WO2015046487A1 - Inorganic particle dispersion liquid, inorganic particle-containing composition, coating film, plastic base with coating film, and display device - Google Patents

Abstract

Provided are: an inorganic particle dispersion liquid which has a sharp particle size distribution, while having a low water content; an inorganic particle-containing composition; a coating film; a plastic base with a coating film; and a display device. This inorganic particle dispersion liquid is obtained by dispersing inorganic particles into a dispersion medium with use of a dispersant having a hydrolyzable group. This inorganic particle dispersion liquid contains a basic substance and has a water content of 1% by mass or less.

Description

Inorganic particle dispersion, inorganic particle-containing composition, coating film, plastic substrate with coating film, display device

The present invention relates to an inorganic particle dispersion, an inorganic particle-containing composition, a coating film, a plastic substrate with a coating film, and a display device.
This application claims priority on September 30, 2013 based on Japanese Patent Application No. 2013-202984 filed in Japan, the contents of which are incorporated herein by reference.

Inorganic particles such as zirconia, titania, and silica are used by being dispersed in a binder such as a resin.
For example, a plastic substrate used in a display device such as a liquid crystal display (LCD), a plasma display (PDP), or an electroluminescence display (EL) is required to have transparency, refractive index, mechanical properties, and the like. Thus, a functional film is formed by applying a composition obtained by mixing inorganic fine particles having a high refractive index and a resin to a plastic substrate.

As a method of combining inorganic particles and a binder, a dispersion in which inorganic particles whose surface is modified with a dispersant having a hydrolyzable group such as an alkoxide in the presence of water is dispersed in a solvent, and a binder is used. The method of mixing is common.
Hydrolyzable groups such as alkoxides have the property that hydroxyl groups hydrolyzed by the coexistence of water under acidic or basic conditions adsorb and dehydrate and condense on inorganic particles.
Since the surface of the inorganic particles is usually hydrophilic, in order to maintain high transparency by combining with the binder, the surface of the inorganic particles is hydrophobized with a dispersant or the like, and the dispersibility of the inorganic particles in the organic solvent is increased. It is important to increase.

As such a dispersion, an inorganic particle dispersion obtained by adding a hydrolysis catalyst and surface-treating metal oxide particles with a silane coupling agent has been proposed (for example, see Patent Document 1).
In addition, the metal oxide fine particles are made organic by a silane coupling agent during the bead mill treatment, and the metal oxide fine particles are reacted with an isocyanate compound having a polymerizable functional group during the ultrasonic treatment, thereby forming the metal oxide fine particles. Dispersed dispersions have been proposed (see, for example, Patent Document 2).

JP 2009-108123 A JP 2010-254889 A

However, since the dispersion described in Patent Document 1 described above is subjected to the dispersion treatment by hydrolyzing the silane coupling agent, there are many steps, and water is contained in the dispersion. In addition to being unable to obtain a dispersion having a sharp particle size distribution, long-term storage stability was unstable.
In addition, since a large amount of water is contained, there is a problem in that, when a coating film is formed by mixing with a binder component such as a resin, foreign matter or the like is easily generated on the appearance of the coating film, and the film formability is not excellent.

The dispersion described in Patent Document 2 has a low water content because it has not undergone the hydrolysis process, but the desired dispersibility cannot be obtained by the first stage dispersion treatment. Processing was necessary and the process was complicated. In addition, since the isocyanate compound reacts with a hydroxyl group, there is a problem that a usable solvent is limited.

The present invention has been made to solve the above problems, and has an inorganic particle dispersion, an inorganic particle-containing composition, a coating film, and a coating film having a sharp particle size distribution and a low water content. An object is to provide a plastic substrate and a display device.

As a result of diligent research to solve the above-mentioned problems, the present inventors have carried out surface treatment and dispersion of inorganic particles using a basic substance in the dispersion treatment of inorganic particles, thereby adsorbing inorganic particles. Since surface treatment can be performed with a minimum amount of water such as water, an inorganic particle dispersion having a sharp particle size distribution and a low water content can be obtained, and the number of steps in the dispersion treatment is also reduced. As a result, the present invention has been completed.

That is,
[1] The inorganic particle dispersion liquid of the present invention is a dispersion liquid in which inorganic particles are a dispersant having a hydrolyzable group and dispersed in a dispersion medium, which contains a basic substance and has a water content. An inorganic particle dispersion characterized by being 1% by mass or less.

[2] The inorganic particle-containing composition of the present invention is an inorganic particle-containing composition comprising the inorganic particle dispersion of the present invention and a binder component.

[3] The coating film of the present invention is a coating film formed using the inorganic particle-containing composition of the present invention.

[4] The plastic substrate with a coating film of the present invention is a plastic substrate with a coating film, wherein the coating film of the present invention is provided on at least one surface of the plastic substrate.

[5] The display device of the present invention is a display device comprising at least one of the coating film of the present invention and the substrate with a coating film of the present invention.

According to the present invention, an inorganic particle dispersion having a sharp particle size distribution, excellent dispersion stability of inorganic particles, and excellent long-term storage stability of the dispersion, and an inorganic particle-containing composition containing the inorganic particle dispersion A coating device formed using the inorganic particle-containing composition, a plastic substrate with a coating film provided with the coating film, and a display device provided with at least one of a coating film and a substrate with a coating film it can.

4 is a scanning ion microscope image of the upper side of the cross section of the coating film of Example 4. FIG. 6 is a scanning ion microscope image of the lower side of the cross section of the coating film of Example 4. FIG. It is a reflection spectrum of Example 4 and Comparative Example 4.

Hereinafter, embodiments will be described.

[Inorganic particle dispersion]
The inorganic particle dispersion liquid of this embodiment is a dispersion liquid in which inorganic particles are a dispersant having a hydrolyzable group and are dispersed in a dispersion medium, which contains a basic substance and has a water content of 1 mass. % Or less.

The content of water in the inorganic particle dispersion of this embodiment is 1% by mass or less, preferably 0.7% by mass or less, more preferably 0.5% by mass or less, and More preferably, it is 4 mass% or less.
When the inorganic particle dispersion contains water in an amount exceeding 1% by mass, not only a dispersion having a sharp particle size distribution can be obtained, but also the stability of long-term storage deteriorates. The water content is preferably as small as possible.
The water content in this embodiment means a value titrated with a Karl Fischer moisture meter (model number: AQL-22320, manufactured by Hiranuma Sangyo Co., Ltd.).

In the inorganic particle dispersion of this embodiment, the value obtained by dividing the particle size (D90) when the cumulative volume percentage of the particle size distribution is 90% by the particle size (D50) when the cumulative volume percentage of the particle size distribution is 50%. Is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and still more preferably 1 or more and 2 or less. Here, the particle size distribution is a particle size distribution of the inorganic particles contained in the inorganic particle dispersion.
By dividing the particle size (D90) when the cumulative volume percentage of the particle size distribution is 90% by the particle size (D50) when the cumulative volume percentage of the particle size distribution is 50%, within the above range The inorganic particles can be uniformly dispersed in the resin, and the refractive index distribution in the film can be made uniform. As a result, color unevenness such as interference fringes can be reduced. Moreover, since coarse particles are reduced, there is also an effect that generation of foreign matters during coating can be suppressed.

In addition, D50 and D90 in this embodiment mean values measured by a particle size distribution meter (trade name: Microtrac UPA150, manufactured by Nikkiso Co., Ltd.) using the dynamic light scattering method as a measurement principle.

D50 in the inorganic particle dispersion liquid of the present embodiment is preferably 1 nm or more and 45 nm or less, and more preferably 1 nm or more and 20 nm or less from the viewpoint of improving the transparency of the inorganic particle dispersion liquid.

As an embodiment of the inorganic particle dispersion liquid of the present embodiment, an inorganic particle dispersion liquid containing inorganic particles, a dispersant having a hydrolyzable group, a basic substance, and a dispersion medium will be described. .

"Inorganic particles"
The inorganic particles in the present embodiment are not particularly limited, and inorganic particles having desired characteristics are appropriately selected and used.
For example, when high refractive index performance is imparted to the inorganic particle dispersion, inorganic particles having a refractive index of 1.9 or more are used. Examples of such inorganic particles include zirconium oxide, zinc oxide, iron oxide, copper oxide, titanium oxide, tin oxide, cerium oxide, tantalum oxide, niobium oxide, tungsten oxide, europium oxide, hafnium oxide, potassium titanate, Metal oxides such as barium titanate, strontium titanate, potassium niobate, lithium niobate, calcium tungstate, antimony-containing tin oxide (ATO), and tin-containing indium oxide (ITO) are preferably used. Among these, zirconium oxide and titanium oxide are particularly preferable from the viewpoint of high refractive index and little influence by coloring.

In addition, when imparting weather resistance to the inorganic particle dispersion, inorganic particles having ultraviolet shielding properties are appropriately selected and used. Examples of such inorganic particles include zinc oxide, titanium oxide, iron oxide, cerium oxide, and the like.
Moreover, when providing electroconductivity to an inorganic particle dispersion liquid, the metal oxide which has electroconductivity is used. Examples of such metal oxides include antimony-containing tin oxide (ATO) and tin-containing indium oxide (ITO).

The average primary particle diameter of the inorganic particles may be appropriately selected depending on the use, but in order to obtain an inorganic particle dispersion excellent in transparency, it is preferably 1 nm or more and 30 nm or less, preferably 5 nm or more and 25 nm. The following is more preferable.

