JP2016020431A - Dispersion liquid of metal oxide particle, composition containing metal oxide particle, coating film, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dispersion liquid of metal oxide particles having high transparency and excellent stability with time, a composition containing metal oxide particles, a coating film, and a display device.SOLUTION: The dispersion liquid of metal oxide particles of the present invention comprises the following metal oxide particles dispersed in a solvent. The metal oxide particles are surface-treated with a silicon compound represented by General Formula (1): R'Si(OR), where R represents a hydrogen atom or an alkyl group, R' represents an organic group, and n and m satisfy n+m=4 and 0<n<4, and have an average primary particle diameter of 3 nm or more and 20 nm or less and a refractive index of 1.9 or more. The solvent contains the following organic solvent by 70 mass% or more: the organic solvent has a solubility parameter of 8.0 or more and 12 or less, and solubility with water of 1.5/100 ml or more. The dispersion liquid contains an amine having 2 or more carbon atoms and contains water by 3 mass% or less with respect to the content of the metal oxide particles.SELECTED DRAWING: None

Description

  The present invention relates to a metal oxide particle dispersion, a metal oxide particle-containing composition, a coating film, and a display device.

Metal oxide particles are used for the purpose of adjusting the refractive index, imparting functionality such as conductivity, antistatic properties, ultraviolet shielding properties, heat ray shielding properties, electromagnetic wave shielding properties, and improving mechanical strength. It is used by being dispersed in a substrate or the like.
For example, a functional film of a plastic substrate used in a display device such as a liquid crystal display (LCD), a plasma display (PDP), or an electroluminescence display (EL) requires transparency, refractive index, mechanical properties, and the like. . Therefore, a functional film is provided by applying a composition obtained by mixing inorganic oxide particles such as zirconia having a high refractive index and a resin to a plastic substrate (see, for example, Patent Document 1). .

In addition, by adding zirconium having a high refractive index to the sealing resin that covers the light emitting diode (LED) and controlling the refractive index of the sealing resin, it becomes possible to extract emitted light more efficiently. It is known that the brightness is improved.
Among metal oxide particles, antimony-doped tin oxide (ATO) or tin-doped indium oxide (ITO) particles provide a heat ray shielding coating solution and a heat ray shielding film excellent in visible light transmittance and heat ray shielding properties. (For example, refer to Patent Document 2). Among metal oxide particles, zinc oxide particles are used to obtain a highly transparent gas barrier laminate (see, for example, Patent Document 3).

In the above application, when the metal oxide particles are aggregated in the matrix, functions such as transparency and smoothness in the functional film are deteriorated. Therefore, the metal oxide particles are used in a state of an inorganic particle dispersion previously dispersed in a solvent and mixed in a paint or a resin monomer.
Further, in order to prevent the metal oxide particles from aggregating in the step of mixing the inorganic particle dispersion and the resin, the step of drying the coating film, the step of removing the solvent, etc., the metal oxide particles are used as a solvent. It is required to exhibit excellent dispersibility in paints, coating films, substrates and the like. In particular, when the refractive index of the metal oxide particles is 1.9 or more, the optical properties (transparency, etc.) of the paint, coating film, substrate, etc. after blending are easily changed by the scattering of visible light. The dispersion is required to have high dispersibility and stability.
As a method for dispersing metal oxide particles in a solvent, a method is known in which the surface of metal oxide particles is treated with an organosilicon compound having a group that generates a silanol group by hydrolysis of a silane coupling agent or the like. (For example, see Patent Documents 4 to 6).

  Epoxy resin (10.9), acrylic resin (9.5), polystyrene (8.5 to 10.3), urethane resin (10 to 11), phenol resin (11.5), cellulose resin (10 to 12) In order to disperse the metal oxide particles in a resin having a medium polarity (solubility parameter (SP value) is 8.5 to 12) such as polyester resin (10-11), epoxy resin (10-11), etc. Therefore, the SP value of the dispersion medium in the dispersion should be adjusted to the same level as the SP value of the resin so that the surface-treated metal oxide particles have a good affinity for both the dispersion medium and the resin. It was.

Japanese Patent No. 5515828 JP-A-8-281860 JP 2006-264271 A JP 2007-277505 A International Publication No. 2008/035669 Japanese Patent No. 4609068

  However, in the surface treatment with an organosilicon compound, water is indispensable for causing hydrolysis and polycondensation reaction. Since the SP value of water is as high as 23.4, the dispersibility of the surface-treated metal oxide particles is not improved depending on the water content of the organic solvent, and the transparency of the dispersed inorganic particle dispersion is lowered. There has been a problem that it tends to aggregate with time. In particular, metal oxide particles having a refractive index of 1.9 or more have large light scattering, and it has been difficult to obtain a highly transparent dispersed inorganic particle dispersion.

 The present invention has been made in view of the above circumstances, and provides a metal oxide particle dispersion, a metal oxide particle-containing composition, a coating film, and a display device that have high transparency and excellent stability over time. With the goal.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have a silanol group when an amine having 2 or more carbon atoms is used as a reaction catalyst in a medium-polar organic solvent, Alternatively, the surface treatment reaction of the metal oxide particles by the organosilicon compound having a group that generates a silanol group by hydrolysis proceeds with a small amount of water (water content), so that transparency is high and stability over time. The present inventors have found that a metal oxide particle dispersion excellent in the above can be obtained, and have completed the present invention.

That is, the metal oxide particle dispersion of the present invention is surface-treated with a silicon compound represented by the following general formula (1), has an average primary particle diameter of 3 nm or more and 20 nm or less, and a refractive index of 1.9 or more. Metal oxide particles having a solubility parameter of 8.0 or more and 12 or less and dispersed in a solvent containing 70% by mass or more of an organic solvent having a water solubility of 1.5 g / 100 ml or more This is a product particle dispersion, characterized in that it contains an amine having 2 or more carbon atoms, and the content of water is 3% by mass or less of the content of the metal oxide particles.
R ′ _n Si (OR) _m (1)
(Where R is a hydrogen atom or an alkyl group, R ′ is an organic group, n + m = 4, 0 <n <4)

  The metal oxide particle-containing composition of the present invention comprises the metal oxide particle dispersion of the present invention and a binder component.

  The coating film of the present invention is formed using the metal oxide particle-containing composition of the present invention.

  The display device of the present invention includes the coating film of the present invention.

  According to the metal oxide particle dispersion of the present invention, the transparency is high, the dispersion stability of the metal oxide particles is excellent, and the stability of long-term storage of the dispersion is excellent.

  According to the metal oxide particle-containing composition of the present invention, since the metal oxide particle dispersion liquid of the present invention has high transparency and excellent dispersion stability of the metal oxide particles, Excellent stability and stability for long-term storage of the composition.

  According to the coating film of the present invention, since it is formed using the metal oxide particle-containing composition of the present invention, a coating film having excellent transparency can be obtained.

  According to the display device of the present invention, since the coating film of the present invention having excellent transparency is provided, a display device having excellent visibility can be obtained.

The form for implementing the metal oxide particle dispersion liquid of this invention, a metal oxide particle containing composition, a coating film, and a display apparatus is demonstrated.
Note that this embodiment is specifically described in order to better understand the gist of the invention, and does not limit the present invention unless otherwise specified.

[Metal oxide particle dispersion]
The metal oxide particle dispersion of the present embodiment is surface-treated with a silicon compound represented by the following general formula (1), the average primary particle diameter is 3 nm or more and 20 nm or less, and the refractive index is 1.9 or more. A metal oxide in which a certain metal oxide particle is dispersed in a solvent containing 70% by mass or more of an organic solvent having a solubility parameter of 8.0 or more and 12 or less and a water solubility of 1.5 g / 100 ml or more. The particle dispersion contains an amine having 2 or more carbon atoms, and the water content is 3% by mass or less of the content of the metal oxide particles.
R ′ _n Si (OR) _m (1)
(Where R is a hydrogen atom or an alkyl group, R ′ is an organic group, n + m = 4, 0 <n <4)

"Metal oxide particles"
The metal oxide particles in the present embodiment are not particularly limited as long as the refractive index is a metal oxide particle having a refractive index of 1.9 or more. For example, zirconium, zinc, iron, copper, titanium, tin, cerium, tantalum, Metal oxide particles containing one or more metal elements selected from the group of niobium, tungsten, europium and hafnium are preferably used.

Examples of the metal oxide particles composed of one kind of metal element include zirconium oxide (IV) (ZrO ₂ : refractive index 2.05 to 2.4), zinc oxide (II) (ZnO: refractive index 2.01 to 2.01). 2.1), iron oxide (III) (Fe ₂ O ₃ : refractive index 3.01), copper oxide (I) (Cu ₂ O: refractive index 2.71), titanium oxide (IV) (TiO ₂ : refraction) 2.3 to 2.7), tin (IV) oxide (SnO ₂ : refractive index 2.00), cerium oxide (IV) (CeO ₂ : refractive index 2.1), tantalum oxide (V) (Ta ₂ ) O ₅ : refractive index 2.2), niobium oxide (V) (Nb ₂ O ₅ : refractive index 2.4), tungsten oxide (VI) (WO ₃ : refractive index 2.2), europium oxide (III) ( eu ₂ O _3: refractive index 1.98), hafnium oxide (IV) (HfO _2: refractive index .0) or the like is preferably used.

Examples of the metal oxide particles composed of two kinds of metal elements include potassium titanate (K ₂ Ti ₆ O ₁₃ : refractive index 2.68), barium titanate (BaTiO ₃ : refractive index 2.3 to 2.5). ), Strontium titanate (SrTiO ₃ : refractive index 2.37), potassium niobate (KNbO ₃ : refractive index 2.17), lithium niobate (LiNbO ₃ : refractive index 2.35), calcium tungstate (CaWO ₄₎ : refractive index 1.91), antimony doped tin oxide (ATO; Sb solid solution SnO _2: refractive index 1.95 to 2.05), indium doped tin oxide (ITO; an In solid solution SnO _2: refractive index 1.95 ~ 2.05) and the like are preferably used.

  Among these metal oxide particles, zirconium oxide (IV), zinc oxide (II), titanium oxide (IV), antimony-added tin oxide, and indium-added tin oxide are more preferably used from the viewpoint of raw material costs and manufacturing costs. Zirconium (IV) oxide is more preferably used because it is less likely to be colored by absorption / scattering around 400 nm.

The average primary particle diameter of the metal oxide particles is 3 nm or more and 20 nm or less, preferably 8 nm or more and 20 nm or less, more preferably 10 nm or more and 15 nm or less.
The reason why the average primary particle size of the metal oxide particles is limited to the above range is that if the average primary particle size is less than 3 nm, the crystallinity of the metal oxide particles is low and the target refractive index may not be obtained. When the metal oxide particles are dispersed in a solvent, the metal oxide particles are likely to aggregate, so that a highly transparent dispersion may not be obtained, and the specific surface area of the metal oxide particles is increased. This is because the amount of silicon compound necessary for obtaining the liquid increases, and there is a possibility that a sufficient refractive index cannot be obtained as the surface-treated metal oxide particles. On the other hand, if the average primary particle diameter exceeds 20 nm, the dispersed particle diameter when the metal oxide particles are dispersed in the solvent is increased, and a highly transparent dispersion liquid may not be obtained.

  In the present embodiment, the “average primary particle size” means the particle size of each particle itself. As a measuring method of the average primary particle diameter, using a scanning electron microscope (SEM), a transmission electron microscope (TEM), etc., the major axis of each metal oxide particle, for example, each of 100 or more metal oxide particles A method of measuring the major axis, preferably the major axis of each of the 500 metal oxide particles, and calculating the arithmetic average value thereof can be mentioned.

The specific surface area of the metal oxide particles is preferably ^70m 2 / g or more and is ^{95 m} 2 / g or less.
The reason why the specific surface area of the metal oxide particles is preferably in the above range is that the larger the specific surface area of the metal oxide particles is, the more silicon compound and water are required for the surface treatment. The smaller the specific surface area of the oxide particles, the larger the particle size of the metal oxide particles, or the metal oxide particles are strongly agglomerated such as necking, which makes it difficult to obtain a highly transparent dispersion. Because it becomes.

"Silicon compounds"
The silicon compound in this embodiment is represented by the general formula (1). That is, the silicon compound in the present embodiment is an organosilicon compound having a silanol group or a group that generates a silanol group by hydrolysis.
R in the general formula (1) is a hydrogen atom or an alkyl group having 1 to 22 carbon atoms, and the alkyl group may be linear, branched or cyclic. When the alkyl group is cyclic, it may be monocyclic or polycyclic. The alkyl group preferably has 1 to 22 carbon atoms, and in order to obtain a compound having higher affinity for the solvent described later, the number of carbon atoms is preferably 1 or more and 6 or less. preferable.

The linear or branched alkyl group preferably has 1 to 22 carbon atoms. Examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, n -Butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylbutyl group, n-hexyl group, 2-methylpentyl group, 3 -Methylpentyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 2,2-dimethylpentyl group, 2,3- Dimethylpentyl group, 2,4-dimethylpentyl group, 3,3-dimethylpentyl group, 3-ethylpentyl group, 2,2,3-trimethylbutyl group, n- Examples include octyl, isooctyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, heicosyl, docosyl, etc. It is done.
The linear or branched alkyl group preferably has 1 or more and 6 or less carbon atoms from the viewpoint of affinity for the solvent described later.

The cyclic alkyl group preferably has 3 to 10 carbon atoms. Examples of such an alkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, Examples include a cyclononyl group, a cyclodecyl group, a norbornyl group, an isobornyl group, a 1-adamantyl group, and a 2-adamantyl group. Furthermore, examples of the alkyl group include those in which one or more hydrogen atoms of these cyclic alkyl groups are substituted with a linear, branched or cyclic alkyl group.
The cyclic alkyl group preferably has 3 or more and 6 or less carbon atoms from the viewpoint of affinity for the solvent described later.

  Further, one or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom. Examples of the halogen atom substituted for the hydrogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

R ′ in the general formula (1) is an organic group and may be appropriately selected in consideration of the affinity with the solvent described later. For example, acryloyl group, methacryloyl group, vinyl group, propyl group, butadienyl group Styryl group, ethynyl group, cinnamoyl group, maleate group, acrylamide group, amino group, allyl group, epoxy group, glycidoxy group and the like.
The organic group is preferably a functional group having a polymerizable unsaturated group, and the polymerizable unsaturated group is not particularly limited, and examples thereof include acryloyl group, methacryloyl group, vinyl group, propenyl group, butadienyl group, styryl. Group, ethynyl group, cinnamoyl group, maleate group, acrylamide group and the like. These polymerizable unsaturated groups are structural units that undergo addition polymerization with active radical species.

  In the general formula (1), n and m satisfy n + m = 4 and 0 <n <4, and n is preferably 2 or more and 3 or less.

Examples of the silicon compound represented by the general formula (1) include compounds in which an alkoxy group such as a methoxy group, an ethoxy group, and an isopropoxy group, an aryloxy group, an acetoxy group, an amino group, or a halogen atom is bonded to a silicon atom. Among these, a compound in which an alkoxy group is bonded to a silicon atom, that is, an organoalkoxysilane is particularly preferable.
Specific examples of the silicon compound represented by the general formula (1) include vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycidoxypropyl. Trimethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxy Propylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, vinyl Ethyldimethoxysilane, vinylethyldiethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxy Silane, 3-aminopropyltriethoxysilane, tris- (trimethoxysilylpropyl) isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilyl) Propyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane and the like.

  The silicon compound represented by the general formula (1) has a polymerizable unsaturated group such as acryloyl group, methacryloyl group, vinyl group, propenyl group, butadienyl group, styryl group, ethynyl group, cinnamoyl group, maleate group, and acrylamide group. Since it contains a functional group having a functional group, it can be bonded to a resin or the like. Therefore, when the metal oxide particle dispersion of this embodiment is blended into a paint or the like and a coating film is produced, the metal oxide particles are less likely to aggregate. .

  The surface treatment of the metal oxide particles with the silicon compound means that the silicon compound and the metal oxide particles have some interaction and are bonded to each other, and may be bonded by a covalent bond or physical adsorption. It may be bonded by a non-covalent bond such as. Moreover, after pre-hydrolyzing metal oxide particles and allowing some or all of the hydrolysis to proceed, the metal oxide particles may be surface-treated with a silicon compound.

