Surface-treated infrared-absorbing microparticle dispersion liquid and infrared-absorbing transparent substrate

Abstract

Provided are: a surface-treated infrared-absorbing microparticle dispersion liquid obtained by dispersing surface-treated infrared-absorbing microparticles having excellent hot / wet resistance and excellent infrared-absorbing characteristics in a liquid medium; and an infrared-absorbing transparent substrate having a coating layer in which the surface-treated infrared-absorbing microparticles are dispersed. The present invention provides: a surface-treated infrared-absorbing microparticle dispersion liquid which is formed by dispersing surface-treated infrared-absorbing microparticles in a prescribed liquid medium, and which is characterized in that: the surface-treated infrared-absorbing microparticles are dispersed in the prescribed liquid medium; and an infrared-absorbing transparent substrate which is produced using the surface-treated infrared-absorbing microparticle dispersion liquid. The surface-treated infrared-absorbing microparticles are formed by coating the surfaces of the infrared-absorbing microparticles with a film. The film contains one or more substances selected from the group consisting of a hydrolysis product of a metal chelate compound, a polymer of a hydrolysis product of a metal chelate compound, a hydrolysis product of a metal cyclic oligomer compound, and a polymer of a hydrolysis product of a metal cyclic oligomer compound.

Description

[0001] This application is a divisional application of the Chinese patent application with application number 201980030241.1, invention name “Surface-treated infrared absorbing microparticle dispersion and infrared absorbing transparent substrate” and application date April 18, 2019. Technical Field

[0002] The present invention relates to a surface treated infrared absorbing particle dispersion formed by dispersing surface treated infrared absorbing particles coated with a specified coating film in a specified liquid medium, and an infrared absorbing transparent substrate provided with a coating layer in which the surface treated infrared absorbing particles are dispersed. Background Art

[0003] In recent years, the demand for infrared absorbers has been rapidly increasing, and there have been many proposals related to infrared absorbers.

[0004] When considering these proposals from a functional point of view, there are proposals such as those aimed at sufficiently introducing visible light and shielding light in the near-infrared region in the fields of window materials for various buildings and vehicles, maintaining brightness and suppressing the rise in indoor temperature. In addition, there are proposals aimed at preventing infrared rays radiated from the front of PDP (plasma display panel) from causing erroneous operation of remote controllers for cordless phones and home appliances, or adversely affecting transmission-type optical communications.

[0005] Furthermore, these proposals are considered from the perspective of light-shielding components. For example, light-shielding components used as window materials, etc., include: light-shielding films containing inorganic pigments such as carbon black and titanium black that have absorption characteristics from the visible light region to the near-infrared region, or containing black pigments such as organic pigments such as aniline black that have strong absorption characteristics only in the visible light region, and semi-reflective mirror-type light-shielding components that are vapor-deposited with metals such as aluminum.

[0006] For example, the infrared shielding glass proposed in Patent Document 1 is a glass substrate on which a composite tungsten oxide film containing at least one metal ion selected from Group IIIa, Group IVa, Group Vb, Group VIb and Group VIIb of the periodic table is provided as a first layer from the substrate side, and a transparent dielectric film is provided as a second layer on the first layer, and a composite tungsten oxide film containing at least one metal ion selected from Group IIIa, Group IVa, Group Vb, Group VIb and Group VIIb of the periodic table is provided as a third layer on the second layer, and the refractive index of the second transparent dielectric film is lower than the refractive index of the first and third composite tungsten oxide films, so that the glass can be preferably used in areas requiring high visible light transmittance and good infrared shielding performance.

[0007] Furthermore, the infrared shielding glass proposed in Patent Document 2 is provided on a transparent glass substrate in the same manner as in Patent Document 1, wherein a first dielectric film as the first layer is provided from the substrate side, a tungsten oxide film as the second layer is provided on the first layer, and a second dielectric film as the third layer is provided on the second layer.

[0008] Furthermore, the heat shielding glass proposed in Patent Document 3 is provided on a transparent glass substrate in the same manner as Patent Document 1, with a composite tungsten oxide film containing the same metal element as in Patent Document 1 being provided as the first layer from the substrate side, and a transparent dielectric film being provided as the second layer on the first layer.

[0009] In addition, the sunlight control glass sheet with sunlight shielding properties proposed in Patent Document 4 is a metal oxide film selected from one or more of tungsten trioxide (WO3), molybdenum trioxide (MoO3), niobium pentoxide (Nb2O5), tantalum pentoxide (Ta2O5), vanadium pentoxide (V2O5) and vanadium dioxide (VO2) containing additive elements such as hydrogen, lithium, sodium or potassium, which is coated using a CVD method or a spraying method and then thermally decomposed at about 250°C to form.

[0010] Furthermore, the sunlight variable dimming heat insulating material proposed in Patent Document 5 is obtained by using tungsten oxide obtained by hydrolyzing tungstic acid and adding an organic polymer having a specific structure such as polyvinyl pyrrolidone to the tungsten oxide.

[0011] If the sunlight is irradiated to the variable dimming heat insulation material, the ultraviolet rays in the light will be absorbed by tungsten oxide to generate excited electrons and holes. The amount of pentavalent tungsten will increase significantly with a small amount of ultraviolet rays, which will speed up the coloring reaction and increase the coloring concentration. On the other hand, because the light is shielded, the pentavalent tungsten is very quickly oxidized to hexavalent tungsten, thereby increasing the color removal reaction. It is proposed to use this coloring / decolorizing property to make the coloring and decolorizing reaction of sunlight proceed quickly, and an absorption peak will appear at a wavelength of 1250nm in the near-infrared region during coloring, thereby obtaining a variable dimming heat insulation material for sunlight that can shield the near-infrared rays of sunlight.

[0012] On the other hand, the inventors of the present invention disclosed in Patent Document 6 that tungsten hexachloride is dissolved in alcohol, the medium is evaporated in this state, or the medium is evaporated after heating under reflux, and then heated at 100° C. to 500° C., thereby obtaining a tungsten oxide particle powder composed of tungsten trioxide or its hydrate or a mixture of the two. Therefore, it is disclosed that an electrochromic element is obtained using the tungsten oxide particles, and when protons are introduced into a film constituting a multilayer laminate, the optical properties of the film can be changed.

[0013] Further, Patent Document 7 proposes a method for preparing various tungsten bronzes represented by the general formula MxWO3 (where M is a metal element such as an alkali metal, alkaline earth metal, or rare earth element; 0 < x < 1) by using ammonium metatungstate and various water-soluble metal salts as raw materials, heating the dry solid of the mixed aqueous solution at a heating temperature of about 300 to 700°C, and supplying hydrogen added with an inert gas (addition amount: about 50 vol% or more) or water vapor (addition amount: about 15 vol% or less) during the heating. Therefore, it is proposed to perform this operation on a support to manufacture various tungsten bronze salt-coated composites and use them as electrode catalytic materials for fuel cells and the like.

[0014] Further, the inventors of the present invention disclosed in Patent Document 8 an infrared shielding material particle dispersion composed of infrared shielding material particles dispersed in a medium, the optical properties, conductivity, and manufacturing method of the infrared shielding material particle dispersion. The infrared shielding material particles are particles of tungsten oxide represented by the general formula WyOz (where W is tungsten; O is oxygen; 2.2 ≤ z / y ≤ 2.999) and / or particles of composite tungsten oxide represented by the general formula MxWyOz (where 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; W is tungsten; O is oxygen; 0.001 ≤ x / y ≤ 1, 2.2 ≤ z / y ≤ 3.0), and the particle diameter of the infrared shielding material particles is 1 nm or more and 800 nm or less.

[0015] Prior Art Documents

[0016] Patent Documents

[0017] Patent Document 1: Japanese Patent Laid-Open No. 8-59300

[0018] Patent Document 2: Japanese Patent Laid-Open No. 8-12378

[0019] Patent Document 3: Japanese Patent Laid-Open No. 8-283044

[0020] Patent Document 4: Japanese Patent Laid-Open No. 2000-119045

[0021] Patent Document 5: Japanese Patent Laid-Open No. 9-127559

[0022] Patent Document 6: Japanese Patent Laid-Open No. 2003-121884

[0023] Patent Document 7: Japanese Patent Application Laid-Open No. 8-73223

[0024] Patent Document 8: International Publication No. 2005 / 37932

[0025] Patent Document 9: International Publication No. 2010 / 55570 Summary of the invention

[0026] Technical Problems Solved by the Invention

[0027] According to the discussion of the inventors of the present invention, it is found that in the tungsten oxide particles and / or the optical components (transparent substrates, films, resin sheets, etc.) containing composite tungsten oxide particles, water vapor and moisture in the air slowly penetrate into the coating layer and solid resin of the optical component based on the usage and method. However, there is the following problem: if water vapor and moisture penetrate into the coating layer and the solid resin, the surface of the tungsten oxide particles and / or the composite tungsten oxide particles having a hexagonal crystal structure decomposes, the transmittance of light at a wavelength of 200 to 2600 nm increases over time, and the infrared absorption performance of the optical component gradually decreases.

[0028] It should be noted that the "coating layer" in the present invention refers to a solid dielectric film having a predetermined film thickness formed on a substrate at room temperature.

[0029] In addition, in the present invention, "solid resin" refers to a polymer medium that is solid at room temperature, including polymer media other than those formed by three-dimensional crosslinking. In addition, in the present invention, a polymer medium that is solid at room temperature can be referred to as a "resin".

[0030] Furthermore, according to the research of the inventors of the present invention, even in the case of the tungsten oxide fine particles or composite tungsten oxide fine particles dispersed in the medium disclosed in Patent Document 8, the surface of the fine particles is decomposed and degraded by water vapor and moisture in the air. In particular, it was found that the higher the surface activity of the tungsten oxide fine particles and the composite tungsten oxide fine particles, the greater the loss rate of the infrared absorption effect caused by the decomposition and degradation.

[0031] In the above situation, the inventor of the present invention disclosed in Patent Document 9 a kind of infrared shielding particles whose surface is coated with a tetrafunctional silane compound or its partial hydrolyzate and / or an organic metal compound and a method for manufacturing the same. The particles are infrared shielding particles with excellent water resistance and excellent infrared shielding properties. They are tungsten oxide represented by the general formula WyOz and / or composite tungsten oxide particles represented by the general formula MxWyOz, and the average primary particle size of the particles is greater than 1 nm and less than 800 nm.

[0032] However, infrared absorbing materials are basically used outdoors due to their characteristics and are often required to have high weather resistance. As an example of outdoor use, an infrared absorbing transparent substrate having a coating layer containing an infrared absorbing material on at least one surface of the transparent substrate can be cited. However, as market demand increases year by year, the infrared shielding particles disclosed in Patent Document 9 and the infrared absorbing transparent substrate using the same need to further improve water resistance and wet heat resistance.

[0033] The present invention was completed under the above circumstances, and its problem is to provide a surface-treated infrared-absorbing particle dispersion liquid formed by dispersing surface-treated infrared-absorbing particles having excellent moisture and heat resistance and excellent infrared absorption characteristics in a specified liquid medium, and an infrared-absorbing transparent substrate having a coating layer formed by dispersing the surface-treated infrared-absorbing particles.

[0034] Technical means to solve technical problems

[0035] In order to solve the above problems, the inventors of the present invention selected the tungsten oxide particles and / or composite tungsten oxide particles having excellent optical properties as infrared absorbing particles, and studied technical features that can improve the moisture and heat resistance and chemical stability of the infrared absorbing particles. As a result, the following technical features were conceived: the affinity with the surface of the infrared absorbing particles is excellent, and a compound is used and uniformly adsorbed on the surface of each particle, and a strong coating film is further formed on the surface of the particle, thereby coating the surface of each infrared absorbing particle.

