JPH06234186A - Highly gas-barrier transparent electrode film - Google Patents

Abstract

(57) [Summary] [Structure] Silicon oxide layer, transparent conductive layer, and gas barrier polymer layer such as polyvinyl alcohol or polyvinylidene chloride for polymer film base material such as polyether sulfone or polyether ether ketone. A transparent electrode film having an extremely excellent gas barrier property, which is formed by appropriately laminating and. [Effect] A transparent electrode film having transparency and flexibility and high gas barrier property, which is suitable for application to a liquid crystal display device in which water vapor and oxygen must be avoided, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas barrier conductive film having a polymer film as a base material. More specifically, it relates to a conductive film which has transparency in the visible light region, has a low transmittance for gases such as oxygen and water vapor, and has excellent weather resistance, chemical resistance and abrasion resistance. Therefore, the present invention relates to a gas barrier transparent electrode film suitable for application to a liquid crystal display device in which water vapor, oxygen, and other harmful gases must be avoided.

[0002]

2. Description of the Related Art Conventionally, glass has been used as a base material for transparent conductors for liquid crystal displays, but in recent years, 1) it is lightweight, 2) it is easy to increase the area, and 3) it does not crack. ,
4) It has been proposed to use a transparent conductive film having excellent workability as an electrode. However, it has been found that when a conductive film is used, water vapor or oxygen that permeates the film causes performance deterioration of the liquid crystal element. In order to solve such a problem, it has become clear that it is necessary to impart a gas barrier property to the film substrate. Therefore, it has been studied by the present inventors to form a transparent gas barrier layer of silicon oxide on a conductive film by a plasma chemical vapor deposition method (Japanese Patent Application No. 04-212362 and Japanese Patent Application No. 04-33200).
1). That is, specifically, at least a gas of an organosilicon compound and oxygen are introduced into a vacuum container on a polymer film to generate high frequency glow discharge, and silicon oxide is generated on the polymer film at a temperature of 80 ° C. or lower. Is formed, and a transparent conductive layer is further formed by the sputtering method. In this case, the polymer film is A, the transparent conductive layer is B,
If the layer of silicon oxide is C, then a structure such as CAB or CACB is conceivable.

[0003]

However, when the present inventors compared the oxygen transmission rate of the transparent electrode film having the above-mentioned constitution with that of the borosilicate glass substrate used for the liquid crystal display element, the transparent electrode was obtained. It was found that the gas barrier property of the film was not equal to that of borosilicate glass. Then, the inventors of the present invention have made diligent efforts to solve such a problem, and as a result, a transparent conductive film and a silicon oxide layer are appropriately laminated on a transparent polymer film substrate. The inventors have found that a transparent electrode film having a gas barrier transparent polymer layer laminated outside the layer or between a silicon oxide layer and the transparent polymer film has a remarkably excellent gas barrier property, and thus reached the present invention.

[0004]

That is, according to the present invention, a transparent polymer layer is formed on at least one surface of a transparent conductive film obtained by laminating a transparent conductive layer and a silicon oxide layer on a transparent polymer film substrate. A gas barrier transparent electrode film laminated, preferably a transparent polymer film substrate is a gas barrier transparent electrode film that is a polyether sulfone, and a transparent polymer film substrate, A transparent gas film having a gas barrier property of polyetheretherketone, wherein the transparent polymer film (A), the transparent conductive layer (B), the silicon oxide layer (C) and the transparent polymer layer (D) are DCAB. , DCACB, CDA
B, CDACB, CADB or CADCB, which is a gas barrier transparent electrode film laminated in this order,
The layer of silicon oxide is a gas barrier transparent electrode film produced by a low pressure plasma chemical vapor deposition method using at least an organosilicon compound gas and oxygen, and the transparent conductive layer is a gas barrier produced by a sputtering method. sex transparent electrode film, a transparent polymer layer is at least polyvinyl alcohol, gas barrier transparent electrode film comprising a layer of polyvinylidene chloride, oxygen permeability at 23 ° C. is 0.01 cc · ^m-2・ Day ^-1 (1at
m) or less and a gas barrier transparent electrode film having a water vapor transmission rate of 0.1 g · m ⁻² · day ⁻¹ or less at 23 ° C. and 90% relative humidity. .

That is, the present invention has been made to solve the above problems, and in a particularly preferred embodiment, a transparent conductive layer and a silicon oxide layer are appropriately laminated on a transparent polymer film substrate. A transparent polymer layer is laminated outside the silicon oxide layer on at least one surface of the transparent conductive film or between the silicon oxide layer and the transparent polymer film, and the transparent polymer layer is at least polyvinyl alcohol or polychlorinated. A gas barrier transparent electrode film, which is a layer selected from vinylidene, is provided, which provides a high gas barrier transparent electrode film that can be suitably used for liquid crystal display devices. First, referring to the attached drawings, FIGS. 1 to 6 are views showing an example of a layer structure of a gas barrier transparent electrode film of the present invention. In the figure, 1 is a transparent polymer substrate, 2 is a silicon oxide layer, 3 is a transparent conductive layer, 4
Is a transparent polymer layer.

In the present invention, the polymer film as a base material is not particularly limited, but it is desirable that it is transparent, has a high glass transition temperature, and has a low hygroscopic property, and it is preferably polyester, polyether sulfone, polyether ether ketone. , A film made of polycarbonate or polyolefin, etc., and a film made of polyether sulfone and polyether ether ketone is particularly preferable. The thickness of the polymer film is 50-500μ
m is preferred, but is not necessarily limited to this range.

The silicon oxide layer to be laminated on the polymer film substrate used in the present invention can be produced by a physical vapor deposition method, a chemical vapor deposition method, a wet method or the like. Specifically, in the physical vapor deposition method,
There are a vacuum vapor deposition method, an ion plating method, a sputtering method, and the like. As the chemical vapor deposition method, a thermal CVD method, a photo CVD method,
There is a plasma CVD method and the like, and a wet method includes a sol gel method and the like. However, in the present invention, since the base material is a polymer film, it is desirable to form the film at a low temperature, and a physical vapor deposition method or a plasma CVD method is preferable. Especially plasma CV
Film formation by the D method is preferable, and a more specific example of the method will be described. Introducing an organosilicon compound gas such as tetramethyldisiloxane, hexamethyldisiloxane, or trimethylmethoxysilane and oxygen gas into a vacuum container. A high-frequency discharge is generated to form a silicon oxide layer on the polymer film. It is also possible to use a rare gas such as helium when introducing the organosilicon gas. In the sputtering method, a silicon dioxide target is sputtered with argon to deposit a film on the polymer film. The thickness of the silicon oxide layer may be in the range that does not impair the transparency while maintaining the gas barrier property, specifically, 20 to 500 nm.
Is preferable, more preferably 30 to 300 nm, and further preferably 50 to 200 nm. Further, if the thickness is the same, it is more preferable to provide a silicon oxide layer on both surfaces. That is, rather than providing a 200 nm layer on one side,
It is more preferable to provide a 100 nm layer on both sides.

The silicon oxide may contain trace amounts of iron, nickel, chromium, titanium, magnesium, aluminum, indium, zinc, tin, antimony, tungsten, molybdenum, copper and the like. Further, carbon or fluorine may be appropriately contained for the purpose of improving the flexibility of the film. The film thickness can be measured by stylus roughness meter, repetitive reflection interferometer, microbalance, crystal oscillator method, etc. Suitable to get. In addition, there is also a method in which the conditions for film formation are determined in advance, the film is formed on a test substrate, the relationship between the film formation time and the film thickness is investigated, and then the film thickness is controlled by the film formation time.

As the transparent conductive film, there are conventionally known 1) single metal or alloy thin film layers of gold, silver, copper, aluminum, palladium, etc. 2) compound semiconductors such as tin oxide, indium oxide, zinc oxide, copper iodide 3 ) A laminated film combining the above 1) and 2) can be used. The transparent conductive film can be prepared by a physical vapor deposition method or a wet film forming method. As the physical vapor deposition method, a vacuum vapor deposition method, a sputtering method, an ion plating method, an activation reaction vapor deposition method, or the like can be used.
A sol-gel method or the like is known as a wet film forming method. The thickness of the transparent conductive layer may be in a range where sufficient conductivity can be obtained within a range that does not impair transparency, and is 30 nm to 500 nm.
The range of nm is desirable, and more desirably 50 nm to 30
It is in the range of 0 nm.

The composition of the silicon oxide layer and the transparent conductive layer is X.
It can be analyzed by using line photoelectron spectroscopy, X-ray microanalysis, Auger electron spectroscopy, Rutherford backscattering, and the like. For example, when the Rutherford backscattering method is used, the sample film is placed in a vacuum vessel, α particles accelerated to 1 to 4 MeV are irradiated from the sample surface, and the energy of backscattered ions is analyzed. As a result, the composition in the depth direction of the film and the uniformity of the composition can be investigated. Gold or the like may be appropriately vapor-deposited on the surface to prevent charging of the surface layer. Also, when performing analysis by Auger electron spectroscopy, the specimen is placed in an ultrahigh vacuum container, and the surface of the specimen is irradiated with an electron beam accelerated to 1 to 10 keV,
The composition can be investigated by detecting Auger electrons emitted at that time. In this case, since the electric resistance of the test piece is high, it is preferable that the current of the primary electron beam is suppressed to 10 pA or less and the energy is also set to 2 keV or less so that the influence of charging is not exerted. X-ray photoelectron spectroscopy using X-rays instead of electron beams is advantageous in that it is less susceptible to charging than Auger electron spectroscopy. When a silicon oxide layer or a transparent conductive layer is formed on a polymer substrate, corona discharge treatment, plasma treatment, glow discharge treatment, reverse sputtering treatment, surface roughening treatment, chemical treatment is performed as pretreatment of the substrate. It is possible to appropriately carry out the above, or to apply a known undercoat.

In the present invention, such a transparent conductive layer and a silicon oxide layer are appropriately laminated on a transparent polymer film substrate, and the transparent conductive film is provided on the outside of at least one side of the silicon oxide layer or the silicon oxide layer and the transparent layer. A transparent polymer film is a gas barrier transparent electrode film in which a transparent polymer layer is laminated between molecular films, and the transparent polymer layer is at least a layer selected from polyvinyl alcohol and polyvinylidene chloride.

In order to form the polyvinyl alcohol or polyvinylidene chloride layer, a known wet polymer thin film forming method can be used. Specifically, bar coating, roll coating, spin coating, reverse roll coating, dip coating and the like. Specifically, a method for obtaining polyvinyl alcohol is obtained by polymerizing vinyl acetate to give polyvinyl acetate, followed by hydrolysis with an alkali, precipitation, washing and drying. The raw material vinyl acetate is obtained by reacting ethylene with acetic acid.

The polyvinyl alcohol layer is prepared by dissolving polyvinyl alcohol and a glycol-based softening agent (glycerin, etc.) in water at a solid content concentration of about 10%, filtering and defoaming and coating the film with a coater to evaporate and dry the water. Let The polyvinylidene chloride layer is formed by applying vinylidene chloride and vinyl chloride together with pure water, a suspending agent, a catalyst and the like by a coater and then raising the temperature to polymerize. In addition to vinyl chloride, other comonomer components such as acrylic acid ester and vinyl acetate are also used.
The thickness of the transparent polymer layer is not particularly limited, but from the viewpoint of its effect and easy handling, it is 1 to 30 μm.
m, preferably about 3 to 10 μm.

