JP2005226008A - Dispersion for forming solar radiation-shielding body, and solar radiation-shielding body and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar radiation-shielding film and a solar radiation-shielding body by a simple coating method, a kneading method, or the like, by using a dispersion containing tungsten oxide fine particles, capable of making transmittance of near-infrared light low while keeping a visible light transmittance in a high value and excellent in appearance. <P>SOLUTION: The dispersion of tungsten oxide fine particles is prepared by heating tungstic acid while feeding 5% H<SB>2</SB>gas containing N<SB>2</SB>gas as a carrier to provide fine particle powder in which L* has 35.1886 and a* has 0.9252 and b* has -6.2294 in powder color and the composition is W<SB>20</SB>O<SB>58</SB>or W<SB>18</SB>O<SB>49</SB>and carrying out pulverizing and dispersing treatment of a mixture containing the resultant fine particle powder, a polymer-based dispersing agent and a solvent. The dispersion for forming the solar radiation-shielding body is prepared by sufficiently mixing the resultant tungsten oxide fine particle dispersion with a UV- curing resin and a solvent under stirring. The solar radiation-shielding body is obtained by applying the resultant dispersion for forming solar radiation-shielding body onto a PET film (polyethylene terephthalate) and irradiating the dispersion with UV light. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is applied to window materials for vehicles, buildings, offices, general houses, etc., as well as single glass, laminated glass, plastics and fibers used for telephone boxes, show windows, lighting lamps, transparent cases, etc. In particular, the present invention relates to a dispersion for forming a solar shading body and a solar shading body using tungsten oxide fine particles that are transparent in the visible light region and have absorption in the near infrared ray region.

  As a method for removing and reducing heat components from an external light source such as sunlight or a light bulb, conventionally, for example, a film made of a material that reflects infrared rays is formed on the glass surface, and the glass is used as a base material such as a heat ray reflective glass. It was done. As materials for reflecting infrared rays, metal oxides such as FeOx, CoOx, CrOx, and TiOx, and metal materials such as Ag, Au, Cu, Ni, and Al have been selected.

  However, these metal oxides and metal materials have a property of simultaneously reflecting or absorbing visible light in addition to infrared rays that greatly contribute to the thermal effect. For this reason, there existed a problem that the visible light transmittance | permeability of base materials, such as heat ray reflective glass in which the film of these metal oxides and metal materials was formed, fell. In particular, base materials used in building materials, vehicles, telephone boxes, etc. require high visible light transmittance in the visible light region, so materials such as the above metal oxides are used to remove and reduce thermal components. When used, the film thickness had to be very thin.

  In order to form a thin film of metal oxide or metal material, the film is formed as a thin film of 10 nm level by spray baking, CVD, or physical film formation such as sputtering or vacuum evaporation. The method is taken. However, these film forming methods require a large-scale apparatus and vacuum equipment, have drawbacks in productivity and increase in area, and have a drawback that the manufacturing cost of the film increases.

  In addition, if you try to increase the solar radiation shielding properties that remove or reduce the heat component from an external light source such as sunlight with a metal oxide or metal material, the reflectance in the visible light region tends to increase at the same time. Further, there is a drawback that the aesthetic appearance is impaired by giving the base material a lustrous appearance like a mirror. Furthermore, films formed with these materials have a relatively low electrical resistance value and high reflection with respect to radio waves. For example, when used in building materials and vehicles, mobile phones, televisions, radios, etc. There were also drawbacks such as reflection of radio waves and reception failure, and radio interference in the surrounding area.

In order to improve such drawbacks, there is a need for a solar radiation shield that has a low reflectance in the visible light region, a high reflectance in the infrared region, and a surface resistance that can be controlled to approximately 10 ⁶ Ω / □ or more. It has been.

  Antimony tin oxide (hereinafter abbreviated as ATO) and indium tin oxide (hereinafter abbreviated as ITO) are known as materials having high visible light transmittance and excellent solar radiation shielding properties. Since these materials have a relatively low visible light reflectance, the base material on which these materials are formed does not give a glaring appearance. However, since the plasma frequency of these materials is in the near infrared region, the reflection / absorption effect is not yet sufficient in the near infrared region close to visible light. Furthermore, since these materials have a low solar shielding power per unit weight, there is a problem that the amount of use increases and the cost becomes high in order to obtain high solar shielding characteristics.

  Furthermore, a film obtained by slightly reducing tungsten oxide or molybdenum oxide is an example of the solar shading film material. These films are well-known as so-called electrochromic materials, and are transparent when sufficiently oxidized, but are reduced by an electrochemical method to reduce near-red light from the long-wavelength visible light region. Absorption occurs over the outer region. A film having such spectral characteristics appears to be colored blue.

  In Patent Document 1, a composite tungsten oxide film is provided as a first layer from the substrate side on a transparent glass substrate, a transparent dielectric film is provided as a second layer on the first layer, and the second layer is provided on the second layer. There has been proposed a heat ray shielding glass in which a composite tungsten oxide film is provided as a third layer and the refractive index of the second layer is lower than the refractive indexes of the composite tungsten oxide films of the first layer and the third layer.

  Further, in Patent Document 2, a first dielectric film is provided as a first layer on a transparent glass substrate from the substrate side in the same manner as Patent Document 1, and the second layer is oxidized on the first layer. There has been proposed a heat ray shielding glass in which a tungsten film is provided and a second dielectric film is provided as a third layer on the second layer.

  In Patent Document 3, a composite tungsten oxide film containing a metal element is provided as a first layer from the substrate side on a transparent substrate in the same manner as in Patent Document 1, and a second layer is formed on the first layer. A heat ray shielding glass provided with a transparent dielectric film has been proposed.

  Patent Document 4 proposes a method for forming a radio wave transmission type solar radiation shielding film by sputtering using a target made of tungsten in an atmosphere containing carbon dioxide.

JP-A-8-59300 JP-A-8-12378 JP-A-8-283044 Japanese Patent Laid-Open No. 10-183334

  As a manufacturing method of the above-mentioned solar shading body, the sputtering method has been conventionally used as described in Patent Documents 1 to 4. However, a physical film forming method such as sputtering requires a large-scale apparatus and vacuum equipment in the film forming process. For this reason, although it is technically possible to improve productivity and increase the area, there is a problem that the manufacturing cost of the film increases.

  Moreover, from the viewpoint of practical use of the solar shading body, it is required to further improve the light transmittance in the visible light range without deteriorating the shielding performance in the infrared region or near infrared region. Further, when the solar shading body is a single layer film, there is a change in quality due to oxidation of the film and the possibility of being damaged, and the durability as the solar shading body is also a problem.

  The present invention has been made paying attention to the above-described problems, and the problem is that tungsten oxide that can reduce the transmittance of near infrared rays while maintaining the visible light transmittance high as fine particles. Using a fine particle dispersion in which the produced fine particles are dispersed in an appropriate solvent, the appearance characteristics are excellent by a simple coating method, kneading method, etc. without using an expensive physical film forming method. The object is to provide a solar radiation shielding film and a solar radiation shielding body.

  As a result of diligent research, the inventors have produced tungsten oxide fine particles that can reduce the transmittance of near infrared rays while keeping the visible light transmittance high, and dispersing the produced fine particles in a solvent to disperse the fine particles. A liquid was obtained, and a solar radiation shielding film and a solar radiation shielding body were produced by applying a coating method, a kneading method, or the like to the fine particle dispersion. And the solar shading film and the solar shading body manufactured by this simple method can improve the light transmittance in the visible light region without degrading the shielding performance in the infrared region and near infrared region. Has been found to be excellent, and it is possible to improve the durability of the solar radiation shielding body, leading to the present invention.

That is, the first invention according to the present invention is a dispersion for forming a sunscreen, in which sunscreening fine particles are dispersed in a solvent,
The solar shading fine particles have a general formula WyOz (where W is tungsten, O is oxygen, 2.0 <z / y <3.0), or / and a general formula MxWyOz (where M is an alkali metal, Alkaline earth metal, rare earth element, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, One or more elements selected from Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, W is tungsten, O Is represented by oxygen, 0.001 ≦ x / y ≦ 1, 2.0 <z / y ≦ 3.0),
The powder containing the sun-shielding fine particles has a powder color in the L * a * b * color system in which L ^* is 25 to 80, a ^* is −10 to 10, and b ^* is −15 to 15. Yes,
A dispersion for forming a sunscreen, wherein the sunscreening fine particles in the solvent have a dispersed particle diameter of 800 nm or less.

  According to a second aspect of the present invention, the surface of the solar radiation shielding fine particles is coated with a compound containing at least one element selected from Si, Ti, Al, Zr, and Y. It is the dispersion for solar radiation shielding body formation of 1st invention description.

A third invention according to the present invention is selected from Sb, V, Nb, Ta, W, Zr, F, Zn, Al, Ti, Pb, Ga, Re, Ru, P, Ge, In, and Sn. Oxide fine particles containing more than one element,
Or a boron compound represented by the general formula XB _m (wherein X is an element selected from an alkaline earth metal element or a rare earth element including yttrium (Y), B is boron, 4 ≦ m <6.3) Fine particles,
Alternatively, the dispersion for forming a solar radiation shield according to the first or second invention, wherein at least one kind of fine particles selected from fine particles of indium tin composite oxide is dispersed in a solvent. .

  A fourth invention according to the present invention is the dispersion for forming a solar radiation shielding body according to any one of the first to third inventions, which contains an inorganic binder and / or a resin binder.

  According to a fifth aspect of the present invention, there is provided a solar shading body characterized by being formed using the solar shading body-forming dispersion liquid described in any of the first to fourth aspects.

  According to a sixth aspect of the present invention, there is provided a solar shading body characterized in that the solar shading body according to the fifth aspect of the present invention is formed on a transparent substrate.

A seventh invention according to the present invention is the solar radiation shield according to any one of the fifth to sixth inventions,
The transmittance of the solar shield for light has a maximum value at a wavelength of 350 to 600 nm, and has a minimum value at a wavelength of 600 to 1500 nm,
When the maximum value is P, the minimum value is B, and the visible light transmittance of the solar radiation shield is VLT, 40% ≦ VLT ≦ 80%,
Formula: P / B + 0.0333 × VLT ≧ 3.7
It is a solar shading body characterized by satisfying.

The eighth invention according to the present invention is a solar radiation shielding fine particle having a general formula WyOz (W is tungsten, O is oxygen, 2.0 <z / y <3.0), and / or Formula MxWyOz (where M is alkali metal, alkaline earth metal, rare earth element, 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 One or more elements, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1, 2.0 <z / y ≦ 3.0)
The powder containing the sun-shielding fine particles has a powder color in the L * a * b * color system in which L ^* is 25 to 80, a ^* is −10 to 10, and b ^* is −15 to 15. A method for producing a dispersion for forming a solar shading material in which the solar shading fine particles are dispersed in a solvent,
A step of producing the solar shading fine particles by firing the starting material of the solar shading fine particles in an inert gas alone or in a mixed atmosphere of an inert gas and a reducing gas;
The solar radiation shielding fine particles and the solvent are mixed, and the solar radiation shielding fine particles are pulverized and dispersed to have a dispersion particle size of the solar radiation shielding fine particles in the solvent of 800 nm or less. It is the manufacturing method of the dispersion liquid for solar radiation shielding body to do.

According to the present invention, since the tungsten oxide fine particles that can reduce the transmittance of near infrared rays while maintaining a high visible light transmittance are used as the dispersion for forming the solar radiation shielding body, the general formula WyOz and / or MxWyOz is used. And the powder color of the powder containing the tungsten oxide has an L ^* of 25-80 in the L * a * b * color system, a ^* of −10 to 10, and b ^* of −15. When the tungsten oxide fine particles of ˜15 are produced and the tungsten oxide fine particles are dispersed in a solvent to prepare the dispersion for forming the solar radiation shielding body, the dispersed particle diameter of the tungsten oxide fine particles is set to 800 nm or less. As a result, it is possible to form a solar shading film and a solar shading body with improved light transmission in the visible light range without reducing the shielding performance in the infrared or near-infrared region by applying or kneading. To do We were able to obtain a cut for forming a solar radiation-shielding body dispersion.

Hereinafter, embodiments of the present invention will be described in detail.
1. Tungsten oxide fine particles The solar shading fine particles used in the dispersion for forming a solar shield according to the present invention have the general formula WyOz (W is tungsten, O is oxygen, 2.0 <z / y <3.0). Or general formula MxWyOz (where M is alkali metal, alkaline earth metal, rare earth element, 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 One or more elements selected from the following (hereinafter referred to as M element), W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1, 2.0 <z / y ≦ 3.0) Tungsten oxide fine particles. Also, the powder containing the tungsten oxide particles, in the powder colors were evaluated by the L * a * b * color system by the International Commission on Illumination (CIE) has recommended, L ^* is 25 to 80, a ^* has −10 to 10 and b ^* has −15 to 15.

1- (a). Production of Tungsten Oxide Fine Particles Represented by General Formula WyOz Tungsten Oxide Fine Particles Represented by General Formula WyOz (W is Tungsten, O is Oxygen, 2.0 <z / y <3.0) Tungsten acid (H ₂ WO ₄ ), ammonium tungstate, tungsten hexachloride, tungsten hydrate obtained by adding water to tungsten hexachloride dissolved in alcohol and hydrolyzing it, and then evaporating the solvent. It can be obtained by firing one or more selected tungsten compounds in an inert gas alone or in a mixed gas atmosphere of an inert gas and a reducing gas. Here, tungstic acid (H ₂ WO ₄ ), ammonium tungstate, and tungsten hexachloride used as raw materials are not particularly limited.

However, tungsten hydrate obtained by adding water to tungsten hexachloride dissolved in tungstic acid (H ₂ WO ₄ ), ammonium tungstate, tungsten hexachloride, or alcohol, followed by hydrolysis and then evaporating the solvent, In the case of producing tungsten oxide fine particles by firing at least one tungsten compound selected from the above, the firing temperature is preferably 200 ° C. or higher and 1000 ° C. or lower from the viewpoint of desired fine particles and optical properties. When the firing temperature is in the range of 200 ° C. or higher and 1000 ° C. or lower, tungsten oxide fine particles having desired optical characteristics can be produced. The firing time may be appropriately selected according to the firing temperature, but 10 minutes or more and 5 hours or less is sufficient.

Next, tungsten hydrate obtained by adding water to the tungstic acid (H ₂ WO ₄ ), ammonium tungstate, tungsten hexachloride, tungsten hexachloride dissolved in alcohol, hydrolyzing it, and then evaporating the solvent. In order to generate oxygen vacancies in the tungsten oxide fine particles prepared by firing one or more tungsten compounds selected from the above, the tungsten oxide fine particles are either an inert gas alone or an inert gas and a reducing gas. Baking in a mixed gas atmosphere. Here, a gas such as nitrogen, argon, or helium can be used as the inert gas, and a gas such as hydrogen or alcohol can be used as the reducing gas. When the tungsten oxide fine particles are fired in a mixed gas atmosphere of an inert gas and a reducing gas, the concentration of the reducing gas in the inert gas is not particularly limited as long as it is appropriately selected according to the firing temperature. However, it is preferably 20 vol% or less, more preferably 10 vol% or less, and still more preferably 7 to 0.01 vol%. When the concentration of the reducing gas in the inert gas is 20 vol% or less, rapid reduction of the tungsten oxide fine particles can be avoided, and generation of WO ₂ having no solar radiation shielding function can be avoided.

The treatment temperature for generating oxygen vacancies in the tungsten oxide fine particles may be appropriately selected according to the atmosphere, but in the case of an inert gas alone, from the viewpoint of crystallinity and hiding power as the solar shielding fine particles. It exceeds 650 ° C. and is 1200 ° C. or less, preferably 1100 ° C. or less, more preferably 1000 ° C. or less. On the other hand, in the case of a mixed gas of an inert gas and a reducing gas, a temperature at which WO ₂ is not generated may be appropriately selected according to the reducing gas concentration. Furthermore, in the case of a two-step reaction performed under both atmospheres of an inert gas alone and a mixed gas of an inert gas and a reducing gas, for example, a mixed gas atmosphere of an inert gas and a reducing gas at the first step. It is also preferable from the viewpoint of the solar radiation shielding property that baking is performed at 100 ° C. or more and 650 ° C. or less and baking is performed at 650 ° C. and 1200 ° C. or less in an inert gas atmosphere in the second step. The firing time at this time may be appropriately selected according to the temperature, but it is sufficient to be 5 minutes or more and 5 hours or less.

When the manufactured tungsten oxide fine particles are subjected to X-ray diffraction measurement, a WO _3-x phase diffraction peak is observed. Under appropriate conditions, so-called magnetic phase such as W ₂₀ O ₅₈ and W ₁₈ O ₄₉ Existence was confirmed. According to the results of chemical analysis, it is determined that the WO phase is a WyOz with oxygen deficiency (W is tungsten, O is oxygen, 2.0 <z / y <3.0).

1- (b). Tungsten oxide fine particles represented by the general formula MxWyOz (where M is the M element, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1, 2.0 <z / y ≦ 3.0) Is represented by the above-described general formula MxWyOz (where M is the M element, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1, 2.0 <z / y ≦ 3.0). Tungsten oxide fine particles consist of tungsten water obtained by adding water to tungsten hexachloride dissolved in tungstic acid (H ₂ WO ₄ ), ammonium tungstate, tungsten hexachloride, and alcohol, followed by hydrolysis and evaporation of the solvent. A mixed powder obtained by dry-mixing one or more tungsten compounds selected from Japanese and an M element oxide or / and hydroxide powder is an inert gas alone or an inert gas and a reducing gas. And mixed gas atmosphere It is obtained by firing in one step, or by two-stage firing in which firing is performed in a mixed gas atmosphere of an inert gas and a reducing gas in the first step and firing in an inert gas atmosphere in the second step. It is done. Further, in place of the tungsten compound, tungsten oxide fine particles produced in 1- (a) may be used.

As a different method for producing the tungsten oxide fine particles, water is added to tungsten hexachloride dissolved in tungstic acid (H ₂ WO ₄ ), ammonium tungstate, tungsten hexachloride alcohol, and then the solvent is evaporated. A dry powder obtained by drying a mixture obtained by wet-mixing one or more tungsten compounds selected from the hydrates of tungsten and an aqueous solution containing the salt of the M element is used as an inert gas alone or insoluble. Baking in a mixed gas atmosphere of active gas and reducing gas in one step, or baking in a mixed gas atmosphere of inert gas and reducing gas in the first step and further in an inert gas atmosphere in the second step It can also be obtained by performing a two-stage firing, ie firing. Further, in place of the tungsten compound, tungsten oxide fine particles produced in 1- (a) may be used.

  As described above, M element to be added is alkali metal, alkaline earth metal, rare earth element, 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, Nb, V, Mo, Ta, Re One or more elements are preferred. All of these elements can improve the sun shielding properties and weather resistance of the tungsten oxide fine particles, but belong to alkali metals, alkaline earth metals, and transition metals from the viewpoint of improving the sun shielding properties. An element is preferable, and a 4B group element and a 5B group element are preferable from a viewpoint of improving a weather resistance.

Tungsten acid (H ₂ WO ₄ ), ammonium tungstate, tungsten hexachloride dissolved in tungsten hexachloride alcohol, water added to hydrolyze and then hydrated tungsten, tungsten oxide fine particles When the element M is added to one or more selected from the above by a dry mixing method, oxides and hydroxides are preferable as the form of the element M. And, after adding water to this hexagonal oxide dissolved in M element oxide, hydroxide, tungstic acid (H ₂ WO ₄ ), ammonium tungstate, tungsten hexachloride alcohol and hydrolyzing it, the solvent One or more kinds selected from tungsten hydrates and tungsten oxide fine particles obtained by evaporating the above are mixed. The dry mixing may be performed with a commercially available rake machine, kneader, ball mill, sand mill, paint shaker or the like.

Further, as a mixing method different from the dry mixing method, a solvent after adding water to tungsten hexachloride in which tungstic acid (H ₂ WO ₄ ), ammonium tungstate, and tungsten hexachloride are dissolved in alcohol is hydrolyzed. One or more selected from tungsten hydrates and tungsten oxide fine particles obtained by evaporating bismuth, mixed with the M element in the form of a salt as an aqueous solution by a wet mixing method, and then dried to dry powder It is also good to get. In this case, the form of the M element salt is not particularly limited, and examples thereof include nitrates, sulfates, chlorides and carbonates. The drying temperature and time after the wet mixing are not particularly limited.

  Next, in order to generate oxygen vacancies in the tungsten oxide fine particles, firing is performed in an inert gas alone or in a mixed gas atmosphere of an inert gas and a reducing gas in one step, or in the first step, an inert gas. And firing in a mixed gas atmosphere of reducing gas and further firing in an inert gas atmosphere in the second step. The inert gas used alone or the mixed gas of the inert gas and the reducing gas, the concentration of the reducing gas in the inert gas, and the firing temperature are the inert gases described in 1- (a) above. This is the same as the concentration of the reducing gas in the gas or reducing gas or inert gas, and the firing temperature.

  The particle diameters of the tungsten oxide fine particles of the present invention represented by the general formula WyOz manufactured in 1- (a) and the general formula MxWyOz manufactured in 1- (b) described above are solar shading bodies. It can be selected appropriately according to the purpose of use. For example, when the solar shading body is used for applications requiring transparency, the particle diameter is preferably 800 nm or less. If the particle diameter is 800 nm or less, since the particles do not completely block light, visibility in the visible light region can be maintained, and at the same time, transparency can be efficiently maintained.

  In particular, when importance is attached to transparency in the visible light region, the particle diameter is 200 nm or less, preferably 100 nm or less. This is because when the particle size of the particles is small, clear transparency can be obtained. This is because the particles scatter light in the visible light region of 380 nm to 780 nm by geometrical scattering or Mie scattering and give an appearance like frosted glass. Is considered to be due to the Rayleigh scattering region. In the Rayleigh scattering region, the scattered light is reduced in inverse proportion to the sixth power of the particle diameter, so that the scattering is reduced and the transparency is improved as the particle diameter is reduced. Further, when the particle diameter is 100 nm or less, the scattered light is preferably very small. On the other hand, those having a particle size larger than 1 nm can be produced industrially.

  By appropriately selecting the particle diameter, the haze value of the solar shading material fine particle dispersion in which the solar shading material fine particles are dispersed in a medium is set to a visible light transmittance of 85% or less and a haze value of 30% or less. Can do. When the haze value is 30% or less, it is possible to avoid the transparent substrate coated with the solar shading material fine particle dispersion from becoming cloudy glass, and clear transparency can be obtained.

Moreover, the powder containing the solar radiation shielding fine particles according to the present invention has a powder color in the L ^* a * b * color system recommended by the International Commission on Illumination (CIE), and L ^* is 25 to 80, a ^* has −10 to 10 and b ^* has −15 to 15.

Here, the reason why the solar shading fine particles according to the present invention have the powder color and exhibit preferable optical characteristics will be briefly described. First, the interaction between general light and electrons in a substance will be explained. A substance has a specific plasma frequency, light having a longer wavelength than this frequency is reflected, and light having a shorter wavelength is transmitted. Are known. The plasma frequency ω _p is expressed by equation (2).
ω _p ² = nq ² / εm (2)
Here, n is the conduction electron density, q is the charge of the electron, ε is the dielectric constant, and m is the effective mass of the electron.
As is clear from the equation (2), the plasma frequency increases as the conduction electron density of the substance increases, so that even light on the shorter wavelength side is reflected. Since the conduction electron density is 10 ²² / cm ³ for metal, the reflectance is already high in the visible light region for metal, but in the case of tungsten oxide, visible light is transmitted and the absorptance is high from the near infrared region. Tungsten oxide may be used as a solar shading film. On the other hand, when the tungsten oxide fine particles are treated with a reducing gas, the powder color changes from light yellow → yellow green → dark blue → dark blue, and at the same time, the electrical resistance value of the green compact also decreases. This is presumably because oxygen vacancies were generated in the fine particles by treating the tungsten oxide fine particles with a reducing gas, thereby increasing free electrons in the fine particles. That is, it is considered that there is a close relationship between the powder color of the tungsten oxide fine particles, the conduction electron density, and the plasma frequency.

Therefore, the present inventors have investigated in detail the relationship between the powder color obtained by the reduction treatment in the powder containing tungsten oxide fine particles and the characteristics of the solar radiation shield containing the tungsten oxide fine particles, and As a result of obtaining the optimum powder color condition for shielding, the powder containing tungsten oxide fine particles is L ^* a ^* b ^* color system, L ^* is 25 to 80, a ^* is -10 to 10, b ^{When *} is in the range of -15 to 15, it was found that the transmittance of the solar radiation shield has a maximum value at a wavelength of 350 to 600 nm and a minimum value at a wavelength of 600 to 1500 nm. Furthermore, when the powder containing tungsten oxide fine particles has the powder color, in the solar radiation shielding body containing the tungsten oxide fine particles, the maximum value of light transmittance is P, the minimum value is B, and the visible light transmittance is When VLT, 40% ≦ VLT ≦ 80%, the formula (1)
P / B + 0.0333 × VLT ≧ 3.7 (1)
It was found that a solar shading body satisfying the above can be obtained.

  Further, in order to improve the weather resistance of the tungsten oxide fine particles as necessary, the surface of the tungsten oxide fine particles contains a single element or compound containing at least one element selected from Si, Ti, Al, Zr, and Y. It is also preferable to coat with.

2. Dispersion for forming solar radiation shielding body The dispersion liquid for forming solar radiation shielding body according to the present invention contains a solvent and fine particles for solar radiation shielding, and for forming a solar radiation shielding body in which the fine particles for solar radiation shielding are dispersed in the solvent. It is a dispersion. The solar shading fine particles may have the general formula WyOz (W is tungsten, O is oxygen, 2.0 <z / y <3.0), or / and the general formula MxWyOz (where M is One or more elements selected from M elements, W is tungsten, O is oxygen, and 0.001 ≦ x / y ≦ 1, 2.0 <z / y ≦ 3.0). Furthermore, the powder containing the solar shading fine particles has a powder color of L * a * b * color system, L ^* is 25 to 80, a ^* is −10 to 10, and b ^* is −15. 15 is a tungsten oxide fine particle. And the dispersed particle diameter of the said tungsten oxide microparticles | fine-particles disperse | distributed in the said solvent is 800 nm or less. The dispersion of the tungsten oxide fine particles dispersed in the solvent is sufficiently fine up to 800 nm or less, and the dispersion for forming a solar radiation shielding material is uniformly dispersed, thereby satisfying the requirement of the formula (1). A solar shading body can be obtained.

  Here, the dispersed particle diameter of the tungsten oxide fine particles in the dispersion for forming a solar shield is briefly described. The dispersed particle diameter of the tungsten oxide fine particles means the diameter of the aggregated particles produced by agglomeration of the tungsten oxide fine particles dispersed in the solvent, and is measured with various commercially available particle size distribution analyzers. can do. For example, a sample in a state where a simple substance or an aggregate of tungsten oxide fine particles exists is collected from the tungsten oxide fine particle dispersion, and the sample is ELS- manufactured by Otsuka Electronics Co., Ltd. based on the principle of dynamic light scattering. It can be determined by measuring at 8000.

  In the solar shield-forming dispersion, it is desirable that the dispersed particle diameter of the tungsten oxide fine particles is 800 nm or less. When the thickness is 800 nm or less, the requirement of the formula (1) can be satisfied, and the obtained solar shading body becomes a gray film or a molded body (plate, sheet, etc.) having a monotonously reduced transmittance. This is because it can be avoided. Further, if the dispersion for forming the solar radiation shielding body does not contain many aggregated coarse particles, these coarse particles become a light scattering source and cause haze, which causes a decrease in visible light transmittance. This is preferable because it can be avoided.

  The method for dispersing the tungsten oxide fine particles in the solvent is not particularly limited as long as it is a method capable of uniformly dispersing, for example, pulverization / dispersion treatment using a bead mill, a ball mill, a sand mill, a paint shaker, an ultrasonic homogenizer, or the like. A method is mentioned. By the dispersion treatment using these equipments, the tungsten oxide fine particles are dispersed in the solvent, and at the same time, the fine particles are formed by the collision of the tungsten oxide fine particles, so that the tungsten oxide particles can be further finely dispersed. (Ie, pulverized / dispersed).

Further, an oxide containing two or more elements selected from Sb, V, Nb, Ta, W, Zr, F, Zn, Al, Ti, Pb, Ga, Re, Ru, P, Ge, In, and Sn Fine particles,
Or a boron compound represented by the general formula XB _m (wherein X is an element selected from an alkaline earth metal element or a rare earth element including yttrium (Y), B is boron, 4 ≦ m <6.3) Fine particles,
Alternatively, at least one kind of fine particles selected from fine particles of indium tin composite oxide such as In ₄ Sn ₃ O ₁₂ is added to the dispersion for forming a solar shield, and dispersed in a solvent in the dispersion. It is also a preferable configuration.

  With the above-described configuration, it is possible to obtain the effects of improving the solar shading characteristics of the solar shading body, adjusting the color tone of the solar shading body, reducing the amount of added filler, etc., but from the viewpoint of improving the solar shading characteristics, Sb Oxide fine particles containing two or more elements selected from V, Nb, Ta, W, Zr, F, Zn, Al, Ti, Pb, Ga, Re, Ru, P, Ge, In, and Sn Fine particles of indium tin composite oxide are preferred, and boride fine particles are preferred from the viewpoint of adjusting the color tone and reducing the amount of added filler. Further, boride fine particles are preferred from the viewpoint of improving the shielding properties against near infrared rays closer to visible light. In addition, what is necessary is just to select the addition ratio at this time suitably according to the desired solar radiation shielding characteristic.

  In addition, the dispersion for forming a solar radiation shielding body may include an inorganic binder and / or a resin binder. The kind of inorganic binder or resin binder is not particularly limited. Examples of the inorganic binder include silicon, zirconium, titanium, or aluminum metal alkoxides, partially hydrolyzed polycondensates or organosilazanes, and examples of the resin binder include thermoplastic resins such as acrylic resins and epoxy resins. A thermosetting resin such as a resin can be used.

  Further, in the dispersion for forming a solar shielding body, the solvent in which the tungsten oxide fine particles are dispersed is not particularly limited, and coating / kneading conditions, coating / kneading environment, and further, an inorganic binder and a resin binder are added. What is necessary is just to select suitably according to a binder, when it contains.

  Examples of the solvent include water, ethanol, propanol, butanol, isopropyl alcohol, isobutyl alcohol, diacetone alcohol and other alcohols, methyl ether, ethyl ether, propyl ether and other ethers, esters, acetone, methyl ethyl ketone, diethyl Various organic solvents such as ketones, ketones such as cyclohexanone and isobutyl ketone can be used. Moreover, you may adjust pH by adding an acid and an alkali as needed. Furthermore, in order to further improve the dispersion stability of the fine particles in the dispersion, various surfactants, coupling agents and the like can of course be added.

Furthermore, when a film is formed on a transparent substrate using the dispersion for forming a solar shield, the conductivity of the film can be obtained along a conductive path that passes through contact points of the tungsten oxide fine particles. Therefore, for example, by adjusting the amount of the surfactant and the coupling agent in the dispersion for forming the solar shading body, the conductive path can be partially cut, and the surface of 10 ⁶ Ω / □ or more can be obtained. It is easy to reduce the conductivity of the film by using an electric resistance value. Further, the conductivity of the film can also be controlled by adjusting the content of the inorganic binder and / or resin binder in the dispersion for forming the sunscreen.

  Next, when the solar shading body-forming dispersion is applied onto an appropriate transparent substrate to form a film, the application method is not particularly limited. The coating method may be any method that can apply the dispersion liquid flatly and thinly and uniformly, such as spin coating, bar coating, spray coating, dip coating, screen printing, roll coating, and flow coating. The method may be used.

  Further, when the dispersion for forming the solar radiation shielding body contains a metal alkoxide of silicon, zirconium, titanium, or aluminum and a hydrolysis polymer thereof as an inorganic binder, the substrate heating temperature after application of the dispersion is 100 ° C. By setting it as the above, the polymerization reaction of the alkoxide contained in a coating film or its hydrolysis polymer can be almost completed. By almost completing the polymerization reaction, it is possible to avoid water and organic solvents remaining in the film and causing a reduction in the visible light transmittance of the heated film, and therefore the heating temperature is preferably 100 ° C. or higher. More preferably, it is not less than the boiling point of the solvent in the dispersion.

  Moreover, what is necessary is just to harden | cure according to the hardening method of each resin binder, when using a resin binder in the said dispersion liquid for solar radiation shield formation. For example, if the resin binder is an ultraviolet curable resin, ultraviolet rays may be appropriately irradiated. If the resin binder is a room temperature curable resin, it may be left as it is after application. If this structure is taken, the application | coating in the field to the existing window glass etc. is possible.

ここで、τｖは可視光透過率ＶＬＴ、Ｄ_λはＣＩＥ昼光色Ｄ_６５における分光分布の値（ＪＩＳ Ａ ５７５９の添付表参照）、Ｖ_λはＣＩＥ明順応標準比視感度、τ（λ）は分光透過率である。尚、ＣＩＥは国際照明委員会の略称である。 3. As described above, the solar shield formed using the dispersion for forming a solar shield according to the present invention has a maximum light transmittance of 350 to 600 nm and a wavelength of 600 to 600 nm. Solar radiation shielding characteristics satisfying equation (1) when 40% ≦ VLT ≦ 80%, with a minimum value at 1500 nm, a maximum value of light transmittance P, a minimum value B, and a visible light transmittance VLT Have
P / B + 0.0333 × VLT ≧ 3.7 (1)
Here, the visible light transmittance VLT is calculated based on the visible light transmittance calculation method (JIS A 5759), and specifically, each wavelength at intervals of 10 nm between wavelengths 380 nm to 780 nm using a spectrophotometer. The spectral transmittance τ (λ) is measured and calculated by the following equation (3).

Here, τv is the visible light transmittance VLT, D _λ is the value of the spectral distribution in the CIE daylight color D ₆₅ (refer to the attached table of JIS A 5759), V _λ is the CIE light adaptation standard relative luminous efficiency, and τ (λ) is the spectral value. Transmittance. CIE is an abbreviation for the International Lighting Commission.

Here, the derivation method of the formula (1) will be described.
First, a dispersion for forming a solar shading body that contains tungsten oxide fine particles and a binder and serves as a reference is manufactured. Next, the dispersion for forming the standard solar radiation shielding body is applied to a transparent substrate such as a transparent 3 mm glass or a transparent 50 μm PET film, for example, with a film thickness of 10 μm and a predetermined solar radiation shielding characteristic. Form a solar shield that meets the acceptance criteria. And the transmission profile of the solar radiation shield is measured with a spectrophotometer, the maximum value P of the light transmittance and the minimum value B of the transmittance are obtained, the ratio of (maximum value P / minimum value B) is obtained, and This (P / B) value is plotted against visible light transmission (VLT). Hereinafter, while changing the film thickness of the solar shield and changing the value of the VLT, the solar shield characteristics are repeatedly created as a plurality of solar shields showing predetermined acceptance criteria, and the transmission profiles of these solar shields are obtained. Each (P / B) value is obtained by measurement, plotted against the value of VLT, and equation (1) can be obtained from a straight line obtained by linearly approximating these plots.

  For example, a dispersion for forming a standard solar radiation shielding body mainly composed of tungsten oxide fine particles having a dispersed particle diameter of 300 nm, a UV curable resin, and toluene is manufactured, and the dispersion liquid for forming the standard solar radiation shielding body is used. Thus, a plurality of solar shading bodies having different values of visible light transmittance (VLT) are formed. And the (P / B) value of the said solar radiation shield is measured, and the plot which calculates | requires a response | compatibility with a VLT value is performed. FIG. 2 shows an example of the plot. FIG. 2 is a graph in which the horizontal axis represents the VLT value and the vertical axis represents the (P / B) value.

  As shown in FIG. 2, the ratio (P / B) between the maximum value and the minimum value of the transmittance in each solar radiation shielding body in which the solar radiation shielding characteristics show a predetermined acceptance criterion is associated with the value of the visible light transmittance VLT. There is a tendency to change parabolically. However, in 40% ≦ VLT ≦ 80%, which is a range to be considered as a solar radiation shield, linear approximation by the equation (1) is possible with sufficient accuracy. Therefore, when the solar shading characteristic indicated by the solar shading body related to the measurement is the same as or greater than the value on the straight line represented by the equal sign of equation (1), the solar shading body is good. It shows that it has a good solar radiation shielding characteristic. That is, when the solar shading body for measurement has good solar shading characteristics, the VLT value and the (P / B) value satisfy the formula (1).

In addition, as a binder of the said film with a film thickness of 10 micrometers or less, although UV curable resin and a silicate type | system | group binder can be used, if it is transparent in a visible light area | region, it will not specifically limit.
And as for this ratio (P / B) of the maximum value and the minimum value of the film transmittance of light in the solar radiation shielding body, the solar radiation shielding characteristics are more excellent. This is because the transmission profile of tungsten-based oxide fine particles has a maximum value at a wavelength of 350 nm to 600 nm, a minimum value at a wavelength of 600 to 1500 nm, a visible light wavelength range of 380 nm to 780 nm, and a visibility of around 550 nm. Derived from the shape of a bell as a peak. And it is understood that the solar radiation shielding body according to the present invention having the transmission characteristics satisfying the formula (1) effectively transmits visible light and reflects and absorbs other solar radiation effectively.

  On the other hand, the solar radiation shielding body is prepared by kneading a solar radiation shielding body forming dispersion liquid containing a solvent and solar radiation shielding fine particles such as tungsten oxide fine particles dispersed in the solvent into a resin that serves as a base material for the solar radiation shielding body. And can be formed into a plate shape, a sheet shape, a film shape and the like.

  As described above, the solar radiation shielding body according to the present invention is obtained by appropriately applying the solar radiation shielding body-forming dispersion liquid on a transparent substrate, or kneading the solar radiation shielding body-forming dispersion liquid into a resin. Manufactured by molding into a plate, sheet, film, or the like. And when the said solar radiation shielding body is comprised with the transparent base material and the film formed on this, the resin binder or inorganic binder contained in the dispersion liquid for solar radiation shielding body is the said tungsten oxide after application | coating and hardening. This has the effect of improving the adhesion of the fine particles to the substrate and further improving the hardness of the film. Further, a coating made of a metal alkoxide of silicon, zirconium, titanium, or aluminum, or a partially hydrolyzed polycondensation product thereof is applied as a second layer on the coating thus obtained, and silicon, zirconium, By forming an oxide film of titanium or aluminum, it is possible to further improve the binding force, film hardness, and weather resistance of a film mainly composed of tungsten oxide fine particles.

  Moreover, when the dispersion for solar radiation shielding body contains no resin binder or inorganic binder, the film obtained on the transparent substrate has a film structure in which only the tungsten oxide fine particles are deposited. And even if the said film remains as it is, the solar radiation shielding effect is shown. However, on this film, a coating film is formed by further applying a coating solution containing an inorganic binder such as silicon, zirconium, titanium, or aluminum metal alkoxide or a partially hydrolyzed polycondensation product thereof, or a resin binder. A film is recommended. By adopting this configuration, the coating liquid component is formed to fill the gap where the tungsten oxide fine particles of the first layer are deposited, so that the haze of the film is reduced and the visible light transmittance is improved. The binding property to the base material is improved.

  The solar radiation shielding body according to the present invention, which is formed of the transparent base material and the film formed thereon as described above, has tungsten oxide fine particles appropriately dispersed in the film. Therefore, the reflection in the visible light region is less than that of an oxide thin film formed by a physical film forming method having a mirror-like surface in which crystals are densely filled in the film, and a glare appearance can be avoided. On the other hand, since it has a plasma frequency from the visible region to the near infrared region, the plasma reflection associated therewith becomes large in the near infrared region, and the solar radiation shielding property is excellent.

Further, when it is desired to further suppress the reflection of the coating in the visible light region, a film having a low refractive index such as SiO ₂ or MgF ₂ is formed on the coating in which the tungsten oxide fine particles are dispersed. A multilayer film having a luminous reflectance of 1% or less can be easily obtained.

Further, in order to further impart an ultraviolet shielding function to the solar radiation shielding body according to the present invention, at least one kind of particles such as inorganic titanium oxide, zinc oxide and cerium oxide, organic benzophenone and benzotriazole are added. It may be added.
Moreover, in order to improve the visible light transmittance of the solar radiation shielding film, particles such as ATO, ITO, aluminum-added zinc oxide, and indium tin composite oxide may be further mixed. When these transparent particles are added in an increased amount, the transmittance near 750 nm increases, while the near-infrared rays are shielded, so that a solar radiation shielding body having high visible light transmittance and higher solar radiation shielding characteristics can be obtained.

  Further, if the dispersion for forming a solar shading material according to the present invention is added to the dispersion for forming a solar shading material in which particles such as ATO, ITO, aluminum-added zinc oxide, and indium tin composite oxide are dispersed, The added amount can assist the solar shading effect. At this time, since the film color of the tungsten oxide fine particles is blue, the solar radiation effect is assisted at the same time as the film is colored. Furthermore, the minimum required amount of ATO, ITO, etc. can be greatly reduced with only a slight addition amount to ATO, ITO, etc., which are the main components in the dispersion for forming the sunscreen, and the cost of the dispersion can be reduced. Is lowered.

  The dispersion for forming a solar shading body according to the present invention described above does not form the desired solar shading body by utilizing the decomposition or chemical reaction of the liquid component due to heat at the time of firing, and thus has stable characteristics. A solar shading body can be formed. In addition, tungsten oxide particles that exhibit solar radiation shielding effects are inorganic materials, so they have superior weather resistance compared to organic materials. For example, they can be used in areas exposed to sunlight (ultraviolet rays). Almost no deterioration occurs.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.
In addition, the powder color (standard light source D65, 10. Field of view) of fine particles a to g used in each of the following Examples and Comparative Examples, and solar shading obtained using a dispersion liquid in which the fine particles are dispersed ^. The optical characteristics of the bodies A to M were measured using a spectrophotometer U-4000 manufactured by Hitachi, Ltd. The measurement results are shown in FIG. 1 as a list.
In addition, regarding the solar shading characteristics of the obtained solar shading bodies A to M, the maximum value P, the minimum value B, and the visible light transmittance VLT of the light transmittance are obtained from the transmission profile of each solar shading body and obtained. From the obtained numerical values, the value of the left side (P / B + 0.0333 × VLT) of the formula (1) was calculated as “sunlight shielding characteristics”. In each example, the value of the visible light transmittance VLT is controlled by adjusting the film thickness. The measurement results are shown in FIG. 1 as a list.

[Example 1]
A quartz boat containing 50 g of tungstic acid was set in a quartz tube furnace, heated while supplying 5% H ₂ gas with N ₂ gas as a carrier, and fired at a temperature of 600 ° C. for 1 hour to obtain fine particles a. . The powder color of the powder containing the fine particles “a” is L * 35.1886, a * is 0.9252, and b * is −6.2294. As a result of identifying the crystal phase by powder X-ray diffraction, WO ₂ A crystal phase of _.90 or W ₂₀ O ₅₈ was observed.
Next, tungsten oxide fine particles are obtained by pulverizing and dispersing 5% by weight of the fine particles a, 5% by weight of a polymeric dispersant, and 90% by weight of toluene with a paint shaker containing 0.3 mmφZrO ₂ beads for 6 hours. A dispersion was prepared (Liquid A). Here, the dispersion particle diameter of the tungsten oxide fine particles in the dispersion liquid (b) of the tungsten oxide fine particles was 69 nm as shown in FIG.
Next, 1.6 g of the obtained tungsten oxide fine particle dispersion liquid (b) and 0.5 g of UV curable resin were mixed well to prepare a dispersion for forming a solar radiation shielding body (b).
Next, bar no. After applying the above-mentioned dispersion for forming a solar shading body (b) on a PET (polyethylene terephthalate) film having a thickness of 50 μm using a bar coater of No. 8, a high-pressure mercury lamp at 70 ° C. for 1 minute. The solar shading body A according to Example 1 was obtained.
The P / B ratio obtained from the maximum value P and the minimum value B of the light transmittance obtained from the transmission profile of the solar shield A was 2.1. Furthermore, the visible light transmittance VLT calculated by the above-described visible light transmittance calculation method (JIS A 5759) was 63.0%. The solar shading characteristics were calculated by substituting these numerical values into the formula (1). As a result, it was 4.2 as shown in FIG.
From the above, it was confirmed that the solar radiation shielding body A according to Example 1 has excellent solar radiation shielding characteristics.

[Example 2]
As in Example 1, first, 50 g of tungstic acid was calcined in the atmosphere at 600 ° C. for 1 hour, and further heated while supplying 5% H ₂ gas with N ₂ gas as a carrier, and at 600 ° C. for 1 hour. Was fired to obtain fine particles b. The powder color of the powder containing the fine particles b is L * of 34.8152, a * of 1.2234, and b * of −4.8774. As a result of identification of the crystal phase by powder X-ray diffraction, WO ₂ A crystal phase of _.90 or W ₂₀ O ₅₈ was observed.
The fine particles b were treated in the same manner as in Example 1 to prepare a dispersion of tungsten oxide, which was used as a dispersion for forming a solar radiation shield (liquid C). The dispersion particle diameter of the tungsten oxide fine particles in the dispersion liquid (c) of the tungsten oxide fine particles was 78 nm as shown in FIG.
The liquid solution was treated in the same manner as in Example 1 to obtain a solar shield B, and the optical properties of the solar shield B were measured in the same manner as in Example 1. As a result, a P / B ratio of 2.2 and a VLT of 57.9% were obtained, and the solar shading characteristics were calculated to be 4.1 as shown in FIG.
From the above, it was confirmed that the solar radiation shielding body B according to Example 2 has excellent solar radiation shielding characteristics.

[Example 3]
Under a N ₂ atmosphere, tungsten hexachloride was added in small portions in 350 g of ethanol under N ₂ atmosphere and dissolved, and then water was added to hydrolyze. The solution was dried at 70 ° C., and further completely dried at 100 ° C. The solvent was evaporated to obtain a hydrate powder. The obtained hydrate powder was the same as in Example 1, but heated while supplying 3% H ₂ gas using N ₂ gas as a carrier, and baked at 520 ° C. for 1 hour to obtain fine particles c. The powder color of the powder containing the fine particles c is 40.0591, L * is −0.8091, and b * is −6.6679. As a result of identifying the crystal phase by powder X-ray diffraction, WO A crystal phase of _2.90 or W ₂₀ O ₅₈ was observed.
The fine particles c were treated in the same manner as in Example 1 to prepare a tungsten oxide dispersion, which was used as a solar shield-forming dispersion. The dispersion particle diameter of the tungsten oxide fine particles in the dispersion of the tungsten oxide fine particles was 72 nm as shown in FIG.
The dispersion of the tungsten oxide fine particles was treated in the same manner as in Example 1 to obtain a solar shield C, and the optical properties of the solar shield C were measured in the same manner as in Example 1. As a result, a P / B ratio of 1.5 and VLT of 74.0% were obtained, and the solar shading characteristics were calculated to be 4.0 as shown in FIG.
From the above, it was confirmed that the solar radiation shielding body C according to Example 3 has excellent solar radiation shielding characteristics.

[Example 4]
Tungstic acid and magnesium nitrate aqueous solution were mixed and stirred for 30 minutes so that Mg / W = 0.05 (weight ratio), and then this aqueous solution was dried at 110 ° C. to obtain a dried product. The dried product was fired under the same conditions as in Example 2 to obtain fine particles d. The powder color of the powder containing the fine particles d is 35.2259, L * is −0.8483, and b * is −5.3161. As a result of identifying the crystal phase by powder X-ray diffraction, WO A crystal phase of _2.90 or W ₂₀ O ₅₈ was observed.
The fine particles d were treated in the same manner as in Example 1 to prepare a tungsten oxide dispersion, which was used as a solar shading dispersion. The dispersion particle diameter of the tungsten oxide fine particles in the dispersion of the tungsten oxide fine particles was 69 nm as shown in FIG.
The dispersion of the tungsten oxide fine particles was treated in the same manner as in Example 1 to obtain a solar shield D, and the optical properties of the solar shield D were measured in the same manner as in Example 1. As a result, a P / B ratio of 2.1 and a VLT of 62.7% were obtained, and the solar shading characteristics were calculated to be 4.2 as shown in FIG.
From the above, it was confirmed that the solar radiation shielding body D according to Example 4 has excellent solar radiation shielding characteristics.

[Example 5]
Under a N ₂ atmosphere, tungsten hexachloride and copper nitrate were added little by little into 350 g of ethanol, dissolved as Cu / W = 0.01 (weight ratio), and then the liquid was dried at 70 ° C. Further, the solvent was completely evaporated at 100 ° C. to obtain a dry powder.
The obtained dried powder was the same as in Example 1, but heated while supplying 3% H ₂ gas with N ₂ gas as a carrier, and baked at 520 ° C. for 1 hour to obtain fine particles e. The powder color of the powder containing the fine particles e is 37.2794, a * is −0.1294, b * is −3.3322, and the result of identification of the crystal phase by powder X-ray diffraction is WO A crystal phase of _2.90 or W ₂₀ O ₅₈ was observed.
The fine particles e were treated in the same manner as in Example 1 to prepare a tungsten oxide dispersion, which was used as a solar shading dispersion. The dispersion particle diameter of the tungsten oxide fine particles in the dispersion of the tungsten oxide fine particles was 68 nm as shown in FIG.
The dispersion of the tungsten oxide fine particles was treated in the same manner as in Example 1 to obtain a solar shield E, and the optical properties of the solar shield E were measured in the same manner as in Example 1. As a result, a P / B ratio of 2.4 and a VLT of 54.0% were obtained, and the solar shading characteristics were calculated to be 4.2 as shown in FIG.
From the above, it was confirmed that the solar shading body E according to Example 5 has excellent solar shading characteristics.

[Example 6]
Under a N ₂ atmosphere, tungsten hexachloride and cerium nitrate were put in 350 g of ethanol in small amounts and dissolved as Ce / W = 0.01 (weight ratio), and then this solution was dried at 70 ° C., Further, the solvent was completely evaporated at 100 ° C. to obtain a dry powder.
The obtained dried powder was the same as in Example 1, but heated while supplying 3% H ₂ gas with N ₂ gas as a carrier, and baked at 520 ° C. for 1 hour to obtain fine particles f. The powder color of the powder containing fine particles f is 36.9187, a * is −0.1457, b * is −3.9656, and the result of identification of the crystal phase by powder X-ray diffraction is WO A crystal phase of _2.90 or W ₂₀ O ₅₈ was observed.
The fine particles f were treated in the same manner as in Example 1 to prepare a tungsten oxide dispersion, which was used as a solar shading dispersion. The dispersion particle diameter of the tungsten oxide fine particles in the dispersion of the tungsten oxide fine particles was 68 nm as shown in FIG.
The dispersion of the tungsten oxide fine particles was treated in the same manner as in Example 1 to obtain a solar shield F, and the optical properties of the solar shield E were measured in the same manner as in Example 1. As a result, a P / B ratio of 2.0 and a VLT of 61.0% were obtained, and the solar shading characteristics were calculated to be 4.0 as shown in FIG.
From the above, it was confirmed that the solar radiation shielding body F according to Example 6 has excellent solar radiation shielding characteristics.

[Example 7]
10% by weight of the tungsten oxide fine particles a obtained in Example 1, 45% by weight of methyltrimethoxysilane, 25% by weight of ethanol and 20% by weight of water were pulverized for 6 hours with a paint shaker containing 0.3 mmφZrO ₂ beads. A dispersion of tungsten oxide fine particles was prepared by a dispersion treatment (dual liquid).
The dispersion particle diameter of the tungsten oxide fine particles in the dispersion (two liquids) of the tungsten oxide fine particles was 69 nm as shown in FIG.
Then, 32 wt% of the obtained tungsten oxide fine particle dispersion (part 2), 32 wt% of the UV curable resin, and the remaining toluene were thoroughly mixed and stirred to prepare a dispersion for forming a solar shading body (foam). .
The solution was treated in the same manner as in Example 1 to obtain a solar shield G, and the optical properties of the solar shield G were measured in the same manner as in Example 1. As a result, a P / B ratio of 2.1 and a VLT of 63.0% were obtained, and the solar radiation shielding characteristics were calculated to be 4.2 as shown in FIG.
From the above, it was confirmed that the solar radiation shielding body G according to Example 7 has excellent solar radiation shielding characteristics.
In addition, after the solar shading body G was exposed at 60 ° C. under a constant temperature and humidity of 90% for 7 days, the solar shading characteristics were evaluated again. As a result, the solar shading characteristics were 4.1 and the decrease was only 0.1. It was.

