JP3148368B2 - High gas barrier transparent conductive film - Google Patents

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 based on a polymer film, and more particularly, to a transparent conductive film having a high gas barrier property. The present invention relates to a high gas barrier transparent conductive film which can be suitably used.

[0002]

2. Description of the Related Art Conventionally, glass has been used as a base material of a transparent conductor for liquid crystal display. However, in recent years, it has been light weight, easy to enlarge a large area, does not crack, and has excellent workability. Transparent conductive films having such a property have been used for electrodes. However, it has been found that when a conductive film is used, water vapor and oxygen passing through the film cause deterioration of the performance of the liquid crystal element. In order to solve such a problem, it has become clear that it is necessary to impart a barrier property against gas to the film substrate.

In order to provide a barrier property against 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 has been disclosed a transparent conductive film in which a layer of an oxide such as O ₃ or aluminum nitride is provided, and a film containing indium oxide as a main component is formed on at least one surface of these polymer layers (for example, Japanese Patent Application Laid-Open No. 59-204545, JP-A-63-2
05094). However, these oxide and nitride thin films have some degree of transparency and gas barrier properties, but lack the flexibility because the properties of the thin films themselves are equivalent to those of ceramics, and cracks occur in the thin films. It is easy to enter and the barrier property is insufficient, and the characteristics of the polymer film cannot be fully utilized.

In order to obtain a high gas barrier property,
When a metal such as aluminum used in the field of packaging materials is deposited, there is a defect that the transmittance of visible light is impaired at all.

[0005]

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

[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, no crack is generated even in a bending test, and the gas permeability is low. 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 the polymer film substrate And polytetrafluoroethylene (PT
FE) is a sputtered layer composed of metal atoms (M), oxygen atoms (O), carbon atoms (C), and fluorine atoms (F) obtained from a raw material, and the molar ratio of the atoms in the sputtered layer (C +
F) / (M + O) was found to have a layer (MO + PTFE thin film layer) having a specific thickness of 0.04 to 0.4 (MO + PTFE thin film layer), and the present invention was reached.

That is, according to the present invention, a silicon oxide, an aluminum oxide,
At least one metal oxide (MO) selected from the group consisting of magnesium oxide, titanium oxide, and zirconium oxide and metal atoms (M) obtained from polytetrafluoroethylene (PTFE) as raw materials, oxygen atoms ( O), a sputtered layer comprising carbon atoms (C) and fluorine atoms (F),
And the molar ratio (C + F) / (M + O) of the atoms in the sputtered layer is
A thin film layer (MO + PTFE thin film layer) having a thickness of 10 to 500 nm (0.04 to 0.4) is formed, and at least one of the film substrates is a transparent conductive film mainly containing indium oxide. And a transparent conductive film having a high gas barrier property.

The transparent conductive film of the present invention can have various modes. For example, FIGS. 5 to 8 show examples. Here, 1 is a polymer film substrate,
2 is an MO + PTFE thin film layer, and 3 is a transparent conductive film.

In the present invention, the polymer film serving as the base material is not particularly limited. However, since the temperature of the transparent conductive film is 100 ° C. to 200 ° C. in the production process, it is desirable that the polymer film has a certain degree of heat resistance. Examples thereof include polyethersulfone, polycarbonate, polyimide, and polyolefin film, and particularly preferred are polyethersulfone and polyimide. The thickness of the substrate film is not particularly limited, but is usually 5 to 1000.
A size of about μm is usually used. Of course, other than this can be used according to the purpose.

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

The method of measuring the film thickness in the present invention includes a method using a stylus roughness meter, a repetitive reflection interferometer, a microbalance, a quartz oscillator, and the like. The method is suitable for obtaining a desired film thickness because the film thickness can be measured during film formation. MO + PFT
As the molar ratio of atoms in the E thin film (C + F / M + O) increases, the flexibility increases, but on the other hand, transparency decreases, so that the molar ratio (C +
The range of (F / M + O) is preferably from 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 it can be formed by a physical vapor deposition method such as a known film forming method such as a magnetron sputtering method or an ion beam sputtering method. Also, as appropriate
Vacuum evaporation, electron beam evaporation, and ion plating can be combined. Since the base material is a polymer material and has poor heat resistance compared 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 targeted and sputtered 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,
In the case of manufacturing by a reactive ion plating method or the like, PTFE is controlled by controlling the flow rate of fluorocarbon.
Can be controlled. The composition can be measured by infrared spectroscopy or X-ray photoelectron spectroscopy.

Before forming the MO + PTFE thin film, surface treatment such as corona discharge treatment, plasma treatment, glow discharge treatment, reverse sputtering treatment, surface roughening treatment, chemical treatment, etc., or a known under treatment is applied to the polymer film base material. It is also preferable to appropriately perform the application of 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 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 has the following excellent effects because it is constructed as described above. (1) Excellent gas barrier properties. (2) Excellent flexibility. (3) Excellent transparency. (4) Can be used as an electrode.

[0015]

EXAMPLE 1 A film having a molar ratio of atoms (C + F) / (M + O) = 0.1 was formed by magnetron sputtering using a PES of 50 μm as a substrate film and targeting SiO ₂ and PTFE. Created with a thickness of 10 nm to 1000 nm,
A conductive layer containing indium oxide as a main component is formed on the conductive layer.
0 nm was created. Oxygen gas transmittance and visible light transmittance were measured. FIG. 1 shows the relationship between the gas transmittance and the film thickness, and FIG. 2 shows the relationship between the visible light transmittance and the film thickness. Film thickness 50n
transmission of oxygen m is, 0.5cc / m ² / 24hr
(1 atm).

Example 2 A 100 nm-thick PES film was formed as a substrate film by magnetron sputtering using SiO ₂ and PTFE as targets, and a bending test was conducted. A film was prepared in which the value of the molar ratio (C + F) / (M + O) of the atoms in the film was changed, and the radius of curvature when cracks occurred was investigated. FIG. 3 shows the radius of curvature at which the crack occurred,
The relationship of the molar ratio of atoms (C + F / M + O) is shown.

Example 3 A film in which the value of the molar composition ratio (C + F / M + O) of the atoms of the film was changed using 100 μm PES as the base film and SiO ₂ and PTFE as targets by magnetron sputtering was used. It was prepared and the transmittance of visible light was measured.
FIG. 4 shows the relationship between the molar ratio of atoms (C + F / M + O) and the transmittance of visible light.

[Brief description of the drawings]

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

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

FIG. 3 is a diagram showing a relationship between a radius of curvature in which a crack occurs and a molar ratio of atoms (C + F / M + O).

FIG. 4 shows the transmittance of visible light and the molar ratio of atoms (C + F / M +
FIG.

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

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

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

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

[Explanation of symbols]

 Reference Signs List 1 polymer film base layer 2 sputtered layer (MO + PTFE thin film layer) 3 transparent conductive film

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08K 3/22 C08K 3/22 C08L 27/12 C08L 27/12 81/06 81/06

Claims (2)

(57) [Claims] 1. A method according to claim 1, wherein at least one surface of the polymer film substrate has silicon oxide, aluminum oxide, magnesium oxide,
A metal atom (M) obtained from at least one or more metal oxides (hereinafter abbreviated as MO) selected from the group consisting of titanium oxide and zirconium oxide and polytetrafluoroethylene (hereinafter abbreviated as PTFE) as raw materials; The sputtered layer is composed of oxygen atoms (O), carbon atoms (C) and fluorine atoms (F), and the atomic ratio of the atoms in the sputtered layer (C + F) / (M + O) is 0.
A thin film layer having a thickness of 10 to 500 nm (MO + PTFE thin film layer) of 04 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 substrates. Transparent conductive film with gas barrier properties. 2. The high gas barrier transparent conductive film according to claim 1, wherein the polymer film substrate is polyether sulfone.