JPH10128110A - Photocatalyst composition and its forming agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exhibit excellent catalytic activity under sunlight and an indoor illuminating light by preparing a forming agent for a photocatalyst compsn. of a compsn. wherein an aqueous titanium oxide sol and an aqueous soln. and/or an aqueous dispersion of a titanium oxide precursor compd. are mixed. SOLUTION: A photocatalyst compsn. forming agent used for such environmental clarifications as stainproofing, deodorizing, anti-fungus and detoxification of hazardous substances is prepd. of a mixed compsn. wherein an aqueous titanium oxide sol and an aqueous soln. and/or an aqueous dispersion of a titanium oxide precursor compd, are mixed. As the aqueous titanium oxide sol, an aqueous titanium oxide sol prepd. by dispersing titanium oxide particles with a mean particle diameter of 1-300nm is pref. On the other hand, as the titanium oxide precursor compd., all the titanium oxide precursor compd. that can stably exist in water can be used and peroxotitanic acid and/or partial condensate of peroxotitanic acid are pref. used as they are easily handled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a photocatalyst composition and a forming agent therefor.

[0002]

2. Description of the Related Art When a semiconductor particle absorbs light having an energy exceeding a band gap, an electron-hole pair forms an exciton. When this exciton causes a charge transfer or a surface capture reaction in the course of its structural relaxation, it causes a reduction reaction and an oxidation reaction to proceed, respectively, thereby converting light energy and chemical energy. The photocatalytic reaction using such a semiconductor has attracted attention as a method for directly producing fuel from solar energy, but recently, there has been a movement toward application to environmental purification [Chemical and Industrial 48,167 (1)
995)].

As a photocatalyst, titanium oxide has been reported [Nature 237, 37 (1972)]. Titanium oxide itself is harmless, and in the photocatalytic reaction, sunlight can be used as a light source, and a strong oxidizing power is developed on a solid surface to oxidize many organic substances to their final state. Therefore, it is considered that it functions effectively also for the purpose of environmental purification such as antifouling, deodorization, antibacterial and detoxification of harmful substances, and various concrete proposals have been made so far.
In addition, the clean surface of titanium oxide, which is inherently hydrophilic, is always exposed by an antifouling effect [Nikka, 8 (198
6)], it is known that hydrophilicity is maintained and contributes to the development of anti-fogging property.

For example, it has been reported that in a system in which titanium oxide particles are dispersed in water, trichlorethylene is decomposed into carbon dioxide, chloride ions, and the like [J. Catal.
82, 404 (1983)]. However, in such a system, it is difficult to separate and recover the dispersed titanium oxide, so that it has not been developed for industrial use.

Various techniques for immobilizing titanium oxide have been proposed. For example, it has been reported that a titanium oxide coating prepared by applying a titanium oxide sol that has been pulverized in water to a substrate, drying and then heat-treating it at about 500 ° C. has exhibited a catalytic effect equivalent to particles having high catalytic activity. [Che
m. Lett. 723 (1994), JP-A-6-27
No. 8241]. However, the titanium oxide film formed in this manner has a temporary film-like form, but has a disadvantage that it is brittle and is easily broken to lose its catalytic effect.

Attempts have also been made to support titanium oxide particles on silica gel [Bull. Chem. So
c. Jpn. 61, 359 (1988); Cera
m. Soc. Jpn. 102, 702 (1994)].
However, the catalyst concentration was substantially reduced, and was not practical.

Further, an antibacterial tile manufactured by adding titanium oxide particles or fixing the titanium oxide particles with a glaze has also been proposed [International Publication WO 94/94].
No. 11092]. However, such a method is also not practical because the catalyst activity is low because the surface of the catalyst particle is widely shielded.

In order to compensate for the low activity, a sanitary ware having improved antibacterial properties by further supporting silver ions etc. [Nikkei Materials & Technology (144) 57 (199)
4) and industrial materials 43, 96 (1995)], but their antifouling properties were poor.

On the other hand, attempts have been made to provide a titanium oxide film on a substrate by using a method of forming a metal oxide film by a sol-gel method. For example, it has been reported that trichlorethylene in water can be decomposed by using a quartz plate or a quartz tube coated with titanium oxide [Japanese Patent Application Laid-Open No. 7-100378,
Journal of Japan Society on Water Environment 17,324 (1994)]. However, these titanium oxide coating layers require several times of film-forming
It can express photocatalytic activity only after repeating about 0 times.
There is little industrial use.

