JPH10259325A - Water-based coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-based coating composition which can form a coating film having antibacterial action and the action of adsorbing and decomposing chemical substances and retaining the effects for a long term by mixing a colloidal antibacterial having a specified mean particle diameter and obtained by adhering silver to titanium oxide having photocatalysis with an adsorbent formed from a crystalline layered phosphoric acid compound. SOLUTION: A white slurry obtained by adding ammonia water to an aqueous titanium sulfate solution is filtered to obtain a water-containing cake of titanic acid. After the cake is diluted with pure water, hydrogen peroxide is added to the mixture and is decomposed by heating. A mixture of an aqueous solution of a silver ammine complex salt with an aqueous solution of zirconium ammonium carbonate and a silica sol are added to the mixture to obtain a colloidal antibacterial having a mean particle diameter of 3-500 μm and composed of titanium oxide having photocatalysis and silver adhered thereto. 100 pts.wt. (in terms of solid content) coating material is mixed with 0.1-3 pts.wt. (in terms of the solid matter) above antibacterial and 3-55 pts.wt. (in terms of solid content) adsorbent formed from a crystalline layered phosphoric acid compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based coating composition, and more particularly, to an antibacterial action and a chemical substance adsorption / absorption.
The present invention relates to a water-based coating composition having a decomposing action and capable of forming a coating film having a long-lasting effect.

[0002]

2. Description of the Related Art In recent years, the environment surrounding people has been deteriorating.

[0003] Inside the building, the "thermal comfort" is improved, so that the building is highly airtight and sealed.
The environment has low air convection. Despite this environment, indoors are frequently used for chemical building materials, such as formaldehyde contained in adhesives for these building materials and organic phosphorus plasticizers used for vinyl cloth. Sick building (sick house) syndrome, which causes volatile chemicals harmful to the human body (hereinafter referred to as "chemicals") to gradually dissipate indoors after construction, causing residents to have headaches, dizziness, nausea, etc., has become a social problem. ing.

In addition, since the temperature and the humidity are often kept constant throughout the year, a favorable environment is also provided for the propagation of bacteria and mold, and a large amount of bacteria and mold are generated indoors. It has become. And, due to its high airtightness, bacteria and molds do not escape and stay indoors. These microorganisms cause allergic diseases and infectious diseases. Particularly in hospitals and the like, severe hepatitis and methicillin-resistant Staphylococcus aureus (hereinafter referred to as “MR
SA ”. )) And other hospital-acquired infections have also become a problem.

[0005] In order to solve such a problem, coating with various paints is performed. For example, in order to remove indoor chemicals, zeolite, silica gel, activated carbon, phosphate compounds and the like are blended in the paint as an adsorbent, but the coating film formed by such an adsorbent-containing paint Has a drawback that, although it adsorbs chemical substances well in the early stage, it cannot be adsorbed any more when the adsorbent is in a saturated adsorption state, so that the effect is not persistent.

[0006] Further, there are paints containing organic chemicals (for example, thiazole chemicals such as zinc pyrithione, thiazole and isothiazole, phenolic chemicals, bromo chemicals and iodine chemicals) which are highly effective in suppressing the growth of microorganisms. However, there is a problem that the antibacterial function is reduced or disappears within a short period of time because the organic agent keeps the antibacterial effect while eluting from the surface of the coating film after forming the coating film.
On the other hand, inorganic metals such as silver, copper, and zinc are said to have an antibacterial effect, and are attracting attention as having a longer lasting antibacterial effect and higher safety than organic drugs. Although attempts have been made to mix such metals in paints, coatings formed by paints containing silver and copper have a high antibacterial effect, but have the problem of being easily discolored. In order to suppress the discoloration, zeolite, silica gel, and titanium powder are used to support silver, zinc, copper, and the like. When a metal was simply supported on the titanium powder and added to the water-based paint, the metal supported was eluted with time after the formation of the coating film, and as a result, the durability of the antibacterial effect was not obtained.

[0007] For the purpose of both removing chemical substances and having a sustained antibacterial effect, there are those in which titanium oxide having a photocatalytic function is coated on a substrate surface, those in which titanium oxide having a photocatalytic function is added to a paint, and the like. is there. Titanium oxide having a photocatalytic function has both a function of oxidatively decomposing chemical substances by irradiation with light and an antibacterial function of generating OH radicals by light irradiation when oxygen and water are present on the surface. However, the technology of directly coating titanium oxide, which has a photocatalytic function, on the substrate can be performed only under special conditions such as high temperature, so there are many restrictions such as the limitation of the type of substrate and the inability to perform on-site construction. However, there is a drawback that the method cannot be applied particularly to repainting. further,
In the case where titanium oxide having a photocatalytic function is added to the paint, the material resolution of the titanium oxide is too high, and the resin itself in the paint is decomposed, and the physical properties of the coating film are extremely deteriorated, so that it has not been put to practical use. . In addition, since the photocatalyst cannot function in a place where no light is irradiated, there is a disadvantage that an effect cannot be obtained on a coating surface without light irradiation.

[0008] It is also known to obtain a chemical substance adsorption / resolution and antibacterial property by blending in a paint a composite of titanium oxide having a photocatalytic effect and an adsorbent in advance or a composite of silver. However, in practice, although it has antibacterial properties, its practicality is poor because its ability to adsorb chemicals is not so high.

[0009]

At present, no paint composition has been developed which can compensate for all of the above-mentioned various drawbacks. Therefore, the problems to be solved by the present invention are: 1. Adsorb and decompose chemical substances in the air that have a bad effect on the human body. 2. Control the growth of bacteria that cause infectious diseases. An object of the present invention is to provide an aqueous coating composition capable of forming a coating film that satisfies all three points of no discoloration over time.

[0010]

Means for Solving the Problems The present invention relates to the following coating compositions. 1. Aqueous coating composition containing (A) a colloidal antibacterial agent having an average particle diameter of 3 to 500 nm in which silver is attached to titanium oxide having a photocatalytic function and (B) an adsorbent formed by a crystalline layered phosphoric acid compound Wherein the content is (A) 0.1 to 3 parts by weight of solid content and (B) 3 to 55 parts by weight of solid content based on 100 parts by weight of resin solid content of the coating material. Aqueous coating composition. 2. Pigment volume concentration of the aqueous coating composition (hereinafter, "PVC")
That. ) Is 20% to 60%. An aqueous coating composition as described in the above. 3. 1. The crystalline layered phosphate compound is zirconium oxyphosphate. Or 2. An aqueous coating composition as described in the above.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on its embodiments. (A) Antibacterial agent In the aqueous coating composition of the present invention, (A) a titanium oxide having a photocatalytic function with silver adhered thereto, and a colloidal antibacterial agent having an average particle diameter of 3 to 500 nm (hereinafter referred to as “(( A)
Ingredients ". ). As the component (A), a component in which a silver component forms fine particles in the form of a mixture or a compound with titanium oxide or a component in which a silver component is bonded to the surface of titanium oxide is used.

Titanium oxide having a photocatalytic function is classified into an anatase type and a rutile type according to the crystal structure. Since both have a photocatalytic function, either structure may be used. It is desirable to have an anatase type crystal structure having a higher catalytic effect.

The amount of the silver component in the component (A) is desirably in the range of 0.1 to 25% by weight based on the solid content of TiO2. When the silver component is 0.1% by weight or less,
Antibacterial action is not sufficiently exhibited. Further, when the silver component is 25% by weight or more, there is not much difference in the antibacterial action as compared with the case where the silver component is 25% by weight, and the silver component is liable to be discolored easily when the binding amount is large, which is not preferable. .

The component (A) is colloidal and has an average particle diameter of 3 to 500 nm. Average particle size of 50
If the thickness is 0 nm or more, the dispersibility of the component (A) in the coating film becomes poor, and it becomes difficult to maintain the antibacterial effect. On the other hand, when the average particle diameter is 3 nm or less, the stability as a colloid solution is deteriorated.

The component (A) of the present invention is added as a colloid solution. The concentration of the colloid solution can be adjusted, but from the viewpoint of stability, it is preferably 1 to 30% by weight.

The method for producing the component (A) is not particularly limited. For example, the component (A) can be produced by the following method. Note that the present invention is not particularly limited to this method. Aqueous ammonia is gradually added to the aqueous solution of titanium sulfate to form a white slurry. The slurry is filtered to obtain a wet titanic acid cake. Then, the cake is diluted again with pure water, hydrogen peroxide is further added, and the mixture is heated at 80 ° C. for 14 hours to thermally decompose the hydrogen peroxide. Next, silver oxide was dissolved in aqueous ammonia to prepare an aqueous solution of silver ammine complex. An aqueous solution of zirconium ammonium carbonate was added to this aqueous solution to obtain a mixed solution. To the mixture, the above-mentioned aqueous solution of titanic acid was added, and further, silica sol was added.
Heat for 8 hours. Thereafter, the mixture was allowed to stand at room temperature for 48 hours to prepare the component (A) which was a light milky white transparent colloid solution.
The colloid solution can be arbitrarily concentrated using an ultrafiltration membrane.

By using the component (A), elution of silver can be suppressed, so that a sustained antibacterial property can be obtained. In addition, by adding the component (A) which does not cause discoloration of the paint and the coating film seen when silver is added, an aqueous coating composition having no surface discoloration and excellent in various physical properties can be obtained. In addition, by adding the component (A), it becomes possible to decompose chemical substances that cause air pollution, and to suppress the growth of microorganisms that cause infectious diseases.

(B) Adsorbent An adsorbent (B) of the crystalline layered phosphoric acid compound (hereinafter referred to as "component (B)") is added to the aqueous coating composition of the present invention. The component (B) is not particularly limited as long as it is a phosphoric acid compound having a crystal structure in a layered structure. For example, the general formula M (HPO ₄ ) ₂ .nH ₂ O (where M is Zr, Ti,
Ce is an example, and n is an integer), and a crystalline layered phosphate represented by (Al), aluminum tripolyphosphate represented by AlH ₂ P ₃ O ₁₀ .2H ₂ O, and the like can be exemplified. Among these, zirconium oxyphosphate can be suitably used because of its particularly high chemical substance adsorption performance. Such (B)
Among the components, pre-treatment to improve the adsorption function of chemical substances, such as impregnating with hydrazine, impregnating with acid salts of halides of aniline or acid salts of sulfanilamide, and attaching amine salts, etc. It is also possible to perform such pre-processing.

<Aqueous paint> In the present invention, the components (A) and (B) are blended into an aqueous paint, but the aqueous paint is not particularly limited as long as it is a commonly used aqueous paint. . The resin form of the aqueous paint is not particularly limited either, and may be either an aqueous solution or an aqueous dispersion. The resin component is not particularly limited, and a conventionally known resin can be used. For example, alkyd resins, acrylic resins, polyester resins, epoxy resins, fluorine resins, silicone resins, phenol resins, amino resins, melamine resins, urethane resins, and modified resins thereof can be exemplified.
However, like phenolic resin and vinyl chloride resin,
A resin that emits formaldehyde from the resin itself and a resin that releases amine or ammonia such as an amino resin are not desirable. Among such resins, a crosslinked emulsion obtained by reacting a carbonyl group and a hydrazine group, a combination use of the emulsion and an aqueous urethane resin, an aqueous acrylic silicone resin, an aqueous fluororesin, and the like have a problem of chemical resistance and stain resistance. Can be suitably used.

Further, water-based paints include pigments (for example, coloring agents such as titanium white, red iron oxide, oak, carbon black, phthalocyanine blue, azo red and yellow, calcium carbonate, talc, barium sulfate, clay,
Fillers, aggregates, dispersants, curing catalysts, viscosity modifiers, defoamers, plasticizers, etc.
Paint additives commonly used in the field of paints, such as film-forming auxiliaries, preservatives, and rust inhibitors, can be appropriately added as needed. However, it is not preferable to use an additive such as an organic phosphorus-based plasticizer or a tin-based curing accelerator that emits harmful VOCs.

Further, organic chemicals generally used as antibacterial agents and fungicides, such as zinc pyrithione, thiazole, isothiazole chemicals, phenolic chemicals,
A bromo-based agent and an iodine-based agent may be added as long as the paint and the coating film do not discolor.

In addition, a known discoloration inhibitor may be optionally added. Examples include methylbenzotriazole, potassium salts of methylbenzotriazole, methyl 3-benzotriazole-5-t-butyl-4-hydroxypropionate, and the like.

In addition, metals generally known to have antibacterial properties, such as copper, zinc, tin, and lead, may be added to such an extent that paints and coatings do not discolor. Furthermore, it is also possible to add a colloid solution in which these metals are adsorbed on the surface of titanium oxide.

<Blending Ratio> The blending ratio of the aqueous coating composition of the present invention is such that the component (A) is 0.1 to 3 parts by weight (preferably 0 to 3 parts by weight) based on 100 parts by weight of the resin solids of the coating composition. .15 to 1.5 parts by weight) The component (B) has a solid content of 3 to 55 parts by weight (preferably 10 to 1.5 parts by weight).
(35 parts by weight), it is possible to provide a coating film having no discoloration as a coating material and a coating film and having a stable antibacterial action and a chemical substance adsorption / decomposition action over a long period of time.

If the amount of the component (A) is less than 0.1 part by weight, it is difficult to obtain an antibacterial effect and the photocatalysis cannot be obtained. -It is not preferable because the decomposition action does not last long. Conversely, if the amount of the component (A) exceeds 3 parts by weight, discoloration of the paint or coating film will be observed.
Further, since the photocatalytic action becomes stronger, the action of deteriorating the resin itself in the coating film becomes stronger, and as a result, the durability of the coating film decreases, which is not preferable.

When component (B) is less than 3 parts by weight,
The ability to adsorb the chemical substance is reduced, and the adsorption amount of the component (B) reaches saturation faster than the decomposition rate of the harmful chemical substance by the component (A), so that the chemical substance cannot be removed efficiently. On the other hand, if the amount of the component (B) is more than 55 parts by weight, the viscosity of the coating material sharply increases, resulting in poor workability and poor coating stability.

That is, by blending the components (A) and (B) in a well-balanced manner, the antibacterial property of the component (A) is maintained, and the component (B) adsorbs a chemical substance and the photocatalyst of the component (A) The result is a coating composition capable of forming a coating film capable of sustaining the action of decomposing chemical substances by the effect. In particular, by simultaneously blending the component (A) and the component (B), it becomes possible to decompose the adsorbed chemical substance, and it is possible to obtain a coating film having chemical substance adsorption and resolution for a long period of time. It becomes.

<Coating physical properties> The aqueous coating composition of the present invention comprises:
Pigment volume concentration (hereinafter, referred to as “PVC”) is 20% to
Preferably it is 60%. PVC is the volume concentration of the pigment in the dried coating film,

(Equation 1) It is represented by the following equation. If the PVC of the paint is lower than 20%, the coating film surface will be covered with the resin component, and (A)
The antimicrobial effect tends to decrease because the rate at which the components come into contact with microorganisms decreases. In addition, the function of adsorbing harmful chemical substances tends to decrease. On the other hand, if it exceeds 60%, the durability of the coating film tends to decrease, and the contamination of the coating film tends to decrease.

<Others> The coating composition of the present invention can be applied on site by a known method, for example, spraying, brushing, rollers and the like. Further, a dry board, a slate plate, a calcium silicate plate, or the like to be used can be pre-coated at a factory in advance. The coating composition of the present invention can be applied to interior and exterior walls, ceilings, floors, and stairs of buildings, and can also be applied to painting of furniture and daily necessities.

[0030]

Examples of the present invention will be described below. (Synthesis Example 1) Synthesis of antibacterial agent Antibacterial agent 1 was prepared by the following synthesis method. Titanium sulfate is dissolved in pure water to obtain an aqueous solution containing 1.0% by weight in terms of TiO ₂ . While stirring this aqueous solution, 15% by weight
Aqueous ammonia is gradually added to obtain a white slurry.
The slurry is filtered and washed to obtain a wet titanic acid cake. 31.4 g of this cake was diluted by adding pure water so that the concentration of the aqueous solution became 1.0% by weight, and 219.8 g of 33% by weight of hydrogen peroxide was further added thereto, followed by heating at 80 ° C. for 14 hours. Hydrogen oxide is thermally decomposed to form TiO ₂ .
3136 g of a 0% by weight solution were obtained. This titanic acid solution was yellow-brown and transparent, and had a pH of 8.2. Next, 0.68 g of silver oxide was dissolved in 21.3 g of 15% by weight aqueous ammonia and 618.1 g of pure water to obtain an aqueous solution of silver ammine complex salt.
A solution obtained by dissolving 5.4 g in 169.9 g of pure water was added. This mixed aqueous solution was added to the titanic acid aqueous solution, and then 38.7 g of a 20% by weight silica sol was added.
Heated at 50 ° C. for 48 hours. This solution was initially a yellow-brown liquid, but turned into a light milky white transparent colloid solution after 48 hours. The pH of the composite oxide colloid solution was 7.
5, the solid content concentration was 1.0% by weight, and the average particle size of the colloidal particles was 5.0 nm. The colloid solution was concentrated to a concentration of 4.0% by weight using an ultrafiltration membrane to obtain antibacterial agent 1.

Synthesis Example 2 Synthesis of Composite Agent 34.5 g of zinc sulfate crystals (ZnSO4.7H2O) and 6.8 g of silver nitrate crystals were dissolved in 1 liter of distilled water, and a 30% by weight titanium sulfate solution 192 was added to this aqueous solution. 0.0 g was added to adjust a mixed solution having a pH of about 1. This mixture
It contains 0.04 mol of Ag ions, 0.12 mol of Zn ions, and 0.24 mol of Ti ions. About 330 g of a 15% by weight phosphoric acid solution was added dropwise to the mixture at room temperature with stirring, and a white precipitate was formed. The mixture in which a white precipitate was formed was stirred at room temperature for 24 hours. Then, the mixture containing the white precipitate was added with 15
A weight percent sodium hydroxide solution was added dropwise with stirring at room temperature until the pH reached 7.0, whereby a white precipitate was further formed. Further, stirring was continued at room temperature. At this time, when the pH is lowered, the pH is adjusted to 7.7 by further adding a 15% by weight sodium hydroxide solution.
It was kept at zero. Stirring was continued until no decrease in pH was observed, and a white mixed precipitate containing Ag-Zn-Ti was formed (Solution A). Next, the titanium oxide sol (Ti
320 g (including 30% by weight as O ₂ ) were added dropwise, and at the same time, a 15% by weight sodium hydroxide solution was
When the solution was dropped so as to be kept at H7, Ag-Zn-T
A mixed precipitate of i-TiO ₂ was formed. The resulting white precipitate was filtered off with suction and washed thoroughly with warm deionized water.
By drying at 40 ° C. and pulverizing the dried powder to 10 μm or less, a white powder containing Ag—Zn—Ti—TiO 2 was obtained.

Example 1 An aqueous coating composition was prepared using the raw materials shown in Table 1 according to the formulation shown in Table 2.
That is, after adding 80 parts by weight of water to 167 parts by weight of the coloring pigment and sufficiently stirring, the acrylic emulsion 20 was added.
0 parts by weight (100 parts by weight in solid content) and 6 parts of various additives
Add 6 parts by weight and further stir. Then, extender 153
A part by weight was added and stirred to produce an aqueous paint paste.
To the prepared aqueous paint paste, 7.0 parts by weight of antibacterial agent 1 (0.28 parts by weight in solid content) and 13.5 parts by weight of crystalline layered zirconium phosphate were added, and the mixture was sufficiently stirred to obtain an aqueous paint composition. Things. The PVC of the prepared paint was 51.5%. The following test was performed about the produced aqueous coating composition.

1. Antibacterial test A A 5.0 × 5.0 cm filter paper was coated with the prepared aqueous coating composition so that the coating amount was 250 g / m 2, and the temperature was 20 ° C.
A specimen cured at 7 ° C. and a humidity of 65% (hereinafter referred to as “standard state”) for 7 days is used as a test specimen. The bacteria to be tested are of four types: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida.

Each bacterial suspension is adjusted with 10 ml of physiological saline. Add each to 200 ml of saline,
After dispensing 10 ml into a test tube with a Molton stopper, keep the temperature at 30 ° C. This bacterial suspension is applied to an ordinary agar medium,
The number of bacteria after culturing at 28 ° C. for 48 hours was measured and used as a blank. Cut the filter paper of the test piece into 1.0 × 4.0 cm to obtain test pieces (four pieces). The test piece is placed in the test tube prepared in the above, and cultured with shaking for 24 hours. A solution obtained by diluting the culture obtained by shaking culture 100 times with physiological saline was applied to a normal agar medium with a spiral plater.
The number of bacteria after culturing at 8 ° C. for 48 hours was measured, and the sterilization rate was calculated by comparison with a blank. The results are shown in Table 4.

2. Antibacterial test B The aqueous coating composition prepared on an aluminum plate of 150 x 70 x 0.8 mm was applied with a 250 g / m2 applicator and cured under standard conditions for 7 days to prepare a test plate. The test specimen prepared was cut into a size of 5.0 × 5.0 cm. The bacteria to be tested for antibacterial activity are Staphylococcus aureus and Pseudomonas aeruginosa.

Various bacteria are inoculated on a normal agar medium and grown at 35 ° C.
For 24 hours. The cultured various bacteria were collected and diluted with sterile physiological saline to prepare a bacterial solution of about 10 ⁶ / ml. 0.5 ml of the above bacterial solution is inoculated on the surface of the test body, a sterile film is put on the surface, and the bacterial solution is sufficiently contacted with the solution. Bacteria are washed out thoroughly with 10 ml of SCDLP medium,
The number of surviving bacteria in 1 ml of this solution was measured, and the sterilization rate was calculated in comparison with a blank. The number of surviving bacteria was measured by culturing for 48 hours using a standard agar medium, and a blank was filled with 0.5 ml in a Petri dish, covered with a sterile film and sufficiently contacted with the bacterial solution, and then subjected to the same test. Blank was set. The results are shown in Table 4.

3. Storage stability test In a 250 ml plastic container, 2 parts of the aqueous coating composition thus prepared were stored.
50 g was put in a thermostat set at 50 ° C. ± 2 ° C. for 10 days, and the stability (viscosity change, hue change) as a paint was evaluated. The results are shown in Table 5.

4. Water resistance test On a 150 × 70 × 3 mm asbestos slate plate, the prepared aqueous coating composition was applied with an applicator at a coating amount of 250 g / m ² , and cured under standard conditions for 7 days to form a test plate. The prepared test plate was immersed in tap water for 7 days, and the surface state (discoloration, swelling, cracking, etc.) of the coating film was visually evaluated. The results are shown in Table 5.

5. Ultraviolet irradiation test The prepared aqueous coating composition was applied to an asbestos slate board of 150 x 70 x 3 mm at an application amount of 250 g / m2 with an applicator, and cured under standard conditions for 7 days to form a test board. The prepared test plate was tested with a fading test lamp according to JIS K 5400 (1990) 9.7.2 Lightfastness test (mercury lamp type).
Irradiation was performed for 00 hours, and the discoloration of the coating film was evaluated. The results are shown in Table 5.

6. The aluminum plate of the adsorption test 150 × 70 × 0.8mm, subjected coating the aqueous coating composition prepared by an applicator in coat-weight 250 g / m ^2, was tested body was 7 days cured dried at standard conditions. After one test piece is placed in a 3 L odor bag, the air inside is removed and sealing is performed. The odor bag is filled with air adjusted to a concentration of 20 ppm of formaldehyde. Prepare two of these, one in a room with a fluorescent light,
The other was placed in a dark room and left for 2 hours while measuring the formaldehyde concentration with a detector tube every 30 minutes. After measuring for 2 hours, all the air in the smell bag is removed once, and the formaldehyde is again filled with air adjusted to a concentration of 20 ppm, and the same test is performed. Filling with formaldehyde → leaving for 2 hours while measuring the formaldehyde concentration every 30 minutes → gas removal was defined as one cycle and repeated seven times. The results were obtained by graphing the formaldehyde concentration in the odor bag from 5 cycles to 7 cycles.
It was shown to.

(Examples 2 to 7) Using the raw materials shown in Table 1, an aqueous coating composition was prepared according to Example 1 as shown in Table 2. The prepared coating composition was evaluated in the same manner as in Example 1, and the results were shown in Tables 4, 5 and FIGS.
As shown in FIG.

(Comparative Examples 1 to 10) Using the raw materials shown in Table 1, water-based coating compositions were prepared according to Example 1, as shown in Table 3. About the prepared coating composition,
Evaluation was performed in the same manner as in Example 1, and the results were shown in Tables 4 and 5, FIG.
16 to FIG. In addition, about Comparative Example 10, it gelled during preparation of the coating composition and could not be evaluated.

<Results of Examples and Comparative Examples> In the antibacterial test, in Comparative Example 1 containing no antibacterial agent, no antibacterial effect was obtained, and in Comparative Example 8 using a composite agent and rutile-type titanium oxide. Comparative Example 9 in which silver was carried as an antibacterial agent resulted in poor antibacterial effect. In the storage stability test, in Comparative Example 5 in which an antibacterial agent having silver supported on zeolite was used, an increase in viscosity and discoloration (gray) were observed. Comparative Example 6, in which activated carbon was blended, showed an increase in viscosity,
The paint itself was grayish and lacked practicality. Further, in Comparative Example 4 using an antibacterial agent in which silver was supported on rutile-type titanium oxide, discoloration was observed.

Comparative Example 3 in which antibacterial agent 1 was incorporated in a large amount, Comparative Examples 4 and 9 in which an antibacterial agent in which silver was supported on rutile-type titanium oxide, and an antibacterial agent in which zeolite supported silver was used. The result of Comparative Example 5 was that the coating film turned black in the water resistance test. In addition, Comparative Example 4 using an antibacterial agent carrying silver on rutile-type titanium oxide and Comparative Example 5 using an antibacterial agent carrying silver on zeolite
Was slightly discolored to gray in an ultraviolet irradiation test. Further, in Comparative Example 6 in which activated carbon was blended, the coating film was gray from the beginning, resulting in lack of practicality.

In the adsorption test, as shown in FIGS. 1 to 7, the compounds formulated in the range according to the present invention were continuously adsorbed under light irradiation as shown in FIGS. It became clear that the effect could be maintained. On the other hand, as for Comparative Examples 1 and 5, those containing no component having a photocatalytic function showed a decrease in the adsorption effect over time. In Comparative Example 4 having a large titanium particle diameter even when titanium having a photocatalytic action was used in combination, almost no persistence of the adsorption effect by the catalytic action was observed. Furthermore, in Comparative Example 2 in which no adsorbent was added, no adsorption effect was observed except for a slight physical adsorption on the surface of the coating film. Next, Comparative Example 6 using activated carbon as an adsorbent and Comparative Example 7 using silica gel showed an adsorbing effect, but the adsorbing effect itself was low, and there was no sustainability as seen in Examples. Was. Further, for Comparative Example 8 in which a complexing agent combining an antibacterial agent and an adsorbent was added in advance,
The light irradiation slightly improved the adsorption effect, but no remarkable effect was observed. Also, the overall adsorption effect was low.

Therefore, only when the component (A) and the component (B) of the present invention are blended in a specific blending ratio, a coating film having antibacterial properties, excellent storage stability, excellent water resistance and excellent light resistance. Was found to be an aqueous coating composition obtained. In addition, a water-based coating composition that has the function of decomposing chemical substances and that can absorb and decompose chemical substances harmful to the human body over a long period of time to obtain a coating film that can purify the environment. Was revealed.

[0047]

According to the present invention, it is possible to adsorb and decompose chemical substances that may have a bad effect on the human body,
To provide a coating film capable of performing environmental purification over a long period of time, and furthermore to provide a coating film capable of suppressing the growth of microorganisms causing infectious diseases and contamination of the coating film surface. Can be. Further, the present invention can provide an aqueous coating composition which is free from discoloration of the coating film surface over time and has excellent storage stability and various physical properties of the coating.

[Brief description of the drawings]

 Figure 1: Adsorption test results of Example 1 Figure 2: Adsorption test results of Example 2 Figure 3: Adsorption test results of Example 3 Figure 4: Adsorption test results of Example 4 Figure 5: Adsorption test results of Example 5 Fig. 6: Adsorption test result of Example 6 Fig. 7: Adsorption test result of Example 7 Fig. 8: Adsorption test result of Comparative example 1 Fig. 9: Adsorption test result of Comparative example 2 Fig. 10: Adsorption test result of Comparative example 3 Fig. 11: Adsorption test result of Comparative Example 4 Fig. 12: Adsorption test result of Comparative Example 5 Fig. 13: Adsorption test result of Comparative Example 6 Fig. 14: Adsorption test result of Comparative Example 7 Fig. 15: Adsorption test result of Comparative Example 8 Figure 16: Adsorption test result of Comparative Example 9

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hisashi Suzuki 1-25-10 Shimizu, Ibaraki-shi, Osaka

Claims (3)

[Claims] (1) a colloidal antibacterial agent having an average particle diameter of 3 to 500 nm in which silver is attached to titanium oxide having a photocatalytic function and (B) an adsorbent formed by a crystalline layered phosphoric acid compound. It is an aqueous coating composition to be contained, wherein the content is 0.1 to 3 parts by weight in terms of (A) solid content and 3 to 55 parts by weight in terms of solid content with respect to 100 parts by weight of resin solid content of the coating material. An aqueous coating composition comprising: 2. A pigment volume concentration of an aqueous coating composition (hereinafter, referred to as a pigment concentration).
It is called "PVC". ) Is from 20% to 60%. 3. The aqueous coating composition according to claim 1, wherein the crystalline layered phosphoric acid compound is zirconium oxyphosphate.