JP6889575B2 - Cerium oxide nanoparticles, their production methods, dispersions and resin complexes - Google Patents

Description

The present invention relates to cerium oxide nanoparticles, a method for producing the same, a dispersion of cerium oxide nanoparticles, and a resin complex.

In recent years, nanoparticles of metal oxides have greatly contributed to higher functionality and higher performance of various materials such as optical materials, electronic component materials, magnetic recording materials, catalyst materials, and ultraviolet and near-infrared absorbing materials. Attention has been paid.

Among these metal oxides, cerium oxide is useful as an abrasive for glass substrates, alumina substrates, etc., an ultraviolet absorber, an oxidation catalyst, and the like, and its nanoparticles have also been studied in various ways.

For example, Patent Document 1 proposes a method for producing a cerium oxide sol, which comprises a step of preparing a dispersion liquid of a cerium hydroxide gel in the presence of a particle growth modifier, and the method was obtained according to the examples. The cerium oxide nanoparticles had an average particle diameter of 22 nm and a crystallite diameter of 18.5 nm in Example 1, and an average particle diameter of 50 nm and a crystallite diameter of 33 nm in Example 2, so that only nanoparticles having a relatively large particle size could be obtained. In addition, the sol is in water and there is no description about its dispersibility in organic solvents, monomers, etc. In Patent Document 1, a carboxylic acid or a carboxylic acid salt, a hydroxycarboxylic acid, or a hydroxycarboxylic acid salt is used as a particle growth modifier, and specifically, formic acid, acetic acid, oxalic acid, and acrylic acid (unsaturated carboxylic acid). , Monocarboxylic acids such as gluconic acid and monocarboxylic acids, polycarboxylic acids such as malic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, etc. And, such as polyvalent carboxylic acid salt, α-lactic acid, β-lactic acid, γ-hydroxyvaleric acid, glyceric acid, tartrate acid, citric acid, tropic acid, hydroxycarboxylic acid of benzylic acid and hydroxycarboxylic acid salt are exemplified.

Therefore, Patent Document 2 proposes a production method including a step of producing a cerium-surfactant complex compound as a method for producing cerium oxide nanoparticles that are also dispersed in an organic solvent, and as the surfactant, "oleic acid, Capricic acid, decanoic acid, stearic acid, trioctylphosphine oxide (TOPO), triphenylphosphine (TPP), trioctylphosphine (TOP), and alkylamines such as oleylamine, octylamine, hexadecylamine, trialkylamine ( RNH2) (in the formula, R is an alkyl group consisting of 3 to 18 carbons), any one selected from the group, or a mixture thereof. However, according to the examples, it is only described that the cerium oxide nanoparticles obtained by this method are dispersed in an organic solvent such as toluene, hexane and octane, and the dispersibility in a highly polar solvent or monomer other than these is described. There is no description about.

Further, Patent Document 3 provides an aqueous reaction mixture containing a first cerium ion source, a hydroxide ion source, at least one of a nanoparticle stabilizer, and an oxidizing agent at an initial temperature of about 20 ° C. or lower. A method for producing cerium dioxide nanoparticles including the "step" is proposed, and the nanoparticle stabilizer is selected from the group consisting of an alkoxy-substituted carboxylic acid or an α-hydroxycarboxylic acid, an α-ketocarboxylic acid, a polycarboxylic acid and a mixture thereof. , Or those selected from the group consisting of ethylenediamine tetraacetic acid, gluconic acid, lactic acid, tartaric acid, pyruvate, citric acid, and mixtures thereof. However, since its use is mainly as a diesel fuel additive, it is considered that it is dispersed in a non-polar solvent containing diesel fuel, but there is no description about its dispersibility in a highly polar solvent or the like.

Further, Non-Patent Document 1 proposes a method for producing cerium oxide nanoparticles by a hydroxy condensation of a cerium-oleic acid complex in aqueous ammonia, and the obtained cerium oxide nanoparticles are obtained from a solvent oleate ligand (surface-coordinated oleic acid). It is said that it is dispersed in a non-polar solvent due to the hydrophobicity of the residue).

