JP2002265236A - Producing method for fine particle for forming insolation shielding film and application liquid for forming insolation shielding film using the fine particle obtained by the producing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a producing method for a fine particle for forming an insolation shielding film which produces fine particles for forming the insolation shielding film which is capable of forming insolation shielding film of which the insolation transmittance at visible light transmittance of >=80% is less than 70% and the haze value is less than 1% in a shorter time than the conventional method. SOLUTION: This producing method of the fine particle for forming an insolation shielding film is characterized in that indium tin oxide fine particles the averaged grain size of which is <100 nm and tungsten oxide fine particles or rhenium oxide fine particles are mixed and are heated and treated under an atmosphere of inactive gas including alcohol or an atmosphere of mixed gas of a reducing gas and an inactive gas and the fine particles for forming insolation shielding film can be produced in a shorter time than the conventional method thanks to the catalytic action of the tungsten oxide fine particles or rhenium oxide fine particles which are added to tin- containing indium oxide fine particles at the time of heat treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to window materials for vehicles, buildings, offices, and general houses, telephone boxes, show windows, lighting lamps, transparent cases, etc., glass, plastics, and other solar radiations. The present invention relates to fine particles for forming a solar shading film which is applied to a transparent substrate requiring a shielding function. In particular, when the visible light transmittance is 80% or more, the solar transmittance is less than 70% and the haze value is less than 1%. The present invention relates to a method for producing solar shading film-forming fine particles capable of forming a certain solar shading film, and a solar shading film-forming coating solution using the fine particles obtained by this manufacturing method.

[0002]

2. Description of the Related Art As a method for removing or reducing a heat component from an external light source such as sunlight or a light bulb, a method of forming a heat-reflective glass by forming a film reflecting a visible / infrared wavelength on a glass surface. Has been done. As the material, metal oxides such as FeOx, CoOx, CrOx, and TiOx, and metal materials having a large amount of free electrons such as Ag, Au, Cu, Ni, and Al have been selected.

[0003] However, these materials have a property of simultaneously reflecting or absorbing visible light in addition to near infrared rays which greatly contribute to the thermal effect, so that there is a problem that the visible light transmittance is reduced. Since a transparent base material used for a building material, a vehicle, a telephone box or the like needs to have a high transmittance in a visible light region, when using the above-mentioned material, the film thickness must be extremely thin. Therefore, it is common practice to form a 10 nm-level thin film by using a physical film forming method such as spray baking, a CVD method, a sputtering method or a vacuum evaporation method. These film forming methods require a large-scale apparatus and vacuum equipment, and have a problem in that the production cost of the film is high due to problems in productivity and increase in area.

Further, when the film thickness is reduced by using the above-mentioned film forming method and the transmittance of visible light is increased, the solar shading characteristic of the film is reduced. There was also a problem that the film became dark.

[0005] Further, when the solar shading property is to be enhanced by using these materials, the reflectivity in the visible light region tends to be increased at the same time, giving a glare-like appearance like a mirror and impairing the aesthetic appearance. Also existed.

Further, many of these materials have high conductivity in the film. If the conductivity of the film is high, there are also problems such as the fact that radio waves from mobile phones, TVs, radios, and the like are reflected and become unreceivable, and radio interference is caused in surrounding areas.

On the other hand, a resin film in which an organic near-infrared absorbing agent such as a phthalocyanine or metal complex is added to a binder is also used. However, deterioration due to heat and humidity is remarkable as compared with inorganic materials, and there is a defect in weather resistance.

In order to remedy the drawbacks of the conventional solar shading film, as a physical characteristic of the film, the reflectance of light in the visible light region is low and the transmittance is high, and the transmittance of the infrared light region is low. At the same time, it is necessary to be able to form a film whose conductivity can be controlled to about 10 ⁶ Ω / □ or more.

[0009]

By the way, as a material having a high visible light transmittance and having a solar shading function, antimony-containing tin oxide (ATO) and tin-containing indium oxide (I
TO) are also known, and these materials did not give the above-mentioned glaring appearance due to their relatively low visible light reflectance.

However, since the plasma wavelength is on the relatively long wavelength side of the near-infrared region, the reflection and absorption effects of these films in the near-infrared region near visible light have not been sufficient.

