CN116568391A - Particles and transparent coated substrate comprising the same - Google Patents

Abstract

Particles having antimicrobial properties and having a silicon-containing shell and cavities inside thereof are provided. The particles contain 0.5 to 40 mass% of an antibacterial metal component based on oxide, and have cavities inside a silicon-containing shell. The void ratio of the particles is 10% -90%, and the number proportion of the particles with one hollow cavity relative to the whole particles is more than 80%. The transparent film-coated substrate using the particles has sufficient hardness and strength and high antibacterial properties, and is particularly useful for antireflection applications.

Description

Particles and transparent film-coated substrate containing the particles

Technical Field

One embodiment of the present invention relates to particles and a transparent film-coated substrate including the particles.

Background Art

In the past, in order to prevent reflection on the surface of substrates such as sheets or lenses formed by glass or plastic, an anti-reflection film was formed on the surface. For example, a coating method, an evaporation method or a CVD method is used to form a coating of a low-refractive-index material such as a fluororesin or magnesium fluoride on the surface of a glass or plastic substrate. However, these methods are expensive in terms of cost. Therefore, the following method is known (for example, see Japanese Patent Publication No. 7-133105). In this method, a coating liquid containing composite oxide colloidal particles with a refractive index of 1.36 to 1.44 formed by inorganic oxides other than silicon dioxide is applied to the surface of the substrate to form an anti-reflection film.

In addition, a method for producing particles having a shell and a cavity therein is known (see, for example, Japanese Patent Publication No. 2001-233611 and Japanese Patent Publication No. 2013-226539). The particles have a lower refractive index than solid particles. The transparent coating formed using the particles has a low refractive index and excellent anti-reflection performance.

In addition, it is known that inorganic oxide particles such as alumina and silica or composite oxide particles such as silica-alumina are loaded with metal components such as silver or copper to make these particles have antibacterial properties (see, for example, Japanese Patent Publication No. 7-196424 and Japanese Patent Publication No. 2010-273698). Furthermore, antireflection films having an antireflection layer and a layer having an antibacterial function are also known (see Japanese Patent Publication No. 11-052105).

Summary of the invention

Technical problem to be solved by the invention

Compared with particles filled inside, particles with cavities inside have a low refractive index. Therefore, when particles with cavities inside are used for coating, the transparency and anti-reflection performance of the coating are improved. In addition, components requiring transparency and anti-reflection performance include display devices with touch panels such as smart phones, ATMs, and ticket machines. These surfaces may be contaminated by fungi such as Escherichia coli or Staphylococcus aureus or various viruses. Therefore, antibacterial properties are required from a hygienic point of view.

In the past, in order to give antibacterial properties to the coating, it is known to apply an antibacterial agent on the surface of the coating. However, for example, when the antibacterial agent is an organic antibacterial agent, the coating of the antibacterial agent itself is relatively easy. However, in this case, there is the possibility that the coating is eroded by a solvent. In addition, in the case where the fixation and scratch resistance of the coating are poor, the persistence of the antibacterial performance is insufficient. On the other hand, in the case where the antibacterial agent is an inorganic antibacterial agent, since the antibacterial agent is present in the coating, the persistence of the antibacterial performance can be expected. However, the coating (antibacterial layer) containing the antibacterial agent needs to be manufactured separately. However, in the case where the anti-reflection layer and the antibacterial layer are manufactured separately, the effect of the layer outside the outermost surface may be insufficient, and productivity is reduced, and production costs may increase. In contrast, when a low refractive index component and an antibacterial component are combined in a coating, there is the possibility that the anti-reflection performance and antibacterial performance are insufficient, and the transparency and strength of the coating are insufficient.

Therefore, particles having high transparency and antireflection performance and high antibacterial performance when used for coating are required.

Furthermore, a substrate with a transparent coating (anti-reflection film) using the particles is required to have high transparency and anti-reflection performance, sufficient hardness and strength, and high antibacterial performance.

Technical means to solve technical problems

In order to solve such technical problems, the inventors discovered the following particles.

The particles involved in one embodiment of the present invention have a silicon-containing shell and a cavity inside thereof. In addition, the particles contain 0.5% to 40% by mass of an antibacterial metal component based on the oxide. The proportion of the cavity in the particles (porosity) is 10% to 90%. In addition, the number of particles with one cavity in the particles relative to the number of all particles is more than 80%.

The particles have a low refractive index, sufficient hardness and strength, high dispersibility and high antibacterial properties. Based on a coating solution containing such particles, a transparent coating having high transparency and anti-reflection properties, sufficient hardness (pencil hardness) and strength (scratch resistance) and high antibacterial properties can be obtained.

Beneficial Effects

Based on the particles involved in one embodiment of the present invention, a coating solution capable of manufacturing the following coating can be obtained. The coating has high transparency and anti-reflection performance, and excellent adhesion to the substrate. In addition, the coating has sufficient hardness and strength and high antibacterial performance.

DETAILED DESCRIPTION

The particles involved in the present embodiment (hereinafter sometimes referred to as "particles") contain 0.5% to 40% by mass of antibacterial metal components based on oxides. The shape of the particles has a silicon-containing shell and a cavity inside thereof. The proportion of the cavity in the particles (porosity) is 10% to 90%. In addition, the number of particles having one cavity inside the particle shell relative to the total number of particles is 80% or more.

When the content of the antimicrobial metal component of the particles is in the range of 0.5 mass % to 40 mass % based on the oxide, a coating having high antimicrobial property, high transparency and antireflection performance can be obtained by using the particles for coating.

Here, when the content of the antimicrobial metal component is less than 0.5 mass %, it is possible that sufficient antimicrobial performance cannot be obtained. On the contrary, even when the content of the antimicrobial metal component is greater than 40 mass %, the antimicrobial performance will not be further improved, and the antimicrobial metal component will become unstable according to the circumstances, and it is easy to separate from the particles and change color. In addition, transparency and anti-reflection performance are likely to decrease. The content of the antimicrobial metal component is preferably 1 mass % to 30 mass %, and more preferably 3 mass % to 10 mass %.

The outer shell of the particle contains silicon. The silicon-containing material is preferably an oxide. Examples of silicon-containing oxides include oxides containing at least one element of aluminum, zirconium, titanium, zinc, tin and antimony and silicon, and silicon dioxide. These oxides may be single, a mixture or a composite oxide.

By containing silicon in the shell, while the refractive index of the particles is reduced, the compatibility of the particles and the matrix forming components is also improved. Therefore, a transparent coating with low reflectivity can be formed. In addition, since the particles can be highly dispersed in the transparent coating, the strength of the coating is improved. When silicon is represented by silicon dioxide, the silicon content contained in the particles is preferably 50% by mass or more. The content of the silicon component is more preferably 75% by mass or more, more preferably 85% by mass or more, and particularly preferably 90% by mass.

The porosity of the particles is 10% to 90%. Here, if the porosity is less than 10%, it is difficult to obtain a coating having sufficient transparency and anti-reflection performance when the particles are used for coating. On the contrary, if the porosity of the particles is greater than 90%, the structure of the particles is too "sparse", so it is possible that the structure cannot be maintained, and even if the structure can be maintained, it is possible that a coating having sufficient hardness and strength cannot be obtained. The porosity is preferably 13% to 80%, and more preferably 20% to 70%.

The number ratio of particles having one cavity to all particles is 80% or more. If the number ratio is less than 80%, when the particles are used for a coated substrate, the transparency and anti-reflection performance may be insufficient. The number ratio is preferably 95% or more, more preferably 99% or more, and most preferably 100%.

In addition, it is preferred that the cavity inside the shell is shaped along the particle shape. That is, the more uniform the thickness of the shell, the more preferred. In this case, although it still depends on the thickness of the shell, even when stress is applied to the particle, sufficient hardness and strength can be obtained.

The metal component with antibacterial property preferably comprises an element selected from silver, copper, zinc, lead, tin, bismuth, cadmium, chromium, mercury, nickel and cobalt. These metal elements can be used alone or in combination. More preferred metal elements are silver, copper and zinc, and further preferred metal elements are silver and zinc.

The density (A1) of the dry product of the particles based on the He gas adsorption method is preferably 1.95 g/mL to 3.50 g/mL, and the density (B1) of the dry product of the particles based on the N ₂ gas adsorption method is preferably 0.50 g/mL to 2.60 g/mL.

The density based on the gas adsorption method is obtained in the following manner. That is, a powder is obtained by drying a dispersion of particles using an evaporator. Next, a substance obtained by heat-treating (drying) the powder in air at 105°C is used, and the measurement is performed using a dry automatic density meter (manufactured by Micromeritics, AccuPyc1340TC) using He gas or _N2 gas. The above-mentioned density based on the gas adsorption method is thus obtained. In addition, a substance obtained by heat-treating (firing) the powder obtained by drying the above-mentioned powder using an evaporator at 400°C in air is used, and the density (A2) and density (B2) described later are obtained by performing the same measurement.

The density range varies depending on the type of gas used in the measurement, and the detailed reason is not clear. However, it is believed that the reason is that the difference in adsorption state caused by the difference in gas type is expressed as a numerical value based on the particle surface state such as unevenness or pores on the particle surface.

Here, if the density (A1) is less than 1.95 g/mL, the amount of the antimicrobial metal component is small, so that sufficient antimicrobial performance may not be obtained.

On the contrary, if the density (A1) is greater than 3.50 g/mL, the loaded antimicrobial metal component becomes unstable, and the antimicrobial metal component is easily separated from the particles and discolored, etc. In addition, the transparency, antireflection performance, strength and adhesion may be reduced.

In addition, in particles having a density (B1) of less than 0.50 g/mL, it is difficult to maintain the structure of the shell. Therefore, it is difficult to obtain such particles.

On the contrary, if the density (B1) is greater than 2.60 g/mL, the loaded antimicrobial metal component becomes unstable, and the antimicrobial metal component is easily separated from the particles and discolored. In addition, the transparency, antireflection performance, hardness and adhesion may be reduced.

The density (A1) is more preferably 2.00 g/mL to 3.00 g/mL, and further preferably 2.10 g/mL to 2.30 g/mL.

The density (B1) is more preferably 0.80 g/mL to 2.10 g/mL, and further preferably 0.90 g/mL to 1.50 g/mL.

The density (A2) of the particles heat-treated at 400° C. based on a He gas adsorption method is preferably 2.17 g/mL or more.

Here, if the density (A2) is less than 2.17 g/mL, the amount of the antimicrobial metal component is small, so that sufficient antimicrobial performance may not be obtained.

The upper limit of density (A2) is not particularly set. However, if density (A2) is too large, then according to the type of antimicrobial metal component, the reflectivity and haze of the formed transparent film substrate may become higher and the transmittance, strength and adhesion may be reduced. Therefore, for example, for the upper limit of density (A2), when the antimicrobial metal component is silver, it can be 3.70g/mL, when the antimicrobial metal component is copper, it can be 3.50g/mL, and when the antimicrobial metal component is zinc, it can be 3.20g/mL.

The density (A2) is more preferably 2.20 g/mL or more, and further preferably 2.24 g/mL or more.

The ratio (A2/B2) of the density (A2) to the density (B2) of the particles heat-treated at 400°C based on a _N2 gas adsorption method is preferably 1.10 or more.

Here, if the ratio (A2/B2) is less than 1.10, the refractive index of the particles becomes high, so the antireflection performance of the coating may be insufficient.

The upper limit of the ratio (A2/B2) is not particularly set. However, if the ratio (A2/B2) is too large, it may be difficult to maintain the structure of the housing. Therefore, the upper limit of the ratio (A2/B2) is, for example, 4.50.

The ratio (A2/B2) is more preferably 1.30 or more, and further preferably 1.45 or more.

The average particle size of the particles is not particularly limited, but when used for a substrate with a transparent coating, it is preferably 20nm to 180nm. When the average particle size is within this range, the particles can be stably present. In addition, in this case, the dispersibility of the particles in the coating liquid and in the coating is good, and a coating with high transparency, hardness and strength can be obtained. The average particle size is more preferably 30nm to 120nm, and more preferably 40nm to 110nm.

The average thickness of the shell is preferably 5nm to 30nm. Thus, since the structure of the shell can be stably maintained, the particles can exist stably. In addition, a coating with high transparency, hardness and strength can be obtained. Here, in the case of a thin shell with an average thickness of less than 5nm, it is possible that the structure of the particles cannot be maintained. On the contrary, if the average thickness of the shell is greater than 30nm, although it is still related to the type and quantity of the antibacterial metal component, the refractive index of the shell may become too high. The average thickness of the shell is more preferably 5nm to 20nm, and more preferably 7nm to 12nm.

The alkali metal content of the particles is preferably less than 1.00 mass %, based on the oxide.

Here, if the alkali metal content of the particles is 1.00% by mass or more, the particles agglomerate with each other, the dispersibility of the particles in the coating solution and the coating film decreases, and there is a possibility that sufficient film hardness and insufficient transparency cannot be obtained. The alkali metal content is preferably less than 0.10% by mass, and more preferably less than 0.01% by mass. Most preferably, the particles do not contain alkali metals. In addition, in the case where alkaline earth metals are contained in the particles, the above-mentioned "alkali metal content" should be understood as "the total content of alkali metals and alkaline earth metals". In addition, alkali metals represent Li, Na, K, Rb, Cs and Fr; alkaline earth metals represent Be, Mg, Ca, Sr, Ba and Ra.

The particles of this embodiment can also be dispersed in organic substances such as organic solvents and organic resins. In this case, it is preferred to use an organosilicon compound to surface treat the particles. As the organosilicon compound, it is preferred to use an organosilicon compound represented by the following formula (1) (n is 1 to 3). Here, in the case of using an organosilicon compound in which n is 0, it is preferred to use a partial hydrolyzate of the organosilicon compound. Through this surface treatment, an organic compound having a functional group derived from the organosilicon compound of the following formula (1) is contained in the particles. The functional group is at least one selected from an alkyl group, an epoxy group, a vinyl group, a (meth)acryloyloxy group, a mercapto group, an amino group, a phenyl group and a phenylamino group.

R _n -SiX _4-n ···Formula (1)

(In the formula, R is an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, which may be the same as or different from each other. Examples of the substituent include epoxy, vinyl, (meth)acryloyloxy, mercapto, amino and phenylamino. X is an alkoxy, hydroxyl, halogen or hydrogen atom having 1 to 4 carbon atoms, and n represents an integer of 0 to 3.)

Specific examples of the organic silicon compound include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxyethoxy)silane, 7-octenyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, 8-glycidoxyoctyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ- Methacryloxypropyl trimethoxysilane, γ-methacryloxypropyl methyldiethoxysilane, γ-methacryloxypropyl triethoxysilane, γ-acryloxypropyl trimethoxysilane, 8-methacryloxyoctyl trimethoxysilane, N-β (aminoethyl) γ-aminopropyl methyldimethoxysilane, N-β (aminoethyl) γ-aminopropyl trimethoxysilane, N-β (aminoethyl) γ-aminopropyl triethoxysilane, γ-aminopropyl trimethoxysilane, γ-amino Propyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-isocyanatepropyltriethoxysilane, trimethylsilanol, n-propyltrimethylsilane, n-propyltriethylsilane, p-phenylyltrimethoxysilane, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, vinyltrichlorosilane, trimethylbromosilane and diethylsilane, etc.

In the surface treatment of particles, a dispersion containing particles and at least one of water and alcohol is prepared. A predetermined amount of the organosilicon compound represented by formula (1) is added to the dispersion, and water is added as needed to hydrolyze the organosilicon compound. The surface treatment of the particles is performed in this way. The hydrolysis uses an acid or a base as a hydrolysis catalyst as needed. In addition, impurities can be reduced by ion exchange or ultrafiltration or the like before and after the surface treatment as needed.

The organosilicon compound is preferably present in the particles at 0.1 mass % to 30 mass % as R _n —SiO _(4-n)/2 (solid content). When the particles are surface-treated with the organosilicon compound, the compatibility of the particles with the matrix-forming component is improved.

Here, if the amount of the organosilicon compound is less than 0.1% by mass, the effect of its addition cannot be fully obtained. Even if the amount of the organosilicon compound is greater than 30% by mass, not only will the dispersibility of the particles not be further improved, but sufficient antibacterial performance may not be obtained. The amount of the organosilicon compound is more preferably 1% to 25% by mass, more preferably 1% to 20% by mass, and particularly preferably 1% to 15% by mass.

In addition, the shape of the particles is not particularly limited. As the shape of the particles, for example, spherical, ellipsoidal (rugby) shape, cocoon shape, candy shape, chain shape and dice shape are cited. Among them, spherical particles are preferred because they can be evenly dispersed in the coating while having high dispersibility.

[Substrate with transparent coating]

The transparent film-bearing substrate involved in this embodiment includes a substrate and a transparent film containing the above-mentioned particles and a matrix formed on the substrate. The matrix is included as a solid component other than the particles. As the matrix, additives such as resins, polymerization initiators and leveling agents from the coating liquid are cited. Specifically, after the coating liquid is applied to the substrate by a known method, a film is formed on the substrate by drying and ultraviolet irradiation. In the film, the ratio of the solid components of the particles and the matrix forming components in the coating liquid directly becomes the ratio of the particle component and the matrix in the film.

