JP2002060686A - Coating material for removing exhaust gas, process for its application and coated article for removing exhaust gas using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material for removing exhaust gas which may efficiently and surely remove or reduce exhaust gas exhausted from automobiles or plants, does not generate any cracks, etc., on the coated film and retains its action over a long time, a process for its application and a coated article for removing exhaust gas. SOLUTION: The coating material for removing exhaust gas comprises a silicone resin and a photocatalytic material prepared by combining titanium dioxide and zinc oxide, wherein the weight ratio of titanium dioxide to zinc oxide is from 1 to 15. In the process for applying the coating material for removing exhaust gas, the coating material is repetitively applied to and dried on a substrate to form multiple coated layers laminated on each other. Here, the total weight concentration of titanium dioxide to zinc oxide in the coating materials used for forming the coated layers is successively increased toward the top. The coated article for removing exhaust gas is manufactured by applying the coating material via the above process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas removing coating material capable of removing or reducing exhaust gas discharged from automobiles, factories, etc., a method of coating the same, and an exhaust gas removing method using the same. Related to painted objects.

[0002]

2. Description of the Related Art Conventionally, as a material capable of removing or reducing exhaust gas emitted from automobiles and factories, a paint using a photocatalytic material has been attracting attention.
Some have been put to practical use. These conventionally known paints for removing exhaust gas are generally a combination of a highly durable resin such as an acrylic silicon-based or fluorine-based resin and a photocatalytic material such as TiO ₂ , and have a sufficient effect. In order to exhibit the exhaust gas removing ability, it was necessary to contain the photocatalyst material at a very high concentration and to increase the thickness of the coating film.

[0003] However, acrylic-silicon-based or fluorine-based resins are easily decomposed into photocatalysts, and the photocatalyst concentration is extremely high, so that a coating film formed by the above-mentioned paint becomes brittle and easily cracks. Cause the problem that it occurs, the coating film falls down into powder over time,
Eventually, the coating film may disappear, and it has been difficult to maintain the effect over a long period of time. Further, when the thickness of the coating film is increased in order to impart long-term maintainability, stress due to drying and curing is instantaneously applied, and there is a problem that cracks are easily generated. When TiO ₂ is used alone as a photocatalyst, as in the conventional paint, NO, which is the main component of exhaust gas emitted from automobiles and factories, is oxidized to NO ₂ as a first step. Since TiO ₂ has a poor effect of adsorbing NO _2, that is, an acidic gas, there is also a serious problem in that toxic NO ₂ may be released as a result.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object of the present invention is to efficiently and surely remove or reduce exhaust gas discharged from automobiles and factories. Further, it is an object of the present invention to provide an exhaust gas removing coating material, a coating method thereof, and an exhaust gas removing coated material using the same, which can maintain the effect for a long period of time without causing cracks or the like in the coating film. is there.

[0005]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned problems. As a result, the silicone resin is not easily attacked by the high concentration of the photocatalytic material, and
As the photocatalyst material, and titanium dioxide responsible serves to decompose and remove the exhaust gases, the combined use with a specific ratio of zinc oxide responsible for the function of adsorbing acid gases generated in the decomposition process of the exhaust gas, NO ₂ etc. Takeshi It has been found that exhaust gas can be removed or reduced efficiently and reliably while preventing emission of poisonous gas. Furthermore, it has been found that the exhaust gas removing effect can be maintained for a long period of time by forming a multilayer coating layer so that the photocatalytic material has a high concentration from the lower layer to the upper layer. The present invention has been completed based on these findings.

That is, the exhaust gas removing coating material of the present invention contains a silicone resin and a photocatalytic material comprising a combination of titanium dioxide and zinc oxide, and the weight ratio of titanium dioxide / zinc oxide is 1 to 1. Fifteen. The exhaust gas removing coating material according to a preferred embodiment of the present invention is the exhaust gas removing coating material, wherein the titanium dioxide has a particle diameter of 50 nm.
Particles (A) of a particle group having a particle diameter of 3 nm
And a combination of particles (B) of a particle group having a particle size of ３０30 nm. Further, the exhaust gas removing coating material according to a preferred embodiment of the present invention is the exhaust gas removing coating material, wherein the particles (B) / the particles (A)
Is 1 to 15.

According to the method of coating the exhaust gas removing coating material of the present invention, a plurality of coating layers are formed by repeatedly applying and drying the exhaust gas removing coating material of the present invention on a substrate. In this case, the upper coating layer is formed using a coating material having a higher total weight concentration of titanium dioxide and zinc oxide. Also,
In a preferred embodiment of the present invention, the method for coating an exhaust gas removing coating material is the method for coating an exhaust gas removing coating material, wherein the total weight concentration of the lowermost layer of titanium dioxide and zinc oxide is 10% or more and less than 40%; The total weight concentration of titanium dioxide and zinc oxide in the uppermost layer is set to be 60% or more and less than 99%.

[0008] The exhaust gas removing coating material of the present invention is formed by repeatedly applying and drying the exhaust gas removing coating material of the present invention on a substrate, and laminating a plurality of coating layers, and The upper coating layer is formed using a coating material having a higher total weight concentration of titanium dioxide and zinc oxide.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The exhaust gas removing coating material of the present invention contains a silicone resin and a photocatalytic material obtained by combining titanium dioxide and zinc oxide. The silicone resin in the present invention is mainly composed of an inorganic polymer, and has a siloxane bond (-
There is no particular limitation as long as it is a three-dimensional cross-linking compound having (Si-O-Si-). Preferably, 500
It is preferable that 60% or more of the inorganic component (silica) in the resin solid content remains after baking at 60 ° C. for 60 minutes, in order to more reliably suppress the degradation due to the photocatalytic material. Further, the silicone resin may be any of a bake hardening type and a room temperature hardening type, but is preferably a room temperature hardening type when performing on-site construction. Further, the silicone resin may be either of an aqueous type or a solvent type, but is preferably an aqueous type from the viewpoint of the recent VOC problem.

The silicone resin preferably used in the present invention includes, for example, an organosiloxane partial hydrolyzate represented by the following general formula (1). R ² aSiOb (OR ¹ ) c (OH) d (1) (where R ¹ and R ² each independently represent a monovalent hydrocarbon group, and a, b, c and d are a + 2b + c + d
= 4 and 0 ≦ a <3, 0 <b <2, 0 <c
<4 and 0 <d <4. In the general formula (1), R ² is not particularly limited as long as it is a monovalent hydrocarbon group, and is preferably a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms. Group, ethyl group, propyl group, butyl group, pentyl group,
An alkyl group such as a hexyl group, a heptyl group and an octyl group;
Cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aralkyl groups such as 2-phenylethyl group and 3-phenylpropyl group; aryl groups such as phenyl group and tolyl group; alkenyl groups such as vinyl group and allyl group; A halogen-substituted hydrocarbon group such as a γ-chloropropyl group or a 3,3,3-trifluoropropyl group; a γ-methacryloxypropyl group, a γ-glycidoxypropyl group;
Substituted hydrocarbon groups such as 3,4-epoxycyclohexylethyl group and γ-mercaptopropyl group; and the like.

In the general formula (1), R ¹ is not particularly limited as long as it is a monovalent hydrocarbon group. For example, an alkyl group having 1 to 4 carbon atoms is preferable. The general formula (1)
In the above, a, b, c and d are numbers satisfying the above relationship. When a is 3 or more, curing of the applied coating film may not proceed well, and when b is 0, it is a monomer and a cured coating film cannot be formed.
Is 2, it is silica (SiO ₂ ) and the cured coating film tends to crack. When c is 0, the molecular ends are only R ² groups and OH groups which are hydrophilic groups, so that the hydrophilicity of the whole molecule increases and it becomes difficult to maintain for a long time. , It is a monomer and cannot form a cured coating film. When d is 0, the molecular end is R
^{Although only two} groups and an OR ¹ group, which is a hydrophobic group, are advantageous for long-term maintenance, the OR ¹ group lacks crosslinking reactivity at the time of curing of the coating film, so that a sufficient coating film can be obtained. When d is 4, it is a monomer and cannot form a cured coating film.

