JP2897129B2 - Conductive paper, thermoplastic conductive paper and heat-fusible conductive paper - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a conductive paper, and more particularly, to a conductive paper containing, as a stock component, a conductive fiber in which various fibers are coated with two layers of copper and silver. , The conductive fiber, a thermoplastic conductive paper made of a thermoplastic synthetic pulp and composite fiber as a stock, and a heat-fusible property of impregnating or coating a heat-fusible polymer on the conductive or thermoplastic conductive paper. Related to conductive paper.

The conductive paper, thermoplastic conductive paper and heat-fusible conductive paper of the present invention are excellent in conductivity and workability, so that they can be combined with various materials to form a static electricity generation preventing material, an electromagnetic wave shielding material and the like.

[Conventional technology]

BACKGROUND ART Conventionally, conductive paper made by mixing carbon fibers or fibrous metals with fibrous substances such as pulp has been known (see Japanese Patent Publication Nos. 45-32766 and 49-21242).
It is commercially available as an antistatic material.

Recently, many composites comprising a conductive fiber and a fibrous binder of a polymer substance have been proposed (see JP-A-61-127199, JP-A-61-225398, etc.).

Some of the inventors of the present invention have proposed a conductive paper which may contain a synthetic pulp containing a conductive fiber obtained by coating a relatively short fiber synthetic fiber with two layers of copper and nickel and a natural pulp as a main stock. Japanese Patent Application No. 62-110075 proposes conductive fibers obtained by coating relatively short synthetic fibers with two layers of copper and nickel, thermoplastic synthetic pulp and core-sheath composite fibers. Japanese Patent Application No. 63-0445325 has proposed a thermoplastic conductive paper as a component and a heat-fusible conductive paper in which the thermoplastic conductive paper is impregnated or coated with a heat-fusible polymer.

[Problems to be solved by the invention]

2. Description of the Related Art In recent years, miniaturization and high-density of electronic devices have been advanced, and malfunctions and nozzles caused by electromagnetic waves transmitted through the package and the housing material have become serious problems. Also IC
In semiconductor devices such as semiconductors and LSIs, destruction occurs due to electrostatic discharge. Furthermore, in magnetic recording media such as magnetic tapes, ID cards, floppy disks, and hard disks, accidents occur in which recording due to electrostatic discharge or electromagnetic waves is lost.

On the other hand, it is conceivable to improve the performance of conductive paper that has been conventionally marketed to prevent static electricity generation and attach it to the package or housing of electronic equipment.However, to obtain conductive paper with high electromagnetic wave shielding properties, use nickel plating. It is considered that conductive fibers having a large aspect ratio, such as carbon fibers and stainless fibers, are required. However, since carbon fiber plated products and fibrous metals are extremely expensive,
Conductive paper using them is also very expensive and difficult to adopt.

In addition, instead of these conductive fibers, it is also conceivable to cut conductive fibers obtained by coating a relatively long fiber glass fiber or a synthetic fiber with a metal, and make paper in addition to the paper material to obtain conductive paper. The operation of uniformly coating a metal with a large fiber length, that is, a plating method on a fiber having a large aspect ratio,
Since the fibers tend to be pills, it is extremely difficult to form a uniform metal coating. When the conductive fiber is cut short, the cut surface is not coated with metal, and the conductive fiber having a long fiber length has poor dispersibility during paper making and is not uniformly dispersed in the paper layer. Therefore, a conductive paper having high antistatic property and electromagnetic wave shielding property cannot be obtained.

Furthermore, in a recently proposed conductive sheet using a fibrous binder, a long fiber is used as the conductive fiber, and a fibrous binder is used to enhance the adhesion. Is large, and
Since expensive fibers are used, the cost is extremely high.

Further, these conventional conductive papers are easily broken due to bending or the like, and when they are combined with other materials to be composited, it is necessary to attach them with an adhesive, and the workability is extremely high. Low.

