JPS5976994A - Production of conductive paper - Google Patents

Abstract

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

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing conductive paper.

More specifically, a conductive layer mainly composed of a conductive substance of at least 50% by weight and a support layer mainly composed of cellulose pulp of at least 50% by weight are integrated by combining them during papermaking. l'r! ? This paper relates to a method for producing conductive paper with characteristics.

In recent years, with the spread of digital equipment and precision electronic equipment, electromagnetic interference and static electricity interference due to high frequency pulses have become a problem.
The need for electromagnetic shielding and antistatic properties is increasing. Various materials have been proposed as electromagnetic shielding materials and anti-static materials, but there are still no electromagnetic shielding materials that are 1 to 7; However, it is in good condition.

As one of the electromagnetic wave shielding materials, conductive paper made by mixing conductive substances such as carbon fibers and metal fibers with cellulose pulp etc. has been proposed, but in the case of mixed paper, the frost 6 magnetic wave shielding performance It is necessary to increase the ratio of conductive material in order to give I needed to. On the other hand, many of these conductive materials that have magnetic shielding properties are expensive, resulting in high prices, which is economically disadvantageous. The present invention aims to eliminate these drawbacks.

The present inventor has developed a conductive layer mainly made of a conductive material.

By integrating a support layer mainly made of cellulose pulp by paper-making, it has both the conductivity and the strength of paper, and is economically advantageous because it requires a relatively small amount of conductive material per unit. The inventors discovered that conductive paper could be obtained and completed the present invention.

The present invention has electromagnetic shielding properties and electrical training properties by combining the sheets. Although conductive paper is obtained.

The structure includes a conductive layer mainly made of a conductive material having a weight of at least 50% by weight, preferably 70% by weight or more;
heavy tid: Consists of a support layer mainly composed of one or more cellulose pulps.

conductive inorganic powder, carbon fiber, metal fiber, etc., conductive bimodal organic fiber (or flake-like substance).

It contains at least one type of organic conductive fiber such as acrylic fiber containing copper ions, but is not limited to these conductive substances.

The conductive layer has a weight per square meter (1t+?) of 40 seams or less, preferably 20 seams or less, and the volume resistance of this layer alone is 10'Ω・α or less, preferably 10'
It is desirable that Ω・Crn be at the lowest level.

Further, if necessary, cellulose nokuru or other fibrous substances or a binder component may be mixed.

On the other hand, the material constituting the support layer is mainly cellulose pulp, and if necessary, other fibrous materials, binder components 9, etc. may be mixed. It has processing performance such as imparting performance or resin-containing performance for molding, and the basis weight is not particularly limited, but from the economic point of view, it is desirable that it be as thin as possible, with a good basis weight of 4097 ml or less.

These conductive layer and support layer are each formed into a wet sheet by a normal papermaking technique, and then they are combined into a single sheet. Wet papermaking techniques include fourdrinier and circular net.

Paper machines with wire knots, such as short screen and rotoformers, are common, but are not limited to these machines.

Note that the conductive paper obtained in the present invention can be bonded together using an adhesive resin, impregnated with a thermosetting resin and hot-press molded, or composited with other materials in sheet form. It is used as a

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 PVA-based carbon fibers (Toho Rayon: Pesphite, *Yincho 6-Hachi) were dispersed and disintegrated in water, and 10% (based on carbon fibers) of PVA fibers were added as a binder, which was used as a raw material for a conductive layer. On the other hand, the freeness of bleached kraft pulp is 40 <
The paper was beaten to 1 dc and 2.0% (vs.) of a cationic paper strength enhancer was added to form a sheet using a short screen, and the support layer was formed into a sheet using a round screen, and the sheets were combined by combining the sheets. .

At this time, the conductive layer is 10 to 15 m²ted, and the support layer is 18 m²
~20tAt? terrorism fc.

Furthermore, after heat-treating the integrated sheet at 17.0℃, only the conductive layer was peeled off and the volume resistance was measured.
・cm was 0 Example 2 Stainless fiber (manufactured by Japan N Line) 60 weight section.

Bleached clarinet refined to 7-leaness 500CC 40
Mix the weight factor and further add 1.0% cationic paper strength agent.
(For pulp) The material prepared by adding it was used as a raw material for a conductive layer. On the other hand, 80% by weight of rayon was used as the raw material for the support layer.
, 165% by weight of bleached kraft pal beaten in the same manner as in Example 1 and 5% by weight of easily soluble PVAJN fiber were mixed and prepared.
Conductive paper was obtained in the same manner as above. At this time, the square meter area of the conductive layer is 15 to 20 tAr? , the square footage of the support layer is l O
~15 f/rr? Comparative Example The raw material for the conductive layer and the raw material for the support layer of Example 1 were mixed at a ratio of 1:2 and formed into a single layer sheet using a circular paper machine. The weight per square meter at this time was 28 to 30 p-. Please take this sheet
・New Testament 1 whose volume resistance was measured after heat treatment at 70℃
It was 0'Ω・mercenary. This value was unsuitable for use as an electromagnetic shielding material.

Claims (1)

[Claims] /J2 A conductive layer mainly composed of a tetraelectric substance with a weight coefficient of at least 5 () or more and a support layer mainly composed of cellulose pulp of at least 50 tonne weight are integrated by combining them at the time of papermaking. A method for producing conductive paper characterized by: