Antifungal emulsion coating, antifungal fine particle dispersion, and article provided with antifungal fine particle dispersion

Abstract

Provided are an antifungal emulsion coating and an antifungal fine particle dispersion that exhibit an excellent long-term antifungal effect even when exposed to moist hot environments. This antifungal emulsion coating comprises a resin emulsion and composite tungsten oxide fine particles (surface-treated composite tungsten oxide fine particles) having a surface coated with a coating film that contains at least one selection from hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of metal cyclic oligomer compounds, and polymers of hydrolysis products of metal cyclic oligomer compounds. The surface-treated composite tungsten oxide fine particles maintain excellent photothermal conversion characteristics even when exposed to moist hot environments, and due to this the antifungal emulsion coating comprising a resin emulsion and the surface-treated composite tungsten oxide fine particles has the ability to exhibit excellent antifungal effects on a long-term basis.

Description

Antifungal emulsion paint, antifungal microparticle dispersion, and article with antifungal microparticle dispersion

[0001] The present invention relates to an anti-fungal emulsion paint containing composite tungsten oxide microparticles having photothermal conversion properties and a resin emulsion, and in particular to an anti-fungal emulsion paint, an anti-fungal microparticle dispersion, and an article containing the anti-fungal microparticle dispersion, which exhibit excellent anti-fungal effects for a long period of time when a coating film formed using the paint is exposed to a humid and hot environment.

[0002] Mold and other microorganisms are more likely to grow in warm and humid environments, and they attach to and grow on the walls of buildings, which not only ruins the aesthetic appearance of buildings but also poses a problem in terms of environmental hygiene.

[0003] Under these circumstances, antifungal emulsion paints containing organic or inorganic antifungal agents have been proposed.

[0004] For example, Patent Document 1 proposes a paint that inhibits deterioration of the organic antibacterial agent and enhances durability by dissolving silicon dioxide, a silane coupling agent, the organic antibacterial agent 2-(4-thiazolyl)benzimidazole and 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine, and methylmethoxysiloxane in isopropyl alcohol or the like.

[0005] Furthermore, Patent Document 2 proposes an inorganic, transparent, antibacterial and antifungal emulsion paint in which an inorganic component selected from a mixture or compound of a silver salt and a phosphate, or a silver salt, a phosphate and a calcium salt, or a silver salt, a phosphate, a calcium salt and a fluoride, is heated and melted together with a silicate glass component, and the resulting glass mass is cooled to obtain a glass mass, which is then pulverized to form a powder, which is then mixed and dispersed in a transparent paint component.

[0006] However, the paint according to Patent Document 1, which uses an organic antibacterial agent such as 2-(4-thiazolyl)benzimidazole, and the transparent antibacterial and antifungal emulsion paint according to Patent Document 2, which uses the inorganic component, have problems with durability when exposed to a humid and hot environment, and there is room for further improvement.

[0007] JP 2002-235017 A JP 7-62272 A Patent No. 6769562

[0008] The present invention was made in response to the problems with the paints disclosed in Patent Documents 1 and 2, which have poor durability, and aims to provide an anti-mold emulsion paint, an anti-mold microparticle dispersion, and an article containing the anti-mold microparticle dispersion, which exhibit excellent anti-mold effects even when exposed to a humid and hot environment.

[0009] In order to solve the above problems, the present inventors investigated antifungal materials to replace the antibacterial and antifungal agents of Patent Documents 1 and 2, which have poor durability. As a result, they found composite tungsten oxide microparticles that have photothermal conversion properties (generating heat upon absorbing infrared light). They also continued to research configurations that improve the moist heat resistance and chemical stability of composite tungsten oxide microparticles. As a result, they came to the conclusion that it is essential to coat the surface of each composite tungsten oxide microparticle with a compound that has excellent affinity with the surface of the composite tungsten oxide microparticles and that adsorbs uniformly to the surface of each composite tungsten oxide microparticle to form a strong coating film.

[0010] The inventors continued their research and discovered that metal chelate compounds and cyclic metal oligomer compounds are compounds that have excellent affinity for composite tungsten oxide microparticles and that adsorb uniformly onto the surface of each composite tungsten oxide microparticle to form a strong coating film. As a result of further research, they discovered that the hydrolysis products of these compounds, or polymers of the hydrolysis products, that are produced when the metal chelate compounds and cyclic metal oligomer compounds are hydrolyzed are the compounds that adsorb uniformly onto the surface of each composite tungsten oxide microparticle to form a strong coating film.

[0011] Specifically, the inventors discovered a configuration of composite tungsten oxide microparticles (hereinafter sometimes referred to as "surface-treated composite tungsten oxide microparticles") whose surfaces are coated with a coating film containing one or more selected from the group consisting of hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of cyclic metal oligomer compounds, and polymers of hydrolysis products of cyclic metal oligomer compounds. They also discovered that the surface-treated composite tungsten oxide microparticles maintain excellent light-to-heat conversion properties even when exposed to a humid and hot environment, and that by preparing an anti-fungal emulsion paint using the surface-treated composite tungsten oxide microparticles and a resin emulsion, a coating film formed by applying the paint to a substrate maintains excellent light-to-heat conversion properties even when exposed to a humid and hot environment (i.e., maintains anti-fungal effects for a long period of time).

[0012] The applicant has already obtained a patent for surface-treated infrared-absorbing microparticles of tungsten oxide or the like, the surfaces of which are coated with a coating film containing one or more selected from the group consisting of hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of metal cyclic oligomer compounds, and polymers of hydrolysis products of metal cyclic oligomer compounds (see Patent Document 3). However, the present invention was completed upon the discovery of a new use (anti-fungal emulsion paint) for the patented surface-treated infrared-absorbing microparticles.

[0013] That is, the first invention according to the present invention is an anti-fungal emulsion paint characterized in that it contains composite tungsten oxide microparticles whose surfaces are coated with a coating film containing one or more selected from the group consisting of hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of cyclic metal oligomer compounds, and polymers of hydrolysis products of cyclic metal oligomer compounds, and a resin emulsion.

[0014] The second invention according to the present invention is the anti-fungal emulsion paint according to the first invention, characterized in that the coating film has a thickness of 0.5 nm or more. The third invention is the anti-fungal emulsion paint according to the first or second invention, characterized in that the metal chelate compound or the cyclic metal oligomer compound contains one or more metal elements selected from Al, Zr, Ti, Si and Zn. The fourth invention is the anti-fungal emulsion paint according to any of the first to third inventions, characterized in that the metal chelate compound or the cyclic metal oligomer compound has one or more groups selected from an ether bond, an ester bond, an alkoxy group and an acetyl group.

[0015] Next, the fifth invention according to the present invention is the mildew-proofing emulsion paint according to any one of the first to fourth inventions, The composite tungsten oxide fine particles are characterized by being expressed by the general formula MxWyOz (wherein M is one or more elements selected from H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb; W is tungsten; O is oxygen; and 0.001≦x / y≦1, 2.0≦z / y<4.0). A sixth invention is the mildew-proof emulsion paint according to the fifth invention, characterized in that: The seventh invention is characterized in that M of the composite tungsten oxide microparticles expressed by the general formula MxWyOz is one or more elements selected from Cs, K, Rb, Tl, In, and Ba. The seventh invention is the anti-fungal emulsion paint according to the fifth or sixth invention, characterized in that x / y of the composite tungsten oxide microparticles expressed by the general formula MxWyOz satisfies the relationship 0.25≦x / y≦0.35. The eighth invention is the anti-fungal emulsion paint according to any of the first to seventh inventions, characterized in that the composite tungsten oxide microparticles have a hexagonal crystal structure. The ninth invention is the anti-fungal emulsion paint according to any of the first to eighth inventions, characterized in that the average particle size of the composite tungsten oxide microparticles is 10 nm to 200 nm.

[0016] A tenth aspect of the present invention is an anti-fungal microparticle dispersion, characterized in that the dispersion is formed by applying the anti-fungal emulsion paint according to the first aspect, and is composed of composite tungsten oxide microparticles whose surfaces are coated with a coating film containing one or more selected from hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of cyclic metal oligomer compounds, and polymers of hydrolysis products of cyclic metal oligomer compounds, and a solid resin in which the composite tungsten oxide microparticles are dispersed. An eleventh aspect of the present invention is the anti-fungal microparticle dispersion according to the tenth aspect, characterized in that the dispersion is composed of: The composite tungsten oxide microparticles are characterized by being expressed by the general formula MxWyOz (wherein M is one or more elements selected from H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb; W is tungsten; O is oxygen; and 0.001≦x / y≦1, 2.0≦z / y<4.0). A twelfth invention is an antifungal microparticle dispersion according to the eleventh invention, characterized in that: The thirteenth invention is characterized in that, in the anti-fungal microparticle dispersion according to the eleventh or twelfth invention, M of the composite tungsten oxide microparticles represented by the general formula MxWyOz is one or more elements selected from Cs, K, Rb, Tl, In, and Ba. The thirteenth invention is characterized in that, in the anti-fungal microparticle dispersion according to the eleventh or twelfth invention, x / y of the composite tungsten oxide microparticles represented by the general formula MxWyOz satisfies the relationship 0.25≦x / y≦0.35. The fourteenth invention is characterized in that, in the anti-fungal microparticle dispersion according to any of the tenth to thirteenth inventions, the composite tungsten oxide microparticles have a hexagonal crystal structure. The fifteenth invention is characterized in that, in the anti-fungal microparticle dispersion according to any of the tenth to fourteenth inventions, the average particle size of the composite tungsten oxide microparticles is 10 nm to 200 nm.

[0017] Furthermore, a sixteenth aspect of the present invention is an article with an antifungal microparticle dispersion, characterized in that the antifungal microparticle dispersion according to any one of the tenth to fifteenth aspects is formed on a substrate selected from glass, plastic, and metal.

[0018] The antifungal emulsion paint of the present invention contains composite tungsten oxide microparticles (surface-treated composite tungsten oxide microparticles) whose surfaces are coated with a coating film containing one or more selected from the group consisting of hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of cyclic metal oligomer compounds, and polymers of hydrolysis products of cyclic metal oligomer compounds, and a resin emulsion, and the surface-treated composite tungsten oxide microparticles maintain excellent light-to-heat conversion properties even when exposed to a humid and hot environment.

