Multi-functional material having photocatalytic function and manufacture thereof

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to a multifunctional material exhibiting functions such as a deodorizing function, an anti-bacterial (killing) function, and an antifouling function, and a method for producing the same.

【0002】

[Conventional technology]

TiO as a substance that exerts a function of promoting decomposition (oxidation) by causing adsorption or desorption of oxygen molecules to organic compounds such as malodorous components by irradiating with ultraviolet rays.₂ , V₂O₅, ZnO, WO₃ Etc. are known, especially the crystal type is anatase type TiO₂Since particles are highly effective as photocatalysts, it has been conventionally proposed to form a photocatalyst layer on the surface of wall materials, tiles, glass (mirrors), circulation filtration devices, sanitary ware, and the like.

【0003】

As a method for forming the above photocatalyst layer, the following methods have been conventionally performed. A method in which photocatalytic particles are kneaded with a binder and applied to the surface of a base material by a spray coating method or the like, or dip-coated by a dip coating method and then heat-treated (Japanese Patent Laid-Open No. 5-201747).

【0004】

[Problems to be Solved by the Invention]

TiO₂In order for photocatalytic particles such as particles to exert their effects as photocatalysts, it is necessary that the photocatalyst particles are irradiated with ultraviolet rays and that the photocatalyst particles come into contact with substances to be decomposed such as malodorous gas. -If the photocatalyst particles were kneaded into the binder and applied to the base material as in the 2017 No. 47 publication, many photocatalyst particles were buried in the binder layer, and the ultraviolet rays did not reach or they did not come into contact with malodorous gas. Therefore, it is not possible to exert a sufficient catalytic function.

【0005】

[Means for solving problems]

In order to solve the above problems, the following means are applied in the present invention.

【0006】

In a multifunctional material having a photocatalyst function in which a photocatalyst layer is held on the surface of a thermoplastic substrate, the upper layer of the photocatalyst layer is exposed so as to be in contact with the outside air, and a part of the lower layer of the photocatalyst layer is thermoplastic. The photocatalyst particles that are embedded in the base material and that constitute at least the exposed surface layer of the photocatalyst layer are bonded to each other. With such a configuration, the upper layer of the photocatalyst layer is exposed, so that the catalytic function can be fully exerted, and a part of the lower layer of the photocatalyst layer is embedded in the thermoplastic substrate. Therefore, the photocatalyst particles are less likely to be separated from the thermoplastic substrate. Since the photocatalyst particles constituting the exposed portion of the photocatalyst layer are bonded to each other, the wear resistance of the photocatalyst layer can be improved. Here, the thermoplastic base material is a base material that becomes plastic at a temperature equal to or higher than the softening point as it is heated. For example, a base material made of glass, a thermoplastic resin, solder, or the like, or the above-mentioned material is used. Examples thereof include a composite base material having a base material surface.

【0007】

As photocatalytic particles, TiO₂, ZnO, SrTiO₃ , Fe₂O₃ , CdS, CdSe, WO₃ , FeTiO₃ , GaP, GaAs, RuO₂, MoS₃, LaRhO₃ , CdFeO₃ , Bi₂O₃ , MoS₂, In₂O₃ , CdO, SnO₂Etc., and any of these may be used. In addition, TiO₂, SrTiO₃ , Fe₂O₃ , CdS, WO₃ , MoS₃, Bi₂O₃ Since the absolute value of the redox potential of the equivalent electron band is larger than the absolute value of the redox potential of the conduction band, the oxidizing power is larger than the reducing power. Is excellent. In terms of raw material cost, TiO₂, Fe₂O₃ , ZnO is advantageous.

【0008】

As a method of binding the photocatalyst particles constituting the exposed portion of the photocatalyst layer to each other, for example, the gaps between the photocatalyst particles are filled with particles having a particle size smaller than the gaps. When only the photocatalytic particles are bonded to each other, there is no choice but to adsorb or sinter the photocatalytic particles. However, when utilizing the sintering action between photocatalytic particles, it is necessary to sinter at a considerably high temperature, which limits the type of base material. On the other hand, in the case of adsorption, the binding property is not sufficient unless the specific surface area of the photocatalyst particles is made very large and the filling property is improved, and sufficient catalytic activity and abrasion resistance are consumed, such as consuming only the amount of the photocatalyst particles adsorbed at the active site. The method for producing a multifunctional material having a property will be limited. Further, if particles larger than the gaps between the photocatalyst particles are used to strengthen the bonding of 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 that cannot exhibit catalytic activity, and bacteria stay in that portion, so that the antibacterial property is significantly deteriorated. The gaps between the photocatalyst particles referred to here are the neck portion between the photocatalyst particles 2b and 2b as shown in FIG. 3 (a) and the gap between the photocatalyst particles 2b and 2b as shown in FIG. 3 (b). Refers to both pores. Therefore, the particles 2c having a particle size smaller than the gaps between the photocatalyst particles referred to here refer to particles smaller than the gaps between the neck portion between the photocatalyst particles and the pores between the photocatalyst particles.

【0009】

The average particle size of the photocatalyst particles constituting the photocatalyst layer is preferably less than 0.1 μm in order to increase the specific surface area and enhance the photocatalytic activity.

【0010】

Further, as a substance constituting the particles filled in the gaps of the photocatalyst particles, a substance having a vapor pressure higher than the vapor pressure of the substance constituting the photocatalyst particles is selected, and the particles filled in the gaps of the photocatalyst particles are used as a photocatalyst. It is preferable to agglomerate in the neck portion between the particles. This is because, in order to obtain stronger bonds between the photocatalyst particles and increase the peel strength of the photocatalyst layer, it is better to sinter as well as fill the particles. Further, if such a substance having a high vapor pressure is selected for the particles that fill the gap, it also 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, zinc oxide and the like, but tin oxide is preferable from the viewpoint of safety.

【0011】

Further, as the small particles filled in the gaps between the photocatalyst particles, the material is basically not limited, but those having excellent adsorption power are preferable. A material with extremely weak adsorption capacity cannot achieve the purpose of binding the photocatalytic particles to each other, and a material with extremely strong adsorption capacity covers the active site on the surface of the photocatalytic particles rather than being inserted into the gap. This is because the probability increases. From this point of view, the preferred materials for the particles filled in the gaps between the photocatalytic particles are metals or oxides such as Sn, Ti, Ag, Cu, Zn, Fe, Pt, Co, Pd, and Ni. Zeolites, activated carbon, clay and the like used as adsorption carriers are not preferable. Among the above metals or oxides, tin oxide is preferable in that it has an appropriate adsorption capacity, and metals or oxides such as Ag and Cu have unique antibacterial properties other than binding the photocatalytic particles to each other. Since it has deodorant properties, it is preferable in that it also has a function of assisting the action of a photocatalyst in an application utilizing this function, particularly when there is no irradiation with light.

【0012】

The photocatalyst particles constituting the lowermost layer of the photocatalyst layer have a particle size of 1/2 or more and a thickness of a layer containing particles that fill the gaps with the photocatalyst particles in order to make it difficult for the photocatalyst particles to be separated from the thermoplastic substrate. It is preferable that less than a small amount is embedded in the thermoplastic substrate.

【0013】

Further, when the specific gravity of the photocatalyst particles is δt and the specific gravity of the thermoplastic substrate is δb, it is preferable that 0 δt-δb 3.0. If the difference in specific gravity is too small, the photocatalyst particles are not sufficiently embedded in the thermoplastic base material, and the thermoplastic base material and the photocatalyst particles are not sufficiently bonded. If the difference in specific gravity is too large, the photocatalyst particles are formed in the thermoplastic base material. This is because if it is buried and occurs locally, bacteria will stay there and the antibacterial property will decrease.

【0014】

The thickness of the photocatalyst layer is preferably 0.1 μm or more. If it is less than 0.1 μm, the photocatalytic particles are locally embedded in the thermoplastic substrate, and a part where the catalytic activity cannot be exhibited is generated on the surface of the multifunctional material, and bacteria stay in that part, so that the antibacterial property is particularly good. Getting worse. Here, the thickness of the photocatalyst layer includes the portion from the outermost surface to the portion embedded in the thermoplastic base material, and is the thickness obtained by leveling the unevenness of each.

【0015】

The thickness of the photocatalyst layer is preferably 0.4 μm or less. If it exceeds 0.4 μm, the surface becomes whitish and the translucency deteriorates, which is not preferable especially when the thermoplastic substrate is glass.

【0016】

The thickness of the photocatalyst layer is preferably 0.1 μm to 0.4 μm. If it is less than 0.1 μm, the photocatalytic particles are locally embedded in the thermoplastic substrate, and a part where the catalytic activity cannot be exhibited is generated on the surface of the multifunctional material, and bacteria stay in that part, so that the antibacterial property is particularly good. Getting worse. On the other hand, if it exceeds 0.4 μm, the surface becomes whitish and the translucency deteriorates, which is not preferable especially when the thermoplastic base material is glass.

【0017】

The thickness of the photocatalyst layer is preferably 0.1 μm to 0.2 μm. If it is less than 0.1 μm, the photocatalytic particles are locally embedded in the thermoplastic substrate, and a part where the catalytic activity cannot be exhibited is generated on the surface of the multifunctional material, and bacteria stay in that part, so that the antibacterial property is particularly good. Getting worse. If it exceeds 0.2 μm, an iris-colored pattern will be formed due to the interference of light with the film thickness of the photocatalyst layer. Therefore, the design effect of only the background color and pattern of the thermoplastic substrate or their combination is fully utilized. Can not do it.

【0018】

Further, 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, photocatalytic particles (and particles that fill the gaps depending on the manufacturing method) are locally embedded in the thermoplastic substrate, resulting in a portion on the surface of the multifunctional material that cannot exhibit catalytic activity. Since the bacteria can stay in that portion, the antibacterial property is significantly deteriorated. Here, the thickness of the layer containing the particles filled in the gaps between the photocatalyst particles includes the portion from the outermost surface to the portion embedded in the thermoplastic substrate, and the thickness of each unevenness is averaged.

【0019】

The thickness of the layer containing the particles filled in the gaps between the photocatalyst particles is preferably 0.4 μm or less. If it exceeds 0.4 μm, the surface becomes whitish and the translucency deteriorates, which is not preferable especially when the thermoplastic substrate is glass.

【0020】

The thickness of the layer containing the particles filled in the gaps between the photocatalyst particles is preferably 0.1 μm to 0.4 μm. If it is less than 0.1 μm, the photocatalytic particles are locally embedded in the thermoplastic substrate, and a part where the catalytic activity cannot be exhibited is generated on the surface of the multifunctional material, and bacteria stay in that part, so that the antibacterial property is particularly good. Getting worse. On the other hand, if it exceeds 0.4 μm, the surface becomes whitish and the translucency deteriorates, which is not preferable especially when the thermoplastic base material is glass.

【0021】

The thickness of the layer containing the particles filled in the gaps between the photocatalyst particles is preferably 0.1 μm to 0.2 μm. If it is less than 0.1 μm, the photocatalytic particles are locally embedded in the thermoplastic substrate, and a part where the catalytic activity cannot be exhibited is generated on the surface of the multifunctional material, and bacteria stay in that part, so that the antibacterial property is particularly good. Getting worse. If it exceeds 0.2 μm, an iris-colored pattern will be formed due to the interference of light with the film thickness of the photocatalyst layer. Therefore, the design effect of only the background color and pattern of the thermoplastic substrate or their combination is fully utilized. Can not do it.

【0022】

The photocatalyst particles constituting the photocatalyst layer are anatase-type TiO.₂Is a rutile type TiO₂Anatase-type TiO because it has better photocatalytic activity in terms of antibacterial properties than₂Is preferable.

【0023】

Further, the thermoplastic base material is preferably glass because it has excellent translucency and chemical durability.

【0024】

Further, in the method for producing a multifunctional material having a photocatalytic function according to the present invention, a photocatalyst layer composed of photocatalytic particles is formed on a thermoplastic base material, and then the thermoplastic base material is softened to soften the lower layer of the photocatalyst layer. Is partly embedded in a thermoplastic substrate and then solidified. Here, if the viscosity of the thermoplastic base material is too high, the photocatalyst particles are not sufficiently embedded in the thermoplastic base material, and the bond between the thermoplastic base material and the photocatalyst particles is weakened. On the other hand, if the viscosity is too low, the photocatalytic particles will be buried in the thermoplastic substrate, and if it occurs locally, the bacteria will stay and the antibacterial property will be significantly deteriorated. Taking these into consideration, the degree of softening of the thermoplastic substrate is determined.

【0025】

Further, another method for producing a multifunctional material having a photocatalytic function according to the present invention has a photocatalytic function in which the gaps between the photocatalytic particles are filled with particles having a particle size smaller than the gaps and the photocatalytic particles are bonded to each other. A method for producing a multifunctional material, in which a photocatalyst layer is formed by applying a mixture of photocatalyst particles and particles having a small particle size in the form of a sol or a precursor on a thermoplastic substrate. After that, the thermoplastic base material is softened, a part of the lower layer of the photocatalyst layer is embedded in the thermoplastic base material, and then solidified. According to this method, the photocatalyst layer is formed by applying a mixture of the particles that fill the gap and the photocatalyst particles in the state of a sol or a precursor in advance, so that the photocatalyst particles and the particles that fill the gap are mixed. Useful for controlling the ratio.

