JP6383983B2 - Composition for forming metal oxide film and metal oxide film - Google Patents

Description

  The present invention relates to a metal oxide film forming composition and a metal oxide film.

A liquid crystal display is used as a display device of an information terminal such as a personal computer, a mobile phone, and a television. In general, a liquid crystal display has a structure in which liquid crystal is sealed between a pair of substrates on which transparent electrodes are formed. As this substrate, a glass substrate formed of soda lime glass, non-alkali glass or the like is used.
Transparent substrates such as glass substrates with transparent electrodes used in liquid crystal display devices (LCD), plasma display devices (PDP), cathode ray tube display devices (CRT), electroluminescence display devices (EL), display devices represented by touch panels, etc. The material generates approximately 4% of reflected light on one side, which causes a reduction in visibility and transmittance. Therefore, in order to reduce the amount of light reflected from the base material and improve the visibility and transmittance, a film having a refractive index lower than that of the base material, a so-called antireflection film, is formed on the base material surface to reduce the reflectance. The method is used.
In order to obtain a film having a low refractive index, two or more kinds of components selected from the group consisting of a silica sol having a particle size of 5 nm to 30 nm, a hydrolyzate of alkoxysilane, a hydrolyzate of metal alkoxide, and a metal salt A coating solution containing a certain ratio has been proposed (see, for example, JP-A-8-122501).
On the other hand, it is known that a high antireflection effect can also be obtained by alternately laminating a low refractive index film and a high refractive index film on a base material to form a multilayer (for example, JP 2012-252305 A). Issue gazette).

JP-A-8-122501 JP 2012-252305 A

An antireflection film having a lower refractive index is obtained by using the coating solution described in JP-A-8-122501, but an antireflection film having a lower refractive index is required. In the method described in Japanese Patent Application Laid-Open No. 2012-252305, it is necessary to form a low refractive index film and a high refractive index film separately, which causes a problem in process efficiency.
An object of the present invention is to provide a metal oxide film forming composition capable of easily forming a low refractive index antireflection film and a metal oxide film formed using the same.

As a result of intensive studies to solve the above problems, the inventors have made use of a metal oxide film-forming composition containing silica particles having polysiloxane on the surface and at least one aluminum compound. It has been found that the above problems can be satisfied by forming an oxide film, and the present invention has been completed. That is, the gist of the present invention is as follows.
(1) A composition for forming a metal oxide film comprising silica particles having polysiloxane on the surface and an aluminum compound.
(2) An aluminum compound is a composition for metal oxide film formation as described in said (1) containing aluminum containing polysiloxane.
(3) The composition for forming a metal oxide film according to (2), wherein the aluminum-containing polysiloxane is a reaction product of at least one compound selected from the group consisting of aluminum salts and aluminum alkoxides and polysiloxane. It is.
(4) The aluminum-containing polysiloxane is aluminum that is at least one selected from the group consisting of hydrochloride, nitrate, sulfate, acetate, sulfamate, sulfonate, acetoacetate, and basic salts thereof. (2) or (3), which is a reaction product of at least one compound selected from the group consisting of a salt and an aluminum alkoxide and a polysiloxane that is a condensation polymer of an alkoxysilane represented by the following formula (I): It is a composition for metal oxide film formation as described in above.
R ² _k Si (OR ¹ ) _(4-k) (I)
(In the formula, each R ¹ independently represents an alkyl group having 1 to 5 carbon atoms. Each R ² may independently have a substituent and may have a hetero atom. A hydrocarbon group having 1 to 20 carbon atoms, a halogen atom or a hydrogen atom; k represents an integer of 0 to 3)
(5) The content ratio (aluminum / polysiloxane) of aluminum to polysiloxane converted to silicon oxide (SiO ₂ ) of aluminum converted to aluminum oxide (Al ₂ O ₃ ) is 50/50 on an aluminum-containing polysiloxane on a molar basis. It is a composition for metal oxide film formation as described in any one of said (2)-(4) which is -80/20.
(6) The silica particle which has polysiloxane on the surface is a composition for metal oxide film formation as described in any one of said (1)-(5) which is a reaction material of polysiloxane and a silica particle. .
(7) The silica particles having polysiloxane on the surface are any one of the above (1) to (6) which is a reaction product of polysiloxane which is a condensation polymerization product of alkoxysilane represented by the following formula (I) and silica particles. It is the composition for metal oxide film formation as described in any one.
R ² _k Si (OR ¹ ) _(4-k) (I)
(In the formula, each R ¹ independently represents an alkyl group having 1 to 5 carbon atoms. Each R ² may independently have a substituent and may have a hetero atom. A hydrocarbon group having 1 to 20 carbon atoms, a halogen atom or a hydrogen atom; k represents an integer of 0 to 3)
(8) The composition for forming a metal oxide film according to any one of (1) to (7), wherein an average particle diameter of silica particles having polysiloxane on a surface is 1 nm to 200 nm.
(9) The silica particles having polysiloxane on the surface have a content ratio of silica particles to polysiloxane (silica particles / polysiloxane) of 50/50 to 80/20 on a molar basis (1) to (8). It is a composition for metal oxide film formation as described in any one of these.
(10) the content of aluminum in terms of aluminum oxide _(Al 2 _{O 3),} relative to the total amount of polysiloxane and silica particles in terms of silicon oxide (SiO _2), a 1 mol% to 20 mol% wherein (1) It is a composition for metal oxide film formation as described in any one of (9).
(11) The composition for forming a metal oxide film according to any one of (1) to (10), further including an organic solvent having a boiling point of 170 ° C. or higher.
(12) A metal oxide film that is a cured product of the composition for forming a metal oxide film according to any one of (1) to (11).
(13) A metal oxide film-attached base comprising a base material and a cured product of the metal oxide film forming composition according to any one of (1) to (11) disposed on the base material. It is a material.
(14) Applying the composition for forming a metal oxide film according to any one of (1) to (11) above on a base material, and forming the metal oxide film provided on the base material It is a manufacturing method of the base material with a metal oxide film including providing heat to the composition for use.

  According to the present invention, it is possible to provide a metal oxide film forming composition capable of easily forming a low refractive index antireflection film and a metal oxide film formed using the composition.

  In the present specification, a numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. Moreover, content of each component in a composition means the total amount of the said some substance which exists in a composition, unless there is particular notice, when the substance applicable to each component exists in a composition in multiple numbers.

<Composition for forming metal oxide film>
The metal oxide film-forming composition of the present invention comprises silica particles having polysiloxane on the surface (hereinafter also referred to as “A component”) and an aluminum compound (hereinafter also referred to as “B component”). And By including silica particles having a polysiloxane on the surface and an aluminum compound (preferably an aluminum-containing polysiloxane), when this is applied onto a substrate to form a cured product, the refractive index is low and excellent. An antireflection film that is a metal oxide film having hardness can be formed by a simple technique. Furthermore, when a metal oxide film is formed on a glass substrate using the composition for forming a metal oxide film of the present invention, the whitening phenomenon of the glass substrate over time can be effectively suppressed.

Although the details of the reason why the metal oxide film formed by the composition for forming a metal oxide film of the present invention exhibits a low refractive index are not clear, for example, it is considered as follows.
That is, the metal oxide film formed from the metal oxide film forming composition is present in the metal oxide film as compared with the metal oxide film formed from the conventional metal oxide film forming composition. There are many fine voids, and it is considered that a low refractive index can be achieved by these voids.
In general, as a method of forming a metal oxide film having voids in the film, a surfactant is included in the composition for film formation, and the surfactant is removed from the film by heating after film formation. A method of forming a void by doing so is known. In this case, since heating at a high temperature is required, there is a problem in process efficiency, and it may be difficult to sufficiently increase the hardness of the obtained film.
However, the metal oxide film formed from the composition for forming a metal oxide film of the present invention is formed of silica particles having polysiloxane on the surface and an aluminum compound, while maintaining excellent film hardness. It is considered that fine voids are formed in the film.
In addition, when the metal oxide film-forming composition of the present invention is applied to a glass substrate to form a metal oxide film, the detailed mechanism is unknown, but due to the action of the aluminum compound, the glass substrate has a high temperature and high temperature. It can be considered that whitening in a humid environment is suppressed and a lower refractive index can be achieved.

[Component A]
The composition for forming a metal oxide film contains at least one kind of silica particles having polysiloxane on the surface (hereinafter also referred to as “specific silica particles”). In general, by including silica particles, it is possible to adjust the surface shape and refractive index of the metal oxide film to be formed, and to impart other desired functions. In the present invention, it is considered that a metal oxide film having a lower refractive index and excellent hardness can be formed because the silica particles have polysiloxane on the surface.

  Silica particles having polysiloxane on the surface can be obtained, for example, by bringing polysiloxane and silica particles into contact with each other. That is, the silica particles having polysiloxane on the surface are preferably a reaction product of polysiloxane and silica particles, and the reaction of polysiloxane which is a condensation polymer of alkoxysilane represented by the following formula (I) with silica particles. More preferably, it is a product.

R ² _k Si (OR ¹ ) _(4-k) (I)
In the formula, each R ¹ independently represents an alkyl group having 1 to 5 carbon atoms. Each R ² independently represents a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom or a hydrogen atom which may have a substituent and may have a hetero atom. k represents an integer of 0 to 3.

The alkyl group represented by R ¹ preferably has 1 to 3 carbon atoms, and more preferably has 1 to 2 carbon atoms. Specific examples of the alkyl group represented by R ¹ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a 2-butyl group, a sec-butyl group, a tert-butyl group, and a pentyl group. Can do.
In the alkoxysilane represented by the formula (I), when two or more R ¹ are present, they may be the same or different.

Examples of the hydrocarbon group represented by R ² include an alkyl group and an aryl group.
The hydrocarbon group represented by R ² may have a substituent. Substituents include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom; alkenyl groups such as vinyl group and allyl group; aryl groups such as phenyl group; amino group; hydroxy group; sulfanyl group (mercapto group) Cyano group; amide group; ureido group; acryloyloxy group; methacryloyloxy group; glycidyl group; If possible, the substituent may further have a substituent. The hydrocarbon group represented by R ² may have a hetero atom. Examples of the hetero atom include an oxygen atom, a sulfur atom, and a nitrogen atom.

Specific examples of the hydrocarbon group represented by R ² include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, stearyl, vinyl, chloropropyl, hydroxy Examples thereof include a propyl group, a glycidyloxypropyl group, a methacryloxypropyl group, a phenyl group, and a trifluoropropyl group.
Examples of the halogen atom represented by R ² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom or a bromine atom is preferable.
In the alkoxysilane represented by the formula (I), when two or more R ² are present, they may be the same or different.

  k represents an integer of 0 to 3, preferably 0 to 2, and more preferably 0 or 1.

Specific examples of the alkoxysilane represented by the formula (I) where k is 0 include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methoxytriethoxysilane, ethoxytrimethoxysilane, and methoxytripropoxy. Examples include silane, ethoxytripropoxysilane, propoxytrimethoxysilane, propoxytriethoxysilane, and dimethoxydiethoxysilane.
Specific examples of the alkoxysilane represented by the formula (I) and k = 1 are methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane , Butyltrimethoxysilane, butyltriethoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane , Stearyltrimethoxysilane, stearyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropiyl Triethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3 -Methacryloxypropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane and the like.
Specific examples of the alkoxysilane represented by the formula (I) and having k of 2 include dimethyldimethoxysilane and dimethyldiethoxysilane.

Among these alkoxysilanes, tetraalkoxysilanes having an alkoxy group having 1 to 3 carbon atoms such as tetramethoxysilane and tetraethoxysilane can be preferably used.
The alkoxysilane constituting the polysiloxane may be a single type or a combination of two or more types.

The molecular weight of the polysiloxane is not particularly limited and can be appropriately selected depending on the purpose and the like. The molecular weight of the polysiloxane is preferably 1000 to 20000, more preferably 1000 to 8000, from the viewpoint of storage stability. The number average molecular weight of the polysiloxane can be measured by a conventional method using GPC.
The polysiloxane may be produced by the production method described later or may be commercially available.

(Method for preparing polysiloxane)
The method for preparing the polysiloxane is not particularly limited, and can be appropriately selected from commonly used preparation methods. For example, it can be prepared by subjecting at least one alkoxysilane selected from the group consisting of alkoxysilanes represented by the above formula (I) to condensation polymerization in a solvent. Usually, the polysiloxane is preferably obtained as a solution in which the above alkoxysilane is subjected to condensation polymerization in a solvent and dissolved in the solvent.

Specific examples of the method for condensation polymerization of alkoxysilane include a method in which alkoxysilane is hydrolyzed in a solvent such as alcohol or glycol and then condensation polymerization is performed. The hydrolysis reaction may be either partial hydrolysis or complete hydrolysis. In the case of complete hydrolysis, theoretically, it is sufficient to add 0.5 moles of water of all alkoxy groups in the alkoxysilane, but it is usually preferable to add an excess amount of water over 0.5 moles.
The amount of water used in the reaction can be appropriately selected as desired, but it is usually preferably 0.5 to 2.5 moles of all alkoxy groups in the alkoxysilane.

  In addition, for the purpose of accelerating hydrolysis reaction and condensation polymerization reaction, inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as acetic acid, formic acid, succinic acid, maleic acid and fumaric acid; ammonia, methylamine, ethylamine, A catalyst such as a base (alkali) such as ethanolamine or triethylamine; a metal salt such as hydrochloride, sulfate or nitrate; may be used. In addition, the hydrolysis reaction and the condensation polymerization reaction can be further promoted by heating the solution in which the alkoxysilane is dissolved. At that time, the heating temperature and the heating time can be appropriately selected as desired. Examples thereof include a method of heating and stirring at 50 ° C. for 24 hours, a method of heating and stirring for 1 to 3 hours under reflux, and the like.

  As another method, for example, a method of heating and polycondensing a mixture of alkoxysilane, a solvent and oxalic acid can be mentioned. Specifically, after adding oxalic acid to alcohol in advance to obtain an alcohol solution of oxalic acid, the alkoxysilane is mixed while the solution is heated. In that case, it is preferable that the quantity of the oxalic acid to be used shall be 0.2-2 mol with respect to 1 mol of all the alkoxy groups which alkoxysilane has. Heating in this method can be performed at a liquid temperature of 50 to 180 ° C. Preferably, it is a method of heating for several tens of minutes to several tens of hours under reflux so that the liquid does not evaporate or volatilize.

  In preparing polysiloxane, when using a plurality of types of alkoxysilanes, a mixture of a plurality of types of alkoxysilanes may be used in advance, or a plurality of types of alkoxysilanes may be used in combination.

  The solvent used for the condensation polymerization of alkoxysilane (hereinafter also referred to as polymerization solvent) is not particularly limited as long as it is a solvent that dissolves alkoxysilane. Even if the alkoxysilane does not dissolve, any solvent that dissolves with the progress of the condensation polymerization reaction of the alkoxysilane may be used. In general, an alcohol is generated by a condensation polymerization reaction of alkoxysilane, and therefore, an alcohol solvent, a glycol solvent, a glycol ether solvent, or an organic solvent having good compatibility with the alcohol solvent is used.

Specific examples of the polymerization solvent include alcohol solvents such as methanol, ethanol, propanol, butanol, diacetone alcohol; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, 1,3-propanediol, 1, 2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5 -Glycol solvents such as pentanediol, 2,4-pentanediol, 2,3-pentanediol, 1,6-hexanediol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether Ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, Diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, Glycol ether solvents such as pyrene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether; amide solvents such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide An organic solvent such as γ-butyrolactone, dimethyl sulfoxide, tetramethylurea, hexamethylphosphotriamide, m-cresol;
The polymerization solvent may be used alone or in combination of two or more.

(Silica particles)
The silica particles used for preparing the silica particles having polysiloxane on the surface are not particularly limited and can be appropriately selected from commonly used silica particles. Among them, the silica particles preferably have an average particle diameter of 1 nm to 200 nm, more preferably 1 nm to 100 nm, from the viewpoint of adjusting the surface shape and refractive index of the metal oxide film to be formed. More preferably, it is 50 nm, and it is especially preferable that it is 9 nm-45 nm. Sufficient transparency can be imparted to the metal oxide film formed when the average particle diameter of the silica particles is 200 nm or less. Moreover, there exists a tendency for aggregation of a silica particle to be suppressed as the average particle diameter of a silica particle is 1 nm or more.
The average particle diameter of the silica particles is a volume average particle diameter measured as a particle diameter corresponding to 50% of the cumulative volume from the small particle diameter side by measuring the particle size distribution using a dynamic light scattering method.

  The silica particles are preferably used in the state of a colloidal solution (silica sol). The colloidal solution of silica particles may be a silica particle dispersed in a dispersion medium by a commonly used method, or may be a commercially available silica particle colloidal solution (so-called colloidal silica or the like). The silica particles in the colloidal solution may be chain-like or spherical, and are preferably chain-like from the viewpoint of obtaining the effect of the present invention more effectively.

  When a colloidal solution is used as the silica particles, the pH or pKa is preferably adjusted to 1 to 10, more preferably 2 to 7, from the viewpoint of the stability of the metal oxide forming composition.

When a colloidal solution is used as the silica particles, examples of the dispersion medium for the silica particles include water and organic solvents.
Examples of the organic solvent used for the dispersion medium of the colloid solution include alcohol solvents such as methanol, propanol, butanol, ethylene glycol, propylene glycol, butanediol, pentanediol, hexylene glycol, diethylene glycol, dipropylene glycol, and ethylene glycol monopropyl ether; Ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; aromatic hydrocarbon solvents such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone; ester solvents such as ethyl acetate, butyl acetate and γ-butyrolactone; Examples include ether solvents such as tetrahydrofuran and 1,4-dioxane. Of these, alcohol solvents and ketone solvents are preferred. These organic solvents can be used alone or as a dispersion medium by mixing two or more kinds.

Silica particles having polysiloxane on the surface can be prepared by bringing polysiloxane and silica particles into contact with each other. When polysiloxane and silica particles are brought into contact, for example, silanol groups or alkoxysilyl groups in the polysiloxane undergo a condensation reaction with hydroxy groups present on the surface of the silica particles to form silica particles having polysiloxane on the surface. it is conceivable that.
Specifically, for example, silica particles having polysiloxane on the surface can be prepared by mixing a colloidal solution of silica particles and a polysiloxane solution prepared in advance. Mixing of the colloidal solution and the polysiloxane solution may be performed at room temperature or while heating. From the viewpoint of reaction efficiency, the mixing is preferably performed while heating. When mixing is performed while heating, the heating temperature can be appropriately selected according to the solvent and the like. The heating temperature can be, for example, 60 ° C. or higher, and is preferably the reflux temperature of the solvent.

The mixing ratio of polysiloxane and silica particles when preparing silica particles having polysiloxane on the surface can be appropriately selected according to the purpose and the like. For example, the molar ratio of silica particles to polysiloxane (silica particles / polysiloxane) is preferably 50/50 to 80/20, more preferably 50/50 to 70/30, and 60/40 to More preferably, it is 70/30. Here, the number of moles of polysiloxane is calculated as the total number of moles of alkoxysilane charged as a raw material, and the number of moles of silica particles is calculated using the composition formula of silica particles as SiO ₂ .

The volume average particle diameter of the silica particles having polysiloxane on the surface can be appropriately selected according to the purpose and the like. Among them, the volume average particle diameter is preferably 1 nm to 200 nm, more preferably 1 nm to 100 nm, and further preferably 9 nm to 60 nm, from the viewpoint of adjusting the refractive index of the formed metal oxide film. The thickness is preferably 9 nm to 45 nm.
In addition, the volume average particle diameter of the silica particles having polysiloxane on the surface is measured using a dynamic light scattering method.

[B component]
The composition for forming a metal oxide film contains at least one aluminum compound. The composition for forming a metal oxide film contains an aluminum compound in addition to silica particles having polysiloxane on the surface, so that it has a low refractive index and is excellent in hardness and further can suppress whitening of the glass substrate. A metal oxide film can be formed by a simple method.

Examples of the aluminum compound in the component B include an aluminum salt and an aluminum-containing polysiloxane, and preferably contains an aluminum-containing polysiloxane.
The aluminum salt is not particularly limited as long as it can react with polysiloxane, and can be appropriately selected from commonly used aluminum salts. Specifically, the aluminum salt is at least one selected from the group consisting of hydrochloride, nitrate, sulfate, acetate, sulfamate, sulfonate, acetoacetate, and basic salts thereof. preferable.

  The aluminum-containing polysiloxane can be obtained, for example, by bringing polysiloxane into contact with at least one compound selected from aluminum salts and aluminum alkoxides. That is, the aluminum-containing polysiloxane is preferably a reaction product of at least one compound selected from aluminum salts and aluminum alkoxides and polysiloxane, and includes hydrochloride, nitrate, sulfate, acetate, sulfamate, At least one compound selected from the group consisting of aluminum salts and aluminum alkoxides selected from the group consisting of sulfonates, acetoacetates and their basic salts, and the following formula (I): More preferred is a reaction product with polysiloxane which is a condensation polymerization product of alkoxysilane shown.

R ² _k Si (OR ¹ ) _(4-k) (I)
In the formula, each R ¹ independently represents an alkyl group having 1 to 5 carbon atoms. Each R ² independently represents a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom or a hydrogen atom which may have a substituent and may have a hetero atom. k represents an integer of 0 to 3.
A preferred embodiment of the alkoxysilane represented by the formula (I) and a preferred embodiment of the polysiloxane that is a condensation polymer thereof are the same as the polysiloxane in the component A.

The compound that forms the aluminum-containing polysiloxane together with the polysiloxane is preferably at least one selected from the group consisting of aluminum salts and aluminum alkoxides. The aluminum salt is as described above.
The aluminum alkoxide is not particularly limited as long as it can react with the polysiloxane, and can be appropriately selected from commonly used aluminum alkoxides. The alkoxy group in the aluminum alkoxide preferably has 1 to 4 carbon atoms, and more preferably 1 to 3 carbon atoms. Specific examples of the aluminum alkoxide include aluminum trimethoxide, aluminum triethoxide, aluminum tripropoxide, aluminum triisopropoxide, and the like. Among these, aluminum triisopropoxide is preferable.
Aluminum salts and aluminum alkoxides may be used singly or in combination of two or more.

The mixing ratio of the polysiloxane and the compound selected from the group consisting of aluminum salt and aluminum alkoxide (hereinafter also referred to as “specific aluminum compound”) in preparing the aluminum-containing polysiloxane is appropriately selected according to the purpose and the like. be able to. For example, the molar ratio of the specific aluminum compound to the polysiloxane (specific aluminum compound / polysiloxane) is preferably 50/50 to 80/20, more preferably 50/50 to 70/30, More preferably, it is 40-70 / 30. Here, the number of moles of polysiloxane is calculated as the total number of moles of alkoxysilane charged as a raw material. The number of moles of the specific aluminum compound is calculated by converting the total number of moles of the specific aluminum compound charged as a raw material into the number of moles corresponding to aluminum oxide (Al ₂ O ₃ ). That is, 1/2 of the total number of moles of aluminum atoms contained in the prepared specific aluminum compound is defined as the number of moles of the specific aluminum compound.

Specifically, the aluminum-containing polysiloxane is prepared by bringing a polysiloxane prepared in advance into contact with a specific aluminum compound, and the alkoxysilane constituting the polysiloxane is condensation-polymerized in the presence of the specific aluminum compound. Examples of the method include condensation polymerization of alkoxysilanes constituting polysiloxane in the presence of a specific aluminum compound.
As a method for performing condensation polymerization of the alkoxysilane constituting the polysiloxane in the presence of the specific aluminum compound, it is preferable to heat the mixture of the alkoxysilane and the specific aluminum compound. As the alkoxysilane, an alkoxysilane used in the above-described polysiloxane preparation method can be suitably used. The mixture of alkoxysilane and the specific aluminum compound may contain an organic solvent as necessary. As an organic solvent, it can select suitably from the polymerization solvent in the preparation method of polysiloxane mentioned above. As the heat treatment conditions, the heat treatment conditions in the above-described polysiloxane preparation method can be suitably applied.

The content ratio of the silica particles having a polysiloxane on the surface and the aluminum compound in the metal oxide film forming composition can be appropriately selected according to the purpose and the like. As for the content ratio, the content of aluminum converted to aluminum oxide (Al ₂ O ₃ ) is converted into silicon oxide (SiO ₂ ) from the viewpoint of the refractive index of the metal oxide to be formed, the hardness, and the suppression of whitening of the glass substrate. It is preferably selected to be 1 mol% to 20 mol%, more preferably 1 mol% to 10 mol%, more preferably 3 mol% based on the total amount of converted polysiloxane and silica particles. More preferably, it is selected to be from 10 to 10 mol%. Here, when the aluminum compound contains polysiloxane, the amount of polysiloxane contained in the aluminum compound is not considered.
When the aluminum content converted to aluminum oxide (Al ₂ O ₃ ) is 1 mol% or more, a lower refractive index tends to be achieved, and when it is 20 mol% or less, the metal oxide film is formed. There is a tendency that the storage stability of the composition is improved.
The aluminum content converted to aluminum oxide (Al ₂ O ₃ ) can be calculated from the charged raw materials as described above, but the content ratio of aluminum atoms to silicon atoms is calculated by a commonly used measurement method, It can also be determined from the content ratio.

[Other ingredients]
The composition for forming a metal oxide film may further contain other components as necessary in addition to silica particles having polysiloxane on the surface and an aluminum compound. Examples of other components include organic solvents, inorganic particles other than silica particles having polysiloxane on the surface (hereinafter, also simply referred to as “inorganic particles”), and the like.

(Organic solvent)
The metal oxide film forming composition preferably contains at least one organic solvent. The organic solvent may be an organic solvent used for the preparation of silica particles having polysiloxane on the surface and an aluminum-containing polysiloxane, or may be an organic solvent added separately.
Specific examples of the organic solvent include alcohol solvents such as methanol, ethanol, propanol, isopropanol, butanol, hexanol, 1-heptanol and 1-octanol; ester solvents such as ethyl acetate and butyl acetate; ethylene glycol, propylene glycol, 1, Glycol solvents such as 4-butanediol, 1,5-pentanediol, hexylene glycol; glycol ether derivatives such as diethylene glycol diethyl ether and propylene glycol monobutyl ether; glycol ester derivatives such as diethylene glycol monoacetate; diethyl ether, diisopropyl ether and the like Ether solvents; ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone; aromatic hydrocarbon solvents such as benzene and toluene And the like.
Among these, from the viewpoint of obtaining a lower refractive index, 1-heptanol, 1,5-pentanediol, diethylene glycol diethyl ether, hexylene glycol, propylene glycol monobutyl ether, 1,4-butanediol and the like having a boiling point of 170 ° C. or higher It is preferable to include an organic solvent.
These organic solvents can be used individually by 1 type or in combination of 2 or more types.

When the composition for forming a metal oxide film contains an organic solvent, the content of the organic solvent is such that the total solid concentration of the composition for forming a metal oxide film is in the range of 0.5% by mass to 20% by mass. It is preferable that it is the quantity which becomes the range of 0.5 mass%-10 mass%. When the total solid concentration of the composition for forming a metal oxide film is 0.5% by mass or more, it becomes easy to control the film thickness of the formed metal oxide film within a desired range. The film manufacturing process can be simplified. Further, when the total solid content concentration of the composition for forming a metal oxide film is 20% by mass or less, the storage stability of the composition for forming a metal oxide film is improved, and the film thickness of the formed metal oxide film is further increased. Control tends to be easier.
In addition, the total solid content concentration of the composition for forming a metal oxide film is calculated by converting polysiloxane and silica particles as raw materials into silicon oxide (SiO ₂ ) and converting an aluminum compound into aluminum oxide (Al ₂ O ₃ ). Can be calculated. Moreover, it is computable from the total mass of the non-volatile component of the composition for metal oxide film formation.

(Inorganic particles)
The composition for forming a metal oxide film may further contain inorganic particles other than silica particles having polysiloxane on the surface. Examples of the inorganic particles include metal oxide particles such as tungsten oxide, niobium oxide, tantalum oxide, titanium oxide, zirconium oxide, tin oxide, aluminum oxide, hafnium oxide, chromium oxide, cerium oxide, molybdenum oxide, and lanthanum oxide. .
The average particle size of the inorganic particles is preferably 1 nm to 200 nm, more preferably 1 nm to 100 nm, and even more preferably 1 nm to 50 nm.
When the composition for forming a metal oxide film contains inorganic particles, the content is preferably 90% by mass or less, and more preferably 75% by mass or less in the total solid content. The lower limit of the content is not particularly limited, but is preferably 50% by mass or more.

<Method for producing metal oxide film-forming composition>
A method for producing a composition for forming a metal oxide film containing an aluminum-containing polysiloxane as an aluminum compound is obtained by bringing polysiloxane and silica particles into contact to obtain silica particles having polysiloxane on the surface, and an aluminum salt and an aluminum alkoxide. To obtain an aluminum-containing polysiloxane by contacting a polysiloxane with at least one compound selected from the group consisting of: mixing silica particles having a polysiloxane on the surface with the aluminum-containing polysiloxane. preferable. After preparing the silica particle which has polysiloxane on the surface, and aluminum-containing polysiloxane, respectively, the composition for metal oxide film formation which has a desired structure can be efficiently manufactured by mixing these.

  Details of contacting polysiloxane with silica particles to obtain silica particles having polysiloxane on the surface, and contacting at least one compound selected from aluminum salts and aluminum alkoxides with polysiloxane to produce aluminum-containing polysiloxane The details of obtaining are as described above.

  The method for mixing the silica particles having polysiloxane on the surface and the aluminum-containing polysiloxane is not particularly limited, and can be appropriately selected from commonly used mixing methods. When mixing, an organic solvent may be used. The organic solvent can be appropriately selected from the aforementioned organic solvents. The mixing temperature is not particularly limited, and can be set to 20 to 100 ° C., for example.

  The composition for forming a metal oxide film of the present invention can form a metal oxide film having a low refractive index and excellent hardness, so that it can form an antireflection film, a protective film, etc. used in an image display device or the like. It can be suitably applied. In particular, by forming a metal oxide film using a composition for forming a metal oxide film of the present invention on a glass substrate (preferably soda lime glass), it has a low refractive index, high hardness, and high temperature and high humidity. An antireflection film capable of effectively suppressing whitening can be formed.

<Metal oxide film>
The metal oxide film of the present invention is a cured product of the metal oxide film forming composition of the present invention. The metal oxide film can be formed, for example, by applying heat to the metal oxide film forming composition and curing it. Therefore, the aspect of this invention includes use of the composition for metal oxide film formation in manufacture of a metal oxide film.
Details of the method and conditions for applying heat will be described later.

<Base material with metal oxide film>
The base material with a metal oxide film of the present invention includes a base material and a cured product of the composition for forming a metal oxide film disposed on the base material. The metal oxide film, which is a cured product of the metal oxide forming composition of the present invention, is suitable as an antireflection film for a substrate because of its low refractive index and high hardness.
Examples of the substrate include plastic and glass, and are preferably a surface substrate of a display device such as a liquid crystal display device (LCD) or a cathode ray tube display device (CRT), a lens, or the like.

The film thickness of the cured product of the metal oxide film forming composition disposed on the substrate is not particularly limited and can be appropriately selected depending on the purpose and the like. The film thickness of the cured product (metal oxide film) can be, for example, 50 nm to 200 nm, and preferably 100 nm to 110 nm.
The refractive index of the cured product of the metal oxide film-forming composition disposed on the substrate is preferably 1.45 or less, and more preferably 1.23-1.36. As for the hardness of the cured product of the composition for forming a metal oxide film disposed on the substrate, the pencil hardness measured according to JIS K5400 is preferably B or more, more preferably HB or more. , H or more is more preferable.

<Production method of substrate with metal oxide film>
The manufacturing method of a base material with a metal oxide film includes applying a composition for forming a metal oxide film on a base material and applying heat to the composition for forming a metal oxide film provided on the base material. Including. By using the metal oxide film forming composition of the present invention, a metal oxide film having a low refractive index and a high hardness can be formed by a simple method.
Therefore, the aspect of this invention includes use of the composition for metal oxide film formation in manufacture of a base material with a metal oxide film.

  The method for applying the metal oxide film-forming composition onto the substrate is not particularly limited, and can be appropriately selected from commonly used coating methods depending on the substrate, film thickness, and the like. Examples of the application method include a dip coating method, a spin coating method, a spray coating method, a brush coating method, a roll transfer method, a screen printing method, an ink jet method, and a flexographic printing method.

A metal oxide film can be formed by applying heat to the composition for forming a metal oxide film provided on the substrate. The method for applying heat to the metal oxide film-forming composition is not particularly limited, and can be appropriately selected from heating means commonly used depending on the type and purpose of the substrate. Specific examples of the heating means include heating devices such as an oven furnace and a hot plate.
The heating temperature which forms hardened | cured material can be 100 degreeC or more, for example, and it is preferable that it is 100-600 degreeC. Moreover, heating temperature can also be 100-500 degreeC. Moreover, as heating time, it can be set as 0.5 hour-2 hours, for example.

  The manufacturing method of the base material with a metal oxide film includes a drying step of removing at least a part of the solvent from the composition for forming a metal oxide film applied onto the base material prior to the formation of the cured product. May be. The drying step can be performed, for example, by applying heat to the metal oxide film forming composition. The heating temperature in a drying process can be 80-150 degreeC, for example. The heating time can be 30 seconds to 10 minutes.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “%” is based on mass.

Abbreviations used in the following examples and the like are as follows.
TEOS: Tetraethoxysilane AN: Aluminum nitrate 9 hydrate MeOH: Methanol (boiling point 64.7 ° C)
EtOH: ethanol (boiling point 78.4 ° C)
PGME: Propylene glycol monomethyl ether (boiling point 120 ° C)
HG: Hexylene glycol (boiling point 198 ° C)
BCS: ethylene glycol monobutyl ether (boiling point 171 ° C.)
1-Hp: 1-heptanol (boiling point 176 ° C.)
1-Pen: 1,5-pentanediol (boiling point 242 ° C.)
GEDME: Diethylene glycol dimethyl ether (boiling point 162 ° C.)
MeOH-ST: Silica sol having an average particle size of 12 nm, SiO ₂ containing 30% silica particles, and methanol as a dispersion medium.
MA-ST-UP: having an average particle diameter of 12 nm and a chain shape. A silica sol containing 20% by mass of silica particles as SiO ₂ and using methanol as a dispersion medium.
MA-ST-S: Silica sol containing silica particles having an average particle diameter of 9 nm and 20 mass% as SiO ₂ and using methanol as a dispersion medium.
MA-ST-M: silica sol containing silica particles having an average particle diameter of 20 nm and 40% by mass as SiO ₂ and using methanol as a dispersion medium.
MA-ST-L: Silica sol having an average particle diameter of 45 nm, containing 40% by mass of silica particles as SiO ₂ and using methanol as a dispersion medium.

[Measurement of residual alkoxysilane]
The content of residual alkoxysilane remaining in the reaction solution formed in Examples and the like was measured as follows using gas chromatography (hereinafter referred to as GC).
The GC measurement was performed under the following conditions using Shimadzu GC-14B manufactured by Shimadzu Corporation.
Column: Capillary column CBP1-W25-100 (length 25 mm, diameter 0.53 mm, wall thickness 1 μm)
Column temperature: The temperature was raised from a starting temperature of 50 ° C. at 15 ° C./minute to reach an ultimate temperature of 290 ° C. (holding time: 3 minutes).
Sample injection volume: 1 μL, injection temperature: 240 ° C., detector temperature: 290 ° C., carrier gas: nitrogen (flow rate 30 mL / min), detection method: FID method.

[Preparation Example 1-1] Preparation of polysiloxane S1 To a four-necked reaction flask equipped with a reflux tube, EtOH (36.36 g) as a solvent and TEOS (34.72 g) as an alkoxysilane were added and stirred. Next, a mixture of EtOH (18.18 g), water (9.00 g) and 60% nitric acid (1.75 g) diluted to 1/10 was added dropwise as a solvent, and the mixture was stirred for 30 minutes. After stirring, the mixture was refluxed for 3 hours and allowed to cool to room temperature. A polysiloxane (S1) solution was prepared by adding and diluting 40 g of EtOH to 60 g of the obtained solution. When this solution was measured by GC according to the measurement method described above, alkoxysilane was not detected.

[Preparation Example 2-1] Preparation of silica particles having polysiloxane on the surface (T1, hereinafter referred to as “specific silica particles T1”) EtOH (48) as an organic solvent (D1) was added to a four-necked reaction flask equipped with a reflux tube. .45 g), water (4.05 g), and silica sol MeOH-ST (14.00 g) as silica particles were added, and after stirring, refluxed for 2 hours. A solution of polysiloxane S1 (30.00 g) was added dropwise. The mixture was refluxed for a time to prepare specific silica particles T1. Polysiloxane, silica sol, and organic solvent (D1), which are each component of the specific silica particle T1, are shown together in Table 1 together with the addition amount.

[Preparation Examples 2-2 to 2-13] Preparation of Specific Silica Particles T2 to T13 In Preparation Example 2-1, the types and addition amounts of polysiloxane, silica sol, and organic solvent (D1) were changed as shown in Table 1. Except for this, specific silica particles T2 to T13 were prepared in the same manner as in Preparation Example 1, respectively.

[Preparation Example 3-1] Preparation of aluminum-containing polysiloxane U1 In a four-necked reaction flask equipped with a reflux tube, MeOH (19.68 g) as an organic solvent (D2) as a solvent and TEOS (18.75 g) as an alkoxysilane were used. Charged and stirred. Next, a mixture of MeOH (19.68 g) as the organic solvent (D3) and AN (33.78 g) as the aluminum compound (C) and water (1.62 g) was added dropwise and stirred for 30 minutes. After stirring, the mixture was refluxed for 1 hour and allowed to cool to room temperature. Aluminum-containing polysiloxane U1 was prepared as a composition solution composed of a hydrolyzate of lucoxysilane and an aluminum salt by adding 40 g of EtOH to the obtained solution 60 g and diluting. When this solution was measured by GC according to the measurement method described above, alkoxysilane was not detected.

[Preparation Example 3-2, 3-3] Preparation of aluminum-containing polysiloxanes U2 and U3 In Preparation Example 3-1, the types and addition amounts of alkoxysilane, aluminum compound (C) and organic solvent (D2, D3) are shown. Aluminum-containing polysiloxanes U2 and U3 were respectively prepared in the same manner as in Preparation Example 1 except that changes were made as shown in FIG.

<Example 1>
Specific silica particles T1 (47 g) obtained above, aluminum-containing polysiloxane U1 (3 g), and a mixed solvent of HG (10 g) / BCS (10 g) / PGME (30 g) as an organic solvent (D4) at room temperature A coating composition was prepared as a metal oxide forming composition by mixing at (25 ° C.) for 10 minutes.

<Examples 2 to 13>
In Example 1, except that the specific silica particles, the aluminum-containing polysiloxane, and the type and addition amount of the organic solvent (D4) were changed as shown in Table 3, the coating compositions were respectively the same as in Example 1. Prepared.

<Comparative Examples 1-15>
In Example 1, the aluminum-containing polysiloxane was not used, and the types and addition amounts of the specific silica particles and the organic solvent (D4) were changed as shown in Table 3. Each composition was prepared.
In Table 3, “-” indicates that the component was not used.

<Comparative Examples 16-20>
Instead of using specific silica particles as in Examples 1 to 13 and Comparative Examples 1 to 15 described above, the polysiloxane, silica sol, aluminum-containing polysiloxane and organic solvent (D4) shown in Table 4 were used at room temperature (25 ° C. ) For 10 minutes to prepare coating compositions.

<Evaluation>
(Formation of metal oxide film)
The coating composition obtained above was applied onto a soda lime glass (glass thickness 0.7 mm) and a silicon substrate (thickness 0.5 mm), which are base materials, using a spin coater to form a coating film. Formed. Then, after drying at 80 ° C. for 3 minutes on a hot plate, the metal oxide film having a thickness of 100 nm was obtained by being cured by heat treatment in a clean oven at 300 ° C. for 30 minutes.

(Pencil hardness measurement)
No. made by Yasuda Seiki Seisakusho Co., Ltd. Pencil hardness was measured in accordance with JIS K5400 using 553-M, High Uni of Mitsubishi Pencil Co., Ltd. The results are shown in Table 5.

<Refractive index measurement>
The refractive index of the metal oxide film formed on the silicon substrate was measured using an automatic ellipsometer DVA-FLVW manufactured by Mizoji Optical Co., Ltd. The results are shown in Table 5.

  Table 5 shows that the metal oxide film formed using the composition for forming a metal oxide film of the present invention has a low refractive index and a high hardness, and can achieve both a low refractive index and a high hardness.

(Evaluation of whitening under high temperature and high humidity)
Using a soda lime glass substrate on which a metal oxide film formed using the coating compositions of Examples 1 to 5 and Comparative Examples 1 to 5 described above was used, high temperature and high humidity were performed as follows. The whitening evaluation below was performed.
A high-temperature and high-humidity test for 1000 hours was carried out under the conditions of a temperature of 85 ° C. and a humidity of 85% in a small environmental tester SH-221 manufactured by ESPEC Corporation. And the HAZE value was measured about the soda-lime glass substrate before and after the high-temperature and high-humidity test, respectively. The HAZE value was measured using a spectroscopic haze meter TC-1800H manufactured by Tokyo Denshoku Co., Ltd. The results are shown in Table 6.

  From Table 6, it turns out that whitening of a glass substrate can be suppressed by forming a metal oxide film on a glass substrate using the composition for metal oxide film formation of this invention.

The disclosure of Japanese Patent Application No. 2013-128468 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference, Incorporated herein by reference.

Claims (12)

Silica particles having polysiloxane on the surface;
An aluminum compound;
A metal oxide film-forming composition comprising :
The aluminum compound includes an aluminum-containing polysiloxane that is a reaction product of at least one compound selected from the group consisting of an aluminum salt and an aluminum alkoxide and a polysiloxane.
A composition for forming a metal oxide film . Aluminum-containing polysiloxane
Selected from the group consisting of an aluminum salt and an aluminum alkoxide which is at least one selected from the group consisting of hydrochloride, nitrate, sulfate, acetate, sulfamate, sulfonate, acetoacetate and their basic salts At least one compound that is
The composition for forming a metal oxide film according to claim 1, which is a reaction product with polysiloxane which is a condensation polymer of alkoxysilane represented by the following formula (I).
R ² _k Si (OR ¹ ) _(4-k)                   (I)
(Wherein R ¹ Each independently represents an alkyl group having 1 to 5 carbon atoms. R ² Each independently represents a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom or a hydrogen atom which may have a substituent and may have a hetero atom. k represents an integer of 0 to 3) Aluminum-containing polysiloxane is aluminum oxide (Al ₂ O ₃ ) Converted to silicon oxide of silicon (SiO ₂ The composition for forming a metal oxide film according to claim 1 or 2, wherein the content ratio (aluminum / polysiloxane) with respect to the polysiloxane converted to 50) is 50/50 to 80/20 on a molar basis. The composition for forming a metal oxide film according to any one of claims 1 to 3, wherein the silica particles having polysiloxane on the surface are a reaction product of polysiloxane and silica particles. The silica particles having polysiloxane on the surface are a reaction product of polysiloxane which is a condensation polymerization product of alkoxysilane represented by the following formula (I) and silica particles, according to any one of claims 1 to 4. The composition for forming a metal oxide film as described.
R ² _k Si (OR ¹ ) _(4-k)                   (I)
(Wherein R ¹ Each independently represents an alkyl group having 1 to 5 carbon atoms. R ² Each independently represents a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom or a hydrogen atom which may have a substituent and may have a hetero atom. k represents an integer of 0 to 3) The composition for forming a metal oxide film according to any one of claims 1 to 5, wherein an average particle diameter of silica particles having polysiloxane on the surface is 1 nm to 200 nm. The silica particles having polysiloxane on the surface have a content ratio of silica particles to polysiloxane (silica particles / polysiloxane) of 50/50 to 80/20 on a molar basis. The composition for forming a metal oxide film according to the item. Aluminum oxide (Al ₂ O ₃ The aluminum content in terms of silicon oxide (SiO) ₂ The composition for forming a metal oxide film according to any one of claims 1 to 7, wherein the composition is 1 mol% to 20 mol% with respect to the total amount of polysiloxane and silica particles converted into (1). The composition for forming a metal oxide film according to any one of claims 1 to 8, further comprising an organic solvent having a boiling point of 170 ° C or higher. The metal oxide film which is a hardened | cured material of the composition for metal oxide film formation of any one of Claims 1-9. The base material with a metal oxide film containing a base material and the hardened | cured material of the composition for metal oxide film formation of any one of Claims 1-9 arrange | positioned on a base material. Applying the composition for forming a metal oxide film according to any one of claims 1 to 9 on a substrate, and forming the composition for forming a metal oxide film on a substrate. The manufacturing method of the base material with a metal oxide film including providing heat.