the oil-based dispersion aid, so that there are enough active sites on the zirconia surface for the organic acid and modifier to interact with each other to achieve the best modification and dispersion effects. 4. In the method for preparing a nanozirconia dispersion provided in at least one embodiment of the present application, the contents of the added organic acid, modifier, and oil-based dispersion aid must be controlled within the ranges specified in the present application. If the contents are too low, the expected modification effect will not be achieved, and if the contents are too high, the opposite effect will occur and unnecessary economic losses may occur. 5. The nano-zirconia dispersion provided in at least one embodiment of the present application has a high dispersion content of nano-zirconia particles, reaching 45-75 wt%, and a refractive index of 1.420-1.565, and the nano-zirconia monomer dispersion obtained therefrom has a dispersion content of 55-85 wt%, and a refractive index of 1.620-1.720. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is an infrared spectrum diagram of the nano-zirconia dispersion provided in Example 1 of the present invention. [Figure 2] FIG. 1 is an infrared spectrum diagram of the nano-zirconia dispersion provided in Example 5 of the present invention. [Figure 3] FIG. 1 is an infrared spectrum diagram of the nano-zirconia dispersion provided in Example 6 of the present invention. [Figure 4] FIG. 1 is an infrared spectrum diagram of the nano-zirconia dispersion provided in Example 7 of the present invention. [Figure 5] FIG. 1 is an infrared spectrum diagram after adding BYK-9076 (addition amount 40%) used in an example of the present invention to zirconia. [Figure 6] FIG. 1 is an infrared spectrum diagram after adding BYK-9076 (addition amount 5%) used in an example of the present invention to zirconia. DETAILED DESCRIPTION OF THE INVENTION

[0026] The technical solutions of the embodiments of the present application will be described below clearly and completely, but it is clear that the described embodiments are only a part of the embodiments of the present application, and are not all of the embodiments. Based on the embodiments of the present application, all other embodiments that can be obtained by those skilled in the art without any creative work fall within the scope of protection of the present application.

[0027] In the description of the present application, unless otherwise specified, all contents without a clearly specified unit are mass contents, and it is understood that the above-mentioned aqueous zirconia solutions in the raw materials of the present application refer to aqueous nanozirconia solutions in order to obtain a nanozirconia dispersion.

[0028] In order to achieve the above object, the present application provides a nano-zirconia dispersion, in which the amount of nano-zirconia particles contained in the nano-zirconia dispersion is 45 to 75 wt %, and wherein, when the nano-zirconia particles are characterized by infrared spectroscopy, it is found that the nano-zirconia particles have functional groups on their surfaces in the following peak-out range: Hydroxy group: 3200cm -1 ~3600cm -1 , Zr-O-Zr: 480 cm -1 ~850cm -1 , saturated carbon-hydrogen bond: 2850 cm -1 ~2960cm -1 , ester carbonyl group: 1700cm -1 ~1750cm -1 , delocalized conjugated ester group: 1460cm -1 ~1580cm -1 , Si-O-Zr: 800 cm -1 ~1200cm -1 and CO ether bond: 1000 cm -1 ~1200cm -1 It has been found that the successful introduction of these functional groups can significantly improve the oleophilicity of zirconia particles, providing possibilities for the subsequent production of various dispersions and films thereof, as well as positively affecting the improvement of the solids content and refractive index of solvent-based and monomer-based dispersions.

[0029] In some embodiments, the refractive index of the nano-zirconia dispersion is 1.420 to 1.535 when the zirconia content is 45% to 65%, and 1.498 to 1.565 when the zirconia content is 65% to 75%.

[0030] In some embodiments, the refractive index of the nano-zirconia particles in the nano-zirconia dispersion is 2.20 to 2.60.

[0031] In some embodiments, the proportion of the tetragonal phase crystal grain structure in the nano-zirconia particles is 60 to 95%. Zirconia crystal forms are classified into monoclinic, tetragonal, and cubic phases, and it is understood that in the nano-zirconia dispersion of the present invention, the zirconia nanoparticles having the tetragonal phase crystal form represent a mass proportion of all zirconia crystal forms.

[0032] The present application also provides a method for preparing a nano-zirconia dispersion, the method comprising: The method includes the steps of adding an organic solvent to an aqueous zirconia solution and mixing them uniformly, then adding an organic acid and a modifier to the system to modify the zirconia particles, then adding an oil-based dispersion aid, and removing water by rotary evaporation to obtain a nano-zirconia dispersion.

