JP2014047130A - Fluoro aluminate compound grain having gap in inside and production method of the same, and composition and antireflection film including the grain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low refractive index grain that is suitable for an inorganic filler that is used for a low refractive index layer of an antireflection film.SOLUTION: A grain includes at least a fluoro aluminate compound, has a gap in the inside, and shows an excellent low refractive index. The grain can be obtained from a production method that includes: a first process in which a template grain and an aluminum raw material are made to be coexistent and an aluminum compound is made to exist on a template grain surface; a second process in which the aluminum is made to be coexistent with a fluorine raw material further, and the aluminum compound is converted to a fluoro aluminate compound; and a third process in which the template grain is removed.

Description

  The present invention relates to fluoroaluminate compound particles having voids therein and a method for producing the same, and more particularly to particles suitable for application to a low refractive index layer of an antireflection film. Furthermore, the present invention relates to a composition containing the particles and an antireflection film.

  The surface of a transparent article such as an optical component or an image display device that constitutes an optical device is provided with an antireflection film for the purpose of improving light transmittance or suppressing a decrease in visibility due to light reflection. ing. A general antireflection film is formed using a material having a refractive index lower than that of the substrate. As an antireflection film of an optical element that requires a lower reflection effect, a multilayer film in which a high refractive index film and a low refractive index film are alternately laminated is used instead of the single layer. In this case as well, a low refractive index material is important as the uppermost layer on the air side. In any case, as a technique for reducing the reflectance, it is possible to reduce the refractive index of the low refractive index layer on the outermost surface, and as one means, it is effective to use a material having a lower refractive index, Various low refractive index materials have been proposed for this purpose.

  Patent Document 1 discloses a low reflection film formed from ultrafine particles of cryolite (refractive index: 1.34), which is another name for sodium hexafluoroaluminate. The cryolite ultrafine particles are produced by mixing a solution in which sodium and aluminum raw materials are dispersed, suspended or dissolved, and an HF aqueous solution.

JP 2010-107583 A

  The ultrafine particles of cryolite proposed in Patent Document 1 have a low refractive index, and a certain effect of reducing the reflection of the antireflection film can be confirmed by using it. However, a material having a lower refractive index is required. ing.

  An object of the present invention is to provide low refractive index particles suitable for an inorganic filler used in a low refractive index layer of an antireflection film.

  Therefore, the present inventors have found that, as a result of intensive studies to solve such problems, particles containing at least a fluoroaluminate compound and having voids therein exhibit an excellent low refractive index. completed.

That is, the present invention
(1) Particles containing at least a fluoroaluminate compound and having voids inside,
(2) The fluoroaluminate compound is a particle of (1) containing at least an alkali metal and / or ammonium ion,
(3) The particles of (2), which are hollow particles in which cavities are formed,
(4) In powder X-ray diffraction measurement, at least 2θ = 46.8 ± 1.0, 32.7 ± 1.0, 23.0 ± 1.0, 38.6 ± 1.0 (the unit is degree) ) Having a peak at the position (1) to (3),
(5) The particle according to any one of (1) to (4), wherein the void ratio in the volume of the particle is 20 to 95%.
(6) The particle according to any one of (1) to (5), wherein the particle diameter of the particle is 10 nm to 200 nm.
(7) The particles according to any one of (1) to (6) having an organic compound and / or an inorganic compound on the surface,
(8) The particles according to any one of (1) to (7) having a conductive substance on the surface,
(9) A step of allowing the template particles and the aluminum raw material to coexist, and causing an aluminum compound to exist on the surface of the template particles (step 1),
A step of coexisting with a fluorine raw material to convert the aluminum compound into a fluoroaluminate compound (step 2);
Step of removing template particles (Step 3)
A method for producing particles having at least a fluoroaluminate compound and having voids therein,
(10) A step of mixing a dispersion of template particles and an aluminum raw material so that an aluminum compound is present on the surface of the template particles (step 1),
A step of mixing the fluorine raw material with the dispersion of Step 1 to convert the aluminum compound into a fluoroaluminate compound (Step 2);
Step of removing template particles (Step 3)
The method for producing particles according to (9),
(11) The particles according to (10), wherein the step 1 and the step 2 are performed in a single step by mixing an aluminum raw material and a fluorine raw material in a dispersion of template particles and causing the fluoroaluminate compound to exist on the surface of the template particles. Is a manufacturing method of
(12) Step 1 is
The method for producing particles according to any one of (9) to (11), wherein the pH of the mixed solution containing at least template particles and an aluminum raw material is 6 to 11.
(13) While adjusting the pH by mixing the mixed solution with an acidic compound or a basic compound,
While adjusting the pH by mixing the liquid mixture with an acidic compound or a basic compound,
Addition rate in grams equivalent standard of acidic compound or basic compound is not more than 3.6 mol / hr with respect to Al 2 _O 3 ₁ mol when converted the aluminum compound amount in Al ₂ O _3, (12) a manufacturing method,
(14) The template particles are zinc oxide particles,
In the step 3, it is a production method according to any one of (9) to (13), wherein removal of zinc oxide particles as template particles is performed with an acidic aqueous solution having a pH of 2 to 4.
(15) The production method according to any one of (9) to (14), wherein sodium aluminate is used as the aluminum raw material in the step 1, and ammonium fluoride is used as the fluorine raw material in the step 2.
(16) A composition comprising at least the particles according to any one of (1) to (8) and a solvent,
(17) An antireflection film containing the particles according to any one of (1) to (8).

The present invention is a particle containing at least a fluoroaluminate compound and having voids therein, and exhibits an excellent low refractive index. For this reason, the antireflection film using this as a filler can be further reduced in reflection. The composition of the present invention is suitable for producing such an antireflection film.
The particles of the present invention can be suitably used for an antireflection film provided on a substrate such as an optical material such as a lens, an image display surface such as a liquid crystal display, a plate glass such as a window or a showcase, or a transparent plastic.

2 is a transmission electron micrograph of particles obtained in Example 1. FIG. 2 is a transmission electron micrograph of particles obtained in Comparative Example 1. 2 is a powder X-ray diffraction pattern of the particles obtained in Example 1. FIG.

  The technical configuration and operational effects of the present invention are as follows. However, the action mechanism includes estimation, and its correctness does not limit the present invention.

  The first invention of the present invention is a particle containing at least a fluoroaluminate compound and having voids therein. (Hereafter, it may be described as “the particle of the present invention”.)

The fluoroaluminate compound contained in the particles of the present invention is preferably a compound having a basic composition of (Formula 1) A ₃ AlF ₆ (wherein A is a cation). In particular, A preferably contains at least an alkali metal and / or ammonium ion.

When A in Formula 1 contains an alkali metal, examples of the alkali metal include one or more selected from lithium, sodium, potassium, rubidium, and cesium. Among these, lithium, sodium, and potassium are preferable, and sodium Is particularly preferred. Moreover, when an alkali metal and an ammonium ion are included simultaneously, the molar ratio of an alkali metal and an ammonium ion can be set suitably. Specifically, when A = A ′ _3-x (NH ₄ ) _x (A ′ is an alkali metal) in Formula 1, x may be 0.1 or more, and is 0.15 or more. Or 0.8 or less, or 0.7 or less, and there is no particular limitation.

  The shape of the particles of the present invention is not particularly limited, for example, isotropic shapes such as spherical and polyhedral shapes, rod shapes, spindle shapes, anisotropic shapes such as columnar shapes, needle shapes, scale shapes, and plate shapes, and irregular shapes.

  The particles of the present invention have voids therein. “Particles having voids in the interior” mean particles that form a structure having voids in which gas or liquid can exist inside the particles and / or a porous structure having voids that can contain gas, liquid, or the like. To do. When the gas is air having a refractive index of 1.0, the refractive index decreases in proportion to the gas occupancy in the particles as compared to the original refractive index of the particles. The present invention also includes particles capable of forming a nanoporous structure inside and / or at least part of the surface depending on the form, structure, aggregation state, and dispersion state of the particles inside the film. . Specific examples of such a structure include porous particles, particles having one or more voids therein, and cylindrical particles. Examples of the particles having one void inside include so-called hollow particles in which a cavity is formed inside by an outer shell. Examples of the particles having a plurality of voids therein include so-called sponge particles and hollow particles formed by an outer shell having voids and pores. Examples of the cylindrical particles include cylindrical particles, cylindrical particles having a polygonal cross section, and aggregates thereof. Examples of the aggregate include a honeycomb body in which hexagonal cross-section cylindrical bodies are in contact with each other on the wall surface. In the case of a cylinder, both ends of the cylinder may be in communication with the outside, or may be blocked in the middle by a node or the like.

  The particles of the present invention are preferably hollow particles. By making hollow particles, the void ratio (the ratio of voids in the volume of particles and the volume fraction of voids in the particles) can be maximized, that is, the void ratio is maximized and the refractive index is increased. Since it can reduce, it is preferable. Even when the particles are hollow, the shape of the particles is not particularly limited, but isotropic shapes, for example, spherical to substantially spherical or cubic shapes are preferable.

  The particles of the present invention preferably have an average particle size of 10 nm to 200 nm. When the thickness is less than 10 nm, it is not preferable because sufficient voids cannot be formed inside the particles and it is difficult to reduce the refractive index. If it is larger than 200 nm, light in the visible range is scattered by the particles, so that when used for an antireflection film, it is difficult to obtain desired performance, which is not preferable. The average particle size is more preferably 30 to 100 nm. It is more preferable that the particle diameter of all the particles is within the above range.

  The particle diameter of the particles of the present invention is measured using a transmission electron microscope. From the image obtained with the transmission electron microscope, 100 particles are selected, and the particle diameter is measured for each particle. The average value of the measured values obtained is calculated to obtain the average particle diameter. In the present application, the particle diameter of anisotropic particles and irregular particles is the length of the longest part of the particles.

  The particles of the present invention preferably have a porosity of the particles (ratio of voids in the volume of the particles) of 20 to 95%. If it is less than 20%, the refractive index of the particles cannot be sufficiently reduced, and the effect of lowering the refractive index is small, which is not preferable. On the other hand, if it is larger than 95%, the thickness of the component that forms the skeleton of the particle becomes thin, and there is a concern that sufficient strength cannot be obtained and the particle collapses.

The void ratio of the particles of the present invention can be determined by calculation by selecting 100 particles of an image obtained with a transmission electron microscope, measuring the outer diameter and inner diameter, if the shape is hollow. For example, in the case of spherical hollow particles, the void ratio (%) = (r ₃ / R ₃ ) × 100, where R is the outer diameter and r is the inner diameter. Except for the hollow shape, the pore volume is measured using an automatic specific surface area / pore distribution measuring device, and obtained from the following formula 2.
(Expression 2) Porosity = pore volume / {(1 / Na ₃ AlF ₆ true density) + pore volume}
In Equation 2, the true density of Na ₃ AlF ₆ is set to 2.97.

The fluoroaluminate compound of the present invention has at least 2θ = 46.8 ± 1.0 °, 32.7 ± 1.0 °, 23.0 ± 1.0 °, 38.6 ± in powder X-ray diffraction measurement. It preferably has a peak at a position of 1.0 °. By using a compound having such a peak, that is, having a crystal structure, the refractive index of the particles can be reduced. This powder X-ray diffraction pattern is more preferably coincident with Na ₃ AlF ₆ (PDF No. 74-4463). Here, “match” means that the peak position described in the PDF and the measured peak position are within a range of ± 1.0 °.

  Powder X-ray diffraction measurement is performed under the conditions of a radiation source: CuKα, tube voltage / tube current: 40 kV / 40 mA, measurement interval: 0.01 °, scan speed: 5 ° / min.

The particles of the present invention may contain other elements and substances in addition to the fluoroaluminate compound. Examples of such elements include alkaline earth metals such as magnesium, calcium, strontium and barium, zinc and sulfur. Although the existence state of these elements is not clear, even if the A, Al, and F sites in the crystal lattice of the fluoroaluminate compound of Formula 1 are partially substituted, or even if they are present at interstitial positions or grain boundaries It may be present as a separate phase in the particle or as a separate compound particle. Zinc may be contained in an amount of about 1.5% by weight in terms of ZnO, or 1.5% by weight or less. Sulfur may be contained in an amount of about 1.0% by weight in terms of SO ₄ or may be 1.0% by weight or less.

  The chemical composition of the particles of the present invention can be determined, for example, by fluorescent X-ray analysis. The presence of ammonium ions can be confirmed by an absorption peak of Fourier transform infrared spectroscopy. Quantification of each component of fluorine and nitrogen can be performed by ion chromatography and CHN analysis, respectively.

  An organic compound and / or an inorganic compound may further exist on the surface of the particle of the present invention. These compounds can impart various functions to the particles. For example, the dispersibility of the particles can be improved, or conductivity can be imparted to the particles.

  Examples of the organic compound include silicone compounds, other organosilicon compounds, fatty acid compounds, and the like.

  Examples of organosilicon compounds include vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropylmethyldiethoxy. Silane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3- Methacryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N- -(Aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-tri Ethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltri Examples include methoxysilane, bis (triethoxysilylpropyl) tetrasulfide, and 3-isocyanatopropyltriethoxysilane.

  Examples of the fatty acid compounds include caprylic acid, capric acid, lauric acid, myristic acid, isomustic acid, palmitic acid, isopalmitic acid, stearic acid, isostearic acid, arachidic acid, undecylenic acid, oleic acid, myristoleic acid, elaidic acid Linoleic acid, linolenic acid, arachidonic acid, coconut oil fatty acid, beef tallow fatty acid, resin acid (abietic acid), salts thereof, metal salts thereof, and the like, and at least one of these fatty acid compounds is used. be able to. As salt forms, metal salts such as Na, K, Ba, Zn, Ca, Mg, Fe, Zr, Co, Al, Zr, Ti, ammonium salts, monoethanolamine, diethanolamine, triethanolamine, 2-amino Examples thereof include various alkanolamine salts such as 2-methyl-propanol, 2-amino-2-methyl-1,3-propanediol, and triisopropanolamine. Moreover, as dextrin fatty acid ester, it can select from the ester comprised from dextrin and a fatty acid, or its derivative (s). Preferably, for one dextrin molecule, an ester having at least a partial structure in which one molecule of a fatty acid having 8 to 24 carbon atoms is esterified to one of its hydroxyl groups, or a derivative thereof, such as 8 to 8 carbon atoms for one molecule of dextrin Examples include ester bodies having a structure in which one or a plurality of 24 fatty acids and one or more of the hydroxyl groups are ester-bonded, and derivatives in which the hydroxyl groups are further esterified with another fatty acid. .

  The silicone compound is also called polysiloxane, and is an oligomer or polymer obtained by hydrolyzing silanes such as dichlorodimethylsilane and dehydrating and condensing the generated silanol. Examples of the silicone compound (polysiloxane) include dimethylpolysiloxane, dimethoxypolysiloxane, organopolysiloxane such as modified organopolysiloxane, organohydrogenpolysiloxane such as methylhydrogenpolysiloxane, and methylhydrogensiloxane-dimethylsiloxane copolymer. It is a compound containing an oligomer or polymer obtained by dehydration condensation of silanol such as siloxane copolymer such as coalescence, silicone polymer, and triorganosiloxysilicic acid. At least one selected from such silicone compounds can be used.

  As the inorganic compound, various inorganic elements can be used, and examples thereof include at least one inorganic compound selected from silicon, zirconium, tin, titanium, and antimony. preferable.

  In the case of imparting conductivity to the particles, a conductive substance such as a conductive polymer, a conductive metal oxide, metal particles, or carbon powder can be used.

  Examples of the conductive polymer include polyacetylene, polypyrrole, polythiophene, polyaniline, polyphenylene vinylene, polyacene, and derivatives thereof. Examples of the conductive metal oxide include tin oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), phosphorus-doped tin oxide (PTO), tungsten-doped tin oxide, and tin-doped indium oxide (ITO). , Aluminum doped zinc oxide (AZO), niobium doped titanium oxide, antimony oxide and the like. Examples of the metal include gold, silver, copper, aluminum, iron, nickel, palladium, and platinum. Examples of the carbon material include carbon black, graphite, and carbon nanotube.

  The organic compound and / or the inorganic compound (at least one of them may be a conductive material) may be locally attached on the particles of the present invention or may be entirely coated in layers. There is no particular limitation. Although there is no restriction | limiting in particular also about the adhesion order, It is preferable that the inorganic compound adheres on the particle | grains of this invention, and the organic compound adheres on it.

  The abundance of the organic compound and / or inorganic compound on the surface of the particles may be a level that can impart the intended function, and is specifically preferably 0.05 to 100% by weight with respect to the fluoroaluminate compound. 0.1 to 50% by weight is more preferable, and 0.1 to 30% by weight is still more preferable.

Next, the second invention of the present invention is:
A step (step 1) in which template particles and an aluminum raw material are allowed to coexist and an aluminum compound is present on the surface of the template particles;
A step of coexisting with a fluorine raw material to convert the aluminum compound into a fluoroaluminate compound (step 2);
Step of removing template particles (Step 3)
A method for producing particles having at least a fluoroaluminate compound and having voids therein.

  The template particles serve as a template for the aluminum compound in step 1 and are removed in step 3 to form voids inside the particles of the present invention.

  There is no particular limitation on the shape of the template particle, and for example, an isotropic shape such as a spherical shape or a polyhedral shape, an anisotropic shape such as a rod shape, a plate shape, a needle shape, a spindle shape, a flat shape, a scale shape, or a tube shape. , 1 type, or 2 or more types of mixtures chosen from an indefinite shape etc. can be used. By appropriately selecting the form of the template particles, the shape and structure of the particles having voids in the present invention can be controlled. For example, various shapes of hollow particles, cylindrical particles, and the like can be produced by appropriately selecting the shape of the template particles. In addition, by appropriately selecting the shape and aggregation or aggregation state of the template particles, porous particles, so-called sponge particles, hollow particles formed by outer shells having voids and pores, and the like can be produced. When the template particles are appropriately formed and used, cylindrical particles, aggregates thereof, honeycomb bodies, and the like can be produced.

  The particle size of the template particles can be appropriately selected according to the desired porosity and particle size of the particles. For example, when the particle of the present invention is used as a filler for an antireflection film, the particle size of the template particle is preferably 0.5 nm or more and less than 200 nm. When producing hollow particles having a high porosity, the template particles are preferably monodispersed.

  As the template particles, acid or alkali-soluble materials, thermally decomposable materials, enzyme degradable materials, photodegradable materials and the like can be used. Examples of the acid- or alkali-soluble material include metal oxides and metal hydroxides such as zinc oxide, magnesium oxide, zinc hydroxide, and magnesium hydroxide, metal carbonates such as calcium carbonate, and organic polymers. Examples of such organic polymer include polyvinyl alcohol, alginic acid, cellulose resin, and a polymer having an acid group such as a carboxyl group. Examples of the thermally decomposable material include carbon fine particles, organic materials, and micelle aggregates of surfactants formed in an O / W or W / O emulsion. Such organic materials include, for example, acrylic resins, styrene resins, urethane resins, epoxy resins, melamine resins, vinyl resins, thermoplastic resins, thermosetting resins, UV curable resins, cellulose resins, and the like. Examples include resin, starch, protein, collagen, and the like. A protein is mentioned as an enzyme-degradable material. Examples of the photodegradable material include organic materials into which a ketone group, an ether group, a nitro-substituted benzyl group, a borate derivative, or the like is introduced as a photodecomposition start group.

  There is no restriction | limiting in particular as an aluminum compound (henceforth described as "coating Al") on the template particle surface, Arbitrary compounds can be used. Specific examples include aluminum metal, aluminum oxide, aluminum hydroxide, aluminum fluoride, and sodium fluoroaluminate. The covering Al may contain a metal element other than aluminum.

The coating Al may be present on the surface of the template particle, and the form thereof is not limited. Examples of such a state include core / shell type particles in which the core is a template particle and the outer shell is an aluminum compound. The core / shell type particle includes a monodispersed state of an aluminum compound-coated template particle, a template particle Examples include a state in which an agglomerate is coated with an aluminum compound, and an aggregate of particles in which a single template particle is coated with an aluminum compound. The aluminum compound may be high density or low density, and its surface may be porous or smooth. The volume ratio between the aluminum compound and the template particles can be appropriately set according to the desired porosity.

  A method of making an aluminum compound exist on the surface of the template particle, that is, a method of producing a particle containing an aluminum compound on the surface of the template particle (hereinafter sometimes referred to as “Al-coated template particle”) includes the template particle and the aluminum raw material. Coexist. Thus, by reacting template particle (or template particle raw material) with aluminum derived from the aluminum raw material, or by reacting aluminum derived from the aluminum raw material in the presence of the template particle, an aluminum compound is formed on the surface of the template particle. The outer shell is deposited and formed. This step may be performed in any of a gas phase, a liquid phase, and a solid phase.

  As a production method in the liquid phase, for example, at least a dispersion of template particles and an aluminum raw material are mixed, and an aluminum compound is present on the surface of the template particles. Specifically, the aluminum compound can be precipitated around the template particles (outer surface) by adjusting the pH of the mixed solution containing the aluminum element derived from the aluminum raw material. Alternatively, by changing the temperature of the mixed solution, the aluminum compound can be precipitated around the template particles using the difference in solubility. Alternatively, an insoluble aluminum compound can be precipitated around the template particles by adding water to the aluminum compound solution containing the template particles and hydrolyzing the aluminum compound. In the following, the method by pH adjustment will be described in detail.

The order of dispersion of the template particles in the dispersion medium, dissolution of the aluminum raw material, and pH adjustment is not particularly limited as long as Step 1 can be performed. In particular,
A method of mixing a dispersion of template particles and an aluminum raw material or a solution thereof, and adjusting the pH of the mixture with an acid or alkali,
A production method of adjusting the pH of the mixture by adding an aluminum raw material or a solution thereof and an acid or alkali to the dispersion of template particles,
A production method of mixing a dispersion of template particles adjusted in pH and an aluminum raw material solution,
Examples include a production method in which template particles are dispersed in an aluminum raw material solution and the pH of the mixed solution is adjusted. Mixing of the template particles and the aluminum raw material may be performed at one time or gradually, and when performed gradually, either continuous mixing or intermittent mixing may be performed.

  In the case where Step 1 is performed in the liquid phase, the dispersion medium of the template particle dispersion and the solvent of the solution containing the aluminum raw material (hereinafter sometimes referred to as “medium liquid” in some cases) are particularly limited. Examples thereof include water, alcohols, ketones, ethers, esters, glycol ethers, nitrogen-containing compounds, and sulfur-containing compounds.

  Examples of alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, ethylene glycol, polyethylene glycol, propylene glycol, trimethylene glycol, and 1,4-butane. Examples include diol, cyclopentanol, siloxane pentanediol, and cyclohexanol.

  Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, methyl propyl ketone, isopropyl methyl ketone, isobutyl methyl ketone, cyclopentanone, cyclohexanone, acetophenone, and the like.

  Examples of ethers include glyme, diglyme, isopropyl ether, isobutyl ether, methyl isopropyl ether, anisole, tetrahydrofuran, and dioxane.

  Examples of the esters include methyl acetate, ethyl acetate, ethyl acetoacetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, and ethyl butyrate.

  Examples of glycol ethers include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether.

  Examples of the nitrogen-containing compounds include N, N-dimethylacetamide, N-methylacetamide, N, N-dimethylformamide, N-methylformamide, 2-pyrrolidinone, N-methyl-2-pyrrolidinone, 1,3-dimethyl. -2-imidazolidinone and the like.

  Preferred examples of the sulfur-containing compounds include dimethyl sulfoxide and sulfolane.

  However, since the presence of water is essential in the coating Al formation step by pH adjustment, it is preferable that 5 to 100% by mass of water is present in the entire liquid medium. If the water content is less than 5% by mass, the reaction does not proceed sufficiently.

  When preparing a dispersion of template particles, a dispersion treatment may be performed according to the degree of aggregation of the template particles. For example, a wet pulverizer can be used for the dispersion treatment. Examples of the wet pulverizer include a vertical sand mill, a horizontal sand mill, and a ball mill. Moreover, you may use dispersing agents, such as phosphoric acid compounds, such as sodium hexametaphosphate and sodium pyrophosphate, silicic acid compounds, such as sodium silicate and potassium silicate, and an organic dispersing agent as needed. By increasing the dispersibility of the template particles, it becomes easy to finally obtain hollow particles having a uniform particle size and shape. The “dispersion liquid” in the present application is a concept including not only a dispersion liquid but also a suspension liquid.

  The concentration of the template particle dispersion is not particularly limited and may be any concentration, for example, 1 g / liter or more, or 100 g / liter or less, and about 10 g / liter to 40 g / liter. Is appropriate. If the concentration is too high, the viscosity of the dispersion becomes high and handling is not easy. On the other hand, if the concentration is too low, productivity is remarkably deteriorated.

  As an aluminum raw material, the 1 type, or 2 or more types of mixture chosen from aluminum salt and aluminate is mentioned, Their hydrolyzate may be sufficient. Alternatively, aluminum alkoxide may be used. Specifically, the aluminum salt includes aluminum sulfate, aluminum nitrate, and aluminum chloride; the aluminate includes 4 aluminate salts such as sodium aluminate and potassium aluminate, ammonium aluminate salts, tetraethylammonium salts, and the like. Examples thereof include aluminates of amines such as quaternary ammonium salts and ethanolamine. Examples of the aluminum alkoxide include aluminum isopropoxide, aluminum sec-butoxide, and aluminum tert-butoxide.

When the aluminum raw material is dissolved in a liquid medium and used as a solution, the concentration thereof is not limited and can be set to any concentration. For example, 0.5 g / liter or more or 50 g in terms of Al ₂ O ₃ / 5 or less, and about 5 g / liter to 20 g / liter is suitable. If the concentration is too high, the viscosity of the dispersion becomes high and handling is not easy. On the other hand, if the concentration is too low, productivity is remarkably deteriorated.

  In the presence of the template particles, the aluminum element derived from the aluminum raw material is reacted to precipitate the aluminum compound on the surface of the template particles, so that the pH of the dispersion is adjusted. Specifically, the pH is preferably 6-11. By this treatment, an aluminum compound is deposited as an outer shell on the surface of the template particle.

  For adjusting the pH, any acid or alkali, or a solution thereof can be used. The acid is not particularly limited, and may be an inorganic acid or an organic acid. Examples of inorganic acids include hydrochloric acid, sulfuric acid, nitric acid, carbonic acid, phosphoric acid, phosphorous acid, hypophosphorous acid, nitrous acid, and the like. Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, Examples include herbic acid, caproic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, malic acid, tartaric acid, citric acid, lactic acid, gluconic acid, maleic acid, fumaric acid, and succinic acid. The alkali is not particularly limited, and examples thereof include basic compounds such as alkali metal or alkaline earth metal hydroxides or carbonates, and ammonium compounds.

The precipitation rate of the aluminum compound is not particularly limited, but if the precipitation rate is too high, the produced aluminum compound itself aggregates, and the outer surface of the template particle is formed with a homogeneous and dense aluminum compound. There is a risk that it may become difficult or break when it is finally made into particles having voids inside. The precipitation rate of the aluminum compound can be adjusted by, for example, the addition rate of acid or alkali used for pH adjustment or the concentration of acid or alkali. Specifically, with respect to Al 2 _O 3 ₁ mol when converted to aluminum compound amount to the amount of Al ₂ O _3, the rate of addition of acid or alkali, 3.6 mol gram equivalent basis of an acid or a base / It is preferable to set it to not more than time, and more preferably to 1.2 mol / hour or less. In particular, when the pH of the reaction solution is between 6 and 11, the addition rate is preferably 3.6 mol / hour or less for at least a certain period of time. After adjusting the pH, aging may be performed.

  The amount of the aluminum compound with respect to the template particles can be arbitrarily set. By adjusting this ratio, the porosity of the particles of the present invention can be controlled, and when producing hollow particles, the thickness of the outer shell can also be controlled.

  Moreover, it is preferable that the solid content (sum of template particles and aluminum raw material) concentration when producing Al-coated template particles is in the range of 30% by mass or less and 0.1% by mass or more, and 20% by mass or less, 1 More preferably, it is in the range of mass% or more. If the amount exceeds 30% by mass, the stability of the dispersion liquid is lowered, and therefore, it is not preferable.

  There is no restriction | limiting in particular in the temperature of the said reaction liquid, It can set arbitrarily. Specifically, it may be 0 to 95 ° C, or may be room temperature to 70 ° C. When raising the temperature, there is no particular limitation on the temperature raising timing, and the temperature may be raised in any step. After the temperature of the dispersion medium is increased, the template particles are dispersed, the temperature of the mixed solution of the template particles and the surface aluminum raw material is increased, the temperature is increased during the Al coating reaction, or the temperature is increased after the Al coating reaction is completed. be able to.

  After the completion of this step, the Al-coated template particles may be filtered, washed, and dried as necessary, or the step 2 may be performed as it is without performing these treatments.

  In addition, when acid or alkali-soluble inorganic fine particles are used as the template particles, the pH is appropriately adjusted during the step 1. For example, when zinc oxide is used as the template particles, the solution is dissolved when the pH is less than 6, and therefore, it is preferably within the range of 6 or more.

  Next, in step 2, the coated Al of the Al-coated template particles obtained in step 1 coexists with a fluorine raw material, and the coated Al is reacted (fluorinated) with the fluorine raw material to convert it into a fluoroaluminic acid compound. This step may be performed in any of a gas phase, a liquid phase, and a solid phase. Through this step, particles in which the fluoroaluminate compound is present on the surface of the template particles (hereinafter sometimes referred to as “AlF-coated template particles”) are obtained. Hereinafter, the method performed in the liquid phase will be described in detail.

The method for allowing the Al-coated template particles and the fluorine raw material to coexist in the medium is not particularly limited as long as Step 2 can be performed. In particular,
A production method of mixing a dispersion of Al-coated template particles with a fluorine raw material or a solution thereof,
A production method of dispersing Al-coated template particles in a solution of fluorine raw material,
Etc.

  There is no restriction | limiting in particular as a fluorine raw material, Arbitrary substances can be used. Examples thereof include sodium fluoride, ammonium fluoride, hydrofluoric acid (hydrofluoric acid), and the like.

  As the dispersion medium of the Al-coated template particle dispersion liquid or the solvent of the fluorine raw material solution, the medium liquid described in the above-mentioned step 1 can be used. When Step 1 is performed in the liquid phase, the Al-coated template particle dispersion obtained in Step 1 can be used as it is.

  There is no restriction | limiting in particular in the density | concentration of Al coating template particle dispersion liquid, Although it can set arbitrarily, It is preferable that it is the range of 30 mass% or less and 0.1 mass% or more, 20 mass% or less, 1 mass. % Or more is more preferable. If the amount exceeds 30% by mass, the stability of the dispersion liquid is lowered, and therefore, it is not preferable.

  The amount of the fluorine raw material is not particularly limited as long as it is more than an amount capable of producing a predetermined fluoroaluminate compound, and can be arbitrarily set. For example, in order to produce a hexafluoroaluminate compound, the molar ratio of fluorine element to aluminum element is preferably 6 times or more, and if it is less than 6 times, the fluorination of the coated Al becomes insufficient, and hexafluoroaluminate Since a compound cannot be produced, it is not preferable. Even if the molar ratio is too high, it is not preferable because it is excessive for fluorination of the coated Al and becomes waste. Therefore, the molar ratio may be 10 times or less.

  There is no particular limitation on the temperature at which the Al-coated template particles and the fluorine raw material coexist in the liquid medium, and any temperature can be set.

  There is no particular limitation on the time for the Al-coated template particles and the fluorine raw material to coexist in the liquid medium, and any time can be set. However, in order to ensure the fluorination of the surface aluminum compound, it coexists for 1 minute or more (aging). It is preferable to make it 30 minutes or more. Moreover, since productivity will fall even if aging time is too long, it is preferable to set it within 24 hours. Moreover, it is preferable to stir the reaction liquid during aging.

In Step 1 or Step 2, an alkali metal and / or ammonium ion can be contained in the fluoroaluminate compound by coexisting an alkali metal-containing material and / or an ammonium ion-containing material. There is no particular limitation on the alkali metal-containing substance, and a known substance can be used, and the ammonium ion-containing substance is not particularly limited, and a known substance can be used. In particular, it is preferable to use sodium aluminate as the aluminum raw material in step 1 and ammonium fluoride as the fluorine raw material in step 2.

  The steps 1 and 2 may be performed in one step. Specifically, AlF-coated template particles can be produced by mixing an aluminum raw material and a fluorine raw material in a dispersion of template particles and reacting them to precipitate a fluoroaluminate compound.

  After the completion of this step, the AlF-coated template particles may be filtered, washed and dried as necessary, or the step 3 may be performed as it is without performing these treatments.

  Next, in Step 3, the template particles in the AlF-coated template particles obtained in Step 2 are removed. By this step, particles containing a fluoroaluminate compound having voids in the present invention can be obtained.

  In order to remove the template particles from the AlF-coated template particles, as described above, various means can be adopted depending on the type of the template particles, such as dissolution with acid or alkali, decomposition by heat, decomposition by enzyme. One or two or more methods selected from decomposition by light can be mentioned.

  When the template particles are a thermally decomposable material, the template particles can be removed by heating. Although the heating temperature varies depending on the material of the template particles, it is generally preferable that the heating temperature be in the range from the decomposition temperature to 1000 ° C. of the template particles. If the temperature is lower than the decomposition temperature, the template particles may remain, and if it exceeds 1000 ° C., the fluoroaluminate compound may be melted, which is not preferable.

  When the template particle is an acid-soluble material, the template particle can be removed by adding an acid or an acidic cation exchange resin. As the acid, the materials mentioned in the section of pH adjustment can be used.

  Moreover, an acidic cation exchange resin can also be used instead of a liquid acid or an acid solution. Examples of the acidic cation exchange resin include polyacrylic resin-based or polymethacrylic resin-based carboxylic acid groups, and polystyrene-based resins having sulfonic acid groups.

  When zinc oxide is used as template particles, removal of zinc oxide from AlF-coated zinc oxide particles is preferably carried out by adjusting the pH between 2 and 4. If the pH is less than 2, it is not preferable because the surface sodium fluoroaluminate also dissolves. If the pH is more than 4, it is not preferable because it takes time to remove the zinc oxide particles. When the acid is added with a weak acid aqueous solution, it is possible to suppress a rapid drop in pH, particularly a local fluctuation. Examples of the weak acid aqueous solution include a citric acid aqueous solution having a concentration of 10 to 50%.

  When the template particles are an alkali-soluble material, the template particles can be removed by adding an alkali. As the alkali, the materials mentioned in the above-mentioned pH adjustment can be used.

  When the template particle is an enzyme-degradable material, the template particle can be removed by adding an enzyme. When the template particle is a protein, examples of the enzyme include pepsin and chymotrypsin.

  When the template particles are a photodegradable material, the template particles can be removed by irradiating light in a gas phase or a liquid phase. The wavelength of light is preferably 380 nm or less, which has higher energy.

  In addition, the fluorine raw material used in the step 2 and the template particle removing agent used in the step 3 may be performed with one kind of compound, and the steps 2 and 3 may be performed in one step. For example, when hydrofluoric acid is used as a fluorine raw material, it is converted to a fluoroaluminate compound, and hydrofluoric acid itself is an acid. Therefore, when an acid-soluble material such as zinc oxide is used as a template particle, Can be removed.

  After the completion of this step, the obtained particles may be filtered, washed and dried as necessary. Filtration can be appropriately selected from known methods depending on the size and dispersibility of the particles. Washing can also be appropriately selected from known methods. Drying can also be appropriately selected from known methods. Moreover, you may manufacture the below-mentioned dispersion liquid as it is, without performing filtration or washing | cleaning and drying.

  Whether or not the template particles have been removed by the above method can be confirmed by observing with a transmission electron microscope or performing elemental analysis of the obtained fine particles.

  In the production of the particles of the present invention, there may be a separate step of depositing an organic compound and / or an inorganic compound on the surface.

  Specifically, as the step of depositing the organic compound, (1) when the obtained particles are pulverized by a dry pulverizer such as a fluid energy pulverizer or an impact pulverizer, the organic compound is added to the dry pulverizer. (2) After dry pulverization, using a high-speed stirrer such as a Henschel mixer or Super mixer, etc., stirring and mixing the resulting particles and organic compound, (3) Producing Al coated template particles in Step 1 Then, a method of adding and stirring an organic compound to the particles (4) A method of adding an organic compound to the particles after stirring to produce AlF-coated template particles in step 2, and a template in step 3 of (5) For example, after removing the particles, an organic compound is added to the particles and stirred.

  Specifically, as the step of depositing the inorganic compound, after the Al-coated template particles are manufactured in the step 1, the AlF-coated template particles are manufactured in the step 2, or from the AlF-coated template particles in the step 3, the template particles. (Hereinafter, sometimes collectively referred to as “base particles”). It is preferable to carry out in the state of an aqueous slurry in which they are dispersed in water or a liquid medium containing water as a main component. At this time, preliminary pulverization may be performed using a wet pulverizer such as a vertical sand mill, a horizontal sand mill, or a ball mill according to the degree of aggregation of the base particles. The dispersion state may be adjusted by adjusting the pH of the slurry. Moreover, you may use dispersing agents, such as silicic acid compounds, such as phosphoric acid compounds, such as sodium hexametaphosphate and sodium pyrophosphate, sodium silicate, and potassium silicate, as needed.

  Subsequently, at least an inorganic compound is deposited on the surface of the base particles. Examples of the inorganic compound include a hydrated oxide of at least one element selected from silicon, zirconium, titanium, tin, and antimony. In order to deposit the inorganic compound, a water-soluble salt of an inorganic element constituting a desired inorganic compound and a neutralizing agent are added in parallel to the aqueous slurry of the base particles at the same time, or after the addition of the water-soluble salt. A known method such as a method of adding a compatibilizer can be used. Examples of water-soluble salts of inorganic elements include sodium silicate and potassium silicate as water-soluble silicates. Examples of water-soluble zirconium salts include zirconium sulfate, zirconium nitrate, zirconium chloride, and zirconium oxychloride. Examples of water-soluble titanium salts include titanium tetrachloride and titanium sulfate. Examples of water-soluble tin salts include tin sulfate, tin nitrate, tin acetate, and tin oxychloride. Examples of water-soluble antimony salts include antimony chloride and antimony sulfate. As the neutralizing agent, the aforementioned acid or alkali can be used. After depositing the inorganic compound, the deposit is solid-liquid separated from the slurry. For solid-liquid separation, a filtering device such as a rotary press or a filer press, which is usually used industrially, can be used, and at that time, washing may be performed as necessary to remove soluble salts.

  In the production of the particles of the present invention, there may be a separate step of depositing a conductive material on the surface.

  The method for depositing the metal oxide as the conductive material is not particularly limited, but the conductive metal oxide precursor is deposited by the same method as that for depositing the inorganic compound described above, followed by firing. The conductive metal oxide can be deposited. At this time, the compound of the metal used as the oxide matrix and the compound of the element used as the dopant may be appropriately selected to adjust the composition. The state of deposition can be adjusted by neutralization conditions (temperature, time, pH) and firing conditions (temperature, time, firing atmosphere).

  Alternatively, in the presence of the base particles, the surface of the base particles is oxidized by heating a mixture containing a metal carboxylate and an alcohol, or a mixture containing a metal alkoxy group-containing compound and a carboxyl group-containing compound. A method of attaching an object (Japanese Patent Laid-Open No. 2004-99358) can be applied.

  The method for attaching the metal as the conductive material is not particularly limited. For example, the metal is attached to the surface of the low refractive index fine particles by causing a reducing agent to act on a solution containing a metal salt in the presence of base particles. Can be applied. At this time, a metal complexing agent can be used in combination.

  The method for attaching the carbon material as the conductive substance is not particularly limited. For example, after the carbon element-containing substance is attached to the base particles, the carbon-containing substance is carbonized by heating in an inert atmosphere, and the base A method of attaching a carbon material to the surface of the particle can be applied.

  On the other hand, as a method for depositing or coating the conductive polymer on the base particles, for example, JP-A-2-273407 for polypyrrole and JP-A-3-64369 for polyaniline can be referred to. However, it is not limited to these.

  Specifically, for example, base particles are added to a solvent composed of one or more of water, alcohol, and acetonitrile, and in the presence of a conductive polymer such as pyrrole, an oxidizing agent, and a dopant, -30 to 40 ° C. It can manufacture by stirring in the temperature range.

  Examples of the oxidizing agent include halogens such as chlorine, bromine and iodine, ferric chloride, boron trifluoride, arsenic pentafluoride, antimony pentafluoride, aluminum chloride and other metal halides, hydrogen peroxide, peracetic acid , Peroxides such as benzoyl peroxide, persulfuric acid and salts thereof, transition metal compounds, protonic acids, and the like, which can be used alone or in combination.

  In addition, as the dopant, a commonly used acceptor-type dopant can be used. Specifically, halogen anions such as chlorine, bromine, iodine and hydrogen chloride, halide anions such as hexafluoroline and hexafluoroarsenic, sulfonate anions such as alkylbenzene sulfonic acid, perchlorate anions such as potassium perchlorate, Examples thereof include sulfuric acid anions such as sulfuric acid, and these are used alone or in combination.

  As a method other than the above, the conductive material can be deposited on the surface of the base particle by mixing the base particle and the conductive material.

  In addition, when the particles after the production of the Al-coated template particles in the step 1 or the particles after the production of the AlF-coated template particles in the step 2 are used as the base particles, the subsequent steps may be performed subsequently. .

  Next, a third invention of the present invention is a composition containing at least the particles of the first invention and a dispersion medium. The concentration of the particles can be adjusted as appropriate, but specifically, it is preferably 1 to 50% by weight, more preferably 5 to 40% by weight, and still more preferably 10 to 30% by weight.

  The dispersion medium is not particularly limited, and various types can be used as appropriate. Specifically, monohydric alcohol solvents such as water, ethanol, propyl alcohol, isopropyl alcohol, butanol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, capryl alcohol, nonyl alcohol, decyl alcohol, phenol and benzyl alcohol. Petroleum hydrocarbons such as benzene, toluene, xylene, cyclohexane, ethylbenzene, and amylbenzene, and aromatic hydrocarbon solvents such as benzene, toluene, xylene, cyclohexane, ethylbenzene, and amylbenzene , Plant hydrocarbon solvents such as dipentene and turpentine oil, nitro hydrocarbon solvents such as nitroparaffin and nitrobenzene, acetone, methyl ethyl keto , Ketone solvents such as methyl isobutyl ketone, ethyl butyl ketone, diisobutyl ketone, halogenated hydrocarbon solvents such as methylene chloride, chloroform, carbon tetrachloride, perchlorethylene, monochlorobenzene, ethyl ether, isopropyl ether, butyl ether , Ether solvents such as hexyl ether, propylene oxide, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, methyl formate, ethyl formate, butyl formate, methyl acetate, ethyl acetate, butyl acetate, Esters such as amyl acetate, ethyl propionate, butyl propionate, isobutyl propionate, ethyl butyrate, butyl butyrate, methyl lactate, ethyl lactate, butyl lactate, amyl lactate, Lawer oil, soybean oil, evening primrose oil, grape seed oil, rosehip oil, cucumber nut oil, almond oil, sesame oil, wheat germ oil, corn oil, cottonseed oil, avocado oil, olive oil, camellia oil, persic oil, castor oil, peanut oil Oils such as hazelnut oil, macadamia nut oil, medofoam oil, cocoa butter, shea butter, tree wax, coconut oil, palm oil, palm kernel oil, beef tallow, horse fat, mink oil, milk fat, egg yolk oil, turtle oil, Liquid paraffin, liquid isoparaffin, squalane, squalene, petrolatum, paraffin, ceresin, microcrystalline wax and other hydrocarbon oils, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid, undecylenic acid, Fatty acids such as hydroxystearic acid, lanolin fatty acid, Higher alcohols such as myristyl alcohol, cetyl alcohol, cetostearyl alcohol, stearyl alcohol, aralkyl alcohol, behenyl alcohol, oleyl alcohol, jojoba alcohol, batyl alcohol, cholesterol, phytosterol, lanolin alcohol, isostearyl alcohol, isopropyl isostearate, ethyl oleate , Isopropyl myristate, isoisopropyl palmitate, cetyl octanoate, diisostearyl malate, glyceryl tricaprylate, isooctyl isononanoate, isononyl isononanoate, isotridecyl isononanoate, octyldodecyl neopentanoate, isotridecyl neopentanoate, myristyl neopentanoate, diisononane Propylene glycol acid, tri -Ester oils such as glyceryl ethylhexanoate, trimethylolpropane tri-2-ethylhexanoate, beeswax, candelilla wax, whale wax, cotton wax, carnauba wax, bayberry wax, nukarou, ibotarou, orange luffy oil, montan wax, sugarcane wax, shellac wax , Waxes such as lanolin, jojoba oil, methylpolysiloxane, methylphenylpolysiloxane, decamethylcyclotetrasiloxane, alkyl-modified silicone, alcohol-modified silicone, amino-modified silicone, epoxy-modified silicone, olefin-modified silicone, carboxyl-modified silicone, Carbinol modified silicone, phenol modified silicone, methacryl modified silicone, mercapto modified silicone, phosphoric acid modified silicone, fluorine modified Silicones such as silicone, higher fatty acid modified silicone, polyether modified silicone, perfluoropolyether, hydrofluoroether, perfluoromethylcyclopentane, perfluorodimethylcyclohexane, perfluorodimethylcyclobutane, methoxynonafluorobutane, ethoxynonafluorobutane Fluorine oils such as dodecafluoropentane, tetradecafluorohexane, perfluorodecane, perfluorooctane, 4-trifluoromethylperfluoromorpholine, 4-pentafluoroethylperfluoromorpholine, paraaminobenzoic acid, paraamino as UV absorber Benzoic acid monoglycerin ester, N, N-dimethylparaaminobenzoic acid ethyl ester, N, N-diethoxyparaaminobenzoic acid Benzoic acids such as ethyl ester, N, N-dipropoxyparaaminobenzoic acid ethyl ester, anthranilic acids such as homomenthyl-N-acetylanthranylate, amyl salicylate, menthyl salicylate, homomenthyl salicylate, octyl salicylate, phenyl salicylate, benzyl salicylate Salicylic acids such as octylcinnamate, ethyl-4-isopropylcinnamate, methyl-2,5-diisopropylcinnamate, ethyl-2,4-diisopropylcinnamate, propyl-p-methoxycinnamate, isopropyl-p-methoxy Cinnamate, isoamyl-p-methoxycinnamate, octyl-p-methoxycinnamate, 2-ethoxyethyl-p-methoxycinnamate, cyclohexyl-p-methoxy Cinnamic acids such as cinnamate, 2,4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4 -Benzophenones such as phenylbenzophenone and 4-hydroxy-3-carboxybenzophenone, 3-benzylidene-d, l-camphor, urocanic acid, urocanic acid ethyl ester, 2-phenyl-5-methylbenzoxazole, dibenzalazine, dianisoyl Examples thereof include methane, 4-tert-butyl-4′-methoxydibenzoylmethane, a silicone-modified ultraviolet absorber, a fluorine-modified ultraviolet absorber. Of these, one or more can be used as the lipophilic solvent in the present invention.