【0026】

Further, the average particle size of the particles filled in the gaps between the photocatalyst particles is preferably 4/5 or less of the average particle size of the photocatalyst particles. In the current production method, the particles that fill the gaps between the photocatalyst particles adhere not only to the gaps between the photocatalyst particles but also to some extent on the photocatalyst particles. When the particle size of the particles that fill the gap exceeds 4/5 of the average particle size of the photocatalyst particles, the probability of adhesion to the surface of the photocatalyst particles is higher than that of the gaps of the photocatalyst particles, and the bond strength between the photocatalyst particles decreases. To do. In addition, if the particles that fill the gaps are larger than the photocatalytic particles, the photocatalytic particles will be partially covered, and there will be a portion on the surface of the multifunctional material that cannot exhibit catalytic activity, so that bacteria can stay in that portion. Therefore, there is a possibility that the antibacterial property will be significantly deteriorated.

【0027】

The amount of the particles filled in the gaps between the photocatalyst particles with respect to the entire photocatalyst layer is preferably 10% or more and 60% or less in terms of molar ratio. When the photocatalyst layer is fixed to the thermoplastic substrate by heat treatment in a temperature range where the photocatalyst particles do not sinter, if the amount of particles that fill the gap is too small, the photocatalyst particles do not bond firmly with each other, while the gap If the amount of particles that fill the surface is too large, the amount of particles that cover the photocatalytic particles will be large, and there will be a part on the surface of the multifunctional material that cannot exhibit catalytic activity, and bacteria will be able to stay in that part, so it is especially antibacterial. The above range is preferable because the properties are significantly deteriorated.

【0028】

Further, another method for producing a multifunctional material having a photocatalytic function according to the present invention has a photocatalytic function in which the gaps between the photocatalytic particles are filled with metal particles having a particle size smaller than the gaps and the photocatalytic particles are bonded to each other. This method is a method for producing a multifunctional material having a photocatalyst layer, in which a photocatalyst layer composed of photocatalyst particles is formed on a thermoplastic base material, and then the thermoplastic base material is softened to be one of the lower layers of the photocatalyst layer. The part is embedded in a thermoplastic base material, then the thermoplastic base material is solidified, a solution containing the metal particles having a small particle size is applied to the photocatalyst layer, and heat treatment is performed to photocatalyst the metal particles having a small particle size. Immobilize to particles. This method can be carried out relatively easily when the metal particles that fill the gaps are oxides, and when a relatively porous photocatalyst layer is prepared, a large amount of metal particles that fill the gaps are attached. Can be done.

【0029】

Further, another method for producing a multifunctional material having a photocatalytic function according to the present invention has a photocatalytic function in which the gaps between the photocatalytic particles are filled with metal particles having a particle size smaller than the gaps and the photocatalytic particles are bonded to each other. This method is a method for producing a multifunctional material having a photocatalyst layer, in which a photocatalyst layer composed of photocatalyst particles is formed on a thermoplastic base material, and then the thermoplastic base material is softened to soften the photocatalyst layer. The part is embedded in a thermoplastic base material, then the thermoplastic base material is solidified, a solution containing ions of the metal particles having a small particle size is applied to the photocatalyst layer, and then light containing ultraviolet rays is irradiated to the metal. The ions are reduced and immobilized on the photocatalytic particles. This method can be carried out relatively easily when the particles filling the gap are metal, and the metal can be fixed in an extremely short time (several minutes). The lamp used for ultraviolet irradiation may be an ultraviolet lamp, a BLB lamp, a xenon mercury lamp, or a fluorescent lamp.

【0030】

Further, another method for producing a multifunctional material having a photocatalytic function according to the present invention has a photocatalytic function in which the gaps between the photocatalytic particles are filled with metal particles having a particle size smaller than the gaps and the photocatalytic particles are bonded to each other. This method is a method for producing a multifunctional material having a photocatalyst, in which a photocatalyst layer composed of photocatalyst particles is formed on a thermoplastic substrate, and a solution containing ions of metal particles having a small particle size is applied to the photocatalyst layer. Then, by irradiating light containing ultraviolet rays to reduce metal ions and immobilizing them on the photocatalyst particles, the thermoplastic base material is further softened and a part of the lower layer of the photocatalyst layer is embedded in the photocatalyst base material. The thermoplastic substrate is then solidified. According to this method, the heat treatment step can be completed only once, so that the productivity is improved.

【0031】

At least one of the metal species of the solution containing the ions of the metal particles filled in the gaps of the photocatalytic particles has antibacterial properties not only when irradiated with the BLB lamp but also when not irradiated ++ (survival rate of Escherichia coli 10%). (More than 30%), so Cu is used, and the amount of Cu carried is 0.7 μg / cm.² Above, more preferably 1.2 μg / cm² The above is preferable. However, the amount of Cu supported is 10 μg / cm.² If it is super, the surface becomes whitish and the translucency deteriorates, so the upper limit is 10 μg / cm.² And.

【0032】

At least one of the metal species of the solution containing the ions of the metal particles filled in the gaps of the photocatalytic particles is set to Ag because the antibacterial property is ++ not only when irradiated with the BLB lamp but also when not irradiated. Ag carrying amount is 0.05 μg / cm² Above, more preferably 0.1 μg / cm² The above is preferable. However, the amount of Ag carried is 1 μg / cm.² If it is super, the surface becomes whitish and the translucency deteriorates, so the upper limit is 1 μg / cm.² And.

【0033】

The amount of the solution containing the ions of Cu metal particles applied was 0.7 μg / cm for the amount of Cu carried when a 1 wt% copper acetate aqueous solution was used.² 0.2mg / cm² More than 2.7mg / cm² It is preferable to make the following. Furthermore, the amount of the solution containing the ions of Cu metal particles applied is 1.2 μg / cm for the amount of Cu supported.² 0.3mg / cm² More than 2.4mg / cm² It is preferable to make the following.

【0034】

It is preferable to dry the photocatalyst layer coated with the solution containing the ions of the metal particles before irradiating the light containing ultraviolet rays to reduce the metal ions and immobilizing them on the photocatalyst particles. This is because the metal ion concentration at the time of photoreduction is higher in the dried state, the metal immobilization rate with respect to the coating amount is improved, and the productivity is improved.

【0035】

The solvent of the solution containing the ions of the metal particles is preferably ethanol because ethanol is non-toxic and safe, and when ethanol is used, the drying rate is higher than that of an aqueous solvent.

【0036】

The temperature of the thermoplastic substrate when spray-coating the sol or precursor of the photocatalytic particles to form a photocatalytic layer on the thermoplastic substrate is greater than 20 ° C and less than 80 ° C, preferably 40 ° C. It is preferably 60 ° C or more and 60 ° C or less. When the temperature of the thermoplastic substrate exceeds 20 ° C, the coating concentration of the sol or precursor of the photocatalyst particles spray-coated on the thermoplastic substrate increases, and the photocatalyst constituting the exposed part of the photocatalyst layer The particles are well packed and the photocatalytic particles can be bonded to each other to increase the abrasion resistance of the photocatalyst layer. However, when the temperature of the thermoplastic substrate becomes 80 ° C. or higher, the application of the sol or precursor of the photocatalyst particles spray-coated on the thermoplastic substrate becomes uneven, and the photocatalyst layer becomes uneven. When stains adhere, it becomes difficult to remove the stains. Therefore, the temperature of the thermoplastic substrate should be less than 80 ° C.

【0037】

When a dispersion step is provided as a pre-step of the step of applying the photocatalyst particles on the thermoplastic substrate, it is used as a dispersant for dispersing the sol or precursor to be the photocatalyst particles in this dispersion step in the solution. It is preferable to use only the component that vaporizes at a temperature lower than the heat treatment temperature for softening the thermoplastic substrate. In the prior art, the reason why there was no deodorant property below 320 ° C was that TiO in the dispersion process₂Since the dispersant adhering to the particle surface remained without being sufficiently vaporized and evaporated, TiO₂This is because the surface of the particles was not sufficiently exposed on the outermost surface of the thermoplastic substrate, and the photocatalytic function became insufficient. As the dispersant that vaporizes at a low temperature, an organic dispersant having a molecular weight of 10,000 or less and a phosphoric acid-based dispersant are preferable.

【0038】

[Action]

Of the photocatalyst particles constituting the photocatalyst layer, the photocatalyst particles constituting the lower layer on the thermoplastic substrate side are held in a state where a part of them is buried in the thermoplastic substrate, and constitute the surface layer of the photocatalyst layer in contact with the outside air. Since the photocatalytic particles are bonded to each other in a state where the surface of the photocatalyst particles is substantially exposed to the outside, the photocatalytic effect is sufficiently exhibited.

【0039】

[Example]

Examples of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a diagram illustrating a method for manufacturing a multifunctional material having a photocatalytic function according to the present invention, and FIG. 2 is an enlarged view of a main part of FIG. 1 (c). As shown in (a), the thermoplastic base material 1 is prepared.

【0040】

Then, as shown in FIG. 3B, TiO is formed on the surface of the thermoplastic base material 1.₂A photocatalyst layer 2 composed of photocatalyst particles such as particles is formed. At this time, the photocatalyst layer 2 may be placed on the thermoplastic base material 1 with a bonding force that does not fall off from the thermoplastic base material 1 during the subsequent firing.

【0041】

After that, by heat-treating, as shown in FIGS. (C) and 2, the photocatalyst particles 2a constituting the lower layer on the thermoplastic substrate side of the photocatalyst layer 2 are formed into the molten thermoplastic substrate. When a part is settled and the thermoplastic base material is solidified, the part is buried in the thermoplastic base material and is firmly held. In addition, of the photocatalyst layer 2, some of the photocatalyst particles 2b constituting the surface layer in contact with the outside air are bonded to each other by intermolecular force between them or sintering by firing, and other parts are bonded as shown in FIG. 3 (a). Then, as shown in Fig. 3 (b), they are separated. That is, the surface of the photocatalyst particles 2b is substantially exposed to the outside in the surface layer.

【0042】

When the specific gravity of the photocatalyst particles is δt and the specific gravity of the thermoplastic substrate 1 is δb, the relationship is 0 δt-δb 3.0, preferably 0.5 δt-δb 2.0. This is because if the difference in specific gravity between the photocatalyst particles and the thermoplastic base material is too small, the vertical movement speed of the photocatalyst particles in the thermoplastic base material becomes slow when the thermoplastic base material is melted, and the photocatalyst particles after firing become slow. If the difference in specific gravity between the photocatalyst particles and the thermoplastic base material is too large, the vertical movement speed of the photocatalyst particles will increase, and most of the photocatalyst particles will be buried in the thermoplastic base material. Is. Further, the gaps between the photocatalyst particles constituting the exposed portion from the thermoplastic substrate 1, specifically, the neck portion of the photocatalyst particles 2b shown in FIG. 3A, or between the photocatalyst particles 2b shown in FIG. 3B. In order to bond the photocatalytic particles 2b to particles 2c (metals or oxides such as Sn, Ti, Ag, Cu, Zn, Fe, Pt, Co, Pd, Ni, etc.) whose particle size is smaller than the gap. It may be filled.

【0043】

Specific examples are given below. (Example 1) 150-square SiO₂-Al₂O₃-Na / K₂15% TiO on the surface of a glass substrate of O composition₂Aqueous solution of sol is applied by spray coating method, and TiO with a film thickness of 0.8 μm₂Form a layer and then TiO₂A glass base material with laminated layers is placed in a ceramic mold with good releasability, and after heating and firing at different atmospheric temperatures for each example with a roller harbor kiln, it is cooled and solidified to be a multifunctional glass. Got Here TiO₂The sol aqueous solution is, for example, TiCl.₄ Anatase-type TiO obtained by hydrolyzing in an autoclave under hydrothermal conditions in the range of 100 to 200 ° C and having a crystallite diameter of about 0.007 to 0.2 μm.₂Is dispersed in a sol state in an acidic aqueous solution such as nitric acid or hydrochloric acid or a basic aqueous solution such as ammonia in an amount of several% to several tens of percent. Triethanolamine and trimethylol are used as surface treatment agents to improve dispersibility. Amine organic acid salt, pentaerythrit, trimethylolpropane, etc. are added in the range of 0.5% or less. In addition, TiO₂The particle size of the sol was calculated by image processing of SEM observation, and the crystallite diameter was calculated from the integrated width of powder X-ray diffraction. The coating method was a spray coating method, but it is expected that similar results can be obtained with a dip coating method and a spin coating method. The obtained multifunctional glass was evaluated for antibacterial property and wear resistance. For antibacterial properties, the bactericidal effect on Escherichia coli W3110 strain was tested. 0.15 ml (1-5 x 10) of bacterial solution on the outermost surface of multifunctional glass sterilized with 70% ethanol in advance⁴ CFU) was dropped and placed on a glass plate (10 × 10 cm) and brought into close contact with the outermost surface of the glass substrate to prepare a sample. After irradiating with a white lamp (3500 lux) for 30 minutes, the bacterial solution of the irradiated sample and the sample maintained under light-shielding conditions was wiped with sterile gauze and collected in 10 ml of physiological saline to determine the survival rate of the bacterial and evaluated. It was used as an index. For wear resistance, sliding wear was performed using a plastic eraser, and changes in appearance were compared and evaluated. SiO in the following (Table 1)₂-Al₂O₃-Na / K₂Shows changes in antibacterial and wear resistance with changes in firing temperature when a glass substrate with O composition is used.

【0044】

[table 1]

<img file="JPH08131524A_D0001.tif" />【0045】

Here, SiO₂-Al₂O₃-Na / K₂The specific gravity of the glass substrate of O composition was 2.4, and the softening temperature was 680 ° C. Also, the TiO obtained in (Table 1)₂Nos. 1 to 3 were anatase type and had a specific gravity of 3.9, and Nos. 4 and 5 were rutile type and had a specific gravity of 4.2.

【0046】

In (Table 1), No. 1 constitutes the lowest layer of the photocatalyst layer because the firing temperature was only 20 ° C higher than the softening temperature of the glass substrate and the viscosity of the glass substrate was not sufficiently low. Anatase type TiO₂The particles were not sufficiently embedded in the glass substrate, so that they were scratched and peeled off after sliding 5 to 10 times in the abrasion resistance test. Regarding antibacterial properties, it is anatase type with excellent photocatalytic activity, and TiO at 300 ° C or higher.₂According to TG-DTA observation of the sol, the organic components are almost decomposed and vaporized, and TiO₂It is understood that the dispersant such as the surface treatment agent adhering to the surface is vaporized, but the firing temperature is 700 ° C, which is much higher than that, so the value is ++. ..

【0047】

Nos. 3 to 5 are cases where the firing temperature is 800 ° C or more and 1000 ° C or less, but the durability is extremely excellent without any change even in the sliding test of 40 times or more. The cause of this is surface TiO₂It is conceivable that a neck portion is formed due to the initial firing of the particles. In addition, when treated at 1100 ° C, TiO on the surface of the multifunctional glass taken out from the roller hers kiln after cooling and solidifying.₂There were cracks in the layer. This is TiO₂Judging from the TMA measurement of the test piece, TiO₂It is considered that this is due to medium-term sintering with remarkable volume shrinkage of the particles.

【0048】

In Nos. 4 and 5, the antibacterial properties were all worse. There are two possible causes for this. One is TiO₂The 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 glass substrate, and the viscosity of the glass substrate becomes too low to form the photocatalytic layer.₂It is probable that the particles were embedded in the glass substrate. Here, TiO₂It cannot be considered that the cause is only the phase transition of the particles to the rutile type. Rutile type TiO₂Also in, anatase type TiO₂This is because there is some photocatalytic activity, although it is inferior to. For example, TiO directly on a porous alumina substrate₂The sol was spray-coated, fired at 950 ° C, and then cooled and solidified, and the antibacterial property of the material was +. Therefore, the firing temperature is 300 ° C higher than the softening temperature of the glass substrate, and the viscosity of the glass substrate becomes too low, so that the TiO forming the photocatalyst layer is formed.₂It is understood that the fact that the particles are buried in the glass substrate also contributes to this.

【0049】

In addition, elemental analysis of Ti and Si (main component of the glass substrate) by EPMA in the cross-sectional direction of the sample revealed a layer in which Ti and Si were mixed, and TiO, which is a photocatalytic particle.₂Was confirmed to be buried.

【0050】

Example 1 above, that is, at least the photocatalyst is TiO₂, The glass base material is SiO₂-Al₂O₃-Na / K₂At the time of O composition, the following was confirmed. : Multifunctional glass with good antibacterial and abrasion resistance when the multifunctional glass is manufactured under the condition that the firing temperature is higher than the softening temperature of the glass substrate by more than 20 ° C and not higher than 300 ° C. Can be manufactured. The cause is that the viscosity of the glass substrate is TiO in the above temperature range.₂Is considered to be because the value is adjusted so that it can be appropriately embedded in the glass substrate. The multifunctional glass made with: is TiO₂It was confirmed that the particles were embedded in the glass substrate. : When the firing temperature was 800 ° C or higher and 1000 ° C or lower, the wear resistance did not change even after 40 or more sliding tests, and was extremely excellent. TiO₂It is considered that this is due to the strong bond that accompanies the formation of the neck between the particles.

【0051】

(Example 2) 100 × 100 × 5 SiO₂-Al₂O₃-15% TiO on the surface of a glass substrate with a PbO composition₂An aqueous sol solution (same as in Example 1) is applied by a spray coating method, and a TiO having a film thickness of 0.8 μm is applied.₂Form a layer and then TiO₂A glass base material with laminated layers is placed in a ceramic mold with good releasability, and after heating and firing at different atmospheric temperatures for each example with a roller harbor kiln, it is cooled and solidified to be a multifunctional glass. Got

【0052】

SiO in the following (Table 2)₂-Al₂O₃-Shows changes in antibacterial and wear resistance with changes in firing temperature when using a glass substrate with PbO composition.

【0053】

[Table 2]

<img file="JPH08131524A_D0002.tif" />【0054】

Here, SiO₂-Al₂O₃The softening temperature of the glass substrate with the -PbO composition was 540 ° C, and the specific gravity was 3.8. Also obtained TiO₂The crystal types of were all anatase types.

【0055】

In the abrasion resistance test of (Table 2), No. 6 was scratched and peeled off after sliding 10 times or less, but No. 7 and 8 were not scratched even after sliding 10 times or more. Furthermore, No. 9 and 10 gave good results that no scratches were formed even after sliding 40 times or more.

【0056】

No. 9 and 10 did not get scratched even after sliding 40 times or more because the firing temperature was 800 ° C or more, so TiO₂Neck is formed between particles, TiO₂It is probable that the particles were firmly bonded to each other. In No. 6, the reason why the glass base material was scratched and peeled off after sliding 10 times or less was that the firing temperature was only 20 ° C higher than the softening temperature of the glass base material, and the viscosity of the glass base material was sufficiently low. Because it did not, the anatase-type TiO that constitutes the bottom layer of the photocatalytic layer₂It is probable that the particles were not sufficiently embedded in the glass substrate. On the other hand, in Nos. 7 and 8, the reason why the scratches did not occur even after sliding 10 times or more was that the difference between the firing temperature and the softening temperature of the glass substrate was not reached, although the temperature did not reach the temperature at which the neck was formed. The viscosity of the glass substrate is TiO₂It is considered that the value was adjusted so that it could be appropriately embedded in the glass substrate. On the other hand, in the antibacterial property test of (Table 2), No. 6 to 9 gave good results of +++ or ++, but No. 10 was +. This is because the firing temperature is 320 ° C higher than the softening temperature of the glass substrate, and the viscosity of the glass substrate becomes too low, so that the TiO that constitutes the photocatalyst layer is formed.₂It is probable that the particles were buried in the glass substrate.

【0057】

(Example 3) SiO₂-Al₂O₃-15% TiO on a 100 x 100 x 5 glass substrate with a BaO composition₂An aqueous sol solution (same as in Example 1) is applied by a spray coating method, and a TiO having a film thickness of 0.8 μm is applied.₂Formed a layer. Then TiO₂The glass base material in which the layers are laminated is placed in a ceramic mold with good releasability, and the atmosphere temperature is different for each example in a siliconit furnace, and the glass base material is heated and fired, and then cooled and solidified to obtain a multifunctional glass. It was.

【0058】

The following (Table 3) shows the changes in antibacterial properties and wear resistance with changes in the firing temperature of the above multifunctional glass.

【0059】

[Table 3]

<img file="JPH08131524A_D0003.tif" />【0060】

Here, SiO₂-Al₂O₃-BaO composition glass substrate softening temperature is 620 ° C, specific gravity is 2.8, TiO on multifunctional glass₂The crystal types of No. 11 to 13 were anatase type and No. 14 was rutile type.

【0061】

In the abrasion resistance test of (Table 3), No. 11 was scratched and peeled off after sliding 5 times or less, but No. 12 was not scratched even after sliding 10 times or more, and further. , Nos. 13 and 14 gave good results that no scratches were formed even after sliding 40 times or more.

【0062】

No. 13 and 14 did not get scratched even after sliding 40 times or more because the firing temperature was 800 ° C or more, so TiO₂Neck is formed between particles, TiO₂It is probable that the particles were firmly bonded to each other. In No. 11, the reason why the glass was scratched and peeled off after sliding 10 times or less was that the firing temperature was only 20 ° C higher than the softening temperature of the glass substrate, and the viscosity of the glass substrate was sufficiently low. Because it did not, the anatase-type TiO that constitutes the bottom layer of the photocatalytic layer₂It is probable that the particles were not sufficiently embedded in the glass substrate. On the other hand, in No. 12, no scratches were found even after sliding 10 times or more because the difference between the firing temperature and the softening temperature of the glass substrate was the glass base, although it did not reach the temperature at which the neck was formed. The viscosity of the material is TiO₂It is considered that the value was adjusted so that it could be appropriately embedded in the glass substrate. On the other hand, in the antibacterial property test of (Table 3), No. 11 to 13 gave good results of +++ or ++, but No. 14 became-. This is TiO₂Is a rutile type, the firing temperature is 320 ° C higher than the softening temperature of the glass substrate, and the viscosity of the glass substrate becomes too low, TiO forming the photocatalyst layer.₂It is considered that there are two causes that the particles are buried in the glass substrate.

【0063】

(Example 4) 15% TiO on the surface of a 100 × 100 × 5 glass substrate having a different specific gravity for each example.₂TiO with a film thickness of 0.8 μm by spray coating the sol aqueous solution₂Form a layer and then TiO₂The glass substrate on which the above-mentioned material was laminated was placed in a ceramic mold with good releasability, heated and fired at an atmospheric temperature of 750 ° C. using a roller harbor kiln, and then cooled and solidified to obtain a multifunctional glass.

【0064】

The following (Table 4) shows the changes in antibacterial properties and wear resistance associated with changes in the specific gravity of the glass substrate of the above-mentioned multifunctional glass.

【0065】

[Table 4]

<img file="JPH08131524A_D0004.tif" />【0066】

Regarding the antibacterial test, all of Nos. 15 to 18 gave good results of +++. In either case, the firing temperature is higher than the softening temperature of the glass substrate in the range of 30 ° C or more and 300 ° C or less, and the range of the difference between the firing temperature and the softening temperature of the glass substrate determines the viscosity of the glass substrate.₂It is probable that was adjusted to a value that could be appropriately embedded in the glass substrate.

【0067】

Regarding wear resistance, No. 15 was scratched and peeled off after sliding 5 times or less, but Nos. 16 to 18 were not scratched even after sliding 10 times or more. As for the cause, unlike the others in No. 15, the specific gravity of the glass base material is TiO.₂Anatase-type TiO which constitutes the lowest layer of the photocatalytic layer because it is larger than the specific gravity of₂It is probable that the particles were not sufficiently embedded in the glass substrate. Therefore, the wear resistance of multifunctional glass is determined by TiO.₂The specific gravity of the glass base material is also affected, and the specific gravity of the glass base material is TiO.₂It turned out that it worsens when it is larger than the specific gravity of.

【0068】

(Example 5) 150-square SiO₂-Al₂O₃-On the surface of a glass substrate with a BaO composition (softening temperature 620 ° C), TiO₂Sol and SnO₂An aqueous solution in which the sol was mixed and stirred was applied by a spray coating method, and then calcined at 750 ° C. to be cooled and solidified to obtain a multifunctional glass. TiO₂The sol concentration is 4 to 6 wt%, adjusted to pH 11 with an aqueous NH3 solution, and TiO.₂The crystallite diameter of the particles is 0.01 μm, and SnO₂The crystallite diameter of the particles is 0.0035 μm.

【0069】

About the multifunctional glass produced in this way TiO₂And SnO₂SnO for the sum of₂The results of antibacterial and abrasion resistance tests when the amount (molar ratio) was changed are shown in (Table 5) below.

【0070】

[Table 5]

<img file="JPH08131524A_D0005.tif" />【0071】

SnO for abrasion resistance test₂It improved with the increase in the amount of water, and with the addition of 10% or more, no scratches were made and no change occurred even in 40 sliding tests. Regarding the antibacterial test, if the range was up to 20%, it was +++ as in the case of no addition, and if it was up to 60%, it stopped at ++. If more is added, TiO on the surface of the glass substrate₂The probability of covering the particles increased, the antibacterial property deteriorated, and it became-at 100%. Therefore SnO₂Addition amount of TiO in molar ratio₂And SnO₂If the total amount is 10% or more and 60% or less, preferably 10% or more and 20% or less, a multifunctional glass having excellent antibacterial properties and abrasion resistance can be provided.

【0072】

Here the wear resistance is SnO₂It is due to the mechanism shown below that it improves as the amount of. That is, SnO₂Is TiO₂Since the vapor pressure is high at a high temperature of 600 ° C or higher, TiO before sintering₂The spacing between particles 2b is L as shown in Fig. 4 (a)._O However, TiO₂Vapor pressure is high on the surface with positive curvature of particle 2, and the surface with negative curvature, that is, two TiO₂The vapor pressure is low on the surface of the neck where the particles 2b abut. As a result, as shown in Fig. 4 (b), the neck part is TiO.₂SnO with higher vapor pressure than₂Enters, condenses as shown in Fig. 4 (c), and is sintered by the vaporization-condensation mechanism. Then, when sintering is performed by the vaporization-condensation mechanism, TiO after sintering is performed.₂Particle spacing L₂ Is approximately equal to the interval LO before sintering, so cracks and the like do not occur. In this way, TiO is placed on the surface of the glass substrate via the glass substrate.₂In the composite member in which the particle layer is retained, it is exposed on the outermost surface and TiO₂SnO in the gaps between particles₂If the particles are filled and fired at 600 ° C or higher, TiO without cracking.₂Since the neck portion between the particles can be bonded, the wear resistance property is improved.

【0073】

(Comparative Example 6) 150-square SiO as in Example 5₂-Al₂O₃-On the surface of a glass substrate with a BaO composition (softening temperature 620 ° C), TiO₂Sol and SnO₂An aqueous solution in which the sol was mixed and stirred was applied by a spray coating method, and then calcined at 750 ° C. to be cooled and solidified to obtain a multifunctional glass. TiO₂The sol concentration is 4 to 6 wt%, adjusted to pH 11 with an aqueous NH3 solution, and the crystallite size of the particles is 0.01 μm as in Example 5, but SnO.₂The crystallite diameter of the particles was 0.008 μm, which was rather large.

【0074】

The multifunctional glass thus produced was subjected to an antibacterial property test and an abrasion resistance test, and the results of comparison with Example 5 are shown in (Table 6) below.

【0075】

[Table 6]

<img file="JPH08131524A_D0006.tif" />【0076】

As a result, 0.008 μm SnO₂The effect of improving the wear resistance of particles is 0.0035 μm SnO.₂Weaker than with particles, TiO₂Particles and SnO₂When the molar ratio to the total number of particles was 60% or more, no scratches were made and no change occurred even in 40 sliding tests. 0.0035 μm SnO for antibacterial test₂As in the case of using particles, if the range is up to 20%, it is +++ as in the case of no addition, and if it is 60% or less, it stops at ++. If more is added, TiO on the surface of the glass substrate₂The probability of covering the particles increased, the antibacterial property deteriorated, and it became-at 100%.

【0077】

Therefore 0.01 μm TiO₂0.008 μm SnO when using particles₂ It is difficult to add particles to provide a multifunctional glass having excellent antibacterial and abrasion resistance. The cause of this is SnO₂The vapor pressure of particles decreases as the particle size increases, and SnO remains without vaporization.₂TiO if the particles are 0.0035 μm₂It was present in the gaps between the particles and could improve the bond strength, whereas at 0.008 μm it was TiO.₂SnO compared to the interparticle gap₂SnO due to the large particles₂Particles do not enter the gap, rather TiO₂This is probably because the probability of coming on the particles is high. From the above, TiO₂SnO to fill the gaps between particles₂The particle size is TiO₂It is preferably less than 4/5 with respect to the particle size.

【0078】

(Example 7) 150-square SnO₂-Al₂O₃-On the surface of a glass substrate with a BaO composition (softening temperature 620 ° C), TiO₂After applying the sol aqueous solution by the spray coating method, SnO is applied to the composite member that is fired at 750 ° C and cooled and solidified.₂An aqueous sol solution was applied by a spray coating method and then heat-treated at 110 ° C to obtain a multifunctional glass. At this time, TiO₂The same sol aqueous solution as in Example 5 was used, and SnO was used.₂The sol used was 0.0035 μm.

【0079】

The results of antibacterial and abrasion resistance tests on the multifunctional glass thus produced are shown in (Table 7) below.

【0080】

[Table 7]

<img file="JPH08131524A_D0007.tif" />【0081】

SnO for abrasion resistance test₂With the addition of 20% or more of the molar ratio, there was no damage and no change even in the 40-time sliding test. Regarding the antibacterial test, if the range was up to 20%, it was +++ as in the case of no addition, and if it was up to 60%, it stopped at ++. If more is added, TiO on the surface of the glass substrate₂The probability of covering the particles increased, the antibacterial property deteriorated, and it became-at 100%. SnO in this test₂Since the sol is heat-treated at a low temperature of 110 ° C, sintering by the vaporization-condensation mechanism shown in Example 5 does not occur. Despite this, wear resistance improved, but this was TiO₂SnO has a smaller particle size than particles, that is, has a large specific surface area and excellent adsorption power.₂Particles are TiO₂By filling the gaps between the particles, TiO₂It is considered that the bond between the particles was strengthened.

【0082】

(Example 8) 150-square SiO₂-Al₂O₃-On the surface of a glass substrate with a BaO composition (softening temperature 620 ° C), TiO₂After applying the sol aqueous solution by the spray coating method, the composite member that was fired at 750 ° C and cooled and solidified was coated with the copper acetate aqueous solution and dried, and then irradiated with light containing ultraviolet rays to reduce copper ions. It was fixed to a photocatalyst layer to obtain a multifunctional glass. Here, a mercury lamp was used as the irradiation lamp. Here, the size of the Cu particles fixed to the photocatalyst layer was about 0.004 μm on average.

【0083】

The results of antibacterial and abrasion resistance tests on the multifunctional glass thus produced are shown in (Table 8).

【0084】

[Table 8]

<img file="JPH08131524A_D0008.tif" />【0085】

The abrasion resistance test improved as the amount of Cu increased, and by adding 20% or more of the molar ratio, no scratches were made and no change occurred even in the sliding test 40 times. Regarding the antibacterial property test, if it was in the range of 20% or more, it was +++ as in the case of no addition. In the case of Cu, since it has antibacterial activity by itself, no deterioration of antibacterial activity was observed by adding a large amount. However, probably when the amount of Cu added is small, TiO₂It can be considered that the photocatalytic action of the particle layer is dominant, and the action of Cu is dominant when the amount of Cu added is large. When the action of Cu alone is expected, Cu gradually elutes when used in a liquid, so it is considered that the life is shorter than that without a photocatalyst. In addition, the larger the amount of Cu added, the higher the cost. Therefore, it seems meaningless to set the amount of Cu too large. SnO by this example₂Not only oxides such as Cu, but also metals such as Cu TiO₂ It was confirmed that the particles could fill the gaps in the particle layer.

【0086】

(Example 9) 150-square SiO₂-Al₂O₃-On the surface of a glass substrate with a BaO composition (softening temperature 620 ° C), TiO₂After applying the sol aqueous solution by the spray coating method, the copper acetate aqueous solution is applied to the composite member that has been fired at 950 ° C and cooled and solidified, and then the photocatalyst layer is irradiated with light containing ultraviolet rays to reduce copper ions. It was fixed to and a multifunctional glass was obtained. At this time, a BLB lamp was used as the irradiation lamp, and irradiation was performed for several minutes. TiO₂Made a phase transition from anatase to rutile during the heat treatment process. TiO₂The film thickness was adjusted to 0.4 μm during spray coating.

