JP2001328196A - Functional film and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a functional film which has a mechanical strength obtained by compression without using a large amount of binder resin and without firing at a high temperature and which can exert various functions and, besides, is excellent in flatness. SOLUTION: The functional film has a compressed layer of functional particulates on both surfaces of a substrate. The compressed layer is obtained by compressing a functional particulate containing layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a functional film and a method for producing the same. In the present invention, a “functional film” refers to a film having a function, that is, a function that fulfills through physical and / or chemical phenomena. The functional film of the present invention includes a conductive film, a magnetic film, a ferromagnetic film, a dielectric film, a ferroelectric film, an electrochromic film, an electroluminescence film, an insulating film, a light absorption film, a light selective absorption film, and a reflection film. , Anti-reflective film,
Films having various functions such as a catalyst film and a photocatalyst film are included.

[0002] In particular, the present invention relates to a transparent conductive film as a functional film and a method for producing the same. The transparent conductive film can be used for a transparent electrode such as an electroluminescence panel electrode, an electrochromic element electrode, a liquid crystal electrode, a transparent surface heating element, and a touch panel, and can also be used as a transparent electromagnetic wave shielding film.

[0003]

2. Description of the Related Art Functional films are produced by forming layers containing various functional materials on a support. Conventionally, these functional films, the above various functional materials,
Physical vapor phase growth (PVD) such as vacuum deposition, laser ablation, sputtering, and ion plating
Alternatively, it is manufactured by forming a functional film on a support by means of chemical vapor deposition (CVD) such as thermal CVD, optical CVD, or plasma CVD. However, the above method generally requires extensive equipment,
Some of them are not suitable for forming a large-area functional layer.

On the other hand, a method for forming a functional layer by coating using a sol-gel method is also known. In the sol-gel method, in many cases, it is necessary to sinter the inorganic material (functional material) in the liquid at a high temperature after applying the sol-gel liquid. Therefore, a resin film (eg, polyethylene terephthalate or the like) unsuitable for high-temperature heating cannot be used as the support.

[0005] Among the functional films, the following problems have been pointed out particularly in the production of transparent conductive films.

[0006] The transparent conductive film is mainly produced by a sputtering method. There are various methods in the sputtering method.For example, inert gas ions generated by direct current or high-frequency discharge in a vacuum are caused to collide with the target surface at an accelerated rate, and atoms constituting the target are knocked out from the surface and deposited on the support surface. For forming a transparent conductive layer.

[0007] The sputtering method is excellent in that a conductive layer having a low surface electric resistance can be formed even with a relatively large area. However, there is a problem that the apparatus is large and the film forming speed is low. In the future, as the area of the conductive layer increases, the scale of the device is expected to increase. Increasing the scale of the apparatus causes a technical problem that a higher degree of control is required for the control accuracy, and a problem in manufacturing efficiency such as an increase in manufacturing cost. At present, the deposition rate is improved by increasing the number of targets, but this also contributes to an increase in the scale of the apparatus.

[0008] Production of a transparent conductive film by a coating method has also been attempted. In a conventional coating method, a conductive paint in which conductive fine particles are dispersed in a binder resin is coated on a support and dried to form a conductive layer. In the coating method, a large-area conductive layer is easily formed, the apparatus is simple, the productivity is high, and the manufacturing cost is low as compared with the sputtering method. In a conductive film formed by a coating method, conductive particles formed in a conductive layer come into contact with each other to form an electrical path, thereby exhibiting conductivity.

Conventionally, in the production of a transparent conductive film by a coating method, it has been said that a conductive layer cannot be formed unless a large amount of a binder resin is used. Therefore, there is a problem that contact between the conductive fine particles is hindered by the binder resin, and the resulting transparent conductive film has a high electric resistance value (poor in conductivity), and its use has been limited. Further, it is said that when a binder resin is not used, a conductive layer that can withstand practical use cannot be formed unless the conductive material is sintered at a high temperature.

As a conventional coating method, for example, Japanese Patent Application Laid-Open No. 9-1
No. 09259 discloses a first step of applying a conductive paint composed of a conductive powder and a binder resin on a transfer plastic film and drying the conductive paint to form a conductive layer. １００100 kg / cm ² ), heating (7
A method for producing an antistatic transparent conductive film or sheet comprising a second step of treating (0 to 180 ° C.) and a third step of laminating this conductive layer on a plastic film or sheet and thermocompression bonding is disclosed.

In the above manufacturing method, a conductive paint containing a large amount of a binder resin is used. That is, when an inorganic conductive powder is used as the conductive powder, the binder 100
When the conductive powder is used in an amount of 100 to 500 parts by weight and the organic conductive powder is used in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the binder. Since a large amount of binder resin is used, a transparent conductive film having a low electric resistance cannot be obtained by the technique disclosed in the above publication.

Japanese Patent Application Laid-Open No. Hei 8-199096 discloses that
Consisting of tin-doped indium oxide (ITO) powder, solvent, coupling agent, metal organic or inorganic acid salt,
There is disclosed a method for producing a transparent conductive film-coated glass plate, in which a conductive film forming paint containing no binder is applied to a glass plate and fired at a temperature of 300 ° C. or higher. In this method, since no binder is used, the electric resistance value of the conductive film is reduced. However, since it is necessary to perform the firing step at a temperature of 300 ° C. or higher, it is difficult to form a conductive film on a flammable support such as a resin film. The resin film is deformed, melted, carbonized, or burns at medium to high temperatures.
Although it depends on the type of resin film, for example, a polyethylene terephthalate (PET) film has a temperature of 130 ° C.
The temperature before and after is considered to be the limit of heating.

As a manufacturing method other than the coating method, for example, Japanese Unexamined Patent Publication No. Hei 6-13785 discloses that at least a part, preferably all of the voids of a skeleton structure composed of a conductive substance (metal or alloy) powder are used. There is disclosed a conductive film composed of a powder compression layer filled with a resin and a resin layer below the powder compression layer. According to that, when forming a film on a plate material,
First, when a resin, a powdery substance (metal or alloy) and a plate material as a member to be processed are vibrated or stirred in a container together with a film forming medium (steel balls having a diameter of several mm), a resin layer is formed on the surface of the member to be processed. Subsequently, the powder material is captured and fixed to the resin layer by the adhesive force of the resin layer. Further, the vibrating or agitating film-forming medium exerts a striking force on the vibrating or agitating powder material to form a powder compaction layer. However, even in this technique, since a considerable amount of resin is required to obtain the effect of fixing the powder compression layer, it is difficult to obtain a conductive film having a low electric resistance value. Also, the production method is more complicated than the coating method.

Still another manufacturing method is disclosed in
No. 7195 discloses a method of forming a conductive fiber-resin integrated layer by sprinkling conductive short fibers on a film such as PVC and depositing them, followed by pressure treatment. The conductive short fiber is a short fiber such as polyethylene terephthalate obtained by applying a nickel plating or the like to the short fiber. The pressing operation is preferably performed under a temperature condition at which the resin matrix layer shows thermoplasticity.
A high temperature heating and low pressure condition of g / cm ² is disclosed.

[0015]

DISCLOSURE OF THE INVENTION The present invention is intended to provide a material having mechanical strength by compression and capable of exhibiting various functions without using a large amount of binder resin and without firing at a high temperature. Functional film that can be
An object is to provide a functional film having excellent flatness and a method for producing the same.

In particular, an object of the present invention is to provide a transparent conductive film having a low electric resistance value by a coating method and excellent in flatness among the above functional films, and a method for producing the same.

[0017]

In order to solve the above-mentioned problems, the following inventions are provided.

(1) A functional film having a functional fine particle compression layer obtained by compressing a functional fine particle-containing layer on both surfaces of a support.

(2) The functional film as described above, wherein the functional fine particle-containing layer is formed by applying and drying a coating material in which the functional fine particles are dispersed on both surfaces of the support.

(3) The functional film as described above, wherein the functional fine particles are one or more of inorganic fine particles.

(4) The functional fine particle compression layer is formed by coating the functional fine particle-containing layers formed on both surfaces of the support with 44N each.
/ Mm ² obtained by compression with a compression force of ² or more,
The above functional film.

(5) The functional film is a conductive film,
Among magnetic films, ferromagnetic films, dielectric films, ferroelectric films, electrochromic films, electroluminescence films, insulating films, light absorption films, light selective absorption films, reflection films, antireflection films, catalyst films and photocatalytic films The functional film as described above, which is one or more selected from the group consisting of:

(6) The functional film as described above, wherein the functional fine particles are conductive fine particles and have a function as a conductive film.

(7) The conductive fine particles are tin oxide, indium oxide, zinc oxide, cadmium oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO) and aluminum-doped oxide. One or two selected from zinc (AZO)
The functional film as described above, which is at least a kind.

(8) The functional film as described above, wherein the support is a resin film.

(9) A coating material in which functional fine particles are dispersed is coated on both sides of the support, dried to form a functional fine particle-containing layer, and then the functional fine particle-containing layer formed on both surfaces of the support is formed. And a method for producing a functional film, comprising simultaneously compressing the particles to obtain a compressed layer of functional fine particles.

(10) The method for producing a functional film as described above, wherein the functional fine particle-containing layers formed on both surfaces of the support are each compressed with a compressive force of 44 N / m ² or more.

(11) The method for producing a functional film as described above, wherein the compression is performed at a normal temperature (15 to 40 ° C.).

(12) The method for producing a functional film as described above, wherein the compression is performed using a roll press machine.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The functional film of the present invention has a functional fine particle compression layer obtained by compressing a functional fine particle-containing layer on both sides of a support.

In the present invention, the “functional film” is not particularly limited as long as it has a function to perform through physical and / or chemical phenomena. Specifically, conductive films, magnetic films, ferromagnetic films, dielectric films, ferroelectric films, electrochromic films, electroluminescent films, insulating films, light absorbing films, light selective absorbing films, reflective films, antireflective films , Catalyst film,
Films having various functions such as a photocatalyst film are exemplified.

Therefore, in the present invention, functional fine particles that can constitute a desired functional film are used as the functional fine particles. As the functional fine particles, mainly inorganic fine particles having a cohesive force are preferably used. One or more kinds of functional fine particles can be used.

For example, in the production of a transparent conductive film, tin oxide, indium oxide, zinc oxide, cadmium oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), and tin-doped indium oxide (ITO)
O), conductive inorganic fine particles such as aluminum-doped zinc oxide (AZO) are preferably used. Alternatively, organic conductive fine particles may be used. By applying the present invention, excellent conductivity is obtained.

In the production of magnetic films and ferromagnetic films, γ-Fe ₂ O ₃ , Fe ₃ O ₄ , Co-FeOx, B
a Ferrite or other iron oxide-based magnetic powder, α-Fe, Fe
-Co, Fe-Ni, Fe-Co-Ni, Co, Co-
A ferromagnetic alloy powder containing a ferromagnetic metal element such as Ni as a main component is preferably used. By applying the present invention, the saturation magnetic flux density of a magnetic film or a ferromagnetic film is improved.

In the production of dielectric films and ferroelectric films, magnesium titanate, barium titanate, strontium titanate, lead titanate, lead zirconate titanate (PZT), lead zirconate Fine particles of a dielectric or ferroelectric substance such as lanthanum-added lead zirconate titanate (PLZT), magnesium silicate, or a lead-containing perovskite compound are preferably used. By applying the present invention, the dielectric characteristics or the ferroelectric characteristics can be improved.

In the production of metal oxide films exhibiting various functions, iron oxide (Fe ₂ O ₃ ), silicon oxide (S
iO ₂ ), aluminum oxide (Al ₂ O ₃ ), titanium dioxide (TiO ₂ ), titanium oxide (TiO), zinc oxide (Z
Fine particles of metal oxides such as nO), zirconium oxide (ZrO ₂ ), and tungsten oxide (WO ₃ ) are preferably used. By applying the present invention, the filling degree of the metal oxide in the film is increased, and each function is improved. For example, when SiO ₂ , Al ₂ O ₃ or the like supporting a catalyst is used, a porous catalyst film having practical strength can be obtained. When TiO ₂ is used, the photocatalytic function can be improved. Further, when WO ₃ is used, an improvement in the coloring effect of the electrochromic display element can be obtained.

In the production of an electroluminescent film, zinc sulfide (ZnS) fine particles are preferably used. By applying the present invention, an inexpensive electroluminescent film can be manufactured by a coating method.

In the present invention, according to the intended functional film, preferably, a dispersion liquid in which various functional fine particles are dispersed is used as a coating material, which is applied to both surfaces of the support, dried and dried. A fine particle containing layer is formed.

The liquid (dispersion medium) in which functional fine particles such as conductive fine particles are dispersed is not particularly limited.
Various known dispersion media can be used. For example, saturated hydrocarbons such as hexane; aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and diisobutyl ketone; ethyl acetate And esters such as butyl acetate; ethers such as tetrahydrofuran, dioxane and diethyl ether; N, N-dimethylformamide;
Examples include amides such as N-methylpyrrolidone (NMP) and N, N-dimethylacetamide; and halogenated hydrocarbons such as ethylene chloride and chlorobenzene. Among them, a dispersion medium having polarity is preferable. Particularly, alcohols such as methanol and ethanol, and those having an affinity for water such as amides such as NMP have good dispersibility even without using a dispersant. Therefore, it is preferably used. One or more of these dispersion media can be used. In addition, a dispersant may be used depending on the type of the dispersion medium.

Water can also be used as a dispersion medium. When water is used, the support needs to be hydrophilic.
Since the resin film is usually hydrophobic, it easily repels water, and it is difficult to obtain a uniform layer. When the support is a resin film, it is necessary to mix alcohol with water or to make the surface of the support hydrophilic.

The amount of the dispersion medium to be used is not particularly limited as long as the dispersion liquid (paint, functional paint) of the functional fine particles has an appropriate viscosity suitable for application. In particular,
Dispersion medium 100 to 10 per 100 parts by weight of functional fine particles
The amount is preferably about 000 parts by weight, but can be appropriately changed depending on the types of the functional fine particles and the dispersion medium.

The dispersion of the functional fine particles in the dispersion medium can be performed by a known dispersion means such as a sand grinder mill method. In dispersing, it is also preferable to use a medium such as zirconia beads in order to loosen the aggregation of the functional fine particles. In addition, care should be taken not to mix impurities such as dust during dispersion.

In the present invention, the dispersion (paint) of the functional fine particles preferably does not substantially contain a resin for a binder. In particular, when the conductive film does not contain a resin, the contact between the conductive fine particles is not hindered by the resin, the conductivity between the conductive fine particles is secured, and the electric resistance value of the obtained conductive film is reduced. Low. The resin may be contained as long as the amount does not impair the conductivity, but the amount is much smaller than the amount of binder resin used in the conventional technology. In particular,
The upper limit of the content of the resin in the dispersion is represented by the volume before dispersion, and when the volume of the conductive fine particles is 100, 2
It is preferably about 5 or less, more preferably about 20 or less, particularly preferably about 3.7 or less, and most preferably 0. When a large amount of resin is contained so as to serve as a binder, contact between the conductive fine particles is hindered by the binder, electron transfer between the fine particles is hindered, and conductivity decreases.

Even in a functional film (metal oxide film) using WO ₃ fine particles or TiO ₂ fine particles, if no resin is contained, there is no hindrance of contact between the fine particles by the resin. It is planned. As long as the contact between the particles is not inhibited and each function is not impaired,
Although it is possible to include a resin, the amount is, for example, about 80 or less when the volume of each fine particle is 100.

When the catalyst film using Al ₂ O ₃ fine particles does not contain a resin, the surface of the fine particles having a catalytic function is not covered with the resin, and the function as a catalyst is improved. In a catalyst film, the active area as a catalyst increases as the number of voids in the film increases, so it is preferable to use no resin from these viewpoints.

As described above, in the functional film, it is preferable that the dispersion liquid does not contain a resin. Since the amount varies depending on the purpose of the functional film, it may be appropriately determined.

Various additives may be added to the dispersion of the functional fine particles as long as the performance required for each function such as conductivity and catalytic action is not impaired. Examples of these additives include an ultraviolet absorber, a surfactant, and a dispersant.

Next, a dispersion (paint) of the above-mentioned functional fine particles is applied on both sides of the support and dried to form a layer containing functional fine particles.

The support is not particularly limited, and various supports such as resin film, metal, cloth, paper and the like can be used. In the present invention, it is preferable to use a resin film that does not crack even if the compression force in the compression step is increased. The resin film is also preferable in that the adhesion of the functional fine particle layer to the film is good, and is also suitable for applications requiring light weight. In the present invention, since there is no pressing step or firing step at a high temperature, a resin film can be used as a support.

Examples of the resin film include a polyester film such as polyethylene terephthalate (PET), a polyolefin film such as polyethylene or polypropylene, a polycarbonate film, an acrylic film, a norbornene film ("ARTON" manufactured by JSR Corporation) and the like. No. Among them, a PET film is particularly preferred.

In the case of a soft resin film such as a PET film, after drying, a part of the functional fine particles in the functional fine particle-containing layer in contact with the film is embedded in the PET film during the compression step described below, and the compression process is performed. The layer adheres well to the PET film. Even if it is a resin film, if the film surface is hard, fine particles are not embedded, so that the adhesion between the fine particle layer and the support is not good.

In such a case, it is preferable to previously form a soft resin layer on the surface of a hard film, apply fine particles, dry and compress the fine particles. After the compression, the soft resin layer may be cured by heat, ultraviolet light, or the like.

It is preferable that the soft resin layer does not dissolve in the above-mentioned functional fine particle dispersion. In the conductive film, when the resin layer is dissolved, the solution in which the resin is dissolved rises around the conductive fine particles by capillary action, and as a result, the electric resistance value of the obtained conductive film increases. Also in the catalyst film, the solution in which the resin is dissolved rises around the fine particles having the catalytic function due to the capillary phenomenon, and the catalytic function decreases.

When a hard metal is used as the support, the adhesion between the functional fine particle layer and the support is poor. Therefore, if the surface of the support metal is treated with a resin or a soft metal (may be an alloy) is used. Good.

The shape of the support may be a film, a foil,
A mesh shape, a woven fabric, or the like can be used.

The application of the functional fine particle dispersion (paint) on both surfaces of the support can be carried out by a known method without any particular limitation. For example, it can be performed by a coating method such as a reverse roll method, a direct roll method, a blade method, a knife method, an extrusion nozzle method, a curtain method, a gravure roll method, a bar coat method, a dip method, a kiss coat method, and a squeeze method. Further, the dispersion liquid can be attached to the support by spraying or spraying.

The drying temperature depends on the type of dispersion medium used for dispersion, but is preferably about 10 to 150 ° C. If the temperature is lower than 10 ° C, dew condensation of moisture in the air is likely to occur, while if the temperature is higher than 150 ° C, the resin film (support) may be deformed. Also, care should be taken so that impurities do not adhere to the surface of the fine particles during drying.

The thickness of the layer containing the functional fine particles after application and drying may be about 0.1 to 10 μm, depending on the compression conditions in the next step and the use of each functional film finally obtained. .

As described above, when the functional fine particles are dispersed in a dispersion medium, applied, and dried, a uniform layer is easily formed.
When applying and drying a dispersion of these functional fine particles,
The fine particles form a layer even when no binder is present in the dispersion. The reason why a layer can be formed without containing a binder is not always clear, but when the liquid in the coating film is dried by drying, the fine particles gather together due to capillary force, and further, the fine particles It is considered that a layer is formed because the specific surface area is large and the cohesive force is strong. However, the strength of the layer at this stage is weak. Further, the resistance value of the conductive film is high, and the variation of the resistance value is large.

Next, the formed layer containing functional fine particles is compressed to obtain a compressed layer of functional fine particles. By compressing, the strength of the coating film can be improved. That is,
The compression increases the contact points between functional fine particles such as conductive fine particles and the like, and increases the contact surface, thereby increasing the strength of the coating film. Since the fine particles originally have a property of easily aggregating, they become a strong layer by being compressed.

In a conductive film, the strength of the coating film increases and the electrical resistance decreases. In the catalyst film, the coating film strength is increased, and a porous film is formed because no resin is used or the amount of the resin is small. Therefore, a higher catalytic function can be obtained. In other functional films, a high strength film in which fine particles are connected to each other can be obtained, and the amount of fine particles per unit volume increases because no resin is used or the amount of resin is small. Therefore, higher functions can be obtained.

[0063] Compression, for each formed in the support duplex layer, preferably performed at 44N / mm ² or more compression force, more preferably 135N / mm ² or more,
In particular, it is 180 N / mm ² or more. If it is less than 44 N / mm ² , the functional fine particle-containing layer cannot be sufficiently compressed, and it is difficult to obtain a conductive film having excellent conductivity. The higher the compressive force, the higher the coating film strength and the better the adhesion to the support. In the conductive film, a film having more excellent conductivity can be obtained, the strength of the coating film is improved, and the adhesion between the coating film and the support becomes strong. The higher the compression force, the higher the pressure resistance required for the device.
A compression force of up to / mm ² is suitable. Further, it is preferable that the compression is performed at a temperature near normal temperature (15 to 40 ° C.). The compression operation at a temperature near normal temperature is one of the advantages of the present invention.

The compression means is not particularly limited.
Although it can be performed by a sheet press, a roll press, or the like, it is preferable to use a roll press machine. The roll press is a method of sandwiching a film to be compressed between rolls, compressing the roll, and rotating the roll. The roll press is suitable because it is uniformly applied with a high pressure and can be produced in a roll-to-roll manner because of its high productivity.

The roll temperature of the roll press machine is set to room temperature (15
-40 ° C) is preferred. In a heated atmosphere or in compression (hot press) in which a roll is heated, if the compression pressure is increased, a problem such as expansion of the resin film occurs. In order to prevent the resin film of the support from stretching under heating,
When the compression pressure is reduced, the mechanical strength of the coating film decreases.
In conductive films, the mechanical strength of the coating decreases,
Electric resistance increases. When it is necessary to reduce the adhesion of moisture on the surface of the fine particles as much as possible, a heated atmosphere may be used to reduce the relative humidity of the atmosphere, but the temperature must be within a temperature range where the film does not easily elongate. Generally, the temperature range is preferably lower than the glass transition temperature (secondary transition temperature). The temperature may be set slightly higher than the temperature at which the required humidity is obtained in consideration of fluctuations in humidity. In the case of continuous compression by a roll press machine, it is also preferable to adjust the temperature so that the roll temperature does not rise due to heat generation.

If the support is made of metal, the atmosphere can be heated up to a temperature range in which the metal does not melt.

The glass transition temperature of the resin film is
It is determined by measuring dynamic viscoelasticity and refers to the temperature at which the mechanical loss of the main dispersion peaks. For example, regarding a PET film, its glass transition temperature is about 110 ° C.

The roll of the roll press machine is preferably a metal roll because a strong pressure can be applied. If the roll surface is soft, the functional fine particles may be transferred to the roll at the time of compression. Therefore, it is preferable to treat the roll surface with a hard film.

Thus, a compressed layer of functional fine particles is formed on both surfaces of the support. Since a compressive force is applied in the thickness direction when forming the compression layer, the fine particles tend to spread in a direction perpendicular to this direction. For this reason, due to stress distortion, the film may be curved with the compression layer side convex in some cases, and furthermore it may become cylindrical,
In the present invention, the above-mentioned problems can be effectively prevented by forming the above-mentioned compression layer on both surfaces of the support. The thickness of the compressed layer of functional fine particles depends on the application, but is preferably 0.1 to 1
It may be about 0 μm. In addition, in order to obtain a compressed layer having a thickness of about 10 μm, a series of operations of coating, drying, and compressing a dispersion of fine particles may be repeatedly performed.

In the present invention, the above-mentioned compression layer is formed on both surfaces of the support. Examples of the method of coating, drying and compression are as follows.

(I) A liquid (paint) in which functional fine particles are dispersed is coated on one surface of the support, dried to form a layer containing functional fine particles, and then compressed to form a compressed layer of functional fine particles. And Next, on the other surface of the support, coating, drying and compression are performed in the same procedure to provide a functional fine particle compression layer.

(Ii) On one surface of the support, a liquid (paint) in which functional fine particles are dispersed is applied and dried to form a layer containing functional fine particles. Subsequently, on the other surface of the support, coating and drying are performed in the same procedure to form a layer containing functional fine particles. Next, the functional fine particle-containing layers on both surfaces of the support are simultaneously compressed to provide a functional fine particle compressed layer.

(Iii) When applying the above-mentioned paint while continuously transporting a long and strip-shaped support, the paint is applied almost simultaneously on both sides of the support, dried, and then compressed simultaneously. A compressed fine particle layer.

In the above, the methods (ii) and (iii) are particularly preferred because the compressive forces applied to the layers on both surfaces are particularly uniform. According to this method, the stress balance on both sides of the support becomes equal, and a functional film having excellent flatness can be obtained. In addition, the characteristics of the functionality become uniform.

In the above description, a method for obtaining a flat functional film with uniform stress by providing functional fine particle compression layers of the same thickness with the same compression force on both surfaces of the support has been described. However, depending on the application, purpose, etc., for example, in the formation of a compressed layer on both sides of the support, the thickness and the compressive force of the two layers are appropriately different from each other to obtain a desired degree of functionality Obtaining a film is of course also possible.

According to the present invention, in the production of any functional film, a functional coating film having sufficient mechanical strength can be obtained, and the disadvantages of the conventional coating method using a large amount of binder resin can be solved. Therefore, the intended functions can be further improved.

Next, an example in which the present invention is applied to a transparent conductive film will be described.

Using a dispersion in which conductive fine particles are dispersed as a paint (conductive paint), the conductive paint is applied on both sides of the support and dried to form a layer containing conductive fine particles. Thereafter, the conductive fine particle-containing layer is compressed to form a compressed layer of conductive fine particles to obtain a conductive film.

The conductive fine particles in the transparent conductive film are not particularly limited as long as they do not significantly impair the transparency of the conductive film, and inorganic conductive fine particles are used. Alternatively, organic conductive fine particles may be used.

In the present invention, “transparent” means that visible light is transmitted. Regarding the degree of light scattering, the required level differs depending on the use of the conductive film. In the present invention, those having scattering which is generally called translucent are also included.

As the inorganic conductive fine particles, tin oxide,
Indium oxide, zinc oxide, cadmium oxide, etc.
Fine particles such as antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), and aluminum-doped zinc oxide (AZO) are preferred. Among them, ITO is preferable in that superior conductivity can be obtained. Alternatively, a material in which an inorganic material such as ATO or ITO is coated on the surface of transparent fine particles such as barium sulfate can be used. The particle size of these fine particles varies depending on the degree of scattering required according to the use of the conductive film, and also varies depending on the shape of the particles, and cannot be determined unconditionally.
m or less, more preferably 5 to 100 nm.

The organic conductive fine particles include, for example, those obtained by coating the surface of resin fine particles with a metal material.

[0083]

EXAMPLES The present invention will be described below with reference to examples.
It goes without saying that the present invention is not limited to these examples.