The method for preparing the organosiloxane partial hydrolyzate represented by the general formula (1) is not particularly limited. For example, R ¹ in the general formula (1) is an alkyl group (OR ¹ is an alkoxy group). Group), one or more hydrolyzable organosilanes selected from the group consisting of hydrolyzable organochlorosilanes and hydrolyzable organoalkoxysilanes are converted into a large amount of water by a known method. Can be obtained by partially alkoxylating the silanol group of the silanol group-containing polyorganosiloxane obtained by hydrolysis. In this preparation method, when hydrolysis is performed using a hydrolyzable organoalkoxysilane, the unreacted alkoxy group and silanol group are hydrolyzed by hydrolyzing only a part of the alkoxy group by adjusting the amount of water. Since a partial hydrolyzate of an organosiloxane coexisting with the above can be obtained, the above-mentioned treatment of partially alkoxylating the silanol group of the silanol group-containing polyorganosiloxane may be omitted in some cases.

The hydrolyzable organochlorosilane is not particularly restricted but includes, for example, methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane and the like.
The hydrolyzable organoalkoxysilane is not particularly limited, for example, tetramethoxysilane,
Tetraalkoxysilanes such as tetraethoxysilane; methyltrimethoxysilane, methyltriethoxysilane,
Methyltriisopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-
Organotrialkoxysilanes such as trifluoropropyltrimethoxysilane; diorganodialkoxysilanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane; trimethylmethoxysilane, trimethylethoxysilane And triorganoalkoxysilanes such as triethylmethoxysilane, trimethylisopropoxysilane, and dimethylisobutylmethoxysilane.

The catalyst used for partially hydrolyzing the hydrolyzable organosilane is not particularly limited. Examples of the acidic catalyst include water-soluble acids such as hydrochloric acid and nitric acid, and acidic colloidal silica. And the like, and examples of the basic catalyst include an aqueous ammonia solution and basic colloidal silica. The weight average molecular weight of the silicone resin used in the present invention is preferably from 500 to 2,000 in terms of polystyrene. If the weight average molecular weight of the silicone resin is less than 500, cracks tend to occur in the coating film, while if it exceeds 2,000, curing tends not to proceed well, which is not preferable.

The content of the silicone resin in the exhaust gas removing coating material of the present invention is 1 to 90% by weight.
It is preferred that When the content of the silicone resin is less than 1% by weight, it is difficult to form a coating film,
If it exceeds 0% by weight, the exhaust gas removing ability tends to decrease. The photocatalyst material in the present invention is a combination of titanium dioxide and zinc oxide. And titanium dioxide responsible serves to decompose and remove the exhaust gas, by using a combination of zinc oxide responsible for the function of adsorbing acid gases generated in the decomposition process of the exhaust gas, while preventing the release of poisonous gases such as NO ₂ In addition, the exhaust gas can be efficiently and reliably removed or reduced. In addition, zinc oxide can be expected to have an auxiliary effect in decomposing and removing exhaust gas in addition to the above-mentioned acidic gas adsorption ability.

The titanium dioxide is not particularly limited as long as it has photocatalytic activity, but preferably includes anatase type titanium dioxide. The titanium dioxide is preferably formed by combining particles having a large particle diameter and particles having a small particle diameter. If the particle size of titanium dioxide is single, the filling ratio in the coating film will be low, which may cause brittleness of the coating film. A film can be formed. Further, when particles having a large particle diameter are present in the coating film, there is an advantage that the curing shrinkage of the film is buffered and the film is hardly cracked. Specifically, titanium dioxide is a large particle group of particles (A) having a particle diameter of 50 nm to 5 μm.
And a combination of particles (B) of a small particle group having a particle diameter of 3 nm to 30 nm.
When the particle size of the particles (A) is less than 50 nm, the size for supporting the film is insufficient, and the film strength is reduced. On the other hand, when the particle size exceeds 5 μm, the gap between the particles is increased, and The film strength will be reduced. When the particle size of the particles (B) is less than 3 nm, the dispersion of the particles becomes extremely difficult. On the other hand, when the particle size exceeds 30 nm, the specific surface area tends to be small and the activity tends to be poor. Preferably, at least 50% of the total amount of titanium dioxide is composed of a combination of the particles (A) and the particles (B).

The weight ratio of the particles (B) / (A) is preferably from 1 to 15. When the ratio of the particles (B) / particles (A) is less than 1, the activity is improved, but the filling effect and the buffer effect of curing shrinkage are reduced, the film is brittle, and the film tends to be cracked during curing. , 15, the photocatalytic activity tends to decrease. As the zinc oxide,
There is no particular limitation as long as it has photocatalytic activity, and conventionally known ones can be used. The particle size of the zinc oxide particles is not particularly limited, but is preferably 300 nm to 2 μm. If the particle size of the zinc oxide is less than 300 nm, the particles tend to be difficult to disperse, whereas if it exceeds 2 μm, the photocatalytic activity effect of zinc oxide, which is expected to assist titanium dioxide, is reduced. Not preferred.

In the present invention, it is important that the weight ratio of the titanium dioxide / the zinc oxide is 1 to 15. When the weight ratio of titanium dioxide / zinc oxide is less than 1, the concentration of titanium dioxide having high activity becomes low and sufficient decomposability cannot be obtained.
As a result, the zinc oxide concentration becomes low, and the effect of adsorbing the acidic gas cannot be expected. In the present invention, the weight ratio of titanium dioxide / zinc oxide shall be calculated as TiO ₂ / ZnO. The content of the photocatalytic material (titanium dioxide and zinc oxide) in the exhaust gas removing coating material of the present invention is preferably 10 to 99% by weight. If the content of the photocatalyst material is less than 10% by weight, the exhaust gas removal performance tends to decrease, while if it exceeds 99% by weight, it may be difficult to form a coating film.

The exhaust gas removing coating material of the present invention may contain conventionally known additives such as a dispersant and a leveling agent in addition to the silicone resin, titanium dioxide and zinc oxide, if necessary. good. In that case, the content is preferably 1% by weight or less of the photocatalyst material. If it is more than this, it may cause discoloration or the like. In the method for coating the exhaust gas removing coating material of the present invention, the above-described exhaust gas removing coating material of the present invention is formed by stacking a plurality of coating layers by repeatedly applying and drying the coating material on a substrate. In this case, the upper coating layer is formed using a coating material having a higher total weight concentration of titanium dioxide and zinc oxide. In this way, by giving a gradient to the concentration of the photocatalytic material from the bottom layer to the top layer, it is possible to prevent instantaneous stress due to drying and curing of each layer, and to eliminate exhaust gas without causing cracks in the coating film. The effect can be maintained for a long time.

It is preferable that the total weight concentration of the lowermost layer of titanium dioxide and zinc oxide in the laminated coating layers is 10% or more and less than 40%. The bottom layer is
It mainly serves as a base for supporting the upper layer so as not to be broken due to adhesion, and the exhaust gas removing effect may be relatively low. However, when the upper layer coating film disappears due to unexpected physical contact, etc., it is necessary to exert the minimum effect only with the lowermost layer, so the total weight concentration of titanium dioxide and zinc oxide in the lowermost layer Is preferably 10% or more. On the other hand, if the total weight concentration of the lowermost layer of titanium dioxide and zinc oxide is 40% or more, the difference in concentration between the lower layer and the upper layer becomes small, and cracks may occur during drying and curing, which is not preferable.

In the laminated coating layers, the total weight concentration of the uppermost layer of titanium dioxide and zinc oxide is preferably 60% or more and less than 99%. The top layer is
It is important that the layer has the highest priority on the exhaust gas removing effect. If the total weight concentration of titanium dioxide and zinc oxide in the uppermost layer is less than 60%, the exhaust gas is decomposable (NO gas decomposition in Examples). %) Is less than 50%, which is not preferable. On the other hand, when the total weight concentration of titanium dioxide and zinc oxide in the uppermost layer is 99% or more, the resin component tends to be extremely small and the formation of a coating film tends to be difficult. Of the laminated coating layers, the layer sandwiched between the lowermost layer and the uppermost layer preferably has a total weight concentration of titanium dioxide and zinc oxide of 40% or more and less than 60%, but is particularly limited. Not something.

In the present invention, the total weight concentration of titanium dioxide and zinc oxide is calculated by the following equation. In addition,
In the following formula, the photocatalytic material weight is the total weight of titanium dioxide and zinc oxide. Total weight concentration (%) of titanium dioxide and zinc oxide = photocatalytic material weight / (photocatalytic material weight + resin solid content weight) × 1
The concentration gradient of the photocatalytic material between each layer (difference in total weight concentration between titanium dioxide and zinc oxide in each layer) is not particularly limited, but is preferably the total weight concentration of titanium dioxide and zinc oxide in the upper layer. It is preferable that there is a concentration gradient of about 1.5 to 7.0 / total weight concentration of titanium dioxide and zinc oxide in the lower layer.

The total number of coating layers to be laminated is not particularly limited, but is preferably about three or four layers in consideration of workability of construction and the like. The thickness of each layer to be laminated is preferably about 5 to 200 μm. As a method of applying the coating material of the present invention,
There is no particular limitation, for example, spray, roll coater,
A coating film layer can be formed by coating to a desired thickness by a known method such as a gravure coater or the like, and drying and curing. Drying is performed, for example, at a temperature of 15 to 60 ° C. for 0.2 to 2 hours and at a temperature of 100 to 300 ° C. for 0.1 to 2 hours.
It may be performed for ~ 1 hour.

The substrate on which the coating material for removing exhaust gas of the present invention is applied is not particularly limited. For example, a metal substrate, a glass substrate, an enamel, an inorganic building material such as a water glass decorative plate or an inorganic cured material, Inorganic substrates such as ceramics;
Organic substrates such as plastic substrates, wood, wood, and paper; inorganic-organic composite substrates; and the like. As specific examples of the inorganic substrate, as the metal substrate, for example, non-ferrous metals (aluminum, aluminum alloy, copper, zinc, etc.),
Examples include iron, steel (rolled steel, hot-dip galvanized steel, (rolled) stainless steel, and the like), tinplate, and other metals (including alloys) in general. Examples of the glass substrate include sodium glass, Pyrex (registered trademark) glass, quartz glass, and alkali-free glass. What is an enamel?
It is obtained by baking and coating a vitreous enamel on the metal surface, and examples of the base metal include mild steel plate, steel plate, cast iron, aluminum and the like. The water glass decorative plate is, for example, a decorative plate obtained by applying sodium silicate to a cement base such as slate and baking the same. Examples of the inorganic hardened material include fiber-reinforced cement boards, nitriding siding, wood wool cement boards, pulp cement boards, slate / wood wool cement laminates, gypsum board products, clay tiles, thick slate, ceramic tiles, Substrates in which inorganic materials such as architectural concrete blocks, terrazzo, prestressed concrete double T slabs, ALC panels, hollow prestressed concrete panels, etc. are hardened and molded. As ceramics, for example, alumina,
Zirconia, silicon carbide, silicon nitride and the like can be mentioned.

As a specific example of the organic substrate, examples of the plastic substrate include thermosetting or thermoplastic plastics such as polycarbonate resin, acrylic resin, ABS resin, vinyl chloride resin, epoxy resin, and phenol resin; And fiber-reinforced plastics in which these plastics are reinforced with organic fibers such as nylon fibers. As the inorganic-organic composite substrate, for example,
Fiber reinforced plastics in which the above plastics are reinforced with inorganic fibers such as glass fibers and carbon fibers are exemplified.
When the coating material of the present invention is applied on a base material or a layer containing an organic component as a main component (such as a plastic plate or a general coating film), the decomposition of the organic component by photocatalytic activity is prevented. In order to suppress this, it is desirable to apply an inorganic coating material having a high inorganic component ratio under the coating material of the present invention.

When the coating material for removing exhaust gas of the present invention is applied on a substrate, it may be difficult to obtain adhesion to the substrate depending on the material and surface condition of the substrate. Before applying the coating material of the present invention, a primer layer may be previously formed on the surface of the substrate. The primer layer is not particularly limited, whether organic or inorganic. Examples of the organic primer layer include a nylon resin, an alkyd resin, an epoxy resin, an acrylic resin, an organically modified silicone resin (such as an acrylic silicone resin), and a chlorinated rubber resin. And a cured resin layer of an organic primer composition containing 10% by weight or more as a solid content of at least one organic resin selected from the group consisting of a urethane resin, a phenol resin, a polyester resin, and a melamine resin. As the inorganic primer layer, for example, an inorganic resin component such as silicone
Examples include a cured resin layer of an inorganic primer composition containing 0% by weight or more. The thickness of the primer layer is not particularly limited, but is preferably, for example, 0.1 to 50 μm.

Since the coating material of the present invention contains titanium dioxide and zinc oxide which are white, the coated product coated with the coating material of the present invention usually becomes white, but has a strong coloring power. By mixing a pigment that is not easily decomposed into a photocatalyst, for example, carbon,
It is also possible to color lightly. Further, since the coating material of the present invention has a low shielding property, the coloring can be seen through if a colored coating is applied to the base material in advance, so that it is possible to use this to give a desired color. . The exhaust gas removing coating of the present invention is formed by stacking a plurality of coating layers by repeatedly applying and drying the exhaust gas removing coating material of the present invention on a substrate, and forming an upper layer. The coating layer is formed using a coating material having a higher total weight concentration of titanium dioxide and zinc oxide, and is obtained by the above-described coating method of the present invention. The coating material for removing exhaust gas of the present invention has an exhaust gas removing effect, is hardly cracked, and exhibits long-term maintainability. Furthermore, since the coating material of the present invention has a photocatalytic activity, it goes without saying that the painted product of the present invention exhibits an antifouling effect such as rain streak prevention.

The coating material for removing exhaust gas of the present invention is preferably used in various applications where it is exposed to an atmosphere of exhaust gas from automobiles and factories and is exposed to an environment irradiated with light including ultraviolet rays. be able to. Specifically, for example, a side wall, a railing, a retaining wall, a tunnel entrance, a guardrail, a soundproof wall, a soundproof wall, a curb, a tollgate island, a tollgate booth, a display device, a sign device, a parking lot peripheral member, a vehicle stop, a bridge pier. Road peripheral members such as paint blocks, lighting equipment, etc .; factory peripheral members such as factory walls, chimneys, pipes, roofs, and mechanical devices; outer peripheral members such as house outer walls; tiles; apartment outer walls;

[0029]

The present invention will be described below in more detail with reference to Examples of the present invention. However, the present invention is not limited to these Examples. The materials used in the examples and comparative examples are shown below. -Silicone resin: trade name "Fressela-N (aqueous type)" manufactured by Matsushita Electric Works. Main skeleton with a crosslinking type: three-dimensional crosslinked resin solids of siloxane bonds: 36% inorganic components: 75% Paint Properties: aqueous emulsion coating appearance: Colorless transparent Titanium dioxide (a): TiO ₂ powder (trade name "ST4
1) Ishihara Techno, particle size 50 nm, anatase type) 30
1 part by weight, 69.7 parts by weight of ion-exchanged water, and 0.3 part by weight of a dispersant (sodium hexametaphosphate) were dispersed in a paint shaker for 1 hour to form a paste.

Titanium dioxide (b-1): 30 parts by weight of TiO ₂ powder (trade name “ST21” manufactured by Ishihara Techno, particle size: 20 nm, anatase type), 69.7 parts by weight of ion-exchanged water, dispersant (hexamethalin) An acid soda (0.3 parts by weight) was dispersed in a paint shaker for 1 hour to form a paste.・ Titanium dioxide (b-2): TiO ₂ sol (trade name “M
-6 "manufactured by Taki Kagaku Co., Ltd., particle size 5 nm, solid content concentration 6%).・ Zinc oxide: Fine particle zinc oxide (manufactured by Sakai Chemical Co., average particle size 0.29 μm) ・ Comparative resin: Acrylic emulsion (trade name “Acreset EX35” manufactured by Nippon Shokubai, solid content concentration 42%) ・ Substrate-1: Slate Plate ・ Substrate-2: SS steel plate ・ Primer layer-1: Trade name “Epolo E primer” made by Isaam Coating Coating conditions: Brush coating, coating amount 150 g / m ² , 20 ° C. 2
Drying for 4 hours ・ Primer layer-2: trade name “Savilon # 10” manufactured by Kanae Paint Coating conditions: brushing, coating amount 130 g / m ² , 20 ° C. 2
Drying for 4 hours ・ Protective layer-1: Transparent inorganic coating material (trade name “Fressela-N” (aqueous type) manufactured by Matsushita Electric Works) Coating conditions: brushing, coating amount 100 g / m ² , 20 ° C. 2
Drying for 4 hours-Protective layer-2: White inorganic coating material (trade name "Fressela-N (aqueous type)" manufactured by Matsushita Electric Works with white pigment added and dispersed for 1 hour with a paint shaker) 200 g / m ² , 20 ° C 2
Drying for 4 hours (Examples and Comparative Examples: Preparation of Coating Material for Exhaust Gas Removal) Each material was used in a mixing ratio shown in Tables 1 to 10 and stirred and mixed with a disper for 20 minutes to obtain a coating material.

(Examples and Comparative Examples: Preparation of Exhaust Gas Removal Coated Product) Each of the layers shown in Tables 1 to 10 was used as a base in the order of a primer layer, a protective layer, a first layer, a second layer, and a third layer. It was laminated on the material to obtain a painted product. The first layer, the second layer, and the third layer were brush-coated using coating materials prepared at the compounding ratios shown in Tables 1 to 10, and the coating amount was 150 g / m ² , 2
The coating was performed under the condition of drying at 0 ° C. for 2 hours to form a coating. The following evaluations were performed on the coated articles obtained in Examples and Comparative Examples. The results are shown in Tables 1 to 10. <Appearance> Initial stage: Cured at room temperature for one week after preparing a coated product sample, and visually observed.

Long term (after SWOM): For painted product samples,
200 with Sunshine Weatherometer (Suga Test Machine)
After performing the accelerated weathering resistance test for 0 hour, it was visually observed. <Exhaust gas removal performance> Initial: After the coated product sample was prepared, it was cured at room temperature for one week, and evaluated based on the NO gas decomposition rate and NO ₂ gas generation concentration measured as described below. In addition, this evaluation was not performed about the thing in which abnormalities were recognized after the accelerated test. Long-term (after SWOM): A coated product sample was subjected to an accelerated weathering test for 1200 hours with a sunshine weatherometer (Suga testing machine), and then NO measured as follows:
The evaluation was made based on the gas decomposition rate and the NO ₂ gas generation concentration. In addition, this evaluation was not performed about the thing in which abnormalities were recognized after the accelerated test.

(Method of Measuring NO Gas Decomposition Rate and NO ₂ Gas Generation Concentration) Using the measuring apparatus shown in FIG. 1, under the following conditions, the OUT concentration 1 (when the reduction catalyst unit 7 of the NOx total 6 was operated) Of the NO sensor 8) and OU
The T concentration 2 (the concentration detected by the NO sensor 8 when the reduction catalyst unit 7 of the NOx meter 6 was stopped) was measured. Then, the decomposition rate of NO gas and the NO ₂ gas generation concentration were calculated by the following equations, respectively. In FIG. 1, 1 is a Tedlar pack containing NO and air, 2 is a UV source, and 5 is a sample mounted on a punching metal 4 in a quartz cell 3. NO gas decomposition rate (%) = (1−OUT concentration 1 / IN concentration) × 100 NO ₂ gas generation concentration (ppm) = OUT concentration 1−OUT
Concentration 2 [Measurement conditions] NO gas initial concentration (IN concentration): 1.8 ppm (NO +
Air, diluted in Tedlar Pack 1) Flow rate: 2 liters / minute Sample size: 5 × 5 cm (backside slate backer treatment) UV source 2: Black light UV intensity: 1.5 mW / cm ² (356 nm) NOx meter 6: HORIBA, Ltd. Made, CLA510S-NOX

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

[0038]

[Table 5]

[0039]

[Table 6]

[0040]

[Table 7]

[0041]

[Table 8]

[0042]

[Table 9]

[0043]

[Table 10]

[0044]

EFFECTS OF THE INVENTION The exhaust gas removing coating material of the present invention can be used as a high-concentration titanium dioxide having an exhaust gas decomposing effect, zinc oxide having an adsorbing and retaining effect of an acidic gas generated in an exhaust gas decomposing process, and a photocatalytic material. Since it is composed of a silicone resin which is hardly eroded, it is possible to efficiently and reliably remove or reduce exhaust gas discharged from automobiles, factories and the like. According to the method for coating a coating material for exhaust gas removal of the present invention, a concentration gradient is applied so that the concentration of the photocatalyst material becomes higher toward the upper layer, and multilayer coating is performed to increase the thickness and prevent cracks due to curing drying shrinkage. However, the effect can be maintained for a long time without causing cracks or the like in the coating film.

The coating material for removing exhaust gas of the present invention can be used for applications exposed to an exhaust gas atmosphere, and can efficiently and reliably remove or reduce exhaust gas discharged from automobiles and factories. it can.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus for measuring a NO gas decomposition rate and a NO ₂ gas generation concentration used in Examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tedlar pack 2 UV source 3 Quartz cell 4 Punching metal 5 Sample 6 NOx meter 7 Reduction catalyst part 8 NO sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B05D 1/36 B05D 7/24 303B 7/24 302 C09D 5/00 Z 303 B01D 53/36 ZABJ C09D 5 / 00 102C (72) Inventor Takeyuki Yamaki 1048 Kadoma Kadoma, Osaka Pref. Matsushita Electric Works, Ltd. (72) Inventor Hiroji Kishimoto 1048 Odaka Kadoma, Kadoma, Osaka Pref. Matsushita Electric Works F-term (reference) 4D048 AA06 AB03 BA07X BA07Y BA16X BA16Y BB03 CA06 EA01 4D075 AE03 BB24Z CA03 CA50 DA06 DA23 DB02 DB04 DB05 DB06 DB07 DB12 DB13 DB14 DB18 DB21 DB24 DB35 DB37 DB38 DB43 DB46 DB47 DB48 DB61 DC01 DC05 DC38 EA06 EC03 A04 EC03 A04 EC04 BA22B BA48A BC35A BC35B CA02 CA03 CA10 CA13 DA06 EA07 EE06 EE08 FA06 FB23 4J038 DL021 DL031 DL051 DL 071 DL101 GA07 HA216 KA04 KA12 KA20 NA05 NA18 PB05 PB06 PB07 PC02 PC03 PC04 PC06 PC08 PC10

Claims (6)

[Claims] An exhaust gas removing coating material comprising a silicone resin and a photocatalytic material comprising a combination of titanium dioxide and zinc oxide, wherein the weight ratio of titanium dioxide / zinc oxide is 1 to 15. 2. The titanium dioxide has a particle diameter of 50 nm or more.
Particles (A) of a particle group having a particle diameter of 5 μm and a particle diameter of 3 nm to
The exhaust gas removing coating material according to claim 1, comprising a combination with particles (B) of a particle group having a particle size of 30 nm. 3. The exhaust gas removing coating material according to claim 2, wherein the weight ratio of the particles (B) / the particles (A) is 1 to 15. 4. The method according to claim 1, wherein the coating material for exhaust gas removal according to any one of claims 1 to 3 is repeatedly applied to a substrate and dried to form a plurality of coating layers. A coating method for an exhaust gas removing coating material, wherein a coating material having a higher total weight concentration of titanium dioxide and zinc oxide is used in an upper coating layer. 5. The total weight concentration of titanium dioxide and zinc oxide in the lowermost layer is 10% or more and less than 40%, and the total weight concentration of titanium dioxide and zinc oxide in the uppermost layer is 60% or more and less than 99%. The method for coating a coating material for removing exhaust gas according to claim 4, wherein the coating material is used. 6. A coating material for exhaust gas removal according to any one of claims 1 to 3 which is formed by repeatedly applying and drying a coating material on a substrate, and by laminating a plurality of coating layers, and A coating material for removing exhaust gas, wherein a coating material having a higher total weight concentration of titanium dioxide and zinc oxide is formed in a higher coating layer.