JPH09262926A - Transparent conductive laminate for touch panel and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a touch panel usable between two deflection panels without reducing visibility and a visual angle characteristic by laminating a cured matter of a radiation curable resin containing a specific amt. of a specific compd. on an optically isotropic plastic film and subsequently applying corona discharge treatment to the layer of the cured matter to laminate a conductive film thereon. SOLUTION: After cured matter of a radiation curable resin containing a compd. represented by formula in an amt. of 50wt.% or more in a solid ratio is laminated to an optically isotropic plastic film as a protective layer imparting solvent resistance and exerting no effect on the resistance characteristics of a conductive film, corona discharge treatment is applied to the surface thereof and a conductive film is laminated thereon. In the formula, A is an unsaturated alkyl group or an unsaturated alkylcarbonyl group, X is a 1-8C trivalent aliphatic ether compd, Y is a divalent aliphatic or aromatic dicarbonyl compd. and (n) is 0.5-2 is an average value. Herein, optical isotropicity means that a retardation value at least of 590nm is 15nm or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent conductive film laminate having excellent optical characteristics for use in touch panels, and has a particularly excellent visibility and a viewing angle characteristic shared with a liquid crystal panel. The present invention relates to a transparent conductive laminate for a touch panel.

[0002]

2. Description of the Related Art In recent years, a touch panel as an input device combined with a liquid crystal display panel has been widely used as a PDA device from a digital switch element to an analog recognition element by pen input. The basic structure of a conventional touch panel is a combination of a glass substrate transparent conductive film and a PET substrate transparent conductive film, which is used by being superimposed on the upper side of a liquid crystal display panel.

However, according to this method, the visibility of the liquid crystal display panel viewed through the touch panel is poor, and when sunglasses are worn, the visibility is markedly impaired due to the coloring caused by the optical anisotropy of PET. There is a drawback that.

[0004]

Generally, the optical isotropy of a plastic film is inferior to that of glass, and the touch panel placed on the upper side of the liquid crystal display panel significantly reduces the visibility of the liquid crystal display panel, and thus the portable information terminal. The result was that the range of use was limited.

Further, Japanese Laid-Open Patent Publication No. 3-121523 proposes a method of arranging it between two polarizing plates in combination with a liquid crystal display element. However, in this case, since it is a combination with a liquid crystal display element that uses linearly polarized light for the display principle, it causes unnecessary coloring, and there is a problem that the visibility of the liquid crystal display element is reduced. On the other hand, although a device for eliminating the coloring is made by further combining a retardation plate or the like, the structure becomes complicated and optical matching is difficult.

Therefore, unlike PET, a method of using an optically isotropic plastic film and arranging it between two polarizing plates in combination with a liquid crystal display element as a touch panel is being studied. However, such a structure in which a conductive film is laminated on a plastic film alone is inferior in solvent resistance required in a conductive film patterning process, a cleaning process, and a connection terminal bonding process in manufacturing a touch panel.

Further, since the adhesion to the conductive film is poor, the conductive film is spontaneously peeled off or cracked in a durability test or the like.

The present invention solves the drawbacks of the conductive film laminate for a touch panel and provides a touch panel that can be used between two polarizing plates in combination with a liquid crystal display device without reducing the visibility and the viewing angle characteristics. To aim.

[0009]

The conductive film laminate for a touch panel according to the present invention has the following properties as a protective layer that imparts solvent resistance to an optically isotropic plastic film and does not affect the properties of the conductive film. General formula (1)

[0010]

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The invention is characterized in that a cured product of a radiation curable resin containing 50% by weight or more of the compound of solid content is laminated, then corona discharge treatment is applied to the surface thereof, and a conductive film is laminated thereon. A transparent conductive film laminate for a resistive film type touch panel.

In the general formula (1), A is an unsaturated alkyl group or an unsaturated alkylcarbonyl group, and X is a carbon atom of 1
To 8 are trivalent aliphatic ether compounds, Y is a divalent aliphatic or aromatic dicarbonyl compound, and n is in the range of 0.5 to 2 as an average value.

The PET film formed by biaxial stretching has an in-plane optical anisotropy, that is, a retardation value of 100.
It becomes larger than nm, and when it is arranged between the polarizing plates as described above, it is colored and observed. However, such coloring is eliminated by using an optically isotropic film.

The optical isotropy referred to here is at least 590.
The retardation value in nm is 15 nm or less, particularly preferably 10 nm or less. Further, the variation of the slow axis indicating the variation of the optical axis is preferably ± 15 degrees or less,
Particularly preferably, it is ± 10 degrees or less.

A material obtained by curing a radiation curable resin was suitable as the protective layer. The cured product of the radiation curable resin adheres well to the plastic film described above, for example,
Even in the durability test at 60 ° C., 90% RH for 1000 hours, there is no peeling, the appearance is good, and discoloration or clouding does not occur.

Although the film thickness is not particularly limited, it is preferably 2 μm or more from the viewpoint of surface curability. If it is less than 2 μm, the solvent resistance is insufficient. The upper limit of the film thickness is not particularly limited, but it is determined by the balance between solvent resistance and economy.
Preferably it is 20 μm or less, more preferably 10 μm or less.

However, when a conductive film is formed on various radiation curable resins and the conductive film characteristics are evaluated,
The following general formula (1)

[0018]

[Chemical 6]

The fact that a cured product of a radiation curable resin containing 50% by weight or more of the compound of solid content is laminated and the surface is subjected to corona discharge treatment does not deteriorate the characteristics of the conductive film. I liked it.

In the general formula (1), A is an unsaturated alkyl group or an unsaturated alkylcarbonyl group, and X is a carbon atom of 1
To 8 are trivalent aliphatic ether groups, Y is a divalent aliphatic or aromatic dicarbonyl compound, and n is 0.
It is in the range of 5 to 2.

More specifically, in the general formula (1), A is an acryloyl group and X is the following general formula (2).

[0022]

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Y is a trivalent group represented by the following general formula (3) or (4)

[0024]

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[0025]

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A dicarbonyl compound represented by: is preferred.

Here, Z represents a trivalent hydrocarbon group having 1 to 12 carbon atoms, and R represents a hydrogen atom, a halogen atom, or a methyl group or an ethyl group.

Such a radiation curable resin is excellent in curability and does not deteriorate the characteristics of the resistance film when the conductive film is formed thereon. Also, the adhesion of the conductive film is good. That is, when the surface is slightly uncured after the curing treatment, the conductive film is easily peeled off when the conductive film is formed on the surface, and the uncured component modifies the conductive film composition. The resistance value may become too large, or the resistance value may change over time.

It is essential that such a radiation curable resin is contained in the protective layer in a solid content of 50% by weight or more.
Radiation curing becomes difficult with a material other than such a compound, for example, a composition containing 50% by weight or more of a compound that does not exhibit radiation curing, and solvent resistance may be poor. Further, even if it is a radiation curable resin, if the content of components other than the above is 50% by weight or more, the characteristics of the conductive film are deteriorated.

In addition, reactive diluents, leveling agents for improving surface properties, fine particles for roughening the surface of the protective layer and the like may be added in appropriate amounts for the purpose of reducing viscosity and improving reactivity.

When the conductive film is laminated on only one surface and used, a protective layer is not particularly required on the surface on which the conductive film is not provided, but the characteristics such as solvent resistance are not required in the touch panel manufacturing process. The above-mentioned protective layer may be provided if required, but any other composition may be used as long as it is a protective layer satisfying the purpose.

Generally, as a means for laminating such materials,
There are a laminating method, a dipping method, a wet coating method and the like. Among them, the wet coating method was most suitable as a means for laminating the protective layer having the above-mentioned thickness without extremely deteriorating the flatness of the plastic film from the viewpoint of forming a uniform film thickness.

In the laminating method, it is difficult to form the protective layer alone into a film, and the protective layer having the above composition does not adhere well to the plastic film after the curing treatment. Further, in the dipping method, it is difficult to coat a large area with a uniform film thickness and good control. In the case of wet coating, the above composition may be dissolved in a solvent to prepare a solution and used as a coating solution.

With respect to such a protective layer, no problem occurred in the solvent resistance test. However, when conducting films are stacked and the conducting film properties are examined, the conducting film properties are still insufficient. The reason for this is considered as follows.

That is, microscopically, the uncured layer remains on the surface of the protective layer, and various additives added to the coating liquid of the radiation curable resin composition are deposited on the surface. It is also possible. It was expected that such a component would deteriorate the characteristics of the conductive film. Therefore, it is preferable to finally perform the corona discharge treatment.

As a condition for such corona discharge treatment, the strength is 100 W · min / m ² or more, but 130 W · min / m ² or more is preferable, and 160 W · min or more is more preferable in order to obtain a sufficient effect. / M ² or more. On the other hand, if the treatment strength exceeds 1000 W · min / m ² , the film may be deformed as in the phenomenon described under the ultraviolet curing conditions. Therefore, 1000W
-Min / m ² or less is preferable, and 800 is particularly preferable.
W · min / m ² or less.

Generally, ultraviolet ray curing method and electron beam curing method are widely known as the curing method for the radiation curable resin. First, regarding the ultraviolet curing method, since the radiation-curable resin alone does not easily initiate curing, an appropriate amount of an ultraviolet curing initiator is usually added to accelerate curing. At this time, when the curing treatment is performed in an air environment, the outermost surface of the protective layer is hard to be cured even if the inside of the protective layer is cured due to the obstruction of oxygen in the air. Moreover, since the thickness is thinner than that of the ultraviolet curable hard coat which is usually formed with a film thickness of 10 μm or more, the influence of oxygen damage becomes remarkable. Therefore, it is preferable to add 4 to 10 parts by weight of the ultraviolet curing initiator to the radiation curable resin component, which is slightly larger than the amount usually added.

