JP2002119865A - Method for manufacturing multifunctional material having photocatalytic function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a multifunctional material which is excellent in deodorizing function, antibacterial function (bactericidal function), antifouling function or the like and greatly increases holding power of a photocatalytic layer and thereby hardly generates peeling or the like. SOLUTION: The method for manufacturing the multifunctional material having a photocatalytic function is distinguished by providing with a process in which a binder layer is formed on a substrate surface, a process in which a layer made of a mixture composed of photocatalyst particles of <0.3 μm average grain size and any particles among tin oxide, zinc oxide and bismuth oxide having grain size of <=4/5 grain size of the photocatalyst is formed on the binder layer, and a sintering process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing function,
The present invention relates to a multifunctional material exhibiting functions such as a fungus function and an antifouling function, and a method for producing the same.

[0002]

2. Description of the Related Art TiO2, V2O5, and ZnO are substances that exhibit the function of promoting the decomposition (oxidation) of organic compounds such as malodorous components by irradiating them with ultraviolet rays by causing them to adsorb or desorb oxygen molecules. , WO3, etc. are known,
In particular, since anatase-type TiO2 particles have a high effect as a photocatalyst, it has been proposed to form a photocatalyst layer on the surface of a wall material, a tile, a glass (mirror), a circulating filtration device, a sanitary ware, or the like. .

As a method for forming the photocatalyst layer, the following method has been conventionally used. TiO2 is directly applied on the surface of plastic, ceramic, resin, etc. by CVD, sputtering, electron beam evaporation, etc.
A method for forming a photocatalytic layer composed of particles and the like. A method in which photocatalyst particles are kneaded with a binder and applied to the substrate surface by spray coating or the like, or dip-coated by dip coating and then heat-treated (Japanese Patent Laid-Open No.
-201747).

[0004]

When the CVD method, the sputtering method, the electron beam evaporation method, or the like is used, the equipment becomes large-scale and the yield is poor, so that the manufacturing cost increases.

On the other hand, in order for photocatalyst particles such as TiO2 particles to exhibit the effect as a photocatalyst, it is necessary to irradiate the photocatalyst particles with ultraviolet rays and to contact the photocatalyst particles with a substance to be decomposed such as an odorous gas. However, Japanese Patent Laid-Open No. 5-2017
If the photocatalyst particles were kneaded with a binder and applied to a substrate as in JP-B-47, many photocatalyst particles would be buried in the binder layer, and would not reach ultraviolet rays or come in contact with odorous gas. , Cannot exhibit a sufficient catalytic function.

[0006]

Means for Solving the Problems In order to solve the above problems, the present invention has the following means.

[0007] In a multifunctional material having a photocatalytic function in which a photocatalytic layer is held on a base material surface via a binder layer, an upper layer of the photocatalytic layer is exposed from the binder layer so as to be in contact with the outside air. The lower layer was partly buried in the binder layer. With this configuration, the upper layer of the photocatalyst layer is exposed, so that the catalytic function can be sufficiently exhibited. The lower layer of the photocatalyst layer is partially embedded in the binder layer, so that the photocatalyst layer is partially buried in the binder layer. Particles are less likely to peel from the substrate.

Here, the substrate may be any of tile, sanitary ware, ceramics such as glass, resin, metal, wood or a composite thereof.

The photocatalyst particles include TiO 2, Zn
O, SrTiO3, Fe2O3, CdS, CdSe, WO3, Fe
TiO3, GaP, GaAs, RuO2, MoS3, LaRhO3,
CdFeO3, Bi2O3, MoS2, In2O3, CdO, SnO2
And any of these may be used.
In addition, TiO2, SrTiO3, Fe2O3, CdS, WO3, Mo
For S3, Bi2O3, MoS2, In2O3, CdO, etc., since the absolute value of the redox potential of the equivalent electronic band is larger than the absolute value of the redox potential of the conduction band, the oxidizing power is larger than the reducing power, and the organic compound is decomposed. Excellent deodorant, antifouling or antibacterial action. In terms of raw material costs, TiO2, Fe2O3, and ZnO are advantageous.

Further, the binder layer may be made of, for example, a glaze,
It is made of a thermoplastic material such as inorganic glass, thermoplastic resin, and solder. By configuring the binder layer with a thermoplastic material in this manner, a photocatalyst can be applied on the binder layer at a normal temperature by a simple and inexpensive method such as a spray coating method. And the photocatalyst can be firmly bonded, which is advantageous in the production cost.

Further, the multifunctional material having a photocatalytic function according to the present invention is constituted by laminating a photocatalyst layer made of photocatalyst particles on a sheet-like binder layer made of a thermoplastic material or embedding a part thereof. If such sheet-shaped multifunctional material is heated after pasting it on existing tiles, sanitary ware, building materials, etc., the existing tiles will be deodorized, stainproof, antibacterial, antifungal And other functions can be added.

The average particle size of the photocatalyst particles constituting the photocatalyst layer is preferably less than 0.3 μm in order to increase the specific surface area and enhance the photocatalytic activity.

Further, in order to enhance the abrasion resistance of the photocatalyst layer,
It is preferable that the photocatalyst particles constituting a portion of the photocatalyst layer exposed from the binder layer are bonded to each other.

The photocatalyst layer has a thickness of 0.1 μm to 0.9 μm.
μm is preferred. If the thickness is less than 0.1 μm, the photocatalyst particles are locally embedded in the binder layer, and a portion where the catalytic activity cannot be exerted on the surface of the multifunctional material occurs. I do. On the other hand, when the thickness exceeds 0.9 μm, the thickness varies greatly, and it becomes difficult to remove stains when stains adhere to the sample. Here, the thickness of the photocatalyst layer is a thickness including the portion from the outermost surface to the portion embedded in the lower layer of the binder layer, and the thickness of each unevenness.

Here, a design effect can be obtained by changing the thickness of the photocatalyst layer. That is, when the thickness is set to 0.2 μm or more and less than 0.4 μm, an iris pattern can be formed by the interference of light with respect to the photocatalyst layer film thickness portion. Alternatively, if only the combination thereof is desired, the portion that causes the light interference action is excluded from 0.1 μm or more and less than 0.2 μm or 0.4 μm.
The thickness of the photocatalyst layer should be less than 1 μm. Such a method can be applied to a wide range of tiles, sinks, bathtubs, large and small urinals, sinks, countertops, and the like.

As a method of bonding the photocatalyst particles constituting the portion of the photocatalyst layer exposed from the binder layer, for example, the gap between the photocatalyst particles is filled with particles having a smaller particle size than the gap. In the case where the photocatalyst particles are bonded to each other only by the photocatalyst particles, the only method is to adsorb or sinter the photocatalyst particles. However, when utilizing the sintering action between photocatalyst particles, sintering must be carried out at a considerably high temperature. On the other hand, in the case of adsorption, if the specific surface area of the photocatalyst particles is not so large and the packing property is not good, the binding property is not high In order to produce a multifunctional material having sufficient catalytic activity and abrasion resistance, for example, the method consumes only the active site adsorption amount of the photocatalyst particles. Further, if particles larger than the gap between the photocatalyst particles are used to strengthen the bond between the photocatalyst particles, not only a sufficient bonding force cannot be obtained, but also the photocatalyst particles exposed on the surface of the multifunctional material are partially covered. As a result, there is a portion on the surface of the multifunctional material where no catalytic activity can be exerted, and bacteria remain in that portion, so that the antibacterial property is significantly deteriorated. Here, the gap between the photocatalyst particles means the photocatalyst particles 3b and 3b as shown in FIG.
3b and both pores between the photocatalyst particles 3b, 3b as shown in FIG. 3 (b). Therefore, the particles 3c having a particle size smaller than the gap between the photocatalyst particles referred to here are particles smaller than any gap between the neck portion between the photocatalyst particles and the pores between the photocatalyst particles.

The material of the small particles to be filled in the gaps between the photocatalyst particles is not basically limited, but those having excellent adsorption power are preferable. An extremely weak material cannot achieve the purpose of binding the photocatalyst particles to each other, and a material having an extremely strong adsorption capability covers the active points on the surface of the photocatalyst particle rather than being inserted into a gap. This is because the probability increases. From this viewpoint, the preferable material of the particles filled in the gap between the photocatalyst particles is Sn, Ti, Ag, Cu, Zn, Fe, Pt, Ct.
Metals or oxides such as o, Pd, Ni, etc., and zeolite, activated carbon, clay and the like conventionally used as an adsorption carrier are not preferred. Of the above metals or oxides, tin oxide is preferable in that it has an appropriate adsorption capacity,
In addition, metals or oxides such as Ag and Cu have unique antibacterial properties and deodorant properties in addition to binding the photocatalyst particles to each other. Therefore, the action of the photocatalyst especially in the absence of light irradiation in applications utilizing this function. It is preferable in that it also has a function of assisting.

It is preferable that the average particle size of the particles filled in the gaps between the photocatalyst particles is 4/5 or less of the average particle size of the photocatalyst particles. Particles filling the gaps between the photocatalyst particles adhere to not only the gaps between the photocatalyst particles but also onto the photocatalyst particles to some extent in the current manufacturing method. The particle size of the particles filling the gap is 4 / the average particle size of the photocatalyst particles.
If it exceeds 5, the probability of adhering to the surface of the photocatalyst particles is higher than the gap between the photocatalyst particles, and the bonding strength between the photocatalyst particles decreases. Also, if the particles filling the gap are larger than the photocatalyst particles, they will partially cover the photocatalyst particles, and there will be a part on the surface of the multifunctional material that cannot exhibit catalytic activity, so that bacteria can stay in that part. Therefore, the antibacterial property may be significantly deteriorated.

The average particle diameter of the particles filled in the gaps between the photocatalyst particles is less than 0.008 μm.
It is preferable because the specific surface area is increased and an appropriate adsorption force can be obtained.

The amount of the particles filled in the gaps between the photocatalyst particles with respect to the photocatalyst particles is 10% or more and 6% or more in terms of molar ratio.
It is preferably 0% or less. When fixing the photocatalyst layer via a binder to the base material by heat treatment in a temperature range where sintering of the photocatalyst particles does not occur, if the amount of particles filling the gap is too small, the photocatalyst particles do not strongly bind to each other, On the other hand, if the amount of particles that fill the gap is too large, the amount of particles covering the photocatalyst particles will increase, and a portion that cannot exhibit catalytic activity on the surface of the multifunctional material will occur, and bacteria will be able to stay in that portion, Particularly, the above range is preferable because the antibacterial property is significantly deteriorated.

Further, as the substance constituting the particles to be filled in the gaps between the photocatalyst particles, a substance having a vapor pressure higher than the vapor pressure of the substance constituting the photocatalyst particles is selected and filled in the gap between the photocatalyst particles. Preferably, the particles are aggregated at the neck between the photocatalyst particles. This is because, in order to obtain a stronger bond between the photocatalyst particles and increase the peel strength of the photocatalyst layer, it is better not only to fill but also to sinter. Further, if such a substance having a high vapor pressure is selected as the particles for filling the gap, it functions as a sintering aid and can lower the sintering temperature. Examples of such a substance having a high vapor pressure include tin oxide, bismuth oxide, and zinc oxide, and tin oxide is preferable in terms of safety.

The thickness of the layer containing the particles filled in the gaps between the photocatalyst particles is preferably 0.1 μm or more. If the thickness of this layer is less than 0.1 μm, photocatalyst particles (and particles that fill gaps depending on the manufacturing method) are locally embedded in the binder layer, resulting in a portion where the catalytic activity cannot be exhibited on the surface of the multifunctional material. Since bacteria can be retained in the portion, the antibacterial property is particularly remarkably deteriorated.
Here, the thickness of the layer containing the particles to be filled in the gaps between the photocatalyst particles includes the portion from the outermost surface to the portion embedded in the lower layer of the binder, and is a uniform thickness of each of the irregularities.

Here, a design effect can be obtained by changing the thickness of the photocatalyst layer. That is, when the thickness is set to 0.2 μm or more and less than 0.4 μm, an iris pattern can be provided by the interference effect of light on the photocatalytic layer film thickness portion. Also, if there is no coloring by the particles that fill the gaps, if the appearance only needs to be the ground color of the base material, the pattern, or the combination thereof, the portion that causes the above-described light interference is excluded.
The thickness of the photocatalyst layer may be formed to be not less than m and less than 0.2 μm or not less than 0.4 μm and less than 1 μm. Such an approach is
It can be applied to a wide range of tiles, wash basins, bathtubs, large and small urinals, sinks, countertops, etc.

The depth of burying the photocatalyst particles constituting the lowermost layer of the photocatalyst layer in the binder layer is １ ／ of the particle size.
As described above, it is preferable that the photocatalyst particles are embedded in the binder layer by a thickness less than the thickness of the layer including the particles that fill the gap. By embedding the photocatalyst particles in the binder layer in a size of at least 1/2 of the particle size, the lowermost layer of the photocatalyst particle layer and the binder layer are firmly bonded to each other, and the thickness of the layer containing the particles that fills the gap with the photocatalyst particles is larger than the thickness. If buried, the photocatalyst particles will not be exposed on the outermost surface, which will not be able to exhibit catalytic activity on the surface of the multifunctional material. Becomes significantly worse.

The base material can be used as a tile or a stone material used as a paving stone for artificial waterfalls or fountains of a water circulation system in parks and department stores. By utilizing a multifunctional material having a photocatalytic function for such an application, it is possible to decompose organic dirt deposited in water using artificial lighting or light including natural ultraviolet rays with circulation. In addition, it is possible to prevent breeding of bacteria, molds and the like, generation of algae, and accompanying water odor, thereby creating a cleaner environment.

The multifunctional material having a photocatalytic function according to the present invention is used as a device for preventing bacterial infection in hospitals, but can be used as an antifungal and antiviral device because it can decompose other organic substances.

Further, according to the method for producing a multifunctional material having a photocatalytic function according to the present invention, a binder layer made of a thermoplastic material is formed on a substrate made of ceramic, resin, metal or the like. A photocatalyst layer made of photocatalyst particles is formed thereon, and thereafter, the binder layer is softened and a part of the lower layer of the photocatalyst layer is embedded in the binder layer,
Then it solidifies. Here, if the viscosity of the binder layer is too high, the binder layer and the photocatalyst particles do not bond sufficiently. Conversely, if the viscosity is too low, the photocatalyst particles are buried in the binder layer. The degree of softening of the binder layer is determined in consideration of these factors, since the antibacterial properties are significantly deteriorated due to the stagnation.

Another method for producing a multifunctional material having a photocatalytic function according to the present invention is to form a photocatalyst layer made of photocatalyst particles on a sheet-shaped binder layer made of a thermoplastic material, Is placed or adhered on a substrate made of ceramic, resin, metal or the like, and thereafter, the binder layer is softened, a part of the lower layer of the photocatalyst layer is embedded in the binder layer, and then solidified. According to this method, existing tiles, sanitary ware, building materials, and the like can be later provided with functions such as deodorant properties, antifouling properties, antibacterial properties, and antifungal properties.

Another method for producing a multifunctional material having a photocatalytic function according to the present invention is directed to a photocatalyst in which the gap between the photocatalyst particles is filled with particles having a smaller particle size than the gap and the photocatalyst particles are bonded to each other. A method for producing a multifunctional material having a function, comprising forming a binder layer made of a thermoplastic material on a substrate such as ceramic, resin or metal, and then forming a photocatalyst on the binder layer. A mixture of particles and the particles having the small particle size in a sol or precursor state is applied to form a photocatalyst layer.After that, the binder layer is softened, and a part of the lower layer of the photocatalyst layer becomes a binder layer. Buried and then solidified. According to this method, the photocatalyst layer is formed by applying a mixture in which the particles for filling the gap and the photocatalyst particles are mixed in a sol or a precursor state in advance, and thus the photocatalyst particles and the particles for filling the gap are mixed. Useful for controlling the ratio.

Another method for producing a multifunctional material having a photocatalytic function according to the present invention is directed to a photocatalyst in which the gap between the photocatalyst particles is filled with particles having a smaller particle size than the gap, and the photocatalyst particles are bonded to each other. It is a method of producing a multifunctional material having a function, this method, on a sheet-like binder layer made of a thermoplastic material, the photocatalyst particles and the small particles of the particle size were mixed in a sol or precursor state The mixture is applied to form a photocatalyst layer, and the sheet-like binder layer on which the photocatalyst layer is formed is placed or adhered on a base material such as ceramic, resin, or metal, and thereafter, the binder layer is softened. Then, a part of the lower layer of the photocatalyst layer is embedded in the binder layer, and then solidified.

Another method for producing a multifunctional material having a photocatalytic function according to the present invention is directed to a photocatalyst in which the gap between the photocatalyst particles is filled with particles having a smaller particle size than the gap, and the photocatalyst particles are bonded to each other. A method for producing a multifunctional material having a function, comprising forming a binder layer made of a thermoplastic material on a substrate such as ceramic, resin or metal, and then forming a photocatalyst on the binder layer. A photocatalyst layer composed of particles is formed, and thereafter, the binder layer is softened, a part of the lower layer of the photocatalyst layer is embedded in the binder layer, and then the binder layer is solidified. Is applied and heat-treated to immobilize the small-sized particles on the photocatalyst particles. This method can be carried out relatively easily when the particles filling the gaps are oxides, and can make a large amount of particles filling the gaps when a relatively porous photocatalytic layer is formed. .

Another method for producing a multifunctional material having a photocatalytic function according to the present invention is directed to a photocatalyst in which the gap between the photocatalyst particles is filled with particles having a smaller particle size than the gap, and the photocatalyst particles are bonded to each other. A method for producing a multifunctional material having a function, comprising forming a photocatalyst layer made of photocatalyst particles on a sheet-shaped binder layer made of a thermoplastic material, and then forming the photocatalyst layer on the sheet-shaped binder. The layer is placed or adhered on a substrate made of ceramic, resin or metal, and thereafter, the binder layer is softened, a part of the lower layer of the photocatalyst layer is embedded in the binder layer, and then the binder layer is solidified. Then, a solution containing the small-sized particles is applied to the photocatalyst layer, and heat treatment is performed to fix the small-sized particles to the photocatalyst particles.

In another method for producing a multifunctional material having a photocatalytic function according to the present invention, a gap between photocatalyst particles is filled with metal particles having a smaller particle size than the gap, and the photocatalyst particles are bonded to each other. A method for producing a multifunctional material having a photocatalytic function, the method comprising forming a binder layer made of a thermoplastic material on a base material such as ceramic, resin or metal, and then forming a binder layer on the binder layer. A photocatalyst layer composed of photocatalyst particles is formed, and thereafter, the binder layer is softened, a part of the lower layer of the photocatalyst layer is embedded in the binder layer, and then the binder layer is solidified. A solution having a photocatalytic function characterized in that a solution containing ions of metal particles is applied, and thereafter, light containing ultraviolet rays is irradiated to reduce the metal ions and immobilize them on the photocatalyst particles. Method of manufacturing capacity material. This method can be carried out relatively easily when the particles filling the gap are metal, and fix the metal in a very short time (several minutes).
Can be done with Further, a lamp used for ultraviolet irradiation may be any of an ultraviolet lamp, a BLB lamp, a xenon mercury lamp, and a fluorescent lamp.

In another method for producing a multifunctional material having a photocatalytic function according to the present invention, a gap between the photocatalyst particles is filled with metal particles having a smaller particle size than the gap, and the photocatalyst particles are bonded to each other. A method for producing a multifunctional material having a photocatalytic function, which method comprises forming a photocatalyst layer made of photocatalyst particles on a sheet-shaped binder layer made of a thermoplastic material, and then forming the photocatalyst layer on the sheet-like sheet. The binder layer is placed or adhered on a substrate made of ceramic, resin, metal, or the like, and thereafter, the binder layer is softened so that a part of the lower layer of the photocatalyst layer is embedded in the binder layer. After solidification, a solution containing ions of the metal particles having the small particle diameter is applied to the photocatalyst layer, and thereafter, the metal ions are reduced by irradiating light including ultraviolet rays and fixed to the photocatalyst particles. To.

In another method for producing a multifunctional material having a photocatalytic function according to the present invention, the gap between the photocatalyst particles is filled with metal particles having a smaller particle size than the gap, and the photocatalyst particles are bonded to each other. A method for producing a multifunctional material having a photocatalytic function, the method comprising forming a binder layer made of a thermoplastic material on a base material such as ceramic, resin or metal, and then forming a binder layer on the binder layer. A photocatalyst layer composed of photocatalyst particles is formed, a solution containing the ions of the metal particles having the small particle diameter is applied to the photocatalyst layer, and thereafter, the metal ions are reduced by irradiating light including ultraviolet rays and fixed to the photocatalyst particles. Then, the binder layer is softened, a part of the lower layer of the photocatalyst layer is embedded in the binder layer, and then the binder layer is solidified. According to this method, the heat treatment step can be performed only once, so that the productivity is improved.

In another method for producing a multifunctional material having a photocatalytic function according to the present invention, a gap between the photocatalyst particles is filled with metal particles having a smaller particle size than the gap, and the photocatalyst particles are bonded to each other. A method for producing a multifunctional material having a photocatalytic function, the method comprising forming a photocatalyst layer made of photocatalyst particles on a sheet-like binder layer made of a thermoplastic material, A solution containing ions of metal particles is applied, and thereafter, light including ultraviolet rays is applied to reduce the metal ions to be fixed to the photocatalyst particles. Further, the sheet-like binder layer on which the photocatalyst layer is formed is made of ceramic, resin or metal. Or the like, and then the binder layer is softened, a part of the lower layer of the photocatalyst layer is embedded in the binder layer, and then the binder layer is solidified.

The photocatalyst particles may be ZnO, and the metal particles filling the gaps between the photocatalyst particles may be Ag or Ag2O. Here, the Ag or Ag2O particles not only strengthen the bond between the ZnO particles that are photocatalysts, but also enhance the photocatalytic effect of ZnO, and have an antibacterial effect.
It also has a deodorizing effect. In addition, by selecting ZnO as a photocatalyst, coloring due to Ag ions can be eliminated, and the color of the background of the substrate, the pattern, or the design effect due to the combination thereof can be improved.

Further, a solution containing a salt which forms a colorless or white salt which is insoluble with a metal ion filled in the gap between the photocatalyst particles is brought into contact with the photocatalyst layer, and thereafter, a light containing ultraviolet light is irradiated. May be irradiated. By doing so, the coloring due to the particles filling the gap can be eliminated without depending on the combination of ZnO and Ag or Ag2O, and the color of the ground of the base material can be eliminated. The design effect due to the patterns or their combination can be improved.

Further, the photocatalyst particles may be made of TiO 2, and the heat treatment temperature for softening the binder layer may be 800 ° C. or more and 1000 ° C. or less. Ti above 800 ° C
Since a neck portion is formed between the O2 particles by the initial sintering, the bonding strength between the TiO2 particles is improved.
If the temperature exceeds 0 ° C., the process shifts to the middle-stage sintering step, and the volume shrinkage of the photocatalyst layer accompanying the solid phase sintering of TiO 2 becomes remarkable, so that cracks are easily generated.

The photocatalyst particles are made of TiO 2, the metal particles filled in the gaps between the photocatalyst particles are made of Ag, and a solution containing a salt which forms an insoluble colorless or white salt with ions of this metal is used. It may be an aqueous solution of a halide such as KI, KCl, or FeCl3. Since Ag forms an insoluble and colorless or white salt such as AgI and AgCl with an alkali halide, it is possible to improve the design of the base material by improving the background color, pattern, or combination thereof.

Further, the binder layer is selected to have a softening temperature lower than the softening temperature of the base material. The softening temperature of the binder layer is more than 20 ° C. and less than 320 ° C., preferably 40 ° C. or more and 300 ° C. or less. The heat treatment is performed at an ambient temperature in the range of not more than ℃ and lower than the softening temperature of the substrate. If the heat treatment temperature is lower than the temperature 20 ° C. higher than the softening temperature of the binder layer, the viscosity of the binder layer is too high, so that the binder layer and the photocatalyst particles are not sufficiently bonded, and conversely, the temperature is 320 ° C. lower than the softening temperature of the binder layer. If the heat treatment temperature is higher than ℃ higher temperature, the viscosity of the binder layer is too low and the photocatalyst particles will be buried in the binder layer, and if it occurs locally, bacteria will stay there, resulting in a decrease in antibacterial properties It depends.

