JP7152841B2 - Coating liquid for forming transparent film and base material with transparent film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coating liquid capable of forming a transparent film having a low contact angle with water, high hardness (pencil hardness) and high strength (scratch resistance), and a substrate with a transparent film using the same.

2. Description of the Related Art Conventionally, substrates such as sheets and lenses made of glass, plastic, etc. are provided with a hard coat film on the substrate surface in order to improve the scratch resistance of the surface.

For display applications where the hard coat film is used on the outermost surface, a high contact angle type is required in order to impart antifouling properties. On the other hand, for touch panel applications such as tablets and smartphones, a low contact angle type is required because an additional layer is provided on the hard coat or an adhesive or resin is attached.

Moreover, when the coating liquid is dried and cured, the transparent coating shrinks, the substrate is pulled, and there is a problem that the substrate with the transparent coating curls (curves). For example, in the case of a coating liquid containing a large amount of solvent, curling is likely to occur due to shrinkage from a wet film to a dry film due to evaporation (concentration) of the solvent during drying. In addition, when a resin such as a polyfunctional acrylic monomer having a large cure shrinkage rate is used, curling is likely to occur due to shrinkage during curing. In recent years, thin substrates have been used to further improve transparency, or to reduce the weight of display devices and mobile phones using substrates with transparent coatings, and the problem of curling has become more pronounced. .

Therefore, Patent Document 1 discloses a hard coat film obtained by laminating an active energy ray-curable resin layer on at least one side of a substrate, and a method for producing the same. In this hard coat film, the cured resin layer has a surface hardness of H or more and a water droplet contact angle of 60° or less. Specifically, resin compositions for curing such as unsaturated polyester resin, acrylic, addition polymerization, thiol-acrylic hybrid, cationic polymerization, cationic polymerization and radical polymerization hybrid system are applied to plastic film substrates. After the material is applied, it is irradiated with active energy rays such as ultraviolet rays to be cross-linked and cured, and is contacted with a gas containing a specific amount of fluorine gas to form an active energy ray-curable resin layer.

Patent Literature 2 discloses a paint that forms a transparent film that is less curled even on a thin substrate and has excellent adhesion to the substrate, hardness, scratch resistance, transparency, and the like. Specifically, a polyfunctional urethane acrylate resin having 4 or more functional groups, a low-functional acrylate resin having 2 or 3 functional groups, metal oxide fine particles having an average particle size in the range of 5 to 500 nm, and an organic and a solvent, and the concentration ratio (C _B /C _A ) between the concentration (C _A ) of the polyfunctional urethane acrylate resin and the concentration (C _B ) of the low-functional acrylate resin is in the range of 0.05 to 0.5. A paint is disclosed.

JP-A-7-173310 Japanese Unexamined Patent Application Publication No. 2013-64038

However, in Patent Document 1, since the cured resin layer is the main component, the hardness of the hard coat film is only about H to 2H, and it is difficult to increase the hardness beyond that. A hard coat film cannot be obtained.

Next, in Patent Document 2, since the polyfunctional urethane acrylate resin is hydrophobic, the surface of the transparent film is also hydrophobic, and the contact angle with water increases. In addition, when the content of the surface-treated metal oxide fine particles in the transparent coating is increased in order to increase the hardness, the resulting transparent coating is whitened or curled. This is probably because the polyfunctional urethane acrylate resin is hydrophobic, whereas the surface-treated metal oxide fine particles are hydrophilic, so sufficient compatibility cannot be obtained. Furthermore, the polyfunctional urethane acrylate resin is a special compound, so it is expensive and has low weather resistance and light resistance.

The present invention provides a coating liquid (coating liquid for forming a transparent film) that can obtain a hard-coated transparent film that has a low contact angle with water, high hardness, and suppresses curling even on a thin substrate, and a coating solution that uses the same. An object of the present invention is to provide a base material with a transparent film.

A coating liquid for a transparent film according to the present invention comprises an alkylene oxide-modified (meth)acrylate resin, surface-treated metal oxide particles having an organosilicon compound on the surface of the metal oxide particles, and an organic solvent. is. This alkylene oxide-modified (meth)acrylate resin is a polyfunctional (meth)acrylate monomer resin having 3 to 10 (meth)acrylate functional groups and 3 to 40 alkylene oxide groups. The surface-treated metal oxide particles are provided with an organosilicon compound of 0.1 to 50 parts by mass as R _n —SiO _{2 (4-n)/2} with respect to 100 parts by mass of the metal oxide particles. Its average particle size is 5 to 500 nm. The surface-treated metal oxide particles are contained in the coating liquid in an amount of 30 to 90% by mass based on the total solid content of the alkylene oxide-modified (meth)acrylate resin and the surface-treated metal oxide particles.
Also, the alkylene oxide-modified (meth)acrylate resin is preferably an ethylene oxide-modified (meth)acrylate resin.

In the substrate with a transparent film according to the present invention, the transparent film contains an alkylene oxide-modified (meth)acrylate resin and surface-treated metal oxide particles having an organosilicon compound on the surface of the metal oxide particles. The average particle size of the surface-treated metal oxide particles is 5-500 nm. The surface-treated metal oxide particles are contained in the transparent coating in an amount of 30 to 90% by mass based on the total solid content of the alkylene oxide-modified (meth)acrylate resin and the surface-treated metal oxide particles. Here, the transparent film preferably has a contact angle with water of less than 70° and a pencil hardness of 3H or more.
Further, the contact angle of the transparent film is preferably lower than that of the transparent film not containing the surface-treated oxide particles.

In the present invention, since the alkylene oxide-modified (meth)acrylate resin containing a highly polar alkylene oxide group contained in the coating liquid has good compatibility with the surface-treated metal oxide particles, the surface-treated metal oxide particles are alkylene oxide groups. It is sufficiently dispersed in an oxide-modified (meth)acrylate resin, has a low contact angle, and even a thin substrate of 20 to 70 μm provides a transparent coated substrate with high hardness and strength and little curling.

<<Coating liquid for forming transparent film>>
The coating liquid of the present invention comprises an alkylene oxide-modified (meth)acrylate resin, surface-treated metal oxide particles having an average particle size of 5 to 500 nm in which an organosilicon compound is provided on the surface of the metal oxide particles, and an organic solvent. including. This coating liquid may further contain an additive such as a polymerization initiator.
Specifically, this alkylene oxide-modified (meth)acrylate resin is a polyfunctional (meth)acrylate monomer resin having 3 to 10 (meth)acrylate functional groups and 3 to 40 alkylene oxide groups. In the surface-treated metal oxide particles, an organosilicon compound is provided on the surface of the metal oxide particles in an amount of 0.1 to 50 parts by mass as R _n —SiO _(4-n)/2 with respect to 100 parts by mass of the metal oxide particles. surface-treated metal oxide particles. The surface-treated metal oxide particles have an average particle diameter of 5 to 500 nm, and the total solid content of the alkylene oxide-modified (meth)acrylate resin and the surface-treated metal oxide particles in the coating liquid is 30 to 90 nm. % by mass.

