JPH09254303A - Transparent conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the curling of a film by a method wherein solvent-resistant layer made of the cured film of a resin composition, which is prepared by mixing radiation curing type resin and the hydrolyzate of alkoxysilane represented by the formulae at the mixing ratio ranging from the specified rang and provided on both the sides of a film under the condition that a gas barrier layer made of metal oxide is provided on one of the under layers of the solvent-resistant layers and a transparent electrically conductive layer is provided on one of their outermost layers. SOLUTION: This transparent electrically conductive film is produced by providing at least a gas barrier layer, a solvent-resistant layer and a transparent electrically conductive layer on a plastic film. The solvent-resistant layer is made of the cured film of a resin composition, which is prepared by mixing radiation curing type resin A and the hydrolyzate B of alkoxysilane represented by the formula I or II, in which R, is methyl group, ethyl group or organic group containing vinyl group, acryloyl group, methacryloyl, group, amino group and epoxy group R is methyl group and ethyl group, at the ratio of A:B is set to be (0:1)-(1:3) in the weight ratio of solids. Further, at the under layer of at least one of the solvent-resistant layer, a gas barrier layer made of metal oxide is provided and, at the outermost surface of one of the solvent-resistant layer, a transparent electrically conductive layer is provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to transparency, optical isotropy, smoothness, solvent resistance, adhesion between layers including after durability test, gas barrier property, and little change in gas barrier property due to environment. Regarding the transparent conductive film having the characteristics of excellent curl of the laminated film in addition to excellent characteristics, for example, as a transparent conductive substrate of a transparent electrode substrate of a liquid crystal panel, an electroluminescence panel, an electrochromic panel, a surface heating element, etc. It can be used.

[0002]

2. Description of the Related Art In recent years, liquid crystal display elements have been required to be lighter and thinner and to be larger in size, as well as to be highly demanded for long-term reliability, flexibility of shape, curved surface display and the like. In particular, as the use of portable and mobile devices such as pagers (pagers), mobile phones, electronic organizers, and pen input devices becomes widespread, the conventional thick, heavy, and fragile glass substrates are replaced by plastics. A liquid crystal panel using a substrate as a substrate has been studied, and some have begun to put it into practical use.

Such a plastic substrate satisfies the demand for lightness and thinness, and is disclosed in Japanese Patent Laid-Open No. 56-13010 and is known.

Further, a plastic substrate having improved air permeation resistance and water vapor permeation resistance (hereinafter collectively referred to as gas barrier property), which is a problem of the plastic substrate especially for liquid crystal applications, is also disclosed in JP-A-61-41122. Sho 61-7392
No. 4, Japanese Patent Application Laid-Open No. 3-9323, etc.

However, among the conventional plastic substrates described above, those using a polyvinyl alcohol-based resin layer as a gas barrier layer for imparting gas barrier properties have a resistance to permeation in a low humidity atmosphere of 50% RH or less. High temperament, but higher humidity, eg 9
There is a drawback that the gas barrier property at 0% RH is poor. Further, the polyvinyl alcohol resin layer is directly under the transparent conductive layer,
Alternatively, when it is provided in the outermost layer, there is a problem that it is easily attacked by an aqueous solution. In addition, there are polyacrylonitrile, polyvinylidene chloride, and the like as organic gas barrier layer materials, but they are difficult to apply from the viewpoints of handleability and environmental problems.

On the other hand, JP-A-61-183810 discloses a plastic substrate provided with a metal oxide as a gas barrier layer. In this case, a gas barrier property almost independent of humidity can be obtained, but if the layer is thickened to obtain the required gas barrier property, there is a problem that mechanical properties, that is, the gas barrier layer is cracked by slight bending, and therefore is good. It is difficult to provide good gas barrier properties while maintaining good mechanical properties. Moreover, when such a metal oxide, particularly silicon oxide which has good productivity and is preferably used, is present in the outermost layer, there is a drawback that it is easily eroded by an alkaline aqueous solution.

To solve such a problem, Japanese Patent Laid-Open No. 6-175
Japanese Laid-Open Patent Publication No. 143 discloses that a curable resin is laminated on or under the metal oxide layer from the viewpoint of improving scratch resistance. However, high gas barrier properties, adhesion of each layer, and solvent resistance including an alkaline aqueous solution have not been examined, and problems remain.

[0008]

When a plastic substrate is used as the liquid crystal display panel substrate, transparency, optical isotropy, smoothness, solvent resistance, adhesion between layers including after durability test, gas barrier property High performance is required in various characteristics such as a small change in gas barrier property due to the environment.

That is, when the transparency and optical isotropy of the substrate are poor, problems such as deterioration of display brightness and contrast and occurrence of coloring occur. In addition, when the flatness of the substrate is low, the thickness of the liquid crystal layer becomes non-uniform, and the alignment unevenness of the liquid crystal is generated to deteriorate the display quality.

Solvent resistance is a necessary property in the process of producing a liquid crystal panel, and is an acidic aqueous solution used for etching the transparent conductive layer, an alkaline aqueous solution used for resist development,
N-methylpyrrolidone used when forming a liquid crystal alignment film, γ-
If the resistance to an organic solvent such as butyrolactone is low, the appearance and flatness of the substrate are deteriorated.

If the adhesion between the layers laminated on the substrate is low, peeling, cracks, etc. are likely to occur at the time of making the panel, and if the adhesion decreases over time, the impact resistance decreases. However, this results in poor long-term reliability of the panel.

