JPH10114543A - Anticlounding coating film and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an anticlouding coating film excellent in visible light transmissivity, durability and wear resistance and not distorting a reflected image or an image seen through the film by forming a prescribed thin multiple oxide film on the surface of a substrate and subjecting the film to specified treatment. SOLUTION: A thin multiple oxide film is formed on the surface of a substrate, preferably float glass from a soln. contg. metallic alkoxide type compds. or dispersed fine particles of oxides each having a low equilibrium vapor pressure. The multiple oxide film is, e.g. a silica-alumina film formed by coating the substrate with a soln. prepd. by adding a silica sol to an alumina sol and carrying out firing at 200-680 deg.C. The multiple oxide film is heated preferably to 50-200 deg.C and immersed in hot pure water preferably at 80-100 deg.C preferably for 1-10min to obtain the objective anticlouding coating film having the same neutral reflected color tone as the glass substrate, maintaining superior anticlouding performance and widely applicable to various window materials or mirrors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vehicle, a building material,
The present invention relates to an antifogging film suitable for use as a window glass or a mirror for industrial use, and a method for producing the same.

[0002]

2. Description of the Related Art In order to impart anti-fogging properties to a glass substrate surface, it is a general technique to form a hydrophilic film on the glass substrate surface.

For example, it has been known for a long time that a surfactant is applied to the surface of a glass substrate to make the surface hydrophilic, and a water-soluble organic polymer such as polyacrylic acid or polyvinyl alcohol is used as the surfactant. Attempts have been made to increase the durability by adding / blending-(for example, JP-A-52-101680).

Further, for example, there is a method of applying a hydrophilic organic polymer represented by polyethylene oxide such as polyethylene glycol or polyvinylpyrrolidone to a glass surface and treating the hydrophilic surface (for example, Japanese Patent Laid-Open Publication Akira
48-89278, JP-A-1-37268, etc.).

Further, a hydrophilic polymer such as cellulose, glycols and glycerin is formed on the surface and inside of a porous membrane made of a hydrophobic polymer via a coating film of a copolymer of polyvinyl alcohol and vinyl acetate. (See, for example, Japanese Patent Publication No. 5-67330).

Further, as a physical method, a hydrophilization treatment such as a plasma treatment or a laser irradiation treatment has been put into practical use. Generally, it is effective for a short period after the treatment, but there is a problem in sustainability. It is said that there is. Chemical methods include a method of generating radicals on the surface and graft-polymerizing a polymerizable compound having a hydrophilic residue, a method of breaking the bond on the surface with an acid or a basic substance, and changing the surface to a hydrophilic residue. And so on.

However, these methods only provide hydrophilicity temporarily or in a relatively short period of time, and it is difficult to expect sufficient sustainability of the anti-fogging effect, and it is difficult for the water film to become uniform and to see through. Although the image and the reflection image are distorted and have antifogging properties, it is difficult to employ them in actual use.

[0008]

As described above, for example, hydrophilicity due to physical treatment can maintain its effect only for a short period of time, and a polyethylene oxide-based organic polymer film generally has water resistance and water resistance. Not enough durability
The strength of the film is also low, and it cannot be said that it is practically sufficient for some applications.

Further, for example, in a method in which cellulose or the like is fixed on the surface and inside of a porous film via a film of a copolymer of polyvinyl alcohol and vinyl acetate, the film is extremely soft. Moreover, it is difficult to expect chemical durability, and the use to be used is limited.

Further, for example, a coating made of an inorganic substance
Substances having relatively high film strength but exhibiting hydrophilicity have high solubility in water and the coating easily disappears, so that their use is practically limited.

It is an object of the present invention to provide an anti-fogging film having excellent durability, high hardness, high transparency, and a uniform water film, which does not distort a transparent or reflected image. It is in.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to add a silica sol to an alumina sol solution and apply the composite solution to a substrate.
By firing at 0 to 680 ° C., a composite oxide film (first layer) made of a metal oxide containing silica and alumina is formed. Next, the formed film is heated to 50 to 200 ° C.,
An antifogging film characterized by being immersed in hot water of 80 to 100 ° C. and a method for producing the same.

That is, according to the present invention, the thin film formed on the surface of the substrate is a silica-alumina composite oxide film,
An anti-fogging film, wherein the formed composite oxide film is heated and then immersed in hot water of pure water in the heated state.

The heating temperature is 50 to 200 ° C.
The anti-fogging film described above, wherein Further, the immersion treatment with the hot water is performed by heating the hot water at a temperature of 80 to 100 ° C.
The antifogging film described above, which is a process of immersing for 10 minutes.

The above-mentioned anti-fogging film is characterized in that the composite oxide film is formed from a solution in which a metal alkoxide compound or oxide particles having a low equilibrium water vapor pressure is dispersed.

Further, in the above anti-fogging coating, the content of silica is 10 to 40 wt%. Further, in the above anti-fogging film, the reflection color tone of the film is neutral.

The above-mentioned antifogging film, wherein the substrate is float glass. Further, a silica-alumina-based composite sol solution comprising a metal oxide sol solution for forming an amorphous metal oxide or / and a solution to which a metal oxide fine particle dispersion sol is added is applied to a substrate and fired. Forming a silica-alumina-based composite oxide film, heating the substrate with the film, and immersing the substrate in hot water of pure water.

Further, in the above composite sol solution,
The method for producing an anti-fogging film described above, wherein the content of silica in the solution is 1 to 10 wt% and the content of alumina is 1 to 10 wt%.

Further, the heating temperature is 50-200.
The method for producing the above-mentioned antifogging film, wherein the method is characterized in that the temperature is ℃. Furthermore, the immersion treatment with the hot water is performed at a temperature of 80 to
The above-mentioned method for producing an anti-fogging film, which is a process of immersing the film in hot water at 100 ° C. for 1 to 10 minutes.

Further, the calcination is performed at 500 ° C. or more.
An object of the present invention is to provide the above-described anti-fogging thin film and a method for producing the same, wherein the heat treatment is performed at a temperature of 680 ° C. or lower.

[0021]

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention relates to a silica-alumina comprising a metal oxide sol solution for forming an amorphous metal oxide and / or a solution to which a metal oxide fine particle dispersion sol is added. The composite oxide sol solution is applied to a substrate and baked at 200 to 680 ° C. to form a composite oxide film made of a metal oxide containing silica-alumina, and the substrate with the film is heated to 50 to 200 ° C. After warming, 80 ~ 10
The antifogging film is obtained by immersion treatment in hot water of pure water at 0 ° C. for about 1 to 10 minutes.

Thus, for example, a silica-alumina-based composite oxide thin film having a hydrophilic surface and an antifogging property by itself is further heated and immersed in hot water to form a thin film on the surface. By increasing the number of hydroxyl groups, an antifogging film having extremely excellent hydrophilicity and durability can be obtained.

Examples of the substrate used include, but are not limited to, glass (automotive glass, aircraft glass, mirrors, lenses, etc.), metal, and the like. Hereinafter, the present invention will be described in detail.

As the raw material of the composite oxide according to the present invention,
Colloidal silica and alumina fine particle dispersion sol in which ultrafine particles of metal alkoxide, tetraethoxysilane, tetramethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, aluminum sec propoxide, aluminum isopropoxide, or silica are dispersed. .

Specifically, for example, as silica sol,
Corcote P, Corcote 6P (manufactured by Nippon Corcote),
Supercera (manufactured by Daihachi Chemical Industry Co., Ltd.), Atron NSi
[Manufactured by Nippon Soda Co., Ltd.], colloidal silica such as IPA-ST, ST-OXS [manufactured by Nissan Chemical Co., Ltd.], and aluminum fine particle dispersion sol such as alumina sol-10 and alumina clear sol [Kawaken Fine Chemical ( Co., Ltd.) can be used.

The particle diameter of the alumina fine particle dispersion sol is 15 to 30.
Those having a range of about nm are preferred. If the size is larger than this, the transparency of the coating film obtained after firing is slightly deteriorated, and for example, haze (clouding) of about several% occurs. Preferably, the particle size is about 20 nm or less.

The amount of silica used as the metal oxide is preferably in the range of about 10 to 40% by weight of the entire composite oxide thin film.
If the amount of silica is less than about 10% by weight, it is difficult to exhibit a sufficient antifogging effect of the film, and if it exceeds about 40% by weight, the stability of the mixed sol solution is lost. From the viewpoint of the stability of the mixed sol liquid, it is preferably in the range of about 10 to 30 wt%.

The solid content of silica and alumina added to the coating solution is preferably in the range of about 1 to 10% by weight. If the solid content is less than about 1% by weight, a sufficient antifogging effect is hardly exhibited, and if it exceeds about 10% by weight, the stability of the sol solution is lost and precipitation occurs. Preferably, the solid concentration is in the range of about 2 to 7% by weight.

The above composite sol solution can be used by diluting it with water or an organic solvent, if necessary. Examples of the organic solvent used include primary alcohols such as methanol, ethanol and n-butanol, secondary alcohols such as isopropyl alcohol, and tertiary butanols such as tert-butanol. Grade Alco-
And ethers, ketones, cyclohexane and the like or dimethylformamide and the like, and these may be used alone or as a mixture.

The method of applying the above-mentioned composite sol coating solution on a substrate includes a dipping method, a spray method,
Flow-coat method, spin-coat method, bar-coat method, ro-coat method
Known coating means such as a lacquer method, a reverse method, a flexo method, and a printing method can be appropriately employed.

The film applied on the substrate is fired at about 500 to 680 ° C. to form an antifogging film. If the temperature is less than about 500 ° C, the mechanical strength of the film is not sufficient.If the temperature exceeds about 680 ° C, hydroxyl groups on the surface of alumina decrease,
In addition, the transition from amorphous alumina to γ-alumina makes it difficult for the anti-fogging effect to be sufficiently exhibited.

The film thickness of the anti-fogging film is from 100 to 30
About 0 nm is desirable, and if the film thickness is less than about 100 nm, it is difficult to exhibit antifogging performance for a long time,
If it exceeds about 300 nm, the risk of cracks occurring in the film after firing in a single coating operation may increase, or the transparency of the film may deteriorate. Preferably 200-25
A range of about 0 nm is good.

Further, the surface roughness (center line average roughness) of the coating is preferably, for example, about 20 nm or less.
If the surface roughness exceeds about 20 nm, the haze (fogging) of the film increases, and the transparency deteriorates.

Further, the heating temperature of the film of the film-coated substrate during the hot water immersion treatment is preferably in the range of about 50 to 200 ° C. If the heating temperature is less than about 50 ° C, the reactivity of the membrane with hot water is poor, and if it exceeds about 200 ° C, the temperature is too high and water evaporates on the membrane surface, effectively reacting the membrane with hot water. As a result, sufficient anti-fog performance cannot be exhibited.
Preferably, it is in the range of about 80 to 170 ° C.

The pure water used as the hot water is purified water obtained by ion exchange or the like, and has a specific resistance of, for example, 10 × 10 ⁴ Ω · cm or more.
Furthermore, regarding the temperature of hot water during hot water immersion processing,
A temperature of about 80 to 100 ° C is desirable. If the temperature of the hot water is less than about 80 ° C., the reactivity with the anti-fogging film is poor, and it is difficult to expect further improvement and sustainability of the anti-fogging property.

