JP2000296332A - Method of forming photocatalytic film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a photocatalyst film having high activity and high film strength at low temperature. SOLUTION: A substrate 8 consisting of plastic, etc., is fixed to a substrate holder 7 and a raw material 5 for vapor deposition consisting of metallic material is put into a crucible. The substrate 8 is irradiated with mixed excitation rays of oxygen ions, oxygen radical and oxygen plasma from an excitation ray source 6. The raw material 5 for vapor deposition 5 is heated by casting electron beams 4 thereto simultaneously therewith, by which the raw material is evaporated and is adhered onto the substrate 8 to form a metal oxide and the photocatalyst film is thus formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a photocatalytic film having high activity and high film strength at a low temperature.

[0002]

2. Description of the Related Art When a photocatalyst is irradiated with light having a wavelength having energy equal to or greater than the band gap, electrons are generated in a conduction band and holes are generated in a valence band by photoexcitation. The strong reducing power of electrons and the strong oxidizing power of holes generated by this photoexcitation are being considered for use in decomposing and purifying organic substances, decomposing water, removing nitrogen oxides, etc. Practical application is being promoted in some fields.

[0003] Photocatalysts have been studied for their application to antifouling, antibacterial, deodorizing, and purifying harmful gases such as NOx as catalysts capable of obtaining a strong decomposition activity. Also, studies have been made to apply the washing with raindrops by utilizing the superhydrophilic effect of the photocatalyst.
Practical applications have already been made in the field of filters for air purifiers, antifouling of road lighting and fluorescent lights, antifogging and water repellency of mirrors and lenses, antifouling of painted surfaces of automobiles, and antifouling of building materials and tiles. .

As a photocatalyst, for example, titanium oxide having high activity and excellent chemical stability is formed in the form of fine particles or a film. The particulate photocatalyst is generally formed into a film by bonding it to a substrate via an adhesive. As a binder having an adhesive property, a silica-based material or a fluororesin material is used. In the method of fixing the photocatalyst particles with the binder, it is necessary to use a porous material in order to prevent the photocatalyst from being buried in the binder and impairing the catalytic activity. Further, in order to obtain a highly active film, it is necessary to make the binder as porous as possible, and there has been a problem that adhesion and film strength are impaired.

[0005] On the other hand, even in the photocatalyst fixing method using a binder, a film having strong adhesion can be produced by sacrificing photocatalytic activity. Since super hydrophilicity can be obtained even with relatively weak photocatalytic activity, antifouling can be achieved with a large washing effect by raindrops. This has been put to practical use in antifouling of automobiles. However, in a room where a cleaning effect by raindrops cannot be expected, there is a problem that an antifouling effect can hardly be obtained due to weak photocatalytic activity, which is not practical. As described above, in the method of fixing the photocatalyst with the binder, it is difficult to achieve a balance between the film strength and the activity in principle, and a great improvement cannot be expected.

Therefore, as a general method of forming a photocatalytic material directly into a film without using a binder, there is a method of forming a titanium oxide film using a sol-gel method, and a raw material such as titanium alkoxide or titanium chelate is used. The liquid is applied to a substrate, dried, and then baked at a high temperature of 500 ° C. or higher to form a photocatalytic film, thereby forming a photocatalytic film.

In the method of directly forming a photocatalyst film by the sol-gel method, there is no need to use a binder, so that there is no problem that the photocatalyst is buried in the binder, and a film having high film strength and high activity can be obtained. In addition, since a transparent film can be obtained, various colors can be obtained as needed by changing the color of the base, and it can be used for interior-oriented applications.

[0008]

However, in order to obtain an active photocatalyst film by the sol-gel method, it is necessary to heat the film to a temperature at which it is crystallized, and a high-temperature baking of 500 ° C. or more is required. For this reason, it is a technique that can be formed only on a substrate having excellent heat resistance, and there is a problem that the applicable field is extremely limited.

That is, in the conventional method of forming a photocatalytic film by the sol-gel method, it is difficult to form a film having high activity and excellent adhesion and transparency at a low temperature, and it is firmly adhered to plastic. In addition, a highly active photocatalytic film having excellent transparency cannot be formed. Therefore, the field in which the excellent function of the photocatalyst can be exhibited is limited.