When the gas barrier property of the substrate is low, outside air, such as oxygen, nitrogen, and water vapor, easily enters and leaves the liquid crystal layer through the substrate, which easily causes deterioration of the liquid crystal and generation of bubbles. When a metal oxide layer is laminated for the purpose of improving gas barrier properties, solvent resistance to an alkaline aqueous solution or the like becomes a problem. Therefore, it is necessary to stack a layer having high solvent resistance and adhesiveness on the metal oxide.

When a plastic film having such a solvent resistant layer laminated thereon has a large curl, the handleability at the time of manufacturing the panel is deteriorated.

[0014] The present invention has been made in view of such a point.
It is an object of the present invention to provide a transparent conductive film that reduces curling, is excellent in various properties such as transparency, optical isotropy, flatness, solvent resistance, adhesion between layers, and gas barrier properties, and has no curling problem. .

[0015]

The above objects are achieved by the present invention described below. That is, the present invention, at least a gas barrier layer on a plastic film, a solvent resistant layer,
In the transparent conductive film provided with the transparent conductive layer, the radiation curable resin (A) and the alkoxysilane hydrolyzate (B) represented by the following general formula (1) or (2) are used as A:
A solvent resistant layer made of a cured film of a resin composition mixed so that the ratio of B is in the range of 20: 1 to 1: 3 in terms of solid content is provided on both sides, and at least one of the solvent resistant layers is provided. A transparent conductive film comprising a gas barrier layer made of a metal oxide as a lower layer and a transparent conductive layer provided on at least one outermost surface.

[0016]

Embedded image R ¹ —Si (OR ² ) ₃ (1) Si (OR ² ) ₄ (2)

Here, R ¹ is a methyl group, an ethyl group or a vinyl group, an acryloyl group, a methacryloyl group, an amino group, an organic group containing an epoxy group, and R ² is a methyl group or an ethyl group.

As described above, in the present invention, the specific solvent resistant layer is provided on both surfaces, so that the adhesiveness between the layers can be secured without deteriorating the optical characteristics, and the transparent conductive film without curling problem can be obtained. Will be realized.

The details of the present invention will be described below.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, from the viewpoint of eliminating curl, the film thickness of the solvent resistant layers provided on both sides is 2 to 8 μm.
And the ratio dr / df is preferably in the range of 0.4 to 2.5. Here, df is the film thickness of the solvent resistant layer on the metal oxide side, and dr is the film thickness of the solvent layer on the opposite surface side.

The metal oxide used has transparency, mechanical properties,
From the viewpoint of gas barrier properties and adhesion to the solvent resistant layer, the film thickness is preferably 5 to 100 nm, and the material is preferably a silicon oxide having a ratio of the number of oxygen atoms to the number of silicon atoms of 1.5 to 2.0. .

From the viewpoint of optical isotropy required for liquid crystal applications and the like, it is preferable that the transparent conductive film has a retardation value of 20 nm or less and a light transmittance of 80% or more at a wavelength of 550 nm.

From this point of view, the plastic film used has a thickness of 70 to 200 μm formed by the solution casting method.
The optically isotropic plastic film of is preferable.

According to the present invention, a metal oxide gas barrier layer is provided on at least one surface of a plastic film. Further, the following solvent-resistant layers are laminated on both sides thereof.

As the solvent resistant layer, as described above, a cured film obtained by curing a resin composition in which a radiation curable resin is mixed with a hydrolyzate of alkoxysilane is used. Here, the radiation-curable resin is a component necessary for obtaining excellent solvent resistance, and the hydrolyzate of the alkoxysilane is a component necessary for obtaining high adhesion with excellent durability on the metal oxide. Is.

The radiation-curable resin refers to a resin that is cured by irradiation with radiation such as ultraviolet rays and electron beams. Specifically, it does not contain an acryloyl group, a methacryloyl group, a vinyl group or the like in its molecule or unit structure. It is a resin containing a saturated double bond. Among these, a resin containing an acryloyl group is preferable from the viewpoint of reactivity.

Further, the radiation-curable resin used in the present invention preferably has a predetermined solvent resistance under the predetermined curing conditions described below. That is, a mixture obtained by adding 8 parts by weight of a photoinitiator 2-hydroxy-2-methyl-1-phenylpropan-1-one (trade name Darocure 1173 manufactured by Merck & Co., Inc.) to 100 parts by weight of a certain radiation curable resin. Is diluted with a suitable solvent, if necessary, and is coated on a polycarbonate film having a thickness of 100 μm to form a resin layer having a dry film thickness of 3 μm. Then, using a 160 W / cm high-pressure mercury lamp, the accumulated light amount is 8
Irradiation with ultraviolet rays is performed under the condition of 00 mJ / cm ² to cure the resin layer. On top of this resin layer, N-methylpyrrolidone, 3.5 wt% sodium hydroxide aqueous solution, etching solution (35 wt% ferric chloride aqueous solution, 35 wt% hydrochloric acid, water mixed at a ratio of 1: 1: 10) When the appearance changes such as cloudiness, swelling, and dissolution of the resin layer are not visually observed after dropping several drops of each of the above and leaving it at 25 ° C. for 15 minutes, it is said that the radiation-curable resin has solvent resistance. To be evaluated.

These radiation-curable resins may have a single composition or a mixed composition of several kinds, but from the viewpoint of solvent resistance, a polyfunctional acrylate component having two or more acryloyl groups in a molecule or unit structure is used. It is preferably contained in the resin composition. Examples of such polyfunctional acrylate components include dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate,
Examples thereof include various acrylate monomers such as pentaerythritol tetraacrylate, pentaerythritol triacrylate, and trimethylolpropane triacrylate, and polyester-modified or urethane-modified polyfunctional acrylate oligomers, but are not limited thereto.

As the alkoxysilane hydrolyzate, a product obtained by hydrolyzing an alkoxysilane represented by the following general formula (1) or (2) or a mixture thereof by a known method is used.

[0030]

Embedded image R ¹ —Si (OR ² ) ₃ (1) Si (OR ² ) ₄ (2)

Here, R ¹ represents a methyl group, an ethyl group or a vinyl group, an acryloyl group, a methacryloyl group, an amino group, an organic group containing an epoxy group, and R ² represents a methyl group or an ethyl group.

Among these alkoxysilanes, vinyltrimethoxysilane, vinyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane,
Methyltrimethoxysilane, methyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane and the like can be preferably used.

The mixing ratio of the radiation-curable resin and the alkoxysilane hydrolyzate represented by the general formulas (1) and (2) is such that the radiation-curable resin: hydrolyzate is a solid content weight ratio. It is preferably in the range of 20: 1 to 1: 3. When the mixing ratio is less than 20: 1, the adhesion with the metal oxide layer tends to be deteriorated, which is not preferable.
Further, if the mixing ratio exceeds 1: 3, solvent resistance and curability tend to be deteriorated, which is not preferable.

It is also preferable to add an appropriate alkoxysilane to the above resin composition without hydrolysis. A part of the alkoxysilane added in this way is, when the resin composition is coated on the film, rapidly hydrolyzed by the water on the film or in the atmosphere, so that the resin composition is previously added. It exerts the same function as the hydrolyzate of the contained alkoxysilane, and can enhance the adhesion of the layer. As such an alkoxysilane, vinyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and the like are particularly preferably used. The addition amount is preferably within 20% with respect to the total solid content weight. If the amount added is more than 20%, the solvent resistance of the layer tends to decrease, which is not preferable.

The solvent resistant layer composed of the above resin composition is formed on the surface of the metal oxide layer laminated on the plastic film and on the surface opposite thereto by a wet coating method. As a coating method, a known method such as a reverse roll coating method, a micro gravure coating method, a direct gravure coating method, a kiss coating method or a die coating method is used. Further, by diluting the resin composition with an appropriate organic solvent, it is possible to adjust the viscosity of the coating liquid and the film thickness of the layer.

The surface treatment of the metal oxide layer is preferably carried out for the purpose of improving the wettability of the coating liquid on the metal oxide layer. As such surface treatment, known techniques such as corona treatment, plasma treatment and alkali treatment can be used.

Curing of the solvent resistant layer formed by the wet coating method is carried out by irradiating radiation such as ultraviolet ray curing method and electron beam curing method. Here, in order to increase the denseness of the layer, it is more preferable to carry out the curing after evaporating the solvent component contained in the coating.

When the ultraviolet curing method is used, an appropriate amount of a known photoreaction initiator is added to the above resin composition. As the photoreaction initiator, for example, diethoxyacetophenone,
2-methyl-1- {4- (methylthio) phenyl} -2
-Morpholinopropane, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone and other acetophenone compounds, benzoin, benzyldimethyl ketal and other benzoin compounds, benzophenone, benzoylbenzoic acid Benzophenone compounds such as thioxanthone, 2,4-
Examples thereof include thioxanthone compounds such as dichlorothioxanthone. Further, in order to further improve the curability, triethanolamine, methyldiethanolamine, 4-
It is also effective to add a suitable amount of a known reaction initiation aid such as ethyl dimethylaminobenzoate.

The above-mentioned solvent resistant layer is not limited to the initial stage in which it is laminated on the metal oxide layer, but also at 60 ° C. and 90% RH.
250 under wet heat condition or heat resistance condition of 90 ° C, 0% RH
Deterioration of the adhesiveness was not observed even when the durability test was performed for more than an hour. Further, regarding the solvent resistance, the resistance to an acidic aqueous solution used for etching the transparent conductive layer, an alkaline aqueous solution used for peeling the resist film, an organic solvent such as N-methylpyrrolidone used for forming the liquid crystal alignment film, and the like is sufficient. It had excellent solvent properties.

However, when the metal oxide layer is provided on one side of the plastic film and the solvent resistant layer is provided only on the metal oxide layer side and not on the opposite side, the curing shrinkage of the solvent resistant layer is large, A large curl in which the laminated surface side of the solvent resistant layer was concave was generated. When the laminated film has a curl as described above, the handleability is poor, and it becomes difficult to attach the transparent conductive film particularly when a liquid crystal display panel is manufactured, which causes problems in productivity and quality.

Here, for the evaluation of curl, the film to be evaluated is cut into a square of 10 cm on each side, and 130 ° C.
After 2 hours of heat treatment at 25 ° C. and 50% RH for 3 days, it floats from the horizontal planes of the four corners when left standing on a horizontal plane with the surface on which the transparent conductive layer is provided facing down. Each height was measured and averaged as a positive value to evaluate as a curl value. If the surface on which the transparent conductive layer is provided is concave,
When placed on a horizontal plane with the surface on which the transparent conductive layer was provided facing upward, the heights floating from the horizontal planes at the four corners were measured and averaged as a negative value to evaluate as a curl value. When this value was within ± 10 mm, curl did not pose a practical problem, so this was used as the evaluation standard.

By the way, the above-mentioned curl has a structure in which the above-mentioned solvent-resistant layer is provided not only on the side of the above-mentioned metal oxide layer but also on the opposite surface thereof, that is, the solvent-resistant layer is provided on both sides of the present invention. It turns out that it can be put in the range of.

However, even if the solvent-resistant layers on both surfaces have the same composition, it is not effective if the film thicknesses differ greatly from each other. From this point of view, the film thickness df of the solvent-resistant layer on the metal oxide side is examined. The effect of curl improvement is more remarkable by adjusting the film thicknesses of the solvent-resistant layer on the opposite surface side to the ratio dr / df so that the ratio dr / df is in the range of 0.4 to 2.5. It was If this ratio is not within the above range, the curl value is ± 1.
It is out of the 0 mm range. From this point, it is preferable that the film thickness ratio of both solvent resistant layers is within these ranges.

When the thickness of either of the solvent-resistant layers is less than 2 μm, the solvent-resistant effect of the solvent-resistant layers deteriorates. In addition, curing was insufficient due to oxygen damage and the surface sometimes showed tackiness. Film thickness is 8
When it exceeds μm, the curing shrinkage stress becomes large and the adhesiveness with the lower layer deteriorates. In particular, the adhesion with the metal oxide layer has deteriorated. From this point, the thickness of both solvent resistant layers is preferably 2 to 8 μm.

The metal oxide applicable to the gas barrier layer of the present invention may be any metal oxide having a gas barrier property, and examples thereof include silicon oxide, aluminum oxide and magnesium oxide. The film of these metal oxides can be manufactured by a known sputtering method, vacuum deposition method, ion plating method, plasma CVD method, or the like.

The film thickness of the metal oxide of this gas barrier layer is
When the thickness is 5 nm or less, the number of pinholes in the formed film is large and the gas barrier property is almost lost. Also, the film thickness is 100 nm
If it is thicker than that, the film often breaks easily when it is bent, which causes deterioration of workability, deterioration of gas barrier property, and deterioration of transparency. Therefore, the film thickness is preferably in the range of 5 to 100 nm.

Among the metal oxides, from the viewpoints of productivity, optical properties, surface smoothness, mechanical properties, film stress, gas barrier properties, etc., silicon oxides composed of SiO, SiO ₂ or a mixture thereof, particularly silicon. A silicon oxide having an average atomic ratio of oxygen of 1.5 to 2 is preferable. From the viewpoint of transparency, the average atomic ratio of oxygen to silicon is preferably 1.5 or more, and when the average atomic ratio is less than 1.5, transparency is poor even at a film thickness of about 5 nm, and it becomes difficult to obtain a material having a high light transmittance at 400 nm. Oops. In addition, the mechanical properties have also deteriorated.

By the way, when the transparent conductive film of the present invention is used for liquid crystal, its transparency is 550 nm.
The light transmittance at m is 80% or more, and the haze value is 1%.
The following is preferred. In particular, the light transmittance before laminating the transparent conductive layer is preferably 80% or more even at a wavelength of 400 nm. When the light transmittance of these is lower than 80%, when the liquid crystal cell is constructed by using the light transmittance, the light utilization efficiency is lowered, the display is darkened, and the contrast is lowered. Further, when the haze value is higher than 1%, when the liquid crystal cell is constructed by using the haze value, the transmitted light is scattered and the polarization degree of the polarized light transmitted through the polarizing plate is lowered. This reduces the contrast.

Here, the light transmittance is the transmittance of parallel rays measured by a known visible spectrophotometer, and the haze value is the value measured using COH-300A manufactured by Nippon Denshoku Co., Ltd. The ratio of oxygen to silicon in the silicon oxide can be measured by a known technique such as X-ray photoelectron spectroscopy, X-ray microspectroscopy, Auger electron spectroscopy and the like.

Polycarbonate and polyarylate are preferably used as the material of the plastic film of the present invention from the viewpoints of the above-mentioned optical characteristics and thermal characteristics required during processing.

In general, the higher the average molecular weight of these resins, the higher the glass transition temperature. In addition, mechanical characteristics are improved. From such a viewpoint, as the polycarbonate, a polycarbonate composed of a bisphenol component consisting of bisphenol A alone is used, and among them, a polycarbonate having an average molecular weight of 30,000 or more and a glass transition temperature of 150 ° C. or more is preferably used. Further, in order to improve heat resistance, for example, 9,9 bis (4-
Hydroxyphenyl) fluorene or 1,1 bis (4-hydroxyphenyl) 3,3,5-trimethylcyclohexane may be added. However, the selection of the optimum average molecular weight and copolymerization conditions is carried out in a balance between heat resistance, mechanical properties and economic efficiency. Here, the average molecular weight means the number average molecular weight, and can be easily determined by a known measuring means such as GPC.

As a method for continuously forming a plastic film, there are generally a melt extrusion method, a solution casting method and the like. Among them, the solution casting method has a retardation value of 20 nm or less and a slow axis variation of ± 15.
It has optical isotropy of less than 70 degrees and a thickness of 70-200 μm
Thus, a plastic film having sufficient optical isotropy can be obtained even in a liquid crystal panel under the most severe conditions. Further, in the film surface on the side in contact with the air layer during film formation (hereinafter referred to as the air surface), the surface roughness Ra is 1 nm or less, and on the film surface on the side in contact with the support during film formation (hereinafter referred to as the support surface). Also, it is possible to obtain very excellent flatness with a surface roughness Ra of about several nm.

It should be noted that the retardation value is a product Δn · d of the known refractive index difference of birefringence and Δn and the film thickness d, and it is necessary to be a measured value at a wavelength in the visible light range. Generally, a polymer has a wavelength dispersion characteristic of a refractive index, and therefore, 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 multi-wavelength birefringence measuring device M-150 manufactured by JASCO Corporation.

For the surface roughness Ra value, TOPO-3D manufactured by WYKO Co., which uses the phase shift interferometry as a measurement principle, was used to scan a square portion of 256 μm square on the film at a magnification of 40 × at an interval of 1 μm. Is the value of the center line average roughness obtained when the measurement is performed.

Further, in the present invention, an anchor coat layer and a polyvinyl alcohol resin layer are first provided on the surface of the plastic film opposite to the surface on which the metal oxide is laminated, and the solvent resistant layer is laminated thereon. Thereby, a more excellent gas barrier property can be obtained by the synergistic effect with the excellent gas barrier property of the polyvinyl alcohol-based resin layer under a low humidity environment. Specifically, when the oxygen permeability was measured using Ocono 2 / 20ML manufactured by MOCON, 1 cc / (m ² ···) under the measurement conditions of 30 ° C. and 50% RH.
air resistance of 20 cc / (m ² · day · atm) or less is obtained under the measurement conditions of 30 ° C. and 90% RH, and a transparent conductive layer is formed by using Percontran W1A manufactured by MOCON. When the water vapor permeability is measured with the opposite surface of the surface to be installed on the humidification side, 40 ° C, 90% RH
Under the measurement conditions of, a water vapor permeation resistance of 20 g / (m ² · day · atm) or less can be obtained.

The polyvinyl alcohol resin layer is a polymer resin containing 50 mol% or more of at least one component selected from the group consisting of a vinyl alcohol component and a vinyl alcohol copolymerization component. The vinyl alcohol copolymer may, for example, be a vinyl alcohol / vinyl acetate copolymer, a vinyl alcohol / vinyl butyral copolymer, an ethylene / vinyl alcohol copolymer or a cross-linked product thereof.

In order to enhance the adhesion between the polyvinyl alcohol resin layer and the plastic film, it is preferable to use the anchor coat layer as described above. As such an anchor coat layer, a urethane-based cured resin layer is preferable, and among them, a phenoxy-based cured resin layer is particularly preferable.

The transparent conductive film is manufactured by providing a transparent conductive layer on the surface of the laminated film in which the above respective layers are laminated. As is well known, a thin film of a metal such as tin, indium and titanium or an oxide thereof is applied to this transparent conductive layer, and it can be provided by a known thin film forming means such as a vapor deposition method and a sputtering method.

In particular, the transparent conductive layer of the present invention is mainly composed of amorphous indium oxide, contains 5 to 15% by weight of tin as its composition, and has a film thickness of 20 to 2.
A transparent conductive layer in the range of 00 nm is preferred. A highly crystalline indium oxide film has higher transparency and conductivity than an amorphous one, and in that respect, it is preferable as a transparent electrode material, but on a highly flexible film such as the substrate of the present invention. In the case where the crystalline film is formed, the film is liable to be broken when it is bent, and there is a problem in reliability and handleability during assembly.

Here, the crystallinity of indium oxide,
Amorphous is defined as follows. When the surface of the formed indium oxide is observed with a transmission electron microscope, when crystals are present, it is observed that fine crystals of about 100 nm at most are scattered on the amorphous surface. According to this observation method, the area ratio of the fine crystal grains per unit area (100 μm ² ) is 20.
% Or less is defined as non-crystalline.

Although indium oxide is originally a transparent electric insulator, it becomes a semiconductor when it contains a trace amount of impurities or when it is slightly oxygen-deficient. Preferred semiconductor metal oxides include indium oxide containing tin or fluorine as an impurity, and particularly preferably, indium oxide containing 5 to 15% by weight of tin is
It is preferably used because it exhibits good conductivity while maintaining high transparency.

The thickness is 20 to 200n.
The range of m is suitable. If the thickness is less than 20 nm, the sheet resistance becomes electrically high, and it becomes difficult to utilize it as a good transparent conductive film. On the other hand, when the thickness is more than 200 nm, it is difficult to obtain a value of 80% or more as the light transmittance of the transparent conductive film at a wavelength of 550 nm, and the transparent conductive film is easily broken when bent, which makes the handling difficult.

As described above, the present invention has various characteristics such as transparency, optical isotropy, smoothness, solvent resistance, adhesion between layers including after durability test, gas barrier property, and little change in gas barrier property due to environment. In addition to being excellent, it realizes a transparent conductive film that has the feature that the curl of the laminated film is small.For example, it can be applied to transparent electrode substrates of liquid crystal panels that require high optical characteristics and durability. The present invention provides a transparent conductive film that can be widely applied to transparent conductive substrates such as electroluminescent panels, electrochromic panels, and surface heating elements.

Hereinafter, examples of the present invention will be described together with comparative examples. The evaluation of solvent resistance and adhesiveness in Examples and Comparative Examples was carried out in the following manner.

Regarding the organic solvent resistance, a few drops of N-methylpyrrolidone, which is a typical solvent for the liquid crystal alignment film precursor material, was dropped on the sample surface on the side where the solvent resistant layer was formed, and the temperature was set to 25 ° C.
It was evaluated by visually observing changes in appearance such as cloudiness, swelling, and dissolution after standing for 10 minutes, and when no change was confirmed, it was evaluated as having organic solvent resistance.

Regarding the resistance to 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 was dipped for a minute, then washed thoroughly with running water, dried, and visually observed for appearance. When no change was confirmed, it was evaluated as having alkaline 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, and water 1: 1: 1) was used.
(Mixed in a ratio of 0) at 25 ℃ for 10 minutes,
After that, it was washed sufficiently with running water, dried, and visually observed for appearance. When no change was confirmed, it was evaluated as having an acid aqueous solution resistance.

The adhesion was evaluated by the following cross-cut test (cross-cut tape method) in accordance with JIS standard 5400. That is, 1m in length and width on the surface of the test piece with a knife
Cuts are made at m intervals to form 100 grids.
A cellophane tape (product name: Cellophane tape manufactured by Nichiban Co., Ltd.) was adhered thereon, and then peeled off at a stretch in a direction of 90 degrees from the surface and evaluated by the number of eyes left on the surface. Therefore, 100/100 indicates perfect adhesion and 0/100 indicates complete peeling.

Example 1 A polycarbonate resin having an average molecular weight of 37,000 and containing bisphenol A alone as a bisphenol component was added to methylene chloride in an amount of 20% by weight.
Dissolved. Then, this solution was cast on a polyester film having a thickness of 175 μm as a support by a die coating method to form a film. Then, the polycarbonate film was dried in a drying oven until the residual solvent concentration of the polycarbonate film became 13% by weight, and the polycarbonate film was peeled from the polyester film. Next, this polycarbonate film was dried in a drying oven at a temperature of 120 ° C. while balancing the tensions in the length and width until the residual solvent concentration reached 0.08% by weight.

The polycarbonate film thus obtained had a thickness of 102 μm and a surface roughness Ra of 0.5 nm on the air side and 2.1 nm on the support side.

As a gas barrier layer on the air surface of this polycarbonate film, SiO was used as a vapor deposition source, and vacuum vapor deposition was performed at a vacuum degree of 67 mPa to give a thickness of 25 n.
m, a silicon oxide layer having an average atomic ratio of oxygen to silicon of about 1.7 was formed.

Subsequently, 1 is formed on the surface of the silicon oxide layer.
After performing corona treatment at a strength of 00 W · min / m ² , a solvent resistant layer was laminated as follows.

Vinyl trimethoxysilane (trade name: KBM100 manufactured by Shin-Etsu Chemical Co., Ltd.)
3) Add 148 parts by weight and stir vigorously to give
54 parts of 01N hydrochloric acid water was gradually added, and the mixture was slowly stirred for 3 hours to obtain a hydrolyzed solution of vinyltrimethoxysilane.

Next, trimethylolpropane triacrylate (trade name Aronix M-30 manufactured by Toagosei Kagaku Co., Ltd.)
9) 50 parts by weight, 100 parts by weight of the above-mentioned hydrolysis solution of vinyltrimethoxysilane, 10 parts by weight of unhydrolyzed vinyltrimethoxysilane, and 2-hydroxy-2-methyl-1-phenylpropane-as a photoinitiator. A coating liquid was prepared by mixing 8 parts by weight of 1-on (Dalocure 1173 manufactured by Merck & Co., Inc.) and 0.02 part by weight of silicone oil (trade name SH28PA manufactured by Toray Dow Corning Silicone Co., Ltd.) as a leveling agent.

This coating solution was coated on the silicon oxide layer using a bar coater, heated at 60 ° C. for 1 minute to volatilize and remove the residual solvent in the coating film, and then using a 160 W / cm high pressure mercury lamp. The coating film was cured by irradiating it with ultraviolet rays under the condition of an integrated light amount of 800 mJ / cm ² to form a solvent resistant layer having a thickness of 4 μm.

Next, an anchor coat layer and a polyvinyl alcohol resin layer were sequentially laminated on the film surface opposite to the laminated surface of the one-sided laminated film obtained above in the following manner.

The anchor coat layer was a phenoxy type cured resin layer. Specifically, 20 parts by weight of Fenototo YP-50 manufactured by Tohto Kasei Co., Ltd. as a phenoxy resin, 50 parts by weight of methyl ethyl ketone and 30 parts by weight of 2-ethoxyethyl acetate as a solvent were mixed, and then, as an isocyanate as a curing agent, Takeda Chemical Industries After coating a solution prepared by mixing 10 parts by weight of A3 manufactured by the company using a Meyer bar, a heat treatment was performed at 130 ° C. for 5 minutes to form a layer having a thickness of 1.5 μm, which was used as an anchor coat layer.

The polyvinyl alcohol resin layer is available from
Kuraray's polyvinyl alcohol (trade name PVA-11)
7) A solution obtained by heating and dissolving 10 parts by weight and 90 parts by weight of water was coated on the anchor coat layer using a Meyer bar, and heat-treated at 130 ° C. for 10 minutes to give polyvinyl alcohol having a film thickness of 2.5 μm. A resin layer was formed.

