JPH11188270A - Coating solution for forming transparent coating film having photocatalytic activity and substrate with transparent coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating compsn. capable of forming a coating film having tight adhesion to a substrate and high photocatalytic activity and excellent in transparency by low temp. treatment and to obtain a substrate with a transparent coating film. SOLUTION: Fine compound titanium oxide particles and a binder are dissolved or dispersed in water and/or an org. solvent to obtain the objective coating soln. for forming a transparent coating film. The compound titanium oxide comprises Ti and one or more elements selected from the group comprising Cu, Ag, Zn, Cd, V, Bi, Cr, Mo, Mn and Fe. The binder comprises titanium peroxide, compound titanium peroxide comprising Ti and one or more elements selected from the group comprising Cu, Ag, Zn, Cd, Al, Zr, Si, Sn, V, Nb, Sb, Bi, Cr, Mo, W, Mn and Fe and an org. high molecular compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating for forming a transparent film having a photocatalytic action on the surface of a ceramic substrate, a plastic substrate and glass for the purpose of antifouling, sterilization or deodorization. The present invention relates to a liquid, and a substrate having such a transparent film and having an antifouling, antibacterial or deodorizing function.

[0002]

BACKGROUND OF THE INVENTION Recently, products utilizing the photocatalysis of titania have attracted attention. For example, tiles having a titania film formed on the surface thereof, curtains containing titania, deodorants having titania supported on activated carbon or zeolite, etc. are commercially available and have gained reputation.

[0003] These are all intended to have an antifouling, antibacterial or deodorizing effect due to the decomposition of contaminants, microorganisms or odorous substances attached to the surface by the photocatalytic action of titania.

When the titania particles are irradiated with ultraviolet rays, electrons or holes are generated inside the titania particles, which are diffused on the surface of the particles and act as an oxidizing agent or a reducing agent. It is said to be due to action.

[0005] Such a titania film having a photocatalytic action needs to be thick in order to enhance photocatalytic activity. Further, in order for electrons or holes generated inside the particles upon light irradiation to quickly move to the surface of the film, the film needs to be dense. For this reason,
Usually, high temperature treatment during film formation promotes fusion between particles to increase the density of the film and increase the hardness of the film. However, when the processing temperature of the film is increased, the crystal structure of titania is increased. Changes from anatase type to rutile type,
There was a problem that the photocatalytic activity was reduced.

[0006] Further, such a titania film having a photocatalytic action is treated at a high temperature at the time of film formation, and thus it is difficult to form it on glass, plastic, wood, fiber, cloth or the like which does not have heat resistance. There were also problems.

[0007] Therefore, a coating solution for forming a film is prepared using titania particles that have been subjected to high temperature treatment, and this coating solution is applied on a substrate to form a film, thereby forming a cured film at a relatively low temperature. Have been tried.

However, the titania particles treated at a high temperature generally have a large particle diameter and a high refractive index, so that light scattering by the titania particles in the coating is large, and a high transparency coating cannot be obtained. there were.

The present applicant has previously developed and proposed a coating composition capable of forming a film having high photocatalytic activity and excellent transparency by low-temperature treatment in order to solve the above problems. (Japanese Patent Application No. 8-321857). However, the coatings obtained from this coating composition have not yet been satisfactory in terms of photocatalytic activity.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems associated with the prior art as described above, and has a strong adhesion to a substrate, a higher photocatalytic activity and a higher transparency. An object of the present invention is to provide a coating solution for forming a transparent film, which can form an excellent film by low-temperature treatment, and a substrate with a transparent film on which such a transparent film is formed.

[0011]

SUMMARY OF THE INVENTION A first coating liquid for forming a transparent coating according to the present invention is a coating liquid for forming a transparent coating, wherein composite titanium oxide fine particles and a binder are dissolved or dispersed in a solvent comprising water and / or an organic solvent. [A] the composite titanium oxide fine particles are Cu, Ag, Zn, Cd, V, Bi, Cr, M
composite titanium oxide fine particles comprising one or more elements selected from the group consisting of o, Mn and Fe, and Ti; and [B] the binder comprises (b-1) titanium peroxide or ( b-2) Cu, Ag, Zn, Cd, Al, Zr, Si, Sn, V,
A composite titanium peroxide composed of one or more elements selected from the group consisting of Nb, Sb, Bi, Cr, Mo, W, Mn, and Fe, Ti, and (b-3) an organic polymer A coating solution for forming a transparent film, comprising a compound.

[0012] The second coating liquid for forming a transparent coating according to the present invention is a coating liquid for forming a transparent coating, wherein the composite titanium oxide fine particles and a binder are dissolved or dispersed in a solvent comprising water and / or an organic solvent. [C] The composite titanium oxide fine particles are composed of Al, Zr, Si, Sn, Nb, Sb and W
One or more elements selected from the group consisting of:
Composite titanium oxide fine particles comprising Ti and [D] wherein the binder is (d-1) Cu, Ag, Zn, Cd, V, Bi, Cr,
One or two selected from the group consisting of Mo, Mn and Fe
It is characterized by comprising a composite titanium peroxide comprising at least one or more elements and Ti, and (d-2) an organic polymer compound.

The organic polymer compound is preferably a polysaccharide. The substrate with a transparent film according to the present invention is characterized by having a transparent film formed using the coating liquid for forming a transparent film.

[0014]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the first and second coating solutions for forming a transparent film and the substrate with a film according to the present invention will be described more specifically.

[First Coating Solution for Forming a Transparent Film] The first coating solution for forming a transparent film according to the present invention comprises [A] composite titanium oxide fine particles and titanium peroxide (b-1) or a composite. A binder [B] composed of titanium peroxide (b-2) and an organic polymer compound (b-3) is dissolved or dispersed in a solvent composed of water and / or an organic solvent.

First, the composite titanium oxide fine particles will be described. Composite titanium oxide fine particles [A] The composite titanium oxide fine particles [A] used in the present invention are C
u, Ag, Zn, Cd, V, Bi, Cr, Mo, Mn and Fe, one or more elements selected from the group consisting of
fine particles made of a composite oxide of an element (a) other than i) and the Ti element.

Such composite oxides include (1) a composite oxide in which titanium oxide and an element (a) other than Ti are chemically bonded,
(2) a solid solution of titanium oxide and an oxide of element (a) other than Ti; (3) a mixture of titanium oxide and a cluster of element (a) other than Ti; (4) an element other than titanium oxide and Ti ( It means a homogeneous mixture with the oxide of a). The cluster refers to a whisker-like crystalline oxide of the element (a) other than Ti.

Further, the composite oxide may be a mixture of the above (1) to (4), and the surface of the fine particles composed of such a composite oxide may be one of the elements (a) other than Ti. Alternatively, the composite oxide includes a structure covered with two or more kinds of oxides or a structure in which each oxide is sequentially stacked.

The composite ratio of Ti and the element (a) other than Ti in such a composite oxide is such that each oxide is made of TiO 2
As _{2, MO x, TiO 2 /} MO x ( weight ratio) 50/5
It is preferably in the range of 0 to 99.9 / 0.1. Ti
When O ₂ / MO _x exceeds 99.9 / 0.1, the effect of compounding is small, and when TiO ₂ / MO _x is less than 50/50, the amount of titanium oxide is too small and the light absorption characteristics of the composite oxide. , The chemical reactivity is poor, and the effect of the photocatalytic action aimed at by the present invention may be reduced.

The composite titanium oxide fine particles used in the present invention
[A] is particularly excellent in absorbing light having a wavelength in the range of 300 to 450 nm, and has high conductivity, chemical activity, and affinity with an organic solvent.

The average particle diameter of the composite titanium oxide fine particles [A] is 0.4 μm or less, preferably 0.005 to 0.5 μm.
A range of 2 μm is desirable. If the particles are in this range,
Light scattering by the particles is small, and a highly transparent coating film can be obtained.

The method for producing such composite titanium oxide fine particles [A] is not particularly limited, and a conventional method for producing fine particles is employed. For example, an alkali is added to a mixed aqueous solution of a titanium salt such as titanium chloride and a salt of a metal other than titanium, and the mixture is neutralized and hydrolyzed to obtain a composite hydroxide (or hydrated oxide). The composite titanium oxide fine particles can be obtained by high-temperature treatment at a temperature of about 900 ° C.

The titanium oxide alkoxide and the metal alkoxide other than titanium are hydrolyzed in a water-alcohol mixed solvent to obtain a composite hydroxide, which is then calcined to obtain composite titanium oxide fine particles. Obtainable. When composite titanium oxide fine particles are produced by such hydrolysis of alkoxide, high-purity composite titanium oxide fine particles can be obtained.

The composite titanium oxide fine particles thus obtained
[A] may be adjusted to a desired particle size by a pulverizing treatment, a classification operation, or the like, if necessary. In the above method, high-temperature treatment is performed to increase the crystallinity of the composite oxide. However, without drying the composite hydroxide obtained by the above method, a composite hydroxide dispersion (sol or hydrogel dispersion ) Can also be used to obtain composite titanium oxide fine particles having the same high crystallinity as in the case of the high-temperature treatment. Specifically, an acid, an amine, a peroxide, or the like as a deflocculant is added to the above-described dispersion, and the dispersion is heated in a pressure vessel such as an autoclave. The temperature of the hydrothermal treatment is preferably in the range of about 50 ° C. or higher and lower than the critical temperature of the solvent. By performing such a hydrothermal treatment, a monodispersed liquid of composite titanium oxide fine particles having high crystallinity can be obtained. In the present invention, this monodispersed liquid can be used as it is as a compounding material of the coating liquid without drying. At this time, when the dispersion medium is water, the solvent may be replaced with an organic solvent as needed. Further, the fine particles may be surface-treated by adding a silane coupling agent to the monodispersed liquid. By such a silane coupling treatment, the stability of the coating solution is improved,
In addition, since the dispersibility in the coating solution is also improved, the catalytic function of the transparent film is also improved.