In view of the above, the tin-containing indium oxide (IT)
Regarding O), a proposal has been made to improve the reflection / absorption effect of the film in the near-infrared region by performing a deoxidation treatment by the following method. For example, a method of heating tin-containing indium oxide (ITO) in a pressurized inert gas in Japanese Patent Application Laid-Open No. 7-70481 is disclosed in JP-A-8-41441. A method of performing heat treatment in a nitrogen gas containing gas is disclosed in
JP-A-120946 proposes a method of heat-treating tin-containing indium oxide (ITO) in an inert gas or a reducing gas.

However, in each of these methods, the heat treatment time is as long as several hours, and there is a problem in productivity.

The present invention has been made in view of such a problem.
Solar radiation shielding film formation capable of producing solar radiation shielding film forming fine particles capable of forming a solar radiation shielding film having a solar transmittance of less than 70% at 0% or more and a haze value of less than 1% in a shorter time than before. It is an object of the present invention to provide a method for producing fine particles for use, and a coating liquid for forming a solar shading film using the fine particles obtained by this method.

Therefore, in order to achieve this object, the present inventors have mixed the above-mentioned tin-containing indium oxide fine particles, ie, indium tin oxide fine particles, with tungsten oxide fine particles or rhenium oxide fine particles, and performed the above-described heat treatment. As a result, it has been found that the heat treatment time under a specific gas atmosphere can be significantly reduced by the catalytic action of the tungsten oxide fine particles or the rhenium oxide fine particles, and the amount of residual impurities composed of chloride ions, nitrate ions, and sulfate ions is small. The present inventors have found that the above effect is further enhanced by mixing indium tin oxide fine particles and tungsten oxide fine particles or rhenium oxide fine particles, thereby completing the present invention.

[0015]

That is, the invention according to claim 1 is based on a method of manufacturing fine particles for forming a solar shading film, and comprises fine particles of indium tin oxide and fine particles of tungsten oxide having an average particle size of 100 nm or less. The invention according to claim 2, wherein the mixture is mixed with rhenium oxide fine particles and heat-treated in an inert gas atmosphere containing alcohol or in a mixed gas atmosphere of a reducing gas and an inert gas. Presupposes a method of manufacturing fine particles for forming a solar shading film,
Indium tin oxide fine particles and tungsten oxide fine particles or rhenium oxide fine particles having an average particle diameter of 100 nm or less and containing 0.6% by weight or less of residual impurities composed of chlorine ions, nitrate ions and sulfate ions contained in the particles. And subjecting the mixture to heat treatment in an inert gas atmosphere containing an inert gas or an alcohol, or in a mixed gas atmosphere of a reducing gas and an inert gas.

Further, the invention according to claim 3 is based on the method for producing the solar shading film forming fine particles according to claim 1 or 2, wherein the mixing ratio of the indium tin oxide fine particles and the tungsten oxide fine particles is as follows. 99.9: 0.1 by weight ratio
The invention according to claim 4 is based on the method for producing the solar radiation shielding film-forming fine particles according to claim 1 or 2, wherein the indium tin oxide fine particles and the rhenium oxide fine particles are provided. Is 9 by weight.
9.9: 0.1 to 99: 1.

Next, a fifth aspect of the present invention relates to a coating liquid for forming a solar shading film to which the fine particles for forming a solar shading film obtained by the above manufacturing methods are applied.

That is, the invention according to claim 5 is based on the premise that the coating liquid for forming a solar shading film is premised, and contains the fine particles for forming a solar shading film according to any one of claims 1 to 4, a solvent and a binder. It is a feature.

[0019]

Embodiments of the present invention will be described below in detail.

First, according to the method for producing fine particles for forming a solar shading film according to the present invention, fine particles of indium tin oxide having an average particle diameter of 100 nm or less and fine particles of tungsten oxide or rhenium oxide are mixed, Wherein the heat treatment is carried out in an inert gas atmosphere containing a gas or a mixed gas atmosphere of a reducing gas and an inert gas (claim 1), and the fine particles for forming a solar shading film according to the present invention. Another production method comprises the steps of: preparing an indium tin oxide fine particle having an average particle diameter of 100 nm or less and containing 0.6% by weight or less of a residual impurity composed of chlorine ions, nitrate ions, and sulfate ions in a particle; After mixing with the fine particles or rhenium oxide fine particles, under an inert gas atmosphere containing an inert gas or alcohol, or
The heat treatment is performed in a mixed gas atmosphere of a reducing gas and an inert gas (claim 2). The average particle size of the indium tin oxide fine particles indicates the average particle size of the fine particles observed with a transmission electron microscope (TEM).

The fine particles obtained by these methods are dispersed in a solvent and a binder to obtain a coating liquid for forming a solar shading film. In the indium tin oxide fine particles to be mixed, the tin content in terms of element is preferably 1 to 15% by weight. If the amount is less than 1% by weight, the effect of adding tin is not seen, and if it exceeds 15% by weight, the solid solution of tin may be insufficient.

The average particle diameter of the indium tin oxide fine particles must be 100 nm or less as described above. If the average particle size exceeds 100 nm, it becomes a light scattering source, causing clouding (haze) in the film and causing a decrease in visible light transmittance. In addition, although the size of the particles is represented by the average particle size here, a fine powder having a small ratio of coarse powder exceeding 100 nm and a narrow particle size distribution is preferable,
In addition, the lowest particle size economically available is fine particles of about 2 nm. However, the lower limit of the particle size is not limited to this.

Next, tungsten may be in any form as long as it is an oxide, such as WO ₃ or WO ₂ .

The mixing ratio of the indium tin oxide fine particles to the tungsten oxide fine particles is 99.9: 0.1 to 80:20 by weight from the viewpoint of processing efficiency and optical characteristics.
Preferably, it should be set in the range of 99: 1 to 85:15. If the content of the tungsten oxide fine particles is less than 0.1%, the effect of addition cannot be obtained, and if the content exceeds 20%, the effect of adding tungsten is exhibited but the solar shading property may be deteriorated. .

On the other hand, the rhenium may be in any form as long as it is an oxide, for example, ReO ₃ , ReO ₂ , Re ₂ O ₇
And the like.

The mixing ratio of the indium tin oxide fine particles and the rhenium oxide fine particles is preferably set in the range of 99.9: 0.1 to 99: 1 by weight from the viewpoint of processing efficiency and optical characteristics. If the content of rhenium oxide fine particles is less than 0.1%, the effect of addition cannot be obtained, and if it exceeds 1%, the effect of adding tungsten is exhibited, but the solar radiation shielding characteristics may be deteriorated. .

Next, the method of mixing the indium tin oxide fine particles and the tungsten oxide fine particles or the rhenium oxide fine particles is not particularly limited as long as they can be uniformly mixed, and a known method can be employed.

Further, the heat treatment of the mixture of the indium tin oxide fine particles and the tungsten oxide fine particles or the rhenium oxide fine particles is carried out by removing the residual impurities comprising chlorine ions, nitrate ions and sulfate ions contained in the indium tin oxide fine particles. Is 0.6% by weight or more, an alcohol is fed using an inert gas alone such as nitrogen, argon, and helium as a carrier gas or a mixed gas such as nitrogen, argon, and helium as a carrier gas,
Alternatively, a mixed gas of a reducing gas such as hydrogen or carbon monoxide and the inert gas is fed. Further, chlorine ions, nitrate ions contained in the indium tin oxide fine particles,
When the amount of the residual impurities composed of sulfate ions is 0.6% by weight or less, feed with an inert gas alone such as nitrogen, argon or helium, or use the inert gas alone as a carrier gas or a mixed gas thereof. Is fed as a carrier gas, or a mixed gas of a reducing gas such as hydrogen or carbon monoxide and the inert gas is fed.

The alcohol to be used is not particularly limited, but methanol is preferred from the viewpoint of volatility and cost.
, Ethanol and propanol. The concentrations and feed amounts of alcohol, hydrogen, and carbon monoxide in the inert gas may be appropriately selected so as to obtain processing efficiency and desired optical characteristics.

Next, the processing temperature is preferably in the range of 200 to 400 ° C. Even when the temperature exceeds 400 ° C., the effect of adding the tungsten oxide or rhenium oxide fine particles is exerted, but aggregation and sintering of the above oxide particles are liable to occur.
If the temperature is lower than 00 ° C., the effect of adding the tungsten oxide or rhenium oxide fine particles may not be sufficiently exhibited. The heat treatment time is appropriately selected in consideration of the atmosphere and the temperature.

Impurities such as chlorine ions, nitrate ions, and sulfate ions remaining in the indium tin oxide fine particles may become a reduction inhibitory factor in the deoxidizing treatment of the indium tin oxide fine particles. The content is preferably 6% by weight or less, more preferably 0.3% by weight or less. As described above, tungsten oxide is mixed with fine particles of indium tin oxide and fine particles of tungsten oxide or rhenium oxide having a residual impurity amount of 0.6% by weight or less composed of chloride ions, nitrate ions, and sulfate ions. Alternatively, the effect of adding rhenium oxide fine particles is further exhibited.

Next, the coating solution for forming a solar shading film is obtained by dispersing the above indium tin oxide fine particles in a solvent and a binder, but the solvent is not particularly limited. And it is appropriately selected according to the inorganic binder and the resin binder. For example, water, ethanol, propanol, butanol, isopropyl alcohol, isobutyl alcohol, diacetone alcohol
Alcohols such as alcohol, ethers such as methyl ether, ethyl ether and propyl ether, esters,
Various organic solvents such as ketones such as acetone, methyl ethyl ketone, diethyl ketone, cyclohexanone, and isobutyl ketone can be used, and the pH may be adjusted by adding an acid or an alkali as needed. further,
In order to further improve the dispersion stability of the fine particles in the coating liquid, it is of course possible to add various surfactants and coupling agents.

The types of the inorganic binder and the resin binder are not particularly limited. Examples of the inorganic binder include metal alkoxides of silicon, zirconium, titanium, and aluminum, partially hydrolyzed polycondensates thereof, and organosilazane. However, a thermoplastic resin such as an acrylic resin and a thermosetting resin such as an epoxy resin can be used as the resin binder.

The method of dispersing the indium tin oxide fine particles is not particularly limited as long as it is a method of uniformly dispersing in the coating solution.
For example, a bead mill, ball mill, sand mill, paint shaker, ultrasonic homogenizer and the like can be mentioned.

In order to provide a further ultraviolet shielding function of the solar shading film, one or more of inorganic fine particles such as titanium oxide, zinc oxide and cerium oxide, and organic benzophenone and benzotriazole are added. May be.

[0036]

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

The visible light transmittance and solar radiation transmittance of the obtained film were measured using a spectrophotometer U-4000 manufactured by Hitachi, Ltd. The haze value was measured using HR-200 manufactured by Murakami Color Research Laboratory. In the film evaluation, the film was formed with three types of bar coaters having different wire diameters, and the visible light transmittance, the solar radiation transmittance, and the haze value of the three types of films obtained with these different thicknesses were measured. As the interpolated values from the three-point plot, the solar radiation transmittance and the haze value when the visible light transmittance was 86% were determined.

Example 1 Indium tin oxide fine particles (manufactured by Sumitomo Metal Mining Co., Ltd.) having a tin content of 10% by weight, a residual impurity amount of 0.7% by weight, and an average particle size of 0.03 μm, and tungsten trioxide The mixing ratio with the fine particles was set to 99: 1 by weight, and mixing was performed for 30 minutes.

This was placed in a 500 ml separable flask, heated with stirring by feeding methanol-containing nitrogen carrier gas, and treated at 300 ° C. for 9 minutes to obtain indium to which tungsten trioxide was added. Tin oxide fine particles were obtained.

20% by weight of the above fine particles, 63.3% by weight of methyl isobutyl ketone, 16.7% by weight of a dispersant, and 0.3 mm zirconia beads equivalent to a filling rate of 63% were applied for 24 hours with a paint shaker. Dispersed.

Next, a coating liquid consisting of 67.5% by weight of the above dispersion, 27.5% by weight of an acrylic resin solution dissolved in methyl isobutyl ketone as a binder, and 5% by weight of a curing agent was applied to Bar No. 40, no. 24, no. 6 and applied to a soda lime glass substrate of 100 mm × 100 mm × 3 mm, and baked at 180 ° C. for 30 minutes to obtain a solar shading film a. Table 1 below shows the solar transmittance (%) and the haze value (%) of the solar shading film a.

Then, as can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film a according to Example 1 were 67.0% and 0.62%, respectively.

Example 2 The mixing ratio of indium tin oxide fine particles and tungsten trioxide fine particles was 9 by weight.
Except for 8: 2, a solar shading film b according to Example 2 was obtained in the same manner as in Example 1. Table 1 below also shows the solar transmittance (%) and the haze value (%) of this solar shading film b.

As can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film b according to Example 2 were 68.0% and 0.80%, respectively.

Example 3 The mixing ratio of indium tin oxide fine particles and tungsten trioxide fine particles was 9 by weight.
A solar shading film c according to Example 3 was obtained in the same manner as in Example 1 except that the ratio was 6: 4. Table 1 below also shows the solar transmittance (%) and the haze value (%) of the solar shading film c.

Then, as can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film c according to Example 3 were 67.1% and 0.60%, respectively.

Example 4 The mixing ratio of indium tin oxide fine particles and tungsten trioxide fine particles was 8 by weight.
Except for 8:12, a solar shading film d according to Example 4 was obtained in the same manner as in Example 1. The solar transmittance (%) and the haze value (%) of this solar shading film d are also shown in Table 1 below.

As can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film d according to Example 4 were 67.0% and 0.35%, respectively.

Example 5 The mixing ratio of indium tin oxide fine particles and tungsten trioxide fine particles was 8 by weight.
A solar shading film e according to Example 5 was obtained in the same manner as in Example 1 except that the ratio was set to 2:18. The solar transmittance (%) and the haze value (%) of the solar shading film e are also shown in Table 1 below.

Then, as can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film e according to Example 5 were 68.9% and 0.75%, respectively.

[Comparative Example 1] The above-mentioned indium tin oxide fine particles were prepared by adding 300 wt.
When the heat treatment was performed at 9 ° C. for 9 minutes, the solar radiation transmittance became 70% or more. Therefore, the treatment time was set to 60 minutes, and otherwise the same as in Example 1, except for the solar shading film f according to Comparative Example 1.
I got The solar transmittance (%) and the haze value (%) of the solar shading film f are also shown in Table 1 below.

As can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film f according to Comparative Example 1 were 66.0% and 0.40%, respectively.

Comparative Example 2 A solar shading film g according to Comparative Example 2 was obtained in the same manner as in Example 1 except that the treatment time was 180 minutes under the condition that no tungsten trioxide was added.
Table 1 below also shows the solar transmittance (%) and the haze value (%) of the solar shading film g.

Then, as can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film g according to Comparative Example 2 were 66.5% and 0.46%, respectively.

As a result, in order to obtain a solar shading film having the same characteristics as the solar shading film according to each embodiment, it is necessary to set the processing time to 60 minutes or 180 minutes longer than 9 minutes of each embodiment. It was confirmed that there was.

Example 6 A solar shading film h according to Example 6 was carried out in the same manner as in Example 1 except that the processing temperature was 350 ° C.
I got The solar transmittance (%) and the haze value (%) of this solar shading film h are also shown in Table 1 below.

As can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar shading film h according to Example 6 were 68.1% and 0.35%, respectively.

Example 7 The same operation as in Example 1 was carried out except that a treatment was carried out at 300 ° C. for 60 minutes using 5% H ₂ gas using N ₂ as a carrier instead of the methanol-containing nitrogen carrier gas. A solar shading film i according to Example 7 was obtained. Table 1 below also shows the solar transmittance (%) and the haze value (%) of this solar shading film i.

As can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film i according to Example 7 were 66.0% and 0.63%, respectively.

[Comparative Example 3] The above-mentioned indium tin oxide fine particles were prepared by adding 300 wt.
When the heat treatment was performed at 60 ° C. for 60 minutes, the solar radiation transmittance became 70% or more. Therefore, the treatment time was set to 480 minutes, and otherwise, the solar radiation shielding film j according to Comparative Example 3 was obtained in the same manner as in Example 7. Was. Table 1 below also shows the solar transmittance (%) and the haze value (%) of the solar shading film j.

