JP2001261376A - Anti-fogging film, and substrate with anti-fogging film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an anti-fogging film having a high film strength and excellent adhesivity to a substrate. SOLUTION: This anti-fogging film is formed by removing one-dimensionally grown columnar phases 2 from a composite film 4 consisting of a great number of the columnar phases 2 and a matrix phase 3 surrounding the columnar phases on a substrate 1 and has a great number of one-dimensionally penetrated pores enclosed by walls continuous from one surface of the film to the other surface and <=30 deg. contact angle to water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antifogging film having one-dimensionally penetrating pores (hereinafter, also referred to as one-dimensionally penetrating pores). More specifically, the present invention relates to a highly durable anti-fogging film which can be suitably used as a fogging preventing film on a window glass, a mirror or an optical lens surface.

[0002]

2. Description of the Related Art When a mirror in a bathroom or a basin comes into contact with air containing a large amount of water vapor, water droplets having a size of about the wavelength of light or more adhere to the surface, and the water droplets reflect light irregularly, causing clouding. . In addition, on the inner surface of the window glass of a building cooled by outside air, the inner surface of a windshield of an automobile, or the surface of glasses,
Water droplets having a size on the order of the wavelength of light or more adhere thereto, and when light is scattered by the water droplets, clouding occurs. They are,
This is because minute water droplets adhere to the glass surface, which should be transparent.

[0003] The root cause of this problem is that the surface of glass used for mirrors and windows exhibits a property intermediate between hydrophilicity and hydrophobicity (a contact angle of pure water of about 50 to 90 °), and droplets are formed. This is due to the hemispherical attachment to the glass surface. Such a problem can occur not only with glass but also with metals, ceramics, or certain plastics having the same wettability to water as glass.

In order to solve the problem that the surface is fogged by the attachment of minute droplets, a hydrophilic film is formed on the surface of glass or plastics so that the surface does not become hemispherical even if water droplets adhere. A method of expressing anti-fogging property by doing so has been proposed. Specifically, A) a method of hydrophilizing the surface of glass or plastics with an organic cationic surfactant such as dimethylalkylammonium chloride, B) a transparent resin film into which a surfactant or titanium oxide is kneaded is made of glass or plastic. A method of attaching to the surface of plastics has been proposed.

Further, C) a method of forming a porous inorganic film (alumina or alumina-silica based) on the surface of glass or plastics, etc. to improve the hydrophilicity by unevenness of the surface has been attempted. .

[0006] However, in the method A), since the surfactant has a weak adhesive force, when used for a window glass or a windshield of an automobile, the surfactant component is immediately desorbed and the hydrophilic effect and the anti-fog effect are obtained. There was a problem that disappeared. B)
In the method (1), there is a problem that the surfactant component is eluted from the transparent resin film to reduce the hydrophilic effect, and the transparent resin film is deteriorated by sunlight and loses transparency.

The method C) can be expected to have some improvement in durability as compared with the method using the organic film. However, in such a film, when the porosity of the film is increased to increase the anti-fogging effect, the strength of the film itself, and the adhesion strength between the film and the substrate are reduced, causing a problem inconsistent in characteristics. There were many.

In general, when a porous inorganic film is formed, a ceramic slurry containing fine powder such as silica or alumina is prepared, and the slurry is applied to the surface of glass or plastics by a dip method or a doctor blade method. A method of heating, drying or sintering is used later, but it is difficult to make the pore diameter of the pores contained in the film uniform in the film formed by this method, and usually a hole of several tens of μm always exists. is there. If such a large hole is present on the membrane surface, there is a problem that fine particles such as tobacco tar and various dusts floating in the air are stuck in the hole and it is difficult to remove them by simple washing.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and provides an antifogging film and a substrate with an antifogging film having high film strength and excellent adhesion to the substrate. Aim. Another object of the present invention is to provide the anti-fogging film and the substrate provided with the anti-fogging film, on which dirt is easily removed.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a method for forming a columnar phase, which has been grown one-dimensionally, in a composite film composed of a number of columnar phases grown one-dimensionally on a substrate and a matrix phase surrounding the columnar phase. An antifogging film formed by removing the film and having a large number of one-dimensionally penetrating pores surrounded by a continuous wall from one surface to the other surface of the film, and having a contact angle to water of 30 °. Provided is an anti-fogging film characterized by the following.

In the present invention, the matrix phase is a material constituting the anti-fogging film, and the matrix phase is a dense body. The anti-fogging film of the present invention is formed by a two-stage process. That is, in the first stage, a composite film composed of a large number of one-dimensionally grown columnar phases and a matrix phase surrounding the columnar phase is formed, and then, in the second stage, one-dimensionally in the composite film is formed. The grown columnar phase is removed by etching, leaving only the matrix phase.

As a method of forming a composite film in the first stage, a method of directly forming a composite film composed of a one-dimensionally grown columnar phase and a matrix phase surrounding the columnar phase by a physical film forming method (hereinafter, referred to as a composite film). First, an amorphous precursor film is formed on a substrate,
Next, a eutectic reaction is caused by heat treatment, thereby forming a composite film composed of a one-dimensionally grown columnar phase and a matrix phase surrounding the columnar phase (hereinafter, also referred to as a second composite film forming method). Is mentioned.

FIG. 1 is a schematic view showing a procedure for forming the anti-fogging film of the present invention. In the figure, a to d show the procedure for forming the antifogging film of the present invention using the first method for forming a composite film,
a shows a state in which a composite film 4 composed of a columnar phase 2 and a matrix phase 3 is formed on a substrate 1 by a physical film forming method (initial);
b is a state in which the composite film 4 is similarly formed (middle stage), c is a state in which the formation of the composite film 4 is completed, d is a columnar phase 2 which has grown one-dimensionally by selective etching, and the anti-fog of the present invention is obtained. The state where the film 5 is formed is shown.

Further, eh show the procedure for forming the anti-fogging film of the present invention using the second method of forming a composite film, and e shows the amorphous precursor film 6 containing a transition metal on the substrate 1. F, a state in which a eutectic structure was formed on the film surface by heat treatment, and g, a eutectic reaction interface moved to the film-substrate interface by oxygen diffusion from the surface, and finally grew one-dimensionally. A eutectic structure composed of a columnar phase (transition metal oxide crystal) 2 and a matrix phase 3 surrounding the columnar phase 2 is formed, and a composite film 4 is formed. H indicates that the columnar phase 2 grown one-dimensionally by selective etching is removed. And a state in which the antifogging film 5 of the present invention is formed, respectively.

In the first method for forming a composite film, the physical film forming method for forming the composite film includes sputtering, vapor deposition,
A CVD method, a laser ablation method, a molecular beam epitaxy method, and the like can be given. Among them, the sputtering method is
It is particularly preferable because a dense film is easily obtained, a film having high adhesion to a substrate is obtained, and mass productivity and large-area film-forming property are excellent.

When a composite film is formed by a sputtering method, the method for forming a target using a material for forming a columnar phase and a material for forming a matrix phase is not particularly limited. A mixture of powder and a powder of a material forming a matrix phase can be used as a target.

Also, a composite target in which a number of small pieces each having a size of about several mm and made of a material forming a matrix phase are arranged on a target made of a material forming a columnar phase, and thus a composite target can be suitably used. Conversely, a composite target in which a number of small pieces each having a size of about several mm and made of a material forming a columnar phase are arranged on a target formed of a material forming a matrix phase can also be suitably used.

When a composite film is produced by the first method for forming a composite film, the combination of the material of the columnar phase and the material of the matrix phase may be any combination that causes a phase separation between the material of the columnar phase and the material of the matrix phase. I just need. In the present invention, since the columnar phase is used in the pores after the etching and the matrix phase surrounding the columnar phase is used as a residual phase, the material of the columnar phase is a metal that easily grows in a columnar form, and is an acid / alkali. It is preferable to use a metal or an alloy which easily dissolves in the matrix phase material and has a small binding energy to the matrix phase material and is easily reduced.

Examples of the material of the columnar phase include V, Cr, M
One or more kinds selected from 3d transition metals such as n, Ni, Fe, Co, Cu, and Zn and alloys containing the same as a main component, alkaline earth metals such as Mg and alloys containing the same as a main component are exemplified. In addition, Al, In, Sn and P
b can also be used.

Examples of the matrix phase used as the residual phase include oxides such as silica, alumina, titania, mullite, cordierite, spinel, zeolite and forsterite; carbides such as silicon carbide, titanium carbide and zirconium carbide; Borides such as titanium boride, zirconium boride and boron carbide; nitrides such as silicon nitride, titanium nitride and zirconium nitride; Cr, Ni and C
and at least one selected from metals such as u, Au, Al, and Pt.

In the first method for forming a composite film, the mixing ratio of the material of the columnar phase and the matrix phase and the film forming conditions are controlled to form a fine particle in which the matrix phase surrounds the one-dimensionally grown columnar phase. An organization is formed. For example, when a composite film is formed by a sputtering method, the average diameter of the growing columnar phase changes depending on the volume fraction of the columnar phase and the matrix phase and the film forming conditions (Ar gas pressure during sputtering).

Since the diameter of the one-dimensional through pores substantially matches the diameter of the columnar phase growing one-dimensionally, the average pore diameter of the one-dimensional through pores finally obtained after etching is the antifogging film of the present invention. It can be changed by the mixing ratio of the materials of the phase and the matrix phase and the film forming conditions (Ar gas pressure during sputtering, substrate temperature, etc.). For example, in the case of a Co—SiO ₂ system, the particle size of Co in a film formed at an Ar gas pressure of 2 Pa is 8 nm, whereas the particle size of Co in a film formed at an Ar gas pressure of 8 Pa is 8 nm. It has been confirmed that the thickness becomes about 40 nm.

In the second method for forming a composite film, the amorphous precursor film may be formed by a physical film forming method such as a sputtering method, an evaporation method, a CVD method, a laser ablation method, a molecular beam epitaxy method, or a sol. A solution method such as a gel method, a spray pyrolysis method or a coating method, and a plating method can be used. Among them, the sputtering method is particularly preferable because a dense film is easily obtained, a film having high adhesion to a substrate is obtained, and mass productivity and large-area film forming property are excellent.

When an amorphous precursor film is formed by a sputtering method or the like, the method of forming a target using a material for forming a columnar phase and a material for forming a matrix phase is not particularly limited. A mixture of the powder of the material to be formed and the powder of the material to form the matrix phase can be used as the target. For example,
When forming an Fe—Si—O-based amorphous precursor film, a mixture of FeO powder and SiO ₂ powder can be used as a target.

In the second method for forming a composite film, the combination of elements contained in the amorphous precursor film formed first includes a transition metal, other metal elements, and oxygen. As an example of the transition metal, any material can be used as long as it separates from other metals contained in the film and becomes a separate compound phase after the heat treatment. However, considering the ease of handling during the heat treatment, V, Cr , Mn, Ni, Fe, Co, Cu, Zn, and other 3d transition metals, alloys containing these metals as main components, and other rare earth elements such as polyvalent cations Ce, Nd, Sm, and Er. One or more types may be mentioned.

The metal element other than the transition metal may be any element that does not react with the transition metal during the subsequent heat treatment. This metal element becomes a matrix phase surrounding the columnar phase (transition metal compound needle-like crystal) during heat treatment and becomes a component constituting a film having one-dimensional through-pores after etching, and thus is selected depending on the purpose of use of the film. For example, Si, A
1, Mg, Zr, Sn, In and the like.

When an amorphous precursor film is formed by sputtering, the diameter of a columnar phase which grows one-dimensionally by a heat treatment performed later changes depending on the Ar gas pressure at the time of sputtering. For example, in the case of a Fe—Si—O-based film, A of 2 Pa
When the film formed at r gas pressure is heat-treated at 600 ° C, about 4n
Hematite (Fe ₂ O ₃ ) with a diameter of m
When a film is formed at the Ar gas pressure of a, hematite having a diameter of about 20 nm is precipitated by performing the same treatment. Since the diameter of the one-dimensional through pores substantially matches the diameter of the columnar phase that grows one-dimensionally, the average pore diameter of the one-dimensional through pores finally obtained after etching is the anti-fogging film of the present invention. (Ar gas pressure during sputtering).

In the second method for forming the composite film, the transition metal oxide and the other metal and the amorphous precursor film containing oxygen are heat-treated to separate and deposit the transition metal oxide and the other metal oxide. Causes a eutectic decomposition reaction.
It is important that the two-phase precipitation from the amorphous phase occurs simultaneously and from the film surface. The treatment conditions for heating may be any conditions under which a eutectic decomposition reaction occurs.
That is, the temperature may be a temperature at which a eutectic decomposition reaction occurs and a temperature at which the reaction proceeds at a sufficient speed. Specifically, a temperature of about 400 to 650 ° C. is preferable.

In order to cause the eutectic decomposition reaction, it is necessary to change the valence of the transition metal. As this method, there are two methods, a method of treating the amorphous precursor film in an oxidizing atmosphere and a method of treating the amorphous precursor film in a reducing atmosphere. In the case of an eutectic reaction of an oxide, when a treatment is performed in a reducing atmosphere, heterogeneous nuclei may be formed and a uniform eutectic structure may not be formed. In this case, a uniform eutectic structure can be formed by heat treatment in an oxidizing atmosphere.

In the second step, only the columnar phase extending one-dimensionally is selectively etched and removed from the composite film formed in the first step using an acid or an alkali. As the acid used in this etching treatment, an acid suitable for selectively removing only the columnar phase, such as sulfuric acid, hydrochloric acid, nitric acid, oxalic acid, and acetic acid, is selected. For example, in order to remove metallic cobalt from the metallic cobalt / silica composite film produced by the first method for forming a composite film, only metallic cobalt can be completely removed only by treating with a 0.1 mol / L nitric acid aqueous solution for several minutes.

In the case of the Fe—Si—O composite film formed by the second method of forming a composite film, the one-dimensionally expanded hematite is soluble in an aqueous hydrochloric acid solution, whereas Is insoluble in the same solution, so about 6 mol / L
Selective etching can be performed by immersing the film in a hydrochloric acid aqueous solution.

The anti-fogging film of the present invention is formed as described above, and has a large number of one-dimensionally penetrated pores surrounded by a continuous wall from one surface to the other surface of the film. Anti-fog film having a contact angle to water of 30 °
These are the following films. If the contact angle with water exceeds 30 °, a sufficient antifogging effect cannot be obtained.

The antifogging film of the present invention is composed of at least one selected from oxides, carbides, borides, nitrides and metals, and is selected according to the intended use. Oxides are most preferred from the viewpoints of properties, ease of formation, and the like. Further, from the viewpoint of anti-fogging property, silica is preferable.

In the antifogging film of the present invention, the average pore diameter of the pores penetrating one-dimensionally is preferably 1 to 500 nm. If it is less than 1 nm, a sufficient anti-fogging effect cannot be obtained, and if it is more than 500 nm, a sufficient anti-fogging effect cannot be obtained, and the strength of the film or the adhesion to the substrate may be reduced.

Further, the specific surface area of the antifogging film of the present invention is 2
It is preferably from 0 to 2000 m ² / g. 20m ² /
If the amount is less than 200 g, a sufficient antifogging effect cannot be obtained.
If it exceeds 0 m ² / g, sufficient film strength may not be obtained.

The present invention also provides a substrate having an antifogging film having the antifogging film on a substrate. When the first method for forming a composite film is used as the substrate on which the antifogging film of the present invention is formed, a substrate or film such as glass, ceramics, metal, or plastics can be used. When using the method, a substrate or a film of glass, ceramics, heat-resistant metal or the like can be used.

