JPH10229950A - Bathtub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bathtub so that scale can hardly be adhered to the water vapor-liquid boundary face. SOLUTION: The inside surface of this bathtub is provided with a substantially-transparent surface layer containing photocatalytic particles, a water repellent silicone and a substance for preventing the silicone from becoming hydrophilic due to optical excitation by the photocatalyst, or with such a layer containing photocatalytic particles and the water repellent silicone and further a substance fixed at least on a part of this layer for preventing the silicone from becoming hydrophilic due to optical excitation by the photocatalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bathtub to which dirt hardly adheres to a brackish water surface.

[0002]

2. Description of the Related Art Soil components in bathtubs are roughly classified into scales and scales. The descaling is composed of dirt, lipids and soap scum discharged by humans, and adheres intensively to the brackish water surface. The scale is composed of bacteria, microorganisms and proteins, lipids, calcium carbonate, etc., and is mainly generated by immersion of bath water, drying at the time of spouting, and drying after dehydration. A particularly difficult and laborious task in cleaning a bathtub has been cleaning dirt stuck to a brackish water surface.

[0003]

Therefore, there is a need for a bathtub in which dirt hardly adheres to the brackish water surface.

As a method for preventing the adhesion of dirt, it is known that it is better to impart water repellency to the surface of a substrate. When water repellency is imparted to the surface of the base material, the surface energy is significantly reduced, so that it becomes difficult for dirt components to adhere. As one of the methods, there is a method of forming a surface layer made of a water-repellent silicone on a substrate surface. However, with this structure, the contact angle with water is reduced to about 70 ° due to the adhesion of dirt over time, and the effect of water repellency is not maintained. Therefore, as another method for solving the above-mentioned problem, there is a method of forming a surface layer comprising a photocatalyst and a water-repellent silicone on the surface of a substrate. According to this method, it is possible to decompose the adhered dirt over time based on the oxidative decomposability of the photocatalyst. However, in this configuration, for example, when exposed to sunlight, the silicon becomes hydrophilic by the photoexcitation of the photocatalyst, so that the water repellency of the surface cannot be maintained. In view of the above circumstances, an object of the present invention is to provide a bathtub that can maintain the water repellency of the inner surface for a long period of time, and to provide a bathtub that is less likely to adhere dirt to a brackish water surface.

[0005]

According to the present invention, in order to solve the above-mentioned problems, photocatalyst particles and a water-repellent silicone are provided on the inner surface.
And a surface layer containing a substance for preventing hydrophilicity of the water repellent silicone by photoexcitation of the photocatalyst is formed, or the photocatalyst particles and the water repellent silicone are formed on the inner surface. A bath containing a water-repellent silicone, wherein a substance for preventing the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst is fixed to at least a part of the surface of the layer. I do. Preventing the silicon from becoming hydrophilic by photoexcitation of the photocatalyst by making the surface layer contain a substance such as cobalt or a cobalt compound for preventing the photocatalyst from becoming hydrophilic by photoexcitation. Can be. And because it contains a photocatalyst, based on the oxidative decomposability of the photocatalyst,
Dirt that adheres over time can be broken down. Therefore, the water repellency of the inner surface can be maintained, and the bathtub is less likely to adhere to the brackish surface.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In one embodiment of the present invention, as shown in FIG. 1, a bathtub according to the present invention comprises at least an inner surface of a bathtub containing photocatalyst particles, silicone, and a photocatalyst such as cobalt or a cobalt compound. A layer containing a substance for preventing hydrophilicity due to light excitation is formed. In another embodiment, as shown in FIG. 2, a layer containing photocatalyst particles and a water-repellent silicone is formed on at least the inner surface of the bath, and at least a part of the surface of the layer is formed on the layer. A substance for preventing hydrophilicity due to photoexcitation of a photocatalyst of a water-repellent silicone such as cobalt or a cobalt compound is fixed. An intermediate layer of silica, silicone, acrylic silicon or the like may be provided between the bathtub substrate and the surface layer.

A photocatalyst has an energy greater than the energy gap between the conduction band and the valence band of the crystal.
A substance capable of generating conduction electrons and holes by excitation of electrons in the valence band (photoexcitation) when irradiated with light (excitation light) having a short wavelength (excitation light).
Oxides such as zeta-type titanium oxide, zinc oxide, tin oxide, ferric oxide, bismuth trioxide, tungsten trioxide and strontium titanate can be suitably used. In order to optically excite the photocatalyst, a light source such as a fluorescent lamp, an incandescent lamp, a black light, a xenon lamp, a mercury lamp, and a germicidal lamp is used. As these light sources, dedicated light sources may be used, or indoor lighting of a bathroom may be used.

The silicone has an average composition formula R _p SiO _{(4-p) / 2} (where R is a functional group comprising one or more monovalent organic groups, or a monovalent organic group) A resin represented by the following formula: X is an alkoxy group or a halogen atom, and p is a number satisfying 0 <p <2. Is available.

As the cobalt compound, cobalt alloy, cobalt oxide, cobalt chloride, cobalt sulfate, cobalt iodide, cobalt bromide, cobalt acetate, cobalt chlorate, cobalt nitrate and the like can be suitably used.

The thickness of the surface layer is preferably set to 0.4 μm or less. Then, cloudiness due to irregular reflection of light can be prevented, and the surface layer becomes substantially transparent. Further, it is more preferable that the thickness of the surface layer be 0.2 μm or less. Then, it is possible to prevent the surface layer from being colored by light interference. Also, the thinner the surface layer, the better its transparency. Further, when the film thickness is reduced, the wear resistance of the surface layer is improved.

A metal such as Ag, Cu and Zn can be added to the surface layer. The surface layer to which the metal is added can kill bacteria and fungi attached to the surface even in a dark place.

Pt, Pd, Ru, Rh, I
A platinum group metal such as r or Os can be added.
The surface layer to which the metal is added can enhance the redox activity of the photocatalyst, and can improve the decomposability of organic contaminants and the decomposability of harmful gases and odors.

Next, a surface layer containing photocatalyst particles, water-repellent silicone, and a substance for preventing the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst is formed on the surface of the substrate. The method of manufacturing the water-repellent member described above will be described. The production method in this case is basically based on applying a coating composition on the surface of a substrate and curing the coating composition.

Here, the coating composition contains a precursor of silicon as an essential component of a substance for preventing photocatalytic particles, cobalt or a cobalt compound or the like from becoming hydrophilic by photoexcitation of a photocatalyst. Solvents such as ethanol and propanol, catalysts that promote hydrolysis of silicone precursors such as hydrochloric acid, nitric acid, sulfuric acid, acetic acid and maleic acid, and basic compounds such as tributylamine and hexylamine Silicon compounds such as acidic compounds such as aluminum, aluminum triisopropoxide and tetraisopropyl titanate;
And a surfactant for improving the dispersibility of the coating liquid such as a silane coupling agent.

As cobalt or a cobalt compound, a water-soluble cobalt compound is preferably used. As the water-soluble cobalt compound, for example, cobalt chloride, cobalt sulfate, cobalt iodide, cobalt bromide, cobalt acetate, cobalt chlorate, cobalt nitrate and the like can be suitably used.

[0016] Here silicone - The precursor emissions in the average composition formula _{R p SiX q O (4-} pq) / 2 ( wherein, R consists of one or more organic groups monovalent functional X or a functional group comprising two or more selected from a monovalent organic group and a hydrogen group, X is an alkoxy group or a halogen atom, and p and q are 0 <p <2, 0 <
a film-forming element composed of a siloxane represented by the following formula: q <4) or a general formula R _p SiX _4-p (where R is one or more monovalent organic groups) Wherein X is an alkoxy group or a halogen atom, and p is 1 or 2. A film-forming element comprising a hydrolyzable silane derivative to be
Can be suitably used.

Here, as the coating film forming element comprising the hydrolyzable silane derivative, methyltrimethoxysilane,
Methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, ethyltributoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, Phenyltributoxysilane,
Dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, diethyldibutoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, phenyl Methyldipropoxysilane, phenylmethyldibutoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltripropoxysilane, n-propyltributoxysilane, γ-glycoxydoxypropyltrimethoxysilane, γ -Acryloxypropyltrimethoxysilane and the like can be suitably used.

The film-forming element composed of the siloxane includes partial hydrolysis and dehydration-condensation polymerization of the hydrolyzable silane derivative, or partial hydrolyzate of the hydrolyzable silane derivative, tetramethoxysilane, tetramethoxysilane, It can be produced by dehydration polycondensation with a partial hydrolyzate such as ethoxysilane, tetrapropoxysilane, tetrabutoxysilane, diethoxydimethoxysilane and the like.

The coating method of the coating composition includes spray coating, dip coating, flow coating, spin coating, roll coating, brush coating, and sponge. A method such as coating can be suitably used. As a curing method, it can be carried out by polymerizing by heat treatment, standing at room temperature, ultraviolet irradiation, or the like.

Next, a layer containing photocatalyst particles and a water-repellent silicone is formed on the surface of the base material, and at least a part of the surface of the layer is formed by photoexcitation of the photocatalyst by the water-repellent silicone. A method for manufacturing a water-repellent member to which a substance for preventing hydrophilicity is fixed will be described. The production method in this case is basically based on the photo-excitation of a photocatalyst such as cobalt or a cobalt compound after coating and curing a coating composition containing photocatalyst particles and a water-repellent silicone precursor. By applying a solution containing a substance for preventing hydrophilization and fixing the solution to the surface.

Here, the coating composition has photocatalyst particles and a precursor of a water-repellent silicone as essential components, and in addition, a solvent such as water, ethanol, propanol, hydrochloric acid, nitric acid, and the like. Catalysts that promote the hydrolysis of silica precursors such as sulfuric acid, acetic acid and maleic acid, basic compounds such as tributylamine and hexylamine, and acidic compounds such as aluminum triisopropoxide and tetraisopropyl titanate Such as a catalyst for curing a precursor of silica,
A surfactant such as a silane coupling agent for improving the dispersibility of the coating liquid may be added.

[0022] Here silicone - The precursor emissions in the average composition formula _{R p SiX q O (4-} pq) / 2 ( wherein, R consists of one or more organic groups monovalent functional X or a functional group comprising two or more selected from a monovalent organic group and a hydrogen group, X is an alkoxy group or a halogen atom, and p and q are 0 <p <2, 0 <
a film-forming element composed of a siloxane represented by the following formula: q <4) or a general formula R _p SiX _4-p (where R is one or more monovalent organic groups) Wherein X is an alkoxy group or a halogen atom, and p is 1 or 2. A film-forming element comprising a hydrolyzable silane derivative to be
Can be suitably used.

Here, as the coating film forming element comprising the hydrolyzable silane derivative, methyltrimethoxysilane,
Methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, ethyltributoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, Phenyltributoxysilane,
Dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, diethyldibutoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, phenyl Methyldipropoxysilane, phenylmethyldibutoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltripropoxysilane, n-propyltributoxysilane, γ-glycoxydoxypropyltrimethoxysilane, γ -Acryloxypropyltrimethoxysilane and the like can be suitably used.

The film-forming element composed of the siloxane includes partial hydrolysis and dehydration-condensation polymerization of the hydrolyzable silane derivative, or a partial hydrolyzate of the hydrolyzable silane derivative, tetramethoxysilane, tetramethoxysilane and tetramethoxysilane. It can be produced by dehydration polycondensation with a partial hydrolyzate such as ethoxysilane, tetrapropoxysilane, tetrabutoxysilane, diethoxydimethoxysilane and the like.

The coating method of the above coating composition includes spray coating, dip coating, flow coating, spin coating, roll coating, brush coating, and sponge. A method such as coating can be suitably used. As a curing method, it can be carried out by polymerizing by heat treatment, standing at room temperature, ultraviolet irradiation, or the like.