Japanese Unexamined Patent Publication No. 2006-182604 Japanese Unexamined Patent Publication No. 2009-511403 Special Table 2010-502559

Crystal Growth & Design 2008, Vol. 8, No. 10, 3725-3730

In the above prior art, these cerium oxide nanoparticles are dispersed in water or a non-polar solvent, but are not dispersed in a polar solvent such as an ester-based or alcohol-based solvent. Therefore, acetic acid is used from a non-polar solvent such as toluene. There is a demand for cerium oxide nanoparticles that are widely dispersed in polar solvents such as ethyl and 2-propanol.

Therefore, it is an object of the present invention to provide cerium oxide nanoparticles having excellent dispersibility in a wide range of solvents, monomers and the like from polar to non-polar, a method for producing the same, a dispersion thereof and a resin composite.

As a result of diligent studies, the present inventor has found that cerium oxide nanoparticles surface-treated with a hydroxyl group-free carboxylic acid and a hydroxyl group-containing carboxylic acid exhibit excellent dispersibility in a wide range of solvents, monomers, etc. from polar to non-polar. The heading, the present invention was completed.

That is, the present invention
(1) A step of dissolving a metal salt of a hydroxyl group-free carboxylic acid and a metal salt of a hydroxyl group-containing carboxylic acid in aqueous ammonia,
The step of adding an aqueous solution of diammonium cerium nitrate to the obtained solution, and
The step of subjecting the obtained mixture to a hydrothermal reaction and
A method for producing cerium oxide nanoparticles, which comprises
(2) The method for producing cerium oxide nanoparticles according to (1), wherein the hydroxyl group-free carboxylic acid is an aliphatic monocarboxylic acid or an aromatic monocarboxylic acid.
(3) The method for producing cerium oxide nanoparticles according to (1) or (2), wherein the hydroxyl group-free carboxylic acid has 3 or more and 22 or less carbon atoms.
(4) The method for producing cerium oxide nanoparticles according to any one of (1) to (3), wherein the hydroxyl group-containing carboxylic acid is a hydroxyl group-containing aliphatic monocarboxylic acid.
(5) The method for producing cerium oxide nanoparticles according to any one of (1) to (4), wherein the hydroxyl group-containing carboxylic acid has 6 or more and 22 or less carbon atoms.
(6) (1) the cerium oxide particles obtained in any of the manufacturing method of (5), Ru dispersed in a dispersion medium containing at least one selected from organic solvents, monomers and polymerizable oligomers A method for producing a cerium oxide nanoparticles dispersion, which is characterized by the above.
(7) A step of dispersing the cerium oxide nanoparticles obtained by any of the production methods (1) to (5) in a dispersion medium containing at least one selected from a monomer and a polymerizable oligomer.
The step of polymerizing the obtained dispersion and
A method for producing a cerium oxide nanoparticles-dispersed resin complex, which comprises.
Is.

The cerium oxide nanoparticles of the present invention are excellent in dispersibility in a wide range of organic solvents, monomers, polymerizable oligomers, and resins from non-polar solvents to polar solvents without using a dispersant. Therefore, by dispersing and polymerizing the cerium oxide nanoparticles in a monomer or a polymerizable oligomer, or by directly dispersing them in a resin, it is possible to obtain a transparent material having an ultraviolet absorbing power and a high refractive index. It can also be applied to fuel additives that reduce environmental pollutants and improve flammability.

It is the observation result by the transmission electron microscope of the cerium oxide nanoparticles of this invention. It is an ultraviolet-visible light absorption spectrum of the cerium oxide nanoparticle toluene dispersion liquid of this invention.

Hereinafter, embodiments for carrying out the present invention will be described in detail. It should be noted that the present embodiment is only one embodiment for carrying out the present invention, and the present invention is not limited to the present embodiment, and various modified embodiments are provided without departing from the gist of the present invention. It is possible.

The cerium oxide nanoparticles of the present invention are characterized in that they are surface-treated with a hydroxyl group-free carboxylic acid and a hydroxyl group-containing carboxylic acid.

Examples of the hydroxyl group-free carboxylic acid used in the present invention include hydroxyl group-free aliphatic and aromatic monocarboxylic acids, and if it is an aliphatic, it may be saturated or unsaturated, and has an aromatic such as branched or phenyl group. It is a monocarboxylic acid having 3 to 22 carbon atoms which may have a group substituent, and the carbon number is preferably 6 to 22 in consideration of dispersibility in an organic solvent, a monomer and the like. More specifically, propionic acid, butyric acid, valeric acid, caproic acid, capric acid, octyl acid, pelargonic acid, capric acid, neodecanoic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, Saturated monocarboxylic acids such as heptadecanoic acid, stearic acid, nonadecanoic acid, eicosanoic acid, heneicosanoic acid, docosanoic acid, unsaturated fatty acids such as oleic acid, linoleic acid, linoleic acid, fatty acids obtained by saponification and decomposition of fish oil, and theirs. Geometric isomers, 3-phenylpropionic acid, cinnamic acid and the like are exemplified. Further, the hydroxyl group-free aromatic monocarboxylic acid is a monocarboxylic acid in which a carboxylic acid residue is directly bonded to an aromatic ring, and examples thereof include benzoic acid and toluic acid.

The hydroxyl group-containing carboxylic acid used in the present invention includes a hydroxyl group-containing aliphatic monocarboxylic acid having 6 to 22 carbon atoms which may have an aromatic substituent such as a branched or phenyl group regardless of whether it is saturated or unsaturated. Preferably, specifically, mevalonic acid, pantoic acid, 2-hydroxydecanoic acid, 3-hydroxyhexanoic acid, 2-hydroxystearic acid, 12-hydroxystearic acid, ricinoleic acid and the like are exemplified.

The hydroxyl group-free carboxylic acid, particularly an aliphatic carboxylic acid or an aromatic carboxylic acid, imparts hydrophobicity to the surface of cerium oxide nanoparticles and contributes to dispersion stability in an organic solvent or the like. Further, when the dispersion medium is an organic solvent, monomer or polymerizable oligomer having a carbonyl group or a hydroxyl group, the hydroxyl group of the hydroxyl group-containing carboxylic acid contributes to the stability of the dispersion by hydrogen bonding with the carbonyl group or the hydroxyl group. It is thought that it will be done.

The cerium oxide nanoparticles of the present invention are a mixture obtained by dissolving the metal salt of the hydroxyl group-free carboxylic acid and the metal salt of the hydroxyl group-containing carboxylic acid in aqueous ammonia, adding an aqueous solution of diammonium cerium nitrate to the solution. Is produced by subjecting to a hydrothermal reaction.

This hydrothermal reaction is carried out in a closed container at 120 to 240 ° C., preferably 150 to 200 ° C. If the temperature is lower than 120 ° C., the reaction is slow (the reaction time may exceed 24 hours), which is not practical, and if the temperature exceeds 200 ° C., the apparatus becomes large-scale.

After the hydrothermal reaction, the cerium oxide nanoparticles of the present invention can be obtained by purification by a conventional method. For example, the cerium oxide nanoparticles of the present invention can be obtained as a yellow powder by purifying and drying by removing the supernatant of the reaction solution, filtering and washing with a solvent, or ultrasonic washing and centrifugation in a solvent.

The cerium oxide nanoparticles thus obtained are monodisperse having a particle size of several nm to several tens of nm, and the average particle size is preferably 1 to 20 nm, and 1 to 1 in consideration of the transparency of the dispersion. 10 nm is more preferable.
In the present invention, the average particle size was determined by the Scherrer equation for the crystallite size from the powder X-ray diffraction data, and was considered to be equivalent to that value. FIG. 1 shows the observation results of Example 4 described later with a transmission electron microscope, but all the particles were 10 nm or less and no aggregation was observed. In fact, in Example 4, 100 particles were randomly selected from the observation with a transmission electron microscope, and the average value obtained from the biaxial average values of the major axis and the minor axis was compared with the above-mentioned crystallite size. The former has 4.5 nm, and the latter has 3.9 nm, which are almost the same values.