Further, a CVD film [J. Chem. Soc. , Farada
y Trans. 1, 81, 3117 (1985) "and an attempt to express high catalytic activity equivalent to particles [J. Photochem. Photobiol, A,
50, 283 (1989)] and the announcement of photodegradation of cigarette moss [Nikkan Kogyo Shimbun January 5, 1995]. [Recent developments in photocatalysis, 12
(1994)], and industrial use was difficult.

[0011] As described above, although titanium oxide is capable of exhibiting the function of environmental purification by using inexhaustible sunlight, its industrial use has not been advanced much.

[0012] Titanium oxide generally has two crystal phases, anatase type and rutile type, and both phases are known to exhibit photocatalytic activity. Generally, the anatase type is considered to have a higher effect, but the activation factor is not limited to the crystal system and cannot be determined unconditionally.

The energy band structure of semiconductor fine particles such as titanium oxide has a quantum size effect, and the light absorption wavelength range also depends on the particle diameter. Commercially available titanium oxide particles for photocatalysts exhibited high catalytic activity by controlling the particle size, active surface, and the like. However, as described above, there was a situation where an effective immobilization method could not be found.

On the other hand, when a titanium oxide film is provided on a substrate such as glass by a sol-gel method or sputtering, an anatase type phase is usually obtained. When observing the UV spectrum of these anatase type titanium oxide films, it is reported that they hardly interact with light near 400 nm [J. Mater. Sci. 23, 2259 (19
88), Bull. Chem. Soc. Jpn. 67,
843 (1994)]. Therefore, energy required for excitation was not obtained from sunlight, and almost no catalytic activity was observed.

The anatase type obtained by the sol-gel method is
When calcined at 000 ° C., a dislocation to a rutile type phase occurs [J. M
ater. Sci. 28, 2353 (1993)]. Further, a rutile-type phase can be obtained even when calcined at 650 ° C. using a sol prepared from an alcohol solution of titanium alkoxide and diethanolamine [molten salts 31, 158 (19)
88)].

Although these rutile types exhibit cloudiness,
Because of strong interaction with light near 400 nm, it was expected to exhibit strong activity even in sunlight, but in fact, these films also hardly exhibited a catalytic effect. This is thought to be because the rutile-type film is oriented on the (110) plane having a small catalytic activity [Chemical Industry, 1988, Apr.
82, Chem. Lett. , 1994, 855].

As described above, the film formation method by the sol-gel method, etc., which was expected to be effective as a method for immobilizing titanium oxide, was used. However, the anatase type does not absorb sunlight, and the rutile type does not. Conventionally, such a titanium oxide film cannot be effectively used under sunlight.

[0018]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photocatalyst composition which exhibits excellent catalytic activity under sunlight or indoor lighting.

Another object of the present invention is to provide a photocatalyst composition-forming agent capable of easily fixing titanium oxide and producing a practical photocatalyst composition.

[0020]

According to the present invention, there is provided a photocatalyst composition forming agent obtained by mixing an aqueous titanium oxide sol and an aqueous solution and / or aqueous dispersion of a titanium oxide precursor compound.
And a photocatalyst composition formed using the photocatalyst composition forming agent.

Generally, a powder composed of fine particles is an aggregate of a plurality of particles that are strongly condensed, so that many wasteful surface characteristics are required and handling is difficult. It has been known that titanium oxide particles are similarly pulverized and dispersed in water under a specific auxiliary agent to form a stable aqueous titanium oxide sol. It was also widely marketed and easily available.

In the present invention, a water-soluble titanium oxide precursor compound which exists stably even in water and can be converted to titanium oxide by heat treatment is used. Therefore, it is suitable for use as an aqueous coating agent, which has recently become popular.

The aqueous titanium oxide sol of the present invention includes all sols in which water is used as a dispersion medium and in which titanium oxide particles are peptized.

As the titanium oxide particles, both crystalline and amorphous such as anatase and rutile can be used. The preparation of such sols is known and can be easily manufactured. For example, metatitanic acid generated by heating and hydrolyzing an aqueous solution of titanium sulfate or titanium chloride is neutralized with aqueous ammonia, and precipitated hydrous titanium oxide is filtered, washed, and dehydrated to obtain an aggregate of titanium oxide particles. . When this aggregate is peptized under the action of nitric acid, hydrochloric acid, or aqueous ammonia, an aqueous titanium oxide sol is obtained.

In the present invention, a sol obtained by dispersing an aggregate in water under strong shear stress without using an acid or an alkali may be used. Further, the aqueous titanium oxide sol is also commercially available as a titania sol and can be easily obtained.

Aqueous titanium oxide sols can also be prepared by peptizing commercial titanium oxide particles under the action of acids or alkalis or dispersing them in water under strong shear stress. Sols prepared may also be used.

The aqueous titanium oxide sol has an average particle size of 1 to 3.
It is preferably an aqueous titanium oxide sol in which 00 nm titanium oxide particles are dispersed. The titanium oxide particles constitute a photocatalyst composition. If the average particle size is smaller than 1 nm, the wavelength range of the interacting light becomes smaller, and the solar energy becomes inactive. If it is larger than 300 nm, it becomes difficult to obtain high activity. In particular, the thickness is preferably 1 to 100 nm.

The average particle size in the present invention means the average particle size of a mixture of primary particles and aggregated particles.

The titanium oxide precursor compound in the present invention is used as an aqueous solution and / or aqueous dispersion.

As the titanium oxide precursor compound in the present invention, any titanium oxide precursor compound that can stably exist even in water can be used. For example, peroxotitanic acid, a partial condensate of peroxotitanic acid, titanium lactate, titanium triethanolaminate and the like can be mentioned. Because of easy handling, peroxotitanic acid and / or a partial condensate of peroxotitanic acid are preferably used.

The peroxotitanic acid and the partial condensate of peroxotitanic acid can be obtained by the method described in JP-A-62-252319. For example, an aqueous solution of peroxotitanic acid can be prepared by mixing and stirring the alkoxide of titanium and aqueous hydrogen peroxide while cooling, and then removing the liberated alcohol and oxides thereof. By subjecting such an aqueous solution to heat treatment at about 90 ° C., a solution and / or dispersion containing a polymer in which peroxotitanic acid is partially condensed can be obtained.

An aqueous solution of peroxotitanic acid can also be obtained by adding a hydrogen peroxide solution to a slurry of titanium oxide hydrate prepared by hydrolyzing titanium chloride, titanium alkoxide, or the like, and mixing, stirring, and dissolving it. can get.

The photocatalyst composition molding agent of the present invention is produced by mixing the aqueous titanium oxide sol and the aqueous solution and / or dispersion of the titanium oxide precursor compound.

Since water is a common solvent, no special operation is required, and a mixed solution can be produced by simple mixing.

The mixing of the two can be easily performed by performing a treatment such as adjusting the pH. In addition, by gradually adding the other while stirring one, it is possible to mix without causing inconvenience such as gelation even when the pH or concentration is greatly different. Further, depending on the combination, a mixed solution can be produced without inconvenience by mixing both at once and stirring for 1 to 2 minutes.

Usually, the pH of the aqueous solution and / or dispersion of peroxotitanic acid or the like also depends on the degree of polymerization,
It is in the range of 5-10. Mixing of such an aqueous solution and / or dispersion with an aqueous titanium oxide sol having a pH of 5 or more does not require any special operation, and can be easily performed to produce a stable mixed solution. The mixed solution thus obtained is suitable as a molding agent for a photocatalyst composition of the present invention, and a tough and highly active photocatalyst composition can be produced.

On the other hand, the mixing of an aqueous titanium oxide sol having a pH of less than 5 with an aqueous solution and / or dispersion of peroxotitanic acid or the like may rapidly increase the viscosity in the initial stage. However, even in such a case, the viscosity of the photocatalyst composition of the present invention can be produced by reducing the viscosity thixotropically by performing a treatment such as continuing stirring or applying a strong shear stress.

Other components can be added to the photocatalyst composition forming agent of the present invention. The addition of surfactants, defoamers, viscosity modifiers, and the like is generally performed for the purpose of improving moldability and is also effective in the present invention.

Alcohols such as methanol, ethanol and propanol; polyhydric alcohols such as ethylene glycol, propylene glycol, hexylene glycol and glycerin; glycol derivatives such as ethylene glycol monoethyl ether and ethylene glycol monomethyl ether acetate; Acetone, ketones such as methyl ethyl ketone, ethyl acetate, esters such as methyl benzoate, ethers such as tetrahydrofuran and dioxane,
Amides such as dimethylformamide and dimethylacetamide, amines such as dimethylamine and triethanolamine, acids, alkalis, diacetone alcohol, dimethylsulfoxide, tetramethylsulfone, nitrobenzene, and polyethylene glycol can be added as required.

The photocatalyst composition of the present invention comprises titanium oxide particles (first component) formed from an aqueous titanium oxide sol and titanium oxide (second component) formed from a precursor compound of titanium oxide. . With such a configuration, high catalytic activity and excellent shape retention can be obtained.

The photocatalyst composition of the present invention is obtained by fixing the first component having high catalytic activity with the second component, and complements each other to exhibit high catalytic activity, form stability and durability.

In the present invention, the form of the “composition” is not particularly limited as long as it is composed of the first component and the second component.

Since the action site of the photocatalyst is the surface as described above, the particulate form is most effective, but it is difficult to handle the particles not only in the reaction field but also after the reaction. On the other hand, the use efficiency of the surface is low in the bulk block form. Therefore, the film form is most effective in terms of moldability, handleability, utilization efficiency, and the like.

In the case of a film form, the thinner the film thickness, the higher the utilization efficiency. However, from the viewpoint of moldability, the film thickness is 5 nm.
It is preferable that it is above. Further, since the use efficiency is not increased even if the thickness is increased, the film thickness is preferably 100 μm or less.

A film made of the photocatalyst composition of the present invention can be formed by applying the photocatalyst composition-forming agent of the present invention on a substrate, drying and heat-treating.

The coating method includes spray coating, dip coating, spin coating, screen printing, flexographic printing and the like.

The use of the photocatalyst composition-forming agent of the present invention facilitates the formation of a thin film, and the resulting thin film has high catalytic activity.
Also, because a transparent or translucent film can be easily formed,
Light energy can be effectively captured.

The transparent film can be prepared by controlling the particle diameter of the titanium oxide particles of the first component, the pH of the aqueous titanium oxide sol, the film forming process, and the like, and keeping the average particle diameter at 100 nm or less.

Such a transparent film can be applied to a molded article made of a transparent material, and can provide a new function without impairing the appearance and expression of the substrate. As the transparent material, glass is particularly preferable.

The titanium oxide particles of the first component are excited by absorbing light from sunlight or the like, and contribute to the development of photocatalytic activity. The titanium oxide particles in the present invention exist in a shape close to the primary particles and / or in a lightly aggregated shape, and realize high catalytic activity.

The titanium oxide particles of the first component are preferably crystalline. In particular, at least 6 of the titanium oxide particles
Preferably, 0% is of the anatase type.

In the titanium oxide particles of the first component, 40%
May be contained within a range not exceeding the following. Since the rutile-type crystal is excited even by light having lower energy than the anatase type, it is expected that the exciton formed in the rutile phase acts on the anatase phase, thereby making the photocatalyst composition of the present invention more active. You.

The titanium oxide of the second component functions as a binder for fixing the titanium oxide particles of the first component and maintaining the form, and also contributes to the development of a photocatalytic effect.

Normally, titanium oxide in the second component is considered to have almost no catalytic action, similarly to a thin film formed by the sol-gel method. However, in the present invention,
Part of the light energy absorbed by the micro-dispersed titanium oxide particles of the first component is transmitted to the titanium oxide of the second component, and it is determined that this becomes the excitation energy and expresses the catalytic activity. .

The titanium oxide particles as the first component constituting the photocatalyst composition of the present invention preferably have an average particle diameter of 1 to 300 nm. If it is smaller than 1 nm, the wavelength range of the interacting light becomes smaller, and the solar energy becomes inactive. On the other hand, when it is larger than 300 nm, it is difficult to obtain a molded article of the tough photocatalyst composition.

The content of the titanium oxide particles of the first component is preferably 0.5 to 98% by weight based on the photocatalyst composition. At 0.5% by weight or more, limited light energy can be effectively taken in. At 98% by weight or less, particles are strongly fixed, and both high photoactivity and durability are realized.

The content of the titanium oxide as the second component is 2% with respect to the photocatalyst composition since excellent shape retention can be obtained.
It is preferred that the content be at least 10% by weight.

