JPH02239518A - Manufacture of transparent conductive laminated body - Google Patents

Abstract

PURPOSE:To enhance the transparency and heat insulating property of a transparent conductive laminated body by subjecting the surface of a film base material to the high-frequency spatter etching treatment, and then forming a conductive thin film while continuing the treatment. CONSTITUTION:A long-sized PET film 1 as a base material is set in a vacuum container 2. After the inside of the vacuum container 2 is exhausted, algon gas is introduced therein and a high-frequency voltage is applied to a main can 9 and a film 1 is moved while being caused to discharge, and the high frequency spatter etching treatment is carried out. After the spatter etching treatment, the film 1 wound up is moved in the reverse direction and oxygen gas is continuously introduced therein to make a mixed gas atmosphere of algon gas and oxygen gas, and the high-frequency spatter etching treatment is carried out and an ITO thin film is formed simultaneously by the reactive DC magnetron spattering method using an alloy target (10) of In and Sn, thereby fabricating a transparent conductive laminated body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a transparent conductive laminate comprising a transparent conductive thin film provided on the surface of a transparent plastic film base material. [Prior Art] This type of transparent conductive laminate is widely used in various applications such as organic dispersion EL (electroluminescence) and transparent electrodes of touch panels, as well as antistatic and electromagnetic shielding. As a conductive thin film, ITO (Ind
A method using a thin film of Tiri Oxide (Tiri Oxide) is particularly well known. [Problems to be Solved by the Invention] By the way, the above-mentioned ITOi film is generally formed on a substrate such as a glass plate at a high temperature of 300 to 500°C, but when a plastic film is used as a base material, Due to its heat resistance, it must be formed at a temperature of 200° C. or lower.

For this reason, in transparent conductive laminates based on plastic films, the transparency of the conductive thin film is inferior to those based on glass plates, etc., and their heat resistance is insufficient. However, there were disadvantages such as an increase in resistance when used at high temperatures. In view of the above circumstances, the present invention aims to improve the transparency and heat resistance of a transparent conductive laminate using a transparent plastic film as a base material. [Means for Solving the Problems] As a result of intensive studies to achieve the above object, the present inventors discovered that prior to forming an XTO thin film etc. on the surface of a plastic film base material, The present invention was completed based on the knowledge that if the surface is subjected to a specific etching treatment and the above-mentioned thin film is formed while this treatment is continued, the transparency and heat resistance of the thin film improve.

In addition, in the present invention, when forming a transparent conductive thin film such as a DrO thin film on the surface of a transparent plastic film base material, the surface of the film base material is subjected to high frequency sputter etching treatment, and then this treatment is performed. The present invention relates to a method for manufacturing a transparent R-conductive laminate, which is characterized in that the above-mentioned conductive thin film is formed in succession. [Structure and operation of the invention] The material of the plastic film base material in the present invention is not particularly limited as long as it is transparent, and various materials can be used. Strength. From the viewpoint of heat resistance, it is most preferable to use a polyethylene terephthalate (hereinafter referred to as 1) ET film. The thickness of this film base material is usually about 15 to 200 μm.

In the present invention, the surface of such a plastic film base material is first subjected to high-frequency sputter etching treatment.
This high frequency spatter etching process is
As disclosed in Japanese Patent Application No. 22108, etc., a high frequency voltage is applied between both negative and positive electrodes in a vacuum container, and positive ions generated by the discharge are accelerated in the dark part of the cathode where the ion energy is large in the discharge region. This is made to collide with the surface of a plastic film base material placed on the cathode, thereby etching the base material surface.

The device for this purpose consists of a cathode and an anode placed facing each other in a vacuum container, the cathode being connected to a high frequency power source via an impedance matching box, and the anode being connected to the ground side of the high frequency power source. Furthermore, a shielding electrode is disposed outside the cathode and maintained at ground potential. Examples of such devices include those disclosed in the above-mentioned gazette and other publications such as Japanese Patent Publication No. 56-1337 and Japanese Patent Publication No. 56-1340.

In this high-frequency sputter etching process, the atmospheric gas is not particularly limited, but from the viewpoint of adhesion between the base material and the conductive thin film, argon gas is generally used alone, or argon gas is used as the main gas, and nitrogen gas or helium gas is used. It is preferable to use a mixed gas containing other gases such as , neon gas, hydrogen gas, oxygen gas, and air. In addition, the atmospheric pressure, that is, the degree of vacuum consisting of such a gas composition, is usually 1 × 1 O - l X 1 0 -' TOr
, especially IXlOI~IX10-"Tor
It is preferable to set it within the range of r. If the vacuum is too high, the glow discharge tends to become unstable, and if the vacuum is too low, it is difficult to obtain good results in terms of adhesion between the base material and the conductive thin film.

Furthermore, the amount of discharge treatment expressed as the product of the high frequency output (W/1) per unit area of the electrode and the discharge treatment time is usually 0.
It is best to set it in the range of 1 to 30 W・sec/Cj. If this processing amount is too small, a sufficient effect cannot be obtained; on the contrary, ζ
If it becomes too strong, the film base material may be deformed or colored, which is not preferable.

In the present invention, after performing such a high frequency sputter etching process, the above gas atmosphere is maintained, or after being evacuated to a high vacuum, the same gas as above is introduced and the same degree of vacuum is adjusted. Then, while continuing the high-frequency sputter etching process described above, a transparent conductive thin film is formed. Here, if the high-frequency sputter etching process is stopped when forming the conductive thin film, the effect of improving the transparency and heat resistance of the thin film is reduced, as is clear from the comparative examples described later. This is because favorable changes occur in the adhesion of the thin film formed thereon to the substrate surface and the film structure due to the high-frequency sputter etching treatment applied in advance.
This seems to be because, while this change is well maintained by continuing the above treatment, this retention effect is lost when the above treatment is stopped. As the material for the transparent conductive "In!", various conventionally known materials can be used, but the above-mentioned ITO thin film is particularly preferred from the viewpoint of transparency and conductivity.
As a target, an alloy of In and Sn or In
, O, and SnO2, a film is formed by DC magnetron sputtering according to a conventional method. The thickness of the conductive thin film varies depending on the material and purpose of the thin film, but it is usually appropriate to set the sheet resistance to 20 to 5,000 Ω/mouth for about 20 to 2,000 people. ．． The transparent conductive laminate obtained in this way can maintain the transparency of the conductive thin film even if the temperature at which the thin film is formed does not adversely affect the plastic film base material, for example, at a temperature of 200°C or lower. It is characterized by excellent heat resistance. Therefore, the transparent conductive laminate obtained by the method of the present invention can be used very effectively for the various applications mentioned above. [Effects of the Invention] According to the method of the present invention, it is possible to easily improve the transparency and heat resistance of a transparent conductive laminate using a plastic film base material.

〔Example〕

Next, embodiments of the present invention will be described to provide a more comprehensive explanation.

Example 1 A long PET film sheet having a thickness of 100 μm as a base material is set in a vacuum container 2 as shown in the drawing. Inside the vacuum container 2, a feeding outlet 3, a take-up roll 4, guide rolls 5 to 8, a main can 9, and a target 10 for forming a thin film are arranged. one end of which is wound onto the take-up roll 4.
I am guided by. Note that 11 and 12 are gas supply units for supplying argon gas and oxygen gas into the vacuum container 2. First, the inside of the vacuum container 2 is filled with 4XlO-'T using a vacuum bomb.
After evacuating the chamber to a pressure of less than orr, argon gas was introduced and the degree of vacuum was adjusted to 3X10-'Torr. Then,
High frequency power was applied to the main can 9, and the film 1 was moved while being discharged to perform high frequency sputter etching. The high frequency power at this time was 0.05 W/1, and the processing time was 30 seconds. After this sputter etching process, the film l
4XIO-'
After adjusting the degree of vacuum to Torr, high-frequency sputter etching is performed, and at the same time, reactive DC magnetron sputtering is performed using a target IO made of an alloy target of In and Sn (Sn is IO by weight% relative to In). , ITOF with sheet resistance of 300Ω/mouth
iI. A film was formed to produce the desired transparent conductive laminate. Comparative Example I A transparent conductive laminate was produced in the same manner as in Example 1, that is, by the conventional method, except that high-frequency sputter etching was not performed before and during the formation of the ITO thin film. Comparative Example 2 A transparent conductive laminate was produced in the same manner as in Example 1, except that the high-frequency svanter etching treatment was not performed only during the formation of the ITO thin film. Example 2 A transparent conductive laminate was produced in the same manner as in Example 1, except that an ITO thin film with a sheet resistance of 300 Ω/mouth was formed using an alloy target in which the amount of Sn was 5% by weight relative to In. was created. Comparative Example 3 A transparent conductive aS body was produced in the same manner as in Example 2, except that the high-frequency swirler etching process was not performed only when forming the ITO thin film.

Example 3 In. A sintered body of O, and SnOz (SnO. is ■n, 0,
A transparent conductive laminate was produced in the same manner as in Example 1, except that an ITO thin film with a sheet resistance of 300 Ω/hole was formed using a target consisting of 10% by weight of 10% by weight). Comparative Example 4 A transparent conductive laminate was produced in the same manner as in Example 3, except that the high frequency sputter etching treatment was not performed only when forming the ITO thin film.

The transparency and heat resistance of each of the laminates according to Examples 1 to 3 and Comparative Examples 1 to 4 above were examined by the following methods.

The results were as shown in the table below. <Transparency> Light transmittance at a wavelength of 550 ns was measured using a spectrophotometer. Heat resistance〉 Sheet resistance R after being left in an oven at 175℃ for 1 hour,
, and the initial sheet resistance R. rate of change in resistance (R
l/R@) was calculated. Note that the sheet resistance is Van
It was measured by the method of der Paw. As is clear from the above table, the method of the present invention makes it possible to produce a transparent conductive laminate with excellent transparency and heat resistance.

[Brief explanation of drawings]

The drawing is a schematic diagram showing an example of the configuration of an apparatus used in the method of the present invention. l...Plastic film base material, 10...Target for thin film formation Patent applicant Nitto Denko Corporation

Claims (1)

[Claims] (1) In forming a transparent conductive thin film on the surface of a transparent plastic film base material, the surface of the above film base material is subjected to high frequency sputter etching treatment, and then this process is continued while forming the above conductive thin film. A method for producing a transparent conductive laminate, characterized by: