JP2003170060A - Surface-treated product having photocatalytic function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-treated product having a photocatalytic function not developing an interference color of light even if a primer film and a photocatalyst film are formed on the surface of a substrate and capable of keeping the design effect of the substrate without damaging the picture, pattern, hue, character or the like applied to the surface of the substrate itself. <P>SOLUTION: In the surface-treated product having the primer film formed by coating the surface of the substrate with a substrate treatment agent containing perhydropolysilazane and the photocatalyst film laminated on the primer film, the thicknesses of both of the primer film and the photocatalyst film are controlled to 0.01-0.5 μm. <P>COPYRIGHT: (C)2003,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment comprising a base film formed by applying a base treatment agent containing perhydropolysilazane on the surface of a substrate, and a photocatalytic film laminated on the base film. It is about products.

[0002]

2. Description of the Related Art A photocatalyst represented by titanium oxide is intended for removing NOx and SOx on articles having an antifouling property, antibacterial property, deodorizing property, hydrophilic property, antifogging effect and the like, and on highways and the like. Application to environmental pollution prevention applications has been studied, and some of them have already been put into practical use as indoor and outdoor articles. As a method of fixing a photocatalyst such as titanium oxide to the substrate surface of these articles, for example, after applying and drying a sol liquid such as titanium alkoxide or titanium chelate,
A sol-gel method of performing a heat treatment, a binder method of dispersing titanium oxide fine particles in an inorganic resin or a fluororesin called a binder, and applying the dispersion are generally used.

However, when the substrate on which the photocatalyst is fixed is a substrate having relatively poor weather resistance, such as a polyethylene resin, a polypropylene resin, or a polystyrene resin, if the photocatalyst is directly fixed on the surface of the substrate, the oxidizing action of the photocatalyst causes The substrate is decomposed, and as a result, the fixed photocatalyst may fall off the surface of the substrate. In order to solve this problem, Japanese Patent Application Laid-Open No. 2000-17229 discloses that silicon alkoxide and SiO ₂ are formed by using a sol-gel method.
Silica (SiO ₂ ) from the mixture with fine particles to the surface of the substrate
A method has been proposed in which a base film for a photocatalyst film mainly composed of is formed and a photocatalytic film is formed on the surface. However, the base film for photocatalytic film formed using silicon alkoxide requires a long time for the curing reaction at the time of film formation, and since it is formed using the sol-gel method, the volume of the film at the time of the reaction is large. There is a problem that the rate of decrease is large, cracks are generated in the film, the film becomes cloudy, and the organic functional groups contained in the silicon alkoxide remain in the formed film, so that they are contained in the film. There is also a problem that the organic functional group thus obtained is decomposed by the photocatalyst, causing deterioration of the film.

[0004] In order to solve these problems,
Japanese Patent Application Laid-Open No. 2000-189795 proposes a method in which perhydropolysilazane is used as a starting material instead of forming a silica film (undercoat) using silicon alkoxide. That is, a method of applying perhydropolysilazane to the surface of a substrate, then applying a photocatalyst coating solution to an upper layer thereof, and irradiating ultraviolet rays to oxidize the perhydropolysilazane to obtain a silica film (undercoat), and A method has been proposed in which heated water molecules are allowed to react with the surface of perhydropolysilazane applied to a silica film to form a silica film, and a photocatalyst coating solution is applied on the silica film. According to these methods, by using perhydropolysilazane, a silica film can be obtained in a shorter time than silicon alkoxide, and perhydropolysilazane has less volume shrinkage when forming a silica film. Therefore, a film with few defects can be obtained.

However, when two types of films, a silica film and a photocatalytic film, are formed on the surface of the substrate, interference colors of light appear on the surface of the substrate on which the film is formed, and a pattern attached to the surface of the substrate itself, Another problem arises in that the pattern, color tone, characters and the like are impaired, and the design property of the substrate cannot be maintained. In addition, these films may be made of a relatively simple resin such as a polyethylene resin, a polypropylene resin, a polystyrene resin, a polycarbonate resin, a phthalic acid resin, an epoxy resin, or a resin mixture of one or more selected from these modified resins. When applied to a non-weather resistant substrate having poor weather resistance, there is a problem that the surface of the substrate deteriorates due to the influence of ultraviolet rays, and the silica film and the photocatalytic film are relatively easily peeled off from the surface of the substrate.

[0006]

The inventors of the present invention have conducted intensive studies to solve such problems, and as a result, have found that a substrate formed by applying a substrate treating agent containing perhydropolysilazane to the surface of a substrate is formed. In a surface treatment product having a film and a photocatalytic film laminated on the undercoat,
The thickness of the undercoating film and the photocatalytic film are both 0.01 to 0.1.
By controlling it within the range of 5 μm, it is possible to solve the problem of interference color of light, and further, it is possible to solve the problem of peeling of the film by adding an ultraviolet absorber to the undercoating agent. Heading, the present invention has been completed.

[0007] Accordingly, an object of the present invention is to provide a base film and a photocatalyst film on the surface of a substrate, without the appearance of interference colors of light, and the pattern, pattern,
An object of the present invention is to provide a surface-treated product having a photocatalytic function capable of maintaining the design of a base without impairing color tone, characters, and the like. Another object of the present invention is to provide an undercoating film and a photocatalytic film on the surface of a substrate, in addition to the absence of light interference color, and the peeling of the film when applied to a non-weatherproof substrate. It is an object of the present invention to provide a surface-treated product having a photocatalytic function capable of preventing as much as possible.

[0008]

That is, the present invention relates to a base coat formed by applying a base treatment agent containing perhydropolysilazane to the surface of a substrate, and a photocatalytic coat laminated on the base coat. In the surface treatment product having
The film thickness of both the undercoat film and the photocatalytic film is 0.01 to 0.1.
It is a surface-treated product having a photocatalytic function, which is controlled within a range of 5 μm.

Further, the present invention provides an undercoating agent containing a perhydropolysilazane, which contains an inorganic ultraviolet absorber, and a base coat formed by applying the base treatment agent, and a base coat formed on the base coat. A surface treatment product having a photocatalytic function, wherein both the thickness of the undercoat film and the thickness of the photocatalyst film are controlled within the range of 0.01 to 0.5 μm. It is.

The surface treated product having a photocatalytic function according to the present invention has an undercoat formed on the surface of a substrate and a photocatalytic film laminated on the undercoat. The base coat is formed for the purpose of protecting the base so that the base is not deteriorated by the function of the photocatalyst included in the photocatalyst coat.

In the present invention, an undercoating agent containing perhydropolysilazane is applied to form the undercoating. Perhydropolysilazane is formed only from Si—N bonds and Si—H bonds, and includes C—C bonds, C—O
When it is oxidized by oxygen or moisture in the air without an organic functional group consisting of a bond or the like, it becomes a SiO ₂ silicon compound consisting only of a Si—O bond. That is, since the film formed of perhydropolysilazane does not contain organic substances such as organic functional groups such as CC bonds and CO bonds that are susceptible to decomposition by the photocatalytic function, it may be deteriorated by the photocatalyst. No undercoating can be formed.
In addition, since perhydropolysilazane has a small volume change rate at the time of conversion to a SiO ₂ silicon compound, it is possible to form an undercoat film with few cracks and few defects when forming a film.

Further, the temperature for converting the perhydropolysilazane contained in the undercoating agent into the SiO ₂ silicon compound and curing it at room temperature is possible. It is not limited to a heat-resistant substrate. Further, the perhydropolysilazane contained in the undercoating agent of the present invention can form a transparent film when hydrogen H or nitrogen N is oxidized and converted into a silicon compound. That is, even if a base coat is formed on the surface of the base, the pattern, pattern, color tone, aesthetic appearance, and the like attached to the surface of the base are not impaired.

In addition to the above-mentioned perhydropolysilazane, the undercoating agent used in the present invention includes aromatic hydrocarbons having no hydroxyl group such as toluene, xylene and benzene, n-hexane, octane, nonane and decane. And organic solvents such as non-hydroxyl-containing aliphatic hydrocarbons, such as cyclopentane, cyclohexane, and methylcyclopentane.
As for these proportions in the undercoating agent, the perhydropolysilazane usually has a solid concentration of 0.1 to 0.1%.
The content is in the range of 5% by mass, preferably 0.1 to 3% by mass, and the organic solvent having no hydroxyl group is usually 95 to 99.1.
%, Preferably 97 to 99.1% by mass. If the concentration of perhydropolysilazane at this time is less than 0.1% by mass, the film thickness after curing becomes thin, and it becomes necessary to repeatedly coat and the like, which lowers the efficiency.
If the amount is more than 10% by mass, the curing time is shortened and the workability is deteriorated. In addition, as a specific example of the surface treatment agent containing perhydropolysilazane, Clariant Japan Co., Ltd. product name: N-
P110, manufactured by Clariant Japan Co., Ltd .: NP
140 and the like.

In the surface-treated product having a photocatalytic function of the present invention, the substrate used may be a weather-resistant substrate having relatively excellent weather resistance, a non-weather-resistant substrate having relatively poor weather resistance, or a mixture thereof. Or a substrate made of a laminate. As a weather-resistant substrate having relatively excellent weather resistance,
Examples thereof include inorganic substances such as metals, glass, and stones, simple substances such as fluororesins, polyurethane resins, acrylic resins, and polyester resins, and resin mixtures of one or more selected from modified resins thereof. Further, as the non-weather resistant substrate having relatively poor weather resistance, one or two kinds selected from a single substance such as a polyethylene resin, a polypropylene resin, a polystyrene resin, a polycarbonate resin, a phthalic acid resin, an epoxy resin or a modified resin thereof are used. Examples of the resin mixture comprising the above, or those in which a layer made of a poorly weatherable material such as a pigment, a paint, or a film is formed on the surface of the above-mentioned weatherable substrate or non-weatherproof substrate, Can be.

When the substrate is a non-weatherproof substrate having relatively poor weather resistance, it is necessary to add an ultraviolet absorber to the undercoating agent applied to the substrate surface. This is because when a non-weatherproof substrate is used, the surface of the substrate is deteriorated due to the influence of ultraviolet rays, and the undercoat or photocatalytic film formed on the surface is relatively easily formed due to the deterioration of the surface of the substrate. In order to solve the problem of peeling, the ultraviolet light transmitted through the photocatalytic film formed on the substrate surface by forming the undercoat film containing the ultraviolet absorbent is absorbed by the ultraviolet absorbent contained in the undercoat film. Thus, even if the substrate on which the base film and the photocatalytic film surface are formed is a non-weatherproof substrate, deterioration of the substrate surface due to ultraviolet rays can be prevented.

With respect to the ultraviolet absorber used above,
Preferably, it is an inorganic ultraviolet absorber. When an organic UV absorber is used, the organic UV absorber contained in the undercoat is decomposed by the photocatalytic function of the photocatalytic film formed on the undercoat, causing deterioration of the undercoat. As a cause, if an inorganic ultraviolet absorber is used, it will not be decomposed by the photocatalytic function.
Specific examples of such an inorganic ultraviolet absorber include zinc oxide, rutile-type titanium oxide, chromium oxide, and the like. However, when an undercoat is formed, an oxide capable of obtaining a transparent undercoat can be obtained. Zinc and rutile type titanium oxide are preferred. In addition, zinc oxide is more preferable from the viewpoint of decomposition of organic substances and transparency.

The ratio of the inorganic ultraviolet absorber added to the undercoating agent in the present invention varies depending on the inorganic ultraviolet absorber used. For example, when the ultraviolet absorber is zinc oxide, The amount is usually adjusted to 0.1 to 10% by mass, preferably 0.1 to 5% by mass based on the undercoating agent. If the proportion of this zinc oxide is less than 0.1% by mass, the effect of absorbing ultraviolet light cannot be sufficiently obtained, and if it exceeds 10% by mass, the strength of the film is reduced due to the large number of particles, and the underlying film is destroyed. And the adhesion to the substrate or the photocatalyst layer may be reduced. In addition, as a specific example of the surface treatment agent containing the inorganic ultraviolet absorber as described above, Clariant Japan
(Trade name) UP-110 or the like manufactured by K.K.

In the present invention, the thickness of the undercoat formed by applying the above-mentioned undercoating agent on the surface of the substrate is 0.01 μm.
≧ 0.5 μm, preferably ≧ 0.01 μm
2 μm or less, more preferably 0.01 μm or more and 0.1 μm
It is controlled within the range of less than m. As described above, a transparent film can be obtained by applying the undercoating agent containing perhydropolysilazane in the present invention. However, as the thickness of the transparent undercoat formed on the surface of the substrate is increased, the reflected light on the surface of the undercoat and the thickness of the undercoat are reduced to a thickness corresponding to half the wavelength of visible light. The reflected light on the bottom surface causes interference. The appearance of the interference color impairs the design, pattern, color tone, characters, and the like provided on the surface of the base, and thus the design of the base itself cannot be maintained. In the case of the undercoat film formed on the surface of the substrate according to the present invention, if the thickness exceeds 0.5 μm, the interference color of light clearly appears on the undercoat film. If the film thickness is 0.2 μm or less, the thickness of the film is １ ／ of the wavelength in the visible region or less, so that the design of the substrate is clearly maintained regardless of the shading of the pattern applied to the substrate. Can be. On the other hand, if the thickness of the undercoat is less than 0.01 μm, the effect of protecting the substrate cannot be sufficiently obtained, and it is difficult to form a continuous undercoat.

The photocatalyst film of the present invention is laminated on a base film formed on the surface of a substrate. Examples of the photocatalyst contained in the photocatalyst film include titanium oxide, zinc oxide, tungsten oxide, iron oxide, zinc sulfide, cadmium sulfide, strontium titanate, etc., and have high photocatalytic activity and chemical resistance. Titanium oxide is preferred because of its excellent properties.

The method of laminating the photocatalyst film containing the above photocatalyst on the undercoat film of the present invention varies depending on the type of the photocatalyst to be contained and the heat resistance temperature of the substrate. In the case of, the titanium oxide fine particles are used in an inorganic substance such as silicon oxide, titanium phosphate, and titanium peroxide, or in a resin that is less deteriorated by a photocatalyst such as a silicone resin or a fluorine resin, or a sol solution such as a silicon alkoxide. And a sol-gel method in which a sol solution of titanium alkoxide, titanium chelate or the like is applied and fired to form a film made of titanium oxide. In the above, it is preferable to use a binder that can be cured at room temperature, such as silicon oxide, titanium phosphate, or titanium peroxide, although it depends on the curing temperature of the binder. The temperature at which the photocatalytic film formed by this method is usually formed is from room temperature to about 200 ° C., and thus the substrate on which the photocatalytic film is formed is not particularly limited to a heat-resistant substrate.

The photocatalyst film of the present invention formed by the method described above does not contain an organic substance such as a C—C bond or a C—O bond which is easily decomposed by the function of the photocatalyst. Without,
Since the photocatalyst film is a transparent film, even if this photocatalyst film is laminated on the underlayer film formed on the surface of the substrate, the pattern, pattern, color tone, characters, etc. attached to the surface of the substrate may be damaged. Absent.

In the present invention, the photocatalytic film laminated on the undercoat formed on the substrate surface has a thickness of 0.01 μm.
It is controlled within a range from m to 0.5 μm, preferably from 0.01 μm to 0.2 μm. The photocatalytic film formed by applying the photocatalytic film forming agent becomes a transparent film, but when the thickness of the transparent photocatalytic film laminated on the undercoat film formed on the surface of the substrate is increased, the wavelength of visible light is reduced. At a film thickness corresponding to １ ／, the reflected light on the surface of the photocatalytic film and the reflected light on the bottom surface of the base film interfere with each other. The appearance of the interference color impairs the design, pattern, color tone, characters, and the like provided on the surface of the base, and thus the design of the base itself cannot be maintained. In the photocatalytic film according to the present invention, if the film thickness exceeds 0.5 μm, the interference color of light clearly appears on the photocatalytic film. If the film thickness is 0.2 μm or less, the thickness of the film is １ ／ of the wavelength in the visible region or less. Can be maintained. On the other hand, if the thickness of the photocatalyst film is less than 0.01 μm, the effect of the photocatalyst cannot be sufficiently obtained, and it is difficult to form a continuous undercoat film.

The method for applying the undercoating agent to the surface of the substrate and the method for applying the photocatalytic film-forming agent to the undercoating in the present invention are not particularly limited, and include spray coating, roll coating, dip coating, spin coating, and the like. A general method such as brush coating can be employed. The thickness of each of the above-mentioned films is at most 0.5 μm, and the moldability of the substrate is maintained, so that a pre-coating method of painting before processing and assembling the product can also be adopted. In addition, the undercoating film and the photocatalytic film in the present invention can be formed at room temperature to about 200 ° C., and the time required for the film to cure is about several tens of seconds to several minutes. , Post-coat after product assembly, existing buildings,
On-site painting for indoor and outdoor equipment is also possible.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below based on examples and comparative examples.

Examples 1 to 5 and Comparative Examples 1 to 3 A coated steel plate (150 mm × 70 mm × 0.4 m) coated with a polyester coating so as to form a 30 μm coating film was used as a substrate.
m), the substrate surface was degreased with ethanol as a pretreatment, and then dried at room temperature for 1 hour. In order to form a base coat on the surface of the pretreated substrate, Cl-Ant Japan Co., Ltd. product name: N-P110 (1% by weight of perhydropolysilazane) is applied by a bar coater, and then 110 ° C. for 10 minutes. It dried and each formed the film thickness shown in Table 1.

Next, a commercial product of TKC-304 (trade name: TKC-304) having a titanium oxide concentration of 5.3% by weight, a titanium phosphate of 3.8% by weight (in terms of anhydrate), and water. The solid content concentration of 9.1% by weight) was diluted 6 times with pure water to prepare a 1.5% by weight solid content aqueous solution. (Takelite Co., Ltd., trade name: TAIKELITE A1225, a composition containing 25% by weight of alkyl ammonium sulfate) was added so as to have a solid concentration of 0.2% by weight to obtain a photocatalytic film forming paint. This photocatalyst film forming paint was applied to the upper layer of the base film formed on the surface of the substrate using a bar coater, and dried at 110 ° C. for 30 minutes to form a photocatalyst film having a film thickness shown in Table 1. To 5 and Comparative Examples 1 to 3 were obtained.

Example 6 A polycarbonate resin plate (150 mm × 70 mm × 2 mm) was used as a substrate, and as a pretreatment, the surface of the substrate was degreased with ethanol, and then dried at room temperature for 1 hour. In order to form a base coat on the surface of the pretreated base, a UV-absorbent-containing trade name: UP110 (1% by weight of perhydropolysilazane, 1% by weight of zinc oxide) manufactured by Clariant Japan K.K. After coating with a coater, the coating was dried at 25 ° C. for 30 minutes to form a film having the thickness shown in Table 1.

Next, using a coating material for forming a photocatalyst film prepared in the same manner as in Examples 1 to 5 and Comparative Examples 1 to 3, a bar coater was applied to the upper layer of the undercoat film formed on the substrate surface. Then, it was dried at 110 ° C. for 30 minutes to form a photocatalytic film having a film thickness shown in Table 1, and a test piece of Example 6 was obtained.

Comparative Example 4 Table 1 was prepared in the same manner as in Examples 1 to 5 and Comparative Examples 1 to 3, except that a polycarbonate resin plate (150 mm × 70 mm × 2 mm) was used as the base.
Was formed on the surface of the substrate to obtain a test piece of Comparative Example 4.

[Confirmation of Interference Color] Each test piece obtained by the above-mentioned method was visually observed under a fluorescent lamp in the room to confirm the appearance of interference color. し な い: No expression at all, ：: Slightly blue depending on visual direction May present, but no problem,
Δ: The color was slightly evaluated depending on the visual direction, and X: clearly expressed (showed a rainbow color).
Table 1 shows the results.

[Accelerated weathering test] Each test piece obtained by the above method was exposed for 3000 hours using a sunshine weather meter based on JIS K 5400, and then the deterioration of the substrate was confirmed. : Slight chalking, ×: chalking and chalking were evaluated. Table 1 shows the results.

[Confirmation of Gas Decomposition Performance] For each of the test pieces of Examples 1 to 6 and Comparative Examples 1 to 4 obtained by the above method, a photocatalyst film was formed and stored in a dark place overnight. After the visual evaluation in the accelerated weather resistance test, the storage in a dark place overnight was performed on the NO ₂ gas decomposition performance test.

The above-mentioned NO ₂ gas decomposition performance test was carried out in a 2 liter test chamber, a 2 liter buffer tank,
The test was performed using a test device having a total volume of 9 liters and a cushion tank having a volume of 5 liters. In addition, a circulation pump is connected to the test chamber and each tank via a hose, and when NO ₂ gas for evaluation is charged into the test apparatus, the test chamber and each tank are moved by the circulation pump. It has a structure that gas can circulate inside. Further, this test apparatus is provided with two 15 W black lights so that a test piece installed in the test chamber can be irradiated with ultraviolet rays. In addition, this test apparatus was installed in a dark room.

Each test piece was set in the test chamber, and the air in the test apparatus was evacuated to 76 cmHg by a vacuum pump. Then, the atmosphere was filled with 10 ppm NO ₂ gas, and the pressure was adjusted to atmospheric pressure. NO ₂ gas was circulated in a circulating amount. The black light for irradiating the test piece with ultraviolet light was turned on 30 minutes before the start of irradiation, but until the start of ultraviolet light irradiation, light was shielded by a shielding plate so that the test piece was not irradiated with ultraviolet light. Cut off. After leaving for 2 hours from the filling of the NO ₂ gas, the shielding plate was removed, and ultraviolet irradiation was started on each test piece. At this time, the amount of ultraviolet light irradiated on the surface of the test piece was set to 1 mW / cm ² .

For the measurement of the concentration of NO ₂ gas in the test chamber, gas was sampled from a sampling valve and a gas detection tube was used. The measurement of the NO ₂ gas concentration was performed every hour after gas filling, and was continued until 8 hours after gas filling. In addition, the concentration measurement at the lapse of 2 hours after gas filling was performed before the start of ultraviolet irradiation on the test piece. In order to measure the amount of NO ₂ gas spontaneously reduced, an empty test apparatus was used which was the same as the above test apparatus, except that no UV irradiation was performed, and which had the same environment as above and had no test piece installed. Under such conditions, the measurement of NO ₂ gas concentration was performed at the same timing as above in an empty test room where no test piece was installed.

In the NO ₂ gas decomposition performance test performed as described above, the measured value of the NO ₂ gas concentration (X) in the test room in which the test piece was placed 6 hours after the irradiation with the ultraviolet light was compared with the test room in which the test piece was not placed. By comparing with the measured NO ₂ gas concentration value (Y), if X is smaller than Y, it can be determined that the test piece has decomposed and removed the gas. ○: X is 1/2 or less of Y, Δ:
X is smaller than Y but larger than 1/2 of Y. X: X and Y
Was not changed. Table 1 shows the results.

[0037]

[Table 1]

With respect to the appearance of interference color in each test piece,
As shown in the comparative example, the undercoating or photocatalytic coating was 0.3
μm, a slight interference color was confirmed, which was 0.5 μm.
Above m, an interference color was clearly developed. On the other hand, in Examples 1 to 6, no interference color was confirmed, and particularly in Examples 1 and 2, no interference color was confirmed.

In the accelerated weathering test, when the undercoat was not formed (Comparative Example 3), the polyester coating applied to the substrate deteriorated, and a part of the photocatalytic coating dropped off. In Comparative Example 4 in which the undercoat did not contain the ultraviolet absorber, the polycarbonate resin as the substrate was slightly whitened, whereas in Example 5 in which the underlayer contained the ultraviolet absorber, the substrate was good without whitening. .

Regarding the NO ₂ gas decomposition performance, after the formation of the photocatalytic film, NO ₂ gas decomposition was confirmed in all the test pieces. However, after the accelerated weathering test, the amount of NO ₂ gas decomposed in Comparative Example 3, in which the photocatalyst film had fallen off, was slightly reduced.

[0041]

According to the surface-treated product of the present invention, even if an undercoating film and a photocatalytic film are formed on the surface of the substrate, no interference color of light is exhibited, and the pattern, pattern, It is a surface-treated product having a photocatalytic function that can maintain the design of the base without impairing the color tone, characters, and the like. Further, even when the substrate to which the surface-treated product having a photocatalytic function according to the present invention is applied is a non-weather-resistant substrate having relatively poor weather resistance, the coating is peeled off by adding an inorganic UV absorber to the undercoating agent. Can be prevented as much as possible. The surface-treated product having a photocatalytic function of the present invention has excellent durability formed from a film that is not easily deteriorated, so that it has antifouling properties, antibacterial properties, deodorizing properties, hydrophilic properties,
It is useful in the development of new articles having the effect of preventing fogging and the like, and in promoting environmental pollution prevention measures for removing NOx and SOx on expressways and the like.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C09D 5/00 C23C 28/04 B01D 53/36 J 183/16 102D C23C 28/04 ZAB F-term (reference) 4D048 AA06 AB03 BA06X BA07X BA41X EA01 4G069 AA03 AA08 BA04B BA48A CA01 CA12 CA13 CA17 CD10 DA06 EB15X EB15Y ED02 EE10 FA01 FA03 FB23 4J038 DM021 HA166 HA216 HA356 KA04 KA08 KA12 NA05 NA19 PA07 PC02 A02A02 A02 A02 BC

Claims (5)

[Claims] 1. A surface-treated product having a base film formed by applying a base treatment agent containing perhydropolysilazane to the surface of a substrate, and a photocatalytic film laminated on the base film. And a photocatalytic film having a photocatalytic function, wherein both the thickness of the photocatalytic film and the thickness of the photocatalytic film are controlled within the range of 0.01 to 0.5 μm. 2. The film thickness of both the undercoat film and the photocatalyst film is controlled within the range of 0.01 to 0.2 μm.
A surface-treated product having a photocatalytic function according to item 1. 3. The surface-treated product having a photocatalytic function according to claim 1, wherein the undercoating agent contains an inorganic ultraviolet absorber. 4. The surface-treated product having a photocatalytic function according to claim 1, wherein the substrate is a weather-resistant substrate having relatively excellent weather resistance. 5. The surface-treated product having a photocatalytic function according to claim 3, wherein the substrate is a non-weather-resistant substrate having relatively poor weather resistance.