[0010] In view of the above, an object of the present invention is to form a photocatalytic film at a low temperature so that a photocatalytic film having high activity and high film strength can be provided on a plastic having low heat resistance.

[0011]

The object of the present invention is to provide a thin film forming method, such as a vapor deposition method or a sputtering method, for forming a highly active photocatalytic film on a substrate having low heat resistance. The electron, ion, and the like existing in the space where the metal material or the metal oxide material serving as the photocatalyst is placed so that the film can be formed without heating the substrate and suppressing the temperature rise of the substrate. The photocatalytic film is formed at a low temperature by utilizing the energy of the active particles. The active particles are, for example, radicals (free atoms) in a plasma, which is a space where ions and electrons of molecules and atoms are present, excited atoms and molecules,
Very chemically active particles. In order to utilize these, the substrate may be irradiated with low-energy excitation rays.

That is, a metal material or a metal oxide material is once decomposed to a molecular or atomic level by a vapor deposition method or a sputtering method, and a film is formed on a substrate to form a photocatalytic film. The irradiation causes the raw material molecules or raw material atoms to be in a high energy state, so that the crystallization of the formed photocatalytic film can be promoted at a low temperature, and the crystallinity of the photocatalytic film can be improved to achieve high activation. Further, by irradiating the substrate with the excitation beam, the surface of the substrate is cleaned by electrons and ions and the surface is modified, thereby increasing the film strength.

As described above, a low-energy excitation beam using only one of an ion beam, an electron beam, a radical beam, and a plasma or a combination thereof is irradiated onto a substrate made of plastic, rubber, ceramics, or the like having low heat resistance. Meanwhile, since a metal material or a metal oxide material is formed on a substrate by a vapor deposition method or a sputtering method, a photocatalyst film can be directly formed without using a binder, and there is no problem that the photocatalyst is buried in the binder, and high activity is achieved. A photocatalytic film is formed. In addition, in the conventional sol-gel method, high-temperature heating of about 500 ° C. or more is necessary to crystallize the photocatalytic film. This is unnecessary, and a crystallized film can be formed well even at a low temperature. Also,
When a titanium oxide photocatalytic film is formed using titanium or titanium oxide as a raw material, a transparent film can be easily obtained.

Here, when the kinetic energy of the charged particles in the excitation beam is set to 200 eV or less, as a result of studies by the inventors, it has been found that a photocatalytic film having high activity at a low temperature can be formed. When the kinetic energy exceeds 200 eV, the formed film is sputtered, so that the film forming speed is reduced and the film cannot be formed efficiently. In addition, when irradiation with high-energy excitation rays is performed, the surface temperature of the substrate increases, which causes a problem that the method cannot be applied to a substrate having low heat resistance.

When a plastic is used as the substrate, it is preferable to form a buffer film which is not affected by photocatalysis on the plastic substrate. Then, a photocatalytic film is formed on the buffer film. Because the photocatalytic film has high activity, if the photocatalytic film is formed directly on the plastic, there is a problem that the plastic is decomposed by the photocatalytic action, and the plastic is deteriorated and the adhesion is reduced. However, once a buffer film is formed on a plastic by vapor deposition or sputtering, even if a photocatalyst film is formed thereon, the buffer film is not decomposed by the photocatalyst. Can be prevented from being decomposed. As the buffer film, for example, an inorganic material such as silica, alumina, or a metal may be used, and is formed in a film shape.

Further, instead of the inorganic material, a fluororesin film or a silicone resin film which does not receive a photocatalytic action may be formed. Since the fluororesin or silicone resin is not decomposed by the photocatalyst, even if a photocatalyst film is formed on this buffer film, the plastic is protected by the fluororesin or the silicone resin, and the activity of the photocatalyst prevents the plastic from being decomposed. it can.

The plastic used is a polyimide resin, polyester resin, hydrocarbon resin, polyether resin, or acrylic resin. Note that the polyester resin includes a polycarbonate resin. Examples of the hydrocarbon resin include a polyethylene resin, a polypropylene resin, a polystyrene resin, and an ABS (acrylonitrile-butadiene-styrene) resin. Examples of the polyether resin include a polyacetal resin and a polyphenylene oxide resin. As the acrylic resin, there is a methyl methacrylate resin. Further, the shape is a plate-like molded product or a film shape. In particular, a film-like film is excellent in flexibility, so a photocatalyst sheet with a photocatalyst film formed on the film can be placed on the surface of any shape of industrial products such as appliances, equipment, electrical appliances, and building materials. It can be attached and can easily impart antifouling, antibacterial, and purifying functions, and can utilize a photocatalytic film.

By the way, in the vapor deposition method and the sputtering method, it is necessary to place a substrate in a vacuum chamber of a thin film forming apparatus when forming a film. In particular, when the surface area of the photocatalyst formation surface is large, the substrate may not be accommodated in the vacuum chamber. Further, even if the dimensions can be accommodated in the vacuum chamber, the number of substrates that can be accommodated in the vacuum chamber is limited, and there is a problem that the production efficiency is low. Therefore, since the film-shaped substrate can be wound in a roll shape, the wound film can be drawn out, and the photocatalyst film can be continuously formed while being wound up in a roll-to-roll manner. Therefore, the production efficiency is improved, and the production cost can be extremely reduced.
Furthermore, since the film thus produced can be used as a photocatalyst film simply by sticking it to a sheet of a predetermined shape on the surface of an industrial product, regardless of the material of the industrial product that requires the function of the photocatalyst, There is an advantage that a film suitable for forming can be freely selected.

Further, a fluororesin or a silicone resin may be used as a substrate, and a photocatalyst film can be directly formed thereon. And since these resins are relatively excellent in flexibility, by making them into a film form,
As described above, the production efficiency is improved, and there is no need to form a buffer film between the substrate and the photocatalyst film, so that the film formation time can be shortened and the production cost can be greatly reduced.

The polyimide resin has a high heat resistance temperature of about 300 ° C., and is suitable for sticking to the surface of equipment such as an electric appliance requiring heat resistance. In addition, when the photocatalytic film is formed on the film, the film can be heated to the heat-resistant temperature of the polyimide resin, so that the film strength is increased, and particularly, the adhesion between the photocatalyst film and the film is excellent and the reliability is high. A photocatalyst sheet can be obtained. In addition, when the photocatalytic film is formed, the temperature of the film rises because of the irradiation with excitation light.However, the polyimide resin has a high heat resistant temperature, so that the excitation light can be sufficiently irradiated, and a highly active photocatalytic film can be obtained relatively easily. Can be Further, even if the temperature of the film becomes high due to process variations during manufacturing, the problem that the film is stretched or deteriorated by heat hardly occurs, and a high-quality photocatalytic film can be obtained.

Further, a polyester resin, a polycarbonate resin, and a polypropylene resin can be obtained at a low cost and at the same time, a film having excellent transparency. Therefore, there is an advantage that a transparent photocatalyst sheet can be formed, and a photocatalyst film in consideration of interior properties can be easily produced. Polyester resin and polycarbonate resin are inexpensive but have relatively excellent heat resistance, and are not easily deformed even when the film temperature rises due to manufacturing process variations. A high-quality, versatile photocatalyst sheet having the feature of withstanding can be obtained. ABS resin is inexpensive and is used in large quantities for the exterior of household appliances.
The resin film can be easily thermocompression-bonded to various devices and the like using the ABS resin.

Since the photocatalyst film of the present invention does not use a binder, a transparent film can be formed. By forming a transparent film such as silica as a buffer film on plastic, a transparent photocatalyst film is obtained. . For this reason, by changing the color of the base, various colors can be obtained as needed, which is optimal when used for applications that emphasize interiors. In particular, a transparent photocatalyst sheet can be easily produced by using a transparent resin film. Since home appliances require interior design,
It is necessary to use various colors as needed. However, when a transparent photocatalyst sheet is attached, the interior can be considered without impairing the colors of various devices and the like, and the range of use can be expanded.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a thin film forming apparatus used for forming a photocatalytic film according to an embodiment of the present invention. This device is an electron beam evaporation device, 1 is a vacuum chamber, 2 is a vacuum exhaust port, 3 is an electron beam source for generating an electron beam 4, 5 is a deposition material,
6 is an excitation radiation source, 7 is a substrate holder, 8 is a substrate, 9 is an evaporation source, and 10 is a bias power supply.

Then, a substrate 8 made of plastic, rubber, ceramics or the like in the form of a plate or a film is fixed to a substrate holder 7, a deposition material 5 made of an inorganic material is placed in a crucible, and the material is evacuated to vacuum. Oxygen ions,
The substrate 8 is irradiated with a mixed excitation line of oxygen radicals and oxygen plasma. At the same time, the evaporation source 5 is irradiated with the electron beam 4 and heated to evaporate and adhere to the substrate 8 to form the buffer film 11. Here, the inorganic material is a material that does not receive a photocatalytic action, and is specifically a metal such as silica, alumina, or aluminum, silver, copper, or zinc.

When a fluorine resin or a silicone resin is used instead of the inorganic material, the buffer film 11 made of the fluorine resin or the silicone resin is formed. That is, these resins are not subjected to the photocatalysis, and protect the substrate 8 from the photocatalysis.

Next, the vapor deposition material 5 made of a metal raw material or a metal oxide raw material is put into a crucible, and the electron beam 4 evaporates the vapor deposition raw material 5 while irradiating the substrate 8 with the same excitation ray as described above. Decomposes into molecules or atoms and forms buffer film 1
Then, a photocatalyst made of a metal oxide is deposited on the substrate 1 to form a film. Thus, a photocatalyst film 12 as shown in FIG. 2 is formed. At this time, the raw material adhering to the substrate 8 is brought into a high energy state by the excitation beam, and crystallization of the formed photocatalytic film 12 proceeds without heating the substrate 8.
Here, the metal raw material or the metal oxide raw material is titanium oxide, tungsten oxide, vanadium oxide, zirconium oxide, titanium, tungsten, or the like.

When a fluororesin or a silicone resin which is not decomposed by a photocatalyst is used as the substrate 8, a vapor deposition material 5 made of a metal material or a metal oxide material is put in a crucible, and oxygen, ions, oxygen radicals, oxygen plasma, etc. While irradiating the substrate 8 with the mixed excitation beam, the evaporation source 5 is vaporized by the electron beam 4 to be decomposed into molecules or atoms, and is deposited directly on the substrate 8 to form a photocatalyst formed of a metal oxide. Do. Thereby, the photocatalyst film 12 as shown in FIG. 3 is formed.

As described above, by forming a film while irradiating the substrate with the excitation light, the photocatalytic film can be formed at a low temperature, so that the photocatalytic film can be formed on a substrate made of plastic or the like having low heat resistance. Then, the crystallization of the photocatalyst film is promoted, and the photocatalyst film becomes closer to a single crystal, thereby reducing defects. Therefore, a photocatalytic film having high crystallinity is obtained, and the activity is increased. In addition, since the surface of the substrate or the surface of the buffer film formed on the substrate is cleaned and becomes uneven by the excitation rays, the photocatalytic film formed on this surface adheres firmly, and the film strength is reduced. Become stronger. Since an introduction gas is not required at the time of vapor deposition, the structure of the forming apparatus is simplified, and the forming time can be shortened.

Although a photocatalytic film can be formed on a substrate such as plastic as described above, it must be formed on the surface of an industrial product such as an electric appliance in order to exhibit a photocatalytic effect in actual use. In the case of a small product that can be accommodated in a vacuum chamber of a vapor deposition apparatus, a photocatalytic film may be formed directly on the surface of the product by the above-described forming method. When the product cannot be accommodated in the vacuum chamber, the substrate is formed into a film shape, a photocatalytic film is formed on the substrate, and a photocatalyst sheet according to the shape of the product can be attached to the surface of the product.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention. That is, even if a sputtering method is used instead of the vapor deposition method, the photocatalytic film can be formed by performing the sputtering while irradiating the excitation light in the same manner.

[0031]

(Example 1) SiO was used as a deposition material,
While irradiating a 6 cm × 3 cm polyester resin substrate with a mixed excitation line of oxygen ions, oxygen radicals, and oxygen plasma, a buffer film made of silicon oxide (silica) was formed by EB (electron beam) evaporation. Next, using TiO as a deposition material, a titanium oxide photocatalyst was formed by EB deposition while irradiating the substrate with a mixed excitation line of oxygen ions, oxygen radicals, and oxygen plasma. At this time, a DC voltage was applied to the substrate holder holding the substrate, and the voltage was adjusted so that the kinetic energy of the charged particles in the excitation line became 80 eV. The excitation beam irradiation used was an excitation beam source EBS-23 manufactured by Cryovac. The film thickness is 30
The film formation time was adjusted to be 00 °.

Example 2 A titanium oxide photocatalyst was formed by EB evaporation while TiO was used as a deposition material and a substrate was irradiated with a mixed excitation line of oxygen ions, oxygen radicals, and oxygen plasma. The substrate is 6cm x 3cm
The substrate was made of a silicone resin as described above, and the excitation beam irradiation was performed using an excitation beam source EBS-23 manufactured by Cryovac. During the film formation, a DC voltage was applied to the substrate holder, and the kinetic energy of the charged particles in the excitation beam was adjusted to 80 eV. The film formation time was adjusted so that the film thickness was 3000 °.

Example 3 A titanium oxide photocatalyst was formed by EB vapor deposition while irradiating a substrate with a mixed excitation line of oxygen ions, oxygen radicals, and oxygen plasma using TiO as a vapor deposition material. The substrate is 6cm x 3cm
The substrate was made of a fluororesin, and the excitation beam was irradiated using an excitation beam source EBS-23 manufactured by Cryovac. During the film formation, a DC voltage was applied to the substrate holder, and the kinetic energy of the charged particles in the excitation beam was adjusted to 80 eV. The film formation time was adjusted so that the film thickness was 3000 °.

Comparative Example 1 A titanium oxide photocatalyst was formed by EB vapor deposition using TiO as a vapor deposition material. At this time, oxygen gas was introduced so that the oxygen gas pressure became 5 × 10 ⁻⁵ Torr. The substrate is 6cm x 3cm
Was used. The film thickness is 300
The film formation time was adjusted to be 0 °.

(Comparative Example 2) A titanium oxide photocatalyst was produced by EB vapor deposition while irradiating a 6 cm x 3 cm polyester resin substrate with a mixed excitation line of oxygen ions, oxygen radicals and oxygen plasma using TiO as a vapor deposition material. A film was formed. At this time, a DC voltage was applied to the substrate holder, and the voltage was adjusted so that the kinetic energy of the charged particles in the excitation line became 80 eV. The excitation beam irradiation used was an excitation beam source EBS-23 manufactured by Cryovac. The film thickness is 3
The film formation time was adjusted to be 000 °.

Comparative Example 3 A titanium oxide photocatalyst was formed by EB vapor deposition while irradiating a substrate with a mixed excitation line of oxygen ions, oxygen radicals, and acid plasma using TiO as a vapor deposition material. The substrate is 6cm x 3cm
The substrate was made of a silicone resin as described above, and the excitation beam irradiation was performed using an excitation beam source EBS-23 manufactured by Cryovac. During the film formation, a DC voltage was applied to the substrate holder, and the kinetic energy of the charged particles in the excitation line was adjusted to 220 eV. The film formation time was adjusted so that the film thickness was 3000 °.

The samples obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were separately placed in a 5 liter container,
One acetaldehyde was injected so as to have a concentration of 100 ppm. Next, using a 6 W black light, the photocatalytic film on the sample surface was irradiated with ultraviolet rays, and the time required for the acetaldehyde concentration to decrease to 1 ppm was measured.

After measuring the acetaldehyde decomposition rate, the sample was irradiated with black light, and the total irradiation time was 24 hours.
Irradiation was continued until 0 hour. Thereafter, it was examined whether or not the sample was discolored and whether or not the photocatalytic film was peeled off by rubbing with a finger. Table 1 shows the results. Table 1 also shows the presence / absence of substrate deformation and the film formation rate after sample preparation in each of the examples and comparative examples.

[0039]

[Table 1] After forming a buffer film of silica on the polyester film,
In the sample of Example 1 in which the titanium oxide photocatalyst was formed by EB vapor deposition while irradiating an excitation beam with the kinetic energy of the charged particles set to 80 eV, the acetaldehyde content was 2.3.
Decomposed in time. The same level of acetaldehyde decomposition rate was obtained also in the samples of Examples 2 and 3 using a silicone resin and a fluororesin as the substrate. On the other hand, in the sample of Comparative Example 1 in which the excitation light was not irradiated at the time of forming the titanium oxide film, the acetaldehyde decomposition rate was extremely slow at 1/10 or less. Further, in the sample of Comparative Example 2 in which the titanium oxide photocatalytic film was directly formed without providing the buffer film on the polyester film, the acetaldehyde decomposition rate was the same level as that of the samples of Examples 1 to 3, but the black time was 240 hours. After light irradiation, discoloration of the substrate was observed. In addition, adhesion strength was reduced, and peeling of the film was observed. Silicone resin, fluororesin, and silica are hardly decomposed by the photocatalyst, but polyester is decomposed by the photocatalyst, so it is considered that the discoloration of the substrate and the decrease in adhesion strength occurred.

In the sample of Comparative Example 3 in which the excitation line intensity at the time of forming the titanium oxide photocatalytic film was increased to 200 eV or more,
The acetaldehyde decomposition rate was at the same level as the samples of Examples 1 to 3, but the film formation rate was less than half of the samples of Examples 1 to 3. After the film formation, the substrate was deformed. That is, it is considered that the film formed on the substrate is sputtered by the excitation beam because the intensity of the excitation beam is too high, and the film formation rate is reduced. Further, it is considered that the substrate was heated at a high temperature due to the high irradiation intensity of the excitation beam, and the substrate was thermally deformed.

Example 4 White ABS of 6 cm × 3 cm
A sample of the photocatalyst film produced in Example 1 was adhered to the resin substrate surface with an epoxy resin.

Comparative Example 4 White ABS of 6 cm × 3 cm
A resin substrate was used as Comparative Example 4.

The samples of Example 4 and Comparative Example 4 were 1 m
^In the acrylic box of No. ³ , 10 cigarettes were burned. After removing each sample from the box, the color of the sample was checked. Next, a 6 W white fluorescent lamp was irradiated for 240 hours at a distance of 10 cm from the sample. Thereafter, the color of each sample was examined. Table 2 shows the results.

[0044]

[Table 2] Both the samples of Example 4 and Comparative Example 4 were stained by cigarette smoke and colored yellow before irradiation with a fluorescent lamp. However, in the sample of Example 4, the yellow color due to the tobacco after the irradiation with the fluorescent lamp disappeared and the sample became white, and the purifying action by the action of the photocatalyst was observed. On the other hand, in the sample of Comparative Example 4 in which the photocatalytic film was not formed, the tobacco stain remained even after irradiation with the fluorescent lamp, and coloring was observed.

[0045]

As is apparent from the above description, in the method for forming a photocatalytic film according to the present invention, a high-activity photocatalytic film having a high film strength is formed at a low temperature by performing film formation while irradiating excitation light. be able to. Therefore, a highly active photocatalyst film can be formed even on plastics such as ABS resin having a low heat-resistant temperature.

Here, when a film-like substrate having a buffer film formed of an inorganic material, a fluororesin, or a silicone resin, or a fluororesin or a silicone resin film itself is used as the substrate, a high strength that does not cause deterioration of the film strength occurs. A reliable photocatalyst sheet is obtained. Since such a photocatalyst sheet is flexible, it can be easily adhered to the surface of various industrial products, and can exhibit the functions of the photocatalyst such as antifouling and deodorization everywhere.

Further, since a photocatalyst film having high activity and excellent transparency can be obtained, when a photocatalyst film is formed on a transparent film such as a polyester resin, a polycarbonate resin or a polypropylene resin, a transparent photocatalyst sheet can be obtained. Can be produced. Therefore, by changing the color tone of the base, the photocatalyst sheet can be made into various colors as required, so that the function of the photocatalyst is added to industrial equipment in consideration of interior properties, especially household appliances such as electric appliances. Suitable for the case.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a film forming apparatus for forming a photocatalytic film of the present invention.

FIG. 2 is a cross-sectional view of a photocatalyst sheet on which a buffer film is formed.

FIG. 3 is a cross-sectional view of a photocatalyst sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Vacuum exhaust port 3 Electron beam source 4 Electron beam 5 Deposition material 6 Excitation beam source 7 Substrate holder 8 Substrate 9 Evaporation material 10 Bias power supply 11 Buffer film 12 Photocatalytic film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 21/06 B01J 37/02 301P 35/02 301Q 37/02 301 C23C 14/08 E 14/10 C23C 14 / 08 B01D 53/36 J 14/10 G 102D 104Z (72) Inventor Norihiro Matsuoka 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Kuraichi Ogawa 2 Ayumino, Izumi-shi, Osaka 7-1-1, Osaka Prefectural Institute of Advanced Industrial Science and Technology (72) Inventor Toshinori Nosaka 2-7-1, Ayumino, Izumi-shi, Osaka Pref.Osaka Prefectural Institute of Advanced Industrial Science and Technology (72) Inventor Akio Okamoto Osaka 2-7-1, Ayumino, Izumi City Inside the Osaka Prefectural Institute of Advanced Industrial Science and Technology (72) Inventor: 3372 Ikebecho, Tsuzuki-ku, Yokohama, Kanagawa Prefecture Inside CBC Ings Inc. (72) Inventor Shinobu Chiba 3372 Ikebe-cho, Tsuzuki-ku, Yokohama-shi, Kanagawa Prefecture Inside CBC Ings Inc. (72) Inventor Mikio Takahashi 3372 Ikebe-cho, Tsuzuki-ku, Yokohama-shi, Kanagawa Prefecture F-term ( Reference) 4D048 AA06 AA17 AA22 AB01 AB02 AB03 BA06X BA07X BB03 BB20 4G069 AA03 AA08 AA11 BA03B BA04B BA22A BA22B BA48A BB06B CA01 CA02 CA08 CA10 CA11 CA13 CA17 DA06 EA08 FA03 FB02 4K02 AA07 CAA13CA13

Claims (11)

[Claims] 1. A photocatalyst, wherein a photocatalytic film is formed by depositing a metal material or a metal oxide material on a substrate by vapor deposition or sputtering in the presence of ions, electrons or active particles. Method of forming a film. 2. A method according to claim 1, wherein the step of irradiating the substrate with low-energy excitation rays using one or more of ions, electrons, radicals, and plasma while depositing a metal material or a metal oxide on the substrate by vapor deposition or sputtering. A method for forming a photocatalyst film, comprising forming a photocatalyst film made of a metal oxide by film formation. 3. The method for forming a photocatalytic film according to claim 2, wherein the kinetic energy of the charged particles in the excitation beam is 200 eV or less. 4. The method according to claim 1, wherein the substrate is made of plastic. 5. The method for forming a photocatalytic film according to claim 4, wherein a fluororesin or a silicone resin is used as the plastic. 6. The method for forming a photocatalytic film according to claim 4, wherein a buffer film made of a material not subjected to photocatalysis is formed on the substrate, and the photocatalytic film is formed thereon. 7. The method according to claim 6, wherein the buffer film is any one of an inorganic film, a fluororesin film, and a silicone resin film. 8. The method for forming a photocatalyst film according to claim 6, wherein the buffer film is transparent. 9. The method for forming a photocatalytic film according to claim 4, wherein the substrate is in the form of a film. 10. The method according to claim 6, wherein the substrate is any one of a polyimide resin, a polyester resin, and a hydrocarbon resin. 11. A photocatalyst sheet comprising a photocatalyst film formed on a film-like substrate by the method according to claim 1. Description: