JPH08211374A - Transparent conductive film - Google Patents

Abstract

PURPOSE: To obtain a transparent conductive film having total durability against solvents, excellent adhesion property, and sufficient air permeability resistance, surface smoothness and optical characteristics by using hardened layers of each specified resin as an anchor coating layer and a solvent-resistant layer. CONSTITUTION: An anchor coating layer, glass barrier layer, solvent-resistant layer and transparent conductive layer are formed on a polymer film. The anchor coating layer is formed by thermally hardening a thermally crosslinking resin prepared by mixing phenoxy-base resin selected from phenoxy resin, phenoxyether resin and phenoxyester resin having a repeating unit expressed by formula and a polyfunctional isocyanate compd. having two or more isocyanate groups. The solvent-resistant layer is formed by hardening a crosslinking resin comprising a novolac type epoxy resin or silicone base resin. In formula, R<1> -R<6> are hydrogen or C1-C3 alkyl groups, R<7> is C2-C5 alkylene group, X is an ether group or ester group, (m) is an integer 0 to 3 and (n) is an integer 20 to 300.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a polymer film (also called a plastic film), an anchor coat layer,
Regarding a transparent conductive film provided with a gas barrier layer, a solvent resistant layer, and a transparent conductive layer, more specifically, it has good air permeation resistance and oxygen vapor resistance against oxygen, nitrogen, carbon dioxide, etc., which are the main components of air. In addition to being excellent, the invention relates to a highly reliable transparent conductive film that does not deteriorate even when subjected to mechanical, thermal, and solvent influences, a liquid crystal display panel, a photoconductive photosensitive member, a surface heating element, The present invention relates to a transparent conductive film that can be applied to transparent electrodes of organic electroluminescence, touch panels, solar cells, etc., and is suitable for transparent electrodes of liquid crystal display panels, which are particularly demanding in terms of display quality and durability.

[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, conventional transparent, thick, heavy, and fragile glass substrates are used for transparent electrodes. Instead, a liquid crystal panel using a transparent conductive film having a plastic film as a substrate has been studied, and some have begun to put it into practical use.

The transparent conductive film of such a plastic substrate satisfies the demand for lightness and thinness, and is disclosed in Japanese Patent Laid-Open No. 56-130.
No. 010, etc., and its basic laminated structure is known.

[0004]

Although the transparent electrode substrate of the transparent conductive film of the conventional plastic substrate satisfies the requirements of lightness and thinness, freedom of shape, and curved surface display as compared with that of the glass substrate, it is durable. It has the drawbacks of poor air permeability, water vapor permeation resistance, smoothness, flatness, optical properties, and long-term reliability.

When a transparent electrode substrate having inferior air permeation resistance and water vapor permeation resistance is used, in the case of a liquid crystal display panel, air and water vapor permeate into the liquid crystal part to generate bubbles, resulting in a display-incapable point. Display quality is deteriorated. Especially, under severe conditions such as vehicle mounting, this defect easily occurs and becomes a serious problem.

Further, when the smoothness and flatness are low, the gap of the liquid crystal layer is not uniform, and the substrate itself also has optical unevenness, which naturally causes unevenness in the display color, and moreover, it is uniform. It no longer exhibits voltage transmittance characteristics. In particular, when the thermal durability of the liquid crystal panel electrode substrate is low, the flatness is likely to be lost, which becomes a serious problem under severe conditions such as vehicle mounting.

Further, when the substrate itself has birefringence,
The display quality of the display is deteriorated due to the coloring of the display and deterioration of the contrast.

These are because the liquid crystal display panel follows the principle of electrically switching the polarization direction in the liquid crystal layer in order to exhibit the display function.

In order to solve these problems, Japanese Unexamined Patent Publication No.
In Japanese Patent Laid-Open No. 1-41122, Japanese Patent Laid-Open No. 63-71829, Japanese Patent Laid-Open No. 3-9323, and the like, plastic substrates to which various functions are added have been proposed. However, although the plastic substrates proposed to them have their respective effects, the overall durability against various solvents used for electrode processing, the adhesiveness between the plastic film of the substrate and the layer above it. However, the current situation is that they are not sufficient.

The present invention has been made in view of the above circumstances, and is excellent in overall durability and adhesiveness to the above-mentioned solvents, and is also excellent in other air permeation resistance, surface smoothness, and optical characteristics, and comparable to a glass substrate. It is an object of the present invention to provide a transparent conductive film of a plastic substrate which can be used for a liquid crystal display panel without any means.

[0011]

The above object can be achieved by the present invention described below. That is, the present invention, on a polymer film, an anchor coat layer, a gas barrier layer, a solvent resistant layer, in a transparent conductive film provided with a transparent conductive layer,
The anchor coat layer is a polyfunctional isocyanate containing at least one phenoxy resin selected from a phenoxy resin, a phenoxy ether resin, and a phenoxy ester resin composed of a repeating unit represented by the following general formula (A) and two or more isocyanate groups. It is a layer obtained by thermosetting a thermally crosslinkable resin mixed with a compound, and the solvent resistant layer is a layer obtained by curing a crosslinkable resin composed of a novolac type epoxy resin or a silicone resin. Is a transparent conductive film.

[0012]

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(Wherein R ¹ to R ⁶ are the same or different hydrogen or an alkyl group having 1 to 3 carbon atoms, R ⁷ is an alkylene group having 2 to 5 carbon atoms, X is an ether group, an ester group, and m is An integer of 0 to 3 and n is an integer of 20 to 300.) Hereinafter, the present invention will be described in detail.

When a transparent conductive film is used as a transparent electrode substrate for a large-sized liquid crystal display panel, which is the most demanding, when a fine display is performed by simple matrix driving, coloration of the display and reduction of contrast are suppressed, and the hue of the panel is uneven. In order to reduce the above, the polymer film has a retardation value of 30 nm or less, and an optical isotropy in which the variation of the slow axis is within ± 30 degrees, and further the retardation value is 20 nm or less. Further, those having a high degree of optical isotropy in which the variation of the slow axis is within ± 15 degrees are preferable. The thickness of the polymer film is preferably 70 to 200 μm, although it depends on the application.

It is possible to obtain a film satisfying the above-mentioned optical characteristics by a general film forming method such as a melt extrusion method and a solution casting method. Among them, particularly in the solution casting method, this highly isotropic polymer film having a high optical isotropy, that is, a retardation value of 20 nm or less, and a slow axis variation of ± 15 degrees or less. Is preferably used because it can be produced.

The retardation value described here is the product Δnd of the known difference Δn in birefringence and the film thickness d.
It is necessary that the measured value is at a wavelength in the visible light range, and since plastic generally has wavelength dispersion characteristics of refractive index, the measured value is 590 nm as a typical value. 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, a multi-wavelength birefringence measuring device M- manufactured by JASCO
It can be easily measured at 150 or the like.

The material for the polymer film of the present invention includes:
Polyarylate, polycarbonate and the like which satisfy the above optical characteristics are preferably used.

Of these, polycarbonate is preferable from the viewpoint of optical characteristics and thermal characteristics. Generally, the higher the average molecular weight, the higher the glass transition temperature. In addition, mechanical characteristics are improved. From such a viewpoint, among polycarbonates, a polycarbonate which is composed of a bisphenol component consisting only of bisphenol A and has a molecular weight of 30,000 or more and a glass transition temperature of 150 ° C. or more is preferable. In order to improve heat resistance, for example, 9,9 bis (4-hydroxyphenyl) fluorene or 1,1 bis (4-hydroxyphenyl) 3,3,5-trimethylcyclohexane is added as a copolymerization component. It doesn't matter. 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.

The gas barrier layer of the present invention has a thickness of 100 μm or less which does not impair practical flexibility as the thickness of the barrier layer,
The oxygen transmission rate required for electrode substrates for liquid crystal display panels is 1
It is preferable that the basic characteristics of cc / square meter · day · atm or less and water vapor transmission rate of 20 g / square meter · day · atm or less can be achieved. From this point, a polymer resin containing 50 mol% or more of at least one selected from the group consisting of an acrylonitrile component, a vinyl alcohol component, a vinyl alcohol copolymer component, and a vinylidene halide component is preferably applied.

Further, among these polymer resins, when the acrylonitrile component is present, the selectivity of the solvent is limited, and when the vinylidene halide component is present, halogen is generated during incineration, and the workability and the environment are high. From the viewpoint of problems, polyvinyl alcohol-based resins, particularly polyvinyl alcohol-based resins containing at least 50 mol% or more of a vinyl alcohol component and a vinyl alcohol copolymer component are particularly preferable. The vinyl alcohol copolymer may, for example, be a vinyl alcohol-vinyl acetate copolymer, a vinyl alcohol-vinyl butyral copolymer or an ethylene-vinyl alcohol copolymer.

The oxygen transmission rate here means MOCON.
Value measured at 25 ° C. using Oxytran 2/20 MH manufactured by Mfg. Co., Ltd.
It is a value measured using A at 25 ° C. and 90% RH.

As the anchor coat layer used to improve the adhesion between the polymer film and the gas barrier layer, polyurethane resin, water-soluble polyester or the like has been generally used conventionally. However, after the anchor coat layer is formed, the tackiness and tackiness of the surface, which are said to be tackiness, often cause problems in winding the film, and an anchor coat layer that does not retain tackiness at the time of film formation is desired.

From this point of view, in the present invention, the anchor coat layer is represented by the following general formula A in which a tack-free surface can be obtained by a heat treatment for a relatively short time of about 15 minutes, and if necessary, about 5 minutes. Of a phenoxy resin, a phenoxy ether resin, or a phenoxy ester resin composed of repeating units, and a heat-crosslinkable resin obtained by mixing a polyfunctional isocyanate compound containing two or more isocyanate groups with each other. The layer thus obtained is used.

[0025]

[Chemical 4]

Here, R ¹ to R ⁶ are the same or different hydrogen or an alkyl group having 1 to 3 carbon atoms, R ⁷ is an alkylene group having 2 to 5 carbon atoms, X is an ether group, an ester group, and m is 0. To 3 and n is an integer from 20 to 300.

Among them, R ¹ and R ² are methyl groups, R ³ and R
⁴ , R ⁵ and R ⁶ are hydrogen and R ⁷ is a pentylene group,
It is preferable from the viewpoint of easy synthesis and cost.

Examples of the polyfunctional isocyanate compound containing two or more isocyanate groups include the following.

2,6-tolylene diisocyanate, 2,
4-tolylene diisocyanate, tolylene diisocyanate-trimethylolpropane adduct, t-cyclohexane-1,4-diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate,
Hexamethylene diisocyanate, 1,3,6-hexamethylene triisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane-4,
4'-diisocyanate, hydrogenated diphenylmethane-4,
4'-diisocyanate, lysine diisocyanate, lysine ester triisocyanate, triphenylmethane triisocyanate, tris (isocyanatophenyl) thiophosphate, m-tetramethylxylylene diisocyanate, p-tetramethylxylylene diisocyanate, 1,6,11- Undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyl octane, bicycloheptane triisocyanate,
Examples thereof include polyisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate, mixtures thereof, and polyhydric alcohol adducts.

Of these, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, tolylene diisocyanate-trimethylolpropane adduct and hexamethylene diisocyanate are particularly preferred from the viewpoints of versatility and reactivity.

The thermoplastic resin of the present invention can be obtained by mixing the above phenoxy resin with a polyfunctional isocyanate compound. At that time, a solvent capable of dissolving both of them, for example, methyl ethyl ketone, methyl isobutyl ketone, cellosolve acetate, ethyl acetate, etc. may be dissolved and mixed to obtain a heat-crosslinkable resin solution suitable for coating. Then, this heat-crosslinkable resin solution is formed on a plastic film by a wet coating method and cured by heat treatment to form a tack-free anchor coat layer having good adhesion to a gas barrier layer such as a polyvinyl alcohol-based resin layer. Obtainable.

By the way, it is important that the thermally crosslinkable resin of the present invention is a mixture in which a phenoxy resin and a polyfunctional isocyanate compound are present at the same time. Adhesion decreases as the phenoxy resin becomes closer to itself. On the other hand, when the polyfunctional isocyanate compound is close to a single compound, the resulting anchor coat layer does not easily crosslink or polymerize, and thus becomes brittle or remains in a liquid state. The coat layer is easily broken, and it becomes difficult to stack a gas barrier layer having a uniform film thickness and optical characteristics.

From this point of view, that is, the adhesiveness and the tackiness of the surface of the obtained anchor coat layer, the composition ratio of the phenoxy resin to the polyfunctional isocyanate compound is such that the polyfunctional isocyanate is the number of moles of hydroxyl groups in the phenoxy resin. A value obtained by dividing the number of moles of isocyanate in the compound [NCO / OH] is preferably 0.2 or more and 3 or less.

The adhesiveness is JIS-K-711.
The peel strength between the plastic film and the polyvinyl alcohol-based resin layer measured at 25 ° C. by the T-peel test of 3 standards is evaluated. If this value is 150 g / cm or more, it may indicate interfacial peeling in a durability test or the like. From the point that no deterioration was observed, 150 g / cm was taken as the standard, and above this was considered good adhesion.

Below that, the adhesiveness between the polymer film and the organic gas barrier layer is not sufficient, and for example, in the durability test, the adhesive peeling test of cellophane tape or the like easily peels off. In such a laminated film, peeling occurs in the manufacturing process of the liquid crystal cell, resulting in poor appearance and poor reliability.

The tackiness was evaluated as follows. That is, it was evaluated by touching with a finger, or by bringing the anchor coat layers into close contact with each other or with the anchor coat layer and another plastic film, and whether or not the close contact state was maintained.

The solvent resistant layer is conventionally a phenoxy resin,
Phenoxyether resin, phenoxyester resin, acrylic resin, melamine resin, phenol resin, urethane resin and other heat-crosslinkable resin crosslinked products are used, but sufficient for alkaline liquids and organic solvents exposed during liquid crystal display device fabrication. Satisfactory solvent resistance has not yet been obtained.

In the solvent resistant layer of the present invention, a layer obtained by curing a crosslinkable resin made of a novolac type epoxy resin or a silicone resin satisfying the solvent resistance is used.

As the novolac type epoxy resin, the novolac type epoxy resin represented by the following general formula (B) is preferably applied from the viewpoint of desired solvent resistance.

[0040]

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Here, R ¹ is H or CH ₃ , R ² and R ³ are H or glycidyl phenyl ether groups, and n is 1
Is an integer from 50 to 50.

N has a distribution in general, and a certain number cannot be specified, but it is preferable that the average number is large.
It is preferably 3 or more, more preferably 5 or more.

