JPH09202650A - Water-repellent, oil-repellent and antistaining membrane and its formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily and inexpensively prepare a water-repellent and oil-repellent antistaining membrane which is formed by coating a specific coating layer formed on a substrate body with a water-repellent membrane, thus shows increased impregnation, supporting and holding properties of the water-repellent membrane. SOLUTION: This membrane comprises a substrate body made of a transparent glass plate, a flower pedal-like transparent alumina coating membrane formed on the substrate body and a water-repellent membrane coated on the alumina layer. The flower pedal-like transparent alumina membrane is formed with a coating liquid containing at least an aluminum alkoxide such as aluminum sec-butoxide and a stabilizer such as ethyl acetoacetate, drying and then subjecting the formed amorphous alumina membrane to a hydrothermal treatment, then drying and firing. In addition, the water-repellent membrane is preferably formed with a coating liquid containing a fluorine-containing silane (for example, a fluoroalkylsilane) and heat treated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water- and oil-repellent antifouling film excellent in heat resistance and weather resistance as well as exhibiting super water repellency, and a method for forming the same, which is used for vehicles, ships, and aircraft. Provided is a useful water- and oil-repellent antifouling film and a method for forming the same, which can be widely used for interior and exterior window glass for interior or construction, mirror glass, decorative glass, and various building materials and building materials. is there.

[0002]

2. Description of the Related Art In recent years, in the field of semiconductors, water repellency has been imparted to surfaces of various architectural materials such as window materials made of glass substrates, metals and plastics, and fabrics. Has been proposed to improve the water repellency, in particular, to provide super water repellency.

For example, Japanese Examined Patent Publication (Kokoku) No. 7-86146 describes a water-repellent, oil-repellent antifouling coating and a method for forming the coating.
A water- and oil-repellent antifouling film having a chemisorption monomolecular film containing fluorine at least through a siloxane bond formed on the surface of a substrate having irregularities of less than 0 nm and having irregularities of less than 400 nm on the surface. In addition, the step of forming irregularities of less than 400 nm on the substrate surface and the chlorosilane group (SiCl _n X _3-n
Group, n = 1,2,3, X is a functional group), the other end is immersed in a non-aqueous organic solvent in which a chlorosilane-based surfactant having a fluorocarbon group is dissolved, the substrate, A method for producing a water-repellent, oil-repellent and antifouling coating having irregularities of less than 400 nm on the surface, including a step of forming a chemisorption monomolecular film made of an activator on the surface of a substrate.

Above all, it is described that the uneven shape is formed by sandblasting, a chemical etching method using hydrofluoric acid, an electrolytic etching method, or a rubbing method using a sandpaper.

For example, Japanese Patent Application Laid-Open No. Hei 6-116430 discloses that
The water- and oil-repellent film and its manufacturing method are described.
A water-repellent and water-repellent film comprising an inorganic hard film having minute irregularities formed on at least one surface of a plastic film, and a chemisorption monomolecular film containing fluorine formed on the minute irregularities of the inorganic hard film through a siloxane bond. Oily film. Also, a step of forming an inorganic hard film on at least one surface of the plastic film, a step of performing plasma discharge treatment on the surface of the inorganic hard film in a gas containing carbon and fluorine, to form fine unevenness, and the unevenness The surface of the formed inorganic hard film is subjected to plasma discharge treatment with a gas containing at least oxygen to make the uneven surface hydrophilic, and the plastic film having the inorganic hard film formed on the uneven surface is treated with fluorocarbon. A compound containing a group and a chlorosilyl group is immersed in a solution dissolved in a non-aqueous solvent to form a chemisorption monomolecular film containing fluorine on the uneven surface of the inorganic hard film through a siloxane bond. A method for producing a water- and oil-repellent film is described.

In particular, the thickness of the inorganic hard film is 0.02 to
10 μm, and the roughness of fine irregularities is 0.01 to 0.
It is described as 3 μm. Further, for example, JP-A-7-197017 describes a solid having a water-repellent surface and a method for producing the same, in which at least a part of the surface has an uneven structure with a large period, and the uneven structure has the above-mentioned periodic structure. A solid having a water-repellent surface having a multi-step concavo-convex structure including a concavo-convex structure having a smaller period and having a surface area multiplication factor of 5 or more. In addition, by performing mechanical processing on the solid surface, by performing a chemical reaction treatment such as electroplating,
It describes a method of producing solids each having a water-repellent surface by precipitating crystals or aggregating particles.

Among them, the multi-step concavo-convex structure has a solid surface on which mechanical processing including cutting, grinding and electrolytic processing, electrical processing including laser processing, chemical processing including electrolysis, chemical reaction and diffusion-controlled aggregation. Processing, lithographic, plasma processing, vacuum deposition, etc.
It is described that the period is 1 mm or less and 10 nm or more.

Further, for example, in Japanese Patent Laid-Open No. 7-206475,
A water-repellent layer-carrying member is described, wherein a plurality of concave portions and convex portions are alternately and repeatedly formed on the surface, and the surface is coated with a water-repellent film made of a water-repellent material. The pitch of the recesses or protrusions covered by the water-repellent film is in the range of 20 μm to 150 μm,
There is described a water-repellent layer-carrying member having a concave portion and a convex portion formed so that the depth of the concave portion with respect to the pitch or the surface roughness of a virtual surface obtained by connecting the top portions of the convex portions is 500 μm or less.

Among them, it is described that the concave portion or the convex portion is formed into a quadrangular pyramid shape by photolithography, and the concave portion or the convex portion is alternately and repeatedly formed to form a Fresnel lens.

Further, for example, the water-repellent coating and its coating method described in JP-A-6-122838, JP-A-6-34
No. 5881, a water-repellent material and a method for producing the same, and a method for producing a super-water-repellent paint described in JP-A-7-26168, and an organic film described in JP-A-7-76797 and a method for forming the same There are proposals related to paints such as a fluorine-containing compound composite described in JP-A-4-283268.

Further, for example, the Chemical Society of Japan, 1992,
(12), pages 1511 to 1514, the preparation of a sponge-like alumina thin film by the sol-gel method is described, an alumina thin film is formed using aluminum nitrate nonahydrate, and the alumina thin film is heated in hot water. The surface structure changes into a sponge-like structure after being treated with, and has a sponge-like structure composed of aggregates of fibrous fine particles with pores of 100 to 200 nm and lengths of 50 to 100 nm and widths of around 5 nm. Alumina thin films are described.

[0012]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention As described above, for example, a water-repellent oil-repellent antifouling coating and a method for forming the same as described in JP-B-7-86146, and a water-repellent coating described in JP-A-6-116430. Oil-repellent film and its manufacturing method, solid having a water-repellent surface described in JP-A-7-197017 and its production method, and any of the water-repellent layer-carrying member described in JP-A-7-206475, water droplets Although a contact angle with respect to about 160 ° has been obtained, for example, etching with acid or fluorine to form an opaque or uneven shape thereof, various mechanical processing, electrical processing, chemical processing, There is a problem that a complicated process such as photolithography and plasma processing is required, and it is difficult to process a thin film.

Further, for example, the sponge-like alumina thin film has a small size of pore-like voids and surface irregularities, and the sponge-like structure composed of aggregates of the fibrous fine particles has insufficient shape characteristics. For example, there is a problem that it is difficult to sufficiently exhibit its performance as an underlayer film.

Therefore, the main object of the present invention is to make the peculiar voids and the peculiar shape into an aggregate and to control the transparent alumina film so as to increase the specific surface area. While exhibiting performance and bringing more practical application, a water-repellent film is formed on the surface of the water-repellent film at the same time to enhance the impregnating property, carrying property or holding property of the water-repellent film. The purpose is to utilize the unique irregularities on the surface of the surface layer to exert a synergistic effect, and to obtain a more excellent superhydrophobic film in a more stable state.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has a water repellent film impregnating property, carrying property or holding property on a substrate, for example, a glass substrate. As a base layer film, a transparent alumina film with a fine, firm, and petal-like shape with a higher specific surface area, which is more controlled so that the unique voids and the unique shape are aggregated, can be obtained. By forming it and coating it on top of it, the performance of impregnation, supportability or holding property of the water-repellent film is enhanced, and at the same time, the unique unevenness of the surface layer is utilized to synergize. The effect is exhibited, and the excellent super water-repellent film is brought to exert its performance remarkably, the optical characteristics are not impaired, the hardness is also improved, and the heat resistance or weather resistance is excellent, and the construction is improved. For construction or own Window materials, such as for cars, there is provided a useful oil-repellent antifouling film and its formation method in various film-coated glass article or the like for various building materials.

