WO2019058737A1

WO2019058737A1 - Cesium tungsten oxide film and method for manufacturing same

Info

Publication number: WO2019058737A1
Application number: PCT/JP2018/027262
Authority: WO
Inventors: 佐藤　啓一; 勲雄安東
Original assignee: 住友金属鉱山株式会社
Priority date: 2017-09-22
Filing date: 2018-07-20
Publication date: 2019-03-28

Abstract

Provided are a cesium tungsten oxide film which has high heat ray shielding performance and transmissibility to radio waves, and a method for manufacturing a cesium tungsten oxide film with which such a film can be manufactured by a dry method. The cesium tungsten oxide film comprises cesium, tungsten, and oxygen as the main components, wherein when the atomic ratio of cesium and tungsten is Cs/W, Cs/W is 0.1 to 0.5, and the film has a hexagonal crystal structure. The method for manufacturing a cesium tungsten oxide film in which cesium, tungsten, and oxygen are the main components comprises: a film-forming step in which a film is formed using a cesium tungsten oxide target; and a heat treatment step in which the film is heat treated at a temperature of at least 400°C to less than 1000°C. Either the film-forming step or the heat treatment step is carried out in an oxygen-containing atmosphere.

Description

Cesium tungsten oxide film and method of manufacturing the same

The present invention relates to a cesium tungsten oxide film suitable as a light shielding member, and a method of manufacturing the same. This application is related to Japanese Patent Application No. Japanese Patent Application No. 2017-182575 filed on Sep. 22, 2017 in Japan, and Japanese Patent Application No. Japanese Patent Application No. 2018-A filed on February 2, 2018 in Japan. This application claims priority on the basis of which the present application is incorporated by reference.

Various materials have been proposed as light shielding members used for window materials and the like. For example, Patent Document 1 describes a half mirror type light shielding member of a dry film on which a metal such as aluminum is vapor-deposited as a light shielding member such as a window material. There is also a light shielding member formed by sputtering silver or the like. However, when this type of light-shielding member is used, the appearance is a half mirror, so that it is reflective for outdoor use and has a problem in landscape. Furthermore, since metal films such as aluminum and silver have high conductivity, there is a problem that radio waves are also reflected to make it difficult to connect a mobile phone, a smart phone or the like.

On the other hand, Patent Document 2 proposes using a composite tungsten oxide thin film as a light shielding member. A composite tungsten oxide thin film is known as a material that exhibits excellent optical characteristics, such as efficiently shielding sunlight, particularly light in the near infrared region, and maintaining high transmittance in the visible light region. In Patent Document 2, as a method of forming such a composite tungsten oxide thin film, the composite tungsten oxide fine particles are dispersed in an appropriate solvent to form a dispersion, and after the medium resin is added to the obtained dispersion, , It has been proposed to coat the substrate surface. In the fine particle dispersed film, the radio wave is transmitted through the space between the fine particles, so the problem of radio wave shielding does not occur.

Patent Document 3 discloses a composite tungsten oxide film produced by applying a solution containing a raw material compound of composite tungsten oxide to a substrate and then heat treating it. Since this film has a low surface resistance (sheet resistance) of 1.0 × 10 ¹⁰ Ω / □ or less, it is a radio wave blocking film which does not transmit radio waves. Moreover, since the volume shrinkage by drying and baking is large, there exists a problem that the crack and peeling of a film | membrane are easy to generate | occur | produce the application baking film which apply | coated and heat-treated the solution.

As another means of obtaining such a composite tungsten oxide thin film, there are dry methods such as vapor deposition and sputtering. The dry process thin film has an advantage that large volume shrinkage does not occur as in the coating and baking method. In addition, there is an advantage that it is not necessary to use a dispersant or medium resin which is not directly related to the light shielding performance. That is, since no medium resin or the like is used, it can be subjected to a high temperature manufacturing process. For example, it can be provided to the production process of tempered glass subjected to high temperature heat treatment. If manufacturing equipment such as a large sputtering apparatus capable of processing a large window material can be used, the dry process is performed from the viewpoint of obtaining a film with uniform film thickness and high quality, and having high productivity. It is preferable to use it. In addition, such a large sized sputtering device etc. are commercially available.

Patent Document 4 proposes a composite tungsten oxide film produced by a sputtering method. A composite tungsten oxide film composed of tungsten and at least one element selected from the group consisting of group IVa, group IIIa, group VIIb, group VIb and group Vb of the periodic table is formed on a glass substrate . However, the oxide film of this composition has an infrared transmittance of 40% or more, and the heat ray shielding performance is not sufficient, and there is a problem that the function can not be exhibited unless it is a multilayer film with another transparent dielectric film.

Further, Patent Document 5 discloses a method of producing a target material of a composite tungsten oxide containing an alkali metal such as cesium and an alkaline earth metal by a hot pressing method. However, there is no specific description of a film produced using this target, and there is a problem that even if this target is simply formed by sputtering, it transmits 70% or more of infrared rays and the heat ray shielding performance is low.

More specifically, among the compositions described in Patent Document 5, the Cs-W-O-based tungsten oxide material which is said to have the highest infrared absorption characteristics and is generally used for heat ray shielding materials is disclosed in Patent Document 5 When a sintered body target was produced according to the method and a sputtering film was formed on a glass substrate, it was found that there is a problem that the infrared ray transmittance is high and the heat ray shielding performance is low. Also, this film was amorphous as a result of X-ray diffraction.