【0087】

The multifunctional glass thus produced was subjected to an antibacterial property test and an abrasion resistance test. As for the abrasion resistance test, good results are shown in this temperature range even without addition. Even with the addition of Cu, there was no damage and no change in the sliding test 40 times as in the case of no addition. The antibacterial test is shown in Fig. 5. TiO when no additives are added₂However, it is bad as + because of rutile. The antibacterial property increased as Cu was added to it. And the Cu loading amount (consumption amount) is 0.7 μg / cm not only when irradiating with BLB lamp but also when not irradiating.²If the above is achieved, the antibacterial activity becomes ++ and the amount of Cu supported is 1.2 μg / cm.² If the above is achieved, the antibacterial activity becomes +++. From the above, in order to provide multifunctional glass with excellent antibacterial and wear resistance, the Cu loading amount is 0.7 μg / cm.² The above is good, more preferably 1.2 μg / cm²The above is good.

【0088】

By the way, the amount of Cu supported is dramatically improved by adding a drying step after applying the cupric acetate aqueous solution and before irradiating the BLB lamp. The relationship is shown in Fig. 6. It is considered that this is because the metal ion concentration at the time of photoreduction is higher when dried.

【0089】

The Cu loading amount is maximized when the Cu coating amount is optimized (Figs. 7 and 7 are examples of copper acetate with a Cu concentration of 1 wt%). In the case of Fig. 7, the supported amount is 0.7 μg / cm.² To achieve the above, apply 0.2 mg / cm² More than 2.7mg / cm² Below, the supported amount is 1.2 μg / cm² To achieve the above, apply 0.3 mg / cm² More than 2.4mg / cm² It can be done as follows.

【0090】

(Example 10) 150-square SiO₂-Al₂O₃-On the surface of a glass substrate with a BaO composition (softening temperature 680 ° C), TiO₂After applying the sol aqueous solution by the spray coating method, the composite member that was fired at 950 ° C and cooled and solidified was coated with the silver nitrate aqueous solution, dried, and then irradiated with light containing ultraviolet rays to reduce silver ions and photocatalyst. It was fixed to a layer to obtain a multifunctional glass. At this time, a BLB lamp was used as the irradiation lamp, and irradiation was performed for several minutes. Also TiO₂Made a phase transition from anatase to rutile during the heat treatment process. TiO₂The film thickness was adjusted to 0.4 μm during spray coating.

【0091】

The multifunctional glass thus produced was subjected to an antibacterial property test and an abrasion resistance test. As for the abrasion resistance test, good results are shown in this temperature range even without addition. Even with the addition of Ag, there were no scratches or changes in the 40 sliding tests as in the case without the addition.

【0092】

The antibacterial test is shown in Fig. 8. TiO when no additives are added₂However, it is bad as + because of rutile. The antibacterial property increased as Ag was added to it. And not only when irradiating with BLB lamp, but also when not irradiating, Ag carrying amount is 0.05 μg / cm² If the above is achieved, the antibacterial activity becomes ++, and the amount of Ag carried is 0.1 μg / cm.² If the above is achieved, the antibacterial activity becomes +++. Therefore, in order to provide multifunctional glass with excellent antibacterial and wear resistance, the Ag loading amount is 0.05 μg / cm.² The above is good, more preferably 0.1 μg / cm²The above is good. However, if the amount of Ag carried is large, it will be colored from brown to black, and the appearance will be poor. However, the amount of Ag carried is 1 μg / cm.² If it is below, there is no coloring. From the above, the amount of Ag carried is 0.05 μg / cm.² More than 1 μg / cm² The following is better, more preferably 0.1 μg / cm² More than 1 μg / cm² The following is good.

【0093】

(Example 11) 150-square SiO₂-Al₂O₃-On the surface of a glass substrate with a BaO composition (softening temperature 680 ° C), TiO₂After applying the sol aqueous solution by the spray coating method, the composite member that was fired at 950 ° C and cooled and solidified was coated with the silver nitrate aqueous solution, dried, and then irradiated with light containing ultraviolet rays to reduce silver ions and photocatalyst. It was fixed to a layer to obtain a multifunctional glass. At this time, a BLB lamp was used as the irradiation lamp, and irradiation was performed for several minutes. Also TiO₂Made a phase transition from anatase to rutile during the heat treatment process.

【0094】

Regarding the multifunctional glass produced in this way, TiO₂Abrasion resistance test, antibacterial property test and stain resistance test were carried out by changing the film thickness of. As for the abrasion resistance test, good results were shown in all of the film thicknesses within 2 μm tested this time, and even in the 40 times sliding test, no scratches were made and no change occurred. For the antibacterial test, ++ is obtained when the film thickness is 0.1 μm or more, and +++ is obtained when the film thickness is 0.2 μm or more. Therefore TiO₂The film thickness of is preferably 0.1 μm or more, preferably 0.2 μm or more.

【0095】

[Effect of the invention]

As is clear from the above description, according to the present invention, the photocatalyst particles are fixed to the thermoplastic base material, and in particular, the photocatalyst particles constituting the surface layer portion of the photocatalyst layer are not buried in the thermoplastic base material. , The surface of the photocatalytic particles is substantially exposed to the outside, and the photocatalytic effect can be sufficiently exerted. Further, among the photocatalyst particles, some of the particles constituting the lower layer of the photocatalyst layer are embedded in the thermoplastic base material, so that the holding power of the photocatalyst layer is significantly improved and peeling or the like is less likely to occur.

[Simple explanation of drawings]

[Figure 1]

The figure explaining the manufacturing method of the multifunctional material which has a photocatalytic function which concerns on this invention. [Figure 2]

Enlarged view of the main part of Fig. 1 (c) [Fig. 3]

TiO₂Enlarged view between particles [Fig. 4]

(a) ~ (c) are TiO₂Diagram explaining the mechanism of particle sintering [Fig. 5]

Graph showing test results for antibacterial test [Fig. 6]

A graph showing the test results on the amount of Cu supported when a drying step is added before irradiation with the BLB lamp. [Fig. 7]

Graph showing the relationship between the amount of Cu supported and the amount of Cu applied [Fig. 8]

Graph showing test results for antibacterial test [Explanation of symbols]

1 ... thermoplastic base material, 2 ... photocatalyst layer, 2a ... photocatalyst particles constituting the lower layer on the thermoplastic base side of the photocatalyst layer, 2b ... the surface layer of the photocatalyst layer in contact with the outside air Constituting photocatalytic particles, 2c ... Particles filled to bond photocatalytic particles to each other.