JPH0768691A - Transparent conductive film - Google Patents

Abstract

PURPOSE:To continuously apply function imparting processing containing a heating process to the rear surface of the transparent conductive membrane forming surface of a heat-resistant transparent conductive film by a roll process. CONSTITUTION:A transparent conductive membrane is laminated to a plastic film substrate with a glass transition temp. of 120 deg.C or higher and a protective film wherein a self-adhesive layer with a thermal decomposition temp. of 120 deg.C or higher and tackiness of 50g/cm or less is provided on a plastic film substrate with a glass transition temp. of 120 deg.C or higher is further laminated to the membrane through the self-adhesive layer. By this constitution, the processing enhancing the quality and function of a film liquid crystal display element, a dispersion type electroluminescent element or a transparent touch panel input device can be applied by continuous process good in productivity.

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 used for a film liquid crystal display device, an organic dispersion type electroluminescence device, a transparent touch panel input device and the like.

[0002]

2. Description of the Related Art Conventionally, a transparent conductive film obtained by laminating an oxide thin film of indium and tin on the surface of a polyester film by a method such as sputtering has been used as a film liquid crystal display element or an organic dispersion type electroluminescence element. It is used as a material for transparent electrode substrates of transparent touch panel input devices. However, since a thin film exhibiting a transparent conductive function usually has a thickness of 0.1 μm or less and is vulnerable to mechanical rubbing or hitting, careful handling is required. It is possible to prevent this thin film from being damaged by bonding a protective film during transportation and storage, but in processing the element or device, it may include a step of heating to a high temperature. Since there is nothing with high heat resistance, the surface of the transparent conductive thin film is cut into cut sheets so as not to be scratched and fixed to a glass plate or the like, and then processed into single sheets. In addition, an undercoat layer may be applied between the transparent conductive thin film and the base material film so that it will not be damaged even if it is rubbed or hit, and the type, composition and crystal structure of the transparent conductive thin film can be improved. ing. However, the single-wafer processing loses the maximum advantage of allowing the film to be processed in the roll process as a continuous body, and there is no problem even if it comes into contact with the transfer roll in the roll process. Is eager to develop. on the other hand,
Examination of undercoats and thin films has not yet yielded sufficient results. Conventionally, a transparent conductive film has been developed which is not damaged by heat even if a heating step of 120 ° C. or more is added in the processing process. This makes it possible to form a barrier layer on the back surface of a film having a transparent conductive thin film laminated thereon by a heating process and to laminate a heat resistant polarizing plate and a retardation film at a thermal process. However, continuous processing of the film by a roll process has a problem of damage to the transparent conductive thin film.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a heat-resistant material which can be continuously processed by a roll process in which a heating step of 120 ° C. or higher is not added to the working process and the transparent conductive thin film is not damaged. It is to provide a transparent conductive film.

[0004]

Means for Solving the Problems In order to solve the above problems, the present invention is a thin film of a heat-resistant transparent conductive film obtained by laminating a thin film 1 having transparent conductivity on a plastic film 2 substrate having a glass transition temperature of 120 ° C. or higher. A plastic film 3 having a glass transition temperature of 120 ° C. or higher and a pressure-sensitive adhesive layer 4 having a thermal decomposition temperature of 120 ° C. or higher and an adhesive force of 50 g / cm or less is provided on the base of the protective film via the adhesive layer. It was solved by sticking together.

Examples of the plastic films 2 and 3 having a glass transition temperature of 120 ° C. or higher include films made of resins such as polycarbonate, polyarylate, polysulfone, polyethersulfone, polyetherimide and polyetheretherketone. Pyrolysis temperature is 120
Adhesive layer 4 having an adhesive force of 50 g / cm or less at a temperature of ℃ or more
The adhesive material used for is selected from acrylic adhesive material, silicone adhesive material, EVA resin adhesive material and the like. A coating or extrusion laminating method is used to provide the adhesive material on the surface of the plastic film. The adhesive force between the surface of the plastic film and the adhesive must be sufficiently larger than the adhesive force between the transparent conductive thin film 1 and the adhesive layer 4.
For that purpose, corona treatment or primer coating on the surface of the plastic film is effective.
The adhesive force between the transparent conductive thin film 1 and the adhesive layer 4 is 50 g / cm.
In the case of the above, it becomes difficult to peel off, a special design is required for the automatic peeling mechanism in the roll process, the productivity is hindered, and the transparent conductive thin film may be damaged during peeling, which is not preferable. The thickness of the plastic film is preferably thin in terms of cost, but is thicker in terms of the reinforcing effect of the transparent conductive film in a laminated state. It is preferable that the thickness of the pressure-sensitive adhesive layer 4 is thin because the heat resistance of the plastic film of the base material is not easily impaired. The glass transition temperature of the adhesive is 120 ° C.
Even if it is less than the following, the adhesive function is not impaired even at high temperature, so that there is no problem.

As the transparent conductive thin film 1 in the present invention, an indium oxide (I) containing 5 to 10 wt% of tin is used.
TO) is most suitable, but oxides such as gold, silver, palladium, nickel, cadmium, antimony and zinc can also be selected. As a method for laminating these thin films on a plastic film, a vacuum vapor deposition method, a sputtering method,
The ion plating method is selected. Before forming the transparent conductive thin film, it is also effective to apply an undercoat to the surface of the plastic film to improve the adhesion.

[0007]

Example 1 A roll-shaped polyetherimide film (Sumilite FS-1450 manufactured by Sumitomo Bakelite Co., Ltd.,
A glass transition temperature of 216 ° C. and a thickness of 25 μm) was coated with an acrylic pressure-sensitive adhesive material to a thickness of 5 μm to prepare a heat resistant protective film. This heat-resistant protective film was also undercoated on a polyether sulfone film (Sumilite FS-5300 manufactured by Sumitomo Bakelite Co., Ltd., glass transition temperature 223 ° C., thickness 100 μm) in the same roll shape, and ITO was sputtered onto the surface of the film. And thickness is 0.0
The transparent conductive film having a thickness of 3 μm was attached to the ITO surface. A roll of this laminated film is unrolled, and a barrier property imparting varnish containing polyvinyl alcohol as a main component is applied by a reverse coater on the surface on which the heat-resistant protective film is not attached, and the roll is continuously dried in a dryer at 150 ° C. for 10 minutes. It was transferred, dried and then wound again. Even in the dryer, the heat-resistant protective film was not peeled off or deformed. There were 50 supporting rolls in contact with the heat-resistant protective film side of this coating and drying machine, but the heat-resistant protective film of the wound laminated film was peeled off and the ITO surface was magnified 100 times with a polarizing microscope equipped with a differential interference device. No scratches were observed on the ITO surface even when observed with.

(Example 2) Polycarbonate resin (GE
Heat resistance by extruding and laminating EVA resin (Evaflex manufactured by Mitsui DuPont Co., Ltd.) on one of the surfaces of Pexan 141 made of P and glass transition point 145 ° C. to form a film of 300 μm by the extrusion film forming method. A protective film was prepared and wound into a roll. This heat-resistant protective film was also extruded into a roll-shaped polycarbonate film (glass transition temperature 145 ° C., thickness 300 μm).
m) was undercoated, and ITO was attached to the ITO surface of a transparent conductive film having a thickness of 0.1 μm formed on the surface by sputtering. A phase difference plate (thickness 1 was prepared by uniaxially stretching a polycarbonate film by applying an epoxy resin adhesive to the surface of the laminated film which is unrolled and having no heat-resistant protective film attached thereto while unrolling.
00 μm) and they are bonded by a belt type continuous heating press under heating conditions of 120 ° C., 2 Kg / cm ² , and 5 minutes,
I wound up again. The heat-resistant protective film was not peeled or deformed even after pressing. The belt surface was in full contact with the surface on the heat resistant protective film side,
Peel off the heat-resistant protective film of the wound laminated film I
No scratches were observed on the ITO surface even when the TO surface was observed at 100 times with a polarizing microscope equipped with a differential interference device.

Comparative Example 1 The barrier coating of Example 1 was applied without attaching a heat resistant protective film on the ITO surface. When the ITO surface after coating was observed with a polarizing microscope equipped with a differential interference device at a magnification of 100 times, numerous scratches that were considered to be caused by contact with the supporting roll of the coating dryer were observed on the ITO surface. (Comparative Example 2) The barrier coating of Example 1 was heat-resistant with a protective film (Sanitec E manufactured by San-A Chemical Industry Co., Ltd.) having a polyester film having a glass transition temperature of 80 ° C. as a base and an acrylic adhesive applied thereto. When it was used instead of the protective film, the polyester film contracted inside the drier, causing uneven coating of the coating film. (Comparative Example 3) The barrier coating of Example 1 was heat-resistant with a protective film (Sanitec PAC manufactured by San-A Chemical Co., Ltd.) in which EVA resin was co-extruded and laminated on a polyethylene film having a glass transition temperature of -125 ° C. When it was used instead of the protective film, the polyethylene film contracted after leaving the dryer, the whole laminated film curled greatly, and it was bent and damaged by the support roll.

[0010]

EFFECTS OF THE INVENTION According to the present invention, it is possible to perform a process requiring a heating step on a back surface of a transparent conductive film having a high heat resistance on which a transparent conductive thin film is formed, in a continuous process in a roll shape. Become.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an embodiment of the present invention.

Claims (1)

[Claims] 1. A plastic film substrate having a glass transition temperature of 120 ° C. or higher is laminated with a transparent conductive thin film, and a plastic film substrate having a glass transition temperature of 120 ° C. or higher is further deposited on the thin film, and a thermal decomposition temperature is set. Is 120 ° C
A transparent conductive film, characterized in that the protective film provided with an adhesive material layer having an adhesive force of 50 g / cm or less is bonded via the adhesive material layer.