[0019] Therefore, even if a coating film formed by applying the antifungal emulsion paint of the present invention to a substrate is exposed to a humid and hot environment, the coating film maintains its excellent light-to-heat conversion properties (antifungal effect), thereby enabling the antifungal effect of the antifungal emulsion paint to be exerted for a long period of time.

[0020] 1 is a plan view schematically showing the crystal structure of a composite tungsten oxide having a hexagonal crystal structure. 2 is a transmission electron microscope photograph of surface-treated composite tungsten oxide particles at 300,000 magnifications according to Example 1. 3 is a diagram illustrating the configuration of a high-frequency plasma reaction device used in Example 5.

[0021] Hereinafter, embodiments of the present invention will be described in detail.

[0022] First, the anti-fungal emulsion paint according to the present invention containing surface-treated composite tungsten oxide microparticles will be described in the following order: [1] composite tungsten oxide microparticles; [2] surface treatment agent for composite tungsten oxide microparticles; [3] method for surface coating of composite tungsten oxide microparticles; and [4] anti-fungal emulsion paint, anti-fungal microparticle dispersion, and article with anti-fungal microparticle dispersion.

[0023] In addition, the above-mentioned "coating film" of composite tungsten oxide microparticles whose surfaces are coated with "a coating film containing one or more selected from the group consisting of hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of metal cyclic oligomer compounds, and polymers of hydrolysis products of metal cyclic oligomer compounds" may be abbreviated as simply "coating film" in this specification.

[0024] [1] Composite tungsten oxide microparticles The composite tungsten oxide microparticles whose surfaces are coated with the above-mentioned "coating film" are represented by the general formula MxWyOz (wherein M is one or more elements selected from H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb; W is tungsten; O is oxygen; and 0.001≦x / y≦1, 2.0≦z / y<4.0).

[0025] It is generally known that materials containing free electrons exhibit an absorption / reflection response to electromagnetic waves in the region around the wavelength of 200 nm to 2600 nm of sunlight due to plasma oscillation.

[0026] When such a material is made into fine particles of 800 nm or less, the electronic state of the surface of the fine particles can significantly absorb light in this range and convert the light into heat. The composite tungsten oxide fine particles absorb light and convert it into heat, generating heat and functioning as antifungal fine particles.

[0027] Here, in explaining the absorption of sunlight by composite tungsten oxide particles, the absorption of sunlight by tungsten oxide particles (WO3) will be explained.

[0028] Generally, tungsten oxide (WO3) does not have effective free electrons, so it has little absorption and reflection characteristics in the infrared region, and is not effective as infrared absorbing microparticles.However, it is known that by using WO3 with oxygen deficiency or a composite tungsten oxide that is made by adding an electropositive element such as Na to WO3, free electrons are generated in tungsten oxide or composite tungsten oxide, and the absorption characteristics derived from free electrons are exhibited in the infrared region.The analysis of the single crystals of these materials with free electrons has suggested the response of free electrons to light in the infrared region.

[0029] Hereinafter, the tungsten oxide microparticles and composite tungsten oxide microparticles, which are specific examples of the "infrared absorbing microparticles" described in Patent Document 3, will be described in the following order: (1) tungsten oxide microparticles, (2) composite tungsten oxide microparticles, (3) particle diameter of the composite tungsten oxide microparticles, and (4) method for producing the composite tungsten oxide microparticles.

[0030] (1) Tungsten Oxide Fine Particles The tungsten oxide fine particles described in Patent Document 3 are expressed by the general formula WyOz (where W is tungsten, O is oxygen, and 2.2≦z / y≦2.999).

[0031] In tungsten oxide represented by the general formula WyOz, the composition range of tungsten and oxygen is preferably such that the composition ratio of oxygen to tungsten is less than 3, and further, when the infrared absorbing nanoparticles are described as WyOz, it is preferable that 2.2≦z / y≦2.999. If the value of z / y is 2.2 or more, it is possible to prevent the appearance of unintended WO2 crystalline phase in the tungsten oxide, and it is possible to obtain chemical stability as a material, so that it becomes an effective infrared absorbing nanoparticle. On the other hand, if the value of z / y is 2.999 or less, the required amount of free electrons is generated, and it becomes an efficient infrared absorbing nanoparticle.

[0032] (2) Composite Tungsten Oxide Fine Particles Composite tungsten oxide is obtained by adding an element M, which will be described later, to the above-mentioned tungsten oxide (WO3).

[0033] Furthermore, by combining the control of the oxygen content with the addition of element M, which generates free electrons, to the WO3, more efficient infrared absorbing particles can be obtained. By adopting this configuration, free electrons are generated in the composite tungsten oxide, and strong absorption characteristics resulting from the free electrons are exhibited particularly in the near-infrared region, making the WO3 effective as near-infrared absorbing particles for wavelengths around 1000 nm.

[0034] When the general formula of the composite tungsten oxide microparticles, which combines the control of the oxygen amount with the addition of the element M that generates free electrons, is expressed as MxWyOz (where M is the above-mentioned M element, W is tungsten, and O is oxygen), it is desirable to satisfy the relationships 0.001≦x / y≦1 and 2.0≦z / y<4.0.

[0035] Here, the element M in the composite tungsten oxide microparticles is preferably one or more selected from H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb.

[0036] Furthermore, from the viewpoint of stability in the MxWyOz to which the element M is added, the element M is more preferably one or more elements selected from alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, and Re; and from the viewpoint of improving the optical properties and weather resistance of the composite tungsten oxide microparticles, it is even more preferable that the element M is an alkaline earth metal element, transition metal element, Group 4B element, or Group 5B element.

[0037] Regarding the value of x / y, which indicates the amount of element M added, if the value of x / y is greater than 0.001, a sufficient amount of free electrons is generated in the composite tungsten oxide, and the desired infrared absorption effect can be obtained.The larger the amount of element M added, the greater the supply of free electrons and the higher the infrared absorption efficiency, but when the value of x / y is about 1, this effect also saturates.Furthermore, if the value of x / y is less than 1, it is preferable because it is possible to avoid the generation of impurity phases in the composite tungsten oxide microparticles.

[0038] Furthermore, with regard to the value of z / y, which indicates the control of the oxygen content, in the composite tungsten oxide expressed as MxWyOz, the same mechanism as that of the tungsten oxide expressed as WyOz described above works, and in addition, even when z / y = 3.0 or 2.0≦z / y≦2.2, there is a supply of free electrons due to the amount of element M added. Therefore, 2.0≦z / y<4.0 is preferable, 2.2≦z / y<3.7 is more preferable, and 2.45≦z / y≦3.5 is even more preferable.

[0039] Furthermore, when the composite tungsten oxide microparticles have a hexagonal crystal structure, the microparticles have improved transmittance in the visible light region and improved absorption in the infrared region. This hexagonal crystal structure will be described with reference to FIG. 1, which is a plan view showing the structure.

[0040] In FIG. 1, six octahedra formed of WO units indicated by the reference symbol 1 are assembled to form a hexagonal void, and an element M indicated by the reference symbol 2 is arranged in the void to form one unit, and a large number of these units are assembled to form a hexagonal crystal structure.

[0041] In order to obtain the effects of improving light transmission in the visible light region and improving light absorption in the infrared region, it is sufficient that the composite tungsten oxide microparticles contain the unit structure described with reference to FIG. 1, and the composite tungsten oxide microparticles may be crystalline or amorphous.

[0042] When cations of element M are added to and present in these hexagonal voids, light transmission in the visible light region is improved and light absorption in the infrared region is improved. Generally, the hexagonal crystal is easily formed when an element M having a large ionic radius is added. Specifically, the hexagonal crystal is easily formed when one or more elements selected from Cs, K, Rb, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn are added, more preferably when one or more elements selected from Cs, K, Rb, Tl, In, and Ba are added.

[0043] A typical example is Cs 0.33 WOz, Cs 0.03 Rb 0.30 WOz, Rb 0.33 WOz, K 0.33 WOz, Ba 0.33 Preferred examples include WOz (2.0≦z≦3.0), etc. Of course, elements other than these may also be used as long as the above-mentioned element M is present in the hexagonal gaps formed by the WO units, and the present invention is not limited to the above-mentioned elements.

[0044] When the composite tungsten oxide microparticles having a hexagonal crystal structure have a uniform crystal structure, the amount of the added element M is preferably 0.2 or more and 0.5 or less, more preferably 0.20 or more and 0.37 or less, and even more preferably 0.25 or more and 0.35 or less, in terms of the value of x / y.Theoretically, when the value of x / y is 0.33, it is considered that the above-mentioned element M is arranged in all of the hexagonal voids.As mentioned above, when the value of x / y is close to 0.33, a hexagonal crystal structure can be formed.

[0045] In addition, tetragonal and cubic composite tungsten oxides other than hexagonal are also effective as infrared-absorbing microparticles. The absorption position in the infrared region tends to change depending on the crystal structure, with the absorption position tending to shift to longer wavelengths in the order cubic < tetragonal < hexagonal. Additionally, the order of lowest absorption in the visible light region is hexagonal, tetragonal, and cubic. However, there are cases where antifungal emulsion paints do not want to color the surface to which they are applied, and they are required to be transparent to visible light. For this reason, it is preferable to use hexagonal composite tungsten oxide for the antifungal emulsion paint of the present invention, which transmits more light in the visible region and absorbs more light in the infrared region.

[0046] (3) Particle Diameter of Composite Tungsten Oxide Microparticles Composite tungsten oxide microparticles largely absorb light in the near-infrared region, particularly in the vicinity of 1000 nm wavelength, and therefore the transmitted color tone is often blue to green.

[0047] The composite tungsten oxide microparticles used in the present invention preferably have a particle diameter of 1 nm or more and 800 nm or less, more preferably 200 nm or less. From the viewpoint of exhibiting better infrared absorption properties, the particle diameter of the composite tungsten oxide microparticles is preferably 10 nm or more and 100 nm or less, more preferably 10 nm or more and 80 nm or less, and most preferably 10 nm or more and 60 nm or less. It has been found that the most excellent infrared absorption properties are exhibited when the particle diameter is in the range of 10 nm or more and 60 nm or less.

[0048] Here, the particle size refers to the average value of individual composite tungsten oxide microparticles, and is the average particle size of the composite tungsten oxide microparticles contained in the antifungal emulsion paint, antifungal microparticle dispersion, and article with antifungal microparticle dispersion described below. The particle size is calculated from an electron microscope image of the composite tungsten oxide microparticles. Meanwhile, the following dispersed particle size of the composite tungsten oxide microparticles can be selected depending on the intended use. The dispersed particle size is different from the above-mentioned particle size and is a concept that also includes the particle size of aggregates.