[0033] The nano-zirconia dispersion preparation method provided in the above examples involves adding an organic acid and a modifier to a dispersion of zirconia particles mixed with water and an organic solvent, subjecting the dispersion to a lipophilic modification treatment, removing the water, and obtaining a zirconia dispersion in a pure organic solvent phase. The stability and dispersibility of the dispersion can then be enhanced by adding an oil-based dispersion aid. This solution does not require complex operations or dispersing equipment, is simple, and processing based on this method offers significant advantages over dispersions prepared using prior art methods that involve replacing the dispersing medium.

[0034] In some embodiments, modifying the zirconia particles by adding an organic acid and a modifier to the system specifically includes: Adding an organic acid and a modifier to the system at atmospheric pressure and 50 to 150°C to modify the zirconia particles; or The organic acid and the modifier are dissolved in the organic solvent, and the solution is added to a dispersion liquid obtained by mixing an aqueous zirconia solution and an organic solvent under atmospheric pressure and a temperature of 50 to 150° C., thereby modifying the zirconia particles.

[0035] In some embodiments, the volume ratio of the added organic solvent to the aqueous zirconia solution is (3-5):1.

[0036] In some embodiments, the organic solvent is at least one of butanone, methyl isobutyl ketone, propylene glycol methyl ether, and ethylene glycol methyl ether.

[0037] In some embodiments, the organic acid is selected from at least one of saturated or unsaturated monocarboxylic acids, polycarboxylic acids, and hydroxycarboxylic acids, and the organic acid is added in an amount of 3 to 20 wt % based on the content of nanozirconia.

[0038] In some embodiments, the monocarboxylic acid is selected from at least one of formic acid, acetic acid, propionic acid, butyric acid, isooctanoic acid, acrylic acid, and methacrylic acid; the polycarboxylic acid is selected from at least one of oxalic acid, malonic acid, succinic acid, phthalic acid, fumaric acid, and maleic acid; and the hydroxycarboxylic acid is selected from at least one of lactic acid, malic acid, tartaric acid, and citric acid.

[0039] In some embodiments, the modifier is at least one of 3-(methacryloyloxy)propyltrimethoxysilane and 3-glycidyletheroxypropyltrimethoxysilane, and the modifier is added in an amount of 5 to 20 wt % based on the content of the nanozirconia.

[0040] In the preparation method of nano-zirconia dispersions provided in the examples of this application, organic acids and modifiers are added to treat the surface of zirconia. This improves the lipophilicity of the zirconia particles, while also allowing the zirconia particles to be uniformly dispersed and more fully bonded to the modifier. Furthermore, the presence of the organic acid promotes hydrolysis and grafting of the modifier, while the presence of the modifier promotes grafting of the organic acid with zirconia, promoting each other. The oil-based dispersion aid also plays a positive role in promoting the grafting of the organic acid and modifier with zirconia. The amount of organic acid added may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 wt% of the nanozirconia content or any point value within the above range, and the amount of modifier added may be 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 wt% of the nanozirconia content or any point value within the above range.

[0041] In some embodiments, the oil-based dispersing aid is selected from at least one of anionic dispersants, cationic dispersants, nonionic dispersants, and polymeric dispersants, and is preferably a phosphate ester-based dispersing aid, and is added in an amount of 5 to 20 wt% based on the content of nano-zirconia.

[0042] It is understood that an oil-based dispersing aid is added in the above step to further improve the stability and dispersibility of the dispersion. In particular, the oil-based dispersing aid should be added after the organic acid and modifier are added to the dispersion, ensuring that there are enough active sites on the surface of the zirconia particles for the organic acid and modifier to perform surface treatment. The amount of the oil-based dispersing aid added can be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 wt% of the nanozirconia content, or any point value within the above range.

[0043] In some embodiments, the oil-based dispersing aid may be selected from dispersants BYK-9076 and BYK-90777, among others, manufactured by BYK, Germany.

[0044] In the above examples, BYK-9076 is a high molecular weight copolymer silyl ammonium salt, and Figure 5 shows the infrared spectrum of zirconia after adding BYK-9076 (40%). -2 The hydroxyl group peak at 2926 cm corresponds to the hydroxyl groups remaining on the zirconia surface. -2 is the saturated hydrocarbon peak of BYK9076, and 1633 cm -2 is the peak of water adsorbed on the zirconia inorganic powder, and 1060 cm -2 is Si-O-Zr produced by grafting BYK9076 onto zirconia, and has a peak at 565cm -2 is the Zr-O-Zr of zirconia. The appearance of the Si-O-Zr peak in the product in Figure 5 demonstrates that BYK-9076 can graft onto zirconia to form Si-O-Zr functional groups. Figure 6 shows the infrared spectrum of zirconia after the addition of BYK-9076 (5%). Figures 5 and 6 show that the Si-O-Zr peak appears when BYK-9076 is added, regardless of the amount added. BYK9077 is a high-molecular-weight copolymer with pigment-affinity groups. Therefore, when BYK9076 is used as an oil-based dispersing aid, it provides Si-O-Zr functional groups together with the modifier, further increasing the number of Si-O-Zr functional groups in the resulting nanozirconia dispersion and improving the refractive index of the nanozirconia dispersion. The structure of BYK9077 is similar to that of BYK9076, but due to greater steric hindrance and less grafting with zirconia, its infrared spectrum shows hydroxyl group peaks, water peaks, and Zr-O-Zr of zirconia.

[0045] The present application also provides a nano-zirconia-monomer dispersion prepared by adding a photocurable resin to a nano-zirconia dispersion based on any one of the above technical solutions and then removing the organic solvent in the dispersion by vacuum distillation. Note that the monomer dispersion in the present application refers to a dispersion to which a single component is added, and does not specifically refer to the monomer or its oligomer contained in the photocurable component.

[0046] In some embodiments, the nano-zirconia content of the nano-zirconia monomer dispersion is 55-85 wt % and the refractive index of the nano-zirconia monomer dispersion is 1.620-1.720. It is understood that the nano-zirconia content of the monomer dispersion may also be 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84 wt %, or any point value within the above range.

[0047] In some embodiments, the photocurable resin is selected from acrylic or methacrylic acid-based monomers or oligomers thereof containing ester, urethane, ether, silicon, halogen, and / or phosphorus-containing groups, and any of the monomers or oligomers thereof may be commercially available.

[0048] In some embodiments, the photocurable resin is added in an amount of 15 to 45 wt% based on the total mass of zirconia and photocurable resin, and it is understood that the content of the photocurable resin may be 20, 25, 30, 35 wt%, or any point value within the above range.

[0049] In some embodiments, the photocurable resin is at least one of phenoxybenzyl acrylate, methyl acrylate, and methyl methacrylate.

[0050] The present application also provides a nano-zirconia dispersion prepared by a preparation method based on any one of the above technical solutions, or an optical film prepared using a nano-zirconia monomer dispersion based on any one of the above technical solutions.

[0051] In some embodiments, the optical film is one of a brightness enhancing film, an anti-reflection film, and other optical films having a highly refractive coating layer.

[0052] In order to more clearly and in detail describe the nanozirconia dispersion provided in the examples of the present application, the preparation method thereof, and the resulting monomer dispersion, specific examples are provided below.

[0053] Example 1 Propylene glycol methyl ether (PGME) solvent was added to the zirconia aqueous solution and mixed uniformly. After that, isooctanoic acid (addition amount: 5% of the zirconium content) and 3-(methacryloyloxy)propyl trimethoxysilane (addition amount: 10% of the zirconium content) were added to the above system in order to modify the zirconia particles. Next, oil-based dispersing aid BYK-9076 (addition amount: 5%) was added, and the water was removed by rotary evaporation to obtain a nano-zirconia organic PGME-type dispersion.

[0054] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.475, when the concentration was 65%, the refractive index was 1.535, and when the concentration was 75 wt%, the refractive index was 1.565.

[0055] The attached Figure 1 is an infrared spectrum of Example 1. Here, 3418 cm -1 The absorption peak at 589 cm is a characteristic absorption peak of the hydroxyl group on the surface of zirconia particles. -1 and 496 cm -1 is a characteristic absorption peak of Zr-O-Zr. -1 is a characteristic peak of saturated carbon-hydrogen bonds, and 1718 cm-1 is the characteristic peak of the ester carbonyl group, and 1561 cm -1 and 1463 cm -1 is the characteristic absorption peak of the delocalized conjugated ester group, and 1170 cm -1 is the characteristic absorption peak of Si-O-Zr, and 1025 cm -1 is the characteristic absorption peak of the CO ether bond, which indicates that isooctanoic acid and 3-(methacryloyloxy)propyltrimethoxysilane were successfully grafted onto the surface of zirconia particles. Example 2

[0056] The preparation method was the same as in Example 1, except that the amount of isooctanoic acid added was 3% of the zirconium content, the amount of 3-glycidyl ether oxypropyl trimethoxy silane added was 5% of the zirconium content, and the amount of oil-based dispersing agent BYK-9076 added was 10% of the zirconium content to obtain a nano-zirconia organic PGME-type dispersion.

[0057] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.470, when the concentration was 65%, the refractive index was 1.529, and when the concentration was 75 wt%, the refractive index was 1.558. Example 3

[0058] The preparation method was the same as in Example 1, except that the amount of isooctanoic acid added was 12% of the zirconium content, the amount of modifier 3-(methacryloyloxy)propyltrimethoxysilane added was 15% of the zirconium content, and the amount of oil-based dispersing agent BYK-9077 added was 15% of the zirconium content, resulting in a nanozirconia organic PGME-type dispersion.

[0059] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.461, when the concentration was 65%, the refractive index was 1.522, and when the concentration was 75 wt%, the refractive index was 1.552. Example 4

[0060] The preparation method was the same as in Example 1, except that the amount of isooctanoic acid added was 20% of the zirconium content, the amount of modifier 3-glycidyl ether oxypropyl trimethoxy silane added was 20% of the zirconium content, and the amount of oil-based dispersing agent BYK-9077 added was 20% of the zirconium content, resulting in a nano-zirconia organic PGME-type dispersion.

[0061] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.449, when the concentration was 65%, the refractive index was 1.509, and when the concentration was 75 wt%, the refractive index was 1.540. Example 5

[0062] The preparation method was the same as in Example 1, except that the organic acid was 12-hydroxystearic acid, and the amount of acid added was 5% of the zirconium content, to obtain a nanozirconia organic PGME-type dispersion.

[0063] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.467, when the concentration was 65%, the refractive index was 1.525, and when the concentration was 75 wt%, the refractive index was 1.554.

[0064] The attached Figure 2 shows the infrared spectrum of Example 5. Here, -1 The absorption peak at 586 cm is a characteristic peak of the surface hydroxyl groups of zirconia particles. -1 and 483 cm -1 is a characteristic absorption peak of Zr-O-Zr. -1 is a characteristic peak of saturated carbon-hydrogen bonds, and 1715 cm -1 is the characteristic peak of the ester carbonyl group, and 1562 cm -1 and 1463 cm -1 is the characteristic absorption peak of the delocalized conjugated ester group, and 1169 cm -1is the characteristic absorption peak of Si-O-Zr, and 1032 cm -1 is the characteristic absorption peak of the CO ether bond, which indicates that 12-hydroxystearic acid and 3-(methacryloyloxy)propyltrimethoxysilane were successfully grafted onto the surface of zirconia particles. Example 6

[0065] The preparation method was the same as in Example 1, except that the organic acid added was acetic acid, and the amount of acid added was 5% of the zirconium content, to obtain a nano-zirconia organic PGME-type dispersion liquid.

[0066] In the nano-zirconia organic PGME dispersion, when the nano-zirconia concentration was 45 wt%, the refractive index was 1.420, when the concentration was 65%, the refractive index was 1.498, and when the concentration was 75 wt%, the refractive index was 1.530.

[0067] The attached Figure 3 shows the infrared spectrum of Example 6. -1 The absorption peak is a characteristic peak of the surface hydroxyl groups of zirconia particles, and is at 589 cm -1 and 496 cm -1 is a characteristic absorption peak of Zr-O-Zr. -1 is a characteristic peak of saturated carbon-hydrogen bonds, and 1711 cm -1 is the characteristic peak of the ester carbonyl group, and 1558 cm -1 and 1465 cm -1 is the characteristic absorption peak of the delocalized conjugated ester group, and 1167 cm -1 is a characteristic absorption peak of Si-O-Zr, and 1031 cm -1 is the characteristic absorption peak of the CO ether bond, which indicates that acetic acid and 3-(methacryloyloxy)propyltrimethoxysilane were successfully grafted onto the surface of zirconia particles. Example 7

[0068] The preparation method was the same as in Example 1, except that the organic acid added was propionic acid, and the amount of acid added was 5% of the zirconium content, to obtain a nanozirconia organic PGME-type dispersion.

[0069] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.457, when the concentration was 65%, the refractive index was 1.513, and when the concentration was 75 wt%, the refractive index was 1.548.

[0070] The attached Figure 4 shows the infrared spectrum of Example 7. -1 The absorption peak is a characteristic peak of the surface hydroxyl groups of zirconia particles, and is at 580 cm -1 and 490cm -1 is a characteristic absorption peak of Zr-O-Zr. -1 is a characteristic peak of saturated carbon-hydrogen bonds, and 1714 cm -1 is the characteristic peak of the ester carbonyl group, and 1563 cm -1 and 1467 cm -1 is the characteristic absorption peak of the delocalized conjugated ester group, and 1109 cm -1 is a characteristic absorption peak of Si-O-Zr, and 1027 cm -1 is the characteristic absorption peak of the CO ether bond, which indicates that propionic acid and 3-(methacryloyloxy)propyltrimethoxysilane were successfully grafted onto the zirconia particle surface. Example 8

[0071] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Example 1, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0072] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.675, when the content was 75 wt%, the refractive index was 1.700, and when the content was 85 wt%, the refractive index was 1.720. Example 9

[0073] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Example 2, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0074] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.660, when the content was 75 wt%, the refractive index was 1.687, and when the content was 85 wt%, the refractive index was 1.706. Example 10

[0075] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Example 3, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0076] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.644, when the content was 75 wt%, the refractive index was 1.667, and when the content was 85 wt%, the refractive index was 1.687. Example 11

[0077] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Example 4, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0078] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.620, when the content was 75 wt%, the refractive index was 1.643, and when the content was 85 wt%, the refractive index was 1.662. Example 12

[0079] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Example 5, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0080] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.650, when the content was 75 wt%, the refractive index was 1.676, and when the content was 85 wt%, the refractive index was 1.695. Example 13

[0081] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Example 6, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0082] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.621, when the content was 75 wt%, the refractive index was 1.641, and when the content was 85 wt%, the refractive index was 1.656. Example 14

[0083] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Example 7, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0084] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.631, when the content was 75 wt%, the refractive index was 1.657, and when the content was 85 wt%, the refractive index was 1.678. Comparative Example 1

[0085] The preparation method was the same as in Example 1, except that the content of isooctanoic acid added was 0, resulting in a nanozirconia organic PGME-type dispersion. The zirconia particles had hydroxy groups, Zr-O-Zr, and Si-O-Zr on their surfaces, but did not have ester carbonyl groups, CO ether bonds, conjugated ester groups, or saturated carbon-hydrogen bond groups.

[0086] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.395, when the concentration was 65%, the refractive index was 1.434, and when the concentration was 75 wt%, the refractive index was 1.472. Comparative Example 2

[0087] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion prepared in Comparative Example 1, and the mixture was distilled under reduced pressure to remove the organic solvent. As a result, the final product, zirconia, precipitated, but no nanozirconia dispersion containing photocurable phenoxybenzyl acrylate was obtained. Comparative Example 3

[0088] Propylene glycol methyl ether (PGME) solvent was added to the zirconia aqueous solution and mixed uniformly. After homogeneous mixing, the oil-based dispersing agent BYK-9076 (5%) was added to the above system. Then, isooctanoic acid (5% of the zirconium content) and 3-(methacryloyloxy)propyl trimethoxysilane (10% of the zirconium content) were added to modify the zirconia particles. The water was removed by rotary evaporation to obtain a nanozirconia organic PGME dispersion. The zirconia particles possessed hydroxyl groups, Zr-O-Zr, Si-O-Zr groups, conjugated ester groups, ester carbonyl groups, and CO ether bond groups on their surfaces, but no saturated carbon-hydrogen bond groups.

[0089] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.398, when the concentration was 65%, the refractive index was 1.445, and when the concentration was 75 wt%, the refractive index was 1.484. Comparative Example 4

[0090] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Comparative Example 3, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0091] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.575, and when the content was 75 wt%, the refractive index was 1.598. Comparative Example 5

[0092] The preparation method was the same as in Comparative Example 3, except that the oil-based dispersing aid BYK-9076 (addition amount: 5%) was added to the system, followed by the addition of 12-hydroxystearic acid (addition amount: 5% of the zirconium content) and 3-(methacryloyloxy)propyl trimethoxysilane (addition amount: 10% of the zirconium content) to modify the zirconia particles, resulting in a nanozirconia organic PGME-type dispersion.The zirconia particles had hydroxy groups, Zr-O-Zr, Si-O-Zr groups, conjugated ester groups, ester carbonyl groups, and CO ether bond groups on their surfaces, but no saturated carbon-hydrogen bond groups.

[0093] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.396, when the concentration was 65%, the refractive index was 1.442, and when the concentration was 75 wt%, the refractive index was 1.480. Comparative Example 6

[0094] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Comparative Example 5, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0095] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.570, and when the content was 75 wt%, the refractive index was 1.594. Comparative Example 7

[0096] The preparation method was the same as in Example 5, except that the amounts of 12-hydroxystearic acid, 3-(methacryloyloxy)propyltrimethoxysilane, and oil-based dispersing agent BYK-9076 added were each 25% of the zirconium content, resulting in a nanozirconia organic PGME-type dispersion.The zirconia particles have hydroxy groups, Zr-O-Zr and Si-O-Zr groups, CO ether bonds, ester carbonyl groups, and saturated carbon-hydrogen bond groups on their surfaces, but no conjugated ester groups.

[0097] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.398, when the concentration was 65%, the refractive index was 1.447, and when the concentration was 75 wt%, the refractive index was 1.481. Comparative Example 8

[0098] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Comparative Example 7, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0099] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.567, and when the content was 75 wt%, the refractive index was 1.591. Comparative Example 9

[0100] The preparation method was the same as in Example 1, except that the amount of isooctanoic acid, 3-glycidyl etheroxypropyl trimethoxysilane, and oil-based dispersing agent BYK-9076 added was 30% of the zirconium content, resulting in a nanozirconia organic PGME-type dispersion. The zirconia particles had hydroxyl groups, Zr-O-Zr and Si-O-Zr groups, CO ether bonds, ester carbonyl groups, and saturated carbon-hydrogen bond groups on their surfaces, but no conjugated ester groups.

[0101] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.389, when the concentration was 65%, the refractive index was 1.446, and when the concentration was 75 wt%, the refractive index was 1.485. Comparative Example 10

[0102] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Comparative Example 9, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0103] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.557, and when the content was 75 wt%, the refractive index was 1.582. Comparative Example 11

[0104] The preparation method was the same as in Example 1, except that the content of 3-(methacryloyloxy)propyltrimethoxysilane was set to 0 to obtain a nano-zirconia organic PGME dispersion. The zirconia particles had hydroxyl groups, Zr-O-Zr, and Si-O-Zr on their surfaces, but did not have ester carbonyl groups, CO ether bonds, conjugated ester groups, or saturated carbon-hydrogen bond groups.

[0105] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.399, when the concentration was 65%, the refractive index was 1.439, and when the concentration was 75 wt%, the refractive index was 1.477. Comparative Example 12

[0106] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion prepared in Comparative Example 11, and the mixture was distilled under reduced pressure to remove the organic solvent. As a result, the final product, zirconia, precipitated, and no nanozirconia dispersion containing photocurable phenoxybenzyl acrylate was obtained. Comparative Example 13

[0107] The preparation method was the same as in Example 1, except that the oil-based dispersion aid added was DISPERBYK-111 (addition amount: 5% of the zirconium content), and a nano-zirconia organic PGME-type dispersion was obtained. The zirconia particles had hydroxy groups, Zr-O-Zr, COOH, saturated carbon-hydrogen bond groups, ester carbonyl groups, and CO ether bonds on their surfaces, but did not have Si-O-Zr or conjugated ester groups.

[0108] In the nano-zirconia organic PGME dispersion, when the concentration of nano-zirconia was 45 wt%, the refractive index was 1.391, when the concentration was 65%, the refractive index was 1.443, and when the concentration was 75 wt%, the refractive index was 1.481. Comparative Example 14

[0109] Phenoxybenzyl acrylate was added to the nanozirconia organic PGME-type dispersion obtained in Comparative Example 13, and the mixture was distilled under reduced pressure to remove the organic solvent, yielding a nanozirconia dispersion containing photocurable phenoxybenzyl acrylate.

[0110] In the dispersion, when the content of nano-zirconia was 55 wt%, the refractive index was 1.560, and when the content was 75 wt%, the refractive index was 1.587.

[0111] Table 1. Differences between Examples 1-14 and Comparative Examples 1-14 and summary of the product data obtained JPEG0007789190000001.jpg176170

[0112] The examples of the present application and comparative examples will be compared and analyzed below. Without the addition of an organic acid (Comparative Example 1) or modifier (Comparative Example 11), there was no mutually promoting effect between the organic acid and the modifier, and the zirconia of Comparative Examples 1 and 11 only had Si-O-Zr provided by the oil-based dispersion aid on its surface, resulting in failure to prepare the monomer-type dispersions of Comparative Examples 2 and 12. This explains why the effects of the organic acid, modifier, and oil-based dispersion aid on the zirconia particles mutually promote each other, and how this change in promoting effect leads to differences in the surface graft groups of the zirconia particles, which in turn affects whether or not the dispersions can be successfully prepared.

