JP2003236977A - Stainproof member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stainproof member with higher water repellency and oil repellency than those of conventional stainproof members and high adhesiveness and abrasion resistance of a coating film. <P>SOLUTION: The stainproof member is a high stainproof member and is characterized by comprising an uneven coating film comprising at least a metal oxide on the surface of a base material and a water repellent coating film applied on the uneven coating film surface and a surface mean roughness Ra of the outermost layer being 0.004-10 μm. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention of the present application relates to a member having an antifouling surface to which dust, water-based and oil-based dirt hardly adheres. More specifically, the invention of this application relates to an antifouling member which is a member used around a bathroom, a kitchen, an exterior or the like, and which has an uneven coating and a water-repellent coating on the surface of a base material.

[0002]

2. Description of the Related Art Exhaust gas and dust from automobiles and factories
Soars by the air flow and adheres to everything outdoors. Since these stains impair the aesthetics of the building, measures such as wiping and cleaning are desired. However, cleaning the walls and roof is not easy and inevitably stains are left for a long time. The left-over dirt accumulates and flows down along the surface of the exterior material etc. due to rainfall, but when it is dried, the rain streaks remain as striped dirt.

On the other hand, even indoors, in the vicinity of a bathroom or a kitchen, stains are apt to be generated due to scattering of soap bubbles or oil, and discoloration occurs when these are stuck. Such discoloration not only impairs the appearance, but also gives the viewer an unsanitary impression.

Therefore, as a method of imparting antifouling property to various members used indoors and outdoors, a method of making the surfaces of the members hydrophilic has been studied. Specifically, a coating agent containing a photocatalyst is applied to the surface of the base material, the hydrophilicity of the surface coating film is enhanced by irradiation of ultraviolet rays, and the dirt is washed off outdoors by rain and indoors by a water stream.

However, in such a hydrophilic coating film, the effect of the photocatalyst is not exerted in the weather or area where the irradiation amount of ultraviolet rays is small, or in the north side of the building, under the eaves, indoors, etc., and sufficient hydrophilicity is obtained. There were many cases where I could not get it. Also,
Such a hydrophilic coating film cannot sufficiently prevent even oil stains in the kitchen or the like.

[0006]

Therefore, as a method of imparting antifouling property to a member, a method of forming a water-repellent coating film on the surface of the member is being studied, which is contrary to the above-mentioned hydrophilization by photocatalyst.

[0007] For example, an exterior member having a surface coated with a fluorine-based coating agent repels water, so that it is difficult for rain streaks to form and striped stains can be prevented. Similarly, in the case of an interior member whose surface is coated with a fluorine-based coating agent, even if water-based stains such as soap bubbles or oil-based stains such as cooking oil adhere, the stains can be prevented from accumulating and discoloration accompanying light stains. .

However, a coating film obtained by a conventional fluorine-based coating agent has a water contact angle of 90 to 100.
And the oil contact angle was 40 to 50 °, and sufficient water repellency or oil repellency could not be exhibited depending on the size of the droplets that adhere. As a result, dirt often sticks,
It is necessary to perform frequent cleaning and careful wiping work, and the maintenance is time-consuming.

Further, such a fluorine-based coating film had low adhesion to the substrate and low abrasion resistance. Therefore, there is also a problem that the coating film is peeled off after long-term use and sufficient water / oil repellency is not maintained.

Therefore, the invention of this application has been made in view of the above circumstances, solves the problems of the prior art, and has higher water / oil repellency than the conventional antifouling member. It is an object of the present invention to provide an antifouling member that exhibits high coating film adhesion and abrasion resistance.

[0011]

In order to solve the above-mentioned problems, the invention of the present application is, first of all, a member having a high antifouling property, which comprises at least a metal oxide on the surface of a base material. And a water-repellent coating applied on the surface of the uneven coating, and the surface average roughness of the outermost layer is Ra 0.004 to 1
An antifouling member having a thickness of 0 μm is provided.

Secondly, the invention of this application provides the antifouling member as described above, wherein the concavo-convex film is obtained by depositing a metal oxide on the surface of a substrate by a vapor phase method.

Thirdly, the invention of this application also provides the above-mentioned antifouling member, wherein the uneven coating film is obtained by applying a silicone-based resin coating material containing at least a metal oxide to the surface of the base material. To do.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The antifouling member of the invention of this application is
It is obtained by forming at least fine unevenness of a metal oxide on the surface of a base material and then applying a water-repellent coating agent on the uneven coating, and the surface average roughness of the outermost layer is Ra 0.004. It is characterized by being ~ 10 μm.

In the antifouling member of the invention of this application, the concavo-convex coating film applied to the surface of the base material may be made of at least a metal oxide. Examples of the metal oxide include silica, alumina, titanium oxide, antimony oxide, zinc oxide, tin oxide, zirconium oxide, and the like, and one or a combination of two or more of these can be used to form the uneven coating. . The average particle diameter of these metal oxides is Ra 0.004 when the surface roughness of the finally obtained antifouling member is determined.
There is no particular limitation as long as it is in the range of about 10 μm. It can be appropriately changed according to the method of forming the uneven coating, the material of the water-repellent coating formed on the surface of the uneven coating, the film thickness, and the like. Preferably, the average particle size is 0.01 to 10 μm.

As a method for forming such a concavo-convex coating film, a vapor phase method in which a metal oxide is attached to the surface of a substrate by sputtering, vacuum deposition, ion plating, plasma CVD, or the like, or a binder such as a silicone resin coating An example is a coating method in which a metal oxide is mixed with and applied.

Among them, the uneven coating film formed by the vapor phase method is particularly preferable because it has excellent adhesion to the substrate and abrasion resistance. A sputtering method is particularly preferable for forming a concavo-convex film having a desired roughness on a substrate in a short time. The thickness and surface roughness of the uneven coating film obtained by the sputtering method differ depending on the conditions such as the degree of vacuum, the concentration of argon ions, the sputtering time and the apparatus used. Therefore, it suffices to appropriately select the conditions according to each sputtering method.

On the other hand, in the case of the antifouling member of the invention of this application, when a concavo-convex film is obtained by applying a silicone resin coating containing a metal oxide, a curtain roll coater, a roll coater, a spray, a dip coat, Since the uneven coating can be formed by applying a general coating method such as a bar coater, it is simple and preferable.

At this time, the silicone resin coating material used as the binder may be polysiloxane having an organic group such as an alkyl group or an aryl group, and its composition is not particularly limited.

Specifically, assuming that the wear resistance is high,
SiX ₄ or R ¹ _n SiX _4-n (wherein X is a hydrolyzable group, R ¹ is the same or different, and is a monovalent hydrocarbon group having 1 to 8 carbon atoms which may have a substituent. The hydrolyzate and partial hydrolyzate of the silicon alkoxide represented by At this time, R ¹ is not particularly limited, but is, for example, a linear alkyl group such as methyl, ethyl, n-propyl or n-butyl, i-propyl, i-butyl or t.
Examples thereof include branched alkyl groups such as butyl.

A coating film formed from such a silicone resin coating is known to have high crack resistance, but a molecular weight of 200 to 500 is particularly required to increase hardness.
It is preferable to polymerize (cure) so as to be about 0. The curing reaction proceeds by a hydrolysis reaction with water that is added to the paint or is present, but at this time,
The amount of water with respect to 1 mol of the X group is preferably 0.001 mol or more in the entire metal oxide-containing silicone resin coating material. If the amount of water is less than 0.001 mol, the hydrolysis reaction does not proceed sufficiently, resulting in poor film forming properties and poor crack resistance of the formed coating film. Furthermore, the curing reaction of the silicone-based resin coating material proceeds rapidly by adding various acidic catalysts as catalysts. Specifically, acetic acid, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycolic acid, maleic acid, malonic acid, toluenesulfonic acid, organic acids such as oxalic acid, hydrochloric acid, Examples of acidic catalysts include inorganic acids such as nitric acid and halogenated silanes, acidic colloidal silica, and acidic sol fillers such as titania oxide sol.

Therefore, when the uneven coating is formed from the metal oxide-containing silicone resin coating material, the silicone resin coating material contains one or more metal oxides and one or more metal oxides.
One kind or two or more kinds of acidic catalysts can be mixed to obtain a metal oxide-containing silicone resin paint.

The silicone resin coating material as described above may be diluted with various organic solvents for easy handling. As the type of organic solvent, methanol, ethanol, isopropanol, n-butanol, which has high compatibility with water in the silicone resin coating,
Lower aliphatic alcohols such as isobutanol, ethylene glycol, ethylene glycol monobutyl ether,
Examples thereof include ethylene glycol derivatives such as ethylene glycol monoethyl ether acetate, diethylene glycol, and diethylene glycol monobutyl ether, diethylene glycol derivatives, and diacetone alcohol. From these, one kind or two or more kinds can be appropriately used. Furthermore, one or more of toluene, xylene, heptane ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, etc. may be added in combination with these hydrophilic organic solvents. By adding these organic solvents, the water content is diluted and the progress of partial hydrolysis of the silicon alkoxide can be controlled.

The metal oxides added to the silicone resin coating material as described above include silica, alumina, titanium oxide, antimony oxide, zinc oxide, tin oxide, as described above.
It is selected from zirconium oxide, which may be powder or sol. As the sol, commercially available organosilica sol, alumina sol, antimony oxide sol, titania sol, water dispersibility such as zirconia sol,
Alternatively, a non-aqueous organic solvent dispersible sol such as alcohol can be used. Generally, these sols have a solid content of 20-5.
Contains 0% by weight. When a sol-like metal oxide is used, the sum of the water content and the water content for curing the silicone resin coating material may be 0.001 mol with respect to 1 mol of the X group in the silicon alkoxide as described above. .

Further, the method of mixing the metal oxide and the silicone resin coating material is not particularly limited. For example, a method of uniformly dispersing powdery or sol-like metal oxide in a silicone resin coating material with a disperser can be mentioned. Examples of the disperser include a homogenizer, a disper, a paint shaker, and a bead mill.

The silicone resin and the metal oxide are preferably mixed so that the weight ratio of the solid content thereof (metal oxide / (silicone resin + metal oxide)) is in the range of 0.5 to 0.95. If the weight ratio of the metal oxides is less than 0.5, sufficient water / oil repellency cannot be obtained, and if more than 0.95 metal oxides are added, the amount of silicone resin component is small and film-forming properties are low. Deteriorates and peeling and abrasion of the coating film easily occur.

The method of applying the metal oxide-containing silicone resin coating material on the surface of the substrate as described above is not particularly limited, but various general coating methods as described above can be applied. After applying the metal oxide-containing silicone-based resin coating material, heating may be performed in order to accelerate the curing reaction. The heating temperature is not particularly limited, but may be in the range of 40 to 100 ° C.

Furthermore, the thickness of the resulting uneven coating is 0.01
The thickness of the concavo-convex film is preferably 0.05 to 100 μm in order to obtain a coating film in which high adhesion is maintained for a long period of time and cracks and peeling do not occur, although it may be about 1000 μm. Such a concavo-convex film also has the effect of anchoring the water-repellent coating film formed thereon. Therefore, the adhesion of the water-repellent coating film is improved, and the antifouling property of the member is maintained for a long time.

In the antifouling member of the invention of this application, a water-repellent coating film is formed by further applying a water-repellent coating agent on the surface of the uneven coating film made of at least a metal oxide as described above. The water-repellent coating agent used at this time is selected from various known materials. For example, fluorine-containing resin such as fluoroalkylsilane, dimethyl silicone, polydimethylsiloxane diol, amino-modified silicone, epoxy-modified silicone oil,
Examples thereof include silicone oils such as carboxyl-modified silicone oil.

The water-repellent coating agent may be applied by a general method such as a roll coater, spray, dip coating or bar coater, or it may be formed on a substrate surface by impregnating a water-repellent coating agent with a cloth or the like. Alternatively, it may be integrally laminated on the surface of the uneven coating. Then, a water-repellent coating film is obtained by treating at room temperature or under heating at several 100 ° C. for several seconds and drying the water-repellent coating agent. The film thickness of the water-repellent coating film is not particularly limited and may be about 0.001 to 10 μm.

As described above, the antifouling member of the invention of this application is characterized in that the surface average roughness of the outermost layer is Ra 0.004 to 10 μm. That is, the surface of the member after the uneven coating is applied and the water-repellent coating is applied on the surface is not smooth but has fine unevenness. By providing such unevenness, higher water / oil repellency (that is, antifouling property) is exhibited as compared with a member having a conventional water-repellent coating film. Further, when the water-repellent coating film is formed, since the water-repellent coating film can be anchored to the uneven coating film formed in advance, such antifouling property is maintained for a long time. Furthermore, in the antifouling member of the invention of this application, the uneven coating film made of at least a metal oxide,
Has high wear resistance. Therefore, with such an antifouling member, the occurrence of scratches is suppressed and the beauty is maintained for a long time.

As described above, the antifouling member of the invention of this application is a member around the bathroom such as a bathroom mirror, a bathroom wall, a bathtub, a floor pan, a drainage pit, a kitchen sink, a currant, a kitchen counter, a range hood, and tableware. Parts around the kitchen such as a dryer,
It is applied to outer walls of buildings such as siding, glass, concrete, metal, gates, exterior members for outer gutters, rain gutters, roofing materials, entrance doors, shutters, sashes, etc. The material is not particularly limited. Examples of the base material include various materials such as a metal plate, a wooden plate, an inorganic plate, and a resin plate.

The embodiments of the present invention will be described in more detail below with reference to examples. Of course, the present invention is not limited to the following examples, and it goes without saying that various aspects are possible in details.

[0034]

Example 1 To 208 parts by weight of tetraethoxysilane, 356 parts by weight of methanol was added, and further 18 parts by weight of water and 18 parts by weight of 0.01N hydrochloric acid were added and mixed well using a disper. Next, add silica sol (ST-ZL, manufactured by Nissan Chemical Industries, particle size 70 to 100 μm) in a weight ratio of solid matter so that silica sol / (silicone resin + silica sol) becomes 0.5, and then a constant temperature bath at 60 ° C. The mixture was heated for 2 hours, and diluted with methanol so that the total solid content was 5% to obtain a coating agent for uneven coating.

An aluminum plate colored in white with an acrylic urethane paint (Ubi White, manufactured by Natco Co., Ltd.) was used as a substrate. The coating agent was applied by a roll coater and then baked at 200 ° C. for 5 minutes. Fluoroalkylsilane (TSL 8262, G
E Toshiba Silicone Co., Ltd.) was applied and baked at 150 ° C. for 10 minutes.

After firing, excess fluoroalkylsilane was removed to prepare a water-repellent test piece. <Example 2> In the same manner as in Example 1, an alumina sol (alumina sol 520, manufactured by Nissan Chemical Industries, Ltd.) was used in place of the organosilica sol to prepare a test piece. <Example 3> In the same manner as in Example 1, silicone oil (YF3965,
A test piece was prepared using GE Toshiba Silicone Co., Ltd.). <Example 4> In the same manner as in Example 1, a powder shaker Aerosil # 380 was used in place of the silica sol and dispersed with a paint shaker to prepare a test piece. <Example 5> A silica film was formed on the same substrate surface as in Example 1 by sputtering to prepare a test piece. <Comparative Example 1> An aluminum plate colored with the acrylic urethane-based paint (Ubi White, manufactured by Natco) used in Example 1 was used as a test piece. <Comparative Example 2> A fluoroalkylsilane impregnated in a waste cloth is applied to an aluminum plate colored white with an acrylic urethane-based paint (Ubi White, manufactured by Natco Co., Ltd.), and the mixture is applied at 150 ° C for 10
After baking for a minute, excess fluorosilicone was removed to obtain a test piece.

The following items were tested for the test pieces as described above.

(1) Contact angle: A contact angle meter (Kyowa Interface Co., Ltd. CA-DT) was used to measure the contact angle of the test piece with respect to a water droplet of 3 μl.
It was measured by.

(2) Average Roughness: The average roughness of the coating film was measured using an atomic force microscope (Nanopix 1000, Seiko Instruments Inc.).

(3) Abrasion resistance: Using a traverse type abrasion tester, a canvas cloth was brought into contact with the coated surface of each test piece and slid back and forth 1000 times (load 100 g / cm ² , stroke 10).
0 mm) and an abrasion test was conducted. The degree of occurrence of scratches on the coating film surface after the abrasion test was observed with an optical microscope to determine the abrasion resistance. (◎: No scratches, ○: Several scratches per cm ² occurred, ×: Many scratches) (4) Adhesion test: The contact angle was measured after the abrasion resistance test and compared with the contact angle before the test. Then, the adhesion of the coating film was evaluated.

(5) Cleanability: 1 g of modified oil manufactured by Matsushita Seiko was placed on the coating film, the oil was wiped off while applying a force of 1 kg / cm ² to the waste cloth, and the removal condition was visually evaluated.

(6) Antifouling resistance: After exposing the test piece to the outdoors for one month, the color difference was measured using a color difference meter (X-right SP-88, manufactured by Nippon Lithographic Equipment Co., Ltd.).

The above evaluation results are shown in Table 1.

[0044]

[Table 1] From the table, it has an uneven coating and a water-repellent coating, and the average surface roughness is
The test pieces having Ra of 0.004 to 10 μm (Examples 1 to 5) exhibited high water repellency and cleanability. Also, the coating film adhesion was high. Particularly, in the case where the silica coating film was formed by sputtering (Example 5), the abrasion resistance was remarkably high.

On the other hand, the test piece (Comparative Example 1) having a smooth surface without forming the uneven coating and the water-repellent film had low water repellency and poor cleanability. It was also confirmed that the abrasion resistance was low and the coating film was easily peeled off, so that the contamination was remarkable.

Further, when the water-repellent coating film was formed without forming the concavo-convex film (Comparative Example 2), although the water repellency was observed, the coating film adhesion was low and the abrasion resistance was poor. . Therefore, the antifouling property that can withstand long-term use was not obtained.

[0047]

As described above in detail, the invention of this application provides an antifouling member having higher water and oil repellency than conventional members. Since dirt is unlikely to adhere to such a member and dirt that has once adhered can be easily removed, the burden of maintenance such as cleaning can be reduced. Furthermore, since the coating adhesion and the abrasion resistance of the coating are high, the beauty is maintained for a long time.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4D075 AE03 BB85Y CA02 CA03                       CA13 CA34 CA36 CA37 CB27                       CB33 DA06 DB01 DB12 DB13                       DB14 DB21 DB31 DC02 DC38                       EA12 EB01 EB16 EB22 EB38                       EB43 EC02 EC03 EC05                 4F100 AA17B AA20 AB10 AH06                       AK25 AK52 AK52B AT00A                       BA03 BA07 BA10A BA10C                       CC00B CC00C DD01B DD02B                       DD07C EH46B EH66B GB07                       GB08 JB06 JB06C JK06                       JK09 JL06 JL11 JM01 YY00C

Claims (3)

[Claims] 1. A member having high antifouling property, comprising an uneven coating film made of at least a metal oxide on the surface of a base material, and a water-repellent coating film applied on the surface of the uneven coating film, and the surface of the outermost layer. An antifouling member having an average roughness Ra of 0.004 to 10 µm. 2. The antifouling member according to claim 1, wherein the uneven coating film is obtained by depositing a metal oxide on the surface of a base material by a vapor phase method. 3. The antifouling member according to claim 1, wherein the uneven coating film is obtained by applying a silicone-based resin coating material containing at least a metal oxide to the surface of the base material.