"Organic solvent"
The solvent in the present embodiment contains 70% by mass or more and 80% by mass or more of an organic solvent having a solubility parameter (SP value) of 8.0 or more and 12 or less and a water solubility of 1.5 g / 100 ml or more. It is preferable to contain, and it is more preferable to contain 90 mass% or more.
The reason why the content of the organic solvent is limited to the above range is that when the content of the organic solvent is less than 70% by mass, when the coating film is formed using the metal oxide particle dispersion of this embodiment, When removing the solvent from the metal oxide particle dispersion liquid of the embodiment, the metal oxide particles may aggregate or gel, or the water necessary for hydrolysis of the silicon compound may not be dissolved. After mixing the form of the metal oxide particle dispersion into the paint, the volatilization rate increases when forming a coating film using the paint or removing the solvent from the paint, so that the metal oxide particles segregate. It is because there is a possibility of doing.

The reason why the solubility parameter of the organic solvent is limited to the above range is that the metal oxide particle dispersion of this embodiment is an epoxy resin (SP value: 10.9), an acrylic resin (SP value: 9.5), Polystyrene (SP value: 8.5 to 10.3), urethane resin (SP value: 10 to 11), phenol resin (SP value: 11.5), cellulose resin (SP value: 10 to 12), polyester resin ( It is because it can mix | blend suitably with resin (SP value: 8.5-12) of medium polarity like SP value: 10-11) and an epoxy resin (SP value: 10-11).
The reason why the solubility parameter of the organic solvent is limited to the above range is that when the solubility parameter is not within the above range, the difference in polarity between the metal oxide particle dispersion of this embodiment and the above resin is large. When it is difficult to obtain a transparent paint, or when forming a coating film using the paint containing the metal oxide particle dispersion liquid of this embodiment, or when removing the solvent from the paint, the metal oxide This is because the particles may be aggregated or gelled.

  Examples of the organic solvent in the present embodiment include methyl isobutyl ketone (SP value: 8.4), butyl acetate (SP value: 8.5), ethyl acrylate (SP value: 8.6), diacetone alcohol ( SP value: 9.2), methyl ethyl ketone (SP value: 9.3), cyclohexanone (SP value: 9.9), 1-methoxy-2-propanol (SP value: 9.5), dodecanol (SP value: 9) 8-10.3), cyclopentanone (SP value: 10.4), 2,3-butanediol (SP value: 11.1), 1-propanol (SP value: 11.9), and the like. .

In the present embodiment, the solubility parameter ((cal / cm) ^1/2 ) is, for example, J. It can be calculated by the method described in VII 675 to 713 of “Polymer Handbook fourth edition” by Brandrup et al. (Especially formulas B3 and B8). Moreover, the value of Table 1 (VII 711) of the said literature, Table 7 (VII 688-694), and Table 8 (VII 694-697) can be used.

The boiling point of the organic solvent is preferably 80 ° C. or higher.
The reason why the boiling point of the organic solvent is preferably in the above range is that, when the boiling point of the organic solvent is less than 80 ° C., the metal oxide particle dispersion liquid of the present embodiment is blended into the paint, and then the paint is used. This is because when the coating film is formed or when the solvent is removed from the paint, the volatilization rate becomes high, and the metal oxide particles may be segregated.

  The reason why the solubility of water in the organic solvent is limited to the above range is that if the solubility of the water in the organic solvent is not in the above range, the amount of water necessary for hydrolysis of the silicon compound cannot be dissolved in the organic solvent. Because there is a fear.

Examples of the organic solvent having a solubility parameter of 8.0 or more and 12 or less and a water solubility of 1.5 g / 100 ml or more include methyl isobutyl ketone (MIBK), cyclohexanone, diacetone alcohol, 1-methoxy-2 -Propanol (PGM), isopropanol, methyl ethyl ketone (MEK), ethyl acetate and the like.
As the organic solvent, a solvent having a solubility parameter of 8.0 or more and 12 or less and a water solubility of 1.5 g / 100 ml or more may be used alone, or a mixed solvent in which two or more kinds are mixed. Also good.

  The solvent in the present embodiment removes the solvent from the coating speed and the drying speed when forming a coating film using a paint containing the metal oxide particle dispersion liquid of the present embodiment in addition to the organic solvent described above. In order to adjust the volatilization rate at the time, a high boiling point solvent, a dispersing agent or the like may be included.

"Amine"
The amine having 2 or more carbon atoms in the present embodiment plays a role as a catalyst in the surface treatment of the metal oxide particles by the silicon compound. In addition, the amine having 2 or more carbon atoms in the present embodiment serves as a dispersant for the metal oxide particles, and suppresses the progress of the surface treatment reaction in a state where the metal oxide particles are aggregated.
Also, amines with 2 or more carbon atoms have their substituents interacting with the metal oxide particles, so the hydrolysis reaction proceeds on the surface of the metal oxide particles and the progress of condensation between silicon compounds is suppressed. And it plays the role of facilitating the surface treatment reaction of the metal oxide particles by the silicon compound. Therefore, the amine in this embodiment preferably has 6 or more carbon atoms, and more preferably has 10 or more carbon atoms.

Examples of the amine having 2 or more carbon atoms in this embodiment include alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine; monoethylamine, diethylamine, and triethylamine , Ethylenediamine, isopropylamine, diethylenetriamine, 2-ethylhexylamine, triethylenetetramine, tetraethylenepentamine, and other aliphatic polyamines; aniline, o-toluidine, methylene orthochloramine, 4,4′-diphenylmethanediamine, 2,4 ′ -Aromatic polyamines such as tolylenediamine, 2,6'-tolylenediamine, 4-aminobenzoic acid; polyaminoamide, polyalkylolaminoa And the like; id, polyoxyethylene alkyl amines, polyester polyamines, polymers having an amino group such as an amino-modified silicone.
Among these, in the metal oxide particle dispersion liquid of the present embodiment, polymers having amino groups such as polyaminoamide and polyalkylolaminoamide that also have a function as a dispersibility / dispersion aid of the metal oxide particles are preferable. .

The product of the amine value of an amine having 2 or more carbon atoms and the content of the amine having 2 or more carbon atoms, that is, (amine value of an amine having 2 or more carbon atoms) × (metal of this embodiment) The content (mass%) of the amine having 2 or more carbon atoms with respect to the whole oxide particle dispersion is preferably 10 or more and 45 or less, and more preferably 25 or more and 42 or less.
The reason why the product of the amine value of the amine having 2 or more carbon atoms and the content of the amine having 2 or more carbon atoms is preferably in the above range is that the product is less than 10 and the reaction catalyst This is because there is a possibility that the hydrolysis reaction of the silicon compound does not proceed sufficiently because the amount of amine as is small. On the other hand, when the product exceeds 45, when the metal oxide particle dispersion liquid of the present embodiment is blended into a paint and a coating film is formed using the paint, the amount of amine is too large. This is because the physical properties of the contained resin may be deteriorated.

In the metal oxide particle dispersion of this embodiment, the water content is 3% by mass or less of the content of the metal oxide particles. That is, when the content of the metal oxide particles in the metal oxide particle dispersion is 100% by mass, the content of water in the metal oxide particle dispersion is 3% by mass of the content of the metal oxide particles. It is as follows.
If the water content exceeds 3% by mass of the metal oxide particle content, the temporal stability in the metal oxide particle dispersion may be impaired. Moreover, since the solubility parameter of water is as high as 23.4, the metal oxide particle dispersion of this embodiment is blended with a paint containing a resin having a medium polarity (SP value: 8.5 to 12). When a coating film is formed using the paint, the polarity in the paint increases as the solvent volatilizes from the paint film, and the metal oxide particles may aggregate or segregate. .
The stability over time of the metal oxide particle dispersion of the present embodiment means that the metal oxide particles are less likely to aggregate over time and the metal oxide particles are stably dispersed in the solvent over a long period of time. That's it.

If the metal oxide particle dispersion liquid of this embodiment contains an amount of water necessary for the hydrolysis of the silicon compound, the water content is preferably as small as possible. Specifically, the content of water in the metal oxide particle dispersion is preferably 1.2% by mass or less based on the entire metal oxide particle dispersion.
The reason why the content of water in the metal oxide particle dispersion is preferably in the above range is that when the water content exceeds 1.2% by mass, the stability over time of the metal oxide particle dispersion is reduced. This is because there is a risk of damage. Here, the content of water necessary for the hydrolysis of the silicon compound is an amount by which hydrolysis necessary for the surface treatment of the metal oxide particles with the silicon compound proceeds, and all the hydrolysis proceeds (hydrolysis). The water content may be less than that required for a rate of 100%). In addition, for the surface treatment reaction, attached water of metal oxide particles and bound water can be used.

The content of the metal oxide particles in the metal oxide particle dispersion of the present embodiment is preferably 10% by mass or more and 60% by mass or less with respect to the entire metal oxide particle dispersion of the present embodiment. 20 mass% or more and 50 mass% or less is more preferable, and 30 mass% or more and 50 mass% or less is further more preferable.
The reason why the content of the metal oxide particles in the metal oxide particle dispersion is preferably in the above range is that when the content of the metal oxide particles is less than 10% by mass, the metal oxide particles are dispersed in the paint or the like. When the liquid is blended and used, the amount of solvent in the paint increases, so there is a risk that the cost of the solvent and the cost of removing the solvent from the coating film formed using the paint may increase. On the other hand, when the content of the metal oxide particles exceeds 60% by mass, the interaction between the metal oxide particles becomes strong, and as a result, the viscosity of the metal oxide particle dispersion increases or the metal oxide particles There is a possibility that the temporal stability of the metal oxide particle dispersion may be lowered, such as gelling of the dispersion.

When the dispersed particle diameter of the metal oxide particles in the metal oxide particle dispersion is sufficiently smaller than the wavelength of light, that is, when α << 1 (generally α <0.4) in the following formula (2) The light scattering by the metal oxide particles is Rayleigh scattering. On the other hand, when the dispersed particle diameter of the metal oxide particles in the metal oxide particle dispersion is larger than the wavelength of light, light scattering by the metal oxide particles is Mie scattering.
α = π · D / λ (2)
In the above formula (2), α is a particle size parameter, D is a dispersed particle size of metal oxide particles, and λ is a wavelength of light.
Therefore, in the visible light region (wavelength 400 nm to 800 nm), when the dispersed particle diameter of the metal oxide particles exceeds about 50 nm, Mie scattering with higher scattering intensity is performed instead of Rayleigh scattering. Since the scattering intensity depends not only on the dispersed particle diameter of the metal oxide particles but also on the refractive index of the metal oxide particles, in particular, the metal oxide particle dispersion including metal oxide particles having a refractive index of 1.9 or more. In order to increase the transparency of the liquid, it is important to maintain the dispersed particle size of the metal oxide particles at about 50 nm or less.

Therefore, it is preferable that the particle size (D90) when the cumulative deposition percentage of the particle size distribution of the metal oxide particle dispersion of the present embodiment is 90% is 60 nm or less, and is 50 nm or less. More preferred.
If the particle size (D90) when the cumulative deposition percentage of the particle size distribution of the metal oxide particle dispersion is 90% is 60 nm or less, the transparency of the metal oxide particle dispersion can be increased.

  In addition, when the particle size distribution of the metal oxide particle dispersion is wide, coarse particles are also increased, so that the transparency of the metal oxide particle dispersion tends to be low. Further, since coarse particles are more likely to settle, it is necessary to obtain a dispersion having a sharp particle size distribution in order to improve the temporal stability of the metal oxide particle dispersion. Therefore, in terms of both transparency and stability over time, in the metal oxide particle dispersion liquid of this embodiment, the particle size (D90) when the cumulative volume percentage of the particle size distribution is 90% is the cumulative volume percentage of the particle size distribution. The value divided by the particle size (D50) at 50% is preferably 3 or less, and more preferably 2 or less. In particular, from the viewpoint of the content of the silicon compound necessary for the preparation of the metal oxide particle dispersion and the crystallinity of the metal oxide particles, the metal oxide containing metal oxide particles having an average primary particle diameter of 10 nm or more and 20 nm or more. When preparing a product particle dispersion, it is important that D90 / D50 is 3 or less. The lower limit of D90 / D50 is 1 or more.

The metal oxide particle dispersion of the present embodiment has a liquid haze value of preferably 35% or less, more preferably 27% or less, and preferably 22% or less when measured on the basis of air. Further preferred.
The reason why the liquid haze value of the metal oxide particle dispersion is preferably in the above range is that when the liquid haze value exceeds 35%, the metal oxide particle dispersion is blended into the paint, and the paint is used. The formed coating film has a strong light scattering, and the coating film may not be suitable for the specification in optical applications, and when used as a protective layer, the design of the underlayer may be impaired. is there.

In addition, the metal oxide particle dispersion of this embodiment preferably has a liquid haze value of 35% or less when the content of metal oxide particles is 30% by mass and the optical path length is 2 mm. % Or less is more preferable, and 22% or less is more preferable.
The reason why the liquid haze value of the metal oxide particle dispersion is preferably in the above range when the content of the metal oxide particles is 30% by mass and the optical path length is 2 mm is that the liquid haze value is 35. If the ratio exceeds 50%, the coating film formed by using the coating composition with the metal oxide particle dispersion liquid becomes strong in light scattering, and the coating film may not be suitable for optical use. This is because, when used as a protective layer or the like, the design of the underlayer may be impaired.
Further, in the metal oxide particle dispersion of this embodiment, the liquid haze value is preferably 25% or less when the content of the metal oxide particles is 10% by mass and the optical path length is 2 mm. % Or less is more preferable, and 15% or less is still more preferable.
The reason why the liquid haze value of the metal oxide particle dispersion is preferably in the above range when the content of the metal oxide particles is 10% by mass and the optical path length is 2 mm is that the liquid haze value is 25. If the ratio exceeds 50%, the coating film formed by using the coating composition with the metal oxide particle dispersion liquid becomes strong in light scattering, and the coating film may not be suitable for optical use. This is because, when used as a protective layer or the like, the design of the underlayer may be impaired.

  Here, the “haze value” is the ratio (%) of the diffuse transmitted light to the total light transmitted light, and the “liquid haze value” is a haze meter (trade name: HAZE METER) using a 2 mm cuvette. It is a haze value of a metal oxide particle dispersion measured by TC-H3DP (manufactured by Tokyo Denshoku).

  Moreover, the metal oxide particle dispersion liquid of the present embodiment may contain other components such as a dispersant, a photosensitizer, and a resin.

[Production Method of Metal Oxide Particle Dispersion]
Although it does not specifically limit as a manufacturing method of the metal oxide particle dispersion liquid of this embodiment, For example, the manufacturing method of a well-known dispersion liquid as described in said patent document 4 is used. In addition, as a method for producing the metal oxide particle dispersion of the present embodiment, for example, after preparing a suspension of metal oxide particles, a silicon compound is added to the suspension, A method of performing a surface treatment reaction, a method of mechanically mixing the components of the metal oxide particle dispersion described above, and the like are also preferably used.

When preparing a suspension of metal oxide particles and then adding a silicon compound to the suspension to carry out a surface treatment reaction of the metal oxide particles, zirconia beads etc. A bead mill, a ball mill, a homogenizer, a disper, a stirrer and the like using the above media are preferably used. In addition, amine or water may be added to the suspension, or may be added during the surface treatment reaction of the metal oxide particles. In addition, amine or water can be added stepwise or continuously in order to adjust the reaction rate of the surface treatment reaction of the metal oxide particles.
When the components of the metal oxide particle dispersion are blended and then mechanically mixed, a bead mill, a ball mill, a homogenizer, a disper, a stirrer, or the like using media such as zirconia beads is preferably used. In addition, amine or water can be added stepwise or continuously in order to adjust the reaction rate of the surface treatment reaction of the metal oxide particles.

  According to the metal oxide particle dispersion liquid of the present embodiment, an amine having 2 or more carbon atoms is used as a reaction catalyst in a medium polarity organic solvent without using a binder. The surface of the metal oxide particles can be treated with the silicon compound by the interaction such as covalent bonding between the silicon compound and the metal oxide particles represented by the formula (1), and the dispersion stability of the metal oxide particles is high. And a metal oxide particle dispersion having excellent dispersion stability for a long period of time can be obtained.

[Metal oxide particle-containing composition]
The metal oxide particle-containing composition of the present embodiment comprises the metal oxide particle dispersion liquid of the present embodiment and a binder component.

"Binder component"
Although a binder component is not specifically limited, For example, a resin monomer, a resin oligomer, a resin polymer, an organosilicon compound, its polymer, etc. can be used conveniently.

The binder component in applications such as a display device is not particularly limited as long as it is a monomer, oligomer, or polymer of a curable resin used for a general hard coat film. A polymer may be used and a monomer or oligomer of a thermosetting resin may be used.
Examples of the photocurable resin monomer include radical polymerization monomers such as monofunctional acrylates, bifunctional acrylates, trifunctional acrylates, and 4-6 functional acrylates, alicyclic epoxy resins, glycidyl ether epoxy resins, urethane vinyl ethers, And cationic polymerization monomers such as polyester vinyl ether.
Examples of the photocurable resin oligomers and polymers include, for example, epoxy acrylate, urethane acrylate, polyester acrylate, copolymer acrylate, polybutadiene acrylate, silicon acrylate, amino resin acrylate, and other radical polymerization oligomers, polymers, and alicyclic epoxies. Examples thereof include cationic polymerization oligomers and polymers such as resins, glycidyl ether epoxy resins, urethane vinyl ethers, and polyester vinyl ethers.
Among these, radically polymerizable monomers, oligomers, and polymers that can be easily blended with a plurality of components and can suppress a curing failure by using a photoinitiator and a light stabilizer are preferably used.
For applications that require scratch resistance and abrasion resistance, a radical polymerization polyfunctional monomer such as dipentaristol hexaacrylate is preferably used.

For applications that require adhesion, flexibility and low shrinkage, radical polymerization oligomers and polymers such as urethane acrylate are preferably used.
The monomers, oligomers and polymers of these photopolymerizable resins can be used alone, or two or more kinds can be mixed and used in accordance with the required function.
Examples of the functional group other than the acryloyl group and methacryloyl group of the polyfunctional monomer include a vinyl group, an allyl group, an allyl ether group, a styryl group, and a hydroxyl group.

  Specific examples of the polyfunctional acrylate include, for example, (meth) trimethylolpropane triacrylate, (meth) ditrimethylolpropane tetraacrylate, (meth) pentaerythritol triacrylate, (meth) pentaerythritol tetraacrylate, (meth) dipenta Examples include polyol polyacrylates such as erythritol hexaacrylate, epoxy (meth) acrylates, polyester (meth) acrylates, urethane acrylates, and polysiloxane acrylates. These polyfunctional acrylates may be used alone or in combination of two or more.

  In the metal oxide particle-containing composition of the present embodiment, the functional group has one or two functional groups as long as the effects of the invention are not inhibited, and monomers, oligomers, dispersants not included in the above-mentioned monomers, Polymerization initiator, antistatic agent, refractive index regulator, antioxidant, ultraviolet absorber, light stabilizer, leveling agent, antifoaming agent, inorganic filler, coupling agent, preservative, plasticizer, flow regulator In addition, various general additives such as a thickener, a pH adjuster, and a polymerization initiator may be appropriately contained.

  Examples of the dispersant include anionic surfactants such as sulfate esters, carboxylic acids, and polycarboxylic acids, cationic surfactants such as quaternary salts of higher aliphatic amines, higher fatty acid polyethylene glycol esters, and the like. Nonionic surfactants, silicon surfactants, fluorine surfactants, polymer surfactants having an amide ester bond, and the like.

  A polymerization initiator is suitably selected according to the kind of monomer to be used. When using a monomer of a photocurable resin, a photopolymerization initiator is used. The kind and amount of the photopolymerization initiator are appropriately selected according to the monomer of the photocurable resin to be used. As the photopolymerization initiator, for example, benzophenone, diketone, acetophenone, benzoin, thioxanthone, quinone, benzyldimethyl ketal, alkylphenone, acylphosphine oxide, phenylphosphine oxide, and the like are known. The photoinitiator of this is mentioned.

Since the metal oxide particle-containing composition of the present embodiment is applied to a substrate to form a coating film, the viscosity is 0.2 mPa · s or more and 500 mPa · s in order to facilitate coating. or less, more preferably 0.5 mPa · s or more and 200 mPa · s or less.
If the viscosity of the metal oxide particle-containing composition is 0.2 mPa · s or more, it is preferable because the film thickness when formed into a coating film does not become too thin and the film thickness can be easily controlled. On the other hand, when the viscosity of the metal oxide particle-containing composition is 500 mPa · s or less, the viscosity is not too high, and the metal oxide particle-containing composition at the time of coating becomes easy to handle, which is preferable.

The viscosity of the metal oxide particle-containing composition is preferably adjusted to the above range by appropriately adding an organic solvent to the metal oxide particle-containing composition.
The organic solvent is not particularly limited as long as it is compatible with the above-described composition containing metal oxide particles. For example, aliphatic hydrocarbons such as hexane, heptane and cyclohexane, and aromatics such as toluene and xylene. Hydrocarbons, alcohols such as methanol, ethanol and propanol, halogenated hydrocarbons such as methylene chloride and ethylene chloride, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-pentanone and isophorone, ethyl acetate and butyl acetate Esters, cellosolves such as ethyl cellosolve, ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether, amide solvents, and ether ester solvents. These solvents may be used alone or in combination of two or more.

  According to the metal oxide particle-containing composition of the present embodiment, since it contains the metal oxide particle dispersion of the present invention, which has high transparency and excellent dispersion stability of the metal oxide particles, Excellent dispersion stability and excellent long-term storage stability of the composition.

[Method for producing metal oxide particle-containing composition]
As a manufacturing method of the metal oxide particle containing composition of this embodiment, the method of mixing each material mentioned above as a component of a metal oxide particle containing composition mechanically is mentioned.
Examples of the mixing device include a stirrer, a self-revolving mixer, a homogenizer, and an ultrasonic homogenizer.

[Coating]
The coating film of this embodiment is formed using the metal oxide particle containing composition of this embodiment.
The film thickness of this coating film is appropriately adjusted depending on the application, but is usually preferably 0.01 μm or more and 20 μm or less, more preferably 0.5 μm or more and 10 μm or less, and more preferably 0.5 μm or more. More preferably, the active area is 2 μm or less.

The manufacturing method of the coating film of this embodiment has the process of forming a coating film by coating on said metal oxide particle containing composition, and the process of hardening this coating film.
Examples of the coating method for forming a coating film include a bar coating method, a flow coating method, a dip coating method, a spin coating method, a roll coating method, a spray coating method, a meniscus coating method, a gravure coating method, a suction coating method, A normal wet coating method such as a brush coating method is used.

As a curing method for curing the coating film, a method of appropriately selecting according to the kind of the binder component and performing thermal curing or photocuring is used.
The energy ray used for photocuring is not particularly limited as long as the coating is cured. For example, energy such as ultraviolet rays, far infrared rays, near ultraviolet rays, infrared rays, X rays, γ rays, electron beams, proton rays, neutron rays, etc. A line is used. Among these energy rays, it is preferable to use ultraviolet rays because the curing speed is fast and the device is easily available and handled.

In the case of curing by ultraviolet irradiation, ultraviolet rays are applied at an energy of 100 to 3,000 mJ / cm ² using a high-pressure mercury lamp, metal halide lamp, xenon lamp, chemical lamp, etc. that generates ultraviolet rays in a wavelength band of 200 nm to 500 nm. The method of irradiating etc. is mentioned.

  In the coating film of the present embodiment, the metal oxide particles having a sharp particle size distribution in the present embodiment, in other words, in the metal oxide particle-containing composition, the size of the metal oxide particles is almost uniform. The metal oxide particles are easily filled uniformly in the coating film without any gaps. Therefore, the film-forming property of the coating film is excellent, and the performance at all locations in the film surface is uniform. Therefore, for example, since the refractive index in the film surface becomes almost uniform, the occurrence of uneven color in the coating film is suppressed, and the visibility can be improved when applied to a display device or the like.

