JP4491911B2 - Conductive film and method for producing the same - Google Patents

Description

【００８９】
実施例１〜４の導電性フィルムはいずれも、電気抵抗値が低く、圧縮層の強度も強く、導電層とアンカコート層との密着性にも優れていた。実施例１〜４の導電性フィルムはいずれも、可視光透過率の点においても透明性にも優れていた。
参考例１では、アンカーコート層を形成していないが、支持体としてハードコートの形成されていない柔らかいＰＥＴフィルムを用いたので、導電層と支持体との密着性に優れていた。
実施例５では、支持体としてアルミニウム箔を用いたが、ＴｉＯ₂ 層とアンカコート層との密着性に優れていた。
【００９０】
上記実施例では、無機微粒子として、ＩＴＯ微粒子、ＴｉＯ₂ 微粒子をそれぞれ用いて、無機機能性フィルムを作製した例を示した。上記実施例と同様にして、種々の性質を有する無機微粒子を用いて、種々の無機機能性フィルムを作製することができる。そのため、前述の実施例はあらゆる点で単なる例示にすぎず、限定的に解釈してはならない。さらに、請求の範囲の均等範囲に属する変更は、すべて本発明の範囲内のものである。
【００９１】
【発明の効果】
本発明によれば、支持体上にアンカーコート層を形成し、前記アンカーコート層上に、機能性微粒子を含む塗料を塗布後、圧縮するという簡便な操作で機能性フィルムが得られる。本発明による機能性フィルムは、前記支持体面が比較的硬い場合であっても、機能性層が良好に形成されたものである。本発明によって、従来の塗布法におけるバインダー樹脂による弊害が解消され、その結果、目的とする機能がより向上した機能性フィルムが得られる。
【００９２】
本発明によれば、機能性フィルムの大面積化にも対応でき、装置が簡便で生産性が高く、低コストで導電性フィルム膜を始め各種の機能性フィルムを製造できる。
【図面の簡単な説明】
【図１】 本発明の機能性フィルムの一例を示す断面図である。
【符号の説明】
(1) ：機能性フィルム
(1b)：支持体フィルム
(1a)：機能性層
(1c)：アンカーコート層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a functional film having a functional layer composed of a compressed layer of functional fine particles on a support and a method for producing the functional film. In the present invention, the functional film includes both a functional film and a functional sheet. Moreover, what a support body is a metal is also contained in the functional film of this invention.
[0002]
The functional layer is a layer having a function, and the function means a function performed through a physical and / or chemical phenomenon. Functional layers include conductive layer, magnetic layer, ferromagnetic layer, dielectric layer, ferroelectric layer, electrochromic layer, electroluminescence layer, insulating layer, light absorption layer, light selective absorption layer, reflection layer, antireflection Layers having various functions such as a layer, a catalyst layer, and a photocatalyst layer are included.
[0003]
Especially this invention relates to the transparent conductive film which has a transparent conductive layer, and its manufacturing method. The transparent conductive film can be used as a transparent electrode such as an electroluminescence panel electrode, an electrochromic element electrode, a liquid crystal electrode, a transparent surface heating element, and a touch panel, and can also be used as a transparent electromagnetic wave shielding film.
[0004]
[Prior art]
Conventionally, functional films made of various functional materials have been used for chemical vapor deposition (PVD) such as vacuum deposition, laser ablation, sputtering, ion plating, and chemical chemistry such as thermal CVD, photo CVD, and plasma CVD. Manufactured by chemical vapor deposition (CVD). These generally require a large-scale apparatus, and some are not suitable for forming a large-area film.
[0005]
It is also known to form a film by coating using a sol-gel method. The sol-gel method is suitable for forming a film having a large area, but in many cases, it is necessary to sinter the inorganic material at a high temperature after coating.
[0006]
For example, the transparent conductive film is as follows. Currently, the transparent conductive film is mainly produced by a sputtering method. There are various types of sputtering methods. For example, an inert gas ion generated by direct current or high frequency discharge in vacuum is accelerated and collided with the target surface, and atoms constituting the target are knocked out from the surface and deposited on the substrate surface. This is a method of forming a film.
The sputtering method is excellent in that a conductive film having a low surface electric resistance can be formed even with a certain large area. However, there is a drawback that the apparatus is large and the film forming speed is slow. As the area of the conductive film is further increased in the future, the apparatus will further increase. This causes a problem that technically the control accuracy must be increased, and a problem that the manufacturing cost increases from another viewpoint. Further, in order to compensate for the slow deposition rate, the number of targets is increased to increase the speed, but this is also a factor that increases the size of the apparatus.
[0007]
Attempts have also been made to produce a transparent conductive film by a coating method. In the conventional coating method, a conductive paint in which conductive fine particles are dispersed in a binder solution is applied onto a substrate, dried and cured, and a conductive film is formed. The coating method has an advantage that a conductive film having a large area can be easily formed, the apparatus is simple, the productivity is high, and the conductive film can be manufactured at a lower cost than the sputtering method. In the coating method, when conductive fine particles come into contact with each other, an electric path is formed and conductivity is expressed. However, the conductive film produced by the conventional coating method has a drawback that the contact is insufficient, and the resulting conductive film has a high electric resistance value (inferior in conductivity), and its application is limited.
[0008]
As a method for producing a transparent conductive film by a conventional coating method, for example, in JP-A-9-109259, a coating composed of conductive powder and a binder resin is applied on a transfer plastic film and dried to form a conductive layer. First step, pressurizing the surface of the conductive layer to a smooth surface (5 to 100 kg / cm²), A second process of heating (70 to 180 ° C.), and a third process 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, 100 to 500 parts by weight of conductive powder with respect to 100 parts by weight of binder, and in the case of organic conductive powder, binder 100 is used. Therefore, a transparent conductive film having a low electric resistance value cannot be obtained.
[0009]
For example, JP-A-8-199096 discloses a coating material for forming a conductive film which is made of tin-doped indium oxide (ITO) powder, solvent, coupling agent, metal organic acid salt or inorganic acid salt and does not contain a binder. The method of apply | coating to a board and baking at the temperature of 300 degreeC or more is disclosed. In this method, since no binder is used, the electrical resistance value of the conductive film is lowered. However, since it is necessary to perform a baking process at a temperature of 300 ° C. or higher, it is difficult to form a conductive film on a support such as a resin film. That is, the resin film melts, carbonizes, or burns at a high temperature. Depending on the type of resin film, for example, a polyethylene terephthalate (PET) film may have a limit of 130 ° C.
[0010]
As a method other than the coating method, Japanese Patent Application Laid-Open No. 6-13785 discloses that at least a part of the voids of the skeleton structure composed of conductive substance (metal or alloy) powder, preferably all the voids are filled with resin. A conductive film comprising a powder compression layer and a resin layer therebelow is disclosed. The manufacturing method will be described by taking as an example the case where a film is formed on a plate material. According to the publication, when a resin, a powder substance (metal or alloy), and a plate as a member to be processed are vibrated or stirred in a container together with a film forming medium (a steel ball having a diameter of several mm), the member to be processed is obtained. A resin layer is formed on the surface. Subsequently, the powder substance is captured and fixed to the resin layer by the adhesive force of the resin layer. Further, the film-forming medium that has been subjected to vibration or agitation applies a striking force to the powder material that has been subjected to vibration or agitation, and a powder compression layer is formed. In order to obtain the fixing effect of the powder compression layer, a considerable amount of resin is required. Further, the production method is more complicated than the coating method.
[0011]
As a method other than the coating method, in Japanese Patent Laid-Open No. 9-107195, conductive short fibers are deposited on a film such as PVC, and this is subjected to pressure treatment to form a conductive fiber-resin integrated layer. A method of forming is disclosed. The conductive short fiber is obtained by applying nickel plating or the like to a short fiber such as polyethylene terephthalate. The pressurizing operation is preferably performed under temperature conditions where the resin matrix layer exhibits thermoplasticity, 175 ° C., 20 kg / cm.²High temperature and low pressure conditions are disclosed.
[0012]
[Problems to be solved by the invention]
From such a background, it is easy to easily form a functional film of a large area on a support, the apparatus is simple, the productivity is high, while taking advantage of the coating method that can produce a functional film at low cost, Development of a method for obtaining a functional film capable of expressing various functions, for example, a transparent conductive film having a low electric resistance value, is desired.
[0013]
Accordingly, an object of the present invention is to provide a functional film that can exhibit various functions by a coating method, for example, a transparent conductive layer having a low electrical resistance value, and to produce the functional film by a coating method. It is to provide a method.
[0014]
In particular, an object of the present invention is to provide a functional film in which the functional layer is well formed even when the support surface on which the functional layer is to be formed is relatively hard, and a method for producing the functional film. There is.
[0015]
[Means for Solving the Problems]
Conventionally, in a coating method, a functional layer cannot be formed unless a large amount of binder resin is used, or if a binder resin is not used, a functional layer can be obtained unless the functional substance is sintered at a high temperature. It was considered impossible.
As for the conductive film, a conductive layer cannot be formed unless a large amount of binder resin is used, or if a binder resin is not used, a conductive layer cannot be obtained unless the conductive material is sintered at a high temperature. It was thought.
[0016]
However, as a result of intensive studies, the inventor has surprisingly been able to express various functions without compression using a large amount of binder resin and without firing at a high temperature and having mechanical strength by compression. We found that a functional layer was obtained. The present inventor has found that a transparent conductive layer having a low resistance value can be obtained by using a conductive material. Further, the present inventor has provided a function in which the functional layer is well formed by providing an anchor coat layer on the support even when the support surface on which the functional layer is to be formed is relatively hard. The inventors have found that a conductive film can be obtained and have reached the present invention.
[0017]
  The present invention provides a support onConductivityHas a compressed layer of fine particlesConductivityA film comprising the support and the filmConductivityBetween the compressed layer of fine particlesThe main component is a resin provided by coatingHas anchor coat layerAnd
  The compressed layer of conductive fine particles is obtained by compressing a conductive fine particle-containing layer formed by applying and drying a dispersion liquid in which conductive fine particles are dispersed and containing no resin on the anchor coat layer. A conductive filmIt is.
  AboveConductivityFilm smellBeforeThe anchor coat layer is preferably soft, for example, a pencil hardness of less than 4H is preferred.Yes.
[0018]
in frontRecordConductivityIn the film,ConductivityThe compressed layer of fine particles is 44 N / mm²It is preferable that it is obtained by compressing with the above compressive force. AboveConductivityThe compressed layer of fine particles is preferably obtained by compressing using a roll press.
[0019]
in frontRecordConductivityIn the film,ConductivityIt is also preferred that the fine particle compression layer is a transparent conductive layer.
[0020]
  AboveConductivityThe present invention is particularly effective when the support surface on which the layer is to be formed is relatively hard, for example, when it is harder than a pencil hardness of 4H. Even in such a case,ConductivityA layer is formed on the support.
[0021]
  The present invention provides the aboveConductivityIt also relates to a film manufacturing method. The present invention provides a support onBased on resinAnchor coat layerBy applicationFormed on the anchor coat layer,Dispersion liquid in which conductive fine particles are dispersed and no resin is containedApply, dry,ConductivityForming a fine particle-containing layer, and thenConductivityCompress the particle-containing layer,ConductivityForming a compressed layer of particulates,ConductivityIt is a manufacturing method of a film.
[0022]
In said method, compression is 44 N / mm²It is preferable to carry out with the above compressive force. In the said method, it is preferable to perform compression at normal temperature. In the above method, the compression is preferably performed using a roll press.
[0023]
  The present inventionIn the aboveConductivityFine particle dispersionThe treeDoes not contain fatYes.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the functional layer is not particularly limited, and includes a conductive layer, a magnetic layer, a ferromagnetic layer, a dielectric layer, a ferroelectric layer, an electrochromic layer, an electroluminescence layer, an insulating layer, and a light absorption layer. , 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. Therefore, in the present invention, functional fine particles that should 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 any functional film production, a functional coating film having sufficient mechanical strength can be obtained by applying the method of the present invention, and a binder in a conventional coating method using a large amount of binder resin. The harmful effects caused by the resin can be eliminated. As a result, the intended function is further improved.
[0025]
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-doped zinc oxide Conductive inorganic fine particles such as (AZO) are used. ITO is preferable in that it provides better conductivity. Or what coated inorganic material, such as ATO and ITO, on the surface of fine particles which have transparency, such as barium sulfate, can also be used. The particle diameter of these fine particles varies depending on the degree of scattering required depending on the use of the conductive film, and cannot be generally described depending on the shape of the particles, but is generally 10 μm or less, preferably 1.0 μm or less, 5 nm to 100 nm is more preferable.
[0026]
Alternatively, organic conductive fine particles may be used. Examples of the organic conductive fine particles include those in which a metal material is coated on the surface of resin fine particles.
[0027]
By applying this production method, excellent conductivity can be obtained. In the present invention, the transparent means that visible light is transmitted. Regarding the degree of light scattering, the required level varies depending on the use of the conductive layer. In the present invention, those having scattering, which is generally referred to as translucent, are also included.
[0028]
In the production of a ferromagnetic layer, γ-Fe₂O_Three, Fe_ThreeO_FourMainly composed of iron oxide magnetic powders such as Co-FeOx and Ba ferrite and ferromagnetic metal elements such as α-Fe, Fe-Co, Fe-Ni, Fe-Co-Ni, Co, and Co-Ni Ferromagnetic alloy powder or the like is used. By applying this production method, the saturation magnetic flux density of the magnetic coating film is improved.