Further, the durability of the anti-fogging effect is affected by the hydrophilicity and water retention of the film surface, so that the contact angle between the film surface and water is low, and it is necessary to absorb as much water as possible. If possible, the anti-fogging effect can be maintained. For this reason, as described above, by immersing the anti-fogging film formed on the substrate in hot water, a large number of hydroxyl groups are formed on the film surface, and the hydrophilicity is improved. That is, as the number of hydroxyl groups on the film surface increases, the ability to adsorb water increases, so that more water can be stored, and the durability of the anti-fogging effect can be improved.

As described above, according to the present invention, the thin film formed on the surface of the substrate is a silica-alumina-based composite oxide film. By immersion treatment in hot water, it exhibits exceptionally excellent anti-fog performance and maintains its anti-fog performance for an extremely long period without defects such as cracks and sufficient visible light transmittance and durability. Industrial articles such as architectural window materials or mirrors, which have excellent wear resistance, do not cause distortion in a perspective image or a reflection image, and have a neutral reflection color. Further, the present invention can provide a useful antifogging thin film which can be widely used for various coatings such as window materials for vehicles such as automobiles, window materials for ships and aircraft, etc., and a method for producing the same. .

[0038]

EXAMPLES Hereinafter, in order to clarify the effects of the present invention, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these. The evaluation of the anti-fogging film of each example was performed by the following evaluation method. Anti-fogging performance evaluation method: After contacting with saturated steam at about 43 ° C. for about 3 minutes, the occurrence of fogging is visually evaluated, and once the sample is dried and the sample temperature is lowered to room temperature, it comes into contact with saturated steam again. Was set as one cycle, and this operation was repeatedly evaluated for 10 cycles.

In Table 1 to be described later, those in which no fogging was observed were marked with ○, and those in which fogging was observed were marked with x. [For example, an anti-fog test for spectacles (JIS S
4040)] [Pass / Fail Judgment] When no fogging occurred even in 10 cycles, it was judged as acceptable.

The sample is left in a freezer at −20 ° C. for about 10 minutes, and after confirming that the temperature of the sample has reached −20 ° C., the sample is left in an environment of about 25 ° C. and about 50% RH for one cycle. The occurrence of fogging was visually evaluated.

In Table 2 described below, those with no fogging are marked with a circle, and those with fogging are marked with a cross.
Marked. [Pass / Fail Judgment] When no fogging occurred in a 10-cycle test, the test was passed. Change of contact angle with time: Measuring equipment Kyowa Interface Science CA-A type (water droplet) Measurement environment Atmosphere (25 ° C) Water droplet Pure water (20 μl) No wiping of surface when measuring contact angle (°).

[Pass / Fail Judgment] Initial contact angle (zero time) is 5
The contact angle is less than approx.
A grade of less than or equal was accepted. Membrane strength evaluation method: Robustness test Load; 100 g / cm ² cotton canvas; campus cloth (JIS L 3102-1961-1206) Number of strokes: 1000 round trips In Table 4 below, visual scratches and clouding due to exhalation are shown. No occurrence was indicated by ○, and scratches caused by clouding were indicated by x.

[Pass / Fail Judgment] When no scratches were generated and no clouding due to exhalation occurred, the sample was judged as acceptable. Taber abrasion test Wear wheel; CS-10F Load; 250 gf Revolution: 1000 times Haze value measuring device; NDH-20D manufactured by Nidecshoku Kogyo Co., Ltd. At the membrane before and after the test
Indicates that the haze value (ΔH) was less than 5% and there was no fogging due to exhalation, and clouding due to exhalation was observed when the membrane haze value (ΔH) before and after the test was 5% or more. Is marked with x.

[Pass / Fail Judgment] The membrane haze value before and after the test (△
H) was less than 5%, and no clouding due to expiration occurred. Coating shape observation: Atomic force microscope (AFM) mode of scanning probe microscope (Seiko Electronics, SPI3700, 5μ)
(m square scan) A photograph of the surface and cross section of the surface of the coating was observed, and the center line average roughness Ra value defined in JIS B 0601 was determined.

Scanning electron microscope (SEM, Hitachi S-415)
) Magnification: 30,000 Photograph observation of the surface layer surface of the film Measurement of film thickness: Measured by DEKTAK (3030, manufactured by Sloan). Others: Whether there are cracks or other defects. Durability by various tests of the membrane. The necessary items for various glass articles, such as window materials for architectural use, industrial use, and vehicles such as automobiles, ships, and aircraft, including changes in visible light transmittance and the effects on optical characteristics were evaluated.

EXAMPLE 1 Float glass (soda lime silicate) having a size of about 100 mm × 100 mm and a thickness of about 2 mm was used as a substrate, and the coated surface was sufficiently polished with cerium oxide. ,
After washing with tap water and rinsing with pure water, it was wiped with isopropyl alcohol or acetone to obtain a glass substrate for coating.

On the other hand, the first layer coating solution composite sol was prepared by the following procedure. First, ethyl silicate (manufactured by Kishida Chemical Co., Ltd.) was used as a starting material for silica, and alumina fine-particle-dispersed sol was converted to alumina clear sol (average particle size: 15 nm, manufactured by Kawaken Fine Chemical) in terms of solid content concentration (wt%).
O ₂ : Al ₂ O ₃ = 20: 80, pure water as solvent (nitric acid added)
A solution was prepared using a mixed solvent of ethanol and ethanol to obtain a coating solution.

First, ethyl silicate and a mixed solvent are mixed and stirred, refluxed at 60 ° C. for about 4 hours, and then cooled to room temperature. Next, the above-described predetermined amount was added while the alumina fine particle-dispersed sol was added dropwise, and the mixture was further stirred at room temperature for about 2 hours or more to obtain a coating solution.

After the coating solution was applied on the glass substrate prepared previously by spin coating, the coating solution was applied at about 150 ° C.
After drying for 10 minutes, it was baked at about 600 ° C. for about 5 minutes to form an antifogging film. The rotation speed for spin coating is about 10
The rotation time was about 30 seconds at 00 rpm / min. The thickness of the antifogging film was about 250 nm as measured by DEKTAK (3030, manufactured by Sloan).

Next, the glass substrate on which the antifogging film was formed was heated to about 150 ° C. and immersed in pure water boiling at about 100 ° C. for about 1 minute. As a result, when the antifogging film of the glass substrate with the SiO ₂ —Al ₂ O ₃ based film was evaluated, Tables 1 and 2
As shown in the figure, no fogging was observed at all in the 10th cycle in the evaluation test of the antifogging performance and the mark was ○, indicating that the antifogging performance was remarkably excellent, and the distortion of the perspective image due to condensation was also observed. Was also not recognized.

As shown in Table 3, the laboratory (25 ° C., 50
% RH), the initial contact angle is less than 5 ° and the change in the contact angle is 12 ° even after leaving for 192 hours.
The angle was less than 20 °, which was extremely good, and excellent antifogging performance could be sufficiently maintained, and it had remarkable antifogging durability.

Further, as shown in Table 4, even in the evaluation test of the film strength, the robustness test showed no scratches, and the breath test after the test showed no clouding and was good, and was marked with a circle. The film haze value (ΔH) before and after the abrasion test was less than 5%, clouding due to exhalation did not occur, the mark was ○, the film strength was remarkable, each passed sufficiently, and it was fully practical. Was to be offered.

Further, regarding the shape of the film, the AFM
Observe photographs of the surface and cross-section of the coating with JIS B 0601
When the center line average roughness Ra value and the like defined in were determined, the surface was uneven at a pitch of several nm, and the surface roughness (center line average roughness) was, for example, within about 15 nm. The SE
A photograph of the surface of the coating was observed with M.

Further, the stimulating purity of the film is about 2% and the reflection color tone is neutral, and it is excellent in durability, stable and reliable, and can be obtained efficiently by simple means without troublesome steps. The intended anti-fogging coating which can be applied to various glass articles including window materials for buildings, industrial use, vehicles such as automobiles, ships, aircrafts, etc. was obtained.

Example 2 A glass substrate on which an antifogging film was formed was heated to about 100 ° C.
Example 1 was repeated except that the sample was immersed in pure water boiling at about 100 ° C. for about 1 minute.

As a result, as shown in Tables 1 to 2 and 4, as in Example 1, all were marked with a circle, and as shown in Table 3, the initial contact angle was less than 5 ° and the contact angle was less than 5 °. Transition
Even after standing for 192 hours, it shows remarkably excellent anti-fog performance, such as being less than 16 ° and 20 °, and can sufficiently maintain excellent anti-fog performance,
It had remarkable antifogging continuity, showed remarkable film strength, and each passed sufficiently and was sufficiently practical.

Further, the shape of the first layer film is also described above.
AFM and SEM were performed as in Example 1, and the surface was the same as in Example 1. In addition, the stimulus purity of the coating was about 2% and the reflection color tone was neutral.
In the same manner as above, the intended anti-fog coating which can be used for various glass articles including window materials for buildings, industrial use, vehicles such as automobiles, ships, aircrafts, etc. was obtained.

Example 3 A glass substrate having an antifogging film formed thereon was heated to about 200 ° C.
Example 1 was repeated except that the sample was immersed in pure water boiling at about 100 ° C. for about 1 minute.

As a result, as shown in Tables 1 to 2 and 4, as in Example 1, all were marked with a circle, and as shown in Table 3, the initial contact angle was less than 5 ° and the contact angle was Transition
Even after standing for 192 hours, it shows extremely excellent antifogging performance, such as being less than 11 ° and 20 °, and can sufficiently maintain excellent antifogging performance,
It had remarkable antifogging continuity, showed remarkable film strength, and each passed sufficiently and was sufficiently practical.

Further, the shape of the first layer film is also described above.
AFM and SEM were performed as in Example 1, and the surface was the same as in Example 1. In addition, the stimulus purity of the coating was about 2% and the reflection color tone was neutral.
In the same manner as above, the intended anti-fog coating which can be used for various glass articles including window materials for buildings, industrial use, vehicles such as automobiles, ships, aircrafts, etc. was obtained.

Example 4 The composition of the sol coating solution was converted to a solid concentration (wt%).
Example ₂ was repeated except that the ratio of SiO ₂ : Al ₂ O ₃ was 30:70.

As a result, as shown in Tables 1 to 2 and 4, as in Example 1, all were marked with a circle, and as shown in Table 3, the initial contact angle was less than 5 ° and the contact angle was less than 5 °. Transition
It shows remarkably excellent anti-fog performance, such as being 14 ° and less than 20 ° even after standing for 240 hours, and can sufficiently maintain excellent anti-fog performance,
It had remarkable antifogging continuity, showed remarkable film strength, and each passed sufficiently and was sufficiently practical.

Further, the shape of the first layer film is also described above.
AFM and SEM were performed as in Example 1, and the surface was the same as in Example 1. In addition, the stimulus purity of the coating was about 2% and the reflection color tone was neutral.
In the same manner as above, the intended anti-fog coating which can be used for various glass articles including window materials for buildings, industrial use, vehicles such as automobiles, ships, aircrafts, etc. was obtained.

Example 5 The composition of a sol coating solution was converted to a solid concentration (wt%).
Example ₂ was repeated except that the ratio was changed to SiO ₂ : Al ₂ O ₃ = 35: 65.

As a result, the contact angle of the coating film with water was not measurable and showed remarkable hydrophilicity.
As shown in Example 1, as in Example 1, all were marked with a circle, and as shown in Table 3, the initial contact angle was less than 5 ° and the transition of the contact angle was 13 ° and 20 ° even after standing for 192 hours. Less than,
It shows remarkably excellent anti-fogging performance, can maintain excellent anti-fogging performance sufficiently, has remarkable anti-fogging persistence, shows remarkable film strength, passes each sufficiently, and is sufficiently practical Was to be offered.

Further, regarding the shape of the first layer,
AFM and SEM were performed as in Example 1, and the surface was the same as in Example 1. In addition, the stimulus purity of the coating was about 2% and the reflection color tone was neutral.
In the same manner as above, the intended anti-fog coating which can be used for various glass articles including window materials for buildings, industrial use, vehicles such as automobiles, ships, aircrafts, etc. was obtained.

COMPARATIVE EXAMPLE 1 A substrate similar to that used in Example 1 was used, and ethyl silicate (manufactured by Kishida Chemical), aluminum alkoxide [Al (O-sec.
-Bu) ₃ ; Kishida Chemical]
A glass substrate was prepared by converting SiO ₂ : Al ₂ O ₃ = 10: 90 in terms of solid concentration (wt%) and using ethanol as a solvent, and having a solid concentration of 3 wt% with respect to the whole solution. The resultant was coated by spin coating, dried at about 150 ° C. for about 10 minutes, and baked at about 600 ° C. for about 5 minutes to obtain an antifogging film.
The rotation speed of the spin coat was 800 rpm for 30 seconds. The thickness of the obtained film was about 250 nm.

As a result, as shown in Tables 1 and 2,
In the evaluation test of anti-fogging performance, the mark was evaluated as "x" three times, and in the evaluation test of the anti-fogging performance, the evaluation was evaluated as "x". The occurrence of fogging was recognized in all 10 cycles. As shown in Table 3, the contact angle of the coating with water was about 7 ° and the initial antifogging property exceeded 5 °, and the contact angle when left in the laboratory gradually increased, and after 48 hours, Is 20 °
In addition, as shown in Table 4, in the evaluation test of the film strength, the robustness test showed that the film was flawed due to scratches and expiration, and the mark x, and the abrasion test before and after the test. The film haze value (ΔH) exceeded 5%, clouding due to expiration also occurred, and the mark was x, indicating that the film strength was unacceptable.
It could not be said that it was the intended anti-fogging film.

COMPARATIVE EXAMPLE 2 The procedure of Example 1 was the same as that of Example 1, except that after sintering at about 600 ° C., no immersion treatment was carried out in pure hot water.

As a result, as shown in Tables 1 and 2,
In the evaluation test of anti-fogging performance, all occurrences of fogging were recognized after 2 cycles, and in the evaluation test of anti-fogging performance, all occurrences of fogging were recognized after 2 cycles. As shown in Table 3, the initial contact angle of the coating with water was about 8
The initial anti-fogging property at 5 ° exceeded 5 °, the contact angle when left in the laboratory gradually increased, and after 72 hours, exceeded 20 ° to 28 °, making it difficult to recognize the anti-fogging property. As shown in the above, in the evaluation test of the film strength, as in Comparative Example 1, both the fastness test and the abrasion test were X, indicating that the film strength was unacceptable.

The desired anti-fogging film could not be said. Comparative Example 3 Example 1 was the same as Example 1 except that it was baked at about 600 ° C. and then immersed in pure water at about 50 ° C. for about 1 minute.

As a result, as shown in Tables 1 and 2,
In the evaluation test of antifogging performance, all occurrences of fogging were recognized after 7 cycles, and in the evaluation test of antifogging performance, all occurrences of fogging were recognized after 5 cycles. As shown in Table 3, the initial contact angle of the coating with water was about 6
°, but the contact angle when left in the laboratory gradually increased to 96
After 20 hours, it exceeds 20 ° and becomes 22 °, making it difficult to recognize the anti-fogging property. Also, as shown in Table 4, in the evaluation test of the film strength, even in the abrasion test in the Taber abrasion test, a comparative example was obtained. As in the case of No. 1, the film showed unsatisfactory film strength in the fastness test.

The desired anti-fogging film could not be said. Comparative Example 4 Example 1 was the same as Example 1 except that after baking at about 600 ° C., it was immersed in pure water at about 70 ° C. for about 1 minute.

As a result, as shown in Tables 1 and 2,
In the evaluation test of anti-fogging performance, all occurrences of fogging were recognized after 8 cycles, and in the evaluation test of anti-fogging performance, all occurrences of fogging were recognized after 7 cycles. As shown in Table 3, the initial contact angle of the coating with water was about 5
°, the contact angle when left in the laboratory gradually increases,
After 0 hour, it exceeds 20 ° and becomes 22 °, making it difficult to recognize the anti-fogging property. Further, as shown in Table 4, even in the evaluation test of the film strength,
Although a circle mark was obtained in the table abrasion test, the film strength was unacceptable in the fastness test as in Comparative Example 1.

The desired anti-fogging film could not be said.

[0076]

[Table 1]

[0077]

[Table 2]

[0078]

[Table 3]

[0079]

[Table 4]

[0080]

According to the anti-fogging film of the present invention and the method for producing the same, an oxide thin film having a remarkably excellent anti-fogging performance can be produced at a low cost by a specific means which is stable, secure, and without any troublesome steps and is easy and easy. It can be efficiently obtained with high productivity, has no defects such as cracks, is excellent in sufficient visible light transmittance and durability, and is excellent in wear resistance. Furthermore, the reflection color tone is the same neutral color as the glass substrate, and in order to maintain excellent anti-fog performance, industrial articles such as architectural window materials or mirrors,
Furthermore, it is possible to provide a useful anti-fog coating widely applicable to various anti-fog coatings such as window materials for vehicles including automobiles, window materials for ships and aircraft, and various other anti-fog coatings, and a method for producing the same. is there.

Claims (12)

[Claims] 1. A thin film formed on the surface of a substrate is a silica-alumina-based composite oxide film. After heating the formed composite oxide film, the composite oxide film is heated and heated in pure water. An anti-fogging film characterized by being immersed. 2. The antifogging film according to claim 1, wherein the heating temperature is 50 to 200 ° C. 3. The immersion treatment with hot water is carried out at a temperature of 80 to 10
3. The anti-fogging coating according to claim 1, wherein the coating is immersed in hot water at 0 [deg.] C. for 1 to 10 minutes. 4. The antifogging method according to claim 1, wherein the composite oxide film is formed from a solution in which a metal alkoxide compound or oxide particles having a low equilibrium water vapor pressure is dispersed. Film. 5. The antifogging film according to claim 1, wherein the content of silica is 10 to 40% by weight.
The antifogging film as described in the above. 6. The antifogging film according to claim 1, wherein the reflection color tone of the film is neutral.
The antifogging film as described in the above. 7. The antifogging film according to claim 1, wherein said substrate is float glass. 8. A silica-alumina-based composite sol solution comprising a metal oxide sol solution for forming an amorphous metal oxide or / and a solution to which a metal oxide fine particle dispersion sol is added, is applied to a substrate; After firing, a silica-alumina-based composite oxide film is formed, and after heating the substrate with the film,
A method for producing an antifogging film, comprising immersing in hot water of pure water. 9. The composite sol solution according to claim 1, wherein said solution has a silica content of 1 to 10 wt% and an alumina content of 1 to 10 wt%.
The method for producing an antifogging film according to claim 8, wherein the content is wt%. 10. The method for producing an antifogging film according to claim 8, wherein the heating temperature is 50 to 200 ° C. 11. The immersion treatment with hot water is performed at a temperature of 80 to 10
The method for producing an anti-fogging film according to any one of claims 8 to 10, wherein the treatment is immersion in hot water at 0 ° C for 1 to 10 minutes. 12. The method according to claim 8, wherein the calcination is a heat treatment performed at a temperature of 500 ° C. or more and 680 ° C. or less.