JP-A-9-107815 Patent No. 4096205 JP, 2006-096656, A Unexamined-Japanese-Patent No. 8-12378 JP, 2010-180449, A

As described above, the heat ray shielding performance of the composite tungsten oxide film by the dry method is not sufficient yet.

Therefore, the present invention has been made to solve such a situation, and a cesium tungsten oxide film having a high heat ray shielding performance and radio wave permeability, and producing such a film by a dry method The present invention provides a method of producing a cesium tungsten oxide film.

The present inventors consider that the heat ray shielding performance is based on the crystalline state of the film to the above-mentioned problems, and crystallize this film, etc., to obtain the crystalline state and heat ray shielding performance of cesium tungsten oxide film by dry method. The relationship was thoroughly analyzed, and as a result, the present invention was achieved.

That is, one embodiment of the present invention is a cesium tungsten oxide film containing cesium, tungsten, and oxygen as main components, and when the atomic ratio of cesium and tungsten is Cs / W, Cs / W is 0.1 or more It has a hexagonal crystal structure which is 0.5 or less.

According to one aspect of the present invention, it has high heat ray shielding performance by containing cesium and tungsten, which are heat ray shielding materials having high infrared absorption characteristics, at an appropriate ratio and having a hexagonal crystal structure. Can.

At this time, in one aspect of the present invention, the angle ratio of the diffraction angle 2θ (002) of the hexagonal (002) plane by X-ray diffraction using CuKα rays and the diffraction angle 2θ (200) of the hexagonal (200) plane. (002) / 2θ (200), the 2θ (002) / 2θ (200) can be 0.83 or more and 0.85 or less.

A composite tungsten oxide film having such characteristics is preferable because it has a hexagonal crystal structure.

In one embodiment of the present invention, the intensity ratio of the diffraction intensity I (002) of the hexagonal (002) plane to the diffraction intensity I (200) of the hexagonal (200) plane by X-ray diffraction using CuKα rays When I (002) / I (200), I (002) / I (200) can be 0.3 or more.

The composite tungsten oxide film having such properties can have high heat ray shielding performance.

In one embodiment of the present invention, the ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm can be 0.3 or less.

According to one aspect of the present invention, the visible light is transmitted while the infrared rays are blocked at a high rate, so that it can be said that it has high heat ray shielding performance.

Further, in one embodiment of the present invention, a sputtered film with a thickness of 30 nm or more and 1200 nm or less can be used.

Since the cesium tungsten oxide film according to one embodiment of the present invention is mainly formed by sputtering, it is not necessary to use a surfactant, a solvent, a dispersant, or a medium resin, and is formed thin. It is possible. In addition, since a large volume shrinkage is not involved, a film free from cracking and peeling can be formed.

The cesium tungsten oxide film according to an embodiment of the present invention may have a sheet resistance exceeding 1.0 × 10 ¹⁰ Ω / □.

According to one aspect of the present invention, it can be said that the radio wave transparency is provided without reflecting radio waves.

Another aspect of the present invention is a method for producing a cesium tungsten oxide film containing cesium, tungsten and oxygen as main components, which is a film forming step of forming a film using a cesium tungsten oxide target, and a film Can be heat-treated at a temperature of 400 ° C. or more and less than 1000 ° C., and either the film formation step or the heat treatment step can be performed under an atmosphere containing oxygen.

According to another aspect of the present invention, a hexagonal crystal structure can be formed by heat-treating the film after the film forming step. In addition, by performing either the film forming step or the heat treatment step in an atmosphere containing oxygen, a cesium tungsten oxide film with high heat ray shielding performance can be obtained in a dry manner.

In another embodiment of the present invention, in the film forming step, sputtering is performed in a mixed gas of argon and oxygen, and then in the heat treatment step, the film is heated at a temperature of 400 ° C. to 900 ° C. in an inert or reducing atmosphere. It can be heat treated.

When the film formation step is performed in an atmosphere containing oxygen, it is preferable to carry out under the above conditions.

In another embodiment of the present invention, after sputtering film formation in argon gas in the film forming step, the film can be heat treated in air at a temperature of 400 ° C. to 600 ° C. in the heat treatment step.

When the heat treatment step is carried out in an atmosphere containing oxygen, it is preferable to carry out under the above conditions.

According to the present invention, it is possible to obtain a cesium tungsten oxide film having a high heat ray shielding performance and radio wave permeability, and such a film can be manufactured by a dry method.

FIG. 1 is a process diagram showing an outline of a process in a method of manufacturing a cesium tungsten oxide film according to an embodiment of the present invention.

Hereinafter, a cesium tungsten oxide film according to the present invention and a method of manufacturing the same will be described in the following order with reference to the drawings. In addition, this invention is not limited to the following example, In the range which does not deviate from the summary of this invention, it can change arbitrarily.
1. Cesium tungsten oxide film Method of producing cesium tungsten oxide film 2-1. Film formation process 2-2. Heat treatment process

<1. Cesium tungsten oxide film>
First, the cesium tungsten oxide film will be described. A cesium tungsten oxide film (Cs-W-O-based tungsten oxide film) according to an embodiment of the present invention contains cesium (Cs), tungsten (W) and oxygen (O) as main components, and atoms of cesium and tungsten Assuming that the ratio is Cs / W, Cs / W is 0.1 to 0.5 (in the present specification, "-" means a lower limit or more and an upper limit or less. The same applies hereinafter), And, it has a hexagonal crystal structure. As described above, by containing cesium and tungsten, which are heat ray shielding materials having high infrared absorption characteristics, at an appropriate ratio and having a hexagonal crystal structure, a film having high heat ray shielding performance can be obtained. .

