JPH02160310A - Transparent conductive film - Google Patents

Abstract

PURPOSE:To cause the film in the title to have conductivity not only along the direction of its surface but also along that of thickness, by forming a transparent, conductive thin film made of metal oxide on the surface of a porous plastic film, and fixing conductive materials also in the micro holes of the film. CONSTITUTION:A transparent, conductive thin layer made of metal or metal oxide is formed on the surface (a single face or both) of a porous plastic film and the metal or metal oxide is fixed also in the micro holes of the film. For the metal or metal oxide, indium, tin and cadmium, etc., are mentioned as the metal, and tin oxide, indium oxide, etc., as the metal oxide. The thin layer of metal or metal oxide formed on the surface of the porous plastic film and the metal or metal oxide fixed in the micro holes of the film are in contact with each other for electrical conduction, so that conductive passages are formed along both the direction of the surface and that of thickness of the film.

Description

DETAILED DESCRIPTION OF THE INVENTION (#:Field of Application) The present invention relates to a transparent conductive film that uses a plastic film as a base material and has 24-dimensional conductivity not only on its surface but also in its thickness direction.

(Prior Art) A transparent 2!4 electroporated film in which a thin film of metal or metal oxide is provided on a plastic film surface is already known (Japanese Patent Laid-Open No. 74838/1983).

JP-A No. 61-74839, etc.).

And, the transparent conductive film used in the process includes electrodes for liquid crystal displays, electrodes for electroluminescent display devices, electrodes for conductive light-guiding photoreceptors, Brown Kan, Tanizashi Measuring Instruments, etc. It can be used for various oak applications such as the window part of Shizuka / l11.

By the way, the above-mentioned conventional transparent 4-layer film VC2K4
#lIL property is naturally limited to the in-plane direction of the film, and the conductivity f! in the film thickness direction. It does not indicate sex money.

(Problem to be solved by the invention) Therefore, the present invention is applicable not only to the surface direction of the film.

The overall objective is to provide a transparent film r that is conductive even in the thickness direction.

(Elaborate means to solve problems) This is the result of repeated studies by the inventor to achieve the above objective.

A porous plastic film having countless micropores is used as a base material, and a transparent conductive thin layer made of metal or metal oxide is formed on the surface of the film, and at the same time, the above-mentioned conductive substance is also formed in the micropores. By electrodeposition, passages can be formed in the surface direction and thickness direction of the film, and the film is pressed to a lever under 1k IP #constant temperature condition 1. It was discovered that by minimizing the diameter of the micropores, the film could be made transparent to the extent that it could be used for practical purposes. 1. The present invention was completed. Tightening 1 Then, the porous plastic film is pressed under a temperature condition higher than the melting point of the plastic, and the film is compressed. This is obtained by making it transparent.

The material of the porous plastic film used in the present invention is not particularly specified, but has the heat resistance required for the use of the transparent conductive film obtained by the film,
Preferred examples of this porous plastic film include polyethylene (hereinafter referred to as PE), ultra high molecular weight polyethylene (hereinafter referred to as PE), which can be selected depending on the mechanical strength.
UIiPE,! PTFE) and polytetrafluoroethylene (hereinafter referred to as PTFE).

The thickness, porosity, and diameter of the micropores of this porous plastic film are not particularly critical.

Normally, the thickness is about 0.01 to 2 lines, and the average pore diameter is about 1 to 30 μm.
.

The porosity is about 10-90%.

Various methods for manufacturing such porous plastic films have been described by Jfl et al. For example, a porous UrlPE film is prepared by mixing UdPg powder and a monomer and stretching the resulting composition into a film as described in JP-A-50-126763. It can be obtained by a method of molding and then removing the liquid from the molded product.

Also, JP-A No. 5T)-141665, JP-A No. 5O
-1436L) Publication No. 6 or Jikai 14551-21
UHP 1g8 tied by the method described in Publication No. 910
It can also be obtained by a method in which the porous cylindrical body is then cut into a film shape by RIJ.

Patent application 1988-192480 related to the proposal of the applicant
A porous UMPE film can also be obtained by the method described in the specification of the patent.
The method vC disclosed in Japanese Patent Publication No. 51-18991 and the like can be used. for example.

PTFE powder wood and liquid lubricant (naphtha, fluid) rough-in 4 ml are mixed in a predetermined ratio, this mixture is compressed and pre-molded, and further extruded, rolled, etc. to form a film-formed VC.
A method in which the liquid lubricant is removed and then stretched to make it porous (after this stretching, the stretched state is maintained and heated to the temperature of the melting point of PTFE, yielding a PTFE porous film of g8. ) can be applied.

To obtain the transparent film of the present invention, first of all.

Surface of porous plastic film (double-sided or single-sided)
Forms a transparent tetraelectric thin layer made of Vζ metal or metal oxide, and also contains gold within the micropores! Alternatively, a metal oxide is specified.

As these metals or metal oxides, those conventionally used in the production of transparent conductive films can be used. Specific examples of metals include indicum, tin, cadmium, nm, titanium, antimony-6 aluminum, tungsten, and moly. Puden, chrome, mental, nickel, S gold, gold, silver.

Examples include steel and palladium. Examples of metal oxides include tin oxide, indium oxide, indium oxide-tin oxide mixture, tin oxide-antimony mixture, and the like.

Table 11IIli of porous plastic film and incorporation of metal or metal oxide into micropores, L4f process, evaporation method.

This can be done by known thin film forming techniques such as sputtering and plating.

However, there is a transparent abrasive gorilla that includes the above-mentioned four-core gIJ.

"Since it is commercially available under the name Shintoronco (Shinto Paint Co., Ltd.), etc., there is a method of applying it to a porous plastic film with this paint and heating and drying it. A conductive substance can be applied to the surface 2 and within the micropores of the porous film at a constant current by a method of drying with heat.

By the above operation, a thin layer of gold f4 or gold li4 oxide is formed on the surface of the porous plastic film. Thin layer and film micropore P3vc fixed 4
Contact conduction occurs between the metal oxide and the surface direction 2 of the film.
Thus, a VC4m path in the thickness direction is formed.

2. The thickness of the thin layer is 1-1 as long as the transparency of 1-2 and the conductivity can maintain practicality! Although it can be set as desired, it is usually about 1 uuoX or more.

To obtain the transparent conductive film of the present invention, the porous plastic film in which the metal or metal oxide is fixed in the fine pores on the A side is first pressed. This pressurizing step is to make the porous plastic film transparent, and is carried out by setting the temperature above the melting point of the plastic film.

〃Although the mouth pressure can be carried out in a batch method using a hot press, there is a method in which the porous plastic film is passed through one or more pairs of rolling rolls maintained at a temperature higher than the melting point of the plastic. The method of heating and pressurizing with a conveyor belt like a press is used for continuous production.

The degree of pressure applied may vary depending on factors such as temperature and the thickness of the porous plastic film, but is typical.

The thickness of the film after pressing is set to about 90% or less, preferably about 40 to 60%, of the thickness before pressing.

Assuming the above (Dtlu cut uEE degree), the total transmittance should be approximately 80% or more while maintaining the level of metal or metal oxide on the surface of the porous plastic film and within the micropores. It was found that the V'C pore diameter could be minimized and transparency could be achieved.

During this pressurization, in order to prevent tin from forming on the surface of the porous plastic film, an Alt heat-retaining film (fluorine d Jll film, polyimide film, polyethylene terephthalate film, etc.) are preferably worked together.

(Example) Hereinafter, the entire history of the present invention will be explained in detail with reference to Examples.

Examples Thickness: 50μ, porosity: 30%, average pore size: 5μ.

An opaque porous PE film with a melting point of 125°C is placed in a plating bath, and the thickness is rUU on both sides of the plate.
A transparent tin thin l- layer is formed, and tin gold is also fixed in the micropores. Resistance to drowsiness after being pecked was IXIυΩ/α in the fitting direction, 0 (IXIUΩ/1 in the thickness direction), and bidirectional conductivity was observed.

Next, this porous PE film was sandwiched between two PTFE protective films and passed through a pair of metal rolling rolls maintained at a temperature of 2 LIU"C, thereby reducing the thickness of the porous PE film. Pressure was applied to a thickness of 30 μm to obtain a transparent conductive film.

The electrical resistance of this transparent 4-electronic film has a plane direction of IXH)
Ω/(1m, thickness direction is l x 11) il/G
m, bidirectional conductivity, and total light transmittance of 82% (J
IS-67141/C) and has sufficient transparency.

Example 2 Thickness lυOAtm, pores $60%, average pore diameter 0.
On both sides of an opaque porous P TFE film (unfired film) with a 6μ groove and a melting point of 327°C, a transparent 4-density paint (manufactured by Oshizuka Toyo Co., Ltd., trade name: Nntron) with Injikum's motto was applied, and the temperature was 15υ. Heat and dry at °C for 5 minutes.

As a result, transparent indium thin layers each having a thickness of IIJOOA are formed on both sides of the porous PTFE film, and indium is also fixed in the micropores. Next, this porous PTFE film fr, two sheets By passing between a pair of metal rolling rolls, the polyimide-wrapped film was maintained at a diameter of 35υ'CK and a temperature of 35υ'CK.

Pressure was applied so that the porous PTFg film had a thickness of 50μ, and the f'rFE film as a base material was formed to form an n-order transparent conductive film.

The electrical resistance of this transparent conductive film is 1×10 in the plane direction.
Ω/cut, thickness direction is 1×10 Ω/c! In IL,
When poured in two directions 4', the total fused permeability was 85%.

It had sufficient transparency.

Example 3 Groove thickness 100μ, porosity 50%, average pore diameter 10μ
An opaque porous PE film with a melting point of 13°C (1°C) was soaked in 4ilc liquid and pulled up.
Heat dry at 2Lj°C for 113 minutes).

The conductive bath liquid used is tin oxide powder (average particle size 0.2 μm), 11! Indicum (average particle size 0.2μ)
rp<) & th4PE powder (average particle size 6μ groove) as a binder was distributed so that the actual weight ratio was 1:1:1, and the total concentration of these three was 30%. To achieve this, we used a material in which V was dispersed with toluene and V.

On top of this, one layer of porous UklPE-y film was added on each side, and a 1A 11% transparent tin oxide-indium oxide thin film was added (a thin film in which both oxides were dispersed in UklPE as a binder). )m) was formed, tin oxide-indium oxide was also fixed on the VC@hole. The electrical resistance after this work is IXIU'Ω/1 in the plane direction,
The thickness direction is 1X10 Ω/(:!IL, and it is 4-electroelectric in two directions.

Next, this porous Uf (PE film) was
The porous 1 is sandwiched between E-made protective films and passed between a pair of metal pressing rolls maintained at a temperature of 2 (JO°C).
The original pressure was applied so that the thickness of the PE film was 90 μm to obtain a transparent conductive film.

The electrical resistance of this transparent conductive film is lXl0 in the plane direction.
Ω/cI! L, the thickness direction is IXI (JΩ/), so it is bidirectionally conductive, and the total transmittance is 80%.

I was captivated by its luminous transparency.

(Effects of the Invention) The present invention is structured as described above, and since the metal or metal oxide is fixed not only on the surface of the base film but also in the thickness direction, It is possible to provide a transparent film that shows two-way four-fold injection.

Machi FtF Taganito Hizuka Giko Co., Ltd. Representative: Goro Kama

Claims (1)

[Claims] A thin layer of metal or metal oxide is formed on the surface of the porous plastic film, and the metal or metal oxide is also fixed in the micropores, and then the porous plastic film is heated at a temperature higher than the melting point of the plastic. A transparent conductive film obtained by applying pressure to make the film transparent.