JPH0975245A - Washstand bowl and method for cleaning it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bowl for a washstand wherein dregs of soap and stains of oil and fat can be easily washed off with running water. SOLUTION: A bowl 1 for a washstand has a bowl surface 5 covered with a surface layer contg. a photo-semiconductor. This bowl surface 5 is irradiated with UV rays from a UV lamp. and the bowl surface exhibits hydrophilic properties in accordance with photoexcitation of the photo-semiconductor. When the surface of the bowl is sufficiently hydrophilic, hydrophobic stains (such as oil and fat, carbon black and smoke) do not stick on the bowl surface in the presence of water. In addition, the stains sticked when there exists no water are washed off by making water run out. On the other hand, hydrophilic stains (mad stain, dust etc.) stick on the surface but the stains are washed off by making water run out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wash basin bowl such as a vanity and a hand wash, and a cleaning method thereof. In particular, the present invention relates to a wash basin bowl which is less likely to be stained with soap residue and grease and has excellent cleanliness, and a method for obtaining such a wash basin bowl.

[0002]

2. Description of the Related Art A washbasin bowl is a pottery having a glaze layer on its surface. Soap debris adheres well to the surface of this washbasin bowl. Soap residue is soap (R-COONa) from which Na is removed and Ca is attached ((R-COO) ₂ Ca). If this soap residue adheres to the bowl surface, it will be rough and dirty. Further, when bacteria grow on the surface of the soap dregs, slime and yellowing occur, resulting in a more unclean state. The same situation occurs when oil stains are attached.

Recently, photocatalysts and antibacterial metals (Ag, Cu, etc.)
There is a new technology / new product that makes the surface of the bowl have antibacterial properties, but if the above-mentioned soap residue or grease stains the surface of the bowl, the antibacterial action will not reach the bacteria directly. Antibacterial ability is weakened.

An object of the present invention is to provide a washbasin bowl in which soap residue and oil stains can be easily removed with running water. Another object of the present invention is to strengthen the contact between bacteria and the bowl surface, which is provided with antibacterial properties, by preventing the attachment of soap residue and oil stains, so that the antibacterial performance can be exhibited more effectively.

[0005]

In order to solve the above problems, the present invention has a bowl surface covered with a surface layer containing an optical semiconductor, and the bowl surface is hydrophilic in response to photoexcitation of the optical semiconductor. It is characterized by exhibiting sex.

If the bowl surface is sufficiently hydrophilic, hydrophobic stains (oils, carbon black, soot, etc.) will not adhere to the bowl surface in the presence of water. Also, with respect to dirt attached when water does not exist, dirt is removed by flowing water. On the other hand, hydrophilic dirt (mud dirt, dust, etc.) adheres to the bowl surface, but if water is poured, the dirt will fall off.

Further, the method of cleaning a washbasin bowl of the present invention comprises the steps of preparing a washstand having a bowl surface coated with a layer containing an optical semiconductor, and the surface of the layer by photoexciting the optical semiconductor. Is made hydrophilic, and the step of rinsing the bowl surface with water to release deposits and / or contaminants attached to the surface of the layer from the surface. By this method, it is possible to provide a washbasin bowl with high cleanliness that can maintain cleanliness by simple water washing.

Next, the relationship between the optical semiconductor and hydrophilicity will be described. The present inventor discovered that the surface of an optical semiconductor is highly hydrophilized when the optical semiconductor is photoexcited. That is, when the photo-semiconductive titania is photoexcited with ultraviolet rays, the surface is highly hydrophilized so that the contact angle with water is 10 ° or less, more specifically 5 ° or less, and particularly about 0 °, and It was discovered that irradiation with light maintains and restores a high degree of hydrophilicity, and that under certain conditions, a highly hydrophilized state is maintained even in a dark place for 3 weeks or longer.

When the light having a wavelength of energy higher than the band gap energy of the photosemiconductor is irradiated with sufficient illuminance for a sufficient time, the surface of the photosemiconductor-containing layer becomes hydrophilic. At present, the surface hydrophilization phenomenon caused by photoexcitation of an optical semiconductor cannot always be clearly explained. It seems that the hydrophilization phenomenon by the photo-semiconductor is not necessarily the same as the photo-decomposition of a substance by the photocatalytic redox reaction conventionally known in the field related to the application to the chemical reaction of the photo-semiconductor. In this regard, conventional dogma regarding the photocatalytic redox reaction is photoexcited by electron - hole pairs are generated, the generated electrons are superoxide ions by reducing surface oxygen (O ₂ ^-) to generate the hole by oxidizing the surface hydroxyl groups to produce the hydroxyl radical (· OH), these highly reactive oxygen species (O ₂ ^- and · O
The substance was decomposed by the redox reaction of H).

However, the hydrophilization phenomenon due to the photo-semiconductor is inconsistent with the conventional knowledge about the photocatalytic decomposition of substances in at least two respects. First, according to the conventional theory, in photo semiconductors such as rutile and tin oxide, the energy level of the conductor is not sufficiently high, so the reduction reaction does not proceed, and as a result, the electrons photoexcited by the conductor are not excited. It was thought that the electron-hole pairs generated by photoexcitation recombine without participating in the redox reaction. On the other hand, it was confirmed that the hydrophilization phenomenon caused by the optical semiconductor also occurs in the optical semiconductors such as rutile and tin oxide.

Secondly, conventionally, the decomposition of a substance by a photocatalytic oxidation-reduction reaction is carried out when the thickness of the optical semiconductor layer is at least 100 nm.
It is thought that it will not happen unless it is above. On the other hand, it was observed that hydrophilization by the optical semiconductor occurs even when the thickness of the optical semiconductor-containing layer is on the order of several nm.

[0012] Therefore, although it cannot be concluded clearly, it is considered that the hydrophilization phenomenon by the photo-semiconductor is a phenomenon slightly different from the photodecomposition of the substance by the photocatalytic redox reaction. However, it was confirmed that the surface is not hydrophilized unless the light having an energy higher than the band gap energy of the optical semiconductor is irradiated. Possibly, polarity is applied to the surface of the optical semiconductor-containing layer by the generated conduction electrons and holes by the excitation of the optical semiconductor water hydroxyl (OH ^-)
It is considered that the surface is chemically adsorbed in the form of, and a physically adsorbed water layer is further formed thereon, and the surface becomes hydrophilic.

Once the surface of the photosemiconductor-containing layer has been made highly hydrophilic by photoexcitation, even if the member is kept in a dark place,
The hydrophilicity of the surface lasts for some time. When contaminants are adsorbed on the surface hydroxyl groups with the lapse of time and the surface gradually loses hydrophilicity, hydrophilicity is restored by photoexcitation again.

In order to first hydrophilize the photosemiconductor-containing layer, any light source having a wavelength of energy higher than the band gap energy of the photosemiconductor can be used. In the case of an optical semiconductor in which the photoexcitation wavelength is located in the ultraviolet region such as titania, under the condition that sunlight hits the substrate coated with the optical semiconductor-containing layer, the ultraviolet rays contained in the sunlight are preferably used. be able to. An optical semiconductor can be optically excited by an artificial light source indoors or at night. As will be described later, when the optical-semiconductor-containing layer is made of silica-containing titania, it can be easily made hydrophilic even with weak ultraviolet rays contained in a fluorescent lamp.

After the surface of the photosemiconductor-containing layer is once made hydrophilic, the hydrophilicity can be maintained or restored by relatively weak light. For example, in the case of titania, the hydrophilicity can be sufficiently maintained and restored even with weak ultraviolet rays contained in an interior illumination lamp such as a fluorescent lamp.

The photo-semiconductor-containing layer exhibits hydrophilicity even if it is very thin, and in particular, the photo-catalyst semiconductor material made of a metal oxide has sufficient hardness, so that the photo-semiconductor-containing layer has sufficient durability and abrasion resistance. Have.

When the base material is made of a non-heat resistant material such as plastics or when the base material is coated with a paint, a photo-oxidation resistant paint containing an optical semiconductor is used as described later. The optical semiconductor-containing layer can be formed by applying it to the surface and curing it.

Optical Semiconductor The optical semiconductor used in the hydrophilic fiber of the present invention is most preferably titania (TiO ₂ ). Titania is harmless, chemically stable, and available at low cost. Furthermore, since titania has a high band gap energy and therefore requires ultraviolet light for photoexcitation and does not absorb visible light in the process of photoexcitation, color development by a complementary color component does not occur.

As titania, both anatase and rutile can be used. The advantage of the anatase type titania is that a sol in which very fine particles are dispersed can be easily obtained on the market, and a very thin thin film can be easily formed. Rutile-type titania has a lower conduction band level than anatase-type titania, but can be used for the purpose of hydrophilization by an optical semiconductor. The substrate coated with the optical semiconductor-containing layer made of titania, the titania photoexcited by UV light, water is a hydroxyl group (OH ^-) are chemisorbed on the surface in the form of, formed more physically adsorbed water layer thereon, As a result, the surface is believed to be highly hydrophilic. When the washbasin bowl is a glaze-coated pottery, in order to form the optical semiconductor layer on the glaze without polymerization and curing reaction, the glaze is appropriately softened at a temperature (900-
The optical semiconductor (particles or the like) can be fixed to the glaze surface at 1,000 ° C. The stable phase of titanium oxide in this temperature range is the rutile type.

Other photo-semiconductors usable in the present invention include ZnO, SnO ₂ , SrTiO ₃ , WO ₃ and Bi _2.
There are metal oxides such as O ₃ and Fe ₂ O ₃ . It is considered that these metal oxides are likely to adsorb the surface hydroxyl group (OH ⁻ ) because the metal element and oxygen are present on the surface similarly to titania. Also, particles of an optical semiconductor may be mixed with a metal oxide that is not an optical semiconductor, such as silica. In particular, when an optical semiconductor is mixed with silica or tin oxide, the surface can be highly hydrophilized.

As an example of the method for producing an optical semiconductor layer made of such titania containing silica, a precursor of amorphous silica (eg, tetraethoxysilane, tetraisopropoxysilane, tetra-n-propoxysilane, tetrabutoxysilane, tetra A mixture of tetraalkoxysilane such as methoxysilane; silanol which is a hydrolyzate thereof; or polysiloxane having an average molecular weight of 3,000 or less) and crystalline titania sol is applied to the surface of the substrate, and hydrolyzed as necessary. After decomposing to form silanol, the silanol is subjected to dehydration polycondensation by heating at room temperature or if necessary, to form an optical semiconductor layer in which titania is bound with amorphous silica.

Shape of photocatalyst layer by firing of amorphous titania
Light forming substrate is a metal, ceramic, if it is formed of a heat resistant material such as glass, the contact angle with water was excellent in abrasion resistance that exhibits a high degree of hydrophilicity of the extent that the 0 ° One of the preferred ways of forming the semiconductor-containing layer is to first coat the surface of the substrate with amorphous titania and then phase change the amorphous titania to crystalline titania (anatase or rutile) by firing. Any of the following methods can be adopted for forming amorphous titania.

(1) Hydrolysis and Dehydration Polycondensation of Organic Titanium Compounds Titanium alkoxides such as tetraethoxy titanium, tetraisopropoxy titanium, tetra n-propoxy titanium, tetrabutoxy titanium, tetramethoxy titanium, hydrochloric acid or ethyl amine. After adding such a hydrolysis inhibitor and diluting it with an alcohol such as ethanol or propanol, the mixture is spray-coated, flow-coated, while the hydrolysis is partially or completely allowed to proceed. Spin coating,
Apply dip coating, roll coating, or other coating method to the surface of the substrate, and
Dry at a temperature of 00 ° C. Drying completes the hydrolysis of titanium alkoxide to produce titanium hydroxide,
A layer of amorphous titania is formed on the surface of the substrate by dehydration polycondensation of titanium hydroxide. Instead of titanium alkoxide, other organotitanium compounds such as titanium chelate or titanium acetate may be used.

(2) Formation of amorphous titania from an inorganic titanium compound An inorganic titanium compound such as TiCl ₄ or Ti (SO
₄ ) Apply the acidic aqueous solution of ₂ to the surface of the substrate by spray coating, flow coating, spin coating, dip coating, or roll coating. Then, the inorganic titanium compound is subjected to hydrolysis and dehydration polycondensation by drying at a temperature of about 100 to 200 ° C. to form a layer of amorphous titania on the surface of the substrate. Alternatively, amorphous titania may be applied to the surface of the substrate by chemical vapor deposition of TiCl ₄ .

(3) Formation of amorphous titania by sputtering Amorphous titania is deposited on the surface of a substrate by irradiating a target of metallic titanium with an electron beam in an oxidizing atmosphere.

(4) Firing Temperature Amorphous titania is fired at a temperature of at least the crystallization temperature of anatase. By firing at a temperature of 400 to 500 ° C. or higher, amorphous titania can be converted to anatase type titania. By firing at a temperature of 600 to 700 ° C. or higher, amorphous titania can be converted to rutile type titania.

Opto-semiconductor layer made of silica-containing titania Another preferred method for forming an opto-semiconductor-containing layer exhibiting a high degree of hydrophilicity such that the contact angle with water is 0 ° and having excellent abrasion resistance is titania. Forming an optical semiconductor-containing layer made of a mixture with silica on the surface of the base material. The ratio of silica to the total of titania and silica is 5-90.
Mol%, preferably 10 to 70 mol%, more preferably 10 to 50 mol%. Any of the following methods can be adopted to form the optical semiconductor-containing layer made of silica-containing titania.

(1) A suspension containing particles of anatase-type or rutile-type titania and silica particles is applied to the surface of a base material and sintered at a temperature below the softening point of the base material. (2) Amorphous silica precursor (for example, tetraalkoxysilane such as tetraethoxysilane, tetraisopropoxysilane, tetra-n-propoxysilane, tetrabutoxysilane, tetramethoxysilane, etc .; silanol which is a hydrolyzate thereof; Alternatively, a mixture of polysiloxane having an average molecular weight of 3,000 or less) and crystalline titania sol is applied to the surface of the base material, and if necessary, hydrolyzed to form silanol, and then heated at a temperature of about 100 ° C. or higher. By subjecting silanol to dehydration polycondensation, an optical semiconductor-containing layer in which titania is bound with amorphous silica is formed.
In particular, when the dehydration condensation polymerization temperature of silanol is carried out at a temperature of about 200 ° C. or higher, the degree of polymerization of silanol can be increased and the alkali resistance performance of the photosemiconductor-containing layer can be improved.

(3) Amorphous titania precursor (organic titanium compound such as titanium alkoxide, chelate or acetate, or inorganic titanium compound such as TiCl ₄ or Ti (SO ₄ ) ₂ ) is added to a solution of silica. Amorphous titania thin film in which silica particles are dispersed by applying a suspension of particles dispersed on the surface of a substrate and subjecting a titanium compound to hydrolysis and dehydration polycondensation at a temperature from room temperature to 200 ° C. To form. Then, the amorphous titania is phase-changed into crystalline titania by heating the titania to a temperature above the crystallization temperature and below the softening point of the substrate.

(4) Amorphous in a solution of a precursor of amorphous titania (organic titanium compound such as titanium alkoxide, chelate or acetate, or inorganic titanium compound such as TiCl ₄ or Ti (SO ₄ ) ₂ ). Precursors of silica (eg, tetraethoxysilane, tetraisopropoxysilane, tetra-n-propoxysilane, tetrabutoxysilane, tetramethoxysilane, and other tetraalkoxysilanes; silanols that are hydrolysates thereof; or average molecular weight 3, 000 or less polysiloxane) is mixed and applied to the surface of the base material. Then, these precursors are subjected to hydrolysis and dehydration polycondensation to form a thin film composed of a mixture of amorphous titania and amorphous silica. Then, the amorphous titania is phase-changed into crystalline titania by heating the titania to a temperature above the crystallization temperature and below the softening point of the substrate.

Photo-semiconductor layer made of tin oxide-containing titania Still another preferable method for forming a photo-semiconductor-containing layer having a high degree of hydrophilicity such that the contact angle with water is 0 ° and excellent in abrasion resistance is as follows. That is, an optical semiconductor-containing layer made of a mixture of titania and tin oxide is formed on the surface of the base material. The ratio of tin oxide to the total of titania and tin oxide is 1 to
It can be 95% by weight, preferably 1 to 50% by weight. Any of the following methods can be adopted for forming the optical semiconductor-containing layer made of tin oxide-containing titania.

(1) A suspension containing particles of anatase type or rutile type titania and tin oxide particles is applied to the surface of a base material and sintered at a temperature below the softening point of the base material. (2) Tin oxide particles are added to a solution of an amorphous titania precursor (organic titanium compound such as titanium alkoxide, chelate, or acetate, or an inorganic titanium compound such as TiCl ₄ or Ti (SO ₄ ) ₂ ). Apply the dispersed suspension to the surface of the base material and apply the titanium compound from room temperature to 2
By subjecting to hydrolysis and dehydration polycondensation at a temperature of 00 ° C., a thin film of amorphous titania in which tin oxide particles are dispersed is formed. Then, the amorphous titania is phase-changed into crystalline titania by heating the titania to a temperature above the crystallization temperature and below the softening point of the substrate.

Still another preferred method of forming a photosemiconductor layer exhibiting a high degree of hydrophilicity such that the contact angle with water of the silicone paint containing photosemiconductor is 0 ° is uncured or partially cured silicone ( It is to use a composition in which photo-semiconductor particles are dispersed in a film-forming element composed of an organopolysiloxane) or a silicone precursor. When this composition is applied to the surface of a base material and the film-forming element is cured, and then the photo-semiconductor is photoexcited, the organic group bonded to the silicon atom of the silicone molecule is replaced with a hydroxyl group by the action of the photo-semiconductor, The surface of the semiconductor-containing layer is made hydrophilic.

There are several advantages to this approach. Since the photo-semiconductor-containing silicone coating can be cured at room temperature or a relatively low temperature, it can be applied to non-heat resistant materials such as plastics and organic materials. This coating composition containing an optical semiconductor can be applied to an existing base material whose surface needs to be hydrophilized by dipping, brush coating, spray coating, roll coating or the like at any time, if necessary. Hydrophilization of an optical semiconductor by photoexcitation can be easily performed with a light source such as sunlight.

Furthermore, when a coating film is formed on a plastically workable base material such as a steel plate, it is possible to easily plastically process the steel plate as necessary after curing the coating film and before photoexcitation. it can. Before photo-excitation, the organic group is bonded to the silicon atom of the silicone molecule, so the coating film has sufficient flexibility, so it is possible to easily plastically process the steel sheet without damaging the coating film. You can After the plastic working, when the photo-semiconductor is photoexcited, the organic group bonded to the silicon atom of the silicone molecule is replaced with a hydroxyl group by the photo-semiconductor action, and the surface of the coating film is made hydrophilic.

Since the photo-semiconductor-containing silicone composition has a siloxane bond, it has sufficient resistance to the photo-oxidation action of the photo-semiconductor. Still another advantage of the photo-semiconductor-containing layer made of a photo-semiconductor-containing silicone coating is that after the surface is once hydrophilized, the photo-semiconductor-containing layer maintains hydrophilicity for a long period of time even if kept in a dark place, and it has a property like a fluorescent lamp. It is to recover the hydrophilicity even with the light of the interior lighting.

As the film forming element, methyltrichlorosilane, methyltribromosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltri-t-butoxysilane; ethyltrichlorosilane, ethyltribromosilane, Ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltri-t-butoxysilane; n-propyltrichlorosilane, n-propyltribromosilane, n-propyltrimethoxysilane,
n-propyltriethoxysilane, n-propyltriisopropoxysilane, n-propyltri-t-butoxysilane; n-hexyltrichlorosilane, n-hexyltribromosilane, n-hexyltrimethoxysilane, n
-Hexyltriethoxysilane, n-hexyltriisopropoxysilane, n-hexyltrit-butoxysilane; n-decyltrichlorosilane, n-decyltribromosilane, n-decyltrimethoxysilane, n-decyltriethoxysilane, n -Decyltriisopropoxysilane, n-decyltri-t-butoxysilane; n-octadecyltrichlorosilane, n-octadecyltribromosilane, n-octadecyltrimethoxysilane, n-octadecyltriethoxysilane, n-octadecyltriisopropoxysilane, n-octadecyltri-t-butoxysilane; phenyltrichlorosilane, phenyltribromosilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriisopropoxysilane, phenyltrisilane -Butoxysilane; tetrachlorosilane, tetrabromosilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane; dimethyldichlorosilane, dimethyldibromosilane, dimethyldimethoxysilane, dimethyldiethoxysilane; diphenyldisilane Chlorosilane, diphenyldibromosilane, diphenyldimethoxysilane,
Diphenyldiethoxysilane; phenylmethyldichlorosilane, phenylmethyldibromosilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane; trichlorohydrosilane, tribromohydrosilane, trimethoxyhydrosilane, triethoxyhydrosilane, triisopropoxyhydrosilane, tri-t -Butoxyhydrosilane; vinyltrichlorosilane, vinyltribromosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane,
Vinyltri-t-butoxysilane; trifluoropropyltrichlorosilane, trifluoropropyltribromosilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, trifluoropropyltriisopropoxysilane, trifluoropropyltrit-butoxysilane; γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriisopropoxy Silane, γ-glycidoxypropyltri-t-butoxysilane; γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryl Riloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltriisopropoxysilane, γ-methacryloxypropyltri-t-butoxysilane; γ-aminopropylmethyldimethoxysilane, γ- Aminopropylmethyldiethoxysilane, γ
-Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropyltri-t-butoxysilane; γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane , Γ-mercaptopropyltrimethoxysilane, γ-
Mercaptopropyltriethoxysilane, γ-mercaptopropyltriisopropoxysilane, γ-mercaptopropyltri-t-butoxysilane; β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β-
(3,4-epoxycyclohexyl) ethyltriethoxysilane; and their partial hydrolysates; and mixtures thereof can be used.

In order to ensure good hardness and smoothness of the silicone coating, 10 mol% of three-dimensional cross-linking siloxane is used.
It is preferable to contain the above. Further, in order to provide sufficient flexibility of the coating film while ensuring good hardness and smoothness, it is preferable to contain the two-dimensional crosslinked siloxane in an amount of 60 mol% or less. Further, in order to increase the rate at which the organic group bonded to the silicon atom of the silicone molecule is replaced with a hydroxyl group by photoexcitation, use a silicone in which the organic group bonded to the silicon atom of the silicone molecule is an n-propyl group or a phenyl group. Is preferred. Instead of the silicone having a siloxane bond, an organopolysilazane compound having a silazane bond can be used.

Addition of antibacterial enhancer The photo-semiconductor-containing layer can be doped with a metal such as Ag, Cu or Zn. In order to dope an optical semiconductor with Ag, Cu, or Zn, soluble salts of these metals are added to a suspension of optical semiconductor particles, and the resulting solution is used to form an optical semiconductor-containing layer. it can. Alternatively, after forming the photo-semiconductor-containing layer, soluble salts of these metals may be applied and photo-reduced to be precipitated by light irradiation.

The photo-semiconductor-containing layer doped with Ag, Cu, or Zn can kill bacteria adhering to the surface. Further, this optical semiconductor-containing layer is a mold, algae,
Inhibits the growth of moss-like microorganisms. Therefore, the surface of the washbasin bowl can be kept clean for a long period of time.

[0041] doped optical semiconductor-containing layer of the optical activity enhancer further, Pt, Pd, Rh, R
It can be doped with platinum group metals such as u, Os, Ir. Similarly, these metals can be doped into the optical semiconductor by photoreduction precipitation or addition of a soluble salt. When the optical semiconductor is doped with a platinum group metal, the redox activity of the optical semiconductor can be enhanced, and contaminants attached to the surface can be decomposed.

Photoexcitation / Ultraviolet Irradiation In the present invention, it is preferable that the optical semiconductor-containing layer is formed of an optical semiconductor such as titania which has a high band gap energy and is photoexcited only by ultraviolet rays. In that case, visible light is not absorbed by the optical semiconductor-containing layer, and the bowl is not colored by the complementary color component. Anatase-type titania can be photoexcited with ultraviolet rays having a wavelength of 387 nm or less, rutile-type titania of 431 nm or less, tin oxide of 344 nm or less, and zinc oxide of 387 nm or less.

As the ultraviolet light source, a fluorescent lamp, an incandescent lamp,
Interior lighting such as metal halide lamps and mercury lamps can be used. Under the conditions of exposure to sunlight, the photosemiconductor is naturally spontaneously photoexcited by the ultraviolet rays contained in sunlight.

Photoexcitation has a surface contact angle with water of preferably about 10 ° or less, more preferably about 5 ° or less, and particularly about 0 °.
It can be performed until it reaches or it can be performed. Generally, if photoexcited with an ultraviolet illuminance of 0.001 mW / cm ² ,
It can be made superhydrophilic until the contact angle with water becomes about 0 ° in a few days. Since the illuminance of ultraviolet rays contained in sunlight falling on the surface of the earth is about 0.1 to 1 mW / cm ² , the surface can be made superhydrophilic in a shorter time by exposing to sunlight.

When the photo-semiconductor-containing layer is formed of titania-containing silicone, the photocatalyst is photoexcited with sufficient illuminance so that the surface organic group bonded to the silicon atom of the silicone molecule is replaced with a hydroxyl group in a sufficient amount. Is preferred.
The most advantageous way to do this is to use sunlight. Once the surface is highly hydrophilized, the hydrophilicity persists at night. Each time it is exposed to sunlight again, the hydrophilicity is restored and maintained. When providing the washbasin bowl of the present invention to the user, it is desirable to make the bowl surface super-hydrophilic in advance.

In the present invention, the thickness of the surface layer containing the optical semiconductor is preferably less than 0.2 μm. This is to prevent white turbidity or interference fringes that impair aesthetics.

[0047]

Embodiments of the present invention will be described below. FIG.
It is sectional drawing which shows the outline of a structure of the washbasin bowl which concerns on one Example of this invention. The body 3 of the washbasin bowl 1 of FIG. 1 is made of pottery. The bowl surface 5 which is the upper concave surface of the bowl body 3
An optical semiconductor (titanium oxide) -containing layer described later in detail is formed in the.

A large number of washing water ports 14 are opened inside the upper edge of the bowl body 3. The wash water port 14 communicates with a wash water passage 13 that is annularly provided in the upper edge portion of the bowl body 3. A wash water pipe 19 is connected to the wash water passage 13 to supply tap water. That is, when the flush valve 21 provided in the flush water pipe 19 is opened,
Water enters the wash water passage 13 from the wash water pipe 19 and flows out from the wash water port 14 into the bowl surface 5 (wash water 15).

An ultraviolet lamp 11 is arranged on a part of the upper edge of the bowl body 3. The ultraviolet lamp 11 irradiates the bowl surface 5 with ultraviolet light to optically excite the photo-semiconductor layer on the surface of the bowl surface 5 to exhibit hydrophilicity and antibacterial action. UV lamp 11
A light-shielding cover 7 is provided on the upper part of the lamp to cover the upper part of the lamp.
Is provided. The cover 7 protects a user of the bowl 1 (standing on the right side of the drawing) from being exposed to ultraviolet rays.

An optical sensor 9 is installed on the upper surface of the cover 7. The optical sensor 9 detects the presence of the user. By the signal of the presence or absence of the user captured by the sensor 9,
The ultraviolet lamp 11 and the flush valve 21 are controlled as described below.

FIG. 2 is a block diagram showing the configuration of the control system of the washbasin bowl of FIG. The control device 31 controls the ultraviolet lamp 11 and the flush valve 21 based on the signal from the optical sensor 9 and the time information from the built-in timer 33. There are the following control methods. The UV lamp is turned on for a certain period of time and the water washing valve is opened. As a result, the bowl surface 5 is made hydrophilic and washed. Turn on the ultraviolet lamp only at night. The implication is that once hydrophilized, its surface can be maintained in that state for about one day, so if it was reset to 0 in the morning, that state can be maintained during use. Also, it is suitable for performing the above operation at night, especially in public restrooms and the like, where there are few people coming and going. The use of the wash basin bowl is detected by opening and closing the optical sensor 9 and the faucet 2, and after every use, the ultraviolet lamp is turned on and the flush valve is opened. The implications are that cleaning with water that does not contain filth is expected to have a better effect, and in public toilets and restrooms that are frequently used, wash surfaces that are always clean before the user. This is so that the ball can be served.

An example (experiment) relating to the material treatment of the bowl surface will be described below. Example 1 A tile plate having the same composition as that of sanitary ware was prepared, and a mixture of anatase-type titanium oxide sol and silica sol was applied onto the tile plate and baked at 930 ° C. to form a titania-silica mixed layer on the tile surface. During this time, the titanium oxide particles in the surface layer changed phase to rutile type during the firing. The obtained sample was irradiated with a BLB lamp at an illuminance of 0.5 mW / cm ² for 1 day.
The specific composition of the above mixture was 1 part by weight of rutile type titania and 1 part by weight of silica.

Example 2 A tile plate having the same composition as that of sanitary ware was prepared, and a mixture of anatase type titanium oxide sol and silica sol was applied on the tile plate and baked at 930 ° C. to form a titania-silica mixed layer on the tile surface. . During this time, the titanium oxide particles in the surface layer changed phase to rutile type during the firing. Then, an aqueous solution of silver nitrate was applied to the tile to fix silver on the titania-silica mixed layer by photoreduction. The obtained sample was irradiated with a BLB lamp at an illuminance of 0.5 mW / cm ² for 1 day. The specific composition of the mixture is 100 parts by weight of rutile type titania, 100 parts by weight of silica, and 0.2 parts by weight of silver.

Example 3 A tile plate having the same composition as that of sanitary ware was prepared, and anatase-type titanium oxide sol and tetraethoxysilane were applied on it and dried at 100 ° C. During this time, tetraethoxysilane was hydrolyzed and dehydrated and polymerized into amorphous silica. A BLB lamp was applied to the obtained sample with an illuminance of 0.5 mW / cm ²
For 1 day. The specific composition of the mixture is 1 part by weight of anatase and 1 part by weight of amorphous silica.

Example 4 A tile plate having the same composition as that of sanitary ware was prepared, and anatase-type titanium oxide sol, silver nitrate and tetraethoxysilane were coated on the tile plate and dried at 100 ° C. During this time, tetraethoxysilane was hydrolyzed and dehydrated and polymerized into amorphous silica. A BLB lamp was applied to the obtained sample with an illuminance of 0.
Irradiation was carried out at 5 mW / cm ² for 1 day. The specific composition of the mixture is 50 parts by weight of anatase, 50 parts by weight of amorphous silica,
Silver nitrate is 2 parts by weight in terms of silver weight.

Comparative Example A tile plate having the same composition as sanitary ware was irradiated with a BLB lamp for 1 day at an illuminance of 0.5 mW / cm ² .

The following items were evaluated for each of the obtained samples. Contact angle with water Examples 1 to 4 showed a high contact angle of 0 ° and a high degree of hydrophilicity. On the other hand, the comparative example had a contact angle of 30 °.

Antibacterial property The antibacterial property was tested under the following conditions. As a result, silver-doped Examples 2 and 4 showed good antibacterial property with a viability of less than 10%. On the other hand, the survival rate is 7 in the comparative example.
When it was 0% or more, no antibacterial property was observed.

Soil Removability Under the following conditions, the soil liquid removability containing soap residue and lard was examined by changing the glossiness of the bowl surface.
No. 4 maintained the glossiness of 90% or more, and all were good. On the other hand, the comparative example showed that the glossiness was 60% or less, and it was easily stained.

[0060]

As is apparent from the above description, the present invention can provide a washbasin bowl that is excellent in cleanliness in a washbasin bowl such as a washstand and a hand wash because it is unlikely to have soap residue or grease stains.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the outline of the configuration of a washbasin bowl according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control system of the washbasin bowl of FIG.

[Explanation of symbols]

 1 Washbasin bowl 2 Faucet 3 Bowl body 5 Bowl surface 7 Shading cover 9 Optical sensor 11 Ultraviolet lamp 13 Wash water passage 14 Wash water port 15 Wash water 17 Drain port 19 Wash water pipe 21 Wash valve 31 Control device 33 Timer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B32B 27/18 B32B 27/18 Z (72) Inventor Toshiya Watanabe 2 Nakajima, Kokurakita-ku, Kitakyushu, Fukuoka No. 1-1 No. 1 Totoki Co., Ltd. (72) Inventor Eiichi Kojima 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu, Kitakyushu, Fukuoka Prefecture (72) Inventor Atsushi Kitamura Kokura Kitakyushu, Fukuoka 2-1-1 Nakajima, Kita-ku Totoki Equipment Co., Ltd.

