JPS63135598A - 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] [Industrial application field] The present invention relates to conductive paper.

[Prior Art] Conventionally, conductive papers containing carbon fiber or carbon black (Japanese Patent Publication No. 59-2E159?, Japanese Patent Publication No. 1983
-4H88), and those in which metal fibers such as brass, aluminum, and stainless steel are inserted together with valves and synthetic fibers (#Opening/closing 58-183799. 59-47500
) etc. are known. In addition, conductive paper containing electroless heavy plated glass fibers and conductive fiber Marat containing nickel-coated carbon fibers
8198) is also known.

However, conductive paper containing carbon fiber or carbon black has low conductivity as a conductive paper (10-3 to 1010 cm) because the conductivity of the conductive substances such as carbon fiber and carbon black is low (10-3 to 1010 cm), and it is not suitable for electromagnetic shielding materials or radio waves. When used as a reflective material, it does not show sufficient performance.

Conductive paper using brass fibers or aluminum fibers has high conductivity, but because the metal fibers are easily oxidized, it is difficult to maintain high conductivity over a long period of time. In addition, since the brass fibers and aluminum fibers currently on the market are manufactured using a cutting method, the minimum fiber diameter is approximately 30 JLm.
Not suitable for making thin paper.

Conductive paper using stainless steel fibers has high conductivity and the metal fibers have high corrosion resistance, so it can maintain high conductivity over a long period of time. Additionally, since stainless steel fibers are generally manufactured using the pultrusion method, the fiber diameter is small (around 10 gm), making it suitable for making thin paper. However, since stainless steel fibers have a high specific gravity (approximately 8), it is difficult to uniformly disperse the fibers during paper making. Also, because of its high specific gravity, it is disadvantageous for making light conductive paper. Furthermore,
Since the stainless steel fiber i-fiber is manufactured by the pultrusion method as described above, it has the disadvantage of poor productivity and high cost.

On the other hand, conductive wire paper using electroless Ni-plated glass fiber can improve conductivity by increasing the thickness of the plating film, and the m-group diameter is around 1107z, so thin conductive paper It is also easy to make. Since the conductive film is made of Ni, it has high corrosion resistance, and the conductivity of the conductive paper can be maintained for a long period of time. Since the conductive t-fiber is manufactured by a plating method, productivity is also high. However, since electroless heavy plating films generally contain phosphorus or boron, their specific resistance is 10 to 100 times higher than that of pure Gu (specific resistance: 1.72 x 10-6 Ωcm) or Ni (specific resistance?, 24 x 10-5 Ωc+w). Large (10-4 to 10-6)
Ωcm), therefore, the electroless Ni plating film is pure C.
In order to obtain a low resistance value equivalent to that of u or Ni, the plating film thickness must be increased, which not only increases cost but also increases the specific gravity of the fibers, causing the same disadvantages as in the case of stainless steel fibers.

Conductive fiber mats containing nickel-coated carbon fibers have high corrosion resistance and relatively high conductivity due to the older metal coating. Therefore, it is possible to make a highly conductive mat and maintain its conductivity for a long period of time.

Furthermore, since carbon fiber is used, the specific gravity of the conductive fibers is light, making it possible to create a lightweight conductive mat.

However, the specific resistance of Ni (7,24X 10-6Ω
cm) is Cuc7) specific resistance (1,72X 10-6Ωa
m), so in order to achieve the same low resistance value with the Ni coating as the copper coating, it is necessary to increase the thickness of the Ni coating, which avoids an increase in the specific gravity of the conductive fiber and increased cost. do not have.

[Problems to be Solved by the Invention] An object of the present invention is to solve the aforementioned various problems that the prior art had.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and includes a first layer of a Cu film or an old film formed on the surface by electroless plating, and A glass fiber having a metal layer consisting of a second layer of Cu coating formed on the layer by electroplating, and a third layer of Ni coating formed on the second layer by electroless plating or electroplating. To provide a conductive paper made of glass m fibers and fibers other than the glass fibers intertwined to form a paper shape.

The metal-coated glass fiber in the present invention includes a first layer consisting of a Cu coating or a Ni coating formed on the surface of the glass fiber by electroless plating, and a second layer consisting of a Cu coating formed thereon by electroplating. A glass fiber is used which has a layer and a third layer thereon consisting of a Ni coating formed by electroless plating or electroplating or an old coating formed by electroless plating.

As the glass fiber used for the metal-coated glass fiber in the present invention, generally industrially produced long fiber glass can be used. The larger the surface area per unit weight of glass fiber, the higher the conductivity of the conductive paper containing a certain weight of glass fiber, and because it is advantageous for making thin conductive paper, the diameter of the glass fiber is preferably small. It is preferably 23 pLm or less, more preferably 13 μm or less.

A Cu coating or an old coating is formed as a first layer on the surface of the glass fiber by electroless plating, and the reason is as follows. That is, the raw materials used for plating are easily available, the conductivity can be ensured when electroplating the second layer, and the plating process is relatively easy.

If the thickness of the first layer is too thin, the conductivity will decrease, and if it is too thick, the productivity of the plating process will decrease, so both are not preferred. The preferred thickness is in the range of 0.01 to 0.5 μm, particularly preferably in the range of 0.05 to 0.2 μm.

The second layer on the first layer is mainly for imparting electrical conductivity, and the Cu coating is formed by electroplating, which allows a thick coating to be easily obtained. If the thickness of the Cu coating is too thin, a conductive paper with excellent conductivity cannot be obtained, and if it is too thick, the productivity will decrease, so both are not preferred. A desirable thickness is 0.1 gm or more, and a range of 0.2 to 2 gm is particularly desirable.

On the other hand, the third layer is provided mainly to protect the second layer Cu film, and the old film is used from the viewpoint of corrosion resistance. The thickness of such a coating is not preferable because if it is too thin, the protection of the Cu coating will be insufficient, and if it is too thick, productivity will decrease. Desired thickness is 0.01-0.5 g
m, with a range of 0.05 to 0.2 gm being particularly desirable.

In the conductive paper of the present invention, the content of such glass fibers is preferably 10 to 89 percent by weight, preferably 30 to 95 percent by weight, particularly 40 to 70 percent by weight, based on the weight of the conductive paper. It is desirable because it can provide shielding effect or radio wave reflection performance.

Further, in the conductive paper of the present invention, the amount of glass fiber is 5 to 200 g/m2, preferably 30 to 150 g/m2.
m2, particularly 35 to 100 g/m2, is desirable because high conductivity, electromagnetic shielding effect, or radio wave reflection performance can be obtained.

The conductive paper of the present invention is made of the above-mentioned glass fibers and fibers other than the glass fibers intertwined to form a paper shape, and the latter fibers include pulp, vegetable fibers such as Manila hemp, polyester, polyvinyl alcohol, and polyethylene terephthalate. A wide range of synthetic and inorganic fibers are used. Among these, vegetable fibers are particularly preferred since they act as a binder for glass fibers. When using fibers such as inorganic fibers that do not act as a binder for glass fibers as the latter fibers, or when using vegetable fibers whose binder action is insufficient, a binder may be added separately. Examples of such binders include polyvinyl alcohol and polyethylene terephthalate.

[Example] Example 1 A first layer of an old coating with a thickness of about 0.1 gm was applied to roving type glass fiber (continuous long fibers made of a bundle of about 3000 monofilaments with a diameter of 13 pm) as follows. was formed. That is, glass fiber was dissolved in an aqueous solution of stannous chloride.
After being immersed for a minute, it was washed with water and immersed in an aqueous palladium chloride solution for 1 minute. This glass fiber was immersed for 150 seconds in a solution of 20 g of nickel sulfate/1 liter of water, 30 g of sodium hypophosphite/1 liter of water, 20 g of sodium acetate/1 liter of water, and 10 g of sodium citrate/1 liter of water to form the first layer. was formed.

Next, as a second layer, a copper sulfate solution (250 g/1 liter of water) was plated for 3 minutes at a current of IOA to form a layer of approximately 0.51 Lr.
A Cu film of s was formed.

Then, as the third layer, nickel sulfate (240g/1 sentence of water)
Electroplating was performed using nickel chloride 45g/l and boric acid 30g/JJ at a current of 3A for 150 seconds, resulting in approximately 0. N of IILm
A coating was formed on the second layer.

The glass m-fiber thus obtained was immersed in an aqueous solution containing 5% polyether oxide as a surface treatment agent, then pulled up and cut into a length of 13 mm. This was placed in water, and a sufficiently opened Manila hemp with the same weight as the glass fiber was added, a surfactant was added as a dispersant, and polyetheramide was added as a thickener, and the mixture was thoroughly stirred. It was made into a slurry. This slurry was made into paper using a round steel paper machine and dried to obtain conductive paper with a basis weight of 150 g/m2.

When the sheet resistance of this conductive paper was measured, it was found to be 1.0×10
It was °Ω/mouth. The electromagnetic shielding performance of this conductive paper was measured using an electromagnetic shielding effect measuring device (Model 17301 manufactured by Atopan Test Co., Ltd.) in terms of electric and magnetic fields, and the results are shown in FIGS. 1 and 2, respectively. That is, 500
At MHz, it showed an attenuation rate of 45 dB for electric field and 33 dB for magnetic field, and was found to have sufficient electromagnetic shielding performance.

This conductive paper is impregnated with unsaturated polyester resin, 1
It was heated to 20° C. and pressed to obtain a molded plate with a thickness of 3 mm. When we measured the radio wave reflection characteristics of this molded plate, we found that the reflection loss was at most 0.00θ at a frequency of 12.4 GHz.
dB characteristics, and was found to exhibit sufficient performance as an antenna material for satellite communication reception.

Example 2 A metal-coated glass am produced in the same manner as in Example 1 was immersed in a solution containing 5% polyether oxide as a surface treatment agent, then pulled up and cut to a length of 25 mm. Place this in water, add % of the weight of fully opened timber pulp to the weight of the glass fiber added,
A surfactant as a dispersant and a polyetheramide as a thickener were respectively added and sufficiently stirred to form a slurry. This slurry was made into paper using a Fourdrinier paper machine and dried to obtain conductive paper with a basis weight of 125 g/m2.

When the sheet resistance of this conductive paper was measured, it was found to be 4.5 Xl
It was 0-1Ω/mouth.

A polypropylene film having a thickness of 30 ILm was press-bonded and laminated on both sides of this conductive paper. When the electromagnetic shielding performance of this conductive paper/polypropylene laminate product was measured using the same measuring device as in Example 1, it was found that 500M
It showed an attenuation rate of 47 dB for electric field and 38 dB for magnetic field at Hz, and was found to have sufficient electromagnetic shielding performance. The results of these measurements are shown in FIGS. 3 and 4.

Example 3 A metal-coated glass fiber prepared in the same manner as in Example 1 was sprayed with an aqueous solution containing 10% polyether oxide as a surface treatment agent, and cut into lengths Bam. Put this in water before it dries, add polyethylene terephthalate fiber of the same weight as the added metal-coated glass fiber, add a surfactant as a dispersant, polyetheramide as a thickener, and stir thoroughly. The mixture was made into a slurry. This slurry was made into a membrane paper, heated and dried to obtain a conductive paper having a basis weight of 75 g/m2.

When the sheet resistance of this conductive paper was measured, it was found to be 2.8 Xl
It was 0I Ω/mouth.

[Effect of the invention] Since the conductive paper of the present invention has high conductivity,
It has excellent effects such as high electromagnetic shielding performance and high radio wave reflection performance. In addition, by reducing the content of metal-coated glass fiber contained in the conductive paper, it is possible to achieve a conductivity of about 102 to 106 Ω/2 in sheet resistance.
This product is recognized to be effective in removing static electricity and preventing static electricity.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the electrolytic shielding effect of the conductive paper according to the present invention. FIG. 2 is a diagram showing the magnetic field shielding effect of the conductive paper according to the present invention.

Claims (2)

[Claims] (1) A first layer of Cu coating or Ni coating formed on the surface by electroless plating, a second layer of Cu coating formed on the first layer by electroplating, and a non-coated layer on the second layer. Glass fibers having a metal layer consisting of a third layer of Ni coating formed by electrolytic plating or electroplating, and conductive paper made by intertwining the glass fibers with fibers other than the glass fibers. (2) The conductive paper according to claim 1, wherein the glass fiber is contained in a range of 10 to 99% by weight.