As can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar shading film j according to Comparative Example 3 were 67.1% and 0.46%, respectively.

As a result, in order to obtain a solar shading film having the same characteristics as the solar shading film i according to the seventh embodiment, it is necessary to set the processing time to 480 minutes which is longer than the 60 minutes of the seventh embodiment. confirmed.

Example 8 Fine particles of indium tin oxide [manufactured by Sumitomo Metal Mining Co., Ltd.] having a tin content of 10% by weight, a residual impurity amount of 0.1% by weight, and an average particle size of 0.03 μm, and tungsten trioxide Example 8 was repeated in the same manner as in Example 1 except that the mixing ratio with the fine particles was 99: 1 by weight, the methanol-containing nitrogen carrier gas was fed, heated, and treated at 300 ° C. for 3 minutes. Such a solar shading film k was obtained. The solar transmittance (%) and the haze value (%) of the solar shading film k are also shown in Table 1 below.

Then, as can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film k according to Example 8 were 66.7% and 0.58%, respectively.

Example 9 5% with N ₂ as a carrier
A solar shading film 1 according to Example 9 was obtained in the same manner as in Example 8, except that treatment was performed at 260 ° C. for 40 minutes using H ₂ gas.
The solar transmittance (%) and the haze value (%) of the solar shading film 1 are also shown in Table 1 below.

Then, as can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film 1 according to Example 9 were 69.9% and 0.90%, respectively.

Example 10 300 ° C. using N ₂ gas
Example 1 was performed in the same manner as in Example 8 except that the treatment was performed for 10 minutes.
0 was obtained. The solar transmittance (%) and the haze value (%) of the solar shading film m are also shown in Table 1 below.

As can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film m according to Example 10 were 69.8% and 0.64%, respectively.

Comparative Example 4 Indium tin oxide fine particles having a tin content of 10% by weight, a residual impurity amount of 0.7% by weight, and an average particle size of 0.03 μm under conditions using N ₂ gas [Sumitomo Metal Mining Co., Ltd. ) Was heat-treated at 300 ° C. for 9 minutes, the solar radiation transmittance became 70% or more. Therefore, the processing time was set to 60 minutes, and other than that, according to Comparative Example 4 in the same manner as in Example 1. A solar shading film n was obtained. This solar shading film n
Table 1 also shows the solar transmittance (%) and haze value (%) of
Shown in

As can be seen from Table 1,
The solar radiation transmittance and the haze value of the solar radiation shielding film n according to Comparative Example 4 were 69.6% and 0.60%, respectively.

As a result, the same effect as that of the solar shading film m according to Example 10 to which indium tin oxide fine particles having a tin content of 10% by weight, a residual impurity amount of 0.1% by weight and an average particle size of 0.03 μm were applied. In order to obtain a solar shading film with characteristics,
It was confirmed that the processing time needed to be 60 minutes, which was longer than the 10 minutes of Example 10.

[0072]

[Table 1] Example 11 Tin content: 10% by weight, residual impurity content: 0.
The mixing ratio of indium tin oxide fine particles (manufactured by Sumitomo Metal Mining Co., Ltd.) and rhenium trioxide fine particles having a weight ratio of 79.5% and an average particle size of 0.03 μm was 99.5: 0.5 by weight.
Mix for 0 minutes.

This was placed in a 500 ml separable flask, and a methanol-containing nitrogen carrier gas was fed and heated with stirring, and treated at a temperature of 300 ° C. for 7 minutes to obtain indium to which rhenium trioxide was added. Tin oxide fine particles were obtained.

20% by weight of the above fine particles, 63.3% by weight of methyl isobutyl ketone, 16.7% by weight of a dispersant, and 0.3 mm zirconia beads corresponding to a filling rate of 63% were applied for 24 hours with a paint shaker. Dispersed.

Next, a coating liquid consisting of 67.5% by weight of the above dispersion, 27.5% by weight of an acrylic resin solution dissolved in methyl isobutyl ketone as a binder, and 5% by weight of a curing agent was added to Bar No. 40, no. 24, no. 6 and applied to a soda lime glass substrate of 100 mm × 100 mm × 3 mm, and baked at 180 ° C. for 30 minutes to obtain a solar radiation shielding film o. Table 2 below shows the solar transmittance (%) and the haze value (%) of the solar shading film o.

Then, as can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar radiation shielding film o according to Example 11 were 67.7% and 0.30%, respectively.

Example 12 The mixing ratio of indium tin oxide fine particles and rhenium trioxide fine particles was 99.
A solar shading film p according to Example 12 was obtained in the same manner as in Example 11 except that the ratio was 9: 0.1. Table 2 below also shows the solar transmittance (%) and the haze value (%) of the solar shading film p.

Then, as can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar shading film p according to Example 12 were 67.5% and 0.30%, respectively.

Example 13 The mixing ratio of indium tin oxide fine particles and rhenium trioxide fine particles was 99.
A solar shading film q according to Example 13 was obtained in the same manner as in Example 11 except that the ratio was set to 2: 0.8. Table 2 below also shows the solar transmittance (%) and the haze value (%) of the solar shading film q.

Then, as can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar radiation shielding film q according to Example 13 were 68.5% and 0.29%, respectively.

[Comparative Example 5] When the above indium tin oxide fine particles were heated at 300 ° C for 7 minutes under the condition that rhenium trioxide was not added, the solar transmittance became 70% or more. Was set to 60 minutes, and the other conditions were the same as in Example 11 to obtain a solar shading film r according to Comparative Example 5. Table 2 below also shows the solar transmittance (%) and the haze value (%) of the solar shading film r.

Then, as can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar radiation shielding film r according to Comparative Example 5 were 66.0% and 0.40%, respectively.

Comparative Example 6 The processing time was 180 minutes under the condition that rhenium trioxide was not added.
In the same manner as in Example 1, a solar shading film s according to Comparative Example 6 was obtained. Table 2 also shows the solar transmittance (%) and the haze value (%) of the solar shading film s.

Then, as can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar shading film s according to Comparative Example 6 were 66.5% and 0.46%, respectively.

As a result, in order to obtain a solar shading film having the same characteristics as those of the solar shading films according to Examples 11 to 13, the processing time was set to 60 minutes, longer than 7 minutes in each of the examples.
It was confirmed that the time needed to be 80 minutes.

Example 14 A solar shading film t according to Example 14 was obtained in the same manner as in Example 11 except that the treatment temperature was 350 ° C. Table 2 below also shows the solar transmittance (%) and the haze value (%) of the solar shading film t.

Then, as can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar radiation shielding film t according to Example 14 were 68.6% and 0.39%, respectively.

Example 15 The same operation as in Example 11 was carried out except that a treatment was carried out at 300 ° C. for 60 minutes using 5% H ₂ gas using N ₂ as a carrier instead of the methanol-containing nitrogen carrier gas. A solar shading film u according to Example 15 was obtained. Table 2 also shows the solar transmittance (%) and the haze value (%) of the solar shading film u.

Then, as can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar radiation shielding film u according to Example 15 were 66.8% and 0.29%, respectively.

[Comparative Example 7] When the above-mentioned indium tin oxide fine particles were heated at 300 ° C for 60 minutes without adding rhenium trioxide, the solar radiation transmittance became 70% or more. Was set to 480 minutes, and the other conditions were the same as in Example 15 to obtain a solar shading film v according to Comparative Example 7. The solar transmittance (%) and the haze value (%) of the solar shading film v are also shown in Table 2 below.

As can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar radiation shielding film v according to Comparative Example 7 were 67.1% and 0.46%, respectively.

As a result, the solar shading film u according to Example 15
It was confirmed that in order to obtain a solar shading film having the same characteristics as described above, it is necessary to set the treatment time to 480 minutes, which is longer than 60 minutes in Example 15.

Example 16 Indium tin oxide fine particles [manufactured by Sumitomo Metal Mining Co., Ltd.] having a tin content of 10% by weight, a residual impurity amount of 0.1% by weight, and an average particle size of 0.03 μm, and rhenium trioxide The mixing ratio with the fine particles is 99.5 by weight ratio:
0.5, and the methanol-containing nitrogen carrier gas
And then heated at 270 ° C. for 40 minutes to obtain a solar shading film w according to Example 16 in the same manner as in Example 11. Table 2 below also shows the solar transmittance (%) and the haze value (%) of the solar shading film w.

