JP6187540B2 - Composite tungsten oxide fine particles for solar radiation shield formation, dispersion thereof, and solar radiation shield - Google Patents

Description

The present invention is a method for producing a composite tungsten oxide fine particle for forming a solar radiation shield that is transparent in the visible light region and has an absorption in the near infrared region, and the composite tungsten oxide fine particle for solar radiation shield formation is dispersed. Composite tungsten oxide dispersion for solar radiation shield formation,
In addition, it relates to a solar radiation shield.

As a method of removing and reducing infrared rays that are contained in sunlight or light from a light bulb and that cause the human body to feel as heat or cause an increase in indoor temperature, glass that has been formed with a metal film made of a material that reflects the infrared rays is conventionally used. Many means using heat ray reflective glass have been used. Examples of the infrared reflective material include metal oxides such as FeO _x , CoO _x , CrO _x , and TiO _x , Ag
Metal materials such as Au, Cu, Ni, and Al are selected.

However, these metal oxides and metal materials have the property of reflecting or absorbing visible light at the same time, in addition to infrared rays that greatly contribute to heat feeling and temperature rise. For this reason, there existed a problem that visible light transmittance fell by use of the said heat ray reflective glass. In particular, a window base material used for building materials, vehicles, and the like requires high transmittance in the visible light region. Therefore, in the heat ray reflective glass, when a material such as the metal oxide is used, the film thickness has to be very thin.

In heat ray reflective glass, in order to make the film thickness of a material such as a metal oxide very thin, a physical film forming method such as spray baking, CVD method, sputtering method or vacuum deposition method is used.
A method of forming a thin film having a thickness of 10 nm is employed.
However, these film forming methods require a large-scale apparatus and a vacuum apparatus, and there are problems in productivity and an increase in area, and there is a problem that the manufacturing cost of the film increases. In addition, if these materials are used to improve the solar radiation shielding characteristics of the heat ray reflective glass, the reflectance in the visible light region also tends to increase at the same time. There was also a drawback that would damage.

On the other hand, a film formed with these materials has a relatively low electrical resistance value and high reflection with respect to radio waves. For this reason, heat ray reflective glass is used for mobile phones, global positioning systems (GPS),
There is a problem in that radio waves from TVs, radios, etc. are reflected, causing interference in the surrounding area as well as the room where the glass is installed.

In order to improve the problems of such heat ray reflective glass, the physical properties of the film formed on the glass surface are such that the light reflectance in the visible region is low, the reflectance in the infrared region is high, and the film surface It is considered that a film whose resistance value can be controlled to about 10 ⁶ Ω / □ or more is necessary.

Here, antimony tin oxide (hereinafter sometimes abbreviated as ATO) or indium tin oxide (hereinafter abbreviated as ITO), which is a material having high visible light transmittance and excellent heat ray absorption characteristics. There is a method of absorbing infrared rays using a fine particle dispersion. Since these materials have a relatively low visible light reflectance, they do not give a glaring appearance to the heat ray reflective glass. However, since these materials have an absorption wavelength region in the higher wavelength region from the mid-infrared region, the heat ray shielding effect is not sufficient in the infrared region closer to the visible light region where the solar radiation intensity is strong. Furthermore, since these materials have a low solar shielding ability per unit weight, there is a problem that the amount used is increased in order to obtain a high solar shielding ability, and the raw material cost is increased.

Furthermore, as an infrared shielding material having solar radiation shielding ability, a film formed by slightly reducing tungsten oxide, molybdenum oxide, and vanadium oxide can be given. These films are materials used as so-called electrochromic materials. In addition, it is transparent in a sufficiently oxidized state, and when it is reduced by an electrochemical method, it is a material that develops absorption from the long-wavelength visible light region to the near-infrared region.

In Patent Document 1, on a transparent glass substrate, as a first layer from the substrate side, at least one kind selected from the group consisting of IIIa group, IVa group, Vb group, VIb group and VIII group of the periodic table is used. A composite tungsten oxide film containing metal ions is provided, a transparent dielectric is provided as a second layer on the first layer, and a group IIIa, IVa, or Vb of the periodic table is provided as a third layer on the second layer. , VIb group and
A heat ray shielding glass is proposed in which a composite tungsten oxide film containing at least one metal ion selected from the group consisting of group VIII is provided, and the refractive index of the transparent dielectric film of the second layer is lower. Yes. Further, according to this document, it has been proposed that a composite tungsten oxide film containing metal ions is formed by a sputtering method particularly from the viewpoint of increasing the area and productivity.

In Patent Document 2, the same method as Patent Document 1 is used, on a transparent glass substrate, the first from the substrate side.
Providing a first dielectric film as a layer, and providing a tungsten oxide film as a second layer on the first layer;
A heat ray shielding glass in which a second dielectric film is provided as a third layer on the second layer has been proposed.

In Patent Document 3, a composite tungsten oxide film containing the same metal element is provided as a first layer from the substrate side on a transparent substrate by the same method as 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.

In Patent Document 4, by using a target made of tungsten and sputtering in an atmosphere containing carbon dioxide, it is possible to stably produce a tungsten oxide film having high heat shielding properties and uniform optical characteristics in a plane. A method of forming a transmissive heat ray shielding film has been proposed.

As described in Patent Document 1 to Patent Document 4, conventionally, a sputtering method has been used as a method for manufacturing an infrared shielding film containing a tungsten compound. However, such a physical film formation method requires a large-scale apparatus and vacuum equipment. As a result, there is a problem from the viewpoint of productivity, and even though it is technically possible to increase the area, there is also a problem that the manufacturing cost of the film increases. Further, from the viewpoint of a solar radiation shield, there is a problem that it is desired to further improve the light transmittance in the visible light region without reducing the shielding performance in the infrared region and the near infrared region. From the viewpoint of productivity, when the infrared shielding film is a single-phase film, there is a problem of low durability that the infrared shielding film is easily oxidized and easily damaged.

In order to solve the above-described problem, Patent Document 5 discloses tungsten oxide fine particles used for a solar radiation shielding body (fine particle dispersion) that can reduce infrared transmittance while keeping visible light transmittance high, a manufacturing method thereof, and MxWyOz. The represented composite tungsten oxide fine particles have been proposed.
In the composite tungsten oxide fine particles represented by MxWyOz, the value of x is 0.001 ≦
The value of x ≦ 1, z / y is in the range of 2.2 ≦ z / y ≦ 2.999, and the element M is alkali metal, alkaline earth metal, rare earth metal, 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,
One or more elements selected from Ta and Re.

The visible light transmissive solar shading material (fine particle dispersion) in which the composite tungsten oxide fine particles described in Patent Document 5 are dispersed is useful from the viewpoint of reducing the infrared transmittance while keeping the visible light transmittance high. Material. However, there has been a problem that when the solar shading body is irradiated with strong light including ultraviolet rays, the solar shading body becomes deep blue and the visible light transmittance is lowered (hereinafter referred to as “light coloring”). .) However, this light coloring has a property of returning to the original state by leaving the solar shading body in a dark place for a certain period of time (several days).

In order to solve the above problem, in Patent Document 6, Cu, Fe, Mn, Ni, Co, in the crystal of composite tungsten oxide fine particles represented by MxWyOz or / and on the surface of the fine particles are disclosed.
Proposed tungsten-containing oxide fine particles characterized by containing one or more elements selected from Pt, Au, Ag, Na, In, Sn, Cs, and Rb, or a compound thereof. Yes.

Further, Patent Document 7 (described by the general formula _{W n O 3n-1, W} n O 3n-2) tungsten oxide called Magneli phase in the composite tungsten oxide nanoparticles having a hexagonal
It is described that the addition of good infrared shielding properties and weather resistance can be improved by mixing these.

JP-A-8-59300 JP-A-8-12378 JP-A-8-283044 Japanese Patent Laid-Open No. 10-183334 JP 2005-187323 A JP 2007-238353 A WO2005 / 037932 Publication

According to the study by the present inventors, the composite tungsten oxide described in Patent Document 5 is
It is a solar shading material that has high visible light transmittance and can shield excellent infrared transmittance. However, it has been found that when the sunscreen material is contained in an organic binder to form a single phase film, the sunscreen properties of the sunscreen material are deteriorated by heat.

Further, according to the study by the present inventors, Cu, Fe, Mn, Ni, Co, Pt, Au are present in the crystal of composite tungsten oxide fine particles described in Patent Document 6 and / or on the surface of the fine particles.
In addition, one or more elements selected from Ag, Na, In, Sn, Cs, and Rb, or tungsten-containing oxide fine particles to which the compound is added, have a part of the excess amount in the added element. It has been found that there is a case where it is deposited as a metal having low solar radiation shielding ability or not having solar radiation shielding ability and becomes an electron conduction type particle and absorbs or reflects light in the visible light region. Furthermore, by using the method described in the document, Cu having a high addition effect is also obtained.
It has also been found that Fe and Fe accelerate the deterioration of the binder resin that forms the solar shading body, and may cause inadequate adhesion between substrates and insufficient film strength.

Furthermore, the present inventors have found in Patent Document 7 that a good infrared shielding property is added and light resistance is improved by mixing the magnetic phase, but the heat resistance is not sufficient.

The present invention has been made under the above-described circumstances, and the problem to be solved is that the visible light transmittance is kept high and the infrared transmittance is kept low, while being excellent in heat resistance, light Provided are a composite tungsten oxide fine particle for forming a solar shading body having light resistance capable of suppressing coloring, a method for producing the same, a composite tungsten oxide fine particle dispersion for forming a solar shading body using the fine particle, and a solar shading body. It is to be. The solar shading body according to the present invention is a concept including a solar shading film.

As a result of intensive studies, the present inventors have made a mixture of tungsten and cesium with a molar ratio of tungsten and cesium within a predetermined range, with tungstic acid (H ₂ WO ₄ ) powder and cesium carbonate (Cs ₂ CO ₃ ) powder. Visible light transmittance is obtained by firing a mixed powder or a mixed powder obtained by drying a mixture of a tungstic acid (H ₂ WO ₄ ) powder and an aqueous cesium carbonate solution in a reducing atmosphere within a predetermined temperature range. Has been found that it is possible to obtain composite tungsten oxide fine particles for forming a solar shading body that have excellent heat resistance and light resistance that suppresses photo-coloring while maintaining high infrared transmittance and low infrared transmittance. The present invention has been completed.

That is, the first invention for solving the above-described problem is
It is represented by the general formula CsxWyOz (where Cs is cesium, W is tungsten, O is oxygen, 0.30 ≦ x / y ≦ 0.33, 2.2 ≦ z / y ≦ 3.0). A composite tungsten oxide fine particle for forming a solar radiation shielding body having a crystal structure,
The amount of tungsten oxide other than hexagonal does not exceed 10 wt% or less,
The amount of WO ₂ is not more than 1 wt%,
The amount of W produced is 0% by weight,
Including one or more of tungsten oxides other than the hexagonal crystals or the WO ₂
It is a composite tungsten oxide fine particle for forming a solar shading body characterized by having a c-axis lattice constant of from 7.61101 to 7.61242.

The second invention is
A composite tungsten oxide fine particle dispersion for forming a solar radiation shield, comprising the composite tungsten oxide fine particles for forming a solar radiation shield according to the first invention, a solvent, and a dispersant.

The third invention is
Further, the composite tungsten oxide fine particle dispersion for forming a solar shading body according to the second invention, further comprising a resin binder.

The fourth invention is:
A solar radiation shielding body characterized in that the composite tungsten oxide fine particles for solar radiation shielding formation according to the first invention are dispersed in a resin.

According to the present invention, the composite tungsten oxide for forming a solar shading body has high visible light transmittance, low infrared transmittance, excellent heat resistance, and light resistance to suppress photo-coloring. It was possible to obtain an object fine particle, a method for producing the same, a composite tungsten oxide fine particle dispersion for forming a solar shield using the fine particle, and a solar shield.

It is a differential thermothermal weight simultaneous measurement (TG-DTA) result of the mixed powder of the tungstic acid powder and cesium carbonate powder according to the present invention. 1 is a diagram illustrating a crystal structure of a composite tungsten oxide fine particle for forming a sunscreen according to the present invention.

Hereinafter, the form for implementing this invention is demonstrated concretely.
The present inventors have prepared a mixed powder of a tungstic acid (H ₂ WO ₄ ) powder and a cesium carbonate (Cs ₂ CO ₃ ) powder, or a tungstic acid (H ₂ WO ₄ ) powder and a cesium carbonate aqueous solution. In the mixed powder obtained by drying the mixture, the mixing molar ratio of tungsten and cesium is 0.33.
A mixed powder satisfying ≦ Cs / W ≦ 0.37 was produced. And by baking the mixed powder at a temperature of 500 ° C. or higher and 600 ° C. or lower in a mixed gas atmosphere of an inert gas and a reducing gas,
General formula Cs _x W _y O _z (where Cs is cesium, W is tungsten, O is oxygen, 0.30
≦ x / y ≦ 0.33, 2.2 ≦ z / y ≦ 3.0), and cesium-added tungsten oxide fine particles having a hexagonal crystal structure as a main phase were obtained.

And the present inventors, while maintaining the visible light transmittance and infrared transmittance equivalent to the composite tungsten oxide fine particles according to the prior art, the cesium-added tungsten oxide fine particles according to the present invention, It has been found that it is excellent in heat resistance and light resistance in which photo-coloring is suppressed, and has been found to be optimal as a composite tungsten oxide fine particle for forming a solar shading body.
Furthermore, the present inventors have conceived a composite tungsten oxide fine particle dispersion for forming a solar radiation shield using the cesium-added tungsten oxide fine particles according to the present invention.

And, by using the composite tungsten oxide fine particle dispersion for solar radiation shielding using the cesium-added tungsten oxide fine particles according to the present invention, a simple coating method or By using the kneading method, the solar shading body according to the present invention could be produced. The solar radiation shielding body according to the present invention has improved light transmittance in the visible light region, improved heat resistance, and suppressed light coloring while maintaining the shielding performance in the infrared region and near infrared region.
Hereinafter, the cesium-added tungsten oxide fine particles used as the composite tungsten oxide fine particles for forming the sunscreen according to the present invention will be described.

1. Cesium-added tungsten oxide fine particles according to the present invention, and production method thereof Tungstic acid (H ₂ WO ₄ , tungsten trioxide monohydrate), cesium carbonate (Cs)
_{When the 2} CO ₃ ) aqueous solution is mixed, it reacts with a large amount of gas generation to produce a mixture. In general, tungsten trioxide having cubic crystals is known to intercalate cesium non-stoichiometrically in the voids. Therefore, the gas generation reaction is considered to be carbon dioxide gas generated by cesium intercalating in the tungsten trioxide crystal.

When the crystal structure of the mixed dry powder obtained by drying the mixture of the generated tungstic acid and cesium carbonate aqueous solution is analyzed by XRD, X-ray diffraction very similar to cesium tungsten oxide (CsW ₂ O ₆ , cubic crystal) Showed a peak.

The mixed dry powder was heat-treated in a reducing gas stream while simultaneously measuring differential thermogravimetric weight. Then, a peak was confirmed in the differential heat (DTA) curve around 373 ° C., and it was confirmed from the structural analysis that the phase transition was from cubic to hexagonal (see FIG. 1).

Here, FIG. 1 is a graph of the differential thermothermal weight simultaneous measurement (TG-DTA) result of a mixed powder sample of tungstic acid powder and cesium carbonate powder according to the present invention.
The horizontal axis of the graph is temperature, and the vertical axis is ΔTG, TG, and DTA, which indicate a solid line, a two-dot chain line, and a broken line, respectively.

In the TG (thermogravimetric) curve of FIG. 1, a decrease in the weight of the mixed powder sample was confirmed from around 550 ° C. When a mixed powder sample prepared at 550 ° C. or higher was subjected to structural analysis, WO ₂ , W, and the like were confirmed. WO ₂ , W, and the like are produced when cesium-added tungsten oxide or the raw material tungstic acid undergoes reductive decomposition, which is considered to be a cause of weight reduction of the mixed powder sample. In particular, WO ₂ has a strong coloring power, and if it is contained even in a small amount, the transmittance is lowered. Therefore, W
The amount of O ₂ produced is preferably 1% by weight or less.

The upper limit of the cesium entering the voids of the hexagonal tungsten oxide is 0.33 in terms of the Cs / W molar ratio. However, the stoichiometric Cs / W molar ratio of 0.33 (stoichiometry)
When cesium is mixed and charged into tungsten oxide by composition, a portion that becomes cesium poor may be generated due to uneven mixing of tungsten oxide and cesium. It is considered that tungsten oxide other than hexagonal crystals is formed in the portion of tungsten oxide that becomes the cesium poor. Since tungsten oxides other than hexagonal crystals have no solar radiation shielding function, if they are produced in large amounts as impurities, the solar radiation shielding function of the solar radiation shielding body is lowered. there,
The amount of tungsten oxide other than the hexagonal crystal is preferably 10% by weight or less,
More preferably, it is 1% by weight or less.

On the other hand, in order to suppress the formation of tungsten oxides other than the hexagonal crystal, when the amount of cesium added is excessive, it is considered that cesium accumulates on the particle surface as cesium hydroxide if it is slightly excessive. It has little effect on the body membrane properties. Further, when excessive cesium is added, a portion in which tungsten oxide is excessively doped with cesium having a Cs / W molar ratio of 0.33 or more is generated. In a portion where cesium having a Cs / W molar ratio of 0.33 or more is excessively doped, phase transition is inhibited, and cesium tungstate having a square lattice structure is generated and mixed. If the amount of the cesium tungstate having the square lattice structure is small, the film characteristics of the solar radiation shield are not greatly affected. However, if the cesium tungstate having a square lattice structure is increased, the solar transmittance of the solar shield is deteriorated.

Above, and tungstic acid _(H 2 WO _4), mixed powder was mixed cesium carbonate _(Cs 2 CO _3), or, tungstic acid _(H 2 WO ₄₎ and cesium carbonate _(Cs 2 CO ₃₎ solution were mixed In the case of producing the dried mixed dry powder, it is preferable that 0.33 ≦ Cs / W ≦ 0.37 in the Cs / W molar ratio in order to suppress generation of a heterogeneous phase having low solar radiation shielding characteristics. More preferably, Cs / W = 0.35.

Tungstic acid (H ₂ WO ₄ ) and cesium carbonate (Cs ₂ ) from the viewpoint of desired properties and optical characteristics and heat resistance characteristics of the cesium-doped tungsten oxide fine particles according to the present invention.
The firing temperature of the mixed dry powder with CO ₃ ) is 500 ° C. or more and 600 ° C. or less.
From the result of the TG-DTA measurement for the mixed dry powder, the mixed dry powder is 3
This is because the phase transition from cubic to hexagonal at 73 ° C or higher was found. Furthermore, if the firing temperature is 500 ° C. or higher, it is unnecessary and preferable to significantly extend the firing time in order to complete the phase transition. Moreover, since the weight reduction is confirmed from around 550 ° C. and the cesium-added tungsten oxide gradually undergoes reductive decomposition, the calcination temperature is preferably 600 ° C. or less, which is less affected by reductive decomposition.

The treatment time during firing may be appropriately selected according to the treatment temperature, but may be 1 hour or more and 5 hours or less. When firing in a mixed gas atmosphere of an inert gas and a reducing gas, the concentration of the reducing gas in the inert gas may be appropriately selected according to the processing temperature, and is not particularly limited.
0 vol% or less, preferably 10 vol% or less, more preferably 5 v from the viewpoint of safety.
ol% or less.

Here, the tungsten compound used in the present invention is preferably tungstic acid from the viewpoint of raw material costs and exhaust gas treatment. As for the cesium compound, cesium carbonate is desirable from the viewpoint of raw material costs and exhaust gas treatment.

2. Cesium-added tungsten oxide fine particles and pulverized fine particles of the cesium-added tungsten oxide fine particles The cesium-added tungsten oxide fine particles according to the present invention obtained by the above-described steps are represented by the general formula Cs _x W _y O _z (where Cs is cesium , W is tungsten, O is oxygen, 0.30 ≦
cesium-added tungsten oxide fine particles represented by x / y ≦ 0.33, 2.2 ≦ z / y <3.0).

The cesium-added tungsten oxide according to the present invention represented by Cs _x W _y O _z is a solar-shielding fine particle having a characteristic of shielding infrared rays while maintaining high visible light transmittance and excellent in heat resistance. is there. And if the value of z / y is 2.2 or more, W which does not have solar radiation shielding function
If generation of O ₂ is avoided and less than 3.0, sufficient conduction electrons are generated, so that a sufficient solar radiation shielding function is exhibited. Further, if the value of x / y is 0.30 or more, conduction electrons are generated, and if it is 0.33 or less, the generation of impurities can be avoided and the heat resistance is excellent. More preferably, excellent heat resistance characteristics are exhibited when the value of x / y is in the range of 0.32 to 0.33.

Moreover, the particle diameter of the cesium-added tungsten oxide fine particles according to the present invention can be appropriately selected depending on the purpose of use of the fine particles. For example, when used for an application that maintains the transparency of the solar shading body, the average dispersed particle size is preferably 800 nm or less, more preferably 100 nm or less, and even more preferably 50 nm or less. When the average dispersion particle size of tungsten oxide or composite tungsten oxide exceeds 800 nm, the light in the visible light region having a wavelength of 380 nm to 780 nm is scattered by geometric scattering or Mie scattering.
The appearance of the produced solar shading body is not preferable because it looks like frosted glass. Average dispersed particle size is 10
When the thickness is 0 nm or less, geometric scattering or Mie scattering is reduced, and a Rayleigh scattering region is obtained. In the Rayleigh scattering region, the scattered light is reduced in inverse proportion to the sixth power of the average dispersed particle size, so that the visible light scattering is reduced and the appearance is improved. Further, it is preferable that the average dispersed particle size is 50 nm or less because scattered light is extremely reduced.

As a simple method for measuring the particle diameter, a particle size distribution meter is generally used. However, in the case of a very small nanoparticle having an active surface generated by pulverization like the fine particle according to the present invention, aggregation and dispersion are repeated in a solution. For this reason, the particle size distribution meter measures the size of the secondary particles, and cannot accurately measure the size of the primary particles.
On the other hand, in order to measure the size of the primary particles, TEM observation is effective, but the measurement takes time and labor and is not a practical method.
Therefore, in the present invention, the transmitted scattered light intensity of the cesium-added tungsten oxide fine particles is measured. As described above, when the particle size of the fine particles is reduced, a Rayleigh scattering region is formed, and the scattered light is reduced in inverse proportion to the sixth power of the average dispersed particle size, so that the transmitted scattered light intensity changes according to the change in the particle size. Therefore, by examining the relationship between the transmitted scattered light intensity and the TEM particle size in advance, the size of the primary particles can be estimated from the transmitted scattered light intensity.
The measurement of the transmitted scattered light intensity is performed by measuring a sample that has been placed in a cell having a predetermined thickness in the state of a fine particle dispersion or a film formed by coating. At that time, the concentration and film thickness of the fine particle dispersion are adjusted so that the total light transmittance of the sample is approximately the same.

The particle diameter of the cesium-added tungsten oxide according to the present invention is determined by grain growth determined by the particle diameter of the tungstic acid as a raw material and the firing temperature zone. The cesium-added tungsten oxide is appropriately pulverized to have the above-described particle size, whereby scattering in the visible light region is reduced and high transparency is obtained.
Since this grinding requires a certain level of grinding energy, it is not sufficient to break up the aggregates of secondary particles using ultrasonic vibration or ultracentrifugal force treatment. The method used is suitable.

In the cesium-added tungsten oxide, WO ₆ octahedrons represented by squares in FIG. 2 are bonded to each other to form a hexagonal tunnel. In this tunnel, cesium is stored non-stoichiometrically, and the stored cesium is ionized. In addition, this planar structure has a vertical direction (c
Stacked in the axial direction). As a result, cesium ions are stably held in the structure having tungsten oxide as a skeleton, so that the values of the lattice constant a and the lattice constant c of tungsten oxide are stabilized as they approach the theoretical values. The cesium in the structure contributes as an electron supplier to the tungsten oxide and functions to increase the infrared absorption ability. Therefore, the cesium detachment leads to a decrease in the solar shielding ability.
However, the lattice constant of the cesium-added tungsten oxide particles greatly changes before and after the pulverization by the above-described pulverization performed to reduce the scattering in the visible light region. For this reason, the cesium-added tungsten oxide fine particles after pulverization are changed to a structure in which the contained cesium is easily detached.
Accordingly, it is desirable that the cesium-added tungsten oxide fine particles are fine particles that need only be pulverized less frequently. Specifically, the particle diameter of the cesium-added tungsten oxide fine particles before pulverization is preferably 500 nm or less, more preferably 300 nm or less.

3. Composite tungsten oxide fine particle dispersion for solar radiation shield formation The above-described cesium-added tungsten oxide fine particles and dispersant are mixed and dispersed in an appropriate solvent to form the solar radiation shield according to the present invention. Composite tungsten oxide fine particle dispersion. The said solvent is not specifically limited, What is necessary is just to select suitably according to the said binder, when a coating condition, a coating environment, and also the resin binder is contained. For example, at least one selected from ketones, esters, hydrocarbons, ethers, and alcohols is preferable. Specific examples include ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; toluene, xylene and the like And hydrocarbons such as ethyl ether and isopropyl ether, and alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, and tert-butanol. Of these, ketones and esters are more preferable because they are low in danger and toxicity and are easy to handle. Further, an additive such as a surfactant may be added.

The method for dispersing the cesium-added tungsten oxide fine particles in the solvent is not particularly limited as long as the fine particles are uniformly dispersed in the dispersion, and examples thereof include a bead mill using media beads, a ball mill, and a paint shaker. . By the dispersion treatment step using these equipments, the cesium-added tungsten oxide fine particles can be dispersed in the solvent and simultaneously pulverized with a medium agitating medium to be finer and dispersed.

4). Solar shield The coating method for forming a film by applying the composite tungsten oxide fine particle dispersion for forming the solar shield on a transparent substrate is, for example, spin coating, bar coating, spray coating, dip Any method such as a coating method, a screen coating method, a roll coating method, and a flow coating method can be used as long as the dispersion can be applied flatly and thinly and uniformly.

Moreover, when the said composite tungsten oxide fine particle dispersion for solar radiation shielding body is a dispersion containing a resin binder, what is necessary is just to harden | cure according to the hardening method of each resin after apply | coating the said dispersion to a base material. 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, the resin binder may be left as it is after application. For this reason, the composite tungsten oxide fine particle dispersion liquid for solar radiation shielding body which has the said structure can be apply | coated to the existing glass etc. on the spot.

The obtained solar shading body has solar transmittance (ST) and visible light transmittance (VLT) as optical characteristics.
Evaluated.
The solar transmittance value creates a graph of visible light transmittance (VLT) VS solar transmittance (ST),
Plot 5 points. From the line connecting the plotted points, the visible light transmittance (VLT) value is 70%.
The solar radiation transmittance (ST) value at that time was calculated and obtained.
The heat resistance of the cesium-added tungsten oxide fine particles is that the solar radiation shield is stored in a thermostatic bath at 120 ° C. in the atmosphere for 12 days, and then the solar radiation transmittance is measured to determine the difference in solar radiation transmittance before and after the heat resistance test (ΔST). Evaluation was made by calculating. The light shielding of the sunscreen is performed by irradiating the sunscreen at 60 ° C. and 35% RH at an illuminance of 100 mW / cm ² for 60 minutes, and the difference in visible light transmittance before and after the light irradiation (ΔVLT). Was evaluated by calculating.
In the above evaluation, even if the same sample is used, results may vary from test to test. Therefore, it is possible to perform stable evaluation by preparing a reference sample and comparing the changes in ST and VLT relative to each other. It became.

5. Summary The cesium-added tungsten oxide fine particles according to the present invention can be produced by firing at 500 ° C. or more and 600 ° C. or less in a mixed gas atmosphere of an inert gas and a reducing gas. And the cesium addition tungsten oxide fine particle dispersion was able to be manufactured using the cesium addition tungsten oxide fine particle which concerns on this invention similarly to the composite tungsten oxide fine particle which concerns on the prior art.

The cesium-added tungsten oxide fine particle dispersion according to the present invention can be used to form a solar shading body by a simple coating method or the like without using an expensive physical film forming method. A solar shading body that has excellent light transmission in the visible light region without degrading the shielding performance, and has improved heat resistance characteristics and light coloring related to the shielding performance over the conventional solar shading body using cesium-added tungsten oxide fine particles Can be manufactured at a low manufacturing cost.

Furthermore, by dispersing the cesium-added tungsten oxide fine particles according to the present invention into an appropriate resin by a kneading method or the like, light transmittance in the visible light region can be obtained without reducing the shielding performance in the infrared region or near infrared region. It was possible to manufacture a solar shading body having excellent heat resistance characteristics related to shielding performance compared to the conventional solar shading body using cesium-added tungsten oxide fine particles at a low production cost.

In addition, the formation of the solar shield using the composite tungsten oxide fine particle dispersion for forming the solar shield according to the present invention uses a decomposition reaction or a chemical reaction of the cesium-added tungsten oxide fine particles according to the present invention. Therefore, the solar radiation shielding body according to the present invention with stable characteristics of the fine particles could be formed.

Further, the cesium-added tungsten oxide fine particles according to the present invention obtained by firing in a reducing atmosphere in a temperature range of 373 ° C. or higher and 600 ° C. or lower are more heat resistant than the composite tungsten oxide fine particles according to the prior art. The characteristics and light resistance have been improved, and the excellent solar shading effect has been sustained.
For example, even if it is used for a portion exposed to sunlight or the temperature of the solar shading body is increased, the color and various functions are hardly deteriorated as compared with the composite tungsten oxide fine particles according to the prior art.
Further, the solar shading body according to the present invention using the composite tungsten oxide fine particle dispersion for solar shading formation according to the present invention has suppressed appearance abnormality due to photo-coloring, and maintains an excellent solar shading effect. Can demonstrate. As a result, solar radiation that requires solar shading functions for window materials for vehicles, buildings, offices, general households, etc., and for single-panel glass and laminated glass used in telephone boxes, show windows, lighting lamps, transparent cases, etc. Long-term stable solar radiation shielding has become possible in a wide range of fields such as shields.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples.

[Example 1]
An aqueous solution in which 1.95 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) is well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Industry Co., Ltd.) are sufficiently obtained. A mixed solution was obtained by mixing. The amount of cesium carbonate added was such that the molar ratio of Cs in cesium carbonate to W in tungstic acid was 0.33.
And the said mixed solution was fully dried in 100 degreeC air | atmosphere, and the obtained residual mixture was mixed for 15 minutes using the crusher. Then, 9 g of the mixture was set in a quartz furnace and heated while supplying 1% H ₂ gas using N ₂ gas as a carrier, and subjected to a reduction treatment at a temperature of 600 ° C. for 60 minutes to obtain fine particles (a) Got. Performed XRD measurement of the fine particles (a), x / y value in the Rietveld analysis microparticles of _{(a) (Cs x W y} O z), lattice constant, cesium tungstate phase of tetragonal lattice structure (in the present invention " It may be described as “different phase 1”.)
, The amount of WO ₂ phase (may be described as “different phase 2” in the present invention), the amount of W phase (sometimes described as “different phase 3” in the present invention), and the particles before grinding The diameter was determined. The results are shown in Table 1.

Next, 10% by weight of the fine particles (a), 10% by weight of a polymer dispersion (EFKA4400, manufactured by BASF), and 80% by weight of methyl isobutyl ketone were weighed so as to have a total weight of 20 g. The weighed product was added to 0.3 mmφZrO ₂ beads (Toray serum beads H manufactured by Toray
IP treated product) Loaded into a 70 cc glass bottle containing 120 g, and pulverized and dispersed using a paint shaker to form a composite tungsten oxide fine particle dispersion (A
Liquid).

Here, the evaluation of the size of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (liquid A) for solar radiation shielding was evaluated by the scattering intensity (transmitted light) of the finely dispersed fine particles in the resin. went.
Specifically, a sample film is prepared by fixing the weight ratio of the cesium-added tungsten oxide fine particles and the UV curable resin component, and the value of the total light transmittance (hereinafter sometimes abbreviated as Tt) of the sample film. Was adjusted to 50%. When the transmitted scattered light intensity of the sample film with the film thickness adjusted was measured, the maximum peak was 1.17%.
On the other hand, in the film produced under the conditions, the maximum peak of transmitted scattered light intensity is 1.2 to 1.3.
%, The cesium-added tungsten oxide fine particles were observed with a TEM. As a result, primary particles having a particle diameter of about 20 nm were observed.

Next, 6.0 g of the obtained composite tungsten oxide fine particle dispersion liquid (liquid A) for formation of solar shading material
Then, 3.0 g of UV curable resin was weighed, mixed and stirred to produce a composite tungsten oxide fine particle dispersed resin liquid (AA liquid) for formation of a solar radiation shield. Then, using a suitable bar coater so that the total light transmittance was 68.5%, a composite tungsten oxide fine particle-dispersed resin liquid (AA liquid) for solar radiation shielding was applied onto a glass substrate having a thickness of 3 mm. Thereafter, the solvent was removed at 70 ° C. for 1 minute, and irradiation with a high-pressure mercury lamp was performed to obtain a solar radiation shielding body (A) according to Example 1.

Here, using a spectrophotometer (U-4000, manufactured by Hitachi High-Tech Fielding Co., Ltd.), the solar transmittance was measured as an optical characteristic of the solar shield (A). With this value as the “initial value”, a heat resistance test and a light resistance test were conducted. In the heat resistance test, the solar radiation shield (A) was placed in the atmosphere 12
It was carried out by storing in a thermostatic bath at 0 ° C. for 12 days. The light resistance test was applied to the solar shield (A) 10
The irradiation was performed for 1 hour with a metal halide lamp at an intensity of 0 mW / cm ² .

(Cesium-doped tungsten oxide fine particles according to the prior art)
The evaluation of heat resistance and light resistance described above was carried out by simultaneously carrying out a heat resistance test and a light resistance test using a solar radiation shield using cesium-added tungsten oxide fine particles according to the prior art as a comparative sample. Sunscreen using added tungsten oxide fine particles (
The change of the solar transmittance and the visible light transmittance with A) was compared, and the improvement rate was calculated.
That is, after the test, the improvement rate is 100% when there is no change in the solar transmittance and the visible light transmittance, and the improvement rate is 0% when the solar transmittance and the visible light transmittance change as much as the comparative sample. did. Table 2 shows the results of the heat resistance and light resistance test.

In addition, the manufacturing method of the cesium addition tungsten oxide microparticles | fine-particles based on the prior art mentioned above is demonstrated.
For 34.57 kg of tungstic acid (H ₂ WO ₄ , manufactured by Japan Inorganic Chemical Industry Co., Ltd.)
An aqueous solution in which 7.43 kg of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) was dissolved in 6.70 kg of water was added and mixed, and then moisture was removed while stirring at 100 ° C. to obtain a dry powder. .
Next, the dry powder was heated while supplying 5% H ₂ gas using N ₂ gas as a carrier, and calcined at 800 ° C. for 5.5 hours to obtain Cs _0.33 WO ₃ fine particles. .

[Example 2]
An aqueous solution in which 2.06 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) was well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Co., Ltd.) were sufficiently mixed, Fine particles (b) were obtained in the same manner as in Example 1 except that a mixture was obtained. Table 1 shows the x / y value, the lattice constant, the amount of different phases, and the particle size before pulverization of the fine particles (b).