  In addition, pigment dispersions, oils, surfactants, ultraviolet absorbers, preservatives, antioxidants, film forming agents, humectants, thickeners, dyes, pigments, fragrances and the like are appropriately added to the dispersion of the present invention. Can be blended. For example, alkyl ether sulfates such as POE lauryl sulfate triethanolamine, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, higher alkyl sulfates such as sodium lauryl sulfate and potassium lauryl sulfate, N-acyl sarcosine acid, N- Higher fatty acid amide sulfonates such as sodium myristoyl-N-methyltaurine, higher fatty acid ester sulfates such as hydrogenated coconut oil fatty acid sodium glycerol sulfate, higher fatty acid ester sulfonates, higher fatty acid alkylolamide sulfates, fatty acid soaps , Sulfosuccinate, secondary alcohol sulfate, POE alkyl ether carboxylic acid, POE alkyl allyl ether carboxylate, α-olefin sulfonate, lauroyl mono Anionic surfactants such as sodium tanolamide succinate, N-palmitoyl aspartate diethanolamine, sodium caseinate, alkyltrimethylammonium salts such as stearyltrimethylammonium chloride, alkylpyridinium salts such as distearyldimethylammonium dialkyldimethylammonium chloride, alkyl Quaternary ammonium salt, alkylamine salt, alkyldimethylbenzylammonium salt, alkylisoquinolinium salt, dialkyl morpholinium salt, POE alkylamine, polyamine fatty acid derivative, amyl alcohol fatty acid derivative, benzalkonium chloride, benzethonium chloride, etc. Cationic surfactant, 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium Imidazoline-based amphoteric surfactants such as salts, betaine-based amphoteric surfactants such as alkylbetaine, amidebetaine, and lauryldimethylaminoacetic acid betaine, glycerin fatty acid esters such as glyceryl sesquioleate and glyceryl monostearate, hexaglyceryl polyricinoleate Polyglycerin fatty acid esters such as diglyceryl monostearate and decaglyceryl dekaoleate, sorbitan fatty acid esters such as sorbitan monooleate and sorbitan sesquioleate, propylene glycol fatty acid esters such as propylene glycol monostearate, POE sorbitan monooleate, etc. POE glycerin fatty acid ester such as POE sorbitan fatty acid ester, POE glycerin triisostearate, POE monooleate, POE dis POE fatty acid esters such as allate, POE alkyl ethers such as POE lauryl ether and POE stearyl ether, POE POP alkyl ethers such as POE / POP hydrogenated lanolin, hydrogenated castor oil derivatives, glycerin alkyl ethers, alkanolamides, sucrose fatty acid esters Dextrin fatty acid esters, starch fatty acid esters, nonionic surfactants such as hydroxystearic acid, phospholipids such as lecithin, glycolipids such as trehalose lipid, perfluoroalkyl phosphate, perfluoroalkyl sulfonate, Fluorine surfactants such as fluoroalkyl carboxylates, etc., alkyl methacrylate methacrylate copolymers, natural or synthetic clay minerals such as bentonite, smectite and kaolin, organic amine cuticles Organically-modified clay minerals such as down-modified bentonite, can be exemplified aerosol or the like. Specific products include DISPERBYK-140, DISPERBYK-145, DISPERBYK-182, DISPERBYK-191, DISPERBYK-2025, DISPERBYK-2150, DISPERBYK-2163, DISPERBYK-2164, BYK-9076, BYK-9076, BYK-9076 For example).

  Next, a fourth invention of the present invention is an antireflection film containing at least the particles of the first invention. Since the particles of the present invention have a low refractive index, a coating film formed using this as a filler can realize excellent antireflection performance.

  Next, the antireflection film of the present invention will be described. The antireflection film is formed on the substrate. Examples of the substrate include substrates such as glass, polycarbonate, acrylic resin, PET, TAC and other plastic sheets, plastic films, plastic lenses, plastic panels, and the like, cathode ray tubes, fluorescent display tubes, liquid crystal display plates, and the like. . The film is formed on the surface of the base material. Depending on the application, the film may be a single film or a protective film, a hard coat film, a planarizing film, a high refractive index film, an insulating film, a conductive film on the base material. It is formed in combination with a resin film, a conductive metal fine particle film, a conductive metal oxide fine particle film, or a primer film used as necessary. When used in combination, the coating of the present invention is not necessarily formed on the outermost surface. Such a film can be obtained by applying a coating solution described later to a substrate by a known method such as a dipping method, a spray method, a spinner method, a roll coating method, drying, and further firing if necessary. it can.

  The coating solution is a mixed solution of the composition (sol) of the third invention of the present invention and a film-forming matrix, and an organic solvent and other compounds may be mixed as necessary. The matrix for forming a film refers to a component that can form a film on the surface of a substrate, and can be selected and used from a resin that meets conditions such as adhesion to the substrate, hardness, and coating properties, For example, conventionally used polyester resin, acrylic resin, urethane resin, vinyl chloride resin, epoxy resin, melamine resin, fluorine resin, silicon resin, butyral resin, phenol resin, vinyl acetate resin, UV curable resin, electron beam curing Resins, emulsion resins, water-soluble resins, hydrophilic resins, mixtures of these resins, coating resins such as copolymers and modified products of these resins, hydrolyzable organosilicon compounds such as alkoxysilanes, etc. Can be mentioned.

  When a coating resin is used as the matrix, for example, an organic solvent-dispersed sol in which water as a dispersion medium of the sol is replaced with an organic solvent such as alcohol, preferably has a void inside the first invention of the present invention. Particles can be used, and if necessary, after treating the particles with a known coupling agent, the organic solvent dispersion sol dispersed in an organic solvent and the coating resin are diluted with a suitable organic solvent and applied. It can be liquid.

  On the other hand, when using a hydrolyzable organosilicon compound as a matrix, for example, by adding water or an acid or alkali as a catalyst to a mixture of alkoxysilane and alcohol, a partially hydrolyzed product of alkoxysilane is obtained, The sol can be mixed with this and diluted with an organic solvent as necessary to obtain a coating solution. When a hydrolyzable organosilicon compound is used as the matrix, if the hydrolyzate has a large molecular weight or particle size, the strength of the resulting coating or the adhesion to the substrate may decrease. A hydrolyzate having a small particle size is used.

  The weight ratio between the particles and the matrix in the coating solution is preferably in the range of particles / matrix = 1/99 to 9/1. If the weight ratio exceeds 9/1, the strength of the coating is insufficient and lacks practicality, whereas if it is less than 1/99, the effect of adding the particles does not appear. The refractive index of the coating film formed on the surface of the substrate is 1.10 to 1.42 but a low refractive index, although it varies depending on the mixing ratio of particles and matrix components and the refractive index of the matrix used. In the particles of the present invention, even when the dispersion medium enters the cavity, the dispersion medium is detached and becomes voids when the film is dried, and the film-forming component such as resin remains in the outer shell, and after the resin is cured, This is because the pores are blocked and the cavities inside the particles are retained.

  Further, when the refractive index of the base material is 1.60 or less, a film having a refractive index of 1.60 or more (hereinafter referred to as an intermediate film) is formed on the surface of the base material, and It is recommended to form a film containing particles. When the refractive index of the intermediate coating is 1.60 or more, a film having a large difference from the refractive index of the coating containing the particles of the present invention and excellent antireflection performance can be obtained. The refractive index of the intermediate coating can be adjusted by the type of metal oxide fine particles used, the mixing ratio of metal oxide and resin, and the refractive index of the resin used. The coating solution for forming an intermediate coating is a mixed solution of metal oxide particles and a matrix for forming a coating, and an organic solvent is mixed as necessary. As the film forming matrix, the same film as the film containing the particles of the present invention can be used. By using the same film forming matrix, a film having excellent adhesion between the two films can be obtained.

Example 1
(Step 1) Zinc oxide particles (FZO-50, average particle size 20 nm, manufactured by Ishihara Sangyo Co., Ltd.) as template particles were suspended in pure water at a concentration of 120 g / liter to obtain a suspension.
Next, 120 g of the suspension, an aqueous sodium silicate solution as a dispersant, 5 wt% in terms of SiO _{2 with} respect to zinc oxide, and 130 g of zircon beads (0.5 mm in diameter) are placed in a 225 ml glass container. Disperse with a paint shaker for a period of time to make a slurry.
From the slurry, a slurry equivalent to 5 g as zinc oxide was separated, and pure water was added to adjust the total volume to 500 ml, to obtain a zinc oxide dispersion (zinc oxide equivalent concentration 10 g / liter).
While stirring this zinc oxide dispersion, 1 L of a sodium aluminate aqueous solution (aluminum oxide equivalent concentration 5 g / liter) as an aluminum raw material was mixed for 30 minutes to prepare a mixed solution. The pH at this time was 11.5.
After adjusting the temperature of the mixture to 70 ° C., a 2.5% aqueous sulfuric acid solution was added dropwise over 3 hours to adjust the pH of the mixture to 7. At this time, the dropping rate of sulfuric acid (gram equivalent) with respect to 1 mol of aluminum oxide was 1.2.
(Step 2) After pH adjustment, 500 ml of an aqueous ammonium fluoride solution was mixed with the mixed solution over 1 hour so that F / Al = 6 (molar ratio), and then aged for 1 hour.
(Step 3) After aging, a 10% aqueous citric acid solution was added while stirring the mixed solution to adjust the pH to 3. Stirring was stopped and the supernatant after spontaneous sedimentation was replaced with pure water for washing to obtain a dispersion (sample A) in which the hexafluoroaluminate compound was suspended. In the physical property evaluation to be described later, for those using dry powder, the solid content in the dispersion was collected by sedimentation with a centrifuge and dried at 120 ° C.

Example 2
Sample B was obtained in the same manner as in Example 1 except that a 20% aqueous citric acid solution was used as the citric acid to be added in Step 3.

Example 3
Sample C was obtained in the same manner as in Example 1 except that a 50% aqueous citric acid solution was used as the citric acid to be added in Step 3.

Example 4
In Step 1, 500 milliliters of zinc oxide dispersion having a zinc oxide equivalent concentration of 40 g / liter was used as the zinc oxide dispersion, and a sodium aluminate aqueous solution having an aluminum oxide equivalent concentration of 20 g / liter was used as the sodium aluminate aqueous solution. Sample D was obtained in the same manner as in Example 1 except that.

Example 5
Sample E was obtained in the same manner as in Example 4 except that a 50% aqueous citric acid solution was used as the citric acid added in Step 3.

Example 6
In Step 2, Sample F was obtained in the same manner as in Example 5 except that the concentration of the sulfuric acid aqueous solution to be dropped was 10%.

Comparative Example 1
An aqueous solution obtained by adding sodium silicate equivalent to 0.25 g as SiO _{2 to} 500 g of pure water is mixed with 1 L of an aqueous solution of sodium aluminate (aluminum oxide equivalent concentration 5 g / liter) as an aluminum raw material for 30 minutes to prepare a mixed solution. did.
After adjusting the temperature of the mixture to 70 ° C., a 2.5% aqueous sulfuric acid solution was added dropwise over 3 hours to adjust the pH of the mixture to 7. At this time, the dropping rate of sulfuric acid (gram equivalent) with respect to 1 mol of aluminum oxide was 1.2 (mol / hour).
After adjusting the pH, 500 ml of an aqueous ammonium fluoride solution was mixed with the mixed solution over 1 hour so that F / Al = 6 (molar ratio), and then aged for 1 hour.
After aging, the pH of the mixture was adjusted to 3 by adding 10% aqueous citric acid while stirring the mixture. Stirring was stopped and the supernatant after spontaneous sedimentation was replaced with pure water to perform washing, and a dispersion (sample G) in which the hexafluoroaluminate compound was suspended was obtained.

Evaluation 1
As a result of observation of a transmission electron microscope (H-7000, manufactured by Hitachi, Ltd.) for Samples A to G, particles A to F of Examples 1 to 6 were confirmed to have hollow structure particles. A transmission electron microscope image of Sample A is shown in FIG. On the other hand, Sample G was a solid particle. A transmission electron microscope image of Sample G is shown in FIG. The average values of the major axis, the outer shell thickness, and the porosity of the sample A particles were 27 nm, 3.2 nm, and 44.3%, respectively. It can be seen that the refractive index estimated from the porosity is 1.19, which is lower than the refractive index of sample G, 1.34.

Evaluation 2
As a result of performing powder X-ray diffraction measurement (Ultima IV, manufactured by Rigaku Corporation) for samples A to G, all of samples A to G show a diffraction pattern that matches Na ₃ AlF ₆ (PDF No. 74-4463). It was confirmed. The powder X-ray diffraction pattern of Sample A is shown in FIG.

Evaluation 3
As a result of component analysis by fluorescent X-ray (RIX-2100, manufactured by Rigaku Corporation) for sample A, the composition of sample A is Al ₂ O ₃ : 48%, Na ₂ O: 50%, ZnO: 0.7% , SO ₄ : 0.8%, almost all of the zinc oxide as template particles was removed, and it was found that the substance was composed of aluminum and sodium.

  From these evaluation results, it was confirmed that Samples A to F are hollow particles made of a fluoroaluminate compound and have a low refractive index.

The particles of the present invention exhibit an excellent low refractive index. For this reason, the antireflection film using this as a filler can be further reduced in reflection. The composition of the present invention is suitable for producing such an antireflection film.
The particles of the present invention can be suitably used for an antireflection film provided on a substrate such as an optical material such as a lens, an image display surface such as a liquid crystal display, a plate glass such as a window or a showcase, or a transparent plastic.

Claims (17)

Particles containing at least a fluoroaluminate compound and having voids inside. The particle according to claim 1, wherein the fluoroaluminate compound contains at least an alkali metal and / or an ammonium ion. The particle according to claim 1, which is a hollow particle having a cavity formed therein. In powder X-ray diffraction measurement, at least 2θ = 46.8 ± 1.0, 32.7 ± 1.0, 23.0 ± 1.0, 38.6 ± 1.0 (unit is degree) The particle | grains in any one of Claims 1-3 which have a peak in. The particle | grains in any one of Claims 1-4 whose ratio of the space | gap in the volume of the said particle | grain is 20 to 95%. The particle according to claim 1, wherein a particle diameter of the particle is 10 nm to 200 nm. The particle | grains in any one of Claims 1-6 which have an organic compound and / or an inorganic compound on the surface. The particle according to any one of claims 1 to 7, having a conductive substance on the surface. A step (step 1) in which template particles and an aluminum raw material are allowed to coexist and an aluminum compound is present on the surface of template particles
A step of coexisting with a fluorine raw material to convert the aluminum compound into a fluoroaluminate compound (step 2);
Step of removing template particles (Step 3)
A method for producing particles having at least a fluoroaluminate compound and having voids therein. A step of mixing a dispersion of template particles and an aluminum raw material so that an aluminum compound is present on the surface of the template particles (step 1);
A step of mixing the fluorine raw material with the dispersion of Step 1 to convert the aluminum compound into a fluoroaluminate compound (Step 2);
Step of removing template particles (Step 3)
The manufacturing method of Claim 9 which has these. The manufacturing method according to claim 10, wherein the step 1 and the step 2 are performed in one step, in which an aluminum raw material and a fluorine raw material are mixed in a dispersion of template particles, and a fluoroaluminate compound is present on the surface of the template particles. Step 1 is
The manufacturing method according to any one of claims 9 to 11, wherein the pH of a mixed solution containing at least template particles and an aluminum raw material is set to 6 to 11. While adjusting the pH by mixing the liquid mixture with an acidic compound or a basic compound,
Addition rate in grams equivalent standard of acidic compound or basic compound is not more than 3.6 mol / hr with respect to Al 2 _O 3 ₁ mol when converted the aluminum compound amount in Al ₂ O _3, The manufacturing method according to claim 12. The template particles are zinc oxide particles;
The manufacturing method according to claim 9, wherein in step 3, removal of zinc oxide particles as template particles is performed with an acidic aqueous solution having a pH of 2 to 4. The manufacturing method according to claim 9, wherein sodium aluminate is used as the aluminum raw material in step 1 and ammonium fluoride is used as the fluorine raw material in step 2. A composition comprising at least the particles according to claim 1 and a solvent. An antireflection film containing the particles according to claim 1.

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