JP2001332131A - Functional film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-performance functional film enabling high productivity, which can be manufactured without requiring heating operation at high temperatures. SOLUTION: A functional coating is prepared by dispersing functional fine particles in a solvent, which is coated to the functional film and dried, and then it is compressed. The functional film includes a film having various functions such as 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 absorbing film, a film selectively absorbing light, a reflecting film, a reflection preventing film, catalyst film, a photocatalyst film or the like. For example, a film composed by laminating fine particle- containing layers 2a, 2b on a substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a functional film. In the present invention, the functional film is defined as follows. That is, the functional film is a film having a function, and the function means a function performed through physical and / or chemical phenomena. Functional films include conductive films, magnetic films, ferromagnetic films, dielectric films, ferroelectric films, electrochromic films, electroluminescent films, insulating films, light absorbing films,
Films having various functions such as a light selective absorption film, a reflection film, an antireflection film, a catalyst film, and a photocatalyst film are included.

[0002] In particular, the present invention relates to a transparent conductive film.
The transparent conductive film is an electroluminescent panel electrode,
It can be used as a transparent electrode such as 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 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.

[0004] Further, formation of a film by coating using a sol-gel method is also 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 disadvantage that the conductive particles have insufficient contact with each other, and thus the resulting conductive film has a high electric resistance (poor conductivity). 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.) and a third step of laminating this conductive layer on a plastic film or sheet and thermocompression bonding are disclosed.

In this method, a large amount of binder resin is used (in the case of inorganic conductive powder, binder 1
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. 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.
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 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. 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.

As a method 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.
A high temperature / low pressure condition of / cm ² is disclosed.

[0013]

From such a background,
It is easy to form a large-area functional film easily, the equipment is simple, the productivity is high, and the functional film can be manufactured at low cost. It is desired to develop a method capable of obtaining a highly functional film.

Accordingly, an object of the present invention is to provide a high-performance functional film which has high productivity, does not require a high-temperature heating operation during production, and has high performance.

[0015]

The above object is achieved by the following constitution. (1) a fine particle-containing layer containing functional fine particles,
A functional film in which the fine particle-containing layer contains a solvent in an amount of 10 to 1500 g / m ³ . (2) The functional film according to the above (1), which is formed through a coating and compression process. (3) The above (1) or (2) provided on a support
Functional membrane. (4) The functional film according to the above (3), wherein the support is a resin. (5) 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, catalysts The functional film according to any one of the above (1) to (4), which is selected from a film and a photocatalytic film. (6) The functional film according to any one of (1) to (4), wherein the functional fine particles are conductive fine particles, and have a function as a conductive film. (7) The conductive fine particles are made of 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 ( (6) The functional film according to the above (6), which is a conductive inorganic fine particle selected from AZO).

Conventionally, in a coating method, a functional film cannot be formed unless a large amount of a binder resin is used, or
It was thought that when a binder resin was not used, a functional film could not be obtained unless the functional substance was sintered at a high temperature.

However, as a result of intensive studies, the present inventor has found that
Surprisingly, it has been found that a functional film can be formed only by compressing a coating film containing functional fine particles without using a large amount of binder resin and without firing at a high temperature.

Moreover, the functional film obtained by compression is
It has sufficiently high mechanical strength and high functions such as low electric resistance.

The functional film of the present invention has a low solvent content in the fine particle-containing layer. Therefore, when forming the fine particle-containing layer by compressing the fine particle-containing coating film, it is difficult for the coating film to adhere to the compression means such as a roll. As a result, a high-quality fine particle-containing layer is obtained, and Maintenance work such as cleaning is reduced, and productivity is increased.

[0020]

DETAILED DESCRIPTION OF THE INVENTION As described above, in the present invention, a functional film having sufficiently high mechanical strength and high performance can be fired at a high temperature without using a large amount of binder resin. Obtained without doing.

The functional film of the present invention has a fine particle containing layer containing functional fine particles. The fine particle-containing layer is formed by dispersing functional fine particles in a solvent to prepare a functional coating, applying the coating, drying, and compressing the coating.

A feature of the functional film of the present invention is that the solvent content in the film is 10 to 1500 g / m ³ , preferably 100 to 1 g / m ³ .
200 g / m ³ . The functional film of the present invention has such a small residual solvent amount. Therefore, when the functional film is manufactured by compressing the coating film, there is an advantage that the coating film is less likely to adhere to a compression means such as a roll. Also,
Therefore, the film strength is increased, and the adhesion strength to the substrate is also increased. When a fine particle-containing layer is formed, a functional coating material in which functional fine particles are dispersed in a solvent is used. Therefore, the amount of the solvent in the layer cannot be reduced to zero, and the above-described solvent remains.

The functional film of the present invention does not contain any resin as a binder at least at the time of compression, or contains only a resin that does not function as a binder. In addition, the resistance value of the conductive film can be extremely reduced.

In the present invention, the function of the functional film is not particularly limited. The functional film of the present invention, for example, 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, Reflective film, anti-reflective film,
Films having various functions such as a catalyst film and a photocatalyst film are included.

The functional fine particles contained in the fine particle containing layer include:
It may be appropriately selected from inorganic particles and / or organic particles according to the intended function, and is not particularly limited, but inorganic fine particles having a cohesive force are preferred. In the present invention, even when any of the functional fine particles is used, a functional film having sufficient mechanical strength can be obtained, and the harmful effects of the binder resin in the conventional coating method using a large amount of the binder resin can be solved. Can be. As a result, the intended function is further improved.

The conductive fine particles used in the production of the transparent conductive film are not particularly limited as long as they do not significantly impair the transparency of the conductive film. For example, tin oxide, indium oxide, zinc oxide, cadmium oxide, antimony Conductive inorganic fine particles such as doped tin oxide (ATO), fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), and aluminum-doped zinc oxide (AZO) are used.
Further, 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. Among these, ITO is preferable because more excellent conductivity can be obtained. In addition to these,
Organic conductive fine particles may be used. Examples of the organic conductive fine particles include, for example, those obtained by coating the surface of resin fine particles with a metal material. By applying the present invention, excellent conductivity is 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 film. In the present invention, those having scattering which is generally called translucent are also included.

In manufacturing a ferromagnetic film, γ-Fe ₂ O
₃ , iron oxide-based magnetic powders such as Fe ₃ O ₄ , Co—FeO _x , 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 the present invention, the saturation magnetic flux density of the magnetic coating film is improved.

In the production of a dielectric film or a ferroelectric film,
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 invention,
An improvement in dielectric characteristics or ferroelectric characteristics can be obtained.

In manufacturing a metal oxide film 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 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. In addition, WO
_{When 3} is used, an improvement in the coloring effect in the electrochromic display element can be obtained.

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

The particle diameter r of these functional fine particles differs depending on the use of the functional film, for example, depending on the required degree of scattering and the like, and cannot be said unconditionally depending on the shape of the particles. Particle size r = 10 μm or less;
1.0 μm or less is preferable, and 5 nm to 100 nm is more preferable.

The fine particle-containing layer preferably does not contain a resin at least at the time of compression. That is, it is preferable that the resin amount = 0. For example, in a conductive film, if a resin is not used, the resin does not hinder contact between the conductive fine particles. Therefore, conductivity between the conductive fine particles is ensured, and the electrical resistance of the obtained conductive film is reduced. Also, in a fine particle containing layer using WO ₃ fine particles or TiO ₂ fine particles, if no resin is used,
Since the contact between the fine particles is not hindered by the resin, each function is improved. Further, in a catalyst film using Al ₂ O ₃ fine particles or the like, 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 film, the more voids inside the film, the more active sites as a catalyst, and from this viewpoint, it is preferable to use no resin.

However, the functional film of the present invention may contain a resin in such an amount that the function such as conductivity is not significantly impaired. 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 functional film is an amount that does not function as a binder, specifically, when the volume of the conductive fine particles is 100, preferably less than 25, more preferably Less than 20, more preferably 3.7
Less than the volume.

It is preferable that the functional film does not contain a resin from the viewpoint of functions such as electric resistance, but the resin also has an effect of reducing light scattering of the functional film.
Therefore, in consideration of both improvement in haze and improvement in function, a resin may be appropriately added within the range of the volume ratio as needed.

The kind of the resin that can be contained in the functional film is not particularly limited, and a thermoplastic resin or a polymer having rubber elasticity can be used alone or in combination of two or more. Examples of the resin, fluorine-based polymer, silicone resin, acrylic resin, polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose,
Regenerated cellulose diacetylcellulose, polyvinyl chloride, polyvinylpyrrolidone, polyethylene, polypropylene, SBR, polybutadiene, polyethylene oxide and the like can be mentioned.

Examples of the fluoropolymer include polytetrafluoroethylene, polyvinylidene fluoride (PVDF),
Examples thereof include vinylidene fluoride-ethylene trifluoride copolymer, ethylene-tetrafluoroethylene copolymer, and propylene-tetrafluoroethylene copolymer. Further, a fluorine-containing polymer in which hydrogen in the main chain is substituted with an alkyl group can also be used. A resin having a higher density is preferable because the volume is smaller even when a larger weight is used.

In the present invention, in order to obtain a functional film, one obtained by dispersing functional fine particles selected from the above various functional fine particles in a solvent according to the purpose of the functional film is used as a functional paint. This functional paint is applied on a support and dried to form a fine particle-containing coating film. Next, the fine particle-containing coating film is compressed to obtain a compressed layer of functional fine particles, that is, a fine particle-containing layer.

The solvent for dispersing the functional fine particles is not particularly limited, and various known solvents can be used. For example, as a solvent, 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 ,
Esters such as ethyl acetate and butyl acetate, ethers such as tetrahydrofuran, dioxane and diethyl ether; amides such as N, N-dimethylformamide, N-methylpyrrolidone (NMP) and N, N-dimethylacetamide; ethylene chloride; Examples thereof include halogenated hydrocarbons such as chlorobenzene, cyclohexanone, and the like. Among these, polar solvents are preferred, and in particular, alcohols such as methanol and ethanol, N
Those having an affinity for water, such as amides such as MP, have good dispersibility even without using a dispersant, and thus are suitable.
These solvents may be used alone or in combination of two or more. Further, a dispersant can be used depending on the type of the solvent.

Further, water can be used as a solvent.
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 film. 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 solvent used is not particularly limited as long as the dispersion of the fine particles has a viscosity suitable for coating. For example, the solvent 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 solvent.

The fine particles may be dispersed in the solvent by a known dispersion technique. For example, it can be dispersed by a sand grinder mill method or the like. 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.

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.
As described below, the resin film is preferable in that the adhesion of the fine particle-containing layer to the film is good, and is also suitable for applications in which weight reduction is required. According to the present invention, a resin film can be used as a support because a pressurizing step at a high temperature and a baking step are unnecessary when forming the fine particle-containing layer.

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. .

In the case of a resin film such as a PET film, in the compression step after drying, the functional fine particles in contact with the PET film feel as if they are embedded in the PET film. It adheres well.

The dispersion of the functional fine particles is coated on the support and dried to form a fine particle-containing layer. The application of the fine particle dispersion on the support can be performed by a known method without any particular limitation. For example,
Reverse roll method, direct roll method, blade method,
Knife method, extrusion nozzle method, curtain method,
It can be performed by a coating method such as a gravure roll method, a bar coating method, a dip method, a kiss coating method, and a squeezing method. Further, the dispersion liquid can be attached to the support by spraying or spraying.

The drying temperature depends on the type of the solvent used for dispersion, but is preferably about 20 to 150 ° C. Below 20 ° C,
The amount of the residual solvent in the fine particle-containing layer tends to exceed the range defined in the present invention, and if it 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 dried fine particle-containing coating film may be appropriately determined according to the compression conditions in the next step and the use of the functional film, and may be about 0.1 to 10 μm.

As described above, when the functional fine particles are dispersed in a liquid, applied, and dried, it is easy to produce a uniform film. When the dispersion liquid of the fine particles is applied and dried, the fine particles can form a film even when the binder is not present in the dispersion liquid. 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, being a fine particle has a large specific surface area and a strong cohesive force,
I think it will be a film. However, the strength of the film at this stage is weak. Further, the conductive film has a high electric resistance value and a large variation.

Next, the fine particle-containing coating film is compressed to obtain a compressed film. Since the fine particles originally have a property of easily aggregating, they become a strong film by being compressed. In other words, the compression increases the number of contact points between the functional fine particles and the number of contact surfaces, thereby increasing the film strength.

In the conductive film, the strength of the coating increases and the electrical resistance decreases. The catalyst film becomes a porous film because the strength of the coating film is increased and the resin is not used or the amount of the resin is small. Therefore, a higher catalytic function can be obtained. Also in other functional films, a high strength film in which the fine particles are connected to each other can be obtained, and since no resin is contained or the resin content is small, the filling amount of the fine particles per unit volume increases. 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 , the fine particle-containing layer cannot be sufficiently compressed, and it is difficult to obtain a high-performance functional film such as a conductive film having excellent conductivity. 13
A compression force of 5 N / mm ² or more is more preferable, and 180 N / mm ²
A compression force of ² or more is more preferred. As the compressive force is higher, the strength of the coating film is improved, the adhesion to the support is improved, and a conductive film having higher conductivity is obtained. The higher the compression force, the higher the pressure resistance of the device must be.
Generally, a compression force of up to 1000 N / mm ² is appropriate.
Further, it is preferable that the compression is performed at a temperature near normal temperature (15 to 40 ° C.). One of the advantages of the present invention is that compression can be performed at a temperature near normal temperature.

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. When 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, and the electrical resistance of the conductive film 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.

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, a PET film has a glass transition temperature of about 110 ° C.

If the support is made of a metal, the atmosphere can be heated to a temperature at which the metal does not melt. In addition, a high temperature treatment may be performed on a support having a certain degree of heat resistance, such as a metal or ceramic.

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.

Thus, a compressed layer containing functional fine particles is formed. The thickness of the compression layer depends on the application, but may be about 0.1 to 10 μm. Also, 10
In order to obtain a compressed layer having a thickness of about μm, a series of operations of coating, drying, and compressing a dispersion of fine particles may be repeatedly performed. Further, in the present invention, it is of course possible to form a functional film on both surfaces of the support. The functional film obtained in this way shows excellent functionality such as excellent conductivity and catalytic action, and is manufactured using a small amount of resin that does not use a binder resin or does not function as a binder. Regardless, it has practically sufficient film strength and excellent adhesion to a support.

The functional film of the present invention may be composed of only one layer or two or more layers containing fine particles, or may be a laminate of a fine particle containing layer and another layer. In the configuration example shown in FIG. 1, a fine particle-containing layer 2 is formed on a support 1. The configuration example shown in FIG. 2 is a configuration in which two fine particle containing layers 2a and 2b are laminated.

The functional film having such a configuration, particularly in the configuration shown in FIG. 1, can be applied to a conductive material such as a touch panel or a sheet heating element, or an electromagnetic wave shielding material such as an electromagnetic wave shield for a PDP. 2 can be applied to conductive materials such as electrodes for inorganic EL and electrodes for solar cells.

[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.

Sample No. 1 ATO fine particles having an average primary particle size of 20 nm (Ishihara Sangyo Co., Ltd.)
300 parts by weight of ethanol were added to 100 parts by weight of SN-100P (manufactured by SN-100P), and the medium was dispersed as zirconia beads using a disperser. The obtained coating liquid was applied on a PET film having a thickness of 50 μm using a bar coater, and dried by sending warm air of 60 ° C. for 1 minute. The thickness of this coating film was 1.7 μm. The film on which the coating film is formed in this manner is hereinafter referred to as a film before compression.

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 (roll chrome plating is applied to the roll surface) without rotating the rolls and without heating the rolls. Then, the film before compression was sandwiched and compressed. At this time, the pressure per unit length in the film width direction was 750 N / mm. next,
When the pressure was released and the length of the compressed portion in the longitudinal direction of the film was measured, it was 1.9 mm. From this result, it was determined that the compression was performed at a pressure of 395 N / mm ² per unit area.

Next, the same pre-compression film as that used in the preliminary experiment was sandwiched between metal rolls, and the rolls were rotated at a feed speed of 4 m / min while compressing under the above-mentioned conditions. A sample No. 1 having the thus-prepared ATO-containing coating film as a functional film was obtained. The thickness of this functional film was 0.9 μm.

The amount of residual solvent in this functional membrane was measured by gas chromatography and was 552 g / m ³ . Note that no ATO fine particles were adhered to the surface of the roll used for compression.

The electrical resistance of this functional film is 72 kΩ.
Met. From the results of the 90 degree peel test, the coating strength was 6
N / 12 mm or more. The measurement of the electric resistance and the 90-degree peel test were performed according to the procedure described below.

(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 corners at diagonal positions to measure electric resistance.

(90 degree peel test) This will be described with reference to FIG. Support film 11b in test sample 11
A double-sided tape 12 was applied to the surface opposite to the surface on which the functional film 11a was formed. This is 25mm x 100mm
Cut out. Next, the test sample 11 was stuck to the stainless steel plate 13 with the double-sided tape 12. Then, cellophane tape 14 for fixing was attached to both ends (25 mm side) of sample 11 so that test sample 11 was not peeled off.
(FIG. 3 (a)).

A cellophane tape (width 12 mm, manufactured by Nitto Denko No. 29) 15 was attached to the surface of the functional film 11 a of the test sample 11 so as to be parallel to the long side of the sample 11. The sticking length between the cellophane tape 15 and the sample 11 was 50 mm. The end of the cellophane tape 15 to which the cellophane tape 15 was not attached was attached to the tensiometer 16, and the cellophane tape 15 was set so that the angle formed between the adhered surface and the non-adhered surface 15a was 90 degrees. The cellophane tape 15 was pulled off at a speed of 100 mm / min. At this time, the speed at which the cellophane tape 15 was peeled off and the stainless steel plate 1 on which the test sample 11 was stuck.
By controlling so that the moving speed of No. 3 was the same, the non-sticking surface 15a of the cellophane tape 15 and the surface of the test sample 11 were always at 90 degrees. Tensiometer 16
The force F required when peeling was measured. (FIG. 3
(B)).

After the test, the surface of the functional film from which the cellophane tape was peeled off and the surface of the peeled cellophane tape were examined. When the adhesive is present on both surfaces, the functional film was not destroyed, but the adhesive layer of the cellophane tape was destroyed, ie, the value of the force F required when the adhesive was peeled off. Therefore, the strength of the functional film is equal to or more than the value F.

In this test, the upper limit of the strength of the adhesive was 6
Since the adhesive strength is N / 12 mm, the presence of the adhesive on both surfaces as described above indicates that the strength of the functional film is 6 N / 12 mm or more. A value smaller than this indicates that the functional film has no adhesive on the surface and the functional film is partially adhered to the cellophane tape surface, and that value indicates that destruction occurred in the functional film.

Sample No. 2 Sample No. 2 was obtained in the same manner as in Sample No. 1, except that a mixed solvent consisting of 200 parts by weight of ethanol and 100 parts by weight of cyclohexanone was used instead of 300 parts by weight of ethanol. About this sample Sample No.1
As a result of the measurement, the amount of the residual solvent in the functional film was found to be 1,420 g / m ³ . Note that no ATO fine particles were adhered to the surface of the roll used for compression. The electrical resistance of this functional film was 71 kΩ. And 90
From the results of the degree peel test, the coating film strength was 6 N / 12 mm or more.

[0075]

The fine particle-containing layer in the functional film of the present invention has a low solvent content despite being formed by using a coating method. Therefore, when forming the fine particle-containing layer by compressing the fine particle-containing coating film, it is difficult for the coating film to adhere to the compression means such as a roll. As a result, a high-quality fine particle-containing layer is obtained, and Maintenance work such as cleaning is reduced, and productivity is increased. In addition, since the solvent content is small, the film strength is increased,
The adhesion strength to the substrate also increases.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration example of a functional film of the present invention.

FIG. 2 is a schematic sectional view showing a configuration example of a functional film of the present invention.

FIG. 3 is a diagram for explaining a 90-degree peel test in an example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support 2, 2a, 2b Fine particle containing layer 11 Test sample with conductive film formed 11a Conductive film 11b Support film 12 Double-sided tape 13 Stainless steel plate 14 Cellophane tape for fixing 15 Cellophane tape 15a Cellophane tape non-sticking surface 16 Tensiometer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Kawahara 1-13-1, Nihonbashi, Chuo-ku, Tokyo TDC Corporation F-term (reference) 4F100 AA25B AA27 AA28B AA33B AH02 AK42 AR00B AT00A BA02 BA07 DE01B EH46 EJ17 GB41 JG01 JG01B JG04B JG05B JG06B JL08B JM00B JN01 JN06B JN08B JN13B YY00B 5E321 AA21 BB32 BB53 GG05 GH01 5G307 FA01 FA02 FB01 FC03 FC05 FC10

Claims (7)

[Claims] 1. A functional film comprising a fine particle-containing layer containing functional fine particles, wherein the fine particle-containing layer contains a solvent in an amount of 10 to 1500 g / m ³ . 2. The functional film according to claim 1, which is formed through a coating and compression process. 3. The method according to claim 1, wherein the support is provided on a support.
Functional membrane. 4. The functional film according to claim 3, wherein the support is a resin. 5. A conductive film, a magnetic film, a ferromagnetic film, a dielectric film,
The ferroelectric film, an electrochromic film, an electroluminescence film, an insulating film, a light absorption film, a light selective absorption film, a reflection film, an antireflection film, a catalyst film, and a photocatalyst film, wherein the film is selected from the group consisting of: Functional membrane. 6. The functional film according to claim 1, wherein said functional fine particles are conductive fine particles, and have a function as a conductive film. 7. The conductive fine particles are made of 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. 7. The functional film according to claim 6, which is a conductive inorganic fine particle selected from zinc (AZO).