JP2003321782A - Method of manufacturing composite material having photocatalytic coating film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a composite material having a photocatalytic coating film composed of titanium-containing oxynitride expressing photocatalytic activity and/or hydrophilicity by the irradiation with visible ray. <P>SOLUTION: A coating film containing titanium-containing oxide or the precursor material applied on the surface of a base material is brought into contact with a plasma gas formed by plasma-treating ammonia gas, a gaseous mixture of ammonia with hydrogen, a gaseous mixture of ammonia and hydrogen with nitrogen or a gaseous mixture of hydrogen with nitrogen under an atmospheric pressure to reform the coating film into the photocatalytic coating film composed of titanium-containing oxynitride. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite material having a photocatalytic coating that exhibits photocatalytic activity and / or hydrophilicity upon irradiation with visible light. Suitable for use as an interior / exterior material that requires functions.

[0002]

2. Description of the Related Art In recent years, there is a need for environment-purifying products having functions such as antibacterial, deodorant, and antifouling due to the growing interest in pollution control, health, comfort, and cleanliness. Attention has been paid. Above the "photocatalyst" refers to the absorption of light energy, the excited electrons are superoxide anion of reactive oxygen species by reducing oxygen (· O ₂ ^-) to generate a, active oxygen holes oxidize water It is a substance that oxidizes and decomposes organic substances and the like that come into contact with the surface of the photocatalyst by generating seed hydroxyl radicals (OH. Furthermore, when the photocatalyst is titanium oxide, it can exhibit superhydrophilicity of 5 ° or less at a contact angle of water.

By utilizing this characteristic, for outdoor use, anti-fouling treatment for oil, inorganic dust, carbon, etc. which are the main components of urban pollution, anti-fog treatment for ensuring visibility, and for indoor use, Sanitary treatment such as antibacterial and deodorant can be performed.

For example, Japanese Patent No. 2756474 proposes a hydrophilic substrate having a titanium oxide photocatalyst bonded to the surface. Furthermore, by utilizing the property of the n-type semiconductor, the metal material can also be subjected to galvanic protection.

Here, it is not enough that the reaction for producing active oxygen species occurs only when the band gap energy of the photocatalyst is larger than the production energy of active oxygen species {1.36 eV (2.18 × 10 ^-19 J)}. The lower end of the conduction band and the upper end of the valence band are O ₂ / O ₂ ^- ( ^- 0.13eV (-0.2
1 × 10 ^-19 J)) level and O ₂ / H ₂ O (1.23 eV (1.97 × 10
^-19 J)) Must be positioned so as to sandwich the level. Since this redox level is an equilibrium level, a certain overvoltage is required to cause the reaction of generating active oxygen species, and the lower limit level of the conduction band is lower than the O ₂ / O ₂ ⁻ level. It is desirable to locate it on the negative side and to place the upper level of the valence band on the positive side of the O ₂ / H ₂ O level.

[0006] Currently, the anatase type titanium oxide in practical use as a photocatalyst material, the upper end of the lower end and the valence band of the conduction band O ₂ / O ₂ ^- and level and O ₂ / H ₂ O level However, since the upper level of the valence band is located on the positive side sufficiently deeper than the O ₂ / H ₂ O level, the band gap energy is as large as 3.2 eV (5.13 × 10 ^-19 J). However, the photocatalytic activity and the hydrophilic property cannot be exhibited by irradiation with visible light, and the above properties can be exhibited only by irradiation with ultraviolet light.

For example, when sunlight or a fluorescent lamp is used as the light source, the spectral distribution spectrum of ultraviolet rays is at most 3
It is ~ 4%, and the intensity of near-ultraviolet light is 1-2 in daylight.
mW / cm ² is only about 1 μW / cm ^{2 for} indoor fluorescent lamps. Therefore, it is desired to develop a photocatalytic material capable of exhibiting photocatalytic activity and hydrophilic properties even when irradiated with visible light, in order to effectively utilize light energy and to exert a sufficient function even in a fluorescent lamp environment.

