JPH10152782A - Hydrophilic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrophilic member which sufficiently exhibits a hydrophilicity impartation effect by photoexcitation of an optical semiconductor even when a surface layer contg. the optical semiconductor is fixed onto a base material contg. Cu atoms by forming the optical semiconductor-contg. layer not contg. the Cu atoms on the base material surface. SOLUTION: The optical semiconductor-contg. layer is formed via a layer for preventing the diffusion of the Cu atom species on the surface of the base material contg. the Cu atoms, for example, bronze, brass, etc., so that the layer surface exhibits the hydrophilicity at a high degree according to the photoexcitation of the optical semiconductor. The layer contg. the optical semiconductor is provided with the layer for preventing the diffusion of the Cu atoms to the surface layer, by which the substrate layer is prevented from receiving the influence of the Cu atoms any more and the purposes are achieved. Then, the effects of improving water washability, rainfall washing performance, etc., on the article surfaces are eventually sufficiently exhibited. The layer for preventing the diffusion of the Cu is preferably composed of materials not contg. Cu; for example, silica, silicone resin, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for making a surface of a substrate containing Cu atoms highly hydrophilic, such as a brass, brass, or bronze substrate. More particularly, the present invention relates to a technique for preventing the surface from being soiled by making the surface of the article highly hydrophilic, or for self-cleaning (self-cleaning) or easily cleaning the surface.

[0002]

2. Description of the Related Art The present inventors have proposed PCT / JP96 / 00.
No. 733, it has been found that when an optical semiconductor-containing layer is formed on a substrate surface, the layer surface exhibits a high degree of hydrophilicity of 10 ° or less in terms of a contact angle with water in response to optical excitation of the optical semiconductor. Further, it has been found that such effects as anti-fogging and improved visibility of transparent members such as glass, lenses and mirrors, and improved water-washing and rain-washing of the article surface can be obtained.

[0003]

However, as described in Example 1 below, when Cu is added to a surface layer containing an optical semiconductor, the rate of hydrophilization by optical excitation of the optical semiconductor is significantly reduced. It has been found. Therefore,
When the surface layer containing the optical semiconductor is directly fixed on the bronze, brass, brass products, etc. of the faucet fittings and parts thereof, the rate of hydrophilization by optical excitation of the optical semiconductor is small. It is difficult to sufficiently exhibit effects such as improvement in rainfall washability. The present invention has been made in view of the above circumstances, even when the surface layer containing an optical semiconductor is fixed on a substrate containing Cu atoms, the decrease in the rate of hydrophilicity due to photoexcitation of the optical semiconductor. It is an object of the present invention to provide a hydrophilic member that does not occur, and thus can sufficiently exhibit the effects of improving the water washability and rainfall washability of the article surface.

[0004]

According to the present invention, in order to solve the above-mentioned problems, an optical semiconductor-containing layer containing no Cu atoms is formed on the surface of a substrate, and the layer is formed in response to optical excitation of the optical semiconductor. Provided is a hydrophilic member having a surface exhibiting high hydrophilicity. In one embodiment, an optical semiconductor-containing layer is formed on a surface of a substrate containing Cu atoms via a layer for preventing diffusion of the atomic species, and the layer surface is formed in response to optical excitation of the optical semiconductor. Are highly hydrophilic. By providing a layer for preventing the diffusion of Cu atoms to the surface layer, the surface layer containing the optical semiconductor can be made of C
Even when it is no longer affected by u atoms and is fixed on a substrate containing Cu atoms, the photo-semiconductor can sufficiently exhibit a hydrophilizing effect by photoexcitation, thereby improving the water washing property and rain washing property of the article surface. The effect of is fully exhibited.

[0005]

Next, the components of the present invention will be described. The substrate containing Cu atoms refers to, for example, bronze, brass, brass, and the like. The layer that prevents the diffusion of Cu is preferably made of a material that does not contain Cu. For example, if you want to use the color of the base for design purposes, use silica, silicon,
Transparent materials such as silicate compounds such as resin, acrylic resin, and water glass can be suitably used. In addition, a coloring material may be used for the layer for preventing the diffusion of Cu, and this layer may have a design property. In that case, glaze; Ag, Pt
Materials such as colored metals; and the like can be suitably used. Cu
Is preferably 0.02 μm or more. Then, diffusion of Cu from the substrate to the surface layer can be effectively prevented.