The conductive paper proposed by the inventors of the present invention uses conductive fibers having a relatively short fiber length, so that the dispersibility of the conductive fibers in the stock component is improved, resulting in excellent conductive properties. Although it has electromagnetic wave shielding properties, it has been required to improve moisture resistance, corrosion resistance and production cost since the conductive fibers are based on copper-nickel double-layer coated fibers. Further, there remains room for improvement in workability.

The first object of the present invention is to provide a conductive paper excellent in antistatic property, electromagnetic wave shielding property, moisture resistance and corrosion resistance.
The second and third objects are to provide a thermoplastic conductive paper and a heat-fusible conductive paper having good processability.

[Means for solving the problem]

The present inventors have conducted intensive studies to achieve the above object, and as a result, conductive paper containing conductive fibers obtained by plating two layers of copper and silver on various fibers having a short fiber length in this order has extremely excellent electromagnetic wave shielding properties. It is excellent in moisture resistance and corrosion resistance, and the conductive paper obtained by making the conductive fiber, the thermoplastic synthetic pulp and the composite fiber has good workability, and is heat-fusible to the conductive paper. The present inventors have found that conductive paper impregnated or coated with the above polymer has excellent heat-sealing properties to various materials, and completed the present invention.

The present invention, the core fiber having an average fiber length of 2 mm or less,
A conductive paper (first invention), comprising 3 to 60% by weight of conductive fibers coated with copper and silver in two layers in that order;
The above-mentioned conductive paper contains a thermoplastic synthetic pulp of 20 to 90% by weight and a core-sheath type composite fiber of 5 to 70% by weight as a stock material other than the conductive fiber. 2) a heat-fusible conductive paper (third invention) characterized in that the heat-fusible polymer is impregnated and / or coated on the conductive paper of the first invention or the thermoplastic conductive paper of the second invention. Invention).

In the present invention, the conductive fiber has an average fiber length of 2 mm.
It is a fiber in which the following various fibers having relatively short fiber lengths are used as a core and two layers of copper and silver are coated by a plating method.

Glass fibers and / or synthetic fibers are used as the fibers used for the conductive fiber core. As glass fibers, the average fiber length is 2 mm or less, and the aspect ratio (fiber length /
Glass-cut fibers and milled fibers having a uniform wire diameter of from 20 to 200 are preferably used, and more preferably those having a specific surface area of 0.1 m ² / g or less. Further, as synthetic fibers, the average fiber length is 2 mm or less, the fiber diameter is 1 to 3 denier, and the aspect ratio (fiber length /
Thermoplastic synthetic fibers such as nylon fibers, polyester fibers, vinylon fibers, and acrylonitrile fibers having a relatively short fiber length (diameter) of 20 to 200 are used. As the synthetic fibers, those having a uniform wire diameter and a small specific surface area are preferable, and those having a specific surface area of 0.2 m ² / g or less are more preferably used.

The conductive fiber is a fiber having an aspect ratio of 20 to 200, which is obtained by plating the above-mentioned fiber with copper and further coating copper and silver in two layers by plating silver on a copper coating. The coating ratio of copper to the fiber is 20 to 50% by weight, preferably 25% by weight or more, more preferably 35% by weight or more. Further, the covering ratio by silver may be any degree that can prevent oxidation of copper, and usually,
0.5 to 10% by weight is employed.

In general, chemical copper plating is used for copper plating of fibers, and electroplating or chemical plating (including substitution plating) can be used for silver plating, and these can be used in combination. Usually, displacement plating is preferably employed.

Conductive sheet of the present first invention contains said conductive fibers and fibrous material, optionally a stock plus various additives by a conventional method the basis weight of the paper is 50 g / m ² or more, preferably 80-12
It is a paper-like material of 0 g / m ² . The content of the conductive fiber in the conductive paper varies depending on the purpose of use of the conductive paper, the metal coverage of the conductive fiber, the aspect ratio, and the like, but is 3 to 60% by weight on a dry basis. In particular, in the case of conductive paper having high electromagnetic wave shielding properties, the content of conductive fibers on a dry basis is preferably 20% by weight or more, more preferably 30% by weight or more.