[0036] The inventors of the present invention have further studied and found metal chelates or metal cyclic oligomer compounds as compounds that have excellent affinity for the infrared absorbing fine particles and form a strong coating film on the surface of the fine particles. Then, based on the results of further studies, the inventors found compounds that hydrolyzates of the metal chelates and metal cyclic oligomer compounds or polymers of the hydrolyzates generated when the metal chelates and metal cyclic oligomer compounds are hydrolyzed are uniformly adsorbed on the surface of each infrared absorbing fine particle and form a strong coating film.

[0037] That is, the surface of the tungsten oxide particles and / or composite tungsten oxide particles is coated with a coating film containing at least one selected from the group consisting of a metal chelate hydrolysate, a polymer of a hydrolysate of a metal chelate compound, a hydrolysate of a metal cyclic oligomer compound, and a polymer of a hydrolysate of a metal cyclic oligomer compound (hereinafter referred to as "surface-treated infrared-absorbing particles"). It was found that the surface-treated infrared-absorbing particles have excellent resistance to moisture and heat.

[0038] Then, the inventors of the present invention have come up with an infrared absorbing transparent substrate having a coating layer in which surface-treated infrared absorbing fine particles are dispersed. In addition, the inventors have come up with the idea that a dispersion of surface-treated infrared absorbing fine particles dispersed in a specific liquid medium is preferably used as a coating liquid for forming the coating layer, thereby completing the present invention.

[0039] That is, the first invention to solve the technical problem is as follows:

[0040] A surface-treated infrared absorbing particle dispersion liquid is formed by dispersing the surface-treated infrared absorbing particles in a liquid medium, wherein:

[0041] The surface treated infrared absorbing particles are infrared absorbing particles whose surfaces are coated with a film containing one or more selected from the group consisting of hydrolysates of metal chelate compounds, polymers of hydrolysates of metal chelate compounds, hydrolysates of metal cyclic oligomer compounds, and polymers of hydrolysates of metal cyclic oligomer compounds.

[0042] The second invention is as follows:

[0043] According to the surface treated infrared absorbing fine particle dispersion of the first invention, the metal chelate compound or the metal cyclic oligomer compound contains one or more metal elements selected from the group consisting of Al, Zr, Ti, Si and Zn.

[0044] The third invention is as follows:

[0045] In the surface treated infrared absorbing fine particle dispersion according to the first or second invention, the metal chelate compound or the metal cyclic oligomer compound has one or more selected from the group consisting of an ether bond, an ester bond, an alkoxy group, and an acetyl group.

[0046] The fourth invention is as follows:

[0047] The surface treated infrared absorbing fine particle dispersion according to any one of the first to third inventions, wherein the infrared absorbing fine particles are infrared absorbing fine particles represented by the following general formula: general formula WyOz (wherein W is tungsten, O is oxygen, and 2.2≤z / y≤2.999) and / or 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, 0.001≤x / y≤1, and 2.0≤z / y≤3.0).

[0048] The fifth invention is as follows:

[0049] According to the surface treated infrared absorbing fine particle dispersion according to the fourth invention, M is one or more elements selected from the group consisting of Cs, K, Rb, Tl, In, and Ba.

[0050] The sixth invention is as follows:

[0051] The surface treated infrared absorbing fine particle dispersion according to any one of the first to fifth inventions, wherein the infrared absorbing fine particles are tungsten oxide fine particles having a hexagonal crystal structure and / or composite tungsten oxide fine particles having a hexagonal crystal structure.

[0052] The seventh invention is as follows:

[0053] The surface treated infrared absorbing fine particle dispersion according to any one of the first to sixth aspects of the present invention, wherein the surface treated infrared absorbing fine particle dispersion further contains a glass coating agent.

[0054] The eighth invention is as follows:

[0055] The surface treated infrared absorbing fine particle dispersion according to the seventh invention, wherein:

[0056] The liquid medium is one or more selected from aromatic hydrocarbons, ketones, ethers, alcohols, and water.

[0057] The glass coating agent is one or more selected from the group consisting of silane coupling agents and silane alkoxides.

[0058] The ninth invention is as follows:

[0059] According to the seventh invention, the surface treated infrared absorbing fine particle dispersion liquid, wherein the liquid medium is one or more selected from aromatic hydrocarbons, ketones, and ethers,

[0060] The glass coating agent is one or more selected from polysilazane and polyorganosilane.

[0061] The tenth invention is as follows:

[0062] An infrared absorbing transparent substrate is an infrared absorbing transparent substrate formed by providing a coating layer on at least one surface of one or more transparent substrates, wherein:

[0063] The coating layer contains surface treated infrared absorbing particles,

[0064] The surface treated infrared absorbing particles are infrared absorbing particles whose surface is coated with a film containing one or more selected from the group consisting of hydrolysates of metal chelate compounds, polymers of hydrolysates of metal chelate compounds, hydrolysates of metal cyclic oligomer compounds, and polymers of hydrolysates of metal cyclic oligomer compounds.

[0065] The eleventh invention is as follows:

[0066] According to the infrared absorbing transparent substrate of the tenth invention, the metal chelate compound or the metal cyclic oligomer compound contains one or more metal elements selected from the group consisting of Al, Zr, Ti, Si and Zn.

[0067] The twelfth invention is as follows:

[0068] According to the infrared absorbing transparent substrate of the tenth or eleventh invention, the metal chelate compound or the metal cyclic oligomer compound has one or more selected from the group consisting of an ether bond, an ester bond, an alkoxy group, and an acetyl group.

[0069] The thirteenth invention is as follows:

[0070] The infrared absorbing transparent substrate according to any one of the tenth to twelfth inventions, wherein

[0071] The infrared absorbing particles are infrared absorbing particles represented by the following general formula:

[0072] Infrared absorbing particles represented by the general formula WyOz (wherein W is tungsten, O is oxygen, 2.2≤z / y≤2.999) and / or 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, 0.001≤x / y≤1, and 2.0≤z / y≤3.0).

[0073] The fourteenth invention is as follows:

[0074] According to the infrared absorbing transparent substrate of the thirteenth invention, the M is one or more elements selected from the group consisting of Cs, K, Rb, Tl, In, and Ba.

[0075] The fifteenth invention is as follows:

[0076] The infrared absorbing transparent substrate according to any one of the tenth to fourteenth inventions, wherein the infrared absorbing fine particles are tungsten oxide fine particles having a hexagonal crystal structure and / or composite tungsten oxide fine particles having a hexagonal crystal structure.

[0077] The sixteenth invention is as follows:

[0078] The infrared absorbing transparent substrate according to any one of the tenth to fifteenth aspects of the present invention, wherein the coating layer further contains a glass coating agent.

[0079] The seventeenth invention is as follows:

[0080] According to the infrared absorbing transparent substrate of the sixteenth invention, the glass coating agent is one or more selected from the group consisting of a silane coupling agent, a silane alkoxide, a polysilazane, and a polyorganosilane.

[0081] The eighteenth invention is as follows:

[0082] The infrared absorbing transparent substrate according to any one of the tenth to seventeenth inventions, wherein the transparent substrate is at least one selected from a transparent glass substrate and a transparent resin substrate.

[0083] Effects of the Invention

[0084] The surface-treated infrared absorbing fine particles of the present invention and the surface-treated infrared absorbing fine particle powder containing the surface-treated infrared absorbing fine particles have excellent infrared absorbing properties and excellent resistance to moisture and heat. As a result, by using a dispersion of the surface-treated infrared absorbing fine particles containing the surface-treated infrared absorbing fine particles as a coating liquid and providing a coating layer on a predetermined substrate, an infrared absorbing transparent substrate having excellent infrared absorbing properties and excellent resistance to moisture and heat can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 is a schematic plan view of the crystal structure of a composite tungsten oxide having a hexagonal crystal structure.

[0086] Figure 2 This is a transmission electron microscope photograph of the surface treated infrared absorbing fine particles of Example 1 at a magnification of 300,000. DETAILED DESCRIPTION

[0087] With respect to the infrared absorbing transparent substrate having a coating layer in which surface-treated infrared absorbing particles are dispersed, and the surface-treated infrared absorbing particle dispersion which is preferably a coating liquid forming the coating layer of the present invention, [1] infrared absorbing particles, [2] a surface treatment agent for infrared absorbing particles, [3] a method for coating the surface of infrared absorbing particles, [4] a method for producing a powder of surface-treated infrared absorbing particles, [5] a heat treatment of the powder of surface-treated infrared absorbing particles, [6] a dispersion of surface-treated infrared absorbing particles, and [7] an infrared absorbing transparent substrate are described in detail in this order.

[0088] [1] Infrared absorbing particles

[0089] The infrared absorbing particles used in the infrared absorbing transparent substrate, the surface-treated infrared absorbing particle dispersion, and the surface-treated infrared absorbing particle powder of the present invention are infrared absorbing particles represented by the following general formula: WyOz (wherein W is tungsten, O is oxygen, 2.2≤z / y≤2.999), and / or MxWyOz (wherein M is 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, one or more elements selected from the group consisting of Yb, W is tungsten, O is oxygen, 0.001≤x / y≤1, 2.0≤z / y≤3.0).

[0090] It is generally known that materials containing free electrons have a high wavelength due to plasma vibration.

[0091] Electromagnetic waves around the region of 200nm to 2600nm sunlight show reflection and absorption responses. Therefore, it is known that if the powder particles of the material are formed into particles smaller than the wavelength of light, the geometric scattering in the visible light region (wavelength 380nm to 780nm) is reduced and transparency in the visible light region can be obtained.

[0092] In addition, the term "transparency" in the present invention means "little scattering of light in the visible light region and high transmittance".

[0093] On the other hand, since there are no effective free electrons in tungsten oxide (WO3), the absorption and reflection characteristics in the infrared region are few, and it cannot be effectively used as an infrared absorbing micromaterial. However, it is known that by forming WO3 with oxygen deficiency or adding positive elements such as Na to WO3, the technical characteristics of composite tungsten oxides will generate free electrons in tungsten oxide or composite tungsten oxides, and absorption characteristics derived from free electrons will be shown in the infrared region. Therefore, it is suggested that by analyzing single crystals of these materials with free electrons, free electron response can be generated for light in the infrared region.

[0094] The inventors of the present invention have found a particularly effective range for infrared absorbing particles in a specific portion of the composition range of tungsten and oxygen, and have conceived tungsten oxide particles and composite tungsten oxide particles that are transparent in the visible light region and absorb in the infrared region.

[0095] Here, the tungsten oxide particles and / or composite tungsten oxide particles having a hexagonal crystal structure of the infrared absorbing particles of the present invention are described in order: (1) tungsten oxide particles, (2) composite tungsten oxide particles, and (3) infrared absorbing particles.

[0096] (1) Tungsten oxide particles

[0097] The tungsten oxide fine particles of the present invention are fine particles of tungsten oxide represented by the general formula WyOz (wherein W is tungsten, O is oxygen, and 2.2≤z / y≤2.999).

[0098] It is known that in the tungsten oxide represented by the general formula WyOz, the composition range of tungsten and oxygen is such that free electrons can be generated in the tungsten oxide by reducing the composition ratio of oxygen to tungsten to less than 3.

[0099] Furthermore, when the infrared absorbing particles are referred to as WyOz, it is preferably 2.2≤z / y≤2.999. If the z / y value is 2.2 or more, the WO2 crystal phase other than the target can be avoided in the tungsten oxide, and chemical stability as a material can be obtained, so that it can become an effective infrared absorbing particle. On the other hand, if the z / y value is less than 2.999, a necessary amount of free electrons will be generated, and it will become an infrared absorbing particle with better efficiency.

[0100] (2) Composite tungsten oxide particles

[0101] The composite tungsten oxide (WO3) is obtained by adding the following element M. Then, by controlling the oxygen content of the WO3 and using the element M that generates free electrons in combination, better infrared absorbing particles can be obtained. By adopting this technical feature, free electrons are generated in the composite tungsten oxide, and strong absorption characteristics derived from free electrons are exhibited in the near-infrared region, which can effectively become near-infrared absorbing particles with a wavelength of about 1000nm.

[0102] When the general formula of infrared absorbing particles used in combination with the control of the oxygen amount and the addition of the element M for generating free electrons is recorded as MxWyOz (wherein M is the following element M, W is tungsten, and O is oxygen), infrared absorbing particles that satisfy the relationship of 0.001≤x / y≤1, 2.2≤z / y≤3 are preferred.

[0103] Here, the element M in the composite tungsten oxide is preferably selected from one or more of 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.

[0104] Furthermore, from the viewpoint of stability of 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. In addition, from the viewpoint of improving optical properties and weather resistance when used as infrared absorbing microparticles, the element M is particularly preferably an element belonging to an alkali metal, an alkaline earth metal element, a transition metal element, a VIB group element, or a VB group element.

[0105] For the x / y value representing the amount of element M added, if the x / y value is greater than 0.001, the composite tungsten oxide will generate a sufficient amount of free electrons, and the target infrared absorption effect can be obtained. Then, the more the element M is added, the more the free electron supply increases, and the infrared absorption efficiency also increases. When the x / y value is about 1, the effect is saturated. In addition, if the x / y value is less than 1, it is possible to avoid the generation of impurity phases in the infrared absorption particles, so it is preferred.

[0106] In addition, regarding the z / y value indicating the control of the oxygen amount, the composite tungsten oxide represented by MxWyOz acts in the same mechanism as the tungsten oxide represented by WyOz, and when z / y=3.0 or 2.0≤z / y≤2.2, there is a supply of free electrons due to the addition of the element M. Therefore, it is preferably 2.0≤z / y≤3.0, more preferably 2.2≤z / y≤3.0, and particularly preferably 2.45≤z / y≤3.0.

[0107] Furthermore, when the composite tungsten oxide particles have a hexagonal crystal structure, the transmittance of the particles in the visible light region is improved, and the absorption in the infrared region is also improved. Figure 1 Provide explanation.

[0108] Figure 1 In the figure, six octahedrons formed by WO6 units represented by symbol 11 are assembled to form a hexagonal void, and the element M represented by symbol 12 is arranged in the void to form one unit, and a plurality of these one units are assembled to form a hexagonal crystal structure.

[0109] In order to obtain the effect of improving light transmission in the visible light region and the effect of improving light absorption in the infrared region, the composite tungsten oxide fine particles contain Figure 1 The unit structure described above is sufficient, and the composite tungsten oxide fine particles may be crystalline or amorphous.

[0110] When the composite tungsten oxide fine particles having a hexagonal crystal structure have a uniform crystal structure, the amount of element M added is preferably 0.2 or more and 0.5 or less, and more preferably 0.33, in terms of x / y value. When the x / y value is 0.33, it is considered that the element M is arranged in all hexagonal voids.

[0111] When cations of element M are added to the hexagonal voids, light transmission in the visible light region is improved, and light absorption in the infrared region is also improved. Here, generally speaking, when an element M with a larger ionic radius is added, it is easier to form the hexagonal crystal. Specifically, when one or more of Cs, K, Rb, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn are added, more preferably when one or more of Cs, K, Rb, Tl, In, and Ba are added, it is easier to form the hexagonal crystal. As typical particles, Cs 0.33 WOz、Cs 0.03 R 0.30 WOz、Rb 0.33 WOz, K 0.33 WOz、Ba 0.33 WOz (2.0≤Z≤3.0), etc. Of course, even if it is an element other than these, it is not limited to the above elements as long as the above element M exists in the hexagonal voids formed by the WO6 unit.

[0112] In addition to hexagonal crystals, tetragonal and cubic composite tungsten oxides are also effective as infrared absorbing particles. According to the crystal structure, there is a tendency for the absorption position in the infrared region to change, and the absorption position tends to move toward the long wavelength side in the order of cubic crystal <tetragonal crystal <hexagonal crystal. In addition, with this phenomenon, the order of absorption reduction in the visible light region is as follows: hexagonal crystal, tetragonal crystal, cubic crystal. Therefore, in order to further transmit light in the visible light region and further shield light in the infrared region, it is preferred to use hexagonal composite tungsten oxide. However, the optical property tendency described here is at best a rough tendency, and there will be changes depending on the type of added elements, the amount of addition, and the amount of oxygen, and the present invention is not limited to this.

[0113] (3) Infrared absorbing particles

[0114] The infrared absorbing particles of the present invention contain the tungsten oxide particles and / or composite tungsten oxide particles. The infrared absorbing particles of the present invention greatly absorb near-infrared light, especially light with a wavelength of about 1000 nm, so the transmitted color tone is mostly blue to green.

[0115] Furthermore, the particle size of the infrared absorbing fine particles of the present invention is preferably 1 nm or more and 800 nm or less, and more preferably 100 nm or less. From the viewpoint of exerting more excellent infrared absorption characteristics, the particle size of the fine particles is preferably 10 nm or more and 100 nm or less, more preferably 10 nm or more and 80 nm or less, and particularly preferably 10 nm or more and 60 nm or less. It was found that the most excellent infrared absorption characteristics can be exerted when the particle size is within the range of 10 nm or more and 60 nm or less.

[0116] Here, the particle size refers to the average diameter of each unagglomerated infrared absorbing fine particle, and is the average particle size of the infrared absorbing fine particles contained in the infrared absorbing transparent substrate, the surface-treated infrared absorbing fine particle dispersion, and the surface-treated infrared absorbing fine particle powder described below. It should be noted that the particle size is calculated from an electron microscope image of the infrared absorbing fine particles.

[0117] On the other hand, the dispersed particle size of the infrared absorbing fine particles of the present invention can be selected according to the intended use, and the dispersed particle size is a concept including the aggregate particle size which is different from the particle size.

[0118] When the infrared absorbing microparticles of the present invention are used for maintaining transparency, they preferably have a dispersed particle size of 800 nm or less. The reason is that particles with a dispersed particle size of less than 800 nm will not completely shield light due to scattering, thereby maintaining visibility in the visible light region and also maintaining transparency efficiently. In particular, when transparency in the visible light region is important, it is preferred to further consider scattering caused by particles.

[0119] When the reduction of scattering brought by the infrared absorbing particles is emphasized, the dispersed particle size is preferably less than 200nm, and more preferably less than 100nm. The reason is that if the dispersed particle size of the particles is small, the scattering of light in the visible light region of wavelength 400nm to 780nm caused by geometric scattering or Mie scattering is reduced, and as a result, the infrared absorbing film can be prevented from being like foggy glass and unable to obtain clear transparency. That is, if the dispersed particle size is less than 200nm, the geometric scattering or Mie scattering is reduced, and it becomes a Rayleigh scattering region. In the Rayleigh scattering region, the scattered light is proportional to the sixth power of the particle size, so as the dispersed particle size decreases, the scattering decreases, and thus the transparency improves.

[0120] Furthermore, if the dispersed particle size is below 100 nm, scattered light is very small, so it is preferred. From the viewpoint of avoiding light scattering, the smaller the dispersed particle size, the more preferred. If the dispersed particle size is above 1 nm, it is easy to carry out industrial production.

[0121] The infrared absorbing fine particles of the present invention dispersed in a medium with a dispersed particle size of 800 nm or less can have a visible light transmittance of 85% or less and a haze value of 30% or less. If the haze value is greater than 30%, it will be like foggy glass and clear transparency cannot be obtained.

[0122] The dispersed particle size of the infrared absorbing fine particles can be measured using ELS-8000 manufactured by Otsuka Electronics Co., Ltd., etc., based on the dynamic light scattering method.

[0123] Furthermore, among tungsten oxide particles and composite tungsten oxide particles, so-called “Magneli phase” having a composition ratio of 2.45≤z / y≤2.999 is chemically stable and has excellent absorption characteristics in the infrared region, and therefore is preferably used as infrared absorbing particles.

[0124] In addition, from the viewpoint of giving play to excellent infrared absorption characteristics, the crystallite diameter of the infrared absorption particles is preferably 1 nm or more and 200 nm or less, more preferably 1 nm or more and 100 nm or less, and further preferably 10 nm or more and 70 nm or less. When measuring the crystallite diameter, the measurement of the X-ray diffraction pattern using the powder X-ray diffraction method (θ-2θ method) and the analysis using the Rietveld method are used. In the measurement of the X-ray diffraction pattern, for example, the powder X-ray diffraction device "X'Pert-PRO / MPD" manufactured by Spectris PANalytical Co., Ltd. can be used.

[0125] [2] Surface treatment agent for infrared absorbing particles

[0126] The surface treatment agent used for coating the surface of the infrared absorbing fine particles of the present invention is at least one selected from the group consisting of hydrolyzates of metal chelate compounds, polymers of hydrolyzates of metal chelate compounds, hydrolyzates of metal cyclic oligomer compounds, and polymers of hydrolyzates of metal cyclic oligomer compounds.

[0127] The metal chelate compound or metal cyclic oligomer compound preferably contains one or more selected from the group consisting of an ether bond, an ester bond, an alkoxy group, and an acetyl group from the viewpoint of being preferably a metal alkoxide, a metal acetylacetonate, a metal carboxylate, and the like.

[0128] Here, the surface treatment agent of the infrared absorbing fine particles of the present invention is described in the order of (1) metal chelate compound, (2) metal cyclic oligomer compound, (3) metal chelate compound, hydrolyzate of metal cyclic oligomer compound, and polymers thereof, and (4) addition amount of the surface treatment agent.

[0129] (1) Metal chelate compounds

[0130] The metal chelate compound used in the present invention is preferably at least one selected from the group consisting of Al-, Zr-, Ti-, Si-, and Zn-based chelate compounds containing an alkoxy group.

[0131] Examples of aluminum chelate compounds include aluminum alkoxides such as aluminum ethoxide, aluminum isopropoxide, aluminum sec-butoxide, and aluminum diisopropoxide mono-sec-butoxide, or polymers thereof; aluminum ethyl acetoacetate diisopropoxide, aluminum tris(ethyl acetoacetate), aluminum octyl acetoacetate diisopropoxide, aluminum stearyl acetone diisopropoxide, aluminum bis(ethyl acetoacetate) monoacetylacetonate, aluminum tris(acetylacetonate), and the like.

[0132] These compounds are alkoxy-containing aluminum chelate compounds obtained as follows: aluminum alkoxide is dissolved in, for example, a non-protonic solvent, petroleum solvent, hydrocarbon solvent, ester solvent, ketone solvent, ether solvent, amide solvent, etc., β-diketone, β-ketoester, monohydric or polyhydric alcohol, fatty acid, etc. are added to the solution, and the solution is heated to reflux and subjected to a ligand substitution reaction.

[0133] Examples of the zirconium dioxide chelate compound include zirconium alkoxides such as zirconium ethoxide and zirconium butoxide, or polymers thereof; zirconium tributoxystearate, zirconium tetraacetylacetonate, zirconium tributoxysacetylacetonate, zirconium bis(acetylacetonate)dibutoxysacetonate, zirconium ethyl acetylacetate tributoxysacetonate, and zirconium bis(acetylacetonate)butoxysacetylacetonate.

[0134] Examples of the titanium chelate compound include titanium alkoxides such as methyl titanate, ethyl titanate, isopropyl titanate, butyl titanate, and 2-ethylhexyl titanate, and polymers thereof; titanium acetylacetonate, titanium tetraacetylacetonate, titanium octanediol, titanium ethyl acetoacetate, titanium lactate, and titanium triethanolamine.

[0135] Silicon chelate compounds can use tetrafunctional silane compounds represented by the general formula Si(OR)4 (wherein R is the same or different monovalent hydrocarbon group with 1 to 6 carbon atoms) or their hydrolysis products. Specific examples of tetrafunctional silane compounds include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, etc. In addition, it can be applied to silane monomers (or oligomers) formed by hydrolyzing part or all of the alkoxy groups of these alkoxysilane monomers to form silanol groups (Si-OH), as well as polymers that undergo self-condensation through hydrolysis reactions.

