JP2001328194A - Functional film and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a functional film capable of exhibiting various functions by a coating method, for example, a functional film having a transparent conductive film having a low electric resistance value, and a method for producing the same. In particular, the present invention provides a functional film in which a functional layer is well formed even when the support surface is relatively hard. SOLUTION: A compressed layer 1 of functional fine particles is formed on a support 1b.
a functional film having an anchor coat layer 1c between the support 1b and the compressed layer 1a of the functional fine particles. The anchor coat layer 1c contains a resin as a main component. The compressed layer 1a of functional fine particles is obtained by compressing a functional fine particle-containing layer formed by applying and drying a liquid in which functional fine particles are dispersed on the anchor coat layer 1c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a functional film having a functional layer comprising a compressed layer of functional fine particles on a support and a method for producing the same. In the present invention, the functional film includes both a functional film and a functional sheet. Further, those having a support made of metal are also included in the functional film of the present invention.

[0002] A functional layer is a layer having a function, and a function means a function performed through physical and / or chemical phenomena. Functional layers include conductive layers, magnetic layers, ferromagnetic layers, dielectric layers, ferroelectric layers, electrochromic layers, electroluminescent layers, insulating layers, light absorbing layers,
Layers having various functions such as a light selective absorption layer, a reflection layer, an antireflection layer, a catalyst layer, and a photocatalyst layer are included.

In particular, the present invention relates to a transparent conductive film having a transparent conductive layer and a method for producing the same. Transparent conductive films include electroluminescent panel electrodes, electrochromic device electrodes, liquid crystal electrodes, transparent heating elements,
In addition to being used as a transparent electrode such as a touch panel, it can be used as a transparent electromagnetic wave shielding film.

[0004]

2. Description of the Related Art Conventionally, functional films made of various functional materials have been produced by physical vapor deposition (PVD) such as vacuum deposition, laser ablation, sputtering, ion plating, thermal CVD, optical CVD, and the like. It is manufactured by chemical vapor deposition (CVD) such as plasma CVD. These generally require a large-scale apparatus, and some of them are not suitable for forming a large-area film.

[0005] Also, formation of a film by coating using a sol-gel method is known. The sol-gel method is also suitable for forming a large-area film, but often requires sintering the inorganic material at a high temperature after coating.

For example, a transparent conductive film is as follows. At present, transparent conductive films are mainly manufactured by a sputtering method. There are various methods of sputtering, for example, accelerated collision of inert gas ions generated by direct current or high-frequency discharge in a vacuum onto the target surface, and strike out atoms constituting the target from the surface,
This is a method of forming a film by depositing it on the substrate surface. The sputtering method is excellent in that a conductive film having a low surface electric resistance can be formed even with a relatively large area. However, there is a disadvantage that the apparatus is large and the film forming speed is low. As the area of the conductive film is further increased in the future, the size of the device will be further increased. This technically causes problems such as the necessity of increasing control accuracy, and another problem arises that manufacturing costs increase.
Further, the number of targets is increased to compensate for the low film formation speed, and the speed is increased. However, this also causes a problem in that the size of the apparatus is increased.

[0007] 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 solution is applied on a substrate, dried, and cured to form a conductive film. The coating method has such advantages that a large-area conductive film can be easily formed, the apparatus is simple, the productivity is high, and the conductive film can be manufactured at lower cost than the sputtering method. In the coating method, the conductive fine particles come into contact with each other to form an electric path, thereby exhibiting conductivity. However, a conductive film produced by a conventional coating method has a defect that the contact is insufficient and the resulting conductive film has a high electric resistance value (poor in conductivity), and its use is limited.

As a method for producing a transparent conductive film by a conventional coating method, for example, Japanese Patent Application Laid-Open No. 9-109259 discloses a method in which a paint composed of a conductive powder and a binder resin is applied onto a transfer plastic film, dried, and dried. First step of forming a layer, pressurizing the conductive layer surface to a smooth surface (5 to 100 kg /
cm ² ), a second step of heating (70 to 180 ° C.)
A production method comprising a third step of laminating this conductive layer on a plastic film or sheet and thermocompression bonding is disclosed. In this method, a large amount of binder resin is used (in the case of inorganic conductive powder, binder 1 is used).
100 parts by weight, 100 to 500 parts by weight of conductive powder, and in the case of organic conductive powder, 0.1 to 30 parts by weight of conductive powder with respect to 100 parts by weight of binder)
A transparent conductive film having a low electric resistance cannot be obtained.

For example, Japanese Patent Application Laid-Open No. Hei 8-199096 discloses a method for forming a binder-free conductive film comprising tin-doped indium oxide (ITO) powder, a solvent, a coupling agent, and an organic or inorganic acid salt of a metal. A method is disclosed in which a paint 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 of the conductive film is reduced. But 300 ° C
Since it is necessary to perform the firing step at the above temperature, it is difficult to form a conductive film on a support such as a resin film. That is, the resin film is melted, carbonized, or burned by the high temperature. Depending on the type of resin film, for example, polyethylene terephthalate (P
For ET) films, a temperature of 130 ° C. would be the limit.

As a method other than the coating method, see Japanese Patent Application Laid-Open No. 6-1
Japanese Patent No. 3785 discloses a powder compression layer in which at least a part, preferably all of the voids of a skeleton structure composed of a conductive substance (metal or alloy) powder is filled with a resin, and a resin under the powder compressed layer. A conductive coating comprising a layer is disclosed.
The production method will be described by taking a case where a film is formed on a plate material as an example. According to the publication, first, a resin, a powdery substance (metal or alloy) and a plate material to be processed are vibrated or agitated 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. 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. A significant amount of resin is required to obtain the effect of fixing the powder compression layer. Further, the production method is more complicated than the coating method.

[0011] Other than the coating method, see JP-A-9-19-1
JP-A-07195 discloses a method in which conductive short fibers are sprinkled and deposited on a film such as PVC, and this is subjected to a pressure treatment to form a conductive fiber-resin integrated layer. The conductive short fiber is a short fiber such as polyethylene terephthalate, which is coated with nickel plating or the like. The pressing operation is preferably performed under a temperature condition at which the resin matrix layer shows thermoplasticity.
High temperature and low pressure conditions of g / cm ² are disclosed.

[0012]

From such a background,
A large-area functional film can be easily formed on a support, and various functions can be expressed while taking advantage of the application method that the functional film can be manufactured at a low cost with a simple apparatus and high productivity. It is desired to develop a method for obtaining a functional film, for example, a transparent conductive film having a low electric resistance value.

It is an object of the present invention to provide a functional film having a functional layer capable of exhibiting various functions by a coating method, for example, a functional film having a transparent conductive layer having a low electric resistance value, and to provide the functional film by a coating method. It is to provide a method for producing a film.

In particular, an object of the present invention is to provide a functional film in which a functional layer is well formed even when the surface of a support on which the functional layer is to be formed is relatively hard, and a method for producing the functional film. Is to provide.

[0015]

Means for Solving the Problems Conventionally, in a coating method,
If a large amount of binder resin is not used, the functional layer cannot be formed, or if no binder resin is used,
It was thought that a functional layer would not be obtained without sintering the functional material at a high temperature. Regarding the conductive film, the conductive layer cannot be formed unless a large amount of the binder resin is used, or if the binder resin is not used, the conductive layer cannot be obtained unless the conductive material is sintered at a high temperature. Was considered.

However, as a result of intensive studies, the present inventor has found that
Surprisingly, it was found that a functional layer having mechanical strength and exhibiting various functions can be obtained by compression without using a large amount of binder resin and without firing at a high temperature. The present inventors have found that when a conductive substance is used, a transparent conductive layer having a low resistance value can be obtained. Furthermore, the present inventor has proposed that even when the surface of the support on which the functional layer is to be formed is relatively hard, the function of the functional layer can be favorably formed by providing an anchor coat layer on the support. The inventors have found that a functional film can be obtained, and have reached the present invention.

The present invention provides a functional film having a compressed layer of functional fine particles on a support, wherein the functional film has an anchor coat layer between the support and the compressed layer of functional fine particles. It is. In the functional film, the anchor coat layer preferably contains a resin as a main component. The anchor coat layer is preferably soft, and for example, preferably has a pencil hardness of less than 4H.
The anchor coat layer is provided by coating.

In the above-mentioned functional film, the compressed layer of the functional fine particles is formed by applying and drying a liquid in which the functional fine particles are dispersed on an anchor coat layer formed on a support. It is obtained by compressing the containing layer. In the functional film, the compressed layer of the functional fine particles is preferably obtained by compressing with a compression force of 44 N / mm ² or more. The compressed layer of the functional fine particles is preferably obtained by compression using a roll press.

When conductive fine particles are used as the functional fine particles in the functional film, a functional film having a conductive layer can be obtained. In the functional film, the compressed layer of the functional fine particles is preferably a transparent conductive layer.