When a cesium tungsten oxide film according to an embodiment of the present invention is formed by sputtering, the Cs / W of the film is approximately equal to the Cs / W of the target composition. In the case of forming a film different in Cs / W, the film can be formed by sputtering deposition using a target with a composition different in Cs / W. When Cs / W is out of the range of 0.1 to 0.5, the film does not contain a hexagonal crystal structure, and the heat ray shielding performance is degraded. In addition, targets having Cs / W outside the range of 0.1 to 0.5 are also difficult to manufacture due to deterioration in sinterability and processability. Since the oxygen concentration of the film affects the electron state through the oxygen vacancies of the crystal structure and has an important influence on the heat ray shielding performance, it is necessary to control to an appropriate oxygen concentration, but the oxygen concentration of the film is measured It is difficult to do. Therefore, utilizing the fact that the crystal structure changes slightly when the oxygen vacancies change, the angle ratio by X-ray diffraction described later is controlled.

It can be known by X-ray diffraction analysis of the film that it has a hexagonal crystal structure. Cs-W-O-based tungsten oxide is known to have a crystal structure such as hexagonal crystal, cubic crystal, tetragonal crystal, orthorhombic crystal, and amorphous structure, but a cesium tungsten oxide according to one embodiment of the present invention The film is characterized by having a hexagonal crystal structure. However, crystal structures such as cubic crystals other than hexagonal crystals, tetragonal crystals, and orthorhombic crystals, and amorphous structures may be included.

The angle ratio of the diffraction angle 2θ (002) of the hexagonal (002) plane to the diffraction angle 2θ (200) of the hexagonal (200) plane by X-ray diffraction using CuKα rays is 2θ (002) / 2θ (200) When it is assumed that 2θ (002) / 2θ (200) is 0.83 to 0.85. In the crystal structure database, ICDD reference code 01-081-1244 describes standard X-ray diffraction peak intensities and diffraction angles of hexagonal cesium tungsten oxide.

Since the diffraction angle of (002) plane is 23.360 degrees and that of (200) plane is 27.801 degrees in ICDD reference code 01-081-1244, the standard angle ratio 2θ (002) / 2θ (200) is 0.840. It is considered that the angle ratio changes as the a-axis length and the c-axis length change when the number of atoms is excessive or insufficient compared to the standard hexagonal crystal structure. Direct measurement of the a-axis or c-axis length requires extremely careful and precise measurement, but using an angle ratio, which is a relative comparison of diffraction angles, makes it easy to know the change in the crystal state relatively easily. Can. If the angle ratio is out of the range of 0.83 to 0.85 including the standard of 0.840, it is considered that large excess and deficiency of atoms are caused, and the heat ray shielding performance is lowered.

The angle ratio of the diffraction angle 2θ (002) of the hexagonal (002) plane to the diffraction angle 2θ (200) of the hexagonal (200) plane by X-ray diffraction using CuKα rays is 2θ (002) / 2θ (200) In this case, a film in which 2θ (002) / 2θ (200) satisfies 0.83 to 0.85 has high heat ray shielding performance. Here, the high heat ray shielding performance can be represented by the ratio of the infrared ray transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm. For example, if the visible light transmittance at a wavelength of 550 nm is 65% or more and the infrared transmittance at a wavelength of 1400 nm is 20% or less, the ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm is 0. It is 3 or less. The cesium tungsten oxide film according to an embodiment of the present invention can satisfy this condition.

The intensity ratio of the diffraction intensity I (002) of the hexagonal (002) plane to the diffraction intensity I (200) of the hexagonal (200) plane by X-ray diffraction using CuKα ray is I (002) / I (200) And I (002) / I (200) becomes 0.3 or more.

Since the relative strength of the (002) plane to the (200) plane is described as 26.2% in the above-mentioned ICDD reference code 01-081-1244, the standard intensity ratio I (002) / I (200) Is 0.26. On the other hand, the intensity ratio of the present invention at which high heat ray shielding performance is exhibited is 0.3 or more. Since the cesium tungsten oxide film according to one embodiment of the present invention is larger than the intensity ratio of this standard, it is considered that the growth of the hexagonal ab plane is suppressed and there is a tendency of c-plane orientation. Although the detailed mechanism is unknown, when the intensity ratio goes out of this range, the sheet resistance decreases and the radio wave transmission performance decreases. Such a crystalline state different from the standard is considered to be due to the formation of a thermal non-equilibrium amorphous film by sputtering or vacuum evaporation.

The cesium tungsten oxide film according to an embodiment of the present invention is preferably formed to a thickness of 30 nm to 1200 nm. Since the cesium tungsten oxide film according to an embodiment of the present invention is a sputtered film obtained by sputtering film formation or the like as described later, for example, a solution described in Patent Document 3 is applied and heat treated It is not necessary to use a surfactant, a solvent, a dispersant, or a medium resin as in a film, and the film can be formed thin and uniform. In addition, since the cesium tungsten oxide film according to the embodiment of the present invention is not accompanied by a large volume contraction at the time of heat treatment, a film having no crack or peeling can be formed. If the film thickness is less than 30 nm, the ratio of the infrared transmittance to the visible light transmittance exceeds 0.3, and it becomes difficult to obtain sufficient heat ray shielding performance. When the thickness exceeds 1200 nm, although sufficient heat ray shielding performance is maintained, productivity decreases due to an increase in target usage, an increase in sputtering deposition time, and the like.

The cesium tungsten oxide film according to an embodiment of the present invention has a sheet resistance of more than 1.0 × 10 ¹⁰ Ω / □, more preferably 1.0 × 10 ¹¹ Ω / □ or more. When this sheet resistance becomes lower than this value, the free electrons of the film shield the electrostatic field and reflect the radio waves, so the radio wave permeability is lowered. The sheet resistance can be measured, for example, using a resistivity meter.

<2. Method of producing cesium tungsten oxide film>
Next, a method of manufacturing a cesium tungsten oxide film will be described. FIG. 1 is a process diagram showing an outline of a process in a method of manufacturing a cesium tungsten oxide film according to an embodiment of the present invention. One embodiment of the present invention is a method for producing a cesium tungsten oxide film containing cesium, tungsten and oxygen as main components, which is a film forming step S1 of forming a film using a cesium tungsten oxide target, and a film And heat treatment step S2 of heat treatment at a temperature of 400 ° C. or more and less than 1000 ° C. Either the film forming step S1 or the heat treatment step S2 is performed in an atmosphere containing oxygen.

Thus, a hexagonal crystal structure can be formed by heat treating the film after the film formation step S1, and either the film formation step S1 or the heat treatment step S2 is performed in an atmosphere containing oxygen. Thus, a cesium tungsten oxide film having high heat ray shielding performance can be obtained in a dry manner. Each step will be described in detail below.

(2-1. Film formation process)
First, in the film forming step S1, a film is formed using a cesium tungsten oxide target. The method of producing the cesium tungsten oxide sintered body target used in the film forming step S1 is not particularly limited, but the Cs / W of the target composition is preferably 0.1 to 0.5. It is because it is reflected in Cs / W of the obtained film. For example, the cesium tungsten oxide target described in Patent Document 5 described above may be used. However, the crystal structure of the target is not particularly limited because it does not directly affect the crystal structure of the film. The target preferably has a relative density of 70% or more and a specific resistance of 1 Ω · cm or less. Such a target can be produced by hot pressing sintering cesium tungsten oxide powder in a vacuum or an inert atmosphere. The sintered body produced in this manner is because it has mechanical strength in target production, strength to withstand brazing temperature at bonding, and conductivity capable of direct current sputtering.

The film formation method is preferably vacuum deposition film formation or sputtering film formation. In particular, a direct current sputtering film forming method in which a direct current voltage or a pulse voltage is applied to the target is more preferable. This is because the deposition rate is high and the productivity is excellent. The substrate is not particularly limited, but glass is preferred. It is because it is transparent to the visible light region and does not deteriorate or deform in the heat treatment step S2 of the next step. The thickness of the glass is preferably 0.1 mm to 10 mm, and is not particularly limited as long as it is a thickness generally used for window glass for buildings, glass for automobiles, display devices and the like. Also, instead of glass, a transparent heat-resistant polymer film may be used.

The sputtering gas is argon gas or a mixed gas of argon and oxygen. Whether argon gas or mixed gas is used is related to the heat treatment step S2 of the next step. If the oxygen concentration of the mixed gas is high, the film forming rate is reduced and the productivity is reduced. Therefore, the oxygen concentration is preferably less than 20%, and more preferably 5 to 10%. When argon gas is used as the sputtering gas, the argon gas purity is preferably 99% or more and less than 1% oxygen concentration. The film formed by sputtering is usually amorphous, but a diffraction peak based on crystals may appear when X-ray diffraction analysis is performed. This is because a hexagonal crystal structure is formed again in the subsequent heat treatment step S2.

(2-2. Heat treatment process)
Next, in the heat treatment step S2, the film obtained in the film formation step S1 is heat treated to form a hexagonal crystal structure. At this time, heat treatment is performed by selecting an atmosphere according to the gas at the time of sputtering film formation so that the oxygen concentration of the film is in an appropriate range. At this time, either the film forming step S1 or the heat treatment step S2 is performed in an atmosphere containing oxygen.

When film formation is performed using a mixed gas of argon and oxygen as a sputtering gas in the film formation step S1, the heat treatment of the film in the heat treatment step S2 is performed at a temperature of 400 ° C. to 900 ° C. in an inert or reducing atmosphere. As the inert or reducing atmosphere, nitrogen gas, argon gas, a mixed gas of hydrogen and nitrogen, a mixed gas of hydrogen and argon, or the like can be used. When the film forming step S1 is performed in an atmosphere containing oxygen, when the heat treatment step S2 is heat treated in an oxidizing atmosphere such as air or oxygen, the oxidation of the film proceeds excessively to reduce oxygen vacancies, and the crystal structure Changes, the angle ratio of X-ray diffraction becomes smaller than 0.83, and the heat ray shielding performance is lowered. When the heat treatment temperature is lower than 400 ° C., the film remains amorphous and does not crystallize, or even when crystallized, the diffraction peak of hexagonal crystal in X-ray diffraction is extremely weak and the heat ray shielding performance is low. The hexagonal crystal structure maintains its structure even at high temperatures of 900 ° C. or higher in an inert or reducing atmosphere, but if the heat treatment temperature is higher than 1000 ° C., the film may be altered by the reaction of the film with the glass substrate. Disappearance of the membrane occurs due to exfoliation. In addition, deformation of the glass substrate also occurs at such high temperatures. Since formation of hexagonal crystals proceeds rapidly, a heat treatment time of 5 to 60 minutes is sufficient.

On the other hand, it is considered that the film formed by using only argon gas as the sputtering gas in the film forming step S1 is in a state where the oxygen concentration of the film is appropriate or excessive. At this time, in the heat treatment step S2, the heat treatment is performed in an oxidizing atmosphere containing oxygen. When heat treatment is performed with an inert gas such as nitrogen gas that does not contain oxygen, the intensity ratio of X-ray diffraction becomes smaller than 0.3, the sheet resistance decreases, and radio wave transmission can not be obtained. When the heat treatment is performed in an oxidizing atmosphere containing oxygen, the oxygen concentration in the film can be maintained in a more appropriate range, and the heat ray shielding performance can be further enhanced. Therefore, in the heat treatment step S2, it is preferable to select air as the heat treatment atmosphere. Alternatively, the heat treatment may be performed in an atmosphere with an oxygen concentration of 5 to 20%. The heat treatment furnace in the case of an air atmosphere may not have a special closed structure. The heat treatment temperature is 400 ° C. to 600 ° C. When the heat treatment temperature is lower than 400 ° C., the crystallization of the film is insufficient and the heat ray shielding performance is low. If the heat treatment temperature is higher than 600 ° C., the X-ray diffraction angle ratio becomes smaller than 0.83 because of excessive oxidation, and the heat ray shielding performance is lowered. A heat treatment time of 5 to 60 minutes is sufficient.

EXAMPLES Hereinafter, the present invention will be more specifically described using examples, but the present invention is not limited to the following examples.

Example 1
In Example 1, cesium tungsten oxide powder (made by Oguchi Electronics Co., Ltd., model number: YM-01) having a Cs / W atomic ratio of 0.33 is introduced into a hot press, and a vacuum atmosphere, temperature 950 ° C., pressing pressure It sintered on conditions of 250 kgf / cm < ² >, and produced the cesium tungsten oxide sintered compact. As a result of chemical analysis of the sintered body composition, Cs / W was 0.33. The oxide sintered body was machined to a diameter of 153 mm and a thickness of 5 mm by machining and bonded to a stainless steel backing plate using a metal indium brazing material to prepare a cesium tungsten oxide target.

Next, this target is attached to a sputtering apparatus (manufactured by ULVAC, Inc., model number SBH2306), ultimate vacuum degree 5 × 10 ⁻³ Pa or less, sputtering gas 5% oxygen / 95% argon mixed gas, sputtering gas pressure 0.6 Pa A cesium tungsten oxide film having a film thickness of 400 nm was formed on a glass substrate (EXG manufactured by Corning, 0.7 mm in thickness) under the condition of a DC power of 600 W (film forming process S1). As a result of X-ray diffraction of the film formation at this time using an X-ray diffractometer (manufactured by PANalytical Co., Ltd.), no diffraction peak was observed and the film was amorphous.

This film was introduced into a lamp heating furnace (manufactured by Yonekura Mfg. Co., Ltd., model number HP-2-9), and heat treated at a temperature of 500 ° C. for 10 minutes in a nitrogen atmosphere (heat treatment step S2). As a result of chemical analysis of this film, the Cs / W atomic ratio was 0.31.

As a result of X-ray diffraction of the heat-treated film using an X-ray diffractometer (manufactured by PANalytical), a diffraction peak derived from hexagonal cesium tungsten oxide was observed. The angle ratio 2θ (002) / 2θ (200) of the angle 2θ (002) of the hexagonal crystal (200) to the angle 2θ (002) of the hexagonal crystal (200) was 0.835. Further, the diffraction intensity of the hexagonal crystal (002) plane The intensity ratio I (002) / I (200) of the diffraction intensity I (200) of I (002) to the hexagonal (200) plane was 0.40. The transmittance T 'and the reflectance R were measured using model number V-670) The transmittance T' and the reflectance R show the interference fringes specific to the film. The removed transmittance T was determined.
Transmittance T = T '/ (1-R) (Equation 1)

The visible light transmittance at a wavelength of 550 nm of the obtained film was high at 80%, and the infrared transmittance at a wavelength of 1400 nm was a low value of 6%. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a low value of 0.07. (Note that the ratio is a value calculated by using measured values without rounding the transmittance of each wavelength.)

Moreover, as a result of measuring the sheet resistance of the obtained film | membrane using a resistivity meter (Mitsubishi Chemical company make, Hiresta), it was a high resistance with 2.5 * 10 < ¹² > ohm / square. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 2)
In Example 2, sputter deposition and heat treatment were performed in the same manner as in Example 1 except that the target of Example 1 was used, and the heat treatment time was 60 minutes. The Cs / W of the obtained film was 0.30. As a result of X-ray diffraction of this film, the angle ratio was 0.840 and the intensity ratio was 0.42. The visible light transmittance at a wavelength of 550 nm of the obtained film was high at 88%, and the infrared transmittance at a wavelength of 1400 nm was a low value of 13%. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a low value of 0.14. Moreover, the sheet resistance of the obtained film was 2.8 × 10 ¹² Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 3)
In Example 3, sputter deposition and heat treatment were performed in the same manner as in Example 1 except that the target of Example 1 was used, the film thickness was 1200 nm, the heat treatment temperature was 400 ° C., and the heat treatment time was 60 minutes. The Cs / W of the obtained film was 0.32. As a result of X-ray diffraction of this film, the angle ratio was 0.841 and the intensity ratio was 0.41. The visible light transmittance at a wavelength of 550 nm of the obtained film was high at 80%, and the infrared transmittance at a wavelength of 1400 nm was a low value of 18%. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a low value of 0.22. The sheet resistance of the obtained film was 1.2 × 10 ¹¹ Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 4)
In Example 4, sputter deposition and heat treatment were performed in the same manner as in Example 1 except that the target of Example 1 was used and the sputtering gas was changed to 10% oxygen / 90% argon. The Cs / W of the obtained film was 0.32. As a result of X-ray diffraction of this film, the angle ratio was 0.840 and the intensity ratio was 0.43. The visible light transmittance at a wavelength of 550 nm of the obtained film was as high as 72%, and the infrared transmittance at a wavelength of 1400 nm was as low as 3%. The ratio of infrared transmittance at a wavelength of 1400 nm to visible light transmittance at a wavelength of 550 nm was a low value of 0.05. Moreover, the sheet resistance of the obtained film was 1.1 × 10 ¹¹ Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 5)
In Example 5, sputtering was performed in the same manner as in Example 1 except that the target of Example 1 was used, the sputtering gas was 10% oxygen / 90% argon, and the heat treatment atmosphere was 1% hydrogen / 99% nitrogen atmosphere. The film and heat treatment were performed. The Cs / W of the obtained film was 0.31. As a result of X-ray diffraction of this film, the angle ratio was 0.841 and the intensity ratio was 0.39. The visible light transmittance at a wavelength of 550 nm of the obtained film was high at 80%, and the infrared transmittance at a wavelength of 1400 nm was a low value of 10%. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a low value of 0.13. In addition, the sheet resistance of the obtained film was 1.1 × 10 ¹⁰ Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 6)
In Example 6, the target of Example 1 was used, the sputtering gas was 10% oxygen / 90% argon, the film thickness was 200 nm, the heat treatment atmosphere was 5% hydrogen / 95% nitrogen atmosphere, and the heat treatment time was 60 minutes. Sputter deposition and heat treatment were performed in the same manner as in Example 1 except for the above. The Cs / W of the obtained film was 0.32. As a result of X-ray diffraction of this film, the angle ratio was 0.833 and the intensity ratio was 0.37. The visible light transmittance at a wavelength of 550 nm of the obtained film was as high as 68%, and the infrared transmittance at a wavelength of 1,400 nm was as low as 8%. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a low value of 0.11. In addition, the sheet resistance of the obtained film was 1.2 × 10 ¹⁰ Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 7)
In Example 7, sputter deposition is performed in the same manner as in Example 1 except that the target of Example 1 is used, the sputtering gas is argon, the heat treatment atmosphere is air, the heat treatment temperature is 400 ° C., and the heat treatment time is 60 minutes. And heat treatment. The Cs / W of the obtained film was 0.30. As a result of X-ray diffraction analysis of this film, the angle ratio was 0.844 and the intensity ratio was 0.40. The visible light transmittance at a wavelength of 550 nm of the obtained film was high at 66%, and the infrared transmittance at a wavelength of 1400 nm was a low value of 18%. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a low value of 0.27. In addition, the sheet resistance of the obtained film was 2.2 × 10 ¹² Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 8)
In Example 8, sputter deposition and heat treatment were performed in the same manner as in Example 1 except that the target of Example 1 was used, the sputtering gas was argon, and the heat treatment atmosphere was air. The Cs / W of the obtained film was 0.32. As a result of X-ray diffraction analysis of this film, the angle ratio was 0.842 and the intensity ratio was 0.41. The visible light transmittance at a wavelength of 550 nm of the obtained film was high at 80%, and the infrared transmittance at a wavelength of 1400 nm was a low value of 2%. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a low value of 0.02. In addition, the sheet resistance of the obtained film was 1.5 × 10 ¹³ Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 9)
In Example 9, sputter deposition is performed in the same manner as in Example 1 except that the target of Example 1 is used, the sputtering gas is argon, the heat treatment atmosphere is air, the heat treatment temperature is 600 ° C., and the heat treatment time is 5 minutes. And heat treatment. The Cs / W of the obtained film was 0.31. As a result of X-ray diffraction analysis of this film, the angle ratio was 0.836 and the intensity ratio was 0.48. The visible light transmittance at a wavelength of 550 nm of the obtained film was as high as 76%, and the infrared transmittance at a wavelength of 1,400 nm was as low as 14%. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a low value of 0.18. Also, the sheet resistance of the obtained film was 7.4 × 10 ¹³ Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 10)
In Example 10, sputter deposition and heat treatment were performed in the same manner as in Example 1 except that the target of Example 1 was used and the film thickness was changed to 30 nm. The Cs / W of the obtained film was 0.33. As a result of X-ray diffraction analysis of this film, the angle ratio was 0.837 and the intensity ratio was 0.36. The visible light transmittance at a wavelength of 550 nm of the obtained film was as high as 85%, and the infrared transmittance at a wavelength of 1400 nm was as low as 20%. The ratio of the infrared transmittance at a wavelength of 1,400 nm to the visible light transmittance at a wavelength of 550 nm of the obtained film was a low value of 0.24. Moreover, the sheet resistance of the obtained film was 1.3 × 10 ¹² Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 11)
In Example 11, the sputtering deposition and heat treatment are carried out in the same manner as in Example 1 except that the target of Example 1 is used, the glass substrate is synthetic quartz glass, the heat treatment temperature is 900 ° C., and the heat treatment time is 30 minutes. went. The Cs / W of the obtained film was 0.35. As a result of X-ray diffraction analysis of this film, the angle ratio was 0.845 and the intensity ratio was 0.66. The visible light transmittance at a wavelength of 550 nm of the obtained film was as high as 60%, and the infrared transmittance at a wavelength of 1400 nm was as low as 7%. The ratio of the infrared transmittance at a wavelength of 1,400 nm to the visible light transmittance at a wavelength of 550 nm of the obtained film was a low value of 0.12. In addition, the sheet resistance of the obtained film was 1.1 × 10 ¹⁰ Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Example 12)
Cesium tungsten oxide powder with a Cs / W atomic ratio of 0.33 (manufactured by Oguchi Electronics Co., Ltd., model number: YM-01) and tungsten trioxide powder (manufactured by High Purity Chemical Co., Ltd.) each having a weight ratio of 2: 1 A target was produced in the same manner as in Example 1 except that the mixture was mixed and charged into the hot press apparatus. As a result of chemical analysis of the target composition, Cs / W was 0.15. Next, sputter film formation and heat treatment were performed in the same manner as in Example 1 except that the sputtering gas was changed to 10% oxygen / 90% argon. The Cs / W of the obtained film was 0.14. As a result of X-ray diffraction of this film, the angle ratio was 0.843 and the angle ratio was 0.49. The visible light transmittance at a wavelength of 550 nm of the obtained film was high at 89%, and the infrared transmittance at a wavelength of 1400 nm was a low value of 19%. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a low value of 0.21. In addition, the sheet resistance of the obtained film was 1.7 × 10 ¹¹ Ω / □. Therefore, it turned out that it absorbs infrared region, has high heat ray blocking performance, and also has radio wave transmittance while maintaining sufficient transparency in the visible light region.

