JPS61281401A - Manufacture of conducting film - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to transparent synthetic resins that are essentially insulators (
The present invention relates to a method of manufacturing a conductive film without significantly reducing transparency when imparting conductivity by mixing a conductive filler to a resin (hereinafter abbreviated as "resin").

[Prior art]

In general, resins are often insulators and are used for electrical parts, insulating materials for electric wires, etc. Methods of imparting conductivity to these resins include adding a large amount of carbon filler or metal filler to the resin, applying an antistatic agent to the surface of the molded product, or coating the surface of the molded product with an ITO film. be. In the latter method, when the resin has transparency, the transparency is not impaired, but conductivity is imparted only in the plane direction of the resin.

On the other hand, the former method imparts conductivity to the entire resin, but requires the addition of a large amount of filler to obtain high conductivity, and even transparent resins almost always lose their transparency. I end up. Furthermore, various conductive polymers in which the resin itself is conductive have been developed recently, but in terms of stability and mass production, it is still a long time before they are put into practical use.

[Purpose of the invention]

The present invention has transparency and conductivity throughout the resin, which was not possible with conventional methods of adding carbon-based fillers or metal-based fillers, or methods of coating with antistatic agents or metal films such as ITO films. In order to obtain a transparent conductive film, we conducted various studies on the combination of conductive filler and resin and the method of forming the film. #1 We found that extremely high conductivity can be obtained by forming a film using a solution or liquid casting method, which does not require much heat, compared to other forming methods, and we conducted further research and developed the present invention. This is what led to this.

[Structure of the invention]

The present invention uses a mixture of 100 parts by weight of a transparent synthetic resin and 1 to 200 parts by weight of conductive mica having an aspect ratio of 3 to 60 to form a film on a support using a solution or liquid casting method. This is a method for producing a conductive film, which is characterized by peeling the conductive film from the support.

Transparent resins used in the present invention include polystyrene, l-licarbonate, z+) vinyl alcohol, polyester, polyurethane, -9 vinyl chloride, II) 4-
Methylpentene-1, cellulose triacetate, ? These include thermoplastic resins such as lyamide and polyvinyl chloride, thermosetting resins such as epoxy resins, urea resins, and melamine resins, and ultraviolet curing resins such as eixacrylate and urethane acrylate.

Further, the conductive mica used in the present invention is mica whose surface is coated with a metal or its oxide, and has an aspect ratio in the range of 3 to 6o. If the aspect ratio is less than 3, the transparency will not be reduced, but the efficiency of imparting conductivity will be extremely reduced. In addition, when the aspect ratio is 61 or more, when the mixture with the resin is dissolved in an organic solvent, the sedimentation is rapid, and when the solution is cast into a film, mica is unevenly distributed in the film, resulting in deterioration of the film appearance and poor conductivity. This will cause deviation.

The solution or liquid casting method of the present invention may be a commonly used method, such as a drum method in which a resin solution or liquid resin is cast onto a rotating drum serving as a support, or a band method in which a metal band is used as a support. Alternatively, it may be cast onto a release paper serving as a support and then wound up with the support as it is. or,
A solution or liquid resin may be poured between two flat plates such as glass plates serving as supports, dried or cooled to solidify, and then the film may be peeled off from the Nana Z-lator.

In addition, stabilizers, pigments, lubricants, etc. may be added if necessary during film formation.

The amount of conductive mica added is 1 to 200 parts by weight, preferably 10 to 200 parts by weight, per 100 parts by weight of the resin.
It is 100 parts by weight. If the amount of mica added is too small, the effect of improving conductivity will be reduced, and if it is too large, transparency will be reduced. The thickness of the film is not particularly limited, but is 5 to 100.
It is preferably within the range of 0 μm, particularly preferably within the range of 10 to 100 μm.

〔Effect of the invention〕

Using the production method of the present invention, a conductive film was obtained which had transparency that was previously impossible to obtain and had conductivity not only in the surface direction but also in the thickness direction.

We are confident that this product will be of great use in the future as an electronics-related material in areas such as recording paper and liquid crystals.

〔Example〕

(IHOOcc dichloromethane without dali carbonate (manufactured by Teijin Kasei) Gunratato L-1250W)
10 f and conductive mica (manufactured by Teikoku Kako ■) Ratio:
20-30) Mix 5F uniformly with a stirrer to make solution A.

Solution A was cast onto a release paper to form a film, and then dried at 60° C. until the weight became constant to obtain film B.

The average thickness of Film B was 60 #1.

On the other hand, as a comparative example, 2 kf of the same recarbonate and 2 kf of the same conductive mica as in Example (1) were added and kneaded in a twin-screw extruder to obtain a 7-gland C. Furthermore, con 7
The land C was extruded to obtain a film D having an average thickness of 55 cotton.

When the volume resistivity and light transmittance of Film B and Film D were measured, the following values were obtained.

(2) 250 cc of a 1=1 mixture of xylene and benzene and urethane (Takelac T- manufactured by Takeda Pharmaceutical Co., Ltd.)
1770) 5F and conductive mica (manufactured by Teikoku Kako ■, aspect ratio 5-10) 59 were uniformly mixed with a stirrer to form solution E.
make.

After casting solution E onto a glass plate, it was dried at 60° C. until the weight became constant to obtain film F. The average thickness of film F was 34 μm. Example (2) is used as a comparative example.
) Same as urethane 1kf and same conductive mica 1
After kneading and granulating KF in a 3t pressure kneader, an attempt was made to make a film of 50 #m or less by extrusion molding, but it was not possible to draw the film, so the take-up speed was reduced and a 0.5 m sheet sample G was produced. I got it.

The volume resistivity of film F and sheet GO and the light transmittance of film F were measured.
/F- level light transmittance was sufficiently maintained.

Claims (4)

[Claims] (1) A mixture of 100 parts by weight of a transparent synthetic resin and 1 to 200 parts by weight of conductive mica having an aspect ratio of 3 to 60 is prepared on a support using a solution or liquid casting method. A method for producing a conductive film, which comprises forming a film and then peeling it off from a support. (2) The method for producing a conductive film according to claim 1, wherein the synthetic resin is a thermoplastic resin. (3) The method for producing a conductive film according to claim 1, wherein the synthetic resin is polycarbonate. (4) The method for producing a conductive film according to claim 1, wherein the synthetic resin is polyurethane.