According to its use, a previously known hard coating layer, an anti-glare layer, a high refractive index layer or a conductive layer may be arranged between the transparent coating and the substrate. As these layers, a plurality of layers may be combined. For example, in order to further reduce the reflectivity of the transparent coating substrate for use in a display, a combination of a hard coating layer and a high refractive index layer or a combination of a hard coating layer and an anti-glare layer is used.

The film thickness of the transparent coating can be appropriately selected according to the application. For example, if the transparent coating is an antireflection film, the film thickness of the transparent coating is preferably 80 nm to 350 nm.

Here, if the film thickness of the transparent coating is less than 80nm, the strength and scratch resistance of the film may be insufficient, and sufficient anti-reflection performance may not be obtained due to the thin film. On the contrary, if the film thickness of the transparent coating is thicker than 350nm, the anti-reflection performance may be reduced. In addition, cracks may also occur when the shrinkage of the transparent coating is very large. The film thickness is more preferably 85nm to 220nm, and more preferably 90nm to 110nm.

Furthermore, the reflectance of the coated substrate is preferably 2.0% or less, more preferably 1.5% or less.

The haze of the film-coated substrate is preferably 3.0% or less, more preferably 0.3% or less.

The light transmittance of the film-coated substrate is preferably 85.0% or more.

Here, if the light transmittance is less than 85.0%, the image clarity may be insufficient in a display device, etc. The light transmittance is more preferably 90.0% or more.

The antibacterial activity test of the film is carried out in accordance with JIS Z 2801. The antibacterial activity value is preferably 2.0 or more. If the antibacterial activity value is 2.0 or more, it can be judged that the film has antibacterial properties. The antibacterial activity value is more preferably 4.0 or more.

The strength (scratch resistance) of the coating is evaluated by sliding with #0000 steel wool at a load of 1000 g/ ^cm2 . Preferably, no streak-like scratches are observed on the film surface when the sliding frequency is at least 100 times. For the scratch resistance, it is more preferred that no scratches are observed when the sliding frequency is 500 times, and it is further preferred that no scratches are observed when the sliding frequency is 1000 times.

The pencil hardness of the coating is preferably H or higher. Here, if the pencil hardness of the coating is less than H, the hardness as an antireflection film is insufficient. The pencil hardness is more preferably 2H or higher, and further preferably 4H or higher.

As a substrate, a known substrate can be used. The substrate is preferably a transparent resin substrate such as glass, polycarbonate, acrylic resin, polyethylene terephthalate (PET), triacetyl cellulose (TAC), polyimide, polymethyl methacrylate resin (PMMA) and cycloolefin polymer (COP). These substrates have excellent adhesion to the transparent coating formed by the above-mentioned coating liquid. Therefore, by using these substrates, a coated substrate with excellent hardness and strength can be obtained. Therefore, a thin substrate can be used appropriately. The thickness of the substrate is not particularly limited, but is preferably 10 μm to 100 μm, more preferably 20 μm to 80 μm.

[Method for producing pellets]

The method for producing particles according to the present embodiment includes: a first step of producing first particles having a shell containing silica and a cavity inside the shell; and a second step of supporting an antimicrobial metal component on the first particles.

Here, the first particle of the first process can also be manufactured by the method known in the past (for example Japanese Patent Publication No. 2001-233611, Japanese Patent Publication No. 2013-226539). The antimicrobial metal component of the second process can be loaded on the particle by adding a solution of a metal salt or a metal complex ion such as hydrochloride, nitrate, sulfate and acetate or a solution of a metal alkoxide. Wherein, when the antimicrobial metal component is silver, silver nitrate is more preferably used. When the antimicrobial metal component is copper, zinc and tin, hydrochloride, nitrate, sulfate and acetate are more preferably used.

The amount of addition is such that the antimicrobial metal component in the particles is ultimately 0.5 mass % to 40 mass % based on the oxide. Multiple antimicrobial metal components may be added separately or simultaneously. In addition, the antimicrobial metal component may be added multiple times to increase the content.

As long as the content of the antibacterial metal component eventually becomes the desired content, the conditions for adding the antibacterial metal component are not particularly limited. However, the concentration of the dispersion of the first particles is preferably 0.1% to 10% by mass in terms of solid content. In addition, the pH when the antibacterial metal component is added is preferably 6 to 13, and more preferably 8 to 10. Here, if the pH is less than 6, the particles will become unstable and may agglomerate. On the contrary, if the pH is greater than 13, dissolution of the particles themselves may occur, resulting in insufficient loading of the antibacterial metal component. In addition, the temperature when the antibacterial metal component is added is preferably lower than the boiling point of the solvent. For example, when the solvent is water, the temperature is preferably lower than 100°C, and more preferably 30°C to 95°C.

In order to reduce the content of alkali metal and alkaline earth metal in the particle, it is preferred to use ion exchange resin or ultrafiltration membrane to implement cleaning after the second process. Based on oxide, the total content of the alkali metal and alkaline earth metal is preferably less than 1.0 mass %. In addition, in order to reach this content, the raw material with less alkali metal and alkaline earth metal is used in advance to manufacture the first particle, and the content of the alkali metal and alkaline earth metal in the first particle can also be reduced by ion exchange in the first process. In addition, in the second process, the material of the antibacterial metal (for example, the metal alkoxide comprising the antibacterial metal component) containing less content of alkali metal and alkaline earth metal can also be used. In addition, these measures can also be combined.

The finally obtained particles may be used as an aqueous dispersion, may be used after replacement with an organic solvent, or may be used as a powder after drying.

[Coating liquid for film formation]

The particles of this embodiment can be applied to a coating liquid for film formation. The coating liquid contains particles and a matrix-forming component. In addition, the coating liquid may also contain additives such as an organic solvent, a polymerization initiator, a leveling agent, and a surfactant.

Relative to the total amount of solid components such as the particles and matrix-forming components included, the concentration of the particles in the coating solution is preferably 5% to 95% by mass in terms of solid components. Here, if the concentration of the particles is less than 5% by mass, it is possible that the refractive index of the coating film cannot be fully reduced. On the contrary, if the concentration of the particles is greater than 95% by mass, there is the possibility of cracks in the coating film, the possibility of insufficient adhesion to the substrate, and the possibility of deterioration of hardness, strength, transparency, and haze. The concentration of the particles is more preferably 10% to 85% by mass, and more preferably 20% to 70% by mass.

The matrix-forming component is preferably an organic resin matrix-forming component. Examples of the organic resin matrix-forming component include matrix-forming components such as ultraviolet curable resins, thermosetting resins, and thermoplastic resins.

Examples of the ultraviolet curable resin include (meth)acrylic resins, γ-glycidyloxy resins, urethane resins, and vinyl resins.

Examples of the thermosetting resin include urethane resin, melamine resin, silicone resin, butyral resin, reactive silicone resin, phenol resin, epoxy resin, unsaturated polyester resin, and thermosetting acrylic resin.

Examples of the thermoplastic resin include polyester resin, polycarbonate resin, polyamide resin, polyphenylene ether resin, thermoplastic acrylic resin, vinyl chloride resin, fluororesin, vinyl acetate resin, and silicone rubber.

These resins may be copolymers or modified forms of two or more, or may be used in combination. In addition, these resins may also be emulsion resins, water-soluble resins or hydrophilic resins.

The components forming these resins are preferably monomers or oligomers from the viewpoints of particle dispersibility and ease of film coating.

Relative to the total amount of solid components such as the particles and matrix-forming components included, the concentration of the matrix-forming components in the coating solution is preferably 5% to 95% by mass in terms of solid components. Here, if the concentration of the matrix-forming components is less than 5% by mass, it is difficult to form a coating. In addition, even if a coating is obtained, there is also the possibility of cracks in the coating, the possibility of insufficient adhesion to the substrate, and the possibility of deterioration of hardness, strength, transparency and haze. On the contrary, if the concentration of the matrix-forming components is greater than 95% by mass, since the amount of particles is small, it is possible that the refractive index cannot be fully reduced. The concentration of the matrix-forming components is more preferably 15% to 90% by mass, and more preferably 30% to 80% by mass.

As the organic solvent, an organic solvent that can uniformly disperse particles and dissolve or disperse additives such as matrix-forming components and polymerization initiators is used. Among them, hydrophilic solvents and polar solvents are preferred. Examples of hydrophilic solvents include alcohols, esters, glycols, and ethers. Examples of polar solvents include esters and ketones.

Examples of the alcohols include methanol, ethanol, propanol, 2-propanol, butanol, diacetone alcohol, furfuryl alcohol, and tetrahydrofurfuryl alcohol.

Examples of the esters include methyl acetate, ethyl acetate, isopropyl acetate, propyl acetate, isobutyl acetate, butyl acetate, isopentyl acetate, pentyl acetate, 3-methoxybutyl acetate, 2-ethylbutyl acetate, cyclohexyl acetate, and ethylene glycol monoacetate.

Examples of the diols include ethylene glycol and hexylene glycol.

Examples of the ethers include diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol isopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monomethyl ether acetate.

Examples of the ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, butyl methyl ketone, cyclohexanone, methyl cyclohexanone, dipropyl ketone, methyl amyl ketone, and diisobutyl ketone.

Examples of the polar solvent include dimethyl carbonate and toluene.

These may be used alone or in combination of two or more.

As the additive, any additive that has been conventionally used for forming an antireflection film can be used. For example, a polymerization initiator or a leveling agent is used to promote polymerization of the matrix forming component and improve film-forming properties.

Examples of the polymerization initiator include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)2,4,4-trimethylpentylphosphine oxide, 2-hydroxymethyl-2-methylphenyl-propane-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl ketone, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one.

As the leveling agent, for example, acrylic leveling agents, silicone leveling agents, and acrylic silicone leveling agents are mentioned. Among these leveling agents, a leveling agent having a fluorine group is preferably used.

Regarding the concentration of these additives in the coating liquid, for convenience, those contained as solid components during film formation are counted as matrix-forming components, and those contained as solid components after film formation are counted as matrix.

The solid content concentration of the coating liquid (the ratio of the solid content of the particles and the solid content of the matrix-forming component to the coating liquid) is preferably 0.1% by mass to 100% by mass.

Here, when the solid content concentration of the coating liquid is less than 0.1% by mass, the concentration stability of the coating is low, so it is difficult to apply, and it may be difficult to obtain a uniform coating. In addition, in this case, due to the deterioration of haze or appearance, productivity and manufacturing reliability may be reduced. The solid content concentration of the coating liquid of 100% by mass means that there is no organic solvent in the coating liquid. The solid content concentration of the coating liquid is more preferably 1% to 50% by mass.

Example

Examples of this embodiment are described below.

[Example 1]

<Manufacturing of First Particles (First Step)>

430 g of silica-alumina sol (manufactured by JGC Catalysts & Chemicals Co., Ltd., Fiberline USBB-120, average particle size 25 nm, solid content 23% by mass) was mixed with 9.6 kg of pure water, and the resulting mixed solution was heated to 98° C. A 1% by mass sodium hydroxide aqueous solution was added to the mixed solution to adjust the pH to 12.5.

10.2 kg of sodium silicate aqueous solution (SiO ₂ concentration 3.0 mass %) and 10.2 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 1.0 mass %) were added to the mixed solution at the same time. Then, 37.5 kg of sodium silicate aqueous solution (SiO ₂ concentration 3.0 mass %) and 12.5 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 1.0 mass %) were added to the mixed solution (reaction solution) at the same time. During this period, the temperature of the reaction solution was maintained at 98°C. Next, the reaction solution was washed with an ultrafiltration membrane to obtain a dispersion of silicon oxide-alumina particles having a solid content concentration of 3 mass %.

A 35.5% by mass concentrated hydrochloric acid was added dropwise to 50 kg of the dispersion of the silica-alumina particles to adjust the pH to 1.0 and to perform a dealumination treatment. The dissolved aluminum salt was separated by an ultrafiltration membrane and washed to obtain 10 kg of a dispersion of silica particles with a solid content concentration of 5% by mass. Then, 131 g of a 10% by mass aqueous sodium hydroxide solution was added to the dispersion. The dispersion was heat treated in an autoclave at 195°C for 24 hours to obtain an aqueous dispersion of the first particles. The Na ₂ O content of the particles was 0.2% by mass.

<Loading of Antimicrobial Metal Component (Second Step)>

Next, 500 g of the aqueous dispersion of the first particles diluted with pure water to 1.5% by mass was adjusted to 30° C., 70.8 g of a 1.0% by mass silver nitrate aqueous solution was added to the aqueous dispersion while stirring for 30 minutes, and heat treatment was performed at 95° C. for 3 hours. After the heat-treated aqueous dispersion was cooled to room temperature, it was washed with an ultrafiltration membrane and concentrated to obtain an aqueous dispersion of silica particles having a solid content concentration of 1.5% by mass.

Next, 500 g of the aqueous dispersion of the silica particles was subjected to ion exchange for 3 hours using 200 g of a cation exchange resin (manufactured by Mitsubishi Chemical Corporation, Diyion SK1B), and then subjected to ion exchange for 3 hours using 100 g of anion exchange resin (manufactured by Mitsubishi Chemical Corporation, Diyion SA20A). Thereafter, 160 g of an aqueous dispersion of the particles of the present embodiment was produced by subjecting the dispersion to ion exchange for 3 hours at 80°C using 100 g of a cation exchange resin (manufactured by Mitsubishi Chemical Corporation, Diyion SK1B). The solid content concentration of the dispersion was 5% by mass, and the Na ₂ O content of the particles was 50 ppm.

The pellets were measured by the following methods. The characteristics and properties of the pellets in each production process are shown in Table 1 (the same applies to the following examples. In addition, the characteristics and properties of the comparative examples are shown in Table 2).

The physical properties of the particles were determined by image analysis.

Specifically, first, the dispersion of particles was diluted to 0.01% by mass and then dried on a collodion film of a copper element for an electron microscope. Then, the powder obtained was photographed at a magnification of 1 million times using a field emission transmission electron microscope (manufactured by Hitachi High-Tech Nologis, HF5000). For any 1,000 particles of the obtained photographic projection (SEM image, TEM photograph), each item was measured by the following methods (1) to (4).

(1) Particle size

The particle area was obtained from the image processing of the SEM image, and the circle equivalent diameter (circular equivalent diameter) was obtained from the area. The average value of the circle equivalent diameter was taken as the particle size.

(2) Shell thickness

For particles having a cavity inside the outer shell, the outer shell thickness was determined from the TEM photograph, and the average value was taken as the outer shell thickness.

(3) Porosity

The volume of each particle is determined using the particle diameter determined for particles having a cavity inside the shell and the shell thickness determined in (2) above. Next, the ratio of the particle internal volume to the total particle volume is calculated, and the average value is taken as the porosity.

(4) The ratio of particles with one cavity to all particles

The number of cavities in the particles was measured from the TEM images, and the ratio of particles with one cavity to all particles was determined.

(5) Content of antimicrobial metal elements, metal elements other than silicon constituting the outer shell, alkali metals, and alkaline earth metals

The content of antibacterial metal elements (Ag, Cu, Zn, Pb, Sn, Bi, Cd, Cr, Hg, Ni and Co) in the particles, the metal elements other than silicon constituting the shell (Al, Zr, Ti, Zn, Sn and Sb), the content of alkali metals and the content of alkaline earth metals are measured as follows. That is, the particles are dissolved with hydrofluoric acid, and after heating to remove the hydrofluoric acid, pure water is added as needed to obtain a solution. The obtained solution is measured using an ICP inductively coupled plasma emission spectrometer (ICP induction coupling plasma emission spectrometer mass spectrometer) (manufactured by Shimadzu Corporation, ICPM-8500).

(6) Silica content

The particle dispersion was dried at 120° C. for 12 hours, and the powder obtained was measured using a fluorescent X-ray analyzer (manufactured by Hitachi High-Tech Science & Technology Co., Ltd., EA600VX) to determine the content of silicon dioxide (SiO ₂ ) therein.

(7) Density (A1) obtained by He gas adsorption method and density (B1) obtained by _N2 gas adsorption method

The particle dispersion was dried using an evaporator and then dried at 105° C. The powder obtained was placed in a cell and measured using a dry automatic density meter (manufactured by Micromeritics, AccuPyc1340TC) using He gas or N ₂ gas at a gas introduction pressure of 134 kPa and 10 measurements.

(8) Density (A2) of the product heat-treated at 400°C obtained by the He gas adsorption method; and the ratio (A2/B2) of the density (A2) to the density (B2) obtained by the _N2 gas adsorption method.

The dispersion of particles was dried by an evaporator and then heat treated (fired) at 400°C for 1 hour in air. The powder thus obtained was placed in a cell and measured using a dry automatic density meter (manufactured by Micromeritics, AccuPyc1340TC) using He gas or _N2 gas at a gas introduction pressure of 134 kPa and 10 measurements to determine the ratio (A2/B2).

(9) Organic compounds with functional groups

The presence or absence and type of functional groups contained in the particles were determined by the following method.

First, the dispersion of the particles was dried with an evaporator and then dried at 105°C. The powder thus obtained was measured using a Fourier transform infrared spectrometer (FT-IR) (manufactured by JASCO Corporation, FT/IR-6100) using a diffuse reflectance method with the wave number range set to 700cm ^-1 to 4000cm ^-1 , TGS as a detector, the resolution set to 4.0cm ^-1 and the cumulative number set to 50 times. The peaks were detected by this measurement, and the functional groups were determined with reference to the spectral database of organic compounds SDBS (https://sdbs.db.aist.go.jp (National Institute of Advanced Industrial Science and Technology, 2021.01)).

However, no peaks derived from the functional groups were observed for these particles. This is because the particle surface treatment with an organic silicon compound such as 3-methacryloxypropyltrimethoxysilane was not performed in other examples.

<Manufacturing of coating liquid for forming a coating film>

The solvent of 160 g of the aqueous dispersion of particles was replaced with ethanol using an ultrafiltration membrane to obtain an ethanol dispersion of particles having a solid content concentration of 5% by mass. The Na ₂ O content of the particles was 50 ppm.

A coating liquid for forming a film having a solid content concentration of 4% by mass was prepared by mixing a matrix-forming component and an organic solvent with 96 g of the ethanol dispersion of the particles. The matrix-forming components used were: 2.30 g of dipentaerythritol hexaacrylate (DPE-6A manufactured by Kyoei Chemical Co., Ltd., solid content concentration 100% by mass), 0.58 g of 1,6-hexanediol diacrylate (A-HD-N manufactured by Shin-Nakamura Chemical Co., Ltd., solid content concentration 100% by mass), 0.19 g of reactive silicone oil for water-repellent material (X-22-174DX manufactured by Shin-Etsu Chemical Co., Ltd., solid content concentration 100% by mass), 0.43 g of silicone-modified polyurethane acrylate (Ultraviolet UT-4314 manufactured by Nippon Synthetic Chemical Co., Ltd., solid content concentration 30% by mass), and 0.14 g of a photopolymerization initiator (Omnirad TPO manufactured by IGM Resins B.V., solid content concentration 100% by mass). The organic solvent used was 50.2 g of isopropyl alcohol, 30.1 g of methyl isobutyl ketone, and 20.1 g of isopropoxyethanol.

<Manufacturing of Film-Coated Substrate>

A hard coating material (ELCOM HP-1004 manufactured by JGC Catalysts & Chemicals Co., Ltd.) was applied to a TAC film (FT-PB80UL-M manufactured by Panac Co., Ltd., thickness 80 μm, refractive index 1.51) by a bar coating method (#18), and the applied coating material was dried at 80°C for 120 seconds. Then, the applied and dried coating material was cured by irradiating ultraviolet rays at 300 mJ/ ^cm2 , thereby manufacturing a hard coating film. The film thickness of the hard coating film was 8 μm.

Next, the prepared coating liquid was applied to the TAC film having the hard coating film by bar coating (#4), and the applied coating was dried at 80° C. for 120 seconds. Then, the coating was cured by irradiating 400 mJ/cm ² of ultraviolet light in a N ₂ atmosphere, thereby producing a coated substrate.

The following items were measured on the film-coated substrate. The measurement results are shown in Table 3 (the same applies to the following Examples and Comparative Examples).

(10) Appearance

The obtained film-coated substrate was visually inspected to check whether there were defects caused by foreign matter.

No foreign matter defects found: ◎

A small amount of foreign matter defects were found: ０

A large number of foreign body defects were found: △

Overall foreign body defects: ×

(11) Film thickness and reflectivity

The film thickness of the film-coated substrate and the reflectivity at a wavelength of 550 nm were measured using an ellipsometer (EMS-1 manufactured by ULVAC).

(12) Haze, total light transmittance

The haze and total light transmittance of the film-coated substrate were measured using a haze meter (manufactured by Suga Testing Instruments Co., Ltd.).

(13) Antibacterial test

The antibacterial test was conducted in accordance with JIS Z 2801. The antibacterial activity value was calculated by the following formula (2).

Q＝Ut-At ····Formula (2)

(where Q represents the antibacterial activity value, Ut represents the average value of the logarithmic value of the number of viable bacteria per 1 ^cm2 of the untreated test piece after 24 hours, and At represents the average value of the logarithmic value of the number of viable bacteria per 1 ^cm2 of the antibacterial treated test piece after 24 hours).

Staphylococcus aureus (NBRC 12732) and Escherichia coli (NBRC3972) were used as test bacteria, and nutrient broth (meat extract 150 mg/L + peptone 250 mg/L) at a concentration of 1/20 was used as nutrition.

During the measurement, 0.4 mL of bacterial solution was dripped onto a 5 cm square substrate with a film and a non-processed film, and then covered with a 4 cm square PE film to prepare a test piece. The test bacteria on the test piece were cultured for 24 hours at 35°C ± 1°C and a relative humidity of 90% or more. Then, the test bacteria on the test piece were washed and recovered, and the number of viable bacteria per 1 ^cm2 was measured.

(14) Determination of scratch resistance

Using #0000 steel wool, sliding was performed 100 times at a load of 1000 g/cm ^2. The surface of the film-coated substrate after sliding was visually observed and evaluated according to the following criteria.

Evaluation criteria:

No streak scars were found:◎

A few streaky scars were found: ○

A large number of stripe-shaped scars were found: △

The entire surface is scratched: ×

(15) Adhesion

100 squares were made by using a knife to make 11 parallel scratches at intervals of 1 mm vertically and horizontally on the surface of the film-coated substrate. A cellofilm tape was pasted on it, and then the cellofilm tape was peeled off. After that, the number of squares remaining without peeling off the film was counted. The adhesion was evaluated by classifying the number of squares into the following three levels.

The number of remaining squares is 95 or more: ◎

The number of remaining squares is 90 to 94: 0

The number of remaining squares is 85 to 89: △

The number of remaining squares is less than 84: ×

[Example 2]

128 g of an ethanol dispersion of particles having a solid content concentration of 5% by mass was obtained in the same manner as in Example 1. 0.32 g of 3-methacryloxypropyltrimethoxysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) was added thereto, and heat-treated at 30°C for 24 hours. Thereafter, the solvent was replaced with methyl isobutyl ketone (MIBK) using an evaporator, thereby producing an MIBK dispersion of particles having a solid content concentration of 5% by mass. The Na ₂ O content of the particles was 50 ppm. Next, a coating solution and a coated substrate were produced in the same manner as in Example 1, except that the MIBK dispersion of particles was used, and various properties were evaluated.

[Example 3]

In the second step, a MIBK dispersion of particles having a solid content concentration of 5 mass % was prepared in the same manner as in Example 2 except that 7.8 g of an aqueous silver nitrate solution was used. The Na ₂ O content of the particles was 50 ppm. Next, a coating liquid and a film-coated substrate were prepared in the same manner as in Example 1 except that a MIBK dispersion of particles was used, and various properties were evaluated.

[Example 4]

In the second step, a MIBK dispersion of particles having a solid content concentration of 5 mass % was prepared in the same manner as in Example 2, except that 920 g of the silver nitrate aqueous solution was used and the addition time was 90 minutes. The Na ₂ O content of the particles was 50 ppm. Next, a coating liquid and a film-coated substrate were prepared in the same manner as in Example 1, except that the MIBK dispersion of particles was used, and various properties were evaluated.

[Example 5]

<Manufacturing of First Particles (First Step)>

10 g of silica sol (manufactured by JGC Catalysts & Chemicals Co., Ltd., Catalog SI-550, average particle size 5 nm, _SiO2 concentration 20.5 mass %) was mixed with 10.0 kg of pure water, and the resulting mixed solution was heated to 50° C. A 1 mass % sodium hydroxide aqueous solution was added to the mixed solution to adjust the pH to 10.5.

7.9 kg of sodium silicate aqueous solution (SiO ₂ concentration 3.0 mass %) and 7.9 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 1.0 mass %) were added to the mixed solution at the same time. Then, 51.8 kg of sodium silicate aqueous solution (SiO ₂ concentration 3.0 mass %) and 17.1 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 1.0 mass %) were added to the mixed solution (reaction solution) at the same time. During this period, the temperature of the reaction solution was maintained at 50°C. Next, the reaction solution was washed with an ultrafiltration membrane to obtain a dispersion of silicon oxide-alumina particles having a solid content concentration of 3 mass %.

A 35.5% by mass concentrated hydrochloric acid was added dropwise to 50 kg of the dispersion of the silica-alumina particles to adjust the pH to 1.0 and to perform a dealumination treatment. The dissolved aluminum salt was separated by an ultrafiltration membrane and washed to obtain 18 kg of a dispersion of silica particles with a solid content concentration of 5% by mass. Then, 236 g of a 10% by mass aqueous sodium hydroxide solution was added to the dispersion. The dispersion was heat treated in an autoclave at 195°C for 24 hours to obtain an aqueous dispersion of the first particles. The Na ₂ O content of the particles was 0.3% by mass.

In the second step, a MIBK dispersion of particles having a solid content concentration of 5% by mass was prepared in the same manner as in Example 2 except that the first particles diluted with pure water to 1.5% by mass were used. The Na ₂ O content of the particles was 90 ppm. Next, a coating liquid and a film-coated substrate were prepared in the same manner as in Example 1 except that the MIBK dispersion of particles was used, and various properties were evaluated.

[Example 6]

<Manufacturing of First Particles (First Step)>

10 g of silica sol (manufactured by JGC Catalysts & Chemicals Co., Ltd., Catalog SI-50, average particle size 25 nm, _SiO2 concentration 48 mass %) was mixed with 5.0 kg of pure water, and the resulting mixed solution was heated to 98° C. A 1 mass % sodium hydroxide aqueous solution was added to the mixed solution to adjust the pH to 12.5.

65 kg of sodium silicate aqueous solution (SiO ₂ concentration 1.5 mass%) and 65 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 0.5 mass%) were added to the mixed solution at the same time. Then, 37 kg of sodium silicate aqueous solution (SiO ₂ concentration 1.5 mass%) and 12 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 0.5 mass%) were added to the mixed solution (reaction solution) at the same time. During this period, the temperature of the reaction solution was maintained at 98°C. Next, the reaction solution was washed with an ultrafiltration membrane to obtain a dispersion of silicon oxide-alumina particles having a solid content concentration of 3 mass%.

A 35.5% by mass concentrated hydrochloric acid was added dropwise to 50 kg of the dispersion of the silica-alumina particles to adjust the pH to 1.0 and to perform a dealumination treatment. The dissolved aluminum salt was separated by an ultrafiltration membrane and washed to obtain 5 kg of a dispersion of silica particles with a solid content concentration of 5% by mass. Then, 66 g of a 10% by mass aqueous sodium hydroxide solution was added to the dispersion. The dispersion was heat treated in an autoclave at 195°C for 24 hours to obtain an aqueous dispersion of the first particles. The Na ₂ O content of the particles was 0.2% by mass.

In the second step, a MIBK dispersion of particles having a solid content concentration of 5 mass % was prepared in the same manner as in Example 2 except that the first particles diluted with pure water to 1.5 mass % were used. The Na ₂ O content of the particles was 30 ppm.

<Manufacturing of coating liquid and film-coated substrate>

A coating solution with a solid content concentration of 4% by mass was obtained by mixing a matrix-forming component and an organic solvent in 32 g of a MIBK dispersion of particles. The matrix-forming components used were: 4.61 g of dipentaerythritol hexaacrylate, 1.15 g of 1,6-hexanediol diacrylate, 0.38 g of reactive silicone oil for water-repellent material, 0.85 g of silicone-modified polyurethane acrylate, and 0.29 g of a photopolymerization initiator. The organic solvent used was: 80.4 g of isopropyl alcohol, 48.2 g of methyl isobutyl ketone, and 32.1 g of isopropoxyethanol. Next, a coated substrate was prepared in the same manner as in Example 1, except that the coating solution was used, and various properties were evaluated.

[Example 7]

<Manufacturing of First Particles (First Step)>

313 g of silica-alumina sol (Finka Taloid USBB-120 manufactured by JGC Catalysts & Chemicals Co., Ltd.) was mixed with 29.7 kg of pure water, and the resulting mixed solution was heated to 98° C. A 1 mass % sodium hydroxide aqueous solution was added to the mixed solution to adjust the pH to 12.5.

30.0 kg of sodium silicate aqueous solution (SiO ₂ concentration 3.0 mass %) and 30.0 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 1.0 mass %) were added to the mixed solution at the same time. Then, 70.0 kg of sodium silicate aqueous solution (SiO ₂ concentration 1.5 mass %) and 23.3 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 0.5 mass %) were added to the mixed solution (reaction solution) at the same time. During this period, the temperature of the reaction solution was maintained at 98°C. Next, the reaction solution was washed with an ultrafiltration membrane to obtain a dispersion of silicon oxide-alumina particles having a solid content concentration of 3 mass %.

A 35.5% by mass concentrated hydrochloric acid was added dropwise to 50 kg of the dispersion of the silica-alumina particles to adjust the pH to 1.0 and to perform a dealumination treatment. The dissolved aluminum salt was separated by an ultrafiltration membrane and washed to obtain 9 kg of a dispersion of silica particles with a solid content concentration of 5% by mass. Then, 118 g of a 10% by mass aqueous sodium hydroxide solution was added to the dispersion. The dispersion was heat treated in an autoclave at 195°C for 24 hours to obtain an aqueous dispersion of the first particles. The Na ₂ O content of the particles was 0.1% by mass.

In the second step, a MIBK dispersion of particles having a solid content concentration of 5% by mass was prepared in the same manner as in Example 2 except that the first particles diluted with pure water to 1.5% by mass were used. The Na ₂ O content of the particles was 30 ppm. Next, a coating liquid and a film-coated substrate were prepared in the same manner as in Example 1 except that the MIBK dispersion of particles was used, and various properties were evaluated.

[Example 8]

<Manufacturing of First Particles (First Step)>

63 g of silica sol (CATALYDO SI-50 manufactured by JGC Catalysts & Chemicals Co., Ltd.) and 29.9 kg of pure water were mixed and the resulting mixed solution was heated to 98° C. A 1% by mass sodium hydroxide aqueous solution was added to the mixed solution to adjust the pH to 12.5.

10.7 kg of sodium silicate aqueous solution (SiO ₂ concentration 3.0 mass %) and 10.7 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 1.0 mass %) were added to the mixed solution at the same time. Then, 86 kg of sodium silicate aqueous solution (SiO ₂ concentration 3.0 mass %) and 28.6 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 1.0 mass %) were added to the mixed solution (reaction solution) at the same time. During this period, the temperature of the reaction solution was maintained at 98°C. Next, the reaction solution was washed with an ultrafiltration membrane to obtain a dispersion of silicon oxide-alumina particles having a solid content concentration of 3 mass %.

A 35.5% by mass concentrated hydrochloric acid was added dropwise to 40 kg of the dispersion of the silica-alumina particles to adjust the pH to 1.0 and to perform a dealumination treatment. The dissolved aluminum salt was separated by an ultrafiltration membrane and washed to obtain 13 kg of a dispersion of silica particles with a solid content concentration of 5% by mass. Then, 170 g of a 10% by mass aqueous sodium hydroxide solution was added to the dispersion. The dispersion was heat treated in an autoclave at 195°C for 24 hours to obtain an aqueous dispersion of the first particles. The Na ₂ O content of the particles was 0.2% by mass.

In the second step, a MIBK dispersion of particles having a solid content concentration of 5 mass % was prepared in the same manner as in Example 2 except that the first particles diluted with pure water to 1.5 mass % were used. The Na ₂ O content of the particles was 0.018 mass %.

<Manufacturing of coating liquid and film-coated substrate>

A coating solution with a solid content concentration of 4% by mass was prepared by mixing a matrix-forming component and an organic solvent in 56 g of a MIBK dispersion of particles. The matrix-forming components used were: 3.74 g of dipentaerythritol hexaacrylate, 0.94 g of 1,6-hexanediol diacrylate, 0.31 g of reactive silicone oil for water-repellent materials, 0.69 g of silicone-modified polyurethane acrylate, and 0.23 g of a photopolymerization initiator. The organic solvents used were: 69.0 g of isopropyl alcohol, 41.4 g of methyl isobutyl ketone, and 27.6 g of isopropoxyethanol. Next, a coated substrate was prepared in the same manner as in Example 1, except that the coating solution was used, and each property was evaluated.

[Example 9]

<Manufacturing of First Particles (First Step)>

52 g of silica sol (CATALYDO SI-50 manufactured by JGC Catalysts & Chemicals Co., Ltd.) and 4.9 kg of pure water were mixed and the resulting mixed solution was heated to 98° C. A 1% by mass sodium hydroxide aqueous solution was added to the mixed solution to adjust the pH to 12.5.

77 kg of sodium silicate aqueous solution (SiO ₂ concentration 1.0 mass %) and 86 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 0.3 mass %) were added to the mixed solution at the same time. Then, 92 kg of sodium silicate aqueous solution (SiO ₂ concentration 1.0 mass %) and 34 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 0.3 mass %) were added to the mixed solution (reaction solution) at the same time. During this period, the temperature of the reaction solution was maintained at 98°C. Next, the reaction solution was washed with an ultrafiltration membrane to obtain a dispersion of silicon oxide-alumina particles having a solid content concentration of 3 mass %.

A 35.5% by mass concentrated hydrochloric acid was added dropwise to 50 kg of the dispersion of the silica-alumina particles to adjust the pH to 1.0 and to perform a dealumination treatment. The dissolved aluminum salt was separated by an ultrafiltration membrane and washed to obtain 9 kg of a dispersion of silica particles with a solid content concentration of 5% by mass. Then, 118 g of a 10% by mass aqueous sodium hydroxide solution was added to the dispersion. The dispersion was heat treated in an autoclave at 195°C for 24 hours to obtain an aqueous dispersion of the first particles. The Na ₂ O content of the particles was 0.2% by mass.

In the second step, a MIBK dispersion of particles having a solid content concentration of 5 mass % was prepared in the same manner as in Example 2 except that the first particles diluted with pure water to 1.5 mass % were used. The Na ₂ O content of the particles was 40 ppm.

<Manufacturing of coating liquid and film-coated substrate>

A coating solution with a solid content concentration of 4% by mass was prepared by mixing a matrix-forming component and an organic solvent in 64 g of a MIBK dispersion of particles. The matrix-forming components used were: 3.46 g of dipentaerythritol hexaacrylate, 0.86 g of 1,6-hexanediol diacrylate, 0.29 g of reactive silicone oil for water-repellent material, 0.64 g of silicone-modified polyurethane acrylate, and 0.22 g of a photopolymerization initiator. The organic solvent used was: 65.3 g of isopropyl alcohol, 39.2 g of methyl isobutyl ketone, and 26.1 g of isopropoxyethanol. Next, a coated substrate was prepared in the same manner as in Example 1, except that the coating solution was used, and each property was evaluated.

[Example 10]

In the second step, 500 g of the aqueous dispersion of silica particles was subjected to ion exchange for 3 hours using 100 g of a cation exchange resin. However, ion exchange was not performed using an anion exchange resin and ion exchange was not performed again using a cation exchange resin. In addition, a MIBK dispersion of particles having a solid content concentration of 5% by mass was prepared in the same manner as in Example 2. The Na ₂ O content of the particles was 0.09% by mass. Next, a coating solution and a coated substrate were prepared in the same manner as in Example 2 except that the MIBK dispersion of particles was used, and each property was evaluated.

[Example 11]

In the second step, an aqueous dispersion of particles was obtained in the same manner as in Example 1 except that 42.5 g of an aqueous silver nitrate solution was used. The Na ₂ O content of the particles was 60 ppm. Then, a MIBK dispersion of particles having a solid content concentration of 5% by mass was prepared in the same manner as in Example 2 except that 1.92 g of 3-methacryloxypropyltrimethoxysilane was added to the ethanol dispersion of particles having a solid content concentration of 5% by mass prepared in the same manner as in Example 1. The Na ₂ O content of the particles was 50 ppm. Next, a coating liquid and a coated substrate were prepared in the same manner as in Example 1 except that the MIBK dispersion of particles was used, and various properties were evaluated.

[Example 12]

To 50 kg of a dispersion of silicon oxide-alumina particles prepared in the same manner as in Example 1, concentrated hydrochloric acid at a concentration of 35.5% by mass was added dropwise to adjust the pH to 1.0, and a dealumination treatment was performed. The dissolved aluminum salt was separated with an ultrafiltration membrane, and after washing, concentrated hydrochloric acid at a concentration of 35.5% by mass was added dropwise again to adjust the pH to 0.3, and a dealumination treatment was performed. By separating the dissolved aluminum salt with an ultrafiltration membrane and washing, 10 kg of a dispersion of silicon dioxide particles with a solid content concentration of 5% by mass was obtained. Then, 131 g of a sodium hydroxide aqueous solution with a concentration of 10% by mass was added to the dispersion. The dispersion was heat treated in an autoclave at 195°C for 24 hours to obtain an aqueous dispersion of the first particles. The particles had a Na ₂ O content of 0.2% by mass and an Al ₂ O ₃ content of 0.00% by mass.

In the second step, a MIBK dispersion of particles having a solid content concentration of 5% by mass was prepared in the same manner as in Example 1, except that 14.2 g of an aqueous silver nitrate solution was added to the first particles diluted to 1.5% by mass with pure water. The Na ₂ O content of the particles was 30 ppm. Next, a coating liquid and a film-coated substrate were prepared in the same manner as in Example 1, except that the MIBK dispersion of particles was used, and various properties were evaluated.

[Example 13]

In the second step, a MIBK dispersion of particles having a solid content concentration of 5 mass % was prepared in the same manner as in Example 2, except that 132.8 g of a copper nitrate aqueous solution was used instead of the silver nitrate aqueous solution. The Na ₂ O content of the particles was 50 ppm. Next, a coating liquid and a film-coated substrate were prepared in the same manner as in Example 1, except that a MIBK dispersion of particles was used, and various properties were evaluated.

[Example 14]

In the second step, a MIBK dispersion of particles having a solid content concentration of 5 mass % was prepared in the same manner as in Example 2, except that 130.3 g of a zinc nitrate aqueous solution was used instead of the silver nitrate aqueous solution. The Na ₂ O content of the particles was 50 ppm. Next, a coating liquid and a film-coated substrate were prepared in the same manner as in Example 1, except that a MIBK dispersion of particles was used, and various properties were evaluated.

[Example 15]

<Manufacturing of coating liquid and film-coated substrate>

A coating liquid having a solid content concentration of 4% by mass was prepared by mixing a matrix-forming component and an organic solvent in 64 g of the MIBK dispersion of particles prepared in Example 9. The matrix-forming components used were: 3.11 g of dipentaerythritol hexaacrylate, 0.77 g of 1,6-hexanediol diacrylate, 2.16 g of a fluorine-based resin (manufactured by DIC Corporation, Optur DAC-HP, solid content concentration 20% by mass), 0.48 g of a fluorine-based additive (manufactured by DIC Corporation, Megaphage F477, active ingredient 100%), and 0.22 g of a photopolymerization initiator. The organic solvent used was: 65.3 g of isopropyl alcohol, 39.2 g of methyl isobutyl ketone, and 24.8 g of isopropoxyethanol. Next, a coated substrate was prepared in the same manner as in Example 1 except that this coating liquid was used, and various properties were evaluated.

[Example 16]

<Manufacturing of coating liquid for forming high refractive index layer>

A coating liquid for forming a high refractive index layer having a solid content concentration of 5% by mass was obtained by mixing a matrix-forming component and an organic solvent in 26 g of a titanium dioxide-based sol (manufactured by JGC Catalysts & Chemicals Co., Ltd., ELCOM V-9108, particle size 15 nm, solid content concentration 30.5% by mass). The matrix-forming component used was 1.44 g of dipentaerythritol hexaacrylate, 0.36 g of 1,6-hexanediol diacrylate, and 0.1 g of a photopolymerization initiator. The organic solvent used was 172 g of propylene glycol monomethyl ether.

<Manufacturing of Film-Coated Substrate>

The coating liquid for forming a high refractive index layer was applied by a bar coating method (#8) on the hard coating layer of the TAC film having a hard coating film produced in the same manner as in Example 1, and the applied coating was dried at 80° C. for 120 seconds. Then, the dried coating after application was cured by irradiating 1200 mJ/cm ² of ultraviolet rays, thereby producing a high refractive index layer on the hard coating layer. The film thickness of the high refractive index layer was 220 nm.

Next, the coating liquid prepared in Example 9 was applied to the high refractive index layer of the TAC film having a high refractive index layer by a bar coating method (#4), and the applied coating was dried at 80° C. for 120 seconds. Thereafter, the coating was cured by irradiating 400 mJ/cm ² of ultraviolet rays in a N ₂ atmosphere to prepare a coated substrate, and various properties were evaluated.

[Example 17]

<Manufacturing of Anti-glare Layer-Forming Coating Liquid>

A coating liquid for forming an anti-glare layer having a solid content concentration of 35% by mass was obtained by mixing a matrix-forming component and an organic solvent in 10 g of silica powder (manufactured by JGC Catalysts & Chemicals Co., Ltd., silica microbeads P-500). The matrix-forming component used was 30.2 g of dipentaerythritol hexaacrylate, 7.6 g of 1,6-hexanediol diacrylate, and 1.9 g of a photopolymerization initiator. The organic solvent used was 78.2 g of propylene glycol monomethyl ether.

<Manufacturing of coated substrate (17)>

The anti-glare layer-forming coating liquid was applied by a bar coating method (#9) on the hard coating layer of the TAC film having a hard coating film produced in the same manner as in Example 1, and the applied coating was dried at 80° C. for 120 seconds. Then, the applied and dried coating was cured by irradiating ultraviolet rays at 800 mJ/cm ² , thereby producing an anti-glare layer on the hard coating layer.

Next, the coating solution prepared in Example 9 was applied to the anti-glare layer of the TAC film having an anti-glare layer by a bar coating method (#4), and the applied coating was dried at 80° C. for 120 seconds. Thereafter, the coating was cured by irradiating 400 mJ/cm ² of ultraviolet light in a N ₂ atmosphere to prepare a coated substrate, and various properties were evaluated.

[Comparative Example 1]

In the second step, a MIBK dispersion of particles having a solid content concentration of 5 mass % was prepared in the same manner as in Example 2, except that the silver nitrate aqueous solution was not used and 0.34 g of 3-methacryloxypropyltrimethoxysilane was added to 128 g of the ethanol dispersion of particles. The Na ₂ O content of the particles was 50 ppm. Next, a coating liquid and a coated substrate were prepared in the same manner as in Example 1, except that the MIBK dispersion of particles was used, and various properties were evaluated.

[Comparative Example 2]

Silica sol (produced by JGC Catalysts & Chemicals Co., Ltd., Catalog SI-45P, particle size 60 nm, solid content concentration 40.5 mass %) was diluted with pure water to obtain 10 kg of silica sol having a solid content concentration of 5 mass %. Then, 131 g of a sodium hydroxide aqueous solution having a concentration of 10 mass % was added to the silica sol, and heat-treated in an autoclave at 195° C. for 24 hours to obtain an aqueous dispersion of first silica particles. The Na ₂ O concentration of the silica particles was 0.2 mass %. The silica particles were so-called "solid particles" having no cavities inside.

In the second step, a MIBK dispersion of silica particles having a solid content concentration of 5% by mass was prepared in the same manner as in Example 2, except that the first silica particles diluted with pure water to 1.5% by mass were used. The Na ₂ O content of the particles was 80 ppm. Next, a coating liquid and a film-coated substrate were prepared in the same manner as in Example 1, except that the MIBK dispersion of silica particles was used, and various properties were evaluated.

[Comparative Example 3]

<Production of Silver Nanoparticles>

65 g of 25% iron (II) sulfate was added to 729 g of 30% sodium citrate aqueous solution while nitrogen was blown in. After stirring for 30 minutes, 24 g of 10% silver nitrate was added at once and stirred for 6 hours. Centrifugation was performed at 5000 rpm for 10 minutes to recover the precipitate, and the recovered precipitate was suspended in 270 g of pure water by ultrasonic wave to obtain an aqueous dispersion of silver nanoparticles. Then, the solvent of 200 g of the aqueous dispersion of silver nanoparticles was replaced with IPA by using an ultrafiltration membrane to prepare an IPA dispersion of silver nanoparticles with a solid content concentration of 5.0% by mass. The particle size of the silver nanoparticles was 10 nm and the Na ₂ O concentration was 0 ppm. In addition, the particle properties shown in Table 2 are the properties when the particles manufactured in Comparative Example 1 and the silver nanoparticles are mixed at a mass ratio of 95.4:4.6. However, for the determination of the thickness and porosity of the shell, only the particles having cavities on the inner side of the shell are used as the object. In addition, the mixing ratio of the particles produced in Comparative Example 1 and the silver nanoparticles was adjusted so that the apparent porosity and the amount of antimicrobial metal of the mixed product were equivalent to those of the particles of Example 2.

<Manufacturing of coating liquid and film-coated substrate>

A coating solution and a film-coated substrate were prepared in the same manner as in Example 1, except that a solution obtained by mixing 91.6 g of the MIBK dispersion of particles produced in Comparative Example 1 not containing an antimicrobial metal component and 4.4 g of the IPA dispersion of silver nanoparticles was used, and various properties were evaluated.

[Comparative Example 4]

In the second step, a MIBK dispersion of particles having a solid content concentration of 5 mass % was prepared in the same manner as in Example 2, except that 2120 g of the silver nitrate aqueous solution was used and the addition time was 90 minutes. The Na ₂ O content of the particles was 50 ppm. Next, a coating liquid and a film-coated substrate were prepared in the same manner as in Example 1, except that the MIBK dispersion of particles was used, and various properties were evaluated.

[Comparative Example 5]

<Manufacturing of First Particles (First Step)>

188 g of silica-alumina sol (Finka Taloid USBB-120 manufactured by JGC Catalysts & Chemicals Co., Ltd.) was mixed with 89.8 kg of pure water, and the resulting mixed solution was heated to 98° C. A 1 mass % sodium hydroxide aqueous solution was added to the mixed solution to adjust the pH to 12.5.

23.0 kg of sodium silicate aqueous solution (SiO ₂ concentration 3.0 mass%) and 23.0 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 1.0 mass%) were added to the mixed solution at the same time. Then, 15.0 kg of sodium silicate aqueous solution (SiO ₂ concentration 3.0 mass%) and 5.0 kg of sodium aluminate aqueous solution (Al ₂ O ₃ concentration 1.0 mass%) were added to the mixed solution (reaction solution) at the same time. During this period, the temperature of the reaction solution was maintained at 98°C. Next, the reaction solution was washed with an ultrafiltration membrane to obtain a dispersion of silicon oxide-alumina particles having a solid content concentration of 3 mass%.

A 35.5% by mass concentrated hydrochloric acid was added dropwise to 50 kg of the dispersion of the silica-alumina particles to adjust the pH to 1.0 and to perform a dealumination treatment. The dissolved aluminum salt was separated by an ultrafiltration membrane and washed to obtain 9 kg of a dispersion of silica particles with a solid content concentration of 5% by mass. Then, 118 g of a 10% by mass aqueous sodium hydroxide solution was added to the dispersion. The dispersion was heat treated in an autoclave at 195°C for 24 hours to obtain an aqueous dispersion of the first particles. The Na ₂ O concentration of the particles was 0.1% by mass.

In the second step, a MIBK dispersion of particles having a solid content concentration of 5.0 mass% was prepared in the same manner as in Example 2 except that the first particles diluted with pure water to 1.5 mass% were used. The Na ₂ O content of the particles was 40 ppm. Next, a coating liquid and a film-coated substrate were prepared in the same manner as in Example 1 except that the MIBK dispersion of particles was used, and various properties were evaluated.

[Table 1]

[Table 2]

[Table 3]

Claims (9)

1. A granule of the present invention, which comprises a solid particle,

the particles contain 0.5 to 40 mass% of an antibacterial metal component based on oxide,

the particles have a silicon-containing shell and a cavity inside,

the proportion of the cavities in the particles, namely the void ratio, is 10 to 90 percent, and

the number proportion of the particles with one cavity relative to the whole particles is more than 80%.

2. The particle according to claim 1, wherein the antimicrobial metal component comprises at least one element selected from the group consisting of silver, copper, zinc, lead, tin, bismuth, cadmium, chromium, mercury, nickel, and cobalt.

3. The pellet according to claim 1, wherein the density (A1) of the pellet based on He gas adsorption is 1.95 g/mL-3.50 g/mL, and the dry product of the pellet is N-based ₂ The density (B1) of the gas adsorption method is 0.50 g/mL-2.60 g/mL.

4. The pellet as claimed in claim 1, wherein a density (A2) of the heat treated product of the pellet at 400 ℃ based on He gas adsorption is 2.17g/mL or more, and the density (A2) and the heat treated product of the pellet at 400 ℃ are based on N ₂ The ratio (A2/B2) of the density (B2) of the gas adsorption method is 1.10 or more.

5. The particle according to claim 1, wherein the particle has an average particle diameter of 20nm to 180nm and an average thickness of 5nm to 30nm.

6. The particle of claim 1, wherein the alkali metal content of the particle is less than 1.00 mass% on an oxide basis.

7. The particle of claim 1, wherein the particle comprises an organic compound having a functional group.

8. A transparent coated substrate, the transparent coated substrate comprising:

a substrate; and

a transparent coating comprising the particles of claim 1 and a matrix formed on the substrate.

9. The transparent coated substrate of claim 8, wherein the transparent coated substrate further comprises at least one layer selected from the group consisting of a hard coat layer, a high refractive index layer, an antiglare layer, and a conductive layer disposed between the transparent coating and the substrate.