As the curing agent for curing the novolac type epoxy resin, known curing agents such as amine-based, polyaminoamide-based, acid and acid anhydride, imidazole and polymercaptan are used, and particularly, solvent resistance and optical properties are used. Acid anhydrides and alicyclic amines are preferably used because of their thermal properties, and acid anhydrides are particularly preferable.

As acid anhydrides, alicyclic acid anhydrides such as methylhexahydrophthalic anhydride and methyltetrahydrophthalic anhydride, aromatic acid anhydrides such as phthalic anhydride, and aliphatic acids such as dodecenylsuccinic anhydride An acid anhydride can be mentioned, but methylhexahydrophthalic anhydride is preferably used. When using an acid anhydride, it is preferable to add an appropriate amount of a known curing catalyst such as a tertiary amine in order to increase the reaction rate.

Examples of the alicyclic amine include bis (4-amino-3-methyldicyclohexyl) methane, diaminodicyclohexylmethane and isophoronediamine. Among them, bis (4-amino-3-methyldicyclohexyl) methane is used. It is preferably used.

As the silicone-based resin, various known silicone-based resins can be applied, but among them, those containing 40% by weight or more of trialkoxysilane are preferable.
If the content of trialkoxysilane is less than 40% by weight and the content of tetraalkoxysilane is large, the obtained layer becomes too hard and cracks occur in the layer, and the flexibility deteriorates. Further, if the amount of dialkoxysilane or monoalkoxysilane increases, the desired solvent resistance becomes insufficient.

Here, as the trialkoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane,
Vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, N-β ( Aminoethyl) γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane and the like.

Other components include tetraalkoxysilane, dialkoxysilane, monoalkoxysilane, colloidal silica and the like. Examples of the tetraalkoxysilane include methyl silicate, ethyl silicate, propyl silicate and the like. Examples of dialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, and diethyldimethoxysilane, and examples of monoalkoxysilanes include trimethylmethoxysilane.

The silicone resin of the present invention is an acrylic resin, a polyurethane resin, an epoxy resin, a melamine resin, a polyvinyl alcohol resin, a urea resin, etc. from the viewpoint of improving the adhesiveness, etc. within the range of not impairing the transparency. Can be added. This trialkoxysilane is 4
To the silicone-based curable resin containing 0% or more, it is preferable to add an acidic aqueous solution such as hydrochloric acid or acetic acid in order to further accelerate the curing. Further, the composition can be diluted with a volatile solvent, and examples of the solvent include alcohols, esters, ethers, ketones, and mixed solvents thereof.

Epoxy resins and silicone resins have high solvent resistance to various organic solvents, and prevent intrusion of organic solvents from the outside and abnormalities such as cloudiness of the polymer film of the substrate caused by the penetration. be able to. Furthermore, due to its high solvent resistance, it is possible to expand the range of use of the solvent used in the manufacturing process of liquid crystal cells and the like.

As a means for forming each of the above functional layers,
Known coating means such as a Meyer bar coating method, a gravure roll coating method, a wet coating method such as a spin coating method, a depping method, and a laminate coating method can be applied.
The wet coating method is preferable for the present invention because the film forming conditions can be easily controlled from the viewpoint of forming a uniform film thickness.

As described above, the adhesion between the respective layers such as the polymer film and the gas barrier layer is good, and the gas such as oxygen,
A laminated film having sufficient durability against water, organic solvent, etc., high surface hardness, and excellent mechanical properties such as scratch resistance can be obtained.

The transparent conductive film of the present invention can be obtained by forming a transparent conductive layer on the above laminated film.

For the transparent conductive layer, known tin, indium,
Metals such as titanium or oxides of these can be applied,
A material mainly composed of amorphous indium oxide, containing 5 to 15% by weight of tin as a constituent component thereof, and having a film thickness of the transparent conductive layer in the range of 20 to 200 nm has good transparency, conductivity, and conductivity. It is preferable in terms of flexibility and the like.

Highly crystalline indium oxide is preferable as an electrode material because it has high transparency and conductivity as compared with an amorphous material, but a crystalline film is formed on a highly flexible polymer film, When this laminated film is bent, it breaks easily and the handleability becomes poor.

Here, the crystallinity and non-crystallinity of the formed indium oxide are defined as follows. When the surface of the formed indium oxide is observed with a transmission electron microscope, a microcrystal having a diameter of at most about 100 nm is observed on the surface of the amorphous film. In this observation method, the case where the crystal grain area per unit area (100 μm ² ) is 20% or less is defined as amorphous.

Although indium oxide is originally a transparent electric insulator, it becomes a semiconductor when it contains a trace amount of dopant or when it is slightly oxygen-deficient. As a preferable semiconductor metal oxide, an indium oxide containing tin or fluorine as a dopant can be mentioned, and particularly preferably, an indium oxide containing 5 to 15% by weight of tin, while maintaining high transparency, Shows good conductivity.

The thickness is 20 to 200.
The nm range 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 electrode substrate for liquid crystal panels. On the other hand, when the thickness is more than 200 nm, it becomes difficult to obtain a value of 80% or more as the transmittance of the substrate at 550 nm, and the substrate is easily cracked when bent and is difficult to handle.

Further, in a display element such as STN, in which liquid crystal orientation is particularly large and exerts influence on display, smoothness and flatness are important. Specifically, the surface roughness of the transparent conductive layer of the electrode substrate for the liquid crystal panel is important. Is 40 nm or less in Ra value, and further 2
It is preferably 0 nm or less.

Here, the Ra value of the surface roughness is the TOPO- manufactured by WYCO, which uses the phase shift interferometry as a measurement principle.
The center line average roughness Ra obtained by measuring a square surface having a side length of 256 μm on the surface of the film at a magnification of 40 times at an interval of 1 μm using 3D is shown.

By the way, as a result of detailed examination of the polymer film formed by the solution casting method, in which the solution of the above-mentioned raw material polymer is cast on a support such as a belt or a film to form a film, It has been found that the air surface exposed to air during the production of the molecular film has particularly good smoothness and flatness. Specifically, it was possible to obtain a Ra value of 1 nm or less on the air surface side. It was not possible to obtain an Ra value of 1 nm or less on the surface of the support on the side opposite to the air surface which was in contact with the support during manufacturing.

Therefore, in order to obtain an electrode substrate for a liquid crystal display panel having extremely high smoothness and flatness of the electrode surface, a transparent conductive layer is formed on the air surface of the polymer film formed by the solution casting method. It is preferably formed.

In the above-mentioned transparent conductive film of the present invention, various constitutions are possible for the laminated constitution of each layer of the anchor coat layer, the gas barrier layer, the solvent resistant layer and the transparent conductive layer. Specifically, 1 is a polymer film, 2 is an anchor coat layer, 3 is a gas barrier layer, 4 is a solvent resistant layer, and 5 is a transparent conductive layer.
Then, 5/4/1/2/3/4, 5/4/1/2
/ 3/4/2, 5/4/2/1/2/3/4, 5/4 /
2/1/2/3/2/4, 5/4/3/2/1/2/3
/ 4, 5/4/2/3/2/1/2/3/2/4, 5 /
4/3/2/1/4, 5/4/2/3/2/1/4, 5
/ 4/3/2/1/2/4, 5/4/2/3/2/1 /
2/4 etc. are mentioned as a preferable laminated constitution.

Examples will be described below together with comparative examples. In Examples and Comparative Examples, “part” means “part by weight”. Further, each numeral indicating the laminated constitution is the same as that of the laminated constitution described above.

[0065]

【Example】

[Example 1] Using a polycarbonate resin having an average molecular weight of 37,000 in which the bisphenol component was bisphenol A alone, a polycarbonate film was produced by the solution casting method as follows.

That is, the polycarbonate resin was dissolved in methylene chloride in an amount of 20% by weight. Then, this solution was cast on a polyester film having a thickness of 175 μm by a die coating method to form a film. Next, the solvent was removed by evaporation in a drying oven until the residual solvent concentration reached 13% by weight, and then the polycarbonate 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 obtained polycarbonate film has a thickness of 102 μm and a surface roughness Ra of 0.5 n on the air side.
m, the support surface was 2.1 nm. The retardation value of this film at 590 nm was 8 ± 2 nm in the axial direction, and the variation of the slow axis was ± 8 centered in the MD direction.
It was within the degree.

An anchor coat layer, a gas barrier layer and a solvent resistant layer were sequentially laminated on the support surface of this polycarbonate film as follows.

The anchor coat layer is a phenoxy resin,
Phenoxy resin Fenotote YP manufactured by Tohto Kasei Co., Ltd.
50 parts by weight, 90 parts by weight diacetone alcohol, and 10 parts by weight of Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd. as an isocyanate compound ([NCO / OH] = 1.
0) is coated on a polycarbonate film and the temperature is 130 ° C.
It was formed by heat treatment for 10 minutes. The surface of the obtained anchor coat layer had no tackiness.

The gas barrier layer is made of polyvinyl alcohol resin and polyvinyl alcohol PVA-made by Kuraray Co., Ltd.
A solution of 117 dissolved in 12 parts of water and 88 parts of water was applied onto the anchor coat layer, and heat-treated at 110 ° C. for 30 minutes to form a film.

The solvent-resistant layer was a cresol novolac type epoxy resin, and a solution of 100 parts of cresol novolac type epoxy resin EOCN-104S manufactured by Nippon Kayaku Co., Ltd. and 100 parts of methyl ethyl ketone was mixed with 74 parts of methylhexahydrophthalic anhydride. Part, 1,8-diazabicyclo (5,4,0) undecene (5 parts) was uniformly mixed and applied onto the gas barrier layer, and the mixture was applied at 100 ° C. for 3 minutes, and further 13
It was formed by heat treatment at 5 ° C. for 60 minutes.

The thickness of each layer is 3 μm for the anchor coat layer,
The organic gas barrier layer had a thickness of 6 μm, and the solvent resistant layer had a thickness of 8 μm.

Then, only the solvent resistant layer having the same constitution as the above solvent resistant layer was laminated on the air surface on the other side of the obtained laminated film, and then an indium-containing transparent conductive layer was formed thereon. The tin oxide layer was formed by the sputtering method.

As a sputtering target therefor, an indium-tin oxide target having a composition of indium / tin = 90/10 by weight and a packing density of 90% was used.
Then, set the laminated film in the continuous sputtering device,
Ar / O ₂ = 9 after exhausting to a pressure of 1.3 mPa
A gas having a volume mixing ratio of 8.5 / 1.5 was introduced and the atmospheric pressure was set to 0.27 Pa. And the laminated film temperature is 5
The temperature was set to 0 ° C., and DC sputtering was performed at an input power density of 1 W / square cm.

The transparent conductive layer obtained as a result was non-crystalline, with the area ratio of crystal grains being 0%. The thickness was 130 nm, the surface roughness Ra was 3.7 nm, and the surface resistance value was 40Ω in the square measurement in which the electrodes were arranged on the opposite sides of the unit square. Hereinafter, this surface resistance value is shown by Ω / □.

In this way, the laminated structure is 5/4/1/2 /
A transparent conductive film of 3/4 was obtained. This transparent conductive film has a light transmittance of 85% at 550 nm, a haze value of 0.5%, an oxygen transmittance of 0.1 cc / square meter.day.atm, and a water vapor transmission rate of 9 g / square meter.day. The peel strength between the atm and the film and the gas barrier layer was 600 g / cm.

When this transparent conductive film was cut with a cutter knife, cellophane tape was adhered to the cut portion from the protective layer side, and peeled from the cut portion, no delamination was observed.

A sample having a width of 1 cm and a length of 10 cm was cut out and subjected to a bending resistance test. The test was performed by winding a transparent conductive layer on the outside and the inside of a 1 cmφ metal rod 180 degrees,
After maintaining that state for 1 minute, visual observation was performed. As a result, no change in appearance of the transparent conductive layer was observed.

Next, the coloring property between the polarizing plates of this transparent conductive film was examined. First, a 5 cm square sample was cut out. Then, this sample was sandwiched between a pair of polarizing plates, and one polarizing plate and further the sample were rotated to visually observe a change in color. As a result, no color change was visually observed.

Next, a solvent resistance test was conducted. 5% KOH
Water and acetone were immersed in each solution under the conditions of 25 ° C. for 10 minutes and N-methylpyrrolidone at 80 ° C. for 3 minutes, but no change was observed.

Further, when heat treatment was carried out at 130 ° C. for 4 hours, there was no change in warpage and no change in appearance. As a result of examining the rate of change in resistance before and after the heat treatment, the resistance value after the test / initial resistance value = 1.2, and the resistance value did not change significantly.

An STN liquid crystal cell was prepared by using this transparent conductive film as a transparent electrode substrate and the display performance was observed, but the contrast was good and no color unevenness was observed during operation.

Further, a reliability test was conducted on this liquid crystal cell. Two types of reliability tests were performed: a heat resistance test at 90 ° C. for 1000 hours and a humidity resistance test at 60 ° C. and 90% RH for 1000 hours. As a result, no change in appearance and display performance was observed.

As described above, the obtained transparent conductive film had sufficient performance as a transparent electrode for a liquid crystal display panel.

Example 2 Example 1 is the same as Example 1 except that the same anchor coat layer as in Example 1 is provided between the polycarbonate film on the transparent conductive layer side and the solvent resistant layer.
The same structure as, that is, the laminated structure is 5/4/2/1/2 /
A 3/4 transparent conductive film was produced.

The transparent conductive film obtained was 550 n
The light transmittance at m is 85%, the haze value is 0.5%, and the oxygen transmittance is 0.1 cc / square meter · day · atm,
The water vapor transmission rate was 9 g / square meter.day.atm, and the peel strength between the film and the gas barrier layer was 600 g / cm.

When the same tests as in Example 1 were carried out on this transparent conductive film, the same results as in Example 1 were obtained in all cases.

Example 3 The same structure as in Example 2 except that the same gas barrier layer as in Example 1 was provided between the anchor coat layer on the transparent conductive layer side and the solvent resistant layer in Example 2,
That is, a transparent conductive film having a laminated constitution of 5/4/3/2/1/2/3/4 was produced.

The transparent conductive film obtained was 550 n
The light transmittance at m is 85%, the haze value is 0.7%, and the oxygen transmittance is 0.1 cc / square meter · day · atm,
The water vapor transmission rate was 7 g / square meter.day.atm, and the peel strength between the film and the gas barrier layer was 600 g / cm.

When the same tests as in Example 1 were carried out on this transparent conductive film, the same results as in Example 1 were obtained in all cases.

Example 4 A transparent conductive film having the same structure as in Example 1 except that the anchor coat layer had the following composition was prepared.

The composition of the phenoxy resin of the anchor coat layer was 20 parts of phenoxy resin and 40 parts of methyl ethyl ketone.
And 20 parts of 2-ethoxyethyl acetate were mixed, and 5 parts of polyfunctional isocyanate was added to the composition. At this time, NCO / OH was 0.25. The heat treatment conditions were the same as in Example 1, and an undercoat layer having no tackiness on the surface could be formed.

Optical characteristics of the obtained transparent conductive film,
The air resistance and water vapor resistance were the same as in Example 1. The peel strength was 580 g / cm, indicating good adhesion.

The cellophane tape peeling test, bending resistance test, colorability test, solvent resistance test, heat treatment test, and liquid crystal cell test were almost the same as in Example 1, and there were no problems.

Example 5 A transparent conductive film having the same structure as in Example 1 except that the anchor coat layer had the following composition was prepared.

The composition of the phenoxy resin of the anchor coat layer was 20 parts of phenoxy resin and 40 parts of methyl ethyl ketone.
And 20 parts of 2-ethoxyethyl acetate were mixed, and 58 parts of polyfunctional isocyanate was added to the mixture. At this time, NCO / OH was set to 2.9. The heat treatment conditions were the same as in Example 1, and an undercoat layer having no tackiness on the surface could be formed.

Optical characteristics of the obtained transparent conductive film,
The air resistance and water vapor resistance were the same as in Example 1. The peel strength was 270 g / cm, indicating good adhesion.

The cellophane tape peeling test, flex resistance test, colorability test, solvent resistance test, heat treatment test, and liquid crystal cell test were almost the same as in Example 1, and there were no problems.

Example 6 A transparent conductive film having the same structure as in Example 1 was prepared except that the solvent resistant layer had the following composition.

The solvent resistant layer was 18 g of γ-aminopropyltrimethoxysilane and 14.8 of methyltrimethoxysilane.
g, dimethyldimethoxysilane 2.6 g and 0.01N
Hydrochloric acid (11.5 g) was added, and the mixture was stirred for 3 hours while maintaining the temperature at 20 ° C to prepare a coating solution of a silicone resin. This coating liquid was applied by a Meyer bar and heat-treated at 135 ° C. for 10 minutes to form a film. The thickness of the solvent resistant layer was 3.5 μm.

The transparent conductive film obtained had a thickness of 500 n.
The light transmittance at m was 87%, the haze value was 0.4%, and the oxygen transmittance, water vapor transmittance and peel strength were the same as in Example 1.

The cellophane tape peeling test, bending resistance test, colorability test, solvent resistance test, heat treatment test, and liquid crystal cell test were almost the same as in Example 1, and there were no problems.

Comparative Example 1 A transparent conductive film having the same structure as in Example 1 was prepared except that the anchor coat layer was changed to the following in Example 1.

The anchor coat layer was made of polyurethane resin, and a mixture of 100 parts of A310 manufactured by Takeda Pharmaceutical Co., Ltd. as a polyol component of the main ingredient and 25 parts of A3 manufactured by the same company as a polyfunctional isocyanate compound was applied,
It was formed by heat treatment at 30 ° C. for 30 minutes. The thickness of the anchor coat layer was 3 μm, which was the same as in Example 1.

At this time, the surface of the obtained anchor coat layer had tackiness, and when the polycarbonate films formed only with the anchor coat layer were stacked, they adhered to each other. When the films were peeled off from each other, the surface of the anchor coat layer became rough and the gas barrier layer could not be laminated smoothly.

Comparative Example 2 A transparent conductive film having the same structure as in Example 1 was prepared except that the anchor coat layer was changed to the following in Example 1.

The anchor coat layer is Nippon Unicar Co., Ltd.
Aminoalkylalkoxysilane AP-133 was used, which was applied to a polycarbonate film and heat-treated at 130 ° C. for 10 minutes as in Example 1 to form a film. The thickness of the anchor coat layer was 3 μm, which was the same as in Example 1.

A peel strength test of the obtained transparent conductive film gave a result of 15 g / cm. Further, in the same cellophane tape adhesion peeling test as in Example 1, the entire surface was easily peeled off from the gas barrier layer. Therefore, it was difficult to manufacture a liquid crystal cell.

Comparative Example 3 A transparent conductive film having the same structure as in Example 1 was prepared except that the solvent resistant layer was changed to the following in Example 1.

As the solvent resistant layer, bisphenol A type epoxy resin Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd. was used.
00 parts, 100 parts of methyl ethyl ketone, 32 parts of bis (4-amino-3-methyldicyclohexyl) methane,
A mixture of 1 part of γ-glycidoxypropyltrimethoxysilane was applied, and the same as in Example 1 at 100 ° C. for 3 minutes,
Further, it was formed by heat treatment at 130 ° C. for 60 minutes. The thickness of the solvent resistant layer was 8 μm, which was the same as in Example 1.

The transparent conductive film thus obtained was subjected to the same solvent resistance test as in Example 1. The N-methylpyrrolidone swelled so badly that the morphology was not retained, and the transparent conductive film had poor resistance to organic solvents.

[Comparative Example 4] A transparent conductive film having a structure in which the solvent resistant layer on the transparent conductive layer side was omitted from the structure of Example 1, that is, the laminated structure was 5/1/2/3/4, was produced.

The transparent conductive film thus obtained was subjected to the same solvent resistance test as in Example 1. The polycarbonate film was dissolved in N-methylpyrrolidone, and whitening of the polycarbonate film was observed in acetone. Therefore, it is difficult to form the alignment film.

[Comparative Example 5] A transparent conductive film having a laminated structure of 5/4/1/2/3 was prepared by omitting the solvent resistant layer on the side opposite to the transparent conductive layer side in the structure of Example 1. It was made.

The transparent conductive film thus obtained was subjected to the same solvent resistance test as in Example 1. 5% KOH, N-
Dissolution of the gas barrier layer was observed with methylpyrrolidone. Therefore, it is difficult to form the alignment film.

[Comparative Example 6] In the structure of Example 1, the gas barrier layer was omitted, that is, the laminated structure was 5/4.
A transparent conductive film of / 1/2/4 was produced.

The oxygen transmission rate of the obtained transparent conductive film was 17 cc / square meter.day.atm.

When a reliability test similar to that of Example 1 was conducted, air bubbles were generated in the liquid crystal layer and the display characteristics were deteriorated.

[Comparative Example 7] A transparent conductive film having the same structure as in Example 1 was prepared except that the anchor coat layer had the following composition in Example 1.

The composition of the phenoxy resin of the anchor coat layer was 20 parts by weight of phenoxy resin and 40 parts of methyl ethyl ketone.
And 20 parts of 2-ethoxyethyl acetate were mixed, and 2 parts of polyfunctional isocyanate was added to the mixture. At this time, NCO / OH was 0.1. The other conditions were the same as in Example 1.

The peel strength of this transparent conductive film is 1
It was 00 g / cm, and the adhesiveness was poor.

[Comparative Example 8] A transparent conductive film having the same structure as in Example 1 except that the anchor coat layer had the following composition was prepared.

The composition of the phenoxy resin of the anchor coat layer was 20 parts of phenoxy resin and 40 parts of methyl ethyl ketone.
Parts and 20 parts of 2-ethoxyethyl acetate were mixed, and 64 parts of polyfunctional isocyanate was added. At this time, NCO / OH was 3.2. The other conditions were the same as in Example 1.

The peel strength of this transparent conductive film is 2
It was 0 g / cm, and the adhesiveness was poor.

[0125]

INDUSTRIAL APPLICABILITY As described above, the present invention improves the adhesiveness between the polymer film of the substrate and the gas barrier layer by using the hardened layer of the specific thermoplastic resin as the anchor coat layer, and the productivity of the gas barrier layer is uniform. Can be formed into
In addition, by using a cured layer of novolac type epoxy resin or silicone resin for the solvent resistant layer, the solvent resistance is remarkably improved, and the air resistance and the air resistance required for transparent electrodes of liquid crystal display panels are comprehensively improved. It is a transparent conductive film that satisfies water vapor permeability, smoothness, flatness, optical characteristics, and long-term reliability and is comparable to a transparent electrode on a glass substrate.

As described above, the present invention makes a great contribution to the improvement of the characteristics of the transparent conductive film of the polymer film substrate, and has its application.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Tamura 4-3-2 Asahigaoka, Hino City, Tokyo Teijin Limited Tokyo Research Center

Claims (5)

[Claims] 1. A transparent conductive film having an anchor coat layer, a gas barrier layer, a solvent resistant layer and a transparent conductive layer provided on a polymer film, wherein the anchor coat layer is a repeating unit represented by the following general formula (A). It is obtained by thermosetting a heat-crosslinkable resin obtained by mixing at least one phenoxy resin selected from the group consisting of phenoxy resin, phenoxy ether resin, and phenoxy ester resin, and a polyfunctional isocyanate compound containing two or more isocyanate groups. A transparent conductive film, wherein the solvent-resistant layer is a layer obtained by curing a crosslinkable resin composed of a novolac type epoxy resin or a silicone resin. Embedded image (Here, R ¹ to R ⁶ are the same or different hydrogen or an alkyl group having 1 to 3 carbon atoms, and R ⁷ is 2 to 5 carbon atoms.
Alkylene group, X is an ether group, an ester group, m is 0
To 3 and n is an integer from 20 to 300. ) 2. The transparent conductive film according to claim 1, wherein the polymer film is optically isotropic. 3. The transparent conductive film according to claim 1, wherein the novolac type epoxy resin is a novolac type epoxy resin represented by the following general formula (B). Embedded image (Here, R ¹ is H or CH ₃ , R ² and R ³ are H or a glycidyl phenyl ether group, and n is an integer of 1 to 50.) 4. The transparent conductive film according to claim 1, wherein the silicone resin is a silicone resin containing 40% by weight or more of trialkoxysilane. 5. The transparent conductive film according to claim 1, wherein the gas barrier layer is a polyvinyl alcohol resin layer.