The present invention is particularly effective when the surface of the support on which the functional layer is to be formed is relatively hard, for example, a pencil hardness of 4H or more, and even in such a case, the functional layer is supported. Formed on the body.

The present invention also relates to a method for producing the functional film. In the present invention, an anchor coat layer is formed on a support, a liquid in which functional fine particles are dispersed is coated and dried on the anchor coat layer to form a functional fine particle-containing layer, and then, the functional fine particles are formed. A method for producing a functional film, comprising compressing a content layer to form a compressed layer of functional fine particles.

In the above method, the compression is set to 44 N / mm ^2.
It is preferable to perform the above compression. In the above method, it is preferable that the compression is performed at normal temperature. In the above method, the compression is preferably performed using a roll press.

In the above method, the dispersion of the functional fine particles may contain a small amount of resin, but it is particularly preferable that the dispersion contains no resin. When the dispersion of the functional fine particles contains a resin, the content of the resin is represented by volume,
When the volume of the functional fine particles is 100, the volume is preferably less than 25.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the functional layer comprises:
Without being particularly limited, a conductive layer, a magnetic layer, a ferromagnetic layer,
Layers having various functions such as a dielectric layer, a ferroelectric layer, an electrochromic layer, an electroluminescence layer, an insulating layer, a light absorption layer, a light selective absorption layer, a reflection layer, an antireflection layer, a catalyst layer, and a photocatalyst layer. included. Therefore, in the present invention, the functional fine particles that constitute the target layer are used. The functional fine particles are not particularly limited, and mainly inorganic fine particles having a cohesive force are used. In the production of any functional film, by applying the method of the present invention, a functional coating film having sufficient mechanical strength can be obtained, and a binder in a conventional coating method using a large amount of a binder resin. The adverse effects of the resin can be eliminated. As a result, the intended function is further improved.

For example, in the production of a transparent conductive layer, tin oxide, indium oxide, zinc oxide, cadmium oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), aluminum Conductive inorganic fine particles such as doped zinc oxide (AZO) are used. ITO is preferred because more excellent 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 diameter of these fine particles varies depending on the degree of scattering required according to the use of the conductive film, and cannot be unconditionally determined depending on the shape of the particles, but is generally 10 μm or less, and is 1.0 μm or less.
μm or less is preferable, and 5 nm to 100 nm is more preferable.

Alternatively, organic conductive fine particles may be used. As organic conductive fine particles, for example,
A material in which a metal material is coated on the surface of a resin fine particle is exemplified.

By applying the present manufacturing method, excellent conductivity can be obtained. 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 layer. In the present invention,
In general, there are scattering materials which are generally called translucent.

In manufacturing a ferromagnetic layer, γ-Fe ₂ O
₃ , iron oxide-based magnetic powders such as Fe ₃ O ₄ , Co—FeOx, and Ba ferrite, α-Fe, Fe—Co, Fe—N
i, a ferromagnetic alloy powder containing a ferromagnetic metal element such as Fe-Co-Ni, Co, or Co-Ni as a main component is used.
By applying this manufacturing method, the saturation magnetic flux density of the magnetic coating film is improved.

In manufacturing a dielectric layer or a ferroelectric layer,
Magnesium titanate, barium titanate, strontium titanate, lead titanate, lead zirconate titanate (PZT), lead zirconate, lanthanum-added lead zirconate titanate (PLZT), magnesium silicate Fine particles of a dielectric or ferroelectric material such as a system and a lead-containing perovskite compound are used. By applying the present manufacturing method, the dielectric characteristics or the ferroelectric characteristics can be improved.

In the production of a metal oxide layer exhibiting various functions, iron oxide (Fe ₂ O ₃ ), silicon oxide (SiO ₂ )
₂ ), aluminum oxide (Al ₂ O ₃ ), titanium dioxide (TiO ₂ ), titanium oxide (TiO), zinc oxide (Zn)
Fine particles of metal oxides such as O), zirconium oxide (ZrO ₂ ), and tungsten oxide (WO ₃ ) are used. By applying this manufacturing method, the degree of filling of the metal oxide in the film is increased, and each function is improved. For example, when SiO ₂ or Al ₂ O ₃ carrying a catalyst is used, a porous catalyst layer having practical strength can be obtained. When TiO ₂ is used, the photocatalytic function can be improved. In addition, WO
_{When 3} is used, an improvement in the coloring effect in the electrochromic display element can be obtained.

In the manufacture of the electroluminescent layer, zinc sulfide (ZnS) fine particles are used.
By applying the present manufacturing method, an inexpensive electroluminescent layer can be manufactured by a coating method.

In the present invention, a liquid in which functional fine particles selected from the above various functional fine particles are dispersed is used as a functional paint according to the purpose. This functional paint is applied and dried on an anchor coat layer preferably containing resin as a main component provided on a support to form a layer containing functional fine particles. Thereafter, the layer containing the functional fine particles is compressed to form a compressed layer of the functional fine particles to obtain a functional layer.

The liquid in which the functional fine particles such as the conductive fine particles are dispersed is not particularly limited, and various known liquids can be used. For example, as a liquid, 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, esters such as butyl acetate, ethers such as tetrahydrofuran, dioxane, 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 these, a liquid having polarity is preferable,
Especially alcohols such as methanol and ethanol, NMP
Those having an affinity for water, such as amides, have good dispersibility even without using a dispersant, and are suitable. These liquids can be used alone or in combination of two or more. Further, a dispersant can be used depending on the type of the liquid.

Further, water can be used as the liquid.
When water is used, the surface of the anchor coat layer needs to be hydrophilic. An anchor coat layer containing a resin as a main component is usually hydrophobic, so that it easily repels water, and it is difficult to obtain a uniform film. When the anchor coat layer is mainly composed of a resin, it is necessary to mix alcohol with water or to make the surface of the anchor coat layer hydrophilic.

The amount of the liquid used is not particularly limited as long as the dispersion of the fine particles has a viscosity suitable for coating. For example, the liquid is about 100 to 100,000 parts by weight based on 100 parts by weight of the fine particles. It may be appropriately selected according to the types of the fine particles and the liquid.

The fine particles may be dispersed in the liquid by a known dispersion technique. For example, the particles are dispersed by a sand grinder mill method. At the time of dispersion, it is also preferable to use a medium such as zirconia beads in order to loosen the aggregation of the fine particles. At the time of dispersion, care should be taken not to mix impurities such as dust.

It is preferable that the dispersion liquid of the fine particles does not contain a resin. That is, it is preferable that the resin amount = 0. If a resin is not used in the conductive film, the resin does not hinder contact between the conductive fine particles. Therefore, the conductivity between the conductive fine particles is ensured,
The obtained conductive film has a low electric resistance value. As long as the amount does not impair the conductivity, it is possible to contain a resin,
The amount is smaller than the amount used as a binder resin in the prior art. For example, the upper limit of the content of the resin in the dispersion liquid is less than 25 when the volume of the conductive fine particles is 100, expressed as the volume before dispersion. In the prior art, strong compression was not performed, so that a large amount of binder had to be used to obtain the mechanical strength of the coating film. If the resin is used in such an amount that it plays a role as a binder, contact between the conductive fine particles is hindered by the binder, electron transfer between the fine particles is hindered, and the conductivity is reduced.

On the other hand, the resin has the effect of improving the haze of the conductive film. However, in terms of conductivity,
The resin is preferably used in a volume range of less than 25, and more preferably in a volume range of less than 20, when the volume of the conductive fine particles is expressed as 100 before dispersion and the volume of the conductive fine particles is 100. preferable. Although the effect of improving haze is reduced, it is most preferable not to use a resin from the viewpoint of conductivity.

Even in a functional layer using WO ₃ fine particles or TiO ₂ fine particles, if no resin is used, the resin does not hinder contact between the fine particles.
Each function is improved. As long as the contact between the fine particles is not hindered and the respective functions are not impaired, it is possible to contain a resin.
When it is set to 0, the volume is, for example, about 80 or less.

In the catalyst layer using Al ₂ O ₃ fine particles, if no resin is used, the surface of the fine particles having a catalytic function will not be covered with the resin. For this reason,
The function as a catalyst is improved. In the catalyst layer, the more voids inside the membrane, the more active sites as a catalyst, so from this viewpoint it is preferable to use no resin.

As described above, it is preferable not to use a resin in the functional layer at the time of compression (that is, in the dispersion of the fine particles), and it is preferable to use a small amount of the resin even if it is used. The amount of the resin when used, depending on the purpose of the functional layer,
Since it may vary to some extent, it may be determined appropriately.

Various additives may be added to the dispersion of the fine particles as long as the performance required for each function such as conductivity and catalysis is satisfied. For example, ultraviolet absorbers,
It is an additive such as a surfactant and a dispersant.

The support is not particularly limited, and may be a resin film, glass, ceramics, metal, cloth,
Various materials such as paper can be used. However, in the case of glass, ceramics, and the like, it is highly likely that the glass will be broken at the time of compression in a later step, and therefore it is necessary to consider this point. The shape of the support may be a film, a foil, a mesh, a fabric, or the like.

As the support, a resin film which does not break even when the compression force in the compression step is increased is preferable. Resin films are also suitable for applications where weight reduction is required. In the present invention, a resin film can be used as a support because there is no pressurizing step at a high temperature or a firing step. 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, and a norbornene film (arton, manufactured by JSR Corporation).
And the like.

In the case of a resin film such as a PET film, a part of functional fine particles such as conductive fine particles in contact with the PET film during the compression step after drying is made of PET.
It feels like it is embedded in the film, and this fine particle layer adheres well to the PET film.

However, if the support is made of a hard material such as glass or metal, or a resin film having a hard coat layer formed on its surface and having a hard surface (for example, having a pencil hardness of 4H or more), fine particles may be formed. Is not embedded in the support, so that adhesion between the fine particle layer and the support cannot be obtained.

Therefore, in the present invention, an anchor coat layer mainly composed of a soft resin is previously formed on a glass surface, a metal surface, or a hard film surface, and functional fine particles are dispersed on the anchor coat layer. The dried solution is applied, dried and compressed. The anchor coat layer is required to be soft enough to form a compressed layer of functional fine particles with good adhesion. Therefore, the anchor coat layer has, for example, a pencil hardness of 4
It is preferably softer than H, and more preferably softer than 2H. The degree of softness required for the anchor coat layer also varies depending on the hardness of the surface of the support used, the type and particle size of the functional fine particles, the compression pressure, and the like.

A soft resin can be used for the anchor coat layer, and examples of such a resin include an acrylic resin, a urethane resin, a vinyl chloride resin, and a silicone resin. The anchor coat layer may contain fine particles such as silica for adjusting the hardness of the anchor coat layer, and a filler for coloring and absorbing ultraviolet rays, as long as the adhesion is not adversely affected. Also,
Before forming the anchor coat layer, the support may be subjected to a surface treatment such as a corona treatment. After the compression, the soft resin layer may be cured by heat, ultraviolet light, or the like.

It is preferable that the resin of the anchor coat layer does not dissolve in the liquid in which the functional fine particles are dispersed. In the conductive layer, when the resin layer is dissolved, a solution containing the resin comes around the conductive fine particles due to a capillary phenomenon, and as a result, the electric resistance value of the obtained conductive layer increases. Also in the catalyst layer, the solution containing the resin comes around the fine particles having the catalytic function due to the capillary phenomenon, and the catalytic function is reduced.

When a hard metal is used as the support,
Soft metal (may be alloy) as anchor coat layer
Can also be used. The formation of the anchor coat layer can be performed by a conventional method.

The dispersion liquid of the fine particles is coated on the anchor coat layer and dried to form a layer containing functional fine particles such as a layer containing conductive fine particles. The application of the fine particle dispersion,
The method can be performed 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 liquid 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 tends to occur, and if the temperature exceeds 150 ° C., the resin film support is deformed. At the time of drying, care is taken so that impurities do not adhere to the surface of the fine particles.

The thickness of the functional fine particle-containing layer such as the conductive fine particle-containing layer after coating and drying depends on the compression conditions in the next step and the use of each functional film such as the final conductive film. It may be about 10 μm.

As described above, when the functional fine particles such as the conductive fine particles are dispersed in a liquid, applied and dried, a uniform film can be easily formed. When the dispersion of the fine particles is applied and dried, the fine particles form a film even when the binder is not present in the dispersion. Although the reason for forming a film without the presence of a binder is not always clear, fine particles gather together due to capillary force when the liquid is dried and the amount of liquid decreases. Furthermore, the fact that the particles are fine particles has a large specific surface area and a strong cohesive force, so it is thought that they may become a film. However, the strength of the film at this stage is weak. In the conductive layer, the resistance value is high, and the variation in the resistance value is large.

Next, the formed layer containing functional fine particles such as the layer containing conductive fine particles is compressed to obtain a compressed layer of functional fine particles such as conductive fine particles. The compression improves the strength of the film. That is, by compressing, the number of contact points between functional fine particles such as conductive fine particles increases, and the contact surface increases. For this reason, the strength of the coating film increases. Since the fine particles originally have a property of easily aggregating, they become a strong film by being compressed.

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

The compression is preferably performed with a compression force of 44 N / mm ² or more. If the pressure is lower than 44 N / mm ² ,
A layer containing functional fine particles such as a layer containing conductive fine particles cannot be sufficiently compressed, and for example, it is difficult to obtain a conductive layer having excellent conductivity. 135N / mm ² or more compressive force and more preferably, compressive force of 180 N / mm ² is more preferable. The higher the compressive force, the higher the strength of the coating film and the better the adhesion to the support. In the conductive layer, a layer having more excellent conductivity is obtained, the strength of the conductive layer is improved, and the adhesion between the conductive layer and the anchor coat layer becomes strong. Since the higher the compressive force, the higher the pressure resistance of the device must be increased, a compressive force of up to 1000 N / mm ² is generally appropriate. 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 can be performed by a sheet press, a roll press or the like without any particular limitation, but is preferably performed using 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 preferably applied with a high pressure uniformly, and can be produced in a roll-to-roll manner, so that productivity is increased.

The roll temperature of the roll press is preferably room temperature. In a heated atmosphere or in a compression (hot press) in which a roll is heated, when the compression pressure is increased, a problem such as the resin film being elongated occurs. If the compression pressure is reduced to prevent the resin film of the support from stretching under heating, the mechanical strength of the coating film decreases. In a conductive film, the mechanical strength of the coating film decreases, and the electrical resistance increases.
If there is a reason 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 range is within the range where the film does not easily stretch. It is. Generally, the temperature is 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. It is also preferable to adjust the temperature so that the roll temperature does not rise due to heat generation when continuously compressed by a roll press. 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, looking at a PET film, its glass transition temperature is around 110 ° C.

The roll of the roll press machine is preferably a metal roll because a strong pressure is applied. In addition, if the roll surface is soft, fine particles may be transferred to the roll during compression. Therefore, it is preferable to treat the roll surface with a hard film.

In this way, a compressed layer of functional fine particles such as conductive fine particles is formed. The thickness of the compressed layer of functional fine particles such as conductive fine particles depends on the application, but may be 0.1 to
It may be about 10 μm. Further, 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 liquid of fine particles may be repeatedly performed. Further, in the present invention, it is of course possible to form each functional layer such as a conductive layer on both surfaces of the support. Each functional layer such as a transparent conductive layer obtained in this manner exhibits excellent functionality such as excellent conductivity and catalytic action, and uses a small amount of resin that does not use a binder resin or does not function as a binder. Despite the use of such a film, it has practically sufficient film strength and excellent adhesion to an anchor coat layer.

[0063]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples. In Examples 1 to 4, ITO was used as a conductive film.
This is an example using fine particles.

Example 1 As shown in FIG.
(1b) has an anchor coat layer (1c), and the anchor coat layer
A functional film (1) having a functional layer (1a) on (1c) was prepared.

(Formation of Support) A silicone hard coat liquid KP-854 (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to a 50 μm-thick PET film, dried, cured at 90 ° C. for 2 hours, and cured to a thickness of 2 μm. Of a silicone hard coat layer was formed.

(Formation of Anchor Coat Layer) A silane curing agent CR-15 (GE) was added to 100 parts by weight of silicone varnish TSR-145 (manufactured by GE Toshiba Silicone, pencil hardness HB).
1.5 parts by weight (manufactured by Toshiba Silicone Co., Ltd.), 120 parts by weight of ethanol and 80 parts by weight of toluene were further added to prepare an anchor coat layer coating solution. This coating solution was applied to the hard coat surface of the PET film, dried, and cured at 90 ° C. for 2 hours to form a 1.5 μm thick anchor coat layer.

(Formation of Functional Layer) Primary particle size is 5 to 30 n
m ITO fine particles SUFP-HX (Sumitomo Metal Mining Co., Ltd.)
100 parts by weight of ethanol) and 300 parts by weight of ethanol were added, and the medium was dispersed as zirconia beads using a disperser.
The obtained coating liquid was applied on the anchor coat layer using a bar coater, and dried by sending warm air at 50 ° C. The resulting film is hereinafter referred to as a pre-compression ITO film. The thickness of the ITO-containing coating film was 1.7 μm.

First, a preliminary experiment for confirming the compression pressure was performed. Room temperature (23 ° C.) using a roll press equipped with a pair of 140 mm-diameter metal rolls (having a roll surface subjected to hard chrome plating) without rotating the rolls and without heating the rolls The above-mentioned ITO film before compression was sandwiched and compressed. At this time, the pressure per unit length in the film width direction was 660 N / mm. Next, the pressure was released, and the length of the compressed portion in the longitudinal direction of the film was 1.9 mm. From this result, it can be said that compression was performed at a pressure of 347 N / mm ² per unit area.

Next, the same pre-compressed ITO 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 ITO film was obtained. The thickness of the ITO compression layer was 1.0 μm.

(Electrical Resistance) The film on which the conductive film was formed was cut into a size of 50 mm × 50 mm. A tester was applied to two diagonal corners to measure electric resistance, and it was 1 kΩ.

Example 2 (Formation of Support) An acrylic hard coat solution (manufactured by Nippon Kayaku) was applied on a 50 μm-thick PET film, and dried.
The composition was cured by irradiation with ultraviolet rays to form an acrylic hard coat layer having a thickness of 2.5 μm.

(Formation of Anchor Coat Layer) 100 parts by weight of toluene was added to 100 parts by weight of an acrylic resin solution 103B (manufactured by Taisei Kako, pencil hardness H) to prepare an anchor coat layer coating solution. This coating solution was applied to the hard coat surface of the PET film and dried at 90 ° C. to form a 4.5 μm thick anchor coat layer.

(Formation of Functional Layer) A dispersion of ITO fine particles was applied on the anchor coat layer in the same manner as in Example 1, dried and compressed. 1.0μ thickness of ITO compression layer
m of the conductive film was obtained. The measured electric resistance was 1 kΩ.

Example 3 As a support, a PET film on which an acrylic hard coat layer having a thickness of 2.5 μm as in Example 2 was formed was used.

(Formation of Anchor Coat Layer) Except that 100 parts by weight of an acrylic resin solution 1BR-305 (manufactured by Taisei Kako Co., Ltd., pencil hardness 2H) was used instead of the acrylic resin solution 103B used in Example 2. In the same manner as in Example 2, an anchor coat layer having a thickness of 4.5 μm was formed.

(Formation of Functional Layer) A dispersion of ITO fine particles was applied on the anchor coat layer in the same manner as in Example 1, dried and compressed. 1.0μ thickness of ITO compression layer
m of the conductive film was obtained. The measured electric resistance was 1 kΩ.

Example 4 This is an example in which the anchor coat layer contains an ultraviolet absorber. As a support, a PET film having a 2 μm thick silicone hard coat layer formed thereon as in Example 1 was used.

(Formation of Anchor Coat Layer) Fresella NA (manufactured by Matsushita Electric Works, Ltd.), which is a silicone containing an ultraviolet absorber, was used. 600 parts by weight of solution B was added to 100 parts by weight of solution A of Fressella NA to prepare an anchor coat layer coating solution. This coating solution is applied to the hard coat surface of the PET film, dried, cured at 90 ° C. for 2 hours, and
An anchor coat layer having a thickness of μm was formed.

(Formation of Functional Layer) A dispersion of ITO fine particles was applied on the anchor coat layer in the same manner as in Example 1, dried and compressed. 1.0μ thickness of ITO compression layer
m of the conductive film was obtained. The measured electric resistance was 1 kΩ.

Reference Example 1 A 50 μm thick PET film on which a hard coat was not formed was used as a support. No anchor coat layer was formed on the PET film.

(Formation of Functional Layer) A dispersion of ITO fine particles was applied directly on the PET film in the same manner as in Example 1, dried and compressed. 1.0 thickness of ITO compression layer
A μm conductive film was obtained. The measured electric resistance was 1 kΩ.

[Comparative Example 1] As a support, a P having a 2 μm thick silicone hard coat layer as in Example 1 was formed.
An ET film was used. No anchor coat layer was formed on the hard coat surface of the PET film. (Formation of Functional Layer) A dispersion of ITO fine particles was applied directly to the hard coat surface of the PET film in the same manner as in Example 1, dried and compressed. Part of the ITO fine particles adhered to the roll, and a uniform layer was not obtained.

Comparative Example 2 As a support, a PET film having an acrylic hard coat layer having a thickness of 2.5 μm as in Example 2 was used. No anchor coat layer was formed on the hard coat surface of the PET film. (Formation of Functional Layer) A dispersion of ITO fine particles was applied directly to the hard coat surface of the PET film in the same manner as in Example 1, dried and compressed. Part of the ITO fine particles adhered to the roll, and a uniform layer was not obtained.

Example 5 Example 5 is an example using TiO ₂ fine particles as a photocatalyst film application. As a support, a 23 μm-thick aluminum foil (1080H1
8) was used. (Formation of anchor coat layer) The same anchor coat layer coating solution as in Example 1 was used. This coating solution was applied on the aluminum foil, dried, and cured at 90 ° C. for 2 hours.
An anchor coat layer having a thickness of 1.5 μm was formed.

(Formation of Functional Layer) The primary particle size is 30 to 70.
nm TiO_TwoEthanol 900 in 100 parts by weight of fine particles
Add parts by weight and disperse the media as zirconia beads
Disperse in the machine. The obtained coating liquid is anchored to the support.
Apply to the coated surface using a bar coater and heat at 50 ° C.
It was dried by blowing air. The resulting film is then
TiO before compression _TwoCalled film. TiO_TwoContaining coating
The thickness of the film was 0.7 μm.

First, a preliminary experiment for confirming the compression pressure was performed in the same manner as in Example 1. Using the same roll press as in Example 1, without rotating the rolls and without heating the rolls, at room temperature (23 ° C.) the T
The iO ₂ film was sandwiched and compressed. At this time, the pressure per unit length in the film width direction was 220 N / mm.
Next, the pressure was released and the length of the compressed portion in the longitudinal direction of the film was 0.8 mm. From this result, it can be said that compression was performed at a pressure of 275 N / mm ² per unit area.

Next, the same TiO ₂ film before compression 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 TiO ₂ film was obtained. The thickness of the TiO ₂ compression layer was 0.5 μm.

[0088]

[Table 1]

Each of the conductive films of Examples 1 to 4 had a low electric resistance, a high strength of the compression layer, and an excellent adhesion between the conductive layer and the anchor coat layer. Example 1
Each of the conductive films No. 4 was also excellent in transparency in terms of visible light transmittance. In Reference Example 1, an anchor coat layer was not formed, but a soft PET film on which a hard coat was not formed was used as a support, so that the adhesion between the conductive layer and the support was excellent. In Example 5, the aluminum foil was used as the support.
The adhesion between the O ₂ layer and the anchor coat layer was excellent.

In the above embodiment, the inorganic fine particles were made of IT
An example was shown in which an inorganic functional film was produced using O fine particles and TiO ₂ fine particles, respectively. Various inorganic functional films can be produced using inorganic fine particles having various properties in the same manner as in the above examples. Therefore, the above-described embodiments are merely illustrative in every respect,
It should not be interpreted restrictively. Furthermore, all modifications belonging to the equivalent scope of the claims are within the scope of the present invention.

[0091]

According to the present invention, a functional film is formed by a simple operation of forming an anchor coat layer on a support, applying a paint containing functional fine particles on the anchor coat layer, and compressing the coating. can get. The functional film according to the present invention has a functional layer formed well even when the support surface is relatively hard. According to the present invention,
The harmful effects of the binder resin in the conventional coating method are eliminated, and as a result, a functional film in which the intended function is further improved can be obtained.

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

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of the functional film of the present invention.

[Explanation of symbols]

 (1): functional film (1b): support film (1a): functional layer (1c): anchor coat layer

Continued on front page F-term (reference) 4F100 AA33 AK01C AK42 AK52 AR00B AT00A BA02 BA03 BA07 BA10A BA10B CC00C DE01B EH46C EJ19B EJ65C GB41 JB07 JG01B JG04 JG05 JG06 JL08 JN01B JN02 JN02 JN02 JN02 JN02 JN01

Claims (9)

[Claims] 1. A functional film having a compressed layer of functional fine particles on a support, wherein the functional film has an anchor coat layer between the support and the compressed layer of functional fine particles. 2. The functional film according to claim 1, wherein the anchor coat layer contains a resin as a main component. 3. The functional film according to claim 1, wherein the anchor coat layer is provided by coating. 4. The functional fine particle-containing layer formed by applying and drying a liquid in which functional fine particles are dispersed on an anchor coat layer formed on a support, and compressing the functional fine particle-containing layer. Claim 1 obtained by performing
4. The functional film according to any one of items 3 to 3. 5. The compressed layer of the functional fine particles has a pressure of 44 N /
It is obtained by compressing in mm ² or more compression strength, functional film according to any one of claims 1 to 4. 6. The functional film according to claim 1, wherein the compressed layer of the functional fine particles is obtained by compressing using a roll press. 7. The functional film according to claim 1, wherein the functional fine particles are conductive fine particles. 8. The functional film according to claim 1, wherein the compressed layer of the functional fine particles is a transparent conductive layer. 9. An anchor coat layer is formed on a support,
On the anchor coat layer, a liquid in which functional fine particles are dispersed is applied and dried to form a functional fine particle-containing layer. Thereafter, the functional fine particle-containing layer is compressed to form a compressed layer of functional fine particles. A method for producing a functional film, comprising: