JP2007230789A - Manufacturing process for inorganic oxide fine particle, inorganic oxide fine particle obtained by it and composition and optical film using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing process for an inorganic oxide fine particle which disperses well in an organic solvent and has a strong affinity with an organic polymer, an optical film which is produced from a coating composition containing the inorganic oxide fine particle, has an excellent scratch resistance and an anti-reflection function and an optical film which has a sufficient anti-reflection function and an excellent scratch resistance by imparting a hollow structure to the inorganic oxide fine particle. <P>SOLUTION: The manufacturing process for the inorganic oxide fine particle comprises hydrolyzing and condensing the silica precursor portion of an cationic surfactant and/or an inorganic oxide precursor in the presence or absence of the inorganic oxide precursor in a W/O type emulsion in which an aqueous phase is emulsified in an oil phase and the cationic surfactant having the silica precursor portion is dissolved to generate an inorganic oxide fine particle with a particle size of 5 nm to 1 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing inorganic oxide fine particles. Furthermore, this invention relates to the inorganic oxide microparticles obtained by the said manufacturing method, the composition containing the inorganic oxide microparticles | fine-particles, and the antireflection film formed using them.

Optical films are used for various purposes (for example, as polarizing films, optical compensation films, and retardation films) in image display devices (for example, liquid crystal display devices).
Antireflection films are used in a wide range of fields for the purpose of reducing reflectivity using the principle of optical interference. Since the antireflection film is disposed on the outermost surface of the display, high scratch resistance is required. The antireflection film is generally required to have a film thickness of 1 μm or less. In order to realize high scratch resistance at a film thickness of 1 μm or less, it is necessary to have strength of the film itself and adhesion to a layer provided below.

The method of blending fine particles to improve the scratch resistance, the strength of the cured product, and the adhesion with other materials that are in contact is not limited to the antireflection film, but other technical fields (for example, adhesives, exterior paints, Hard coat) is also widely known. In order to improve the scratch resistance and the strength of the cured product, inorganic fine particles having higher hardness than organic fine particles are preferably used. On the other hand, the antireflection film is generally composed of an organic material.
When blending inorganic fine particles in an organic material, it is necessary that the inorganic fine particles do not cause unnecessary aggregation. In general, a method is adopted in which inorganic fine particles are dispersed in a solvent having affinity for the organic material and then mixed with the organic material. In order to produce an antireflection film with stable performance, it is important to stably disperse inorganic fine particles in an organic material.

As a method for producing inorganic fine particles dispersed in an organic material, a method using an alkoxysilane containing a polymerization group or a hydrolysis condensate thereof has attracted attention. Specifically, production of particles by using a specific polyalkoxypolysiloxane and a polymerizable silane coupling agent in combination has been proposed (for example, see Patent Document 1). However, it is difficult to sufficiently advance the reaction between the polyalkoxypolysiloxane and the polymerizable silane coupling agent. When the reaction is insufficient, the introduction rate of the polymerizable group is lowered, and the scratch resistance and strength of the cured product are insufficient.
Moreover, the partial cohydrolysis condensate of the alkoxysilane and tetraalkoxysilane containing an organic functional group is reported (for example, refer patent document 2). However, the storage stability of the liquid was not sufficient.
As described above, according to the conventional technique, the scratch resistance and strength of the film or the storage stability of the liquid are insufficient, and further improvement has been demanded.

  On the other hand, a low refractive index property is required for the antireflection film. As a method for reducing the refractive index by mixing inorganic fine particles with an organic material, a method using hollow silica fine particles is disclosed (for example, see Patent Document 3). The hollow silica fine particles are likely to aggregate similarly to the non-hollow silica fine particles, and it has been difficult to obtain a uniform dispersion or a uniform coating surface.

JP-A-9-169847 Japanese Patent Laid-Open No. 9-40909 JP 2001-233611 A

An object of the present invention is to provide a method for producing inorganic oxide fine particles having high dispersibility in an organic solvent and high affinity with an organic polymer for forming a thin film.
Another object of the present invention is to provide an optical film having an excellent anti-scratch property and an antireflection function, using a coating composition containing inorganic oxide fine particles obtained by the production method.
Furthermore, an object of the present invention is to provide an optical film having sufficient antireflection performance and excellent scratch resistance by imparting a hollow structure to inorganic oxide fine particles.

The above object of the present invention has been achieved by the following means.
(1) Coexistence or non-coexistence of an inorganic oxide precursor in a W / O emulsion in which an aqueous phase is emulsified in an oil phase and a cationic surfactant having a silica precursor site is dissolved. A method for producing inorganic oxide fine particles, comprising hydrolyzing and condensing the silica precursor portion and / or the entire inorganic oxide precursor to produce inorganic oxide fine particles having a particle size of 5 nm to 1 μm .

(2) The method for producing inorganic oxide fine particles according to (1), wherein the inorganic oxide is an oxide of silicon, titanium, zirconium or aluminum.
(3) The method for producing inorganic oxide fine particles according to (1) or (2), wherein the inorganic oxide precursor is an alkoxide or carboxylate of silicon, titanium, zirconium or aluminum.
(4) The reaction according to any one of (1) to (3), wherein an acid or a base is used as a catalyst in a reaction of hydrolyzing and condensing a silica precursor site and / or an inorganic oxide precursor. A method for producing inorganic oxide fine particles.
(5) The production of inorganic oxide fine particles according to any one of (1) to (4), wherein the cationic surfactant is a compound represented by the following general formula (I): Method.

[Wherein, R ¹ and R ⁶ each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 20 carbon atoms; R ² and R ⁵ each independently represent 1 carbon atom; An alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms; R ³ , R ⁴ , R ⁷ and R ⁸ are each independently an alkyl group having 1 to 20 carbon atoms or a carbon atom number; Is a substituted alkyl group having 1 to 20; L ¹ , L ² , L ³ and L ⁴ are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, and having 6 to 20 carbon atoms. A divalent linking group selected from the group consisting of an arylene group, -O-, -S-, -CO-, -NR- and combinations thereof, wherein R is a hydrogen atom or a carbon atom number of 1 to 5 an alkyl group; ^{Z 1} Z ² and Z ³ are each independently a hydroxyl or hydrolyzable group; X ¹ is an anion.

(6) The production of inorganic oxide fine particles according to any one of (1) to (4), wherein the cationic surfactant is a compound represented by the following general formula (II): Method.

［式中、Ｒ^１１は、炭素原子数が１乃至２０のアルキル基または炭素原子数が１乃至２０の置換アルキル基であり；Ｒ^１２およびＲ^１３は、炭素原子数が４乃至２０のアルキル基または炭素原子数が４乃至２０の置換アルキル基であって、アルキル基または置換アルキル基のアルキル部分が少なくとも一つの分岐を有するか、あるいは置換アルキル基が末端以外の炭素原子においてアルコキシ基により置換されており；Ｌ^１１は、単結合または炭素原子数が１乃至５のアルキレン基、炭素原子数が６乃至２０のアリーレン基、−Ｏ−、−Ｓ−、−ＣＯ−、−ＮＲ−およびそれらの組み合わせからなる群より選ばれる二価の連結基であって、Ｒは水素原子または炭素原子数が１乃至５のアルキル基であり；Ｚ^１１、Ｚ^１２およびＺ^１３は、それぞれ独立に、水酸基もしくは加水分解可能な基であり；Ｘ^１１は陰イオンである］。

[Wherein R ¹¹ is an alkyl group having 1 to 20 carbon atoms or a substituted alkyl group having 1 to 20 carbon atoms; R ¹² and R ¹³ are alkyl groups having 4 to 20 carbon atoms; Or a substituted alkyl group having 4 to 20 carbon atoms, wherein the alkyl group or the alkyl part of the substituted alkyl group has at least one branch, or the substituted alkyl group is substituted with an alkoxy group at a carbon atom other than the terminal. L ¹¹ represents a single bond or an alkylene group having 1 to 5 carbon atoms, an arylene group having 6 to 20 carbon atoms, —O—, —S—, —CO—, —NR—, and their a divalent linking group selected from the group consisting, R represents a hydrogen atom or a carbon atoms is an alkyl group of 1 to 5; Z ^11, Z ¹² and Z ¹³ is Each independently a hydroxyl or hydrolyzable group; X ¹¹ is an anion.

(7) The method for producing inorganic oxide fine particles according to any one of (1) to (6), wherein the inorganic oxide fine particles have a hollow structure.
(8) Inorganic oxide fine particles obtained by the production method according to any one of (1) to (7).
(9) A composition containing the inorganic oxide fine particles according to (8).
(10) An optical film comprising the composition according to (9).
(11) The optical film as described in (10), which has an antireflection function.

According to the production method of the present invention, a silica precursor part and / or an inorganic oxide precursor is hydrolyzed / condensed using an aqueous phase in a reverse micelle prepared from a cationic surfactant having a silica precursor as a reaction field. By doing so, it is possible to produce inorganic oxide fine particles whose outer surface is modified with organic molecules. Further, according to the production method of the present invention, inorganic oxide fine particles having high dispersibility in an organic solvent can be obtained, and an inorganic structure having a hollow structure by reducing the amount of the inorganic oxide precursor added in the above reaction. Oxide fine particles can also be obtained.
In addition, the inorganic oxide fine particles of the present invention have improved dispersibility in an organic solvent due to the outer surface being modified by a cationic surfactant having a silica precursor added during production. The composition containing it is excellent in dispersion stability. Furthermore, an optical film formed using the coating composition has high scratch resistance.
Furthermore, when the hollow structure inorganic oxide fine particles obtained by the production method of the present invention are used, a film having an antireflection function having high scratch resistance and low refractive index can be obtained.

  The present invention prepares a W / O emulsion in which a cationic surfactant having a silica precursor is dissolved by emulsifying a water phase in an oil phase, and the silica precursor site and the emulsion in the emulsion This is a method for producing fine inorganic oxide particles in which fine particles are produced by a reaction of hydrolyzing and condensing an inorganic oxide precursor.

