JP2003171578A - Coating liquid and photocatalyst functional product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating liquid easily recovering hydrophilicity by light irradiation even when it is polluted by a lipophilic substance and capable of forming a film having excellent mechanical strengths and to provide a photocatalyst functional product obtained by use of it. <P>SOLUTION: The coating liquid contains a ceramic, a non-metallic inorganic material other than the ceramic (silica, aluminum oxide, aluminum hydroxide, aluminosilicate, alkali earth metal oxide, alkali earth metal hydroxide, calcium phosphate, molecular sieves, activated carbon or hydroxide or amorphous oxide of a metal element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, Ag, Au, Zn, Cd, Ga, In, Tl, Ge, Sn, Pb, Bi, La, and Ce), a dispersing medium and a carboxylic acid-based compound. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating liquid and a photocatalyst functional product. This coating liquid is used for imparting hydrophilicity to various materials.

[0002]

2. Description of the Related Art Various coating liquids have been reported so far. Particularly in recent years, attention has been focused on a method of making the surface of various materials hydrophilic by a photocatalyst and a coating liquid used at that time. Here, "to make the catalyst catalytically hydrophilic" means that the catalyst in the film on the surface of the material is activated by light irradiation to make the film hydrophilic by itself or a low hydrophilic substance ( Lipophilic substances, etc.) to restore the hydrophilicity of the membrane, or both. As a material for forming such a film, a titanium oxide coating liquid for photocatalyst is commercially available. However, a film obtained from a commercially available titanium oxide coating liquid for photocatalyst has a hydrophilic property to some extent and exhibits an antifogging effect and a self-cleaning effect when exposed to sunlight, but the film is contaminated with lipophilic substances. Once it spreads over the entire surface, there is a problem that it takes a long time to restore hydrophilicity, and improvement has been demanded.

Further, since the outdoor side walls and signs may be exposed to wind and rain and snowfall, and the wave-dissipating blocks and the like may be exposed to waves during stormy weather, the films formed on these surfaces are not only hydrophilic but also hydrophilic. It was necessary to have sufficient mechanical strength.

[0004]

DISCLOSURE OF THE INVENTION The present invention can easily recover hydrophilicity by irradiation with light even if it is contaminated with a lipophilic substance,
An object of the present invention is to provide a photocatalytic functional product having a film having excellent mechanical strength, a coating liquid capable of forming such a film, and a photocatalytic functional product using the coating liquid.

[0005]

Means for Solving the Problems As a result of studying a method for forming a film having enhanced mechanical strength without impairing hydrophilicity, the present inventors have found that a coating liquid containing a certain non-metal inorganic material and an organic substance is used. Is a film that easily recovers hydrophilicity by light irradiation even if it is contaminated with a lipophilic substance.
Moreover, they have found that a material having excellent mechanical strength can be obtained, and have completed the present invention.

That is, the present invention provides a coating solution containing ceramics, a non-metal inorganic material other than the ceramics, a dispersion medium and a carboxylic acid compound.

The present invention also provides a photocatalyst functional product obtained by forming a film on the surface of a substrate using the above coating liquid.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The coating liquid of the present invention contains ceramics, a non-metal inorganic material other than the ceramics, a dispersion medium, and a carboxylic acid compound.

The ceramic contained in the coating liquid is a non-metal inorganic material which is a constituent of the film and can exhibit photocatalytic activity when exposed to light such as visible light and ultraviolet light when formed into a film. Well, for example, Ti, Z
r, Hf, V, Nb, Ta, Cr, Mo, W, Mn, T
c, Re, Fe, Co, Ni, Ru, Rh, Pd, O
s, Ir, Pt, Cu, Ag, Au, Zn, Cd, G
a, In, Tl, Ge, Sn, Pb, Bi, La, Ce
Examples include oxides, nitrides, sulfides, oxynitrides, oxysulfides, and the like of one or more metal elements such as.
Above all, it is recommended to use an oxide of Ti, W, or Nb, which exhibits high catalytic activity upon irradiation with light, and anatase-type titanium oxide is particularly preferable. This ceramic is preferably particles having an average particle diameter of 500 nm or less,
Furthermore, it is preferable that the particles are 200 nm or less, and particularly 100 nm or less. Ceramics have an average particle size of 5
When the particles are larger than 00 nm, when stored for a long time,
There may be a problem that the ceramics settle. Further, it is preferable that this ceramic is crystalline, because a film that exhibits photocatalytic hydrophilicity is easily obtained.

The above anatase type titanium oxide is, for example,
Titanium trichloride [TiCl ₃ ], titanium tetrachloride [TiC
l ₄ ], titanium sulfate [Ti (SO ₄ ) ₂ · mH ₂ O, 0 ≦ m
≦ 20], titanium oxysulfate [TiOSO ₄ · nH ₂ O,
0 ≦ n ≦ 20], titanium compound such as titanium oxychloride [TiOCl ₂ ] and sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonia, hydrazine, hydroxylamine, monoethanolamine, acyclic amine The compound, a base such as a cycloaliphatic amine compound, is reacted at pH 2 to 7, preferably pH 3 to 5, the resulting product is mixed with a base such as ammonia, and after aging, the aged product is washed, A method of drying and firing, or a mixed solution of a titanium compound such as titanium oxysulfate and hydrogen peroxide, was mixed with an amount of ammonia in excess of the amount required to convert the titanium compound into titanium hydroxide and reacted. After that, the solid product obtained by solid-liquid separation of this product can be washed, dried, and calcined at 300 ° C. to 500 ° C. Wear. The titanium oxide may be, if necessary, a compound showing solid acidity such as tungsten oxide, niobium oxide, iron oxide, nickel oxide or a solid such as lanthanum oxide, cerium oxide and zinc oxide. A basic compound or a compound such as bismuth oxide or indium oxide may be supported.

When tungsten oxide (WO ₃ ) is used as the ceramic contained in the coating liquid, the tungsten oxide can be obtained by, for example, a method of firing a tungsten compound such as ammonium metatungstate. The firing may be performed under the condition that the tungsten compound can be changed to tungsten oxide, and can be performed in the air at 250 ° C. to 600 ° C., for example. Further, niobium oxide (Nb ₂ O ₅ ) can be obtained, for example, by baking a niobium compound such as niobium hydrogen oxalate or by dissolving a niobium alkoxide such as niobium pentaethoxide or niobium pentaisopropoxide in an alcohol. It can be obtained by a method in which an acidic solution consisting of an inorganic acid and an alcohol is mixed with the solution and concentrated to obtain a viscous solution, which is then calcined.

Here, the coating liquid in which anatase type titanium oxide, tungsten oxide or niobium oxide, which exhibits high catalytic activity upon irradiation with light, is a dispersoid has been described in detail. As the dispersoid, the above-mentioned titanium oxide, tungsten oxide or oxide is used. Other than niobium, for example, zinc oxide (Z
nO), zinc sulfide (ZnS), tin oxide (SnO ₂ ), etc., coating liquids containing ceramics, such as a non-metallic inorganic material and a carboxylic acid-based compound, are also sustained. It can be used as a coating liquid capable of forming a film having hydrophilicity and having high mechanical strength.

The non-metal inorganic material contained in the coating liquid is other than the above-mentioned ceramics, for example, amorphous silica, silica such as silica sol, amorphous alumina, aluminum (hydr) oxide such as alumina sol. Aluminosilicates such as zeolites, kaolinite, magnesium oxide, calcium oxide, strontium oxide,
Alkaline earth metal (hydr) oxides such as barium oxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide and barium hydroxide, calcium phosphate, molecular sieves or activated carbon. In addition, this non-metal inorganic material is Ti, Zr, Hf, V, Nb, Ta, C.
r, Mo, W, Mn, Tc, Re, Fe, Co, Ni,
Ru, Rh, Pd, Os, Ir, Pt, Cu, Ag, A
u, Zn, Cd, Ga, In, Tl, Ge, Sn, P
It may be a hydroxide of a metal element such as b, Bi, La or Ce, or an amorphous oxide of these metal elements. These can be used alone or in combination of two or more. Since these non-metal inorganic materials tend to have a large specific surface area when dried, the contact area between the ceramics and the non-metal inorganic materials becomes large, and each bond is strengthened. Presumed to be present. The amount of the non-metal inorganic material is usually 0.01 mol times or more, preferably 0.05 mol times or more with respect to the ceramic in the coating liquid. The larger the amount of the non-metal inorganic material, the higher the mechanical strength when formed into a film.
On the other hand, when the amount of the non-metallic inorganic material is too large, the mechanical strength is improved, but the photocatalytic activity may be decreased.
It is preferably not more than 2 times, more preferably not more than 2 times.

Examples of the carboxylic acid compound contained in the coating liquid include monocarboxylic acids such as formic acid, acetic acid and propionic acid, dicarboxylic acids such as oxalic acid, glutaric acid, succinic acid, malonic acid, maleic acid and adipic acid. Tricarboxylic acids such as citric acid, ammonium acetate, ammonium oxalate, ammonium hydrogen oxalate, ammonium citrate, ammonium carboxylates such as ammonium hydrogen citrate, lithium oxalate, lithium hydrogen oxalate, sodium oxalate, sodium hydrogen oxalate, sodium oxalate, potassium oxalate Group IIa metal (alkali metal) salts of carboxylic acids, such as potassium hydrogen oxalate, magnesium oxalate, calcium oxalate, strontium oxalate, barium oxalate II
Group a metal (alkaline earth metal) salts, Group IIIa metal salts of carboxylic acids such as yttrium oxalate, vanadium oxalate, niobium oxalate, Group Va metal salts of carboxylic acids such as tantalum oxalate, chromium oxalate, molybdenum oxalate, oxalic acid Group VIa metal salts of carboxylic acids such as tungsten, Group VIIa metal salts of carboxylic acids such as manganese oxalate, iron oxalate, ammonium iron oxalate, cobalt oxalate, nickel oxalate, ruthenium oxalate,
Group VIII metal salts of carboxylic acids such as rhodium oxalate, palladium oxalate, osmium oxalate, iridium oxalate, platinum oxalate, Group Ib metal salts of carboxylic acids such as copper oxalate, silver oxalate, gold oxalate, and carvone such as zinc oxalate. Group IIb metal salts of acids,
Group IIIb metal salts of carboxylic acids such as aluminum oxalate, gallium oxalate and iridium oxalate, group IVb metal salts of carboxylic acids such as germanium oxalate, tin oxalate, lead oxalate, carboxylic acids such as lanthanum oxalate, cerium oxalate and samarium oxalate. Examples thereof include lanthanoid salts of acids. Further, in the production of the coating liquid of the present invention, as the carboxylic acid compound, in addition to each of the above compounds, a compound capable of becoming these in a dispersion medium, for example, a hydrate of the above carboxylate salt or a carboxylic acid anhydride, It can also be used. When a hydrate of a carboxylate is used, the dispersion medium contains a carboxylate, and when a carboxylic anhydride is used,
A carboxylic acid will be contained in the dispersion medium. By including such a carboxylic acid compound, the coating liquid has a highly hydrophilic film, that is, even when the entire surface of the film is contaminated with a lipophilic substance, the hydrophilic property is restored by light irradiation and the hydrophilic property is continuously maintained. It becomes possible to form a film exhibiting the property. The amount of the carboxylic acid compound is usually 0.005 mol times or more based on the ceramic in the coating liquid. The larger the amount of the carboxylic acid compound, the better the dispersion stability of the ceramics in the coating solution and the hydrophilicity of the obtained film.
It is preferably molar times or more, and more preferably 0.03 times or more. On the other hand, if the amount of the carboxylic acid compound is too large, not only the effect commensurate with the amount is not obtained, but the hydrophilicity of the obtained film may be reduced, so that the amount is 400 mol times or less, further 5 mol times or less. Preferably there is.

In the present invention, the dispersion medium in which the ceramics are dispersed includes various aqueous media, alcoholic media such as ethanol, methanol, 2-propanol and butanol, and ketone media such as acetone and 2-butanone. Can be applied. The dispersion medium used is preferably one that dissolves the carboxylic acid compound contained in the coating liquid, and is preferably selected appropriately according to the carboxylic acid compound. When the carboxylic acid compound contained in the coating liquid is a metal salt of oxalic acid, many of the metal salts are water-soluble, and therefore the dispersion medium is an aqueous medium, specifically, ion-exchanged water. Water or hydrogen peroxide water can be used. Even if the metal salt is poorly soluble in water, it may be possible to dissolve it in water by using oxalic acid together.

In addition, the coating agent, the method of using it,
Organic compounds other than the carboxylic acid compounds shown above can be included depending on the application. Examples of the organic compound include a silylating agent and a surfactant.

By using the coating agent of the present invention containing a specific non-metal inorganic material and organic substance, a strong film exhibiting hydrophilicity can be formed. The film is formed by, for example, applying a coating agent to the surface of a substrate such as glass, plastic, metal, ceramics, or concrete, and then maintaining the substrate in air at room temperature to 200 ° C., or the substrate surface. After applying the coating agent to
It can be performed by a method of blowing hot air of 80 to 200 ° C. In the film thus formed, sunlight or mercury lamp,
When light is emitted from a fluorescent lamp, halogen lamp, sodium lamp, light emitting diode, EL lamp, gas lamp, etc.,
The membrane exhibits high hydrophilicity.

The coating liquid shown above is prepared by mixing, for example, ceramics, a non-metal inorganic material, a carboxylic acid compound, and a dispersion medium selected from an aqueous medium, an alcoholic medium and a ketonic medium, and a mixture thereof. Can be obtained by a dispersion treatment, or a method of mixing ceramics, a carboxylic acid compound, and the dispersion medium, subjecting this mixture to a dispersion treatment, and then mixing a nonmetallic inorganic material.

The ceramic used here may be a compound of a metal element and oxygen, nitrogen or sulfur, which has a crystal structure determined by X-ray diffraction, and is, for example, Ti or Z.
r, Hf, V, Nb, Ta, Cr, Mo, W, Mn, T
c, Re, Fe, Co, Ni, Ru, Rh, Pd, O
s, Ir, Pt, Cu, Ag, Au, Zn, Cd, G
It is an oxide, nitride, sulfide, oxynitride or oxysulfide of a metal element such as a, In, Tl, Ge, Sn, Pb, Bi, La or Ce. These can be used alone or in combination of two or more.

The carboxylic acid compound mixed with the ceramic includes monocarboxylic acid, dicarboxylic acid,
Tricarboxylic acid, ammonium carboxylate, alkali metal salt of carboxylic acid, alkaline earth metal salt of carboxylic acid,
Group IIIa metal salt of carboxylic acid, Group Va metal salt of carboxylic acid,
Group VIa metal salts of carboxylic acids, Group VIIa metal salts of carboxylic acids, Group VIII metal salts of carboxylic acids, Group Ib metal salts of carboxylic acids, Group IIb metal salts of carboxylic acids, Group IIIb metal salts of carboxylic acids, Carboxylic acids Group IVb metal salts and lanthanoid salts of carboxylic acids, as well as compounds that can be these, for example, hydrates of the above carboxylates, carboxylic acid anhydrides, and the like.
The amount of the carboxylic acid compound to be mixed may be generally an amount commensurate with the desired content of the carboxylic acid compound in the coating liquid. From the viewpoint of dispersing ceramics, the more carboxylic acid compounds are used, the more easily they can be dispersed. Therefore, a dispersion treatment is performed by mixing more carboxylic acid compounds than the desired carboxylic acid compound content of the coating liquid. You can go. In this case, after the dispersion treatment, an operation of removing a part of the carboxylic acid compound in the coating liquid described later is performed. In addition, during the dispersion treatment, an operation of adjusting the pH by adding an acid or a base is performed, if necessary. Examples of the acid used at this time include hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid and the like, and examples of the base include ammonia, urea, hydrazine, lithium hydroxide, and the like.
Sodium hydroxide, potassium hydroxide, cesium hydroxide,
Rubidium hydroxide etc. are mentioned.

The dispersion treatment is carried out by, for example, a method using a wet mill, a method using ultrasonic irradiation, abrupt depressurization of the mixture, or stirring with a blade rotating at a high speed to generate cavities in the liquid. It can be carried out by a method of utilizing a pressure change generated when the cavity disappears, a method of dispersing by a shearing force generated by rotation of a stirring blade or a screw, and the like. These methods can be performed alone or in combination of two or more. In the case of the wet mill method, beads or balls made of a material such as zirconia or alumina can be used as the dispersion medium. The outer diameter of these is preferably 0.65 mm or less, more preferably 0.5 mm or less, and particularly preferably 0.3 mm or less. Also, in the case of the method using ultrasonic irradiation, the dispersion treatment is usually performed at 1 Wh as ultrasonic output per 1 g of ceramics.
Or more, preferably 10 Wh or more, and 10 kWh or less,
It can be preferably performed under the condition of 3 kWh or less. These dispersion treatments are performed under the condition that the crystal structure of the ceramic main component is not substantially changed, that is, the crystal structure obtained from the X-ray diffraction spectrum of the ceramic main component can be retained without causing phase transition. Preference is given to performing at temperatures below 90 ° C., for example. From the viewpoint of maintaining the crystal structure of ceramics, the dispersion treatment is preferably performed at a low temperature, more preferably 80 ° C. or lower, and further preferably 75 ° C. or lower. On the other hand, if the temperature of the dispersion process becomes too low,
Since the stability of the obtained coating liquid may be lowered, 10 ° C. or higher, more preferably 20 ° C. or higher is suitable.
The time of the dispersion treatment may be appropriately selected depending on the temperature of the dispersion treatment and the type of equipment used, and is usually 1 minute or longer, preferably 1 hour or longer, and 50 hours or shorter, preferably 24 hours or shorter. The dispersion processing may be performed in multiple times.

If necessary, the dispersion-treated mixture is subjected to an operation of removing coarse particles by centrifugation or an operation of adjusting the ceramic content by dilution.
Further, the mixture subjected to the dispersion treatment with an excess of the carboxylic acid compound with respect to the desired carboxylic acid compound content is subjected to an operation of removing a part of the carboxylic acid compound to adjust the concentration to a predetermined value. To do. The carboxylic acid compound can be removed by, for example, light irradiation, heating, addition of an oxidizing agent or a reducing agent, ion exchange membrane treatment, ozone treatment, hydrothermal treatment, or the like. Further, the mixture subjected to the dispersion treatment is subjected to an operation of adjusting the pH by adding an acid or a base, if necessary. Examples of the acid used at this time include hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid and the like, and examples of the base include ammonia, urea, hydrazine, lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, Rubidium hydroxide etc. are mentioned.

The dispersion-treated mixture or the mixture subjected to any of the above operations can be used as a coating liquid. The ceramic content of the coating liquid may be appropriately selected according to the type of the substrate to be the film forming target and the desired film thickness, but is usually 0.1% by weight or more and 30% by weight or less, and preferably Is 1% by weight or more,
It is 10% by weight or less. This coating liquid is glass,
A film can be formed on the surface of a substrate by applying it to a material such as plastic, metal, ceramics, or concrete and drying it.

The coating liquid of the present invention is preferably stored under the condition that it is not exposed to light. For example, it is stored in a dark room, or the transmittance of ultraviolet light and visible light is 10 each.
It is preferable to store it in a light-shielding container whose content is not more than%.
When the coating liquid is put in a transparent glass container and stored indoors for a long time with a lighting device, it may be difficult to form a smooth film.

The photocatalyst functional product of the present invention comprises a substrate surface,
A film is formed using the above coating liquid.

Examples of the base material include various materials constituting the photocatalyst functional product, such as glass, plastic,
There are metals, ceramics, concrete, etc. The film formation can be performed by spin coating, dip coating, doctor blade, spraying or brush coating. In the film formation, the coating liquid is usually sprayed or brushed and then dried. The drying temperature may be appropriately selected depending on the types of the dispersion medium and the non-metal inorganic material contained in the coating liquid. This photocatalyst functional product usually has a thickness of 0.02 μm or more, preferably 0.
It has a film of 1 μm or more and 1 μm or less.
When the film is activated by irradiation with light, the film exhibits hydrophilicity and prevents the photocatalytically functional product from being soiled or fogging. Examples of photocatalytic functional products are window glass, mirrors, washbasins, tiles, road side walls, road signs, road lighting, road reflectors, sound insulation plates, building exterior walls, street lights, gate posts, gates, post boxes, rain gutters. , Roof tiles, solar cells, solar water heaters, automobiles, bicycles, trains, airplanes, ships, door mirrors, containers, refrigerators, microwave ovens, tableware dryers, wave-dissipating blocks, tents, kennels, vending machines, and the like.

[0027]

EXAMPLES The present invention will be described in detail below with reference to examples. In this embodiment, the titanium oxide coating liquid will be described, but the present invention is not limited to this embodiment.

Example 1 3388 g of titanium oxysulfate (made by Teika) was added to 2258 of water.
g, and 1309 g of 35 wt% hydrogen peroxide solution (Kishida Chemical Co., Ltd.) was added to the resulting solution to prepare a mixed solution. Ion exchange into a reaction vessel equipped with a pH electrode and a pH controller connected to the pH electrode and having a mechanism for supplying 25 wt% ammonia water (special grade reagent, manufactured by Wako Pure Chemical Industries) to adjust the pH to a constant value 4700 g of water was added. Set the pH of the pH controller to 4 and p
H was adjusted to the set value with dilute sulfuric acid. The rate of supplying the ammonia water was set to 17.9 ml / min. In this reaction container, when the pH of the liquid in the container becomes lower than the set value, ammonia water starts to be supplied and is continuously supplied at the above rate until the pH reaches the set value. The mixed solution obtained above was added to this reaction vessel at 14.9 ml / min while stirring at 117 rpm, and reacted with aqueous ammonia supplied to the reaction vessel by a pH controller to obtain a product. The reaction temperature at this time is 23 ° C to 3 ° C.
It was in the range of 5 ° C. 1 while stirring the resulting product
After maintaining for a while, 25% by weight aqueous ammonia (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was supplied to obtain a slurry. The total amount of ammonia water supplied to the reaction vessel is 3746 g
And twice the amount required to convert titanium oxysulfate to titanium hydroxide. The above slurry was filtered, and the obtained solid substance was washed with ion-exchanged water and dried to obtain a powder. This powder was calcined in air at 370 ° C. for 1 hour and then cooled to room temperature to obtain particulate anatase-type titanium oxide having a water content of 15% by weight.

Oxalic acid dihydrate [C ₂ H ₂ O ₄ .2H ₂ O] (reagent for sulfur dioxide automatic analyzer, manufactured by Wako Pure Chemical Industries, Ltd.) 1.58
g was dissolved in 88.42 g of water, and 10 g of the particulate anatase-type titanium oxide was mixed with the obtained aqueous oxalic acid solution.
This mixture was mixed with a medium agitator (trade name "4TSG-1 / 8",
Igarashi Machinery Co., Ltd.), medium: outer diameter 0.3 mm
Zirconia beads, processing temperature: 20 ° C., processing time:
The dispersion treatment was performed under the condition of 9 hours to obtain a mixed liquid.

100 g of this mixed solution and 20 g of silica sol (trade name "Snowtex ST-O", manufactured by Nissan Chemical Industries) are mixed to obtain a coating solution. If the glass plate is immersed in a mixed solution of ammonia water and hydrogen peroxide solution, ultrasonically cleaned, then the above coating solution is brushed on one side of the glass plate taken out, and naturally dried to form a film. A photocatalytic function can be imparted to the glass plate.

[0031]

According to the coating agent of the present invention, hydrophilicity can be imparted to the surface of materials such as glass, plastic, metal, ceramics and concrete. Further, the photocatalyst functional product of the present invention has a strong film exhibiting hydrophilicity, and since this film prevents fouling or fogging, the number of times of washing etc. can be reduced over a long period of time by using this product. .

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 5/00 C09D 5/00 Z C09K 3/00 C09K 3/00 R 112 112 (72) Inventor Hiroyuki Ando Sumitomo Chemical Industrial Co., Ltd. F-term 5-1 Sokai-cho, Niihama-shi, Ehime (reference) 4G047 CA02 CB05 CC03 CD03 CD07 4G069 BA01A BA02A BA02B BA04A BA04B BA05A BA07A BA08A BA48A BCA25 BC36A30A BC30A16A BC16A BC52A BC53A BC57A BC61A BC65A BC69A BD05A CD10 DA06 EC22Y ED02 FA03 FB23 ZA43A 4J038 AA01 HA146 HA186 HA426 HA436 HA446 HA456 JA43 KA06 KA09 NA06

Claims (4)

[Claims] 1. A coating liquid comprising ceramics, a non-metal inorganic material other than the ceramics, a dispersion medium, and a carboxylic acid compound. 2. The ceramic is crystalline.
The coating liquid described. 3. The non-metal inorganic material is silica, aluminum oxide, aluminum hydroxide, aluminosilicate, alkaline earth metal oxide, alkaline earth metal hydroxide, calcium phosphate, molecular sieve, activated carbon, or
Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W,
Mn, Tc, Re, Fe, Co, Ni, Ru, Rh, P
d, Os, Ir, Pt, Cu, Ag, Au, Zn, C
d, Ga, In, Tl, Ge, Sn, Pb, Bi, La
The coating liquid according to claim 2, which is a hydroxide of a metal element selected from and Ce or an amorphous oxide of these metal elements. 4. The substrate according to any one of claims 1 to 3 on the surface thereof.
A photocatalytic functional product obtained by forming a film using the coating liquid according to the item.