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, the major axis of each metal oxide particle, for example, 100 or more metal oxide particles, preferably using a scanning electron microscope (SEM), a transmission electron microscope (TEM), etc. Includes a method of measuring the major axis of each of the 500 metal oxide particles and calculating the arithmetic average value thereof.

The content of the inorganic particles in the inorganic particle dispersion may be appropriately adjusted according to the use, but is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.
By setting the content of the inorganic particles in the inorganic particle dispersion to the above range, good dispersion stability of the inorganic particles in the inorganic particle dispersion can be obtained.

"Dispersant with hydrolyzable group"
The dispersant having a hydrolyzable group in the present embodiment has a hydrolyzable group, and the surface of the inorganic particles is modified to make the particle surface hydrophobic, thereby improving the dispersibility of the inorganic particles in a solvent or a resin. For example, a dispersant having an alkoxy group is preferably used.
Examples of such a dispersant having an alkoxy group include metal alkoxides, silane coupling agents, silicone compounds, and the like.
As an alkoxy group, a methoxy group and an ethoxy group are preferable.

Although it does not specifically limit as a metal alkoxide, An alkoxysilane is preferable.
As the alkoxysilane, tetraalkoxysilane is preferable.
Tetraalkoxysilanes include tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetraisopropoxysilane, tetra n-butoxysilane, tetraisobutoxysilane, tetrasec-butoxysilane, tetrat-butoxysilane, tetraphenoxy Examples thereof include silane, monoethoxytrimethoxysilane, monobutoxytrimethoxysilane, monopentoxytrimethoxysilane, monohexoxytrimethoxysilane, dimethoxydiethoxysilane, dimethoxydibutoxysilane and the like.
Among these, tetramethoxysilane and tetraethoxysilane are preferably used because they have a high silicon (Si) content and are easy to adjust the concentration when dispersed in a solvent, and have high hydrolysis / condensation reactivity. be able to.
These tetraalkoxysilanes may be used alone or in combination of two or more.

The silane coupling agent is not particularly limited as long as it has an alkoxy group. Vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, etc. Is mentioned.

Silane coupling agents include allyltrimethoxysilane, allyltriethoxysilane, vinylethyldimethoxysilane, vinylethyldiethoxysilane, 3-glycidoxypropylethyldimethoxysilane, 3-glycidoxypropyltriethyldiethoxysilane. P-styrylethyldimethoxysilane, p-styrylethyldiethoxysilane, 3-acryloxypropylethyldimethoxysilane, 3-acryloxypropylethyldiethoxysilane, 3-methacryloxypropylethyldimethoxysilane, 3-methacryloxypropylethyl Examples include diethoxysilane, allylethyldimethoxysilane, and allylethyldiethoxysilane.

Further, as silane coupling agents, vinyldiethylmethoxysilane, vinyldiethylethoxysilane, 3-glycidoxypropyldiethylmethoxysilane, 3-glycidoxypropyldiethylethoxysilane, p-styryldiethylmethoxysilane, p-styryldiethyl Ethoxysilane, 3-acryloxypropyldiethylmethoxysilane, 3-acryloxypropyldiethylethoxysilane, 3-methacryloxypropyldiethylmethoxysilane, 3-methacryloxypropyldiethylethoxysilane, allyldiethylmethoxysilane, allyldiethylethoxysilane, etc. Can be mentioned.
These silane coupling agents may be used alone or in combination of two or more.

The silicone compound is not particularly limited as long as it has an alkoxy group, and a silicone resin having a methoxy group or an ethoxy group is used.

The addition amount of the dispersant having an alkoxy group is appropriately adjusted to such an extent that good dispersibility is obtained. The addition amount of the dispersant having an alkoxy group is, for example, preferably 5% by mass or more and 120% by mass or less, and preferably 10% by mass or more and 110% by mass or less with respect to the total mass of the inorganic particles. More preferably, it is 15 mass% or more and 100 mass% or less.

"Basic substances"
The basic substance in the present embodiment is a substance having a hydrogen ion index (pH) greater than 7 when mixed with water, and the water content of the inorganic particle dispersion is 1% by mass or less. However, there is no particular limitation as long as the substance can be mixed uniformly.
Examples of such basic substances include alkali metal or alkaline earth metal hydroxides, amines, and the like, and amines are preferable in terms of easy handling.

Examples of the alkali metal or alkaline earth metal hydroxide include inorganic basic substances such as calcium hydroxide, magnesium hydroxide, manganese hydroxide, aluminum hydroxide, iron hydroxide, potassium hydroxide, and sodium hydroxide. Is mentioned.

Examples of the amines include amines, amides, amine dispersants, amine surfactants, amide type monomers, amine solvents, amide solvents, and the like.
As the amine, any of primary amine, secondary amine, and tertiary amine may be used, and these may be mixed and used, but it is more preferable to use a tertiary amine.
As the amide type monomer, for example, an acrylamide type monomer or a methacrylamide type monomer is preferably used. Examples of such amide type monomers include hydroxyethyl acrylamide, hydroxyethyl methacrylamide, dimethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide, N- [3- (dimethylamino) propyl] acrylamide, N- [3- ( Dimethylamino) propyl] methacrylamide and the like.

The added amount of the basic substance is a value obtained by dividing the particle size (D90) when the cumulative volume percentage of the particle size distribution is 90% by the particle size (D50) when the cumulative volume percentage of the particle size distribution is 50%. Although it may be appropriately adjusted so as to be 1 or more and 4 or less, it is preferable that the basic substance is contained in the inorganic particle dispersion liquid by 0.01% by mass or more and 1% by mass or less.
By containing the basic substance in the inorganic particle dispersion liquid, hydrolysis of the dispersant having an alkoxy group such as a silane coupling agent is promoted even when the water content is 1% by mass or less, and the particles Inorganic particles can be dispersed in a dispersion medium in a state where the diameters are uniform.

"Dispersion medium"
The dispersion medium is not particularly limited as long as the inorganic particles are easily dispersed and other than water. Examples of the dispersion medium include aliphatic hydrocarbons such as hexane, heptane, and cyclohexane, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, ethanol, and propanol, and halogenation such as methylene chloride and ethylene chloride. Hydrocarbons, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as 2-pentanone and isophorone, esters such as ethyl acetate and butyl acetate, cellosolves such as ethyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. Ethers, amide solvents, ether ester solvents, resin monomers, resin oligomers, and the like.

Examples of the method for producing the inorganic particle dispersion of the present embodiment include a method of mechanically mixing the above-described materials as constituents of the inorganic particle dispersion and dispersing the inorganic particles in a solvent.
Examples of the dispersing device include a stirrer, a self-revolving mixer, a homogenizer, and an ultrasonic homogenizer.

According to the inorganic particle dispersion liquid of the present embodiment, the inorganic particles are dispersed in a dispersion medium with a dispersant having a hydrolyzable group, contain a basic substance, and have a water content of 1% by mass or less. Therefore, since it has a sharp particle size distribution, it is excellent in the dispersion stability of the inorganic particles and in the stability of long-term storage of the dispersion.

In the inorganic particle dispersion of this embodiment, the value obtained by dividing the particle size (D90) when the cumulative volume percentage of the particle size distribution is 90% by the particle size (D50) when the cumulative volume percentage of the particle size distribution is 50%. However, if it is 1 or more and 4 or less, it is more excellent in the dispersion stability of inorganic particles, and it is excellent in the stability of long-term storage of the dispersion.

Moreover, when D50 is 1 nm or more and 45 nm or less, an inorganic particle dispersion excellent in transparency can be obtained.
In addition, when the inorganic particles are particles having a refractive index of 1.9 or more, an inorganic particle dispersion having a high refractive index can be obtained.
Furthermore, when the inorganic particles are particles having ultraviolet shielding properties, an inorganic particle dispersion having excellent weather resistance can be obtained.

[Inorganic particle-containing composition]
The inorganic particle containing composition of this embodiment contains the inorganic particle dispersion liquid of this 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 or oligomer of a curable resin used for a general hard coat film, and a monomer or oligomer of a photocurable resin may be used. Alternatively, a monomer or oligomer of a thermosetting resin may be used.
It is preferable to use a monomer of a photocurable resin because it is easy to obtain a film having high transparency and a strong hard coat property. Among the monomers of the photocurable resin, one or more acryloyl groups and It is preferable to use a crosslinkable compound having either one or both of methacryloyl groups.

Although it does not specifically limit as a crosslinkable compound which has any one or both of 1 or more acryloyl group and methacryloyl group in a molecule | numerator, The polyfunctional acrylate excellent in reactivity, transparency, a weather resistance, and hardness is preferable. Here, polyfunctional means having three or more functional groups. All of the three or more functional groups may be the same functional group or different functional groups.
Examples of the functional group other than the acryloyl group and methacryloyl group possessed by the crosslinkable compound 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.

The inorganic particle-containing composition of the present embodiment has one or two functional groups within a range that does not inhibit the effects of the invention, and is not included in the above-mentioned monomers. Initiators, antistatic agents, refractive index modifiers, antioxidants, UV absorbers, light stabilizers, leveling agents, antifoaming agents, inorganic fillers, coupling agents, preservatives, plasticizers, flow regulators, 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 inorganic 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 or less in order to facilitate coating. Preferably, it is 0.5 mPa · s or more and 200 mPa · s or less.
If the viscosity of the inorganic 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, if the viscosity of the inorganic particle-containing composition is 500 mPa · s or less, the viscosity is not too high, and the inorganic particle-containing composition is preferably handled at the time of coating.

The viscosity of the inorganic particle-containing composition is preferably adjusted to the above range by appropriately adding an organic solvent to the inorganic particle-containing composition.
The organic solvent is not particularly limited as long as it is compatible with the inorganic particle-containing composition. For example, aliphatic hydrocarbons such as hexane, heptane, and cyclohexane, and aromatic hydrocarbons such as toluene and xylene. , 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, esters such as ethyl acetate and butyl acetate , 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 inorganic particle-containing composition of the present embodiment, since the inorganic particle of the present embodiment contains an inorganic particle dispersion having a sharp particle size distribution, the dispersion stability of the inorganic particles is excellent, and the composition can be stored for a long time. Excellent stability.

[Method for producing inorganic particle-containing composition]
As a manufacturing method of the inorganic particle containing composition of this embodiment, the method of mixing each material mentioned above as a component of an inorganic 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 inorganic particle containing composition of this embodiment.
Although the film thickness of this coating film is suitably adjusted according to a use, it is preferable that they are 0.01 micrometer or more and 20 micrometers or less normally, and it is more preferable that they are 1 micrometer or more and 10 micrometers or less.

The manufacturing method of the coating film of this embodiment has the process of forming a coating film by apply | coating said inorganic particle containing composition on a to-be-coated article, 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.

For curing by ultraviolet irradiation, a high pressure mercury lamp that generates ultraviolet light in the wavelength band of 200 nm ~ 500 nm, a metal halide lamp, xenon lamp, using a chemical lamp or the like, at the 100 ~ 3,000mJ / cm ² energy, ultraviolet The method of irradiating etc. is mentioned.

In the coating film of the present embodiment, the inorganic particles having a sharp particle size distribution in the present embodiment, in other words, in the inorganic particle-containing composition, the size of the inorganic particles is almost uniform. The particles are easily filled uniformly without 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 inorganic particles having a sharp particle size distribution are used, the inorganic 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 inorganic particles having a refractive index of 1.9 or more, the amount of inorganic particles required to improve the refractive index can be reduced as compared with the conventional case. Accordingly, even in a thin film of 10 nm to 200 nm, the entire coating film is uniformly filled with inorganic particles, and the voids in the film can be reduced uniformly, so that the refractive index of the coating film can be improved. it can.
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.
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 inorganic particle containing composition of this embodiment, the coating film excellent in 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 obtained by coating the inorganic particle-containing composition of the present embodiment on the substrate body using a known coating method to form a coating film and curing the coating film. It is done.

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, the difference between the maximum value and the minimum value of reflectance within a range of 500 nm or more and 750 nm or less is preferably 1% or less, and preferably 0.8% or less. More preferred is 0.7% or less.
When the difference between the maximum value and the minimum value of the reflectance of the coated plastic substrate within the range of 500 nm or more and 750 nm or less is 1% or less, the coated plastic substrate of this embodiment has optical interference. This is preferable because the occurrence of ripples due to the above is suppressed, and a coating film in which color unevenness is suppressed is obtained.

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 this embodiment is formed, a plastic substrate with a coating film having excellent film forming properties can be obtained.

[Display device]
The display device of the present embodiment includes at least one of the coating film of the present embodiment and the plastic substrate with a coating film of the present embodiment, that is, the coating film of the present embodiment and the plastic substrate with a coating film of the present embodiment. Either one or both.
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 the refractive index between the transparent substrate and the ITO electrode is mitigated by providing the coating film of the present embodiment in which inorganic particles having a refractive index of 1.9 or more are selected as a layer between the transparent substrate and the ITO electrode. Thus, the bone appearance phenomenon can be suppressed.
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 the present embodiment, since it includes at least one of the coating film of the present embodiment and the plastic substrate with a coating film of the present embodiment, which is excellent in film formability, optical in the coating film surface is provided. Since there is almost no variation in characteristics, 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]
"Inorganic particle dispersion"
Zirconium oxide (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 30% by mass, 3-methacryloxypropyltrimethoxysilane 6.0% by mass, alkyldimethylamine 0.4% by mass, propylene glycol monomethyl ether After mixing 63.6% by mass, dispersion treatment was performed using a bead mill to obtain an inorganic particle dispersion of Example 1.

"Evaluation of inorganic particle dispersion"
As a result of measuring the moisture content of the obtained inorganic particle dispersion with a Karl Fischer moisture meter (model number: AQL-22320, manufactured by Hiranuma Sangyo Co., Ltd.), the water content was 0.3% by mass.
Moreover, as a result of measuring the particle size distribution of the obtained inorganic particle dispersion with a particle size distribution meter (trade name: Microtrac UPA150, manufactured by Nikkiso Co., Ltd.), D50 is 25 nm, D90 is 35 nm, and D90 / D50 is 1.4. Met.
It was confirmed that this inorganic particle dispersion had the same particle size distribution characteristics after 6 months, and was excellent in long-term storage stability. The evaluation results are shown in Table 1.

"Inorganic particle-containing composition"
The obtained inorganic particle dispersion was 5.4% by mass, dipentaerythritol hexaacrylate was 0.19% by mass, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl)- [Benzyl] phenyl} -2-methyl-propan-1-one and 0.02% by mass of propylene glycol monomethyl ether were mixed to obtain an inorganic particle-containing composition of Example 1.

"Plastic substrate with coating film"
40% by mass of dipentaerythritol hexaacrylate, 2 of 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one A composition for forming a hard coat film was obtained by mixing 58% by mass of mass% and methyl isobutyl ketone.

This composition for forming a hard coat film was applied to a 100 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. to form a coating film.
Next, using a high-pressure mercury lamp (120 W / cm), the coating film was exposed to ultraviolet rays with an energy of 250 mJ / cm ² to cure the coating film, thereby obtaining a substrate with a hard coat film.
Next, the inorganic particle-containing composition of Example 1 was applied on the hard coat film of the substrate with the hard coat film by a bar coating method so that the dry film thickness was 100 nm, and heated at 90 ° C. to dry. To form a coating film.
Next, using a high-pressure mercury lamp (120 W / cm), the coating film was exposed to ultraviolet rays so as to have an energy of 250 mJ / cm ² , and the coating film was cured to obtain a plastic substrate with a coating film of Example 1. .

"Evaluation of plastic substrate with coating film"
"Total light transmittance and haze value of plastic substrate with coating film"
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.
The evaluation results are shown in Table 1.

"Refractive index of coating film"
The refractive index of the coating film was measured using a prism coupler model 2010 (Mericon).

"Color unevenness of plastic substrate with coating film"
The color unevenness of the plastic substrate with a coating film was evaluated by visually observing with a gap of 30 cm between the substrate and the eyes, and when there was no color unevenness or almost inconspicuous, and x when there was color unevenness.
The evaluation results are shown in Table 1.

"Measurement of reflection spectrum of plastic substrate with coating"
Using a spectrophotometer (trade name: V-570, manufactured by JASCO Corp.), the reflection spectrum in the range of 500 nm to 750 nm was measured for the plastic substrate with a coating film of Example 1.
As a result, the difference between the maximum value and the minimum value of the reflectance of the plastic substrate with a coating film in the range of 500 nm to 750 nm was 1% or less.

[Example 2]
"Inorganic particle dispersion"
Zirconium oxide (average primary particle size 12 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 30% by mass, 3-methacryloxypropyltrimethoxysilane 4.5% by mass, amine-based dispersant 0.4% by mass, methyl isobutyl ketone After mixing 65.1% by mass, dispersion treatment was performed using a bead mill to obtain an inorganic particle dispersion of Example 2.

"Evaluation of inorganic particle dispersion"
As a result of evaluating in the same manner as in Example 1, the water content was 0.3% by mass.
Further, D50 was 18 nm, D90 was 25 nm, and D90 / D50 was 1.4.
It was confirmed that this inorganic particle dispersion had the same particle size distribution characteristics after 6 months, and was excellent in long-term storage stability. The evaluation results are shown in Table 1.

"Inorganic particle-containing composition, plastic substrate with coating"
Except having used the inorganic particle dispersion liquid of Example 2, the inorganic particle containing composition of Example 2 and the plastic substrate with a coating film of Example 2 were obtained in the same manner as Example 1.

"Evaluation of plastic substrate with coating film"
About the plastic base material with a coating film of Example 2, the total light transmittance, the haze value, the refractive index of the coating film, and the color unevenness of the plastic base material with a coating film were evaluated in the same manner as in Example 1.
The evaluation results are shown in Table 1.
Further, when the reflection spectrum of the coated plastic substrate within the range of 500 nm to 750 nm was measured in the same manner as in Example 1, the difference between the maximum value and the minimum value of the reflectance of the coated plastic substrate was 1% or less.

[Example 3]
Zinc oxide (trade name: ZnO650, average primary particle size 25 nm, manufactured by Sumitomo Osaka Cement Co., Ltd.) 10% by mass, tetramethoxysilane 10% by mass, dimethylaminopropylacrylamide 0.4% by mass, isopropyl alcohol 77.6%. After mixing by mass%, a dispersion treatment was performed using a bead mill to obtain an inorganic particle dispersion of Example 3.

"Evaluation of inorganic particle dispersion"
As a result of evaluating in the same manner as in Example 1, the water content was 0.3% by mass.
Further, D50 was 30 nm, D90 was 90 nm, and D90 / D50 was 3.0.
It was confirmed that this inorganic particle dispersion had the same particle size distribution characteristics after 6 months, and was excellent in long-term storage stability. The evaluation results are shown in Table 1.

[Example 4]
"Inorganic particle-containing composition"
58% by mass of the inorganic particle dispersion of Example 2, 11% by mass of dipentaerythritol hexaacrylate, 2-hydroxy-1- {4- [2- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl } 0.5% by mass of 2-methyl-propan-1-one and 30.5% by mass of propylene glycol monomethyl ether were mixed to obtain an inorganic particle-containing composition of Example 4.

"Plastic substrate with coating film"
The inorganic particle-containing composition of Example 4 was applied to a 100 μm thick polyethylene terephthalate film by a bar coating method so as to have a dry film thickness of 1.5 μm, dried by heating at 90 ° C. Formed.
Next, using a high-pressure mercury lamp (120 W / cm), the coating film was exposed to ultraviolet rays so as to have an energy of 250 mJ / cm ² , and the coating film was cured to obtain a plastic substrate with a coating film of Example 4. It was.

About the plastic base material with a coating film of Example 4, the total light transmittance, haze value, and the color nonuniformity of the plastic base material with a coating film were evaluated similarly to Example 1. The refractive index of the coating film was measured using an Abbe refractometer (model number: DR-M2, manufactured by Atago Co., Ltd.).
The evaluation results are shown in Table 1.

"Observation of filling state of inorganic particles in coating film"
In order to confirm the filling state of the inorganic particles in the coating film, the cross section of the film was observed using a focused ion beam processing observation apparatus. A scanning ion microscope image of the upper side of the coating film cross section is shown in FIG. 1, and a scanning ion microscope image of the lower side of the coating film cross section is shown in FIG.
From the scanning ion microscope images shown in FIG. 1 and FIG. 2, it was confirmed that the coating was filled with inorganic particles without any gaps.

"Measurement of reflection spectrum of plastic substrate with coating"
The reflection spectrum in the range of 500 nm to 750 nm was measured for the plastic substrate with a coating film of Example 4 using a spectrophotometer (trade name: V-570, manufactured by JASCO Corporation).
The results are shown in FIG.
As a result, the difference between the maximum value and the minimum value of the reflectance of the coated plastic substrate within the range of 500 nm to 750 nm was 0.5%.

[Comparative Example 1]
Instead of using 6.0% by mass of 3-methacryloxypropyltrimethoxysilane, 0.4% by mass of alkyldimethylamine, and 63.6% by mass of propylene glycol monomethyl ether, 4 of 3-methacryloxypropyltrimethoxysilane was used. An attempt was made to prepare an inorganic particle dispersion of Comparative Example 1 containing no basic substance in the same manner as in Example 1 except that 5% by mass and 65.5% by mass of methyl ethyl ketone were used. Inorganic particles settled and no dispersion was obtained.

[Comparative Example 2]
Instead of using 6.0% by mass of 3-methacryloxypropyltrimethoxysilane, 0.4% by mass of alkyldimethylamine, and 63.6% by mass of propylene glycol monomethyl ether, 4 of 3-methacryloxypropyltrimethoxysilane was used. An inorganic particle dispersion of Comparative Example 2 containing a large amount of water was obtained in the same manner as in Example 1 except that 3% by mass of 5% by mass, 1% by mass of sodium hydroxide aqueous solution and 62.5% by mass of methyl ethyl ketone were used. It was.

"Evaluation of inorganic particle dispersion"
As a result of evaluation in the same manner as in Example 1, the water content was 3.3% by mass.
Further, D50 was 30 nm, D90 was 135 nm, and D90 / D50 was 4.5.
It was confirmed that the inorganic particle dispersion liquid was not excellent in long-term dispersion stability because the inorganic particles settled after two months. The evaluation results are shown in Table 1.

"Inorganic particle-containing composition, plastic substrate with coating"
Except for using the inorganic particle dispersion liquid of Comparative Example 2, the inorganic particle composition of Comparative Example 2 and the plastic substrate with a coating film of Comparative Example 2 were obtained in the same manner as in Example 1.

"Evaluation of plastic substrate with coating film"
The plastic substrate with a coating film of Comparative Example 2 was evaluated for total light transmittance, haze value, refractive index of the coating film, and color unevenness of the plastic substrate with a coating film.
The evaluation results are shown in Table 1.
Further, when the reflection spectrum of the coated plastic substrate within the range of 500 nm to 750 nm was measured in the same manner as in Example 1, the difference between the maximum value and the minimum value of the reflectance of the coated plastic substrate was It was over 1%.

[Comparative Example 3]
Instead of using 6.0% by mass of 3-methacryloxypropyltrimethoxysilane, 0.4% by mass of alkyldimethylamine, and 63.6% by mass of propylene glycol monomethyl ether, 4 of 3-methacryloxypropyltrimethoxysilane was used. In the same manner as in Example 1 except that 5% by mass, 3% by mass of 1% by mass acetic acid aqueous solution, and 62.5% by mass of methyl ethyl ketone were used. An attempt was made to prepare an inorganic particle dispersion, but even when dispersed with a bead mill, the inorganic particles settled and a dispersion was not obtained.

[Comparative Example 4]
"Inorganic particle-containing composition"
60% by mass of the inorganic particle dispersion of Comparative Example 2, 11% by mass of dipentaerythritol hexaacrylate, 2-hydroxy-1- {4- [2- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl } 0.5% by mass of 2-methyl-propan-1-one and 28.5% by mass of propylene glycol monomethyl ether were mixed to obtain an inorganic particle-containing composition of Comparative Example 4.

"Plastic substrate with coating film"
The inorganic particle-containing composition of Comparative Example 4 was applied to a 100 μm-thick polyethylene terephthalate film by a bar coating method so as to have a dry film thickness of 1.5 μm, dried by heating at 90 ° C. Formed.
Next, using a high-pressure mercury lamp (120 W / cm), the coating film was exposed to ultraviolet rays with an energy of 250 mJ / cm ² to cure the coating film, and a plastic substrate with a coating film of Comparative Example 4 was obtained. It was.

About the plastic base material with a coating film of the comparative example 4, the total light transmittance, the haze value, and the color nonuniformity of the plastic base material with a coating film were evaluated similarly to Example 1. The refractive index of the coating film was measured using an Abbe refractometer (model number: DR-M2, manufactured by Atago Co., Ltd.).
The evaluation results are shown in Table 1.

"Measurement of reflection spectrum of plastic substrate with coating"
With respect to the plastic substrate with a coating film of Comparative Example 4, the reflection spectrum in the range of 500 nm to 750 nm was measured using a spectrophotometer (trade name: V-570, manufactured by JASCO Corporation).
The results are shown in FIG.
As a result, the difference between the maximum value and the minimum value of the reflectance of the plastic substrate with a coating film in the range of 500 nm to 750 nm was 1.7%.

From the results of Table 1, when comparing Examples 1 to 3 and Comparative Examples 1 to 3, the inorganic particle dispersions of Examples 1 to 3 are excellent in dispersion stability of the inorganic particles, It was confirmed that the dispersion was excellent in stability during long-term storage.
From the results of Table 1, when Example 1 and Example 2 are compared with Comparative Example 2, in Examples 1 and 2, total light transmittance, haze value, refractive index of coating film, and plastic with coating film It was confirmed that the color unevenness of the base material was improved as compared with Comparative Example 2.
Moreover, when the reflection spectrum of Example 4 and the reflection spectrum of Comparative Example 4 are compared, even when the film thickness is as thick as 1.5 μm, the plastic substrate with a coating film of Example 4 It was confirmed that the amplitude of ripple caused by light interference was small, and color unevenness was suppressed visually.
Further, in order to adjust the refractive index of Comparative Example 4 to the same refractive index as that of Example 4, it is necessary to increase the content of zirconium oxide of Comparative Example 4, and Example 4 has less zirconium oxide than the conventional film. It was confirmed that the refractive index could be improved by the amount.

The inorganic particle dispersion of the present invention can be applied to all industrial uses in which the inorganic particle dispersion is conventionally used. For example, it can be applied to optical film use, house exterior use, heat ray shielding use, and the like. it can.

Claims (7)

1. A dispersion in which inorganic particles are dispersed in a dispersion medium with a dispersant having a hydrolyzable group,
   Containing basic substances,
   An inorganic particle dispersion, wherein the water content is 1% by mass or less.
2. The value obtained by dividing the particle size (D90) when the cumulative volume percentage of the particle size distribution is 90% by the particle size (D50) when the cumulative volume percentage of the particle size distribution is 50% is 1 or more and 4 or less. The inorganic particle dispersion according to claim 1.
3. An inorganic particle-containing composition comprising the inorganic particle dispersion according to claim 1 or 2 and a binder component.
4. A coating film formed using the inorganic particle-containing composition according to claim 3.
5. A plastic substrate with a coating film, wherein the coating film according to claim 4 is provided on at least one surface of the plastic substrate.
6. 6. The plastic substrate with a coating film according to claim 5, wherein a difference between a maximum value and a minimum value of reflectance within a range of 500 nm or more and 750 nm or less is 1% or less.
7. A display device comprising at least one of the coating film according to claim 4 and the plastic substrate with a coating film according to claim 5 or 6.

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