Next, the same operation as in Example 1 was performed except that the fine particles (b) were used instead of the fine particles (a), and the composite tungsten oxide fine particle dispersion liquid (B solution) for forming the solar radiation shielding material and solar radiation shielding were used. body(
B) was obtained. Here, the dispersion particle diameter of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (liquid B) for solar radiation shielding body evaluation was evaluated based on the intensity of transmitted and scattered light when contained in the UV curable resin. The maximum peak was 1.29%.
And the heat resistance and light resistance test was implemented similarly to Example 1 with respect to the solar radiation shielding body (B) produced similarly to Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Example 3]
Fine particles (c) were obtained by carrying out the same operation as in Example 1, except that the mixture produced in Example 2 was subjected to a reduction treatment at 500 ° C. for 120 minutes. Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle diameter before pulverization of the fine particles (c).
Next, the same operation as in Example 1 was performed except that the fine particles (c) were used in place of the fine particles (a), and a composite tungsten oxide fine particle dispersion (liquid C) for forming a solar radiation shielding body, a solar radiation shielding body. (C
) Here, the dispersion particle size of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (liquid C) for solar radiation shielding was evaluated by the intensity of the transmitted scattered light when contained in the UV curable resin. The maximum peak was 1.22%.
And the heat-resistant and light-proof test was implemented similarly to Example 1 with respect to the solar radiation shield (C) produced similarly to Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Example 4]
An aqueous solution in which 2.06 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) is well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Industry Co., Ltd.) are sufficiently mixed. Then, the same operation as in Example 3 was performed to obtain fine particles (d) except that the residue was dried in the atmosphere at 100 ° C. to obtain a residual mixture. Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle size before pulverization of the fine particles (d).
Next, except that the fine particles (d) were used in place of the fine particles (a), the same operation as in Example 1 was performed, and the solar cell shielding composite tungsten oxide fine particle dispersion (liquid D) and solar radiation shielding were performed. body(
D) was obtained. Here, the dispersion particle diameter of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (liquid D) for solar radiation shielding was evaluated by the intensity of the transmitted scattered light when contained in the UV curable resin. The maximum peak was 1.25%.
And the heat-resistant and light resistance test was implemented similarly to Example 1 with respect to the solar radiation shielding body (D) produced like Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Example 5]
An aqueous solution in which 2.12 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) is well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Industry Co., Ltd.) are sufficiently mixed. Then, fine particles (e) were obtained in the same manner as in Example 3 except that the residue was dried in the air at 100 ° C. to obtain a residual mixture. Table 1 shows the x / y value, the lattice constant, the amount of different phases, and the particle size before pulverization of the fine particles (e).
Next, except for using the fine particles (e) in place of the fine particles (a), the same operation as in Example 1 was performed, and the composite tungsten oxide fine particle dispersion liquid (E solution) for forming the solar radiation shielding material and the solar radiation shielding were used. body(
E) was obtained. Here, the dispersion particle diameter of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (E liquid) for solar radiation shielding was evaluated by the intensity of the transmitted scattered light when it was contained in the UV curable resin. The maximum peak was 1.24%.
And the heat-resistant and light-proof test was implemented similarly to Example 1 with respect to the solar radiation shield (E) produced like Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Example 6]
An aqueous solution in which 2.15 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) was well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Co., Ltd.) were sufficiently mixed. Fine particles (f) were obtained in the same manner as in Example 3 except that the residue was dried in the air at 100 ° C. to obtain a residual mixture. Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle size before pulverization of the fine particles (f).
Next, the same operation as in Example 1 was performed except that the fine particles (f) were used instead of the fine particles (a), and the composite tungsten oxide fine particle dispersion liquid (F solution) for solar radiation shielding, solar radiation shielding was performed. body(
F) was obtained. Here, the dispersion particle size of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (F solution) for solar radiation shielding was evaluated by the intensity of transmitted and scattered light when contained in the UV curable resin. The maximum peak was 1.31%.
And the heat-resistant and light resistance test was implemented similarly to Example 1 with respect to the solar radiation shield (F) produced similarly to Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Example 7]
An aqueous solution in which 2.18 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) is well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Industry Co., Ltd.) are sufficiently mixed. Fine particles (g) were obtained in the same manner as in Example 1 except that the mixture was dried in the air at 100 ° C. to obtain a residual mixture. Table 1 shows the x / y value, the lattice constant, the amount of different phases, and the particle size before pulverization of the fine particles (g).
Next, except that the fine particles (g) were used in place of the fine particles (a), the same operation as in Example 1 was performed, and the solar cell shielding composite tungsten oxide fine particle dispersion (liquid G) and solar radiation shielding were performed. body(
G) was obtained. Here, the dispersed particle diameter of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (liquid G) for forming a solar radiation shield is evaluated by the intensity of the transmitted scattered light when contained in the UV curable resin. The maximum peak was 1.24%.
And the heat-resistant and light-proof test was implemented similarly to Example 1 with respect to the solar radiation shielding body (G) produced like Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Comparative Example 1]
Tungstic acid (H ₂ WO ₄ , manufactured by Japan Inorganic Chemical Industry Co., Ltd.) 9.06 g and water were sufficiently mixed and dried in the atmosphere at 100 ° C., except that a residual mixture was obtained. The operation was performed to obtain fine particles (h). Table 1 shows the x / y value, the lattice constant, the amount of different phases, and the particle size before pulverization of the fine particles (h).
Next, the same operation as in Example 1 was performed except that the fine particles (h) were used instead of the fine particles (a), and the composite tungsten oxide fine particle dispersion liquid (H liquid) for solar radiation shielding body formation and solar radiation shielding were used. body(
H) was obtained. Here, the dispersion particle diameter of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (H liquid) for solar radiation shielding was evaluated by the intensity of the transmitted scattered light when contained in the UV curable resin. The maximum peak was 1.22%.
Then, heat resistance and light resistance tests were conducted in the same manner as in Example 1 on the solar radiation shield (H) produced in the same manner as in Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Comparative Example 2]
An aqueous solution in which 0.59 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) is well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Co., Ltd.) are sufficiently mixed. Except for drying in the atmosphere at 100 ° C. to obtain a residual mixture, the same operation as in Example 1 was performed to obtain fine particles (i). Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle size before pulverization of the fine particles (i).
Next, the same operation as in Example 1 was performed except that the fine particles (i) were used instead of the fine particles (a), and the composite tungsten oxide fine particle dispersion liquid (I liquid) for forming the solar radiation shielding material and the solar radiation shielding were used. body(
I) was obtained. Here, the dispersion particle diameter of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (I liquid) for solar radiation shielding was evaluated by the intensity of the transmitted scattered light when contained in the UV curable resin. The maximum peak was 1.34%.
And the heat-resistant and light-proof test was implemented similarly to Example 1 with respect to the solar radiation shielding body (I) produced like Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Comparative Example 3]
An aqueous solution in which 1.18 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) is well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Co., Ltd.) are sufficiently mixed. Then, the same procedure as in Example 1 was performed to obtain fine particles (j) except that the residue was dried in the atmosphere at 100 ° C. to obtain a residual mixture. Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle size before pulverization of the fine particles (j).
Next, the same operation as in Example 1 was performed except that the fine particles (j) were used instead of the fine particles (a), and the composite tungsten oxide fine particle dispersion liquid (J liquid) for forming the solar radiation shielding material and the solar radiation shielding were used. body(
J) was obtained. Here, the dispersion particle size of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (liquid J) for forming a solar radiation shield was evaluated by the intensity of the transmitted scattered light when contained in the UV curable resin. The maximum peak was 1.29%.
And the heat-resistant and light-proof test was implemented similarly to Example 1 with respect to the solar radiation shield (J) produced like Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Comparative Example 4]
An aqueous solution in which 1.65 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) is well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Industry Co., Ltd.) are sufficiently mixed. Then, fine particles (k) were obtained in the same manner as in Example 1 except that the residue was dried in the air at 100 ° C. to obtain a residual mixture. Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle size before pulverization of the fine particles (k).
Next, the same operation as in Example 1 was performed except that the fine particles (k) were used instead of the fine particles (a), and the composite tungsten oxide fine particle dispersion liquid (K solution) for forming the solar radiation shielding material and solar radiation shielding were used. body(
K) was obtained. Here, the dispersion particle diameter of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (K solution) for solar radiation shielding is evaluated by the intensity of the transmitted scattered light when it is contained in the UV curable resin. The maximum peak was 1.34%.
Then, heat resistance and light resistance tests were conducted in the same manner as in Example 1 on the solar radiation shield (K) produced in the same manner as in Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Comparative Example 5]
An aqueous solution in which 1.77 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) is well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Co., Ltd.) are sufficiently mixed. Fine particles (l) were obtained in the same manner as in Example 1 except that the residue was dried in the air at 100 ° C. to obtain a residual mixture. Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle size before pulverization of the fine particles (l).
Next, the same operation as in Example 1 was performed except that the fine particles (l) were used in place of the fine particles (a), and the composite tungsten oxide fine particle dispersion liquid (L solution) for forming the solar radiation shielding material and solar radiation shielding were used. body(
L) was obtained. Here, the dispersion particle diameter of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (L liquid) for solar radiation shielding is evaluated by the intensity of the transmitted scattered light when contained in the UV curable resin. The maximum peak was 1.32%.
And the heat-resistant and light-proof test was implemented similarly to Example 1 with respect to the solar radiation shield (L) produced similarly to Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Comparative Example 6]
An aqueous solution in which 2.36 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) is well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Industry Co., Ltd.) are sufficiently mixed. Then, fine particles (m) were obtained in the same manner as in Example 1 except that the residue was dried in the atmosphere at 100 ° C. to obtain a residual mixture. Table 1 shows the x / y value, lattice constant, amount of heterogeneous phase, and particle size before pulverization of the fine particles (m).
Next, except for using the fine particles (m) in place of the fine particles (a), the same operation as in Example 1 was performed, and the composite tungsten oxide fine particle dispersion liquid (M liquid) for forming the solar shading material, the solar radiation shielding was used. body(
M) was obtained. Here, the dispersion particle diameter of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (liquid M) for solar radiation shielding was evaluated by the intensity of the transmitted scattered light when contained in the UV curable resin. The maximum peak was 1.25%.
And the heat-resistant and light resistance test was implemented similarly to Example 1 with respect to the solar radiation shielding body (M) produced similarly to Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Comparative Example 7]
An aqueous solution in which 2.65 g of cesium carbonate (Cs ₂ CO ₃ , manufactured by Kemetal Japan) is well dissolved in pure water and 9.06 g of tungstic acid (H ₂ WO ₄ , manufactured by Nippon Inorganic Chemical Co., Ltd.) are sufficiently mixed. Fine particles (n) were obtained in the same manner as in Example 1 except that the residue was dried in the air at 100 ° C. to obtain a residual mixture. Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle diameter before pulverization of the fine particles (n).
Next, the same operation as in Example 1 was performed except that the fine particles (n) were used instead of the fine particles (a), and a composite tungsten oxide fine particle dispersion liquid (N liquid) for forming a solar radiation shield, solar radiation shielding was used. body(
N) was obtained. Here, the dispersion particle size of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (N solution) for solar radiation shielding body evaluation was evaluated based on the intensity of transmitted scattered light when contained in the UV curable resin. The maximum peak was 1.25%.
And the heat-resistant and light-proof test was implemented similarly to Example 1 with respect to the solar radiation shield (N) produced similarly to Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

[Comparative Example 8]
The mixture produced in Example 1 was heated while supplying 1% H ₂ gas with N ₂ gas as a carrier, and was subjected to reduction treatment at a temperature of 1000 ° C. for 16 minutes, as in Example 1. The fine particles (o) were obtained. Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle size before pulverization of the fine particles (o).
Next, a composite tungsten oxide fine particle dispersion liquid (O liquid) for solar radiation shielding was obtained in the same manner as in Example 1 except that the fine particles (o) were used instead of the fine particles (a). Using this dispersion, a solar shield was produced in the same manner as in Example 1. However, a transparent film could not be obtained from tungsten mixed as a different phase.

[Comparative Example 9]
The mixture produced in Example 1 was heated while supplying 1% H ₂ gas with N ₂ gas as a carrier, and was subjected to reduction treatment at a temperature of 900 ° C. for 18 minutes, as in Example 1. To obtain fine particles (p). Table 1 shows the x / y value, the lattice constant, the amount of different phases, and the particle size before pulverization of the fine particles (p).
Next, a composite tungsten oxide fine particle dispersion liquid (P solution) for solar radiation shielding was obtained in the same manner as in Example 1 except that the fine particles (p) were used instead of the fine particles (a). Using this dispersion, a solar shield was produced in the same manner as in Example 1. However, a transparent film could not be obtained from tungsten mixed as a different phase.

[Comparative Example 10]
The mixture produced in Example 1 was heated while supplying 1% H ₂ gas with N ₂ gas as a carrier, and was subjected to a reduction treatment at a temperature of 800 ° C. for 20 minutes, as in Example 1. Thus, the fine particles (q) were obtained. Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle size before pulverization of the fine particles (q).
Next, a composite tungsten oxide fine particle dispersion (Q liquid) for solar radiation shielding was obtained in the same manner as in Example 1 except that the fine particles (q) were used in place of the fine particles (a). Using this dispersion, a solar shield was produced in the same manner as in Example 1. However, a transparent film could not be obtained from tungsten mixed as a different phase.

[Comparative Example 11]
The mixture produced in Example 1 was heated while supplying 1% H ₂ gas with N ₂ gas as a carrier, and was subjected to reduction treatment at a temperature of 700 ° C. for 23 minutes, as in Example 1. Thus, fine particles (r) were obtained. Table 1 shows the x / y value, the lattice constant, the amount of the different phase, and the particle size before pulverization of the fine particles (r).
Next, a composite tungsten oxide fine particle dispersion liquid (R liquid) for solar radiation shielding body formation, a solar radiation shielding body (R), as in Example 1, except that the fine particle (r) was used instead of the fine particle (a). Got.
Here, the dispersion particle size of the cesium-added tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion (R solution) for solar radiation shielding is evaluated by the intensity of the transmitted scattered light when it is contained in the UV curable resin. The maximum peak was 1.30%.
And the heat-resistant and light resistance test was implemented similarly to Example 1 with respect to the solar radiation shielding body (R) produced like Example 1 using this dispersion resin liquid. Table 2 shows the results of the heat resistance and light resistance test.

As is clear from the results shown in Table 2, the solar shields A to F according to Examples 1 to 6 are compared with the solar shields K to R using the conventional cesium-added tungsten oxide. Turned out to be high. In particular, in Examples 2 and 3, a solar shading body having high solar shading ability and high weather resistance could be obtained. The solar shading body according to the present invention is used for window materials for vehicles, buildings, offices, ordinary houses, telephone boxes, show windows, lamps for lighting, transparent cases, etc. When used as a solar shading body that requires a solar shading function such as fiber, the solar shading characteristics are hardly deteriorated and can be used as a highly reliable product.

Claims (4)

It is represented by the general formula CsxWyOz (where Cs is cesium, W is tungsten, O is oxygen, 0.30 ≦ x / y ≦ 0.33, 2.2 ≦ z / y ≦ 3.0). A composite tungsten oxide fine particle for forming a solar radiation shielding body having a crystal structure,
The amount of tungsten oxide other than hexagonal does not exceed 10 wt% or less,
The amount of WO ₂ is not more than 1 wt%,
The amount of W produced is 0% by weight,
Including one or more of tungsten oxides other than the hexagonal crystals or the WO ₂
A composite tungsten oxide fine particle for forming a solar radiation shielding material, wherein the c-axis lattice constant is from 7.61101 to 7.61242.   A composite tungsten oxide fine particle dispersion for solar radiation shielding, comprising the composite tungsten oxide fine particles for solar radiation shielding according to claim 1, a solvent, and a dispersant.   The composite tungsten oxide fine particle dispersion for forming a solar shading body according to claim 2, further comprising a resin binder.   The solar radiation shielding body, wherein the composite tungsten oxide fine particles for solar radiation shielding formation according to claim 1 are dispersed in a resin.