In addition to the photocatalyst composition of the present invention,
Metals such as Pd and Pt, V (IV), Mn (III), F
e (III), Ni (II), Mo (V), Ru (III), Rh
Metal ions such as (III), Re (V) and Os (III), zinc oxide, aluminum oxide, antimony oxide, silver oxide, silicon oxide, zirconium oxide, tin oxide, cerium oxide, tungsten oxide, iron oxide, copper oxide And various materials depending on the purpose, such as metal oxides such as strontium titanate and barium titanate.

The photocatalyst composition of the present invention oxidizes many organic substances to the final stage, and exhibits antibacterial, antifouling, odorproof, antifogging properties and the like. Since the photocatalyst composition of the present invention formed into a film can be applied to substrates having various shapes, various products can be provided with antibacterial, antifouling, odorproof, and antifogging properties.

The glass, ceramics, tile, cement, concrete, etc., on the surface of which the photocatalyst composition of the present invention is applied, are used for windows, mirrors, walls, roofs, floors, ceilings, interior materials and the like. Since it is possible to prevent adhesion of dirt and generation of algae, it is also effective to use it on the light receiving surface of a solar battery or a solar water heater. Further, it is also effective to apply it to the surface of glass beads, balloons and the like and install it in water or on the water surface to purify water.

[0061]

The photocatalyst composition of the present invention is excited by light energy obtained in a general living environment such as sunlight and exhibits high catalytic activity. As a light energy source, it is also effective for light emitted from a fluorescent lamp which is a general indoor lighting lamp. It is also effective against light from a black light, a filament lamp, a xenon lamp, a mercury lamp, and the like.

The photocatalyst composition of the present invention functionally combines the capture of light energy with the catalytic activity, and exhibits a highly efficient photocatalytic action.

In order for the catalyst to exhibit its function, a)
Light energy is absorbed, b) excitons are formed by the absorbed energy, and c) excitons move to a reaction field to exhibit their catalytic function. Titanium oxide is currently considered to be the most practical and excellent photocatalyst.

Further, since the wavelength of light having energy corresponding to the band gap is about 400 nm, the titanium oxide fine particles absorb sufficient excitation energy from sunlight, and the formed excitons move to the surface. To exert a catalytic action.

The titanium oxide particles, which are the first component of the photocatalyst composition of the present invention, are immobilized without impairing the photoactivity possessed by the titanium oxide particles. Demonstrate.

On the other hand, the titanium oxide as the second component constituting the photocatalyst composition of the present invention has a function of fixing the titanium oxide particles as the first component at the position and the form in which the titanium oxide particles are to be used. Moreover, the second component, titanium oxide, exhibits high activity even in the form of a thin film from which the catalytic activity could not be effectively brought out conventionally.

This is because the titanium oxide particles of the first component interacted with the titanium oxide of the second component in the thin film and activated. That is, the exciton in the above-mentioned route c) moves to the particle / membrane interface and acts on the second component titanium oxide in the film to form a new exciton. Such excitons move to the film surface, and exhibit high catalytic activity.

[0068]

【Example】

Example 1 While stirring 1 liter of cold water, 20 g of titanium tetrachloride which had been cooled in advance was added little by little. Next, a predetermined amount of 29% aqueous ammonia was added to neutralize the mixture, and the mixture was allowed to stand at room temperature, whereby precipitation of titanium oxide hydrate occurred. The precipitate was taken out by filtration, washed well with water, and dispersed in pure water while irradiating ultrasonic waves to obtain 200 g of a dispersion having a titanium oxide concentration of 2% by weight. 30
28.1 g of an aqueous solution of hydrogen peroxide, stirred at 70 ° C. for 3 hours, transferred to a pressure-resistant container, and treated at 95 ° C. for 2 days to obtain an aqueous solution of peroxopolytitanic acid having a titanium oxide concentration of 1.72% by weight. (A) was obtained.

In 10 g of (A), pH 10, average particle size 1
3.19 g of titania sol (a) (manufactured by Taki Kagaku Co., Ltd.) having a thickness of 0 nm and a titanium oxide concentration of 15.1% by weight (all listed in the catalog) were added, mixed and stirred, and a titanium oxide film forming agent ( 1) was obtained.

This (1) was spin-coated on a commercially available float glass, dried at 100 ° C., and then baked at 500 ° C. for 10 minutes, whereby the titanium oxide matrix formed from (A) was formed from (a). Titanium oxide particles (average particle size 2
(35-35 nm) were uniformly arranged, and a glass with a transparent titanium oxide film having a thickness of 110 nm was obtained.

(Embodiment 2) Instead of (a) of Embodiment 1,
A titanium oxide film was formed in the same manner as in Example 1 except that 1.6 g of titania sol (b) having a pH of 1.5, an average particle diameter of 7 nm, and a titanium oxide concentration of 30% by weight (all values described in the catalog) was used. Agent (2) was obtained.

This (2) was spin-coated on a commercially available float glass in the same manner as in Example 1 to obtain a glass having a thickness of 150 nm and a fogged glass-like glass with a titanium oxide film.

Example 3 Titanium isopropoxide was added to 2
To 80 g of isopropanol solution containing 8 g, 40 g of isopropanol solution containing 7 g of water were added and mixed,
After stirring and standing at room temperature, precipitation of titanium oxide hydrate occurred. After thoroughly washing the precipitate, the precipitate was dispersed in water while irradiating with ultrasonic waves to obtain 200 g of a dispersion having a titanium oxide concentration of 1.9% by weight. To this, 26.5 g of 30% hydrogen peroxide solution was added, stirred at 70 ° C. for 3 hours, transferred to a pressure-resistant container, and treated at 95 ° C. for 2 days to obtain a peroxopolytitanium having a titanium oxide concentration of 1.66% by weight. Acid solution (B)
I got

A titanium oxide film forming agent (3) was obtained in the same manner as in Example 1 except that 12.4 g of (B) was used instead of (A) of Example 1. Then, in the same manner as in Example 1, the titanium oxide particles (average particle diameter: 25 to 35 nm) formed from (a) are uniformly arranged in the titanium oxide matrix formed from (B), and the film thickness is 100 n.
m of glass with a transparent titanium oxide film was obtained.

Example 4 An isopropanol solution containing 7.2 g of water in a solution of 25.6 g of titanium isopropoxide, 3.3 g of zirconium normal propoxide and 100 g of isopropanol containing a small amount of 1-propanol After adding 40 g and mixing and stirring,
Upon standing at room temperature, a white precipitate formed. After thoroughly washing the precipitate, the precipitate was dispersed in water while being irradiated with ultrasonic waves to obtain 200 g of a dispersion having a solid content of 2.1% by weight.
To this, 28.3 g of 30% hydrogen peroxide solution was added, and 70 ° C.
After stirring for 3 hours at, the mixture was transferred to a pressure vessel and treated at 95 ° C for 2 days to obtain an aqueous solution (C) of zirconium-containing peroxotitanic acid having a solid concentration of 1.85% by weight.

To 15 g of this (C), titania sol (c) (manufactured by Ishihara Sangyo Co., Ltd.) having a pH of 11.5, an average particle diameter of 20 nm, and a titanium oxide concentration of 35% by weight (all listed in the catalog) was added. 8 g was added, mixed and stirred to obtain a titanium oxide film forming agent (4).

In the same manner as in Example 1 except that (4) was used instead of (1) in Example 1, the titanium oxide matrix formed from (C) was formed from (c) in the titanium oxide matrix formed from (C). A glass with a transparent titanium oxide film containing zirconium and having a thickness of 130 nm was obtained in which titanium oxide particles (average particle diameter: 50 to 60 nm) were uniformly arranged.

Example 5 To 150 g of a solution of isopropanol containing 22.7 g of titanium isopropoxide and 5.3 g of tetrapropoxysilane was added 50 g of an isopropanol solution containing 9 g of water, followed by mixing and stirring. Upon standing at room temperature, a white precipitate formed. After thoroughly washing the precipitate, the precipitate was dispersed in water while irradiating ultrasonic waves to obtain 200 g of a dispersion having a solid content of 2.3% by weight. 35% of 30% hydrogen peroxide solution was added to this,
After stirring for 3 hours at, the mixture was transferred to a pressure vessel and treated at 95 ° C for 2 days to obtain an aqueous solution (D) of silicon-containing peroxotitanic acid having a solid content of 1.98% by weight.

The 12.9 g of (D) was added to the 0.4 of (a).
5 g is added, mixed and stirred, and a titanium oxide film forming agent (5)
I got

This (5) is spin-coated on a commercially available float glass, dried at 100 ° C., and baked at 650 ° C.
A glass with a transparent titanium oxide film having a thickness of 25 nm was obtained.

Example 6 0.3 g of (a) was added to 15 g of (A), mixed and stirred to obtain a titanium oxide film forming agent (6).

A glass with a transparent titanium oxide film having a thickness of 30 nm was obtained in the same manner as in Example 5, except that (6) was used in place of (5) in Example 5.

(Example 7) To 15 g of (B), 0.58 g of (a) was added, mixed and stirred to obtain a titanium oxide film forming agent (7).

A glass with a transparent titanium oxide film having a thickness of 30 nm was obtained in the same manner as in Example 5, except that (7) was used instead of (5) in Example 5.

(Comparative Example 1) Instead of (1) in Example 1,
A glass with a transparent titanium oxide film having a thickness of 100 nm was obtained in the same manner as in Example 1 except that (A) was used as it was.

(Comparative Example 2) Instead of (A) in Comparative Example 1,
A glass with a transparent titanium oxide film having a thickness of 110 nm was obtained in the same manner as in Comparative Example 1 except that (B) of Example 3 was used as it was.

(Comparative Example 3) Instead of (A) in Comparative Example 1,
A zirconium-containing glass with a transparent titanium oxide film having a thickness of 100 nm was obtained in the same manner as in Comparative Example 1 except that (C) of Example 4 was used as it was.

Comparative Example 4 A commercially available float glass without a titanium oxide film was prepared.

The antifouling properties and photocatalytic activity of the glasses of Examples 1 to 4 and Comparative Examples 1 to 4 were examined and are shown in Table 1.

The antifouling properties were evaluated with a 5% ethanol solution of a commercially available water-soluble dye, exposed to sunlight for 6 hours from 10:00 to 16:00, and evaluated based on the contaminant removal rate determined by the following equation.

Contaminant removal rate (%) = (ΔE ₁ −ΔE ₂ )
/ ΔE ₁ × 100, where ΔE ₁ indicates the color difference of the contaminant mark glass with respect to the film-coated glass, and ΔE ₂ indicates the color difference between the contaminant mark glass and the film-coated glass after exposing the contaminant mark glass to sunlight for 6 hours. .

The photocatalytic activity was evaluated from the decomposition rate of acetaldehyde. The measurement was determined by filling a predetermined amount of acetaldehyde in a closed container and measuring the concentration after irradiation with black light for 30 minutes.

Further, Examples 1, 3 to 7 and Comparative Examples 1 to
The contact angle of water was measured for the glass No. 4 and shown in Table 2. The measurement was performed using a contact angle meter manufactured by Kyowa Interface Chemical Co., Ltd. after irradiating the test piece left at room temperature for one month with black light for one hour.

As is clear from Table 1, the glass with the film comprising the photocatalyst composition of the present invention had a high contaminant removal rate and photocatalytic activity, and had excellent antifouling, deodorizing and air purifying performance. . Further, as shown in Table 2, the film-coated glass comprising the photocatalyst composition of the present invention exhibited a highly hydrophilic surface and also had excellent antifogging properties.

In addition to the above evaluations, the antibacterial properties, adhesion to the substrate, strength, and durability were also evaluated. As a result, the glasses of Examples 1 to 7 had sufficient performance without any practical problems. It was confirmed that it had excellent performance.

[0096]

[Table 1]

[0097]

[Table 2]

[0098]

According to the photocatalyst composition-forming agent of the present invention, titanium oxide particles can be easily fixed, and a high activity and practical photocatalyst composition can be produced. Further, the production of a transparent film is easy, and processing into various shapes is possible. Further, the obtained composition has high adhesion to a substrate, and is excellent in strength, durability and the like.

The photocatalyst composition of the present invention has excellent antifouling, deodorizing, antifogging, antibacterial, and durability properties under sunlight or indoor lighting.

Claims (5)

[Claims] 1. A photocatalyst composition forming agent comprising a mixture of an aqueous titanium oxide sol and an aqueous solution and / or aqueous dispersion of a titanium oxide precursor compound. 2. The photocatalyst composition-forming agent according to claim 1, wherein the titanium oxide precursor compound is peroxotitanic acid and / or a partial condensate of peroxotitanic acid. 3. A photocatalyst composition formed using the photocatalyst composition forming agent according to claim 1. 4. The photocatalyst composition according to claim 3, wherein said photocatalyst composition is in the form of a film. 5. A glass article with a photocatalyst composition formed by applying the photocatalyst composition-forming agent according to claim 1 on a glass substrate.