JP2019196440A - Coated film and aqueous composition - Google Patents

Abstract

To provide a coated film capable of maintaining the antifouling property, the alga-proofing property and the antifungal property over a long term even when exposed to an outdoor environment, and an aqueous composition that forms the coated film.SOLUTION: A coated film containing an antibacterial metal-containing compound has a total content mass of the antibacterial metal-containing compound in the coated film after passing 2500 hours by an exposure test according to JIS K 5600-7-7 of 5% or larger relative to a total content mass of the antibacterial metal-containing compound in the coated film before the exposure test, has pores in the coated film and has the porosity of the coated film of 1 to 30%.SELECTED DRAWING: None

Description

  The present invention relates to a coating film and an aqueous composition.

By forming a coating film on various base materials using coating materials, it is possible to impart physical properties that do not appear on each base material alone, and it has been sold and developed as various high value-added products. .
In particular, by coating with a hydrophilic coating film, it is possible to impart antifouling properties, antifogging properties, etc., so a wide range of building applications such as building materials and window glass, automotive applications such as automobile bodies and headlamp covers, etc. In the field, expression of functions by the coating film is expected.

  However, the coating film having hydrophilicity usually tends to propagate microorganisms such as bacteria, molds, and algae, which not only causes poor appearance and deterioration of the coating film, but also may cause bad odor due to bacteria, etc. Contamination due to breeding has attracted attention as a problem to be solved, and various techniques have been proposed.

For example, a hydrophilic coating film imparted with an antifungal property by adding a compound exhibiting an antifungal property to the hydrophilic polymer has been proposed (for example, see Patent Document 1).
Moreover, the photocatalyst coating film which exhibits antifouling property has also been proposed in which a photocatalyst combined with an antibacterial metal is blended (see, for example, Patent Documents 2 and 3).

JP 2009-256571 A Japanese Patent No. 5343176 Japanese Patent No. 5361513

  However, in the hydrophilic coating film proposed in Patent Document 1, since the polymer as the binder component of the coating film is easily deteriorated by ultraviolet rays in the outdoor environment, the hydrophilicity and antifouling property of the coating film are reduced. In addition, there is a problem that the antifungal agent may flow out due to decomposition or rainwater, and the effect may not be maintained for a long time.

  Moreover, in the photocatalyst coating film currently disclosed by patent document 2 and patent document 3, although the degradation and the outflow by rainwater are suppressed by using a slightly water-soluble antibacterial metal containing compound, titanium oxide and the said antibacterial As the result, it is difficult to suppress the detachment of the antibacterial metal-containing compound exposed on the coating surface for a long time because the interaction with the active metal-containing compound is weak such as van der Waals force. There is a problem that the effect on bacteria and the like may not last for a long time.

  Therefore, in the present invention, even when exposed to an outdoor environment such as ultraviolet light or rainwater, a coating film that maintains antifouling, antialgal and antifungal properties over a long period of time, and this It aims at providing the aqueous composition which forms a coating film.

As a result of intensive studies to solve the above-mentioned problems of the prior art, the present inventors have found that the antibacterial metal-containing compound remains more than a specific amount after the accelerated weathering test, and has a specific range ratio in the coating film. The present invention was completed by finding that the above-mentioned problems of the prior art can be solved by a coating film having voids, and that the coating film can be provided by an aqueous composition containing antibacterial metal particles, colloidal silica, and a specific compound. I came to let you.
That is, the present invention is as follows.

[1]
A coating film containing an antibacterial metal-containing compound,
The total content mass of the antibacterial metal-containing compound in the coating film after 2500 hours has elapsed in an exposure test according to JIS K 5600-7-7,
5% or more based on the total content of the antibacterial metal-containing compound in the coating film before the exposure test,
There are voids in the coating film,
The porosity of the coating film is 1 to 30%.
Coating film.
[2]
An aqueous composition for forming the coating film described in [1] above,
water and,
Antibacterial metal particles A;
A compound B containing in the molecule a functional group B1 that interacts with the antibacterial metal particle A and a functional group B2 that is at least one selected from the group consisting of a silanol group and a functional group that interacts with a siloxane bond;
Colloidal silica C,
Containing,
The aqueous composition whose ratio with respect to the mass of the said colloidal silica C of the mass of the said antibacterial metal particle A is 0.01 to 10.0%.
[3]
Compound B is
The aqueous composition according to [2] above, which is a silane compound containing a thiol group or an amino group as the functional group B1 at the molecular end.
[4]
The aqueous composition according to [2] or [3], wherein the ratio of the mass of the compound B to the mass of the antibacterial metal particles A is 1 to 300%.
[5]
The ratio of the average particle diameter of the antibacterial metal particles A to the average particle diameter of the colloidal silica C, (average particle diameter of the antibacterial metal particles A) / (average particle diameter of the colloidal silica C) is 0.01 to 10. The aqueous composition according to any one of [2] to [4], which is 10.
[6]
The aqueous composition according to any one of [2] to [5], wherein the content of the colloidal silica C is 50 to 99% with respect to the total solid content contained in the aqueous composition.
[7]
The aqueous composition according to any one of [2] to [6], wherein the antibacterial metal particle A is at least one selected from the group consisting of gold, silver, copper, and a compound thereof. .
[8]
The aqueous composition according to any one of [2] to [7], further including particles D having photocatalytic activity.
[9]
The aqueous composition according to [8], wherein the particles D having photocatalytic activity are at least one selected from the group consisting of titanium oxide, tungsten oxide, and silica-coated titanium oxide.

  According to the present invention, even when exposed to an outdoor environment such as ultraviolet light or rainwater, a coating film that maintains antifouling, algal and antifungal properties over a long period of time, and this An aqueous composition for forming a coating film can be provided.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist.

[Coating]
The coating film of this embodiment is a coating film containing an antibacterial metal-containing compound, and the antibacterial metal in the coating film after 2500 hours has passed in an exposure test in accordance with JIS K 5600-7-7. The total content mass of the containing compound is 5% or more with respect to the total content mass of the antibacterial metal-containing compound in the coating film before the exposure test, and there are voids in the coating film, The porosity is 1-30%.

(Antimicrobial metal-containing compounds)
The coating film of this embodiment contains an antibacterial metal-containing compound.
The antibacterial metal-containing compound refers to a compound containing a metal having a growth inhibitory function against E. coli cells, and the antibacterial metal-containing compound includes a known simple metal, its salt, its oxide, and its nitridation. Antibacterial metal-containing compounds such as products, metal complexes and the like.
Examples of the elements used in the antibacterial metal-containing compound include metal elements having a minimum inhibitory concentration (MIC) of metal ions for E. coli cells of 20 mM or less, and specifically, elements such as gold, silver, copper, and zinc. Is mentioned.
Examples of the compound using these metal elements include chloroauric acid, silver nitrate, silver chloride, silver bromide, silver iodide, copper sulfate pentahydrate, copper nitrate, copper nitride, copper iodide, copper hydroxide. And salts such as copper oxide, cuprous oxide, copper acrylate and zinc nitrate, complexes such as copper pyrithione, copper phthalocyanine and zinc pyrithione, and combinations of cyclic compounds such as porphyrin and crown ether with metal ions.
Among these antibacterial metal-containing compounds, the inclusion of antibacterial metal particles A, which will be described later, is preferable because deterioration of the antibacterial metal-containing compound itself and outflow due to rainwater and the like are small.

The coating film of this embodiment is characterized in that the antibacterial metal-containing compound exhibits a specific residual rate after a predetermined exposure test.
That is, the coating film of this embodiment is subjected to a 2500 hour test in an exposure test based on JIS K 5600-7-7, and the content of the antibacterial metal-containing compound in the coating film after the test is The ratio to the antibacterial metal-containing compound is 5% or more.
Since the exposure test in accordance with JIS K 5600-7-7 is a standard used for the long-term durability test of the coating film, is the test more effective for long-term anti-algal and anti-mold properties of the coating film? This is preferable as an accelerated test for verification. The exposure time of 2500 hours is a judgment time for evaluating the weather resistance in the standard for architectural finish coating materials defined in JIS A 6909, and is preferable as a time for judging the durability of the coating film.

The antibacterial metal-containing compound is a problem that the coating resin is deteriorated or a highly soluble metal salt or the like is extracted by rain water or the like, and the content in the coating film is easily lowered after a long period of time. have.
Therefore, in this embodiment, the residual rate of the antibacterial metal-containing compound after the exposure test is specified as 5% or more.
As a method for adjusting the residual amount of the antibacterial metal-containing compound, specifically, for increasing the residual amount in the coating film, for example, an antibacterial metal-containing compound is previously contained in an organic resin such as an acrylic resin. , A method in which a functional group of a side chain of a polymer is reacted with an antibacterial metal-containing compound in a water-based composition for forming a coating film, metal ions in inorganic particles such as zeolite and mesoporous silica And a method of preparing an aqueous composition using antibacterial metal particles A, compound B and colloidal silica C, which will be described later, are effective.

The coating film of this embodiment divides the total content mass of the antibacterial metal-containing compound in the coating film after the exposure test by the total content mass of the antibacterial metal-containing compound in the coating film before the exposure test. What is represented by the indication, [(total content of antibacterial metal-containing compound after exposure test) / (total content of antibacterial metal-containing compound before exposure test)] × 100, that is, the residual rate after the exposure test 5% or more.
The total content mass means the total amount when a plurality of types of antibacterial metal-containing compounds are included.
When the residual ratio of the antibacterial metal-containing compound is 5% or more, the antialgae and antifungal properties are maintained. Preferably it is 10% or more, more preferably 20% or more. The upper limit is not particularly limited, but is preferably 100%.

(Void)
The coating film of this embodiment has voids in the coating film.
The coating film of this embodiment has a porosity of 1 to 30%.
The porosity is a volume fraction occupied by air contained in the coating film, and can be measured by a method described in Examples described later.
It is preferable that the said space | gap exists immediately after a coating film is formed, and it is preferable to have a space | gap even after the exposure test based on JISK5600-7-7 mentioned above.

The presence of 1% or more voids in the coating film ensures a sufficient specific surface area of the voids in the coating film, which allows metal ions released from antibacterial metal-containing compounds and multilayer coating films. In this case, the agent from the lower layer of the coating film of this embodiment is preferable because it diffuses in the voids and is easily extracted on the surface of the coating film, and the anti-algae and antifungal properties are further improved.
In addition, the presence of 1% or more voids is preferable because distortion due to heat and moisture expansion and contraction of the coating film is absorbed and cracks are reduced.
When the porosity is 30% or less, the specific surface area of the voids in the coating film is appropriately suppressed, and thereby the proportion of the space where the constituent components in the coating film do not contact each other is suppressed and contained in the coating film It is preferable because the solids can be sufficiently bonded and interacted with each other, or the lower layer substrate or coating film and the coating film constituents of this embodiment, and the adhesion of the coating film is improved.

The porosity in the coating film can be controlled by selecting the shape of a plurality of particles contained in the coating film, adjusting the particle diameter ratio or mixing ratio thereof, or adjusting the film forming conditions. .
Specifically, blending particles having a morphology other than spherical, such as pearl or linear, adjusting the glass transition temperature and minimum film formation temperature of the organic resin to be blended, and the blending ratio of the resin, The coating film obtained by drying the aqueous composition can be controlled within a predetermined numerical range by an operation of intentionally decomposing the organic matter by sintering.

  The coating film of this embodiment has a porosity of 1 to 30%, preferably 5 to 28%, and more preferably 10 to 25%.

[Aqueous composition]
The aqueous composition of the present embodiment is an aqueous composition that forms the coating film of the present embodiment described above,
water and,
Antibacterial metal particles A;
A compound B containing in the molecule a functional group B1 that interacts with the antibacterial metal particle A and a functional group B2 that is at least one selected from the group consisting of a silanol group and a functional group that interacts with a siloxane bond;
Colloidal silica C,
Containing,
The ratio of the mass of the antibacterial metal particles A to the mass of the colloidal silica C is 0.01 to 10.0%.

The coating film in this embodiment can be obtained by a known coating application method using the aqueous composition of this embodiment.
Moreover, you may implement pre-processing, such as a heating and a corona treatment, by the kind of coating film in the base material or the lower layer of the said coating film. Furthermore, the aqueous composition of this embodiment may be applied a plurality of times to form a multilayer coating film, or a coating film made of another composition may be formed on the coating film surface.

(Antimicrobial metal particles A)
The antibacterial metal particle A refers to, for example, a metal particle having a minimum inhibitory concentration (MIC) of metal ion for E. coli cells of 20 mM or less.
The minimum inhibitory concentration (MIC) is the minimum concentration of a drug (referred to here as a metal ion) necessary to inhibit the growth of bacteria.