[0113] In Comparative Examples 3 and 5, the addition of 5% oil-based dispersion aid BYK9076 first resulted in a lack of surface active sites on the zirconia. The long-carbon chain isooctanoic acid and 12-hydroxystearic acid have significant steric hindrance, making grafting to the limited active sites on the zirconia surface difficult. Therefore, saturated hydrocarbons are not present in Comparative Examples 3 and 5. The nanozirconia content in the monomer-type dispersion was at most 75 wt%, and the refractive indexes were 1.598 and 1.594, significantly lower than the refractive indexes of the 75 wt% monomer-type dispersions in Examples 8 to 14, which ranged from 1.641 to 1.700, not to mention the higher refractive index of the 85 wt% dispersions in Examples 8 to 14. In Examples 1 to 7 of the present application, when the zirconia particles were first modified by adding a modifier and an organic acid, the zirconia had sufficient surface active sites for the organic acid and modifier to act on, resulting in better modification and dispersion effects.

[0114] In Comparative Examples 7 and 9, 12-hydroxystearic acid and isooctanoic acid have long electron-donating carbon chains and are added in large amounts (25% and 30%). The grafting of such large amounts of electron-donating groups directly weakens or eliminates the electron-deficiency of the zirconia center. Therefore, conjugated ester groups do not appear, and the nanozirconia content in the monomer dispersion is at most 75 wt%, resulting in refractive indices of only 1.591 and 1.582. In the examples of this application, the amount of organic acid added is small and insufficient to offset the electron-deficiency of the zirconia center, resulting in the presence of conjugated ester groups.

[0115] Example 1 used a different oil-based dispersing aid than Comparative Example 13. In Comparative Example 13, a COOH peak was present on the surface of the zirconia particles, but no Si-O-Zr or conjugated ester group peaks were present. This indicates that the organic acid and modifier in Comparative Example 13 did not interact with the zirconia through a grafting process, but simply coated the zirconia surface. Furthermore, the refractive index of the solvent-based dispersion at each concentration in Comparative Example 13 was lower than that of Example 1. At the same time, the refractive index of the monomer-based dispersion in Comparative Example 14, with a nanozirconia content of up to 75 wt%, was 1.587, significantly lower than the refractive index of the 75 wt% monomer-based dispersion in Example 8 (1.700), let alone the higher refractive index of the 85 wt% dispersion in Example 8. This indicates that the oil-based dispersing aid BYK9076 significantly affected the grafting of the organic acid and modifier to the zirconia particles, which in turn affected the number and type of grafted groups on the zirconia particle surface, thereby significantly improving the refractive index of the dispersion.

[0116] Based on the above, the preparation methods provided in Examples 1-7 of the present application utilize the mutually promoting effects of organic acids, modifiers, and oil-based dispersion aids on zirconia particles. By controlling the content of each agent within the ranges provided in the examples, the desired functional groups can be grafted onto the surface of the nanozirconia particles, ultimately resulting in a nanozirconia dispersion with good dispersion uniformity and a high refractive index. This nanozirconia dispersion can significantly improve the refractive index of high-refractive coating layers in subsequent preparations of brightness enhancement films or anti-reflection films, thereby improving film performance. The refractive index data in Table 1 show that for solvent-based dispersions, under the same 75 wt% conditions, the refractive indexes of Examples 1-7 ranged from 1.530 to 1.565, while the refractive indexes of Comparative Examples 1, 3, 5, 7, 9, 11, and 13 ranged from 1.472 to 1.485, a difference of 0.058 to 0.08. Numerically, the difference in refractive index is not large, but from the perspective of the refractive index of the dispersion, the difference is like heaven and earth. For example, if brightness enhancement films are manufactured using dispersions with a refractive index difference of 0.01 and applied to displays, the light transmittance will be 89% and 93%, which is the difference between a B-class screen and an A-class screen.

Claims

1. A method for preparing a nano-zirconia monomer dispersion, comprising the steps of: The method includes a step of preparing a nano-zirconia monomer dispersion by adding a photocurable resin to a nano-zirconia dispersion and removing the organic solvent from the dispersion by vacuum distillation, The amount of nano-zirconia particles contained in the nano-zirconia dispersion is 45 to 75 wt %, and the refractive index of the nano-zirconia dispersion is 1.420 to 1.565; The infrared spectrum of the nano-zirconia particles shows that functional groups in the following peak-out section are present on the surface of the particles: Hydroxy group: 3200 cm －１ ~3600cm －１ , Zr-O-Zr: 480cm －１ ~850cm －１ , saturated carbon-hydrogen bond: 2850 cm －１ ~2960cm －１ , ester carbonyl group: 1700 cm －１ ~1750cm －１ , delocalized conjugated ester group: 1460 cm －１ ~1580cm －１ , Si-O-Zr: 800cm －１ ~1200cm －１ and C—O ether bond: 1000 cm －１ ~1200cm －１ 10. A method for preparing a nano-zirconia monomer dispersion, wherein the following has been found to be grafted onto the nano-zirconia monomer dispersion:

2. 2. The method for preparing a nano-zirconia monomer dispersion according to claim 1, wherein the refractive index of the nano-zirconia dispersion is 1.420 to 1.535 when the zirconia content is 45% to 65%, and 1.498 to 1.565 when the zirconia content is 65% to 75%.