In the production method of the present invention, a W / O emulsion, that is, water-in-oil droplets, is formed, and a reverse micelle of a surfactant having a silica precursor is formed. Then, by hydrolyzing and condensing the silica precursor part, or the silica precursor part and the inorganic oxide precursor in the aqueous phase in the reverse micelle, the outer surface is coated with the surfactant and is excellent in inorganic properties. Oxide fine particles can be produced. At this time, in the hydrolysis reaction / condensation reaction, it is preferable to use an acid or a base as a catalyst.
Since the inorganic hydroxide, which is a hydrolysis product of the inorganic oxide precursor, has a negative charge in water, it binds strongly to the positive charge of the surfactant due to electrostatic interaction, and the surfactant Therefore, the condensation reaction of the inorganic hydroxide can proceed preferentially from the oil / water interface. When the amount of the inorganic oxide precursor added is small, hollow structure particles can be obtained. When the amount of the inorganic oxide precursor added is large, particles having a non-hollow structure are obtained.

[Cationic Surfactant Having Silica Precursor Site]
The cationic surfactant having a silica precursor site (in the present invention, the silica precursor site refers to a site capable of forming a siloxane bond linked by a condensation reaction or hydrolysis and condensation), and converts ammonium ions to cation. It is preferable that the surfactant be an ion. The ammonium ion is preferably a quaternary ammonium ion.
The cationic surfactant having a silica precursor site preferably has a hydrophobic group, and the hydrophobic group is preferably a hydrocarbon group, more preferably an aliphatic group, and an alkyl group. It is particularly preferred.
The counter anion of the cationic surfactant having a silica precursor site is a halide ion, an aliphatic sulfonate ion, an aromatic sulfonate ion, a monoalkyl sulfate ion, a carboxylate ion, PF ₆ ⁻ , BF ₄ ⁻ , ClO ₄ ⁻ is preferred.

  The cationic surfactant having a silica precursor site is preferably a compound represented by the following general formula (I) or (II).

In general formula (I), R ¹ and R ⁶ are each independently a hydrogen atom, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom) or an alkyl group having 1 to 20 carbon atoms (an alkyl group) The chain group preferably has a chain structure rather than a cyclic structure, and the chain alkyl group may have a branched structure, and the alkyl group preferably has 1 to 10 carbon atoms. To 6 (more preferably 1 to 3 (methyl, ethyl, propyl, isopropyl) being most preferred). Among these, R ¹ and R ⁶ are particularly preferably hydrogen atoms.

In the general formula (I), R ² and R ⁵ are each independently an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, and having 1 to 20 carbon atoms. An alkyl group is preferred.
The alkyl group preferably has a chain structure rather than a cyclic structure. The chain alkyl group may have a branch. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and most preferably 1 to 3 (methyl, ethyl, propyl, isopropyl).
The alkoxy group preferably has a chain structure rather than a cyclic structure. The chain alkoxy group may have a branch. The number of carbon atoms of the alkoxy group is preferably 1 to 10, more preferably 1 to 6, and most preferably 1 to 3 (methoxy, ethoxy, propoxy, isopropoxy).

In the general formula (I), R ³ , R ⁴ , R ⁷ and R ⁸ are each independently an alkyl group having 1 to 20 carbon atoms or a substituted alkyl group having 1 to 20 carbon atoms. R ³ and R ⁴ are preferably each independently an alkyl group having 3 to 10 carbon atoms or a substituted alkyl group having 3 to 10 carbon atoms. R ⁷ and R ⁸ are preferably each independently an alkyl group having 1 to 3 carbon atoms or a substituted alkyl group having 1 to 3 carbon atoms.
The alkyl group preferably has a chain structure rather than a cyclic structure. The chain alkyl group may have a branch. The number of carbon atoms of the alkyl group represented by R ³ and R ⁴ is preferably 1 to 15, more preferably 2 to 12, and particularly preferably 3 to 10. The number of carbon atoms of the alkyl group represented by R ⁷ and R ⁸ is preferably 1 to 10, more preferably 1 to 6, and 1 to 3 (methyl, ethyl, propyl, isopropyl). Most preferred.

  The alkyl part of the substituted alkyl group is the same as the above alkyl group. Examples of the substituent of the substituted alkyl group are halogen atom, aryl group, acyl group, carboxyl, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl, substituted carbamoyl group, cyano, alkoxy group, aryloxy group, hydroxyl, acyloxy group, Alkylsulfonyloxy group, arylsulfonyloxy group, amino, substituted amino group, amide group, sulfonamido group, ureido, substituted ureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, nitro group, alkylthio group, arylthio group, alkyl Including sulfonyl group, arylsulfonyl group, sulfamoyl, substituted sulfamoyl group, sulfo and heterocyclic group.

The substituted part of the substituted carbamoyl group, substituted amino group, substituted ureido group and substituted sulfamoyl group is preferably an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms.
The substituent of the substituted alkyl group is preferably a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), aryl group, carboxyl, hydroxyl, amino, substituted amino group and acyloxy group (eg, methacryloyloxy, acryloyloxy). More preferred are carboxyl, hydroxyl, amino, substituted amino group, methacryloyloxy and acryloyloxy.

In the general formula (I), L ¹ , L ² , L ³ and L ⁴ are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, an arylene group having 6 to 20 carbon atoms,- A divalent linking group selected from the group consisting of O-, -S-, -CO-, -NR- and combinations thereof. L ¹ , L ² , L ³ and L ⁴ are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, —O—, —CO—, —NR— and combinations thereof. A divalent linking group selected is preferable. R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
The alkylene group preferably has a chain structure rather than a cyclic structure. The chain alkylene group is preferably a linear alkylene group. The number of carbon atoms of the alkylene group is preferably 1 to 4, and more preferably 1 to 3. A straight-chain alkylene group having 1 to 3 carbon atoms (methylene, dimethylene, trimethylene) is particularly preferable.
The arylene group is preferably phenylene or naphthylene, and more preferably phenylene.
The alkyl group preferably has a chain structure rather than a cyclic structure. The chain alkyl group may have a branch. The alkyl group preferably has 1 to 4 carbon atoms, and most preferably 1 to 3 (methyl, ethyl, propyl, isopropyl).

  The following is a divalent combination consisting of a single bond or an alkylene group having 1 to 5 carbon atoms, an arylene group having 6 to 20 carbon atoms, -O-, -S-, -CO-, and -NR. Examples of linking groups are shown. In the following example, left and right may be reversed. AL represents an alkylene group.

Lex11: -CO-O-
Lex12: -CO-O-AL-
Lex13: -AL-CO-O-
Lex14: -AL-CO-O-AL-
Lex15: -CO-NR-
Lex16: -CO-NR-AL-
Lex17: -AL-CO-NR-
Lex18: -AL-CO-NR-AL-
Lex19: -NR-CO-NR-

Lex20: -NR-CO-NR-AL-
Lex21: -AL-NR-CO-NR-AL-
Lex22: -O-CO-NR-
Lex23: -O-CO-NR-AL-
Lex24: -AL-O-CO-NR-
Lex25: -AL-O-CO-NR-AL-
Lex26: -CO-O-CO-
Lex27: -CO-O-CO-AL-
Lex28: -AL-CO-O-CO-AL-
Lex29: -O-AL-

In the general formula (I), Z ¹ , Z ² and Z ³ are each independently a hydroxyl group or a hydrolyzable group. Specific examples of the hydrolyzable group include an alkoxy group, carboxylate (eg, acetylacetonate), halogen and the like. Z ¹ , Z ² and Z ³ are preferably each independently an alkoxy group having 1 to 5 carbon atoms. The alkoxy group preferably has a chain structure rather than a cyclic structure. The chain alkoxy group may have a branch. Most preferably, the alkoxy group has 1 to 3 carbon atoms (methoxy, ethoxy, propoxy, isopropoxy).

In the general formula (I), X ¹ is an anion. Examples of anions include halide ions (F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ ), aliphatic sulfonate ions, aromatic sulfonate ions, monoalkyl sulfate ions, carboxylate ions, PF ₆ ⁻ , BF ₄ ^−. , ClO ₄ ^- including the. The anion is preferably Br ⁻ , I ⁻ , p-toluenesulfonic acid ion, CH ₃ COO ⁻ , PF ₆ ⁻ , BF ₄ ⁻ or ClO ₄ ⁻ , and Br ⁻ , I ⁻ or p-toluenesulfonic acid. More preferably, it is an ion.

  Examples of surfactants having a silica precursor represented by the general formula (I) are shown below (in addition, each compound is shown by a combination of the general formula and the table, and the letters and titles in the general formula names respectively) The letters in the middle correspond.)

  Next, the compound represented by the following general formula (II) will be described.

In the compound represented by the general formula (II), R ¹¹ is an alkyl group having 1 to 20 carbon atoms or a substituted alkyl group having 1 to 20 carbon atoms.
The alkyl group preferably has a chain structure rather than a cyclic structure. The chain alkyl group may have a branch. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and most preferably 1 to 3 (methyl, ethyl, propyl, isopropyl).
The alkyl part of the substituted alkyl group is the same as the above alkyl group. The example of the substituent of a substituted alkyl group is the same as that of general formula (I).

In the compound represented by the general formula (II), R ¹² and R ¹³ are an alkyl group having 4 to 20 carbon atoms or a substituted alkyl group having 4 to 20 carbon atoms. The alkyl part of the alkyl group or substituted alkyl group has at least one branch, or the substituted alkyl group is substituted with an alkoxy group at a carbon atom other than the terminal. The number of carbon atoms in the alkyl group and substituted alkyl group is preferably 6 to 14, and more preferably 7 to 12. The example of the substituent of a substituted alkyl group is the same as that of general formula (I).
An alkyl group having 4 to 20 carbon atoms having a branch, a substituted alkyl group having 4 to 20 carbon atoms having a branch, and 4 to 20 carbon atoms substituted with an alkoxy group at a carbon atom other than the terminal. Examples of substituted alkyl groups are shown below.

R13-1: 2-ethylhexyl R13-2: 2-propylpentyl R13-3: 3,7-dimethyloctyl R13-4: 3,5,5-trimethylhexyl R13-5: 2,4,4-trimethylpentyl R13 -6: 2,6-dimethylheptyl R13-7: 2,4,4-trimethylpentyl R13-8: 7-acryloyloxy-3,7,7-trimethyloctyl R13-9: 4-butyl-4-methylpentyl R13-10: 3- ethoxyhexyl ^{Incidentally,} R ^{11, R 12,} and ^{R 13} may form a ring that any or all of connecting with each other.

In the compound represented by the general formula (II), L ¹¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, an arylene group having 6 to 20 carbon atoms, -O-, -S-,- A divalent linking group selected from the group consisting of CO-, -NR- and combinations thereof is preferred. R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
Specific examples of the alkylene group and arylene group and preferred ranges thereof are the same as those in the general formula (I).
The alkyl group preferably has a chain structure rather than a cyclic structure. The chain alkyl group may have a branch. The alkyl group preferably has 1 to 4 carbon atoms, and most preferably 1 to 3 (methyl, ethyl, propyl, isopropyl).
A divalent linking group consisting of a single bond or an alkylene group having 1 to 5 carbon atoms, an arylene group having 6 to 20 carbon atoms, -O-, -S-, -CO-, and -NR- combination. Examples are the same as those in the general formula (I).

In the general formula (II), Z ¹¹ , Z ¹² and Z ¹³ are each independently a hydroxyl group or a hydrolyzable group. Specific examples of the hydrolyzable group include an alkoxy group, carboxylate (eg, acetylacetonate), halogen and the like. Z ¹¹ , Z ¹² and Z ¹³ are preferably each independently an alkoxy group having 1 to 5 carbon atoms. The alkoxy group preferably has a chain structure rather than a cyclic structure. The chain alkoxy group may have a branch. Most preferably, the alkoxy group has 1 to 3 carbon atoms (methoxy, ethoxy, propoxy, isopropoxy).

In the compound represented by the general formula (II), X ¹¹ is an anion. The definition and examples of the anion are the same as those in the general formula (I).
Below, the example of the cationic surfactant which has a silica precursor represented by general formula (II) is shown.

  The method for synthesizing the compound represented by the general formula (I) or (II) is not particularly limited. For example, the compound can be synthesized by a multistage reaction as described later, and a desired organic amine compound is synthesized. It can be synthesized by reacting with an alkoxysilane compound.

[W / O type emulsion]
The W / O emulsion comprises a cationic surfactant having an oil phase, an aqueous phase, and a silica precursor, or a hydrolyzed / condensed product of the surfactant. The aqueous phase is emulsified in the oil phase. The oil phase (O) forms a continuous phase, and the water phase (W) forms a discontinuous phase.

The oil phase is preferably composed of an organic solvent with low polarity. The low-polar organic solvent is preferably an organic solvent that does not mix with water and separates into two phases when no surfactant is present.
Examples of organic solvents are saturated hydrocarbons (eg, hexane, heptane, octane, nonane, decane, isooctane, cyclohexane), aromatic hydrocarbons (eg, benzene, toluene, xylene), halogenated hydrocarbons (eg, dichloromethane, Chloroform, carbon tetrachloride), ether (eg, diethyl ether), ester (eg, ethyl acetate). The organic solvent is preferably hexane, heptane, octane, nonane, decane, isooctane, benzene, toluene or xylene, more preferably hexane, octane, decane, isooctane or toluene. Two or more organic solvents may be mixed and used.

The aqueous phase may be substantially pure water (eg, deionized water).
The aqueous phase can contain any additive and can contain inorganic salts. The emulsified state can be adjusted by adding an inorganic salt. By adjusting the emulsified state, the suspended emulsion can be made into a uniform transparent emulsion. Examples of inorganic salts include alkali metal halides (eg, lithium fluoride, sodium fluoride, potassium fluoride, lithium chloride, sodium chloride, potassium chloride, lithium bromide, sodium bromide, potassium bromide, lithium iodide) , Sodium iodide, potassium iodide), alkaline earth metal halide salts (eg, magnesium chloride, calcium chloride, magnesium bromide, calcium bromide, magnesium iodide, calcium iodide), ammonium halide salts (eg, Ammonium fluoride, ammonium chloride, ammonium bromide, ammonium iodide), alkali metal sulfates (eg, lithium sulfate, sodium sulfate, potassium sulfate), alkaline earth metal sulfates (eg, magnesium sulfate), and ammonium sulfate.
Inorganic salts include lithium chloride, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, lithium bromide, sodium bromide, potassium bromide, calcium bromide, lithium iodide, sodium iodide, potassium iodide, calcium iodide. Sodium sulfate, potassium sulfate and magnesium sulfate are preferred, lithium chloride, magnesium chloride, calcium chloride, lithium bromide, lithium iodide, lithium sulfate, sodium sulfate, potassium sulfate and magnesium sulfate are more preferred, and lithium sulfate and magnesium sulfate are preferred. Most preferred. Two or more inorganic salts may be used in combination. The amount of water or aqueous solution forming the aqueous phase with respect to the organic solvent forming the oil phase is not particularly limited as long as it is an amount suitable for generating inorganic oxide fine particles, and is cationic with the silica precursor used. Although it can be appropriately determined according to the type and amount of the surfactant and the inorganic oxide precursor, water or an aqueous solution is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the organic solvent, It is more preferable that it is 1-10 mass parts.
The amount of the inorganic salt added to water is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and most preferably 1 to 5 parts by mass with respect to 100 parts by mass of water.

  In the W / O type emulsion, two or more kinds of cationic surfactants having a silica precursor may be used. A cationic surfactant having a silica precursor and another surfactant may be used in combination.

  In the three-component composition of surfactant-organic solvent (eg, isooctane) -water, if the molar ratio of water to surfactant is too large, water droplets dispersed in the oil phase will increase, giving a uniform transparent dispersion. Absent. The molar ratio of water to the surfactant is preferably 30 or less, more preferably 20 or less, and most preferably 10 or less. The larger the molar ratio of the organic solvent to the surfactant, the more stable and transparent dispersion is obtained. The molar ratio of the organic solvent to the surfactant is preferably 80 or more, more preferably 100 or more, and most preferably 120 or more.

  In order to prepare a uniform transparent emulsion from a cationic surfactant having a silica precursor, an organic solvent and water, a cationic surfactant having a silica precursor and an organic solvent are first mixed. And then the procedure of adding water is preferred. In order to promote emulsification, ultrasonic waves may be irradiated.

  A small amount of additives may be used in the preparation of the emulsion. Examples of additives include alcohols (eg, ethanol), carboxylic acids (eg, acetic acid), inorganic acids (eg, boronic acid, phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid), ammonia, alkali metal hydroxides (eg, Sodium hydroxide, potassium hydroxide). The additive is preferably ethanol, acetic acid or boronic acid. A preferable addition amount is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and most preferably 0.1 to 1 part by mass with respect to 100 parts by mass of water.

  Whether or not the emulsion is uniformly transparent can be evaluated by the size of the colloidal particles in the emulsion. The size of the colloidal particles in the emulsion can be measured by a light scattering method. Moreover, since the particle diameter is sufficiently smaller than the wavelength of visible light in the dispersion having a particle diameter of several nanometers to several tens of nanometers, the particle diameter can be evaluated by utilizing the low turbidity. In the production method of the present invention, the turbidity can be evaluated by measuring the absorbance at 500 to 700 nm in the W / O type emulsion. When the absorbance of the emulsified dispersion in the cell having an optical path length of 1 cm is 0.002 or less, it can be determined that the intended reverse micelle having a sufficiently small particle diameter is generated.

[Preparation of inorganic oxide fine particles]
As a method for preparing inorganic fine particles that can be stably dispersed in an organic material, the present inventor forms reverse micelles in an organic solvent using a surfactant having a silica precursor, and in the aqueous phase in the reverse micelles, A method for hydrolyzing and condensing the precursor was studied. If possible, the reaction field is a fine aqueous phase with a particle size of nanometer to micrometer covered with a surfactant silica precursor, so even when inorganic oxide precursors coexist. This is because particles reflecting the shape of the aqueous phase can be obtained while the silica precursor of the surfactant is efficiently condensed. Further, since the hydrophobic part of the surfactant is covalently bonded to the surface of the inorganic fine particles thus obtained, it is possible to improve the dispersion stability of the particles in the organic solvent. Conceivable.
However, commercially available trimethoxysilylpropyloctadecyldimethylammonium chloride (TMSOAC) can form micelles (oil-in-water droplets) in an aqueous solution, but does not form reverse micelles (water-in-oil droplets) in a low polarity organic solvent. Therefore, reverse micelles cannot be used as a mold for producing fine particles.
In the method for producing inorganic oxide fine particles of the present invention, a W / O emulsion, that is, a water-in-oil droplet, is formed, a cationic surfactant having a silica precursor is dissolved therein, and the surfactants are mixed. Silica fine particles are produced by a condensation reaction. Furthermore, it is also possible to produce inorganic oxide fine particles containing a metal other than silicon by adding an inorganic oxide precursor described later to the W / O emulsion.

The inorganic oxide is preferably an oxide of silicon (silica), titanium (titania), zirconium (zirconia), aluminum (alumina) or a composite thereof, more preferably silica, titania, zirconia, or a composite thereof, Silica, zirconia, or a composite thereof is most preferred.
In the production method of the present invention, spherical or nearly spherical fine particles can be generated by using the above-mentioned W / O emulsion. The fine particles close to a sphere are specifically shapes in which the ratio of the major axis to the minor axis is 2 or less. In the production method of the present invention using a W / O emulsion, both hollow particles and non-hollow particles can be produced.
When used in the low refractive index layer of the antireflection film, the fine particles are preferably hollow particles. In the production method using the W / O emulsion, inorganic oxide fine particles having a particle diameter of 5 nm to 1 μm can be produced. The particles used in the low refractive index layer of the antireflective film preferably have an average particle size of 30% to 150%, more preferably 35% to 80%, and more preferably 40% to 60% of the film thickness of the low refractive index layer. Most preferred. For example, when the thickness of the low refractive index layer is 100 nm, the particle size of the inorganic oxide fine particles is preferably 30 to 150 nm, more preferably 35 to 80 nm, and most preferably 40 to 60 nm.