[Example 8]
A quartz boat containing 50 g of the same tungstic acid as in Example 1 was set in a quartz tube furnace, heated while supplying 5% H ₂ gas using N ₂ gas as a carrier, and reduced at a temperature of 550 ° C. for 1 hour. After the treatment, fine particles g were obtained by firing at 800 ° C. for 1 hour in an N ₂ gas atmosphere. The powder color of the powder containing fine particles g is 36.9288, a * is 1.2573, and b * is −9.1526. As a result of identifying the crystal phase by powder X-ray diffraction, W * A crystalline phase of ₁₈ O ₄₉ was observed.
Next, 5% by weight of the fine particles h, 5% by weight of a polymeric dispersant, and 90% by weight of toluene are weighed, and crushed and dispersed for 3 hours with a paint shaker containing 0.3 mmφZrO ₂ beads to form a solar radiation shield. Dispersion liquid (liquid A) was prepared. Here, when the dispersion particle diameter of the tungsten oxide fine particles in the dispersion liquid for forming the sunscreen (liquid A) was measured, it was 51 nm as shown in FIG.
Next, 1.6 g of the obtained solar shielding body-forming dispersion (liquid A) and 0.5 g of UV curable resin were weighed, mixed and stirred to prepare a solar shielding body-forming dispersion (liquid B). . And the solar radiation shielding body H was obtained like Example 1 except having used the bar coater of bar No30.
And the optical characteristic of the solar radiation shield H was measured similarly to Example 1. FIG. As a result, the P / B ratio was 8.8, the VLT was 42.0%, and the solar shading characteristics were calculated to be 10.2 as shown in FIG.
From the above, it was confirmed that the solar radiation shielding body H according to Example 8 has excellent solar radiation shielding characteristics.

[Example 9]
As a reduction treatment of Example 8, heating was performed while supplying 0.67% H ₂ gas using N ₂ gas as a carrier, and reduction treatment was performed at a temperature of 800 ° C. for 1 hour to obtain fine particles h. The powder color of the powder containing the fine particles h is L * of 36.4698, a * of 3.3011, and b * of −5.9936. As a result of identification of the crystal phase by powder X-ray diffraction, W * A crystalline phase of ₁₈ O ₄₉ was observed.
Next, in the same manner as in Example 8, a dispersion for forming a sunscreen (Liquid A) was prepared. Here, when the dispersion particle diameter of the tungsten oxide fine particles in the dispersion for forming the sunscreen (liquid A) was measured, it was 172 nm as shown in FIG.
Next, a solar shading body I was obtained in the same manner as in Example 8. As a result of measuring the optical characteristics of the solar shading body I in the same manner as in Example 1, a P / B ratio of 1.8 and VLT 69.2% were obtained. The solar shading characteristics were calculated as shown in FIG. 1
From the above, it was confirmed that the solar radiation shielding body I according to Example 9 has excellent solar radiation shielding characteristics.

[Comparative Example 1]
Although it was the same as Example 1, the solar radiation shield J using commercially available (made by Kanto Chemical Co., Inc.) WO ₃ (fine particles i) as tungsten oxide fine particles was manufactured.
The powder color of the powder containing the fine particles g is 92.5456, a * is -11.3853, and b * is 34.5477. As a result of identifying the crystal phase by powder X-ray diffraction, WO ₃ A crystalline phase of was observed.
The dispersion particle diameter of the tungsten oxide fine particles in the dispersion of the tungsten oxide fine particles prepared from the fine particles g was 69 nm as shown in FIG.
The dispersion of the tungsten oxide fine particles was treated in the same manner as in Example 1 to obtain a solar shield J. The optical properties of the solar shield J were measured in the same manner as in Example 1. As a result, a P / B ratio of 1.1 and a VLT of 69.7% were obtained, and the solar shading characteristics were calculated to be 3.4 as shown in FIG.
From the above, it was confirmed that the solar radiation shielding body J according to Comparative Example 1 is inferior in solar radiation shielding characteristics to the solar radiation shielding bodies according to Examples 1 to 9.

[Evaluation]
When examining the solar shading characteristics of the solar shading bodies according to Examples 1 to 9 from the solar shading characteristics described in FIG. 1, all exceeded 3.7, but the solar shading body according to the comparative example Since the solar radiation shielding characteristic remained at 3.4, the superiority of the solar radiation shielding body according to the example was confirmed.

It is a table | surface of the measurement result of the solar radiation shielding body which concerns on an Example and a comparative example. It is a graph which shows the solar radiation shielding characteristic of the solar radiation shielding body which concerns on this invention.

Claims (8)

A dispersion for forming a sunscreen, in which the sunscreening fine particles are dispersed in a solvent,
The solar shading fine particles have a general formula WyOz (where W is tungsten, O is oxygen, 2.0 <z / y <3.0), or / and a general formula MxWyOz (where M is an alkali metal, Alkaline earth metal, rare earth element, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, One or more elements selected from Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, W is tungsten, O Is represented by oxygen, 0.001 ≦ x / y ≦ 1, 2.0 <z / y ≦ 3.0),
The powder containing the sun-shielding fine particles has a powder color in the L * a * b * color system in which L ^* is 25 to 80, a ^* is −10 to 10, and b ^* is −15 to 15. Yes,
A dispersion for forming a solar radiation shielding body, wherein a dispersion particle size of the solar radiation shielding fine particles in the solvent is 800 nm or less.   The surface of the fine particle for shielding solar radiation is coated with a compound containing at least one element selected from Si, Ti, Al, Zr, and Y. Dispersion. Fine particles of oxide containing two or more elements selected from Sb, V, Nb, Ta, W, Zr, F, Zn, Al, Ti, Pb, Ga, Re, Ru, P, Ge, In, and Sn ,
Or a boron compound represented by the general formula XB _m (wherein X is an element selected from an alkaline earth metal element or a rare earth element including yttrium (Y), B is boron, 4 ≦ m <6.3) Fine particles,
3. The dispersion for forming a solar shading body according to claim 1, wherein at least one kind of fine particles selected from fine particles of indium tin composite oxide is dispersed in a solvent.   The dispersion for forming a sunscreen according to any one of claims 1 to 3, wherein an inorganic binder or / and a resin binder are contained.   A solar shading body, which is formed by using the solar shading body-forming dispersion liquid according to claim 1.   The solar radiation shielding body according to claim 5, wherein the solar radiation shielding body is formed on a transparent substrate. It is a solar radiation shielding body in any one of Claims 5-6,
The transmittance of the solar shield for light has a maximum value at a wavelength of 350 to 600 nm, and has a minimum value at a wavelength of 600 to 1500 nm,
When the maximum value is P, the minimum value is B, and the visible light transmittance of the solar radiation shield is VLT, 40% ≦ VLT ≦ 80%,
Formula: P / B + 0.0333 × VLT ≧ 3.7
A solar shading body characterized by satisfying the above. Sunlight shielding fine particles having a general formula WyOz (W is tungsten, O is oxygen, 2.0 <z / y <3.0) or / and a general formula MxWyOz (where M is an alkali metal) , Alkaline earth metals, rare earth elements, 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, W is tungsten, O is represented by oxygen, 0.001 ≦ x / y ≦ 1, 2.0 <z / y ≦ 3.0),
The powder containing the sun-shielding fine particles has a powder color in the L * a * b * color system in which L ^* is 25 to 80, a ^* is −10 to 10, and b ^* is −15 to 15. A method for producing a dispersion for forming a solar shading material in which the solar shading fine particles are dispersed in a solvent,
A step of producing the solar shading fine particles by firing the starting material of the solar shading fine particles in an inert gas alone or in a mixed atmosphere of an inert gas and a reducing gas;
The solar radiation shielding fine particles and the solvent are mixed, and the solar radiation shielding fine particles are pulverized and dispersed to have a dispersion particle size of the solar radiation shielding fine particles in the solvent of 800 nm or less. The manufacturing method of the dispersion liquid for solar radiation shielding body to do.

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