JP2893414B2 - Method of forming electrode layer of flexible conductor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for forming an electrode layer on a flexible conductor in which electrode layers are disposed on upper and lower surfaces.

[Prior Art] A flexible conductive sheet in which a conductive powder such as a metal powder or a carbon powder is dispersed in an organic material such as a synthetic rubber or a synthetic resin and an electrode layer is disposed on the front and back surfaces thereof is known. When the powder is compressed by applying a force in the thickness direction from the outside, the conductive powders are connected to each other and are electrically cross-linked between the electrode layers, thereby reducing the resistance between the electrode layers. Therefore, by measuring the resistance value between the electrode layers, the application of the pressure can be detected, which can be used for various applications.

[Problems to be Solved by the Invention] The electrode layer of the conventional flexible conductive sheet is formed by applying a silver paste to the front and back surfaces of the primary vulcanized flexible conductive sheet by rolling with a roll. It was done by.

By the way, for mass processing, it is necessary to overlap the conductive sheets with the electrode layers formed on the front and back surfaces and transport them to the vulcanizer in the next step, and the silver paste mutually transfers or peels off due to the overlap. For example, the silver paste layer formed by spreading in a stretched manner was broken, and the silver paste layer had to be reformed.

In particular, a major problem in manufacturing is that the electrode layer forming step, which is a relatively domestic industrial work, and the vulcanizing step requiring a vulcanizer are performed in completely different places. After performing the primary vulcanization, it is necessary to transfer the conductive sheet to another place, apply the electrode layer, transfer it to the vulcanizer again, and perform the secondary vulcanization. However, it was troublesome and workability was bad.

An object of the present invention is to eliminate such disadvantages of the conventional method.

[Means for Solving the Problems] According to the present invention, an electrode paint formed by dispersing silver, synthetic rubber, or the like in a solvent is spread on a transfer plate obtained by impregnating / baking a glass cloth with a fluororesin. The carrier is formed, and the carriers are respectively applied from the application side to the front and back surfaces of the primary vulcanized flexible conductive sheet, and after the secondary vulcanization in the applied state, the transfer plate is removed. The electrode layer is transferred to the front and back surfaces of the conductive sheet.

Here, the transfer plate obtained by impregnating / baking the above-mentioned glass cloth with a fluororesin has good high-temperature releasability and is suitably used. Here, the glass cloth is a plain or special woven glass fiber, and a transfer plate formed by impregnating the glass cloth with a fluororesin and baking at a high temperature has a high chemical resistance due to the characteristics of the fluororesin and an organic solvent. Will not be dissolved.

An electrode paint layer made of silver, synthetic rubber, or the like is applied on the transfer plate to form a carrier. Then, the carrier is attached to the front and back surfaces of the primary vulcanized conductive sheet, and subsequently subjected to secondary vulcanization, whereby the electrode layer formed by solidifying the electrode paint layer is bonded to the conductive sheet side. Thereafter, the transfer plate is peeled off. At this time, the transfer plate has good releasability due to the fluorine resin, and the electrode layer does not transfer to the transfer plate side.

Example With reference to FIG. 1, a method for forming an electrode layer according to the present invention will be described.

In FIG. 1A, reference numeral 1 denotes a transfer plate, which is formed by impregnating a glass cloth formed into a cloth by flat weaving or special weaving of glass fiber with a fluororesin such as Teflon resin and baking at a high temperature. . This thickness is about 0.05 to 1.00 mm. This is characterized by being excellent in chemical resistance due to fluororesin, hard to adhere to various materials, and having good releasability.

As shown in FIG. 1B, an electrode paint formed by mixing and dispersing silver and synthetic rubber in toluene is applied to the transfer plate 1 in an extended manner by a roll 4 or the like. 2 to form a carrier 3. This rolling promotes dispersion of the solvent. Thereafter, a large number of carriers 3 are stacked and transferred to a vulcanization step (FIG. 1C). At this time, since the respective carriers 3 are laminated via the transfer plate 1, they are not joined to each other due to the releasability of the transfer plate 1. Therefore, the support 3 can be formed and stored in a large amount, and the production management becomes easy. On the other hand, a conductive sheet 10 (first material) in which conductive powder is dispersed in a flexible material.
Press vulcanization is performed by applying a pressure of about 100 to 200 kg / cm ² using a vulcanizer. After the vulcanization, the carriers 3 having the electrode paint layer 2 formed on the transfer plate 1 on the front and back surfaces of the conductive sheet 10 are applied from the application surface side (first).
(E). Since this attaching work does not require any liquid agent or complicated equipment, the conductive sheet 10 can be taken out from the vulcanizer and immediately performed. Then, a secondary vulcanization is performed by applying a pressure of about 50 to 150 kg / cm ² at a high temperature in a vulcanizer. At this time, the thermal expansion coefficient of the glass constituting the transfer plate 1 is similar to that of the ceramic mixed in the conductive sheet 10, and therefore, the electrode paint layer 2 is unlikely to be broken or cracked due to the difference in thermal expansion. Also, unlike ordinary fluororesin sheets, they have high strength at high pressure and high temperature.

After the vulcanization, the transfer plates 1 are peeled off from the front and back surfaces of the conductive sheet 10, respectively (FIG. 1). At this time, the electrode layer 11 formed by solidifying the electrode paint layer 2 is formed on the front and back surfaces of the conductive sheet 10. In this peeling operation, the transfer plate 1 has good releasability due to the action of the fluorine resin, so that only the transfer plate 1 can be easily peeled.

Thus, the flexible conductor 12 shown in FIG. 1 is formed.

[Effects of the Invention] In the present invention, the front and back surfaces of the conductive sheet 10 are formed by the carrier 3 having the electrode coating layer 2 formed on the transfer plate 1 obtained by impregnating / baking a glass cloth with a fluorine resin as described above. After covering and vulcanizing this, the transfer plate 1 is removed to remove the conductive sheet.
Since the electrode layer 11 is formed on the front and back surfaces of the conductive sheet 10, a) The electrode paint layer 2 can be formed in advance in advance regardless of the manufacturing process of the conductive sheet 10, and production control is easy. .

(B) Even if a large number of carriers 3 are stacked in advance, the electrode coating layer 2 is not transferred by the transfer plate 1 and can be stored and transported in a large amount, which is suitable for mass processing.

C) Even if the surface of the uppermost electrode coating layer 2 of the transfer plate 1 laminated as described above becomes dirty, the electrode coating layer 2 is turned over and is applied on the conductive sheet 10 and the surface is not exposed. Because it will be a surface
The appearance of the conductor is not impaired.

D) In the case of secondary vulcanization with a press, the electrode paint layer is conventionally directly pressurized. Therefore, the fluororesin layer formed on the pressurized surface of the press peels off, and the electrode becomes smooth due to abrasion. It was sometimes damaged. By the way, in the present invention, since the pressure is applied via the transfer plate, there is no such problem.

E) The carrier sheet 3 is formed in advance and the conductive sheet 10
After primary vulcanization and removal from the vulcanizer, the conductive sheet
Workability is good, for example, the carrier 3 can be attached to the front and back surfaces of No. 10 and the process can immediately proceed to secondary vulcanization.

F) Even during secondary vulcanization, pressure is applied while protecting the electrode coating layer 2 with the transfer plate 1, so that the electrode layer 11 is not damaged during vulcanization.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a manufacturing process diagram of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Transfer board 2 ... Electrode paint layer 3 ... Carrier 10 ... Conductive sheet 11 ... Electrode layer

Claims (1)

(57) [Claims] An electrode coating comprising silver and synthetic rubber dispersed in a solvent is spread on a transfer plate obtained by impregnating / baking a glass cloth with a fluororesin to form a carrier. The carriers are respectively applied to the front and back surfaces of a flexible conductive sheet obtained by dispersing a conductive powder in a vulcanized flexible material from the coating surface side, and then transferred after secondary vulcanization in the applied state. A method for forming an electrode layer of a flexible conductor, comprising removing the plate and transferring the electrode layer to the front and back surfaces of the conductive sheet.