[0014]

EXAMPLES Hereinafter, specific examples of the present invention will be described based on Examples and Comparative Examples. (Example 1) A parallel plate using tetramethyldisiloxane (hereinafter abbreviated as TMDSO) having helium as a carrier gas and oxygen as source gases on both surfaces of a polyether sulfone (hereinafter abbreviated as PES) film having a thickness of 50 μm 13. By plasma CVD apparatus having die electrode
Plasma discharge was generated at a high frequency of 56 MHz to form a 100-nm-thick silicon oxide layer under the conditions shown in Table 1.
A transparent conductive layer containing indium oxide as a main component was formed on one surface of the film by a sputtering method under the conditions shown in Table 2 to 50 n.
m formed. Further, a solution obtained by diluting Gohsenol KH-17 (Nippon Gosei Kagaku) to 10% by volume with pure water was coated on the surface opposite to the surface on which the transparent conductive layer was formed by a bar coating method, and then dried at 120 ° C. for 5 minutes. Then, a polyvinyl alcohol layer having a thickness of 5 μm was formed.

After obtaining a film by such a method, AS
Was measured for oxygen permeability in accordance with TM-D1434, was 0.004cc · m ^-2 · day ^-1. Furthermore, the oxygen transmission rate at a relative humidity of 100% is ASTM-
When measured according to D3985, 0.01 cc ・ m ^-2・
It was below day ^-1 . The film was wound around a stainless steel rod having a diameter of 10 mm (surface roughness Ra <1.6 μm), and the change in oxygen permeability before and after the winding was measured by ASTM-
Measured according to D1434 and change in water vapor transmission rate according to ASTM-
It was measured according to E96 (38% C, 90% RH). The results are shown in Table 3.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

[Table 3]

Comparative Example 1 Plasma C having parallel plate electrodes using tetramethyldisiloxane (hereinafter abbreviated as TMDSO) having helium as a carrier gas and oxygen as source gases on both surfaces of a PES film having a thickness of 50 μm.
Plasma discharge was generated at a high frequency of 13.56 MHz by a VD device, and a silicon oxide layer having a film thickness of 100 nm was formed under the conditions shown in Table 1. A transparent conductive layer containing indium oxide as a main component is formed on one surface of the film by a sputtering method.
0 nm was formed.

After obtaining a film by such a method, AS
Was measured for oxygen permeability in accordance with TM-D1434, was 0.07cc · m ^-2 · day ^-1. further,
Oxygen permeability at 100% relative humidity is ASTM-D3
When measured according to 985, it is 0.11 cc ・ m ^-2・ da
It was y ^-1 . The film was wound around a stainless steel rod having a diameter of 10 mm (surface roughness Ra <1.6 μm), and the change in oxygen permeability before and after the winding was measured by ASTM-D143.
Measured in accordance with 4 and change in water vapor transmission rate according to ASTM-E96
(38% C, 90% RH). The results are shown in Table 4. It can be seen that after the bending test, the transmittance for oxygen and water vapor deteriorates sharply.

[0021]

[Table 4]

(Comparative Example 2) Gosenol KH-17 (Nippon Gosei Kagaku) on one side of a PES film having a thickness of 50 μm.
Was coated with pure water to a volume of 10% by bar coating and then dried at 120 ° C. for 5 minutes to give a thickness of 5 μm.
m polyvinyl alcohol layer was formed. After obtaining a film by such a method, the oxygen permeability was measured according to ASTM-D1434. As a result, it was found to be 0.45 cc · m ⁻² · d.
It was ay ^-1 . Furthermore, when the oxygen transmission rate at a relative humidity of 100% was measured according to ASTM-D3985, it was 11 cc · m ⁻² · day ^-1 .

(Example 2) TMDS using helium as a carrier gas on both sides of a PES film having a thickness of 50 μm
Plasma discharge was generated at a high frequency of 13.56 MHz by a plasma CVD apparatus having parallel plate electrodes using O and oxygen as source gases, and the film thickness was 100 n under the conditions shown in Table 1.
m silicon oxide layer was formed. A transparent conductive layer containing indium oxide as a main component was formed to a thickness of 50 nm on one surface of the film by a sputtering method. Furthermore, Kurehalon DO600 (Kureha Chemical)
And a sodium pyrophosphate solution were coated by a bar coating method and then dried at 100 ° C. for 5 minutes to form a polyvinyl alcohol layer having a thickness of 7 μm.

After obtaining a film by such a method, AS
Was measured for oxygen permeability in accordance with TM-D1434, was 0.005cc · m ^-2 · day ^-1. Furthermore, the oxygen transmission rate at a relative humidity of 100% is ASTM-
When measured according to D3985, 0.01 cc ・ m ^-2・
It was below day ^-1 . The film was wound around a stainless steel rod having a diameter of 10 mm (surface roughness Ra <1.6 μm), and the change in oxygen permeability before and after the winding was measured by ASTM-
Measured according to D1434 and change in water vapor transmission rate according to ASTM-
It was measured according to E96 (38% C, 90% RH). The results are shown in Table 5.

[0025]

[Table 5]

Comparative Example 3 A PES film having a thickness of 50 μm was coated on one surface with Klehalon DO600 (Kureha Chemical Co., Ltd.) and a sodium pyrophosphate solution by a bar coating method and then dried at 120 ° C. for 5 minutes to give a film having a thickness of 7 μm. A polyvinyl alcohol layer was formed. After obtaining the film by such a method was measured for oxygen permeability in accordance with ASTM-D1434, was 0.45cc · m ^-2 · day ^-1. Furthermore, the oxygen transmission rate at a relative humidity of 100% is A
11cc when measured according to STM-D3985
It was m ^-2 · day ^-1.

[0027]

From the above Examples and Comparative Examples, it is understood that the film according to the present invention not only exhibits extremely excellent gas barrier property in a wide humidity range but also exhibits excellent flexibility. Thus, according to the present invention, it is possible to obtain a transparent conductive film having an extremely excellent gas barrier performance, which is suitable as, for example, an electrode for liquid crystal display.

[Brief description of drawings]

FIG. 1 is a layer structure diagram of a gas barrier transparent electrode film of the present invention.

FIG. 2 is a layer structure diagram of a gas barrier transparent electrode film of the present invention.

FIG. 3 is a layer structure diagram of a gas barrier transparent electrode film of the present invention.

FIG. 4 is a layer structure diagram of a gas barrier transparent electrode film of the present invention.

FIG. 5 is a layer constitution diagram of a gas barrier transparent electrode film of the present invention.

FIG. 6 is a layer structure diagram of a gas barrier transparent electrode film of the present invention.

[Explanation of symbols]

 1 Transparent Polymer Base Material 2 Silicon Oxide Layer 3 Transparent Conductive Layer 4 Transparent Polymer Layer

Claims (8)

[Claims] 1. A gas barrier transparent electrode film in which a transparent polymer layer is laminated on at least one surface of a transparent conductive film obtained by laminating a transparent conductive layer and a silicon oxide layer on a transparent polymer film substrate. . 2. The gas barrier transparent electrode film according to claim 1, wherein the transparent polymer film substrate is polyether sulfone. 3. The gas barrier transparent electrode film according to claim 1, wherein the transparent polymer film substrate is polyetheretherketone. 4. The transparent polymer film (A), the transparent conductive layer (B), the silicon oxide layer (C) and the transparent polymer layer (D) are D.
CAB, DCACB, CDAB, CDACB, CADB
Alternatively, the gas barrier transparent electrode film according to any one of claims 1 to 3, which is laminated in the order of CADCB. 5. The gas barrier transparent electrode film according to claim 1, wherein the silicon oxide layer is formed by a low pressure plasma chemical vapor deposition method using at least an organosilicon compound gas and oxygen. . 6. The gas barrier transparent electrode film according to claim 1, wherein the transparent conductive layer is formed by a sputtering method. 7. The transparent polymer layer comprises at least a layer of polyvinyl alcohol and polyvinylidene chloride.
7. A gas barrier transparent electrode film as described in any one of to 6. 8. The oxygen permeability at 23 ° C. is 0.01
cc ・ m^-2・ Day ^{ー 1}(1 atm) or less,
The water vapor transmission rate at 23 ° C and 90% relative humidity,
0.1 gm^-2・ Day^{ー 1}What is in claims 1 to 7 below
A gas barrier transparent electrode film described therein.