The amount of surface treatment with the hydroxyl group-free carboxylic acid and the hydroxyl group-containing carboxylic acid is 5% by mass or more and 30% by mass or less with respect to the obtained cerium oxide nanoparticles. If it is less than 5% by mass, the dispersibility in an organic solvent, a monomer or the like is insufficient, and if it exceeds 30% by mass, the refractive index is significantly lowered, which is not preferable. Here, the amount of surface treatment with the hydroxyl group-free carboxylic acid and the hydroxyl group-containing carboxylic acid was taken as the mass reduction rate when the temperature was raised to 900 ° C. at a rate of 40 ° C./min under a nitrogen atmosphere.

Since the surface of the cerium oxide nanoparticles of the present invention is appropriately hydrophobized and does not easily aggregate, it is excellent in dispersibility in organic solvents, monomers, resins and the like. Therefore, for example, not only can it be easily uniformly dispersed in an organic solvent by using an ultrasonic homogenizer, but also cerium oxide nano can be dispersed in a monomer or a polymerizable oligomer and then polymerized or dispersed in a resin. A resin composite in which the particles are finely dispersed in the resin can be obtained. The cerium oxide nanoparticle dispersion and the resin composite of the present invention may contain an antioxidant, a mold release agent, a polymerization initiator, a dye pigment, a dispersant and the like, depending on the purpose.

Examples of the organic solvent include alcohols such as ethanol, 2-propanol, butanol, octanol and cyclohexanol, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and γ-. Esters such as butyrolactone, diethyl ether, tetrahydrofuran, ethylene grease monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethers such as dioxane, acetone, methyl ethyl ketone, methyl isobutyl ketone , Ketones such as acetylacetone and cyclohexanone, aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, and amides such as dimethylformamide, N, N-dimethylacetacetamide and N-methylpyrrolidone are preferably used. One or more of the solvents can be used.

As the above-mentioned monomer and polymerizable oligomer, any of radically polymerizable, polycondensable, ring-opening polymerizable and the like can be used. For example, as the radically polymerizable monomer, a (meth) acrylic monomer such as methyl acrylate and methyl methacrylate, a (meth) acrylic monomer having a reactive functional group such as a glycidyl group, an isocyanate group and a vinyl ether group, and styrene. As the contractile polymerizable monomer such as vinyl-based monomer, a monomer forming polyamide or polyester, a combination of polyisocyanate with polyol and polythiol, etc., and as a ring-opening polymerizable monomer, an epoxy-based monomer and the like can be preferably used. .. Further, as the polymerizable oligomer, urethane acrylate-based oligomers, epoxy acrylate-based oligomers, acrylate-based oligomers and the like can be preferably used.

A resin complex can be obtained by dispersing the cerium oxide nanoparticles of the present invention in a monomer or a polymerizable oligomer and then polymerizing the particles, or by dispersing them in a resin. The cerium oxide nanoparticles of the present invention are suitably used for applications that require high refractive index and transparency by taking advantage of their ultraviolet absorbing ability.
Here, as the resin for dispersing the cerium oxide nanoparticles of the present invention, a thermoplastic resin such as polyolefin such as polyethylene and polypropylene, polyester such as polylactic acid and polyethylene terephthalate, polyamide, poly (meth) acrylate, polyphenylene ether and polyurethane , One or more selected from polystyrene, cyclic polyolefin, polycarbonate and the like are preferably used.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In Examples and Comparative Examples, "parts" means "parts by mass" and "%" means "% by mass".

In the present invention, the crystal structure of the cerium oxide nanoparticles is prepared by using an X-ray diffractometer (X'Pert PRO MRD manufactured by PANAlytic), and the measurement conditions are as follows: X-ray tube voltage 45 kV, X-ray tube electric current 40 mA, scanning range 2θ. The average particle size was measured at 10.0-65.0 °, and the half-wavelength β was obtained from the analysis intensity of the (111) plane where 2θ was near 28.6. The crystallite size D was obtained with the constant K set to 0.9 and the wavelength λ of the X-ray tube set to 1.54056, and used as the value.

(Number 1)
D = K ・ λ / (β ・ cosθ)

Further, for dispersibility in the organic solvent or monomer, various organic solvents or monomers are added to the synthesized cerium oxide particles so as to have a concentration of 50%, and an ultrasonic cleaner (3 frequency ultrasonic wave manufactured by Vervocreer Co., Ltd.) is added. After several minutes of treatment with the washer VS-100III), a transparent one was visually evaluated as ◯, a translucent one was evaluated as Δ, and a cloudy or precipitated substance was evaluated as ×.

(Example 1)
1.8 g (10 mmol) of sodium octanoate, 0.45 g (1.4 mmol) of sodium ricinoleate and 10 mL of a 25% aqueous ammonia solution were added to 30 g of pure water and stirred to prepare a transparent solution. A solution prepared by dissolving 3.84 g (7 mmol) of diammonium diammonium nitrate in 30 g of pure water was added to this solution, and the mixture was stirred to obtain a pale yellow suspension. After hydrothermal treatment of this suspension in an autoclave at 150 ° C. for 15 hours, the supernatant was removed, and the obtained precipitate was filtered, washed with water, and dried to obtain 1.40 g of surface-treated cerium oxide nanoparticles in yellow. Obtained as a powder. The surface treatment amount of the cerium oxide nanoparticles was 25.38% from the mass reduction rate of heating to 900 ° C. at a rate of 40 ° C./min in a nitrogen atmosphere by the thermogravimetric measuring device Pyris1TGA manufactured by PerkinElmer.

(Example 2)
5.4 g (32 mmol) of sodium octanoate, 1.35 g (4.2 mmol) of sodium ricinoleate and 30 mL of a 25% aqueous ammonia solution were added to 20 g of pure water and stirred to prepare a transparent solution. A solution prepared by dissolving 11.52 g (21 mmol) of diammonium cerium nitrate in 10 g of pure water was added to this solution, and the mixture was stirred to obtain a pale yellow suspension. After hydrothermal treatment of this suspension in an autoclave at 150 ° C. for 15 hours, the supernatant was removed, and the obtained precipitate was filtered, washed and dried to obtain 4.68 g of surface-treated cerium oxide nanoparticles in yellow. Obtained as a powder. The surface treatment amount of the cerium oxide nanoparticles was 24.61% as measured in the same manner as in Example 1.

(Example 3)
3.76 g (26 mmol) of octanoic acid, 1.01 g (3.3 mmol) of ricinoleic acid, 24 mL of a 25% aqueous ammonia solution and 6 mL of a 6 M aqueous sodium hydroxide solution were added to 16 g of pure water and stirred to prepare a transparent solution. A solution prepared by dissolving 9.22 g (17 mmol) of diammonium cerium nitrate in 8 g of pure water was added to this solution, and the mixture was stirred to obtain a pale yellow suspension. After hydrothermal treatment of this suspension in an autoclave at 150 ° C. for 15 hours, the supernatant was removed, and the obtained precipitate was filtered, washed with water, and dried to obtain 3.8 g of surface-treated cerium oxide nanoparticles in yellow. Obtained as a powder. The surface treatment amount of the cerium oxide nanoparticles was 26.42% as measured in the same manner as in Example 1.

(Example 4)
3.12 g (22 mmol) of octanoic acid, 0.84 g (2.8 mmol) of ricinoleic acid, 20 mL of a 25% aqueous ammonia solution and 5 mL of a 6M aqueous sodium hydroxide solution were added to 15 g of pure water and stirred to prepare a transparent solution. A solution prepared by dissolving 7.68 g (17 mmol) of diammonium cerium nitrate in 20 g of pure water was added to this solution, and the mixture was stirred to obtain a pale yellow suspension. The suspension was hydroheat-treated at 180 ° C. for 15 hours in an autoclave, the supernatant was removed, and the obtained precipitate was filtered, washed with water and dried to obtain 3.0 g of a yellow powder. The surface treatment amount of the cerium oxide nanoparticles was measured in the same manner as in Example 1 and was 23.46%. Regarding the powder obtained here, the measurement results by a field emission type analytical transmission electron microscope (Topcon Technohouse EM002BF) are shown as FIG. 1, and it can be seen that all the particles are 10 nm or less.

(Example 5)
3.12 g (22 mmol) of octanoic acid, 0.85 g (2.8 mmol) of 12-hydroxystearic acid, 20 mL of 25% aqueous ammonia solution and 5 mL of 6M aqueous sodium hydroxide solution were added to 15 g of pure water and stirred to prepare a transparent solution. .. A solution prepared by dissolving 7.68 g (17 mmol) of diammonium cerium nitrate in 20 g of pure water was added to this solution, and the mixture was stirred to obtain a pale yellow suspension. After hydrothermal treatment of this suspension in an autoclave at 180 ° C. for 15 hours, the supernatant was removed, and the obtained precipitate was filtered, washed with water and dried to obtain 2.98 g of surface-treated cerium oxide nanoparticles in yellow. Obtained as a powder. The surface treatment amount of the cerium oxide nanoparticles was 21.77% as measured in the same manner as in Example 1.

(Comparative Example 1)
2.13 g (7 mmol) of sodium oleate and 10 mL of a 25% aqueous ammonia solution were added to 30 g of pure water and stirred to prepare a transparent solution. A solution prepared by dissolving 3.84 g (7 mmol) of diammonium diammonium nitrate in 30 g of pure water was added to this solution, and the mixture was stirred to obtain a pale yellow suspension. After hydrothermal treatment of this suspension in an autoclave at 150 ° C. for 6 hours, the supernatant was removed, and the obtained precipitate was filtered, washed and dried to obtain 1.39 g of surface-treated cerium oxide nanoparticles in yellow. Obtained as a powder. The surface treatment amount of the cerium oxide nanoparticles was 38.38% as measured in the same manner as in Example 1.

(Comparative Example 2)
1.20 g (7.2 mmol) of sodium octanoate and 10 mL of a 25% aqueous ammonia solution were added to 30 g of pure water and stirred to prepare a transparent solution. A solution prepared by dissolving 33.84 g (7 mmol) of diammonium cerium nitrate in 30 g of pure water was added to this solution, and the mixture was stirred to obtain a pale yellow suspension. After hydrothermal treatment of this suspension in an autoclave at 150 ° C. for 15 hours, the supernatant was removed, and the obtained precipitate was filtered, washed and dried to give 1.17 g of surface-treated cerium oxide nanoparticles yellow. Obtained as a powder. The surface treatment amount of the cerium oxide nanoparticles was 15.34% as measured in the same manner as in Example 1.

(Comparative Example 3)
2.0 g (12 mmol) of sodium octanate and 10 mL of a 25% aqueous ammonia solution were added to 30 g of pure water and stirred to prepare a transparent solution. A solution prepared by dissolving 3.84 g (7 mmol) of diammonium diammonium nitrate in 30 g of pure water was added to this solution, and the mixture was stirred to obtain a pale yellow suspension. After hydrothermal treatment of this suspension in an autoclave at 150 ° C. for 15 hours, the supernatant was removed, and the obtained precipitate was filtered, washed with water and dried to obtain 1.19 g of surface-treated cerium oxide nanoparticles in yellow. Obtained as a powder. The surface treatment amount of the cerium oxide nanoparticles was 15.23% as measured in the same manner as in Example 1.

(Comparative Example 4)
4.20 g (14 mmol) of ricinoleic acid, 20 mL of a 25% aqueous ammonia solution and 5 mL of a 6M sodium hydroxide aqueous solution were added to 15 g of pure water and stirred to prepare a transparent solution. A solution prepared by dissolving 7.68 g (14 mmol) of diammonium cerium nitrate in 30 g of pure water was added to this solution, and the mixture was stirred to obtain a pale yellow suspension. After hydrothermal treatment of this suspension in an autoclave at 180 ° C. for 15 hours, the supernatant was removed, and the obtained precipitate was filtered, washed with water, and dried to obtain 2.75 g of surface-treated cerium oxide nanoparticles in yellow. Obtained as a powder. The surface treatment amount of the cerium oxide nanoparticles was 15.23% as measured in the same manner as in Example 1.

For the cerium oxide particles obtained in Examples 1 to 5 and Comparative Examples 1 to 4, the dispersibility and transparency of the dispersion in the organic solvent or monomer in 50% of the cerium oxide particles, and the crystals calculated from the Scherrer formula. Table 1 shows the coating amount of the surface treatment agent on cerium oxide estimated from the particle diameter and thermal mass measurement.

(Manufacturing Example 1)
Surface-treated cerium oxide nanoparticles content after drying in a toluene mixed solution of 1 part of 2-acryloyloxyethyl succinate (refractive index = 1.463) and 2 parts of ethoxylated o-phenylphenol acrylate (refractive index = 1.577) The surface-treated cerium oxide nanoparticles of Example 4 are added so as to have a concentration of 45%, spin-coated on a glass substrate so as to have a film thickness of 1 μm in the presence of a photopolymerization initiator, and photopolymerized by irradiation with ultraviolet rays. A cured film was obtained in. The refractive index of the cured film at 589 nm using a film thickness monitor (manufactured by Otsuka Electronics Co., Ltd .: FE-300UV) was 1.640.
In addition, when the transmittance at 300-800 nm was measured with an ultraviolet-visible spectrophotometer, it was confirmed that it shielded more ultraviolet rays than the cured film containing only glass and acrylate (Comparative Production Example 1) (Comparative Production Example 1). (See FIG. 2).
Furthermore, when the permeation value and haze value of the cured film were measured, the permeation value was 89.0 and the haze value was 0.07, confirming the transparency.

(Comparative Manufacturing Example 1)
When the surface-treated cerium oxide nanoparticles were removed in Production Example 1, the refractive index of the cured film having a film thickness of 1 μm was 1.562, the transmission value was 90.0, and the haze value was 0.08.

The cerium oxide produced in Comparative Example 1 did not dissolve or disperse in the monomer, so that a resin composition that could be evaluated could not be obtained.

Claims (7)

A step of dissolving a metal salt of a hydroxyl group-free carboxylic acid and a metal salt of a hydroxyl group-containing carboxylic acid in aqueous ammonia,
The step of adding an aqueous solution of diammonium cerium nitrate to the obtained solution, and
The step of subjecting the obtained mixture to a hydrothermal reaction and
A method for producing cerium oxide nanoparticles, which comprises . The method for producing cerium oxide nanoparticles according to claim 1, wherein the hydroxyl group-free carboxylic acid is an aliphatic monocarboxylic acid or an aromatic monocarboxylic acid. The method for producing cerium oxide nanoparticles according to claim 1 or 2, wherein the hydroxyl group-free carboxylic acid has 3 or more and 22 or less carbon atoms. The method for producing cerium oxide nanoparticles according to any one of claims 1 to 3, wherein the hydroxyl group-containing carboxylic acid is a hydroxyl group-containing aliphatic monocarboxylic acid. The method for producing cerium oxide nanoparticles according to any one of claims 1 to 4, wherein the hydroxyl group-containing carboxylic acid has 6 or more and 22 or less carbon atoms. The cerium oxide particles obtained in any of the manufacturing method of claims 1 5, characterized in Rukoto dispersed in a dispersion medium containing at least one selected from organic solvents, monomers and polymerizable oligomers A method for producing a cerium oxide nanoparticles dispersion. A step of dispersing the cerium oxide nanoparticles obtained by the production method according to any one of claims 1 to 5 in a dispersion medium containing at least one selected from a monomer and a polymerizable oligomer.
The step of polymerizing the obtained dispersion and
A method for producing a cerium oxide nanoparticle-dispersed resin complex, which comprises.

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