Further, as a method for producing such composite titanium oxide fine particles, a method described in Japanese Patent Application Laid-Open No. 63-229139, filed by the present applicant, can be used.

That is, a dispersion of a mixture of a hydrate of titanium oxide and a hydrate of the above-mentioned metal oxide is prepared, and hydrogen peroxide is added thereto to form a uniform aqueous solution of the hydrate. Is heated to 60 ° C. or more, composite titanium oxide fine particles can be obtained.

Binder [B] In the present invention, (b-1)
Titanium peroxide or (b-2) composite titanium peroxide, and (b-
3) A binder [B] composed of an organic polymer compound is used.

Titanium peroxide (b-1) is usually TiO ₃ .n
It is a compound represented by H ₂ O. Such titanium peroxide (b-1) is a salt such as titanium tetrachloride, titanium hydroxide,
It can be obtained by reacting a titanium compound such as a titanium complex of titanium alkoxide or acetylacetonate with a peroxide such as hydrogen peroxide.

The composite titanium peroxide (b-2) is Ti
And Cu, Ag, Zn, Cd, Al, Zr, Si, Sn, V, Nb, Sb, B
1 selected from the group consisting of i, Cr, Mo, W, Mn and Fe
Species or two or more elements (hereinafter, elements other than titanium (b)
) And a part of Ti of the titanium peroxide (b-1) is replaced with an element (b) other than titanium.
Is replaced by

The composite titanium peroxide (b-2) is
The titanium compound can be obtained by reacting a compound such as a salt, hydroxide, alkoxide or acetylacetonate complex of an element other than titanium with a peroxide such as hydrogen peroxide. For example, when hydrogen peroxide is added to a water-alcohol solution of isopropoxytitanium and isopropoxyzirconium and then heat-treated, a composite peroxide of titanium and zirconium is obtained. Such titanium peroxide (b-1) or composite titanium peroxide (b-1-
2) is usually in a solution state.

The titanium peroxide (b-1) or the composite titanium peroxide (b-2) is used as the composite titanium oxide fine particles.
Since it has a refractive index similar to that of [A], light scattering due to the film constituents is small, and a film having excellent transparency can be formed.

In particular, when a composite peroxide of Ti, Zr and / or Si is used as the titanium peroxide or the composite titanium peroxide, the adhesion to the base material and the affinity to the organic solvent are improved. It is preferable because it greatly improves.

The above-mentioned titanium peroxide or composite titanium peroxide may be used by reacting it with an organic amine or acetylacetone. When a transparent coating is formed using a coating solution containing a peroxide as a binder as described above, the peroxide is decomposed in the heat treatment in the formation step, and the densification of the coating can be promoted. Further, when the above-mentioned titanium peroxide or composite titanium peroxide is contained as a binder, the binder itself has photocatalytic activity and conductivity, so that the photocatalytic activity is promoted, and the photocatalytic activity of the coating film is enhanced. Can be higher. Further, since the refractive index of the binder is almost the same as the refractive index of the composite titanium oxide fine particles, it is possible to form a film having high transparency and small haze. Furthermore, even if the treatment is performed at a low temperature of about 150 ° C., since the hardness of the film can be increased, it is possible to form a film having excellent adhesion to a substrate such as glass and plastic, and A thick film of about 1 μm can be easily formed with one coat.

Organic polymer compound contained in binder
As (b-3), polysaccharides such as chitosan and cellulose are preferable. Such an organic polymer compound in the binder
When (b-3) is contained, stress accompanying shrinkage of the film in the drying step at the time of film formation is alleviated, cracks of the film are prevented, and the film can be made thicker. Further, the wettability of the coating liquid to the base material is improved, and the viscosity of the coating liquid is increased, so that the workability during coating can be improved.

Preparation of Transparent Film Forming Coating Solution The transparent film forming coating solution according to the present invention is prepared by dissolving or dispersing the above composite titanium oxide fine particles and a binder in a solvent comprising water and / or an organic solvent. can do.

Examples of the organic solvent include alcohols such as methanol, ethanol, propanol, butanol, diacetone alcohol, furfuryl alcohol, ethylene glycol and hexylene glycol; esters such as methyl acetate, ethyl acetate; diethyl ether; Ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetone, methyl ethyl ketone,
Ketones such as acetylacetone and acetoacetate are exemplified. These can be used alone or in combination of two or more.