The method of applying a solution containing a substance for preventing the photocatalyst such as cobalt or a cobalt compound from being hydrophilized by photoexcitation and fixing it on the surface includes, for example, cobalt chloride, cobalt sulfate, cobalt iodide, bromide, and the like. cobalt,
Spray coating method, dip coating method, flow coating method, spin coating method, roll coating method, brushing water-soluble cobalt compounds such as cobalt acetate, cobalt chlorate and cobalt nitrate Coating, sponge coating, etc., photoreduction, heat treatment, alcohol
This is performed by fixing by a method such as reduction using a sacrificial oxidizing agent such as toluene.

[0027]

【Example】

Reference example. Anatase type titanium oxide sol (Nissan Chemical, TA
-15, nitric acid peptized type, pH = 1), silica sol (Nippon Synthetic Rubber, Glasca A solution, pH = 4), methyltrimethoxysilane (Nippon Synthetic Rubber, Glasca B solution) and ethanol are mixed. The coating liquid obtained by stirring for 2 to 3 hours was applied on a 5 × 10 cm square glazed tile base material (TOTOKIKI, AB02E11) by spray coating.
A heat treatment was performed at 200 ° C. for 15 minutes to obtain a # 1 sample having a surface layer formed of 11 parts by weight of anatase type titanium oxide particles, 6 parts by weight of silica, and 5 parts by weight of silicone. The contact angle of the # 1 sample with water was 92 °. Here, the contact angle with water was evaluated using a contact angle measuring device (Kyowa Interface Science, CA-X150) by the contact angle with water 30 seconds after a water droplet was dropped from the micro syringe. Next, the surface of the # 1 sample was irradiated for one day with an ultraviolet illuminance of 0.3 mW / cm ² using an ultraviolet light source (Sankyo Electric, Black Light Blue (BLB) fluorescent lamp) to obtain a # 2 sample. As a result, the contact angle with water of the # 2 sample was hydrophilized to 0 °. Next, # 1 sample and #
One sample was irradiated with a mercury lamp at an ultraviolet irradiance of 22.8 mW / cm ² for 2 hours, and the surface of each of the # 3 samples obtained was subjected to Raman spectroscopic analysis. As a result, a peak of methyl group observed on the surface of sample # 1 was not observed in sample # 3, but a peak of hydroxyl group was observed instead. From the above,
It can be seen that the organic group bonded to the silicon atom in the silicon molecule on the surface of the film by the photoexcitation of the anatase type titanium oxide which is a photocatalyst is replaced by a hydroxyl group and becomes hydrophilic.

Embodiment 1 FIG. Anatase type titanium oxide sol (Nissan Chemical, TA-15, peptized nitrate, pH = 1),
Silica sol (Nippon Synthetic Rubber, Glasca A solution, pH = 4)
And methyltrimethoxysilane (Nippon Synthetic Rubber, Glasca B solution), cobalt chloride hexahydrate, and ethanol, and agitated for 2-3 hours. After coating with an acrylic silicon-based primer by a coating method, the composition is applied to a silicon-hard coated PMMA plate base material and heat-treated at 90 ° C. for 3 hours to obtain 11 parts by weight of anatase type titanium oxide particles. # 4 sample having a surface layer comprising 6 parts by weight of silica, 5 parts by weight of silicon, and 0.2 parts by weight of cobalt was obtained. The contact angle of the # 4 sample with water is 9
It was 7 ゜. Here, the contact angle with water was evaluated using a contact angle measuring device (Kyowa Interface Science, CA-X150) by the contact angle with water 30 seconds after a water droplet was dropped from the micro syringe. Next, an ultraviolet light source (Sankyo Electric,
Black Light Bull (BLB) fluorescent lamp).
Irradiation was performed at an ultraviolet illuminance of 3 mW / cm ² for 1 day to obtain a # 5 sample. As a result, the contact angle of the # 5 sample with water was still 95 °, maintaining water repellency. Therefore, it can be understood from the above that the hydrophilicity of the silicon on the surface of the coating film due to the photoexcitation of the anatase type titanium oxide as a photocatalyst is inhibited by cobalt. This is considered because the substitution of the hydroxyl group for the organic group bonded to the silicon atom in the silicon molecule on the surface of the coating is inhibited by cobalt.

