JPH10201655A - Bathtub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make water drops hardly adhere to the surface of the apron part of a bathtub over a long period by forming a surface layer containing an optical catalyst particle, water repelling silicone, and a material for preventing the water repelling silicone from being hydrophilic by the optical excitation of the optical catalyst on the apron part surface of the bathtub. SOLUTION: On the surface of the apron part base material of a bathtub, a surface layer containing an optical catalyst particle, silicone, and a material for preventing the silicone from being hydrophilic by the optical excitation of the optical catalyst such as cobalt or a cobalt compound is formed. Otherwise, a layer containing an optical catalyst particle and water repelling silicone is formed, and a material for preventing the water repelling silicone from being hydrophilic by the optical excitation of the optical catalyst such as cobalt or a cobalt compound is fixed to at least a part of this layer surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bathtub which is less likely to cause water stains on an apron.

[0002]

2. Description of the Related Art Hollow, polyester, marbright, stainless steel, FRP, acrylic and the like are used in bathtubs. It is often observed that white algae-like stains are formed on the apron of the bathtub.
In particular, in the case of a blue hollow bathtub, the stains are conspicuous because the contrast with the background is large, and there is a problem that the beauty, texture and luxury of the hollow bathtub are impaired.

[0003]

It is considered that the water stain occurs as follows. In other words, calcium ions and the like contained in the attached water droplets remaining in the apron portion of the bathtub react with carbon dioxide in the air to form a salt such as calcium carbonate, which is dried as the waterdrops dry and becomes a surface of the apron portion of the bathtub. It precipitates and is fixed. Therefore, in order to prevent water stains from being generated on the apron portion of the bathtub and not to impair the aesthetics, texture and luxury of the bathtub, a bathtub in which water droplets hardly adhere and remain on the apron portion of the bathtub is desired.

[0004] As a method of preventing the adhesion of water droplets, it is known that it is better to impart water repellency to the surface of a substrate. 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, when exposed to sunlight outdoors, the silicone is hydrophilized by 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 surface of an apron portion of a bathtub for a long time, and to provide a bathtub that does not easily adhere to water droplets on the surface of the apron portion of the bathtub for a long time. And

[0005]

According to the present invention, in order to solve the above-mentioned problems, photocatalyst particles are provided on an apron surface of a bathtub.
A substantially transparent surface layer containing a water-repellent silicone and a substance for preventing the water-repellent silicone from being hydrophilized by photoexcitation of the photocatalyst is formed, or on a substrate surface, A substantially transparent layer containing photocatalyst particles and water-repellent silicone is formed, and at least a part of the surface of the layer is used to prevent the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst. A bathtub characterized in that the substance is fixed. 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. In addition, since the photocatalyst is contained, it is possible to decompose the dirt adhering with time based on the oxidative decomposability of the photocatalyst. Therefore, the water repellency of the apron surface of the bathtub can be maintained permanently, and a bathtub to which water droplets are unlikely to adhere for a long time can be provided.

[0006] In a preferred embodiment of the present invention, the surface of the apron section of the bathtub is not horizontal. By doing so, the water droplets flow from a high place to a low place in the apron part, so that they are less likely to adhere and remain, so that water stains are less likely to occur in the apron part of the bathtub.

In a preferred embodiment of the present invention, the inside of the bathtub is inclined so as to be higher than the outside of the bathtub. By doing so, since the water droplets flowing in the apron portion are not dropped into the bathtub, the bath can be used more comfortably when taking a bath.

[0008]

FIG. 1 is a plan view showing an example of a bathtub according to the present invention. 2 and 3 are enlarged cross-sectional views of an essential part showing an example of an apron surface of a bathtub. In FIG. 2, photocatalyst particles, silicone, and
A surface layer containing a substance for preventing hydrophilicity due to photoexcitation of a photocatalyst such as cobalt or a cobalt compound is formed. In FIG. 3, a layer containing photocatalyst particles and a water-repellent silicone is formed, and at least a part of the surface of the layer is hydrophilized by photoexcitation of a photocatalyst of a water-repellent silicone such as cobalt or a cobalt compound. The substance to prevent is fixed. For the material of the bathtub, as before,
Hollow, polyester, mar bright, stainless steel,
FRP, acrylic, etc. can be used. An intermediate layer made of silicon, amorphous silica, acrylic silicon or the like may be provided between the 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. Illumination such as sunlight, a fluorescent lamp, an incandescent lamp, a metal halide lamp, a mercury lamp, and a xenon lamp can be used as a light source used for photoexcitation of the photocatalyst. For the photocatalyst is photoexcited, the illuminance of the excitation light may be at 0.001 mW / cm ² or more, but preferably that it 0.01 mW / cm ² or more, 0.
More preferably, it is 1 mW / cm ² or more.

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, a 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 in 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.

Here, the precursor of the silicone is an average compositional formula of R _p SiX _q O _{(4-pq) / 2} (where R is a functional group comprising one or more monovalent organic groups) 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 above-mentioned siloxane includes partial hydrolysis and dehydration-condensation polymerization of the above-mentioned hydrolyzable silane derivative, or partially hydrolyzate of the above-mentioned 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.

Next, a layer containing the photocatalyst particles and the water-repellent silicone is formed on the surface of the substrate, and at least a part of the layer surface is formed by the 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.

[0024] 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 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 becoming hydrophilic by photoexcitation and fixing the solution on the surface is exemplified by, for example, cobalt chloride, cobalt sulfate, cobalt iodide, and bromide. 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.

[0029]

【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 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 stirred for 2-3 hours. Coating on a 10 cm square hollow steel plate substrate coated with silica by a coating method and heat-treating at 150 ° C. for 30 minutes to obtain 11 parts by weight of anatase type titanium oxide particles and silica 6
A # 4 sample having a surface layer composed of 5 parts by weight of silicon, 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 was 97 °. Here, the contact angle with water is measured using a contact angle measuring device (Kyowa Interface Science, CA-X150).
The evaluation was made based on the contact angle with water 30 seconds after the water droplet was dropped from the micro syringe. Next, the surface of the # 4 sample was irradiated with ultraviolet light of 0.3 mW / cm ² for one day using an ultraviolet light source (Sankyo Electric, Black Light Blue (BLB) fluorescent lamp) 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. Further, when the # 5 sample was tilted, the water droplets fell while rolling.

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)
, Methyltrimethoxysilane (Nippon Synthetic Rubber, Glasca B solution) and ethanol were mixed, and the coating solution obtained by stirring for 2 to 3 hours was coated with silica by a spray coating method. 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, which is applied on a 10 cm square hollow steel base material and heat-treated at 150 ° C. for 30 minutes. Was formed. Further, 0.3 g of an aqueous solution of cobalt chloride hexahydrate having a cobalt metal concentration of 50 μmol / g was applied thereon, and then an ultraviolet illuminance of 0.4 mW / The cobalt was fixed on the substrate by irradiating it with ultraviolet rays of cm ² for 10 minutes to obtain a # 6 sample. The contact angle of the # 6 sample with water was 97 °. 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 Blue (BLB) fluorescent lamp) was placed on the # 6 sample surface.
And irradiated with ultraviolet light of 0.3 mW / cm ² for one 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. When the # 7 sample was tilted, the water droplets fell while rolling.

[0032]

According to the present invention, in the bathtub, on the surface of the apron portion, photocatalyst particles, water-repellent silicone, and a substance for preventing the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst. A layer containing photocatalyst particles and a water-repellent silicone is formed on the surface of the apron portion, and the water-repellent silicone is formed on at least a part of the surface of the layer. The apron surface can maintain water repellency for a long period of time by fixing a substance for preventing hydrophilicity of the photocatalyst by photoexcitation of the photocatalyst, so that a bathtub that can prevent water droplet adhesion for a long time can be provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a view showing a surface structure of a bathtub apron section of the present invention.

FIG. 2 is a diagram showing another surface structure of the bathtub apron section of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 27/18 B32B 27/18 Z33 / 00 33/00 C08K 3/20 C08K 3/20 C08L 83/04 C08L 83/04

Claims (5)

[Claims] 1. A photocatalyst particle on a surface of a bathtub apron part,
A bath tub comprising a surface layer containing a water-repellent silicone and a substance for preventing the water-repellent silicone from becoming hydrophilic by photoexcitation of the photocatalyst. 2. A substantially transparent layer containing photocatalyst particles and a water-repellent silicone is formed on the surface of a bathtub apron, and at least a part of the surface of the layer is formed of the water-repellent silicone. A bath tub on which a substance for preventing the photocatalyst from becoming hydrophilic by photoexcitation is fixed. 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. 4. The bathtub according to claim 1, wherein the surface of the bathtub apron is not horizontal. 5. The bathtub according to claim 4, wherein the surface of the bathtub apron is inclined so that the inside of the bathtub is higher than the outside of the bathtub.