JP2002050230A - Transparent conductive film, transparent conductive sheet and touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive film or a transparent conductive sheet having excellent durability for pen-input when used for a touch panel and no damage even after 100,000-time sliding test under the load of 5.0 N by using a polyacetal pen, and a touch panel using the same. SOLUTION: The transparent conductive film is formed by laminating a cured material layer mainly containing a cured resin and a transparent conductive thin film in this sequence on a transparent plastic film substrate. The volume of volatile constituent contained in the transparent conductive film is 30 ppm or less. The transparent resin film is laminated with the medium of adhesive onto other surface of the transparent conductive thin film of the transparent conductive film. Furthermore, either are of the panel plates at least comprises the transparent conductive film or the transparent conductive sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a transparent conductive film or transparent conductive sheet comprising a cured plastic layer and a transparent conductive thin film laminated in this order on a transparent plastic film substrate.
And a touch panel using them.
In particular, the present invention relates to a transparent conductive film or a transparent conductive sheet having excellent pen sliding durability when used for a pen input touch panel, and a touch panel using these.

[0002]

2. Description of the Related Art A transparent conductive film obtained by laminating a transparent and low-resistance thin film on a transparent plastic film substrate is used for applications utilizing its conductivity, such as liquid crystal displays and electroluminescent (EL) displays. Such flat panel displays and transparent electrodes of touch panels are widely used in applications in the electric and electronic fields.

In recent years, with the spread of portable information terminals and notebook personal computers with a touch panel, a touch panel having better pen sliding resistance than ever has been required.

When a pen is input to the touch panel, the transparent conductive thin film on the fixed electrode side and the transparent conductive thin film on the movable electrode (film electrode) come into contact with each other. No destruction such as peeling occurs
A transparent conductive film having excellent pen sliding resistance is required.

[0005]

However, the conventional transparent conductive film has the following problems.

[0006] A transparent conductive thin film is formed on a transparent plastic film substrate having a thickness of 120 µm or less, and is adhered to another transparent substrate with an adhesive layer (JP-A-2-66809). Proposed. However, after using the polyacetal pen described in the sliding durability test described below and performing 100,000 times of linear sliding tests under a load of 5.0 N, the transparent conductive thin film peels off and has a durability against pen input. Was inadequate. For this reason, there is a problem that the display quality deteriorates when used for a display with a touch panel due to the whitening of the peeled portion.

Further, a transparent conductive film in which a layer formed by hydrolysis of an organosilicon compound is provided on a transparent plastic film substrate and a crystalline transparent conductive thin film is further laminated is disclosed in, for example, JP-A-131171, JP-A-61-79647, JP-A-61-18
3809, JP-A-2-194943, JP-A-2-276630 and JP-A-8-64034.

[0008] However, these transparent conductive films are very brittle because they are crystalline transparent conductive thin films.
Using a polyacetal pen described in the sliding durability test described below, a crack occurs in the transparent conductive thin film after 100,000 linear sliding tests with a load of 5.0 N. In addition, since a heat treatment at about 190 ° C. is required after sputtering the transparent conductive thin film, there is a disadvantage that processing cost is increased.

Further, Japanese Patent Application Laid-Open Nos. Hei 2-5308 and
000-62074 proposes a conductive plastic laminate in which a transparent conductive thin film is formed on a cured film layer. However, this laminate is sufficient for use as a transparent electrode of a liquid crystal display, but has insufficient sliding durability when used for a touch panel. This is because the residual volatile components are gasified from the cured film layer during the formation of the transparent conductive thin film and are generated, thereby deteriorating the film quality of the transparent conductive thin film.

In view of the above-mentioned conventional problems, an object of the present invention is to provide excellent pen input durability when used for a touch panel,
In particular, a transparent conductive film using a polyacetal pen described in the sliding durability test described below and having no deterioration of the transparent conductive thin film even after 100,000 times of sliding tests under a load of 5.0 N,
Provided are a transparent conductive sheet and a touch panel using the same.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and a transparent conductive film, a transparent conductive sheet, and a touch panel which can solve the above-mentioned problems are provided. It is as follows.

That is, the first invention of the present invention is a transparent conductive film comprising a cured plastic layer mainly composed of a curable resin and a transparent conductive thin film laminated in this order on a transparent plastic film substrate. The transparent conductive film is characterized in that the amount of volatile components contained in the transparent conductive film is 30 ppm or less.

A second invention is the transparent conductive film according to the first invention, wherein the cured product layer is mainly composed of an ultraviolet-curable resin.

According to a third aspect of the present invention, the adhesive force between the cured conductive layer containing the curable resin as a main component and the transparent conductive thin film is 0.1 N / 15 mm or more.
Or the transparent conductive film according to the second aspect of the invention.

According to a fourth aspect of the present invention, the transparent conductive thin film is made of an indium-tin composite oxide.
A transparent conductive film according to any one of the first to third aspects.

According to a fifth aspect of the present invention, the transparent conductive thin film is made of a tin-antimony composite oxide.
A transparent conductive film according to any one of the first to third aspects.

According to a sixth aspect of the present invention, there is provided the transparent conductive film according to any one of the first to fifth aspects, wherein a hard coat layer is laminated on the surface of the transparent conductive film opposite to the transparent conductive thin film surface. It is.

A seventh invention is the transparent conductive film according to the sixth invention, wherein the hard coat layer has an antiglare effect.

An eighth invention is the transparent conductive film according to the sixth or seventh invention, wherein the hard coat layer is subjected to a low reflection treatment.

A ninth invention is directed to a transparent conductive film according to any one of the first to eighth inventions, which has a surface opposite to the transparent conductive thin film surface,
A transparent conductive sheet characterized by laminating a transparent resin sheet via an adhesive.

According to a tenth aspect of the present invention, there is provided a touch panel in which a pair of panel plates having the transparent conductive thin film are disposed via a spacer so that the transparent conductive thin films are opposed to each other, and at least one of the first to third panel plates is provided. A touch panel, comprising the transparent conductive film or the transparent conductive sheet according to any one of the nineteenth inventions.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The transparent plastic film substrate used in the present invention means that an organic polymer is melt-extruded or solution-extruded, and if necessary, stretched in the longitudinal and / or width directions, cooled, and heat-set. And organic polymers such as polyethylene, polypropylene, polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene terephthalate, nylon 6, nylon 4, nylon 66, nylon 12, polyimide,
Polyamide imide, polyether sulfane, polyether ether ketone, polycarbonate, polyarylate, cellulose propionate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyetherimide, polyphenylene sulfide, polyphenylene oxide, polystyrene, syndiotactic polystyrene And norbornene-based polymers.

Among these organic polymers, polyethylene terephthalate, polypropylene terephthalate, polyethylene-2,6-naphthalate, syndiotactic polystyrene, norbornene-based polymer, polycarbonate, polyarylate and the like are preferable. Further, these organic polymers may be obtained by copolymerizing a small amount of a monomer of another organic polymer or blending another organic polymer.

The thickness of the transparent plastic film substrate used in the present invention is preferably in the range of more than 10 μm and 300 μm or less, particularly preferably in the range of 70 to 260 μm. If the thickness of the plastic film is 10 μm or less, the mechanical strength is insufficient, and particularly, the deformation due to pen input when used for a touch panel becomes too large, resulting in insufficient durability. On the other hand, when the thickness exceeds 300 μm, when used for a touch panel, the pen load for deforming the film becomes large, which is not preferable.

The transparent plastic film substrate used in the present invention may be a corona discharge treatment, a glow discharge treatment, a flame treatment, an ultraviolet irradiation treatment, an electron beam irradiation treatment, an ozone treatment or the like, as long as the object of the present invention is not impaired. May be applied.

The curable resin used in the present invention is not particularly limited as long as it is a resin that can be cured by application of energy such as heating, ultraviolet irradiation, or electron beam irradiation. Preferably, it is a component. Examples of such an ultraviolet-curable resin include, for example, polyfunctional acrylate resins such as acrylic acid or methacrylic acid ester of polyhydric alcohol, diisocyanate, polyhydric alcohol and hydroxyalkyl ester of acrylic acid or methacrylic acid. And a polyfunctional urethane acrylate resin. If necessary, a monofunctional monomer such as vinylpyrrolidone, methyl methacrylate, styrene or the like can be added to these polyfunctional resins and copolymerized.

The UV-curable resin is usually used after adding a photopolymerization initiator. As the photopolymerization initiator, a known compound that absorbs ultraviolet rays to generate a radical can be used without particular limitation. Examples of such a photopolymerization initiator include various benzoins, phenyl ketones,
Benzophenones and the like can be mentioned. The addition amount of the photopolymerization initiator is usually 1 to 5 parts by weight per 100 parts by weight of the ultraviolet curable resin.

In the cured product layer used in the present invention, it is preferable to use a resin incompatible with the curable resin in addition to the curable resin as a main component. By using a small amount of an incompatible resin in combination with the curable resin of the matrix, phase separation occurs in the curable resin and the incompatible resin can be dispersed in particles. By the dispersed particles of the incompatible resin,
Irregularities can be formed on the surface of the cured product.

When the curable resin is the above-mentioned ultraviolet curable resin, examples of the incompatible resin include polyester resin, polyolefin resin, polystyrene resin and polyamide resin.

The polyester resin preferably has a high molecular weight of 5,000 to 50,000 in weight average molecular weight, and particularly preferably 8,000 to 30,000.
If the weight average molecular weight of the polyester resin is less than 5,000, it tends to be difficult to disperse the polyester resin into particles of an appropriate size in the cured product layer, which is not preferable. On the other hand, when the weight average molecular weight of the polyester resin exceeds 50,000, the solubility in a solvent is reduced when preparing a coating solution, which is not preferable.

The high molecular weight polyester resin is a non-crystalline saturated polyester resin obtained by polymerizing a dihydric alcohol and a dihydric carboxylic acid, and is dissolved in a common solvent with the above-mentioned ultraviolet-curable resin. Is what you can do.

As the dihydric alcohol, for example,
Ethylene glycol, propylene glycol, 1,3-
Examples thereof include butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, and hydrogenated bisphenol A.

Examples of the divalent carboxylic acid include isophthalic acid, terephthalic acid, adipic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and the like.

As long as the solubility in the solvent is not insufficient, a trivalent or higher alcohol such as trimethylolpropane or pentaerythritol and a trivalent or higher carboxylic acid such as trimellitic anhydride or pyromellitic anhydride are used. Can be copolymerized.

In the present invention, the blending ratio of the UV-curable resin and the high-molecular-weight polyester resin, which are the main components of the cured layer, is 0.1 to 20 parts by weight of the polyester resin per 100 parts by weight of the UV-curable resin. Preferably, the amount is 0.2 to 10 parts by weight, particularly preferably 0.5 to 5 parts by weight. The blending amount of the polyester resin is 0.1 per 100 parts by weight of the ultraviolet curable resin.
When the amount is less than the weight part, the number of projections formed on the surface of the cured product layer is undesirably reduced. On the other hand, the blending amount of the polyester resin is 20 per 100 parts by weight of the ultraviolet curable resin.
If the amount exceeds the weight part, the strength of the cured product layer tends to decrease. Further, since the polyester resin has a difference in the refractive index from the ultraviolet curable resin, the haze value of the cured product layer tends to increase and the transparency tends to deteriorate, which is not preferable. However, a film having a high haze value can be used as an anti-glare film by positively utilizing the deterioration of transparency due to dispersed particles of a high molecular weight polyester resin.

The above-mentioned ultraviolet curable resin, photopolymerization initiator and high molecular weight polyester resin are dissolved in a common solvent to prepare a coating solution. There is no particular limitation on the solvent used, for example, ethyl alcohol, alcohol solvents such as isopropyl alcohol, ethyl acetate, ester solvents such as butyl acetate, dibutyl ether, ethylene glycol monoethyl ether and the like. Ether solvents, methyl isobutyl ketone, ketone solvents such as cyclohexanone, toluene,
Aromatic hydrocarbon solvents such as xylene and solvent naphtha can be used alone or as a mixture. The concentration of the resin component in the coating solution can be appropriately selected in consideration of the viscosity and the like according to the coating method, but usually, the UV curable resin, the photopolymerization initiator and the high molecular weight The proportion occupied by the total amount of the polyester resin is 20 to 80% by weight. Further, if necessary, other known additives, for example, a silicone-based leveling agent, can be added to the coating liquid.

In the present invention, the prepared coating solution is coated on a transparent plastic film substrate. The coating method is not particularly limited, and a conventionally known method such as a bar coating method, a gravure coating method, and a reverse coating method can be used. The solvent of the coated application liquid is removed by evaporation in the next drying step. In this step, the high molecular weight polyester resin uniformly dissolved in the coating liquid becomes fine particles and precipitates in the ultraviolet curable resin. After the coating film is dried, the plastic film is further irradiated with ultraviolet rays, and the ultraviolet curable resin is crosslinked and cured to form a cured product layer. In this curing step, the fine particles of the high molecular weight polyester resin are fixed in the hard coat layer and also form projections on the surface of the cured product layer.

The thickness of the cured product layer is 0.1 to 15 μm
It is preferably in the range of, more preferably 0.5 to
It is in the range of 10 μm, particularly preferably in the range of 1 to 8 μm. When the thickness of the cured product layer is less than 0.1 μm, the protrusions described later are not sufficiently formed.
If it is thicker, it is not preferable from the viewpoint of productivity.

A transparent conductive thin film is formed on the cured material layer thus formed by a vacuum process such as sputtering. If a volatile component is contained in the cured material layer and / or the plastic film, a vacuum is formed. Affects the process.

[0040] For example, indium-
When forming a tin composite oxide thin film, the sputtered indium atoms and the gas volatilized from the cured layer collide in the gas phase, the energy of the indium atoms decreases,
As a result, the quality of the transparent conductive thin film formed on the cured product layer may be poor.

Further, gas components volatilized from the cured product layer are taken in as impurities in the thin film, and a transparent conductive thin film having poor film quality is formed. When a transparent conductive film on which such a transparent conductive thin film having poor film quality is laminated is used for a touch panel, the transparent conductive thin film is deteriorated by abrasion after 100,000 times of linear sliding tests under a load of 5.0 N, which is not preferable. .

For example, as a volatile component present in the cured product layer, the solvent of the coating solution used for coating the cured product layer, the residual photopolymerization initiator which did not contribute to the ultraviolet curing reaction, and And by-products.

In order to reduce these volatile components,
It is preferable to perform a heat treatment after the crosslinking reaction by ultraviolet irradiation. The temperature at this time is preferably in the range of 100 to 200 ° C. If the temperature is lower than 100 ° C., the effect of reducing volatile components is insufficient. If the temperature exceeds 200 ° C., it is difficult to maintain the flatness of the film, which is not preferable.

It is also an effective means to reduce the volatile components by exposing the film to vacuum in a vacuum chamber for performing sputtering or the like. At this time, it is possible to further reduce the volatile component by increasing the temperature of the roll that comes into contact with the film or by using film heating together with an infrared heater.

The transparent conductive thin film used in the present invention includes:
There is no particular limitation as long as the material has both transparency and conductivity, but indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide,
Zinc-aluminum composite oxides, indium-zinc composite oxides, silver and silver alloys, copper and copper alloys, gold, and the like have a single layer or a stacked structure of two or more layers. Among them, indium-tin composite oxide or tin-antimony composite oxide is preferable from the viewpoint of environmental stability and circuit workability.

The thickness of the transparent conductive thin film is preferably in the range of 4 to 800 nm, particularly preferably 5 to 500 nm. When the thickness of the transparent conductive thin film is less than 4 nm, it is difficult to form a continuous thin film and to exhibit good conductivity. If the thickness is larger than 800 nm, the transparency tends to decrease.

The method for forming the transparent conductive thin film in the present invention includes a vacuum deposition method, a sputtering method, a CVD method,
An ion plating method, a spray method, and the like are known, and the above method can be appropriately used depending on a required film thickness.

For example, in the case of a sputtering method, a normal sputtering method using an oxide target, a reactive sputtering method using a metal target, or the like is used. At this time, oxygen, nitrogen, water vapor, or the like may be introduced as a reactive gas, or means such as ozone addition, plasma irradiation, or ion assist may be used in combination. Also,
As long as the object of the present invention is not impaired, DC, AC,
A bias such as a high frequency may be applied.

The temperature at which the transparent conductive thin film is formed on the transparent plastic film is preferably set to 150 ° C. or less. In order for the temperature at the time of film formation to exceed 150 ° C., it is necessary to extremely reduce the feed speed of the plastic film, which lowers productivity and is industrially undesirable.

The degree of vacuum at the time of sputtering is preferably in the range of 0.01 to 10 Pa. If the degree of vacuum is higher than 0.01 Pa, stable discharge cannot be performed, so that sputtering is not stable. Also, 10
Even if the degree of vacuum is lower than Pa, stable discharge cannot be performed, so that sputtering is not stable. Also, evaporation method,
The same applies to other methods such as the CVD method.

In these film forming processes, the plastic film on which the cured product layer is laminated is kept in a vacuum at least immediately before film formation. This vacuum exposure makes it possible to further reduce the amount of volatile components. The transparent conductive film whose volatile component amount is reduced to 30 ppm or less through the above volatile component removal process has excellent film quality of the transparent conductive thin film. Therefore, when used for a touch panel, a polyacetal pen (tip shape) :
No deterioration of the transparent conductive thin film is observed even after 100,000 linear sliding tests are performed with a load of 5.0 N using a load of 0.8 mmR).

In order to improve the adhesion between the transparent conductive thin film and the cured product layer, it is effective to subject the cured product layer to surface treatment. As a specific method, a carbonyl group, a carboxyl group, a discharge treatment method of irradiating a glow or corona discharge to increase a hydroxyl group, an amino group, a hydroxyl group, an acid or an alkali to increase a polar group such as a carbonyl group. For example, a chemical treatment method for the treatment may be used.

In order to further improve the abrasion resistance of the outermost layer (pen input surface) when a touch panel is formed, the surface opposite to the surface on which the transparent conductive thin film of the transparent plastic film is formed (when the touch panel is formed). It is preferable to provide a hard coat layer on the outermost pen input surface). The hardness of the hard coat layer is preferably 2H or more in pencil hardness. If the hardness is lower than 2H, the hard coat layer of the transparent conductive film is insufficient in abrasion resistance.

The thickness of the hard coat layer is 0.5 to 10
μm is preferred. When the thickness is less than 0.5 μm, the scratch resistance tends to be insufficient, and when the thickness is more than 10 μm, it is not preferable from the viewpoint of productivity.

The film-forming component of the curable resin composition used in the hard coat layer preferably has an acrylate-based functional group, for example, a polyester resin, a polyether resin, an acrylic resin having a relatively low molecular weight, (Meth) of polyfunctional compounds such as epoxy resin, urethane resin, alkyd resin, spiro acetal resin, polybutadiene resin, polythiol polyene resin and polyhydric alcohol
Oligomers or prepolymers such as acrylates, and monofunctional monomers and polyfunctional monomers such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone and the like as reactive diluents, for example, trimethylol Propane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate,
Dipentaerythritol hexa (meth) acrylate,
Those containing relatively large amounts of 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate and the like can be used.

Mixtures of polyester acrylate and polyurethane acrylate are particularly preferred. The reason is,
This is because polyester acrylate has a very hard coating film and is suitable as a hard coat layer. However,
Polyester acrylate alone has low impact resistance and tends to be brittle, so polyurethane acrylate is used in combination to impart impact resistance and flexibility to the coating. The mixing ratio of polyurethane acrylate to 100 parts by weight of polyester acrylate is preferably 30 parts by weight or less. If this compounding ratio exceeds 30 parts by weight, the coating film tends to be too soft and the impact resistance tends to be insufficient.

As the method of curing the curable resin composition, a usual curing method, that is, a method of curing by heating, irradiation with an electron beam or ultraviolet rays can be used. For example,
In the case of electron beam curing, 50 to 1000 keV, preferably emitted from various electron beam accelerators such as Cockloft-Walton type, Handie graph type, Resonant transformation type, Insulating core transformer type, Linear type, Dynamitron type, High frequency type, etc. Is 100-3
An electron beam having an energy of 00 keV is used. In the case of ultraviolet curing, ultraviolet rays emitted from light rays such as an ultrahigh-pressure mercury lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, a carbon arc, a xenon arc, and a metal halide lamp can be used.

Further, in the case of ionizing radiation curing, acetophenones, benzophenones, Michler benzoyl benzoate, α-amyloxime ester, tetramethylthiuram monosulfide may be used as a photopolymerization initiator in the curable resin composition. , Thioxanthones, n-butylamine, triethylamine, tri-
It is preferable to mix n-butylphosphine and the like. In the present invention, it is particularly preferable to mix urethane acrylate as an oligomer and dipentaerythritol hexa (meth) acrylate as a monomer.

In order to impart an antiglare property to the hard coat layer, it is effective to disperse inorganic particles such as CaCO ₃ or SiO ₂ in the curable resin or to form an uneven shape on the surface of the hard coat layer. It is. For example, in order to form irregularities, a coating liquid containing a curable resin composition is applied, a shaped film having a convex shape on its surface is laminated, and ultraviolet light is irradiated from above the shaped film to form a curable resin. After curing, the resin is obtained by peeling off only the shaped film.

The above-mentioned imprinting film may be a film obtained by providing a desired convex shape on a base film such as polyethylene terephthalate (hereinafter abbreviated as PET) having releasability, or a base film such as PET. And a delicate convex layer may be used. The formation of the convex layer can be obtained by, for example, applying a resin composition comprising inorganic particles and a binder resin on a base film. As the binder resin, for example, an acrylic polyol crosslinked with a polyisocyanate is used, and as the inorganic particles, CaCO ₃ , SiO _2, or the like can be used. In addition, a mat type PET in which inorganic particles such as SiO ₂ are kneaded during the production of PET can also be used.

When this molding film is laminated on a coating film of an ultraviolet-curable resin and then irradiated with ultraviolet light to cure the coating film, when the molding film is a PET-based film, the film is exposed to ultraviolet light. There is a disadvantage that the short wavelength side is absorbed and curing of the ultraviolet curable resin is insufficient. Therefore, it is necessary to use a molding film having a transmittance of 20% or more for laminating the coating film of the ultraviolet curable resin.

Further, in order to further improve the transmittance of visible light when used in a touch panel, a low reflection treatment may be applied to the hard coat layer. In the low reflection treatment, it is preferable that a material having a refractive index different from the refractive index of the hard coat layer is laminated as a single layer or two or more layers. In the case of a single-layer structure, it is preferable to use a material having a smaller refractive index than the hard coat layer. In the case of a multilayer structure of two or more layers, a layer having a refractive index larger than that of the hard coat layer is used for a layer adjacent to the hard coat layer, and a layer above the hard coat layer has a smaller refractive index. It is good to choose the material. The material constituting such a low reflection treatment is not particularly limited, as long as it satisfies the above-described relationship of the refractive index, whether it is an organic material or an inorganic material. For example, CaF ₂ , Mg
F ₂ , NaAlF ₄ , SiO ₂ , ThF ₄ , ZrO ₂ , Nd ₂
O ₃ , SnO ₂ , TiO ₂ , CeO ₂ , ZnS, In ₂ O ₃ ,
It is preferable to use a dielectric such as.

The low reflection treatment may be a dry coating process such as a vacuum evaporation method, a sputtering method, a CVD method, or an ion plating method, or a wet coating process such as a gravure method, a reverse method, or a die method.

Further, prior to lamination of the low-reflection treatment layer, known treatments such as a corona discharge treatment, a plasma treatment, a sputter etching treatment, an electron beam irradiation treatment, an ultraviolet irradiation treatment, a primer treatment, and an easy adhesion treatment are performed as pretreatments. Surface treatment may be applied to the hard coat layer.

By using the transparent conductive film of the present invention and laminating a transparent resin sheet via a pressure-sensitive adhesive and a surface on which a transparent conductive thin film is not formed, a transparent conductive laminated sheet used for a fixed electrode of a touch panel is obtained. can get. That is, by making the fixed electrode made of resin from glass, a lightweight and hard-to-break touch panel can be manufactured.

The pressure-sensitive adhesive is not particularly limited as long as it has transparency. For example, acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, and rubber-based pressure-sensitive adhesives are suitable. Although the thickness of the pressure-sensitive adhesive is not particularly limited, it is usually desirable to set the thickness in the range of 1 to 100 μm. When the thickness of the pressure-sensitive adhesive is less than 1 μm, it is difficult to obtain practically no problematic adhesion, and when the thickness exceeds 100 μm, it is not preferable from the viewpoint of productivity.

The transparent resin sheet to be bonded through the pressure-sensitive adhesive is used for imparting the same mechanical strength as glass, and the thickness is preferably in the range of 0.05 to 5 mm. When the thickness of the transparent resin sheet is less than 0.05 mm, the mechanical strength is insufficient compared with glass. On the other hand, when the thickness exceeds 5 mm, it is too thick and is not suitable for use in a touch panel. The material of the transparent resin sheet may be the same as the transparent plastic film described above.

FIG. 9 shows an example of a touch panel using the transparent conductive film of the present invention. This is a touch panel in which a pair of panel plates having a transparent conductive thin film are arranged via a spacer so that the transparent conductive thin films face each other, and the transparent conductive film of the present invention is used for one panel plate. Things.

In this touch panel, when characters are input with the pen, the transparent conductive thin films facing each other come into contact with each other due to pressing from the pen, and are electrically turned on, and the position of the pen on the touch panel is detected. can do. By continuously and accurately detecting the pen position, characters can be recognized from the locus of the pen. In this case, if the transparent conductive film of the present invention is used for the movable electrode on the pen contact side, the pen touch durability is excellent, so that a stable touch panel can be provided for a long time.

FIG. 10 is a sectional view of a plastic touch panel without using a glass substrate, obtained by using the transparent conductive film and the transparent conductive sheet of the present invention. Since this plastic touch panel does not use glass, it is extremely lightweight and does not break due to impact.

[0071]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. The performance of the transparent conductive film and the pen input durability test of the touch panel were measured by the following methods.

<Light Transmittance and Haze> JIS-K71
NDH-1001 manufactured by Nippon Denshoku Industries Co., Ltd.
Light transmittance and haze were measured using DP.

<Surface resistivity> Measured by a four-terminal method according to JIS-K7194. The measuring machine is Mitsubishi Yuka Co., Ltd.
Manufactured by Lotest AMCP-T400.

<Amount of Volatile Components> 3 g of the transparent conductive film was cut into strips having a size of 3 cm × 0.5 cm, and a solid purge and trap device (manufactured by Nippon Kagaku Kogyo, JHS-10)
Heat desorption in He at 100 ° C. for 15 minutes according to 0).
The desorbed components are cold-trapped to the adsorbent (quartz wool) with liquid nitrogen, and rapidly heated to a GC-MS device (HP6890 and HP597, manufactured by Hulett Packard).
Introduced in 3), the amount of volatile components in the transparent conductive film was quantified.

<Pen input durability test> A 5.0 N load was applied to a polyacetal pen (tip shape: 0.8 mmR), and a sliding test of 100,000 times (50,000 reciprocations) was performed on the touch panel. . The sliding distance at this time was 30 mm, and the sliding speed was 60 mm / sec. After this sliding durability test,
It was visually observed whether the sliding portion was whitened. In addition, a pen load 0.5N
A mark of 0 mmφ was written and evaluated whether the touch panel could read it accurately. In addition, pen load 0.5
The ON resistance (resistance value when the movable electrode (film electrode) and the fixed electrode contacted each other) when the sliding portion was pressed with N was measured.

<Measurement of Adhesive Force> An ionomer film having a thickness of 40 μm was coated with a polyester adhesive to a thickness of 75 μm.
m of a polyethylene terephthalate film to prepare a laminate for measuring adhesive force. The ionomer surface of the laminate for measuring adhesive force was opposed to the transparent conductive thin film surface of the transparent conductive film, and heat-sealed at 130 ° C.
The laminate was separated from the laminate for measuring adhesive force and the transparent conductive film by a 180 ° peeling method, and the peeling force was defined as the adhesive force. The peeling speed at this time was 1000 mm / min.

Example 1 Acrylic resin containing photopolymerization initiator (Dainichi Seika Kogyo Co., Ltd.)
Manufactured by Seika Beam EXF-01J) in toluene / ME
A mixed solvent of K (8/2; weight ratio) was added so that the solid content concentration became 50% by weight, and the mixture was stirred and uniformly dissolved to prepare a coating solution. Biaxially oriented polyethylene terephthalate film having an easily adhesive layer on both sides (Toyobo Co., Ltd.
A4340, thickness 188 μm) and a coating film thickness of 5
The prepared coating solution was applied to a thickness of μm using a Meyer bar, dried at 80 ° C. for 1 minute, and then irradiated with an ultraviolet irradiation device (UB042-5, manufactured by Eye Graphics Co., Ltd.).
UV irradiation using AM-W type (light quantity: 300 mJ)
/ Cm ² ) to cure the coating. Next, heat treatment was performed at 180 ° C. for 1 minute to reduce volatile components.

Next, a transparent conductive thin film made of a tin-antimony composite oxide was formed on the cured product layer. At this time, the target was tin oxide containing 5% by weight of antimony oxide (manufactured by Mitsui Kinzoku Mining Co., Ltd., density 5.
7 g / cm ³ ), and a DC power of ² W / cm ² was applied. Further, a film was formed by a DC magnetron sputtering method under an atmosphere of 0.4 Pa while flowing Ar gas at a flow rate of 130 sccm and O ₂ gas at a flow rate of 15 sccm. However, instead of a normal DC, in order to prevent arc discharge, a 3 μs
A pulse having a width of 50 kHz was applied.

The temperature of the center roll was set to 20 ° C., and sputtering was performed. Also, the oxygen partial pressure of the atmosphere is measured by a sputter process monitor (manufactured by Hakuto Co., Ltd., SPM2).
At 00), the sample was fed back to an oxygen gas flow meter and a DC power source so that the degree of oxidation in the tin-antimony composite oxide thin film was kept constant. As described above, a transparent conductive thin film made of a tin-antimony composite oxide having a thickness of 27 nm was deposited.

Further, this transparent conductive film was used as one panel plate, and as the other panel plate, a 20 nm thick indium oxide composite oxide thin film (tin oxide: 10% by weight) was formed on a glass substrate by plasma CVD. A transparent conductive thin film (manufactured by Nippon Soda: S500) was used.
The two panel plates were arranged via epoxy beads having a diameter of 30 μm so that the transparent conductive thin films faced each other, to produce a touch panel.

Example 2 Acrylic resin containing photopolymerization initiator (Dainichi Seika Kogyo Co., Ltd.)
100 parts by weight of Seika Beam EXF-01J (manufactured by Toyobo Co., Ltd., Byron 2)
00, weight average molecular weight 18,000), and a mixed solvent of toluene / MEK (8/2; weight ratio) was added thereto as a solvent so that the solid content concentration became 50% by weight, followed by stirring. The solution was uniformly dissolved to prepare a coating solution. Biaxially oriented polyethylene terephthalate film (Toyobo Co., Ltd.
A4340, thickness 188 μm) and a coating film thickness of 5
The prepared coating solution was applied to a thickness of μm using a Meyer bar. After drying at 80 ° C. for 1 minute, an ultraviolet irradiation device (UB042- manufactured by Eye Graphics Co., Ltd.)
UV irradiation using 5 AM-W type (light quantity: 300m)
J / cm ² ) to cure the coating. Then, at 180 ° C
For 1 minute to reduce volatile components.

Further, in order to expose the plastic film on which the cured product layer was laminated to vacuum exposure, a rewinding process was performed in a vacuum chamber. The pressure at this time is 0.002
Pa and the exposure time was 10 minutes. The temperature of the center roll was 40 ° C.

Next, a transparent conductive thin film made of an indium-tin composite oxide was formed on the cured product layer. At this time, indium oxide containing 5% by weight of tin oxide (manufactured by Mitsui Kinzoku Mining Co., Ltd., density 7.1 g / c
m ³ ), and a DC power of ² W / cm ² was applied. Also, 130 sccm of Ar gas and 10 sccc of O ₂ gas
m, and a film was formed by DC magnetron sputtering under an atmosphere of 0.4 Pa. However, normal DC
Instead, in order to prevent arc discharge, a pulse of 5 μs width was applied to 50 pulses using RPG-100 manufactured by NI Japan.
The voltage was applied at a frequency of kHz. The center roll temperature is 4
At 0 ° C., sputtering was performed.

Further, while constantly monitoring the oxygen partial pressure of the atmosphere with a sputter process monitor (SPM200, manufactured by Hakuto Co., Ltd.), the oxygen gas was controlled so that the degree of oxidation in the indium-tin composite oxide thin film was constant. Foot back to flow meter and DC power supply. As described above, the thickness 22n
A transparent conductive thin film made of m indium-tin composite oxide was deposited. Further, a touch panel was produced in the same manner as in Example 1 using this transparent conductive film.

Example 3 The laminate of the transparent plastic film substrate / cured material layer of Example 2 was cured on the surface opposite to the surface of the cured material layer by ultraviolet curing comprising a mixture of polyester acrylate and polyurethane acrylate as a hard coat layer resin. Mold resin (EXN, manufactured by Dainichi Seika Kogyo Co., Ltd.) has a thickness of 5 μm after drying.
Was applied by a gravure reverse method, and the solvent was dried. Thereafter, the resin was passed under a 160 W ultraviolet irradiation device at a speed of 10 m / min to cure the ultraviolet curable resin, thereby forming a hard coat layer. Then, at 180 ° C
For 1 minute to reduce volatile components.

On the cured product layer of the laminate consisting of the hard coat layer / transparent plastic film substrate / cured product layer,
In the same manner as in Example 2, an indium-tin composite oxide thin film was formed. Further, a touch panel was produced in the same manner as in Example 1 using this transparent conductive film.

Example 4 In the same manner as in Example 2, a laminate composed of a transparent plastic film substrate / cured material layer was produced. On the surface of the laminate opposite to the surface of the cured product layer, an ultraviolet-curable resin comprising a mixture of polyester acrylate and polyurethane acrylate as a hard coat layer resin (Dainichi Seika Kogyo Co., Ltd.)
EXG) was applied by a gravure reverse method so that the film thickness after drying was 5 μm, and the solvent was dried. Then, a mat-shaped film of polyethylene terephthalate film with a fine convex shape formed on the surface (Toray Industries, Inc.)
X) was laminated so that the mat surface was in contact with the ultraviolet curable resin. The surface shape of the mat-shaped film has an average surface roughness of 0.40 μm and an average interval of peaks of 160 μm.
m, and the maximum surface roughness is 25 μm.

The film laminated in this way is
The resin was passed under a 0 W ultraviolet irradiation device at a speed of 10 m / min to cure the ultraviolet curable resin. Next, the mat-shaped film was peeled off to form a hard coat layer having an anti-glare effect by performing concave processing on the surface. Then, 18
Heat treatment was performed at 0 ° C. for 1 minute to reduce volatile components.

On the cured product layer of the laminate consisting of the antiglare hard coat layer / transparent plastic film substrate / cured product layer, an indium oxide composite oxide thin film was formed as a transparent conductive thin film in the same manner as in Example 2. Filmed. Further, using this transparent conductive film as one panel plate, a touch panel was produced in the same manner as in Example 1.

Example 5 A laminate composed of an antiglare hard coat layer / transparent plastic film substrate / cured material layer / transparent conductive thin film layer was prepared in the same manner as in Example 4. TiO ₂ (refractive index: 2.30, film thickness 15 n)
m), SiO ₂ (refractive index: 1.46, film thickness 29 nm),
TiO ₂ (refractive index: 2.30, film thickness 109 nm), Si
O ₂ (refractive index: 1.46, film thickness 87 nm) was laminated to form an antireflection treatment layer. In order to form a TiO ₂ thin film, the degree of vacuum is set to 0.27 Pa by a direct current magnetron sputtering method using titanium as a target, Ar gas is 500 sccm, and O ₂ gas is 80 s.
The flow was at a flow rate of ccm. Further, a cooling roll at 0 ° C. was provided on the back surface of the substrate to cool the transparent plastic film. At this time, a power of 7.8 W / cm ² was supplied to the target, and the dynamic rate was 23 nm · m / min.

In order to form an SiO ₂ thin film, silicon is used as a target, the degree of vacuum is set to 0.27 Pa, and Ar gas is set to 5 by DC magnetron sputtering.
00 sccm and O ₂ gas were flowed at a flow rate of 80 sccm. In addition, a cooling roll of 0 ° C. is provided on the back of the substrate,
The clear plastic film was cooled. At this time, a power of 7.8 W / cm ² was supplied to the target, and the dynamic rate was 23 nm · m / min. Further, using this transparent conductive film as one panel plate, a touch panel was produced in the same manner as in Example 1.

Example 6 A transparent conductive film produced in the same manner as in Example 2 was attached to a 1.0 mm-thick polycarbonate sheet via an acrylic pressure-sensitive adhesive to produce a transparent conductive laminated sheet. did. Using this transparent conductive laminated sheet as a fixed electrode, and using the transparent conductive film of Example 6 as a movable electrode, a touch panel was produced in the same manner as in Example 1.

Comparative Example 1 A transparent conductive film was produced in the same manner as in Example 1 except that the process of reducing volatile components at 180 ° C. for 1 minute was not performed. Further, a touch panel was produced in the same manner as in Example 1 using this transparent conductive film.

Comparative Example 2 A transparent conductive film was produced in the same manner as in Example 2, except that the heat treatment at 180 ° C. for 1 minute and the process of exposure to vacuum for 10 minutes were not performed to reduce volatile components. Further, a touch panel was produced in the same manner as in Example 1 using this transparent conductive film.

Table 1 shows the measurement results of the above Examples and Comparative Examples.
And FIGS.

From the results shown in Table 1, it was found that the transparent conductive films of Examples 1 to 6 had a small amount of volatile components and had good film quality. The touch panel using this transparent conductive film has no whitening even after performing a sliding test 100,000 times by applying a load of 5.0N to a polyacetal pen (tip shape: 0.8 mmR), and has a low ON resistance. There was no abnormality. Also, the input symbol ○ was correctly recognized.

On the other hand, Comparative Examples 1 and 2 had a large amount of volatile components and poor film quality. Therefore, when used for a touch panel, a polyacetal pen (tip shape: 0.8 mm
After applying a load of 5.0 N to R) and performing the sliding test 100,000 times, the sliding portion became white and the ON resistance also increased. Also, the input symbol 印 was not recognized accurately by the sliding portion.

[0098]

[Table 1]

[0099]

The transparent conductive film of the present invention is obtained by laminating a cured product layer mainly composed of a curable resin and a transparent conductive thin film on a transparent plastic film substrate in this order. Is 30 ppm or less, a transparent conductive thin film having good film quality can be formed. For this reason, the pen input touch panel using the transparent conductive film has excellent pen input durability such that peeling, cracking, and the like do not occur even when opposing transparent conductive thin films come into contact with each other by pressing the pen. It also has excellent position detection accuracy and display quality. Therefore,
It is suitable as a pen input touch panel.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an output shape from a touch panel according to a first embodiment.

FIG. 2 is an explanatory diagram illustrating an output shape from a touch panel according to a second embodiment.

FIG. 3 is an explanatory diagram illustrating an output shape from a touch panel according to a third embodiment.

FIG. 4 is an explanatory diagram illustrating an output shape from a touch panel according to a fourth embodiment.

FIG. 5 is an explanatory diagram illustrating an output shape from a touch panel according to a fifth embodiment.

FIG. 6 is an explanatory diagram illustrating an output shape from a touch panel according to a sixth embodiment.

FIG. 7 is an explanatory diagram showing an output shape from a touch panel of Comparative Example 1.

FIG. 8 is an explanatory diagram showing an output shape from a touch panel of Comparative Example 2.

FIG. 9 is a cross-sectional view of a touch panel obtained by using the transparent conductive film of the present invention.

FIG. 10 is a cross-sectional view of a plastic touch panel without using a glass substrate, obtained by using the transparent conductive film and the transparent conductive sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sliding test part 2 Touch panel output form 10 Transparent conductive film 11 Transparent plastic film base material 12 Cured material layer 13 Transparent conductive thin film 14 Hard coat layer 20 Bead 30 Glass plate 40 Transparent conductive sheet 41 Adhesive 42 Transparent resin sheet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C23C 14/35 C23C 14/35 Z 5G307 16/40 16/40 16/50 16/50 G06F 3/03 310 G06F 3/03 310C 320 320G 3/033 360 3/033 360H (72) Inventor Katsuya Ito 2-1-1 Katada, Otsu-shi, Shiga F-term in Toyobo Co., Ltd. Research Laboratory F-term (reference) 4F100 AA33C AK01A AK01B AK25 AK42 AR00D AT00 AT00A BA04 BA07 BA10A BA10D EH66 EJ08B GB41 JB12B JB14B JG01C JK01 JL05 JM02C JN01A JN01C JN06D 4K029 AA11 BA45 BA47 BA50 BB02 BC09 BD01 CA05 DC39 FA07 4K06 ABA13 BC13 ABC13A13 BC12A01 FC01 FC02

Claims (10)

[Claims] 1. A transparent conductive film in which a cured product layer mainly comprising a curable resin and a transparent conductive thin film are laminated in this order on a transparent plastic film substrate, wherein the transparent conductive film is Contains 3 volatile components
A transparent conductive film having a content of 0 ppm or less. 2. The transparent conductive film according to claim 1, wherein the cured product layer contains an ultraviolet-curable resin as a main component. 3. An adhesive force between the cured conductive layer mainly composed of the curable resin and the transparent conductive thin film is 0.1 N /.
3. The device according to claim 1, wherein the length is 15 mm or more.
The transparent conductive film according to the above. 4. The transparent conductive film according to claim 1, wherein the transparent conductive thin film is made of an indium-tin composite oxide. 5. The transparent conductive film according to claim 1, wherein the transparent conductive thin film is made of a tin-antimony composite oxide. 6. The transparent conductive film according to claim 1, wherein a hard coat layer is laminated on a surface of the transparent conductive film opposite to a surface of the transparent conductive thin film. 7. The transparent conductive film according to claim 6, wherein the hard coat layer has an antiglare effect. 8. The transparent conductive film according to claim 6, wherein a low reflection treatment is applied to the hard coat layer. 9. A transparent conductive sheet, characterized in that a transparent resin sheet is adhered to the surface of the transparent conductive film according to claim 1 through an adhesive. 10. A touch panel in which a pair of panel boards having the transparent conductive thin film are arranged via a spacer so that the transparent conductive thin films face each other, at least one of the panel boards is any one of claims 1 to 9. A touch panel comprising the transparent conductive film or the transparent conductive sheet according to any one of the above.