(Inorganic oxide precursor)
An inorganic oxide precursor can be used for the preparation of the inorganic oxide fine particles. In the present invention, the inorganic oxide precursor refers to a compound capable of forming a “metal atom-oxygen atom bond” or “semimetal atom-oxygen atom bond” linked by hydrolysis and condensation, such as silicon, titanium, zirconium or An aluminum alkoxide or carboxylate is preferable, and an alkoxysilane, titanium alkoxide, zirconium alkoxide, aluminum alkoxide titanium carboxylate (eg, titanium tetraacetylacetonate) or zirconium carboxylate (zirconium tetraacetylacetonate) is more preferable.
Examples of alkoxysilane include tetraalkoxysilane (eg, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane), alkyltrialkoxysilane (eg, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane) Octyltriethoxysilane, decyltrimethoxysilane). Examples of titanium alkoxides include titanium tetraalkoxides (eg, titanium tetramethoxide, titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, titanium tetra tert-butoxide), titanium dialkoxides (eg, Titanium bis (ethyl acetoacetate) diisopropoxide). Examples of zirconium alkoxides include zirconium tetraalkoxides (eg, zirconium tetraethoxide, zirconium tetrapropoxide, zirconium tetraisopropoxide, zirconium tetrabutoxide, zirconium tetra tert-butoxide). Examples of aluminum alkoxide include aluminum tetraalkoxide (eg, aluminum tetraisopropoxide).

As the inorganic oxide precursor, a partial condensate of an inorganic oxide precursor may be used. Two or more inorganic oxide precursors may be used in combination. The inorganic oxide precursor is preferably tetraethoxysilane, titanium tetraisopropoxide, titanium tetrabutoxide, zirconium tetraisopropoxide, zirconium tetrabutoxide, titanium tetraacetylacetonate, zirconium tetraacetylacetonate, tetraethoxysilane, titanium Tetraacetylacetonate is more preferred.
When two or more types of inorganic oxide precursors are used in combination, all the inorganic oxide precursors can be added simultaneously. Moreover, after adding a part of inorganic oxide precursor and advancing reaction, the remaining inorganic oxide precursor can also be added.

The addition amount of the cationic surfactant having the silica precursor and the inorganic oxide precursor is not particularly limited as long as the inorganic oxide fine particles can be generated. However, the amount of silica added to the number of moles of water in the reaction system is not limited. The amount of the cationic surfactant having a precursor is preferably 0.02 to 0.67, and the amount of the inorganic oxide precursor is preferably 0 to 0.5.
Furthermore, the shape of the inorganic oxide fine particles is changed to a hollow structure by the number of moles of the cationic surfactant having the silica precursor, the number of moles of the added inorganic oxide precursor, and the number of moles of water in the reaction system. It is possible to control the non-hollow structure. The number of moles of the cationic surfactant having a silica precursor is M ₁ , the number of moles of the added inorganic oxide precursor is M ₂ , and the number of moles of water in the reaction system is M ₃ , (0.75 M _{When the} α value represented by ₁ + M ₂ ) / M ₃ is defined, the α value when producing a spherical inorganic oxide having a hollow structure is preferably 0.01 to 1, and preferably 0.01 to 0.5. More preferably, 0.01 to 0.25 is most preferable. Moreover, 0.1-2 are preferable, 0.1-2 are more preferable, 0.25-2 are more preferable, and 0.5-2 are the most preferable when manufacturing the spherical inorganic oxide of a non-hollow structure.

(catalyst)
A catalyst can be added for the purpose of promoting the hydrolysis and condensation of the silica precursor site or inorganic oxide precursor of the cationic surfactant having a silica precursor. Examples of the catalyst include organic acids (eg, acetic acid), inorganic acids (eg, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid), alkali metal hydroxides (eg, sodium hydroxide), ammonia, and amines. The catalyst is preferably acetic acid, hydrochloric acid, sodium hydroxide or ammonia, more preferably hydrochloric acid or ammonia.
When using an acid as a catalyst, 0-5 are preferable, as for pH of an aqueous phase, 1-4 are more preferable, and 2-3 are the most preferable. When a base is used as a catalyst, the pH of the aqueous phase is preferably 9 to 14, more preferably 10 to 13, and most preferably 11 to 12.

(Hydrolysis / condensation process)
The process for producing inorganic oxide fine particles preferably comprises a hydrolysis / condensation step for producing inorganic oxide fine particles at room temperature and, if necessary, a baking step under heating.
In the hydrolysis / condensation step, a cationic surfactant having a silica precursor, water, and an organic solvent are mixed. A catalyst, an inorganic oxide precursor, an inorganic salt, and an additive can also be mixed as needed. The procedure of the mixing operation is preferably the final mixing operation in which the cationic surfactant having the silica precursor and the inorganic oxide precursor are brought into contact with the catalyst. More preferably, the mixing operation in which the cationic surfactant having the silica precursor and the inorganic oxide precursor are in contact with water and the catalyst is the last. The following mixing procedures (I) and (II) are preferable as specific mixing procedures.
(I): An aqueous solution of an inorganic salt, a catalyst and an additive, and an organic solvent dispersion of a cationic surfactant having a silica precursor are prepared in advance and mixed to prepare a W / O emulsion. Thereafter, an inorganic oxide precursor is added.
(II): An aqueous solution of an inorganic salt, a catalyst, and an additive, a cationic surfactant having a silica precursor, and an organic solvent dispersion of an inorganic oxide precursor are prepared in advance. / O type emulsion is prepared.
It is preferable that the mixing is always performed with stirring. In order to promote emulsification and dispersion, ultrasonic waves may be irradiated. Moreover, as long as the cationic surfactant or inorganic oxide precursor which has a silica precursor is not mixed with water or a catalyst, you may heat at the temperature below the boiling point of an organic solvent. During the mixing operation, after the mixing operation in which the inorganic oxide precursor comes into contact with water or the catalyst, the temperature of the composition is kept constant at a certain temperature within the range of 15 to 25 ° C. In the hydrolysis / condensation step, after mixing a cationic surfactant having a silica precursor, water, an organic solvent, a catalyst, an inorganic oxide precursor, and, if necessary, an inorganic salt and an additive, The temperature of the reaction composition is kept constant at a temperature in the range of 15-25 ° C. and stirred for 1 to 7 days.

(Baking process)
In the firing step, the inorganic oxide sol or gel produced in the hydrolysis / condensation step is heat-treated at a maximum of 800 ° C. Preferred steps are the following (i) to (viii).
(I): The composition obtained in the hydrolysis / condensation step is heated in an open system at 60 to 100 ° C. for 1 to 24 hours. The solvent is distilled off and the residue is dried.
(Ii): The composition obtained in the hydrolysis / condensation step is heated in an autoclave at 60 to 150 ° C. for 1 to 24 hours. The solvent is distilled off and the residue is dried.
(Iii): The inorganic oxide obtained in the step (i) is heated in an electric furnace at 200 ° C. to 800 ° C. for 1 to 24 hours under an inert gas stream or in a vacuum.
(Iv): The inorganic oxide obtained in the step (ii) is heated at 200 ° C. to 800 ° C. for 1 to 24 hours in an electric furnace under an inert gas stream or under vacuum.
(V): The inorganic oxide obtained in step (i) is dissolved in a hydrocarbon such as isooctane and heated at 200 ° C. to 800 ° C. for 1 to 24 hours in an autoclave. The solvent is distilled off and the residue is dried.
(Vi): The inorganic oxide obtained in step (ii) is dissolved in a hydrocarbon such as isooctane and heated at 200 ° C. to 800 ° C. for 1 to 24 hours in an autoclave. The solvent is distilled off and the residue is dried.
(Vii): The inorganic oxide obtained in the step (v) is heated at 200 ° C. to 800 ° C. for 1 to 24 hours in an electric furnace under an inert gas stream or under vacuum.
(Viii): The inorganic oxide obtained in the step (vi) is heated in an electric furnace at 200 ° C. to 800 ° C. for 1 to 24 hours under an inert gas stream or in a vacuum.

  Hereinafter, the silica fine particle production mechanism using reverse micelles composed of a cationic surfactant having the silica precursor of the present invention will be described.

  As is apparent from the above scheme, the W / O emulsion described above is arranged so that the silica precursor site is inside the reverse micelle, and in the hydrolysis / condensation step, the alkoxy group or the like of the silica precursor site is hydrolyzed. Silica fine particles are produced by decomposing, condensing with a siloxane bond, firing as necessary, and further proceeding with a condensation reaction.

[Low refractive index layer]
(Low refractive index binder)
The hollow fine particles of inorganic oxide can be used for the low refractive index layer of the antireflection film.
The low refractive index layer of the antireflection film preferably contains a fluorine-containing polymer as a low refractive index binder in addition to the hollow fine particles. The fluoropolymer preferably has a dynamic friction coefficient of 0.03 to 0.15 and a contact angle with water of 90 to 120 °. The fluorine-containing polymer can have a crosslinked structure. The crosslinked structure can be introduced into the fluoropolymer by heat or ionizing radiation.

  As the fluorine-containing polymer, a hydrolysis / dehydration condensate of a perfluoroalkyl group-containing silane compound (eg, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane) can be used. Further, a fluorine-containing crosslinked copolymer of a fluorine-containing monomer and a monomer for imparting crosslinking reactivity may be used.

Examples of fluorine-containing monomers include fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole), (meta ) A partially or fully fluorinated alkyl ester derivative of acrylic acid (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals), M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ether. Perfluoroolefin is preferred. In view of refractive index, solubility, transparency and availability, hexafluoropropylene is particularly preferable.
Monomers for imparting crosslinking reactivity include monomers having a self-crosslinkable functional group in the molecule (eg, glycidyl (meth) acrylate, glycidyl vinyl ether) and non-crosslinkable functional groups (eg, carboxyl, hydroxy, amino, (Eg, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid). Crosslinkable reactive groups by non-crosslinkable functional groups of repeating units synthesized from monomers having noncrosslinkable functional groups by polymer reaction (for example, reaction of acrylic acid chloride on hydroxy of repeating units) (E.g., (meth) acryloyl) can be introduced.

  In addition to the fluorine-containing monomer and the monomer for imparting crosslinking reactivity, a monomer that does not contain a fluorine atom may be copolymerized from the viewpoint of solubility in a solvent and film transparency. Examples of monomers that can be used in combination include olefins (eg, ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride), acrylic esters (eg, methyl acrylate, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate), Methacrylic acid ester (eg, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate), styrene, styrene derivatives (eg, divinylbenzene, vinyltoluene, α-methylstyrene), vinyl ether (eg, methyl vinyl ether, Ethyl vinyl ether, cyclohexyl vinyl ether), vinyl esters (eg, vinyl acetate, vinyl propionate, vinyl cinnamate), acrylamide (N-tert-butylacrylamide, N-cyclohexyl acrylic) Amides), methacrylamide, acrylonitrile and derivatives thereof.

  You may introduce | transduce a crosslinked structure into a fluorine-containing polymer using a hardening | curing agent (It describes in each gazette of Unexamined-Japanese-Patent No. 10-25388 and 10-147739.).

  The fluoropolymer is preferably a random copolymer of perfluoroolefin and vinyl ether or vinyl ester. The fluorine-containing polymer preferably has a group capable of undergoing a crosslinking reaction alone. The group capable of crosslinking reaction alone is preferably a radical reactive group (eg, acryloyl, methacryloyl) and a ring-opening polymerizable group (eg, epoxy group, oxetanyl group). The repeating unit having a crosslinkable group is preferably 5 to 70 mol%, more preferably 30 to 60 mol% of the polymer.

(Film-forming binder)
The low refractive index layer preferably has a film-forming binder. The film-forming binder has a function of increasing the film strength, the stability of the coating solution, and the productivity of the coating film. The film-forming binder is preferably 10% by mass or more, more preferably 20% by mass or more and 100% by mass or less, and more preferably 30% by mass or more and 95% by mass or less, of the film-forming component excluding inorganic particles. Is most preferred.
A film-forming binder is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as a main chain, and more preferably a polymer having a saturated hydrocarbon chain as a main chain. The binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure is preferably a (co) polymer of monomers having two or more ethylenically unsaturated groups.

  Monomers having two or more ethylenically unsaturated groups are esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) ) Acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipenta Erythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate Rate), vinylbenzene and derivatives thereof (eg, 1,4-divinylbenzene, 2-acryloylethyl 4-vinylbenzoate, 1,4-divinylcyclohexanone), vinylsulfone (eg, divinylsulfone), acrylamide (eg, methylene) Bisacrylamide) and methacrylamide are preferred. Two or more of these monomers may be used in combination.

(Polymerization initiator)
Polymerization of the monomer having an ethylenically unsaturated group can be carried out by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.

Photo radical polymerization initiators are acetophenone compounds, benzoin compounds, benzophenone compounds, phosphine oxide compounds, ketal compounds, anthraquinone compounds, thioxanthone compounds, azo compounds, peroxide compounds, 2,3-dialkyldione compounds, disulfide compounds, fluoroamines. Compounds and aromatic sulfonium compounds are preferred. Examples of acetophenone compounds include 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone is included. Examples of benzoin compounds include benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. Examples of the benzophenone compound include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of the phosphine oxide compound include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. The radical photopolymerization initiator is also described in the latest UV curing technology (P.159, issuer; Kazuhiro Takasawa, publisher; Technical Information Association, Inc., published in 1991). Commercially available photocleavable photoradical polymerization initiators (for example, Irgacure 651, 184, 907 manufactured by Ciba Geigy Japan, Inc.) may be used.
0.1-15 mass parts is preferable with respect to 100 mass parts of polyfunctional monomers, and, as for the usage-amount of a photoinitiator, 1-10 mass parts is more preferable.

  In addition to the photopolymerization initiator, a photosensitizer may be used. Examples of photosensitizers include butylamine, triethylamine, tributylphosphine, Michler's ketone and thioxanthone.

The thermal radical initiator is preferably an organic or inorganic peroxide, organic azo or diazo compound.
Examples of organic peroxides include benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide. Examples of inorganic peroxides include hydrogen peroxide, ammonium persulfate, and potassium persulfate. Examples of azo compounds include 2-azo-bis-isobutyronitrile, 2-azo-bis-propionitrile, 2-azo-bis-cyclohexanedinitrile. Examples of the diazo compound include diazoaminobenzene and p-nitrobenzenediazonium.

[Antireflection film]
The antireflection film having a low refractive index layer preferably has a haze value of 3 to 70%, more preferably 4 to 60%. The antireflection film preferably has an average reflectance of 450 nm to 650 nm of 3.0% or less, and more preferably 2.5% or less. When the antireflection film has a haze value and an average reflectance in the above range, good antiglare properties and antireflection properties can be obtained without deteriorating the transmitted image.

(Support)
The transparent support of the optical film (antireflection film) is preferably a polymer film. Examples of the polymer constituting the polymer film include cellulose acylate (eg, cellulose triacetate, cellulose diacetate, cellulose acetate propionate, cellulose acetate butyrate, polyamide, polycarbonate, polyester (eg, polyethylene terephthalate, polyethylene naphthalate) , Polystyrene, polyolefin, norbornene resin, amorphous polyolefin. Commercially available polymer film (for example, TAC-TD80U, TD80UF manufactured by Fuji Photo Film Co., Ltd. for cellulose acetate film, JSR for norbornene resin film) ZEONEX manufactured by Nippon Zeon Co., Ltd. may be used for Arton and Amorphous Polyolefin Films manufactured by KK Film, polyethylene terephthalate film and polyethylene naphthalate film are preferable, cellulose triacetate film is more preferable, cellulose acylate film substantially free of halogenated hydrocarbon (eg, dichloromethane) is particularly preferable, and halogenated hydrocarbon is not included. About a cellulose acylate film and its manufacturing method, it is described in Invention Association public technical bulletin (public technical number 2001-1745, published on March 15, 2001).

(Formation of a low refractive index layer)
The low refractive index layer is preferably formed by applying a coating liquid containing inorganic oxide fine particles, a low refractive index binder, a film-forming binder, and a polymerization initiator on the hard coat film. The solvent used for preparing the coating solution is preferably an organic solvent. Examples of organic solvents are amides (eg, DMF), sulfoxides (eg, DMSO), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, toluene, hexane), alkyl halides (eg, chloroform, dichloromethane), esters (Eg, methyl acetate, butyl acetate), ketone (eg, acetone, methyl ethyl ketone), ether (eg, tetrahydrofuran, 1,2-dimethoxyethane). Two or more organic solvents may be used in combination.
The coating liquid can be applied by a known method (eg, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method, wire bar coating method).

(Evaluation of antireflection film)
The performance of the manufactured hollow inorganic oxide fine particles as a low refractive index material can be evaluated by measuring the refractive index of a film containing the fine particles. Since the hollow inorganic oxide fine particles produced according to the present invention are readily soluble in an organic solvent, the material of the film containing the fine particles is preferably an organic polymer. A thin film is prepared from an organic coating solution containing 100 parts by mass of an organic polymer and 100 to 10 parts by mass of hollow inorganic oxide fine particles, and the refractive index is measured. When the refractive index of the organic polymer thin film containing the hollow inorganic oxide fine particles is smaller than the refractive index of the organic polymer, surfactant or inorganic oxide, it can be determined that it functions as a low refractive index material.

[Synthesis Example 1]
(Production of Compound (A-19))
Compound (A-19) was produced according to Scheme 1.

A mixture of 25.4 g of 4-bromobutanoic acid (A-19a), 25.0 g of 2-ethyl-1-hexanol (A-19b) and 38.0 g of p-toluenesulfonic acid monohydrate was dissolved in toluene. Refluxed for 2 hours. Water generated by dehydration condensation was removed from the reaction system as needed by azeotropic distillation. The reaction mixture was washed with an aqueous sodium hydrogen carbonate solution, the solvent was distilled off under reduced pressure, and the residue was purified by distillation under reduced pressure to obtain 31.1 g of compound (A-19c) (first stage).
A mixture of 27.2 g of the compound (A-19c) and 230 mL of a 2.0M tetrahydrofuran solution of dimethylamine (A-19d) was stirred at room temperature for 25 hours. Tetrahydrofuran and remaining dimethylamine (A-19d) were distilled off. Hexane was added to the residue, washed with a saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried over sodium sulfate, and the solvent was distilled off. The residue was purified by silica chromatography to obtain 20.0 g of compound (A-19e) (second stage).
A mixture of 24.6 g of iodoacetic acid (A-19f), 22.0 g of 2-ethyl-1-hexanol (A-19b) and 38.0 g of p-toluenesulfonic acid monohydrate was dissolved in 500 mL of toluene. Reflux for hours. Water generated by dehydration condensation was removed from the reaction system as needed by azeotropic distillation. The reaction mixture was washed with an aqueous sodium bicarbonate solution, the solvent was distilled off under reduced pressure, and the residue was purified by distillation under reduced pressure to obtain 31.7 g of compound (A-19g) (third stage).
31.6 mL of a 1.58M hexane solution of butyllithium was added to a tetrahydrofuran solution of 7.8 mL of diisopropylamine at 0 ° C., and the mixture was stirred at 0 ° C. for 15 minutes. Thereafter, the mixture was cooled to −78 ° C., 12.2 g of compound (A-19e) and 9.6 mL of hexamethylphosphoramide in tetrahydrofuran were added, and the mixture was stirred at −78 ° C. for 25 minutes. While maintaining the temperature of the reaction solution at −78 ° C., a solution of 14.9 g of compound (A-19g) in tetrahydrofuran was added, and the mixture was stirred at −78 ° C. for 5 hours. Thereafter, the temperature was gradually raised to 0 ° C. over 24 hours. Hexane was added to the reaction mixture, followed by washing with dilute hydrochloric acid, and the solvent was distilled off. The residue was purified by column chromatography to obtain 2.1 g of Compound (A-19h) (Step 4).
A mixture of 1.0 g of the compound (A-19h) and 1.38 g of 3-bromopropyltriethoxysilane (A-19i) was stirred in tetrahydrofuran at 50 ° C. for 7 days. After distilling off tetrahydrofuran, the remaining 3-bromopropyltriethoxysilane (A-19i) was distilled off at 90 ° C. under reduced pressure to obtain 1.69 g of compound (A-19) (fifth stage).

¹ H NMR (400 MHz, CDCl ₃ )
0.66 (t, J = 7.6 Hz, 2H), 0.85-0.94 (m, 12H), 1.21-1.41 (m, 25H (δ1.23, J = 7.2) Triplet included)), 1.53-1.65 (m, 2H), 1.80-2.10 (m, 3H), 2.19-2.31 (m, 1H), 2.73-2 .92 (m, 3H), 3.31 (s, 3H), 3.33 (s, 3H), 3.40-3.65 (m, 4H), 3.83 (q, J = 7.2) , 6H), 3.92-4.10 (m, 4H)

[Synthesis Example 2]
In the same manner as in Scheme 1, compound (A-20) was produced.
¹ H NMR (400 MHz, CDCl ₃ )
0.66 (t, J = 7.6 Hz, 2H), 0.84-0.94 (m, 12H), 1.21-1.42 (m, 16H), 1.52-1.65 (m , 2H), 1.79-2.11 (m, 3H), 2.19-2.31 (m, 1H), 2.73-2.91 (m, 3H), 3.31 (s, 3H) ), 3.33 (s, 3H), 3.39-3.66 (m, 13H (including a singlet of δ3.59)), 3.92-4.10 (m, 4H)

[Synthesis Example 3]
(Production of Compound (B-1))
Compound (B-1) was produced according to Scheme 2.

A mixture of 26.6 g of aspartic acid (B-1a), 65.1 g of 2-ethyl-1-hexanol (A-19b), and 44.0 g of p-toluenesulfonic acid monohydrate was dissolved in 500 mL of toluene. Refluxed for 2 hours. Water generated by dehydration condensation was removed from the reaction system as needed by azeotropic distillation. The reaction mixture was washed with aqueous sodium hydrogen carbonate solution, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography to obtain 65.2 g of compound (B-1b) (first stage).
A mixture of 23.6 g of compound (B-1b), 12.7 g of bromoacetyl bromide (B-1c) and 10.5 g of triethylamine was stirred at room temperature for 18 hours. The reaction mixture was washed with an aqueous sodium chloride solution, the solvent was distilled off under reduced pressure, and the residue was purified by silica column chromatography to obtain 18.1 g of compound (B-1d) (second stage).
A mixture of 7.00 g of the compound (B-1d) and 45 mL of a 2.0M tetrahydrofuran solution of dimethylamine (A-19d) was stirred at room temperature for 12 hours. The precipitated white solid was filtered off, and dimethylamine (A-19d) remaining in the filtrate was distilled off. Hexane was added to the filtrate and washed with saturated aqueous sodium hydrogen carbonate solution. After drying over sodium sulfate, the solvent was distilled off to obtain 5.61 g of compound (B-1e) (third stage).
A mixture of 1.0 g of compound (B-1e) and 1.29 g of 3-bromopropyltriethoxysilane (A-19i) was stirred in tetrahydrofuran at 70 ° C. for 7 days. After distilling off the tetrahydrofuran, the remaining 3-bromopropyltriethoxysilane (A-19i) was distilled off at 100 ° C. under reduced pressure to obtain 1.64 g of the compound (B-1) (fourth stage).

¹ H NMR (400 MHz, CDCl ₃ )
0.64 (t, J = 8.0 Hz, 2H), 0.85-0.92 (m, 12H), 1.21-1.41 (m, 25H (δ1.23, J = 7.2) Triplet included)), 1.53-1.63 (m, 2H), 1.83-1.97 (m, 2H), 2.98-3.02 (m, 2H), 3.38 (s) , 3H), 3.39 (s, 3H), 3.58 (t, J = 8.0 Hz, 2H), 3.83 (q, J = 7.2, 6H), 3.97-4.11 (M, 4H), 4.38 (d, J = 12.8 Hz, 1H), 4.83 (d, J = 12.8 Hz, 1H), 4.90 (q, J = 6.0 Hz, 1H) 9.65 (d, J = 7.6 Hz, 1H).
[Synthesis Example 4]
In the same manner as in Scheme 2, compound (B-2) was produced.
¹ H NMR (400 MHz, CDCl ₃ )
0.65 (t, J = 8.0 Hz, 2H), 0.83-0.92 (m, 12H), 1.20-1.41 (m, 16H), 1.50-1.63 (m , 2H), 1.83-1.97 (m, 2H), 2.98-3.03 (m, 2H), 3.38 (s, 3H), 3.39 (s, 3H), 3. 46 (t, J = 8.2 Hz, 2H), 3.59 (s, 9H), 3.95-4.11 (m, 4H), 4.38 (d, J = 12.8 Hz, 1H), 4.84 (d, J = 13.2 Hz, 1H), 4.90 (q, J = 5.6 Hz, 1H), 9.65 (d, J = 7.6 Hz, 1H).
[Synthesis Example 5]
In the same manner as in Scheme 2, compound (B-6) was produced.
¹ H NMR (400 MHz, CDCl ₃ )
0.64 (t, J = 7.8 Hz, 2H), 0.85-0.93 (m, 12H), 1.20-1.41 (m, 25H (δ 1.23, J = 6.9) Triplet included)), 1.50-1.65 (m, 2H), 1.81-2.00 (m, 2H), 2.10-2.40 (m, 2H), 2.50-2 .75 (m, 2H), 3.38 (s, 3H), 3.41 (s, 3H), 3.57 (t, J = 8.4 Hz, 2H), 3.83 (q, J = 6) .9, 6H), 3.95-4.10 (m, 4H), 4.12 (d, J = 12.6 Hz, 1H), 4.42-4.51 (m, 1H), 5.17. (D, J = 12.6 Hz, 1H), 9.62 (d, J = 6.9 Hz, 1H).

[Synthesis Example 6]
In the same manner as in Scheme 2, compound (B-7) was produced.
¹ H NMR (400 MHz, CDCl ₃ )
0.66 (t, J = 8.0 Hz, 2H), 0.85-0.93 (m, 12H), 1.20-1.41 (m, 16H), 1.50-1.65 (m , 2H), 1.81-2.00 (m, 2H), 2.10-2.40 (m, 2H), 2.45-2.75 (m, 2H), 3.38 (s, 3H) ), 3.41 (s, 3H), 3.42-3.55 (m, 2H), 3.59 (s, 9H), 3.90-4.11 (m, 4H), 4.08 ( d, J = 12.8 Hz, 1H), 4.38-4.52 (m, 1H), 5.19 (d, J = 12.4 Hz, 1H), 9.64 (d, J = 6.8 Hz). , 1H).

[Synthesis Example 7]
(Synthesis of Compound (II-1))
Compound (II-1) was synthesized according to Scheme 3.

A mixture of 51.7 g of 2-ethyl-hexylamine (II-1a) and 38.6 g of 2-ethyl-1-bromohexane (II-1a) was stirred in 300 mL of tetrahydrofuran at room temperature for 2 hours and then refluxed for 6 hours. . After the tetrahydrofuran was distilled off, the residue was dispersed in hexane and washed with an aqueous sodium bicarbonate solution. After distilling off hexane, the residue was purified by silica gel column chromatography to obtain 39.6 g of compound (II-1c) (first stage).
A mixture of 38.6 g of compound (II-1c) and 11.4 g of iodomethane (II-1d) was stirred in 200 mL of tetrahydrofuran at room temperature for 2 hours and then refluxed for 3 hours. After the tetrahydrofuran was distilled off, the residue was dispersed in hexane and washed with an aqueous sodium bicarbonate solution. After distilling off hexane, the residue was purified by silica gel column chromatography to obtain 15.3 g of compound (II-1e) (second stage).
A mixture of 12.7 g of compound (II-1e) and 28.5 g of 3-bromopropyltriethoxysilane (A-19i) was stirred in tetrahydrofuran at 70 ° C. for 7 days. After distilling off the tetrahydrofuran, the remaining 3-bromopropyltriethoxysilane (A-19i) was distilled off at 100 ° C. under reduced pressure to obtain 27.0 g of the compound (II-1) (third stage).

¹ H NMR (400 MHz, CDCl ₃ )
0.64 (t, J = 8.0 Hz, 2H), 0.85-0.92 (m, 12H), 1.21-1.41 (m, 25H (δ1.23, J = 7.2) Including triplets)) 1.71-1.97 (m, 4H), 3.37 (s, 3H), 3.55-3.65 (m, 6H).

[Example 1]
(PH 2-MgSO ₄ Preparation of Aqueous Solution)
To 100 g of an aqueous solution adjusted to pH 2 with hydrochloric acid, 5.00 g of magnesium sulfate (hereinafter referred to as MgSO ₄ ) was added to prepare an aqueous solution of pH 2 —MgSO ₄ .

(Production of silica fine particles (A19-1))
After the compound (A-19) 2.00g was dissolved in isooctane 70.9ML, the pH 2-MgSO ₄ aqueous solution was added 270 mg, to prepare a uniform transparent dispersion. At this time, the water content (molar ratio of water to surfactant) is 5 (α value is 0.15). The reaction solution was stirred for 3 days while maintaining the temperature at 20 ° C. The reaction solution was heated at 65 to 70 ° C. for 24 hours, the solvent was distilled off, and the residue was vacuum dried. The residue was dissolved in 100 mL of isooctane and heated at 200 ° C. for 2 hours in an autoclave. The solvent was distilled off and the residue was dried.

[Example 2]
(Production of silica fine particles (A19-2))
After the compound (A-19) 2.00g was dissolved in isooctane 70.9ML, the pH 2-MgSO ₄ aqueous solution was added 270 mg, to prepare a uniform transparent dispersion. At this time, the moisture content is 5. While maintaining the temperature of the reaction solution at 20 ° C., 319 μL of tetraalkoxysilane (hereinafter TEOS) was added while stirring the reaction solution (α value was 0.25), and the mixture was stirred for 3 days while maintaining 20 ° C. The reaction solution was heated at 65 to 70 ° C. for 24 hours, the solvent was distilled off, and the residue was vacuum dried. The residue was dissolved in 100 mL of isooctane and heated at 200 ° C. for 2 hours in an autoclave. The solvent was distilled off and the residue was dried.

[Example 3]
(Production of silica fine particles (A19-3))
Silica fine particles (A19-3) were produced by the same method as the production of silica fine particles (A19-2) except that the amount of added TEOS was changed from 319 μL to 1.12 mL (α value was 0.50).

[Example 4]
(Production of silica fine particles (A19-4))
Silica fine particles (A19-4) were produced by the same method as the production of silica fine particles (A19-2), except that the amount of TEOS added was changed from 319 μL to 1.91 mL (α value was 0.75).

[Example 5]
(PH 3-MgSO ₄ Preparation of Aqueous Solution)
To 100 g of an aqueous solution adjusted to pH 3 with hydrochloric acid, 5.00 g of magnesium sulfate (hereinafter referred to as MgSO ₄ ) was added to prepare a pH 3-MgSO ₄ aqueous solution.

(Production of silica fine particles (B1-1))
After 2.00 g of compound (B-1) was dissolved in 68.0 mL of isooctane, 260 mg of the pH 3-MgSO ₄ aqueous solution was added to prepare a uniform transparent dispersion. At this time, the moisture content is 5 (α value is 0.15). The reaction solution was stirred for 3 days while maintaining the temperature at 20 ° C. The reaction solution was heated at 65 to 70 ° C. for 24 hours, the solvent was distilled off, and the residue was vacuum dried. The residue was dissolved in 100 mL of isooctane and heated at 200 ° C. for 2 hours in an autoclave. The solvent was distilled off and the residue was dried.

[Example 6]
_(PH12-Li 2 SO ₄ aqueous solution preparation of)
To 100 g of an aqueous solution adjusted to pH 12 with ammonia, 5.00 g of lithium sulfate (hereinafter, Li ₂ SO ₄ ) was added to prepare a pH 12-Li ₂ SO ₄ aqueous solution (α value is 0.15).

(Production of silica fine particles (B1-2))
Silica fine particles (B1-2) were produced under the same conditions as the production method of silica fine particles (B1-1) except that a pH12-Li ₂ SO ₄ aqueous solution was used instead of the pH 3-MgSO ₄ aqueous solution.

[Example 7]
(Production of silica fine particles (B1-3))
After 2.00 g of compound (B-1) was dissolved in 68.0 mL of isooctane, 260 mg of the pH 3-MgSO ₄ aqueous solution was added to prepare a uniform transparent dispersion. At this time, the moisture content is 5. While maintaining the temperature of the reaction solution at 20 ° C., 1.84 mL of tetraalkoxysilane (hereinafter TEOS) was added while stirring the reaction solution (α value was 0.75), and the mixture was stirred for 3 days while maintaining 20 ° C. The reaction solution was heated at 65 to 70 ° C. for 24 hours, the solvent was distilled off, and the residue was vacuum dried. The residue was dissolved in 100 mL of isooctane and heated at 200 ° C. for 2 hours in an autoclave. The solvent was distilled off and the residue was dried.

[Example 8]
(Production of silica fine particles (B1-4))
Silica fine particles (B1-4) were produced under the same conditions as in the production method of silica fine particles (B1-3) except that a pH12-Li ₂ SO ₄ aqueous solution was used instead of the pH2-MgSO ₄ aqueous solution (α value). 0.75).

[Example 9]
(Production of silica fine particles (B6-1))
After 2.00 g of compound (B-6) was dissolved in 66.8 mL of isooctane, 255 mg of the pH 2-MgSO ₄ aqueous solution was added to prepare a uniform transparent dispersion. At this time, the moisture content is 5 (α value is 0.15). The reaction solution was stirred for 3 days while maintaining the temperature at 20 ° C. The reaction solution was heated at 65 to 70 ° C. for 24 hours, the solvent was distilled off, and the residue was vacuum dried. The residue was dissolved in 100 mL of isooctane and heated at 200 ° C. for 2 hours in an autoclave. The solvent was distilled off and the residue was dried.

[Example 10]
(Production of silica fine particles (B6-2))
Silica fine particles (B6-2) were produced under the same conditions as in the production method of silica fine particles (B6-1) except that a pH12-Li ₂ SO ₄ aqueous solution was used instead of the pH2-MgSO ₄ aqueous solution (α value). 0.15).

[Example 11]
(Production of silica fine particles (B6-3))
After 2.00 g of compound (B-6) was dissolved in 66.8 mL of isooctane, 255 mg of the pH 2-MgSO ₄ aqueous solution was added to prepare a uniform transparent dispersion. At this time, the moisture content is 5. While maintaining the temperature of the reaction solution at 20 ° C., 1.80 mL of tetraalkoxysilane (hereinafter TEOS) was added while stirring the reaction solution (α value was 0.75), and the mixture was stirred for 3 days while maintaining 20 ° C. The reaction solution was heated at 65 to 70 ° C. for 24 hours, the solvent was distilled off, and the residue was vacuum dried. The residue was dissolved in 100 mL of isooctane and heated at 200 ° C. for 2 hours in an autoclave. The solvent was distilled off and the residue was dried.

[Example 12]
(Production of silica fine particles (B6-4))
Silica fine particles (B6-4) were produced under the same conditions as the production method of silica fine particles (B6-3) except that a pH12-Li ₂ SO ₄ aqueous solution was used instead of the pH2-MgSO ₄ aqueous solution (α value). 0.75).

[Example 13]
(Production of silica fine particles (II1-1))
After 2.00 g of compound (II-1) was dissolved in 91.6 mL of isooctane, 350 mg of the pH 2-MgSO ₄ aqueous solution was added to prepare a uniform transparent dispersion. At this time, the moisture content is 5 (α value is 0.15). The reaction solution was stirred for 3 days while maintaining the temperature at 20 ° C. The reaction solution was heated at 65 to 70 ° C. for 24 hours, the solvent was distilled off, and the residue was vacuum dried. The residue was dissolved in 100 mL of isooctane and heated at 200 ° C. for 2 hours in an autoclave. The solvent was distilled off and the residue was dried.

[Example 14]
(Production of silica fine particles (II1-3))
After 2.00 g of compound (B-6) was dissolved in 66.8 mL of isooctane, 255 mg of the pH 2-MgSO ₄ aqueous solution was added to prepare a uniform transparent dispersion. At this time, the moisture content is 5. While maintaining the temperature of the reaction solution at 20 ° C., 1.80 mL of tetraalkoxysilane (hereinafter TEOS) was added while stirring the reaction solution (α value was 0.75), and the mixture was stirred for 3 days while maintaining 20 ° C. The reaction solution was heated at 65 to 70 ° C. for 24 hours, the solvent was distilled off, and the residue was vacuum dried. The residue was dissolved in 100 mL of isooctane and heated at 200 ° C. for 2 hours in an autoclave. The solvent was distilled off and the residue was dried.

[Comparative Example 1]
(Production of silica fine particles (TMSOAC-1))
After 2.00 g of TMSOAC was dissolved in 99.8 mL of isooctane, 381 mg of the pH 3-MgSO ₄ aqueous solution was added. A white suspension was obtained. At this time, the moisture content is 5 (α value is 0.15). The reaction solution was stirred for 3 days while maintaining the temperature at 20 ° C. The reaction solution was heated at 65 to 70 ° C. for 24 hours, the solvent was distilled off, and the residue was vacuum dried. The residue was dissolved in 100 mL of isooctane and heated at 200 ° C. for 2 hours in an autoclave. The solvent was distilled off and the residue was dried.

[Comparative Example 2]
(Manufacture of silica fine particles (TMSOAC-2))
Silica fine particles (TMSOAC-2) were produced under the same conditions as in the production method of silica fine particles (TMSOAC-1) except that a pH12-Li ₂ SO ₄ aqueous solution was used instead of the pH 3-MgSO ₄ aqueous solution (α value). 0.15).

[Comparative Example 3]
(Production of silica fine particles (TMSOAC-3))
After 2.00 g of TMSOAC was dissolved in 99.8 mL of isooctane, 381 mg of the pH 3-MgSO ₄ aqueous solution was added. A white suspension was obtained. At this time, the moisture content is 5. While maintaining the temperature of the reaction solution at 20 ° C., 2.70 mL of tetraalkoxysilane (hereinafter TEOS) was added while stirring the reaction solution (α value was 0.75), and the mixture was stirred for 3 days while maintaining 20 ° C. The reaction solution was heated at 65 to 70 ° C. for 24 hours, the solvent was distilled off, and the residue was vacuum dried. The residue was dissolved in 100 mL of isooctane and heated at 200 ° C. for 2 hours in an autoclave. The solvent was distilled off and the residue was dried.

[Comparative Example 4]
(Production of silica fine particles (TMSOAC-4))
Silica fine particles (TMSOAC-4) were produced under the same conditions as in the production method of silica fine particles (TMSOAC-3) except that a pH12-Li ₂ SO ₄ aqueous solution was used instead of the pH 3-MgSO ₄ aqueous solution (α value). 0.75).

(Silica production in aqueous solution)
An inorganic oxide was produced using a surfactant having a silica precursor in an aqueous solution. The production method in an aqueous solution was referred to the description of known literature (Adv. Mater., 12, (2000), 1286-1290).

[Comparative Example 5]
(Production of silica (W-1) in aqueous solution)
An aqueous dispersion of DODAB was prepared by adding 800 mL of ion-exchanged water to 4.96 g of trimethoxysilylpropyloctadecyldimethylammonium chloride (hereinafter TMSOAC), and then added ammonia water and ion-exchanged water to obtain a DODAB concentration of 1.00. A dispersion of 1.00 L of × 10 ⁻² mol / L, pH 8 was prepared. Under stirring, 13.4 mL of tetraethoxysilane was added and stirred at 20 ° C. for 7 days. During stirring, the pH was appropriately checked. If the pH was lowered, a small amount of aqueous ammonia was added to adjust the pH to 8. Then, after heating the reaction solution at 65-70 degreeC for 24 hours, the volatile matter was distilled off and the residue was vacuum-dried.

[Comparative Example 6]
(Production of silica (W-2) in aqueous solution)
In the production of silica (W-1), silica (W-2) was produced under the same conditions except that 6.99 g of compound (A-19) was used instead of 4.96 g of TMSOAC.

[Comparative Example 7]
(Production of silica (W-3) in aqueous solution)
In the production of silica (W-1), silica (W-3) was produced under the same conditions except that 7.28 g of compound (B-1) was used instead of 4.96 g of TMSOAC.
[Comparative Example 8]
(Production of silica (W-4) in aqueous solution)
In the production of silica (W-1), silica (W-4) was produced under the same conditions except that 7.42 g of compound (B-6) was used instead of 4.96 g of TMSOAC.

  Table 3 shows the measurement results of the shape and size of silica produced by the production method described above. The shape and size of the silica were observed using a scanning electron microscope S-5200 manufactured by Hitachi, Ltd. (Note that the particle size was arbitrarily observed by taking micrographs at five locations (approximately 50). -200) silica diameters were averaged.).

(註)
Evaluation of dispersibility: Dispersibility in various organic solvents was evaluated in four stages of A (good) to D (poor) by the following dispersion stability evaluation method in an organic solvent.
H: Hexane T: Toluene M: Methyl ethyl ketone

(Evaluation of dispersion stability in organic solvents)
The silica produced in each example was dispersed in 10 times the mass of hexane, toluene or methyl ethyl ketone to prepare a dispersion having a solid content concentration of 9.1%. Further, 230 parts by mass of hexane in 100 parts by mass of silica fine particle sol (isopropyl alcohol silica sol, IPA-ST-L, average particle diameter 45 nm, silica concentration 30% by mass), which is commercially available inorganic fine particles, Toluene or methyl ethyl ketone was added to prepare dispersions each having a solid content concentration of 9.1% (hereinafter, 45 nm SiO ₂ dispersion). Similarly, 230 parts by mass of hexane, toluene, or methyl ethyl ketone is added to 100 parts by mass of silica fine particle sol (methanol silica sol (trade name), average particle diameter 12 nm, silica concentration 30%, manufactured by Nissan Chemical Industries, Ltd.) Dispersions having a solid content concentration of 9.1% (hereinafter, 12 nm SiO ₂ dispersion) were prepared. Similarly, 100 parts by mass of hollow silica fine particle sol (isopropyl alcohol hollow silica sol, CS-60-IPA manufactured by Catalytic Chemical Industry Co., Ltd., average particle diameter 60 nm, shell thickness 10 nm, silica concentration 20%, silica refractive index 1.31). 120 parts by mass of hexane, toluene, or methyl ethyl ketone was added to prepare a dispersion having a solid content concentration of 9.1% (hereinafter, 60 nm hollow SiO ₂ dispersion). 10 cc of the dispersion thus prepared was collected in a test tube having a diameter of 10 mm, and foreign matters were visually observed. The degree of occurrence of foreign matters that can be visually observed was evaluated in the following four ranks.
A: Foreign matter is not recognized.
B: Foreign matter of about 50 μm is slightly observed.
C: Foreign matter of 500 μm or more is clearly observed.
D: In addition to foreign matters of 500 μm or more, clearly aggregated precipitates are observed.

  As is clear from the results shown in Table 3, silica fine particles having a particle size of 100 nm or less could be produced by a production method using reverse micelles in an organic solvent comprising a surfactant having a silica precursor at the hydrophilic end. Further, when the α value is 0.50 or more, non-hollow structure particles can be produced, and when the α value is 0.25 or less, hollow structure particles can be produced. Furthermore, the obtained silica fine particles were able to disperse well in an organic solvent. In order to form reverse micelles in an organic solvent, a surfactant having three branches such as compounds (A-19), (B-1) and (B-6) is preferred. Silicas (TMSOAC-1) to (TMSOAC-4) produced from trimethoxysilylpropyloctadecyldimethylammonium chloride (TMSOAC) having a linear alkyl chain were white aggregates. Moreover, silica (W-1)-(W-4) obtained by the manufacturing method in aqueous solution was a white amorphous aggregate.

  Further, as apparent from the results of Table 3, the silica fine particles produced according to the present invention have a good dispersibility in hexane or toluene and give a uniform transparent dispersion solution. Furthermore, the compound (B-1) And the silica fine particles produced from the compound (B-6) have a good dispersibility in methyl ethyl ketone and give a uniformly transparent dispersion solution.

[Creation of antireflection film]
(Preparation of coating solution for low refractive index layer)
2-butanone 200 parts by mass, cyclohexanone 150 parts by mass, as a low refractive index binder 30 parts by mass of the following fluorine-containing polymer, photo radical generator (Irgacure 907) 3 parts by mass, dipentaerythritol pentaacrylate and dipentaerythritol After adding 7 parts by mass of a mixture of hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.), 30 parts by mass of silica fine particles dissolved in 580 parts by mass of methyl ethyl ketone are added, and the solid content concentration of the entire coating liquid is 7 A coating solution for a low refractive index layer was prepared by diluting with methyl ethyl ketone so as to have a mass%. In addition, when the name of the silica used in the following 4 tables was (**), the name of the coating solution was expressed as (L-**). (**) μm SiO ₂ represents commercially available silica fine particles having an average particle diameter of (**) μm.
Further, in the above coating liquid preparation method, the only difference is that 531 parts by mass of methyl ethyl ketone is used instead of 30 parts by mass of silica fine particles dissolved in 580 parts by mass of methyl ethyl ketone. blank) was prepared.

(Preparation of antireflection film 301)
A coating solution for low refractive index layer was applied on a triacetyl cellulose film (TD80UF, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm using a bar coater.
The low refractive index layer was dried at 90 ° C. for 30 seconds, and the ultraviolet curing condition was 240 W / cm ² air-cooled metal halide lamp (eye graphics) while purging with nitrogen so that the atmosphere had an oxygen concentration of 0.05 vol% or less. The irradiance was 600 mW / cm ² and the irradiation amount was 600 mJ / cm ² . The film thickness of the low refractive index layer after curing was 85 nm.

(Evaluation of antireflection film)
About the obtained film, the following items were evaluated.
(1) Plane shape of coating film sample Oily black ink was applied to the back surface of the coated sample, and the angle was changed at about 10 cm under a 500 W three-wavelength fluorescent lamp, and visually evaluated.
The unevenness in which reflected light diffuses and appears white and dull was evaluated in the following four stages.
A: Even if you look very carefully, you can't see any haze.
B: Light is diffused slightly when viewed very carefully.
C: A white portion is observed in a haze.
D: One surface has a white haze.

(2) Steel Wool Scratch Resistance (SW Strength) Evaluation Using a rubbing tester, a rubbing test was performed under the following conditions.
Evaluation environmental conditions: 25 ° C., 60% RH, rubbing material: Steel wool (manufactured by Nippon Steel Wool Co., Ltd.) is wound around the rubbing tip (1 cm × 1 cm) of the tester that comes into contact with the sample, and the band is fixed so as not to move. .
Travel distance (one way): 13cm
Rubbing speed: 13 cm / sec Load: 500 g / cm ²
Tip contact area: 1cm x 1cm
Number of rubs: 10 round trips

An oil-based black ink was applied to the back side of the rubbed sample and visually observed with reflected light, and scratches on the rubbed portion were evaluated according to the following 6 levels.
A: Even if you look very carefully, no scratches are visible.
B: Slightly weak scratches are visible when viewed very carefully, but there is no practical problem.
C: Weak scratches are visible.
D: A moderate crack is visible.
E: There is a scratch that can be seen at first glance.
F: The single-sided film is damaged.

(3) Refractive Index Evaluation The refractive index of the formed low refractive index layer for an antireflection film was measured using a refractometer (Abbe refractometer NAR-1T, manufactured by Atago Co., Ltd.).
The results are shown in Table 4.

As is apparent from the results shown in Table 4, the silica fine particles produced according to the present invention not only have good dispersibility in an organic solvent, but also show good dispersibility in organic polymers. Therefore, according to the present invention, a thin film having excellent coating surface properties and high scratch resistance was obtained. Furthermore, a low refractive index could be realized by using hollow fine particles.

Claims (11)

  In a W / O type emulsion in which an aqueous phase is emulsified in an oil phase and a cationic surfactant having a silica precursor site is dissolved, in the presence or absence of an inorganic oxide precursor, A method for producing inorganic oxide fine particles, comprising hydrolyzing and condensing the silica precursor portion and / or the inorganic oxide precursor to produce inorganic oxide fine particles having a particle size of 5 nm to 1 μm.   2. The method for producing inorganic oxide fine particles according to claim 1, wherein the inorganic oxide is an oxide of silicon, titanium, zirconium or aluminum.   The method for producing fine inorganic oxide particles according to claim 1 or 2, wherein the inorganic oxide precursor is an alkoxide or carboxylate of silicon, titanium, zirconium or aluminum.   The inorganic oxide fine particles according to any one of claims 1 to 3, wherein an acid or a base is used as a catalyst in a reaction of hydrolyzing and condensing a silica precursor site and / or an inorganic oxide precursor. Manufacturing method. The method for producing inorganic oxide fine particles according to any one of claims 1 to 4, wherein the cationic surfactant is a compound represented by the following general formula (I).

[Wherein, R ¹ and R ⁶ each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 20 carbon atoms; R ² and R ⁵ each independently represent 1 carbon atom; An alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms; R ³ , R ⁴ , R ⁷ and R ⁸ are each independently an alkyl group having 1 to 20 carbon atoms or a carbon atom number; Is a substituted alkyl group having 1 to 20; L ¹ , L ² , L ³ and L ⁴ are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, and having 6 to 20 carbon atoms. A divalent linking group selected from the group consisting of an arylene group, -O-, -S-, -CO-, -NR- and combinations thereof, wherein R is a hydrogen atom or a carbon atom number of 1 to 5 an alkyl group; ^{Z 1} Z ² and Z ³ are each independently a hydroxyl or hydrolyzable group; X ¹ is an anion. The method for producing inorganic oxide fine particles according to any one of claims 1 to 4, wherein the cationic surfactant is a compound represented by the following general formula (II).

[Wherein R ¹¹ is an alkyl group having 1 to 20 carbon atoms or a substituted alkyl group having 1 to 20 carbon atoms; R ¹² and R ¹³ are alkyl groups having 4 to 20 carbon atoms; Or a substituted alkyl group having 4 to 20 carbon atoms, wherein the alkyl group or the alkyl part of the substituted alkyl group has at least one branch, or the substituted alkyl group is substituted with an alkoxy group at a carbon atom other than the terminal. L ¹¹ represents a single bond or an alkylene group having 1 to 5 carbon atoms, an arylene group having 6 to 20 carbon atoms, —O—, —S—, —CO—, —NR—, and their a divalent linking group selected from the group consisting, R represents a hydrogen atom or a carbon atoms is an alkyl group of 1 to 5; Z ^11, Z ¹² and Z ¹³ is Each independently a hydroxyl or hydrolyzable group; X ¹¹ is an anion.   The method for producing inorganic oxide fine particles according to claim 1, wherein the inorganic oxide fine particles have a hollow structure.   Inorganic oxide microparticles | fine-particles obtained with the manufacturing method as described in any one of Claims 1-7.   A composition containing the inorganic oxide fine particles according to claim 8.   An optical film comprising the composition according to claim 9. The optical film according to claim 10, which has an antireflection function.