In the coating film of this embodiment, since metal oxide particles having a sharp particle size distribution are used, the metal oxide particles are uniformly filled in the film, and there are few voids in the film. Therefore, for example, when it is desired to improve the refractive index using metal oxide particles having a refractive index of 1.9 or more, it is possible to reduce the amount of metal oxide particles necessary to improve the refractive index than before. it can. Accordingly, even in a thin film of 10 nm to 200 nm, the entire coating film is filled with metal oxide particles uniformly, and voids in the film can be reduced uniformly, thereby improving the refractive index of the coating film. be able to.
Moreover, in the coating film of this embodiment, since the performance in all the places in a film surface becomes uniform, even if it is a thick film with a film thickness of 1 micrometer or more, generation | occurrence | production of an optical nonuniformity can be suppressed. Particularly when the silicon compound has a functional group having a polymerizable unsaturated group, the metal oxide particles are bonded to the resin at the time of curing, so that they aggregate in the film at the time of curing or the particle distribution differs between the surface and the inside of the film. Is preferable, and a thick film of 1 μm or more is particularly preferable.
That is, the coating film of this embodiment may be a thin film for adjusting the refractive index, or may be a thick film that can adjust the refractive index and also has a hard coat property, depending on the application. Can be used.

  According to the coating film of this embodiment, since it is formed using the metal oxide particle containing composition of this embodiment, the coating film excellent in transparency and film formability can be obtained.

[Plastic substrate with paint film]
The plastic substrate with a coating film of this embodiment has a base body (plastic base material) formed using a resin material, and the coating film of this embodiment provided on at least one surface of the base body.

  The plastic substrate with a coating film is formed by coating the metal oxide particle-containing composition of the present embodiment on a substrate body using a known coating method, and curing the coating film. Is obtained.

The substrate body is not particularly limited as long as it is a plastic substrate. For example, polyethylene terephthalate, triacetyl cellulose, acrylic, acrylic-styryl copolymer, acrylonitrile-butadiene-styrene copolymer, polystyrene, polyethylene, polypropylene, polycarbonate Those formed from plastic such as vinyl chloride are used.
When used for a display device, it is preferable to use a plastic substrate having optical transparency as the substrate body.

  The substrate body may be in the form of a sheet or film, but is preferably in the form of a film.

  The plastic substrate with a coating film of the present embodiment has a haze value of preferably 1.4% or less, more preferably 1.0% or less, when measured on the basis of air.

  Here, the “haze value” is a ratio (%) of diffuse transmitted light to total light transmitted light, and a haze meter NDH-2000 (manufactured by Nippon Denshoku Co., Ltd.) is used on the basis of air. It means a value measured based on the standard JIS-K-7136.

  In the plastic substrate with a coating film of the present embodiment, a hard coat film may be provided between the plastic substrate and the coating film, or a film having a different performance such as a refractive index from the coating film may be laminated.

  According to the plastic substrate with a coating film of the present invention, since the coating film of the present embodiment is formed, a plastic substrate with a coating film having excellent transparency and film forming property can be obtained.

[Display device]
The display device of this embodiment includes one or both of the coating film of this embodiment and the plastic substrate with a coating film of this embodiment.
The display device is not particularly limited, but in this embodiment, a liquid crystal display device for a touch panel will be described.

[Touch panel]
In the touch panel, when the refractive index difference between the ITO electrode and the transparent base material (plastic base material such as polyethylene terephthalate) is large, a so-called bone appearance phenomenon occurs in which the ITO electrode portion is easily visible.
Therefore, the difference in refractive index between the transparent base material and the ITO electrode is obtained by providing the coating film of this embodiment in which the metal oxide particles having a refractive index of 1.9 or more are selected as a layer between the transparent base material and the ITO electrode. It is possible to relax the bone appearance phenomenon.
The method of providing either one or both of the coating film of this embodiment and the plastic substrate with a coating film of this embodiment on the touch panel is not particularly limited, and may be implemented by a known method. For example, the structure etc. which patterned the ITO electrode on the coating-film surface of the plastic base material with a coating film of this embodiment, and laminated | stacked the orientation film and the liquid crystal layer are mentioned.

  According to the display device of this embodiment, since it has either one or both of the coating film of this embodiment and the plastic substrate with a coating film of this embodiment, which is excellent in transparency and film formability, the coating film Since there is almost no variation in optical characteristics within the surface, a display device with excellent visibility can be obtained.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited by these Examples.

[Example 1]
"Metal oxide particle dispersion"
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-methacryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.1%. After mixing mass%, water 0.6 mass%, and methyl isobutyl ketone (MIBK) 64.7 mass%, a bead mill was used for dispersion treatment to obtain a metal oxide particle dispersion of Example 1. It was.

"Evaluation of metal oxide particle dispersion"
As a result of measuring the moisture content of the obtained metal oxide particle dispersion with a Karl Fischer moisture meter (model number: AQL-22320, manufactured by Hiranuma Sangyo Co., Ltd.), the water content was 0.6% by mass.
Further, the particle size distribution of the obtained metal oxide particle dispersion was measured with a particle size distribution meter (trade name: Microtrac UPA150, manufactured by Nikkiso Co., Ltd.). The results are shown in Table 1.
Moreover, the liquid haze value of the obtained metal oxide particle dispersion was measured with a haze meter (trade name: HAZE METER TC-H3DP, manufactured by Tokyo Denshoku Co., Ltd.) using a 2 mm cuvette.
Further, the temporal stability of the obtained metal oxide particle dispersion was evaluated by particle size distribution after being stored in a refrigerator at 5 ° C. for 90 days and in a thermostat at 25 ° C. for 60 days. The case where the change in D50 was 5 nm or less and the change in D90 was 10 nm or less was rated as ◯, and the case where the change in D50 exceeded 5 nm, or the change in D10 exceeded 10 nm was rated as x.
The results are shown in Tables 1 and 2.

[Example 2]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-methacryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.2%. After mixing mass%, water 0.6 mass% and methyl ethyl ketone (MEK) 64.7 mass%, a bead mill was used for dispersion treatment to obtain a metal oxide particle dispersion of Example 2.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[Example 3]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-methacryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.3%. After mixing mass%, water 0.6 mass%, and methyl ethyl ketone (MEK) 64.6 mass%, the dispersion process was performed using the bead mill, and the metal oxide particle dispersion liquid of Example 3 was obtained.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[Example 4]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-methacryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.2%. The metal oxide particles of Example 4 were mixed with 0.6% by mass, 0.6% by mass of water, and 64.7% by mass of 1-methoxy-2-propanol (PGM), and then dispersed using a bead mill. A dispersion was obtained.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[Example 5]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-methacryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.1%. After mixing mass%, water 0.6 mass%, and methyl ethyl ketone (MEK) 64.8 mass%, a dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Example 5.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[Example 6]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-methacryloxypropyltrimethoxysilane is 3.0% by mass, and alkyldimethylamine (amine value 140) is 0.2%. After mixing 6% by mass of 0.6% by mass of water, 0.6% by mass of water and 66.2% by mass of methyl isobutyl ketone (MIBK), dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Example 6. It was.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[Example 7]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-methacryloxypropyltrimethoxysilane is 4.5% by mass, and polyester acid amide amine salt (amine value 40) is 0. After mixing 4% by mass, 0.6% by mass of water and 64.5% by mass of methyl ethyl ketone (MEK), dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Example 7. It was.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[Example 8]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-acryloxypropyltrimethoxysilane is 6.0% by mass, and alkyldimethylamine (amine value 140) is 0.3%. The metal oxide particles of Example 8 were mixed with 0.6% by mass, 0.6% by mass of water, and 63.1% by mass of 1-methoxy-2-propanol (PGM), and then dispersed using a bead mill. A dispersion was obtained.
The moisture content, particle size distribution, liquid haze value, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[Example 9]
10% by mass of zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.), 1.5% by mass of 3-acryloxypropyltrimethoxysilane, 0.1% of alkyldimethylamine (amine value 140) After mixing 8% by mass of 0.2% by mass of water, 0.2% by mass of water, and 88.2% by mass of methyl isobutyl ketone (MIBK), dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Example 9. It was.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[Example 10]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 40% by mass, 3-acryloxypropyltrimethoxysilane 6.0% by mass, alkyldimethylamine (amine value 140) 0.3% After mixing 5% by mass, 0.8% by mass of water and 52.9% by mass of methyl isobutyl ketone (MIBK), a dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Example 10. It was.
The moisture content, particle size distribution, liquid haze value, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Table 3 and Table 4.

[Example 11]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 40% by mass, 3-acryloxypropyltrimethoxysilane 6.0% by mass, alkyldimethylamine (amine value 140) 0.3% After mixing 52% by mass of 0.92% by mass of water, 0.92% by mass of water and 52.78% by mass of methyl isobutyl ketone (MIBK), dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Example 11. It was.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Table 3 and Table 4.

[Example 12]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 40% by mass, 3-acryloxypropyltrimethoxysilane 6.0% by mass, alkyldimethylamine (amine value 140) 0.3% After mixing 50% by mass, 0.95% by mass of water, and 52.75% by mass of methyl isobutyl ketone (MIBK), dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Example 12. It was.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Table 3 and Table 4.

[Example 13]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 40% by mass, 3-acryloxypropyltrimethoxysilane 6.0% by mass, alkyldimethylamine (amine value 140) 0.3% After mixing 5% by mass, 1.8% by mass of water and 51.9% by mass of methyl isobutyl ketone (MIBK), a dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Example 13. It was.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Table 3 and Table 4.

[Example 14]
Zirconium oxide (IV) (average primary particle diameter 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-acryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.23. After mixing 64% by mass of 0.6% by mass of water, 0.6% by mass of water and methyl isobutyl ketone (MIBK), dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Example 14. It was.
The moisture content, particle size distribution, liquid haze value, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Table 3 and Table 4.

[Example 15]
Zirconium oxide (IV) (average primary particle diameter 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-acryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.23. After mixing 1 mass% of mass%, 0.6 mass% of water, 45.07 mass% of methyl isobutyl ketone (MIBK), and 19.6 mass% of toluene (water solubility 0.035), a dispersion treatment is performed using a bead mill. To obtain a metal oxide particle dispersion of Example 15.
The moisture content, particle size distribution, liquid haze value, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Table 3 and Table 4.

[Example 16]
Zirconium oxide (IV) (average primary particle diameter 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-acryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.23. After mixing mass%, water 0.6 mass%, methyl isobutyl ketone (MIBK) 58.17 mass% and toluene (water solubility 0.035) 6.5 mass%, a dispersion treatment is performed using a bead mill. The metal oxide particle dispersion liquid of Example 16 was obtained.
The moisture content, particle size distribution, liquid haze value, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Table 3 and Table 4.

[Example 17]
Zirconium oxide (IV) (average primary particle diameter 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-acryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.23. After mixing 1% by mass of mass%, 0.6% by mass of water, 45.07% by mass of methyl isobutyl ketone (MIBK) and 19.6% by mass of methanol (SP value: 14.8, boiling point 65 ° C.), a bead mill is used. Then, a dispersion treatment was performed to obtain a metal oxide particle dispersion of Example 17.
The moisture content, particle size distribution, liquid haze value, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Table 3 and Table 4.

[Example 18]
Zirconium oxide (IV) (average primary particle diameter 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-acryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.23. After mixing mass%, water 0.6 mass%, methyl isobutyl ketone (MIBK) 58.17 mass% and methanol (SP value: 14.8, boiling point 65 ° C.) 6.5 mass%, a bead mill was used. Then, a dispersion treatment was performed to obtain a metal oxide particle dispersion of Example 18.
The moisture content, particle size distribution, liquid haze value, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Table 3 and Table 4.

[Comparative Example 1]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 40% by mass, 3-acryloxypropyltrimethoxysilane 6.0% by mass, alkyldimethylamine (amine value 140) 0.3% After mixing 5% by mass, 2.3% by mass of water and 51.4% by mass of methyl isobutyl ketone (MIBK), a dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Comparative Example 1. It was.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 5 and 6.

[Comparative Example 2]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 40% by mass, 3-acryloxypropyltrimethoxysilane 6.0% by mass, alkyldimethylamine (amine value 140) 0.3% After mixing 5% by mass, 2.3% by mass of water and 50.9% by mass of methyl isobutyl ketone (MIBK), a dispersion treatment was performed using a bead mill to obtain a metal oxide particle dispersion of Comparative Example 2. It was.
The moisture content, particle size distribution, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 5 and 6.

[Comparative Example 3]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 30% by mass, 3-methacryloxypropyltrimethoxysilane 4.5% by mass, water 0.6% by mass, methyl ethyl ketone (MEK) Was mixed using a bead mill, and a metal oxide particle dispersion of Comparative Example 3 was obtained.
The moisture content, particle size distribution, liquid haze value, and temporal stability of the obtained metal oxide particle dispersion were measured in the same manner as in Example 1. The results are shown in Tables 5 and 6.

[Comparative Example 4]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 30% by mass, 3-methacryloxypropyltrimethoxysilane 4.5% by mass, 1% acetic acid 3.0% by mass, water After mixing 0.6% by mass and 61.9% by mass of 1-methoxy-2-propanol (PGM), dispersion treatment was performed using a bead mill. Couldn't get.

[Comparative Example 5]
Zirconium oxide (IV) (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-methacryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.05%. After mixing by mass%, water 0.6 mass%, and methyl ethyl ketone (MEK) 64.85 mass%, a dispersion treatment was performed using a bead mill, but the particles settled to obtain a metal oxide particle dispersion. I couldn't.

[Comparative Example 6]
Zirconium oxide (IV) (average primary particle diameter 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) is 30% by mass, 3-acryloxypropyltrimethoxysilane is 4.5% by mass, and alkyldimethylamine (amine value 140) is 0.23. After mixing mass%, water 0.6 mass%, methyl isobutyl ketone (MIBK) 32.6 mass%, toluene (water solubility 0.035) 32.07 mass%, using a bead mill, dispersion treatment However, the particles settled and a metal oxide particle dispersion could not be obtained.

[Example 19]
"Metal oxide particle-containing composition"
62 mass% of the zirconia dispersion liquid of Example 10, urethane acrylate (weight average molecular weight (MW) 20,000-40,000) 10.6 mass%, a polymerization initiator 0.6 mass%, and a polymerization accelerator 0.1% by mass, 6% by mass of isopropyl alcohol, and 20.7% by mass of methyl isobutyl ketone were mixed to obtain a metal oxide particle-containing composition of Example 19. This composition had components other than the solvent, that is, a solid content of 40% by mass, and the content of zirconia in the solid content of 100% by mass was 62% by mass.
The particle size distribution of the obtained composition was measured in the same manner as in Example 1. As a result, D50 was 11 nm, D90 was 16 nm, and D90 / D50 was 1.5.

"Coating"
The obtained metal oxide particle-containing composition was applied to a 50 μm thick polyethylene terephthalate film by a bar coating method so that the dry film thickness was 1 μm, and dried by heating at 90 ° C. for 1 minute. Formed.
Next, using a high-pressure mercury lamp (120 W / cm), the coating film was exposed to ultraviolet light with an energy of 250 mJ / cm ² , and the coating film was cured to obtain a plastic substrate with a coating film of Example 19. .

"Evaluation of plastic substrate with coating film"
"Total light transmittance, haze value"
The total light transmittance and haze value of the plastic substrate with a coating film were measured based on Japanese Industrial Standard JIS-K-7136 using a haze meter NDH-2000 (manufactured by Nippon Denshoku Co., Ltd.) on the basis of air. For measuring the total light transmittance and haze value, a test piece of 100 mm × 100 mm was produced from the produced plastic substrate with a coating film, and the test piece was used.
As a result, the total light transmittance was 89.3%, and the haze value was 0.73%.

"Abrasion resistance"
The scratch resistance of the coated plastic substrate was evaluated.
Using a rubbing tester (manufactured by Taihei Rika Kogyo Co., Ltd.) equipped with # 0000 steel wool, a load of 250 g / cm ² was applied to the coating film surface of the plastic substrate with a coating film and reciprocated 10 times. Then, when the number of scratches was counted visually, it was 10 or less.