Generally, polyfunctional (meth)acrylate monomer resins and polyfunctional (meth)urethane acrylate oligomer resins are often used as resins having good hard coat properties. Some polyfunctional (meth)acrylate monomer resins have relatively low contact angles, but they generally tend to curl. Polyfunctional (meth)urethane acrylate oligomer resins generally have low curling but high contact angles. On the other hand, by optimizing the ratio of alkylene oxide groups and (meth)acrylate functional groups, polyfunctional alkylene oxide-modified (meth)acrylate resins have low hardness, but tend to exhibit relatively low contact angles and low curling. . As described below, the number of acrylate functional groups and alkylene oxide groups in the alkylene oxide-modified (meth)acrylate resin, the amount of surface treatment of the surface-treated metal oxide particles with the organosilicon compound, the average particle diameter of the surface-treated metal oxide particles, and the amount of the surface-treated organosilicon compound in the coating solution are combined under optimum conditions to obtain a hard coat paint that achieves all of high hardness, low contact angle, and low curling properties.

Main components contained in the coating liquid are described in detail below.
《Alkylene oxide-modified (meth)acrylate resin》
By optimizing the ratio of the alkylene oxide group and the (meth)acrylate functional group ((meth)acryloyl group), the alkylene oxide-modified (meth)acrylate resin tends to develop low curling at a relatively low contact angle. If the number of acrylate functional groups is less than 3, the number of bonding sites is reduced, making it difficult to obtain a dense and highly rigid film. Conversely, when the number of acrylate functional groups is more than 10, the number of binding groups per unit volume/unit volume/unit unit is relatively large, so that the film shrinks strongly and curling may occur.
In addition, the alkylene oxide group is a highly polar functional group, and the resulting film surface is hydrophilic, so that the water contact angle of the film is low. If the number of alkylene oxide groups is less than 3, hydrophilization of the film surface is insufficient and the water contact angle is not sufficiently low. Conversely, when the number of alkylene oxide groups is greater than 40, the number of bonding groups per unit volume/unit volume/unit unit becomes relatively small, and the film may not be sufficiently densified. Hardness may not be obtained.

The alkylene oxide (AO) group is preferably an ethylene oxide (EO) group, a propylene oxide (PO) group, or a butylene oxide group. In particular, an ethylene oxide group having a high proportion of oxygen atoms in the unit group and high polarity is preferred.
Alkylene oxide-modified (meth)acrylate resins having 3 or more (meth)acrylate functional groups have relatively large shrinkage. ) By blending the acrylate monomer resin and controlling the shrinkage of the entire film, the adhesiveness to the substrate is further improved, the shrinkage is further suppressed, and the residual stress can be alleviated.
In order to further improve the compatibility between the alkylene oxide-modified (meth)acrylate resin and the surface-treated metal oxide particles, it is preferable to blend a low-functional (meth)acrylate monomer resin. By blending a low-functional (meth)acrylate monomer resin, rapid shrinkage during film formation can be suppressed, preventing particles in the film from being expelled from the shrinkage site, and as a result, surface-treated metal oxide particles improves dispersibility and compatibility in the film. It is also effective in that the viscosity of the paint can be easily lowered. However, since a high blending of the low-functional (meth)acrylate monomer resin leads to a decrease in hardness, the content is preferably as small as possible, and it is preferable to blend the resin in consideration of the balance of curling properties, adhesion and hardness.

As the alkylene oxide-modified (meth)acrylate resin of the present invention, ethylene oxide-modified (meth)acrylate resin, propylene oxide-modified (meth)acrylate resin and butylene oxide-modified (meth)acrylate resin are suitable.
Ethylene oxide-modified (meth)acrylate resins include ethoxylated glycerol tri(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, and ethoxylated ditrimethylolpropane tetra(meth)acrylate. , ethoxylated dipentaerythritol penta(meth)acrylate, and ethoxylated dipentaerythritol hexa(meth)acrylate. They each have 3 to 40 ethylene oxide groups.
Propylene oxide-modified (meth)acrylate resins include propoxylated glycerol tri(meth)acrylate, propoxylated pentaerythritol tri(meth)acrylate, propoxylated pentaerythritol tetra(meth)acrylate, and propoxylated ditrimethylolpropane tetra(meth)acrylate. , propoxylated dipentaerythritol penta(meth)acrylate, and propoxylated dipentaerythritol hexa(meth)acrylate. They each have 3 to 40 propylene oxide groups.
Butylene oxide-modified (meth)acrylate resins include butoxylated glycerin tri(meth)acrylate, butoxylated pentaerythritol tri(meth)acrylate, butoxylated pentaerythritol tetra(meth)acrylate, butoxylated ditrimethylolpropane tetra(meth)acrylate. , butoxylated dipentaerythritol penta(meth)acrylate, and butoxylated dipentaerythritol hexa(meth)acrylate. They each have 3 to 40 butylene oxide groups.
These resins may be used alone or in combination of two or more.

《Surface-treated metal oxide particles》
The surface-treated metal oxide particles are obtained by surface-treating conventionally known metal oxide particles with a conventionally known organosilicon compound. Examples of metal oxide particles include silica, alumina, titania, silica-alumina, silica-zirconia, tin oxide, Sb- or P-doped tin oxide, indium oxide, Sn- or F-doped oxide. Conductive particles such as indium, antimony oxide, and titanium oxide can also be suitably used.

<Average particle size>
The average particle size of the surface-treated metal oxide particles is in the range of 5-500 nm. It is difficult to obtain particles having an average particle size of less than 5 nm, and even if they are obtained, the surface treatment with a surface treatment agent and the stability of the sol are often insufficient. On the other hand, if the average particle size exceeds 500 nm, depending on the content of the surface-treated metal oxide particles, light scattering occurs on the film surface, haze of the transparent film deteriorates, and transparency decreases. The average particle size of the surface-treated metal oxide particles is more preferably in the range of 10-200 nm.

<Surface treatment: surface treatment agent, amount of surface treatment>
It is preferable to surface-treat the metal oxide particles with an organosilicon compound represented by the following formula (1).
R _n —SiX _4-n (1)
However, in the formula, R is an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different. Substituents include epoxy groups, alkoxy groups, (meth)acryloyloxy groups, mercapto groups, halogen atoms, amino groups, and phenylamino groups. X is an alkoxy group having 1 to 4 carbon atoms, a hydroxyl group, a halogen atom or a hydrogen atom; n is an integer of 1 to 3;
The surface-treated metal oxide particles have a solid content in the range of 0.1 to 50 parts by mass as R _n —SiO _(4−n)/2 with respect to 100 parts by mass of the metal oxide particles. Compatibility is improved. Here, if the amount of the organosilicon compound is less than 0.1 parts by mass, the dispersibility of the surface-treated metal oxide particles becomes insufficient, and haze may occur in the resulting transparent coating. Although the obtained contact angle is lowered, the bonding strength with the binder ((meth)acrylate monomer resin) is weakened, so that the adhesiveness and hardness to the substrate may be insufficient. Conversely, even if the surface treatment amount is more than 50 parts by mass, the dispersibility is not further improved, and there is a possibility that the high-density packing of the surface-treated metal oxide particles may be hindered. Although the contact angle is increased, the number of sites that bond with the binder is increased, resulting in increased shrinkage, curling, and insufficient adhesion. Furthermore, when unreacted surface treatment agents (organosilicon compounds) that do not bond with fine particles are bound together, shrinkage increases, so it is preferable to reduce the amount of unreacted surface treatment agents.

《Organic solvent》
As the organic solvent, one capable of dissolving or dispersing additives such as the alkylene oxide-modified (meth)acrylate resin and the polymerization initiator and capable of uniformly dispersing the surface-treated metal oxide particles is used.
As the organic solvent, a hydrophilic solvent or a polar solvent is preferable. Alcohols, esters, glycols, ethers and the like can be used as hydrophilic solvents, and esters, ketones and the like can be used as polar solvents.
Specific examples of organic solvents include alcohols such as methanol, ethanol, propanol, 2-propanol, butanol, diacetone alcohol, furfuryl alcohol, and tetrahydrofurfuryl alcohol, and esters such as methyl acetate, Ethyl acetate, isopropyl acetate, propyl acetate, isobutyl acetate, butyl acetate, isopentyl acetate, pentyl acetate, 3-methoxybutyl acetate, 2-ethylbutyl acetate, cyclohexyl acetate, ethylene glycol monoacetate, etc. Glycols include ethylene glycol. , Hexylene glycol, etc. 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. There are monomethyl ether, propylene glycol monoethyl ether, etc. Ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, butyl methyl ketone, cyclohexanone, methyl cyclohexanone, dipropyl ketone, methylpentyl ketone, diisobutyl ketone, etc. Polar solvents Other examples include dimethyl carbonate and toluene. These may be used alone or in combination of two or more.
In particular, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and diacetone alcohol are effective in controlling the film-forming property of the film, and are preferable from the viewpoint of controlling the appearance (streaks, unevenness, transparency) of the coating film. In addition, when using a triacetyl cellulose base material (TAC base material), if ethyl acetate, acetone, methyl ethyl ketone, cyclohexanone, dimethyl carbonate, etc. are blended, the base material will dissolve, improving adhesion and interference with the base material. This is preferable in terms of reduction of streaks.
Also, the boiling point of the organic solvent is preferably in the range of 50 to 200°C. When the boiling point of the organic solvent is lower than 50° C., the coating film dries quickly, resulting in rapid film formation. In addition, the film thickness tends to be uneven. Therefore, the hardness of the obtained transparent film may be insufficient. If the boiling point of the organic solvent is higher than 200° C., the organic solvent may remain, and voids may be generated when the resin is cured while containing the residual solvent, resulting in insufficient hardness of the resulting transparent film. . The boiling point of this organic solvent is more preferably in the range of 55 to 180°C.

《Other Ingredients》
A photopolymerization initiator may be added to the coating liquid, if necessary. As the polymerization initiator, known ones can be used without particular limitation. 4,4-trimethyl-pentylphosphine oxide, 2-hydroxy-methyl-2-methyl-phenyl-propane-1-ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy- cyclohexyl-phenyl-ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and the like. The amount of the polymerization initiator to be used is preferably 2 to 20 mass %, more preferably 4 to 16 mass % of the solid content concentration of the organic resin.
By the way, leveling agents and surfactants, which are conventionally known additives, tend to be more unevenly distributed on the surface than metal oxide particles when forming a coating. Therefore, if the amount used is excessively large, the desired contact angle with water may not be obtained, or the additive may precipitate on the surface of the film, causing the problem of bleeding out. Therefore, when using these additives, it is preferable to use them within a range that does not affect the performance of the base material with a transparent film.

<<Concentration of coating liquid for forming transparent film>>
The solid content concentration of the coating liquid (concentration of the total solid content of the solid content of the alkylene oxide-modified (meth)acrylate resin and the solid content of the surface-treated metal oxide particles) is preferably in the range of 5 to 70% by mass. . If it is less than 5% by mass, it may be difficult to obtain a uniform film due to the low concentration stability of the paint. In addition, the resulting transparent film may have insufficient hardness and scratch resistance, or may have haze or poor appearance, resulting in a decrease in productivity, production reliability, and the like. Even if it is higher than 70% by mass, the viscosity of the coating liquid increases, the coating property decreases, the haze of the resulting transparent film increases, the surface roughness increases, and the scratch resistance becomes insufficient. There is
More preferably, the solid content concentration of the coating liquid is in the range of 10 to 60% by mass.

<Concentration of surface-treated metal oxide particles>
The surface-treated metal oxide particles in the coating liquid have a solid content of 30 to 90% by mass with respect to the total solid content of the alkylene oxide-modified (meth)acrylate resin and the surface-treated metal oxide particles. . If the amount of the surface-treated metal oxide particles is less than 30% by mass, the effect of suppressing curling, hardness, and scratch resistance may be insufficient when the coating is formed, or the hydrophilicity of the surface of the coating may be insufficient. sufficient and the desired low water contact angle may not be obtained. Conversely, cracks may occur in the transparent film even if the surface-treated metal oxide particles are more than 90% by mass. Moreover, even if a coating is obtained, the adhesion to the substrate may be insufficient, or the coating strength, scratch resistance, transparency, haze, etc. may be deteriorated. The surface-treated metal oxide particle component has a solid content of 50 to 85% by mass with respect to the total solid content of the alkylene oxide-modified (meth)acrylate resin component and the surface-treated metal oxide particle component. is more preferable, and 60 to 80% by mass is even more preferable.

<Concentration of alkylene oxide-modified (meth)acrylate resin>
The alkylene oxide-modified (meth)acrylate resin in the coating liquid has a solid content of 10 to 70% by mass with respect to the total solid content of the alkylene oxide-modified (meth)acrylate resin and the surface-treated metal oxide particles. preferably in
Here, if the alkylene oxide-modified (meth)acrylate resin is less than 10% by mass, cracks may occur in the transparent coating when formed into a coating. Conversely, if the amount of the alkylene oxide-modified (meth)acrylate resin exceeds 70% by mass, the hardness and scratch resistance of the transparent film may become insufficient. The alkylene oxide-modified (meth)acrylate resin component has a solid content of 15 to 50% by mass based on the total solid content of the alkylene oxide-modified (meth)acrylate resin component and the surface-treated metal oxide particle component. and more preferably 20 to 40% by mass.

In the coating liquid having such a concentration ratio of the surface-treated metal oxide particles and the alkylene oxide-modified (meth)acrylate resin, the concentration of the surface-treated metal oxide particles in the coating liquid is 1.5 to 63 as solids. % by mass, and the alkylene oxide-modified (meth)acrylate resin is preferably in the range of 0.5 to 49% by mass as a solid content.

As described above, the coating liquid of the present invention comprises an alkylene oxide-modified (meth)acrylate resin and a surface-treated metal oxide having an average particle size of 5 to 500 nm, in which an organosilicon compound is provided on the surface of metal oxide particles. and an organic solvent. This alkylene oxide-modified (meth)acrylate resin contains 3 to 10 (meth)acrylate functional groups and 3 to 40 alkylene oxide groups. The surface-treated metal oxide particles contain 0.1 to 50 parts by mass of an organosilicon compound as R _n —SiO _{(4-n)/2 per} 100 parts by mass of the metal oxide particles. The coating liquid contains the surface-treated metal oxide particles in an amount of 30 to 90% by mass based on the total solid content of the alkylene oxide-modified (meth)acrylate resin and the surface-treated metal oxide particles.
Constituent elements of a more preferable coating liquid include, first, the alkylene oxide-modified (meth)acrylate resin contains 4 to 8 (meth)acrylate functional groups and 6 to 30 alkylene oxide groups. Next, the surface-treated metal oxide particles contain 1 to 30 parts by mass of an organosilicon compound as R _n —SiO _{2 (4-n)/2} with respect to 100 parts by mass of the metal oxide particles. The coating liquid contains the surface-treated metal oxide particles in an amount of 50 to 85% by mass based on the total solid content of the alkylene oxide-modified (meth)acrylate resin and the surface-treated metal oxide particles.
Further preferable constituents of the coating liquid are as follows. First, the alkylene oxide-modified (meth)acrylate resin contains 4 to 6 (meth)acrylate functional groups and 12 to 24 alkylene oxide groups. Next, the surface-treated metal oxide particles contain 5 to 20 parts by mass of an organosilicon compound as R _n —SiO _{2 (4-n)/2} with respect to 100 parts by mass of the metal oxide particles. The coating liquid contains the surface-treated metal oxide particles in an amount of 60 to 80% by mass based on the total solid content of the alkylene oxide-modified (meth)acrylate resin and the surface-treated metal oxide particles.

[Substrate with transparent film]
A transparent film is directly or indirectly formed on a substrate using the coating liquid described above. A transparent film is mainly formed of surface-treated metal oxide particles and a resin component. Since the transparent film of the present invention has a low contact angle with water, it is particularly useful when an upper layer such as a resin layer is provided on the film of the present invention. That is, the substrate with a transparent film of the present invention preferably has a structure in which a transparent film is provided on a substrate, and an upper layer such as a resin layer is further provided on the transparent film.
"Base material"
As the base material, known ones can be used without particular limitation, and polycarbonate, acrylic resin, polyethylene terephthalate (PET), triacetyl cellulose (TAC), polymethyl methacrylate resin (PMMA), cycloolefin A transparent resin substrate such as a polymer (COP) is preferred. These resin substrates have excellent adhesion to the transparent coating formed from the above-described coating solution, and can provide a substrate with a transparent coating excellent in hardness, scratch resistance, and the like. Therefore, it can be suitably used for thin base materials. The thickness of the substrate is preferably in the range of 20-70 μm. Among them, the TAC substrate tends to curl if the substrate is thin, and therefore it is preferable to use the coating liquid for the transparent film of the present invention in order to suppress the curling.
More preferably, the thickness of the substrate is in the range of 30-60 μm.

《Transparent Coating》
In the transparent film according to the present invention, the amounts of the alkylene oxide-modified (meth)acrylate resin component and the surface-treated metal oxide particle component in the coating solution are directly the proportions of the components in the film. That is, with respect to the total amount of the solid content of the alkylene oxide-modified (meth)acrylate resin component and the solid content of the surface-treated metal oxide particle component having an average particle diameter of 5 to 500 nm, preferably 10 to 200 nm, the alkylene oxide-modified ( The meth)acrylate resin component is preferably present in a solids content of 10 to 70% by mass. Here, if the alkylene oxide-modified (meth)acrylate resin is less than 10% by mass, cracks may occur in the transparent coating. Conversely, even if the alkylene oxide-modified (meth)acrylate resin is more than 70% by mass, the hardness and scratch resistance of the transparent film may be insufficient. The alkylene oxide-modified (meth)acrylate resin component has a solid content of 15 to 50% by mass based on the total solid content of the alkylene oxide-modified (meth)acrylate resin component and the surface-treated metal oxide particle component. and more preferably 20 to 40% by mass.

On the other hand, the surface-treated metal oxide particle component has a solid content of 30 to 90% by mass with respect to the total solid content of the alkylene oxide-modified (meth)acrylate resin component and the surface-treated metal oxide particle component. Preferably. Here, if the amount of the surface-treated metal oxide particles is less than 30% by mass, the effect of suppressing curling, hardness and scratch resistance may be insufficient, or the hydrophilicity of the surface of the film may be insufficient. Water contact angles may not be obtained. Conversely, cracks may occur in the transparent film even if the surface-treated metal oxide particles are more than 90% by mass. Moreover, even if a coating is obtained, the adhesion to the substrate may be insufficient, or the coating strength, scratch resistance, transparency, haze, etc. may be deteriorated. The surface-treated metal oxide particle component has a solid content of 50 to 85% by mass with respect to the total solid content of the alkylene oxide-modified (meth)acrylate resin component and the surface-treated metal oxide particle component. is more preferable, and 60 to 80% by mass is even more preferable.

If the average particle size of the surface-treated metal oxide particles is smaller than 5 nm, it is difficult to obtain them, and even if they are obtained, the surface treatment with a surface-treating agent and the stability of the sol are often insufficient. Further, when the average particle size of the surface-treated metal oxide particles is larger than 500 nm, depending on the content of the surface-treated metal oxide particles, light scattering occurs on the film surface, haze of the transparent film deteriorates, Reduces transparency. Conventionally, the obtained transparent film has a lower contact angle with a film composed of a resin component alone than a film containing surface-treated metal oxide particles, but the surface-treated metal oxide of the present invention has a lower contact angle. A film containing particles has a characteristic that the contact angle is lower than that of a film composed of a resin component alone. Although the reason is not clear, one of the factors is that particles exist on the film surface to form a texture on the film surface, and the surface area of the film relatively increases to promote a low contact angle (Wenzel effect). Conceivable.

The film thickness of the transparent film is preferably 1 to 10 μm. If the thickness of the transparent coating is less than 1 μm, the hardness and scratch resistance of the transparent coating may be insufficient. If the transparent coating is thicker than 10 μm, the shrinkage of the coating is increased, curling is likely to occur, and adhesion to the substrate may be insufficient. Also, if the shrinkage is too great, cracks may occur. The film thickness of this transparent film is more preferably 2 to 10 μm.

The contact angle of the transparent coating with water is preferably less than 70°. If the contact angle is 70° or more, the hydrophilicity may be insufficient and the adhesiveness to the upper layer may be lowered. More preferably, the contact angle of this transparent coating with water is less than 50°.
The pencil hardness of the transparent coating is preferably 3H or more. A pencil hardness of less than 3H is insufficient for a hard coat film. The pencil hardness of this transparent coating is more preferably 4H or more.
The curling property of the transparent coating is preferably less than 20 mm, more preferably less than 10 mm.

Moreover, it is preferable that the light transmittance of the base material with a transparent film is 90.0% or more.
If the light transmittance of the substrate with a transparent film is lower than 90.0%, the definition of images may be insufficient when used in a display device or the like. More preferably, the light transmittance of this substrate with a transparent film is 91.5% or more.
Such a transparent film-coated substrate is suitable for applications requiring thinness and lightness in order to reduce the weight of photoelectric cells, liquid crystal display cells, mobile phones, personal computers, and the like.

Examples of the present invention will be described below, but the present invention is not limited to these examples.
In the examples, silica-alumina fine particles or silica fine particles were used as the metal oxide fine particles.

(Example 1)
<<Preparation of coating liquid (1)>>
Silica-alumina sol dispersion (manufactured by Nikki Shokubai Kasei Co., Ltd.; OSCAL1132; average particle diameter 12 nm, solid content concentration 40.5% by mass, dispersion medium: methanol sol, particle refractive index 1.46) 100 g of γ-methacryloxy 6.08 g of propyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd.: KBM-503, SiO ₂ component: 81.2% by mass) was mixed, 8.80 g of ultrapure water was added, and 0.5% of 5% aqueous ammonia was added. 40 g was added and stirred at 50° C. for 6 hours. As a result, a surface-treated 12 nm silica-alumina sol dispersion was obtained (solid concentration: 40.4% by mass).
Thereafter, the solvent was replaced with propylene glycol monomethyl ether (PGME) using a rotary evaporator to obtain a silica sol PGME dispersion (1) having a solid content of 46.6% by mass. Next, 60.11 g of this silica sol PGME dispersion (1), 12.00 g of EO-modified acrylate binder (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E), and a photopolymerization initiator (Ciba Japan ( 1.80 g of Irgacure 184), 13.59 g of PGME, and 12.50 g of acetone were sufficiently mixed to prepare a coating liquid (1) for forming a transparent film having a solid concentration of 41.8% by mass. Table 1 shows the composition of this coating liquid (1).
<<Measurement of average particle size>>
The average particle size is obtained by taking an electron micrograph, measuring the particle size of arbitrary 100 particles, and obtaining the average value.

<<Preparation of base material (1) with transparent film>>
Coating solution (1) for forming a transparent film is applied to a TAC film (manufactured by Fuji Film Co., Ltd.: FT-PB40UL-M, thickness: 40 μm, refractive index: 1.51) by a bar coater method (#16). After drying at 80° C. for 120 seconds, the substrate was cured by irradiating with ultraviolet rays of 300 mJ/cm ² in an N ₂ atmosphere to obtain a base material (1) with a transparent film. The film thickness of the transparent film was 8 μm.
The film thickness, pencil hardness, contact angle, curling property, scratch resistance, haze, total light transmittance, adhesion and appearance of this substrate with transparent film (1) were evaluated according to the following methods and evaluation criteria. are shown in Table 2.

《Film thickness measurement》
The film thickness was measured with a digital gauge (manufactured by Ono Sokki Co., Ltd. gauge stand ST-0230 and digital gauge counter DG-5100).
《Pencil Hardness Measurement》
Measured with a pencil hardness tester according to JIS-K-5600. A pencil hardness of 3H or more is preferable.
《Measurement of contact angle》
The contact angle was measured with a fully automatic contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.: DM700). The contact angle with water is preferably less than 70°.

<<Evaluation of curling property>>
Coating solution (1) is applied to a TAC film substrate of 14 cm x 25 cm x 40 µm (thickness) so as to form a transparent film with a thickness of 8 µm, left to stand for 20 hours, and then the film is cut into a size of 10 cm x 10 cm. After cutting, the film was placed on a flat plate with the coated surface facing down, and the height from the flat plate of the apex of the substrate that curled (curved) and floated was measured and evaluated according to the following criteria.
<Evaluation criteria>
Less than 10mm: ◎
Less than 10 to 20 mm: ○
Less than 20 to 30 mm: △
30 mm or more: ×
<<Evaluation of abrasion resistance>>
Using #0000 steel wool, the surface of the film was slid 10 times with a load of 500 g/cm ² , visually observed, and evaluated according to the following criteria.
<Evaluation criteria>
No streaky scratches : ◎
Slightly streak-like scratches are observed: ○
Many streaky scratches are observed: △
The surface is entirely scraped : ×
《Measurement of total light transmittance and haze》
The total light transmittance and haze were measured with a haze meter (NDH-5000 manufactured by Nippon Denshoku Co., Ltd.). The uncoated TAC film had a total light transmittance of 93.0% and a haze of 0.3%. It is preferable that the total light transmittance is 90.0% or more and the haze is 0.5% or less.
《Adhesion》
11 parallel scratches were made on the surface of the base material with a transparent film with a knife at intervals of 1 mm in length and width to make 100 squares, and a cellophane tape was adhered to them, and then the cellophane tape was peeled off. Adhesion was evaluated by classifying the number of remaining squares without peeling off into the following four grades.
<Evaluation criteria>
Number of remaining squares 100: ◎
Number of remaining squares 90 to 99: ○
Number of remaining squares 85 to 89: △
Number of remaining squares 84 or less: ×
"exterior"
The surface of the transparent film-coated substrate was visually observed and evaluated according to the following criteria.
<Evaluation criteria>
No appearance defects such as streaks, unevenness, cracks, or bleeding out can be confirmed on the surface: ◎
Almost no visible defects such as streaks, unevenness, cracks, or bleeding out on the surface: ○
Slight appearance defects such as streaks, unevenness, cracks, and bleeding out were observed on the surface: △
Poor appearance such as streaks, unevenness, cracks, and bleeding out were clearly observed on the surface: ×

(Example 2)
<<Preparation of coating liquid (2) for forming transparent film>>
A coating liquid (2) having a solid content concentration of 41.8% by mass was prepared in the same manner as in Example 1, except that the EO-modified acrylate binder was changed to NK Ester A-DPH-24E manufactured by Shin-Nakamura Chemical Co., Ltd. did. Table 1 shows the composition of the obtained coating liquid (2).
<<Preparation of substrate with transparent film (2)>>
A base material (2) with a transparent film was produced and evaluated in the same manner as in Example 1 except that the coating liquid (2) was used. The film thickness of the transparent film was 8 μm.

(Example 3)
<<Preparation of coating liquid (3) for forming transparent film>>
A coating solution (3) having a solid content concentration of 41.8% by mass was prepared in the same manner as in Example 1, except that the EO-modified acrylate binder was changed to NK Ester A-DPH-12E manufactured by Shin-Nakamura Chemical Co., Ltd. did. Table 1 shows the composition of the obtained coating liquid (3).
<<Preparation of substrate with transparent film (3)>>
A base material (3) with a transparent film was produced and evaluated in the same manner as in Example 1 except that the coating liquid (3) was used. The film thickness of the transparent film was 8 μm.

(Example 4)
<<Preparation of coating liquid (4) for forming transparent film>>
A coating liquid (4) having a solid concentration of 41.8% by mass was prepared in the same manner as in Example 1, except that the EO-modified acrylate binder was changed to NK Ester ATM-35E manufactured by Shin-Nakamura Chemical Co., Ltd. Table 1 shows the composition of the obtained coating liquid (4).
<<Preparation of substrate with transparent film (4)>>
A base material (4) with a transparent film was produced and evaluated in the same manner as in Example 1 except that the coating liquid (4) was used. The film thickness of the transparent film was 8 μm.

(Example 5)
<<Preparation of coating liquid (5) for forming transparent film>>
A coating solution (5) having a solid content concentration of 41.8% by mass was prepared in the same manner as in Example 1, except that the EO-modified acrylate binder was changed to NK Ester A-GLY-9E manufactured by Shin-Nakamura Chemical Co., Ltd. did. Table 1 shows the composition of the obtained coating liquid (5).
<<Preparation of substrate with transparent film (5)>>
A base material (5) with a transparent film was produced and evaluated in the same manner as in Example 1 except that the coating liquid (5) was used. The film thickness of the transparent film was 8 μm.

(Example 6)
<<Preparation of coating liquid (6) for forming transparent film>>
A coating solution (6) having a solid content concentration of 41.8% by mass was prepared in the same manner as in Example 1, except that the EO-modified acrylate binder was changed to NK Ester A-DPH-16P manufactured by Shin-Nakamura Chemical Co., Ltd. did. Table 1 shows the composition of the obtained coating liquid (6).
<<Preparation of substrate with transparent film (6)>>
A base material (6) with a transparent film was produced and evaluated in the same manner as in Example 1 except that the coating liquid (6) was used. The film thickness of the transparent film was 8 μm.

(Example 7)
<<Preparation of coating liquid (7) for forming transparent film>>
64.41 g of silica sol PGME dispersion (1) having a solid content concentration of 46.6% by mass obtained in Example 1, and EO-modified acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E)10. 00 g, and 1.50 g of a photopolymerization initiator (Ciba Japan Co., Ltd.: Irgacure 184), 11.59 g of PGME, and 12.50 g of acetone were sufficiently mixed to obtain a coating liquid (7) having a solid content concentration of 41.5% by mass. was prepared. Table 1 shows the composition of the obtained coating liquid (7).
<<Preparation of substrate with transparent film (7)>>
A substrate with a transparent film (7) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (7) was used. The film thickness of the transparent film was 8 μm.

(Example 8)
<<Preparation of coating liquid (8) for forming transparent film>>
42.94 g of the silica sol PGME dispersion (1) having a solid content concentration of 46.6% by mass obtained in Example 1, and EO-modified acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E)20. 00 g, and 3.00 g of a photopolymerization initiator (Ciba Japan Co., Ltd.: Irgacure 184), 21.56 g of PGME, and 12.50 g of acetone were sufficiently mixed to obtain a coating liquid (8) having a solid content concentration of 43.0% by mass. was prepared. Table 1 shows the composition of the obtained coating liquid (8).
<<Preparation of base material (8) with transparent film>>
A substrate with a transparent film (8) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (8) was used. The film thickness of the transparent film was 8 μm.

(Example 9)
<<Preparation of coating liquid (9) for forming transparent film>>
25.76 g of the silica sol PGME dispersion (1) having a solid concentration of 46.6% by mass obtained in Example 1, and EO-modified acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E)28. 00 g, and 4.20 g of a photopolymerization initiator (Ciba Japan Co., Ltd.: Irgacure 184), 29.54 g of PGME, and 12.50 g of acetone were sufficiently mixed to obtain a coating liquid (9) having a solid content concentration of 44.2% by mass. was prepared. Table 1 shows the composition of the obtained coating liquid (9).
<<Preparation of substrate with transparent film (9)>>
A base material (9) with a transparent film was produced and evaluated in the same manner as in Example 1, except that the coating liquid (9) was applied by a bar coater method (#20). The film thickness of the transparent film was 10 μm.

(Example 10)
<<Preparation of coating liquid (10) for forming transparent film>>
Silica alumina sol dispersion (manufactured by Nikki Shokubai Kasei Co., Ltd.; OSCAL1132; average particle diameter 12 nm, solid content concentration 40.5% by mass, dispersion medium: methanol sol, particle refractive index 1.46) 100 g of γ-methacryloxy 12.15 g of propyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd.: KBM-503, SiO ₂ component: 81.2% by mass) was mixed, 17.60 g of ultrapure water was added, and 0.5% of 5% aqueous ammonia was added. 40 g was added and stirred at 50° C. for 6 hours to obtain a surface-treated 12 nm silica-alumina sol dispersion (solid concentration: 40.5% by mass).
Thereafter, the solvent was replaced with propylene glycol monomethyl ether (PGME) using a rotary evaporator to obtain a silica sol PGME dispersion (2) having a solid content of 52.7% by mass.
Next, 53.18 g of silica sol PGME dispersion (2) having a solid content concentration of 52.7% by mass, and 12.00 g of EO-modified acrylate binder (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E), 1.80 g of a photopolymerization initiator (Ciba Japan Co., Ltd.: Irgacure 184), 20.52 g of PGME, and 12.50 g of acetone were sufficiently mixed to prepare a coating liquid (10) having a solid content concentration of 41.8% by mass. did. Table 1 shows the composition of the obtained coating liquid (10).
<<Preparation of base material (10) with transparent film>>
A substrate with a transparent film (10) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (10) was used. The film thickness of the transparent film was 8 μm.

(Example 11)
<<Preparation of coating liquid (11) for forming transparent film>>
Silica-alumina sol dispersion (manufactured by Nikki Shokubai Kasei Co., Ltd.; OSCAL1132; average particle diameter 12 nm, solid content concentration 40.5% by mass, dispersion medium: methanol sol, particle refractive index 1.46) 100 g of γ-methacryloxy 1.22 g of propyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd.: KBM-503, SiO ₂ component: 81.2% by mass) was mixed, 1.76 g of ultrapure water was added, and 0.2 g of 5% aqueous ammonia was added. 40 g was added and stirred at 50° C. for 6 hours to obtain a surface-treated 12 nm silica sol dispersion (solid concentration: 40.4% by mass).
Thereafter, the solvent was replaced with propylene glycol monomethyl ether (PGME) using a rotary evaporator to obtain a silica sol PGME dispersion (3) having a solid content of 41.7% by mass.
Then, 67.12 g of silica sol PGME dispersion (3) having a solid content concentration of 41.7% by mass, and 12.00 g of EO-modified acrylate binder (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E), 1.80 g of a photopolymerization initiator (Ciba Japan Co., Ltd.: Irgacure 184), 6.58 g of PGME, and 12.50 g of acetone were sufficiently mixed to prepare a coating liquid (11) having a solid content concentration of 41.8% by mass. did. Table 1 shows the composition of the obtained coating liquid (11).
<<Preparation of base material (11) with transparent film>>
A base material (11) with a transparent film was produced and evaluated in the same manner as in Example 1 except that the coating liquid (11) was used. The film thickness of the transparent film was 8 μm.

(Example 12)
<<Preparation of coating liquid (12) for forming transparent film>>
Silica alumina sol dispersion (manufactured by Nikki Shokubai Kasei Co., Ltd.; OSCAL1132; average particle diameter 12 nm, solid content concentration 40.5% by mass, dispersion medium: methanol sol, particle refractive index 1.46) 100 g of γ-acrylooxypropyl 6.08 g of trimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd.: KBM-5103, SiO ₂ component 81.2% by mass) was mixed, 8.80 g of ultrapure water was added, and 0.40 g of 5% aqueous ammonia was added. and stirred at 50° C. for 6 hours to obtain a surface-treated 12 nm silica-alumina sol dispersion (solid concentration: 40.4% by mass).
Thereafter, the solvent was replaced with propylene glycol monomethyl ether (PGME) using a rotary evaporator to obtain a silica sol PGME dispersion (4) having a solid content of 46.6% by mass.
Then, 60.11 g of silica sol PGME dispersion (4) having a solid content concentration of 46.6% by mass, and 12.00 g of EO-modified acrylate binder (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E), 1.80 g of a photopolymerization initiator (Ciba Japan Co., Ltd.: Irgacure 184), 13.59 g of PGME, and 12.50 g of acetone were sufficiently mixed to prepare a coating liquid (12) having a solid content concentration of 46.6% by mass. . Table 1 shows the composition of the obtained coating liquid (12).
<<Preparation of substrate with transparent film (12)>>
A base material (12) with a transparent film was produced and evaluated in the same manner as in Example 1 except that the coating liquid (12) was used. The film thickness of the transparent film was 8 μm.

(Example 13)
<<Preparation of coating liquid (13) for forming transparent film>>
2.74 g of tetraethoxysilane to 100 g of a silica-alumina sol dispersion (manufactured by Nikki Shokubai Kasei Co., Ltd.; OSCAL1132; average particle size 12 nm, solid content concentration 40.5% by mass, dispersion medium: methanol sol, particle refractive index 1.46) (manufactured by Tama Chemical Industry Co., Ltd.: normal ethyl silicate-A, SiO ₂ component 28.80%) was mixed, 4.33 g of ultrapure water was added, 0.40 g of 5% aqueous ammonia was added, and the mixture was heated at 50 °C. After stirring for 6 hours, a surface-treated 12 nm silica-alumina sol dispersion was obtained (solid concentration: 38.4% by mass).
Thereafter, the solvent was replaced with propylene glycol monomethyl ether (PGME) using a rotary evaporator to obtain a silica sol PGME dispersion (5) having a solid content of 41.3% by mass.
Then, 67.78 g of silica sol PGME dispersion (5) having a solid content concentration of 41.3% by mass, and 12.00 g of EO-modified acrylate binder (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E), 1.80 g of a photopolymerization initiator (Ciba Japan Co., Ltd.: Irgacure 184), 5.92 g of PGME, and 12.50 g of acetone were sufficiently mixed to prepare a coating liquid (13) having a solid content concentration of 41.8% by mass. . Table 1 shows the composition of the obtained coating liquid (13).
<<Preparation of substrate with transparent film (13)>>
A base material (13) with a transparent film was produced and evaluated in the same manner as in Example 1 except that the coating liquid (13) was used. The film thickness of the transparent film was 8 μm.

(Example 14)
<<Preparation of coating liquid (14) for forming transparent film>>
Silica sol dispersion (manufactured by Nikki Shokubai Kasei Co., Ltd.; SI-30; average particle diameter ₁₂ nm, SiO concentration 40.5% by mass) was added to 1000 g of ion-exchanged water 6000 g, and then a cation exchange resin (Mitsubishi Chemical Corporation SK-1BH (manufactured by SK-1BH) (800 g) was added, and the solution was dealkalized by stirring for 1 hour.
Next, after separating the cation exchange resin, 400 g of an anion exchange resin (manufactured by Mitsubishi Chemical Corporation: SANUPC) was added and stirred for 1 hour for deanion treatment. Next, 400 g of a cation exchange resin (manufactured by Mitsubishi Chemical Corporation: SK-1BH) was added again, stirred for 1 hour, and dealkalized to prepare a silica particle dispersion (A) having a SiO ₂ concentration of 5% by mass. did.
This dispersion liquid was solvent-substituted with methanol using an ultrafiltration membrane to obtain a methanol dispersion liquid (A) having a solid content concentration of 40.5% by mass.
6.08 g of γ-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd.: KBM-503, SiO ₂ component 81.2% by mass) was mixed with 100 g of silica-methanol dispersion (A). 8.80 g of pure water was added, 0.40 g of 5% aqueous ammonia was added, and the mixture was stirred at 50° C. for 6 hours to obtain a surface-treated 12 nm silica sol dispersion (solid concentration: 40.5 mass %).
Thereafter, the solvent was replaced with propylene glycol monomethyl ether (PGME) using a rotary evaporator to obtain a silica sol PGME dispersion (6) having a solid content of 46.6% by mass.
A coating liquid (14) having a solid content concentration of 41.8% by mass was prepared in the same manner as in Example 1, except that the silica-alumina sol was changed to the silica sol PGME dispersion (6). Table 1 shows the composition of the obtained coating liquid (14).
<<Preparation of base material (14) with transparent film>>
A substrate with a transparent film (14) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (14) was used. The film thickness of the transparent film was 8 μm.

(Example 15)
<<Preparation of coating liquid (15) for forming transparent film>>
Silica sol dispersion (manufactured by Nikki Shokubai Kasei Co., Ltd.; SI-80P; _average particle diameter 80 nm, SiO concentration 40.5% by mass) was added to 1000 g of ion-exchanged water 6000 g, and then a cation exchange resin (Mitsubishi Chemical Co., Ltd. SK-1BH (manufactured by SK-1BH) (800 g) was added, and the solution was dealkalized by stirring for 1 hour.
Next, after separating the cation exchange resin, 400 g of an anion exchange resin (manufactured by Mitsubishi Chemical Corporation: SANUPC) was added and stirred for 1 hour for deanion treatment. Next, 400 g of a cation exchange resin (manufactured by Mitsubishi Chemical Corporation: SK-1BH) was added again, stirred for 1 hour, and dealkalized to prepare a silica particle dispersion (B) having a SiO ₂ concentration of 5% by mass. did.
This dispersion liquid was solvent-substituted with methanol using an ultrafiltration membrane to obtain a methanol dispersion liquid (B) having a solid content concentration of 40.5% by mass.
A surface-treated metal oxide fine particle resin PGME dispersion (7) comprising silica having a solid content concentration of 46.6% by mass was prepared in the same manner as in Example 1, except that 100 g of the silica methanol dispersion (B) was used. .
A coating liquid (15) having a solid content concentration of 41.8% by mass was prepared in the same manner as in Example 1, except that the silica-alumina sol was changed to the silica sol PGME dispersion (7). Table 1 shows the composition of the obtained coating liquid (15).
<<Preparation of base material (15) with transparent film>>
A transparent film-coated substrate (15) was produced and evaluated in the same manner as in Example 1 except that the transparent film-forming coating solution (15) was used. The film thickness of the transparent film was 8 μm.

(Example 16)
<<Preparation of coating liquid (16) for forming transparent film>>
Silica-alumina sol dispersion (manufactured by Nikki Shokubai Kasei Co., Ltd.; OSCAL1132; average particle diameter 12 nm, solid content concentration 40.5% by mass, dispersion medium: methanol sol, particle refractive index 1.46) 100 g of γ-methacryloxy 6.08 g of propyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd.: KBM-503, 81.2% by mass of SiO ₂ component) was mixed, 8.80 g of ultrapure water was added, and 0.40 g of 5% aqueous ammonia was added. and stirred at 50° C. for 6 hours to obtain a surface-treated 12 nm silica-alumina sol dispersion (solid concentration: 40.4% by mass).
Thereafter, the solvent was replaced with propylene glycol monomethyl ether (PGME) using a rotary evaporator to obtain a silica alumina sol PGME dispersion (8) having a solid content of 60.0% by mass.
Then, 64.17 g of silica alumina sol PGME dispersion (8) having a solid content concentration of 60.0% by mass, EO-modified acrylate binder (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E) 16.50 g, and a photopolymerization initiator (manufactured by Ciba Japan Co., Ltd.: Irgacure 184) 2.48 g, PGME 4.36 g and acetone 12.50 g are sufficiently mixed to obtain a coating liquid (16) having a solid content concentration of 57.5% by mass. prepared. Table 1 shows the composition of the obtained coating liquid (16).
<<Preparation of base material (16) with transparent film>>
A base material (16) with a transparent film was produced and evaluated in the same manner as in Example 1, except that the coating liquid (16) was applied by a bar coater method (#12). The film thickness of the transparent film was 8 μm.

(Example 17)
<<Preparation of coating liquid (17) for forming transparent film>>
30.06 g of silica sol PGME dispersion (1) having a solid content concentration of 46.6% by mass prepared in Example 1, and EO-modified acrylate binder (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E) 6 .00 g, and 0.90 g of a photopolymerization initiator (Ciba Japan Co., Ltd.: Irgacure 184), 50.54 g of PGME, and 12.50 g of acetone were sufficiently mixed to obtain a coating liquid having a solid content concentration of 20.9% by mass ( 17) was prepared. Table 1 shows the composition of the obtained coating liquid (17).
<<Preparation of substrate with transparent film (17)>>
A substrate with a transparent film (17) was produced and evaluated in the same manner as in Example 1, except that the coating liquid (17) was applied by a bar coater method (#32). The film thickness of the transparent film was 8 μm.

(Example 18)
<<Preparation of coating liquid (18) for forming transparent film>>
In the same manner as in Example 1 except that 0.001 g of an acrylic silicone leveling agent (UVX-3750 manufactured by Kusumoto Kasei Co., Ltd., solid content 50.0%) was added and mixed, the solid content concentration was 41.8% by mass. was prepared. Table 1 shows the composition of the obtained coating liquid (18).
<<Preparation of substrate with transparent film (18)>>
A substrate with a transparent film (18) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (18) was used. The film thickness of the transparent film was 8 μm.

(Example 19)
<<Preparation of substrate with transparent film (19)>>
Coating liquid (1) was applied in the same manner as in Example 1 except that the substrate was changed to a 50 μm PET film (manufactured by Toyobo Co., Ltd.: Cosmoshine A4300) to produce a substrate with a transparent film (19), evaluated. The film thickness of the transparent film was 8 μm.

(Comparative example 1)
<<Preparation of coating liquid (R1) for forming transparent film>>
51.52 g of silica sol PGME dispersion (1) having a solid content concentration of 46.6% by mass, 16.00 g of dipentaerythritol hexaacrylate (manufactured by Kyoeisha Chemical Co., Ltd.: light acrylate DPE-6A), and a photopolymerization initiator ( Ciba Japan Co., Ltd.: Irgacure 184) (2.40 g), PGME (17.58 g), and acetone (12.50 g) were thoroughly mixed to prepare a coating liquid (R1) having a solid concentration of 42.4% by mass. The composition of the obtained coating liquid (R1) is shown in the table.
<<Preparation of substrate with transparent film (R1)>>
A substrate with a transparent film (R1) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (R1) was used. The film thickness of the transparent film was 8 μm.

(Comparative example 2)
<<Preparation of coating liquid (R2) for forming transparent film>>
Except for changing dipentaerythritol hexaacrylate to urethane acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Oligo UA-33H, functional group: urethane acrylate, number of functional groups: 9, molecular weight: 4,000, solid content concentration 100%) A coating liquid (R2) having a solid concentration of 42.4% by mass was prepared in the same manner as in Comparative Example 1. Table 1 shows the composition of the obtained coating liquid (R2).
<<Preparation of substrate with transparent film (R2)>>
A substrate with a transparent film (R2) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (R2) was used. The film thickness of the transparent film was 8 μm.

(Comparative Example 3)
<<Preparation of coating liquid (R3) for forming transparent film>>
A coating liquid (R3) having a solid content concentration of 41.8% by mass was prepared in the same manner as in Example 1, except that the EO-modified acrylate binder was changed to NK Ester A-DPH-48E manufactured by Shin-Nakamura Chemical Co., Ltd. did. Table 1 shows the composition of the obtained coating liquid (R3).
<<Preparation of substrate with transparent film (R3)>>
A substrate with a transparent film (R3) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (R3) was used. The film thickness of the transparent film was 8 μm.

(Comparative Example 4)
<<Preparation of coating liquid (R4) for forming transparent film>>
A coating liquid (R4) having a solid content concentration of 41.8% by mass was prepared in the same manner as in Example 1, except that the EO-modified acrylate binder was changed to NK Ester A-1000 manufactured by Shin-Nakamura Chemical Co., Ltd. Table 1 shows the composition of the obtained coating liquid (R4).
<<Preparation of substrate with transparent film (R4)>>
A substrate with a transparent film (R4) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (R4) was used. The film thickness of the transparent film was 8 μm.

(Comparative Example 5)
<<Preparation of coating liquid (R5) for forming transparent film>>
EO-modified acrylate binder (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E) 40.00 g, and photopolymerization initiator (manufactured by Ciba Japan Co., Ltd.: Irgacure 184) 6.00 g and PGME 41.50 g 12.50 g of acetone was sufficiently mixed to prepare a coating liquid (R5) having a solid concentration of 46.0% by mass. Table 1 shows the composition of the obtained coating liquid (R5).
<<Preparation of substrate with transparent film (R5)>>
A substrate with a transparent film (R5) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (R5) was used. The film thickness of the transparent film was 8 μm.
Here, when compared with the substrate with a transparent film (1) of Example 1 containing the surface-treated metal oxide particles, the substrate with a transparent film (1) has better pencil hardness, scratch resistance, and total light It was found that the transmittance and adhesion were high, the contact angle and curling were low, and the appearance was good.

(Comparative Example 6)
<<Preparation of coating liquid (R6) for forming transparent film>>
Silica alumina sol dispersion (manufactured by Nikki Shokubai Kasei Co., Ltd.; OSCAL1132; average particle diameter 12 nm, solid content concentration 40.5% by mass, dispersion medium: methanol sol, particle refractive index 1.46) 59.26 g, and EO-modified acrylate 16.00 g of a binder (manufactured by Shin-Nakamura Chemical Co., Ltd.: NK Ester A-DPH-18E), 2.40 g of a photopolymerization initiator (manufactured by Chiba Japan Co., Ltd.: Irgacure 184), 9.84 g of PGME, and 12.0 g of acetone. A coating liquid (R6) having a solid content concentration of 42.4% by mass was prepared by thoroughly mixing 50 g. Table 1 shows the composition of the obtained coating liquid (R6).
<<Preparation of substrate with transparent film (R6)>>
A substrate with a transparent film (R6) was produced and evaluated in the same manner as in Example 1 except that the coating liquid (R6) was used. The film thickness of the transparent film was 8 μm.

Claims (4)

Alkylene oxide-modified (meth)acrylate resin,
surface-treated metal oxide particles having an organosilicon compound provided on the surface of the metal oxide particles and having an average particle size of 5 to 500 nm;
an organic solvent that is a hydrophilic solvent or a polar solvent ,
The alkylene oxide-modified (meth)acrylate resin is a polyfunctional acrylate monomer resin having 4 to 8 (meth)acrylate functional groups and 3 to 24 alkylene oxide groups,
The organosilicon compound is R _n —SiO _(4-n)/2 (where R is an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms) per 100 parts by mass of the metal oxide particles. , which may be the same or different, n is an integer of 1 to 3), 0.1 to 50 parts by mass, contained in the surface metal oxide particles,
The surface-treated metal oxide particles are contained in an amount of 50 to 90% by mass based on the total solid content of the alkylene oxide-modified (meth)acrylate resin and the surface-treated metal oxide particles,
A coating liquid for forming a transparent film, characterized by having a solid content concentration of 5 to 70% by mass. 2. The coating liquid according to claim 1, wherein the alkylene oxide-modified (meth)acrylate resin is an ethylene oxide-modified (meth)acrylate resin. 3. The coating liquid according to claim 1, wherein the surface-treated metal oxide particles have an average particle size of 5 to 80 nm. A method for producing a substrate with a transparent coating, which comprises forming a transparent coating on a substrate using the coating liquid according to claim 1 .