As the heat-resistant metal, a stainless steel made of Fe, Ni, Cr, V or the like, or an oxidation-resistant alloy such as Hastelloy is preferable. Further, when the antifogging film of the present invention is formed on a substrate having irregularities on the surface, such as a porous ceramic substrate, if the irregularities on the surface are not so severe, the composite film according to the first forming method, or the second What is necessary is just to form an amorphous precursor film directly by the formation method. When it is difficult to directly form a film in the first stage due to severe irregularities on the surface of the substrate, the irregularities on the surface of the substrate are filled with a resin or other material, and then the surface is polished and smoothed. If the anti-fog film is formed, sufficient adhesion strength can be secured. The anti-fogging film of the present invention can be composed of various compositions. The anti-fog film of the present invention is suitable for an anti-fog film used for windshields of vehicles, window glasses of buildings, mirrors, optical lenses and the like.

[0038]

The antifogging film of the present invention has hydrophilicity high enough that water droplets adhering to the surface penetrate into the film and exhibit an antifogging effect in practical use because continuous pores are present from the film surface to the inside of the film. Have.

Further, since the continuous anti-fogging film of the present invention surrounds the one-dimensional through pores with a continuous matrix phase, the film strength is higher in principle than the conventional porous inorganic film, and the film is not easily bonded to the substrate. Has good adhesion. The high strength of the film means that the conventional porous inorganic anti-fog film is formed by loosely bonding ceramic particles by sintering, etc., whereas the film of the present invention has a completely continuous matrix surrounding the one-dimensional through-pores. This is due to the fact that it is a one-piece molded product.

Further, regarding the adhesion to the substrate, a film having particularly high adhesion can be obtained by forming the first-stage composite film (including the amorphous precursor film by the second forming method) by a sputtering method or the like. . In addition, the conventional porous inorganic film has a contradictory problem in that when the porosity of the film is increased to improve the anti-fogging effect, the strength of the film itself and the adhesion strength between the film and the substrate are reduced. Although it often occurred, in the antifogging film of the present invention, while maintaining a high antifogging effect, the strength of the film and the adhesion to the substrate can both be increased,
An antifogging film having antifogging properties and high durability can be realized.

[0041]

(Example 1) A composite film composed of two phases of metal Co and SiO ₂ was formed on a 1.2 mm thick soda lime glass substrate by using the first method of forming a composite film. At the time of sputtering, a composite target in which a 5 mm square SiO ₂ chip was placed on a metal Co target having a diameter of 15.24 cm was used. 2 of the total surface area on one side of the target
The amount of SiO ₂ chips was adjusted to account for 0%. After evacuating the vacuum chamber to 5 × 10 ⁻⁴ Pa, Ar gas was introduced, the flow rate was adjusted so that the gas pressure inside the vacuum chamber became 2 Pa, and plasma was generated by a high-frequency input of 600 W. The film formation rate was about 0.25 nm / sec, and no active substrate heating or substrate bias application was performed during film formation. A mask was applied to the periphery of the substrate, and no film was formed.

As a result of observing the thus formed Co—SiO ₂ composite film with a TEM (transmission electron microscope), Co crystal particles having an average particle size of about 10 nm were grown in a columnar shape, and an amorphous It was confirmed that the SiO ₂ matrix phase was surrounding.

In the second step, a 500 nm-thick Co—SiO ₂ composite film formed by the above-described method was added at 0.1 mol / mol.
Etching was performed by immersion in an L aqueous nitric acid solution for 5 minutes.
Co-SiO ₂ results columnar phase of Co from the composite film was observed film after removal by etching with SEM (scanning electron microscope), Co columnar phases were eluted, be SiO ₂ matrix phase is left confirmed.

FIG. 2 is an isothermal adsorption / desorption curve at the liquid nitrogen temperature of the antifogging film formed as described above. From the figure,
At around the differential pressure (P / P ₀ ) = 0.6, a clear adsorption and desorption of nitrogen gas was observed, and the obtained antifogging film had many pores with a diameter of about 10 nm, and the ratio of the inner wall of the pores Surface area is about 1000m ²
/ G (an extent corresponding to activated carbon).

The surface of the obtained antifogging film has a diameter of about 1 m.
m of pure water was dropped and the contact angle was measured.
5 °. Further, the obtained anti-fogging film was put into a refrigerator together with the substrate, kept for 1 hour, cooled to about 5 ° C., and then taken out and blown. Fine water droplets adhered to the glass surface having no cloudiness and became cloudy and became opaque.

When the durability of the above antifogging film was examined by a Taber abrasion resistance test, no change was observed in the contact angle of water, antifogging performance, transparency and the like even after 1000 rotations. The Taber abrasion resistance test was conducted by using a commercially available CS10 Taber-type abrasion wheel and abrasive paper of the same quality as AA180 abrasive paper specified in JIS R6252, applying a load of 500 g, and rotating 1000 times at 60 rpm. This was done by abrading the membrane. The same applies to the Taber abrasion resistance test in the following examples.

Comparative Example 1 A coating solution prepared by adding hydrochloric acid to an ethyl silicate aqueous solution in which polystyrene fine particles (average particle size: 0.06 μm) was dispersed was applied to a soda lime glass substrate surface, and then heated to about 400 ° C. To form a porous silica film having a thickness of 500 nm. When the durability was examined by the same Taber abrasion resistance test as in Example 1, the film was partially peeled off at 1000 times, and the transparency was impaired.

(Example 2) The film forming speed was set to about 0.3 nm / s
ec, except that the film thickness was 5
A Co-SiO ₂ composite film of 00 nm was formed. This Co
The structure inside the —SiO ₂ composite film is C
Like the o-SiO ₂ composite film, the amorphous SiO ₂ matrix phase surrounds the columnar phase of the Co crystal particles. In this case, the average particle diameter of the Co crystal is as large as about 20 nm. I understood.

The sample having a thickness of 500 nm prepared by the above method was immersed in a 0.1 mol / L aqueous nitric acid solution for 5 minutes to obtain a C sample.
o The columnar phase was dissolved and removed. As in Example 1, the Co columnar phase eluted, and the SiO ₂ matrix phase remained. The specific surface area of the film and the contact angle with pure water are each about 1000 m
^{It was 2} / g and 13 °, and it was confirmed by an experiment of blowing air that the antifogging effect was almost the same as that of Example 1.

Example 3 Using the same composite target as in Example 1, a Co—SiO ₂ composite film was formed on a 1.2 mm thick soda lime glass substrate as follows. That is, after evacuating the vacuum chamber to 5 × 10 ⁻⁴ Pa, Ar gas was introduced, the flow rate was adjusted so that the gas pressure inside the vacuum chamber became 8 Pa, and plasma was generated by high frequency input of 800 W. The film formation rate was about 0.6 nm / sec, and the substrate temperature was heated to 200 ° C. during the film formation.

The structure inside the Co—SiO ₂ composite film is as follows:
As in the case of the Co—SiO ₂ composite film obtained in Example 1, C
o Amorphous SiO ₂ around columnar phase of crystal grains
The matrix phase surrounds, in this case Co
It was found that the average particle size of the crystals was as large as about 100 nm.

The 1500 nm-thick sample prepared by the above method was immersed in a 0.1 mol / L nitric acid aqueous solution for 15 minutes to dissolve and remove Co particles. As in Example 1, the Co columnar phase eluted, and the SiO ₂ matrix phase remained. The specific surface area of the film and the contact angle with respect to pure water are about 100, respectively.
It was 0 m ² / g and 12 °, and it was confirmed by an experiment of blowing air that the anti-fogging effect was almost the same as that of Example 1.

Example 4 Using the same composite target as in Example 1, a Co—SiO ₂ composite film was formed on a ₂ mm thick Hastelloy plate as follows. That is,
The vacuum chamber 5 × 10 ^- introducing Ar gas ⁴ to Pa in After exhaust, gas pressure inside the vacuum chamber has a plasma is generated by high-frequency input of the flow rate adjusting 400W to be 2 Pa. The deposition rate was about 0.35 nm / sec, and no intentional substrate temperature or bias application was performed during the deposition.

The structure inside the Co—SiO ₂ composite film is as follows:
As in the case of the Co—SiO ₂ composite film obtained in Example 1, C
o Amorphous SiO ₂ around columnar phase of crystal grains
The matrix phase surrounds, in this case Co
The average particle size of the crystals was about 10 nm. The 800 nm thick sample prepared by this method was immersed in a 0.1 mol / L nitric acid aqueous solution for 10 minutes to dissolve and remove Co particles. As in Example 1, the Co columnar phase eluted, and the SiO ₂ matrix phase remained. The specific surface area of the film and the contact angle with respect to pure water were about 1000 m ² / g and 12 °, respectively, and it was confirmed by an experiment of blowing air that the antifogging effect was almost the same as that of Example 1.

Example 5 Using the same composite target as in Example 1, a Co—SiO ₂ composite film was formed on a 5 mm-thick alumina ceramics substrate as follows. That is, after evacuating the vacuum chamber to 5 × 10 ⁻⁴ Pa, Ar gas was introduced, the flow rate was adjusted so that the gas pressure inside the vacuum chamber became 2 Pa, and plasma was generated by a 400 W high frequency input. The deposition rate was about 0.3 nm / sec, and no intentional substrate temperature or bias application was performed during the deposition.

The structure inside the Co—SiO ₂ composite film is as follows:
As in the case of the Co—SiO ₂ composite film obtained in Example 1, C
o Amorphous SiO ₂ around columnar phase of crystal grains
The matrix phase surrounds, in this case Co
The average particle size of the crystals was about 9 nm. A 700 nm-thick sample prepared by this method was immersed in a 0.1 mol / L nitric acid aqueous solution for 10 minutes to dissolve and remove Co particles. As in Example 1, the Co columnar phase eluted, and the SiO ₂ matrix phase remained. The specific surface area of the membrane and the contact angle with respect to pure water are about 1000 m ² / g and 16 °, respectively.
It was confirmed by an experiment of exhalation that the antifogging effect was almost the same as that of Example 1.

Example 6 Using the same composite target as in Example 1, a Co—SiO ₂ composite film was formed on a 1.8 mm-thick polyethylene film sheet as follows. That is, after evacuating the vacuum chamber to 5 × 10 ⁻⁴ Pa, Ar gas is introduced, and the gas pressure inside the vacuum chamber becomes 2P.
Then, the flow rate was adjusted to a, and plasma was generated by a high-frequency input of 400 W. The deposition rate is about 0.2 nm / sec
c, no intentional substrate temperature or bias application was performed during film formation.

The structure inside the Co—SiO ₂ composite film is as follows:
As in the case of the Co—SiO ₂ composite film obtained in Example 1, C
o Amorphous SiO ₂ around columnar phase of crystal grains
The matrix phase surrounds, in this case Co
The average particle size of the crystals was about 15 nm. A 200 nm thick sample prepared by this method was immersed in a 0.1 mol / L nitric acid aqueous solution for 5 minutes to dissolve and remove Co particles. As in Example 1, the Co columnar phase eluted, and the SiO ₂ matrix phase remained. The specific surface area of the membrane and the contact angle with respect to pure water are about 1000 m ² / g and 28 °, respectively.
It was confirmed by an experiment of exhalation that the antifogging effect was almost the same as that of Example 1.

Example 7 An epoxy resin having a thickness of 2 mm was used.
After coating on a porous silica plate and curing,
The surface of the plate is polished with a diamond polishing machine, and the surface is polished smoothly.
I got The same composite target as in Example 1 was placed on this substrate.
Co-SiO as follows. _TwoShape composite membrane
Done. That is, 5 × 10^-FourExhaust to Pa
After that, Ar gas was introduced and the gas pressure inside the vacuum chamber was reduced to 2P.
a and adjust the flow rate so that
A plasma was generated. The deposition rate is about 0.35 nm / s
ec, and active substrate heating and substrate via
No voltage application was performed.

The structure inside the Co—SiO ₂ composite film is as follows:
As in the case of the Co—SiO ₂ composite film obtained in Example 1, C
o Amorphous SiO ₂ around columnar phase of crystal grains
The matrix phase surrounds, in this case Co
The average particle size of the crystals was about 9 nm. A 300 nm-thick sample prepared by this method was immersed in a 0.1 mol / L nitric acid aqueous solution for 5 minutes to dissolve and remove Co particles. As in Example 1, the Co columnar phase eluted, and the SiO ₂ matrix phase remained. The specific surface area of the film and the contact angle with respect to pure water were about 1000 m ² / g and 8 °, respectively, and it was confirmed by an experiment of blowing air that the anti-fogging effect was almost the same as that of Example 1.

Example 8 A Co—TiO ₂ composite film was formed on soda lime glass having a thickness of 1.2 mm as follows. For sputtering, the diameter is 15.24 cm.
A composite target having a 0.5 mm square TiO ₂ chip placed on a metal Co target was used. The amount of TiO ₂ chips was adjusted so as to occupy 30% of the total surface area of one side of the target. After evacuating the vacuum chamber to 5 × 10 ^-4 Pa, Ar gas was introduced, and the gas pressure inside the vacuum chamber was reduced to 2P.
Then, the flow rate was adjusted to a, and plasma was generated by a high-frequency input of 400 W. The deposition rate is about 0.4 nm / sec
c, and no active substrate heating or substrate bias application was performed during film formation.

The structure inside the Co—TiO ₂ composite film is as follows:
As in the case of the Co—SiO ₂ composite film obtained in Example 1, C
o Amorphous TiO ₂ around columnar phase of crystal grains
The matrix phase surrounds, in this case Co
The average particle size of the crystals was about 8 nm. A sample having a thickness of 250 nm produced by this method was immersed in a 0.1 mol / L nitric acid aqueous solution for 5 minutes to dissolve and remove Co particles. As in Example 1, the Co columnar phase eluted, and the TiO ₂ matrix phase remained. The specific surface area of the membrane and the contact angle with respect to pure water are about 1000 m ² / g and 28 °, respectively.
It was confirmed by an experiment of exhalation that the antifogging effect was almost the same as that of Example 1.

When the amorphous TiO ₂ film obtained after the etching was heated in air at 600 ° C. for 1 hour, it was converted into crystalline anatase, and the specific surface area of the film was hardly changed.

Example 9 A Co—SiC composite film was formed on a 1.2 mm thick soda-lime glass as follows. At the time of sputtering, a composite target in which a 0.5 mm square SiC chip was placed on a metal Co target having a diameter of 15.24 cm was used. The amount of the SiC chip was adjusted so as to occupy 40% of the total surface area of one side of the target. After evacuating the vacuum chamber to 5 × 10 ⁻⁴ Pa, Ar gas was introduced, the flow rate was adjusted so that the gas pressure inside the vacuum chamber became 2 Pa, and plasma was generated by high frequency input of 800 W. The deposition rate was about 0.3 nm / sec, and no active substrate heating or substrate bias application was performed during the deposition.

The structure inside the Co—SiC composite film is similar to that of the Co—SiO ₂ composite film obtained in Example 1,
An amorphous SiC matrix phase surrounds the columnar phase of the crystal grains. In this case, the average particle size of the Co crystal was about 6 nm. A sample having a thickness of 250 nm produced by this method was immersed in a 0.1 mol / L nitric acid aqueous solution for 5 minutes to dissolve and remove Co particles. As in Example 1, the Co columnar phase eluted, and the SiC matrix phase remained. The specific surface area of the film and the contact angle with respect to pure water were about 1000 m ² / g and 28 °, respectively, and it was confirmed by an experiment in which breath was blown out that the same anti-fog effect as in Example 1 was obtained.

Example 10 A Co—Si ₃ N ₄ composite film was formed on a 1.2 mm thick soda lime glass as follows. At the time of sputtering, the diameter is 15.24c.
0.5 mm square Si ₃ N ₄ on a metallic Co target
A composite target with a tip was used. The amount of the Si ₃ N ₄ chip was adjusted so as to occupy 40% of the total surface area of one side of the target. After evacuating the vacuum chamber to 5 × 10 ⁻⁴ Pa, Ar gas was introduced and the gas pressure inside the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa.
The flow rate was adjusted to Pa and plasma was generated by high frequency input of 800 W. The deposition rate is about 0.3 nm / s
ec, and no active substrate heating or substrate bias application was performed during film formation.

The structure inside the Co—Si ₃ N ₄ composite film is as follows:
As in the case of the Co—SiO ₂ composite film obtained in Example 1, C
o Amorphous Si ₃ N ₄ around columnar phase of crystal grains
The matrix phase surrounds, in this case Co
The average particle size of the crystals was about 6 nm. A sample having a thickness of 250 nm produced by this method was immersed in a 0.1 mol / L nitric acid aqueous solution for 5 minutes to dissolve and remove Co particles. As in Example 1, the Co columnar phase eluted and the Si ₃ N ₄ matrix phase remained. The specific surface area of the membrane and the contact angle with respect to pure water are about 1000 m ² / g and 28 °, respectively.
It was confirmed by an experiment of exhalation that the antifogging effect was almost the same as that of Example 1.

Example 11 A Co—Cr composite film was formed on a 1.2 mm thick soda-lime glass as follows. At the time of sputtering, a composite target having a 0.5 mm square Cr chip placed on a 15.24 cm diameter metal Co target was used. The amount of the Cr chip was adjusted so as to occupy 40% of the total surface area of one side of the target. After evacuating the vacuum chamber to 5 × 10 ^-4 Pa,
r gas was introduced, the flow rate was adjusted so that the gas pressure inside the vacuum chamber became 2 Pa, and plasma was generated by 800 W high frequency input. The deposition rate is about 0.3 nm / sec,
During film formation, active substrate heating and substrate bias application were not performed.

The structure inside the Co—Cr composite film is similar to that of the Co—SiO ₂ composite film obtained in Example 1, except that a Co columnar crystal particle (columnar phase) is surrounded by a matrix composed of a Cr crystal aggregate. The phase was surrounding, but in this case the average particle size of the Co crystals was about 6 nm. A sample having a thickness of 250 nm produced by this method was immersed in a 0.1 mol / L nitric acid aqueous solution for 5 minutes to dissolve and remove Co particles.
As in Example 1, the Co columnar phase eluted, and the Cr matrix phase remained. The specific surface area of the membrane and the contact angle with respect to pure water are about 1000 m ² / g and 28 °, respectively.
It was confirmed by an experiment of exhalation that the antifogging effect was almost the same as that of Example 1.

Example 12 A Co—ZrB ₂ composite film was formed on a 1.2 mm thick soda lime glass as follows. At the time of sputtering, the diameter is 15.24c.
A composite target in which a 1 cm square ZrB ₂ ceramic chip was placed on a m Co metal target was used. Z occupies 40% of the total surface area of one side of the target.
The amount of rB ₂ ceramic chips was adjusted. 5 vacuum chambers
After evacuating to ^10-4 Pa, Ar gas was introduced, and the flow rate was adjusted so that the gas pressure inside the vacuum chamber became 2 Pa.
Plasma was generated by a high-frequency input of 0 W. The film formation rate was about 0.38 nm / sec, and no active substrate heating or substrate bias application was performed during film formation.

The structure inside the Co—ZrB ₂ composite film is as follows:
As in the case of the Co—SiO ₂ composite film obtained in Example 1, C
o Amorphous ZrB ₂ around columnar phase of crystal grains
The matrix phase surrounds, in this case Co
The average particle size of the crystals was about 10 nm. A sample having a thickness of 450 nm produced by this method was immersed in an aqueous 0.1 mol / L nitric acid solution for 5 minutes to dissolve and remove Co particles. As in Example 1, the Co columnar phase eluted, and the ZrB ₂ matrix phase remained. The specific surface area of the membrane and the contact angle with respect to pure water are about 1000 m ² / g and 22 °, respectively.
It was confirmed by an experiment of exhalation that the antifogging effect was almost the same as that of Example 1.

Example 13 An amorphous precursor film composed of three components of Fe—Si—O was formed on a heat-resistant glass (Corning # 7059) substrate having a thickness of 1.0 mm by a sputtering method. For sputtering, a target obtained by mixing and sintering Fe ₃ O ₄ powder and SiO ₂ powder at a volume ratio of 70% and 30%, respectively, was used. 5 × 10 ^-4 vacuum chamber
After evacuating to Pa, argon gas was introduced, the flow rate of Ar gas was adjusted so that the gas pressure inside the vacuum chamber became 2 Pa, and a high frequency of 4.4 W / cm ² was input to generate plasma. The deposition rate at this time is about 0.2 nm / sec.
Met.

When the formed amorphous precursor film was observed by SEM, an amorphous film having a thickness of about 120 nm was formed on the glass substrate. No defects such as cracks and pores were found in the amorphous film, and a very dense film was formed. Subsequently, the amorphous film was subjected to a heat treatment in air at 600 ° C. for 2 hours. When the Fe ₂ O ₃ —SiO ₂ composite film formed by the heat treatment was observed with a TEM, a needle-like hematite (Fe
₂ O ₃ ) crystal and silica (SiO ₂ ) surrounding it
Formed a eutectic structure. The hematite crystal extended perpendicularly to the film surface from the film surface toward the interface with the substrate, and had a diameter of about 4 nm.

Finally, the film heat-treated by the above method was immersed together with the substrate in an aqueous solution of about 6 mol / L hydrochloric acid at room temperature for 48 hours to remove only hematite. When the cross section of the antifogging film formed by removing hematite was observed with a TEM, an amorphous silica matrix and through pores extending one-dimensionally were observed. The diameter of the through pore was 4 nm, which was almost the same as the diameter of hematite before the acid treatment, and it was confirmed that the through pore was present in the silica film. The specific surface area of the film and the contact angle with respect to pure water are about 800 m ² / g and 8 respectively.
°, and it was confirmed by an experiment of blowing the air that the antifogging effect was almost the same as that of Example 1.

Example 14 An amorphous precursor film composed of three components of Fe—Si—O was formed on a heat-resistant glass (Corning # 7059) substrate having a thickness of 1.0 mm by a sputtering method. For sputtering, a target obtained by mixing and sintering Fe ₃ O ₄ powder and SiO ₂ powder at a volume ratio of 70% and 30%, respectively, was used. 5 × 10 ^-4 vacuum chamber
After evacuating to Pa, argon gas was introduced, the flow rate of Ar gas was adjusted so that the gas pressure inside the vacuum tank became 8 Pa, and a high frequency of 4.4 W / cm ² was input to generate plasma. The deposition rate at this time is about 0.1 nm / sec.
Met.

When the formed amorphous precursor film was observed by SEM, it was found to have a thickness of about 80 nm on a glass substrate.
An amorphous film almost similar to that of Example 13 was formed. No defects such as cracks and pores were found in the amorphous film, and a very dense film was formed. Subsequently, the amorphous film was subjected to a heat treatment in air at 600 ° C. for 2 hours. Fe ₂ O ₃ —S formed by heat treatment
Observation of the iO ₂ composite film with a TEM revealed that, as in Example 13, the one-dimensionally elongated needle-like hematite and the silica surrounding it formed an eutectic structure. The hematite crystal extended perpendicularly to the film surface from the film surface toward the interface with the substrate, and had a diameter of about 20 nm.

Finally, the film heat-treated by the above method was immersed together with the substrate in an aqueous solution of about 6 mol / L hydrochloric acid at room temperature for 48 hours to remove only hematite. The fine structure of the film cross section is T
Observation by EM confirmed that through-pores having a diameter substantially equal to the diameter of hematite before the acid treatment were present in the silica film. The specific surface area of the film and the contact angle with respect to pure water were about 1200 m ² / g and 5 °, respectively, and it was confirmed by an experiment of blowing air that the anti-fogging effect was almost the same as that of Example 1.

Comparative Example 2 The amorphous precursor film obtained in Example 13 was heat-treated at 800 ° C. for 1 hour in air. As a result of observing the film after the heat treatment by TEM,
The hematite crystals were not acicular but spherical, having a diameter of about 10 nm, and were deposited so as to be enveloped in the silica matrix. Subsequently, the film heat-treated by the above method was immersed together with the substrate in a hydrochloric acid aqueous solution of about 6 mol / L, but all the hematite crystals could not be removed even after 100 hours.

[0079]

As described above, the anti-fogging film of the present invention has a large number of one-dimensionally penetrated pores surrounded by a continuous wall from one surface to the other surface of the film. , While maintaining high strength and excellent adhesion to the substrate. Further, the anti-fogging film of the present invention can be applied to various kinds of substrates and can be composed of various compositions.

The diameter of the pores contained in the anti-fogging film of the present invention is substantially uniform at about 1 to 500 nm, and is several tens μm.
There are no such large holes. Therefore, fine particles such as tobacco tar and various dusts floating in the air do not enter, and can be removed by simple washing.

When the antifogging film of the present invention contains oxides, carbides, borides and nitrides as main components, it prevents fogging of mirrors, architectural window glasses, automobile windshields, optical lens surfaces and the like. Suitable for antifogging films and the like. In addition, Cr, N
When a metal such as i, Cu, Au, Al, or Pt is used as a main component, it is suitable for a reflection mirror, a surface coat of a curve mirror, an anti-fog film for an infrared reflection coating, and the like.

Since the antifogging film of the present invention has pores penetrating from the surface to the inside of the film and has a large specific surface area, it has a catalytic function and a catalyst carrying function to photodecompose organic substances attached to the surface. Thereby, an antifouling function can be added, and the film can have a permanent antifogging property.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a procedure for forming an antifogging film of the present invention.

FIG. 2 is an isothermal adsorption / desorption curve of the antifogging film of Example 1 at liquid nitrogen temperature.

[Explanation of symbols]

 1: substrate 2: columnar phase 3: matrix phase 4: composite film 5: anti-fogging film of the present invention 6: amorphous precursor film

Claims (5)

[Claims] 1. A composite film formed by removing a one-dimensionally grown columnar phase in a composite film comprising a plurality of one-dimensionally grown columnar phases on a substrate and a matrix phase surrounding the columnar phase. An antifogging film having a number of one-dimensionally penetrating pores surrounded by a continuous wall from one surface of the film to the other surface, wherein a contact angle with water is 30 ° or less. Anti-fog film. 2. The anti-fogging film according to claim 1, wherein said anti-fogging film comprises at least one selected from oxides, carbides, borides, nitrides and metals. 3. The antifogging film according to claim 1, wherein the pores penetrating one-dimensionally have an average pore diameter of 1 to 500 nm. 4. The antifogging film has a specific surface area of 20 to 2,000 m.
The antifogging film according to claim 1, 2 or 3, which is ² / g. 5. A substrate provided with the anti-fogging film according to claim 1, 2, 3 or 4 on the substrate.