That is, the present invention is a water-repellent, oil-repellent, and antifouling film comprising a petal-shaped transparent alumina film formed on a substrate and a water-repellent film coated on the petal-shaped transparent alumina film. In addition, the petal-like transparent alumina film is formed by drying the film with a coating liquid containing at least an aluminum alkoxide and a stabilizer and heat-treating the amorphous alumina film to be subjected to hot water treatment, drying and firing. The water- and oil-repellent antifouling film described above, which is a petal-shaped transparent alumina film.

Further, the petal-shaped transparent alumina film has an average surface roughness Ra 'value of 17 nm or more and a specific surface area S _R of 1.5 or more obtained by surface-expanding the center line average roughness of the petal-shaped transparent alumina film. The water-repellent, oil-repellent, and antifouling film described above.

Further, the water-repellent and oil-repellent antifouling film is characterized in that the water-repellent film is a coating film obtained by applying a coating solution containing a fluorine-containing silane compound and heat-treating it. Furthermore, the fluorine-containing silane compound is a fluorocarbon.
The water- and oil-repellent antifouling film as described above, which is a fluorine-containing silane compound having a bon group.

Furthermore, the above-mentioned water-repellent, oil-repellent and antifouling film, wherein the substrate is a transparent glass substrate. Further, a coating liquid containing at least an aluminum alkoxide and a stabilizer is applied on a substrate, dried and baked to form an amorphous alumina film, and then the amorphous alumina film is subjected to hot water treatment and dried. After forming a petal-like transparent alumina film by baking, a coating liquid consisting of a fluorine-containing silane compound is applied on the film, and heat-treated to form a water-repellent film. Method of forming dirty film.

Further, the fluorine-containing silane compound is
The method for forming a water- and oil-repellent antifouling film as described above, which is a fluorine-containing silane compound having a fluorocarbon group. Furthermore, each of the above-mentioned methods for forming a water-repellent, oil-repellent, and antifouling film is provided in which the substrate is a transparent glass substrate.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Here, as described above, the water-repellent, oil-repellent, and antifouling property of a petal-shaped transparent alumina film formed on a substrate and a water-repellent film coated on the petal-shaped transparent alumina film. The film is a transparent alumina film that is controlled by combining the unique voids and the unique shape and increasing the specific surface area. Among the things that bring about the effect of
A water-repellent film is formed on it to bring about an improvement in the impregnating property, carrying property or holding property of the water-repellent film,
This is to utilize the unique irregularities on the surface of the surface layer to exert a synergistic effect, and to obtain a more excellent superhydrophobic film in a more stable state.

As the petal-like transparent alumina film as the underlayer film, an amorphous alumina film formed by coating a coating liquid containing at least an aluminum alkoxide and a stabilizer, for example, by drying at about 600 ° C. or lower and heat-treating the film. A hot-water-treated, dried, petal-shaped transparent alumina film obtained by baking, the average surface roughness Ra'value of which the center line average roughness of the petal-shaped transparent alumina film is surface-expanded is 17 nm or more, Moreover, the specific surface area S _R is 1.5 or more.

As the aluminum alkoxide,
For example, aluminum ethoxide, aluminum isopropoxide, aluminum-n-butoxide, aluminum
-sec-butoxide, aluminum-tert-butoxide, aluminum acetylacetonate and the like can be mentioned.

Examples of the stabilizer include β-diketones such as acetylacetone and ethyl acetoacetate,
Examples thereof include alkanolamines such as monoethanolamine, dietanolamine and triethanolamine, and general metal alkoxide stabilizers.

Examples of the diluting solvent include methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, and a diluting solvent used in a general sol-gel method.

As a coating solution containing at least the aluminum alkoxide and the stabilizer, aluminum alkoxide reacts quickly with water in the air to form a gel and becomes cloudy, while it has an effect of preventing this, for example, β-diketone. Alumina alkoxide of dilute alcohol is added to a concentration at which it can be easily coated with a diluting solvent such as various alcohols, for example, by adding a stabilizer such as alkanols and alkanolamines in a molar ratio of about 1 or more. Was diluted to a molar ratio of about 10 or more, preferably about 20 or more, and a small amount of water was added as a catalyst to prepare a coating solution.

The preferred mixing ratio is, for example, aluminum alkoxide: diluting solvent: stabilizer: water = 1: 10 to 100: 0.5 to 2: 0 to 5 in terms of molar ratio. The preparation of the coating liquid in which the respective raw materials are added and mixed is performed, for example, as in Example 1 described later.

Further, as the water repellent agent for the water repellent film, for example,
For example, a fluorine-containing silane compound having a fluorocarbon group
Thing, specifically CF_Three(CH_Two)_TwoSi (OCH_Three)_Three, CF_Three(CH_Two)_TwoSiC
l_Three, CF_Three(CF_Two)_Five(CH_Two)_TwoSi (OCH_Three)_Three, CF_Three(CF_Two)_Five(CH_Two)_TwoSiC
l_Three, CF_Three(CF_Two)₇(CH_Two)_TwoSi (OCH_Three)_Three, CF _Three(CF_Two)₇(CH_Two)_TwoSiC
l_Three, CF_Three(CF_Two)₇(CH_Two)_ThreeSiCH_Three(OCH_Three)_Two, CF_Three(CF_Two)₇(CH_Two)_TwoS
iCH_ThreeCl _TwoEtc., generally CF_Three(CF_Two)_a(CH_Two)_TwoSiR
_bX_c[R: alkyl group, X: alkoxy group or halogen
Group that undergoes hydrolysis, such as a hydrogen atom, a: 0 to an integer of 7, b: 0
~ 2 integer, c: 1 to 3 integer, b + c = 3]
Things.

Further, for example, fluorinated pitch [CF _m , m: 1.1
~ 1.6. Made by Osaka Gas Co., Ltd.]. Or fluororesin, specifically polytetrafluoroethylene [PTFE], tetraethylene-hexafluoropropylene copolymer [PFEP], ethylene-tetrafluoroethylene copolymer [PETFE],
Tetrafluoroethylene-perfluoroalkylvinylether copolymer [PFA], ethylene-chlorotrifluoroethylene copolymer [PECTFE], tetrafluoroethylene-hexafluoropropylene-perfluoroalkylvinylether copolymer Combined [PEPE], polychlorotrifluoroethylene [PCTFE], polyvinylidene fluoride [PVdF], polyvinyl fluoride [PVF] and the like. And graphite fluoride.

As a coating method for forming a film, for example, a dipping method, a spin coat method, a nozzle flow coat method, a spray method, a reverse coat method, a flexo method, a printing method, a flow coat method. The known coating means such as a coating method and a combination thereof can be appropriately adopted. Among them, the pulling rate in the dipping method may be appropriately selected depending on the required film thickness, but it is preferable to pull up at a quiet uniform rate of, for example, about 0.1 to 3.0 mm / sec after immersion.

Furthermore, the drying and firing in forming the amorphous alumina film is, for example, about
The temperature is about 600 ° C. or lower, preferably about 550 ° C. or lower for about 5 to 60 minutes. Regarding the drying and baking after the hot water treatment, for example, only about 100 ° C for about 10 minutes or only after drying, for example, about 300 to 500 ° C for about 10 minutes. Firing,
By forming a petal-like transparent alumina film, it was possible to obtain a petal-like transparent alumina film that could be put into practical use and could be effective.
The thickness of the petal-shaped transparent alumina film was about 50 nm.
It is preferably not less than 400 nm and not more than 400 nm. For drying and baking the water-repellent film, for example, from room temperature to about 10
Only drying for about 10 to 120 minutes at about 0 ℃,
Alternatively, the drying is followed by calcination, for example, about 200 ° C to 450 ° C.
Firing is performed for about 10 minutes at about ℃.

The hot water treatment of the amorphous alumina film is carried out, for example, with hot water at 50 ° C. to 100 ° C.
By immersing the glass substrate with the amorphous alumina film in hot water boiled at about 100 ° C and subjecting the surface layer surface of the amorphous alumina film to deflocculation, etc., as shown in FIGS. As shown, peculiar petal-shaped ones with peculiar minute pore-shaped voids have a surface layer that is randomly aggregated, and it is possible to form peculiar voids and shapes that are aimed at. For example, it becomes a petal-like transparent alumina film which can be formed as a film that exhibits its function and performance more sufficiently as an underlayer film having impregnating property, carrying property, and retaining property. The treatment time of the hot water treatment is preferably about 5 minutes to 24 hours.

Furthermore, as one of the evaluation methods for the obtained petal-shaped transparent alumina film, a scanning electron microscope (SEM) is used.
Observing the top surface of the surface with a magnification of 50
Photograph observation with a side cross-section at a magnification of 10,000 times, and photograph observation with a perspective view of the surface layer surface by a cyclic contact mode atomic force microscope (CC-AFM) and surface expansion of the center line average roughness Ra of the film by the observation. The average surface roughness Ra ′ value and the specific surface area S _R are obtained and displayed. [See Example 1].

As a result, as shown in FIGS. 1 to 3, for example, the size of the voids is about 50 nm to 100 nm and the petals are about 20 nm to 50 nm. Above all, the average surface roughness Ra 'value is Is about 17 nm or more, and the specific surface area S _R is about 1.5 or more, preferably Ra 'value is about 20 nm.
The specific surface area S _R is about 1.7 or more. It goes without saying that problems such as haze will occur when the values of both are extremely large.

Furthermore, as one of the methods for evaluating the water-repellent performance of the water-repellent film, a contact angle meter (manufactured by Elma Co., Ltd.) is used, and water drops (water droplets) in the atmosphere (about 25 ° C.) of the film are used. Amount about 1.7 μ
It was carried out by measuring the contact angle θ (°) with respect to l).
As a result, the contact angle θ was about 140 ° or more, preferably about 150 ° or more and 170 ° or less, and it had super-water repellency.

As described above, according to the water-repellent, oil-repellent and antifouling film of the present invention and the method for forming the same, a petal-shaped transparent alumina film formed on a substrate and a water-repellent film coated on the petal-shaped transparent alumina film. Since it is made of a film, the water-repellent film can be improved in impregnating property, carrying property or retaining property, and is controlled more so as to be an aggregate of the unique void and the unique shape. By forming a transparent alumina film that is fine and firm and has a petal-like shape with an increased specific surface area as a base layer film, and by coating a water-repellent film on it,
It is highly safe and can be obtained easily and efficiently without any troublesome process, and enhances the performance of impregnation, supportability or retainability of the water-repellent film, while at the same time exerting a synergistic effect by utilizing the unique irregularities of the surface layer. , Brings an excellent super water-repellent film and exerts its performance remarkably, without impairing the optical characteristics,
It also has improved hardness and excellent heat resistance, weather resistance, etc., and is useful as a water-repellent, oil-repellent and anti-fouling property for window materials for building construction or automobiles, various glass products with films, or various building materials. A film and a method for forming the film are provided.

[0037]

The present invention will be described below in detail with reference to examples. However, the present invention is not limited to such an embodiment.

Example 1 A clear float glass substrate having a size of about 100 mm × 100 mm and a thickness of about 2 mm was sequentially washed with a neutral detergent, water rinse, alcohol, dried and then wiped with acetone to form a glass substrate for coating. .

Aluminum-sec-Butoxide [Al (O-sec
-Bu) ₃ ] and isopropyl alcohol [IPA] are stirred at room temperature for about 30 minutes, ethyl acetoacetate [EAcAc] is added, and the mixture is stirred at room temperature for about 3 hours, and then water [H ₂ O] and [IPA] are added. ], And Al (O-sec-Bu) ₃ : IPA: EAcAc: H ₂ O in molar ratio
= 1: 20: 1: 2, and stir at room temperature for about 1 hour.
_A coating liquid for the underlayer film, which is a ₂ O ₃ sol, was prepared.

Next, one surface of the glass substrate for coating is masked with a mask material, the glass substrate for coating with masking is immersed in the coating liquid tank for the underlayer film, and then pulled up at a speed of about 1 mm / sec. By removing the mask material, a coating film was formed on the surface of the coating glass substrate by a so-called dipping method.

Then, after drying, a heat treatment of baking at about 500 ° C. for about 10 minutes was performed to obtain a transparent amorphous alumina film.
Next, after soaking in hot water at about 100 ° C for about 0.5 to 2 hours, dry it at about 100 ° C for about 10 minutes,
Further, it was baked at about 400 ° C. for about 10 minutes to obtain a glass substrate with a transparent alumina thin film having a unique surface layer shape.

The following evaluation was made on the obtained transparent alumina thin film of the glass substrate with the transparent alumina thin film having the peculiar surface layer surface shape. [Observation of surface layer] B. Scanning electron microscope (SEM) [Hitachi S-4500
, Acceleration voltage 5.0 kV, magnification 50,000 times]. As a part thereof, a photograph of the surface of the surface viewed from the top and a photograph of the cross section viewed from the side are shown.

Cyclic contact mode of scanning probe microscope Atomic force microscope (CC-AFM) [SEIKO-
Electronic Industry Co., Ltd., SPI3700, 1.0 μm square scan]
Was observed. The average surface roughness Ra ′ value (nm) obtained by surface-expanding the center line average roughness of the alumina thin film and the specific surface area S _R are shown.

That is, the average surface roughness Ra 'value (nm) is JI
The center line average roughness Ra defined in SB 0601 is applied to the measurement surface and expanded in three dimensions, and expressed as "the value obtained by averaging the absolute values of the deviations from the reference surface to the designated surface", It is given by the following formula.

[0045]

[Equation 1]

However, Ra ': average surface roughness value (nm). S ₀ : Area assuming that the measurement surface is ideally flat, | X _R
−X _L | × | X _T −X _B |. F (X, Y): Measuring point (X
, Y), X is the X coordinate, and Y is the Y coordinate. X _R
~ X _L : Range of X coordinate of measurement surface. X _{T to} X _B :
Y coordinate range. Z ₀ : average height in the measurement plane.

The specific surface area (S _R ) is S _R = S / S
₀ [S ₀ : Area when the measurement surface is ideally flat. S
: Actual measurement surface area. ] Is required. The actual surface area of the measurement surface is obtained as follows.

First, the three closest data points (A, B,
C) is divided into small triangles, and then the area ΔS of each small triangle is obtained using the vector product. △ S (△ AB
C) = | AB × AC | / 2 (where AB and AC are the lengths of each side), and the total of ΔS is the required surface area S.

As a result, the surface layer surface of the transparent alumina film in the obtained glass substrate with the transparent alumina thin film was 5.0
Figure 1 shows a SEM photograph of the surface of the surface viewed from the top at a magnification of × 10,000, and Figure 2 shows a SEM photograph of the cross section viewed at a magnification of × 50,000.
As shown in Fig. 5, a fine and intricate peculiar pore-like void of about 50 nm to 100 nm is created, and about 20 nm to 50 nm.
It was a petal-like transparent alumina film that was aggregated by exhibiting a unique petal shape that was randomly and intricately complicated in a small size.

Further, a CC-AFM photograph of the petal-like transparent alumina film in perspective is shown in FIG. 3, and the average surface roughness Ra 'value (nm) is about 26 nm, and the specific surface area (S _R )
Was about 1.8.

Although the film thickness was about 150 nm, a petal-like transparent alumina film could be obtained in the range of about 50 nm to 400 nm without the occurrence of defects such as cracks. The obtained petal-shaped transparent alumina film on a glass substrate with a petal-shaped transparent alumina film, for example, its hardness,
When heat resistance, weather resistance, optical characteristics such as visible light transmittance and visible light reflectance were evaluated, for example, excellent transparency was obtained,
It exhibited excellent reflection reduction properties, improved hardness, and also had heat resistance and weather resistance.

Next, 1 g of fluorinated pitch [C ₆ F ₆ ]
To this, 66 g of 1,1,2-trichloro-1,2,2-trifluoroethane [Cl ₂ FCCClF ₂ , melting point: -35 ° C, boiling point: 47.6 ° C] was added, and the mixture was stirred at room temperature for about 24 hours, and then water repellent. It was used as a film coating liquid.

The non-film surface side of the glass substrate with a petal-shaped transparent alumina film is masked with a mask material, and the glass with a petal-shaped transparent alumina film is immersed in the coating liquid for the water-repellent film in the coating liquid tank for the water-repellent film. The substrate is dipped and pulled up at a speed of about 1.96 mm / sec, and the mask material is not peeled off. The glass substrate with the petal-like transparent alumina film is coated by the dipping method on the petal-like transparent alumina thin film. A coating film was formed.

Next, the water-repellent film of the glass substrate with a petal-shaped transparent alumina film coated with the water-repellent film is dried to obtain a glass substrate with a laminated film in which the water-repellent film and the petal-shaped transparent alumina film are laminated in two layers. It was

Regarding the obtained glass substrate with a laminated film,
The following tests were performed. [Water repellency test] The contact angle θ (°) of the laminated film with respect to water (water droplet amount: about 1.7 μl) in the atmosphere (about 25 ° C.) was measured using a contact angle meter (manufactured by Elma Co., Ltd.). .

The result is that the contact angle θ is about 140 °,
It was a water- and oil-repellent antifouling film that maintained the high contact angle for a relatively long time and had the desired performance. Example 2 First, a petal-shaped transparent alumina film similar to that in Example 1 was formed on the same glass substrate as in Example 1, and then TSL8233 as fluoroalkylsilane [FAS] was used as a coating liquid for the water repellent film.
[Made by Toshiba Silicon Co., Ltd. _{C 8 F 17 C 2 H 4} Si (OCH 3) 3 ] using a coating solution mainly composed of, coated deposited on the petal-like transparent alumina film. Incidentally, the mixing ratio of the water-repellent film coating solution, in a molar _{ratio, C 8 F 17 C 2 H} 4 Si (OCH 3) 3: Methyl alcohol - Le [MeOH]: water [H ₂ O]: hydrochloride [ HCl] = 1: 10: 3: 0.
It was set to around 0005. In addition, heat treatment was performed at about 200 ° C to 400 ° C for about 10 minutes and wiped with a cloth.

The same test as in Example 1 was conducted on the glass substrate with a laminated film obtained by laminating the obtained water-repellent film and the petal-like transparent alumina film in two layers. The result is that the contact angle θ is about 16
It was 5 °, and it was a water- and oil-repellent antifouling film that maintained the high contact angle for a relatively long time and had the desired performance.

Furthermore, the influence of the treatment time of the hot water treatment for obtaining the petal-like transparent alumina film on the contact angle θ was confirmed, and the contact angle θ was about 165 ° during the treatment time of 10 to 120 minutes. It was in the range of to 167 °.

Furthermore, when the influence of the heat treatment temperature of the FAS on the contact angle θ was confirmed, the heat treatment temperature was 400 ° C.
The contact angle θ was in the range of about 166 ° to 155 ° at ˜450 ° C.

[0060] Comparative Example 1 aluminum nitrate nonahydrate _{[Al (NO 3) 3 · 9H} 2 O ] 1,3 butanediol - about 5 to about 90 ° C. was added Le [1,3-Butandiol]
After stirring for 20 hours, a 20 wt% Al (NO ₃ ) ₃ .9H ₂ O solution was prepared as a coating solution.

Then, the same glass substrate for coating as in Example 1 was dipped in the coating solution in the coating solution tank, and then, about 0.
It was coated by a dipping method of pulling up with a pulling speed of 4 mm / sec. Then, after drying at about 100 ° C. for about 2 hours, it was baked at about 500 ° C. for about 5 hours.

Next, hot water treatment at about 100 ° C. for about 2 hours is performed, and after drying at about 100 ° C. for about 30 minutes, about 400 ° C.
It was baked for about 10 minutes. The obtained glass substrate with an alumina thin film was photographed by SEM and CC-AFM as in Example 1.
The average surface roughness Ra 'value (nm) and the specific surface area S _R were evaluated.

As a result, a SEM photograph of 35,000 times magnification is shown in FIG.
As shown in Fig. 5, the surface had a sponge-like shape having pores of about 100 nm to 200 nm, and an aggregate of fibrous particles having a length of about 50 nm to 100 nm and a width of about 5 nm.

Further, the CC-AFM photograph is shown in FIG. 5, and the average surface roughness Ra ′ value (nm) is about 15 nm and the specific surface area (S _R ) is about 1.3. Then
A water-repellent film similar to that of Example 1 was coated on the sponge-like transparent alumina film of the glass substrate with the sponge-like transparent alumina thin film.

The same test as in Example 1 was conducted on the glass substrate with a laminated film obtained by laminating the water repellent film and the sponge-like transparent alumina film in two layers. As a result, the contact angle θ was about 130 ° to 135 °, and it was difficult to say that the film was a water / oil / oil / fouling resistant film having the desired super water repellency.