As the ultraviolet curing initiator, a known photoreaction initiator can be applied. For example, diethoxyacetophenone, 2-
Methyl-1- {4- (methylthio) phenyl} -2-morpholinopropane, 2-hydroxy-2-methyl-1
-Acetophenone-based compounds such as phenylpropan-1-one and 1-hydroxycyclohexyl phenyl ketone,
Examples thereof include benzoin compounds such as benzoin and benzyldimethyl ketal, benzophenone compounds such as benzophenone and benzoylbenzoic acid, and thioxanthone compounds such as thioxanthone and 2,4-dichlorothioxanthone. Further, in order to further improve the curability, it is also effective to add an appropriate amount of a known reaction initiation aid such as triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate as an ultraviolet curing initiator component. .

When the amount of the ultraviolet curing initiator is more than 10 parts by weight, the surface curability is not significantly improved with respect to the added amount. Further, if it is 15 parts by weight or more, the degree of polymerization and the degree of crosslinking are decreased, and the properties as a solvent resistant layer are impaired. In addition, when a large amount of the ultraviolet curing initiator is added, the conductive film is oxidized by the ultraviolet curing initiator or its decomposition product remaining in the protective layer after the curing treatment, so that the resistance value becomes too large or the resistance value changes with time. The drawback of becoming large becomes remarkable.

The curing treatment is preferably performed by coating on a plastic film by a wet coating method or the like, and after the solvent component contained in the coating is evaporated, curing is performed in order to enhance the denseness of the protective layer. Then, ultraviolet light having an integrated light amount of 500 to 2000 mJ / cm ² is irradiated for curing treatment.

When the integrated light amount is lower than 500 mJ / cm ² , the amount of the above-mentioned ultraviolet curing initiator does not sufficiently cure and the surface becomes sticky. In addition, 2000mJ
If it is larger than / cm ² , the UV lamp intensity is strong during the irradiation time of a few seconds, which is the irradiation time of the UV lamp in the normal continuous processing step. The film itself may be deformed or the UV curable resin layer may be burnt.

On the other hand, a large number of ultraviolet lamps are arranged in 2000.
Irradiation larger than mJ / cm ² is possible, but the equipment becomes huge and the equipment cost also becomes a disadvantage.

Further, when the opposite surface of the plastic film is not cooled, the range of the integrated light quantity is 500 to 100.
A range of 0 mJ / cm ² is preferred. When the back surface is not cooled, deterioration of the laminate is likely to occur due to the above reason.

In the protective layer thus hardened, even if a corona treatment is applied as a post-treatment, the influence of the residual solvent and the decomposed product of the ultraviolet curing initiator is large, so that the adverse effect on the conductive film characteristics is observed. . Therefore, heat treatment at a temperature of 100 ° C. or higher for 1 minute or longer is required.

In addition to the above-mentioned conditions in the air environment, in the case of producing in a nitrogen gas environment in which oxygen concentration is less than 2% and in which oxygen damage is less likely to occur, the outermost surface of the protective layer also cures well. . In such a case, the ultraviolet curing initiator was sufficiently cured even if it was reduced to less than 4 parts by weight, which is an amount in which the deterioration of the conductive film was not remarkable. The minimum amount is 0.
5 parts by weight or more is necessary, and if it is less than 5 parts, the surface becomes sticky.

However, an oxygen concentration of 2% or less is indispensable as a condition for the curing to be manifested with such an addition amount, and when the oxygen concentration is higher than this, the effect of oxygen damage is suddenly exhibited. The initiator composition makes it difficult to cure.

In this case, the surface uncured component was remarkably reduced, and the post heat treatment was not necessary, but the surface precipitate remained, so that the corona treatment under the above-mentioned conditions is also necessary.

On the other hand, in the case of electron beam curing, oxygen damage is not greatly affected and it is not necessary to add an ultraviolet curing initiator, so that it is an optimum curing method. However,
There is a demerit that the equipment becomes huge and the equipment cost becomes high. The electron beam curing condition is 3 to 5 Mra.
A strength of d is suitable. If it is less than 3 Mrad, curing is insufficient and the surface of the protective layer becomes sticky. Also, 5M
When it is stronger than rad, coloring due to deterioration of the plastic film itself becomes remarkable.

In this case also, since the surface precipitate remains,
After all, corona treatment under the above-mentioned conditions is necessary.

The optically isotropic plastic film is preferably produced by a solution casting method rather than a melt extrusion film forming method which is a general film forming method. In the melt extrusion method, it is difficult to reduce the retardation value, and at the same time, it is difficult to control the film thickness uniformity in the axial direction and the length direction. Further, it is liable to be accompanied by foreign matter defects due to heat history due to melting, and is not suitable for use in optical applications such as liquid crystal display elements. On the other hand, the solution casting method can produce a film having excellent film thickness uniformity and optical property uniformity, and removal of foreign matter defects is easy in the process.

As a solution casting method, as is well known in the art, a film material is dissolved in a solvent which dissolves well and then continuously cast on a supporting substrate by a method such as a die coating method. A suitable plastic film can be obtained by peeling and drying. In such a drying process, in order to make the plastic film retain the above optical characteristics, the tension and the heat treatment are balanced so that
It is necessary to control the dimensional refractive index and the film thickness.

Since such a plastic film has a feature that it can be formed into a solution, solvent resistance to an organic solvent is not sufficient. Since the molecular skeleton has an amorphous structure and is soluble in organic solvents to the extent that solution film formation is possible, when used as a transparent conductive film laminate for touch panels, it is transparent as a protective layer that improves the solvent resistance of the plastic film. It is necessary to stack different resin layers.

By controlling the three-dimensional optical characteristics of the plastic film, it is possible to provide the functions of visibility and widening of viewing angle, which doubles as the substrate of the touch panel. That is, the refractive index in the in-plane slow axis direction of the plastic film is nx, the refractive index in the in-plane fast axis direction is ny,
When the refractive index in the film thickness direction is nz and the film thickness is d, and the parameter indicating the three-dimensional refractive index anisotropy is K = ((nx + ny) / 2-nz) × d |
By setting K│ ≦ 120 nm, the visibility and widening of the viewing angle of the liquid crystal display device can be achieved.

In order to provide excellent viewing angle characteristics with little change in visibility depending on the visual field, | K | ≦ 12 is preferable.
0 nm is preferable, and | K | ≦ 60 nm is particularly preferable in order to impart more excellent viewing angle characteristics.

The plastic film used in the present invention can be conveniently used as long as it is a solution cast polymer resin having a positive refractive index anisotropy. As typical examples of these resins, polyester resins such as polyarylate resins, engineering plastic resins such as polyether sulfone and polysulfone resins, polycarbonate resins and amorphous polyolefin resins are preferably used. In particular, polycarbonate resin is suitable for this application in terms of mechanical properties, optical properties, and heat resistance. In order to further improve the solubility, optical properties and heat resistance of the polycarbonate resin, various components may be copolymerized and used.

A transparent conductive laminate for a touch panel is manufactured by forming a conductive film as described below on the plastic film with a protective layer thus manufactured.

The transparent conductive film according to the present invention is mainly composed of indium metal oxide (In ₂ O ₃ ) and / or tin metal oxide (SnO ₂ ) in terms of transparency, conductivity, mechanical properties and the like. It is preferable that it is a thing. However, In ₂ O ₃ and SnO ₂ described here represent oxides of each metal atom, and do not necessarily represent stoichiometrically complete oxides. That is, these oxides have stoichiometric numbers that do not impair optical properties.

Further, in a touch panel, particularly in a resistive film type touch panel which detects an input position by the magnitude of the resistance value, a transparent conductive film having a high surface resistance value is desired in order to reduce the power consumption of the touch panel. Furthermore, the uniformity of the resistance value is also required. The high surface resistance referred to here means 500 Ω / □ or more. As a means for obtaining such a high surface resistance value, there is a method of reducing the film thickness.

However, for example, ITO, which is a compound of indium metal oxide and tin metal oxide, must have a film thickness of 15 nm or more in order to sufficiently maintain reliability such as durability. The surface resistance at this time is 500
Since it is less than Ω / □, a high surface resistance value cannot be obtained. Reliability here means 80 ° C dry × 1000h
r heat resistance test, 60 ° C. 90% RH × 1000 hr wet heat resistance test, resistance change R / R0 was 0.8 or more.
When it is 5 or less, there is no change in appearance such as cracking. This is due to the low resistivity of ITO.

From such a viewpoint, SiO is contained in the transparent conductive film.
_The resistivity can be increased by adding a trace amount of at least one metal oxide selected from ₂ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , MgO, and ZnO, and the reliability such as durability is sufficient. A high surface resistance value can be obtained in a stable film thickness region.

Further, the added metal oxide itself has high transparency and does not impair the optical characteristics of the transparent conductive film. Therefore, the presence of the added metal oxide is effective in terms of reliability such as durability of the transparent conductive film without impairing transparency.

However, SiO ₂ , TiO ₂ , and
Al ₂ O 3, ZrO ₂ , MgO and ZnO represent oxides of each metal atom, and do not necessarily represent stoichiometrically complete oxides. That is, these oxides have stoichiometric numbers within a range that does not impair the optical properties.

The amount of metal oxide added to the transparent conductive film is preferably 0.5 to 2% in terms of atomic composition ratio, from the viewpoint of the effect on the resistivity and the transparency of the transparent conductive film itself. . More preferably, it is 0.8 to 1.5%.
The atomic composition ratio here means the following formula a × 100 / (a + b) (%) a: SiO ₂ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , MgO,
Weight of at least one metal oxide selected from ZnO b: Mainly indium metal oxide (In ₂ O ₃ ) and / or
Alternatively, SiO ₂ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , obtained by the weight of tin metal oxide (SnO ₂ ),
It means the content of at least one metal oxide selected from MgO and ZnO.

Further, from the viewpoint of transparency, conductivity, mechanical properties, etc., the transparent conductive metal oxide is mainly indium metal oxide (In ₂ O ₃ ) and / or tin metal oxide (S
nO ₂ ) is preferable.

The film thickness of these transparent conductive films is from 15 nm to 25 nm.
nm is preferable, and 17 to 20 nm is particularly preferable.
If it is less than 15 nm, the film is unstable and there is no improvement effect in terms of reliability such as durability. Further, the variation in the resistance value due to the unevenness of the film thickness also becomes large. Further, if it exceeds 25 nm, the transmittance and the surface resistance value are lowered, which is not preferable.

As a method for forming the transparent conductive film, known methods such as a sputtering method, an ion plating method, a vacuum vapor deposition method, an ion beam sputtering method and a CVD method can be used. Among them, the sputtering method is preferable in terms of film thickness uniformity and composition uniformity in the width direction and the length direction.

Evaluations of various tests described in the following Examples and Comparative Examples were carried out in the following manner.

The light transmittance is the transmittance of parallel light rays at 550 nm measured by a known visible spectrophotometer,
The haze value is a value measured using a trade name “COH-300A” manufactured by Nippon Denshoku.

The retardation value is the product Δn · d of the known refractive index difference of birefringence and Δn and the film thickness d, and it is necessary that the retardation value is a value measured at a wavelength in the visible light range. Since the polymer has a wavelength dispersion characteristic of refractive index, a typical value is a measured value of 590 nm. Further, the dispersion angle of the slow axis is measured at the same wavelength, but the retardation value and the angle of the slow axis can be measured by a well-known birefringence measuring device. For example, it can be easily measured with a product name “M-150” of a multi-wavelength birefringence measuring device manufactured by JASCO Corporation.

Further, the three-dimensional refractive index can be calculated by assuming that the plastic film is a three-dimensional ellipsoid and calculating from the incident angle dependence of the in-plane retardation value. That is, when the three-dimensional refractive index is nx, ny, nz

[0071]

[Equation 1]

[0072]

[Equation 2]

The relational expression of is satisfied.

Therefore, after determining the average refractive index n = (nx + ny + nz) / 3 of the plastic film, the retardation R (θ) at the incident angle θ is set to the incident angle θ.
And the refractive index nx, ny,
nz can be determined. Note that Δn (θ) is the birefringence at the incident angle θ, and d is the thickness of the plastic film. Also, literature values may be used for n.

Regarding the organic solvent resistance, toluene selected as a representative solvent widely used for conductive coatings
Drop a few drops on the protective film to be provided with a conductive film in a 5 ° C. environment, and
It was performed by visually observing changes in appearance such as white turbidity, swelling, and dissolution after being left for minutes, and when no change was confirmed, it was evaluated as having organic solvent resistance.

Regarding the resistance to the alkaline aqueous solution, the sample was immersed in a 3.5 wt% sodium hydroxide aqueous solution used for dissolving the resist after patterning at 25 ° C. for 10 minutes.
It is immersed for a minute, then sufficiently washed with running water, dried, and visually observed for the appearance. When no change is confirmed and the conductive film laminate has a surface resistance change R / R0 is 0.8 ≦ R / R
When 0 ≦ 1.5, it was evaluated as having an alkali aqueous solution resistance.

Regarding the resistance to acidic aqueous solution, the etching solution used for patterning the transparent electrode layer (35% by weight ferric chloride aqueous solution, 35% by weight hydrochloric acid, water 1: 1: 1) was used.
(Mixture in a proportion of 0) at 25 ° C. for 10 minutes, and then thoroughly washed with running water and dried, and visually observing the appearance. When no change is confirmed, an acid-resistant aqueous solution is used. It was evaluated to have sex.

The adhesion was evaluated by a cross-cut test (cross-cut tape method) according to JIS standard 5400.

Regarding the heat resistance, the change in surface resistance value when left for 1000 hours in a dry atmosphere at 80 ° C. R /
When R0 was 0.8 ≦ R / R0 ≦ 1.5, it was evaluated as having heat resistance reliability.

Regarding the reliability of moist heat resistance, 60 ° C. 90% R
When the surface resistance value change R / R0 when left to stand for 1000 hours in an H atmosphere was 0.8 ≦ R / R0 ≦ 1.5, it was evaluated as having wet heat resistance.

[0081]

Example 1 A polycarbonate resin having an average molecular weight of 37,000 consisting of bisphenol A alone as a bisphenol component was dissolved in methylene chloride in an amount of 20% by weight. Then, this solution is applied to a die coating method to have a thickness of 175 μm.
Cast on a polyester film of. Next, the residual solvent concentration was adjusted to 13% by weight in a drying oven, and the film was peeled off from the polyester film. Then, this polycarbonate film was dried in a drying oven at a temperature of 120 ° C. while balancing the vertical and horizontal tensions until the residual solvent concentration became 0.08% by weight.

The film thus obtained has a thickness of 10
The retardation value at 2 μm, the film thickness unevenness in the width direction of ± 3 μm, and 590 nm was 8 ± 2 nm in the width direction, the slow axis was ± 8 degrees centering on the MD direction, and | K | was 80 nm.

A protective layer was laminated on both sides of this plastic film as follows.

Acrylate resin represented by the following general formula (5)

[0085]

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To 100 parts by weight, 7 parts of 1-hydroxycyclohexyl phenyl ketone (trade name "Irgacure 184" manufactured by Ciba-Geigy) which is an ultraviolet curing initiator is added.
Silicone oil (“SH28PA” manufactured by Toray Dow Corning Silicon Co., Ltd.) as a weight part and a leveling agent 0.0
3 parts by weight and 200 parts by weight of isopropanol as a diluent solvent were mixed to prepare a coating liquid.

This coating solution was first wet-coated on one side of a plastic film using a microgravure coater, then heated at 60 ° C. for 1 minute to volatilize and remove the residual solvent in the coating solution, and then 160 W / cm in an air environment. The coating film was cured by irradiating the coating film with ultraviolet rays under the conditions of an integrated light amount of 800 mJ / cm ² using the high pressure mercury lamp of No. 3 to obtain a resin layer having a film thickness of 4 μm.

Next, the same protective layer was formed on the opposite surface.

Then, strength of 200 W is applied to the surface of one protective layer.
・ Corona discharge treatment was applied under the condition of min / m ² .

The conductive film was formed on the surface subjected to the corona discharge treatment as follows.

The film produced above was placed in a DC magnetron sputtering apparatus, and a target of indium oxide: tin oxide: titanium oxide in a weight ratio of 94: 4.7:
A target having a relative density of 70% produced by sintering in 1.3 was set.

Then, after evacuation of the vacuum chamber to 0.13 mPa or less, an argon / oxygen mixed gas (oxygen concentration 1
%) Is introduced, the degree of vacuum is 0.67 Pa, and the input power is 1.0
A conductive film was produced with W / cm ² . T of the conductive film at this time
The iO ₂ content was 1.3%.

Table 1 shows the characteristics of this conductive film laminate. Thus, it was demonstrated that the conductive film laminate had excellent solvent resistance and reliability.

[0094]

Example 2 A protective layer was laminated on both surfaces of the plastic film used in Example 1 as follows.

Vinyl trimethoxysilane (trade name “KBM1 manufactured by Shin-Etsu Chemical Co., Ltd.
003 "), 148 parts by weight of the vinyltrimethoxysilane was added thereto, 54 parts by weight of 0.01 N hydrochloric acid water was gradually added to the solution while vigorously stirring, and the mixture was slowly stirred for 3 hours. Got

As an acrylate resin, 100 parts by weight of trimethylolpropane triacrylate (trade name "Aronix M-309" manufactured by Toagosei Co., Ltd.) was UV-cured with 100 parts by weight of the above-mentioned hydrolyzed solution of vinyltrimethoxysilane. 3 parts by weight of 1-hydroxycyclohexyl phenyl ketone (trade name "Irgacure 184" manufactured by Ciba-Geigy) as an initiator and 0.03 part by weight of silicon oil (trade name "SH28PA" manufactured by Toray Dow Corning Silicon Co.) as a leveling agent. The parts were mixed to obtain a coating liquid.

This coating solution was first wet-coated on one side of a plastic film using a microgravure coater, then heated at 60 ° C. for 1 minute to volatilize and remove the residual solvent in the coating solution, and then a nitrogen environment having an oxygen concentration of 1% was used. 160W below
/ Cm high pressure mercury lamp, 800 mJ / c
The coating film was cured by irradiating it with ultraviolet rays under the condition of m ² to obtain a resin layer having a film thickness of 4 μm. Then, the same protective layer was formed on the opposite surface.

Subsequently, strength of 200 W is applied to the surface of one protective layer.
・ Corona discharge treatment was applied under the condition of min / m ² . The conductive film was formed on the surface subjected to the corona discharge treatment in the same manner as in Example 1.

The characteristics of this conductive film laminate are shown in Table 1. Thus, it was demonstrated that the conductive film laminate had excellent solvent resistance and reliability.

[0100]

Example 3 A protective layer was laminated on both sides of the plastic film used in Example 1 as follows.

Acrylate resin 100 used in Example 1
Silicon oil as a leveling agent for parts by weight (trade name “SH28P” manufactured by Toray Dow Corning Silicone Co.
A ") 0.03 parts by weight and 200 parts by weight of isopropanol as a diluent solvent were mixed to prepare a coating liquid.

This coating solution was first wet-coated on one side of a plastic film using a microgravure coater, then heated at 60 ° C. for 1 minute to volatilize and remove the residual solvent in the coating solution, and then an electron beam having an intensity of 4 Mrad was applied. Irradiate,
A resin layer having a film thickness of 4 μm was obtained.

Then, the same protective layer was formed on the opposite surface.

Subsequently, the strength of 200 W is applied to the surface of one of the protective layers.
・ Corona discharge treatment was applied under the condition of min / m ² .

The conductive film was formed in the same manner as in Example 1 on the surface subjected to the corona discharge treatment.

The characteristics of this conductive film laminate are shown in Table 1. Thus, it was demonstrated that the conductive film laminate had excellent solvent resistance and reliability.

[0107]

Comparative Example 1 The composition of the acrylate resin in Example 1 was changed to 40 parts by weight of the acrylate resin of Example 1, 30 parts by weight of pentaerythritol triacrylate (trade name "Aronix M-305" manufactured by Toagosei Co., Ltd.), and isocyanuric acid. Ethylene oxide modified diacrylate (trade name "Aronix M-215" manufactured by Toagosei Co., Ltd.) 30
The mixture was part by weight. The other conditions were the same as in Example 1.

The characteristics of this conductive film laminate are shown in Table 1. In this way, the solvent resistance and reliability are poor.

[0109]

[Comparative Example 2] In Example 1, the integrated quantity of ultraviolet light of the high-pressure mercury lamp was set to 400 mJ / cm ² . The other conditions were the same as in Example 1. The surface of the protective layer after this curing treatment had tackiness and was insufficiently cured. Further, as shown in Table 1, the solvent resistance was also inferior.

[0110]

[Comparative Example 3] In Example 1, the back surface of the plastic film was cooled, and the cumulative amount of ultraviolet light of the high-pressure mercury lamp was set to 26.
00 mJ / cm ² . The other conditions were the same as in Example 1. The laminated body after this curing treatment was deformed by heat and was no longer usable.

[0111]

Comparative Example 4 In Example 1, the amount of the ultraviolet curing initiator was 3 parts by weight. The other conditions were the same as in Example 1. The surface of the protective layer after this curing treatment had tackiness and was insufficiently cured. Further, as shown in Table 1, the solvent resistance was also inferior.

[0112]

Comparative Example 5 In Example 1, the amount of the ultraviolet curing initiator was set to 15 parts by weight. The other conditions were the same as in Example 1.
The characteristics of this conductive film laminate are shown in Table 1. Thus, the solvent resistance was excellent, but the reliability was poor.

[0113]

Comparative Example 6 In Example 1, no corona treatment was performed. The other conditions were the same as in Example 1. The characteristics of this conductive film laminate are shown in Table 1. In this way, the solvent resistance and reliability are poor.

[0114]

Comparative Example 7 In Example 1, only the corona treatment was performed without post-heat treatment after ultraviolet curing. The other conditions were the same as in Example 1. The characteristics of this conductive film laminate are shown in Table 1. Thus, the solvent resistance was excellent, but the reliability was poor.

[0115]

[Comparative Example 8] In Example 2, the oxygen concentration in nitrogen was adjusted to 3
%. The other conditions were the same as in Example 2. The characteristics of this conductive film laminate are shown in Table 1. Thus, the solvent resistance is poor.

[0116]

Comparative Example 9 In Example 2, the amount of the ultraviolet curing initiator was 0.3 part by weight. The other conditions were the same as in Example 2. The surface of the protective layer after this curing treatment had tackiness and was insufficiently cured. Further, as shown in Table 1, the solvent resistance was also inferior.

[0117]

Comparative Example 10 In Example 2, the amount of the ultraviolet curing initiator was 6 parts by weight. The other conditions were the same as in Example 2. The characteristics of this conductive film laminate are shown in Table 1. Thus, the solvent resistance was excellent, but the reliability was poor.

[0118]

[Comparative Example 11] In Example 3, the electron beam irradiation intensity was set to 2
It was Mrad. The other conditions were the same as in Example 3. The surface of the protective layer after this curing treatment had tackiness and was insufficiently cured. Further, as shown in Table 1, the solvent resistance was also inferior.

[0119]

Comparative Example 12 In Example 3, the electron beam irradiation intensity was set to 6
It was Mrad. The other conditions were the same as in Example 3. The characteristics of this conductive film laminate are shown in Table 1. As described above, although the solvent resistance was excellent, the deterioration of the plastic film due to the electron beam was great and the coloring became severe. Therefore, the light transmittance is poor.

[0120]

[Table 1]

[0121]

INDUSTRIAL APPLICABILITY As described above, the present invention provides a transparent conductive film laminate having excellent optical properties and conductive film properties for a touch panel, and has particularly excellent visibility shared with a liquid crystal panel. It can be particularly suitably used as a transparent conductive laminate for a resistive film type touch panel having excellent viewing angle characteristics.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location H01B 13/00 503 H01B 13/00 503B // C09D 4/00 PDQ C09D 4/00 PDQ 4/02 PDR 4/02 PDR (72) Inventor Toshiaki Yatabe 4-3-2 Asahigaoka, Hino City, Tokyo Teijin Limited Tokyo Research Center

Claims (11)

[Claims] 1. A transparent conductive film laminate for a resistive film type touch panel, wherein a conductive film is provided on at least one surface of a plastic film, on an optically isotropic plastic film,
The following general formula (1) After laminating a cured product of a radiation curable resin containing 50% by weight or more of the compound as a solid content, corona discharge treatment is applied to the surface thereof, and a conductive film is laminated thereon. METHOD FOR TRANSPARENT CONDUCTIVE FILM FOR TOUCH PANEL AND METHOD FOR PRODUCING THE SAME In the general formula 1, A is an unsaturated alkyl group or an unsaturated alkylcarbonyl group, and X is a carbon atom number of 1 to 8.
And a trivalent aliphatic ether group, Y is a divalent aliphatic or aromatic dicarbonyl compound, and n is 0.5 to 0.5 as an average value.
2 range. 2. The radiation curable resin contained in the solid content ratio of 50% by weight or more is represented by the general formula (1), wherein A is an acryloyl group and X is the following general formula (2): Is a trivalent group, and Y is represented by the following general formula (3) or (4): Embedded image It is a dicarbonyl compound shown by these. The transparent conductive film laminated body for resistive film type touch panels of Claim 1 characterized by the above-mentioned. Here, Z represents a trivalent hydrocarbon group having 1 to 12 carbon atoms, and R represents a hydrogen atom, a halogen atom, or a methyl group or an ethyl group. 3. The curing of the protective layer is carried out by adding an ultraviolet curing initiator to the radiation curable resin in an amount of 4 to 10 parts by weight based on the radiation curable resin component. 3. The resistive film type touch panel according to claim 1, wherein the resistive film type touch panel according to any one of claims 1 to 2, characterized in that after being irradiated with ultraviolet light of ˜2000 mJ / cm ² , it is then heat-treated at a temperature of 100 ° C. or higher for 1 minute or longer. For manufacturing a transparent conductive film laminate for a car. 4. The curing of the protective layer is carried out by adding an ultraviolet curing initiator to the radiation curable resin in an amount of 0.5 part by weight or more and less than 4 parts by weight with respect to the radiation curable resin component so that the oxygen concentration is 2 when laminated. In a nitrogen gas environment of less than 50%, the cumulative light intensity is 500
And characterized by being irradiated with ultraviolet light of ~2000mJ / cm ^2, resistive type method for producing a transparent conductive film laminate for a touch panel according to any of claims 1 to 2. 5. The resistance film according to claim 1, wherein the protective layer is cured by irradiating the radiation curable resin with an electron beam of 3 to 5 Mrad during lamination. Method for producing a transparent conductive film laminate for a touch panel. 6. The transparent conductive film for a resistive film type touch panel according to claim 1, wherein the optically isotropic plastic film is a plastic film formed by a solution casting method. Laminate. 7. The refractive index in the in-plane slow axis direction of the optically isotropic plastic film is nx, the refractive index in the in-plane fast axis direction is ny, the refractive index in the film thickness direction is nz, and the film thickness is d. When it does, when it makes K = ((nx + ny) / 2-nz) xd the parameter which shows three-dimensional refractive index anisotropy, | K | ≦ 120 nm, It is characterized in that 7. The transparent conductive film laminate for a resistive film type touch panel according to any one of items 6 and 6. 8. The transparent conductive film laminate for a resistive film type touch panel according to claim 1, wherein the plastic film contains a polycarbonate resin as a main component. 9. The transparent conductive film is a transparent conductive metal oxide film mainly made of indium metal oxide (In ₂ O ₃ ).
5. A transparent conductive film laminate for a resistive film type touch panel according to any one of 1. 10. The transparent conductive metal oxide film is mainly composed of indium metal oxide (In ₂ O ₃ ) and tin metal oxide (SnO ₂ ). 6. A transparent conductive film laminate for a resistive film type touch panel according to any one of 6, 7, 8 and 9. 11. The transparent conductive film comprises SiO ₂ , TiO ₂ , Al ₂ O ₃ , and Zr in a transparent conductive metal oxide film.
The metal oxide according to any one of claims 1, 2, 6, 7, 8, 9 and 10, wherein a trace amount of at least one metal oxide selected from O ₂ , MgO and ZnO is added. A transparent conductive film laminate for a resistive touch panel.