As fibrous materials other than conductive fibers, wood pulp, bast fiber, seed hair fiber, plant natural fiber such as leaf fiber, nylon fiber, vinylon fiber, polyester fiber, polyethylene fiber, synthetic fiber such as polypropylene fiber, glass fiber,
Inorganic fibers such as asbestos fibers and alumina fibers, carbon fibers and the like, and mixtures thereof can be used.

Examples of the additives include a surfactant for improving dispersibility of conductive fibers during papermaking, a surface treatment agent such as a coupling agent, a modified starch for improving binding of fiber components, a vegetable gum, carboxymethyl cellulose, Binders such as polyacrylamide, urea resin and melamine resin, and other aluminum sulfate, calcium carbonate,
Fillers such as clay, coloring agents and the like are used.

The second invention is a felt-like conductive paper obtained by forming a paper material containing the above-mentioned conductive fibers, thermoplastic synthetic pulp and core-sheath composite fibers, and optionally adding various additives, by a conventional method, and The basis weight of this felt-like conductive paper, which is heat-sealed between fibers using a calendar device or the like as necessary, is 50 g /
m ² or more, preferably sheet-like conductive paper 80 to 120 / m ^2.

In the second invention, the thermoplastic synthetic pulp is a papermaking material obtained by processing a thermoplastic synthetic resin, for example, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, or the like into a fibrous form. The core-sheath type composite fiber is a fiber obtained by compounding two kinds of synthetic resins having different melting points into a core-sheath type. For example, a polypropylene fiber or the like having a relatively high melting point is used as a core fiber and has a melting point higher than that of the core fiber. For example, it is a fiber in which polyethylene, ethylene-vinyl acetate copolymer or the like is sheathed and composited.

The content of the conductive fiber in the conductive paper varies depending on the aspect ratio of the conductive fiber and the metal coverage, but is 3 to 60% by weight on a dry basis. In particular, in the case of conductive paper having a high electromagnetic wave shielding property, the content of the conductive fibers is preferably 20% by weight or more, more preferably 30% by weight or more.

As the additives to be added as desired, the same additives as the additives to be added to the conductive paper of the first invention are used.

The heat-fusible conductive paper of the third invention is obtained by impregnating and / or coating a heat-fusible polymer on the conductive paper of the first invention or the thermoplastic conductive paper of the second invention, and Conductive paper with improved heat sealability.

As the heat-fusible polymer, a water-soluble or organic solvent-soluble thermoplastic polymer such as EVA, NBR, SBR, acrylic styrene, or polyurethane is used.

Impregnation of thermoplastic conductive paper with heat fusible polymer and / or
Alternatively, the coating can be easily performed by impregnating or applying a solution in which a heat-fusible polymer is dissolved in a solvent to a thermoplastic conductive paper, drying and removing the solvent.

[Action]

The conductive paper according to the first aspect of the present invention is characterized in that the conductive paper according to the second aspect of the present invention is characterized by containing conductive fibers obtained by coating two layers of copper and silver on a relatively short fiber length in that order, as a stock component. The conductive paper contains the conductive fiber, the thermoplastic synthetic pulp, and the core-sheath composite fiber as a stock component. The heat-fusible conductive paper according to the third invention is characterized in that the heat-fusible polymer is impregnated and / or coated on the conductive paper according to the first or second invention.

In the present invention, as the core of the conductive fiber, by performing a two-layer plating coating of copper and silver using various fibers having a relatively short fiber length, it is possible to achieve a uniform coating compared to long fibers, In addition, a conductive fiber plated with both ends of the core fiber can be obtained.

Since the conductive fiber has a specific gravity of about 1/4 that of the metal fiber, the dispersibility in the stock component is extremely good, so that a conductive paper containing the conductive fiber uniformly can be obtained. In addition, the adhesion between the conductive fibers after papermaking is improved.
In addition, since the coating of the conductive fiber is a copper-silver two-layer coating, not only the conductivity but also the moisture resistance and the corrosion resistance are improved. Better than.

As a result, the conductive paper of the present invention has an electromagnetic wave shielding property in all frequency ranges specified in ASTM-ES-7-83, a conductive fiber content of 30 to 40% by weight, and a basis weight of 80 g / m ² or more. And has an excellent electromagnetic wave shielding property of 40 dB or more, which is equal to or more than conductive paper of the same basis weight containing 60% by weight of stainless steel fiber.

As for the conductivity of the conductive paper, as the aspect ratio of the conductive fiber is larger, that is, it is preferable to use a long fiber rather than a short fiber as a base fiber, but when a long fiber is used, a uniform metal film is obtained. It is difficult to uniformly disperse it in other stock components even during papermaking.

Therefore, as the core fiber, the average fiber length is 2 m in consideration of the formability of the metal film and the dispersibility in the stock component.
It is preferable to use a large aspect ratio of less than m, more preferably, the average fiber length is 0.3 to 1.0 mm,
Use one with an aspect ratio of 20 or more.

The metal deposition rate on the fibers (hereinafter referred to as “metallization rate”) also affects the conductivity of the conductive paper. If the metallization ratio by copper is too small, a uniform copper film is not formed and the conductivity is reduced.If it is too large, the density as a filler increases, and the conductivity contained in the paper per unit volume is increased. Since the total number of conductive fillers decreases, the conductivity decreases. Further, the dispersibility in the stock component is reduced, and it is difficult to obtain conductive paper having uniform conductivity. Therefore, the metallization rate by copper is
It is 20 to 50% by weight, preferably 25 to 45% by weight, and more preferably 35 to 40% by weight. On the other hand, the metallization rate by silver is
By adopting the displacement plating method, a silver thin film having a uniform thickness can be formed, so that 0.5 to 10% by weight can sufficiently prevent oxidation of the copper film, and usually 1.5 to 3% by weight.

In the second invention, when the core of the conductive fiber is made of thermoplastic synthetic fiber, the metal coating is not damaged at the time of forming the conductive paper, and the conductive paper using the same has excellent workability. Having.

In addition, since the conductive fibers used have high conductivity, the amount of conductive fibers for obtaining high shielding properties can be reduced, so that the amounts of synthetic pulp and core-sheath composite fibers can be increased. Therefore, workability is further improved.

The thermoplastic synthetic pulp and the core-sheath composite fiber to be paper-formed together with the conductive fiber, the conductive fiber is firmly fixed by heat fusion between the synthetic pulp using a calender after the paper making, the paper of the conductive paper. The strength is remarkably improved, and the electromagnetic wave shielding property is also improved.

In particular, since the core fiber of the core-sheath type composite fiber has a higher melting point than the sheath material, a decrease in strength due to heat fusion performed at a temperature lower than the melting point of the core fiber is prevented, and the paper strength is significantly improved.

In the thermoplastic conductive paper of the second invention, these act synergistically to provide high electromagnetic wave shielding properties and high strength,
In addition, excellent thermoformability and workability are obtained,
It also has heat-fusibility to different materials.

In the third invention, the conductive paper or the second paper of the first invention is used.
By impregnating and / or coating the thermoplastic conductive paper of the present invention with a heat-fusible polymer, the conductive paper or the thermoplastic conductive paper having the above-mentioned properties exhibits heat-fusibility, without using a special adhesive. It can be combined with a different material, for example, a synthetic resin such as a vinyl chloride resin, an ABS resin, or polypropylene, or wood, by heat fusion alone to form a composite.

〔Example〕

The present invention will be described in more detail with reference to Examples and Comparative Examples.

However, the scope of the present invention is not limited at all by the following examples.

(1) Preparation of conductive fiber (a) Sample F-1 (glass fiber core conductive fiber) A short glass fiber having an average diameter of 11 µm and an average length of 0.5 mm was
After performing a chemical copper plating process by a conventional method and forming a copper coating on the short glass fiber, a displacement silver plating process is subsequently performed to obtain a copper metallization ratio of 24.1% by weight, a silver metallization ratio of 1.4% by weight, and a density of 3.1 g /
Sample F-1 was prepared: a conductive fiber having a glass fiber core of cm ³ and a copper-silver two-layer coating.

(B) Sample F-2 (polyester fiber conductive fiber) A polyester short fiber having an average diameter of 15 μm and an average length of 0.8 mm was chemically copper-plated by a conventional method to form a copper coating on the polyester fiber, followed by replacement. Silver plating treatment, copper metallization rate 42.8% by weight, silver metallization rate 1.4% by weight, density 2.20g / c
copper core polyester fiber of m ³ - conductive fiber having a silver bilayer coating: Sample F-2 was prepared.

(C) Comparative sample CF-1 Commercially available average diameter 8 μm, average length 5 mm, density 7.93 g / cm ³
Stainless steel fiber, conductive fiber for comparison: sample CF-1
And

(D) Comparative sample CF-2 A short glass fiber having the same specification as that used in the preparation of the sample F-1 was subjected to a chemical copper plating treatment by a conventional method to form a copper coating on the short glass fiber, and then subjected to a conventional method. After chemical nickel plating, copper metallization rate 28.3% by weight, nickel metallization rate
Conductive fiber for comparison having a copper-nickel bilayer coating with a glass fiber core of 10.2% by weight and a density of 3.47 g / cm ³ : sample
CF-2 was prepared.

(E) Comparative sample CF-3 Polyester staple fibers having the same specifications as those used in the preparation of sample F-2 were subjected to chemical copper plating by a conventional method to form a copper coating on the polyester fibers, and then chemically coated by a conventional method. perform nickel plating, copper metallization ratio 40.8 wt%, nickel metallization ratio 9.4 wt% copper and the core polyester fibers of density 2.40 g / cm ³ - conductive fibers for comparison with nickel bilayer coating: sample CF-3 was prepared.

(F) Comparative sample CF-4 Polyester long fiber was subjected to chemical copper plating by a conventional method to form a copper coating on the polyester fiber, followed by substitutional silver plating, and further cut to an average length of 3.5 mm. Metallization rate 42.0% by weight, silver metallization rate 1.45% by weight, density 2.18g /
copper core polyester fiber of cm ³ - conductive fibers for comparison with silver bilayer coated: Samples were prepared CF-4.

(2) Conductive paper (a) Preparation of conductive paper The conductive fiber prepared in the above item (1): Sample F-1,
Softwood bleached kraft pulp (NBK) with F-2 or comparative samples CF-1 to CF-4 and a Canadian freeness test value of 370 ml
P) as a stock component, and changing their mixing ratio and basis weight to change the conductive paper: P-1 to P-8 and the conductive paper for comparison: C
P-1 to CP-8 were prepared.

In addition, the papermaking used a hand-making machine and was based on JISP-8209.

(B) Conductive paper evaluation test For the conductive paper prepared in the above item (a), a near-field measurement jig (NFC-1000, manufactured by Electrometric Co., Ltd.) based on surface resistance (Ω / sq) and ASTM ES7-83 ) Was used to measure the electromagnetic wave shielding characteristics.

The conductive papers P-2, P-5, CP-3 and CP-5 were subjected to a temperature and humidity resistance test under the conditions of 80 ° C. × 80% RH × 48 hours, and the surface resistance and electromagnetic shielding after the test were performed. The properties were measured.

Table 1 shows the types of the conductive fibers, the mixing ratio and basis weight in the stock component, and the evaluation test results.

As shown in Table 1, the conductive paper of the present invention has excellent surface resistance and electromagnetic wave shielding properties as compared with the conductive paper for comparison, even if the content of the conductive fiber is low, and in particular, The rate of their decrease after the temperature and humidity resistance test is small, and they have high moisture resistance and high corrosion resistance.

(3) Thermoplastic conductive paper (a) Preparation of thermoplastic conductive paper The conductive fiber prepared in the above (1), polyethylene synthetic pulp (SWP-E620, manufactured by Mitsui Petrochemical Co., Ltd.) and polypropylene fiber are used as cores. A conjugate fiber (NBF, manufactured by Daiwa Spinning Co., Ltd.) with polyethylene as a sheath is used as a main stock component. The mixing ratio and basis weight are changed, and the hand-made machine is used to comply with JIS P-8209. Felt-like conductive paper made and dried, and sheet-like conductive paper obtained by heat-sealing the felt-like conductive paper at a temperature of 140 ° C. using a calender device: Samples P-9 to P-12 were prepared. For comparison, thermoplastic conductive paper containing no composite fiber as a stock component: Softwood bleached kraft pulp (NBKP) having a Canadian freeness test value of 370 ml was added to the stock component instead of the comparative sample CP-9 and the composite fiber. Thermoplastic conductive paper: Comparative sample
CP-10 and CP-11 were prepared.

(B) Evaluation Test of Thermoplastic Conductive Paper Regarding the prepared thermoplastic conductive paper, the above (2)
The electromagnetic wave shielding properties and the surface resistance value (Ω / sq), the elongation at 150 ° C., and the tensile strength (using a testing machine with an Instron thermostat) were measured in the same manner as described in the section.

Table 2 shows the composition of the stock components and the results of the evaluation tests.

As shown in Table 2, the thermoplastic conductive paper of the present invention has:
Compared with a comparative sample containing no conjugate fiber in the stock component, the elongation is extremely large and the strength at the time of heating is large, so that the processability is remarkably improved.

In addition, its electromagnetic wave shielding characteristics exceed 40 dB in all measured frequency ranges, and show excellent electromagnetic wave shielding characteristics.

 Further, the surface resistance value is extremely small.

(3) Heat-fusible conductive paper (a) Preparation of heat-fusible conductive paper Thermoplastic conductive paper prepared in (2) (a) above: A solution of a heat-fusible polymer was added to sample P-9. Was applied and dried to impregnate or coat the heat-fusible polymer to prepare heat-fusible conductive paper: Samples P-13 to P-15.

(B) Evaluation test of heat-fusible conductive paper Thermoplastic conductive paper prepared in (2) (a): Sample P-9 and Sample P prepared in (3) (a)
The -13~P-15, ABS sheet as adherents, polypropylene (PP) sheet, PVC sheet, polystyrene (PS) sheets and wood, under the condition of 140~150 ℃ × 10Kgf / cm ^{2 2}
The composite was prepared by thermocompression bonding for ~ 3 minutes.

Using this composite as a test piece, a tensile tester (Tensilon)
The peel strength of the heat-fusible conductive paper to the base material was measured using TMU-4) according to JIS K 6854.

The surface resistance and the electromagnetic wave shielding property of the prepared composite material were measured in the same manner as the conductive paper prepared in the above (1).

Table 3 shows specifications and evaluation test results of the heat-fusible conductive paper.

As shown in Table 3, the thermoplastic conductive paper and the heat-fusible conductive paper of the present invention have extremely excellent adhesion to a plastic base material, wood and the like without using an adhesive.

In addition, the electromagnetic wave shielding characteristics of a composite material obtained by combining these conductive papers are extremely excellent.