[0049] In the antifungal emulsion paint, antifungal microparticle dispersion, and article with antifungal microparticle dispersion, the dispersion of composite tungsten oxide microparticles that perform light-to-heat conversion enables uniform light-to-heat conversion and the development of an antifungal effect.

[0050] The composite tungsten oxide microparticles preferably have a dispersed particle diameter of 800 nm or less. Dispersion of the composite tungsten oxide microparticles with such a dispersed particle diameter enables uniform light-to-heat conversion and exhibits a mildew-preventing effect.

[0051] In order to disperse the composite tungsten oxide particles more uniformly, the dispersed particle diameter is preferably 200 nm or less, and more preferably 100 nm or less, because the smaller the dispersed particle diameter of the particles, the more uniformly they will disperse.

[0052] The dispersed particle size of the infrared absorbing fine particles can be measured using an ELS-8000 manufactured by Otsuka Electronics Co., Ltd., which is based on the principle of dynamic light scattering.

[0053] Furthermore, from the viewpoint of exhibiting photothermal conversion that leads to excellent antifungal properties, the crystallite diameter of the composite tungsten oxide microparticles is preferably 1 nm or more and 200 nm or less, more preferably 1 nm or more and 100 nm or less, and even more preferably 10 nm or more and 60 nm or less. The crystallite diameter is measured by measuring the X-ray diffraction pattern by powder X-ray diffraction (θ-2θ method) and analyzing by the Rietveld method. The X-ray diffraction pattern can be measured using, for example, a powder X-ray diffractometer "X'Pert-PRO / MPD" manufactured by Spectris PANalytical Co., Ltd.

[0054] (4) Manufacturing Method of Composite Tungsten Oxide Microparticles A configuration example of the manufacturing method of composite tungsten oxide microparticles will be described. According to the manufacturing method of composite tungsten oxide microparticles of this embodiment, composite tungsten oxide microparticles that are effective as the near-infrared absorbing microparticles described above can be manufactured. Therefore, some of the matters that have already been explained will not be explained again.

[0055] The composite tungsten oxide particles represented by the general formula MxWyOz according to this embodiment can be produced, for example, by the following solid-state reaction method or plasma method.

[0056] Each method will be explained below.

[0057] (a) Solid-Phase Reaction Method When composite tungsten oxide microparticles are produced by a solid-phase reaction method, the following steps may be included.

[0058] A tungsten compound and an M element compound are mixed to prepare a raw material mixture (mixing step).

[0059] It is preferable to blend and mix the raw material mixture so that the ratio (molar ratio) of the amounts of substance of the M element and tungsten is the ratio of x to y in the above general formula of the target composite tungsten oxide particles.

[0060] Next, the raw material mixture obtained in the mixing step is heat-treated in an atmosphere containing oxygen (first heat-treatment step).

[0061] Next, the heat-treated product obtained after the first heat treatment step is heat-treated in a reducing gas atmosphere, a mixed gas atmosphere of a reducing gas and an inert gas, or an inert gas atmosphere (second heat treatment step).

[0062] After the second heat treatment step, if necessary, the composite tungsten oxide fine particles may be subjected to a pulverization treatment or the like so as to have a desired particle size.

[0063] The composite tungsten oxide microparticles obtained by the above steps have the above-mentioned photothermal conversion property (generating heat upon absorbing infrared rays) and can also be used as near-infrared absorbing material particles that are excellent in weather resistance.

[0064] Each step will be described in detail below.

[0065] (Mixing Step) The tungsten compound to be subjected to the mixing step can be, for example, one or more compounds selected from the group consisting of tungstic acid (HWO), ammonium tungstate, tungsten hexachloride, and a tungsten hydrate obtained by adding water to tungsten hexachloride dissolved in alcohol to hydrolyze the tungsten, and then evaporating the solvent.

[0066] The M element compound to be subjected to the mixing step may be, for example, one or more selected from oxides, hydroxides, nitrates, sulfates, chlorides, and carbonates of the M element.

[0067] In the mixing step, when mixing the tungsten compound and the M element compound, it is preferable to blend and mix the raw materials so that the mass ratio (M:W) of the M element (M) to tungsten (W) in the resulting raw material mixture is equal to x:y in the target general formula MxWyOz.

[0068] The mixing method is not particularly limited, and either wet mixing or dry mixing can be used. In the case of wet mixing, a mixed powder of the M element compound and the tungsten compound is obtained by drying the mixed liquid obtained after wet mixing. The drying temperature and time after wet mixing are not particularly limited.

[0069] The dry mixing may be carried out using a known mixing device such as a commercially available crusher, kneader, ball mill, sand mill, or paint shaker, and there are no particular limitations on the mixing conditions such as the mixing time and mixing speed.

[0070] (First heat treatment step) The heat treatment temperature in the first heat treatment step is not particularly limited, but is preferably higher than the temperature at which the composite tungsten oxide microparticles crystallize. Specifically, for example, it is preferably 500°C or higher and 1000°C or lower, more preferably 500°C or higher and 800°C or lower.

[0071] (Second Heat Treatment Step) In the second heat treatment step, as described above, heat treatment can be performed in a reducing gas atmosphere, a mixed gas atmosphere of a reducing gas and an inert gas, or an inert gas atmosphere at a temperature of 500°C or higher and 1200°C or lower.

[0072] When a reducing gas is used in the second heat treatment step, the type of reducing gas is not particularly limited, but hydrogen (H2) is preferred. Furthermore, when hydrogen is used as the reducing gas, its concentration is not particularly limited and can be appropriately selected depending on the firing temperature, the amount of the starting materials, etc. For example, it is 20 vol% or less, preferably 10 vol% or less, and more preferably 7 vol% or less. This is because a reducing gas concentration of 20 vol% or less can avoid the formation of WO2, which does not have near-infrared absorption function, due to rapid reduction.

[0073] (b) Plasma method The composite tungsten oxide microparticles represented by the general formula MxWyOz according to this embodiment can also be produced by, for example, a plasma method. When producing the composite tungsten oxide microparticles by a plasma method, the following steps can be included.

[0074] As a starting material, a raw material mixture of a tungsten compound and an M element compound, or a composite tungsten oxide precursor represented by the general formula MxWyOz′ is prepared (raw material preparation step).

[0075] The starting material prepared in the raw material preparation step is supplied into plasma together with a carrier gas, and the target composite tungsten oxide particles are generated through evaporation and condensation processes (reaction step).

[0076] (Raw Material Preparation Step) When preparing a raw material mixture of a tungsten compound and an M element compound as a starting material, it is preferable to blend and mix the raw materials so that the mass ratio (M:W) of the M element (M) to tungsten (W) in the raw material mixture of the tungsten compound and the M element compound is equal to the ratio x:y of x to y in the above-mentioned general formula of the target composite tungsten oxide.

[0077] As the tungsten compound and the M element compound, the same materials as those explained in the solid-phase reaction method can be suitably used, and therefore a description thereof will be omitted here.

[0078] In addition, in the composite tungsten oxide precursor represented by the general formula MxWyOz′, M can be the above-mentioned M element, W can be tungsten, and O can be oxygen, and x, y, and z′ preferably satisfy the relationships 0.001≦x / y≦1 and 2.0<z′ / y.

[0079] A composite tungsten oxide precursor represented by the general formula MxWyOz' can be synthesized, for example, by the solid-state reaction method described above. The x / y ratio in such a composite tungsten oxide precursor preferably matches the x / y ratio in the target composite tungsten oxide particles represented by the general formula MxWyOz.

[0080] (Reaction Step) A mixed gas of an inert gas and oxygen gas can be used as a carrier gas for transporting the starting materials in the reaction step.

[0081] The plasma can be generated, for example, in an atmosphere of an inert gas alone or a mixed gas of an inert gas and hydrogen gas. The plasma is not particularly limited, but thermal plasma is preferred. The raw material supplied into the plasma instantly evaporates, and the evaporated raw material condenses as it reaches the plasma tail flame. It is then rapidly cooled and solidified outside the plasma flame, producing composite tungsten oxide particles. The plasma method can produce, for example, composite tungsten oxide particles with a single crystalline phase.

[0082] The plasma used in the method for producing composite tungsten oxide microparticles according to this embodiment is preferably, for example, DC arc plasma, high frequency plasma, microwave plasma, low frequency AC plasma, or these superpositions, or by the electric method of applying magnetic field to DC plasma, by high power laser, or by high power electron beam or ion beam.In any case, the thermal plasma used should be the thermal plasma with high temperature part of 10000K or more, more preferably 10000K or more and 25000K or less, and particularly, it is preferable that the plasma can control the generation time of particles.

[0083] A specific example of the configuration of the reaction step in the method for producing composite tungsten oxide microparticles according to this embodiment using a plasma method will be described with reference to FIG.

[0084] The device shown in FIG. 3 is a high frequency plasma device.

[0085] The high frequency plasma reactor has a water-cooled quartz double tube 11 and a reaction vessel 12 connected to the water-cooled quartz double tube 11. A vacuum exhaust device 13 is connected to the reaction vessel 12.

[0086] Above the water-cooled quartz double tube 11, a plasma generating gas supply port 14 is provided.

[0087] The water-cooled quartz double tube 11 is configured so that sheath gas for generating high-frequency plasma and protecting the quartz tube can be supplied along the inner wall thereof, and a sheath gas inlet 15 is provided on the upper flange of the water-cooled quartz double tube 11.

[0088] A water-cooled copper coil 16 for generating high frequency plasma is arranged around the water-cooled quartz double tube 11 .

[0089] A raw material powder carrier gas supply port 17 is provided near the plasma generating gas supply port 14 and is connected by a pipe to a raw material powder supply device 18 that supplies raw material powder.

[0090] The plasma generating gas supply port 14, the sheath gas inlet 15, and the raw material powder supply device 18 can be connected to a gas supply device 19 by piping, so that a predetermined gas can be supplied to each member from the gas supply device 19. If necessary, supply ports other than those for the above members can be provided and connected to the gas supply device 19 so that the members in the apparatus can be cooled or a predetermined atmosphere can be created.

[0091] An example of the configuration of a method for producing composite tungsten oxide particles using the above plasma reactor will be described.

[0092] First, the reaction system consisting of the water-cooled quartz double tube 11 and the reaction vessel 12 is evacuated using the vacuum exhaust device 13. The degree of vacuum is not particularly limited, but it can be evacuated to, for example, about 0.1 Pa (about 0.001 Torr). After the reaction system is evacuated, argon gas is supplied from the gas supply device 12, and the reaction system can be filled with argon gas. For example, it is preferable to have an argon gas flow system at 1 atmosphere within the reaction system.

[0093] Furthermore, after that, a plasma gas can be supplied into the reaction vessel 12. The plasma gas is not particularly limited, but for example, argon gas, a mixed gas of argon and helium (Ar-He mixed gas), a mixed gas of argon and nitrogen (Ar-N ２ Any gas selected from the group consisting of a mixture of gases, neon, helium, and xenon can be used.

[0094] The supply flow rate of the plasma gas is not particularly limited, but for example, it can be introduced from the plasma generating gas supply port 14 at a flow rate of preferably 20 L / min or more and 50 L / min or less, more preferably 25 L / min or more and 35 L / min or less. Then, high-frequency plasma can be generated.

[0095] On the other hand, a sheath gas can be supplied from a sheath gas supply port 15 in a spiral manner outside the plasma region along the inner wall of the water-cooled quartz double tube 11. There are no particular limitations on the type or supply rate of the sheath gas, but for example, argon gas is supplied at a rate of 20 L / min to 50 L / min and hydrogen gas is supplied at a rate of 1 L / min to 5 L / min to generate high-frequency plasma.

[0096] A high frequency power supply can then be applied to the water-cooled copper coil 16 for generating high frequency plasma. The conditions of the high frequency power supply are not particularly limited, but for example, a high frequency of 15 kW or more and 50 kW or less can be applied.

[0097] After generating such high-frequency plasma, the raw material can be introduced using a carrier gas from a raw material powder carrier gas supply port 17 by a raw material powder supply device 18. There are no particular limitations on the carrier gas, and for example, a mixed gas consisting of argon gas at a flow rate of 1 L / min to 8 L / min and oxygen gas at a flow rate of 0.001 L / min to 0.8 L / min can be used.

[0098] The starting material mixture or composite tungsten oxide precursor is introduced into the plasma to carry out the reaction. The supply rate of the starting material from the raw material powder carrier gas supply port 17 is not particularly limited. For example, the supply rate is preferably 1 g / min or more and 50 g / min or less, and more preferably 1 g / min or more and 20 g / min or less.

[0099] By setting the supply rate of the starting material to 50 g / min or less, the proportion of the starting material passing through the center of the plasma flame can be sufficiently increased, the proportion of unreacted materials and intermediate products can be suppressed, and the proportion of the desired composite tungsten oxide microparticles produced can be increased. Furthermore, by setting the supply rate of the starting material to 1 g / min or more, productivity can be increased.

[0100] The starting material supplied into the plasma is instantly vaporized in the plasma and undergoes a condensation process to produce composite tungsten oxide fine particles having an average primary particle size of 100 nm or less.

[0101] The particle size of the composite tungsten oxide microparticles obtained by the manufacturing method according to this embodiment can be easily controlled by adjusting the plasma output, plasma flow rate, the amount of raw material powder supplied, and the like.

[0102] After the reaction, the generated composite tungsten oxide particles are deposited in the reaction vessel 12 and can be recovered.

[0103] [2] Surface Treatment Agent for Composite Tungsten Oxide Particles The surface treatment agent used for the "coating film" that coats the surface of the composite tungsten oxide particles is one or more selected from the group consisting of hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of metal cyclic oligomer compounds, and polymers of hydrolysis products of metal cyclic oligomer compounds.

[0104] From the viewpoint that the metal chelate compound and metal cyclic oligomer compound are preferably metal alkoxides, metal acetylacetonates, or metal carboxylates, they preferably have one or more groups selected from an ether bond, an ester bond, an alkoxy group, and an acetyl group.

[0105] Here, the surface treatment agents used in the above-mentioned "coating film" will be described in the following order: (1) metal chelate compounds, (2) metal cyclic oligomer compounds, (3) hydrolysis products of metal chelate compounds and metal cyclic oligomer compounds, and polymers thereof, and (4) the amount of surface treatment agent added.

[0106] (1) Metal Chelate Compound The metal chelate compound is preferably one or more selected from Al-, Zr-, Ti-, Si- and Zn-based chelate compounds containing an alkoxy group.

[0107] Examples of aluminum-based chelate compounds include aluminum alcoholates such as aluminum ethylate, aluminum isopropylate, aluminum sec-butylate, and mono-sec-butoxyaluminum diisopropylate, or polymers thereof, ethyl acetoacetate aluminum diisopropylate, aluminum tris(ethyl acetoacetate), octyl acetoacetate aluminum diisopropylate, stearyl acetoaluminum diisopropylate, aluminum monoacetylacetonate bis(ethyl acetoacetate), and aluminum tris(acetylacetonate).

[0108] These compounds are alkoxy group-containing aluminum chelate compounds obtained by dissolving aluminum alcoholate in an aprotic solvent, petroleum solvent, hydrocarbon solvent, ester solvent, ketone solvent, ether solvent, amide solvent, or the like, adding β-diketone, β-ketoester, monohydric or polyhydric alcohol, fatty acid, or the like to the solution, and heating under reflux to cause a ligand substitution reaction.

[0109] Examples of zirconia-based chelate compounds include zirconium alcoholates such as zirconium ethylate and zirconium butyrate, or polymers thereof, zirconium tributoxystearate, zirconium tetraacetylacetonate, zirconium tributoxyacetylacetonate, zirconium dibutoxybis(acetylacetonate), zirconium tributoxyethylacetoacetate, and zirconium butoxyacetylacetonate bis(ethylacetoacetate).

[0110] Examples of titanium-based chelate compounds include titanium alcoholates such as methyl titanate, ethyl titanate, isopropyl titanate, butyl titanate, and 2-ethylhexyl titanate, and polymers thereof, titanium acetylacetonate, titanium tetraacetylacetonate, titanium octylene glycolate, titanium ethylacetoacetate, titanium lactate, and titanium triethanolaminate.

[0111] As the silicon-based chelate compound, a tetrafunctional silane compound represented by the general formula: Si(OR)4 (where R is the same or different monovalent hydrocarbon group having 1 to 6 carbon atoms), or a hydrolysis product thereof, can be used. Specific examples of tetrafunctional silane compounds include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane. Furthermore, silane monomers (or oligomers) in which some or all of the alkoxy groups of these alkoxysilane monomers have been hydrolyzed to silanol groups (Si-OH), as well as polymers self-condensed through hydrolysis, can also be used.

[0112] Furthermore, hydrolysis products of tetrafunctional silane compounds (meaning the entire hydrolysis product of tetrafunctional silane compounds) include silane monomers in which some or all of the alkoxy groups have been hydrolyzed to form silanol (Si-OH) groups, oligomers of tetramers to pentamers, and polymers (silicone resins) with a weight-average molecular weight (Mw) of about 800 to 8000. Note that not all of the alkoxysilyl groups (Si-OR) in the alkoxysilane monomers are hydrolyzed to form silanol groups (Si-OH) during the hydrolysis reaction.

[0113] Preferred examples of zinc-based chelate compounds include organic zinc carboxylates such as zinc octylate, zinc laurate, and zinc stearate, acetylacetone zinc chelate, benzoylacetone zinc chelate, dibenzoylmethane zinc chelate, and ethyl acetoacetate zinc chelate.

[0114] (2) Metallic Cyclic Oligomer Compound The metallic cyclic oligomer compound is preferably at least one selected from Al-, Zr-, Ti-, Si-, and Zn-based cyclic oligomer compounds. Among them, preferred examples include cyclic aluminum oligomer compounds such as cyclic aluminum oxide octylate, cyclic aluminum oxide isopropylate, and cyclic aluminum oxide stearate.

[0115] (3) Hydrolysis products of metal chelate compounds and metal cyclic oligomer compounds, and their polymers In the present invention, the hydrolysis products in which all of the alkoxy groups, ether bonds, and ester bonds in the above-mentioned metal chelate compounds and metal cyclic oligomer compounds are hydrolyzed to hydroxyl groups or carboxyl groups, partial hydrolysis products in which a portion is hydrolyzed, and / or polymers self-condensed through the hydrolysis reaction are coated on the surface of composite tungsten oxide particles to form a "coating film", thereby obtaining the surface-treated composite tungsten oxide particles of the present invention. That is, the hydrolysis products in the present invention are a concept that includes partial hydrolysis products.

[0116] However, in a reaction system involving an organic solvent such as alcohol, even if sufficient water is generally present in the system based on the stoichiometric composition, not all of the alkoxy groups, ether bonds, or ester bonds in the metal chelate compound or metal cyclic oligomer compound used as the starting material are hydrolyzed, depending on the type and concentration of the organic solvent. Therefore, depending on the conditions of the surface coating method described below, even after hydrolysis, the hydrolysis product may become amorphous, with carbon C incorporated into the molecule. As a result, the "coating film" may contain undecomposed metal chelate compound and / or metal cyclic oligomer compound, but this does not pose any particular problem if it is in a trace amount.

[0117] (4) Amount of Surface Treatment Agent Added The amount of the above-mentioned metal chelate compound or metal cyclic oligomer compound added is preferably 0.05 parts by mass or more and 1,000 parts by mass or less, more preferably 5 parts by mass or more and 500 parts by mass or less, and most preferably 5 parts by mass or more and 50 parts by mass or less, in terms of metal element, per 100 parts by mass of the composite tungsten oxide microparticles.

[0118] This is because, when the metal chelate compound or metal cyclic oligomer compound is 0.05 parts by mass or more, the hydrolysis products of these compounds or polymers of the hydrolysis products have the effect of coating the surface of the composite tungsten oxide microparticles, thereby improving the moist heat resistance.

[0119] Furthermore, if the amount of the metal chelate compound or metal cyclic oligomer compound is 1,000 parts by mass or less, it is possible to avoid excessive adsorption onto the composite tungsten oxide fine particles, and the improvement in moist heat resistance due to the surface coating does not saturate, so that an improvement in the coating effect can be expected.

[0120] Furthermore, by using 1,000 parts by mass or less of the metal chelate compound or the cyclic metal oligomer compound, the amount of the compound adsorbed onto the composite tungsten oxide fine particles becomes excessive, which can prevent the fine particles from easily granulating together via the hydrolysis products of the metal chelate compound or the cyclic metal oligomer compound or the polymers of the hydrolysis products when the medium is removed. By preventing the undesired granulation between the fine particles, good transparency can be ensured.

[0121] In addition, an increase in production costs due to an increase in the amount of metal chelate compound or cyclic metal oligomer compound added and an increase in processing time caused by an excess of the metal chelate compound or cyclic metal oligomer compound can be avoided. Therefore, from an industrial viewpoint, it is preferable that the amount of the metal chelate compound or cyclic metal oligomer compound added be 1,000 parts by mass or less.

[0122] [3] Method for Surface Coating Composite Tungsten Oxide Particles In the method for surface coating composite tungsten oxide particles, first, composite tungsten oxide particles are dispersed in a suitable medium to prepare a composite tungsten oxide particle dispersion for forming a coating film (sometimes abbreviated as "dispersion for forming a coating film" in this specification).

[0123] Then, when a surface treatment agent is added to the prepared coating film-forming dispersion liquid and mixed and stirred, the surface of the composite tungsten oxide microparticles is coated with a coating film containing one or more selected from the group consisting of hydrolysis products of metal chelate compounds, polymerized hydrolysis products of metal chelate compounds, hydrolysis products of cyclic metal oligomer compounds, and polymerized hydrolysis products of cyclic metal oligomer compounds, thereby obtaining the surface-treated composite tungsten oxide microparticles according to this embodiment. During the process of coating the surface of the composite tungsten oxide microparticles, the coating film-forming dispersion liquid to which the surface treatment agent has been added becomes a maturing liquid, which will be described later.

[0124] The surface coating method for composite tungsten oxide fine particles will be described below in the following order: (1) preparation of a dispersion for forming a coating film; (2) a surface treatment method for composite tungsten oxide fine particles using a dispersion for forming a coating film that uses water as a medium; (3) a surface coating method for composite tungsten oxide fine particles using a dispersion for forming a coating film that uses a water-containing organic solvent; (4) coating film thickness; and (5) treatment after mixing and stirring in the dispersion for forming a coating film.

[0125] (1) Preparation of a dispersion for forming a coating film To coat the surfaces of composite tungsten oxide microparticles with a "coating film" and produce surface-treated composite tungsten oxide microparticles, first, the composite tungsten oxide microparticles are dispersed in water or an organic solvent containing water to prepare the dispersion for forming the coating film.

[0126] Meanwhile, the surface treatment agent explained in the above section "[2] Surface treatment agent for composite tungsten oxide fine particles" is prepared.

[0127] Then, when a surface treatment agent is added to the above-mentioned coating film-forming dispersion while mixing and stirring, the surface of the composite tungsten oxide microparticles is coated with a "coating film" containing one or more selected from the group consisting of hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of metal cyclic oligomer compounds, and polymers of hydrolysis products of metal cyclic oligomer compounds.

[0128] In preparing the above-mentioned dispersion for forming a coating film, it is preferable to first finely pulverize the composite tungsten oxide and then disperse it in water or a suitable organic solvent containing water to obtain a monodispersed state. In this case, the dispersion concentration of the composite tungsten oxide is preferably 0.01% by mass or more and 80% by mass or less. Within this dispersion concentration range, the liquid stability of the dispersion is excellent. Furthermore, when an appropriate liquid medium, dispersant, coupling agent, and surfactant are selected, gelation of the dispersion and particle precipitation do not occur even when placed in a thermostatic bath at a temperature of 40°C for more than six months, and the dispersed particle size can be maintained in the range of 1 to 200 nm.

[0129] It is essential to maintain the dispersion state during the above-mentioned pulverization and dispersion treatment steps and to prevent the composite tungsten oxide fine particles from aggregating together. This is because, in the next step, "surface treatment of composite tungsten oxide fine particles," the composite tungsten oxide fine particles aggregate and are surface-coated in the form of aggregates, and these aggregates remain even in the antifungal fine particle dispersion in which the composite tungsten oxide fine particles are dispersed, as described below, and inhibit uniform photothermal conversion, ultimately adversely affecting the antifungal properties.

[0130] Specific examples of the pulverization and dispersion treatment include pulverization and dispersion treatment methods using devices such as a bead mill, a ball mill, a sand mill, a paint shaker, an ultrasonic homogenizer, etc. Among these, pulverization and dispersion treatment using a media such as beads, balls, or Ottawa sand, using a media agitation mill such as a bead mill, a ball mill, a sand mill, or a paint shaker, is preferred because it takes less time to reach the desired dispersed particle size.

[0131] The prepared dispersion for forming a coating film is mixed and stirred while adding a surface treatment agent. At this time, it is desirable to dilute the dispersion for forming a coating film with water or a suitable organic solvent containing water to an appropriate concentration. If the dispersion concentration of the composite tungsten oxide microparticles is diluted to 0.01% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 10% by mass or less, all of the composite tungsten oxide microparticles will be uniformly surface-coated.

[0132] (2) Surface Treatment Method of Composite Tungsten Oxide Particles Using a Water-Based Dispersion for Forming a Coating Film The present inventors have discovered that, in preparing the above-described dispersion for forming a coating film, it is preferable to add the above-described surface treatment agent to the water-based dispersion for forming a coating film while stirring and mixing it, and further to immediately complete the hydrolysis reaction of the added metal chelate compound and metal cyclic oligomer compound.

[0133] In addition, from the viewpoint of uniformly coating the surface of the composite tungsten oxide microparticles, it is preferable to add the surface treatment agent dropwise. This is thought to be influenced by the reaction order of the added surface treatment agent. That is, in a dispersion liquid for forming a coating film using water as a medium, the hydrolysis reaction of the surface treatment agent always precedes, and then the polymerization reaction of the generated hydrolysis product occurs. As a result, it is thought that the amount of carbon C remaining in the surface treatment agent molecules present in the coating film can be reduced compared to when water is not used as a medium. It is thought that by reducing the amount of carbon C remaining in the surface treatment agent molecules present in the coating film, it was possible to form a "coating film" that densely coats the surface of each composite tungsten oxide microparticle.

[0134] When adding the surface treatment agent dropwise, it is also preferable to add the surface treatment agent itself diluted with an appropriate solvent dropwise in order to adjust the amount of the surface treatment agent added per unit time. The solvent used for dilution is preferably one that does not react with the surface treatment agent and has high compatibility with water, which is the medium of the dispersion for forming a coating film. Specifically, alcohol-based, ketone-based, glycol-based, and other solvents can be preferably used.

[0135] The dilution ratio of the surface treatment agent is not particularly limited, but from the viewpoint of ensuring productivity, the dilution ratio is preferably 100 times or less.

[0136] In the above-mentioned dispersion for forming a coating film using water as a medium, the metal chelate compound, the metal cyclic oligomer compound, their hydrolysis products, and polymers of the hydrolysis products are decomposed into metal ions immediately after addition, but the decomposition into the metal ions ends when the dispersion becomes a saturated aqueous solution.

[0137] On the other hand, in the dispersion liquid for forming coating film using water as a medium, composite tungsten oxide microparticles are kept dispersed by electrostatic repulsion.As a result, the surface of all composite tungsten oxide microparticles is covered with a "coating film" comprising one or more selected from the hydrolysis product of metal chelate compound, the polymer of the hydrolysis product of metal chelate compound, the hydrolysis product of metal cyclic oligomer compound, and the polymer of the hydrolysis product of metal cyclic oligomer compound, and it is considered that the surface-treated composite tungsten oxide microparticles of the present invention are produced.The dispersion liquid for forming coating film to which the surface treatment agent is added becomes a matured liquid, and a coating film is formed on the surface of the composite tungsten oxide microparticles.

[0138] (3) Surface Coating Method of Composite Tungsten Oxide Fine Particles Using a Dispersion for Forming a Coating Film Using an Organic Solvent Containing Water As a variation of the above-mentioned method for preparing a dispersion for forming a coating film using water as a medium, a method is also preferred in which an organic solvent containing water is used as the medium for the dispersion for forming a coating film, and the above-mentioned reaction sequence is carried out while adjusting the amount of water added to an appropriate value.

[0139] This preparation method is suitable when it is desired to reduce the amount of water contained in the coating film-forming dispersion for convenience of subsequent steps.

[0140] Specifically, the above-mentioned surface treatment agent and pure water are added dropwise in parallel while stirring and mixing the dispersion for forming a coating film containing an organic solvent as a medium. At this time, the medium temperature, which affects the reaction rate, and the dropping speed of the surface treatment agent and pure water are appropriately controlled. Note that the organic solvent may be any solvent that dissolves in water at room temperature, such as an alcohol, ketone, or glycol solvent, and various solvents can be selected.

[0141] In the "(3) method for surface coating composite tungsten oxide microparticles using a coating film-forming dispersion liquid using an organic solvent containing water," when the surface treatment agent is added dropwise, it is preferable to add the surface treatment agent itself diluted with an appropriate solvent dropwise in order to adjust the amount of the surface treatment agent added per unit time. In this case, the solvent used for dilution is preferably one that does not react with the surface treatment agent and has high compatibility with the organic solvent containing water, which is the medium of the coating film-forming dispersion liquid. Specifically, alcohol-based, ketone-based, glycol-based, and other solvents can be preferably used.

[0142] The procedure for using a commercially available metal chelate compound or metal cyclic oligomer compound as the surface treatment agent and the dilution ratio of the surface treatment agent are the same as those in the above-mentioned "(2) Surface treatment method for infrared absorbing fine particles using a coating film-forming dispersion liquid containing water as a medium."

[0143] (4) Thickness of the coating film The thickness of the "coating film" in the surface-treated composite tungsten oxide microparticles of the present invention is preferably 0.5 nm or more. This is because if the thickness of the "coating film" is 0.5 nm or more, the surface-treated composite tungsten oxide microparticles are considered to exhibit sufficient moist heat resistance and chemical stability. On the other hand, from the viewpoint of ensuring that the surface-treated composite tungsten oxide microparticles have predetermined optical properties, it is considered preferable that the thickness of the "coating film" be 20 nm or less.

[0144] In view of the above, the thickness of the "coating film" is more preferably 0.5 nm or more and 20 nm or less, and even more preferably 1 nm or more and 10 nm or less.

[0145] The thickness of the "coating film" can be measured from a transmission electron microscope image of the surface-treated composite tungsten oxide microparticles.For example, in the transmission electron microscope image of the surface-treated composite tungsten oxide microparticles according to Example 1 shown in Figure 2 below, which is magnified 300,000 times, the part sandwiched between two parallel solid lines, where the lattice fringes (arrangement of atoms in the crystal) of the composite tungsten oxide microparticles are not observed, corresponds to the "coating film".

[0146] (5) Treatment after Mixing and Stirring in Coating Film-Forming Dispersion The surface-treated composite tungsten oxide microparticles according to the present invention obtained by the above-mentioned surface coating method can be used as a raw material for antifungal emulsion paints or antifungal microparticle dispersions in the form of microparticles or in the form of dispersion in a liquid medium or solid medium.

[0147] In other words, the surface-treated composite tungsten oxide microparticles thus produced do not require further heat treatment to increase the density or chemical stability of the coating film, because the density and adhesion of the coating film are already sufficiently high that the desired moist heat resistance can be obtained without the heat treatment.

[0148] As explained above, the surface-treated composite tungsten oxide microparticles according to the present invention do not require heat treatment after the mixing and stirring process, so they do not aggregate, and therefore no dispersion treatment is required to break up the aggregates. As a result, the coating film of the surface-treated composite tungsten oxide microparticles according to the present invention coats the individual composite tungsten oxide microparticles without damaging them. Furthermore, it is believed that the antifungal microparticle dispersion produced using these surface-treated composite tungsten oxide microparticles exhibits excellent moist heat resistance.

[0149] However, it is possible to heat-treat the coating film-forming dispersion or the surface-treated composite tungsten oxide microparticle powder for the purposes of obtaining a surface-treated composite tungsten oxide microparticle powder from the coating film-forming dispersion, drying the obtained surface-treated composite tungsten oxide microparticle powder, etc. In this case, however, care must be taken to ensure that the heat-treatment temperature does not exceed the temperature at which the surface-treated composite tungsten oxide microparticles aggregate to form aggregates.

[0150] This is because the antifungal microparticle dispersion in which the surface-treated composite tungsten oxide microparticles according to the present invention are finally used often requires transparency for their intended use. However, when an antifungal microparticle dispersion is prepared using aggregates of the surface-treated composite tungsten oxide microparticles, the uneven distribution of the surface-treated composite tungsten oxide microparticles may prevent the exhibiting of uniform antifungal properties.

[0151] To avoid such a situation, the agglomerates are disintegrated and redispersed by dry or / and wet methods. Therefore, it is preferable to examine the redispersion conditions so as not to damage or peel off the "coating film" that covers the surface of the surface-treated composite tungsten oxide fine particles.

[0152] [4] Antifungal emulsion paint, antifungal microparticle dispersion, and article with antifungal microparticle dispersion Hereinafter, an antifungal emulsion paint, an antifungal microparticle dispersion, and an article with an antifungal microparticle dispersion using the surface-treated composite tungsten oxide microparticles according to the present invention will be described.

[0153] (1) Antifungal emulsion paint The antifungal emulsion paint of the present invention is characterized by containing composite tungsten oxide microparticles (surface-treated composite tungsten oxide microparticles) whose surfaces are coated with a coating film containing one or more selected from the group consisting of hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of metal cyclic oligomer compounds, and polymers of hydrolysis products of metal cyclic oligomer compounds, and a resin emulsion, and it is preferable that the surface-treated composite tungsten oxide microparticles are dispersed in the emulsion paint in an amount of 0.1% by mass to 50% by mass.

[0154] That is, the antifungal emulsion paint according to the present invention contains a binder resin, water, and surface-treated composite tungsten oxide fine particles, and may also contain a coloring pigment or dye.

[0155] Resins that can be used in the coating material include, for example, homopolymers of acrylic acid esters, methacrylic acid esters, ethylene, vinyl acetate, vinyl versatate, styrene, vinyl chloride, vinylidene chloride, urethane, epoxy, etc., or copolymers or blends of two or more types of resins.

[0156] Additives that can be added include surfactants such as dispersants, wetting agents, antifoaming agents, foaming agents, emulsifiers, and antistatic agents, as well as organic solvents such as film-forming aids, freeze stabilizers, and plasticizers. Thickeners such as methyl cellulose, polyvinyl alcohol, hydroxymethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, and guar gum may also be added. Lightweight aggregates such as expanded clay, pumice, perlite, expanded polystyrene powder, shirasu balloons, and vermiculite, kansui stone, silica sand, and preservatives may also be added.

[0157] Examples of the pigment include white pigments such as zinc oxide, lithopone, and titanium oxide; color pigments such as carbon black, red iron oxide, iron oxide, yellow lead, chromium oxide, phthalocyanine blue, phthalocyanine green, ultramarine, and toluidine red; extender pigments such as gypsum dihydrate, calcium carbonate, silica, bentonite, clay, talc, baryte, and aluminum hydroxide; and metal powder pigments such as copper powder, gold powder, and aluminum powder.

[0158] The antifungal emulsion paint of the present invention can be produced in the same manner as in the production of general water-based paints, by adding various ingredients and mixing and dispersing them using a dispersing device such as a high-speed mill, a ball mill, or a sand mill.

[0159] (2) Antifungal microparticle dispersion and article with antifungal microparticle dispersion The antifungal emulsion paint of the present invention is applied to a substrate selected from the outer walls of buildings, glass, plastic, metal, etc. to form a coating film, and the solvent such as water in the coating film volatilizes to form a hardened film that becomes the antifungal microparticle dispersion, and the antifungal microparticle dispersion is formed on a substrate to form an article with the antifungal microparticle dispersion.

[0160] Examples of the present invention will be specifically described below with reference to comparative examples, but the present invention is not limited to the following examples.

[0161] First, the evaluation methods for the samples according to the following Examples and Comparative Examples will be described.

[0162] (1) Crystal Structure and Crystallite Size The crystal structures of the composite tungsten oxides obtained in the examples and comparative examples were measured.

[0163] The measurement was carried out by using a powder X-ray diffractometer (X'Pert-PRO / MPD manufactured by PANalytical, Spectris Inc.) to measure the X-ray diffraction pattern of the composite tungsten oxide fine particles by powder X-ray diffractometry (θ-2θ method).

[0164] The crystal structure of the composite tungsten oxide constituting the microparticles was identified from the obtained X-ray diffraction pattern, and the crystallite size was calculated from the obtained X-ray diffraction pattern using the Rietveld method.

[0165] (2) Transmission Electron Microscope Observation of Surface-Treated Composite Tungsten Oxide Microparticles The thickness of the coating film on the surface-treated composite tungsten oxide microparticles obtained in the examples was determined by reading the areas of the surface-treated composite tungsten oxide microparticles without lattice fringes as the coating film from photographic data at 300,000 magnification obtained using a transmission electron microscope (HF-2200, manufactured by Hitachi, Ltd.).

[0166] (3) Evaluation of Antifungal Properties (JIS Z 2911) The antifungal properties of the antifungal emulsion paints containing the surface-treated composite tungsten oxide microparticles obtained in the following Examples and the antifungal properties of the antifungal emulsion paints containing the composite tungsten oxide microparticles obtained in the following Comparative Examples were evaluated.

[0167] The evaluation was carried out by applying 1.0 × 10 5 Streaking was performed using a platinum loop to which a bacterial count of bacteria per ml had been attached, and each streaked glass substrate was placed in a desiccator maintained at 25±5°C and a humidity of 80±5%, and the desiccator was left to stand in a location exposed to sufficient sunlight for 14 days.

[0168] The surfaces of the test pieces (glass substrates on which smears had been applied) cultured for 14 days were then observed, and those in which mold growth was barely visible to the naked eye were judged as passing (◎); those in which mold that was clearly visible to the naked eye covered 50% or less of the test piece surface were judged as passing (○); and those in which mold that was clearly visible to the naked eye covered more than 50% of the test piece surface were judged as failing (×).

[0169] The fungal species used were Aspergillus niger and Penicillium pinophilum.

[0170] [Example 1] (1) Production of surface-treated composite tungsten oxide microparticles 25% by mass of cesium composite tungsten oxide powder (YM-01 manufactured by Sumitomo Metal Mining Co., Ltd.) with a Cs / W (molar ratio) of 0.33 was mixed with 75% by mass of pure water, and the resulting mixture was loaded into a paint shaker containing 0.3 mm diameter ZrO beads and subjected to a pulverization and dispersion treatment for 10 hours to produce the Cs according to Example 1. 0.33 A dispersion of WO3 fine particles was obtained.

[0171] The obtained Cs according to Example 1 0.33 A portion of the dispersion of WO3 fine particles was separated, and the solvent was removed from the separated dispersion. Then, X-ray diffraction was used to identify hexagonal Cs 0.3 It was confirmed to be WO3, and its crystallite diameter was measured to be 32 nm.

[0172] Furthermore, the obtained Cs according to Example 1 0.33 The remaining WO3 nanoparticle dispersion was mixed with pure water, and Cs 0.33 A coating film-forming dispersion liquid A according to Example 1 was obtained, in which the concentration of WO3 fine particles was 14% by mass.

[0173] On the other hand, 38.6 mass% of S-75P (manufactured by Kawaken Fine Chemicals Co., Ltd., a mixed liquid of 75 mass% aluminum ethyl acetoacetate diisopropylate and 25 mass% isopropyl alcohol) as an aluminum-based chelate compound and 61.4 mass% isopropyl alcohol (IPA) were mixed to prepare a surface treatment agent a1 according to Example 1.

[0174] Then, 2000 g of the coating film-forming dispersion A according to Example 1 was placed in a beaker, and 968 g of the surface treatment agent a1 according to Example 1 was added dropwise while vigorously stirring with a stirrer.

[0175] After the surface treatment agent a1 was added dropwise, the mixture was stirred at room temperature for a further 24 hours to prepare the aged liquid according to Example 1.

[0176] Next, the medium was evaporated from the aged solution of Example 1 using vacuum fluidized drying, and the resulting dried product was dry-pulverized using a hammer mill to obtain surface-treated composite tungsten oxide microparticles of Example 1.

[0177] When the surface-treated composite tungsten oxide particles obtained in Example 1 were observed under a transmission electron microscope, the average particle diameter was found to be 25 nm and the coating film thickness was found to be 2 nm.

[0178] (2) Production of Antifungal Emulsion Paint Next, 5 g of the surface-treated composite tungsten oxide microparticle powder according to Example 1 was mixed with 45 g of an acrylic resin emulsion paint (46% by mass of aqueous solvent, 54% by mass of acrylic resin), and the resulting mixture was ultrasonically dispersed for 30 minutes to obtain the antifungal emulsion paint according to Example 1.

[0179] (3) Production of Antifungal Microparticle Dispersion Next, the obtained antifungal emulsion paint according to Example 1 was applied to a glass substrate having a thickness of 3 mm using a bar coater to form a coating film.

[0180] The coating film was then allowed to air dry for 24 hours to produce an antifungal microparticle dispersion according to Example 1, and the antifungal properties of the obtained antifungal microparticle dispersion according to Example 1 were evaluated.

[0181] The results are shown in Table 1 below.

[0182] [Example 2] (1) Production of surface-treated composite tungsten oxide microparticles A surface treatment agent a2 according to Example 2 was obtained by mixing 43.75 mass% of S-75P (manufactured by Kawaken Fine Chemicals Co., Ltd., a mixed liquid of 75 mass% aluminum ethyl acetoacetate diisopropylate and 25 mass% isopropyl alcohol) as an aluminum-based chelate compound and 56.25 mass% isopropyl alcohol (IPA).

[0183] Then, the surface-treated composite tungsten oxide microparticles of Example 2 were obtained in the same manner as in Example 1, except that the coating film-forming dispersion A obtained in Example 1 was placed in a 1000 g beaker, and 512 g of the surface treatment agent a2 of Example 2 was added dropwise over 5 hours while vigorously stirring with a stirrer.

[0184] When the surface-treated composite tungsten oxide particles obtained in Example 2 were observed under a transmission electron microscope, the average particle size was 25 nm and the coating film thickness was 2 nm.

[0185] (2) Production of Antifungal Emulsion Paint Next, 5 g of the surface-treated composite tungsten oxide microparticle powder according to Example 2 was mixed with 45 g of an acrylic resin emulsion paint (46% by mass of aqueous solvent, 54% by mass of acrylic resin), and the resulting mixture was ultrasonically dispersed for 30 minutes to obtain an antifungal emulsion paint according to Example 2.

[0186] (3) Production of Antifungal Microparticle Dispersion Next, the obtained antifungal emulsion paint according to Example 2 was applied to a glass substrate having a thickness of 3 mm using a bar coater to form a coating film.

[0187] The coating film was then allowed to air dry for 24 hours to produce an antifungal microparticle dispersion according to Example 2, and the antifungal properties of the obtained antifungal microparticle dispersion according to Example 2 were evaluated.

[0188] The results are also shown in Table 1 below.

[0189] [Example 3] (1) Production of surface-treated composite tungsten oxide microparticles A surface treatment agent a3 according to Example 3 was obtained by mixing 2.66 mass% of S-75P (manufactured by Kawaken Fine Chemicals Co., Ltd., a mixed liquid of 75 mass% aluminum ethyl acetoacetate diisopropylate and 25 mass% isopropyl alcohol) as an aluminum-based chelate compound and 97.34 mass% isopropyl alcohol (IPA).

[0190] The coating film-forming dispersion A obtained in Example 1 was placed in a 1000 g beaker, and 351 g of the surface treatment agent a3 of Example 3 was added dropwise over 5 hours while the dispersion A was vigorously stirred with a stirrer. The procedure was the same as in Example 1, except that surface-treated composite tungsten oxide microparticles of Example 3 were obtained.

[0191] When the surface-treated composite tungsten oxide particles obtained in Example 3 were observed under a transmission electron microscope, the average particle diameter was 25 nm and the coating film thickness was 1 nm.

[0192] (2) Production of antifungal emulsion paint Next, 5 g of the surface-treated composite tungsten oxide microparticle powder according to Example 3 was mixed with 45 g of an acrylic resin emulsion paint (46% by mass of aqueous solvent, 54% by mass of acrylic resin), and the resulting mixture was ultrasonically dispersed for 30 minutes to obtain an antifungal emulsion paint according to Example 3.

[0193] (3) Production of Antifungal Microparticle Dispersion Next, the obtained antifungal emulsion paint according to Example 3 was applied to a glass substrate having a thickness of 3 mm using a bar coater to form a coating film.

[0194] The coating film was then allowed to air dry for 24 hours to produce an antifungal microparticle dispersion according to Example 3, and the antifungal properties of the obtained antifungal microparticle dispersion according to Example 3 were evaluated.

[0195] The results are also shown in Table 1 below.

[0196] [Example 4] (1) Production of surface-treated composite tungsten oxide microparticles A surface treatment agent a4 according to Example 4 was obtained by mixing 50.54 mass% of S-75P (manufactured by Kawaken Fine Chemicals Co., Ltd., a mixed liquid of 75 mass% aluminum ethyl acetoacetate diisopropylate and 25 mass% isopropyl alcohol) as an aluminum-based chelate compound and 49.46 mass% isopropyl alcohol (IPA).

[0197] The coating film-forming dispersion A obtained in Example 1 was placed in a 1000 g beaker, and 554 g of the surface treatment agent a4 of Example 4 was added dropwise over 5 hours while the dispersion A was vigorously stirred with a stirrer. The procedure was the same as in Example 1, except that surface-treated composite tungsten oxide microparticles of Example 4 were obtained.

[0198] When the surface-treated composite tungsten oxide particles obtained in Example 4 were observed under a transmission electron microscope, the average particle size was 25 nm and the coating film thickness was 2 nm.

[0199] (2) Production of antifungal emulsion paint Next, 5 g of the surface-treated composite tungsten oxide microparticle powder according to Example 4 was mixed with 45 g of an acrylic resin emulsion paint (46% by mass of aqueous solvent, 54% by mass of acrylic resin), and the resulting mixture was ultrasonically dispersed for 30 minutes to obtain an antifungal emulsion paint according to Example 4.

[0200] (3) Production of Antifungal Microparticle Dispersion Next, the obtained antifungal emulsion paint of Example 4 was applied to a glass substrate having a thickness of 3 mm using a bar coater to form a coating film.

[0201] The coating film was then allowed to air dry for 24 hours to produce an antifungal microparticle dispersion according to Example 4, and the antifungal properties of the obtained antifungal microparticle dispersion according to Example 4 were evaluated.

[0202] The results are also shown in Table 1 below.

[0203] Example 5 (1) Production of Surface-Treated Composite Tungsten Oxide Fine Particles Composite tungsten oxide fine particles were prepared using a high-frequency plasma reactor shown in FIG.

[0204] In this example, high-frequency plasma was generated by first flowing argon gas at 30 L / min through the plasma generating gas supply port 14, and then supplying a mixture of argon gas at 40 L / min and hydrogen gas at 3 L / min in a spiral fashion through the sheath gas inlet 15. The high-frequency power input was 45 kW.

[0205] Next, using a mixed gas of argon gas at 5 L / min and oxygen gas at 0.01 L / min as a carrier gas, powders of tungstic acid (HWO) and cesium carbonate (CsCO) were weighed out in a ratio equivalent to a Cs / W (molar ratio) of 0.33 and added to water to obtain a slurry, which was then supplied into the plasma from raw material powder supply device 18 at a rate of 2 g / min.

[0206] As a result, the particle diameter of the composite tungsten oxide microparticles recovered at the bottom of the reaction vessel 12 was found to be 10 nm or more and 50 nm or less by TEM observation.

[0207] Furthermore, from the X-ray diffraction of the obtained composite tungsten oxide microparticles according to Example 5, it was found that the hexagonal Cs0.3 It was confirmed to be WO3, and furthermore, quantitative analysis revealed that it was Cs 0.29 WO 3.13 It was.

[0208] Next, 25% by mass of the obtained composite tungsten oxide microparticles according to Example 5 and 75% by mass of pure water were mixed, and the obtained mixture was loaded into a paint shaker containing 0.3 mmφ ZrO beads and subjected to a pulverization and dispersion treatment for 1 hour, thereby obtaining a dispersion of composite tungsten oxide microparticles according to Example 5.

[0209] A portion of the dispersion of composite tungsten oxide microparticles according to Example 5 was separated, and the solvent was removed from the separated dispersion. Then, X-ray diffraction was used to identify hexagonal Cs 0.3 It was confirmed to be WO3, and its crystallite diameter was measured to be 25 nm.

[0210] Furthermore, the remaining dispersion of composite tungsten oxide microparticles according to Example 5 obtained was mixed with pure water to obtain a dispersion for forming a coating film according to Example 5, in which the concentration of composite tungsten oxide microparticles was 14 mass%.

[0211] Then, surface-treated composite tungsten oxide particles according to Example 5 were obtained in the same manner as in Example 1, except that the coating film-forming dispersion according to Example 5 was used.

[0212] When the surface-treated composite tungsten oxide particles obtained in Example 5 were observed under a transmission electron microscope, the average particle diameter was found to be 25 nm and the coating film thickness was found to be 2 nm.

[0213] Cs was evaluated using a flame atomic absorption spectrometer (Varian, model: SpectrAA 220FS). W was evaluated using an ICP optical emission spectrometer (Shimadzu, model: ICPE9000). O was evaluated using an oxygen / nitrogen simultaneous analyzer (Leco, model: ON836).

[0214] (2) Production of antifungal emulsion paint Next, 5 g of the surface-treated composite tungsten oxide microparticles according to Example 5 was mixed with 45 g of an acrylic resin emulsion paint (46% by mass of aqueous solvent, 54% by mass of acrylic resin), and the resulting mixture was ultrasonically dispersed for 30 minutes to obtain the antifungal emulsion paint according to Example 5.

[0215] (3) Production of Antifungal Microparticle Dispersion Next, the obtained antifungal emulsion paint of Example 5 was applied to a glass substrate having a thickness of 3 mm using a bar coater to form a coating film.

[0216] The coating film was then allowed to air dry for 24 hours to produce an antifungal microparticle dispersion according to Example 5, and the antifungal properties of the obtained antifungal microparticle dispersion according to Example 5 were evaluated. The results are also shown in Table 1 below.

[0217] Example 6 (1) Production of Surface-Treated Composite Tungsten Oxide Fine Particles Composite tungsten oxide fine particles were produced by a solid-phase reaction method.

[0218] That is, powders of tungstic acid (H2WO4) and cesium carbonate (Cs2CO3) were weighed in a ratio equivalent to a Cs / W (molar ratio) of 0.27, and then thoroughly mixed in an agate mortar to obtain a mixed powder, which was a raw material powder.

[0219] The raw material powder was heated under a supply of 5% by volume H2 gas with N2 gas as a carrier, and subjected to a reduction treatment at a temperature of 570°C for 1 hour (first heat treatment step).

[0220] That is, the heat treatment was carried out in an atmosphere of a first gas consisting of 5% by volume of hydrogen, which is a reducing gas, and the remainder being nitrogen gas, which is an inert gas.

[0221] Next, the mixture was heated and fired at a temperature of 820° C. for 1.5 hours under a supply of 1% by volume of compressed air using N 2 gas as a carrier (second heat treatment step).

[0222] That is, the heat treatment was carried out in an atmosphere of a second gas consisting of 1% by volume of air as an oxygen source and the remainder being nitrogen gas as an inert gas.

[0223] After the second heat treatment step, the substrate was further fired in an N2 gas atmosphere at 820°C for 0.5 hours.

[0224] From the X-ray diffraction of the obtained composite tungsten oxide microparticles according to Example 6, it was found that the hexagonal Cs 0.3 It was confirmed to be WO3. Quantitative analysis also revealed that it was Cs 0.27 WO 2.70 It was.

[0225] 25% by mass of the obtained composite tungsten oxide microparticles according to Example 6 and 75% by mass of pure water were mixed, and the obtained mixture was loaded into a paint shaker containing 0.3 mmφ ZrO beads and subjected to a pulverization and dispersion treatment for 10 hours, thereby obtaining a dispersion of composite tungsten oxide microparticles according to Example 6.

[0226] A portion of the dispersion of composite tungsten oxide microparticles according to Example 6 was separated, the solvent was removed from the separated dispersion, and then hexagonal Cs was detected by X-ray diffraction. 0.3 It was confirmed to be WO3, and its crystallite diameter was measured to be 30 nm.

[0227] Furthermore, the remaining dispersion of composite tungsten oxide microparticles according to Example 6 obtained was mixed with pure water to obtain a dispersion for forming a coating film according to Example 6, in which the concentration of composite tungsten oxide microparticles was 14 mass%.

[0228] Then, the surface-treated composite tungsten oxide particles according to Example 6 were obtained in the same manner as in Example 1, except that the coating film-forming dispersion according to Example 6 was used.

[0229] When the surface-treated composite tungsten oxide particles obtained in Example 6 were observed under a transmission electron microscope, the average particle size was 25 nm and the coating film thickness was 2 nm.

[0230] (2) Production of antifungal emulsion paint Next, 5 g of the composite tungsten oxide microparticle powder according to Example 6 was mixed with 45 g of an acrylic resin emulsion paint (46% by mass of aqueous solvent, 54% by mass of acrylic resin), and the resulting mixture was ultrasonically dispersed for 30 minutes to obtain an antifungal emulsion paint according to Example 6.

[0231] (3) Production of Antifungal Microparticle Dispersion Next, the obtained antifungal emulsion paint of Example 6 was applied to a glass substrate having a thickness of 3 mm using a bar coater to form a coating film.

[0232] The coating film was then allowed to air dry for 24 hours to produce an antifungal microparticle dispersion according to Example 6, and the antifungal properties of the obtained antifungal microparticle dispersion according to Example 6 were evaluated.

[0233] The results are also shown in Table 1 below.

[0234] Comparative Example 1 (1) Production of Composite Tungsten Oxide Fine Particles Cesium composite tungsten oxide (Cs) with a Cs / W (molar ratio) of 0.33 was used. 0.33 25% by mass of ZrO3 powder (YM-01 manufactured by Sumitomo Metal Mining Co., Ltd.) and 75% by mass of pure water were mixed, and the resulting mixture was loaded into a paint shaker containing 0.3 mm diameter ZrO2 beads, and subjected to a pulverization and dispersion treatment for 10 hours to obtain Cs according to Comparative Example 1. 0.33 A dispersion of WO3 fine particles was obtained.

[0235] The obtained Cs according to Comparative Example 1 0.33 A portion of the dispersion of WO3 fine particles was separated, and the solvent was removed from the separated dispersion. Then, Cs was detected by X-ray diffraction. 0.33 The crystal system of the WO3 fine particles was confirmed to be hexagonal, and the crystallite diameter was measured to be 32 nm.

[0236] Next, using vacuum fluidized drying, Cs according to Comparative Example 1 was 0.33 The solvent was evaporated from the remaining WO3 microparticle dispersion, and the resulting dried product was dry-pulverized in a hammer mill to obtain composite tungsten oxide microparticles according to Comparative Example 1.

[0237] When the obtained composite tungsten oxide microparticles according to Comparative Example 1 were observed under a transmission electron microscope, the average particle diameter was found to be 25 nm.

[0238] (2) Production of anti-fungal emulsion paint Next, 5 g of the composite tungsten oxide microparticle powder according to Comparative Example 1 was mixed with 45 g of an acrylic resin emulsion paint (46% by mass of aqueous solvent, 54% by mass of acrylic resin), and the resulting mixture was ultrasonically dispersed for 30 minutes to obtain an anti-fungal emulsion paint according to Comparative Example 1.

[0239] (3) Production of Antifungal Microparticle Dispersion Next, the obtained antifungal emulsion paint according to Comparative Example 1 was applied to a glass substrate having a thickness of 3 mm using a bar coater to form a coating film.

[0240] The coating film was then allowed to air dry for 24 hours to produce an antifungal microparticle dispersion according to Comparative Example 1, and the antifungal properties of the obtained antifungal microparticle dispersion according to Comparative Example 1 were evaluated.

[0241] The results are also shown in Table 1 below.

[0242]

[0243] [Confirmation] As can be seen from the antifungal property evaluation shown in Table 1, it is confirmed that the antifungal microparticle dispersions according to the examples have superior antifungal properties compared to the antifungal microparticle dispersion according to Comparative Example 1.

[0244] The antifungal emulsion paint of the present invention exhibits antifungal effects over a long period of time, and therefore has industrial applicability as a paint for the exterior walls of buildings and the like that are exposed to humid and hot environments.

[0245] 1 WO6 unit 2 Element M 11 Water-cooled quartz double tube 12 Reaction vessel 13 Vacuum exhaust device 14 Plasma generation gas supply port 15 Sheath gas supply port 16 Water-cooled copper coil for high-frequency plasma generation 17 Raw material powder carrier gas supply port 18 Raw material powder supply device 19 Gas supply device

Claims

1. A mildew-proof emulsion paint, characterized by containing composite tungsten oxide microparticles whose surfaces are coated with a coating film containing one or more types selected from the group consisting of hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of metal cyclic oligomer compounds, and polymers of hydrolysis products of metal cyclic oligomer compounds, and a resin emulsion.

2. 2. The antifungal emulsion paint according to claim 1, wherein the coating film has a thickness of 0.5 nm or more.

3. 2. The mildew-proofing emulsion paint according to claim 1, wherein the metal chelate compound or the cyclic metal oligomer compound contains one or more metal elements selected from the group consisting of Al, Zr, Ti, Si and Zn.

4. 2. The mildew-proofing emulsion paint according to claim 1, wherein the metal chelate compound or the metal cyclic oligomer compound has at least one type of group selected from the group consisting of an ether bond, an ester bond, an alkoxy group and an acetyl group.

5. The antifungal emulsion paint according to any one of claims 1 to 4, characterized in that the composite tungsten oxide microparticles are represented by the general formula MxWyOz (wherein M is one or more elements selected from H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb, W is tungsten, O is oxygen, and 0.001≦x / y≦1, 2.0≦z / y<4.0).

6. The antifungal emulsion paint according to claim 5, characterized in that M of the composite tungsten oxide microparticles represented by the general formula MxWyOz is one or more elements selected from Cs, K, Rb, Tl, In, and Ba.

7. 6. The mildew-proofing emulsion paint according to claim 5, wherein x / y of the composite tungsten oxide fine particles represented by the general formula MxWyOz satisfies 0.25≦x / y≦0.

35.

8. 6. The mildew-proofing emulsion paint according to claim 5, wherein the composite tungsten oxide fine particles have a hexagonal crystal structure.

9. 6. The antifungal emulsion paint according to claim 5, wherein the composite tungsten oxide fine particles have an average particle size of 10 nm to 200 nm.

10. 2. An anti-mildew microparticle dispersion formed by applying the anti-mildew emulsion paint according to claim 1, characterized in that it is composed of composite tungsten oxide microparticles whose surfaces are coated with a coating film containing one or more types selected from the group consisting of hydrolysis products of metal chelate compounds, polymers of hydrolysis products of metal chelate compounds, hydrolysis products of metal cyclic oligomer compounds, and polymers of hydrolysis products of metal cyclic oligomer compounds, and a solid resin in which the composite tungsten oxide microparticles are dispersed.

11. The antifungal microparticle dispersion according to claim 10, characterized in that the composite tungsten oxide microparticles are represented by the general formula MxWyOz (wherein M is one or more elements selected from H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb; W is tungsten; O is oxygen; and 0.001≦x / y≦1, 2.0≦z / y<4.0).

12. The antifungal microparticle dispersion according to claim 11, characterized in that M of the composite tungsten oxide microparticles represented by the general formula MxWyOz is one or more elements selected from the group consisting of Cs, K, Rb, Tl, In, and Ba.

13. 13. The antifungal microparticle dispersion according to claim 11, wherein x / y of the composite tungsten oxide microparticles represented by the general formula MxWyOz satisfies 0.25≦x / y≦0.

35.

14. 13. The antifungal microparticle dispersion according to any one of claims 10 to 12, wherein the composite tungsten oxide microparticles have a hexagonal crystal structure.

15. 13. The antifungal microparticle dispersion according to any one of claims 10 to 12, characterized in that the composite tungsten oxide microparticles have an average particle size of 10 nm to 200 nm.

16. 13. An article with an antifungal microparticle dispersion, comprising the antifungal microparticle dispersion according to any one of claims 10 to 12 formed on a substrate selected from glass, plastic and metal.