3. A method for producing a nano-zirconia dispersion, comprising the steps of adding an organic solvent to an aqueous zirconia solution, mixing the solution uniformly, adding an organic acid and a modifier to the system to modify the zirconia particles, adding an oil-based dispersion aid, and removing water by rotary evaporation to obtain a nano-zirconia dispersion, The method for preparing a nano-zirconia monomer dispersion according to claim 1, characterized in that the organic acid is added in an amount of 3 to 20 wt % based on the content of nano-zirconia, the modifier is added in an amount of 5 to 20 wt % based on the content of nano-zirconia, and the oil-based dispersion aid is added in an amount of 5 to 20 wt % based on the content of nano-zirconia.

4. The modification of the zirconia particles by adding an organic acid and a modifier to the system specifically includes the following: Adding an organic acid and a modifier to the system at atmospheric pressure and 50 to 150°C to modify the zirconia particles; or The method for preparing a nano-zirconia monomer dispersion according to claim 3, characterized in that an organic acid and a modifier are dissolved in the organic solvent, and the resulting solution is added to a dispersion prepared by mixing an aqueous zirconia solution and an organic solvent under atmospheric pressure and a temperature of 50 to 150°C, thereby modifying the zirconia particles.

5. The method for preparing a nano-zirconia monomer dispersion according to claim 3, characterized in that the organic solvent is at least one of butanone, methyl isobutyl ketone, propylene glycol methyl ether, and ethylene glycol methyl ether, and the volume ratio of the added organic solvent to the zirconia aqueous solution is (3-5):

1.

6. 4. The method for preparing a nano-zirconia monomer dispersion according to claim 3, wherein the organic acid is selected from at least one of saturated or unsaturated monocarboxylic acids, polycarboxylic acids, and hydroxycarboxylic acids.

7. 7. The method for preparing a nano-zirconia monomer dispersion according to claim 6, wherein the monocarboxylic acid is selected from at least one of formic acid, acetic acid, propionic acid, butyric acid, isooctanoic acid, acrylic acid, and methacrylic acid, the polycarboxylic acid is selected from at least one of oxalic acid, malonic acid, succinic acid, phthalic acid, fumaric acid, and maleic acid, and the hydroxycarboxylic acid is selected from at least one of lactic acid, malic acid, tartaric acid, and citric acid.

8. 4. The method for preparing a nano-zirconia monomer dispersion according to claim 3, wherein the modifier is at least one of 3-(methacryloyloxy)propyl trimethoxy silane and 3-glycidyl ether oxypropyl trimethoxy silane.

9. 4. The method for preparing a nano-zirconia monomer dispersion according to claim 3, wherein the oil-based dispersing aid is selected from at least one of anionic dispersants, cationic dispersants, nonionic dispersants and polymeric dispersants.

10. 4. The method for preparing a nano-zirconia monomer dispersion according to claim 3, wherein the oil-based dispersion aid is a high molecular weight copolymer silyl ammonium salt.

11. The method for preparing a nano-zirconia monomer dispersion according to any one of claims 1 to 10, characterized in that the nano-zirconia content in the nano-zirconia monomer dispersion is 55 to 85 wt %, and the refractive index of the nano-zirconia monomer dispersion is 1.620 to 1.

720.

12. The method for preparing a nano-zirconia monomer dispersion according to any one of claims 1 to 10, characterized in that the photocurable resin is selected from acrylic or methacrylic acid monomers or oligomers thereof comprising ester, urethane, ether, silicon, halogen and / or phosphorus-containing groups, and the photocurable resin is added in an amount of 15 to 45 wt % based on the total mass of zirconia and the photocurable resin.

13. 13. The method for preparing a nano-zirconia monomer dispersion according to claim 12, wherein the photo-curable resin is at least one of phenoxybenzyl acrylic acid ester, methyl acrylate, and methyl methacrylate.

14. A method for producing an optical film, comprising: A method for producing an optical film, comprising using a nano-zirconia monomer dispersion obtained by the method for preparing a nano-zirconia monomer dispersion according to any one of claims 1 to 10.

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