[0136] In addition, the hydrolysis products of tetrafunctional silane compounds (meaning all hydrolysis products of tetrafunctional silane compounds) include: silane monomers, tetramers and pentamers, and polymers (silicone resins) having a weight average molecular weight (Mw) of about 800 to 8000, in which a part or all of the alkoxy groups are hydrolyzed to form silanol groups (Si-OH). In addition, the alkoxysilyl groups (Si-OR) in the alkoxysilane monomers are not completely hydrolyzed to form silanol groups (Si-OH) during the hydrolysis reaction.

[0137] Preferred zinc chelate compounds include zinc salts of organic carboxylates such as zinc octoate, zinc laurate, and zinc stearate; zinc acetylacetonate chelate, zinc benzoylacetonate chelate, zinc dibenzoylmethane chelate, and zinc ethyl acetoacetate chelate.

[0138] (2) Metallocyclic oligomer compounds

[0139] The metal cyclic oligomer compound of the present invention is preferably at least one selected from Al-based, Zr-based, Ti-based, Si-based, and Zn-based cyclic oligomer compounds, for example, cyclic octanol alumina, cyclic isopropyl alcohol alumina, cyclic stearyl alcohol alumina, and the like.

[0140] (3) Hydrolysis products of metal chelate compounds or metal cyclic oligomer compounds, and polymers thereof

[0141] The present invention hydrolyzes the total amount of alkoxy groups, ether bonds and ester bonds in the metal chelate compound or metal cyclic oligomer compound to obtain a hydrolyzate having a hydroxyl group or a carboxyl group, or hydrolyzes a part of the compound to obtain a partial hydrolyzate, and / or a polymer obtained by self-condensation through the hydrolysis reaction, and coats the surface of the infrared absorbing particles of the present invention to form a coating film, thereby obtaining the surface-treated infrared absorbing particles of the present invention.

[0142] That is, the hydrolyzate of the present invention is a concept including a partial hydrolyzate.

[0143] It should be noted that, in the present invention, “in order to impart moisture-heat resistance to infrared absorbing fine particles, a coating film is formed on the surface of the fine particles using one or more selected from the group consisting of a hydrolysate of a metal chelate compound, a polymer of a hydrolysate of a metal chelate compound, a hydrolysate of a metal cyclic oligomer compound, and a polymer of a hydrolysate of a metal cyclic oligomer compound” is sometimes simply referred to as “coating film”.

[0144] But, for example be present in the reaction system of organic solvents such as alcohol, generally with regard to stoichiometric composition, even if must have sufficient water in system, but according to the kind, concentration of this organic solvent, not all metal chelate compounds as starting materials, alkoxyl group, ether bond, the ester bond of metal cyclic oligomer compound, all hydrolyze.Therefore, according to the condition of following surface coating method, even after being hydrolyzed sometimes, still can take in carbon C in the molecule of this hydrolysate and become amorphous state.As a result, coating film becomes to contain undecomposed metal chelate compounds and / or metal cyclic oligomer compound sometimes.

[0145] When the coating film contains undecomposed metal chelate compounds and / or metal cyclic oligomer compounds, the hydrolysis reaction and dehydration condensation reaction of the silane coupling agent, silane alkoxide, and polysilazane in the glass coating agent used in the subsequent process of preparing the infrared absorbing transparent substrate may proceed rapidly. In addition, as a result of the rapid progress of the reaction, the polymer of the silane coupling agent, silane alkoxide, and polysilazane acts as a crosslinking agent, causing the surface-treated infrared absorbing fine particles in the surface-treated infrared absorbing fine particle dispersion to aggregate, and it may be impossible to obtain the desired infrared absorbing transparent substrate having both visible light transparency and infrared absorption characteristics.

[0146] To avoid this, when the coating film contains undecomposed metal chelate compounds and / or metal cyclic oligomer compounds, it is preferred to promote the decomposition of these compounds by heat treatment as described below, and to allow the reaction to proceed until a hydrolysis product having low reactivity is obtained.

[0147] That is, the coating film used to coat the surface of the infrared absorbing particles of the present invention is preferably a polymer obtained as follows: a part or the total amount of the alkoxy groups, ether bonds, and ester bonds of the metal chelate compound or metal cyclic oligomer compound is hydrolyzed to form a hydrolysis product having hydroxyl groups or carboxyl groups, and the hydrolysis reaction is followed by self-condensation.

[0148] (4) Amount of surface treatment agent added

[0149] The amount of the metal chelate compound or metal cyclic oligomer compound added is preferably 0.05 parts by weight or more and 1000 parts by weight or less in terms of metal element relative to 100 parts by weight of the infrared absorbing fine particles, more preferably 5 parts by weight or more and 500 parts by weight or less, and particularly preferably 50 parts by weight or more and 250 parts by weight or less.

[0150] When the amount of the metal chelate compound or metal cyclic oligomer compound added is 0.05 parts by weight or more, the hydrolyzate of these compounds or the polymer of the hydrolyzate has the effect of coating the surface of the infrared absorbing fine particles, thereby improving the moist heat resistance.

[0151] Furthermore, the amount of the metal chelate compound or metal cyclic oligomer compound added is less than 1000 parts by weight, thereby avoiding excessive adsorption on the infrared absorbing particles. In addition, the improvement in moisture and heat resistance due to surface coating is not saturated, and it is expected that the coating effect will be improved.

[0152] Furthermore, by adding the metal chelate compound or the metal cyclic oligomer compound in an amount below 1000 parts by weight, it is possible to avoid an excessive amount of adsorption on the infrared absorbing microparticles, because when removing the medium, the microparticles are easily granulated with each other through the hydrolyzate of the metal chelate compound or the metal cyclic oligomer compound or the polymer of the hydrolyzate. By avoiding unnecessary granulation between the microparticles, good transparency can be ensured.

[0153] In addition, it is also possible to avoid the increase in the amount of addition and the processing time due to the excess of the metal chelate compound or the metal cyclic oligomer compound, which results in an increase in production cost. From an industrial point of view, the amount of the metal chelate compound or the metal cyclic oligomer compound added is preferably less than 1000 parts by weight.

[0154] Furthermore, the coating film of the surface-treated infrared absorbing particles of the present invention preferably has a thickness of 0.5 nm or more. This is because when the coating film has a thickness of 0.5 nm or more, it is believed that the surface-treated infrared absorbing particles exhibit sufficient moisture and heat resistance and chemical stability. On the other hand, from the perspective of ensuring the specified optical properties of the surface-treated infrared absorbing particles, the coating film preferably has a thickness of 100 nm or less.

[0155] As described above, the film thickness of the coating film is preferably 0.5 nm to 20 nm, and more preferably 1 nm to 10 nm.

[0156] It should be noted that the film thickness of the coating film can be measured from a transmission electron microscope image of the surface-treated infrared absorbing fine particles. Figure 2 In the 300,000-times transmission electron microscope image of the surface treated infrared absorbing fine particles of Example 1 shown, the portion sandwiched between two parallel solid lines where the infrared absorbing fine particles crystal lattice pattern (atomic arrangement in the crystal) is not observed corresponds to the coating film.

[0157] [3] Method for coating the surface of infrared absorbing particles

[0158] When the surface of the infrared absorbing particles of the present invention is coated to produce surface-treated infrared absorbing particles, the infrared absorbing particles are first dispersed in water or an organic solvent containing water to obtain a dispersion of infrared absorbing particles for forming a coating film (also referred to as "dispersion for forming a coating film" in the present invention).

[0159] On the other hand, the surface treatment agent described in "[2] Surface treatment agent for infrared absorbing fine particles" is prepared.

[0160] Then, a surface treatment agent is added to the dispersion liquid for coating film formation while mixing and stirring, thereby producing a substance in which the surface of the infrared absorbing microparticles is coated with a coating film containing one or more selected from the group consisting of hydrolyzates of metal chelate compounds, polymers of hydrolyzates of metal chelate compounds, hydrolyzates of metal cyclic oligomer compounds, and polymers of hydrolyzates of metal cyclic oligomer compounds.

[0161] When preparing the dispersion for forming the coating film of the present invention, it is preferred to finely grind the infrared absorbing particles such as tungsten oxide and / or composite tungsten oxide in advance, and then disperse them in water or a suitable organic solvent containing water to form a monodisperse state. At this time, the dispersion concentration of tungsten oxide and / or composite tungsten oxide is preferably greater than 0.01% by mass and less than 80% by mass. If it is within this dispersion concentration range, the liquid stability of the dispersion is excellent. In addition, when the appropriate liquid medium, dispersant, coupling agent, and surfactant are selected, even if it is placed in a constant temperature bath at a temperature of 40°C, gelation and particle sedimentation of the dispersion will not occur after more than 6 months, and the dispersed particle size can be maintained in the range of 1 to 200 nm.

[0162] Furthermore, in the pulverization and dispersion treatment process, it is important to ensure the dispersed state and prevent the particles from agglomerating. The reason is that during the surface treatment process of the infrared absorbing particles in the next process, the infrared absorbing particles can be prevented from agglomerating and thus being coated with the surface in the form of agglomerates, and even the agglomerates can be prevented from remaining in the infrared absorbing particle dispersion described below, which can prevent the transparency of the infrared absorbing particle dispersion or the infrared absorbing substrate from being reduced.

[0163] As a specific method of the pulverization and dispersion treatment, for example, there can be mentioned a pulverization and dispersion treatment method using a device such as a bead mill, a ball mill, a sand mill, a paint shaker, an ultrasonic homogenizer, etc. Among them, from the viewpoint of a shorter time to reach a desired dispersed particle size, it is preferred to use a bead mill, a ball mill, a sand mill, a paint shaker, etc., which uses a medium medium such as a ball, a grinding ball, Ottawa sand, etc., for pulverization and dispersion treatment.

[0164] The surface treatment agent is added while mixing and stirring the obtained dispersion for coating film formation. At this time, the dispersion for coating film formation is preferably diluted to an appropriate concentration using water or an appropriate organic solvent containing water. The reason is as follows: if the dispersion concentration of tungsten oxide and / or composite tungsten oxide as infrared absorbing particles is diluted to 0.1 mass % or more and 20 mass % or less, more preferably 1 mass % or more and 10 mass % or less, all infrared absorbing particles are uniformly coated on the surface.

[0165] The following describes the addition in the order of (1) a surface coating method of infrared absorbing particles using a coating film forming dispersion containing water as a medium and (2) a surface coating method of infrared absorbing particles using a coating film forming dispersion using an organic solvent containing water.

[0166] (1) Method for coating the surface of infrared absorbing fine particles using a dispersion for coating film formation using water as a medium

[0167] The inventors of the present invention have found that in the preparation of the coating film forming dispersion liquid, the coating film forming dispersion liquid with water as the medium is stirred and mixed while adding the surface treatment agent of the present invention thereto, and the hydrolysis reaction of the added metal chelate compound and metal ring oligomer compound is preferably completed immediately. In addition, from the viewpoint of uniformly coating the surface of the infrared absorbing fine particles, the surface treatment agent is preferably added dropwise.

[0168] It is believed that this is affected by the reaction order of the added surface treatment agent of the present invention. That is, in the dispersion liquid for forming a coating film with water as the medium, the hydrolysis reaction of the surface treatment agent must be carried out first, and then the polymerization reaction to generate the hydrolysis product occurs. As a result, it is believed that the amount of carbon C remaining in the surface treatment agent molecules present in the coating film can be reduced compared to the case where the medium is non-aqueous. By reducing the amount of carbon C remaining in the surface treatment agent molecules present in the coating film, it is believed that a coating film formed by coating the surface of each infrared absorbing fine particle with high density can be formed.

[0169] When the surface treatment agent is added dropwise, it is preferred to add dropwise a substance obtained by diluting the surface treatment agent itself with an appropriate solvent in order to adjust the amount of the surface treatment agent added per unit time. The solvent used for dilution preferably has high compatibility with water as a dispersion medium for forming a coating film, but does not react with the surface treatment agent. Specifically, for example, solvents such as alcohols, ketones, and glycols can be preferably used.

[0170] 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.

[0171] It should be noted that in the dispersion for forming a coating film with water as the medium, the metal chelate compound, metal cyclic oligomer compound, their hydrolysis products, and polymers of the hydrolysis products decompose into metal ions immediately after addition, and the decomposition into the metal ions is completed when it becomes a saturated aqueous solution.

[0172] On the other hand, in the coating film-forming dispersion liquid using water as a medium, the infrared absorbing fine particles of the present invention are surely dispersed by electrostatic repulsion.

[0173] As a result, the surfaces of all infrared absorbing particles are coated with a coating film containing one or more selected from the group consisting of hydrolysates of metal chelate compounds, polymers of hydrolysates of metal chelate compounds, hydrolysates of metal cyclic oligomer compounds, and polymers of hydrolysates of metal cyclic oligomer compounds, thereby producing surface-treated infrared absorbing particles of the present invention.

[0174] (2) Surface coating method of infrared absorbing fine particles using a coating film forming dispersion using an organic solvent containing water

[0175] A variation of the method of coating the surface of infrared absorbing particles using a coating film-forming dispersion containing water as a medium is preferably a method in which an organic solvent containing water is used as the coating film-forming dispersion medium and the reaction sequence is carried out while adjusting the amount of water added to an appropriate value.

[0176] This production method is preferably used when the water content in the coating film-forming dispersion is reduced in view of the convenience of subsequent steps.

[0177] Specifically, the coating film forming dispersion liquid with an organic solvent as a medium is stirred and mixed, and the surface treatment agent of the present invention and pure water are simultaneously added dropwise. At this time, the medium temperature, which may affect the reaction rate, and the dropping speed of the surface treatment agent and pure water are appropriately controlled. In addition, as an organic solvent, any solvent such as alcohols, ketones, glycols, etc. that dissolves in water at room temperature may be selected.

[0178] Furthermore, in this "(2)", when the surface treatment agent is added dropwise, in order to adjust the amount of the surface treatment agent added per unit time, it is preferred to add dropwise the surface treatment agent itself diluted with an appropriate solvent. In this case, the solvent used for dilution is preferably a solvent that has high compatibility with the organic solvent containing water as the medium of the dispersion liquid for forming the coating film but does not react with the surface treatment agent. Specifically, solvents such as alcohols, ketones, and glycols are preferably used.

[0179] In addition, when using a commercially available metal chelate compound or metal cyclic oligomer compound as the surface treatment agent, the measures and the dilution ratio of the surface treatment agent are the same as those in the above-mentioned "(1)".

[0180] [4] Method for producing surface treated infrared absorbing fine particle powder

[0181] The surface treated infrared absorbing fine particle powder of the present invention is obtained as follows: after the infrared absorbing fine particles in the dispersion liquid for forming the coating film are coated on the surface, the solvent in the dispersion liquid (a mixture of the dispersion liquid for forming the coating film, the surface treatment agent, water and other solvents) is removed by appropriate drying treatment. As the equipment for drying treatment, from the viewpoint of being able to heat and / or reduce pressure and easily recover the mixed methyl group of the ultrafine particles, there can be listed: an atmospheric dryer, a universal mixer, a belt mixer, a vacuum fluidized dryer, a vibration fluidized dryer, a freeze dryer, a RIBOCONE, a rotary kiln, a spray dryer, a PALCON dryer, etc., but it is not limited to these.

[0182] When the infrared absorbing fine particles are composite tungsten oxide fine particles, it is desirable to dry them at a temperature higher than the temperature at which the solvent in the dispersion volatilizes and at a temperature at which the element M does not separate in the atmosphere, preferably 150° C. or lower.

[0183] [5] Heat treatment of surface treated infrared absorbing fine particle powder

[0184] As described in “Item [2] Surface treatment agent for infrared absorbing particles (4)”, when the surface-treated infrared absorbing particles and the coating film in the surface-treated infrared absorbing particle powder contain undecomposed metal chelate compounds and / or metal cyclic oligomer compounds, it is preferred to promote the decomposition of the chelate compounds and / or oligomer compounds by heat treatment.

[0185] The heat treatment is carried out in an atmospheric environment or an inert gas environment. In this case, the heat treatment temperature is preferably above the temperature at which the metal chelate compound and / or the metal ring oligomer compound decomposes and below the temperature at which the infrared absorbing particles begin to crystallize. Specifically, when the infrared absorbing particles are tungsten oxide particles or composite tungsten oxide particles, the temperature is preferably in the range of 200° C. or above and below 500° C.

[0186] It should be noted that when the infrared absorbing fine particles are composite tungsten oxide fine particles, it is preferable to perform heat treatment so as not to separate the element M, and the heat treatment environment is preferably an inert gas environment.

[0187] By controlling the temperature, the decomposition of the undecomposed metal chelate compound and / or metal cyclic oligomer compound is promoted without causing the growth of the infrared absorbing fine particles, thereby obtaining the surface treated infrared absorbing fine particles of the present invention.

[0188] [6] Surface treated infrared absorbing microparticle dispersion

[0189] The surface-treated infrared absorbing fine particle dispersion of the present invention can be obtained by using the surface-treated infrared absorbing fine particle powder of the present invention described in "[4] Method for producing surface-treated infrared absorbing fine particle powder" or "[5] Heat treatment of surface-treated infrared absorbing fine particle powder".

[0190] The surface-treated infrared absorbing microparticle dispersion of the present invention is a coating liquid prepared by dispersing the surface-treated infrared absorbing microparticles of the present invention in a liquid medium, and containing a glass coating agent, and further containing an acid, a dispersant, and other additives as required. As the liquid medium, it is preferred to use one or more selected from organic solvents, oils and fats, liquid plasticizers, compounds polymerized by curing, and water.

[0191] The surface-treated infrared-absorbing microparticle dispersion of the present invention is described below in the order of (1) organic solvents, (2) oils and fats, (3) liquid plasticizers, (4) glass coating agents, (5) acids, (6) dispersants, (7) other additives, and (8) methods for producing the surface-treated infrared-absorbing microparticle dispersion.

[0192] (1) Organic solvents

[0193] The organic solvent used in the surface-treated infrared-absorbing fine particle dispersion of the present invention may be, for example, alcohols, ketones, hydrocarbons, glycols, water, or the like.

[0194] For example, alcohol solvents such as methanol, ethanol, 1-propanol, isopropanol, butanol, amyl alcohol, benzyl alcohol, and diacetone alcohol can be used;

[0195] Ketone solvents such as acetone, methyl ethyl ketone, dimethyl ketone, methyl acetone, methyl isobutyl ketone, cyclohexanone, and isophorone;

[0196] Ester solvents such as 3-methylmethoxypropionate and n-butyl acetate;

[0197] Diol derivatives such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol isopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate;

[0198] Amides such as formamide, N-methylformamide, dimethylformamide, dimethylacetamide, and N-methyl-2-pyrrolidone;

[0199] Aromatic hydrocarbons such as toluene and xylene;

[0200] Ethylene dichloride, chlorobenzene, etc.

[0201] Among these organic solvents, dimethyl ketone, methyl ethyl ketone, methyl isobutyl ketone, toluene, propylene glycol monomethyl ether acetate, n-butyl acetate, and the like are particularly preferably used.

[0202] (2) Grease

[0203] The oil used in the surface-treated infrared-absorbing fine particle dispersion of the present invention is preferably a vegetable oil or a compound derived from a vegetable oil.

[0204] As the vegetable oil, for example, drying oils such as linseed oil, sunflower oil, tung oil, and perilla oil; semi-drying oils such as sesame oil, cottonseed oil, rapeseed oil, soybean oil, rice bran oil, and mustard oil; and non-drying oils such as olive oil, coconut oil, palm oil, and dehydrated castor oil can be used.

[0205] As the compound derived from plant oil, fatty acid monoesters obtained by directly reacting fatty acids in plant oil with monoalcohols, ethers, and the like can be used.

[0206] Also, commercially available petroleum-based solvents may be used as the grease.

[0207] Moreover, as commercially available petroleum-based solvents, for example, (registered trademark) ISOPER E, EXXSOL Hexane, EXXSOL Heptane, EXXSOL E, EXXSOL D30, EXXSOL D40, EXXSOL D60, EXXSOL D80, EXXSOLD95, EXXSOL D110, and EXXSOL D130 (all manufactured by Exxon Mobil) can be used.

[0208] (3) Liquid plasticizer

[0209] As the liquid plasticizer added to the surface-treated infrared-absorbing fine particle dispersion of the present invention, for example, plasticizers of compounds of monohydric alcohol and organic acid ester, ester plasticizers such as polyhydric alcohol organic acid ester compounds, phosphoric acid plasticizers such as organic phosphoric acid plasticizers, etc. can be used. It should be noted that all of them are preferably liquid at room temperature.

[0210] Among them, a plasticizer that is an ester compound synthesized from a polyol and a fatty acid can be preferably used. The ester compound synthesized from a polyol and a fatty acid is not particularly limited, and for example, an alcohol ester obtained by the following reaction can be used: a glycol such as triethylene glycol, tetraethylene glycol, and tripropylene glycol, and a monobasic organic acid such as butyric acid, isobutyric acid, hexanoic acid, 2-ethylbutyric acid, heptanoic acid, n-octanoic acid, 2-ethylhexanoic acid, nonanoic acid (nonanoic acid), and decanoic acid are reacted.

[0211] Furthermore, ester compounds formed by tetraethylene glycol, tripropylene glycol and the above-mentioned monobasic organic acid and the like can be used.

[0212] Among them, for example, triethylene glycol dihexanoate, triethylene glycol di-2-ethylbutyrate, triethylene glycol dioctanoate, triethylene glycol di-2-ethylhexanoate and the like fatty acid esters of triethylene glycol can be preferably used. In addition, triethylene glycol fatty acid esters can be preferably used.

[0213] (4) Glass coating agent

[0214] By including a glass coating agent in the surface-treated infrared absorbing fine particle dispersion of the present invention, abrasion resistance can be imparted to the infrared absorbing transparent substrate of the present invention. From this viewpoint, it is preferred that the surface-treated infrared absorbing fine particle dispersion of the present invention further include a glass coating agent.

[0215] As the glass coating agent contained, for example, metal alkoxides and metal organic compounds containing any one or more of Sn, Ti, In, Si, Zr, and Al can be used. Among them, compounds containing Si are preferred, and for example, silane coupling agents, silane alkoxides, polyorganosiloxanes, polysilazanes, and organosilicon compounds having organic groups bonded to silicon atoms, and one or more of the organic groups are organic groups having reactive functional groups, are preferably used. It should be noted that all of them are preferably liquid at room temperature.

[0216] As the polysilazane, for example, perhydropolysilazane, partially organized polysilazane, organosilazane, etc. can be used.

[0217] As an organic silicon compound having an organic group bonded to a silicon atom, and one or more of the organic groups being an organic group having a reactive functional group, a compound having Si and having the following reactive groups: an amino group, a mercapto group, an epoxy group, and a (meth)acryloyloxy group is preferred. For example, the following can be used: 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-ureapropyltriethoxysilane, N-(N-vinylbenzyl-2-amino ethyl)-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropylmethyldimethoxysilane, 3-isocyanatepropylmethyldiethoxysilane, and the like.

[0218] It should be noted that when the glass coating agent is one or more selected from silane coupling agents and silane alkoxides, the liquid medium is preferably one or more selected from aromatic hydrocarbons, ketones, ethers, alcohols, and water. In addition, when the glass coating agent is one or more selected from polysilazanes and polyorganosilanes, the liquid medium is preferably one or more selected from aromatic hydrocarbons, ketones, and ethers.

[0219] (5)Acid

[0220] From the viewpoint of promoting the hydrolysis of the hydrolyzable silicon monomer and the like contained in the glass coating agent, it is preferred to add an acid to the surface-treated infrared-absorbing fine particle dispersion of the present invention.

[0221] Examples of the acid added to the surface treated infrared absorbing fine particle dispersion of the present invention include nitric acid, hydrochloric acid, sulfuric acid, trichloroacetic acid, trifluoroacetic acid, phosphoric acid, methanesulfonic acid, p-toluenesulfonic acid, oxalic acid, etc. Volatile acids are preferred because they evaporate when heated and do not remain in the cured film.

[0222] The acid plays a catalytic role in promoting the hydrolysis of the hydrolyzable silicon monomer and the hydrolysis condensate of the silicon monomer. The amount of acid added to the dispersion can be set without particular limitation within the range in which the catalytic effect can be exerted, and is preferably about 0.001 to 0.1 mol / L in terms of volume ratio relative to the total amount of the dispersion.

[0223] (6) Dispersant

[0224] In order to further improve the dispersion stability of the surface-treated infrared absorbing particles and avoid coarsening of the dispersed particle size due to re-agglomeration, various dispersants, surfactants, coupling agents and the like are preferably added to the surface-treated infrared absorbing particles dispersion of the present invention.

[0225] The dispersant, coupling agent, and surfactant can be selected according to the application, and preferably have an amino group, a hydroxyl group, a carboxyl group, or an epoxy group as a functional group. These functional groups have the effect of adsorbing on the surface of the surface-treated infrared absorbing particles to prevent agglomeration and make them uniformly dispersed. More preferably, it is a polymer dispersant having any of these functional groups in the molecule.

[0226] Preferred specific examples of commercially available dispersants include SOLSPERSE (registered trademark) 3000, SOLSPERSE 9000, SOLSPERSE 11200, SOLSPERSE 13000, SOLSPERSE 13240, SOLSPERSE 13650, SOLSPERSE 13940, SOLSPERSE 16000, SOLSPERSE 17000, SOLSPERSE 18000, SOLSPERSE 20000, SOLSPERSE 21000, SOLSPERSE 24000SC, SOLSPERSE 24000GR, SOLSPERSE 26000, SOLSPERSE 27000, SOLSPERSE 28000, SOLSPERSE 31845, SOLSPERSE 32000, SOLSPERSE 32500, SOLSPERSE 32550, SOLSPERSE 32600, SOLSPERSE 33000, SOLSPERSE 33500, SOLSPERSE 34750, SOLSPERSE 35100, SOLSPERSE 35200, SOLSPERSE36600, SOLSPERSE 37500, SOLSPERSE 38500, SOLSPERSE 39000, SOLSPERSE 41000, SOLSPERSE 41090, SOLSPERSE 53095, SOLSPERSE 55000, SOLSPERSE 56000, SOLSPERSE76500, etc.;

[0227] Disperbyk (registered trademark)-101, Disperbyk-103, Disperbyk-107, Disperbyk-108, Disperbyk-109, Disperbyk-110, Disperbyk-111, Disperbyk-112, Disperbyk-116, Disperbyk-130, Disperbyk-140, Disperbyk-142, Disperbyk-145, Disperbyk-154, Disperbyk-161, Disperbyk-162, Disperbyk-163, Disperbyk-164, Disperbyk-165, Disperbyk-166, Disperbyk-167, Disperbyk-168, Disperbyk-170, Disperbyk-171, Disperbyk-174, Disperbyk-180, Disperbyk-181, Disperbyk-182, Disperbyk-183, Disperbyk-184, Disperbyk-185, Disperbyk-190, Disperbyk-2000, Disperbyk-2001, Disperbyk-2020, Disperbyk-2025, Disperbyk-2050, Disperbyk-2070, Disperbyk-2095, Disperbyk-2150, Disperbyk-2155; Anti-Terra (registered trademark)-U, Anti-Terra-203, Anti-Terra-204; BYK (registered trademark)-P104, BYK-P104S, BYK-220S, BYK-6919, etc.; manufactured by BYK-Chemie·Japan Co., Ltd.

[0228] EFKA EFKA (registered trademark)-4008, EFKA-4046, EFKA-4047, EFKA-4015, EFKA-4020, EFKA-4050, EFKA-4055, EFKA-40 manufactured by Additives 60. EFKA-4080, EFKA-4300, EFKA-4330, EFKA-4400, EFKA-4401, EFKA-4402, EFKA-4403, EFKA-4500, EFKA-4510, EFKA- 4530, EFKA-4550, EFKA-4560, EFKA-4585, EFKA-4800, EFKA-5220, EFKA-6230, JONCRYL (registered trademark)-67, JONCRYL-678, JONCRYL-586, JONCRYL-611, JONCRYL-680, JONCRYL-682, JONCRYL-690, JONCRYL-819, JONCRYL-JDX5050, etc.

[0229] TERPLUS (registered trademark) MD1000, TERPLUS D1180, TERPLUS D1330, etc. manufactured by Otsuka Chemical Co., Ltd.

[0230] AJISPER (registered trademark) PB-711, AJISPER PB-821, AJISPER PB-822, etc. manufactured by Ajinomoto Fine-Techno Co., Ltd.

[0231] (7) Other additives

[0232] In order to control the coating property, leveling property and drying property, various surfactants and resin components may be contained in a small amount within a range of 5% by mass or less of the dispersion liquid in the surface-treated infrared absorbing microparticle dispersion of the present invention. Examples of the surfactant include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants.

[0233] Furthermore, in order to impart flexibility to the infrared absorbing transparent substrate obtained using the dispersion, various organic resins such as silicone resins, acrylic resins, polyester resins, polyurethane resins, hydrophilic organic resins containing polyoxyalkylene groups, and epoxy resins may be contained in a small amount in the range of 5% by mass or less of the dispersion.

[0234] In order to impart crack prevention properties to the infrared absorbing transparent substrate obtained, the dispersion may contain, for example, a thermosetting resin, a thermoplastic resin, an ultraviolet curable resin, etc., in an amount of 20% by mass or less. More specifically, examples include acrylic resins, epoxy resins, polyester resins, amine resins, polyurethane resins, furan resins, silicone resins, and modified products of these resins.

[0235] (8) Method for producing a dispersion of surface-treated infrared absorbing microparticles

[0236] When manufacturing the surface-treated infrared absorbing microparticle dispersion of the present invention, the surface-treated infrared absorbing microparticles of the present invention, the glass coating agent, and the dispersant and / or other additives added as needed are added together to the liquid medium and dispersed. The dispersion method can be listed in the specific method of crushing and dispersion treatment described in "[3] Surface coating method of infrared absorbing microparticles". However, if the crushing and dispersion treatment is excessive, resulting in the crushing of primary particles in the surface-treated infrared absorbing microparticles, sometimes uncoated new surfaces will appear, making it impossible to ensure moisture and heat resistance. Therefore, the crushing and dispersion treatment preferably retains the minimum dispersion limit.

[0237] It should be noted that the "(5) acid" is preferably added in the final stage of the dispersion preparation from the viewpoint of suppressing excessive reaction with the glass coating agent.

[0238] [7] Infrared absorbing transparent substrate

[0239] The infrared absorbing transparent substrate of the present invention has a coating layer formed by using the surface treated infrared absorbing microparticle dispersion of the present invention as a coating liquid on at least one surface of the transparent substrate. The coating layer is obtained by curing a glass coating agent in which the surface treated infrared absorbing microparticles of the present invention are dispersed.

[0240] The infrared absorbing transparent substrate of the present invention has excellent moisture and heat resistance and chemical stability, and is suitable for use as an infrared absorbing material.

[0241] The infrared absorbing transparent substrate of the present invention is described in the order of (1) the transparent substrate used for the infrared absorbing transparent substrate, (2) the method for manufacturing the infrared absorbing transparent substrate, (3) the moisture and heat resistance of the infrared absorbing transparent substrate, and (4) the measurement of the film thickness of the coating layer on the infrared absorbing transparent substrate.

[0242] (1) Transparent substrate used for infrared absorbing transparent substrate

[0243] As the transparent substrate, a transparent glass substrate or a transparent resin substrate can be used, and the surface state and durability of the necessary plate, sheet, film, etc. are not particularly limited as long as they do not cause problems.

[0244] Specific examples of the transparent glass substrate include functional glasses such as transparent glass and green glass.

[0245] Specific examples of transparent resin substrates include plates, sheets, and films containing the following transparent polymers: polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; cellulose polymers such as cellulose diacetate and triacetyl cellulose; acrylic polymers such as polycarbonate polymers and polymethyl methacrylate; styrene polymers such as polystyrene and acrylonitrile-styrene copolymers; olefin polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, and ethylene-propylene copolymers; amide polymers such as vinyl chloride polymers and aromatic polyamides; imide polymers, sulfone polymers, and polyethersulfone polymers; polyetheretherketone polymers; polyphenylene sulfide polymers; vinyl alcohol polymers; vinylidene chloride polymers; vinyl butyral polymers, aromatic ester polymers, polyoxymethylene polymers, epoxy polymers, and transparent polymers such as various binary and ternary copolymers, graft copolymers, and hybrids thereof.

[0246] (2) Method for producing infrared absorbing transparent substrate

[0247] The surface-treated infrared absorbing microparticle dispersion of the present invention is used to form a coating layer on a transparent substrate according to a known method, and then cured according to a specified method to produce an infrared absorbing transparent substrate in which the surface-treated infrared microparticles of the present invention are dispersed in a solid medium. As the curing method, there can be cited a method of curing by drying, irradiating ultraviolet rays or electron beams, and heat treatment.

[0248] Among them, it is preferred to use a surface-treated infrared absorbing microparticle dispersion containing a glass coating agent, and after forming a coating layer, heat treatment is used to solidify the glass coating agent. This is because by adopting this structure, wear resistance can be imparted to the infrared absorbing transparent substrate. The heat treatment temperature after the coating layer is formed is preferably above 100°C and below 600°C, and more preferably above the boiling point of the solvent in the coating liquid and below 500°C. This is because if the heat treatment temperature reaches above 100°C, the polymerization reaction of the metal alkoxide and / or the hydrolyzed polymer of the metal alkoxide contained in the coating layer can be terminated. In addition, if the heat treatment temperature reaches above 100°C, water and organic solvents as solvents will not remain in the coating layer, so these solvents will not become the cause of the reduction in visible light transmittance. On the other hand, if the heat treatment temperature is below 600°C, thermal degradation of the surface-treated infrared absorbing microparticles can be suppressed.

[0249] (3) Moisture and heat resistance of infrared absorbing transparent substrates

[0250] The infrared absorbing transparent substrate of the present invention has a visible light transmittance set at about 80% and when exposed to a hot and humid environment at a temperature of 85°C and a relative humidity of 90% for 9 days, the change in sunlight transmittance before and after the exposure is less than 4.0%, and has excellent resistance to heat and humidity.

[0251] (4) Measurement of film thickness of coating layer on infrared absorbing transparent substrate

[0252] The film thickness measurement of the coating layer on the infrared absorbing transparent substrate of the present invention can be carried out using a stylus surface roughness meter or the like. Specifically, a surface-treated infrared absorbing microparticle dispersion is applied to a specified smooth substrate to obtain a coating film. Before the coating film is cured, a portion of the coating film is peeled off using a razor. The peeled coating film before curing is placed on another smooth substrate, and after curing to form a coating layer using an appropriate method, the height difference between the substrate and the coating layer is measured using a stylus surface roughness meter to obtain the film thickness.

[0253] Example

[0254] Hereinafter, the present invention will be described in detail with reference to the following examples, but the present invention is not limited to the following examples.

[0255] In the Examples and Comparative Examples, the particle size of the fine particles in the dispersion for forming a coating film or the dispersion of the surface-treated infrared absorbing fine particles is expressed as the average value measured by a particle size measuring device based on a dynamic light scattering method (ELS-8000 manufactured by Otsuka Electronics Co., Ltd.). In addition, the crystallite diameter is measured by a powder X-ray diffraction method (θ-2θ method) using a powder X-ray diffraction device (X'Pert-PRO / MPD manufactured by Spectris PANalytical Co., Ltd.), and then calculated using the Rietveld method.

[0256] The thickness of the coating film of the surface treated infrared absorbing particles was determined from 300,000-times photographic data obtained using a transmission electron microscope (HF-2200 manufactured by Hitachi, Ltd.). The portion where the lattice pattern of the infrared absorbing particles was not observed was defined as the coating film, and the thickness of the coating film was read.

[0257] The film thickness of the coating layer on the infrared absorbing transparent substrate of the present invention is measured by using a stylus-type surface roughness meter (SURFCOM-5000DX manufactured by Tokyo Seimitsu Co., Ltd.).

[0258] First, a surface-treated infrared absorbing microparticle dispersion is coated on a 3 mm thick glass substrate using a designated rod coater to form a coating film. Before the coating film is cured, a portion of the coating film is peeled off using a razor. The peeled coating film before curing is placed on another smooth substrate and cured using an appropriate method to form a coating layer to obtain an infrared absorbing transparent substrate. Then, a stylus-type surface roughness meter is used to measure the height difference between the glass substrate and the coating layer to obtain the film thickness of the coating layer.

[0259] The optical properties of the infrared absorbing transparent substrate were measured using a spectrophotometer (U-4100 manufactured by Hitachi, Ltd.), and the visible light transmittance and solar transmittance were calculated in accordance with JIS R 3106. The haze value of the infrared absorbing transparent substrate was measured using a haze meter (HM-150 manufactured by Murakami Color Co., Ltd.) and calculated in accordance with JIS K 7105.

[0260] The method for evaluating the moisture and heat resistance of an infrared absorbing transparent substrate is to expose the infrared absorbing transparent substrate having a visible light transmittance of about 80% to a moist and hot atmosphere at a temperature of 85°C and a relative humidity of 90% for 9 days. Then, for example, in the case of hexagonal cesium tungsten bronze, if the change in solar transmittance before and after the exposure is 4.0% or less, the moisture and heat resistance is judged to be good, and if the change exceeds 4.0%, the moisture and heat resistance is judged to be insufficient.

[0261] [Example 1]

[0262] Hexagonal cesium tungsten bronze (Cs) with a Cs / W (molar ratio) of 0.33 0.33 A mixture of 25 mass % of WO2 (ZrO2) powder (YM-01, 2.0 ≤ Z ≤ 3.0 manufactured by Sumitomo Metal Mining Co., Ltd.) and 75 mass % of pure water was placed in a paint shaker containing 0.3 mm ZrO2 beads and subjected to pulverization and dispersion treatment for 10 hours to obtain CsO2 of Example 1. 0.33 WOz particle dispersion. 0.33 The dispersed particle size of WOz particles was measured and found to be 100 nm. In addition, the particle size measurement was set to a particle refractive index of 1.81 and a non-spherical particle shape. In addition, pure water was used as the background for measurement, and the solvent refractive index was set to 1.33. In addition, after removing the solvent from the obtained dispersion, the Cs 0.33 The crystallite diameter of the WOz particles was found to be 32 nm.

[0263] The obtained Cs 0.33 The dispersion of WOz particles is mixed with pure water to obtain Cs 0.33 The coating film-forming dispersion A of Example 1 having a WOz fine particle concentration of 2 mass %.

[0264] On the other hand, 2.5 mass % of ethyl acetoacetate aluminum diisopropylate as an aluminum-based chelate compound and 97.5 mass % of isopropyl alcohol (IPA) were mixed to form the surface treatment agent a of Example 1.

[0265] 890 g of the obtained coating film-forming dispersion A was placed in a beaker, and while being vigorously stirred using a stirrer equipped with blades, 360 g of the surface treatment agent a was added dropwise over 3 hours.

[0266] After the surface treatment agent a was added dropwise, the mixture was further stirred at a temperature of 20° C. for 24 hours to prepare a aging solution of Example 1. Then, the medium was evaporated from the aging solution using a vacuum fluidized drying method, and the obtained dried solid was heat-treated at 200° C. for 1 hour in a nitrogen atmosphere, and the obtained powder was dry-pulverized using, for example, a hammer mill to obtain a surface-treated infrared absorbing fine particle powder of Example 1.

[0267] Here, regarding the coating thickness of the surface treated infrared absorbing fine particles of Example 1, Figure 2 The 300,000-fold transmission electron microscope photo shown in the figure shows that the thickness is 2 nm (the Cs 0.33 The crystal lattice pattern (atomic arrangement in the crystal) of WOz particles, the film thickness of the part sandwiched by two parallel solid lines).

[0268] 10 g of the surface-treated infrared absorbing fine particle powder of Example 1 was mixed with 23 g of isopropyl alcohol, 16 g of tetramethoxysilane, and 10 g of 3-glycidoxypropyltrimethoxysilane to obtain a mixed solution. The obtained mixed solution was loaded into a paint shaker containing 0.3 mm ZrO2 beads and subjected to pulverization and dispersion treatment for 1 hour. Then, 40 g of 0.1 mol / L nitric acid was added and stirred at a temperature of 20°C for 1 hour to obtain a dispersion of the surface-treated infrared absorbing fine particles of Example 1.

[0269] After removing the solvent from the obtained dispersion of the surface-treated infrared-absorbing fine particles, the crystallite diameter of the surface-treated infrared-absorbing fine particles was measured and found to be 28 nm.

[0270] It should be noted that tetramethoxysilane and 3-glycidoxypropyltrimethoxysilane are glass coating agents of silane alkoxides.

[0271] The surface treated infrared absorbing fine particle dispersion of Example 1 was applied to a 3 mm thick glass substrate using a bar coater (IMC-700 manufactured by Imoto Seisakusho Co., Ltd.) to form a coating film. The coating film was heated at 150° C. for 30 minutes to form a coating layer, thereby obtaining the infrared absorbing transparent substrate of Example 1. In addition, the film thickness of the coating layer was measured and found to be 3 μm.

[0272] The optical properties of the infrared absorbing transparent substrate of Example 1 were measured. The results showed that the visible light transmittance was 79.7%, the solar transmittance was 46.6%, and the haze value was 0.4%.

[0273] The infrared absorbing transparent substrate of Example 1 was exposed to a hot and humid environment at a temperature of 85°C and a relative humidity of 90% for 9 days, and then its optical properties were measured. The results showed that the visible light transmittance was 82.8%, the solar transmittance was 50.5%, and the haze was 0.4%. The changes in the visible light transmittance and the solar transmittance due to exposure to the hot and humid environment were 3.1% and 3.9%, respectively, which were small values, and the haze did not change.

[0274] The production conditions of the surface treated infrared absorbing fine particle powder of Example 1 are shown in Table 1, the production conditions of the surface treated infrared absorbing fine particle dispersion are shown in Table 2, and the optical property evaluation results of the infrared absorbing transparent substrate are shown in Table 3.

[0275] [Examples 2 and 3]

[0276] Except for changing the amount of surface treatment agent a and the time of dropwise addition, the same operation as in Example 1 was carried out to obtain surface treated infrared absorbing microparticle powders, surface treated infrared absorbing microparticle dispersions, and infrared absorbing transparent substrates of Examples 2 and 3, and the same evaluations as in Example 1 were performed.

[0277] The production conditions of the surface treated infrared absorbing fine particle powders of Examples 2 and 3 are shown in Table 1, the production conditions of the surface treated infrared absorbing fine particle dispersion are shown in Table 2, and the optical property evaluation results of the infrared absorbing transparent substrate are shown in Table 3.

[0278] [Example 4]

[0279] The aging solution of Example 1 was left to stand for 1 hour to separate the surface-treated infrared absorbing fine particle powder from the medium in a solid-liquid manner. Then, only the medium as the supernatant was removed to obtain an infrared absorbing fine particle slurry. The obtained infrared absorbing fine particle slurry was dried at 80° C. for 3 hours in an air atmosphere, and the obtained powder was dry-pulverized with a hammer mill to obtain the surface-treated infrared absorbing fine particle powder of Example 4.

[0280] The surface-treated infrared-absorbing fine particle powder of Example 4 was used instead of the surface-treated infrared-absorbing fine particle powder of Example 1. The same operation as Example 1 was carried out to obtain the surface-treated infrared-absorbing fine particle dispersion and infrared-absorbing transparent substrate of Example 4, and the same evaluation as Example 1 was performed.

[0281] The manufacturing conditions of the surface treated infrared absorbing fine particle powder of Example 4 are shown in Table 1, the manufacturing conditions of the surface treated infrared absorbing fine particle dispersion are shown in Table 2, and the optical property evaluation results of the infrared absorbing transparent substrate are shown in Table 3.

[0282] [Example 5]

[0283] Surface treatment agent b of Example 5 was obtained by mixing 2.4 mass % of zirconium tributoxide acetylacetonate and 97.6 mass % of isopropyl alcohol.

[0284] The surface treated infrared absorbing fine particle powder, surface treated infrared absorbing fine particle dispersion and infrared absorbing transparent substrate of Example 5 were obtained in the same manner as in Example 1 except that surface treating agent b was used instead of surface treating agent a, and the same evaluations as in Example 1 were performed.

[0285] The production conditions of the surface treated infrared absorbing fine particle powder of Example 5 are shown in Table 1, the production conditions of the surface treated infrared absorbing fine particle dispersion are shown in Table 2, and the optical property evaluation results of the infrared absorbing transparent substrate are shown in Table 3.

[0286] [Example 6]

[0287] Surface treatment agent c of Example 6 was obtained by mixing 2.6% by mass of bis(ethyl acetoacetate)diisopropoxytitanium and 97.4% by mass of isopropyl alcohol.

[0288] The surface treated infrared absorbing fine particle powder, surface treated infrared absorbing fine particle dispersion and infrared absorbing transparent substrate of Example 6 were obtained in the same manner as in Example 1 except that surface treating agent c was used instead of surface treating agent a, and the same evaluations as in Example 1 were performed.

[0289] The manufacturing conditions of the surface treated infrared absorbing fine particle powder of Example 6 are shown in Table 1, the manufacturing conditions of the surface treated infrared absorbing fine particle dispersion are shown in Table 2, and the optical property evaluation results of the infrared absorbing transparent substrate are shown in Table 3.

[0290] [Example 7]

[0291] A mixed solution obtained by mixing 25 mass % of cubic sodium tungsten bronze powder (manufactured by Sumitomo Metal Mining Co., Ltd.) with a Na / W (molar ratio) of 0.33 and 75 mass % of isopropyl alcohol was loaded into a paint shaker containing 0.3 mm ZrO2 beads and subjected to 10 hours of pulverization and dispersion treatment to obtain a Na0.33WOz fine particle dispersion of Example 7. The Na in the dispersion was measured. 0.33 WO zThe particle size of the dispersed particles was 100 nm. In addition, the particle size measurement was set with a particle refractive index of 1.81 and a non-spherical particle shape. In addition, the background was measured using isopropanol and the solvent refractive index was set to 1.38. In addition, after removing the solvent from the obtained dispersion, the Na 0.33 WO z The crystallite diameter of the microparticles was found to be 32 nm.