〔The invention's effect〕

As shown in the above Examples, the conductive paper of the present invention is compared with a conductive paper in which a conductive fiber having a conventional stainless steel fiber or a copper-nickel two-layer coating is blended as a stock component. Not only does it exhibit extremely excellent conductivity (surface resistance value) and electromagnetic wave shielding properties with a small amount of compounding, it also has excellent moisture resistance and can be manufactured at low cost.

Moreover, the thermoplastic conductive paper not only has extremely excellent conductivity and electromagnetic wave shielding properties, but also has an extremely large elongation and excellent workability.

That is, by using the thermoplastic conductive paper of the present invention, it is possible to manufacture a molded article that was difficult to form using conventional conductive paper such as deep drawing.

Furthermore, since the heat-fusible conductive paper is based on the thermoplastic conductive paper, it is excellent not only in conductivity, electromagnetic wave shielding properties and workability, but also in adhesiveness to various base materials. Therefore, not only is it suitable for the production of various conductive or electromagnetic shielding composite materials, but it is also possible to add conductive or electromagnetic shielding properties to a molded product by heat-sealing it to a molded product made of various materials. Can be used for

The present invention is to provide a thermoplastic conductive paper having improved workability and excellent electromagnetic conductivity and electromagnetic wave shielding properties, and a heat-fusible conductive paper further having excellent adhesion to various base materials. The significance is extremely large.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI D21H 5/20 D (72) Inventor Kei Akira 1-4-1 Higashi, Tsukuba-shi, Ibaraki Pref. Inventor Jiro Takahira 12-54 Goi-Minamikaigan, Ichihara-shi, Chiba Prefecture Nippon Soda Co., Ltd.Functional Products Research Laboratory (72) Inventor Katsuyuki Hayashi 12-54 Goi-minamikaigan, Ichihara-shi, Chiba Prefecture Nippon Soda Co., Ltd. In-house (72) Inventor Noriaki Ishiguro 12-54, Goi-minamikaigan, Ichihara-shi, Chiba Prefecture Nippon Soda Co., Ltd. Inventor Yoshisho Hama 52-2-1, Oya, Oya-cho, Naruto-shi, Tokushima (72) Inventor Setsuo Motobashi 3-6-2, Nihonbashi-Honcho, Chuo-ku, Tokyo Ozu Sangyo Co., Ltd. Person Eiichi Noguchi 3-6-2 Nihonbashi Honcho, Chuo-ku, Tokyo Examiner, Ozu Sangyo Co., Ltd. Ruka Fuchino (58) Field surveyed (Int. Cl. ⁶ , DB name) D21H 13/00-13/48 H05K 9/00

Claims (8)

(57) [Claims] 1. A core having a fiber having an average fiber length of 2 mm or less,
A conductive paper comprising 3 to 60% by weight of conductive fibers coated with copper and silver in two layers in that order. 2. The conductive paper according to claim 1, wherein the fibers used for the core of the conductive fibers are glass fibers and / or synthetic fibers. 3. The conductive paper according to claim 2, wherein the synthetic fibers are nylon fibers or polyester fibers. 4. The conductive paper according to claim 1, wherein 20 to 90% by weight of a thermoplastic synthetic pulp and 5 to 70% by weight of a core-sheath type composite fiber are used as a stock component other than the conductive fiber. Thermoplastic conductive paper characterized by containing. 5. The thermoplastic conductive paper according to claim (4), wherein the thermoplastic synthetic pulp is a polyethylene synthetic pulp. 6. The thermoplastic conductive paper according to claim 4, wherein the core-sheath type composite fiber is a fiber in which a synthetic resin having a lower melting point than the core fiber is composited in a sheath type. 7. A heat-fusible conductive paper, characterized in that the heat-fusible polymer is impregnated and / or coated on the conductive paper according to claim (1) or (4). . 8. The heat-fusible polymer according to claim 7, wherein the heat-fusible polymer is EVA, NBR, SBR, acrylic resin, acrylic-styrene copolymer and / or polyurethane. Conductive paper.