The term "hydrophilic" refers to the property of being easily conformed when water is dropped on the surface, and generally refers to a state where the water wetting angle is less than 90 °. The high hydrophilicity in the present invention refers to a property that the surface is very easy to conform to when water is dropped, and rather forms a water film without forming a water drop. More specifically, the water wetting angle is 10状態 or less, preferably 5 ゜ or less.

[0007] An optical semiconductor is formed by irradiating light (excitation light) having an energy (ie, shorter wavelength) larger than the energy gap between the conduction electron band and the valence band of the crystal. A substance capable of generating conduction electrons and holes by excitation of electrons (photoexcitation) therein, for example, anatase type titanium oxide, rutile type titanium oxide, tin oxide, zinc oxide, bismuth trioxide, Tungsten trioxide, ferric oxide, strontium titanate and the like can be suitably used.
As the light source used for optical excitation of the optical semiconductor, indoor lighting such as a fluorescent lamp, an incandescent lamp, a metal halide lamp, and a mercury lamp, the sun, and a light source in which light from the light source is guided by a low-loss fiber are preferably used. it can. In order for the substrate surface to be highly hydrophilized by optical excitation of the optical semiconductor,
Illuminance of the excitation light, may if 0.001 mW / cm ² or more, preferably that it 0.01 mW / cm ² or more, 0.1
More preferably, it is at least mW / cm ² .

It is desirable that the optical semiconductor-containing layer contains at least one of silica, solid superacid, and silicon. When silica and solid superacid are contained,
It can easily exhibit a high degree of hydrophilicity at lower excitation light illuminance, and can maintain that state for a considerably long time. Even if silicon is contained, the silicon can be produced by photoexcitation of the optical semiconductor.
At least a part of the organic group bonded to the silicon atom in the compound is substituted with a hydroxyl group. Once substituted with a hydroxyl group, as in the case of silica addition, it tends to exhibit a high degree of hydrophilicity with low excitation light illuminance and can maintain that state for a considerably long time. Here, the super-strong acid refers to a strong acid containing a solid oxide having a Hammett acidity function Ho ≦ -11.93 as a component, and specifically, Al ₂ O ₃ supported on sulfuric acid, TiO ₂ supported on sulfuric acid, ZrO supported on sulfuric acid. ₂ , sulfuric acid supported Fe ₂ O ₃ , sulfuric acid supported SiO ₂ , sulfuric acid supported HfO ₂ , TiO ₂ / WO
₃ , WO ₃ / SnO ₂ , WO ₃ / ZrO ₂ , WO ₃ / F
_{e 2 O 3, SiO2 · Al} 2 O 3 or the like can be suitably used. As the silicone, any polyorganosiloxane can be generally used. For example, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane , Ethyltripropoxysilane, ethyltributoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldipropoxysilane, dimethyldibutoxysilane, Diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, diethyldibutoxysilane, phenylmethyldimethoxysilane, phenylmethyl Silane, phenyl methyl dipropoxy silane, phenyl methyl dibutoxy silane, .gamma.-glycidoxypropyltrimethoxysilane, and hydrolysates thereof, partial condensation polymerized material after hydrolysis,
A mixture obtained by hydrolyzing, dehydrating and condensing as required, a mixture or the like thereof as a precursor can be suitably used.

The thickness of the optical semiconductor-containing layer is preferably set to 0.4 μm or less. Then, cloudiness due to irregular reflection of light can be prevented, and the optical semiconductor-containing layer becomes substantially transparent. Further, the thickness of the optical semiconductor-containing layer is set to 0.2 μm.
m or less is more preferable. Then, color formation of the layer due to light interference can be prevented. Further, the thinner the optical semiconductor-containing layer, the higher its transparency. Furthermore, the thinner the film, the better the wear resistance of the layer. On the surface of the surface layer, silica, alumina, silicone,
A wear-resistant or corrosion-resistant protective layer such as a solid superacid or the like which can be hydrophilized or another functional film may be provided.

Ag can be added to the optical semiconductor-containing layer. The layer to which the metal is added can kill bacteria adhering to the surface even in a dark place. In addition, this layer inhibits the growth of microorganisms such as molds, algae and moss. Therefore, adhesion of dirt due to microorganisms is suppressed.

The optical semiconductor-containing layer contains Pt, Pd, R
A platinum group metal such as u, Rh, Os, Ir can be added. The layer to which the metal is added can enhance the oxidation reaction activity of the photosemiconductor by the photocatalysis, thereby improving the deodorizing and purifying action of indoor air and the decomposing and purifying action of pollutants contained in outdoor air.

[0012]

【Example】

Embodiment 1 FIG. (Effect of Cu on photohydrophilization) 86 parts by weight of ethanol, 6 parts by weight of tetraethoxysilane (Wako Pure Chemical), 6 parts by weight of pure water, and 36% hydrochloric acid as a hydrolysis inhibitor of tetraethoxysilane 2 parts by weight were added and mixed to prepare a silica coating solution. This solution was coated with a 10 cm square source by the flow coating method.
It was applied to the surface of a Dalheim glass plate and dried at a temperature of 80 ° C. With drying, the tetraethoxysilane was hydrolyzed to be silanol first, and then a thin film of amorphous silica was formed on the surface of the glass plate by dehydration-condensation polymerization of silanol. Next, tetraethoxy titanium (Merc)
k) To a mixture of 1 part by weight and 9 parts by weight of ethanol, 0.1 part by weight of 36% hydrochloric acid was added as a hydrolysis inhibitor to prepare a titanium oxide coating solution, and this solution was coated with the amorphous silica thin film. Was applied by a flow coating method in dry air. The coating amount is 45 μg /
cm ² . Since the rate of hydrolysis of tetraethoxytitanium is extremely fast, part of the tetraethoxytitanium was hydrolyzed at the coating stage, and titanium hydroxide began to form. Next, the glass plate is maintained at a temperature of about 150 ° C. for 1 to 10 minutes to complete hydrolysis of tetraethoxytitanium and to subject the generated titanium hydroxide to dehydration polycondensation to form amorphous titanium oxide. Was obtained. This sample was fired at a temperature of 500 ° C. to crystallize the amorphous titanium oxide into an anatase type titanium oxide to obtain a plurality of # 1 samples. On the surface of # 1 sample, 0.3 g of an aqueous solution of copper acetate monohydrate having a copper metal concentration of 50 μmol / g
After the application, a BLB fluorescent lamp was irradiated at 0.4 mW / cm ² for 10 minutes to fix iron on the substrate to obtain a # 2 sample. next,#
1, # 2 Apply oleic acid to the sample surface, rub it with a neutral detergent (mama lemon), rinse with tap water and distilled water, and then dry it at 50 ° C for 30 minutes with a dryer to intentionally make the surface Contaminated. Then, the contact angles of the surface of the samples # 1 and # 2 with water were measured using a contact angle measuring instrument (Kyowa Interface Science, CA
-X150), 30 seconds after a water drop was dropped on the sample surface from the microsyringe. The results are shown on the vertical axis of the irradiation time 0 in FIG. As can be seen from the figure, # 1, #
The surface of each of the two samples showed a contact angle with water of about 50 °. Next, the # 1 and # 2 sample surfaces were irradiated with a BLB fluorescent lamp at 0.5 mW / cm ² , and the change over time in the contact angle of the sample surface with water was examined. As a result, the # 1 sample was highly hydrophilized to a contact angle with water of less than 3 ° in about 3 hours, whereas the # 2 sample to which copper was added had a contact angle with water of only about 25 °. Did not decrease, and a state where the rate of hydrophilization decreased was observed. From the above, it has been found that when Cu is added to the surface layer containing an optical semiconductor, the rate of hydrophilization by optical excitation of the optical semiconductor decreases.

Embodiment 2 FIG. (Brass base material, wettability with water, washability) 6 parts by weight of tetraethoxysilane (Wako Pure Chemical Industries, Ltd.), 6 parts by weight of pure water, and 36 parts by weight of ethanol % Hydrochloric acid was added and mixed to prepare a silica coating solution. This solution was applied to the surface of a 10 cm square brass plate by the flow coating method and dried at a temperature of 80 ° C. With drying, the tetraethoxysilane was hydrolyzed to be silanol first, and then a thin layer of amorphous silica was formed on the surface of the brass plate by dehydration-condensation polymerization of silanol. Next, a mixture of 1 part by weight of tetraethoxytitanium (Merck) and 9 parts by weight of ethanol was added to a mixture of 3 parts as a hydrolysis inhibitor.
A titanium oxide coating solution was prepared by adding 0.1 parts by weight of 6% hydrochloric acid, and this solution was applied to the above-mentioned amorphous silica thin film by a flow coating method in dry air. The coating amount was 45 μg / cm ² in terms of titanium oxide. Since the hydrolysis rate of tetraethoxytitanium is extremely fast,
Part of the tetraethoxytitanium was hydrolyzed at the coating stage, and titanium hydroxide began to form. Next, by holding the brass plate at a temperature of about 150 ° C. for 1 to 10 minutes,
While completing the hydrolysis of tetraethoxy titanium,
The produced titanium hydroxide was subjected to dehydration condensation polymerization to obtain a glass plate coated with amorphous titanium oxide. This sample was calcined at a temperature of 500 ° C. to crystallize the amorphous titanium oxide into an anatase type titanium oxide to obtain a # 5 sample.
The following two evaluations were performed on the # 5 sample and a brass plate for comparison. (1) Evaluation of surface hydrophilicity recovery performance upon irradiation with ultraviolet light After oleic acid was applied to the sample surface, rubbed with a neutral detergent (mama lemon), rinsed with tap water and distilled water, and then dried at 50 ° C. with a dryer at 30 ° C. The surface is intentionally contaminated by drying for minutes, and then the BLB fluorescent lamp is turned on by 0.5 mW / cm.
Irradiation was performed at 5 for ² hours, and the change in the contact angle of the sample surface with water was examined. As a result, in the brass plate, the contact angle with water after contamination and after irradiation with the BLB fluorescent lamp was 70 °, which was not changed. On the other hand, in the case of the # 5 sample, water was 50 ° after the contamination. Was highly hydrophilized to almost 0 ° after irradiation with a BLB fluorescent lamp. (2) Water immersion cleaning effect of oleic acid Oleic acid was applied to the sample surface used in the test of (1), and the sample was immersed in water filled in a water tank while keeping the sample surface in a horizontal posture. . As a result, in the stainless steel plate, oleic acid remained attached to the surface of the sample, and even when lightly rubbed with water, the oil only extended on the sample, whereas in the # 5 sample, oleic acid was It rolled up into an oil drop, and was released from the surface of the sample and floated with a light finger rub in water.

[0014]

According to the present invention, there is provided a member in which an optical semiconductor-containing layer is formed on the surface of a substrate containing Cu atoms, wherein the surface of the layer exhibits a high degree of hydrophilicity in response to photoexcitation of the optical semiconductor. The surface layer containing the optical semiconductor is not affected by Cu atoms by providing a layer that prevents diffusion of the optical semiconductor to the surface layer. Even when the optical semiconductor is fixed on a substrate containing Cu atoms, the optical excitation of the optical semiconductor is prevented. Fully exerts the effect of hydrophilization, and accordingly, the effect of improving the water washability and rainfall washability of the article surface can be sufficiently exhibited.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C23C 28/00 C23C 28/00 B G02B 1/10 G02B 1/10 Z

Claims (8)

[Claims] An optical semiconductor-containing layer that does not contain Cu atoms is formed on a surface of a substrate, and the layer surface exhibits a high degree of hydrophilicity in response to photoexcitation of the optical semiconductor. Element. 2. An optical semiconductor-containing layer that does not contain Cu atoms is formed on the surface of the base material, and the surface of the layer exhibits a high degree of hydrophilicity in response to photoexcitation of the optical semiconductor, so that water washing and / or Or a member whose surface is cleaned only by rain washing. 3. An optical semiconductor-containing layer is formed on a surface of a substrate containing Cu atoms via a layer for preventing diffusion of the atomic species, and the surface of the layer is formed in response to optical excitation of the optical semiconductor. A hydrophilic member having a high degree of hydrophilicity. 4. An optical semiconductor-containing layer is formed on a surface of a substrate containing Cu atoms via a layer for preventing diffusion of the atomic species, and the surface of the layer is formed in response to optical excitation of the optical semiconductor. A member that exhibits a high degree of hydrophilicity and whose surface is cleaned only by water washing and / or rain washing. 5. The member according to claim 1, wherein the optical semiconductor-containing layer further contains at least one of silica, a solid superacid, and silicone. 6. A layer which can be made hydrophilic such as silica, alumina, solid superacid, silicon, etc., is provided on the optical semiconductor-containing layer.
A member according to claim 1. 7. The member according to claim 1, wherein the base material is one of bronze, brass, and brass. 8. The member according to claim 1, wherein the member is a faucet.