JP3204356B2 - Transparent conductive film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to films for electronic devices such as EL devices and LCD devices. In particular, it relates to an electrode substrate for manufacturing a liquid crystal cell.

[0002]

2. Description of the Related Art With the development of the information-oriented society, electroluminescence displays and liquid crystal displays have been developed, and in connection with this, transparent conductive materials have made progress. Among them, the electrode base for liquid crystal is becoming thinner and lighter for miniaturization, and the above-mentioned materials are conventionally made of glass plates, but they have problems such as being heavy and being easily broken. It has been studied to make this electrode substrate made of plastic. Polyvinyl alcohol and ethylene-vinyl alcohol copolymers have been used to provide gas and water vapor barrier properties on plastic substrates having electrodes made of this transparent conductive layer, but the gas barrier properties of these substances depend on humidity. In order to exhibit high performance and sufficient performance, use conditions must be limited. Therefore, as a means to overcome this, a transparent metal oxide film has come to be used. Specifically, the transparent metal oxide film here includes silicon oxide and indium oxide. However, although the above-mentioned transparent metal oxide film is a hard film, it is inferior in scratch resistance because it is a very thin film of 2000 ° or less, and this gas barrier property is damaged in a necessary processing step, and thus the transparent metal oxide film is obtained. This is a phenomenon that the film becomes unusable.

[0003]

As a method of avoiding this phenomenon, there is a method of providing a protective film having a surface hardness on a metal oxide film. Generally, in order to have a surface hardness and abrasion resistance, it is necessary to provide a protective film having a surface hardness. A three-dimensional crosslinked polymer is most suitable, and as the resin system, a photocurable resin, a thermosetting resin, an electron beam curable resin, or the like is used. In order to obtain fast curability, a combination of a polyfunctional monomer and a prepolymer is used.
In addition, the adhesion was inferior because importance was placed on hardness. Under such a background, a certain degree of hardness is provided on a metal oxide film as a gas barrier layer so as not to cause a decrease in the barrier properties of the substrate due to the breakage of the barrier layer in the process of processing the material of the substrate. And a transparent conductive film provided with a hard organic cured film having good adhesion.

[0004]

That is, the present invention provides a cured plastic layer (2) on at least one side of a transparent plastic film (1), and a gas barrier transparent metal oxide laminated on the resin layer. Layer (3) and the metal oxide layer
(3) A transparent conductive plastic film having a hard organic material layer (4) on one side and a transparent conductive layer (5) on one of the layers via a cured resin layer (2), Is a photo-cured reaction product of an acrylic monomer and an epoxy acrylate resin, and the epoxy acrylate resin has the following formula

Embedded image [However, n in the formula represents an integer of 1 to 6. ] Is a bisphenol A type epoxy acrylate resin represented by
It is a transparent conductive film provided with a cured film having a weight ratio of 50% or more to the whole resin at the time of the reaction, and each of the above-mentioned layers is (1) / (2) / (3) as shown in FIGS. / (4) / (2)
/ (5), (2) / (1) / (2) / (3) / (4) / (2) / (5) or (5)
A transparent conductive film characterized by being laminated in an arrangement of / (2) / (1) / (2) / (3) / (4).

[0005] The transparent plastic film (1) in the present invention is a base material of the transparent conductive film of the present invention, and includes polyester film, polycarbonate film, polyarylate film, polyether sulfone film and the like. However, a polyether sulfone film is particularly preferable in terms of mechanical strength, optical properties, heat resistance and the like. Film thickness is 50 ~ 300
μm, and preferably 75 to 125 μm.

The cured resin layer (2) is obtained by applying a resin varnish and removing the solvent by drying. In this case, as the resin system, a varnish to which a resin system having film forming properties after removing the solvent, that is, a varnish to which a solid resin is added is preferable from the viewpoint of uniform application,
Specifically, epoxy diacrylate, urethane diacrylate, so-called acrylic prepolymers such as polyester diacrylate and the like as a photocurable resin, and as a thermosetting resin, O-cresol novolak type, bisphenol type epoxy type, urethane type, Acrylic-based, urea-based, melamine-based, unsaturated polyester-based, electron beam-curable resins, and the like. From the viewpoint of productivity and cost, a photocurable resin is generally preferred. As a method of forming the cured resin film on the substrate, a gravure coating method,
There are a reverse roll coating method, a kiss roll coating method, and the like. However, in consideration of industrial production, it is preferable that any of these methods can be cured within 5 minutes. The cured coating must be substantially transparent and optically isotropic.

The transparent metal oxide layer (3) includes silicon oxide, indium oxide, etc.
When the thickness is too large, transparency and flexibility are poor when the thickness is too large, and the performance effect is weak when the thickness is too thin. These film thicknesses are appropriately selected in consideration of the above. These thin films are formed by sputtering,
It is formed by a known means such as an ion plating method and a CVD method.

Next, the hard organic material layer (4) laminated on the above-mentioned metal oxide layer has been studied diligently with an emphasis on obtaining sufficient adhesion over the surface hardness. 5 epoxy acrylate components
Good results were found with coatings containing 0% or more. It is particularly important that the coating film contains 80% or more.
The method for forming the organic material layer is the same as the method for forming the cured resin layer (2)
Preferred is a film formed by the same method as described above. The cured coating must also be substantially transparent and optically isotropic.

Finally, a transparent conductive layer (5) is formed on the coating. The transparent conductive layer is a thin film of a metal oxide, such as indium oxide, tin oxide, and cadmium oxide. Of these, it is particularly preferable to form a thin film of indium oxide containing 5 to 10% by weight of tin oxide. These film thicknesses can be appropriately selected within the range of 50 to 2000 °. These thin films are formed by a known method such as a sputtering method and an ion plating method. Thus, a transparent conductive film having an appropriate hardness and an organic substance layer having good adhesion was obtained.

[0010]

【Example】

<< Embodiment 1 >> FIG. 3 is a schematic view of a transparent conductive film of the present invention, showing a state where a transparent conductive layer (5) is provided. As a transparent plastic film (1), polyether sulfone was prepared. This film is formed by a melt extrusion method. The thickness is 100 μm, the retardation value is 10 nm or less, and the visible light transmittance is 90%. An acrylate-based coating agent was uniformly applied to both surfaces of the transparent plastic film (1) by a roll coater method, heated at 80 ° C. to remove the solvent, and then irradiated with one 80 W / cm high-pressure mercury lamp at an irradiation distance of 15 cm. Irradiation was performed for 10 seconds to form a cured resin layer (2) having a thickness of 5.0 μm. A metal oxide layer (3) consisting of a layer of SiO ₂ having a thickness of 300 ° was formed on one of the coating films by a sputtering method.
The adhesion to the cured resin layer (2) was good. On top of this metal oxide layer (3): Photocurable resin blending ratio Bisphenol A type epoxy acrylate 65% solution (manufactured by Showa Polymer Co., Ltd.) 40 parts by weight 4,4'-diethylaminobenzophenone (Nippon Ciba Geigy Co., Ltd.) 0.9 parts by weight Solvent Butyl acetate / Butyl cellosolve Solvent varnish having a composition consisting of 4/1 by weight and a residual amount of 15 g / m ² was applied with a gravure coater, and heated at 120 ° C. for 2 minutes to remove the solvent, and then 80 W / Cm 2 high pressure mercury lamp, irradiation distance 15c
m for 10 seconds to form an organic material layer with a thickness of 4.0 μm
(4) was formed. Table 1 shows the physical properties of the obtained organic substance layer (4). Finally, a transparent conductive layer of indium oxide and tin oxide was formed on the other cured resin layer (2) by a sputtering method to a thickness of 300 ° to obtain a transparent conductive film.

Example 2 The same procedure as in Example 1 was carried out except that the composition of the organic material layer (4) obtained was such that the bisphenol A type epoxy acrylate resin was about 60% in the composition below. Was done. -Photocurable resin compounding ratio 65% solution of bisphenol A type epoxy acrylate (manufactured by Showa Polymer Co., Ltd.) 23 parts by weight 80% solution of trimethylolpropane triacrylate (manufactured by Dainippon Ink Co., Ltd.) 12.5 parts by weight 4 , 4'-Diethylaminobenzophenone (Nippon Ciba Geigy Co., Ltd.) 0.9 parts by weight Solvent butyl acetate / butyl cellosolve weight ratio 4/1 remaining amount An organic material layer having a thickness of 3.9 μm was formed by the above resin varnish. The properties of the coating film obtained above are shown in Table 1.

<Comparative Example 1> The same operation as in Example 1 was carried out except that the composition of the organic substance layer (4) obtained was such that the bisphenol A type epoxy acrylate resin contained about 40% of the following composition. Was done. -Photocurable resin compounding ratio 65% solution of bisphenol A type epoxy acrylate (manufactured by Showa Polymer Co., Ltd.) 15 parts by weight 85% solution of trimethylolpropane triacrylate (manufactured by Dainippon Ink Co., Ltd.) 18 parts by weight 4.4 '-Diethylaminobenzophenone (manufactured by Nippon Ciba Geigy Co., Ltd.) 0.9 part by weight Solvent butyl acetate / butyl cellosolve weight ratio 4/1 remaining amount An organic material layer having a thickness of 3.6 μm was formed by the above resin varnish. The properties of the coating film obtained above are shown in Table 1.

Comparative Example 2 The same operation as in Example 1 was carried out except that the bisphenol A type epoxy acrylate was changed to a novolak type epoxy acrylate having high rigidity after curing. . -Photocurable resin compounding ratio Novolak type epoxy acrylate resin (Nippon Kayaku Co., Ltd.) 25 parts by weight 1-hydroxy-cyclohexylphenyl ketone (Nippon Ciba Geigy Co., Ltd.) 0.9 parts by weight Solvent Methyl cellosolve acetate An organic material layer having a thickness of 4.0 μm was formed using a resin varnish. The properties of the coating film obtained above are shown in Table 1.

Comparative Example 3 The same operation as in Example 1 was carried out except that the obtained organic substance layer (4) had the following formulation using bisphenol A type epoxy resin as a thermosetting resin. went. -Thermosetting resin compounding ratio Bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd.) 15 parts by weight 2,4,6 tri [dimethylaminomethyl] phenol (manufactured by Kayaku Akzo Co., Ltd.) 0.4 parts by weight Pentaerythritol tetrakis [Β-thiopropionate] (Yodo Chemical Co., Ltd.) 9 parts by weight pentaerythryl-tetrakis [3- (3,5-t-butyl-4-hydroxyphenyl) propionate] (Nippon Ciba Geigy Co., Ltd.) 9 parts by weight Solvent Methyl cellosolve acetate / butyl cellosolve 20 g / m ² of resin varnish having a weight ratio of 4/1 was applied by a kiss coater and cured by heating at 150 ° C. for 5 minutes to obtain a film thickness of 4.5.
A μm organic material layer (4) was formed. Table 1 shows the physical properties of the coating of the organic substance layer (4) obtained above.

Table 1 Paint film Physical properties Cross cut tape test Pencil hardness Film thickness [μm] Example 1 100/100 2H 4.0 Example 2 89/100 2H 3.9 Comparative Example 10 0/100 2H 3.6 Comparative Example 2 0/100 3H 4.0 Comparative Example 3 0/100 H 4.5 * The cross-cut tape test and pencil hardness of the coating film property evaluation method were in accordance with JIS-K-5400.

[0016]

EFFECT OF THE INVENTION By using the transparent conductive film of the present invention, a good liquid crystal display which does not impair the gas barrier properties due to troubles such as cracks in the metal oxide layer (3) during handling in the liquid crystal display processing step. The device was obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a transparent conductive film of the present invention, showing a state where a transparent conductive layer (5) is laminated.

FIG. 2 is a cross-sectional view of the transparent conductive film of the present invention, showing a state where a transparent conductive layer (5) is laminated.

FIG. 3 is a cross-sectional view of the transparent conductive film of the present invention, showing a state where a transparent conductive layer (5) is laminated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent plastic film 2 Cured resin layer 3 Metal oxide layer 4 Organic material layer 5 Transparent conductive layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI H05K 1/03 630 H05K 1/03 630C

Claims (1)

(57) [Claims] 1. A plastic film having transparency
A cured resin layer (2) is provided on at least one surface of (1), and a gas barrier transparent metal oxide layer laminated on the resin layer
(3) and a hard organic material layer on the metal oxide layer (3)
(4) is a transparent conductive plastic film having a transparent conductive layer (5) via a cured resin layer (2) on one of the two, wherein the hard organic material layer is an acrylic monomer and A photocuring reaction product with an epoxy acrylate resin, wherein the epoxy acrylate resin has the following formula: [However, n in the formula represents an integer of 1 to 6. ] Is a bisphenol A type epoxy acrylate resin represented by
A transparent conductive film provided with a cured film having a weight ratio of 50% or more to the whole resin at the time of reaction.