The evaluation test in this example was performed by the following method.

[Electrical Resistance] A test sample having a conductive film formed on both sides of the support was cut into a size of 50 mm × 50 mm. A tester was applied to two corners at diagonal positions to measure electric resistance.

[90 ° Peel Test] A 90 ° peel test was performed to evaluate the adhesion between the conductive film and the support and the strength of the conductive film. This will be described with reference to FIG.

A conductive film (1a) was formed on both surfaces of the support (1b), a double-sided tape (2) was adhered to one conductive film (1a) surface, and this was cut into a size of 25 mm × 100 mm. Sample (1). The double-sided tape surface side of this test sample (1) is stuck on a stainless steel plate (3), and cellophane tapes (4) for fixing are attached to both ends in the longitudinal direction so that the test sample (1) does not peel off. Affixed (FIG. 1 (a)).

Next, as shown in FIG. 1 (b), one end of a cellophane tape (width: 12 mm, manufactured by Nitto Denko No. 29) (5) was placed on the other conductive film (1a) surface using the test sample (1). ) Was attached so as to be parallel to the long side. The length of the sticking surface between the cellophane tape (5) and the test sample (1) was 50 mm. The other end of the cellophane tape (5) was attached to a tensiometer (6), and the cellophane tape (5) was set so that the angle between the sticking surface and the non-sticking surface (5a) was 90 degrees. Next, the cellophane tape (5) was pulled off at a speed of 100 mm / min by a tensiometer (6) to peel it off.
At this time, the speed at which the tape (5) was peeled off and the stainless steel plate (3) on which the test sample (1) was adhered were moved at the same speed, and the non-adhering surface (5) of the cellophane tape (5) was moved.
The angle between a) and the test sample (1) face was always 90 °. The force (F) required for peeling was measured by a tensiometer (6) (FIG. 1 (b)). The same test was performed on the conductive film formed on the other surface of the support.

After the test, the peeled conductive film surface and the cellophane tape surface were examined. When the adhesive is present on both surfaces, the conductive layer was not destroyed, but the adhesive layer of the cellophane tape was destroyed, that is, the force (F) required when the strength of the adhesive was removed. Therefore, the strength of the conductive film is equal to or higher than the value (F).

In this test, the upper limit of the strength of the adhesive was 6
N / 12mm, the evaluation result is 6N / 12m
The symbol "m" indicates that the adhesive is present on both surfaces as described above, and the adhesiveness and the strength of the conductive film are 6N / 1.
2 mm or more. If the value is smaller than this value, it means that there is no adhesive on the surface of the conductive film and the conductive film is partially adhered to the surface of the cellophane tape.

[Bending test] A conductive film having a coating film formed on both sides of a support was measured for a width of 50 mm and a length of 200 m.
m was cut out to obtain a test sample. The test sample was placed on a horizontal flat table with both ends (50 mm side) widened by hand and released. Next, it was observed whether the test sample remained spread on the horizontal flat table or whether the test sample was curved with the conductive film on the outside and rounded into a cylindrical shape. The test sample that had been spread on the flat table was regarded as a good product, and the test sample that was curved and rounded into a cylindrical shape was regarded as a defective product.

In Examples 1 to 6 and Comparative Examples 1 and 2, CR
This is an example in which ATO fine particles are used as conductive fine particles in order to obtain a transparent conductive film for T electromagnetic wave shielding use.

(Example 1) ATO fine particles having a primary particle size of 10 to 30 nm (SN-100P: manufactured by Ishihara Sangyo Co., Ltd.) 1
300 parts by weight of ethanol was added to 00 parts by weight, and the medium was dispersed as zirconia beads with a disperser. The obtained coating solution was applied to both sides of a 25 μm-thick PET film using a bar coater, dried by blowing warm air at 50 ° C., and formed into a film containing both layers of an ATO fine particle-containing layer (“ATO before compression”). Film "). The thickness of the ATO fine particle-containing layer (coating) was 3.4 μm.

Subsequently, the ATO film before compression was compressed. First, a preliminary experiment was conducted to confirm the compression pressure.

Using a roll press equipped with a pair of metal rolls having a diameter of 140 mm (roll chrome plating is applied to the roll surfaces), the rolls were not rotated and the rolls were not heated, and the room temperature was maintained. At 23 ° C., the pre-compression ATO film was sandwiched and compressed. At this time, the pressure per unit length in the film width direction is 1000 N / m
m. Next, the pressure was released, and the length of the compressed portion in the longitudinal direction of the film was 2 mm. From this result, it can be said that compression was performed at a pressure of 500 N / mm ² per unit area.

Next, the same pre-compressed ATO film as that used in the preliminary experiment was sandwiched between metal rolls and compressed under the above conditions, and the rolls were rotated and compressed at a feed speed of 5 m / min. Thus, a compressed ATO film was obtained. The thickness of the ATO coating film after compression was 2 μm.

The electrical resistance of the compressed ATO film is 3
It was 2.5 kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 6 N / 12 mm or more. In the bending test, no bending was observed and the product was good.

(Comparative Example 1)
A film was manufactured in the same manner as in Example 1 except that the O-particle-containing layer was formed only on one surface of the PET film. The thickness of the ATO coating film after compression (only one surface was formed) was 2 μm.

The electric resistance of the compressed ATO film is 3
It was 2.5 kΩ. A 90-degree peel test was performed, and the strength of the coating film was calculated from the results. As a result, the strength of the coating film on both surfaces was 6 N / 12 mm or more. However, when the film was subjected to a bending test, it was found to be defective.

(Example 2) A preliminary experiment was performed in the same manner as in Example 1 except that the pressure per unit length in the film width direction was changed to 660 N / mm and compression was performed. ATO film was obtained. In a preliminary experiment, the pressure was released without compressing and rotating the roll press machine, and then the length of the compressed portion in the longitudinal direction of the film was determined to be 1.9 mm. Was 347 N / mm ² .
In the following examples, the pressure per unit area was calculated in the same manner.

The electric resistance of the compressed ATO film is 3
It was 7.5 kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 6 N / 12 mm or more. In the bending test, no bending was observed and the product was good.

(Example 3) A preliminary experiment was performed in the same manner as in Example 1 except that the pressure per unit length in the film width direction was changed to 330 N / mm and compression was performed. ATO film was obtained. In a preliminary experiment, the pressure was released without compressing the roll press machine, and then the pressure was released and the length of the compressed portion in the longitudinal direction of the film was 1.8 mm. Was 183 N / mm ² .

The electrical resistance of the compressed ATO film is 7
It was 0 kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 6 N / 12 mm or more. In the bending test, no bending was observed and the product was good.

Example 4 A preliminary experiment was conducted in the same manner as in Example 1 except that the pressure per unit length in the film width direction was changed to 165 N / mm and compression was performed. ATO film was obtained. In a preliminary experiment, the pressure was released without rotating the roll press under compression, and the length of the compressed portion in the longitudinal direction of the film was found to be 1.2 mm. Was 138 N / mm ² .

The electric resistance of the compressed ATO film is 8
It was 0 kΩ. When the coating film strength was calculated from the results of the 90 degree peel test, the coating film strength was 5.2 N / 12 mm. In the bending test, no bending was observed and the product was good.

Example 5 A preliminary experiment was performed in the same manner as in Example 1 except that the pressure per unit length in the film width direction was changed to 80 N / mm and compression was performed. ATO film was obtained. In a preliminary experiment, without compressing and rotating the roll press machine,
Next, the pressure was released, and the length of the compressed portion in the longitudinal direction of the film was determined to be 0.9 mm. From the results, the pressure per unit area was 89 N / mm ² .

The electric resistance of the compressed ATO film is 1
It was 45 kΩ. When the strength of the coating film was calculated from the results of the 90 degree peel test, the strength of the coating film was 4.1 N / 12 mm. In the bending test, no bending was observed and the product was good.

(Example 6) A preliminary experiment was performed in the same manner as in Example 1, except that the pressure per unit length in the film width direction was changed to 40 N / mm and compression was performed. ATO film was obtained. In a preliminary experiment, without compressing and rotating the roll press machine,
Next, the pressure was released, and the length of the compressed portion in the longitudinal direction of the film was determined to be 0.9 mm. From the result, the pressure per unit area was 44 N / mm ² .

The electrical resistance of the compressed ATO film is 2
It was 05 kΩ. When the strength of the coating film was calculated from the results of the 90-degree peel test, the strength of the coating film was 3.1 N / 12 mm. In the bending test, no bending was observed and the product was good.

(Comparative Example 2) In Example 1, no compression was performed. That is, a physical property test was performed on the pre-compression ATO film of Example 1. A not compressed
The electric resistance of the TO film was 2250 kΩ. 90
As a result of the degree peel test, it was 0.
A force of 8 N / 12 mm was required. In the bending test, the product was good without any bending.

Each of the conductive films of Examples 1 to 6
The electric resistance value was low, the coating film strength was strong, and the adhesion between the conductive film and the support was excellent. From Examples 1 to 6, the higher the press pressure, the better the conductivity, the stronger the coating film strength,
The adhesion between the conductive film and the support was strong, and the adhesive of the cellophane tape remained on the conductive surface. In addition, all of the conductive films of Examples 1 to 6 were excellent in transparency in terms of visible light transmittance.

On the other hand, Comparative Example 1 was curved since no coating film was formed on both surfaces. In Comparative Example 2, since the compression step was not performed, the electric resistance value was higher and the coating film strength was inferior to those in Examples 1 to 6.

In Examples 7 to 17 and Comparative Examples 3 and 4, in order to obtain a transparent conductive film for use in an electroluminescence panel electrode, ITO fine particles having lower electric resistance than ATO were used as conductive fine particles. It is an example.

Example 7 300 parts by weight of ethanol was added to 100 parts by weight of ITO fine particles (manufactured by Dowa Mining Co., Ltd.) having a primary particle diameter of 10 to 30 nm, and the medium was dispersed as zirconia beads using a dispersing machine. 25 μm of the obtained coating solution
m-thick PET film on both sides using a bar coater, dried by sending warm air at 50 ° C.
A film in which an O fine particle-containing layer is formed on both surfaces (“I before compression I
TO film "). The thickness of each of the ITO fine particle-containing layers was 3.4 μm.

Next, a preliminary experiment was performed in the same manner as in Example 1 to obtain a further compressed ITO film. The pressure per unit length in the film width direction is 1000 N / mm, the compression length in the length direction is 2 mm, and the pressure per unit area is 500 N /
mm ² . The thickness of the ITO coating film (the compressed layer of ITO fine particles) after compression was 2 μm.

The electric resistance of the compressed ITO film was 1.5 kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 6 N / 12 mm or more. In the bending test, no bending was observed and the product was good.

(Comparative Example 3) In Example 7 described above, the IT
A film was produced in the same manner as in Example 7, except that the O fine particle-containing layer was formed only on one surface of the PET film. The thickness (formed on only one side) of the ITO coating film after compression was 2 μm.

The electrical resistance of the compressed ITO film was 1.
It was 5 kΩ. A 90 degree peel test was performed, and the film strength was calculated from the results.
N / 12 mm or more. However, when the film was subjected to a bending test, it was found to be defective.

(Embodiment 8) The same procedure as in Embodiment 7 was carried out except that the compression force was changed.
An O film was obtained. The pressure per unit length in the film width direction was 660 N / mm, the compression length in the length direction was 1.9 mm, and the pressure per unit area was 347 N / mm ² .

The electrical resistance of the compressed ITO film is 2
kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 6 N / 12 mm or more. In the bending test, no bending was observed and the product was good.

(Embodiment 9) The same procedure as in Embodiment 7 was carried out except that the compression force was changed.
An O film was obtained. The pressure per unit length in the film width direction was 330 N / mm, the compression length in the length direction was 1.8 mm, and the pressure per unit area was 183 N / mm ² .

The electrical resistance of the compressed ITO film is 3
kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 6 N / 12 mm or more. In the bending test, no bending was observed and the product was good.

(Embodiment 10) The same procedure as in Embodiment 7 was carried out except that the compression force was changed.
A TO film was obtained. The pressure per unit length in the film width direction is 165 N / mm, the compression length in the length direction is 1.2 mm,
The pressure was 138 N / mm ² per unit area.

The electric resistance of the compressed ITO film is 4
kΩ. When the strength of the coating film was calculated from the results of the 90 degree peel test, the strength of the coating film was 5.4 N / 12 mm. In the bending test, no bending was observed and the product was good.

(Embodiment 11) The same procedure as in Embodiment 7 was carried out except that the compression force was changed.
A TO film was obtained. The pressure per unit length in the film width direction was 80 N / mm, the compression length in the length direction was 0.9 mm, and the pressure per unit area was 89 N / mm ² .

The electric resistance of the compressed ITO film was 6.5 kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 4.2 N / 12 mm.
Met. In the bending test, no bending was observed and the product was good.

(Embodiment 12) The same procedure as in Embodiment 7 was carried out except that the compression force was changed.
A TO film was obtained. The pressure per unit length in the film width direction was 40 N / mm, the compression length in the length direction was 0.9 mm, and the pressure per unit area was 44 N / mm ² .

The electric resistance of the compressed ITO film is 1
It was 1 kΩ. When the film strength was calculated from the results of the 90 degree peel test, the film strength was 3.4 N / 12 mm. In the bending test, no bending was observed and the product was good.

Example 13 Example 8 was the same as Example 8 except that the feed speed during compression was changed to 2.5 m / min.
As above, a compressed ITO film was obtained.

The electrical resistance of the compressed ITO film is 2
kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 6 N / 12 mm or more. In the bending test, no bending was observed and the product was good.

(Example 14) Polyvinylidene fluoride (PVDF: density 1.8 g / cm ³ ) was used as a resin.
A resin solution was prepared by dissolving 100 parts by weight of PVDF in 900 parts by weight of NMP. IT with primary particle size of 10-30nm
O fine particles (density: 6.9 g / cm ³ , Dowa Mining Co., Ltd.)
100 parts by weight), 50 parts by weight of the resin solution and NMP
375 parts by weight were added, and the medium was dispersed as zirconia beads using a disperser. The obtained coating liquid was applied to a P
An ET film was applied using a bar coater and dried (100 ° C., 3 minutes) to obtain an ITO film before compression (I
The PVDF volume was 19 when the volume of the TO fine particles was set to 100).

In the same manner as in Example 7, using a roll press, the film was pressed at a pressure of 660 N / mm per unit length in the film width direction and at a pressure of 347 N / mm per unit area.
The film was compressed at a feed speed of N / mm ² and 5 m / min to obtain a compressed ITO film. The thickness of the ITO coating after compression is 2
μm.

The electrical resistance of the compressed ITO film is 3
kΩ. When the film strength was calculated from the results of the 90 degree peel test, the film strength was 5 N / 12 mm.
In the bending test, no bending was observed and the product was good.

(Example 15) In Example 14, the compression pressure was increased to 330 N per unit length in the film width direction.
/ Mm, a compressed length in the length direction of 1.8 mm, and a pressure per unit area of 183 N / mm ² , except that a compressed ITO film was obtained in the same manner as in Example 14.

The electrical resistance of the compressed ITO film is 4
kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 6 N / 12 mm or more. In the bending test, no bending was observed and the product was good.

(Example 16) In Example 14, the compression pressure was changed to a pressure of 165 N per unit length in the film width direction.
/ Mm, a compression length in the length direction of 1.2 mm, and a pressure per unit area of 138 N / mm ² , except that an ITO film was obtained in the same manner as in Example 14.

The electrical resistance of the compressed ITO film is 6
kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 6 N / 12 mm or more. In the bending test, no bending was observed and the product was good.

Example 17 In Example 14, the compression pressure was increased to 80 N / unit pressure per unit length in the film width direction.
mm, a compressed length in the length direction of 0.9 mm, and a pressure per unit area of 89 N / mm ² , except that the compressed ITO film was obtained in the same manner as in Example 14.

The electric resistance of the compressed ITO film was 9.5 kΩ. When the coating strength was calculated from the results of the 90 degree peel test, the coating strength was 6 N / 12 mm or more. In the bending test, no bending was observed and the product was good.

(Comparative Example 4) In Example 14, no compression was performed. That is, a physical property test was performed on the ITO film before compression in Example 14. The electrical resistance of the uncompressed ITO film was 160 kΩ. 9
As a result of the 0 degree peel test, it took 1 to remove the cellophane tape.
A force of N / 12 mm was required. In the bending test, the product was good without any bending.

Comparative Example 5 PVD was added to 900 parts by weight of NMP.
F100 parts by weight were dissolved to obtain a resin solution. ITO fine particles having a primary particle size of 10 to 30 nm (manufactured by Dowa Mining Co., Ltd.)
100 parts by weight, 1000 parts by weight of the resin solution and NMP
900 parts by weight were added, and the medium was dispersed as zirconia beads using a disperser. The obtained coating liquid is applied to a 25 μm thick P
The ET film was coated on both sides using a bar coater and dried (100 ° C., 3 minutes) to obtain an ITO film. IT
The thickness of each of the O coating films was 2 μm. IT in coatings
The volume of PVDF was 383 when the volume of the O particles was 100.

The electrical resistance of the obtained ITO film was 10
It was 5 kΩ. When the film strength was calculated from the results of the 90 degree peel test, the film strength was 3.4 N / 12 mm. This is because PVDF oozed out to the surface of the coating film due to the large amount of the resin, and the adhesion of the cellophane tape to the surface of the coating film became low, and the coating film was not broken.
In the bending test, no bending was observed and the product was good.

Each of the conductive films of Examples 7 to 17 had a low electric resistance value, a high coating film strength, and excellent adhesion between the conductive film and the support.

As can be seen from Examples 7 to 12 and Examples 14 to 17, the higher the pressing pressure, the better the conductivity, the stronger the coating film strength, and the stronger the adhesion between the conductive film and the support.
The adhesive of the cellophane tape remained on the conductive surface.

[0145] As the conductive fine particles, IT
O provided better conductivity. Example 7
All of the conductive films Nos. To 17 were excellent in transparency in terms of visible light transmittance.

On the other hand, in the case of Comparative Example 3, since no coating film was formed on both surfaces of the support, it was curved. The samples of Comparative Examples 4 and 5 were not subjected to the compression step, and thus had higher electric resistance values and inferior coating film strengths than those of Examples 7 to 12 and 14 to 17, respectively. In Comparative Example 5, a large amount of binder resin was used so that a coating film could be formed without compression as in the conventional case. Although the strength of the coating film was sufficient because a large amount of binder resin was used,
Electric resistance was high.

In the following Examples 18 to 20, functional films were prepared by using fine particles of tungsten oxide (WO ₃ ), fine particles of titanium oxide (TiO ₂ ), and fine particles of aluminum oxide (Al ₂ O ₃ ) as the fine inorganic particles. This is an example.

(Embodiment 18) This embodiment is an example in which WO ₃ fine particles are used for an electrochromic display device.

400 parts by weight of ethanol was added to 100 parts by weight of WO ₃ fine particles having a primary particle size of 50 to 100 nm, and the medium was dispersed as zirconia beads by a disperser. The obtained coating solution was applied on both sides of a PET film having a thickness of 25 μm using a bar coater and dried by sending warm air at 50 ° C. to form a film having WO ₃ fine particle-containing layers formed on both sides (“WO before compression” ₃ film "). The thickness of the WO ₃ fine particle-containing layer (coating film) was 3.4 μm.

In the same manner as in Example 1, using a roll press, the WO ₃ film before compression was pressed at a pressure of 1000 N / mm per unit length in the film width direction and at a pressure of 500 N / mm ² per unit area of 5 m. / Min at a feed rate of / min to obtain a compressed WO ₃ film. The thickness of each WO ₃ coating film after compression was 1.2 μm.

The 90 ° peel test was performed on the compressed WO ₃ film in the same manner as in the case of the conductive film. A force of 6 N / 12 mm was required to peel off the cellophane tape. When the coating film surface after the peel test was examined, the adhesive of the cellophane tape was adhered. When the adhesive surface of the peeled cellophane tape was examined, it was found to be adhesive. Therefore, the strength of the coating film was 6 N / 12 mm or more.

(Embodiment 19) This embodiment is an example using TiO ₂ fine particles as a photocatalytic film application.

900 parts by weight of ethanol was added to 100 parts by weight of TiO ₂ fine particles having a primary particle diameter of 30 to 70 nm, and the medium was dispersed as zirconia beads by a disperser. The obtained coating solution was coated on both sides of a 25 μm thick PET film,
The film was applied using a bar coater and dried by sending warm air at 50 ° C. to obtain a film having a TiO ₂ fine particle-containing layer formed on both sides (“TiO ₂ film before compression”). The thickness of each TiO ₂ fine particle-containing layer (coating) was 1.4 μm.

In the same manner as in Example 1, using a roll press, the TiO ₂ film before compression was pressed at a pressure of 1000 N / mm per unit length in the film width direction and at a pressure of 500 N / mm ² per unit area of 5 m. / Min at a feed rate of / min to obtain a compressed TiO ₂ film. T after compression
The thickness of each of the iO ₂ coating films was 1 μm.

The compressed TiO ₂ film was subjected to a 90 ° peel test in the same manner as in the case of the conductive film. A force of 6 N / 12 mm was required to peel off the cellophane tape. When the coating film surface after the peel test was examined, the adhesive of the cellophane tape was adhered. When the adhesive surface of the peeled cellophane tape was examined, it was found to be adhesive. Therefore, the strength of the coating film was 6 N / 12 mm or more.

Example 20 This example is an example in which Al ₂ O ₃ fine particles are used as a catalyst film.

400 parts by weight of ethanol was added to 100 parts by weight of Al ₂ O ₃ fine particles having a primary particle size of 5 to 20 nm, and the medium was dispersed as zirconia beads by a disperser. The obtained coating liquid was applied to both sides of a 25 μm-thick PET film using a bar coater, and dried by sending warm air at 50 ° C.
A film having an Al ₂ O ₃ fine particle-containing layer formed on both sides (“Al ₂ O ₃ film before compression”) was obtained. The thickness of each of the Al ₂ O ₃ fine particle-containing layers (coating) was 2.4 μm.

In the same manner as in Example 1, using a roll press, the TiO ₂ film before compression was pressed at a pressure of 1000 N / mm per unit length in the film width direction and at a pressure of 500 N / mm ² per unit area of 5 m. / Min at a feed rate of / min to obtain a compressed TiO ₂ film. T after compression
The thickness of each of the iO ₂ coatings was 1.6 μm.

The 90 ° peel test was performed on the compressed Al ₂ O ₃ film in the same manner as in the case of the conductive film. A force of 6 N / 12 mm was required to peel off the cellophane tape. When the coating film surface after the peel test was examined, the adhesive of the cellophane tape was adhered. When the adhesive surface of the peeled cellophane tape was examined, it was found to be adhesive. Therefore, the strength of the coating film was 6 N / 12 mm or more.

In the above embodiment, AT fine particles were used as the inorganic fine particles.
An example was shown in which an inorganic functional film was prepared using O fine particles, ITO fine particles, WO ₃ fine particles, TiO ₂ fine particles, and Al ₂ O ₃ fine particles. Various inorganic functional films can be produced using inorganic fine particles having various properties in the same manner as in the above-described embodiment.

[0161]

According to the present invention, a functional film can be obtained by a simple operation of applying a paint containing functional fine particles to a support and then compressing it. The functional film according to the present invention has sufficient mechanical strength and eliminates the adverse effects caused by the binder resin in the conventional coating method, and as a result, the intended function is further improved. Further, it has excellent flatness.

According to the present invention, a transparent conductive film can be obtained by a simple operation of applying a conductive paint to a support and then compressing the support. The transparent conductive film according to the present invention has excellent conductivity and transparency. Further, it has sufficient mechanical strength, strong adhesion between the conductive film and the support, and can be used for a long time. It also has excellent flatness.

Further, according to the method of the present invention, it is possible to cope with an increase in the area of the conductive film, the apparatus is simple, the productivity is high, and various functional films including the conductive film can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a 90-degree peel test in an example.

[Explanation of symbols]

 Reference Signs List 1 Test sample 1a Conductive film 1b Support 2 Double-sided tape 3 Stainless steel plate 4 Cellophane tape for fixing 5 Cellophane tape 5a Cellophane tape non-sticking surface 6 Tensiometer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B32B 9/00 B32B 9/00 A 31/20 31/20 H01B 5/14 H01B 5/14 A 13/00 503 13/00 503Z F-term (reference) 4D075 BB05Z CA22 DA04 DB31 DC22 EA02 EC02 EC10 4F100 AA00B AA00C AA17B AA17C AA19B AA19C AA25B AA25C AA28B AA28C AA29B AA29 EBAC BA18C AA33ABAC EJ172 EJ19 EJ192 EJ86 EJ86B EJ86C EJ862 GB41 JD14 JG01 JG01B JG01C JG02 JG04 JG06 JG10 JK01 JK06 JK15 JL02 JL08 JN01 JN06 YY00B YY00C 5G307 FA02 FB01 FC10 5G323 AA01

Claims (12)

[Claims] 1. A functional film having a functional fine particle compression layer obtained by compressing a functional fine particle-containing layer on both surfaces of a support. 2. The functional film according to claim 1, wherein the functional fine particle-containing layer is formed by applying and drying a coating material in which the functional fine particles are dispersed on both surfaces of the support. 3. The functional film according to claim 1, wherein the functional fine particles are one or more of inorganic fine particles. 4. The functional fine particle-compressed layer is formed on each of the functional fine particle-containing layers formed on both surfaces of the support by 44 N / m.
obtained by compressing in m ² or more compression strength, functional film according to any one of claims 1 to 3. 5. The functional film is a conductive film, a magnetic film, a ferromagnetic film, a dielectric film, a ferroelectric film, an electrochromic film, an electroluminescent film, an insulating film, a light absorbing film, a light selective absorbing film, and a reflection film. The functional film according to any one of claims 1 to 4, wherein the functional film is at least one selected from a film, an antireflection film, a catalyst film, and a photocatalyst film. 6. The functional film according to claim 1, wherein the functional fine particles are conductive fine particles and have a function as a conductive film. 7. The conductive fine particles include tin oxide, indium oxide, zinc oxide, cadmium oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), and aluminum-doped zinc oxide. The functional film according to claim 6, wherein the functional film is one or more selected from (AZO). 8. The method according to claim 1, wherein the support is a resin film.
The functional film according to any one of claims 1 to 7. 9. A coating material in which functional fine particles are dispersed is coated on both sides of a support and dried to form a functional fine particle-containing layer, and then the functional fine particle-containing layers formed on both surfaces of the support are removed. A method for producing a functional film, which comprises simultaneously compressing to obtain a compressed layer of functional fine particles. 10. The method for producing a functional film according to claim 9, wherein the functional fine particle-containing layers formed on both surfaces of the support are each compressed with a compressive force of 44 N / m ² or more. 11. The compression is performed at normal temperature (15 to 40 ° C.).
The method for producing a functional film according to claim 9. 12. The compression is performed using a roll press machine.
A method for producing the functional film according to any one of claims 9 to 11.