JPH0623903A - Transparent conductive film having high gas barrier properties - Google Patents

Abstract

PURPOSE:To obtain a transparent conductive film having transparency, flexibility and gas barrier properties by forming a membrane layer consisting of metal oxide such as silicon oxide and polytetrafluoroethylene on the single surface of a polymer film base material. CONSTITUTION:A membrane layer 2 with a thickness of 10-500nm having a compsn. wherein a mol ratio of at least one kind of metal oxide selected from a group consisting of silicon oxide, aluminum oxide and magnesium oxide and polytetrafluoroethylene is MO: PTFE =0.40-0.4 is formed on at least the single surface of a polymer film base material 11. A transparent conductive film 3 based on indium oxide is formed on at least one surface of this film base material to obtain a transparent conductive film having high gas barrier properties.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent conductive film having a polymer film as a base material, and more particularly to a transparent conductive film having a high gas barrier property, and further used for a liquid crystal display. The present invention relates to a transparent conductive film having a high gas barrier property which can be preferably used.

[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, it is lightweight, can easily be made large in area, does not crack, and has excellent workability. A transparent conductive film having the property of being used has been used for 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.

In order to impart a barrier property to gas,
SiO, SiO on one or both sides of the polymer film
₂ , TiO ₂ , ZrO ₂ , Al ₂ O ₃ , Ta ₂ O ₅ , Nb ₂
There is disclosed a transparent conductive film in which a layer of oxide such as O ₃ or aluminum nitride is provided, and a coating film containing indium oxide as a main component is formed on at least one surface of these polymer layers (for example, Japanese Patent Laid-Open Publication No. Sho. 59-204545, JP-A-63-2
05094). However, thin films of these oxides and nitrides have transparency and gas barrier properties to some extent, but lack the flexibility because the properties of the thin film itself are similar to those of ceramics, and the thin film is not cracked. It easily enters and the barrier property is insufficient, and the characteristics of the polymer film cannot be fully utilized.

Further, in order to obtain a high gas barrier property,
When a metal such as aluminum used in the field of packaging materials is vapor-deposited, there is a drawback that the visible light transmittance is impaired.

[0005]

As described above, according to the prior art, it was difficult to simultaneously achieve transparency, flexibility and gas barrier property in the transparent conductive film. An object of the present invention is to solve the above-mentioned drawbacks of the conventional methods and provide a transparent conductive film having transparency, flexibility and gas barrier property.

[0006]

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the transmittance is high in the visible light region, cracks are not generated even in a bending test, and the gas transmittance is high. As a remarkably low transparent conductive film, at least one metal oxide (MO) selected from the group consisting of silicon oxide, aluminum oxide, magnesium oxide, titanium oxide and zirconium oxide on at least one surface of a polymer film substrate. And polytetrafluoroethylene (PT
FE) is a molar ratio of PTFE / MO = 0.04 to 0.4
The present invention was accomplished by finding a layer (MO + PTFE thin film) having a specific thickness formed in a specific thickness.

That is, according to the present invention, at least one surface of a polymer film substrate is provided with silicon oxide, aluminum oxide,
At least one metal oxide (hereinafter abbreviated as MO) selected from the group consisting of magnesium oxide, titanium oxide, and zirconium oxide, and polytetrafluoroethylene (hereinafter PTF).
(Abbreviated as E) is a molar ratio of MO: PTFE = 0.04 to
A thin film layer (MO + PTFE thin film) having a thickness of 10 to 500 nm of the composition of 0.4 is formed, and a transparent conductive film containing indium oxide as a main component is formed on at least one of the film base materials. And a transparent conductive film having a high gas barrier property.

The transparent conductive film of the present invention may have various modes, and examples thereof are shown in FIGS. 5 to 8, for example. Here, 1 is a polymer film substrate,
2 is a MO + PTFE thin film layer, and 3 is a transparent conductive film.

In the present invention, the polymer film as a base material is not particularly limited, but since it is 100 ° C. to 200 ° C. in the manufacturing process of the transparent conductive film, it is desirable that it has some heat resistance. Examples thereof include polyether sulfone, polycarbonate, polyimide, polyolefin film and the like, with polyether sulfone and polyimide being particularly preferable. The thickness of the base film is not particularly limited, but is usually 5 to 1000.
About μm is usually used. Of course, other materials can be used depending on the purpose.

The MO + PTFE thin film used in the present invention is preferably a uniform continuous film having a film thickness of 10 nm or more and 500 nm or less. As a result, excellent flexibility and excellent high gas barrier property are exhibited without impairing transparency. When the thickness is less than 10 nm, the gas barrier property is small, and the gas barrier property increases as the film thickness increases.
When the thickness is 100 nm or more, the property tends to be saturated, and when it exceeds 500 nm, the transparency is reduced. Therefore, the thickness of the MO + PTFE thin film of the present invention is preferably in the range of 10 to 500 nm. Furthermore, it is preferably in the range of 20 to 300 nm.

In the present invention, the film thickness can be measured by a stylus roughness meter, a repetitive reflection interferometer, a microbalance, a method using a quartz oscillator, and the like, although not particularly limited. The method is suitable for obtaining a desired film thickness because the film thickness can be measured during film formation. MO + PFT
E The flexibility increases as the molar composition ratio PTFE / MO in the thin film increases, but on the other hand, the transparency decreases, so that the molar composition ratio P in the film of the present invention increases.
The range of TFE / MO is preferably 0.04 to 0.4. More preferably, it is 0.04 to 0.2.

In the present invention, the means for forming the MO + PTFE thin film is not particularly limited, but the MO + PTFE thin film can be formed by a known vapor deposition method such as magnetron sputtering method or ion beam sputtering method. Also, as appropriate
A vacuum vapor deposition method, an electron beam vapor deposition method, and an ion plating method can be combined. Since the base material is a polymer material and it is inferior in heat resistance to metals and ceramics,
It is preferable to make it at a temperature as low as possible. For this purpose, a magnetron sputtering method or an ion beam sputtering method in which a desired metal oxide and PTFE are used as a target and sputtering is performed with argon ions to form a film at room temperature without cooling the substrate is effective. The composition of PTFE can be controlled by changing the ratio of the area occupied by the metal oxide and PTFE on the target surface in the sputtering method. Alternatively, a reactive sputtering method using fluorocarbon as a reactive gas,
When producing by reactive ion plating method etc.
It is possible to control the composition ratio of. The composition can be measured by infrared spectroscopy or X-ray photoelectron spectroscopy.

Before the MO + PTFE thin film is formed, the polymer film substrate is pretreated by corona discharge treatment, plasma treatment, glow discharge treatment, reverse sputtering treatment, surface roughening treatment, chemical treatment, or other known surface treatment. It is also preferable to appropriately apply the coating. Although the MO + PTFE film of the present invention is chemically stable, it is desirable to form a protective layer on the MO + PTFE film if necessary when used under severe conditions for a long period of time. A transparent resin may be used for the protective layer, and examples thereof include polyester resin, acrylic resin, vinyl resin, and polycarbonate.

[0014]

The high gas barrier transparent conductive film of the present invention, which is constructed as described above, has the following excellent effects. (1) Excellent gas barrier property. (2) Excellent flexibility. (3) Excellent transparency. (4) It can be used as an electrode.

[0015]

【Example】

Example 1 Using PES of 50 μm as a base material film, a film having a molar composition ratio of PTFE / MO = 0.1 was prepared in a film thickness range of 10 nm to 1000 nm by targeting SiO ₂ and PTFE by magnetron sputtering. A conductive film layer containing indium oxide as a main component was formed thereon with a thickness of 20 nm. The oxygen gas transmittance and the visible light transmittance were measured. FIG. 1 shows the relationship between gas permeability and film thickness, and FIG. 2 shows the relationship between visible light transmittance and film thickness. Transmittance of oxygen in the film thickness 50nm ^{is, 0.5cc / m 2 / 24hr (} 1 atm)
Met.

Example 2 A 100-μm thick PES film was used as a substrate film, and a 100 nm-thick film was formed by a magnetron sputtering method using SiO ₂ and PTFE as targets, and a bending test was conducted. A film was prepared by changing the value of the molar composition ratio PTFE / MO of the film, and the curvature radius when cracks were generated was investigated. FIG. 3 shows the relationship between the radius of curvature in which a crack is generated and the molar composition ratio PTFE / MO.

Example 3 A PES film having a thickness of 100 μm was used as a base film, and a film was formed by changing the molar composition ratio PTFE / MO of the film by targeting SiO ₂ and PTFE by a magnetron sputtering method. The transmittance was measured. Figure 4
It shows the relationship between the molar composition ratio PTFE / MO and the transmittance of visible light.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between gas permeability and film thickness of a gas barrier layer.

FIG. 2 is a diagram showing the relationship between the transmittance of visible light and the film thickness of a gas barrier layer.

FIG. 3 is a curvature radius in which a crack is generated and a molar composition ratio P.
The figure which shows the relationship of TFE / MO.

FIG. 4 is a diagram showing the relationship between the transmittance of visible light and the molar composition ratio PTFE / MO.

FIG. 5 is a schematic view showing a layer structure of the conductive film of the present invention.

FIG. 6 is a schematic diagram showing a layer structure of a conductive film of the present invention.

FIG. 7 is a schematic diagram showing a layer structure of a conductive film of the present invention.

FIG. 8 is a schematic diagram showing the layer structure of the conductive film of the present invention.

[Explanation of symbols]

 1 Polymer Film Base Layer 2 MO + PTFE Thin Film Layer 3 Transparent Conductive Film

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location C08K 3/22 C08L 27/12 KJG 9166-4J 81/06 LRF 7308-4J

Claims (2)

[Claims] 1. Silicon oxide, aluminum oxide, magnesium oxide, on at least one surface of a polymer film substrate,
At least one metal oxide (hereinafter abbreviated as MO) selected from the group consisting of titanium oxide and zirconium oxide and polytetrafluoroethylene (hereinafter abbreviated as PTFE) are in a molar ratio of MO: PTFE = 0.04. A high gas in which a thin film layer having a thickness of 10 to 500 nm having a composition of 0.4 to 0.4 is formed, and a transparent conductive film containing indium oxide as a main component is formed on at least one of the film base materials. Barrier transparent conductive film. 2. The transparent conductive film having a high gas barrier property according to claim 1, wherein the polymer film substrate is polyether sulfone.