As can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar shading film w according to Example 16 were 69.5% and 0.42%, respectively.

Example 17 300 ° C. using N ₂ gas
A solar shading film x according to Example 17 was obtained in the same manner as in Example 16 except that the treatment was performed for 10 minutes. Table 2 below also shows the solar transmittance (%) and the haze value (%) of the solar shading film x.

Then, as can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar radiation shielding film x according to Example 17 were 69.9% and 0.35%, respectively.

Comparative Example 8 Indium tin oxide fine particles having a tin content of 10% by weight, a residual impurity amount of 0.7% by weight, and an average particle diameter of 0.03 μm under the condition of using N ₂ gas [Sumitomo Metal Mining Co., Ltd. ) Was heat-treated at 300 ° C. for 10 minutes, the solar radiation transmittance was 70% or more. Therefore, the treatment time was set to 60 minutes, and otherwise the same as in Example 11 according to Comparative Example 8. A solar shading film y was obtained. Table 2 below also shows the solar transmittance (%) and the haze value (%) of the solar shading film y.

Then, as can be seen from Table 2,
The solar radiation transmittance and the haze value of the solar radiation shielding film y according to Comparative Example 8 were 69.6% and 0.33%, respectively.

As a result, the same effect as that of the solar shading film x according to Example 17 to which indium tin oxide fine particles having a tin content of 10% by weight, a residual impurity amount of 0.1% by weight, and an average particle size of 0.03 μm were applied. In order to obtain a solar shading film with characteristics,
It was confirmed that the treatment time needed to be 60 minutes, which was longer than the 10 minutes of Example 17.

[0100]

[Table 2]

[0101]

According to the method for producing solar radiation shielding film fine particles according to the present invention, tungsten oxide fine particles or rhenium oxide fine particles added to tin-containing indium oxide fine particles during heat treatment. Of the present invention, the fine particles for forming a solar shading film capable of forming a solar shading film having a solar light transmittance of less than 70% and a haze value of less than 1% when the visible light transmittance is 80% or more are shorter than before. It has the effect of being able to be manufactured in a short time, and according to the coating liquid for forming a solar shading film according to the invention of claim 5, the solar light transmittance is less than 70% when the visible light transmittance is 80% or more. Moreover, it has an effect of forming a solar shading film having a haze value of less than 1%.

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Claims (5)

[Claims] 1. A method for producing fine particles for forming a solar shading film, comprising mixing indium tin oxide fine particles having an average particle diameter of 100 nm or less with tungsten oxide fine particles or rhenium oxide fine particles, and containing an alcohol-containing inert gas. Under gas atmosphere,
Alternatively, a method for producing fine particles for forming a solar shading film, comprising performing heat treatment in a mixed gas atmosphere of a reducing gas and an inert gas. 2. The method for producing fine particles for forming a solar shading film, wherein the average particle size is 100 nm or less and the amount of residual impurities comprising chlorine ions, nitrate ions and sulfate ions contained in the particles is 0.6% by weight or less. A mixture of certain indium tin oxide fine particles and tungsten oxide fine particles or rhenium oxide fine particles under an inert gas atmosphere containing an inert gas or an alcohol, or a mixed gas atmosphere of a reducing gas and an inert gas. A method for producing fine particles for forming a solar shading film, wherein the fine particles are subjected to heat treatment under the following conditions. 3. The mixing ratio of the indium tin oxide fine particles to the tungsten oxide fine particles is 99.9:
The method for producing fine particles for forming a solar shading film according to claim 1, wherein the ratio is 0.1 to 80:20. 4. A mixing ratio of the indium tin oxide fine particles and the rhenium oxide fine particles in a weight ratio of 99.9: 0.
3. The ratio of 1 to 99: 1.
A method for producing fine particles for forming a solar radiation shielding film according to the above. 5. A coating solution for forming a solar shading film, comprising the fine particles for forming a solar shading film according to claim 1, a solvent and a binder.