JP2019098297A - Antibacterial metal carrying photocatalyst, photocatalyst composition, photocatalyst coated film, and photocatalyst coating product - Google Patents

Abstract

To provide a photocatalyst capable of being synthesized by a simple method, high in transparency, and having extremely low colorability, a photocatalyst composition containing an antibacterial metal carrying photocatalyst, excellent in weather resistance or photocatalyst performance, excellent in growth suppression of microorganisms such as mold by an antibacterial metal compound, a photocatalyst coated film, and a photocatalyst coating product.SOLUTION: In the antibacterial metal carrying photocatalyst particle AB, an antibacterial metal particle B is carried on a surface of a photocatalyst particle A having a photocatalyst activity of which a surface is modified by metal oxide having no photocatalyst activity, and average particle diameter of the antibacterial metal particle B is in a range of 0.1 to 20 nm.SELECTED DRAWING: None

Description

  The present invention relates to an antimicrobial metal-loaded photocatalyst, a photocatalyst composition, a photocatalyst coating film, and a photocatalyst-coated product.

  The photocatalyst represented by titanium dioxide is an important function, such as the function of decomposing soil and removing nitrogen oxides, by the development of super-hydrophilicity and / or the generation of reactive oxygen species by exposure to light (ultraviolet light) ).

  Since the paint or coating film which mix | blended the photocatalyst has the said function, it is utilized as an antifouling paint, an environmental purification paint, or a coating product etc. In recent years, there has been an increasing demand for the function of removing harmful substances and microbes which harm the health of consumers, in particular, microbes such as bacteria and molds, and photocatalysts have the ability to remove the above harmful substances and / or microbes. It is expected.

  However, since it is typical that general titanium dioxide exhibits a catalytic effect only with light of a specific wavelength of ultraviolet light, it hardly exhibits such a catalytic effect in a room or under an environment in which sunlight is difficult to hit. Therefore, in recent years, visible light responsive photocatalysts that exhibit photocatalytic activity even in an environment where there is little ultraviolet light, in particular, visible light responsive photocatalysts in a form in which an antimicrobial metal is supported on the photocatalyst surface, etc. have been proposed. See documents 1 and 2).

  In addition, a technology has also been proposed in which a photocatalyst, a resin or the like supporting an antibacterial metal is blended, and the blend is coated on a substrate (see, for example, Patent Document 3).

Patent No. 5129897 gazette JP, 2016-113417, A Patent No. 4395886

  However, in the method of supporting the antibacterial metal as described in Patent Documents 1 and 2, a drying step is necessary in order to support the antibacterial metal compound generated in the reaction solution on the photocatalyst particles. Therefore, the photocatalyst particles are aggregated in the drying step, the transparency of the coating film containing the photocatalyst particles is reduced, and the specific surface area of the particles is reduced, and the photocatalytic activity is reduced. Suitable applications may be limited.

  In addition, as in Patent Document 3, a method of selectively depositing a metal on the surface of a photocatalyst particle using a reduction reaction which is a photocatalytic reaction generated on the surface of the photocatalyst particle is also exemplified by ultraviolet light irradiation. The photocatalyst particles that can be used in the production method of the present invention are limited to those whose surface is not modified with other compounds, and hence there is a possibility that the effect of improving the particle dispersibility and / or the coating film weatherability may not be exhibited. Not only there is a possibility that the reaction time may take a long time, and the productivity may be reduced such that some unreacted material remains.

  The present invention provides an antimicrobial metal-supporting photocatalyst which can be synthesized by a simple method, has high transparency and very low coloring properties, in particular, an antimicrobial metal-supporting photocatalyst suitable for clear coat, and weather resistance performance. An object of the present invention is to provide a photocatalyst composition, a photocatalyst coating film, and a photocatalyst-coated product including an antibacterial metal-supporting photocatalyst which is excellent in photocatalytic performance and excellent in growth inhibition of microorganisms such as mold by antibacterial metal compounds.

  As a result of intensive studies to solve the above problems, the present inventors found that antimicrobial metal particles B having specific conditions on the surface of photocatalytic particles A having photocatalytic activity of which the surface is modified with metal oxides having no photocatalytic activity. It has been found that an antimicrobial metal-supporting photocatalyst can be provided which is loaded with a metal, and a coating film obtained by a specific paint composition containing the antibacterial metal-supporting photocatalyst exhibits good coating film appearance, weatherability and photocatalytic activity. It has also been found that it can be effective against contamination due to reproduction such as mold and / or algae (biological contamination).

That is, the present invention is as follows.
<1>
An antimicrobial metal particle B is supported on the surface of photocatalyst particle A having photocatalytic activity, the surface of which is modified with a metal oxide having no photocatalytic activity, and the average particle diameter of the antimicrobial metal particle B is 0.1 to 20 nm. In the range of, antimicrobial metal-loaded photocatalyst particles AB.
<2>
The metal oxide not having photocatalytic activity comprises at least one selected from the group consisting of silicon dioxide, aluminum oxide and zirconium oxide,
Compounds forming the photocatalyst particle A having the photocatalytic activity are titanium dioxide, zinc oxide, strontium titanate, gallium phosphide, indium phosphide, gallium arsenide, barium titanate, potassium niobate, niobium pentoxide, iron oxide, A group consisting of tantalum pentoxide, K ₃ Ta ₃ Si ₂ O ₃ , tungsten oxide, tin oxide, bismuth oxide, bismuth vanadate, nickel oxide, copper oxide, copper oxide, silicon carbide, molybdenum sulfide, indium lead, ruthenium oxide, and cerium oxide Consisting of at least one selected from
The antimicrobial metal-supported photocatalyst particle AB according to <1>.
<3>
The metal oxide not having photocatalytic activity is silicon dioxide,
The compound forming the photocatalyst particle A having the photocatalytic activity is titanium dioxide,
The antimicrobial metal-supported photocatalyst particle AB described in the item <2>.
<4>
The antibacterial metal-supported photocatalyst particles AB according to any one of <1> to <3>, wherein the average particle diameter of the antibacterial metal-supported photocatalyst particles AB is 1 to 400 nm.
<5>
The antimicrobial metal particle B described in any one of <1> to <4>, which is at least one selected from the group consisting of gold, silver, copper, a gold compound, a silver compound and a copper compound. Antibacterial metal-loaded photocatalyst particles AB.
<6>
The antibacterial metal support according to any one of <1> to <5>, wherein the mass of the antibacterial metal particle B is in the range of 0.1 to 10% with respect to the mass of the photocatalyst particle A. Photocatalytic particles AB.
<7>
The antibacterial metal-supporting photocatalyst particle AB contains the antibacterial metal particle C not supported on the surface of the photocatalyst particle A, and the content thereof is 10 to 3000 ppm with respect to the total solid content of the antibacterial metal-supporting photocatalyst particle AB The antimicrobial metal-loaded photocatalyst particle AB according to any one of <1> to <6>, which is in the range of
<8>
The antimicrobial metal particle C is one or more selected from the group consisting of gold, silver, copper, gold ion, silver ion, copper ion, gold compound, silver compound and copper compound, described in <7>. Antibacterial metal-loaded photocatalyst particles AB.
<9>
The antimicrobial metal-supporting photocatalyst particle AB according to any one of <1> to <8>, water, and colloidal silica, wherein the antimicrobial metal-supporting photocatalyst particle is contained in the composition. The photocatalyst composition whose solid content concentration of AB is 1-30 mass% in total solid content, and whose solid content concentration of colloidal silica is 50-99 mass% in total solid content.
<10>
The photocatalyst composition according to <9>, further comprising polymer emulsion particles D in the composition at a concentration of 0 to 30% by mass of the total solid content.
<11>
The photocatalyst coating film formed from the photocatalyst composition of the <9> or <10> term.
<12>
The photocatalyst coating film formed by laminating | stacking the photocatalyst coating film as described in a <11> term, and the coating film obtained from a composition different from the composition which forms the said photocatalyst coating film.
<13>
The photocatalyst coating products provided with the photocatalyst coating film as described in a <11> or <12> term.
<14>
Mixing an aqueous dispersion of photocatalytic particles A having photocatalytic activity, the surface of which is modified with a metal oxide having no photocatalytic activity, with a water-soluble metal compound containing metal ions, and adding a water-soluble reducing agent The antibacterial metal-supported photocatalyst particle according to any one of <1> to <8>, which comprises forming an antibacterial metal particle B and supporting the same on the photocatalyst particle A by reducing metal ions. AB production method.

  According to the present invention, an antibacterial metal-supporting photocatalyst having high transparency and very low colorability can be provided. In addition, by employing the antibacterial metal-supporting photocatalyst of the present invention, the photocatalytic activity is exhibited without impairing the design of the undercoat layer to which the photocatalyst paint is applied, and not only the weather resistance is excellent but also biological contamination is suppressed. It is possible to provide a photocatalytic coating film that exerts its effect in the long run.

  Hereinafter, modes for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for describing the present invention, and is not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the gist of the present invention.

[Antibacterial metal-loaded photocatalyst particles AB]
The antibacterial metal-supported photocatalyst AB of the present embodiment is an antibacterial metal-supported photocatalyst in which the antibacterial metal particles B are supported on the surface of photocatalytic particles A having photocatalytic activity of which the surface is modified with a metal oxide having no photocatalytic activity. It is photocatalyst particle AB.
The antibacterial metal-supporting photocatalyst particle AB of the present embodiment is characterized in that the average particle diameter of the antibacterial metal particle B is in the range of 0.1 to 20 nm.

  The antibacterial metal-supported photocatalyst particles AB of the present embodiment may be contained in a composition containing water and the like. Therefore, the form of the antibacterial metal-supporting photocatalyst particle AB of the present embodiment includes a liquid form in which it is dissolved, suspended or dispersed in a solvent such as water, that is, the aspect of the photocatalyst aqueous composition is included. . The antibacterial metal-supporting photocatalyst particle AB of the present embodiment can also be obtained as a powder or the like by performing operations such as removal of water and / or drying from the above-described photocatalyst water system composition, and it is solid It may be.

  The antibacterial metal-supporting photocatalyst particle AB in the photocatalyst aqueous composition is not particularly limited as long as it is 0.1% by mass or more, 1.0% by mass or more, based on the total amount of the photocatalyst aqueous composition. .5 mass% or more, 3.0 mass% or more, 5.0 mass% or more, 7.5 mass% or more, 8.0 mass% or more, or 9.0 mass% or more, and 99.9 mass% or less 90.0% by mass or less, 85.0% by mass or less, 80.0% by mass or less, 70.0% by mass or less, 60.0% by mass or less, 50.0% by mass or less, 40.0% by mass or less, 30.0 mass% or less, 20.0 mass% or less, or 10.0 mass% or less may be sufficient. In addition, this value may be 0.1 to 99.9% by mass, preferably 0.5 to 50% by mass, more preferably 1.0 to 30% by mass, and still more preferably 1.5 to 10% by mass.

  The antimicrobial metal particles B in the antimicrobial metal-supporting photocatalyst of the present embodiment are supported on the surface of the photocatalytic particles A having photocatalytic activity, the surface of which is modified with a metal oxide having no photocatalytic activity. The support in the present embodiment means a state of being attached to the photocatalytic particle A having photocatalytic activity via the metal oxide having no photocatalytic activity, or the metal oxide having no photocatalytic activity is not covered It means that the part is directly attached to the surface of the photocatalytic particle A having photocatalytic activity.

  The average particle diameter of the antimicrobial metal particles B supported on the photocatalyst particles A is in the range of 0.1 to 20 nm. If this average particle size is less than 0.1 nm, it will be buried in other particles in the coating film, making it difficult to exert the effect. When the average particle size exceeds 20 nm, the absorption of visible light is increased and not only the coloring peculiar to the metal compound becomes remarkable, but also the specific surface area of the antibacterial metal particle B decreases, so that mold, algae etc. The effect of suppressing the growth of In addition, this average particle diameter can be adjusted by adjustment of the temperature at the time of photocatalyst synthesis, adjustment of the raw material concentration, and adoption of titanium oxide having a predetermined specific surface area.

  Accordingly, the average particle size of the antibacterial metal particles B is in the range of 0.1 to 20 nm, more preferably in the range of 0.5 to 15 nm, and still more preferably in the range of 1.0 to 15 nm. The average particle size of the antibacterial metal particle B is obtained by observing the antibacterial metal-supporting photocatalyst particle AB with an electron microscope, and the number-average equivalent circular diameter (Heywood diameter) of 50 particles of any antibacterial metal particle B confirmed. It is determined from the particle size. Specifically, the average particle size of the antibacterial metal particles B can be measured by the method described in the examples below.

The antibacterial metal-supporting photocatalyst particle AB of the present embodiment can include an antibacterial metal particle C which is not supported on the surface of the photocatalyst particle A. In addition, the antibacterial metal-supporting photocatalyst particle AB may also contain a dispersant, a preservative, and an acid and / or a basic compound for adjusting to any pH without departing from the effects of the present invention. it can.

The average particle size of the antibacterial metal-supporting photocatalyst particle AB of this embodiment is preferably in the range of 1 to 400 nm in average (arithmetic mean) in a solvent or a dispersion medium. When the average particle diameter is 1 nm or more, it is easy to absorb light, and as a result, not only the photocatalytic activity is effectively expressed, but also the dispersibility of the photocatalyst particles in the paint and in the coating film is excellent. In addition, when the average particle diameter is 400 nm or less, sedimentation in the coating is suppressed and storage stability is improved, and when it is blended in the coating, light scattering is suppressed and the transparency of the coating is It is preferable from the point of the improvement and the point that the specific surface area of the photocatalyst particles is increased and the photocatalytic activity is also excellent.

  Therefore, the average particle size of the antibacterial metal-supported photocatalyst AB is not particularly limited, but may be 1 nm or more, 3 nm or more, 5 nm or more, or 10 nm or more. The average particle size may be 400 nm or less, 300 nm or less, 200 nm or less, or 100 nm or less.

  The average particle diameter of the antibacterial metal-supporting photocatalyst particle AB is not particularly limited, but is preferably in the range of 1 to 400 nm, more preferably in the range of 5 to 200 nm, and still more preferably in the range of 10 to 100 nm. . In addition, the smaller the average particle diameter of the antibacterial metal-supporting photocatalyst particles AB (the smaller the average particle diameter of the antibacterial metal particles B if the average particle diameter of the photocatalyst particles A is constant), the colorability of the obtained coating film is Low.

In addition, when the particle shape of inorganic compound AB for photocatalysts has the major axis and minor axis of rod shape etc., it is preferable that the arithmetic mean of the major axis and minor axis is in the said range.
The average particle size of the antibacterial metal-supported photocatalyst particles AB is measured by the method described later. In addition, "the average particle diameter of antibacterial metal carrying | support photocatalyst AB" points out the secondary particle diameter in the state of the particle | grains in particle | grain paint.

(Photocatalyst particles A)
The photocatalyst particle A in the antibacterial metal-supporting photocatalyst particle AB of the present embodiment has its surface modified with a metal oxide having photocatalytic activity and no photocatalytic activity. By modifying the surface of the particles having photocatalytic activity with a metal oxide having no photocatalytic activity, the dispersion stability of the particles and the weather resistance of the coating film are excellent.

  Examples of metal oxides not having photocatalytic activity include silicon dioxide, aluminum oxide, zirconium oxide and the like, and these may be used alone or in combination of two or more. Among them, the dispersion medium having a pH in the neutral region can achieve excellent dispersion stability of the particles, and the particles also improve the hydrophilicity of the coating film into which the particles are incorporated, so that the metal does not have photocatalytic activity. The oxide is preferably silicon dioxide alone.

  In the antibacterial metal-supported photocatalyst AB of the present embodiment, the metal oxide having no photocatalytic activity modifies the surface of the photocatalyst particle A. The amount of the metal oxide not having photocatalytic activity may be 1% or more, 3% or more, 5% or more, 7% or more, or 10% or more, 30% or less, 25% or more based on the mass of the photocatalyst particle A. % Or less, 20% or less, or 15% or less. The amount of the metal oxide not having photocatalytic activity is preferably 1% to 30%. If the amount is 1% or more, the dispersibility of the particles and the weatherability are improved, and if 30% or less, the photocatalytic activity is significantly improved. The amount of metal oxide having no photocatalytic activity that modifies the surface of the photocatalyst particle A is preferably 1% to 30%, more preferably 5% to 25%, based on the mass of the photocatalyst particle A. More preferably, it may be in the range of 10% to 20%.

Examples of the photocatalyst particle A having photocatalytic activity include titanium dioxide (TiO ₂ ), zinc oxide (ZnO), strontium titanate (SrTiO ₃ ), gallium phosphide (GaP), indium phosphide (InP), gallium arsenide (GaAs), barium titanate (eg, 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), tantalum pentoxide _{(Ta 2 O 5), K} 3 Ta 3 Si 2 O 3, tungsten oxide (e.g., WO _3), tin oxide (e.g., SnO _2), bismuth oxide (e.g., Bi ₂ O _3), bismuth vanadate (BiVO _4), nickel oxide (e.g., NiO), copper oxide (e.g., Cu ₂ O), silicon carbide (SiC), sulfide molybdenum (E.g., MoS _2), indium lead (InPb), ruthenium oxide (e.g., RuO _2), and cerium oxide (e.g., CeO _2), and the like.

Among these. From the viewpoint of safety and cost, TiO ₂ (titanium dioxide) is preferable as the photocatalyst particle A (also simply referred to as “photocatalyst particle A”) having photocatalytic activity. The crystal structure of TiO ₂ includes, for example, crystal structures such as anatase type, rutile type, or brookite type, and any may be used.

  The photocatalyst particle A whose surface is modified with a metal oxide not having photocatalytic activity is, for example, a method of suspending titanium dioxide particles in water and forming silicon dioxide etc. on the surface of the particles by sol-gel reaction etc. And can be produced by known methods. Moreover, as a commercial item of the said particle | grains A, for example, Ishihara Sangyo Co., Ltd. MPT-429, Showa Denko Co., Ltd. F-4 S05, Tayca Corporation MT-100 SA, and Fuso Chemical Co. STR-100A etc. are mentioned.

  Specifically, the proportion of the metal oxide having no photocatalytic activity is 3.3. It can be calculated according to the method described in the quantification of surface modified substances.

(Antibacterial metal particles B)
The antibacterial metal particle B used in the present embodiment refers to, for example, a metal having a minimum inhibitory concentration (MIC) of metal ions to E. coli cells of 20 mM or less. The minimum inhibitory concentration (MIC) is the minimum concentration of an agent (herein referred to metal ion) necessary to inhibit bacterial growth.

Examples of the antimicrobial metal particles B of the present embodiment include heavy metals such as silver, gold, palladium, platinum, cobalt, nickel, copper, zinc, lead, manganese and the like. Among these, from the viewpoint of safety and practicability, preferred examples of the antimicrobial metal particles B include gold, silver, copper, platinum and zinc, and more preferred are gold, silver and copper. Can be mentioned. These heavy metals may be used alone or in combination of two or more.

  As the existence form of the antibacterial metal particle B, the form of the above metal simple substance, the form of the metal compound, the form of the ionic state, or the form in the state of being complexed with other compounds can be used. The form of a simple substance, in particular, a form of a metal simple substance or a metal compound which is poorly soluble in water is preferred. This is because the metal simple substance or the metal compound is poorly soluble in water, and the metal ion itself generated by the dissolution of the metal is reduced by absorption of light or photocatalytic reaction of adjacent photocatalyst particles, as a result, This is because the possibility that the color of the coating changes with time can be reduced. In addition, in the case where the single metal or the metal compound is poorly soluble in water, it is possible to suppress the runoff by moisture such as rain in an outdoor environment, thereby maintaining the effect of the present invention. .