Claims (21)

[Claims] 1. A washbasin bowl having a bowl surface covered with a surface layer containing an optical semiconductor, the bowl surface exhibiting hydrophilicity in response to photoexcitation of the optical semiconductor. 2. A bowl surface covered with a surface layer containing a photo-semiconductor and silicone, and corresponding to photo-excitation of the photo-semiconductor, bonded to a silicon atom in a silicone molecule present on the surface of the surface layer. A washbasin bowl characterized in that an organic group is substituted with a hydroxyl group and the bowl surface exhibits hydrophilicity. 3. A washbasin bowl having a bowl surface covered with a surface layer containing an optical semiconductor and silica, wherein the bowl surface exhibits hydrophilicity in response to photoexcitation of the optical semiconductor. 4. The washbasin bowl according to claim 1, wherein the optical semiconductor is rutile type titanium oxide. 5. The surface layer further comprises platinum, ruthenium,
The washbasin bowl according to any one of claims 1 to 4, comprising at least one of palladium, rhodium, osmium, and iridium. 6. The washbasin bowl according to claim 1, wherein the surface layer further contains an antibacterial metal. 7. The washbasin bowl according to claim 6, wherein the antibacterial metal is at least one of silver, copper and zinc. 8. As a hydrophilic action, the bowl surface can be cleaned by rinsing water on the bowl surface to wash away deposits and / or contaminants attached to the bowl surface. ~ The washbasin bowl according to any one of claims 7 to 7. 9. The photocatalytic action of the photosemiconductor can kill or reduce the bacteria and / or fungi attached to the bowl surface in response to the photoexcitation of the photosemiconductor. The washbasin bowl described. 10. The washbasin bowl according to claim 1, wherein the photo-excitation of the optical semiconductor is performed by indoor illumination. 11. In order to perform photoexcitation of the optical semiconductor,
The washbasin bowl according to any one of claims 1 to 9, further provided with an irradiation means capable of emitting the excitation wavelength of the optical semiconductor. 12. The optical semiconductor according to claim 11, wherein the optical semiconductor is crystalline titanium oxide, the irradiating means is an ultraviolet irradiating means, and the irradiating means is provided with a cover for blocking direct sight of a user. Washbasin bowl. 13. The irradiation means comprises a timer and ON / O.
12. A washbasin bowl according to claim 11, wherein FF means is connected and said means is illuminated at regular time intervals. 14. The irradiation means comprises a timer and ON / O.
A washbasin bowl according to claim 11, wherein FF means are connected and the means are illuminated only at night. 15. A bowl use detecting means is additionally provided, and the irradiating means irradiates at regular intervals after use.
The washbasin bowl described in 1. 16. The washbasin bowl according to any one of claims 11 to 15, further comprising a timer and a flushing means connected to each other so that the bowl surface is rinsed with running water at the same time and / or before and after the light irradiation. 17. The washbasin bowl according to claim 1, wherein the surface layer has a thickness of 0.2 μm or less. 18. A step of preparing a wash basin having a bowl surface coated with a layer containing an optical semiconductor, a step of making the surface of the layer hydrophilic by photoexciting the optical semiconductor, and a step of making the bowl surface water. A method of cleaning a washbasin bowl surface, comprising the step of releasing deposits and / or contaminants adhering to the surface of the layer by rinsing with water. 19. A step of preparing a wash basin having a bowl surface coated with a layer containing an optical semiconductor and silicone, the organic compound being bonded to a silicon atom of a silicone molecule on the surface of the layer by photoexciting the optical semiconductor. A step of substituting a group with a hydroxyl group, a step of further photoexciting the photo-semiconductor to make the surface of the layer hydrophilic, a deposit attached to the surface of the layer by rinsing the bowl surface with water, and / or
Alternatively, a method of cleaning the surface of a washbasin bowl is characterized by including the step of releasing contaminants from the surface. 20. Preparing a wash basin having a bowl surface coated with a layer containing an optical semiconductor and an antibacterial metal,
Making the surface of the layer hydrophilic by photoexciting the photosemiconductor, rinsing the bowl surface with water to release deposits and / or contaminants adhering to the surface of the layer from the surface; A method of cleaning a washbasin bowl surface, comprising a step of killing or reducing bacteria and / or fungi attached to the surface of the layer by the antibacterial action of the antibacterial metal. 21. A step of preparing a wash basin having a bowl surface coated with a layer containing an optical semiconductor, silicone and an antibacterial metal, the silicon atom of a silicone molecule on the surface of the layer by photoexciting the optical semiconductor. A step of substituting a hydroxyl group for an organic group bound to, a step of further photoexciting the photo-semiconductor to make the surface of the layer hydrophilic, and a step of rinsing the bowl surface with water to deposit on the surface of the layer Releasing objects and / or contaminants from the surface,
A method of cleaning a washbasin bowl surface, comprising a step of killing or reducing bacteria and / or fungi attached to the surface of the layer by the antibacterial action of the antibacterial metal.