Solid content in the coating solution (composite titanium oxide fine particles
[A] and the combination of titanium peroxide (b-1) or composite titanium peroxide (b-2) in the binder)
It is preferably in the range of 40% by weight, preferably 2-30% by weight.

Further, composite titanium oxide fine particles in the coating solution
[A] and titanium peroxide (b-1) or composite titanium peroxide
(b-2) The weight ratio to (peroxide) is such that the composite titanium oxide fine particles / peroxide is 5/1 to 1/5, preferably 5/1 to 1/5.
/ 2 is desirable.

Further, the organic polymer compound (b-3)
Is contained in an amount of 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, based on the coating solution. As a method of preparing these coating liquids for forming a transparent film,
There is no particular limitation, and for example, it can be obtained by mixing the above composite titanium oxide fine particles and a binder with an appropriate solvent or dispersion medium.

[Second Transparent Film Forming Coating Solution] Next, the second transparent film forming coating solution will be described. Composite titanium oxide fine particles [C] and composite titanium peroxide (d-1)
And a binder [D] composed of an organic polymer compound (d-2) and
It is dissolved or dispersed in a solvent composed of water and / or an organic solvent.

First, the composite titanium oxide fine particles will be described. Composite titanium oxide fine particles [C] The composite titanium oxide fine particles [C] used in the present invention are A
one or more elements selected from the group consisting of l, Zr, Si, Sn, Nb, Sb and W (hereinafter, the element (c) other than Ti)
) And a Ti oxide.

Such composite oxides include (1) a composite oxide in which titanium oxide and an element (c) other than Ti are chemically bonded,
(2) a solid solution of titanium oxide and an oxide of element (c) other than Ti; (3) a mixture of titanium oxide and a cluster of element (c) other than Ti; (4) an element other than titanium oxide and Ti ( It means a homogeneous mixture with the oxide of c).

The composite oxide may be a mixture of the above (1) to (4), and the surface of the fine particles composed of such a composite oxide may be, for example, silica, silica-alumina, silica-zirconia. The structure covered with etc. is also included. Furthermore, for example, a titanium oxide, a titanium oxide / zirconium oxide composite oxide is laminated on a silica core in this order, or a titanium oxide / zirconium oxide composite oxide is deposited on a titanium oxide core.
The composite oxide having a structure in which the silica-alumina composite oxide is laminated in this order, and the surface of the titanium oxide fine particles are T
The composite oxide includes a structure coated with one or more oxides of the element (c) other than i.

The composite ratio of Ti and the element (c) other than Ti in such a composite oxide is determined by the fact that each oxide is made of TiO 2
As _{2, MO x, TiO 2 /} MO x ( weight ratio) 50/5
It is preferably in the range of 0 to 99.9 / 0.1. Ti
When O ₂ / MO _x exceeds 99.9 / 0.1, the effect of compounding is small, and when TiO ₂ / MO _x is less than 50/50, the amount of titanium oxide is too small and the light absorption of the composite oxide is small. The properties, chemical reactivity, etc. are poor, and the effect of the photocatalytic action aimed at by the present invention may be reduced.

Composite titanium oxide fine particles used in the present invention
[C] is the same as the above-mentioned composite titanium oxide fine particles [A], especially 3.
Excellent absorption of light in the wavelength range of 00 to 450 nm,
High conductivity, chemical activity and affinity with organic solvents.

The average particle size of the composite titanium oxide fine particles [C] is 0.4 μm or less, preferably 0.005 to 0.5 μm.
A range of 2 μm is desirable. If the particles are in this range,
Light scattering by the particles is small, and a highly transparent coating film can be obtained.

The method for producing such composite titanium oxide fine particles is the same as that for the composite titanium oxide fine particles [A]. Binder [D] In the present invention, a binder [D] comprising a composite titanium peroxide (d-1) and an organic polymer compound (d-2) is used for the composite titanium oxide fine particles [C]. You.

The composite titanium peroxide (d-1) is composed of Ti, Cu,
It is a peroxide of a composite metal comprising one or more elements (elements other than titanium) selected from the group consisting of Ag, Zn, Cd, V, Bi, Cr, Mo, Mn and Fe.

Such a composite titanium peroxide (d-1)
Like the composite titanium peroxide (b-2), a titanium compound, a salt of an element other than titanium, a hydroxide, a compound such as an alkoxide or an acetylacetonate complex, and a peroxide such as hydrogen peroxide. Can be obtained by reacting Such a composite titanium peroxide is used as a monomer or a polymer, and is usually in a liquid state.

Such a composite titanium peroxide (d-1) is
Since the composite titanium oxide fine particles [C] have a refractive index similar to that of the composite titanium oxide fine particles [C], when such a composite titanium peroxide (d-1) is used as a binder in a coating liquid for forming a transparent coating, the coating component Scattered light, and a film excellent in transparency can be formed.

The above-mentioned composite titanium peroxide may be used by reacting it with an organic amine or acetylacetone. When a transparent coating is formed using a coating solution containing the above-described composite titanium peroxide as a binder, the peroxide is decomposed in the heat treatment in the forming step, and the densification of the coating can be promoted. Further, when the above-mentioned titanium peroxide or composite titanium peroxide is contained as a binder, the binder itself has photocatalytic activity and conductivity, so that the photocatalytic activity is promoted, and the photocatalytic activity of the coating film is enhanced. Can be higher. Further, since the refractive index of the binder is almost the same as the refractive index of the composite titanium oxide fine particles, it is possible to form a film having high transparency and small haze. About 15
Even when treated at a low temperature of about 0 ° C., the hardness of the film can be increased, so that a film having excellent adhesion to a substrate such as glass or plastic can be formed, and about 1 μm
A thick film of about a degree can be easily formed by one coat.

Organic polymer compound contained in binder
Examples of (d-2) include the same as those described above. Preparation of Transparent Film Forming Coating Solution The transparent film forming coating solution according to the present invention is obtained by dissolving or dispersing the composite titanium oxide fine particles [C] and the binder [D] in a solvent composed of water and / or an organic solvent. Can be prepared.

Examples of the organic solvent include the same ones as described above. Solid content in coating solution (composite titanium oxide fine particles
[C] and the composite titanium peroxide (d-1) in the binder) concentration is 1 to 40% by weight, preferably 2 to 3% by weight.
It is preferably in the range of 0% by weight.

Further, composite titanium oxide fine particles in the coating solution
The weight ratio of [C] to the composite titanium peroxide (d-1) is such that the composite titanium oxide fine particles / the composite titanium peroxide are 5/1 to 1/1.
5, preferably 5/1 to 1/2.

Further, the organic polymer compound (d-2)
Is contained in an amount of 0.1 to 5.0% by weight, preferably 0.2 to 4.0% by weight, based on the coating solution. As a method of preparing these coating liquids for forming a transparent film,
There is no particular limitation, and for example, it can be obtained by mixing the above composite titanium oxide fine particles and a binder with an appropriate solvent or dispersion medium.

[Substrate with Transparent Coating] The substrate with a transparent coating according to the present invention is obtained by applying the above-mentioned first or second coating liquid for forming a transparent coating to a substrate such as glass, plastic, ceramic or fiber. Spinner method, bar coater method,
It is obtained by coating by a usual method such as a spray method, a dipping method or a flexo method, followed by drying and heat curing at 150 to 400 ° C. For the curing treatment, a method such as ultraviolet irradiation can be used in combination. The thickness of the transparent coating is about 0.1 to 10 μm, preferably 0.2 to 5 μm.
Is desirably within the range.

The substrate with a transparent film thus obtained has a transparent film having a high photocatalytic activity on its surface, and thus has an effect such as antifouling, antibacterial, antifungal and deodorizing.
Further, it has effects such as hard coat property, heat resistance, and ultraviolet ray shielding property. Further, if the substrate is transparent, a substrate with a transparent coating having excellent transparency can be obtained.

[0058]

According to the present invention, when a transparent film is formed on a substrate by using the coating solution for forming a transparent film according to the present invention, the hardness is high even when heated at a low temperature of about 150 ° C., and the compactness is excellent. A transparent coating is obtained. Therefore, a film having high photocatalytic activity can be formed on the surface of a substrate such as plastic and glass.

Further, since the refractive index of the binder is almost the same as that of the composite titanium oxide fine particles, a film having high transparency and small haze can be obtained. Moreover, since the binder itself has a photocatalytic function and is conductive, the photocatalytic ability of the composite titanium oxide fine particles is promoted, and the photocatalytic activity of the coating film is enhanced.

Further, according to the present invention, the thickness of the transparent film can be easily increased.

[0061]

Hereinafter, the present invention will be described based on examples.
The present invention is not limited to these examples.

[0062]

Example 1 Iron oxide / titanium oxide composite oxide fine particle sol
Dissolved ferric chloride 0.4g in terms of preparing Fe ₂ O ₃ of a titanium tetrachloride 99.6g in terms of TiO ₂ in pure water,
10 kg of a mixed aqueous solution was prepared. In this mixed aqueous solution,
A 28% aqueous ammonia solution at 4 ° C. was rapidly added while cooling so that the liquid temperature did not exceed 10 ° C., and the addition was stopped when the pH reached 7.5. The temperature of the coprecipitated gel of hydrated iron oxide and hydrated titanium oxide formed at this time was 9.8.
° C.

After the obtained coprecipitated gel was dehydrated and washed, 910 g of hydrogen peroxide having a H ₂ O ₂ concentration of 35% by weight and 200 g of pure water were added to 880 g of the coprecipitated gel, and heated at 80 ° C. for 3 hours. As a result, 1990 g of a yellow-orange solution (Solution A) was obtained.

To 995 g of the solution A, 3005 g of water was added, and the mixture was heated in an autoclave at 200 ° C. for 20 hours to obtain a sol in which iron oxide / titanium oxide composite oxide fine particles were dispersed.

After adding 4000 ml of methanol to the sol, adding 2 g of methyltrimethoxysilane, aging at 50 ° C. for 1 hour, removing water by solvent replacement to remove iron oxide / titanium oxide having a solid concentration of 20% by weight. 200 g of a mixed oxide fine particle-dispersed methanol sol was obtained. The average particle diameter of the composite oxide fine particles was 8 nm as measured by a transmission electron microscope photograph.

Preparation of Binder 5 g of chitosan was added to 995 g of the solution A, and the mixture was heated at 80 ° C. for 2 hours to prepare a binder.

[0067] Preparation of transparent film-forming coating liquid wherein the iron oxide-titanium oxide composite oxide fine particles to prepare a dispersion methanol sol 50g and the transparent film-forming coating liquid by mixing the above binder 100 g.

Preparation of Substrate with Transparent Coating The above coating solution was applied on a glass substrate (50 mm × 50 mm) with a spinner, preliminarily dried at 80 ° C., dried at 120 ° C., and cured by heating at 200 ° C. A substrate with a transparent coating was produced. The thickness of the coating was 1 μm, and the hardness of the coating was 6H in pencil hardness.

Measurement of Photocatalytic Activity A quartz container (150 mm long × 150 mm wide × 60 m high)
m), the substrate with the above-mentioned film was put therein, replaced with nitrogen gas, and then sealed. Then, acetaldehyde was injected so that the concentration became 50 ppm, and the distance from the surface of the film was 100 mm.
Black light (ultraviolet wavelength 365 nm,
Irradiation at an intensity of 0.6 mW / cm ² ) was performed for 1 hour. Next, the concentration of acetaldehyde remaining in the container was measured by gas chromatography, and the photocatalytic activity was evaluated based on the reduction rate of acetaldehyde. Table 1 shows the results.

[0070]

Example 2 Vanadium oxide / titanium oxide composite oxide fine
Preparation of particle sol 1.0 g of vanadium sulfate in terms of V ₂ O ₅ and TiO ₂
Then, 99.0 g of titanium tetrachloride was dissolved in pure water to prepare 10 kg of a mixed aqueous solution. To this mixed aqueous solution, a 28% aqueous ammonia solution at 4 ° C. was rapidly added while cooling so that the liquid temperature did not become 10 ° C. or higher. When the pH reached 7.7, the addition was terminated. The temperature of the coprecipitated gel of hydrated vanadium oxide and hydrated titanium oxide formed at this time was 9.5 ° C.

After the thus obtained coprecipitated gel of hydrated vanadium oxide and hydrated titanium oxide was dehydrated and washed, 910 g of 35% hydrogen peroxide solution and 920 g of pure water were added to 880 g of the coprecipitated gel.
0 g was added, followed by heating at 80 ° C. for 3 hours to obtain 1990 g of a green solution (Solution B).

3005 g of water was added to 995 g of the solution B, and the mixture was heated at 200 ° C. for 20 hours in an autoclave to obtain a sol in which vanadium oxide / titanium oxide composite oxide fine particles were dispersed.

After adding 4000 ml of methanol to the sol, adding 2 g of methyltrimethoxysilane and aging at 50 ° C. for 1 hour, water was removed by solvent replacement to remove vanadium oxide / titanium oxide having a solid concentration of 20% by weight. 200 g of a mixed oxide fine particle-dispersed methanol sol was obtained. The average particle size of the composite oxide fine particles was measured by a transmission electron microscope photograph, and was 9 nm.

Preparation of Binder 71.4 g of titanium tetrachloride and 15 g of zirconium oxychloride were dissolved in 400 g of a 5% by weight aqueous hydrochloric acid solution.
To this aqueous solution, 5% by weight of aqueous ammonia was added to obtain a hydrogel. This was filtered and washed, and 100 g of the obtained cake having a solid content of 10% by weight was diluted with pure water to form a 3% by weight suspension.
g and heated at 90 ° C. for 5 hours to obtain a liquid containing a composite peroxide of titanium and zirconium. Chitosan 3
g was added and heated at 80 ° C. for 2 hours to prepare a binder.

Preparation of Transparent Film Forming Coating Solution A transparent film forming coating solution was prepared by mixing 50 g of the above-mentioned vanadium oxide / titanium oxide composite oxide fine particle-dispersed methanol sol and 186 g of the binder described above.

Preparation of Substrate with Transparent Coating The above coating solution was applied to a glass substrate (50 mm × 50 mm) by a spinner method, preliminarily dried at 80 ° C., dried at 120 ° C., and then heat-cured at 200 ° C. Thus, a substrate with a transparent coating was produced. The thickness of the coating was 1 μm, and the hardness of the coating was 6H in pencil hardness. The photocatalytic activity of the prepared substrate with a transparent film was measured in the same manner as in Example 1.

Table 1 shows the results.

[0078]

Embodiment 3 Zirconium oxide / titanium oxide composite oxide
Preparation of fine particle sol 100 g of tetraisopropyl titanate and 11.4 g of zirconium normal propylate were diluted with 288.6 g of isopropyl alcohol. After adding 384 g of 17.5% hydrogen peroxide solution to this solution, the solution was heated at 50 ° C. for 2 hours. Further, the solution was hydrothermally treated at 80 ° C. for 1 hour to prepare a sol in which the composite oxide fine particles were dispersed. Next, isopropyl alcohol and water were evaporated by a rotary evaporator and concentrated to a solid content of 10% to prepare a zirconium oxide / titanium oxide composite oxide fine particle sol. It was 26 nm when the average particle diameter of the composite oxide fine particles was measured by a scanning electron microscope photograph.

Preparation of Transparent Film Forming Coating Solution A transparent film forming coating solution was prepared by mixing 100 g of the sol in which the composite oxide fine particles were dispersed and 100 g of the same binder as in Example 1.

Preparation of Transparent Coated Substrate The coating solution obtained above was applied to a glass substrate (50 mm × 50 mm).
After spin-coating on the top and pre-drying at 80 ° C,
C., and then heat-cured at 200.degree. C. to produce a substrate with a transparent coating. The thickness of the coating was 1 μm, and the hardness of the coating was 6H in pencil hardness. The photocatalytic activity of the prepared substrate with a transparent film was measured in the same manner as in Example 1.

Table 1 shows the results.

[0082]

Embodiment 4 Iron oxide / zirconium oxide / titanium oxide double
Preparation of mixed oxide fine particle sol 0.4 g of ferric chloride in terms of Fe ₂ O ₃ , 0.4 g of zirconium oxychloride in terms of ZrO ₂ , and TiO ₂
Then, 99.2 g of titanium tetrachloride was dissolved in pure water to prepare 10 kg of a mixed aqueous solution. A 28% aqueous ammonia solution of 4 ° C. was added to the mixed aqueous solution at a liquid temperature of 10 ° C.
Add rapidly while cooling so that it does not exceed
When the value of 7.7 reached 7.7, the addition was terminated. The temperature of the co-precipitated gel of hydrated iron oxide, hydrated zirconium and hydrated titanium oxide formed at this time was 9.6 ° C.

After dehydrating and washing the obtained coprecipitated gel, 910 g of hydrogen peroxide solution having a H ₂ O ₂ concentration of 35% by weight and 200 g of pure water were added to 880 g of the coprecipitated gel, and heated at 80 ° C. for 3 hours. As a result, 1990 g of a yellow-orange solution (Solution C) was obtained.

3005 g of water was added to 995 g of this solution C, and the mixture was heated in an autoclave at 200 ° C. for 20 hours to obtain a sol in which iron oxide / zirconium oxide / titanium oxide composite oxide fine particles were dispersed.

After adding 4000 ml of methanol to the sol, adding 2 g of methyltrimethoxysilane and aging at 50 ° C. for 1 hour, water was removed by solvent replacement to obtain an iron oxide / zirconium oxide having a solid content of 20% by weight. -200 g of titanium oxide composite oxide fine particle-dispersed methanol sol was obtained. The average particle size of the composite oxide fine particles was 8.5 nm as measured by a transmission electron micrograph.

Preparation of Binder 5 g of chitosan was added to 995 g of Solution C, and the mixture was heated at 80 ° C. for 2 hours to prepare a binder.

Preparation of Coating Solution for Transparent Film Formation 50 g of methanol sol in which the composite oxide fine particles were dispersed
And 100 g of the binder were mixed to prepare a coating solution for forming a transparent film.

Preparation of Substrate with Transparent Coating The coating solution obtained above was coated on a glass substrate (50 mm × 50 mm).
After spin-coating on the top and pre-drying at 80 ° C,
C., and then heat-cured at 200.degree. C. to produce a substrate with a transparent coating. The thickness of the coating was 1 μm, and the hardness of the coating was 6H in pencil hardness. The photocatalytic activity of the prepared substrate with a transparent film was measured in the same manner as in Example 1.

Table 1 shows the results.

[0090]

Example 5 Preparation of Binder 100 g of titanium tetrachloride in terms of TiO ₂ was dissolved in pure water to prepare a 10 kg aqueous solution. 4 ° C
Of 28% aqueous ammonia was rapidly added while cooling so that the temperature of the solution did not exceed 10 ° C., and the pH was adjusted to 7.7.
When it became, the addition was terminated. The temperature of the hydrated titanium oxide gel formed at this time was 9.5 ° C.

After the obtained gel was dehydrated and washed, 880 g of the coprecipitated gel was mixed with a hydrogen peroxide solution having a H ₂ O ₂ concentration of 35% by weight.
0 g and 200 g of pure water were added, and the mixture was heated at 80 ° C. for 3 hours to obtain 1990 g of a yellow-orange solution (Solution D). 5 g of chitosan was added to 995 g of the solution D, and the mixture was heated at 80 ° C. for 2 hours to prepare a binder.

Preparation of Transparent Film Forming Coating Solution A transparent film forming coating solution was prepared by mixing 50 g of the composite oxide fine particle-dispersed methanol sol prepared in Example 1 and 100 g of the binder described above.

Preparation of Substrate with Transparent Coating The coating solution obtained above was coated on a glass substrate (50 mm × 50 mm).
After spin-coating on the top and pre-drying at 80 ° C,
C., and then heat-cured at 200.degree. C. to produce a substrate with a transparent coating. The thickness of the coating was 1 μm, and the hardness of the coating was 6H in pencil hardness. The photocatalytic activity of the prepared substrate with a transparent film was measured in the same manner as in Example 1.

Table 1 shows the results.

[0095]

[Comparative Example 1] Zirconium oxide / titanium oxide composite oxide
Preparation of Fine Particle Sol In the same manner as in Example 3, composite oxide fine particles having a solid content of 10% were prepared. The average particle diameter of the composite oxide fine particles is
When measured by a transmission electron micrograph, 25 nm
Met.

Preparation of Binder 100 g of tetraisopropyl titanate was dissolved in 288.6 g of isopropyl alcohol, and 21 g of acetylacetone was added to this solution to obtain a titanium acetylacetonate solution. In this titanium acetylacetonate solution,
10 g of a hydrogen peroxide solution having an H ₂ O ₂ concentration of 28% by weight was added, and 7
The mixture was heated at 0 ° C. for 1 hour to obtain a liquid containing titanium peroxide. This solution was mixed with an aqueous solution in which 10 g of chitosan was dissolved in 100 g of pure water, and heated at 80 ° C. for 2 hours to prepare a binder.

Preparation of coating liquid for forming transparent film 100 g of the above composite titanium oxide sol (solid content: 10% by weight)
And 153 g of a binder were mixed to prepare a coating solution for forming a transparent film.

Preparation of Transparent Coating Substrate This coating liquid for forming a transparent coating was applied on a glass substrate by a spinner, preliminarily dried at 80 ° C., dried at 120 ° C., and then heated and cured at 200 ° C. A substrate with a transparent coating having a thickness of 1 μm was prepared. The pencil hardness of the coating is 4
H. The photocatalytic activity of the prepared substrate with a transparent film was measured in the same manner as in Example 1.

Table 1 shows the results.

[0100]

[Table 1]

Claims (4)

[Claims] 1. A coating solution for forming a transparent film, wherein a composite titanium oxide fine particle and a binder are dissolved or dispersed in a solvent comprising water and / or an organic solvent, wherein [A]
The composite titanium oxide fine particles are composed of Cu, Ag, Zn, Cd, V, B
Composite titanium oxide fine particles comprising one or more elements selected from the group consisting of i, Cr, Mo, Mn and Fe, and Ti, and [B] the binder comprises (b-1) titanium oxide Oxide or (b-2) Cu, Ag, Zn, Cd, Al, Zr, Si, Sn, V, Nb, Sb,
A composite titanium peroxide comprising one or more elements selected from the group consisting of Bi, Cr, Mo, W, Mn and Fe, Ti, and (b-3) an organic polymer compound A coating solution for forming a transparent film, comprising: 2. A coating solution for forming a transparent film, wherein the composite titanium oxide fine particles and a binder are dissolved or dispersed in a solvent composed of water and / or an organic solvent, wherein [C]
The composite titanium oxide fine particles are composed of Al, Zr, Si, Sn, Nb, S
Composite titanium oxide fine particles comprising one or more elements selected from the group consisting of b and W, and Ti, and [D] the binder comprises (d-1) Cu, Ag, Zn, Cd, V, Bi, Cr, Mo, Mn and Fe
One or more elements selected from the group consisting of:
A coating liquid for forming a transparent film, comprising: a composite titanium peroxide composed of Ti; and (d-2) an organic polymer compound. 3. The coating liquid for forming a transparent film according to claim 1, wherein the organic polymer compound is a polysaccharide. 4. A substrate with a transparent coating, comprising a transparent coating formed by using the coating liquid for forming a transparent coating according to claim 1.