  The component of the antibacterial metal particle B is preferably at least one selected from the group consisting of gold, silver, copper, a gold compound, a silver compound and a copper compound. Specific examples of the components of the antimicrobial metal particle B include, in the case of gold, for example, gold alone, in the case of silver, silver alone and compounds thereof, for example, silver oxide and silver chloride, copper In the case, a copper simple substance and its compound, for example, copper oxide and copper hydroxide etc. are mentioned.

  The mass of the antibacterial metal particles B according to the present embodiment is preferably in the range of 0.1 to 10% based on the mass of the photocatalyst particles A. When the mass range of the antibacterial metal is 0.1% or more, the anti-algal and antifungal effect can be sufficiently exhibited. When the range is 20% or less, the antibacterial metal-supported photocatalyst particles AB can be obtained. When incorporated in the coating film, not only can the metal-derived coloration be suppressed, but also the amount of the unsupported antibacterial metal particles C is reduced, and furthermore, the suppression of light absorption of titanium oxide by the antibacterial metal particles B is reduced. As a result, it is preferable because maintenance or improvement of photocatalytic activity can be achieved. The mass of the antimicrobial metal particles B is preferably in the range of 0.1 to 10%, more preferably 0.5 to 8.0%, further preferably, based on the mass of the photocatalyst particles A. It is a range of 0.5 to 4.0%. The smaller the proportion of the mass of the antibacterial metal particles B, the lower the colorability of the obtained coating film, in other words, the less the design of the undercoat film is impaired.

(Antibacterial metal particle C)
The antibacterial metal particle C used in the present embodiment may be a non-reacted material of the raw material in the production of supporting the antibacterial metal particle B described later, or may be a non-supported particle. Particles may be added. Therefore, the metal species of the antimicrobial metal particles C and the antimicrobial metal particles B may be the same or different.

  The form of the presence of the antimicrobial metal particle C used in the present embodiment may be any form such as a simple metal, a complex containing metal ions and ions, or a metal salt.

  Moreover, as a kind of antibacterial metal particle C, it is preferable like the above-mentioned antibacterial metal particle B that it is a metal kind selected from any of gold, silver and copper among various antibacterial metals. The antimicrobial metal particle C is more preferably at least one selected from the group consisting of gold, silver, copper, gold ions, silver ions, copper ions, gold compounds, silver compounds, and copper compounds.

The mass of the antibacterial metal particles C used in the present embodiment is preferably 10 to 3000 ppm based on the total solid content of the antibacterial metal-supporting photocatalyst particles AB. By being 10 ppm or more, in addition to the antibacterial metal particle B, the metal component which acts with respect to microorganisms is increased, and since it exerts an effect more, it is preferable. When it is 3000 ppm or less, in the appearance of the coating film, the coloring property derived from the metal is reduced, and it becomes difficult to damage the design of the undercoat film, and the coating film is It is possible to show an improved appearance of the coating, such as being less likely to cause color change. Furthermore, since a single metal and / or a poorly soluble compound is likely to be a starting point such as a crack and a drop in the coating film, not only the physical strength of the coating film is reduced, but the antibacterial metal particle C is It is not preferable because long-term sustainability of the effect can not be expected by detachment. The reason for the origin of the crack or chipping is not clear, but it is presumed that the metal single substance or the poorly soluble compound has weak interaction with other components in the coating film and reduces the physical strength of the contained part There is.
The mass of the antibacterial metal particles C is preferably 10 to 3000 ppm, more preferably 20 to 2500 ppm, and still more preferably 50 to 2000 ppm, based on the total solid content of the antibacterial metal-supported photocatalyst particles AB.

[Method of producing antibacterial metal-loaded photocatalyst particles AB]
The method for producing the antibacterial metal-supported photocatalyst particle AB of the present embodiment is as follows:
Mixing an aqueous dispersion of photocatalytic particles A having photocatalytic activity whose surface is modified with a metal oxide having no photocatalytic activity and a water-soluble metal compound (precursor of antibacterial metal particles B) containing metal ions, and further The antibacterial metal particles B are generated and supported on the photocatalyst particles A by reducing metal ions by adding a water-soluble reducing agent.
including.

  Various chemical reactions can be used as a method of producing the antimicrobial metal particles B, and among them, a water-soluble metal compound containing metal ions as a precursor is dissolved in water to allow water to be dissolved under conditions where metal ions are present. It is preferable to add an active reducing agent to form antimicrobial metal particles B by a reduction reaction, because a high yield can be achieved and the reaction time can be shortened.

  As a method for supporting the antimicrobial metal particles B used in the present embodiment, in order to minimize the formation of non-supported particles, the above-mentioned reduction reaction is carried out under the condition that the dispersing agent etc. is not contained or the content is as low as possible. It is preferable to When the amount of the dispersant contained is as small as possible, the antibacterial metal particles B generated by the reduction reaction become destabilized in the solvent, and as a result, the amount supported on the photocatalyst particles A can be improved.

  Furthermore, by using the photocatalyst particle A whose surface is modified with a metal oxide having no photocatalytic activity, the dispersion stability is improved, and as a result, the synthesis reaction can be performed without adding a dispersant. For this reason, it becomes possible to improve the ratio of the antimicrobial metal particle B supported on the surface of the photocatalyst particle A.

  As a precursor of the antibacterial metal particle B, a salt of a compound listed as an example of the antibacterial metal particle B, for example, a compound which is a salt with an acid such as sulfuric acid and nitric acid is preferable. Specific examples of the precursor of the antimicrobial metal particle B include, for example, tetrachloroauric acid, silver nitrate, copper sulfate, copper nitrate and the like, and combinations thereof.

  The precursor of the antibacterial metal particle B may be a compound having a solubility of 1 g or more, 5 g or more, or 10 g or more at 1 atm and 20 ° C., and 300 g or less, 200 g or less, or 100 g or less It may be a compound that Among these, as this precursor, the solubility in 100 mL of water at 1 atm and 20 ° C. is 10 g / 100 mL from the viewpoint of shortening the time of dissolution operation and preventing the reaction yield decrease due to undissolved matter of the precursor. Compounds having the above are preferred.

  As a water-soluble reducing agent, 1 or more types selected from the group which consists of a citric acid, ascorbic acid, tannic acid, a borohydride salt, a hydrazine etc. are mentioned suitably, for example. Among them, one or more selected from citric acid, ascorbic acid, tannic acid, and salts thereof are preferable because they are highly safe and inexpensive.

Although the temperature at the time of adding a water-soluble reducing agent and performing a reduction reaction can be manufactured also at normal temperature, it is preferable to heat in the range of 40 degreeC-79 degreeC.
At a temperature of 40 ° C. or higher, the reaction rate is fast, so that not only productivity is improved, but also in a high temperature condition such as summer, temperature adjustment is easy, such as a cooling chiller for maintaining the temperature being unnecessary. Because it is preferable. Further, at 80 ° C. or less, the reaction speed is appropriately fast, and not only the dispersion stability of the photocatalyst particles A is improved, but also the dispersion of the antibacterial metal particles B is promoted, and as a result, the average of the antibacterial metal particles B is obtained. It is preferable because the particle diameter is reduced and the loading amount is improved.
The temperature at which the water-soluble reducing agent is added is preferably 40 ° C to 79 ° C, more preferably 45 ° C to 75 ° C, still more preferably 50 ° C to 70 ° C.

[Photocatalyst composition]
The antimicrobial metal-supported photocatalyst particle AB of the present embodiment can be blended with water and colloidal silica to make a photocatalyst composition. That is, one of the present embodiments is a photocatalyst composition including the antibacterial metal-supported photocatalyst particle AB of the present embodiment, water, and colloidal silica.
In the photocatalyst composition of the present embodiment, the solid content concentration of the antibacterial metal-supported photocatalyst particles AB is preferably 1 to 30% by mass in the total solid content of the photocatalyst composition, from the viewpoint of the coating film appearance. When the solid content concentration of the antibacterial metal-supporting photocatalyst particle AB is in this range, a photocatalyst composition having both photocatalytic performance and coating film transparency can be realized. The solid content concentration of the antibacterial metal-supporting photocatalyst particle AB is more preferably 5 to 27% by mass, and still more preferably 10 to 25% by mass, based on the total solid content of the photocatalyst composition.

(Colloidal silica)
As colloidal silica, for example, one prepared by a sol-gel method can also be used, and a commercially available product can also be used. When this is prepared by the sol-gel method, Werner Stober et al; Colloid and Interface Sci. , 26, 62-69 (1968), Rickey D .; See, for example, Badley et al; Lang muir 6, 792-801 (1990), Colorant Society Journal, 61 [9] 488-493 (1988), and the like.

  Examples of colloidal silica include acidic colloidal silica and basic colloidal silica in which water is a dispersion medium, and colloidal silica in which a water-soluble solvent is a dispersion medium.

  As acidic colloidal silica, for example, Snowtex (registered trademark) -O manufactured by Nissan Chemical Industries, Ltd., Snowtex-OS, Adeleite (registered trademark) AT-20Q manufactured by Asahi Denka Kogyo Co., Ltd., Crevosol manufactured by Clariant Japan Ltd. as commercial products (Registered trademark) 20H12, clevozole 30 CAL 25 and the like can be mentioned.

  Examples of basic colloidal silica include silica stabilized by the addition of alkali metal ions, ammonium ions, amines, etc. Specifically, Snowtex-NS, Snowtex-20, manufactured by Nissan Chemical Industries, Ltd. , Snowtex-30, Snowtex-C, Snowtex-C 30, Snowtex-CM 40, Snowtex-N, Snowtex-N 30, Snowtex-K, Snowtex-XL, Snowtex-YL, Snowtex-ZL , Snowtex PS-M, Snowtex PS-L, etc .; Adelite AT-20, Adelite AT-30, Adelite AT-20N, Adelite AT-30N, Adelite AT-20A, Adelite AT-30A, Adelite manufactured by Asahi Denka Kogyo Co., Ltd. AT-40, Adérite AT 50 and the like; manufactured by Clariant Japan Kurebozoru 30R9, Kurebozoru 30R50, Kurebozoru 50R50 like; DuPont Ludox (TM) HS-40, Ludox HS-30, Ludox LS, Ludox SM-30 and the like; and the like.

  As colloidal silica using a water-soluble solvent as a dispersion medium, for example, MA-ST-M (methanol dispersion type with particle size of 20 to 25 nm) manufactured by Nissan Chemical Industries, Ltd., IPAST (isopropyl alcohol dispersion with particle size of 10 to 15 nm) Types), EG-ST (ethylene glycol dispersed type with particle size of 10 to 15 nm), EG-ST-ZL (ethylene glycol dispersed type with particle size of 70 to 100 nm), NPC-ST (particle size of 10 to 15 nm) Ethylene glycol monopropyl ether dispersion type) etc. can be mentioned.

  As colloidal silica, you may use what combined 1 type, or 2 or more types in these.

  Colloidal silica may contain alumina, sodium aluminate or the like as a minor component. The colloidal silica may contain an inorganic base (sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonia or the like) or an organic base (tetramethylammonium or the like) as a stabilizer.

  The average particle size of the colloidal silica is preferably 100 nm or less, more preferably 50 nm or less, and still more preferably 30 nm or less. In addition, particles having an average particle diameter of 10 nm or less are more preferable from the viewpoint that the transparency of the obtained photocatalyst coating film becomes very high.

  The average particle diameter (number average particle diameter) of colloidal silica can be measured based on the method described in the following examples.

  In the photocatalyst composition of the present embodiment, the solid content concentration of colloidal silica having no photocatalytic activity is preferably 50 to 99 based on the total solid content of the photocatalyst composition, from the viewpoint of the hydrophilicity and weatherability of the coating film. It is mass%, More preferably, it is 55-95 mass%, More preferably, it is 60-90 mass%.

(Polymer emulsion particle D)
The photocatalyst composition of the present embodiment can further include polymer emulsion particles D. As the polymer emulsion particles D contained in the photocatalyst composition of the present embodiment, all synthetic resins known to those skilled in the art can be used. In addition to particles synthesized by emulsion polymerization or suspension polymerization in a solvent, particles obtained by forming a resin or powder resin dissolved in a solvent into an emulsion using a surfactant or a suspending agent can also be used.

Examples of the synthetic resin include, for example, solvent-based synthetic resin paint (acrylic resin, epoxy resin, urethane resin, fluorocarbon resin, silicone-acrylic resin, alkyd resin, amino alkyd resin, vinyl resin, Examples thereof include unsaturated polyester resin systems, chlorinated rubber systems, etc., water-based synthetic resin coatings (emulsion systems, aqueous resin systems, etc.), and inorganic coatings.
Among these synthetic resins, silicone resins and fluorine resins which are hardly degradable with respect to the photocatalyst, and further, synthetic resins of a combination of silicone resin and fluorine resin are preferably used.

  Such silicone resins include, for example, alkoxysilanes and / or organoalkoxysilanes, their hydrolysis products (polysiloxanes) and / or colloidal silicas, and furthermore acrylic silicone resins having a silicone content of 1 to 80% by mass. Epoxy-silicone resins, urethane-silicone resins, alkoxysilanes and / or organoalkoxysilanes, and their hydrolysis products (polysiloxanes) and / or resins containing 1 to 80% by mass of colloidal silica, and the like. These silicone resins may be of any of the type dissolved in a solvent, dispersion type, and powder type, and may contain additives such as a crosslinking agent and a catalyst.

  In the photocatalyst composition of the present embodiment, the ratio of the polymer emulsion particles D is preferably 0 to 30% by mass, and more preferably 0 to 30% by mass, based on the total solid content of the photocatalyst composition, from the viewpoint of weatherability. It may be 25% by mass, more preferably 0 to 20% by mass.

  The photocatalyst composition of the present embodiment can also contain a surfactant, a bleaching dye, and the like as long as the effects of the invention are not impaired.

(Surfactant)
The surfactant that can be included in the photocatalyst composition of the present embodiment is not particularly limited, and examples thereof include hydrocarbon surfactants and fluorocarbon surfactants. Thereby, the wettability of the photocatalyst composition of the present embodiment and / or the water-based paint containing the same is improved, and when coating on organic equipment and the like using these, it is possible to further suppress appearance problems such as repelling. Can. In particular, a fluorocarbon surfactant is preferable because it is excellent in surfactant ability in a small amount, and furthermore, the uniformity of the coating film can be further improved. Although it is not clear as these reasons, it is presumed that the photocatalytic composition can reduce the surface tension of the photocatalytic composition by containing a fluorocarbon surfactant (however, the function of the present embodiment). Is not limited to these).

  The component of the fluorocarbon surfactant is not particularly limited, but preferred is a nonionic surfactant or an amphoteric surfactant. Examples of amphoteric surfactants include anionic amphoteric surfactants and cationic amphoteric surfactants. Preferred specific examples include, for example, nonionic surfactants and amphoteric surfactants having a C 3-20 perfluoroalkyl group.

  Specific examples of nonionic surfactants having a C 3 to C 20 perfluoroalkyl group, or amphoteric surfactants include perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkylamine oxides, Perfluoroalkyl ethylene oxide adducts, perfluoroalkyl compounds having an anionic group and a cationic group, and the like can be mentioned. Among these, perfluoroalkyl ethylene oxide adducts and perfluoroalkyl compounds having an anionic group and a cationic group are preferable from the viewpoint of lowering the surface tension of the paint.

As the perfluoroalkyl carboxylate, for example, a commercially available product can also be used. Examples of commercially available products of perfluoroalkyl carboxylates include "Surflon S-211" manufactured by AGC Seimi Chemical Co., Ltd.
As perfluoroalkylamine oxide, for example, commercially available products can also be used. As a commercial item of perfluoroalkyl amine oxide, "Surflon S-241" by AGC Seimi Chemical Co., Ltd., etc. may be mentioned.
For example, commercially available products can be used as the perfluoroalkyl ethylene oxide adduct. Examples of commercially available products such as perfluoroalkyl ethylene oxide adducts include "Megafuck F-444" manufactured by DIC, "Surflon S-242" manufactured by AGC Seimi Chemical, and the like.
As a perfluoroalkyl compound which has an anionic group and a cationic group, a commercial item can also be used, for example. As commercially available products such as perfluoroalkyl compounds having an anionic group and a cationic group, "Surflon S-231", "Surflon S-232", "Surflon S-233" manufactured by AGC Seimi Chemical Co., Ltd. Etc.
These amphoteric surfactants having a perfluoroalkyl group may be used alone or in combination of two or more.

  The content of the fluorocarbon surfactant in the photocatalyst composition is not particularly limited, but is preferably 0.0001 to 1.0% by mass based on the total mass of the photocatalyst composition including water, and more preferably It may be 0.01 to 0.50 mass%. By making content of a fluorocarbon surfactant more than the said lower limit, the uniformity of the coating film obtained will improve further. By making content of a fluorocarbon surfactant below the said upper limit, the weather resistance of the coating film obtained further improves.

The photocatalyst composition of the present embodiment can contain a bleaching dye. In this way, it is possible to prevent troubles such as paint failure, repeated paint, uneven paint and the like.
As the bleaching dye component, those which do not lose color by irradiation of sunlight and do not impair the design of the base are preferable. Although the time until color loss varies depending on the season, irradiation direction, etc., typically, the period until color loss is visually confirmed is preferably 20 days or less, more preferably 10 days or less, and still more preferably 3 days or less may be sufficient.

  The component of the bleaching dye is not particularly limited as long as it has the property of decoloring by irradiation with sunlight, but preferred examples include methylene blue, crystal violet, malachite green, brilliant blue FCF, erythrosine, neukoccin, One or more selected from the group consisting of phloxine, rose bengal, acid red, fast green FCF and the like. Among these, methylene blue is more preferable as the component of the color-fading dye, from the viewpoint of good color developability and fast color loss speed. These may be used singly or in combination of two or more.

  The content of the component of the discolorable dye in the photocatalyst composition is not particularly limited, but is preferably 0.0002 to 0.05% by mass based on the total mass of the photocatalyst composition containing water, more preferably Is 0.001 to 0.02 mass%. By setting the content of the component of the color-fading dye in the water-based coating agent composition to the above-mentioned range, the coloring property and / or the color-fading property of the coating film is further improved. The color development referred to herein means the property that the coated surface and the unpainted surface are colored to the extent that they are visually distinguished from differences in color, and the color fading is color fading to the extent of the color that does not impair the design of the substrate. Say the nature of

  The content of the component of the color-fading dye in the coating film obtained from the photocatalyst composition is not particularly limited, but is preferably 0.01 to 1.0% by mass, more preferably 0.05 to 0.80 mass. %, More preferably 0.1 to 0.70% by mass. By setting the content of the component of the color-fading dye to the above lower limit value or more, the coloring property of the coating film is further improved, and by setting the content to the above upper limit value, the color fading property of the coating film is further improved.

[Photocatalyst coating]
The photocatalyst composition of the present embodiment can form a photocatalyst coating film. That is, one of the present embodiments is a photocatalyst coating film formed from the photocatalyst composition of the present embodiment.
Although the film thickness of the photocatalyst coating film of this embodiment is not particularly limited, it is preferably 0.05 to 50 μm, more preferably 0.1 to 10 μm, and 0.2 to 2.0 μm. More preferable. When the thickness is 50 μm or less, good transparency can be secured, and when the thickness is 0.05 μm or more, functions such as antifouling property and photocatalytic activity can be more effectively exhibited.

  A dispersion stabilizer may be contained in the photocatalyst coating film of the present embodiment from the viewpoint of the dispersion stability of each particle contained therein. Examples of dispersion stabilizers include various water-soluble oligomers selected from the group consisting of polycarboxylic acids and sulfonates, polyvinyl alcohol, hydroxyethyl cellulose, starch, maleated polybutadiene, maleated alkyd resin, polyacrylic acid (salts And synthetic high molecular substances represented by acrylic resin, and various natural high molecular substances represented by acrylic resin. The dispersion stabilizers may be used alone or in combination of two or more.

  In addition, the photocatalyst coating film of the present embodiment is a component to be added and blended to a general paint or molding resin according to the use and usage method thereof, for example, a solvent, a thickener, a leveling agent, and a thixotropic agent Antifoaming agent, freeze stabilizer, matting agent, crosslinking reaction catalyst, pigment, curing catalyst, crosslinking agent, filler, anti-skinning agent, dispersing agent, wetting agent, light stabilizer, antioxidant, UV absorber , Rheology control agent, antifoaming agent, film forming aid, rust inhibitor, dye, plasticizer, lubricant, reducing agent, preservative, fungicide, deodorant, anti-yellowing agent, antistatic agent, A charge control agent or the like, or a combination thereof may be included.

  The photocatalytic coating film of the present embodiment is effective even with its own film alone, but is different from the photocatalytic composition described above in order to further improve the adhesiveness such as adhesion to other objects, protection, and functionality such as design. It is preferable to set it as the multilayer coating film obtained by laminating | stacking the coating film comprised from a composition.

  As a composition different from the above-mentioned photocatalyst composition, for example, in addition to a composition containing an acrylic resin, an acrylic silicone resin, an epoxy resin, a urethane resin and the like, an inorganic composition containing silica, titanium peroxide and the like may be mentioned. it can.

  The photocatalytic coating film of the present embodiment can be obtained by applying the photocatalytic composition to the substrate or the surface of the coating film covering the substrate and drying. Examples of base materials to which the photocatalyst composition is applied include synthetic resins, natural resins, organic bases represented by fibers, metals, ceramics, glass, stones, cement, inorganic bases represented by concrete, and those A combination of

  As a synthetic resin which covers said base material, a thermoplastic resin and curable resin (a thermosetting resin, a photocurable resin, moisture curable resin etc.) are mentioned, for example. Specific examples thereof include, for example, silicone resin, acrylic resin, methacrylic resin, fluorine resin, alkyd resin, amino alkyd resin, vinyl resin, polyester resin, styrene-butadiene resin, polyolefin resin, polystyrene resin, polyketone resin, polyamide resin, Polycarbonate resin, polyacetal resin, polyether ether ketone resin, polyphenylene oxide resin, polysulfone resin, polyphenylene sulfone resin polyether resin, polyvinyl chloride resin, polyvinylidene chloride resin, urea resin, phenol resin, melamine resin, epoxy resin, urethane resin , Silicone-acrylic resins, etc., and composite resins thereof. Moreover, as said natural resin, cellulose resin, isoprene resin represented by natural rubber, protein resin represented by casein, etc. are mentioned, for example.

  When the substrate is a resin plate or fiber, the surface thereof may be treated with a corona discharge treatment, a flame treatment, a plasma treatment or the like, but the surface treatment of these is not essential.

  The photocatalyst coating film of the present embodiment can be obtained by applying the photocatalyst composition by any method depending on the use and the like. Examples of the coating method include spray spraying, flow coating, roll coating, brush coating, dip coating, spin coating, screen printing, casting, gravure printing, and flexo printing.

  The photocatalyst coating film of the present embodiment is obtained by applying a photocatalyst composition and then drying to remove volatile components. At this time, for example, after drying at a temperature of 5 to 80 ° C., a heat treatment of preferably 20 ° C. to 500 ° C. or more preferably 40 ° C. to 250 ° C. may be performed if desired. Good.

[Photocatalyst coating products]
The photocatalyst coated product of the present embodiment is a product provided with the photocatalyst coated film of the present embodiment, and is provided with a substrate and the above-described photocatalyst coated film formed on the substrate. This photocatalyst coated product may be the same as known aspects except that the photocatalyst coating film of the present embodiment is provided. Specific examples of the photocatalyst coated product of the present embodiment include, for example, building materials, building exteriors, building interiors, window frames, window glasses, structural members, building equipment such as houses, covers for vehicle lighting, window glasses, mechanical devices or Exteriors of articles, dustproof covers and coatings, display devices, their covers, traffic signs, various display devices, display objects such as advertising towers, sound barriers for roads, railways, etc., bridges, guardrail exteriors and coatings, tunnel interiors and coatings The exterior parts of electronic devices and electrical devices used outside such as insulators, solar cell covers, solar water heat collection covers, etc., particularly transparent members, exteriors such as plastic houses, greenhouses, etc. may be mentioned. The photocatalytic coated product may be obtained by applying a photocatalytic composition to the surface of a substrate and drying it to form a photocatalytic film on the substrate, but the production method is not limited thereto. For example, the substrate and the photocatalytic coating may be formed simultaneously, or more specifically, integrally formed.

  In addition, after the photocatalyst coating film of the present embodiment is formed on a certain substrate, the photocatalyst coating film peeled off from the substrate or the photocatalyst coating film adhered to the substrate is used as another substrate. It may be adhered by adhesion, fusion or the like.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to the said this embodiment. In the present invention, various modifications are possible without departing from the scope of the invention.

  The present invention is 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 methods shown below.

1. Determination of Surface Modifications Having No Photocatalytic Activity Determination was carried out by the FP method in which quantitative analysis is performed using theoretical and fundamental constant Fundamental Parameter (FP) using a fluorescent X-ray analyzer.

2. Measurement of particle size (average particle size of antibacterial metal-supported photocatalyst particles AB, colloidal silica and polymer emulsion particles D)
The average particle diameter of the antibacterial metal-supported photocatalyst particles AB, colloidal silica and polymer emulsion particles D is appropriately diluted by adding a solvent to the sample such that the solid content in the sample is 0.1 to 20 mass% , And was measured using a wet particle size analyzer (wet particle size distribution analyzer manufactured by Microtrac Bell, trade name "Nanotrac Wave-EX 150").
(Average particle size of antibacterial metal particles B)
The average particle size of the antibacterial metal particles B supported on the photocatalyst particles A was measured as follows. The antibacterial metal-supporting photocatalyst particle AB was diluted with water so that the solid content concentration was 0.5% by mass, and the diluted solution was dropped onto the collodion film. Thereafter, this collodion film is dried under vacuum conditions for 1 hour, the surface is observed by a scanning transmission electron microscope, and 50 particles of the observed antimicrobial metal particles B are optionally selected, and their circle equivalent diameters are selected. The (Heywood diameter) was measured, and their number average particle diameter was calculated.

3. Measurement of Mass of Antibacterial Metal Particle B The mass of the antibacterial metal particle B was determined by the following method.
10 g of the aqueous dispersion (solid content concentration: 2% by mass) of the antibacterial metal-supporting photocatalyst particle AB synthesized was taken without dilution and centrifuged at a speed of 1000 rotations / minute for 10 minutes. After centrifugation, the supernatant was collected with a Pasteur, and the mass of each metal in the supernatant was measured with an inductively coupled plasma mass spectrometer (ICP-MS).

4. Measurement of Content of Antibacterial Metal Particles C The content of the antibacterial metal particles C was a total value of the concentration of the components arbitrarily blended and the values obtained by the following methods (i) and (ii).
(I) Determination of unreacted metal ion 10 g of the aqueous dispersion (solid content concentration: 2% by mass) of the antibacterial metal-supporting photocatalyst particle AB synthesized is taken without dilution, at a speed of 20000 rpm for 1 hour. Centrifugation was performed. Thereafter, the supernatant is collected with a Pasteur, and the concentration of remaining metal ions in the supernatant is measured with an inductively coupled plasma mass spectrometer (ICP-MS), and contained in the antibacterial metal-supported photocatalyst particles AB. The concentration of metal components was determined.
(Ii) Determination of non-supported metal component 10 g of the aqueous dispersion (solid content concentration: 2% by mass) of the antibacterial metal-supported photocatalyst particle AB synthesized is taken without dilution, at a speed of 1000 rpm for 10 minutes. Centrifugation was performed. Thereafter, the supernatant was removed with a Pasteur and the sediment was collected. The amount of the metal component of the precipitate was measured with an inductively coupled plasma mass spectrometer (ICP-MS) to determine the concentration of the metal component contained in the antibacterial metal-supported photocatalyst particle AB.

5. Film thickness of the coating film thickness of the coating film, a film thickness measuring device equipped with a halogen light source (trade name "MHF-D100LR" manufactured by MORITEX Co., Ltd.) (trade name "HandyLambda II THICKNESS" manufactured by SPECTRA · COOP) It measured using.

6. Photocatalytic activity (pigment decomposition activity)
The photocatalytic activity was determined in accordance with JIS R1703-2. Specimen cleaning is performed by irradiating it with ultraviolet light with an illuminance of 1 mW / cm ² for 24 hours, and methylene blue adsorption is performed by immersing the specimen in an adsorption solution with a methylene blue concentration of 0.02 mM for 24 hours, The decomposition measurement of methylene blue is performed by irradiating the test solution (concentration 0.01 mM, injection amount 35 mL) with ultraviolet light with an illuminance of 1 mW / cm ² and measuring the absorption spectrum of the test solution collected after irradiation with a spectrophotometer The degradation activity index (nM / min) was calculated using these measured values. The absorbance measurement wavelength was 664 nm.
[Evaluation criteria]
○: The degradation activity index was 5 nM / min or more.
Δ: The degradation activity index was at least 3 nM / min and less than 5 nM / min.
X: The degradation activity index was less than 3 nM / min.

7. Anti-algal, anti-fungal (short-term)
As to the algicidal properties, the test was carried out by placing the test body in a Petri dish in which algae is present, and placing the Petri dish in a thermostatic bath kept at a constant temperature and humidity. The determination of algal properties was made four weeks after the start of the test. With regard to mold resistance, a mold resistance test was carried out in accordance with JIS Z 2911: 2010. The mold resistance was determined two weeks after the start of the test.
[Evaluation criteria]
○: Growth of algae and mold was not observed.
Δ: Slight growth of algae and mold was observed, but it was judged that there was no problem as a whole.
X: Growth of algae and mold was clearly observed.

8. Anti-algal, anti-fungal (long-term)
A photocatalyst paint composition is applied to a white acrylic plate (70 mm * 150 mm * 2 mm) with a dip coater (DC4200 manufactured by IDEN, lifting speed: 10 mm / sec at descent, 10 mm / sec at rising), and after coating Dried for 2 days. After that, an outdoor exposure test was conducted on a site with a forest near the Kashiwa city, Chiba Prefecture, and on a land where the lawn is growing, with the north face at 90 °. The judgment was made at 2 years 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.

9. Transparency of coating film (white turbidity of coating film)
The color difference was measured with the black paper laid under a glass plate (a flat plate glass manufactured by Test Piece Co .; 60 mm * 60 mm * 2 mm). After that, the photocatalytic coating composition is applied by a dip coater (DC4200 manufactured by Eiden, lifting speed: 10 mm / sec at descent, 10 mm / sec at rising) and dried for 2 days after application. Then, it was left for 10 days under a fluorescent lamp adjusted to an illumination intensity of 5000 Lx, and the color difference of the test body from which the coloring agent was decolorized was measured. The color difference (brightness difference ΔL) before and after the application was evaluated. The color difference was determined from the standard plate using a color guide (manufactured by BYK Gardner). The lower the color difference ΔL, the higher the transparency and the better the appearance.
[Evaluation criteria]
○: The color difference ΔL was less than 1.6.
Δ: The color difference ΔL was less than 1.6 to 3.0.
X: The color difference ΔL was 3.0 or more.

10. Colorability of coating film A white enamel finish material for outer wall (water-based ceramic silicon Shiro) for outer wall is dried on sulfuric acid alumite base material (JIS H 4000 (A1100P; 50 mm * 50 mm * 1 mm) manufactured by Testpiece Co., Ltd.). It applied so that it might become 100 micrometers of post film thickness. Thereafter, the photocatalytic composition is applied by a dip coater (DC4200 manufactured by IDEN, raising and lowering speed: 10 mm / sec at falling, 10 mm / sec at rising) and dried for 2 days after application. Then, it was left for 10 days under a fluorescent lamp adjusted to an illumination intensity of 5000 Lx, and the color difference of the test body from which the coloring agent was decolorized was measured. The color difference (ΔE) before and after application was evaluated. The lower the color difference ΔE, the lower the colorability of the coating film, and the better the appearance.
[Evaluation criteria]
◎: The color difference ΔE was less than 1.6.
O: Color difference ΔE was less than 1.6 to 3.0.
Δ: The color difference ΔE was 3.0 to 5.0.
X: The color difference ΔE was 5.0 or more.

11. Weatherability (color difference after exposure to SWOM 5000 hours)
A test body coated with a photocatalytic coating film is prepared by the above method 10, and an exposure test (black panel temperature 63 ° C., rainfall 18 minutes / 2 hours) using a Suga Test Instruments Co., Ltd. Sunshine Weather Meter (SWOM) Did. The color difference between before exposure and 5000 hours after the start of exposure was measured by the method of the above 10, the color difference before exposure was taken as a standard, and the change in state before and after exposure was evaluated as ΔE. The lower the color difference ΔE, the smaller the change in appearance, that is, the better the weather resistance.
[Evaluation criteria]
○: ΔE was less than 3.
Δ: ΔE was 3 or more and less than 5.
X: ΔE was 5 or more.

12. Synthesis of photocatalyst particle A (silica modified rutile titanium dioxide)
The photocatalyst particles A used in the following production examples were synthesized as follows.
700 mL of a titanium tetrachloride aqueous solution having a concentration of 200 g / L as TiO ₂ and a sodium hydroxide aqueous solution having a concentration of 100 g / L as Na ₂ O were simultaneously added to water so as to maintain the pH of the system at 5-9. Thereafter, the pH of the system was adjusted to 7, followed by filtration and washing until the conductivity of the filtrate was 100 μS / cm, to obtain a wet titanium oxide cake 1 with a solid content concentration of 28.3 mass%. This titanium oxide wet cake 1 had a rutile type 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 is charged in a 3 L flask, and 1 L of nitric acid in 1 N is added so that the molar ratio of titanium oxide to nitric acid (titanium oxide / nitric acid) is 1, and the mixture is heated to a temperature of 95 ° C. An acid heat treatment was performed while maintaining the temperature for 2 hours. Then, the slurry after the acid heat treatment was cooled to room temperature, neutralized (pH = 6.7) using 28% aqueous ammonia, filtered, and washed until the conductivity of the filtrate reached 100 μS / cm. The titanium oxide wet cake 2 having a solid concentration of 25% by mass was obtained.
A 10% by mass aqueous solution of sodium hydroxide is added to the obtained titanium oxide wet cake 2 and repulped, and then dispersed for 3 hours with an ultrasonic cleaner, pH = 10.5, solid content concentration 10% by mass An alkaline titanium oxide sol was obtained. 2 L of this alkaline titanium oxide sol is charged in a 3 L flask and heated to a temperature of 70 ° C., 69.4 ml of an aqueous sodium silicate solution having a concentration of 432 g / L as SiO ₂ is 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 is cooled to room temperature, 5.4 L of pure water is added, impurities are removed and concentrated using a desalting and concentration apparatus, pH = 7.3, solid content concentration 29 mass% The neutral rutile titanium oxide sol of It contained 15 wt% of silicon oxide hydroxide with SiO ₂ basis relative to TiO _2. The average particle size of titanium oxide in this sol was 50 nm.

13. Synthesis of polymer emulsion particle D water dispersion After charging 830 g of ion-exchanged water and 40.0 g of a 10% by mass aqueous solution of dodecylbenzenesulfonic acid in a reactor having a reflux condenser, a dropping tank, a thermometer and a stirrer, The temperature in the reactor was heated to 80 ° C. under stirring. Into this reactor, a mixed solution consisting of 90.7 g of dimethyldimethoxysilane and 83.5 g of methyltrimethoxysilane and 10 g of water were simultaneously added dropwise over about 2 hours while maintaining the temperature in the reactor at 80 ° C. did. At that time, 2 g of a 10% by mass aqueous solution of dodecylbenzenesulfonic acid was added at 1 hour after the mixture liquid consisting of dimethyldimethoxysilane and methyltrimethoxysilane was dropped. After the entire mixture of dimethyldimethoxysilane and methyltrimethoxysilane is dropped, the temperature in the reactor is maintained at 80 ° C. and stirring is continued for about 30 minutes, and then 14.8 g of a 10% by mass aqueous solution of dodecylbenzenesulfonic acid And the temperature in the reactor was maintained at 80.degree. C. and stirring was continued for 2.5 hours.
Next, 26.4 g of a 0.5% by mass aqueous solution of ammonium persulfate is charged, 0.1 g of n-butyl acrylate, 36.7 g of phenyltrimethoxysilane, 27.8 g of tetraethoxysilane, and 3-methacryloxypropyltritriol. A mixture prepared by adding 10 g of water to a mixed solution consisting of 1.1 g of methoxysilane, 0.1 g of diethyl acrylamide, 0.9 g of acrylic acid, a reactive emulsifier (trade name "ADEKAREASOAP SR-1025", manufactured by Asahi Denka Co., Ltd. , 25 g of solid content 25% aqueous solution, 2.3 g of reactive emulsifier (trade name "Aqualon KH-1025" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 25% solid content aqueous solution), 0.5 mass% aqueous solution of ammonium persulfate A mixed solution of 120 g and 256.4 g of ion-exchanged water was simultaneously treated for about 2 hours while maintaining the temperature in the reactor at 80 ° C. The dropped. Further, the temperature in the reactor was maintained at 80 ° C. and stirring was continued for about 2 hours, then cooled to room temperature and filtered through a 100 mesh wire mesh. The solid content was adjusted to 8.5% by mass with ion exchange water, and an aqueous dispersion of polymer emulsion particles D having a number average particle diameter of 20 nm was obtained as polymer particles.

Preparation Example 1 Gold-Supported Titanium Oxide (A-1)
A 500 mL flask was charged with 400 g of an aqueous dispersion (solid content: 2% by mass) of the photocatalyst particle A synthesized by the method described in 12 above, and heated to 65 ° C. When 65 ° C. was reached, 3.83 g of tetrachloroaurate 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 the temperature at 65 ° C., stirred and cooled to room temperature to obtain gold-supported titanium oxide (A-1). The average particle diameter of the antibacterial metal-supporting photocatalyst particles in the obtained composite is 69 nm, and the average particle diameter and mass of gold supported on the photocatalyst particles A are 3 nm and 1.0%, respectively. The content of the gold compound not supported on A was 100 ppm.

Production Example 2 Silver-Supported Titanium Oxide (A-2)
An aqueous solution of tannic acid (concentration: 1% by mass) was prepared by changing the aqueous solution of tetrachloroaurate tetrahydrate (concentration: 1% by mass) used in Preparation Example 1 to 1.26 g of an aqueous solution of silver nitrate (concentration: 5% by mass). It synthesize | combined by the same method except the addition amount having been 3.50 g, and the silver carrying | support titanium oxide (A-2) was obtained. The average particle size of the antibacterial metal-supporting photocatalyst in the resulting composite is 60 nm, and the average particle size and mass of silver supported on the photocatalyst particle A are 4 nm and 0.5%, respectively. The content of the silver compound not supported on the mixture was 550 ppm.

Production Example 3 Silver-Supported Titanium Oxide (A-3)
The same procedure was followed, except that the addition amount of the aqueous silver nitrate solution (concentration: 5% by mass) of [Production Example 2] was 5.04 g, and the addition amount of tannic acid aqueous solution (concentration: 1% by mass) was 13.99 g. Thus, silver-supported titanium oxide (A-3) was obtained. The average particle size of the antibacterial metal-supporting photocatalyst in the resulting composite is 66 nm, and the average particle size and mass of silver supported on the photocatalyst particle A are 7 nm and 1.9%, respectively. The content of the silver compound not supported by was 1200 ppm.

Production Example 4 Silver-Supported Titanium Oxide (A-4)
[Production example 2] The same procedure was followed except that the addition amount of silver nitrate aqueous solution (concentration: 5 mass%) was 10.07 g and that of tannic acid aqueous solution (concentration: 1 mass%) was 27.97 g. Thus, silver-supported titanium oxide (A-4) was obtained. The average particle size of the antibacterial metal-supporting photocatalyst in the obtained composite is 74 nm, and the average particle size and mass of silver supported on the photocatalyst particle A are 16 nm and 3.8%, respectively. The content of the silver compound not supported on was 1900 ppm.

Production Example 5 Silver-Supported Titanium Oxide (A-5)
Synthesis Example 2 was carried out in the same manner except that the addition amount of the silver nitrate aqueous solution (concentration: 5% by mass) was 12.59 g and the addition amount of the tannic acid aqueous solution (concentration: 1% by mass) was 34.97 g. Thus, silver-supported titanium oxide (A-5) was obtained. The average particle size of the antibacterial metal-supporting photocatalyst in the resulting composite is 81 nm, and the average particle size and mass of silver supported on the photocatalyst particle A are 18 nm and 4.7%, respectively. The content of the silver compound not supported on was 2800 ppm.

Preparation Example 6 Copper Oxide-Supported Titanium Oxide (A-6)
[Preparation Example 2] 3.12 g of copper sulfate pentahydrate (concentration: 5 mass%) and the addition amount of tannic acid aqueous solution (concentration: 1 mass%) 5.30 g of silver nitrate aqueous solution (concentration: 5 mass%) The copper oxide-supporting titanium oxide (A-6) was obtained by the same method except using the above. The average particle size of the antibacterial metal-supporting photocatalyst in the resulting composite is 57 nm, and the average particle size and mass of copper oxide supported on the photocatalyst particle A are 4 nm and 0.5%, respectively. The content of copper oxide not supported on A was 800 ppm.

Production Example 7 Copper Oxide-Supported Titanium Oxide (A-7)
The same method is employed except that 9.36 g of copper sulfate pentahydrate (concentration: 5% by mass) used in [Preparation example 6] and 15.90 g of an aqueous tannic acid solution (concentration: 1% by mass) are used. The copper oxide was supported to obtain copper oxide-supporting titanium oxide (A-7). The average particle size of the antibacterial metal-supporting photocatalyst in the resulting composite is 71 nm, and the average particle size and mass of copper oxide supported on the photocatalyst particle A are 5 nm and 1.4%, respectively. The content of copper oxide not supported on A was 1100 ppm.

Preparation Example 8 Silver and Copper Oxide Supported Titanium Oxide (A-8)
A 500 mL flask was charged with 400 g of an aqueous dispersion (solid content: 2% by mass) of the photocatalyst particle A synthesized by the method described in 12 above, and heated to 65 ° C. When the temperature reached 65 ° C., 3.12 g of copper sulfate pentahydrate (concentration: 5% by mass) was added, 2.52 g of an aqueous silver nitrate solution (concentration: 5% by mass) was further added, and the mixture was stirred for 10 minutes. Thereafter, 12.29 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 the temperature at 65 ° C., stirred and cooled to room temperature to obtain silver oxide and copper oxide-supported titanium oxide (A-8). The average particle size of the antibacterial metal-supporting photocatalyst in the resulting composite is 56 nm, and the average particle size and mass of the silver and copper oxide supported on the photocatalyst particle A are 8 nm and 1.4%, respectively. The total content of silver and copper oxide not supported on the photocatalyst particle A was 1900 ppm.

Production Example 9 Copper Oxide-Supported Titanium Oxide (A-9)
392 g of water and 8 g of rutile-type titanium oxide (MT-100WP manufactured by Tayca Corporation) whose surface was modified with silica were added to a 500 mL flask and stirred for 15 minutes. Then, the temperature was raised to 65 ° C., and when it reached 65 ° C., 3.12 g of copper sulfate pentahydrate (concentration: 5% by mass) was added and stirred for 10 minutes. Thereafter, 13.99 g of an aqueous tannic acid solution (concentration: 1% by mass) was added. It stirred for 1 hour, maintaining at 65 degreeC after addition, and it cooled to room temperature after stirring, and copper oxide carrying | support titanium oxide (A-9) was obtained. The average particle size of the antibacterial metal-supporting photocatalyst in the resulting composite is 311 nm, and the average particle size and mass of copper oxide supported on the surface of titanium oxide are 11 nm and 0.3%, respectively. The content of copper oxide not supported on the surface was 2000 ppm.

[Manufacturing Comparative Example 1] Copper oxide-supported titanium oxide (A-10)
In a 3000 mL flask, 1800 g of water and 200 g of rutile-type titanium oxide (JR manufactured by Tayca Co., Ltd.) whose surface was not modified were added and stirred for 15 minutes. Next, a 10% by mass aqueous solution of sodium hydroxide was added, repulping was performed, and then dispersed for 3 hours with an ultrasonic cleaner to obtain an alkaline titanium oxide sol having a pH of 10.5 and a solid content concentration of 10% by mass. 2 L of this alkaline titanium oxide sol is charged in a 3 L flask and heated to a temperature of 70 ° C., 69.4 ml of an aqueous sodium silicate solution having a concentration of 432 g / L as SiO ₂ is 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 is cooled to room temperature, 5.4 L of pure water is added, impurities are removed and concentrated using a desalting and concentration apparatus, pH = 7.3, solid content concentration 29 mass% The neutral rutile titanium oxide sol of It contained 15 wt% of silicon oxide hydroxide with SiO ₂ basis relative to TiO _2.
This titanium oxide sol is diluted to 2% and charged in a 500 mL flask with 400 g, then heated to 65 ° C., and when it reaches 65 ° C., 15.6 g of copper sulfate pentahydrate (concentration: 5 mass%) is added Stir for 10 minutes. Thereafter, 69.95 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 the temperature at 65 ° C., stirred and cooled to room temperature to obtain copper oxide-supported titanium oxide (A-10). The average particle size of the antibacterial metal-supporting photocatalyst in the resulting composite is 503 nm, and the average particle size and mass of copper oxide supported on the titanium oxide surface are 26 nm and 0.5%, respectively, and titanium oxide is The content of copper oxide not supported on the surface was 10000 ppm.

[Manufacturing Comparative Example 2] Silver-supported titanium oxide (A-11)
The same procedure was followed except that the addition amount of the aqueous silver nitrate solution (concentration: 5% by mass) was 30.24 g and that of the aqueous tannic acid solution (concentration: 1% by mass) was 83.94 g. Thus, silver-supported titanium oxide (A-11) was obtained. The average particle size of the antibacterial metal-supporting photocatalyst in the resulting composite is 110 nm, and the average particle size and mass of silver supported on the photocatalyst particle A are 33 nm and 11.0%, respectively. The content of the silver compound not supported on was 9900 ppm.

Production Comparative Example 3 Copper Oxide-Supported Titanium Oxide (A-12)
A 500 mL flask is charged with 400 g of an aqueous dispersion (solid content: 2% by mass) of the photocatalyst particle A synthesized by the method described in 12 above, and a copper oxide dispersion (CUAP15WT% -G180 manufactured by CIK Nanotech Co., Ltd.) is added thereto. The copper oxide carrying | support titanium oxide (A-12) was obtained by adding 12 g and stirring at room temperature for 1 hour. The average particle diameter of the antibacterial metal-supporting photocatalyst in the obtained aqueous dispersion is 80 nm, and the average particle diameter and mass of copper oxide supported on the photocatalyst particle A are 50 nm and 0.5%, respectively. The content of copper oxide not supported on the particles A was 15000 ppm.

Production Comparative Example 4 Silver-Supported Titanium Oxide (A-13)
It manufactured by the same method except temperature having been 90 degreeC among the manufacturing conditions of [manufacture example 3], and silver carrying | support titanium oxide (A-13) was obtained. The average particle size of the antibacterial metal-supporting photocatalyst in the resulting composite is 74 nm, and the average particle size and mass of silver supported on the photocatalyst particle A are 25 nm and 1.8%, respectively. The content of the unsupported silver compound was 2400 ppm.

Example 1
137.1 g of gold-supported titanium oxide (A-1) prepared in Production Example 1 and water-dispersible colloidal silica having a number average particle diameter of 8 nm, which is basic colloidal silica (trade name “Snowtex NS”, Nissan Chemical Industries, Ltd. 123.4 g of solid content of 20% by mass, 1.5 g of a fluorocarbon surfactant ("Megaface F-444" manufactured by DIC Corporation) which is a perfluoroalkyl ethylene oxide adduct, and ion exchange water The photocatalytic composition is formulated by adding 140 g of a color-fading dye ("Methylene Blue", manufactured by Kishida Chemical Co., Ltd.) whose solid content has been adjusted to 0.1 mass%, and adding ion-exchanged water to a total amount of 1000 g. The object was made. A photocatalyst coating film was prepared according to each of the above-mentioned methods for this photocatalyst composition, and various evaluation results are shown in Table 3.

Example 2
A photocatalyst composition was produced in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver-supporting titanium oxide (A-2) prepared in Production Example 2. A photocatalyst coating film was prepared according to each of the above-mentioned methods for this photocatalyst composition, and various evaluation results are shown in Table 3.

[Example 3]
A photocatalyst composition was produced in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver-supporting titanium oxide (A-3) prepared in Production Example 3. A photocatalyst coating film was prepared according to each of the above-mentioned methods for this photocatalyst composition, and various evaluation results are shown in Table 3.

Example 4
A photocatalyst composition was produced in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver-supporting titanium oxide (A-4) prepared in Production Example 4. A photocatalyst coating film was prepared according to each of the above-mentioned methods for this photocatalyst composition, and various evaluation results are shown in Table 3.

[Example 5]
A photocatalyst composition was produced in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver-supporting titanium oxide (A-5) prepared in Production Example 5. A photocatalyst coating film was prepared according to each of the above-mentioned methods for this photocatalyst composition, and various evaluation results are shown in Table 3.

[Example 6]
A photocatalyst composition was produced in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the copper oxide-supporting titanium oxide (A-6) prepared in Production Example 6. A photocatalyst coating film was prepared according to each of the above-mentioned methods for this photocatalyst composition, and various evaluation results are shown in Table 3.

[Example 7]
A photocatalyst composition was prepared in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the copper oxide-supporting titanium oxide (A-7) prepared in Production Example 7. A photocatalyst coating film was prepared according to each of the above-mentioned methods for this photocatalyst composition, and various evaluation results are shown in Table 3.

[Example 8]
A photocatalyst composition was produced in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver and copper oxide-supporting titanium oxide (A-8) prepared in Production Example 8. A photocatalyst coating film was prepared according to each of the above-mentioned methods for this photocatalyst composition, and various evaluation results are shown in Table 3.

[Example 9]
A photocatalyst composition was produced in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the copper oxide-supporting titanium oxide (A-9) prepared in Production Example 9. A photocatalyst coating film was prepared according to each of the above-mentioned methods for this photocatalyst composition, and various evaluation results are shown in Table 3.

[Example 10]
273.7 g of gold-supported titanium oxide (A-1) prepared in Production Example 1 and water-dispersed colloidal silica having a number average particle diameter of 8 nm (trade name “Snowtex NS” manufactured by Nissan Chemical Industries, Ltd., solid content: 20 mass%) 82.1 g, 64.4 g of a polymer emulsion particle D water dispersion (solid content: 8.5 mass%) produced by the method described in 13 above, fluorocarbon surfactant (AGC Seimi Chemical Co., Ltd.) 10.33 g of "Surflon S-232" manufactured by the present invention and 140 g of a dye having a solid content adjusted to 1.0% by mass with ion-exchanged water (manufactured by Kishida Chemical Co., Ltd., "methylene blue"), and the total amount is 1000 g The photocatalyst composition was produced by adding and stirring ion exchange water so that it might become. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

[Example 11]
A photocatalyst composition was produced in the same manner as in Example 10 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver-supporting titanium oxide (A-2) prepared in Production Example 2. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

[Example 12]
A photocatalyst composition was produced in the same manner as in Example 10 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver-supporting titanium oxide (A-3) prepared in Production Example 3. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

[Example 13]
A photocatalyst composition was produced in the same manner as in Example 10 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver-supporting titanium oxide (A-4) prepared in Production Example 4. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

Example 14
A photocatalyst composition was produced in the same manner as in Example 10 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver-supporting titanium oxide (A-5) prepared in Production Example 5. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

[Example 15]
A photocatalyst composition was produced in the same manner as in Example 10 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the copper oxide-supporting titanium oxide (A-6) prepared in Production Example 6. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

[Example 16]
A photocatalyst composition was produced in the same manner as in Example 10 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the copper oxide-supporting titanium oxide (A-7) prepared in Production Example 7. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

[Example 17]
A photocatalyst composition was produced in the same manner as in Example 10 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver and copper oxide-supporting titanium oxide (A-8) prepared in Production Example 8. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

[Example 18]
A photocatalyst composition was produced in the same manner as in Example 10 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the copper oxide-supporting titanium oxide (A-9) prepared in Production Example 9. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

Comparative Example 1
A photocatalyst composition was produced in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the copper oxide-supporting titanium oxide (A-10) prepared in Production Comparative Example 1. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

Comparative Example 2
A photocatalyst composition was prepared in the same manner as Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver-supporting titanium oxide (A-11) prepared in Production Comparative Example 2. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

Comparative Example 3
A photocatalyst composition was produced in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the copper oxide-supporting titanium oxide (A-12) prepared in Production Comparative Example 3. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

Comparative Example 4
A photocatalyst composition was prepared in the same manner as in Example 1 except that the antibacterial metal-supporting photocatalyst particle AB was changed to the silver-supporting titanium oxide (A-13) prepared in Production Comparative Example 4. A photocatalyst coating film was prepared according to each method described above for this photocatalyst composition, and various evaluation results are shown in Table 4.

  By using the antibacterial metal-supporting photocatalyst particle AB of the present invention, a photocatalyst coating film having high transparency and low colorability can be obtained, and the photocatalyst performance can be exhibited without damaging the design of the object to be coated. Moreover, it is not only excellent in weather resistance, but can provide the photocatalyst coating film in which the anti-algal and anti-fungal effects last for a long time. The photocatalytic coating film of the present invention is excellent in self-cleaning property, and has industrial applicability in the fields of building exteriors, interior materials, exterior display applications, automobiles, displays and the like.

Claims (14)

  An antimicrobial metal particle B is supported on the surface of a photocatalyst particle A having photocatalytic activity with the surface modified with a metal oxide having no photocatalytic activity, and the average particle diameter of the antimicrobial metal particle B is 0.1 to 20 nm In the range of, antimicrobial metal-loaded photocatalyst particles AB. The metal oxide not having photocatalytic activity is at least one selected from the group consisting of silicon dioxide, aluminum oxide and zirconium oxide,
The compound forming the photocatalyst particle A having the photocatalytic activity is titanium dioxide, zinc oxide, strontium titanate, gallium phosphide, indium phosphide, gallium arsenide, barium titanate, potassium niobate, niobium pentoxide, iron oxide, A group consisting of tantalum pentoxide, K ₃ Ta ₃ Si ₂ O ₃ , tungsten oxide, tin oxide, bismuth oxide, bismuth vanadate, nickel oxide, copper oxide, copper oxide, silicon carbide, molybdenum sulfide, indium lead, ruthenium oxide, and cerium oxide Consisting of at least one selected from
The antibacterial metal-supported photocatalyst particle AB according to claim 1. The metal oxide not having photocatalytic activity is silicon dioxide,
The compound forming the photocatalyst particle A having the photocatalytic activity is titanium dioxide,
The antibacterial metal-supported photocatalyst particle AB according to claim 2.   The antibacterial metal-loaded photocatalyst particles AB according to any one of claims 1 to 3, wherein the average particle diameter of the antibacterial metal-loaded photocatalyst particles AB is 1 to 400 nm.   The antibacterial property according to any one of claims 1 to 4, wherein the antibacterial metal particle B is at least one selected from the group consisting of gold, silver, copper, a gold compound, a silver compound and a copper compound. Metal-supported photocatalyst particles AB.   The antibacterial metal-supported photocatalyst particle AB according to any one of claims 1 to 5, wherein the mass of the antibacterial metal particle B is in the range of 0.1 to 10% with respect to the mass of the photocatalyst particle A. .   The antibacterial metal-supporting photocatalyst particle AB contains the antibacterial metal particle C not supported on the surface of the photocatalyst particle A, and the content thereof is 10 to 3000 ppm with respect to the total solid content of the antibacterial metal-supporting photocatalyst particle AB The antimicrobial metal-loaded photocatalyst particle AB according to any one of claims 1 to 6, which is in the range of   The antibacterial metal particle C is one or more selected from the group consisting of gold, silver, copper, gold ion, silver ion, copper ion, gold compound, silver compound and copper compound. Antibacterial metal-loaded photocatalyst particles AB.   A composition comprising the antimicrobial metal-supporting photocatalyst particle AB according to any one of claims 1 to 8, water, and colloidal silica, wherein the solid content of the antimicrobial metal-supporting photocatalyst particle AB is in the composition. The photocatalyst composition whose fractional concentration is 1 to 30% by mass in the total solid content, and the solid content concentration of colloidal silica is 50 to 99% by mass in the total solid content.   The photocatalyst composition according to claim 9, further comprising a polymer emulsion particle D in the composition at a concentration of 0 to 30% by mass of the total solid content.   A photocatalytic coating film formed from the photocatalytic composition according to claim 9 or 10.   The photocatalyst coating film formed by laminating | stacking the photocatalyst coating film of Claim 11, and the coating film obtained from the composition different from the composition which forms the said photocatalyst coating film.   A photocatalyst-coated product comprising the photocatalyst coating film according to claim 11 or 12. Mixing an aqueous dispersion of photocatalytic particles A having photocatalytic activity, the surface of which is modified with a metal oxide having no photocatalytic activity, and a water-soluble metal compound containing metal ions, and adding a water-soluble reducing agent The production of the antibacterial metal-supporting photocatalyst particle AB according to any one of claims 1 to 8, which comprises forming the antibacterial metal particle B and supporting the same on the photocatalyst particle A by reducing metal ions. Method.