[0292] The Na in Example 7 0.33 WO z The dispersion of the fine particles and isopropyl alcohol were mixed to obtain a dispersion B for forming a coating film having a concentration of 2% by mass of infrared absorbing fine particles (cubic sodium tungsten bronze fine particles). 520 g of the dispersion B for forming a coating film was placed in a beaker, and while being strongly stirred by a stirrer equipped with blades, 360 g of the surface treatment agent a described in Example 1 and 100 g of pure water d were added dropwise over a period of 3 hours. After the addition, the mixture was stirred at a temperature of 20°C for 24 hours to prepare a aging solution of Example 7. Then, the medium was evaporated from the aging solution by using a vacuum flow drying, and the obtained dry solid was heat-treated at 200°C for 1 hour in a nitrogen atmosphere, and the obtained powder was dry-pulverized by a hammer mill to obtain a surface-treated infrared absorbing fine particle powder of Example 7.

[0293] The surface-treated infrared-absorbing fine particle powder of Example 7 was used instead of the surface-treated infrared-absorbing fine particle powder of Example 1. The same operation as Example 1 was carried out to obtain the surface-treated infrared-absorbing fine particle dispersion and infrared-absorbing transparent substrate of Example 7, and the same evaluation as Example 1 was performed.

[0294] The manufacturing conditions of the surface treated infrared absorbing fine particle powder of Example 7 are shown in Table 1, the manufacturing conditions of the surface treated infrared absorbing fine particle dispersion are shown in Table 2, and the optical property evaluation results of the infrared absorbing transparent substrate are shown in Table 3.

[0295] [Examples 8 to 10]

[0296] Hexagonal potassium tungsten bronze powder with a K / W (molar ratio) of 0.33 was used to replace the hexagonal cesium tungsten bronze powder (Example 8), hexagonal rubidium tungsten bronze powder with a Rb / W (molar ratio) of 0.33 was used to replace the hexagonal cesium tungsten bronze powder, and W of Magneli phase was used. 18 O 49Instead of the hexagonal cesium tungsten bronze powder (Example 10) (all of the above are manufactured by Sumitomo Metal Mining Co., Ltd.), the dispersed particle size and the crystallite diameter of the infrared absorbing particles were measured in the same manner as in Example 1 to obtain dispersion C for coating formation (Example 8), dispersion D for coating formation (Example 9), and dispersion E for coating formation (Example 10).

[0297] The surface treated infrared absorbing fine particle powders, surface treated infrared absorbing fine particle dispersions and infrared absorbing transparent substrates of Examples 8 to 10 were obtained in the same manner as in Example 1 except that coating film forming dispersions C to E were used instead of coating film forming dispersion A, and the same evaluations as in Example 1 were performed.

[0298] The production conditions of the surface treated infrared absorbing fine particle powders of Examples 8 to 10 are shown in Table 1, the production conditions of the surface treated infrared absorbing fine particle dispersions are shown in Table 2, and the evaluation results of the optical properties of the infrared absorbing transparent substrates are shown in Table 3.

[0299] [Example 11]

[0300] The surface-treated infrared absorbing microparticle powder, surface-treated infrared absorbing microparticle dispersion, and infrared absorbing transparent substrate of Example 11 were obtained in the same manner as in Example 1, except that 15 g of low-temperature curing perhydropolysilazane (manufactured by AZ Electronic Materials, trade name: AQUAMICAN P-110) was used instead of 16 g of tetramethoxysilane and 10 g of 3-glycidoxypropyltrimethoxysilane, and 40 g of 0.1 mol / L nitric acid was not added, and the same evaluation as in Example 1 was performed.

[0301] The production conditions of the surface treated infrared absorbing fine particle powder of Example 11 are shown in Table 1, the production conditions of the surface treated infrared absorbing fine particle dispersion are shown in Table 2, and the optical property evaluation results of the infrared absorbing transparent substrate are shown in Table 3.

[0302] In addition, low-temperature curing perhydropolysilazane is a glass coating agent.

[0303] [Example 12]

[0304] 309 g of tetraethoxysilane was used as the surface treatment agent d.

[0305] The surface-treated infrared-absorbing microparticle powder, the surface-treated infrared-absorbing microparticle dispersion, and the infrared-absorbing transparent substrate of Example 12 were obtained in the same manner as in Example 1, except that surface-treatment agent d was used instead of surface-treatment agent diluent a and isopropyl alcohol was not added, and the same evaluations as in Example 1 were performed.

[0306] The production conditions of the surface treated infrared absorbing fine particle powder of Example 12 are shown in Table 1, the production conditions of the surface treated infrared absorbing fine particle dispersion are shown in Table 2, and the optical property evaluation results of the infrared absorbing transparent substrate are shown in Table 3.

[0307] [Example 13]

[0308] 4.4 mass % of zinc acetylacetonate and 95.6 mass % of isopropyl alcohol were mixed to obtain a surface treatment agent dilution liquid e of Example 13.

[0309] The surface-treated infrared absorbing microparticle powder, surface-treated infrared absorbing microparticle dispersion and infrared absorbing transparent substrate of Example 13 were obtained in the same manner as in Example 1 except that surface-treated agent dilution liquid e was used instead of surface-treated agent dilution liquid a, and the same evaluations as in Example 1 were performed.

[0310] The manufacturing conditions of the surface treated infrared absorbing fine particle powder of Example 13 are shown in Table 1, the manufacturing conditions of the surface treated infrared absorbing fine particle dispersion are shown in Table 2, and the optical property evaluation results of the infrared absorbing transparent substrate are shown in Table 3.

[0311] [Comparative Example 1]

[0312] 10g of hexagonal cesium tungsten bronze powder (YM-01, 2.0≤Z≤3.0 manufactured by Sumitomo Metal Mining Co., Ltd.) was mixed with 23g of isopropyl alcohol, 16g of tetramethoxysilane, and 10g of 3-glycidoxypropyltrimethoxysilane, and the resulting mixture was loaded into a paint shaker containing 0.3mm ZrO2 beads, and subjected to 5 hours of pulverization and dispersion treatment. Then, 40g of 0.1 mol / L nitric acid was added, and stirred at 20°C for 1 hour to obtain the surface-treated infrared absorbing microparticle dispersion of Comparative Example 1. After removing the solvent of the obtained surface-treated infrared absorbing microparticle dispersion, the grain size of the hexagonal cesium tungsten bronze particles was measured, and the result was 28nm.

[0313] The surface treated infrared absorbing fine particle dispersion of Comparative Example 1 was applied to a 3 mm thick glass substrate using a bar coater (IMC-700 manufactured by Imoto Seisakusho Co., Ltd.) to form a coating film. The coating film was heated at 150° C. for 30 minutes to form a cured film, thereby obtaining the infrared absorbing transparent substrate of Comparative Example 1. In addition, the film thickness of the coating layer was measured and found to be 3 μm.

[0314] The optical properties of the infrared absorbing transparent substrate of Comparative Example 1 were measured. As a result, the visible light transmittance was 79.3%, the solar transmittance was 46.1%, and the haze value was 0.5%.

[0315] The infrared absorbing transparent substrate of Comparative Example 1 was exposed to a hot and humid environment at a temperature of 85°C and a relative humidity of 90% for 9 days, and the optical properties were measured. The results showed that the visible light transmittance was 83.3%, the solar transmittance was 52.5%, and the haze was 0.9%. The changes in the visible light transmittance and the solar transmittance due to exposure to the hot and humid environment were 4.0% and 6.4%, respectively, which were larger than those in the examples. In addition, the change ratio of the haze was 0.4%.

[0316] Table 3 shows the evaluation results of the optical properties of the infrared absorbing transparent substrate of Comparative Example 1.

[0317] [Comparative Examples 2 to 5]

[0318] The hexagonal cesium tungsten bronze powder was replaced by a cubic sodium tungsten bronze powder with a Na / W (molar ratio) of 0.33 (Comparative Example 2), the hexagonal potassium tungsten bronze powder with a K / W (molar ratio) of 0.33 was replaced by a hexagonal cesium tungsten bronze powder (Comparative Example 3), the hexagonal rubidium tungsten bronze powder with a Rb / W (molar ratio) of 0.33 was replaced by a hexagonal cesium tungsten bronze powder (Comparative Example 4), and the Magneli phase W was used. 18 O 49 The same operation as in Comparative Example 1 was carried out except that the hexagonal cesium tungsten bronze powder (Comparative Example 5) (all manufactured by Sumitomo Metal Mining Co., Ltd.) was replaced with the powder to obtain the infrared absorbing fine particle dispersions and infrared absorbing transparent substrates of Comparative Examples 2 to 5, and the same evaluations as in Example 1 were performed.

[0319] The changes in visible light transmittance and sunlight transmittance of the infrared absorbing transparent substrates of Comparative Examples 2 to 5 caused by exposure to a humid and hot environment are greater than those of the Examples. In addition, the changes in haze of the infrared absorbing transparent substrates of Comparative Examples 2 to 5 caused by exposure to a humid and hot environment are also greater than those of the Examples.

[0320] Table 2 shows the conditions for producing the dispersions of the infrared absorbing fine particles of Comparative Examples 2 to 5, and Table 3 shows the results of evaluating the optical properties of the infrared absorbing transparent substrates.

[0321]

[0322]

[0323]

[0324] DESCRIPTION OF SYMBOLS 11. Octahedron formed of WO6 units 12. Element M

Claims

1. A surface-treated infrared absorbing fine particle dispersion, which is a surface-treated infrared absorbing fine particle dispersion formed by dispersing surface-treated infrared absorbing fine particles in a liquid medium, wherein: The infrared absorbing particles are infrared absorbing particles having a hexagonal crystal structure represented by the general formula MxWyOz, wherein M is one or more elements selected from Cs, K, Rb, Tl, In and Ba, W is tungsten, O is oxygen, 0.001≤x / y≤1, 2.0≤z / y≤3.0, The infrared absorbing particles have a crystallite diameter of 10 nm or more and 70 nm or less, The surface treated infrared absorbing particles are infrared absorbing particles whose surfaces are coated with a film formed of a hydrolyzate of a metal chelate compound, a polymer of a hydrolyzate of a metal chelate compound, a hydrolyzate of a metal cyclic oligomer compound, or a polymer of a hydrolyzate of a metal cyclic oligomer compound. The metal chelate compound or the metal cyclic oligomer compound is a chelate compound or a cyclic oligomer compound of one or more metals selected from the group consisting of Al, Zr, Ti and Zn, The surface treated infrared absorbing fine particle dispersion contains a glass coating agent, The glass coating agent is a silane coupling agent, a silane alkoxide, a polyorganosiloxane, a polysilazane, or an organic silicon compound having an organic group bonded to a silicon atom and one or more of the organic groups being an organic group having a reactive functional group.

2. The surface treated infrared absorbing fine particle dispersion according to claim 1, wherein The organosilicon compound having organic groups bonded to silicon atoms, one or more of which are organic groups having a reactive functional group, has an epoxy group as a reactive group.

3. The surface treated infrared absorbing fine particle dispersion according to claim 1, wherein The glass coating agent comprises tetramethoxysilane and an organic silicon compound having an epoxy group.

4. The surface treated infrared absorbing fine particle dispersion according to claim 3, wherein The organic silicon compound having an epoxy group is 3-glycidoxypropyltrimethoxysilane.

5. The surface treated infrared absorbing fine particle dispersion according to claim 1, wherein The glass coating agent is polysilazane.

6. The surface treated infrared absorbing fine particle dispersion according to claim 1, wherein The metal chelate compound or the metal cyclic oligomer compound has one or more selected from the group consisting of an ether bond, an ester bond, an alkoxy group, and an acetyl group.

7. The surface treated infrared absorbing fine particle dispersion according to claim 1, wherein The metal chelate compound or the metal cyclic oligomer compound contains a Zn element.

8. The surface treated infrared absorbing fine particle dispersion according to claim 1, wherein The film thickness of the coating film of the infrared absorbing fine particles is 0.5 nm or more and 2 nm or less. 9 . An infrared absorbing transparent substrate, which is formed by providing a coating layer on at least one surface of one or more transparent substrates, wherein the coating layer is obtained by curing the surface-treated infrared absorbing fine particle dispersion according to claim 1 .

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