[Example 20]
The zirconia dispersion of Example 10 was 71.3% by mass, dipentaerythritol hexaacrylate was 16.3% by mass, the polymerization initiator was 0.6% by mass, the polymerization accelerator was 0.1% by mass, and isopropyl alcohol was 5%. The metal oxide particle-containing composition of Example 20 was obtained by mixing mass% and 6.7 mass% of methyl isobutyl ketone. This composition had components other than the solvent, that is, a solid content of 50% by mass, and the content of zirconia in the solid content of 100% by mass was 57% by mass.
The particle size distribution of the obtained composition was measured in the same manner as in Example 1. As a result, D50 was 11 nm, D90 was 16 nm, and D90 / D50 was 1.5.

"Evaluation of storage stability of compositions containing metal oxide particles"
The storage stability of the obtained composition was evaluated by the particle size distribution after being stored for 90 days in a refrigerator at 5 ° C and for 60 days in a constant temperature bath at 25 ° C.
The particle size distribution of the composition was measured in the same manner as in Example 1. As a result, D50 was 16 nm, D90 was 25 nm, and D90 / D50 was 1.6.
Moreover, the plastic substrate with a coating film of Example 20 was obtained in the same manner as Example 19 using the metal oxide particle-containing composition of Example 20. About this plastic base material with a coating film, it carried out similarly to Example 1, and measured the total light transmittance and haze value. As a result, the total light transmittance was 89.5%, and the haze value was 0.85%.
Further, in the same manner as in Example 19, the scratch resistance of the plastic substrate with a coating film of Example 20 was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.

[Experiment 1]
The day on which the metal oxide particle-containing composition of Example 19 was produced was defined as 0 storage days.
The particle size distribution of the composition was measured in the same manner as in Example 1.
Moreover, the total light transmittance and haze value of the plastic substrate with a coating film produced in the same manner as in Example 19 were measured using this composition.
Further, in the same manner as in Example 19, the scratch resistance of this coated plastic substrate was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.
The results are shown in Table 7.

[Experiment 2]
After the metal oxide particle-containing composition of Example 19 was stored in a thermostatic bath at 5 ° C. for 30 days, the particle size distribution was measured in the same manner as in Example 1.
Moreover, the total light transmittance and haze value of the plastic substrate with a coating film produced in the same manner as in Example 19 were measured using this composition.
Further, in the same manner as in Example 19, the scratch resistance of this coated plastic substrate was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.
The results are shown in Table 7.

[Experiment 3]
After storing the metal oxide particle-containing composition of Example 19 in a thermostatic bath at 5 ° C. for 60 days, the particle size distribution was measured in the same manner as in Example 1.
Moreover, the total light transmittance and haze value of the plastic substrate with a coating film produced in the same manner as in Example 19 were measured using this composition.
Further, in the same manner as in Example 19, the scratch resistance of this coated plastic substrate was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.
The results are shown in Table 7.

[Experimental Example 4]
After the metal oxide particle-containing composition of Example 19 was stored in a thermostatic bath at 5 ° C. for 90 days, the particle size distribution was measured in the same manner as in Example 1.
Moreover, the total light transmittance and haze value of the plastic substrate with a coating film produced in the same manner as in Example 19 were measured using this composition.
Further, in the same manner as in Example 19, the scratch resistance of this coated plastic substrate was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.
The results are shown in Table 7.

[Experimental Example 5]
After storing the metal oxide particle-containing composition of Example 19 in a thermostatic bath at 25 ° C. for 30 days, the particle size distribution was measured in the same manner as in Example 1.
Moreover, the total light transmittance and haze value of the plastic substrate with a coating film produced in the same manner as in Example 19 were measured using this composition.
Further, in the same manner as in Example 19, the scratch resistance of this coated plastic substrate was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.
The results are shown in Table 7.

[Experimental Example 6]
After storing the metal oxide particle-containing composition of Example 19 in a thermostatic bath at 25 ° C. for 60 days, the particle size distribution was measured in the same manner as in Example 1.
Moreover, the total light transmittance and haze value of the plastic substrate with a coating film produced in the same manner as in Example 19 were measured using this composition.
Further, in the same manner as in Example 19, the scratch resistance of this coated plastic substrate was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.
The results are shown in Table 7.

[Experimental Example 7]
After the metal oxide particle-containing composition of Example 19 was stored in a thermostatic bath at 25 ° C. for 90 days, the particle size distribution was measured in the same manner as in Example 1.
Moreover, the total light transmittance and haze value of the plastic substrate with a coating film produced in the same manner as in Example 19 were measured using this composition.
Further, in the same manner as in Example 19, the scratch resistance of this coated plastic substrate was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.
The results are shown in Table 7.

[Experimental Example 8]
After the metal oxide particle-containing composition of Example 19 was stored in a constant temperature bath at 35 ° C. for 30 days, the particle size distribution was measured in the same manner as in Example 1.
Moreover, the total light transmittance and haze value of the plastic substrate with a coating film produced in the same manner as in Example 19 were measured using this composition.
Further, in the same manner as in Example 19, the scratch resistance of this coated plastic substrate was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.
The results are shown in Table 7.

[Experimental Example 9]
After storing the metal oxide particle-containing composition of Example 19 in a thermostatic bath at 35 ° C. for 60 days, the particle size distribution was measured in the same manner as in Example 1.
Moreover, the total light transmittance and haze value of the plastic substrate with a coating film produced in the same manner as in Example 19 were measured using this composition.
Further, in the same manner as in Example 19, the scratch resistance of this coated plastic substrate was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.
The results are shown in Table 7.

[Experimental Example 10]
After the metal oxide particle-containing composition of Example 19 was stored in a thermostatic bath at 35 ° C. for 90 days, the particle size distribution was measured in the same manner as in Example 1.
Moreover, the total light transmittance and haze value of the plastic substrate with a coating film produced in the same manner as in Example 19 were measured using this composition.
Further, in the same manner as in Example 19, the scratch resistance of this coated plastic substrate was evaluated. As a result, when the number of scratches was counted visually, it was 10 or less.
The results are shown in Table 7.

From the results of Tables 1 to 6, when comparing Examples 1 to 18 and Comparative Examples 1 to 6, the metal oxide particle dispersions of Examples 1 to 18 are excellent in dispersion stability of the metal oxide particles, It was confirmed that the dispersion was excellent in stability during long-term storage.
From the results in Table 7, it was confirmed that the metal oxide particle-containing composition of Example 19 was excellent in storage stability. Moreover, it turned out that the plastic substrate with a coating film produced using the metal oxide particle-containing composition of Example 19 is excellent in transparency and scratch resistance.

  The metal oxide particle dispersion of the present invention can be applied to all industrial uses in which the metal oxide particle dispersion is conventionally used. For example, for optical film use, house exterior use, heat ray shielding use, etc. Can be applied.

Claims (7)

Metal oxide particles having an average primary particle diameter of 3 nm or more and 20 nm or less and a refractive index of 1.9 or more, which are surface-treated with a silicon compound represented by the following general formula (1), have a solubility parameter of 8. It is a metal oxide particle dispersion liquid that is dispersed in a solvent containing 70% by mass or more of an organic solvent that is 0 or more and 12 or less and the solubility of water is 1.5 g / 100 ml or more
Containing an amine having 2 or more carbon atoms,
A metal oxide particle dispersion, wherein the water content is 3% by mass or less of the content of the metal oxide particles.
R ′ _n Si (OR) _m (1)
(Where R is a hydrogen atom or an alkyl group, R ′ is an organic group, n + m = 4, 0 <n <4)   2. The metal oxide particle dispersion according to claim 1, wherein the particle size (D90) when the cumulative volume percentage of the particle size distribution is 90% is 60 nm or less.   The metal oxide particle dispersion according to claim 1 or 2, wherein the liquid haze value is 35% or less when the content of the metal oxide particles is 30% by mass and the optical path length is 2 mm. liquid.   4. The metal oxide particle dispersion liquid according to claim 1, wherein the product of the amine value of the amine and the content of the amine is 10 or more and 45 or less. 5.   A metal oxide particle-containing composition comprising the metal oxide particle dispersion liquid according to any one of claims 1 to 4 and a binder component.   A coating film formed using the metal oxide particle-containing composition according to claim 5.   A display device comprising the coating film according to claim 6.