In order to exhibit a photocatalytic function by irradiation with visible light, it is a necessary condition that the bandgap energy of the photocatalyst is about 3 eV (4.8 × 10 ⁻¹⁹ J) or less capable of absorbing visible light, and various methods are available. Proposed.

For example, in Japanese Patent Laid-Open No. 11-197512, an ion implanter is used to implant anatase-type titanium oxide with a transition metal such as vanadium or chromium.
It is disclosed that visible light activity is exhibited by heat treatment in the atmosphere. However, the method and apparatus described in the above publication are expensive, and it is difficult to apply them to a large area.

Also, Masayoshi Miyoshi et al., Color material, 73 (12), 580 (20
(00) discloses that anatase-type titanium oxide is subjected to hydrogen plasma treatment to form oxygen deficiency, and thereby visible light activity is exhibited. However, if oxygen vacancies are formed and oxygen atoms are removed, an unstable crystal structure is likely to be formed, and it is difficult to maintain the photocatalytic action for a long period of time.

Furthermore, R. Asahi et al., Science, 293,2
69 (2001), using the RF magnetron sputtering method, the upper end of the valence band was shifted to the negative side by mixing the nitrogen 2p orbit with the oxygen 2p orbit that constitutes the valence band of anatase-type titanium oxide. The titanium oxynitride (TiO _2-x N _x ) photocatalytic thin film prepared is disclosed. The TiO _{2 -x} N _x photocatalytic thin film described in the above reference is a photocatalytic material that can exhibit photocatalytic activity and hydrophilicity by irradiation with visible light, but this thin film has a TiO ₂ target of N by the RF magnetron sputtering method. _Since it is manufactured by depositing in a ₂ + Ar gas atmosphere, the equipment is expensive, it is difficult to control the amount of nitrogen contained in the thin film, and it is difficult to control the multi-component element to any composition. There were problems such as difficulties.

[0012]

SUMMARY OF THE INVENTION In view of the above-mentioned conventional techniques, an object of the present invention is to provide a photocatalyst film made of titanium oxynitride which exhibits photocatalytic activity and / or hydrophilicity by irradiation with visible light. It is to provide a method for producing a formed composite material, which is suitable for use as an interior / exterior material that requires, for example, environmental purification or anticorrosion functions.

[0013]

The inventors of the present invention have found that a titanium-containing oxynitride obtained by substituting an oxygen site of a titanium-containing oxide containing titanium dioxide or a titanium composite oxide with a nitrogen element has a photocatalytic activity under visible light irradiation. In order to develop a method capable of advantageously producing a titanium-containing oxynitride photocatalytic thin film, focusing on the fact that it exhibits hydrophilicity and / or hydrophilicity, and further improves abrasion resistance and corrosion resistance, the surface of the base material was investigated. The titanium-containing oxide or its precursor substance is used as the coating film formed in step (1), and the coating material is brought into contact with a gas for nitriding treatment that is plasmaized under atmospheric pressure to obtain a composite material having a photocatalytic coating film of titanium-containing oxynitride. , Found that it can be produced without heating and in a short time,
The present invention has been completed. In particular, since the treatment is performed under atmospheric pressure, the conventional nitriding treatment with plasma must be performed under reduced pressure, and the batch method was inevitable, but continuous treatment can be realized, which is extremely significant. It turned out to be

That is, the gist of the present invention is as follows. (1) After coating the surface of the substrate with a film containing a titanium-containing oxide or a precursor substance thereof, ammonia gas, a mixed gas of ammonia and hydrogen, a mixed gas of ammonia and hydrogen and nitrogen, or a mixture of hydrogen and nitrogen Mixed gas,
Production of a composite material having a photocatalyst film, characterized in that the film is converted to plasma under atmospheric pressure, and the plasmaized gas is brought into contact with the film to modify the film into a photocatalyst film made of titanium-containing oxynitride. Method.

(2) The method for producing a composite material having a photocatalyst coating according to (1) above, wherein the gas is turned into plasma by glow discharge generated by applying an AC voltage.

(3) A method for producing a composite material having a photocatalytic coating as described in (1) or (2) above, wherein the frequency of the AC voltage is 50 Hz to 200 MHz.

(4) Production of a composite material having a photocatalytic coating according to any one of (1) to (3) above, wherein the coating containing a titanium-containing oxide or its precursor substance has an average thickness of 0.01 to 3 μm. Method.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below. Currently used photocatalyst anatase type titanium oxide cannot exhibit photocatalytic activity by irradiation with visible light, but can express photocatalytic activity only by irradiation with ultraviolet rays. This is because the upper level of the valence band of the oxide formed by the 2p orbit of oxygen is O ₂ / H _{2 which is} the oxidation level of water.
The reason is that the bandgap energy is increased due to the deeper position on the positive side than O.

Therefore, as a method of exhibiting a photocatalytic activity by irradiation with visible light, oxynitride obtained by doping an oxide photocatalyst with a nitrogen element is drawing attention. When the oxygen site of the oxide is doped with a nitrogen element, N _2p having a higher energy level than O _{2p of} oxygen is also used for the configuration of the valence band, and as a result, the upper level of the valence band is increased. It is considered that visible light can be absorbed as a result of shifting to the negative side and narrowing the band gap.

Oxynitride photocatalysts include anatase-type TiO _2-x N _x and titanium, niobium, tantalum perovskite or layered perovskite materials such as LaTa.
ON ₂ , CaTaON ₂ , SrTaON ₂ , BaTaON ₂ , LaTiO ₂ N, Ca _1-x La _x T
_{iO 3-x N x, CaNbON} 2, SrNbON 2, BaNbON 2, although such LiLaTaNO ₆ are known, in practice, the cost, safety, in view of stability, the photocatalytic material is titanium-based titanium It is preferably a contained oxynitride. The term “titanium-based titanium-containing oxynitride” used herein refers to a compound in which the proportion of titanium element in the transition metal elements forming the conduction band is 50 atom% or more.

Since the photocatalyst composite material produced by the method of the present invention coats the titanium-containing oxynitride photocatalyst on the substrate, it exhibits photocatalytic activity and / or
Alternatively, since it exhibits hydrophilicity and the crystal structure is doped with a nitrogen element, it is excellent in wear resistance and corrosion resistance.

In order for the titanium-containing oxynitride photocatalytic film to exhibit superhydrophilicity, it is preferable that the photocatalytic film contains a crystal structure of anatase type, rutile type, brookite type or the like. The mechanism of complex oxides such as perovskite type is unknown, but the contact angle with water is usually only 10 to 20 °. Furthermore, in order to maintain the hydrophilicity for a long period of time, silica or silicon oxynitride is added to the solid content of the photocatalytic coating at 10 to 10%.
It is preferable to mix 80% by mass, more preferably 20 to 50
Mass% is mixed.

Next, the method for producing the composite material having the above-mentioned photocatalytic film will be described in detail. In the present invention, as the base material of the composite material, ceramics, tiles, concrete, glass, inorganic materials such as bricks, aluminum, stainless steel, plated steel sheets, metal sheets such as chemical conversion treated steel sheets, coated steel sheets, resins such as acrylic and polycarbonate , Organic materials such as wood, but are not particularly limited thereto.

The shape of the substrate is, for example, a block,
Examples thereof include plates (sheets), films, structural materials, etc., but are not particularly limited thereto. In addition, the size and thickness of the base material are not particularly limited.

When it is necessary to protect the substrate from the oxidative decomposition action of the titanium-containing oxynitride photocatalytic film, it is preferable to provide a barrier layer between them. As the barrier layer, in addition to oxidation protection of the base material, it is possible to impart functionality such as heat ray reflection, radio wave reflection, and conductivity. For example, silicone resin, silica, alumina, zirconia, ITO, titanium nitride. , Silicon carbide and the like, but are not particularly limited thereto.

In the present invention, the above-mentioned base material is coated with a film containing a titanium-containing oxide or its precursor substance,
Ammonia gas, a mixed gas of ammonia and hydrogen, a mixed gas of ammonia and hydrogen and nitrogen, or a mixed gas of hydrogen and nitrogen is plasmatized under atmospheric pressure, and the plasmatized gas is brought into contact with the coating film. And

First, as a method for coating a coating film containing a titanium-containing oxide or its precursor substance on a substrate, a vapor phase method such as a chemical vapor deposition method, a reactive vapor deposition method or a reactive sputtering method, or a sol-gel method. Examples of the liquid phase method include, but are not limited to, liquid phase methods.

Form of the above-mentioned coating by a vapor phase method, for example, a vapor deposition method.
To give an example of the composition method, a chamber in which a base material is installed
ー 1 × 10⁻³After depressurizing to Pa, oxygen partial pressure is 1 to 9
× 10 ^-2Adjust to Pa and irradiate the evaporation source TiO with an electron beam
The substrate on the substrate heated to 100 to 400 ° C.
A case-type titanium oxide film may be formed. At this time, acid
If the temperature is not sufficient, 10-
Heat treatment may be applied for up to 60 minutes.

An example of a method for forming the above-mentioned coating by a liquid phase method, for example, a sol-gel method will be given. Acetylacetone, diethylene glycol, ethyl acetoacetate and other chelating agents are added to 1 mol of titanium alkoxide in an alcohol solvent.
˜2 mol, followed by adding 0.01 to 0.1 mol of carboxylic acid such as oxalic acid and acetic acid, inorganic acid such as boric acid, hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid as an acid catalyst, and then gradually adding 1 to 4 mol of water. The resulting partial hydrolysis solution as a coating solution or when blending other elements, an alcohol solution obtained by mixing the above chelating agent with an alkoxide of another element in the partial hydrolysis solution, or oxychloride, oxynitrate,
A coating solution prepared by mixing alcoholic solutions of inorganic salts such as oxyphosphates, oxyacetates, nitrates, ammonium salts and chlorides and organic acid salts such as acetates and oxalates at a predetermined ratio is used as a base material. The coating may be formed by coating.

As another method, an aqueous crystalline titanium oxide sol such as anatase or brookite, an amorphous titanium oxide aqueous solution such as peroxotitanic acid or orthotitanic acid, or a mixed solution thereof is added to the above inorganic salt or organic salt. The aqueous solutions are mixed at a predetermined ratio to obtain a coating solution. At this time, when the coating solution gels by the addition of the above-mentioned inorganic salt or organic salt solution,
It can be prevented by previously adding a hydroxycarboxylic acid such as lactic acid, malic acid or citric acid to the titanium oxide aqueous solution to form a titanium complex. In addition, when synthesizing the titanium oxide aqueous solution, the above-mentioned inorganic salt or organic salt may be mixed in advance in the starting material. The coating solution may be applied to a base material in the same manner to form the coating film. The method for forming a coating film on a substrate is to adjust the solid content of the sol solution to 0.1 to 10% by mass, preferably 0.5 to 5% by mass in terms of oxide, and apply to the substrate by spraying, dipping, brushing or the like. To form a dry film.

The thickness of the above-mentioned coating is not particularly limited, but the average thickness is preferably in the range of 0.01 to 3 μm. That is, the average film thickness of the coating is 0.01 μm
If it is less than 0.1 μm, it is difficult to form a uniform coating film, and the light absorption efficiency is lowered. On the other hand, since the titanium-containing oxynitride is mainly modified to a range of about 3 μm from the surface, the thickness of the coating is 3 μm.
m is sufficient.

Next, the coating containing the titanium-containing oxide or its precursor substance is subjected to a nitriding treatment. This nitriding process is
Ammonia gas, a mixed gas of ammonia and hydrogen, a mixed gas of ammonia and hydrogen and nitrogen, or a mixed gas of hydrogen and nitrogen (hereinafter referred to as nitriding gas),
Under atmospheric pressure without any particular pressure reduction, plasma is formed by, for example, glow discharge or corona discharge, and the mixed gas that has been turned into plasma is brought into contact with the coating film.

Here, the plasma of the nitriding treatment gas is preferably performed by glow discharge generated by applying a low AC voltage. That is, in order to generate a stable plasma at a low voltage under atmospheric pressure, for example, a dielectric layer is provided on the surface of at least one of a pair of electrodes, and a nitriding gas is supplied between the electrodes, and an alternating voltage is applied. The technique of applying a pulse to form a pulsed electric field between the electrodes is advantageous.

The alternating voltage applied to the glow discharge is the voltage:
1 kV to 50 kV and frequency: 50 Hz to 200 MHz are preferable. This is because, if the voltage is less than 1 kV, it is difficult to stably generate the glow discharge. On the other hand, if the voltage exceeds 50 kV, the plasma velocity increases, the electrode temperature rises, and the glow discharge may become unstable. Also, the frequency is 50
If it is less than Hz, the plasma density is low and the state becomes unstable. On the other hand, if it exceeds 200 MHz, the plasma temperature rises, the electrode temperature rises, and the glow discharge may become unstable.
More preferably, voltage: 5 kV-20 kV and frequency: 1
It is recommended to set it to kHz to 100MHz.

Further, in generating glow discharge,
The dielectric constant of the dielectric layer provided on the surface of at least one of the pair of electrodes is preferably in the range of 2 to 2000. That is, if the dielectric constant is less than 2 or exceeds 2000, the plasma temperature rises, the electrode temperature rises, and the glow discharge may become unstable. More preferably, the dielectric constant is 5 to 1000.

The thickness of the dielectric layer is preferably 0.1-3 mm. That is, the thickness of the dielectric layer is 0.1 mm
If it is less than 3, the withstand voltage is lowered and dielectric breakdown is likely to occur. On the other hand, if it exceeds 3 mm, the applied voltage becomes excessive, the plasma temperature rises, the electrode temperature rises, and the glow discharge may become unstable. There is. More preferably 0.2-2 mm
And

The material of the dielectric layer is not particularly limited, but for example, any one of magnesia, titania, alumina, zirconia, and a mixture of two or more thereof can be applied. Further, since the shape of the electrodes also affects the stabilization of glow discharge, it is advantageous to make the surface between the electrodes curved, and the radius of curvature thereof is preferably 0.5 to 30 mm, more preferably 1 to 20 mm.

On the other hand, as the nitriding gas, ammonia gas, a mixed gas of ammonia and hydrogen, a mixed gas of ammonia and hydrogen and nitrogen, or a mixed gas of hydrogen and nitrogen is used, and the mixing ratio thereof may be arbitrary. Further, when dilution is necessary, an inert gas such as helium, neon and argon may be appropriately mixed.

In order to bring the plasma-processed nitriding gas into contact with the film containing the titanium-containing oxide or its precursor substance, the plasma-processed nitriding gas is jetted toward the film or glow discharge is applied. It can be achieved by passing the coated substrate between the electrodes that are being generated,
The method is not particularly limited to these.

[0040]

EXAMPLES Next, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. (Example 1) A coating solution (1.7% by mass) in which anatase type titanium oxide sol and peroxotitanic acid were mixed at a mass ratio of 7: 3 was spray-coated on a white enamel material (base material) coated with titanium glaze, After drying, it was calcined at 500 ° C. for 10 minutes to prepare a composite material having a coating film with an average film thickness of 0.2 μm. Then, a mixed gas of ammonia and argon (volume ratio NH ₃ : Ar = 1: 1) is plasmatized at atmospheric pressure as a nitriding gas into the composite material having the coating film, and the gas is injected for 30 seconds. The above coating was modified to a photocatalytic coating made of titanium oxynitride. At this time, the photocatalytic coating was of anatase type, and its average film thickness was 0.2 μm. The characteristics of the photocatalytic coating were measured and evaluated by the methods described below. The evaluation results are shown in Table 1.

The plasma treatment of the nitriding gas was carried out by using a plasma generator as a pair of stainless steel electrodes each having a radius of curvature of 10 mm and having a dielectric alumina coating of 300 μm.
Glow discharges were generated under the conditions of an applied voltage of 10 kV and a frequency of 50 MHz, and the nitriding gas was introduced between the electrodes.

Example 2 A film having an average film thickness of 0.2 μm was modified into a photocatalyst film made of titanium oxynitride by the same method as in Example 1 except that ammonia gas was used as the nitriding gas. . Table 1 shows the evaluation results of the characteristics of the photocatalytic coating.

Example 3 A mixed gas of nitrogen and hydrogen (volume ratio N ₂ : H ₂ = 5: 1) was used as an atmosphere gas for nitriding.
In the same manner as in Example 1 except that was used, a film having an average film thickness of 0.2 μm was modified into a photocatalytic film made of titanium oxynitride. Table 1 shows the evaluation results of the characteristics of the photocatalytic coating.

Example 4 As an atmosphere gas for nitriding, a mixed gas of ammonia and hydrogen (volume ratio NH ₃ : H ₂ =
5: 1) except that the same method as in Example 1 was used.
A film having an average film thickness of 0.2 μm was modified into a photocatalytic film made of titanium oxynitride. Table 1 shows the evaluation results of the characteristics of the photocatalytic coating.

(Embodiment 5) As an atmosphere gas for nitriding, a mixed gas of ammonia, nitrogen and hydrogen (volume ratio NH ₃ :
A film having an average film thickness of 0.2 μm was modified into a photocatalyst film made of titanium oxynitride by the same method as in Example 1 except that N ₂ : H ₂ = 5: 5: 1) was used. Table 1 shows the evaluation results of the characteristics of the photocatalytic coating.

Comparative Example 1 A film having an average film thickness of 0.2 μm was formed into a photocatalyst film made of titanium oxynitride by the same method as in Example 1 except that nitrogen gas alone was used as the atmosphere gas for nitriding. Modified. Table 1 shows the evaluation results of the characteristics of the photocatalytic coating.

[0047] (Comparative Example 2) atmospheric gas nitriding treatment, a mixed gas of hydrogen and argon (Ar: except that the H _2, in the same manner as in Example 1, the average film thickness 0.2μm of film The photocatalyst film was modified to titanium oxynitride, and the evaluation results of the properties of the photocatalyst film are shown in Table 1.

(Test Method) [Antibacterial Test] The antibacterial activity was evaluated according to the light irradiation film adhesion method described in the antibacterial activity evaluation test method for antibacterial products of the Antibacterial Product Technology Council. After inoculating 0.1 ml of a bacterial solution with a bacterial concentration of 1.5 × 10 ⁶ cells / ml onto a 5 cm × 5 cm size test material, cover it with a polyethylene film to bring it into close contact, set it in a transparent petri dish, and set the temperature to 25 The lid was covered under the condition of ℃ and relative humidity of 90% or more, and 1000 lux of visible light was irradiated with a white fluorescent lamp for 4 hours or 8 hours, or left in the dark for 4 hours or 8 hours. After that, surviving bacteria were washed out from the test material with physiological saline and cultured in NA medium at 35 ° C. for 24 hours, and the viable cell count was measured. For the antibacterial activity, the number of viable bacteria was less than 10 when the number of viable bacteria was 1 per test material. Staphylococcus aureus IF0 12732 is used as the bacterium, and the white fluorescent lamp is equipped with an ultraviolet cut film (trade name “ObicC” manufactured by King Seisakusho Co., Ltd.) to set the ultraviolet intensity to 0.
It was set to 1 μW / cm ² or less (ultraviolet intensity was measured by a 365 nm ultraviolet sensor).

[Contact Angle] 20 μL of ion-exchanged water was dropped on the test material using a microsyringe, and the water droplets on the test material were measured by an image processing contact angle meter (Kyowa Interface Science Co., Ltd.,
CA-X) was used to measure the contact angle of water by the three-point method.
The contact angle is measured in the initial state before irradiation with visible light, after being irradiated with visible light of 1000 lux for 8 hours using the white fluorescent lamp, and after being left for 24 hours in a dark place. I went the same way.

X-ray photoelectron spectroscopy analysis was performed on the surface of the test material. That is, when the surface of the test material was irradiated with characteristic X-rays and the binding energy was calculated from the kinetic energy of the emitted photoelectrons, all the test materials of the present invention showed TiN bond (bonding) as shown in FIG. Energy ≈ 396e
The existence of V) was confirmed.

[0051]

[Table 1]

From the results shown in Table 1, all the Examples
It can be seen that excellent antibacterial activity and hydrophilicity can be obtained by irradiation with visible light for 8 hours. On the other hand, in Comparative Example 1, the film is not nitrided, and the antibacterial activity and hydrophilicity are not exhibited even when visible light is irradiated. In Comparative Example 2, a slight visible light response is observed because the hydrogen plasma is used in other words.

[0053]

According to the present invention, a method for producing a composite material having a photocatalyst coating made of titanium-containing oxynitride which exhibits photocatalytic activity and / or hydrophilicity not only by ultraviolet irradiation but also by visible light irradiation. Is now available. By using this manufacturing method,
It can be formed by continuous processing without heating the substrate. Furthermore, the composite member obtained by the manufacturing method of the present invention can be used as, for example, an interior material that requires an environmental purification or anticorrosion function, a scenic material such as a sidewall material, an outer wall material, and the like.

The photocatalytic coating made of titanium-containing oxynitride constituting the above composite material is superior in wear resistance and corrosion resistance as compared with the photocatalytic coating made of a single oxide such as titanium oxide, so that the adhesion of the coating is improved. The property is also good.

[Brief description of drawings]

FIG. 1 is a diagram showing a result of X-ray photoelectron spectroscopy analysis.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C01G 23/00 C01G 23/00 Z 4K044 G03F 7/004 521 G03F 7/004 521 // C23C 8/36 C23C 8/36 (72) Inventor Tatsuya Nozawa, 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Prefecture, Research Institute of Kawasaki Steel Co., Ltd. (72) Inventor, Hirohiko Murakami 5-9-7 Tokodai, Tsukuba, Ibaraki ULVAC Tsukuba Super Materials Research Laboratory (72) Inventor Chizuru Ogane 5-9-7 Tokodai, Tsukuba, Ibaraki Stock Company ULVAC Tsukuba Super Materials Research Laboratory F-term (reference) 2H025 AB03 BH03 4G047 CA01 CB04 CC03 CD02 4G069 AA03 AA08 BA48A BB04A BB04B BB11A BB11B BC50A BC50B DA06 EA08 ED02 FB24 4G075 AA24 BA05 BC01 BD14 BD26 CA16 CA25 CA47 CA62 DA18 EB33 EC21 EE01 EE12 FB02 FB04 FB05 FB06 FB11 FB12 FC09 FC11 FC15 FC12 4K028 BA02 BA11 BA22 4K04 BAA 4A04A12

Claims (4)

[Claims] 1. A substrate surface is coated with a film containing a titanium-containing oxide or its precursor substance, and then ammonia gas, a mixed gas of ammonia and hydrogen, a mixed gas of ammonia and hydrogen and nitrogen, or hydrogen and A photocatalytic film characterized by converting a mixed gas of nitrogen into plasma under atmospheric pressure, bringing the plasmatic gas into contact with the film, and modifying the film into a photocatalytic film comprising titanium-containing oxynitride. A method of manufacturing a composite material having: 2. The method for producing a composite material having a photocatalyst film according to claim 1, wherein the gas is turned into plasma by glow discharge generated by applying an alternating voltage. 3. The method for producing a composite material having a photocatalyst coating according to claim 1, wherein the frequency of the alternating voltage is 50 Hz to 200 MHz. 4. The method for producing a composite material having a photocatalyst film according to claim 1, wherein the film containing the titanium-containing oxide or its precursor substance has an average film thickness of 0.01 to 3 μm.