Then, a second solvent resistant layer having the same composition and the same film thickness was formed on the polyvinyl alcohol resin layer in the same manner as the above solvent resistant layer. Then, as a post heat treatment, a treatment was performed at 130 ° C. for 10 minutes.

The adhesion test result of the double-sided laminated film thus obtained was 100/100 on both sides of the film,
The adhesion between the layers was extremely good. In addition, the durability test of 90% RH at 60 ° C and 0% RH at 90 ° C is 25
The result of the adhesion test conducted after 0 hours was 100/10.
At 0, no deterioration in adhesion was observed.

Further, the double-sided laminated film was tested for acid solution resistance, alkali solution resistance, and organic solvent resistance. As a result, no change in appearance was observed and it was found to be excellent in solvent resistance. .

Further, the oxygen permeability of this double-sided laminated film was 0.1 cc / (m under the measurement conditions of 30 ° C. and 50% RH.
² · day · atm), 5 cc / (m ² · day · atm) under the measurement conditions of 30 ° C and 90% RH, and water vapor permeability of 3 g / (m ² · day) under the measurement conditions of 40 ° C and 90% RH.
It was found that the gas barrier property was excellent.

The curl was a very excellent value of -1 mm.

Next, a transparent conductive film was prepared by forming an indium-tin oxide layer as a transparent conductive layer on the silicon oxide layer side of this double-sided laminated film by the sputtering method as follows. The sputtering target is composed of indium and tin in a weight ratio of 9: 1 and a packing density of 90%.
Indium-tin oxide target was used. After setting this laminated film in the sputter device, 1.3mP
After exhausting to a pressure of a, the volume ratio of Ar to O ₂ is 9
A mixed gas of 8.5: 1.5 was introduced and the atmospheric pressure was adjusted to 0.
It was set to 27 Pa. The film temperature was 50 ° C., and DC sputtering was performed at an input power density of 1 W / cm ² to form an indium-tin oxide layer.

The transparent conductive layer obtained as a result was non-crystalline, with the abundance ratio of fine crystal grains being 0% in area ratio.
The film thickness is 130 nm and the surface resistance value is 40 Ω /
It was □. The light transmittance of this transparent conductive film at a wavelength of 550 nm was 84%, and the haze value was 0.4%. Further, the retardation value measured at any 10 points on the film was 8 ± 2 nm, and the slow axis was ± 8 degrees centered on the MD direction. Further, the surface roughness Ra of the transparent conductive layer surface
Was 4.6 nm. The adhesion test result is 100
/ 100, and the adhesiveness of the transparent conductive layer was also good.

Example 2 In the double-sided laminated film of Example 1, the thickness of the solvent resistant layer on the silicon oxide layer was 3 μm,
A double-sided laminated film having the same configuration except that the thickness of the solvent resistant layer on the back surface was 7 μm was prepared and evaluated in the same manner as in Example 1.

The adhesion test result was 100 on both sides of the film.
/ 100, and the adhesion between the layers was extremely good. Further, the result of the adhesiveness test conducted after 250 hours of the durability test of 60 ° C., 90% RH and 90 ° C., 0% RH was 100/100, and no deterioration of the adhesiveness was observed.
The curl was also good at +8 mm.

Example 3 In the double-sided laminated film of Example 1, the thickness of the solvent resistant layer on the silicon oxide layer was 6 μm,
A double-sided laminated film having the same configuration except that the thickness of the solvent resistant layer on the back surface was 4 μm was prepared and evaluated in the same manner as in Example 1.

The adhesion test result was 100 on both sides of the film.
/ 100, and the adhesion between the layers was extremely good. Further, the result of the adhesiveness test conducted after 250 hours of the durability test of 60 ° C., 90% RH and 90 ° C., 0% RH was 100/100, and no deterioration of the adhesiveness was observed.
The curl was also good at -6 mm.

[Comparative Example 1] A double-sided laminated film having the same structure as that of the double-sided laminated film of Example 1 except that the solvent-resistant layer on the back surface of the laminated surface of the silicon oxide layer was the following epoxy-based cured resin layer having a thickness of 7 μm. Was prepared and evaluated in the same manner as in Example 1.

The epoxy-based curable resin layer is specifically a novolac type epoxy-based curable resin cured product, and EPON-104S manufactured by Nippon Kayaku Co., Ltd. is used as the epoxy resin.
100 parts of this was dissolved in 150 parts of methyl ethyl ketone as a solvent, and 74 parts of methylhexahydrophthalic anhydride as an acid anhydride as a curing agent and 5 parts of 1,8-diazabicyclo (5,4,0) undecene as a catalyst were added. Apply the uniformly mixed coating solution with a Meyer bar and apply at 30 ° C at 30 ° C.
It was formed by heat treatment for minutes.

The adhesion test result of the obtained double-sided laminated film was 100/100 on both sides of the film, and the adhesion between the respective layers was extremely good. 60 ℃, 90% R
H and 90 ° C., 0% RH endurance test The result of the adhesion test conducted after 250 hours was 100/100, and no deterioration in adhesion was observed. However, curl
The value was as large as -25 mm, which exceeds the above-mentioned standard.

Comparative Example 2 In the double-sided laminated film of Example 1, a double-sided laminated film having the same constitution as that of the solvent-resistant layers on both sides was the same as that of Example 1 and the layer forming conditions were changed as follows. It was prepared and evaluated in the same manner as in Example 1.

The solvent resistant layer on the silicon oxide layer is formed 60 times after coating.
After heating at ℃ for 1 minute to volatilize and remove the residual solvent in the coating film, a 160 W / cm high-pressure mercury lamp was used to add 2
The coating film was cured by irradiating it with ultraviolet rays under the condition of 400 mJ / cm ² to form a solvent resistant layer having a thickness of 1 μm. On the other hand, the solvent resistant layer on the back surface was set under the same curing conditions as in Example 1, and only the thickness thereof was changed to 4 μm.

The solvent-resistant layer on the silicon oxide layer of the obtained double-sided laminated film was sticky, and the surface was roughened in any of the organic solvent resistance test, alkali solution test and acid solution test, and the solvent resistance The sex became insufficient.

[Comparative Example 3] In the double-sided laminated film of Example 1, the thickness of the solvent resistant layer on the silicon oxide layer was 11 μm.
m, and a double-sided laminated film having the same structure except that the thickness of the solvent resistant layer on the back surface was 4 μm was prepared and evaluated in the same manner as in Example 1.

The results of the adhesion test showed that the solvent resistant layer on the silicon oxide layer was 0/100 immediately after the layer was prepared, which was completely inadequate. Further, the curl was -30 mm, which greatly exceeded the above-mentioned standard.

[Comparative Example 4] In the double-sided laminated film of Example 1, the thickness of the solvent resistant layer on the silicon oxide layer was 3 μm,
A double-sided laminated film having the same structure except that the thickness of the solvent resistant layer on the back surface was 9 μm was prepared and evaluated in the same manner as in Example 1.

The adhesion test result was 100 on both sides of the film.
/ 100, and the adhesion between the layers was extremely good. Further, the result of the adhesiveness test conducted after 250 hours of the durability test of 60 ° C., 90% RH and 90 ° C., 0% RH was 100/100, and no deterioration of the adhesiveness was observed.
However, the curl exceeds the above-mentioned standard by +24 mm
Met.

From the results of Comparative Examples 3 and 4, it can be seen that even if the composition is the same, the curl becomes insufficient when the film thickness ratio of the solvent resistant layers on both sides is as large as 2.5 times or more.

[0101]

INDUSTRIAL APPLICABILITY According to the present invention, a cured layer of a resin composition obtained by mixing the above-mentioned specific hydrolyzate of alcosilane having good adhesion with a metal oxide layer and a radiation curable resin is provided on the metal oxide layer side and Various properties such as transparency, optical isotropy, smoothness, solvent resistance, adhesion between layers including after endurance test, gas barrier property, and little change in gas barrier property due to environment due to the configuration provided on both surfaces on the opposite side. The present invention provides a transparent conductive film which is excellent in curl and has little curl, and provides a transparent conductive film suitable for a transparent electrode substrate of a liquid crystal panel that requires high optical characteristics and durability. In addition, it is widely applicable to electroluminescent panels, electrochromic panels, transparent conductive substrates such as surface heating elements, and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01B 5/14 H01B 5/14 A

Claims (7)

[Claims] 1. A transparent conductive film in which at least a gas barrier layer, a solvent resistant layer, and a transparent conductive layer are provided on a plastic film, which is represented by the radiation curable resin (A) and the following general formula (1) or (2). The alkoxysilane hydrolyzate (B) has a ratio of A: B of 2 by weight of the solid content.
A solvent resistant layer made of a cured film of a resin composition mixed so as to be in the range of 0: 1 to 1: 3 is provided on both sides, and a gas barrier layer made of a metal oxide is provided as an underlayer of at least one of the solvent resistant layers. A transparent conductive film, comprising: a transparent conductive layer provided on at least one outermost surface thereof. Embedded image R ¹ —Si (OR ² ) ₃ (1) Si (OR ² ) ₄ (2) (In the above formula, R ¹ is a methyl group, an ethyl group or a vinyl group, an acryloyl group, a methacryloyl group, an amino group. , An organic group containing an epoxy group, and R ² represents a methyl group or an ethyl group.) 2. The film thickness df of the solvent-resistant layer on the gas barrier layer side of the metal oxide and the film thickness dr of the solvent-resistant layer on the opposite side thereof are both 2 to 8 μm, and the ratio dr / df is 0. 4-
The transparent conductive film according to claim 1, which is 2.5. 3. The transparent conductive film according to claim 1, wherein the metal oxide has a film thickness of 5 to 100 nm. 4. The transparent conductive film according to claim 1, wherein the metal oxide is a silicon oxide having a ratio of the number of oxygen atoms to the number of silicon atoms of 1.5 to 2.0. 5. An anchor coat layer and a polyvinyl alcohol resin layer are first provided on the plastic film surface of the metal oxide opposite to the gas barrier layer side, and the solvent resistant layer is provided thereon. 4. The transparent conductive film according to any one of 4. 6. A transparent conductive film having a retardation value of 20 nm or less and a light transmittance of 80% at a wavelength of 550 nm.
It is above, The transparent conductive film in any one of Claims 1-5. 7. The transparent conductive film according to claim 1, wherein the plastic film is a plastic film having a thickness of 70 to 200 μm formed by a solution casting method.