[0066]

As described above, according to the water- and oil-repellent antifouling film and the method for forming the same of the present invention, a film can be obtained inexpensively and efficiently by a simple and easy film forming means and hot water treatment. It is possible to obtain an alumina oxide thin film which has a surface layer surface which is formed of a petal-like aggregate having a uniquely controlled shape in the film, and which has a unique pore-like void, and which further enhances the specific surface area, For example, as an underlayer film of various functional thin films such as a water-repellent thin film, the performance is remarkably exhibited by being fully embedded by being embedded and coated with outstanding impregnating property, carrying property or retaining property. It can be made super water-repellent without impairing the optical properties, and becomes excellent in adhesion, heat resistance, durability, weather resistance, etc., including architectural construction or automobile window materials, various glass articles, For building materials Suitably adopted to have, it is to provide a useful oil-repellent antifouling film and its formation method.

[Brief description of drawings]

FIG. 1 is a diagram showing a photograph of a surface layer surface of a petal-shaped transparent alumina film, which is a base layer film of the present invention, in Example 1, viewed from the top with a magnification of 50,000 times by SEM.

FIG. 2 is a view showing a photograph of a cross section of a petal-like transparent alumina film, which is a base layer film of the present invention, in Example 1 as viewed sideways by SEM at a magnification of 50000 times.

FIG. 3 is a view showing a photograph of a surface layer surface of a petal-like transparent alumina film, which is the underlayer film of the present invention, in a perspective view by CC-AFM in Example 1.

FIG. 4 is a view showing a photograph of the surface of the surface of the conventional sponge-like transparent alumina film, which is a conventional underlayer film, in Comparative Example 1 as viewed from above by 35,000 times by SEM.

FIG. 5 is a view showing a photograph of a surface layer surface of a conventional sponge-like transparent alumina film, which is a conventional underlayer film, taken by CC-AFM in Comparative Example 1.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location C09K 3/18 104 C09K 3/18 104 (72) Inventor Seiji Tadanaga 6-998 Naka Mozucho, Sakai City, Osaka Prefecture -3 (72) Inventor Hiroshi Inaba 1510 Oguchi-cho, Matsusaka-shi, Mie Central Glass Co., Ltd. Glass Research Institute (72) Inventor Akira Yuasa 1510 Oguchi-cho, Matsusaka-shi, Mie Central Glass Co., Ltd. (72) Inventor Akamatsu Yoshinori 1510 Oguchi-cho, Matsusaka-shi, Mie Central Glass Co., Ltd. Glass Research Institute (72) Inventor Hideki Yamamoto 1510 Oguchi-cho, Matsusaka-shi, Mie Central Glass Co., Ltd. Glass Research Institute

Claims (9)

[Claims] 1. A water- and oil-repellent antifouling film comprising a petal-shaped transparent alumina film formed on a substrate and a water-repellent film coated on the petal-shaped transparent alumina film. 2. An amorphous alumina film formed by drying and heat-treating the petal-like transparent alumina film with a coating liquid comprising at least an aluminum alkoxide and a stabilizer is hot water treated, dried and fired. The water-repellent, oil-repellent, and antifouling film according to claim 1, which is a petal-shaped transparent alumina film. 3. The petal-shaped transparent alumina film has an average surface roughness Ra ′ value of 17 nm or more and a specific surface area S _R of 1.5 or more obtained by surface-expanding the centerline average roughness of the petal-shaped transparent alumina film. The water- and oil-repellent antifouling film according to claim 1 or 2. 4. The water-repellent, oil-repellent and antifouling property according to claim 1, wherein the water-repellent film is a coating film obtained by applying a coating liquid containing a fluorine-containing silane compound and heat-treating the coating liquid. film. 5. The water- and oil-repellent antifouling film according to claim 4, wherein the fluorine-containing silane compound is a fluorine-containing silane compound having a fluorocarbon group. 6. The water- and oil-repellent antifouling film according to claim 1, wherein the substrate is a transparent glass substrate. 7. A substrate is coated with a coating solution containing at least an aluminum alkoxide and a stabilizer, dried and baked to form an amorphous alumina film, and then the amorphous alumina film is subjected to hot water treatment. The water-repellent film is characterized in that after forming a petal-shaped transparent alumina film by drying, baking, and then applying a coating liquid consisting of a fluorine-containing silane compound on it, and heat-treating it to form a water-repellent film. Method for forming oil-repellent antifouling film. 8. The method of forming a water- and oil-repellent antifouling film according to claim 7, wherein the fluorine-containing silane compound is a fluorine-containing silane compound having a fluorocarbon group. 9. The method for forming a water- and oil-repellent antifouling film according to claim 7, wherein the substrate is a transparent glass substrate.