[0029]
In the production of dielectric layers and ferroelectric layers, magnesium titanate, barium titanate, strontium titanate, lead titanate, lead zirconate titanate (PZT), lead zirconate, lanthanum added Dielectric or ferroelectric fine particles such as lead zirconate titanate (PLZT), magnesium silicate, and lead-containing perovskite compounds are used. Application of this manufacturing method can improve dielectric properties or ferroelectric properties.
[0030]
In the production of metal oxide layers that exhibit various functions, iron oxide (Fe₂O_Three), Silicon oxide (SiO₂), Aluminum oxide (Al₂O_Three), Titanium dioxide (TiO₂), Titanium oxide (TiO), zinc oxide (ZnO), zirconium oxide (ZrO)₂), Tungsten oxide (WO_Three) And other metal oxide fine particles are used. By applying this manufacturing method, the filling degree of the metal oxide in the film is increased, so that each function is improved. For example, SiO on which a catalyst is supported₂, Al₂O_ThreeWhen is used, a porous catalyst layer having practical strength can be obtained. TiO₂When is used, the photocatalytic function can be improved. In addition, WO_ThreeWhen is used, an improvement in the coloring effect in the electrochromic display element can be obtained.
[0031]
In the production of the electroluminescence layer, zinc sulfide (ZnS) fine particles are used. By applying this production method, an inexpensive electroluminescent layer can be produced by a coating method.
[0032]
In the present invention, a liquid in which functional fine particles selected from the above-mentioned various functional fine particles are dispersed is used as a functional coating depending on the purpose. This functional coating is applied onto an anchor coat layer, preferably composed mainly of a resin, provided on a support 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 to obtain a functional layer.
[0033]
The liquid in which functional fine particles such as conductive fine particles are dispersed is not particularly limited, and various known liquids can be used. For example, as 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 , 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 And halogenated hydrocarbons such as chlorobenzene. Among these, polar liquids are preferable, and those having an affinity for water such as alcohols such as methanol and ethanol and amides such as NMP have good dispersibility without using a dispersant. It is preferable. These liquids can be used singly or as a mixture of two or more. Moreover, a dispersing agent can also be used according to the kind of liquid.
[0034]
Water can also be used as the liquid. When water is used, the anchor coat layer surface needs to be hydrophilic. Since the anchor coat layer mainly composed of a resin is usually hydrophobic, it easily repels water and it is difficult to obtain a uniform film. When the anchor coat layer contains a resin as a main component, it is necessary to mix alcohol with water or make the surface of the anchor coat layer hydrophilic.
[0035]
The amount of the liquid to be used is not particularly limited, and the fine particle dispersion may have a viscosity suitable for coating. For example, the amount is about 100 to 100,000 parts by weight of the liquid with respect to 100 parts by weight of the fine particles. It is preferable to select appropriately according to the kind of the fine particles and the liquid.
[0036]
The dispersion of the fine particles in the liquid may be performed by a known dispersion method. For example, it is dispersed by a sand grinder mill method. In dispersing, it is also preferable to use media such as zirconia beads in order to loosen the aggregation of the fine particles. Also, care should be taken not to mix impurities such as dust during dispersion.
[0037]
The fine particle dispersion preferably contains no resin. That is, it is preferable that the resin amount = 0. In the conductive film, if the resin is not used, the contact between the conductive fine particles is not hindered by the resin. Therefore, the electrical conductivity between the conductive fine particles is ensured, and the electrical resistance value of the obtained conductive film is low. The resin can be contained in an amount that does not impair the conductivity, but the amount is less 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 is represented by the volume before dispersion, and the volume of the conductive fine particles is 100, and the volume is less than 25. In the prior art, since strong compression is not performed, a large amount of binder must be used to obtain the mechanical strength of the coating film. When an amount of resin that plays a role as a binder is used, contact between the conductive fine particles is inhibited by the binder, electron transfer between the fine particles is inhibited, and conductivity is lowered.
[0038]
On the other hand, the resin has an effect of improving the haze of the conductive film. However, from the viewpoint of conductivity, the resin is preferably used in a volume range of less than 25 when the volume of the conductive fine particles is represented as 100 and expressed as a volume before dispersion, and a volume of less than 20 It is more preferable to use within the range. Moreover, although the effect of improving haze is reduced, it is most preferable not to use a resin from the viewpoint of conductivity.
[0039]
WO_ThreeFine particles and TiO₂Even in a functional layer using fine particles or the like, if the resin is not used, the contact between the fine particles is not hindered by the resin, so that each function can be improved. It is possible to include a resin as long as the contact between the fine particles is not hindered and does not impair each function, but the amount is, for example, about 80 or less when the volume of each fine particle is 100. Volume.
[0040]
Al₂O_ThreeIn a catalyst layer using fine particles or the like, the surface of fine particles having a catalytic function is not covered by the resin unless a resin is used. For this reason, the function as a catalyst is improved. In the catalyst layer, the more voids inside the membrane, the more active points as a catalyst. Therefore, it is preferable not to use a resin as much as possible from this viewpoint.
[0041]
Thus, it is preferable not to use a resin in the functional layer at the time of compression (that is, in the fine particle dispersion), and even if it is used, a small amount is preferable. The amount of the resin to be used may be appropriately determined because it can be changed to some extent according to the purpose of the functional layer.
[0042]
Various additives may be blended in the fine particle dispersion within a range satisfying performance required for each function such as conductivity and catalytic action. For example, additives such as ultraviolet absorbers, surfactants, and dispersants.
[0043]
As a support body, various things, such as a resin film, glass, ceramics, a metal, cloth, paper, can be used, without being specifically limited. However, since glass, ceramics, and the like are likely to break during the subsequent compression, it is necessary to consider this point. In addition to the film shape, the support may be a foil shape, a mesh shape, a woven fabric, or the like.
[0044]
As the support, a resin film that does not break even when the compression force in the compression step is increased is suitable. The resin film is also suitable for applications that require weight reduction. In the present invention, a resin film can be used as a support since there is no pressurization step at high temperature and no firing step.
Examples of the resin film include polyester films such as polyethylene terephthalate (PET), polyolefin films such as polyethylene and polypropylene, polycarbonate films, acrylic films, norbornene films (manufactured by JSR Corporation, Arton, etc.), and the like.
[0045]
In 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 is embedded in the PET film during the compression step after drying. It adheres well to the film.
[0046]
However, if the support is a hard material such as glass or metal, or a resin film having a hard coat layer formed on its surface and a hard surface (for example, a hardness of 4H or higher), the fine particles are the support. The fine particle layer and the support cannot be adhered because they are not embedded in the substrate.
[0047]
Therefore, in the present invention, an anchor coat layer mainly composed of a soft resin is formed in advance on a glass surface, a metal surface, or a hard film surface, and a liquid in which functional fine particles are dispersed on the anchor coat layer. Apply, dry and compress. The anchor coat layer is required to be soft enough to form a compressed layer of functional fine particles with good adhesion. Accordingly, the anchor coat layer is preferably softer than, for example, a pencil hardness of 4H, and more preferably softer than 2H. The degree of softness required for the anchor coat layer also varies depending on the hardness of the support surface to be used, the type and particle size of functional fine particles, the compression pressure, and the like.
[0048]
A soft resin can be used for the anchor coat layer, and examples of such a resin include acrylic resin, urethane resin, vinyl chloride resin, and 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 ultraviolet absorption, as long as the adhesion is not adversely affected.
Further, before forming the anchor coat layer, the support may be subjected to a surface treatment such as a corona treatment. After compression, the soft resin layer may be cured with heat, ultraviolet light, or the like.
[0049]
The resin of the anchor coat layer is preferably one that 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 capillary action, 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 a catalytic function due to capillary action, and the catalytic function is lowered.
[0050]
When a hard metal is used as the support, it is possible to use a soft metal (or an alloy) as the anchor coat layer. The anchor coat layer can be formed by a conventional method.
[0051]
The fine particle dispersion is applied onto the anchor coat layer and dried to form a functional fine particle-containing layer such as a conductive fine particle-containing layer.
The application of the fine particle dispersion is not particularly limited and can be performed by a known method. 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, or a squeeze method. It is also possible to deposit the dispersion on the support by spraying or spraying.
[0052]
The drying temperature depends on the type of liquid used for dispersion, but is preferably about 10 to 150 ° C. If it is less than 10 ° C, condensation of moisture in the air tends to occur, and if it exceeds 150 ° C, the resin film support is deformed. Also, care should be taken so that impurities do not adhere to the surface of the fine particles during drying.
[0053]
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. do it.
[0054]
Thus, when functional fine particles such as conductive fine particles are dispersed in a liquid, applied, and dried, a uniform film can be easily formed. When the fine particle dispersion is applied and dried, the fine particles form a film even if no binder is present in the dispersion. The reason for forming a film without the presence of a binder is not necessarily clear, but when the liquid is reduced after drying, fine particles gather together due to capillary force. Furthermore, the fact that it is a fine particle has a large specific surface area and a strong cohesive force, so it is thought that it may become a film. However, the strength of the film at this stage is weak. In addition, the conductive layer has a high resistance value and a large variation in resistance value.
[0055]
Next, the formed functional fine particle-containing layer such as the conductive fine particle-containing layer is compressed to obtain a compressed layer of functional fine particles such as the conductive fine particles. By compressing, the strength of the film is improved. That is, by compressing, the contact points between functional fine particles such as conductive fine particles increase and the contact surface increases. For this reason, the coating film strength increases. Since the fine particles originally have a property of easily agglomerating, they become a strong film by being compressed.
[0056]
In the conductive layer, the coating strength increases and the electrical resistance decreases. In the catalyst layer, the coating film strength is increased, and the resin layer is not used or the amount of the resin is small, so that the catalyst layer becomes a porous layer. Therefore, a higher catalytic function can be obtained. Also in other functional layers, it is possible to form a high-strength film in which fine particles are connected to each other, and since no resin is used or the amount of resin is small, the filling amount of fine particles in a unit volume increases. Therefore, higher functions can be obtained.
[0057]
Compression is 44 N / mm²It is preferable to carry out with the above compressive force. 44 N / mm²If the pressure is less than 1, the functional fine particle-containing layer such as the conductive fine particle-containing layer cannot be sufficiently compressed. For example, it is difficult to obtain a conductive layer having excellent conductivity. 135 N / mm²The above compressive force is more preferable, 180 N / mm²The compression force of is more preferable. The higher the compression force, the better the coating strength and the better the adhesion with 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 is strengthened. The higher the compression force, the higher the pressure resistance of the device, so generally 1000 N / mm²The compression force up to is appropriate. Moreover, it is preferable to perform compression at the temperature near normal temperature (15-40 degreeC). A compression operation at a temperature near room temperature is one of the advantages of the present invention.
[0058]
The compression is not particularly limited and can be performed by a sheet press, a roll press, or the like, but is preferably performed using a roll press machine. Roll press is a method in which a film to be compressed is sandwiched between rolls and compressed, and the roll is rotated. A roll press is suitable for increasing productivity because it is uniformly pressurized and can be produced roll-to-roll.
[0059]
The roll temperature of the roll press machine is preferably normal temperature. In the compressed atmosphere (hot press) in which the heated atmosphere or the roll is heated, there is a problem that the resin film stretches when the compression pressure is increased. When the compression pressure is weakened so that the resin film of the support does not stretch under heating, the mechanical strength of the coating film decreases. In the conductive film, the mechanical strength of the coating film decreases and the electrical resistance increases. When there is a reason for wanting to minimize moisture adhesion on the surface of fine particles, a heated atmosphere may be used to lower the relative humidity of the atmosphere, but the temperature range is within the range where the film does not easily stretch. It is. Generally, it is a temperature range below the glass transition temperature (secondary transition temperature). In consideration of fluctuations in humidity, the temperature may be a little higher than the required temperature. 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, it is possible to create a heated atmosphere up to a temperature range in which the metal does not melt.
[0060]
The glass transition temperature of the resin film is obtained by measuring dynamic viscoelasticity, and indicates a temperature at which the dynamic loss of main dispersion reaches a peak. For example, when looking at a PET film, its glass transition temperature is around 110 ° C.
[0061]
The roll of the roll press machine is preferably a metal roll because a strong pressure is applied. Further, if the roll surface is soft, fine particles may be transferred to the roll during compression, and therefore it is preferable to treat the roll surface with a hard film.
[0062]
In this way, a compressed layer of functional fine particles such as conductive fine particles is formed. The thickness of the functional fine particle compressed layer such as conductive fine particles may be about 0.1 to 10 μm, although it depends on the application. Moreover, in order to obtain a thick compressed layer of about 10 μm, a series of operations of applying a dispersion of fine particles, drying, and compression may be repeated. Furthermore, in the present invention, it is of course possible to form each functional layer such as a conductive layer on both sides of the support. Each functional layer such as a transparent conductive layer thus obtained exhibits excellent functionality such as conductivity and catalytic action, and does not use a binder resin or a small amount of resin that does not function as a binder. In spite of being prepared, it has a practically sufficient film strength and excellent adhesion to the anchor coat layer.
[0063]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Examples 1-4 are examples using ITO fine particles as conductive film applications.
[0064]
[Example 1]
As shown in FIG. 1, a functional film (1) having an anchor coat layer (1c) on the support (1b) and a functional layer (1a) on the anchor coat layer (1c) was prepared.
[0065]
(Formation of support)
A silicone hard coat liquid KP-854 (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied onto a 50 μm thick PET film, dried, and cured at 90 ° C. for 2 hours to form a 2 μm thick silicone hard coat layer.
[0066]
(Formation of anchor coat layer)
Silicone varnish TSR-145 (GE Toshiba Silicone, pencil hardness HB) 100 parts by weight, silane-based curing agent CR-15 (GE Toshiba Silicone) 1.5 parts by weight, ethanol 120 parts by weight and toluene 80 parts by weight To obtain 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 an anchor coat layer having a thickness of 1.5 μm.
[0067]
(Formation of functional layer)
300 parts by weight of ethanol was added to 100 parts by weight of ITO fine particles SUFP-HX (manufactured by Sumitomo Metal Mining Co., Ltd.) having a primary particle size of 5 to 30 nm, and the media was dispersed as zirconia beads with a disperser. The obtained coating liquid was applied onto the anchor coat layer using a bar coater, and dried by sending hot air of 50 ° C. The obtained film is hereinafter referred to as a pre-compression ITO film. The thickness of the ITO-containing coating film was 1.7 μm.
[0068]
First, a preliminary experiment for confirming the compression pressure was performed.
Room temperature (23 ° C.) without rotating the roll and heating the roll using a roll press machine having a pair of metal rolls having a diameter of 140 mm (the roll surface is hard chrome plated) The 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, when the pressure was released and the length of the compressed portion in the longitudinal direction of the film was examined, it was 1.9 mm. From this result, 347 N / mm per unit area²It will be compressed with the pressure of.
[0069]
Next, the pre-compression ITO film similar to that used in the preliminary experiment was sandwiched between metal rolls and compressed under the above conditions, and the roll was rotated and compressed at a feed rate of 5 m / min. In this way, a compressed ITO film was obtained. The thickness of the ITO compressed layer was 1.0 μm.
[0070]
(Electrical resistance)
The film on which the conductive film was formed was cut into a size of 50 mm × 50 mm. The electrical resistance was measured by applying a tester to two corners at the diagonal positions and found to be 1 kΩ.
[0071]
[Example 2]
(Formation of support)
An acrylic hard coat solution (manufactured by Nippon Kayaku Co., Ltd.) was applied onto a 50 μm thick PET film, dried, and cured by irradiating with ultraviolet rays to form a 2.5 μm thick acrylic hard coat layer.
[0072]
(Formation of anchor coat layer)
100 parts by weight of toluene was added to 100 parts by weight of 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 an anchor coat layer having a thickness of 4.5 μm.
[0073]
(Formation of functional layer)
On the anchor coat layer, a dispersion of ITO fine particles was applied in the same manner as in Example 1, dried and compressed. A conductive film having an ITO compressed layer thickness of 1.0 μm was obtained. When the electrical resistance was measured, it was 1 kΩ.
[0074]
[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.
[0075]
(Formation of anchor coat layer)
4 in the same manner as in Example 2 except that 100 parts by weight of the 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. An anchor coat layer having a thickness of 5 μm was formed.
[0076]
(Formation of functional layer)
On the anchor coat layer, a dispersion of ITO fine particles was applied in the same manner as in Example 1, dried and compressed. A conductive film having an ITO compressed layer thickness of 1.0 μm was obtained. When the electrical resistance was measured, it was 1 kΩ.
[0077]
[Example 4]
This is an example in which an ultraviolet absorber is contained in the anchor coat layer.
As a support, a PET film on which a 2 μm-thick silicone hard coat layer as in Example 1 was formed was used.
[0078]
(Formation of anchor coat layer)
Fresella NA (manufactured by Matsushita Electric Works Co., Ltd.), which is a silicone containing an ultraviolet absorber, was used.
600 parts by weight of B solution was added to 100 parts by weight of A solution of Frescera NA 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 an anchor coat layer having a thickness of 4 μm.
[0079]
(Formation of functional layer)
On the anchor coat layer, a dispersion of ITO fine particles was applied in the same manner as in Example 1, dried and compressed. A conductive film having an ITO compressed layer thickness of 1.0 μm was obtained. When the electrical resistance was measured, it was 1 kΩ.
[0080]
[Reference Example 1]
A 50 μm thick PET film on which no hard coat was formed was used as a support. An anchor coat layer was not formed on the PET film.
[0081]
(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. A conductive film having an ITO compressed layer thickness of 1.0 μm was obtained. When the electrical resistance was measured, it was 1 kΩ.
[0082]
[Comparative Example 1]
As a support, a PET film on which a 2 μm-thick silicone hard coat layer as in Example 1 was formed 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. A part of the ITO fine particles adhered to the roll, and a uniform layer was not obtained.
[0083]
[Comparative Example 2]
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. 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. A part of the ITO fine particles adhered to the roll, and a uniform layer was not obtained.
[0084]
[Example 5]-Reference examples
  Example 5 is a TiO 2 photocatalytic film.₂This is an example using fine particles.
  As the support, an aluminum foil (1080H18) having a thickness of 23 μm 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 onto the aluminum foil, dried, and cured at 90 ° C. for 2 hours to form an anchor coat layer having a thickness of 1.5 μm.
[0085]
(Formation of functional layer)
TiO with primary particle size of 30-70 nm₂900 parts by weight of ethanol was added to 100 parts by weight of fine particles, and the media was dispersed as zirconia beads with a disperser. The obtained coating liquid was applied to the anchor coat surface of the support using a bar coater, and dried by sending hot air of 50 ° C. The obtained film is hereinafter referred to as TiO before compression.₂It is called a film. TiO₂The thickness of the contained coating film was 0.7 μm.
[0086]
In the same manner as in Example 1, first, a preliminary experiment for confirming the compression pressure was performed. Using the same roll press as in Example 1, the TiO before compression was performed at room temperature (23 ° C.) without rotating the roll and heating the roll.₂The film was sandwiched and compressed. At this time, the pressure per unit length in the film width direction was 220 N / mm. Next, when the pressure was released and the length of the compressed portion in the longitudinal direction of the film was examined, it was 0.8 mm. From this result, 275 N / mm per unit area²It will be compressed with the pressure of.
[0087]
Next, the pre-compression TiO similar to that used in the preliminary experiment₂The film was sandwiched between metal rolls and compressed under the above conditions, and the roll was rotated and compressed at a feed rate of 5 m / min. In this way, the compressed TiO₂A film was obtained. TiO₂The thickness of the compressed layer was 0.5 μm.
[0088]
[Table 1]

[0089]
Each of the conductive films of Examples 1 to 4 had a low electrical resistance value, a strong compressive layer, and excellent adhesion between the conductive layer and the anchor coat layer. Each of the conductive films of Examples 1 to 4 was 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 without a hard coat was used as a support, and thus the adhesion between the conductive layer and the support was excellent.
In Example 5, aluminum foil was used as the support, but TiO₂The adhesion between the layer and the anchor coat layer was excellent.
[0090]
In the above embodiment, as the inorganic fine particles, ITO fine particles, TiO₂The example which produced the inorganic functional film using each fine particle was shown. In the same manner as in the above examples, various inorganic functional films can be produced using inorganic fine particles having various properties. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications belonging to the equivalent scope of the claims are within the scope of the present invention.
[0091]
【The invention's effect】
According to the present invention, a functional film can be obtained 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 then compressing. In the functional film according to the present invention, the functional layer is well formed even when the support surface is relatively hard. By this invention, the bad influence by the binder resin in the conventional coating method is eliminated, As a result, the functional film which the target function improved more is obtained.
[0092]
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 showing an example of a functional film of the present invention.
[Explanation of symbols]
(1): Functional film
(1b): Support film
(1a): Functional layer
(1c): Anchor coat layer

Claims (8)

A conductive film having a compressive layer of the conductive fine particles on the support, between the support and compression layer of the conductive fine particles, an anchor coat layer mainly composed of resin provided by coating Yes, and
The compressed layer of conductive fine particles is obtained by compressing a conductive fine particle-containing layer formed by applying and drying a dispersion liquid in which conductive fine particles are dispersed and containing no resin on the anchor coat layer. A conductive film. The compressive conductive layer of the fine particles, is obtained by compressing at 44N / mm ² or more compression strength, conductive film according to claim 1. Compressed layer of the conductive fine particles is obtained by compressing by using a roll press machine, the conductive film according to claim 1 or 2. The compressive conductive layer of the fine particles is a transparent conductive layer, a conductive film according to any one of claims 1-3. The anchor coat layer mainly composed of resin is formed by coating on a support, wherein the anchor coat layer, coating the dispersion conductive fine particles do not contain dispersed and resin, dry, conductive fine particle-containing layer It is formed and subsequently compressing the conductive fine particle-containing layer comprises forming a compressed layer of conductive fine particles, method for producing a conductive film. Compression of the conductive fine particle-containing layer is 44 N / mm ² The manufacturing method of the electroconductive film of Claim 5 performed by the above compressive force. The manufacturing method of the electroconductive film of Claim 5 or 6 which compresses the said electroconductive fine particle content layer using a roll press machine. The manufacturing method of the conductive film of any one of Claims 5-7 which compresses the said electroconductive fine particle content layer at normal temperature (15-40 degreeC).

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