When a dispersing step is provided as a step prior to the step of applying the photocatalyst particles on the binder layer, a dispersant for dispersing the sol or precursor to be the photocatalyst particles in the dispersion step in the solution. It is preferable to use only components that vaporize at a temperature lower than the heat treatment temperature for softening the binder layer. In the prior art,
The lack of deodorization at a temperature lower than 320 ° C. means that the dispersing agent adhered to the surface of the TiO2 particles in the dispersing step was sufficiently vaporized and remained without evaporating, so that the surface of the TiO2 particles was sufficiently exposed to the outermost surface of the substrate. This is because the photocatalytic function became insufficient. As the dispersant that evaporates at a low temperature, an organic dispersant having a molecular weight of 10,000 or less and a phosphoric acid-based dispersant are preferable.

When the specific gravity of the photocatalyst particles is δt and the specific gravity of the binder layer is δb, 0 ≦ δt−δb ≦ 3.
It is preferably 0. If the specific gravity difference is too small, the photocatalyst particles are not sufficiently embedded in the binder layer, and the binder layer and the photocatalyst particles are not sufficiently bonded.If the specific gravity difference is too large, the photocatalyst particles are buried in the binder layer. If it occurs locally, bacteria stay on the bottom and the antibacterial property is reduced. As an application method of this method, δt
Even when −δb> 3.0 is required, a second binder layer satisfying 0 ≦ δt−δb ≦ 3.0 may be interposed between the binder layer and the photocatalyst particles. Also δt
When −δb <0, pressurizing during the heat treatment has the same effect as increasing the specific gravity difference Δt−δb. Therefore, H
By IP processing and hot press processing, 0 ≦ δt−δb ≦
The same effect as in the case of 3.0 can be obtained.

[0044]

The photocatalyst particles constituting the lower layer on the binder layer side of the photocatalyst particles constituting the photocatalyst layer are partially retained in the binder layer, and the photocatalyst constituting the surface layer of the photocatalyst layer which is in contact with the outside air. Since the particles are bonded to each other with the surface substantially exposed to the outside, the photocatalytic effect is sufficiently exhibited.

[0045]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a view for explaining a method for producing a multifunctional material having a photocatalytic function according to the present invention, and FIG.
FIG. 1D is an enlarged view of a main part of FIG. 1D. In the present invention, a base material 1 is first prepared as shown in FIG. Substrate 1
Examples thereof include ceramic, resin, metal, glass, and wood.

Then, a binder layer 2 is formed on the surface of the substrate 1 as shown in FIG. The binder layer 2 is selected from a material whose softening temperature is lower than the softening temperature of the substrate 1. For example, when the substrate 1 is a tile, an enamel or a ceramic, the glaze layer or the printed layer can be used as the binder layer 2 as it is.

Next, a photocatalyst layer 3 made of photocatalyst particles such as TiO2 particles is formed on the binder layer 2 as shown in FIG. At this time, the photocatalyst layer 3 only needs to be mounted on the binder layer 2 with such a bonding force that the photocatalyst layer 3 does not fall off the binder layer 2 in the subsequent baking.

Alternatively, a binder layer 2
Before forming a photocatalyst layer, a photocatalyst layer 3 is formed on the binder layer 2 as shown in FIG.
May be placed on the substrate 1.

Thereafter, heat treatment is performed at an ambient temperature higher than the softening temperature of the binder layer 2 and higher than 20 ° C. and lower than 320 ° C. and lower than the softening temperature of the base material 1 to obtain the heat treatment shown in FIG. As shown in FIG. 2, a part of the photocatalyst particles 3 a constituting the lower layer of the photocatalyst layer 3 on the binder layer side is settled in the molten binder layer and the binder layer is solidified, so that the part is in the binder layer. Buried in and firmly held. Further, as shown in FIG. 3A, a part of the photocatalyst particles 3b constituting the surface layer of the photocatalyst layer 3 which is in contact with the outside air is bonded to each other by intermolecular force and sintering by sintering. Are separated from each other as shown in FIG. That is, the surface of the photocatalyst particles 3b is exposed to the outside substantially in the surface layer.

Here, the reason why the heat treatment temperature is set higher than the softening temperature of the binder layer 2 in the range of more than 20 ° C. and less than 320 ° C. is that if the temperature is lower than 20 ° C., it takes time for the softening of the binder layer and the photocatalyst becomes harder. On the other hand, when the temperature exceeds 320 ° C., the photocatalyst particles are buried in the binder layer due to the rapid melting of the binder layer, and irregularities are generated. Desirably, the temperature is 40 ° C. or more and 300 ° C. or less.

When the specific gravity of the photocatalyst particles is δt and the specific gravity of the binder layer 2 is δb, 0 ≦ δt−δb ≦ 3.0.
Preferably, the relationship of 0.5 ≦ δt−δb ≦ 2.0 is satisfied. This is because, when the difference in specific gravity between the photocatalyst particles and the binder layer is too small, when the binder layer is melted, the vertical movement speed of the photocatalyst particles in the binder layer becomes slow, and the photocatalyst particles are easily separated after firing, If the difference in specific gravity between the photocatalyst particles and the binder layer is too large, the moving speed of the photocatalyst particles in the vertical direction increases, and most of the photocatalyst particles may be buried in the binder layer. The gap between the photocatalyst particles constituting the portion exposed from the binder layer 2, specifically, the photocatalyst particles 3 shown in FIG.
b, or the photocatalyst particles 3b shown in FIG.
Between the particles 3c (Sn,
Metals or oxides such as Ti, Ag, Cu, Zn, Fe, Pt, Co, Pd, and Ni) may be filled to bond the photocatalyst particles 3b to each other.

[0052]

EXAMPLES Specific examples will be described below. (Example 1) On the surface of a ceramic tile substrate of 150 squares, S
After forming a binder layer composed of iO2-Al2O3-Na / K2O frit by a spray coating method and drying it, a 15% aqueous solution of TiO2 sol is applied by a spray coating method to form a 0.8 m thick TiO2 layer. Then, the base material on which the binder layer and the TiO2 layer were laminated was heated and fired with a roller hearth kiln at different ambient temperatures for each example, and then cooled and solidified to obtain a multifunctional material. Here, the aqueous solution of TiO2 sol means, for example, anatase-type TiO2 having a crystallite diameter of about 0.007 to 0.2 μm obtained by hydrolyzing TiCl in an autoclave under hydrothermal conditions in the range of 100 to 200 ° C. In an acidic aqueous solution such as nitric acid or hydrochloric acid or a basic aqueous solution such as ammonia
To improve the dispersibility by adding an organic acid salt of triethanolamine and trimethylolamine, pentaerythritol, trimethylolpropane, etc. in a range of 0.5% or less as a surface treatment agent. It has been added. The particle size of the TiO2 sol was determined by image processing using SEM observation, and the crystallite size was determined from the integral width of powder X-ray diffraction. In addition, although the coating method was performed by the spray coating method, it is expected that similar results can be obtained by the dip coating method and the spin coating method. The obtained multifunctional material was evaluated for antibacterial properties and abrasion resistance. For antibacterial properties, Escherichia coli
W3110 strain). 70% in advance
Bacterial solution 0.15 on top of multifunctional material sterilized with ethanol
ml (1-5.times.10@4 CFU), and the glass plate (1
(0 × 10 cm) and adhered to the outermost surface of the substrate to obtain a sample. After irradiating with a white light (3500 lux) for 30 minutes, the bacterial solution of the irradiated sample and the sample maintained under light-shielding conditions were wiped with sterile gauze, collected in 10 ml of physiological saline, and the survival rate of the bacteria was determined. The index was used. With respect to abrasion resistance, sliding wear using a plastic eraser was performed, and changes in appearance were compared and evaluated. The following (Table 1) shows ceramic tile as a base material, and SiO2-Al2O3-Na / K2 as a binder.
Antibacterial property with the change of firing temperature when using O frit,
Shows the change in wear resistance.

[0053]

[Table 1]

Here, the SiO 2-used as a binder was used.
The specific gravity of the Al2O3-Na / K2O frit was 2.4, the film thickness when applied was 200 .mu.m, and the softening temperature was 680.degree. The TiO2 obtained in (Table 1) was No. 1 to No. 3.
Is anatase type, specific gravity is 3.9, No.
About 4 and 5, it was a rutile type and specific gravity was 4.2.

In Table 1, No. 1 shows that the sintering temperature was only 20 ° C. higher than the softening temperature of the binder, and the viscosity of the binder did not become sufficiently low. The TiO2 particles were not sufficiently buried in the binder layer, so that they were scratched and peeled after 5 to 10 slides in the abrasion resistance test. Regarding antibacterial properties, it is an anatase type having excellent photocatalytic activity, and at 300 ° C. or higher, organic components are almost decomposed and vaporized by TG-DTA observation of TiO 2 sol.
It is understood that the dispersant such as a surface treatment agent attached to the O2 surface has been naturalized, but the firing temperature was 700 ° C., which was much higher than that, and the value was excellent as ++.

Nos. 3 to 5 have sintering temperatures of 800 ° C. or higher and 10
In each case, the durability was extremely excellent without any change even in a sliding test of 40 times or more. This may be due to the formation of a neck due to the initial firing of the TiO2 particles on the surface. In the case of treatment at 1100 ° C., cracks occurred in the TiO 2 layer on the surface of the multifunctional material taken out from the roller hearth kiln after cooling and solidification. Judging from the TMA measurement of the TiO2 test piece, this is considered to be due to the medium-term sintering accompanied by significant volume shrinkage of the TiO2 particles.

In Nos. 4 and 5, the antibacterial properties were all negative. There are two possible causes for this. One is Ti
The other is that the O2 particles have undergone a rutile-type phase transition, and the other is that the firing temperature is 300 ° C. higher than the softening temperature of the binder.
It is conceivable that the TiO2 particles constituting the photocatalyst layer were buried in the binder layer because the viscosity was too high and the viscosity of the binder was too low. Here, it cannot be considered that the only cause is that the TiO2 particles have undergone a rutile type phase transition. This is because rutile-type TiO2 is slightly inferior to anatase-type TiO2, but has some photocatalytic activity. For example, the antibacterial property of the material obtained by spray-coating a TiO2 sol directly on a porous alumina substrate, firing at 950 ° C., and cooling and solidifying was +. Therefore, the firing temperature is higher than the softening temperature of the binder by more than 300 ° C., and the viscosity of the binder is too low, so that the TiO2 particles constituting the photocatalyst layer are buried in the binder layer. It is understood that there is.

Further, by elemental analysis of Ti and Si (main component of binder) by EPMA or the like in the cross-sectional direction of the sample, a layer in which Ti and Si were mixed was observed, and it was found that TiO2 as photocatalyst particles was embedded. confirmed.

In the first embodiment, at least the photocatalyst is TiO2 and the binder layer is SiO2-Al2O3-Na / K2.
At the time of O frit, the following was confirmed. When the multifunctional material is manufactured under the condition that the sintering temperature is higher than the softening temperature of the binder by more than 20 ° C. and not higher than 300 ° C., the multifunctional material having good antibacterial property and abrasion resistance can be manufactured. The cause is considered to be that the viscosity of the binder is adjusted to a value at which the TiO2 can be appropriately embedded in the binder layer in the above temperature range. In the multifunctional material prepared in the above, it was confirmed that the TiO2 particles were embedded in the binder layer.
When the firing temperature is 800 ° C or higher and 1000 ° C or lower,
In each case, the abrasion resistance was extremely excellent without any change even in a sliding test of 40 times or more. This is thought to be due to the strong bond between the TiO2 particles and the formation of the neck.

(Example 2) SiO 2 -Al 2 was coated on a surface of a 100 × 100 × 5 alumina base material (alumina purity: 96%).
Spray binder layer consisting of O3-PbO frit
After forming by coating method and drying, 15% Ti
An O2 sol aqueous solution (same as in Example 1) was applied by a spray coating method to form a TiO2 layer having a thickness of 0.8 μm, and then a base material having a binder layer and a TiO2 layer laminated thereon was applied to a roller hearth kiln. After heating and firing at different ambient temperatures for each example, the resultant was cooled and solidified to obtain a multifunctional material.

The following Table 2 shows changes in antibacterial and abrasion resistances with changes in firing temperature when alumina was used as the base material and SiO 2 -Al 2 O 3 -PbO frit was used as the binder.

[0062]

[Table 2]

Here, the SiO 2-used as a binder was used.
The softening temperature of the Al2O3-PbO frit was 540 DEG C., the specific gravity was 3.8, and the film thickness when applied was 150 .mu.m. The crystal forms of TiO2 obtained were all anatase.

In the wear resistance test of (Table 2), No. 6
Was scratched and stripped by sliding less than 10 times,
Nos. 7 and 8 were not damaged even after 10 or more slides.
In o.9 and 10, good results were obtained in which no damage was caused even after sliding more than 40 times.

In Nos. 9 and 10, no scratch was found even after sliding more than 40 times, because the firing temperature was 800 ° C. or more, a neck was formed between the TiO2 particles, and the TiO2 particles were strongly bonded to each other. Probably because. No. 6 caused scratching and peeling by sliding less than 10 times, because the firing temperature was only 20 ° C. higher than the softening temperature of the binder, and the viscosity of the binder did not become sufficiently low. This is probably because the anatase type TiO2 particles constituting the lowermost layer of the photocatalyst layer were not sufficiently embedded in the binder layer. On the other hand, in No. 7 and 8, no damage was found even after sliding 10 times or more because the difference between the sintering temperature and the softening temperature of the binder did not reach the temperature at which the neck portion was formed. It is considered that the viscosity was adjusted to a value at which TiO2 could be appropriately embedded in the binder layer. On the other hand, in the antibacterial test of (Table 2), Nos. 6 to 9 obtained good results of +++ or ++, but No. 10 became +. This is probably because the firing temperature was 320 ° C. higher than the softening temperature of the binder, and the viscosity of the binder was too low, so that the TiO2 particles constituting the photocatalyst layer were embedded in the binder layer.

(Example 3) The SiO2-Al2O3-BaO frit is melted and solidified in a mold in a mold, then processed and processed.
× 100 × 1 glass sheet is prepared and 15%
A TiO2 sol aqueous solution (same as in Example 1) was applied by a spray coating method to form a TiO2 sol having a thickness of 0.8 μm.
A layer was formed. Thereafter, the glass sheet was placed on an alumina base material (100 × 100 × 5), heated and fired in a siliconit furnace at different atmospheric temperatures for each example, and then cooled and solidified to obtain a multifunctional material.

The following Table 3 shows changes in antibacterial properties and abrasion resistance of the above-mentioned multifunctional materials according to the firing temperature.

[0068]

[Table 3]

Here, the SiO 2-used as a binder was used.
The softening temperature of the Al2O3-BaO frit is 620 DEG C., the specific gravity is 2.8, and the crystal form of TiO2 on the multifunctional material is No. 11-13.
No. 14 was an anatase type, and No. 14 was a rutile type.

In the wear resistance test of (Table 3), No. 1
No. 1 was scratched and peeled by sliding less than 10 times, but No. 12 was not damaged even by sliding more than 10 times, and No. 13 and 14 was more than 40 times sliding. However, good results were obtained in which no scratches occurred.

In Nos. 13 and 14, no scratch was found even after sliding more than 40 times. Since the firing temperature was 800 ° C. or more, a neck was formed between the TiO2 particles, and the TiO2 particles were strongly bonded to each other. Probably because. In No. 11, scratches were caused by sliding less than 10 times and peeled off because the firing temperature was only 20 ° C. higher than the softening temperature of the binder, and the viscosity of the binder did not become sufficiently low. This is probably because the anatase type TiO2 particles constituting the lowermost layer of the photocatalyst layer were not sufficiently embedded in the binder layer.
On the other hand, in No. 12, no scratch was found even after 10 times of sliding, but the difference between the sintering temperature and the softening temperature of the binder did not reach the temperature at which the neck was formed, but the viscosity of the binder was reduced. This is probably because TiO2 was adjusted to a value that could be properly embedded in the binder layer. On the other hand, in the antibacterial test of (Table 3), No. 11 to 13 obtained good results as +++ or ++, but No. 14 became-. This is because TiO2 is of rutile type, the sintering temperature is 320 ° C. higher than the softening temperature of the binder, and the viscosity of the binder becomes too low, so that the TiO2 constituting the photocatalyst layer is formed.
It is considered that the particles were buried in the binder layer for two reasons.

From the above, TiO2 was previously added to the binder.
In the method of obtaining a multifunctional material by applying the particles and then sticking and firing on the substrate, the same effect as the method of applying the binder to the surface of the substrate and then applying the TiO2 particles to obtain the multifunctional material is obtained. It was confirmed that it could be obtained.

Example 4 An acrylic resin binder was applied to the surface of a 100 × 100 × 5 polyimide resin base material, and then a 15% TiO 2 sol aqueous solution was applied by a spray coating method. 0.8 µm TiO2
After forming a layer, the substrate on which the binder layer and the TiO2 layer were laminated was fired at 150 DEG C. in a nichrome furnace to obtain a multifunctional material.

The following Table 4 shows changes in the antibacterial and abrasion resistances of the above-mentioned multifunctional materials according to the firing temperature.

[0075]

[Table 4]

In Table 4, the method of preparing the 15% TiO2 sol aqueous solution was changed as follows. No.1
5: The 15% TiO2 sol aqueous solution used in Example 1 was used as it was. No. 16: TiCl aqueous solution in autoclave 1
After hydrolysis at 10 to 150 ° C., the product is pH adjusted with nitric acid.
The dispersion was adjusted to 0.8 and dispersed without using a surface modifier, and then used after removing aggregates. In this case spray
Coating was performed immediately after removing the aggregates.

Here, the specific gravity of TiO2 is 3.9, the crystal type is anatase, the specific gravity of the acrylic resin is 0.9, and the temperature at which the viscosity corresponding to the glass softening point is 70 ° C.

Regarding the abrasion resistance, no scratch was found in any of Nos. This is presumably because the range of the difference between the firing temperature and the softening temperature of the binder was such that the viscosity of the binder could be adjusted to a value at which TiO2 could be properly embedded in the binder layer.

On the other hand, regarding the antibacterial test, NO.
However, it was found that multifunctional materials having antibacterial properties can be produced even at a temperature lower than 30 ° C. by obtaining favorable results of ++ for .16. This difference is DTA-T
G, 200 to 350 in the TiO2 sol of No. 15
Although some components decompose and evaporate at ℃, they are not recognized in NO.16, so it is considered that this is caused by the presence or absence of organic components covering TiO2. In addition, here, the difference in specific gravity between anatase and acrylic resin was 3, but it was confirmed that with such a difference, the TiO2 particles constituting the photocatalyst layer had good antibacterial properties without being embedded in the binder layer.

(Example 5) A binder layer made of frit or the like having a different specific gravity was formed on the surface of a 100 × 100 × 5 alumina substrate by spray coating, dried, and dried to form a 15% aqueous solution of TiO 2 sol. A TiO2 layer having a thickness of 0.8 μm is formed by spray coating, and then the base material on which the binder layer and TiO2 are laminated is heated and baked at an ambient temperature of 750 ° C. using a roller hearth kiln, and then cooled and solidified to obtain a multi-function. Wood was obtained.

The following Table 5 shows changes in antibacterial properties and abrasion resistance of the above multifunctional materials with changes in firing temperature.

[0082]

[Table 5]

Regarding the antibacterial test, all of the samples Nos. 17 to 20 were as good as +++. In any case, the sintering temperature is 30 ° C. or more and 300 ° C. or higher than the softening temperature of the binder.
It is considered that the range of the difference between the firing temperature and the softening temperature of the binder was adjusted to a value at which the viscosity of the binder was adjusted so that TiO2 could be appropriately embedded in the binder layer.

Regarding the abrasion resistance, No. 17 was scratched and peeled off by sliding 5 times or less,
In No. 20, no scratch was found even after sliding 10 times or more. The reason is that the specific gravity of the binder is larger than that of TiO2 in No. 17 unlike the others, so that the anatase type TiO2 particles constituting the lowermost layer of the photocatalyst layer were not sufficiently embedded in the binder layer. it is conceivable that. Therefore, it has been found that the abrasion resistance of the multifunctional material is also affected by the specific gravity of TiO2 and the binder, and is deteriorated when the specific gravity of the binder is larger than the specific gravity of TiO2.

(Example 6) An SiO2-Al2O3-BaO frit (softening temperature of 6)
20 ° C.), and a Ti layer is formed thereon.
An aqueous solution obtained by mixing and stirring an O2 sol and a SnO2 sol was applied by a spray coating method, and then calcined at 750 ° C. and solidified by cooling to obtain a multifunctional material. The TiO2 sol concentration is 4 ~
The pH was adjusted to pH11 with NH3 aqueous solution at 6 wt%, and TiO2
The crystallite diameter of the particles is 0.01 μm, and the crystallite diameter of the SnO2 particles is 0.0035 μm.

The multifunctional material thus produced was made of TiO 2
The results of the antibacterial test and the abrasion resistance test when the amount (molar ratio) of SnO2 was varied with respect to the results are shown in Table 6 below.

[0087]

[Table 6]

The wear resistance test improved with an increase in the amount of SnO 2, and when added in an amount of 10% or more, no damage was caused and no change occurred even in 40 sliding tests. Regarding the antibacterial test, if the range was up to 20% or more, it was +++ as in the case of no addition, and it stopped at ++ up to 60%. If more is added, the T
The probability of covering the iO2 particles increases, and the antibacterial property deteriorates.
At 0%, it became-. Therefore, the amount of SnO2 added should be 10% or more and 60% or less, preferably 10% or less, of the amount of TiO2 in a molar ratio.
% To 20% or less, it is possible to provide a multifunctional material having excellent antibacterial properties and abrasion resistance.

Here, the wear resistance is improved with an increase in the amount of SnO2 due to the following mechanism. That is, SnO2 is T
Since the vapor pressure is higher at temperatures higher than 600 ° C than i02,
Before sintering, the interval between the TiO2 particles 3b is LO as shown in FIG. 4 (a), but the surface of the TiO2 particles 3 having a positive curvature has a high vapor pressure and a surface having a negative curvature. That is, the surface of the neck portion where the two TiO2 particles 3b come into contact has a low vapor pressure. As a result, SnO2 having a higher vapor pressure than TiO2 enters the neck portion as shown in FIG.
As shown in FIG. 4 (c), it is condensed and sintered by a vaporization-condensation mechanism. When sintering is performed by the vaporization-condensation mechanism, cracks and the like do not occur because the interval L2 between the TiO2 particles after sintering is substantially equal to the interval Lo before sintering. As described above, the TiO2 is applied to the surface of the base material via the binder.
In the composite member holding the particle layer, if the SnO2 particles are filled in the gaps between the TiO2 particles exposed at the outermost surface and fired at 600 [deg.] C. or more, the neck portion between the TiO2 particles is bonded without generating cracks. As a result, the wear resistance is improved.

Comparative Example 7 A binder layer made of SiO 2 --Al 2 O 3 --BaO frit (softening temperature: 620 ° C.) was formed on the surface of a 150 square porcelain tile base material as in Example 6, and a TiO 2 sol was formed thereon. And SiO2 sol were mixed and agitated aqueous solution was applied by spray coating method.
It was baked at ℃ and solidified by cooling to obtain a multifunctional material. Note that TiO2
The sol concentration is adjusted to PH11 with an aqueous NH3 solution at 4 to 6 wt%, and the crystallite size of the particles is 0.01 μm as in Example 6.
However, the crystallite diameter of the SnO2 particles was as large as 0.008 μm.

An antibacterial test and an abrasion resistance test were performed on the multifunctional material thus produced, and the results of comparison with Example 6 are shown in Table 7 below.

[0092]

[Table 7]

As a result, the effect of improving the abrasion resistance of the 0.008 μm SnO 2 particles was weaker than when the 0.0035 μm SnO 2 particles were used, and the sliding ratio was finally increased 40 times when the molar ratio to the TiO 2 particles was 60% or more. No damage was found in the dynamic test, and no change occurred. As to the antibacterial test, as in the case of using SnO2 particles of 0.0035 μm, if the range was up to 20% or more, it was +++ as in the case of no addition, and if it was 60% or less, it stopped at ++.
When added more, the probability of covering the TiO2 particles on the surface of the substrate increased, and the antibacterial property deteriorated.
Therefore, when 0.01 μm TiO 2 particles are used, it is difficult to add 0.008 μm SnO 2 particles to provide a multifunctional material having excellent antibacterial properties and abrasion resistance. This is because the vapor pressure of the SnO2 particles decreases as the particle size increases, and when the SnO2 particles remaining without vaporization are 0.0035 μm, they are present in the gaps between the TiO2 particles, and the bonding strength can be improved. On the other hand, at 0.008 μm, the SnO2 particles are larger than the gaps between the TiO2 particles, so that the probability that the SnO2 particles do not enter the gaps but rather reach the TiO2 particles is increased. From the above, it is preferable that the size of the SnO2 particles to fill the gaps between the TiO2 particles is less than 4/5 of the TiO2 particle diameter.

(Example 8) A binder layer made of SnO2-Al2O3-BaO frit (softening temperature: 620 ° C) was formed on the surface of a 150-square ceramic tile base material.
After applying the aqueous solution of TiO2 sol by the spray coating method, the composite member baked at 750 ° C. and cooled and solidified is subjected to Sn coating.
An O2 sol aqueous solution was applied by a spray coating method and then heat-treated at 110 ° C. to obtain a multifunctional material. At this time Ti
The same O2 sol solution as in Example 6 was used.
The sol used was 0.0035 μm.

The results of the antibacterial test and the abrasion resistance test performed on the multifunctional material thus produced are shown below (Table 8).
Shown in

[0096]

[Table 8]

The abrasion resistance test improved as the amount of SnO2 increased, and the addition of a molar ratio of 20% or more resulted in a 40% increase in the wear resistance test.
No damage was found in the rotational sliding test, and no change occurred. For the antibacterial test, if it is in the range up to 20% or more, it is +++ as in the case of no addition, and 60%
Stopped at ++ if not until. When added more, the probability of covering the TiO2 particles on the surface of the substrate increased, and the antibacterial property deteriorated. In this test, since the SnO2 sol was heat-treated at a low temperature of 110 ° C., the sintering by the vaporization-condensation mechanism shown in Example 6 did not occur. Nevertheless, the abrasion resistance was improved, but this was because SnO2 particles having a smaller particle size than TiO2 particles, that is, having a large specific surface area and excellent adsorption power, filled gaps between TiO2 particles.
It is considered that the bonding between the TiO2 particles was strengthened.

(Example 9) A binder layer made of SiO 2 -Al 2 O 3 -BaO frit (softening temperature: 620 ° C.) was formed on the surface of a 150-square ceramic tile base material.
An aqueous solution of sol is applied by a spray coating method, and then an aqueous solution of copper acetate is applied to the composite member which has been baked at 750 ° C., cooled and solidified, and dried, and then irradiated with light including ultraviolet rays to reduce copper ions. It was fixed on the photocatalyst layer to obtain a multifunctional material. Here, a mercury lamp was used as the irradiation lamp. Here, the average size of the Cu particles fixed to the photocatalyst layer was about 0.004 μm.

The results of the antibacterial test and the abrasion resistance test performed on the multifunctional material thus produced are shown in Table 9.

[0100]

[Table 9]

The wear resistance test improved with an increase in the amount of Cu, and the addition of a molar ratio of 20% or more did not cause any damage or change even in the 40 times of the sliding test. Regarding the antibacterial test, if the range was up to 20% or more, it was +++ as in the case of no addition. Since Cu itself has an antibacterial activity, deterioration of the antibacterial activity by adding a large amount was not observed. However, when the amount of Cu added is small, the photocatalytic action of the TiO2 particle layer is predominant, and when the amount of Cu is large, C
It can be considered that the action by u is dominant. Cu
When only the action is expected, Cu is gradually eluted when used in a liquid, and therefore, it is considered that the life is shorter as compared with the case without a photocatalyst. Also, when the amount of Cu added becomes large, the cost increases accordingly. Therefore, it seems that it is meaningless to set the Cu amount too large. This example confirmed that not only oxides such as SnO2, but also metals such as Cu could be particles that fill the gaps in the TiO2 particle layer.

Example 10 A binder layer composed of SiO 2 -Al 2 O 3 -BaO frit (softening temperature: 620 ° C.) was formed on the surface of a 150 square porcelain tile base material, and a TiO 2 sol aqueous solution was spray-coated thereon. After coating by a method, an aqueous solution of copper acetate is applied to the composite member that has been baked at 950 ° C. and cooled and solidified, and then irradiated with light including ultraviolet rays to reduce the copper ions while fixing to the photocatalyst layer to form a multifunctional material. Obtained.
At this time, irradiation was performed for several minutes using a BLB lamp as an irradiation lamp. TiO2 changed its phase from anatase to rutile during the heat treatment process. The thickness of TiO2 was adjusted to 0.4 .mu.m during spray coating.

The multifunctional material thus produced was subjected to an antibacterial test and an abrasion resistance test. Regarding the abrasion resistance test, good results are shown in this temperature range even without addition. C
Even in the case where u was added, no damage was caused in the sliding test for 40 times as in the case of no addition, and no change occurred.
FIG. 5 shows the antibacterial test. Ti without additive
Bad because O2 is rutile. The antibacterial property of adding Cu increased. The Cu loading amount is 0.7 μg / cm not only when the BLB lamp is irradiated but also when the irradiation is not performed.
When it is 2 or more, the antibacterial activity becomes ++, and when the amount of supported Cu becomes 1.2 μg / cm2 or more, the antibacterial activity becomes +++. From the above, in order to provide a multifunctional material excellent in both antibacterial properties and abrasion resistance, the amount of supported Cu is 0.7 μg / cm 2.
And more preferably 1.2 μg / cm 2 or more.

Incidentally, the amount of supported Cu is dramatically improved when a drying step is performed after the application of the aqueous solution of copper acetate and before the irradiation with the BLB lamp. FIG. 6 shows the relationship. This is presumably because the concentration of metal ions when photoreduced is higher when dried.

The amount of supported Cu is maximized when the amount of applied Cu is optimized (FIGS. 7 and 7 are examples of copper acetate having a Cu concentration of 1 wt%). In the case of FIG. 7, the amount of applied Cu is 0.7 μg. / Cm2
To achieve the above, 0.2 mg / cm2 or more and 2.7 mg / c
0.3 m to less than 1.2 μg / cm 2
The concentration may be from g / cm2 to 2.4 mg / cm2.

(Example 11) A binder layer made of SiO 2 -Al 2 O 3 -BaO frit (softening temperature: 680 ° C.) was formed on the surface of a 150-square ceramic tile base material, and a TiO 2 sol aqueous solution was spray-coated thereon. An aqueous silver nitrate solution is applied to the composite member that has been baked at 950 ° C., cooled and solidified after application by a method, dried and then irradiated with light including ultraviolet rays to fix silver ions on the photocatalyst layer and fix the multifunctional material. I got At this time, irradiation was performed for several minutes using a BLB lamp as an irradiation lamp. In addition, TiO2 changed its phase from anatase to rutile during the heat treatment process. The thickness of TiO2 was adjusted to 0.4 .mu.m during spray coating.

The multifunctional material thus produced was subjected to an antibacterial test and an abrasion resistance test. Regarding the abrasion resistance test, good results are shown in this temperature range even without addition. A
Even when g was added, no damage was found in the sliding test for 40 times as in the case where no g was added, and no change occurred.

FIG. 5 shows the antibacterial test. In the case of no addition, since TiO2 is rutile, it is bad as +. The addition of Ag increased the antibacterial properties. In addition, the Ag carrying amount is 0.0
When the concentration exceeds 5 μg / cm 2, the antibacterial activity becomes ++ and A
When the amount of supported g becomes 0.1 μg / cm 2 or more, the antibacterial activity becomes +++. Therefore, in order to provide a multifunctional material excellent in both antibacterial properties and abrasion resistance, the amount of supported Ag is 0.05 μg.
/ Cm 2 or more, more preferably 0.1 μg / cm 2
The above is good. However, when the amount of Ag carried is large, the color is changed from brown to black, and the appearance is poor. However, the Ag loading amount is 1
If it is less than μg / cm 2, there is no coloring. From the above, Ag
The loading amount is preferably 0.05 μg / cm 2 or more and 1 μg / cm 2 or less, more preferably 0.1 μg / cm 2 or more and 1 μg / cm 2.
cm2 or less is good.

(Example 12) A binder layer composed of SiO 2 -Al 2 O 3 -BaO frit (softening temperature: 680 ° C.) was formed on the surface of a 150 square ceramic tile base material, and a TiO 2 sol aqueous solution was spray-coated thereon. An aqueous silver nitrate solution is applied to the composite member that has been baked at 950 ° C., cooled and solidified after application by a method, dried and then irradiated with light including ultraviolet rays to fix silver ions on the photocatalyst layer and fix the multifunctional material. I got At this time, irradiation was performed for several minutes using a BLB lamp as an irradiation lamp. In addition, TiO2 changed its phase from anatase to rutile during the heat treatment process.

[0110] The multifunctional material produced in this way was
The abrasion resistance test, antibacterial test and stain resistance test were carried out by changing the thickness of O2 to various values. Regarding the abrasion resistance test, good results were obtained in the range of 2 μm or less tested this time, and no damage was caused and no change occurred in the 40 times of the sliding test. In the antibacterial test, the film thickness becomes ++ when the film thickness is 0.1 μm or more and ++ when the film thickness is 0.2 μm or more. Therefore, the thickness of TiO2 is preferably 0.1 μm or more.
Preferably, it is 0.2 μm or more.

(Example 13) A binder layer made of SiO 2 -Al 2 O 3 -BaO frit (softening temperature: 620 ° C.) was formed on the surface of a 150-square ceramic tile base material, and a zinc chloride aqueous solution or a TiO 2 sol aqueous solution was formed thereon. Spray
After coating and drying by a coating method, an aqueous solution of silver nitrate was applied, and then fixed to the photocatalytic layer while irradiating with light including ultraviolet rays to reduce silver ions. After that, 900 ° C or more and 1000
It was baked at below ℃ and solidified by cooling to obtain a multifunctional material. At this time, irradiation was performed for several minutes using a BLB lamp as an irradiation lamp.
In addition, TiO2 changed its phase from anatase to rutile during the heat treatment process. In addition, Ag whose surface is fixed is
Since the color changed from brown to white, it is considered that the color changed to silver oxide during firing. However, the adhesion of Ag was fixed discretely, and the observation showed that the growth of Ag particles before and after calcination was hardly observed.

The multifunctional material thus produced was subjected to an antibacterial test and an abrasion resistance test. Regarding the abrasion resistance test, good results are shown in this temperature range even without addition. A
Even when g was added, no damage was found in the 40 times of the sliding test as in the case where no g was added, and no change occurred. The antibacterial test is shown in FIG. In the case of no addition, since TiO2 is rutile, it is bad as +. The addition of Ag increased the antibacterial properties.

Example 14 A binder layer made of SiO 2 -Al 2 O 3 -BaO frit (softening temperature: 620 ° C.) was formed on the surface of a 150-square ceramic tile base material, and a TiO 2 sol aqueous solution was spray-coated thereon. After coating by the method, a silver nitrate aqueous solution is applied to the composite member which has been baked at 900 ° C. or higher and 1000 ° C. or lower and cooled and solidified, and then fixed to the photocatalytic layer while irradiating light including ultraviolet rays to reduce silver ions, Further, a 0.1 mol / l KI aqueous solution was applied thereon at a rate of 0.1 cc / cm 2, and further irradiated with ultraviolet rays for about 5 seconds to obtain a multifunctional material. At this time, the supported amount of Ag was 2μ.
g / cm2. By applying a 0.1 mol / l KI aqueous solution at a rate of 0.1 cc / cm2 and further irradiating with ultraviolet light for about 5 seconds, the brown-black multi-functional material is decolorized to white and the appearance is improved. did.

(Example 15) A binder layer composed of SiO 2 -Al 2 O 3 -BaO frit (softening temperature: 620 ° C.) was formed on the surface of a 150-square ceramic tile base material, and a TiO 2 sol aqueous solution was spray-coated thereon. After application by the method, the multifunctional material obtained by firing at 820 ° C. and cooling and solidifying is placed at an angle, and while irradiating light including ultraviolet rays onto the multifunctional material, a public bath is placed on the multifunctional material. While circulating the bath water collected in the above, the water was dropped continuously, and the change of the bath water was observed. For comparison, a similar device was dropped on a substrate having no photocatalyst layer. In the observation after 14 days, the bath water dropped on the multifunctional material showed a unique difference in the degree of turbidity as compared with the bath water dropped on the substrate not provided with the photocatalytic layer. Although it was not possible, there was a difference in the water odor. That is, in the bath water that was dropped on the substrate without the photocatalyst layer, a rather strong drenched water odor was observed, and slime-like slime and organic precipitates were observed on the substrate, whereas None of the bath water was dropped on the multifunctional material. According to the above simulation experiment, it is considered that this multifunctional material can be used as an artificial waterfall or water fountain paving stone in a water circulation system in a park, a department store, or the like.

[0115]

As is apparent from the above description, according to the present invention, the photocatalyst particles are fixed via the binder layer made of a material lower than the softening temperature of the base material. Since the photocatalyst particles constituting the photocatalyst particles are not buried in the binder layer, the surface of the photocatalyst particles is substantially exposed to the outside, and the photocatalytic effect can be sufficiently exhibited. Further, among the photocatalyst particles, some of the particles constituting the lower layer of the photocatalyst layer are buried in the binder layer, so that the holding power of the photocatalyst layer is greatly improved, and peeling or the like hardly occurs.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for producing a multifunctional material having a photocatalytic function according to the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1 (d).

Fig. 3 Enlarged view between TiO2 particles

FIGS. 4A to 4C are diagrams for explaining the mechanism of sintering of TiO2 particles.

FIG. 5 is a graph showing test results for an antibacterial test.

FIG. 6 is a graph showing test results on the amount of supported Cu when a drying step is performed before irradiation with a BLB lamp.

FIG. 7 is a graph showing the relationship between the amount of Cu carried and the amount of Cu applied;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base material, 2 ... Binder layer, 3 ... Photocatalyst layer, 3a ... Photocatalyst particle which comprises the lower layer of the binder layer side of the photocatalyst layer, 3b ... Photocatalyst particle which comprises the surface layer in contact with outside air among the photocatalyst layers, 3c ... Particles filled to combine photocatalytic particles.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 23/72 B01J 37/02 301A 37/02 301 301M C03C 17/34 Z C03C 17/34 C04B 41/89 A C04B 41/89 B01D 53/36 JH (72) Inventor Eiichi Kojima 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Totoki Equipment Co., Ltd. (72) Mitsuyoshi Machida Ogura, Kitakyushu-shi, Fukuoka 2-1, 1-1 Nakajima, Kita-ku Toto Kiki Co., Ltd. (72) Inventor Yoshimitsu Saeki 2-1-1, Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Toto Kiki Co., Ltd. (72) Inventor Tatsuhiko Kuga Fukuoka 2-1 Nakajima, Kokurakita-ku, Kitakyushu City, Tochigi Equipment Co., Ltd. (72) Yasushi Nakajima 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka No. F-term (reference) in TOTO KOGYO CO., LTD. CD10 DA06 EA11 EB18X EB18Y EC22Y FA01 FA03 FB23 FB24 FB30

Claims (1)

[Claims] 1. A step of forming a binder layer on the surface of a base material, comprising: photocatalyst particles having an average particle size of less than 0.3 μm on the binder layer; tin oxide and zinc oxide having a particle size of 4/5 or less of the photocatalyst; A method for producing a multifunctional material having a photocatalytic function, comprising: a step of forming a layer made of a mixture with any one of bismuth oxide particles; and a firing step.