JPH1043078A - Bathtub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make water drops hard to stick and stay, and for this reason, make lime deposit hard to generate by microscopically dispersing hydrophilic parts of photocatalyst oxide particles, and water repellent parts of a water repellent fluororesin on the surface of the apron part of a bathtub. SOLUTION: On the surface of a bathtub apron part, a surface layer which has a structure wherein parts presenting hydrophilic property where photocatalyst oxide particles are exposed so as to come into contact with the outside air, and part presenting water repellent property where a water repellent fluororesin is exposed so as to come into contact with the outside air, are microscopically dispersed on the surface, and the contact angle with water of the surface of which, is 90 deg. or higher, is formed. For the photocatalyst oxide, e.g. an oxide such as anatase-type titanium dioxide, rutile-type titanium dioxide, and zinc oxide can be used. For a light source to be used for the optical excitation of the photocatalyst, e.g. a fluorescent lamp, an incandescent lamp, a metal halide lamp, and a mercury lamp, can be used. For the water repellent fluororesin e.g. polytetrafluoroethylene, polychlorotrifluoroethylene, and polyhexafluoropropylene, etc., can be used.

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 stain on a bathtub apron.

[0002]

2. Description of the Related Art Bathtubs are made of enamel, polyester, marbrite, stainless steel, FRP, acrylic or the like. It is often observed that the apron portion of the bathtub has a white ring-shaped stain, a scale stain. In particular, in the case of a blue enamel tub, the stain is conspicuous because the contrast with the background is large, and there is a problem that the aesthetic appearance, texture and luxury of the enamel tub are significantly 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. It precipitates and is fixed. Therefore, in the present invention, it is an object of the present invention to provide a bathtub to which water droplets adhere to an apron portion of a bathtub and are unlikely to remain. I do.

[0004]

According to the present invention, in order to solve the above-mentioned problems, a photocatalytic oxide particle is exposed on the surface of a bath apron portion so as to be in contact with the outside air, and a hydrophilic portion is provided. The surface layer having both a water-repellent portion exposed so as to be in contact with the outside air and having a structure in which both surfaces are microscopically dispersed and a contact angle of water on the surface with 90 ° or more is formed. A bathtub is provided. A structure in which both a hydrophilic part exposed to contact the photocatalytic oxide particles with the outside air and a water-repellent part exposed to the water-repellent fluororesin contact with the outside are microscopically dispersed on the surface. In this case, since the hydrophilic surface and the water-repellent surface are adjacent to each other, the hydrophilic adherent that easily adapts to the hydrophilic surface does not adapt to the adjacent water-repellent portion. Conversely, hydrophobic deposits that are easily adapted to the water-repellent surface do not adapt to adjacent hydrophilic portions. Therefore, neither the hydrophilic deposit nor the hydrophobic deposit is fixed to the member surface, and the surface is maintained in a clean state. Furthermore, the presence of a photocatalyst
Since the photocatalytic oxide particles exposed in contact with the outside air in response to the photoexcitation of the photocatalyst maintain the hydrophilic portion permanently, both the hydrophilic portion and the water-repellent portion are present. A structure that is microscopically dispersed on the surface is maintained. That is, when the contact angle with water is set to 90 ° or more, the state is maintained according to the photoexcitation of the photocatalyst, and it is difficult for water droplets to adhere. Therefore, it is possible to form a surface on which water droplets are not easily adhered, and it is possible to provide a bathtub which does not easily cause water stain on the bathtub apron portion and does not impair the aesthetics, texture and luxury of the bathtub.

[0005] In a preferred embodiment of the present invention, the surface of the bathtub apron is not horizontal. By doing so, the water droplets flow from a high place to a low place in the apron portion, so that the water droplets are hardly adhered and do not remain, so that water stains are less likely to be generated in the bathtub apron portion.

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.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view showing an example of a bathtub according to the present invention. On the surface of the bathtub apron portion, a photocatalytic oxide particle is exposed so as to be in contact with the outside air, and has a hydrophilic portion. A surface layer in which both the water-repellent portion exposed so that the water-repellent fluororesin comes into contact with the outside air has a structure in which both surfaces are microscopically dispersed and the surface has a contact angle of 90 ° or more with water. Are formed. As the material of the bathtub, enamel, polyester, marbrite, stainless steel, FRP, acrylic, and the like can be used as in the related art. In addition, a transparent intermediate layer may be provided between the bathtub apron base material and the surface layer for the purpose of improving adhesion to the base material and the like.

[0008] A photocatalyst emits light (excitation light) having an energy (ie, a shorter wavelength) larger than the energy gap between the conduction band and the valence band of the crystal when the electrons in the valence band are irradiated. A substance capable of generating conduction electrons and holes by excitation (photoexcitation). Photocatalytic oxides include, for example, anatase-type titanium oxide, rutile-type titanium oxide, zinc oxide, tin oxide, and ferric oxide. And oxides such as bismuth trioxide, tungsten trioxide and strontium titanate. As a light source used for photoexcitation of the photocatalyst, a dedicated light source may be attached to a bathroom, a portable light source may be used, or a light source in an environment such as sunlight or general lighting in a bathroom may be used. As the light source to be used, for example, a fluorescent lamp, an incandescent lamp, a metal halide lamp, a mercury lamp, a xenon lamp, a germicidal lamp, a black light, etc. can be suitably used.In particular, when the photocatalyst is titanium oxide, a preferable light source is This is an illumination lamp that emits light containing both visible light and ultraviolet light. In order for the surface of the base material to be highly hydrophilized by photoexcitation of the photocatalyst, the illuminance of the excitation light may be 0.001 mW / cm ² or more.
It is preferably at least W / cm ^2, more preferably at least 0.1 mW / cm ² .

As the water-repellent fluororesin, polytetrafluoroethylene, polychlorotrifluoroethylene, polyhexafluoropropylene, tetrafluoroethylene-hexafluoropropylene copolymer 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.

[0013] Both the hydrophilic part exposed to the photocatalytic oxide particles in contact with the outside air and the water-repellent part exposed to the water-repellent fluororesin in contact with the outside are microscopically dispersed on the surface. Whether or not it has the structure described above can be confirmed by the following method. One such method is performed as follows. That is, first, a solution containing a metal having a large atomic number such as Ag, Pt, or Pd such as silver nitrate, silver lactate, chloroplatinic acid, or palladium chloride is applied to the substrate surface, and the substrate surface is irradiated with excitation light of a photocatalyst. Ag, P
A metal having a large atomic number, such as t or Pd, is deposited on the substrate surface. Since the deposition reaction of the metal is based on the reduction action of the metal by the photocatalyst, at this time, the metal adheres to the hydrophilic portion exposed by the photocatalytic oxide particles in contact with the outside air, but the water-repellent fluororesin Is hardly adhered to a portion exhibiting water repellency exposed so as to be in contact with the outside air.
Next, by observing the reflected electron image of the scanning electron microscope, if the density (contrast) is dispersed, the photocatalytic oxide particles are exposed so as to be in contact with the outside air and exhibit a hydrophilic property. It is concluded that both the water-repellent portions exposed so that the fluororesin comes into contact with the outside air have a structure microscopically dispersed on the surface. As another observation method, elemental analysis of the surface may be performed using an energy dispersive X-ray analyzer (EDX) or an electron probe microanalyzer (EPMA) instead of observing the density using a backscattered electron image. . As another observation method, if the metal is colored such as silver, the color may be observed by an optical microscope instead of observing the density by a reflected electron image.

Next, on the surface of the base material, both a portion exhibiting hydrophilicity in which the photocatalytic oxide particles are exposed to the outside air and a portion exhibiting water repellency in which the water-repellent fluororesin is exposed in contact with the outside air A method for producing an antifouling member having a surface layer having a structure in which is dispersed microscopically on the surface will be described. The manufacturing method in this case is basically based on applying the coating composition to the surface of the substrate and fixing the coating composition to the surface of the substrate.

Here, the coating composition contains photocatalyst particles and a water-repellent fluororesin as essential components, and water,
A solvent such as ethanol or propanol, a cross-linking agent for a fluororesin, or a surfactant for improving the dispersibility of a coating solution may be added.

As the method of applying the coating composition, methods such as spray coating, dip coating, flow coating, spin coating, roll coating, brush coating, and sponge coating can be suitably used. The coating composition is heat-treated at a temperature of 300 ° C. or higher at which the fluororesin melts, and when a crosslinking agent for the fluororesin is added, heat treatment at a temperature at which the fluororesin is cured by the crosslinking agent, pressure treatment, and heat treatment. It can be fixed by a method such as a combination of pressure treatment and the above heat treatment, or fixing by impact pressure. Further, before fixing by the above method, the surface of the substrate may be blasted or the like to provide irregularities. Then, the adhesion between the substrate and the surface layer can be improved.

[0017]

【Example】

Example. Anatase type titanium oxide sol (Ishihara Sangyo, ST
S-11) and polytetrafluoroethylene (PTF
E) mixing the particles (Daikin Industries, D-1) and distilled water,
The coating liquid obtained by stirring for 30 minutes is applied on a glaze enamel substrate of 5 × 10 cm square by a spray coating method, and heat-treated at 380 ° C. for 3 minutes to obtain 4 parts by weight of anatase type titanium oxide particles, Fluoroethylene particles 6
A surface layer consisting of parts by weight was formed to obtain a # 1 sample. # 1
According to the surface observation of the sample, both the photocatalytic oxide particles exposed to the outside air and exhibiting hydrophilicity and the water-repellent fluororesin exposed to the outside air exhibiting water repellency are both microscopically visible on the surface. It was confirmed that a surface layer having a structure dispersed in was formed. Next, the contact angle of the surface of the # 1 sample with water was measured. Here, the contact angle with water was evaluated using a contact angle measuring device (Kyowa Interface Science, CA-X150) based on the contact angle with water 30 seconds after dropping. As a result, the contact angle with water becomes 120 ° and a value of 90 ° or more,
When the # 1 sample was tilted, the water droplets fell while rolling. Next, an ultraviolet light source (Sankyo Electric Co., Ltd., black light blue (BLB) fluorescent lamp) was applied to the # 1 sample to form a 0.5
The sample was irradiated with ultraviolet rays at an ultraviolet illuminance of mW / cm ² for about 1 day to obtain a # 2 sample. The contact angle with water was measured for the # 2 sample. As a result, the contact angle with water became 110 ° and a value of 90 ° or more. When the # 2 sample was tilted, the water droplets fell while rolling.

[0018]

According to the present invention, it is possible to provide a bathtub in which water droplets are less likely to adhere to and remain on the apron portion of the bathtub. Become.

[Brief description of the drawings]

FIG. 1 is a plan view of a bathtub according to the present invention.

Claims (3)

[Claims] 1. Both a hydrophilic part exposed on the surface of a bathtub apron so that photocatalytic oxide particles come into contact with the outside air and a water-repellent part exposed on a water-repellent fluororesin so as to come into contact with the outside air. Has a structure in which is dispersed microscopically on the surface, and a surface layer having a contact angle of 90 ° or more with water on the surface is formed. 2. The bathtub according to claim 1, wherein the surface of the bathtub apron is not horizontal. 3. The bathtub according to claim 2, wherein the surface of the bathtub apron is inclined so that the inside of the bathtub is higher than the outside of the bathtub.