JP2005044706A - Electron emissive wire and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron emissive wire capable of enhancing energy efficiency because an electron can be emitted under normal temperatures by applying a voltage between a metal wire and an anode and no energy for heating is required, and capable of enhancing durability because no deterioration is caused by transpiration of an oxide. <P>SOLUTION: This electron emissive wire 1 is composed of a metal wire 2, and carbon nano-fiber 3 radially adhering to the surface of the metal wire 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electron emission wire and an electron emission wire manufacturing method, and more particularly to an electron emission wire capable of emitting electrons at room temperature and an electron emission wire manufacturing method.

Conventionally, as a filament of a fluorescent display tube, an electron emission wire in which a tungsten wire is coated with an oxide of barium, strontium, and calcium has been used (for example, see Non-Patent Document 1).
In addition, carbon nanofibers, which are carbon fibers having a fiber diameter φ≈150 nm and a fiber length L = 10 to 20 μm, are commercially available (see, for example, Non-Patent Document 2).
Futaba Electronics Co., Ltd., booklet “Fluorescent display tube Communication between light and technology”, page 14 Showa Denko KK, vapor grown carbon fiber <VGCF>, Internet (http://www.sdk.co.jp/contents/division/)

In the conventional electron emission wire, it was necessary to energize the tungsten wire to raise the temperature to about 600 ° C.
However, since much energy is used for heating, there is a problem that energy efficiency is poor. Moreover, there is a problem that the oxide may evaporate due to high temperature and may deteriorate in a short time.
Therefore, an object of the present invention is to provide an electron emission wire that can emit electrons at room temperature and a method for manufacturing the electron emission wire.

In a first aspect, the present invention provides an electron emission wire characterized in that carbon nanofibers are attached to the surface of a metal wire.
In the electron emission wire according to the first aspect, since carbon nanofibers are used as an electron emission material, electrons can be emitted at room temperature by applying a voltage between the metal wire and the anode. Therefore, energy for heating becomes unnecessary and energy efficiency can be improved. In addition, there is no deterioration due to evaporation of oxides, and durability can be improved.

In a second aspect, the present invention provides an electron emission wire characterized in that carbon nanofibers are attached radially to a metal wire in the electron emission wire having the above-described configuration.
In the electron emission wire according to the second aspect, since the carbon nanofibers are attached radially, the electric field concentrates on the carbon nanofibers, and electrons can be emitted with high efficiency.

In a third aspect, the present invention provides a method for producing an electron-emitting wire, characterized in that a coating mixed with carbon nanofibers is applied to a metal wire, baked, and the carbon nanofibers are adhered to the surface of the metal wire. provide.
In the method for manufacturing an electron emission wire according to the third aspect, the electron emission wire can be manufactured by using an electric wire coating facility.

According to the electron emission wire of the present invention, electrons can be emitted at room temperature. Therefore, energy for heating becomes unnecessary and energy efficiency can be improved. In addition, there is no deterioration due to evaporation of oxides, and durability can be improved.
According to the method for manufacturing an electron emission wire of the present invention, an electron emission wire can be manufactured by using an electric wire manufacturing facility.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited thereby.

FIG. 1 is a configuration diagram of an electron emission wire 1 according to Embodiment 1 of the present invention.
The electron emission wire 1 includes a metal wire 2 and carbon nanofibers 3 that are radially attached to the surface of the metal wire 2.

  The metal wire 2 is a copper wire or a nickel wire having a diameter d = 20 to 200 μm. Copper wires and nickel wires are easier to handle because they are more flexible than tungsten wires.

  The carbon nanofiber 3 has a structure in which a plurality of graphene sheets are closed in a cylindrical shape, and has a diameter φ = 20 to 200 nm and a length L = 2 to 20 μm.

The electron emission wire 1 can be manufactured by applying a coating material mixed with the carbon nanofibers 3 to the metal wire 2 and baking it so that the carbon nanofibers 3 adhere to the surface of the metal wire 2.
As shown in FIG. 2, before or during baking, when the metal wire 2 is passed through the center of the cylindrical electrode E and a voltage is applied between the cylindrical electrode E and the metal wire 2, the carbon nanofibers 3 are formed by an electric field. Can stand up radially.
In order to obtain energization between the metal wire 2 and the carbon nanofiber 3, it is preferable to use a conductive paint or carbonize the paint by baking.

  The electron emission wire 1 can also be manufactured by plating using a plating solution in which the carbon nanofibers 3 are mixed.

  The electron emission wire of the present invention can be used as a filament of a fluorescent display tube or a discharge wire of an ion generator.

It is a block diagram which shows the electron emission wire which concerns on Example 1 of this invention. It is explanatory drawing of the manufacturing method of the electron emission wire which concerns on Example 1 of this invention.

Explanation of symbols

1 Electron emission wire 2 Metal wire 3 Carbon nanofiber

Claims (3)

An electron emission wire characterized in that carbon nanofibers are attached to the surface of a metal wire. 2. The electron emission wire according to claim 1, wherein carbon nanofibers are radially attached to the metal wire. A method for producing an electron-emitting wire, comprising: applying a paint mixed with carbon nanofibers to a metal wire, baking the paint, and attaching the carbon nanofibers to the surface of the metal wire.

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