In the aqueous composition of the present embodiment, the ratio of the mass of the antibacterial metal particles A to the mass of the colloidal silica C, [(mass of the antibacterial metal particles A) / (mass of the colloidal silica C)] × 100 (%) That is, the value expressed as% by dividing the mass of the antibacterial metal particles A by the mass of the colloidal silica C is preferably 0.01 to 10.0%.
When the mass proportion of the antibacterial metal particles A is 0.01% or more, the antialgae and fungicide properties can be exhibited, and when it is 10% or less, the coating film derived from the antibacterial metal-containing compound is colored. Is preferable.

In the aqueous composition of the present embodiment, the ratio of the mass of the antibacterial metal particles A to the mass of the colloidal silica C is more preferably 0.01% or more, 0.05% or more, 0.1% or more, 0 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more, 2.5% or more, 3.0% or more, 3.5% or more, 10.0% or less, 9 0.5% or less, 9.0% or less, 8.5% or less, 8.0% or less, 7.5% or less, 7.0% or less, 6.5% or less, 6.0% or less, 5.5 % Or less and 5.0% or less.
The specific numerical range is preferably 0.01 to 10.0%, more preferably 0.05% to 0.05% from the viewpoint of the balance between the algaeproofing, antifungal properties, and the colorability of the coating film. The range is 8.0%, more preferably 0.1 to 5.0%.

In the aqueous composition of the present embodiment, the average particle diameter of the antibacterial metal particles A is the ratio of the average particle diameter of the colloidal silica C, (average particle diameter of the antibacterial metal particles A) / (average particle of the colloidal silica C). (Diameter) is preferably 0.01 to 10.0.
In the coating film, the ratio of the average particle diameter is 0.01 or more, for example, the average particle diameter of the antibacterial metal particles A is constant and the average particle diameter of the colloidal silica C is suppressed to 0.01 or more. Since the specific surface area of the colloidal silica C is secured, the hydrophilicity of the coating film, that is, the antifouling property is improved, which is preferable.
The average particle size ratio is 10.0 or less, for example, the particle size of colloidal silica C is constant, and the particle size of the antibacterial metal particles A is suppressed to 10.0 or less so that the transparency of the coating film is achieved. Moreover, since the colorability derived from a metal is suppressed, it is preferable.

This ratio of average particle diameter (average particle diameter of antibacterial metal particles A) / (average particle diameter of colloidal silica C) is 0.01 or more, 0.02 or more, 0.03 or more, 0.04 or more, 0 0.05 or more, 1.0 or more, and 2.0 or more are preferable, 10.0 or less, 9.0 or less, 8.0 or less, 7.0 or less, 6.0 or less, 5.0 or less, 4.0 or less 3.0 or less is preferable.
The specific numerical range of this ratio (average particle diameter of antibacterial metal particles A) / (average particle diameter of colloidal silica C) is 0.01 from the viewpoint of the balance of transparency, colorability and hydrophilicity of the coating film. It is preferable that it is-10.0, More preferably, it is 0.01-5.0, More preferably, it is 0.02-3.0.

Examples of the antibacterial metal particles A include heavy metals such as silver, gold, palladium, platinum, cobalt, nickel, copper, zinc, lead, and manganese.
Among these, as antibacterial metal particles A, gold, silver, copper, platinum, and zinc can be preferably used from the viewpoint of safety and practicality, and gold, silver, and copper are more preferable. Can be mentioned. These heavy metals may be used alone or in combination of two or more.

Examples of the existence form of the antibacterial metal particles A include the form of the metal simple substance, the form of the metal compound, the form of the ionic state, the form of a state complexed with other compounds, and the like. In particular, a form of a simple metal or a metal compound which is hardly soluble in water is preferable.
This is because the metal simple substance or the antibacterial metal-containing compound is hardly soluble in water, so that the metal ions themselves generated by the dissolution of the metal are reduced by absorbing light, and as a result, the color of the coating film changes with time. This is because the possibility of changing can be reduced. In addition, when the metal simple substance or the antibacterial metal-containing compound is hardly soluble in water, it is prevented from flowing out with moisture such as rain in the outdoor environment, thereby maintaining the effect of the present invention. be able to.

The component of the antibacterial metal particle A is preferably at least one selected from the group consisting of gold, silver, copper, a gold compound, a silver compound, and a copper compound.
As an example of the component of the antibacterial metal particle A, in the case of gold, for example, simple substance of gold, in the case of silver, simple substance of silver and its compound, for example, in the case of copper, such as silver oxide and silver chloride Copper simple substance and its compound, for example, copper oxide, copper hydroxide, etc. are mentioned.

  As a method for producing the antibacterial metal particles A, various chemical reactions can be used. Among them, a water-soluble antibacterial metal-containing compound containing a metal ion as a precursor is dissolved in water and metal ions are present. Below, the method of adding the water-soluble reducing agent and generating the antibacterial metal particles A by the reduction reaction is preferable because a high yield can be achieved and the reaction time can be shortened.

(Compound B)
The aqueous composition of the present embodiment has at least one functional group selected from the group consisting of a functional group B1 that interacts with the antibacterial metal particle A, a functional group that interacts with a silanol group and a siloxane bond in the molecule. Contains the compound B containing the group B2.

By containing the compound B, when the coating film is formed, the antibacterial metal particle A and the functional group B1 interact, and the functional group B2 interacts with colloidal silica C and the like, which will be described later. The effect of immobilizing A in the coating film is improved. Accordingly, the antibacterial metal particles A are prevented from dropping off from the coating film surface or crack cross-section due to external factors such as rainwater or the expansion and contraction of the coating film, and as a result, the anti-algal and anti-mold properties are maintained for a long time. .
Moreover, regarding the coating film formed with an inorganic compound, by containing this compound B, the interaction between the inorganic compound and the antibacterial metal particles A is improved, and the toughness of the coating film is also improved. The crack resistance of the coating film becomes good.

In the compound B, examples of the functional group B1 that interacts with the antibacterial metal particle A include an aromatic group and a polar group, and examples of the aromatic group include a phenyl group, a naphthyl group, and an imidazole group. It is done. Examples of the polar group include an epoxy group, a thiol group, and an amino group.
In particular, the use of a thiol group or amino group that has a strong interaction with a metal is preferable because the effect of fixing the antibacterial metal particles A to the coating film is enhanced.

Further, the compound B contains in its molecule a functional group B2 which is at least one selected from the group consisting of a silanol group and a functional group that interacts with a siloxane bond.
Examples of the functional group B2 include a silanol group and an amide group. In particular, a silanol group is preferable from the viewpoint of strong hydrogen bonding with a silanol group of colloidal silica, good compatibility with water, and solubility and dispersibility.
The silanol group may be an alkoxysilane group before hydrolysis or a siloxane bond by condensation. In particular, from the viewpoint of further enhancing the above-described immobilization effect by interacting with both the antibacterial metal particles A and the colloidal silica C, the compound B contains a thiol group or an amino group as the functional group B1, and as the functional group B2. It is preferably a silane compound containing at least one selected from the group consisting of a silanol group and a functional group that interacts with a siloxane bond.

  Examples of the compound B having a thiol group or an amino group and having a silanol group include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-aminopropyltri Examples thereof include hydrolysates such as methoxysilane, 3-aminopropylmethyldimethoxysilane, and 3-aminopropyltriethoxysilane, or compounds in which they are partially condensed.

In the aqueous composition of the present embodiment, the ratio of the mass of the compound B to the mass of the antibacterial metal particles A [(mass of the compound B) / (mass of the antibacterial metal particles A)] × 100 (%), that is, The value expressed as% by dividing the mass of the compound B by the mass of the antibacterial metal particles A is preferably in the range of 1 to 300%.
When it is 1% or more, the antibacterial metal particles A are preferably immobilized on the coating film and crack resistance is exhibited, and when it is 300% or less, an excess that does not interact with the antibacterial metal particles A is preferable. Is preferable because the compound B is reduced and the storage stability of the aqueous composition is improved and the porosity of the coating film is prevented from being lowered.

The ratio of the mass of the compound B to the mass of the antibacterial metal particles A is preferably 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 300% or less, 290% or less, 280%. Below, 270% or less, 260% or less, 250% or less, 230% or less, 210% or less, or 200% or less is preferable.
As a specific numerical range, from the viewpoint of the immobilization effect of the antibacterial metal particles A in the coating film and the balance such as the storage stability of the aqueous composition, it is preferably in the range of 1 to 300%. More preferably, it is 2-280%, More preferably, it is 4-250%.

(Colloidal silica C)
Examples of the colloidal silica C include acidic colloidal silica and basic colloidal silica using water as a dispersion medium.

  Examples of the acidic colloidal silica include commercially available products such as Snowtex (registered trademark) -O, Snowtex-OS manufactured by Nissan Chemical Industries, Adelite (registered trademark) AT-20Q manufactured by Asahi Denka Kogyo Co., Ltd., and clebosol manufactured by Clariant Japan. (Registered trademark) 20H12, clebosol 30CAL25, etc. can be mentioned.

  Examples of basic colloidal silica include silica stabilized by the addition of alkali metal ions, ammonium ions, amines, and the like. Specifically, SNOWTEX-NS, SNOWTEX-20 manufactured by Nissan Chemical Industries, Ltd. , SNOWTEX-30, SNOWTEX-C, SNOWTEX-C30, SNOWTEX-CM40, SNOWTEX-N, SNOWTEX-N30, SNOWTEX-K, SNOWTEX-XL, SNOWTEX-YL; Examples include Adelite AT-20, Adelite AT-30, Adelite AT-20N, Adelite AT-30N, Adelite AT-20A, Adelite AT-30A, and Adelite AT-40.

  As the colloidal silica, one of these or a combination of two or more may be used.

The content of colloidal silica C in the aqueous composition is preferably 50 to 99% with respect to the mass of the total solid content contained in the aqueous composition.
When it is 50% or more, not only the hydrophilic property is exhibited and the antifouling property is improved, but also the interaction with the above-mentioned compound B is improved and the antibacterial metal particles A are easily fixed in the coating film. Therefore, long-term algae and fungicides are improved.
Moreover, by being 99% or less, the content of antibacterial metal particles A and other components such as synthetic resins and surfactants is relatively increased, and long-term anti-algal and anti-fungal properties are exhibited. It is preferable because it is advantageous in forming a coating film.

The ratio of the mass of colloidal silica C in the aqueous composition to the total solid content in the aqueous composition is preferably 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, and 99 % Or less, 95% or less, 90% or less, 85% or less, or 80% or less is preferable.
The specific numerical range is preferably 50 to 99%, more preferably 55 to 98%, and still more preferably 60 from the viewpoint of the balance of hydrophilicity, algae resistance, mold resistance, and film formability. ~ 95%.

  In the present specification, “total solid content” means the total mass of non-volatile components contained in the aqueous composition. Moreover, the method based on JISK5601-1-2 is used for the measurement of a non volatile matter.

(Particle D having photocatalytic activity)
The aqueous composition in the present embodiment may further contain photocatalyst particles D having photocatalytic activity.
By including the photocatalyst particles D, it is possible to further improve the antifouling property by utilizing organic matter decomposition and super hydrophilicity known as photocatalytic action.

Examples of the particles D having photocatalytic activity include titanium oxide (TiO ₂ ), zinc oxide (ZnO), strontium titanate (SrTiO ₃ ), gallium phosphide (GaP), and barium titanate (for example, BaTiO ₃ , BaTiO _4). Or BaTi ₄ O ₉ ), potassium niobate (K ₂ NbO ₃ ), niobium pentoxide (Nb ₂ O ₅ ), iron oxide (eg Fe ₂ O ₃ ), tungsten oxide (eg WO ₃ ), oxidation Examples include tin (for example, SnO ₂ ), copper oxide (for example, Cu ₂ O), and the like.
In addition, for the purpose of improving the dispersion stability in the dispersion medium, the above particles can be used with the surface modified and coated with silicon dioxide (silica), aluminum oxide (alumina) or the like.

  Among these, as the photocatalyst particles D having photocatalytic activity, it is preferable to use at least one or more of titanium oxide, tungsten oxide, and silica-coated titanium oxide from the viewpoint of safety and cost. Examples of the crystal structure of titanium oxide include an anatase type, a rutile type, and a brookite type, and any of them may be used.

Antibacterial metal particles A may be supported on the surface of the particles D having photocatalytic activity.
It is known that antibacterial metal particles A interact with a photocatalytic compound and exhibit physical properties such as visible light responsiveness, and exhibit antibacterial effects and the like even in an indoor environment with little ultraviolet light.

(Other ingredients)
In the aqueous composition of the present embodiment, synthetic resin, emulsion particles, antifoaming agent, coloring agent, coupling agent, thickener, thixotropic agent, freezing stabilizer, matting agent, as long as the effect is not lost. Cross-linking reaction catalyst, pigment, curing catalyst, cross-linking agent, filler, anti-skinning agent, dispersant, wetting agent, light stabilizer, antioxidant, ultraviolet absorber, rheology control agent, antifoaming agent, film-forming aid Contains other components such as rust preventive, dye, plasticizer, lubricant, reducing agent, preservative, antifungal agent, deodorant, anti-yellowing agent, antistatic agent or charge preparation agent Also good.

  The coating film and aqueous composition of this embodiment can be formed on a substrate or a coating film, and the substrate and coating film can be applied to various materials.

The present invention will be specifically described by the following production examples, examples and comparative examples, but these do not limit the scope of the present invention.
Various physical properties were measured by the following methods.

1. Quantitative determination of antibacterial metal and calculation of residual ratio of antibacterial metal in antibacterial metal-containing compound in coating film after JIS K 5600-7-7 test In each example after JIS K 5600-7-7 test The antibacterial metal in the coating film was quantified as follows. In addition, the metal element analyzed in each Example made the analysis object the element of the antibacterial metal particle A contained in each coating film, ie, any element of gold | metal | money and silver copper.
On a polypropylene plate (Takiron P310A, 2 × 70 × 150 mm) substrate, a commercially available white enamel paint (aqueous ceramic silicon manufactured by SK Kaken Co., Ltd.) was applied using a spray and dried at room temperature for 2 days to 0 A 15 g coating was formed.
Thereafter, each aqueous composition was applied onto the white enamel coating film using a spray, dried and cured at room temperature for 7 days to form a 5 mg coating film, and two test specimens were produced.
For one of the specimens, the white enamel coating and the coating containing each aqueous composition were peeled off from the polypropylene substrate, the mass was weighed, and the dissolution treatment was performed using acid and ultrasonic waves. By analyzing the amount of metal contained in the coating film using a plasma mass spectrometer (ICPMS-2030, manufactured by Shimadzu Corporation), the amount of the antibacterial metal-containing compound was quantified, and the obtained value (μg / g) was defined as the amount M0 of the antibacterial metal-containing compound before the test.
Further, another one-piece specimen that was not subjected to the above analysis was subjected to an exposure test for 2500 hours in accordance with JIS K 5600-7-7. Thereafter, the amount of the antibacterial metal-containing compound was quantified using the measurement method and apparatus described above, and the obtained value (μg / g) was defined as the amount M1 of the antibacterial metal-containing compound after the test. ) Was used to calculate the residual ratio (%) of the antibacterial metal-containing compound in the coating film.

2. Measurement of porosity in coating film The porosity (volume fraction occupied by air) in the coating film was determined as follows.
Each aqueous composition was spin-coated on a glass substrate (5 × 5 cm) and dried at room temperature to form a coating film.
Then, using a reflective spectral film thickness meter (FE-3000 manufactured by Otsuka Electronics Co., Ltd.), the reflectance for each wavelength of 230 to 800 nm was measured, and the glass was measured using the reflective spectral film thickness meter on the back side of the glass substrate. The refractive index of the substrate was measured.
Next, between 230 and 800 nm on the coating film side, the intensity of the reflected light that interferes with the glass substrate and the coating film at intervals of 2 nm is measured, and the refractive index and interference of the glass substrate for each measured wavelength. Using the intensity of the reflected light, the measured values were fitted by the least square method by calculating the refractive index and film thickness of the coating film, and the refractive index α1 (nm) of the coating film was obtained.
Furthermore, the refractive index α2 was calculated using the following formula (2), assuming that no voids exist in the coating film.
In addition, the theoretical refractive index of each compound used in each Example calculated | required the following values.
Particle A: Gold = 0.34, Silver = 0.12, Copper oxide = 2.71
Compound B: 3-mercaptopropyltrimethoxysilane = 1.44, 3-aminopropyltrimethoxysilane = 1.42, phenyltrimethoxysilane = 1.46
Silica C: Colloidal silica = 1.45
Particle D: Titanium oxide = 2.25

  Using the following formula (3), α1 and α2 determined above were used to determine the porosity α3 in the coating film.

3. Measurement of average particle size (average particle size of antibacterial metal particles A)
The average particle diameter of the antibacterial metal particles A was determined by the following method. Each aqueous composition containing the antibacterial metal particles A was dropped onto the collodion film.
Then, after drying for 1 hour under vacuum conditions, the surface was observed with a scanning transmission electron microscope, 50 arbitrary antibacterial metal particles A observed were selected, and the number average particle diameter was calculated.
(Average particle diameter of colloidal silica C)
The average particle size of colloidal silica C is diluted by adding water so that the solid content in the sample is 0.1 to 20% by mass, and a wet particle size analyzer (NanotracWave-EX150 manufactured by Microtrac Bell Co., Ltd.) is used. The 50% cumulative diameter when measured by using a volume distribution was defined as the average particle diameter.

4). Antifouling property The antifouling property of the coating film was evaluated as follows.
A white enamel finishing material for outer walls (aqueous ceramic silicon manufactured by SK Kaken Co., Ltd.) is applied onto a sulfated alumite base material (JIS H 4000 (A1100P) 1 × 70 × 150 mm, manufactured by Test Piece) to a film thickness of 100 μm after drying. And cured at room temperature for 2 days. The composition of each example was applied onto the coating film by spraying, dried and cured at room temperature for 7 days to obtain about 5 mg of a coating film, and a test specimen was prepared.
The color difference before and after coating of the obtained specimen was measured, and the color difference before coating was evaluated as ΔE as a standard.
The lower the color difference ΔE, the smaller the change in appearance, that is, the better the weather resistance. The color difference was obtained from a standard plate using a color guide (BYK Gardner).
[Evaluation criteria]
○: Color difference ΔE was less than 1.6.
Δ: Color difference ΔE was 1.6 to less than 3.0.
X: Color difference ΔE was 3.0 or more.

5. Low coloring property The low coloring property of the coating film was evaluated as follows.
A white enamel finishing material for outer walls (aqueous ceramic silicon manufactured by SK Kaken Co., Ltd.) is applied onto a sulfated alumite base material (JIS H 4000 (A1100P) 1 × 70 × 150 mm, manufactured by Test Piece) to a film thickness of 100 μm after drying. And cured at room temperature for 2 days. After curing, the color difference before coating was measured, the composition of each example was sprayed onto the coating film, dried and cured at room temperature for 7 days to obtain about 5 mg coating film, and a test specimen was prepared. .
The color difference of the obtained specimen was measured, the color difference before coating was used as a standard, and the change in state before and after coating was evaluated as ΔE.
The lower the color difference ΔE, the smaller the change in appearance, that is, the better the weather resistance. The color difference was obtained from a standard plate using a color guide (BYK Gardner).
[Evaluation criteria]
○: Color difference ΔE was less than 1.6.
Δ: Color difference ΔE was 1.6 to less than 3.0.
X: Color difference ΔE was 3.0 or more.

6). Algae / mold resistance (long term)
A white enamel finishing material for outer walls (aqueous ceramic silicon manufactured by SK Kaken Co., Ltd.) is applied onto a sulfated alumite base material (JIS H 4000 (A1100P) 1 × 70 × 150 mm, manufactured by Test Piece) to a film thickness of 100 μm after drying. And cured at room temperature for 2 days.
The aqueous composition of each example was applied onto the coating film by spraying, dried and cured at room temperature for 7 days to obtain about 5 mg of a coating film, and a test specimen was prepared.
Then, after conducting a 2500 hour exposure test in accordance with JIS K 5600-7-7, there is a forest in the vicinity of Choshi City, Chiba Prefecture, and the test specimen is exposed outdoors at 90 ° north on the land where lawn grows. The test was conducted.
Judgment was made one year after exposure.
[Evaluation criteria]
○: Growth of algae and mold was not observed by visual observation.
Δ: Growth of algae and mold was not observed by visual observation, but growth was observed by loupe observation at a magnification of 7 times.
X: Growth of algae and mold was observed by visual observation.

7. Crack resistance of the coating film The antifouling property of the coating film was evaluated as follows. A white enamel finishing material for outer walls (aqueous ceramic silicon manufactured by SK Kaken Co., Ltd.) is applied onto a sulfated alumite base material (JIS H 4000 (A1100P) 1 × 70 × 150 mm, manufactured by Test Piece) to a film thickness of 100 μm after drying. And cured at room temperature for 2 days.
The aqueous composition of each example was applied onto the coating film by spraying, dried and cured at room temperature for 7 days to obtain about 5 mg of a coating film, and a test specimen was prepared.
The obtained specimen was placed outdoors in Kawasaki-ku, Kawasaki City so that the coating film was on the south surface and perpendicular to the ground, and was exposed for one year.
One year later, 100-fold magnification observation was performed with a microscope (VHX-5000, manufactured by Keyence Corporation), and evaluation was performed according to the following criteria.
[Evaluation criteria]
○: The maximum width of the cracks seen in the visual field was less than 1.5 μm.
(Triangle | delta): The maximum width of the crack seen in a visual field was the range of less than 1.5-3.0 micrometers.
X: The maximum width of the crack seen in the visual field was 3.0 μm or more.

8). Synthesis of particles D with photocatalytic activity (silica modified rutile titanium dioxide)
Particles D (photocatalyst particles D) having photocatalytic activity used in the production examples described later were synthesized as follows.
700 mL of a titanium tetrachloride aqueous solution having a concentration of 200 g / L as TiO ₂ and an aqueous sodium hydroxide solution having a concentration of 100 g / L as Na ₂ O were added in parallel so as to maintain the pH of the system at 5 to 9.
Thereafter, the pH of the system was adjusted to 7, then filtered, and washed until the filtrate had a conductivity of 100 μS / cm, to obtain a titanium oxide wet cake 1 having a solid content concentration of 28.3 mass%.
This titanium oxide wet cake 1 had a rutile structure, and its average particle size was 8 nm.
The obtained rutile-type titanium oxide wet cake 1 was diluted with pure water to prepare a 1 mol / L slurry. 1 L of this slurry was charged into a 3 L flask, 1 L of 1N nitric acid was added so that the molar ratio of titanium oxide and nitric acid (titanium oxide / nitric acid) was 1, and the mixture was heated to a temperature of 95 ° C. The acid heat treatment was performed by maintaining the temperature for 2 hours.
Next, the acid-heated slurry is cooled to room temperature, neutralized with 28% aqueous ammonia (pH = 6.7), filtered, and washed until the filtrate has a conductivity of 100 μS / cm. A titanium oxide wet cake 2 having a solid content of 25% by mass was obtained.
To the obtained titanium oxide wet cake 2, a 10% by mass sodium hydroxide aqueous solution was added, repulped, and then dispersed for 3 hours with an ultrasonic washer, pH = 10.5, solid content concentration 10% by mass. An alkaline titanium oxide sol was obtained.
This alkaline titanium oxide sol 2L was charged into a 3 L flask, heated to a temperature of 70 ° C., 69.4 mL of a sodium silicate aqueous solution having a concentration of 432 g / L as SiO ₂ was added, and then heated to 90 ° C. After aging for 1 hour, 10% sulfuric acid was added to adjust the pH to 6, and the surface of titanium oxide was surface treated with a hydrous oxide of silicon.
The obtained titanium oxide sol was cooled to room temperature, 5.4 L of pure water was added, impurities were removed and concentrated using a desalting and concentrating device, pH = 7.3, solid content concentration 29% by mass A neutral rutile-type titanium oxide sol was obtained.
It contained 15 wt% of silicon oxide hydroxide with SiO ₂ basis relative to TiO _2.
The average particle diameter of titanium oxide in this sol was 50 nm.

[Production Example 1] Gold-supported titanium oxide (A-1)
400 g of an aqueous dispersion (solid content: 2% by mass) of photocatalyst particles D synthesized by the method described in 8 above was charged into a 500 mL flask and heated to 65 ° C.
When the temperature reached 65 ° C., 3.83 g of tetrachloroauric acid tetrahydrate aqueous solution (concentration: 1% by mass) was added and stirred for 10 minutes. Thereafter, 0.79 g of an aqueous tannic acid solution (concentration: 1% by mass) was added. After the addition, the mixture was stirred for 1 hour while maintaining at 65 ° C., then the temperature was raised to 80 ° C., and after reaching 80 ° C., 0.12 g of 3-mercaptopropyltrimethoxysilane (KBM-803 manufactured by Shin-Etsu Chemical) was added and stirred for 6 hours. did.
After 6 hours, the mixture was cooled to room temperature to obtain gold-supported titanium oxide (A-1).
The average particle diameter of the antibacterial metal particles in the obtained composite was 8 nm.

[Production Example 2] Silver-supported titanium oxide (A-2)
The aqueous solution of tetrachloroauric acid tetrahydrate (concentration: 1% by mass) used in [Production Example 1] was 3.78 g of an aqueous silver nitrate solution (concentration: 5% by mass), and the aqueous tannic acid solution (concentration: 1% by mass). Was added in an amount of 10.5 g and 3-mercaptopropyltrimethoxysilane was 0.24 g, and synthesized in the same manner as in [Production Example 1] to obtain silver-supported titanium oxide (A-2). . The average particle diameter of the antibacterial metal-carrying particles in the obtained composite was 4 nm.

[Production Example 3] Copper oxide-supported titanium oxide (A-3)
The silver nitrate aqueous solution (concentration: 5% by mass) used in [Production Example 2] was 6.24 g of copper sulfate pentahydrate (concentration: 5% by mass), and the addition amount of the tannic acid aqueous solution (concentration: 1% by mass) Was synthesized in the same manner as in [Production Example 2] except that 0.16 g of 3-mercaptopropyltrimethoxysilane was used and copper oxide-supported titanium oxide (A-3) was obtained. The average particle diameter of the antibacterial metal particles in the obtained composite was 5 nm.

[Production Example 4] Silver colloid (A-4)
400 g of ion-exchanged water was charged into a 500 mL flask and heated to 80 ° C. When the temperature reached 80 ° C., 1.25 g of an aqueous silver nitrate solution (concentration: 5% by mass) was added and stirred for 5 minutes. Thereafter, 1.04 g of an aqueous tannic acid solution (concentration: 1% by mass) and 1.75 g of an aqueous sodium citrate dihydrate solution (concentration: 10% by mass) were added simultaneously.
After the addition, the mixture was stirred for 1 hour while maintaining at 80 ° C. and then cooled to 25 ° C. After reaching 25 ° C., 1.02 g of an aqueous ammonia solution (concentration: 1% by mass) was added and stirred for 5 minutes.
Thereafter, 4.0 mg of 3-mercaptopropyltrimethoxysilane (KBM-803 manufactured by Shin-Etsu Chemical Co., Ltd.) was added and stirred for 6 hours to obtain a silver colloid (A-4).
The average particle diameter of the antibacterial metal particles in the obtained composite was 8 nm.

[Production Example 5] Copper oxide colloid (A-5)
Ion-exchanged water 400 g and sodium citrate dihydrate aqueous solution (concentration: 10% by mass) 2.96 g were charged into a 500 mL flask and heated to 80 ° C.
When the temperature reached 80 ° C., 23.20 g of an aqueous ammonia solution (concentration: 5% by mass) was added and stirred for 5 minutes. Thereafter, 3.20 g of an aqueous copper sulfate pentahydrate solution (concentration: 5% by mass) was added and stirred for 5 minutes, and then 16.37 g of an aqueous tannic acid solution (concentration: 1% by mass) was added.
After the addition, the mixture was stirred for 1 hour while maintaining at 80 ° C., cooled to 25 ° C., and stirred for 5 minutes after reaching 25 ° C. Thereafter, 2.0 mg of 3-mercaptopropyltrimethoxysilane (KBM-803 manufactured by Shin-Etsu Chemical Co., Ltd.) was added and stirred for 6 hours to obtain a copper oxide colloid (A-5).
The average particle diameter of the antibacterial metal particles in the obtained composite was 11 nm.

[Production Example 6] Silver colloid (A-6)
Synthesized by the same method as in [Production Example 4] except that 3-mercaptopropyltrimethoxysilane in [Production Example 4] was changed to 3-aminopropyltrimethoxysilane (KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.) Colloid (A-6) was obtained.
The average particle diameter of the antibacterial metal particles in the obtained composite was 8 nm.

[Production Example 7] Silver colloid (A-7)
400 g of ion-exchanged water was charged into a 500 mL flask and heated to 80 ° C.
When the temperature reached 80 ° C., 1.25 g of an aqueous silver nitrate solution (concentration: 5% by mass) was added and stirred for 5 minutes.
Thereafter, 1.04 g of an aqueous tannic acid solution (concentration: 1% by mass) and 1.75 g of an aqueous sodium citrate dihydrate solution (concentration: 10% by mass) were added simultaneously.
After the addition, the mixture was stirred for 1 hour while maintaining at 80 ° C., and then cooled to room temperature to obtain a silver colloid (A-7).
The average particle diameter of the antibacterial metal particles in the obtained composite was 4 nm.

[Production Example 8] Silver colloid (A-8)
Synthesized by the same method as in [Production Example 4] except that 3-mercaptopropyltrimethoxysilane in [Production Example 4] was changed to phenyltrimethoxysilane (KBM-103 manufactured by Shin-Etsu Chemical Co., Ltd.). -8) was obtained.
The average particle diameter of the antibacterial metal particles in the obtained composite was 8 nm.

[Production Example 9] Silver colloid (A-9)
A silver colloid (A-9) was obtained by synthesis in the same manner as in [Preparation Example 4] except that the amount of 3-mercaptopropyltrimethoxysilane added in [Preparation Example 4] was 0.32 mg. .
The average particle diameter of the antibacterial metal particles in the obtained composite was 4 nm.

[Example 1]
137.1 g of gold-supported titanium oxide (A-1) produced in Production Example 1 and basic colloidal silica, water-dispersed colloidal silica with an average particle size of 10 nm (Snowtex NS, manufactured by Nissan Chemical Industries, solid content 20) (Mass%) 123.4 g, 1.5 g of a fluorocarbon surfactant (manufactured by DIC, MegaFuck F-444) which is a perfluoroalkylethylene oxide adduct and a solid content of 0.1 mass% with ion-exchanged water. An aqueous composition was prepared by blending 140 g of an adjusted fading dye (methylene blue, manufactured by Kishida Chemical Co., Ltd.), adding ion-exchanged water so that the total amount becomes 1000 g, and stirring.
A photocatalyst coating film was produced from this aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

[Example 2]
Aqueous composition in the same manner as in [Example 1] except that the gold-supported titanium oxide (A-1) in [Example 1] was changed to the silver-supported titanium oxide (A-2) prepared in Production Example 2. A product was made.
A photocatalyst coating film was produced from this aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

Example 3
In the same manner as in [Example 1] except that the gold-supported titanium oxide (A-1) in [Example 1] was changed to the copper oxide-supported titanium oxide (A-3) prepared in Production Example 3, A composition was prepared.
A photocatalyst coating film was produced from this aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

Example 4
550 g of silver colloid (A-4) prepared in Production Example 4 and basic colloidal silica, water-dispersed colloidal silica with an average particle size of 10 nm (Snowtex NS, solid content 20 mass%, manufactured by Nissan Chemical Industries, Ltd.) 123 .53 g, 8.97 g of an acrylic-silicone emulsion (G639S manufactured by Asahi Kasei Co., Ltd.) diluted with ion-exchanged water to 30% by mass, and a perfluoroalkylethylene oxide adduct (Surflon S-232 manufactured by AGC Seimi Chemical Co., Ltd.) ) 10.33 g and 140 g of a fading dye (methylene blue manufactured by Kishida Chemical Co., Ltd.) whose solid content was adjusted to 0.1% by mass with ion-exchanged water were added and stirred with ion-exchanged water so that the total amount became 1000 g. By doing this, an aqueous composition was prepared.
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

Example 5
An aqueous composition was prepared in the same manner as in [Example 4] except that the silver colloid (A-4) in [Example 4] was changed to the silver colloid (A-5) prepared in Production Example 5. .
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

Example 6
An aqueous composition was prepared in the same manner as in [Example 4] except that the silver colloid (A-4) in [Example 4] was changed to the silver colloid (A-6) prepared in Production Example 6. .
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

Example 7
550 g of the copper oxide colloid (A-5) prepared in Production Example 5 and basic colloidal silica, water-dispersed colloidal silica having an average particle diameter of 10 nm (Snowtex NS, manufactured by Nissan Chemical Industries, Ltd., solid content 20% by mass) 96.08 g, 27.27 g of an acrylic-silicone emulsion (G612 manufactured by Asahi Kasei Co., Ltd.) diluted to 30% by mass with ion-exchanged water, and a perfluoroalkylethylene oxide adduct (Surflon S- manufactured by AGC Seimi Chemical Co., Ltd.) 232) 10.33 g and 140 g of a fading dye (methylene blue, manufactured by Kishida Chemical Co., Ltd.) whose solid content is adjusted to 0.1% by mass with ion-exchanged water are added and added with ion-exchanged water so that the total amount becomes 1000 g. An aqueous composition was prepared by stirring.
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

Example 8
An aqueous composition was prepared in the same manner as in [Example 7] except that in [Example 7], colloidal silica was changed to 109.80 g and acryl-silicone emulsion was changed to 18.12 g.
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

Example 9
550 g of the copper oxide colloid (A-5) prepared in Production Example 5 and basic colloidal silica, water-dispersed colloidal silica having an average particle diameter of 5 nm (Snowtex NXS, Nissan Chemical Industries, Ltd., solid content: 15% by mass) 36.60 g, basic colloidal silica, water-dispersed colloidal silica having an average particle size of 22 nm (Snowtex N40 manufactured by Nissan Chemical Industries, Ltd., solid content 40% by mass) 48.04 g, and a concentration of 30 with ion-exchanged water 8.97 g of acrylic-silicone emulsion (G639S manufactured by Asahi Kasei Co., Ltd.) diluted to mass%, 10.33 g (Surflon S-232 manufactured by AGC Seimi Chemical Co.) which is a perfluoroalkylethylene oxide adduct, and solid with ion-exchanged water Fading dye (Methylene blue manufactured by Kishida Chemical Co., Ltd.) whose amount was adjusted to 0.1% by mass Blended with 140 g, by the total amount is stirred with the ion-exchanged water so as to be 1000 g, to prepare an aqueous composition.
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

Example 10
An aqueous composition was prepared in the same manner as in [Example 4] except that the silver colloid (A-4) in [Example 4] was changed to the silver colloid (A-7) prepared in Production Example 7. .
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

Example 11
An aqueous composition was prepared in the same manner as in [Example 4] except that the silver colloid (A-4) in [Example 4] was changed to the silver colloid (A-8) prepared in Production Example 7. .
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

Example 12
An aqueous composition was prepared in the same manner as in [Example 4] except that the silver colloid (A-4) in [Example 4] was changed to the silver colloid (A-9) prepared in Production Example 7. .
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

[Comparative Example 1]
The silver colloid (A-4) produced in Production Example 4 was concentrated 10 times by vacuum distillation.
Polyvinyl alcohol powder (PVA217 manufactured by Kuraray Co., Ltd.) was slowly added to 549 g of the colloidal solution concentrated 10 times while stirring.
After the addition, 13.73 g of water-dispersed colloidal silica having an average particle diameter of 12 nm (Snowtex NS, solid content: 20% by mass) manufactured by Nissan Chemical Industries, Ltd. and a fluorocarbon surfactant (Surflon S-232 manufactured by AGC Seimi Chemical Co., Ltd.) 10 .33 g and 140 g of a fading dye (manufactured by Kishida Chemical Co., “methylene blue”) whose solid content was adjusted to 1.0 mass% with ion-exchanged water were mixed, and the mixture was stirred with ion-exchanged water so that the total amount became 1000 g. By doing this, an aqueous composition was prepared.
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

[Comparative Example 2]
An aqueous composition was prepared in the same manner as in [Example 4] except that, in [Example 4], the silver colloid (A-4) was changed to a copper sulfate pentahydrate aqueous solution (concentration: 100 ppm).
A coating film was prepared from the aqueous composition according to each of the above methods, and various evaluation results are shown in Table 3.

  The coating film and aqueous composition of the present invention have industrial applicability as materials for coating on architectural exteriors, interior materials, exterior display applications, automobiles, displays, and the like.

Claims (9)

A coating film containing an antibacterial metal-containing compound,
The total content mass of the antibacterial metal-containing compound in the coating film after 2500 hours has elapsed in an exposure test according to JIS K 5600-7-7,
5% or more based on the total content of the antibacterial metal-containing compound in the coating film before the exposure test,
There are voids in the coating film,
The porosity of the coating film is 1 to 30%.
Coating film. An aqueous composition for forming the coating film according to claim 1,
water and,
Antibacterial metal particles A;
A compound B containing in the molecule a functional group B1 that interacts with the antibacterial metal particle A and a functional group B2 that is at least one selected from the group consisting of a silanol group and a functional group that interacts with a siloxane bond;
Colloidal silica C,
Containing,
The aqueous composition whose ratio with respect to the mass of the said colloidal silica C of the mass of the said antibacterial metal particle A is 0.01 to 10.0%. Compound B is
The aqueous composition according to claim 2, which is a silane compound containing a thiol group or an amino group as the functional group B1 at the molecular end.   The water-based composition of Claim 2 or 3 whose ratio with respect to the mass of the said antibacterial metal particle A of the mass of the said compound B is 1 to 300%.   The ratio of the average particle diameter of the antibacterial metal particles A to the average particle diameter of the colloidal silica C, (average particle diameter of the antibacterial metal particles A) / (average particle diameter of the colloidal silica C) is 0.01 to The aqueous composition according to any one of claims 2 to 4, which is 10.   The aqueous composition according to any one of claims 2 to 5, wherein a content of the colloidal silica C is 50 to 99% with respect to a total solid content contained in the aqueous composition.   The aqueous composition according to any one of claims 2 to 6, wherein the antibacterial metal particle A is at least one selected from the group consisting of gold, silver, copper, and a compound thereof.   The aqueous composition according to any one of claims 2 to 7, further comprising particles D having photocatalytic activity.   The aqueous composition according to claim 8, wherein the particles D having photocatalytic activity are at least one selected from the group consisting of titanium oxide, tungsten oxide, and silica-coated titanium oxide.