Embodiment 2 FIG. Anatase type titanium oxide sol (Nissan Chemical, TA-15, peptized nitrate, pH = 1),
Silica sol (Nippon Synthetic Rubber, Glasca A solution, pH = 4)
, Methyl trimethoxysilane (Nippon Synthetic Rubber, Glasca B solution) and ethanol were mixed and stirred for 2 to 3 hours. Coated on a PMMA plate base material coated with a silicone hard coat after coating with a primer of
Heat treatment was performed for a time to form a surface layer comprising 11 parts by weight of anatase type titanium oxide particles, 6 parts by weight of silica, and 5 parts by weight of silicone. Furthermore, a cobalt metal concentration of 50μ
After applying 0.3 g of an aqueous solution of cobalt chloride hexahydrate (mol / g), an ultraviolet light source (Sankyo Electric, Black Light Blue)
(BLB) fluorescent light) using an ultraviolet illuminance of 0.4 mW / c
The substrate was irradiated with ultraviolet rays of m ² for 10 minutes to fix cobalt on the substrate, thereby obtaining a # 6 sample. The contact angle of the # 6 sample with water was 96 °. Here, the contact angle with water was evaluated using a contact angle measuring device (Kyowa Interface Science, CA-X150) by the contact angle with water 30 seconds after a water droplet was dropped from the micro syringe. Then, the surface of the sample # 6 was coated with an ultraviolet light source (Sankyo Electric, Black Light Blue- (BLB) fluorescent lamp) to 0.3
Irradiation was performed at an ultraviolet irradiance of mW / cm ² for 1 day to obtain a # 7 sample. As a result, the contact angle of the # 7 sample with water was still 94 °, maintaining water repellency. Therefore, it can be understood from the above that the hydrophilicity of the silicon on the surface of the coating film due to the photoexcitation of the anatase type titanium oxide as a photocatalyst is inhibited by cobalt. This is considered because the substitution of the hydroxyl group for the organic group bonded to the silicon atom in the silicon molecule on the surface of the coating is inhibited by cobalt.

Embodiment 3 FIG. The # 5 sample, the # 7 sample, and the polytetrafluoroethylene plate for comparison were immersed vertically in bath water so that the upper part was exposed to the air, allowed to stand for one week, and the adhesiveness of the scale attached to the brackish water surface Was examined. The adhesiveness of the descaling was examined by a change in the state when rubbed with a cloth after the test. As a result, the descaling of the # 7 sample was more clean than that of the polytetrafluoroethylene plate.

[0031]

According to the present invention, in the bathtub, on the inner surface,
A substantially transparent surface layer containing photocatalyst particles, water-repellent silicone, and a substance for preventing the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst is formed. Alternatively, a substantially transparent layer containing the photocatalyst particles and the water-repellent silicone is formed on the inner surface,
Further, a material for preventing the hydrophilicity of the water-repellent silicone by photoexcitation of the photocatalyst is fixed to at least a part of the surface of the layer, so that the surface of the member maintains the water-repellency for a long time. It becomes possible, and even if the attached scale is solidified, it does not firmly adhere to the brackish water surface.

[Brief description of the drawings]

FIG. 1 is a view showing a surface structure of an inner surface of a bathtub according to the present invention.

FIG. 2 is a diagram showing another surface structure of the inner surface of the bathtub according to the present invention.

Claims (3)

[Claims] 1. A surface layer containing photocatalyst particles, a water-repellent silicone, and a substance for preventing the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst is provided on at least an inner surface of the bathtub. A bathtub characterized by being formed. 2. A substantially transparent layer containing photocatalyst particles and a water-repellent silicone is formed on at least the inner surface of the bathtub, and the water-repellent silicone is formed on at least a part of the surface of the layer. A bath for fixing a substance for preventing the photocatalyst from becoming hydrophilic by light excitation. 3. The bathtub according to claim 1, wherein the substance for preventing the photocatalyst from becoming hydrophilic by photoexcitation is cobalt or a cobalt compound.