(Comparative example 1)
In Comparative Example 1, sputter deposition was performed in the same manner as in Example 1 except that the target of Example 1 was used and heat treatment was not performed. The Cs / W of the obtained film was 0.31. As a result of X-ray diffraction analysis of this film, no diffraction peak was observed and the film was amorphous, so no angle ratio and no intensity ratio were obtained. Although the visible light transmittance at a wavelength of 550 nm of the obtained film is as high as 99%, the infrared transmittance at a wavelength of 1400 nm is also as high as 99%, so the infrared light was not blocked. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a high value of 1.00. In addition, since the obtained film did not shield infrared rays, the sheet resistance was not measured. Therefore, it turned out that a heat ray blocking performance is low.

(Comparative example 2)
In Comparative Example 2, sputter deposition and heat treatment were performed in the same manner as in Example 1 except that the target of Example 1 was used, the heat treatment temperature was 300 ° C., and the heat treatment time was 60 minutes. The Cs / W of the obtained film was 0.32. As a result of X-ray diffraction analysis of this film, the diffraction peaks of hexagonal crystals were extremely weak, so that the angle ratio and the intensity ratio were not determined. Although the visible light transmittance at a wavelength of 550 nm of the obtained film is as high as 99%, the infrared transmittance at a wavelength of 1400 nm is also as high as 99%, so the infrared light was not blocked. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a high value of 1.00. In addition, since the obtained film did not shield infrared rays, the sheet resistance was not measured. Therefore, it turned out that a heat ray blocking performance is low.

(Comparative example 3)
In Comparative Example 3, sputter deposition and heat treatment are performed in the same manner as in Example 1 except that the target of Example 1 is used, the glass substrate is synthetic quartz glass, the heat treatment temperature is 1000 ° C., and the heat treatment time is 60 minutes. Did. As a result, the film peeled off from the glass substrate and disappeared.

(Comparative example 4)
In Comparative Example 4, sputter deposition and heat treatment were performed in the same manner as in Example 1 except that the target of Example 1 was used, the heat treatment atmosphere was oxygen, and the heat treatment temperature was 600 ° C. The Cs / W of the obtained film was 0.30. As a result of X-ray diffraction analysis of this film, the intensity ratio was as large as 0.40, but the angle ratio was as small as 0.825. Although the visible light transmittance at a wavelength of 550 nm of the obtained film is as high as 99%, the infrared transmittance at a wavelength of 1400 nm is also as high as 99%, so the infrared light was not blocked. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a high value of 1.00. In addition, since the obtained film did not shield infrared rays, the sheet resistance was not measured. Therefore, it turned out that a heat ray blocking performance is low.

(Comparative example 5)
In Comparative Example 5, sputtering was performed in the same manner as in Example 1 except that the target of Example 1 was used, the sputtering gas was argon, the heat treatment atmosphere was air, the heat treatment temperature was 300 ° C., and the heat treatment time was 60 minutes. The film and heat treatment were performed. The Cs / W of the obtained film was 0.32. As a result of X-ray diffraction analysis of this film, the diffraction peaks of hexagonal crystals were extremely weak, so that the angle ratio and the intensity ratio were not determined. The visible light transmission of wavelength 550 nm of the obtained film was as low as 37%, and the infrared light transmission of wavelength 1400 nm was as high as 91%. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a high value of 2.50. In addition, since the obtained film did not shield infrared rays, the sheet resistance was not measured. Therefore, it turned out that a heat ray blocking performance is low.

(Comparative example 6)
In Comparative Example 6, sputter deposition and heat treatment were performed in the same manner as in Example 1 except that the target of Example 1 was used, the sputtering gas was argon, the heat treatment atmosphere was air, and the heat treatment temperature was 650 ° C. The The Cs / W of the obtained film was 0.30. As a result of X-ray diffraction analysis of this film, the intensity ratio was as large as 0.32, but the angle ratio was as small as 0.821. Although the visible light transmittance at a wavelength of 550 nm of the obtained film is as high as 96%, the infrared transmittance at a wavelength of 1400 nm is also as high as 99%, so the infrared light was not blocked. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a high value of 1.03. In addition, since the obtained film did not shield infrared rays, the sheet resistance was not measured. Therefore, it turned out that a heat ray blocking performance is low.

(Comparative example 7)
In Comparative Example 7, the weight ratio of cesium tungsten oxide powder (manufactured by Oguchi Electronics Co., Ltd., model number: YM-01) having a Cs / W atomic ratio of 0.33 and tungsten trioxide powder (manufactured by High Purity Chemical Co., Ltd.) A target was produced in the same manner as in Example 1 except that the respective components were mixed so as to be 1: 2 and charged into a hot press. As a result of chemical analysis of the target composition, Cs / W was 0.07. Next, sputter deposition and heat treatment were performed in the same manner as in Example 1. The Cs / W of the obtained film was 0.06. As a result of X-ray diffraction of this film, the intensity ratio was 0.36, but the angle ratio was as large as 0.855. Although the visible light transmittance at a wavelength of 550 nm of the obtained film is as high as 99%, the infrared transmittance at a wavelength of 1400 nm is also as high as 80%, so the infrared light was not blocked. The ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was a high value of 0.81. In addition, since the obtained film did not shield infrared rays, the sheet resistance was not measured. Therefore, it turned out that a heat ray blocking performance is low.

(Comparative example 8)
In Comparative Example 8, Ag was sputtered onto the film of Example 1 to form a film having a thickness of 15 nm. The sheet resistance at that time was 5 ohms / square, and it turned out that it does not have radio wave permeability.

The conditions and results of Examples 1 to 12 and Comparative Examples 1 to 8 are summarized in Table 1. As can be seen from Table 1, in Examples 1 to 12, the visible light transmittance at a wavelength of 550 nm is 65% or more, and the infrared transmission at a wavelength of 1400 nm is obtained by applying a heat treatment under conditions suitable for sputter deposition. Ratio was 20% or less, and it was found that a cesium tungsten oxide film having a high heat ray shielding performance was obtained, in which the ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm was 0.3 or less . Furthermore, since the sheet resistance exceeded 1.0 × 10 ¹⁰ Ω / □, it was found to have radio wave transmission. On the other hand, in Comparative Example 1 in which the heat treatment is not performed only by sputtering, and Comparative Examples 2 to 7 which do not satisfy the requirements of the cesium tungsten oxide film according to an embodiment of the present invention and the manufacturing method thereof The rate is 80% or more, and the heat ray shielding performance is low. Further, the light shielding member formed by sputtering silver (Ag) as in Comparative Example 8 does not have radio wave transmission.

In addition, although one embodiment and each example of the present invention were explained in detail as mentioned above, it is possible for a person skilled in the art that many modifications can be made without departing substantially from the novel item and the effect of the present invention. It will be easy to understand. Accordingly, all such modifications are intended to be included within the scope of the present invention.

For example, in the specification or the drawings, the terms described together with the broader or synonymous different terms at least once can be replaced with the different terms anywhere in the specification or the drawings. Further, the configurations of the cesium tungsten oxide film and the method of manufacturing the same are not limited to those described in the embodiment and each example of the present invention, and various modifications can be made.

Since the cesium tungsten oxide film according to the present invention has excellent heat ray shielding performance and radio wave transmission, it has industrial applicability for use as a light shielding member such as a window material.

Claims

A cesium tungsten oxide film containing cesium, tungsten and oxygen as main components,
When the atomic ratio of the cesium and the tungsten is Cs / W, the Cs / W is 0.1 or more and 0.5 or less, and has a hexagonal crystal structure. Object film.
The angle ratio of the diffraction angle 2θ (002) of the hexagonal (002) plane to the diffraction angle 2θ (200) of the hexagonal (200) plane by X-ray diffraction using CuKα rays is 2θ (002) / 2θ (200) The cesium tungsten oxide film according to claim 1, wherein the 2θ (002) / 2θ (200) is 0.83 or more and 0.85 or less.
The intensity ratio of the diffraction intensity I (002) of the hexagonal (002) plane to the diffraction intensity I (200) of the hexagonal (200) plane by X-ray diffraction using CuKα ray is I (002) / I (200) The cesium tungsten oxide film according to claim 1 or 2, wherein I (002) / I (200) is 0.3 or more.
The cesium tungsten oxide film according to any one of claims 1 to 3, wherein the ratio of the infrared transmittance at a wavelength of 1400 nm to the visible light transmittance at a wavelength of 550 nm is 0.3 or less.
The cesium tungsten oxide film according to any one of claims 1 to 4, which is a sputtered film having a thickness of 30 nm or more and 1200 nm or less.
Cesium tungsten oxide film according to any one of claims 1 to 5 sheet resistance, characterized in that more than 1.0 × 10 10 Ω / □.
A method of producing a cesium tungsten oxide film containing cesium, tungsten and oxygen as main components,
Forming a film using a cesium tungsten oxide target;
Heat-treating the film at a temperature of 400 ° C. or more and less than 1000 ° C .;
A method for producing a cesium tungsten oxide film, comprising performing any of the film forming step or the heat treatment step in an atmosphere containing oxygen.
In the film forming step, after sputtering film formation in a mixed gas of argon and oxygen, in the heat treatment step, the film is heat treated at a temperature of 400 ° C. to 900 ° C. in an inert or reducing atmosphere. Item 8. A method for producing a cesium tungsten oxide film according to Item 7.
8. The cesium tungsten oxide film according to claim 7, wherein the film is formed by sputtering in argon gas in the film forming step, and then the film is heat treated in air at a temperature of 400 ° C. to 600 ° C. in the heat treatment step. Method of manufacturing product film.