JPH0529702B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a material containing carbon as a main component and provided in a cylindrical shape on a fibrous surface (herein, they are collectively referred to simply as carbon).

The present invention aims to provide such carbon having an optical energy band width of 2.0 eV or more, particularly 2.6 to 4.5 eV, and a fibrous structure having a cylindrical structure, the cylindrical having a thickness of 30 μ or less. There is.

Conventionally, carbon was thought to be conductive carbon such as graphite. Diamond is a well-known single crystal of carbon, and diamond is known to have many properties such as hardness and the highest thermal conductivity coefficient among insulators. This Dunyamond was first synthesized only under ultra-high pressure and ultra-high temperature, and other carbons were poor conductors with graphite-like hardness and brittleness.

However, in the present invention, when the plasma vapor phase method is used, this carbon has an optical energy band gap width of 2.6 to 2.6.
It has been found that it has very industrially important properties: it has an insulating property of 4.5 eV, and its synthesis temperature is below 650°C, particularly between 200 and 400°C. The present invention aims to obtain a reinforcing organic substance by forming this carbon into a cylindrical shape on the surface of a fibrous core, and then mixing these carbon fibers with plastic or the like.

In the present invention, the carbon fiber has a fiber core made of an organic substance such as nylon or tetron in its center, and is formed by forming a cylindrical coating of reacted carbon on the surface or surface of the fiber core.

This cylindrical shape has a central part made of fibers or simply carbonized fibers, but a cylindrical surface with a thickness of less than 30μ and an extremely high hardness, that is, optically more than 2.0eV, especially 2.6~ The coating has a cylindrical shape and has an energy band width of 4.5 eV and has a hardness similar to that of diamond, and therefore has strong properties against bending strength and the like.

The present invention will be described below with reference to the drawings.

FIG. 1 shows an outline of a plasma CVD (vapor phase method) apparatus used in the present invention.

In the drawing, a reactor 1 is provided with electromagnetic energy 2 by means of induction or capacitance. Furthermore, the acetylene 8, which is a hydrocarbon, passes through a flow meter 5 and reaches an excitation chamber. This reactive gas is composed of hydrogen, diluted by carrier gas 7, and both activated or decomposed by applying microwave electromagnetic energy 3 of 2.45 GHz. This activated or decomposed reactive gas is further bonded by direct current, radio frequency or microwave, typically 13.56 MHz electromagnetic energy 2 to polymerize the finely powdered core or heated to form a fibrous core 12. Formed in the form of a film on the surface of This core is rolled from roll 10 to roll 9, during which a carbon film is formed on its surface, and in order to further increase its thickness, it is rolled again from roll 9 to roll 10, and this process is repeated until the thickness is increased. It gets thicker.

Moreover, instead of one fiber, 100 to ¹⁰⁴ fibers were placed in the reaction space at the same time, each with a spacing of 1 to 10 mm, increasing the effective surface area and improving the carbon absorption efficiency.

This reactive gas and the core fiber are heated to 150 to 650°C by heaters 14 and 15 to accelerate the reaction. Unwanted substances after the reaction reach the rotary pump 11 via the exhaust 11. This is during the reaction
It is critical to provide an atmosphere of 0.001 to 10 torr, typically 0.1 to 0.5 torr, to the reactive gas.

50-5000W for excitation chamber 4, typically 200-500W
Microwaves were introduced and were effective in cleaving hydrogen in C-H bonds. Furthermore, in order to give kinetic energy to the activated carbon and cause them to collide with each other and bond,
Providing 100-300 W of electromagnetic energy at a frequency of 13.56 MHz was important to create a large optical bandwidth (termed Eg).

If the carbon formed is simply thermally decomposed, Eg
was 0.1 to 1.5 eV, and in that case, the hardness was also not sufficient. Furthermore, when electromagnetic energy 3.2 is given, it becomes 2.6 to 4.5 eV, typically 3.0 to 3.5 eV,
In this case, the Vickers hardness also had an excellent value of 4500 to 5500 Kg/mm or more. It also had a high thermal conductivity of 5.0 (W/cmdeg).

When carbon is made on the surface of a fibrous core, the thickness of the core can be changed arbitrarily, but the actual diameter is 300μ (0.3mm) or less, and especially when the surface is 30μ or less, Typically on the fiber surface of 10-100μ
Carbon with a thickness of 30μ or less, for example 1 to 10μ (in this case, the core will also be carbon as a component, but since its optical band width Eg is less than 2eV on average, only the surface thickness is considered) The interior is hollow, similar to that of honeydew bamboo, and the result is a fibrous structure that is both extremely light and strong.

Of course, this fibrous structure may be formed by directly carbonizing the core in plasma to form the highly hard carbon of the present invention in a thickness of 0.1 to 5 μm on its surface.

Such carbon fibers were mixed into general plastic to form a composite. Because such materials are light in weight,
For use in aircraft, etc., and for Eg of 2.0eV or more, especially
If it has 2.6 eV or more, or 3.5 eV or more, it can be used as tempered glass or a part thereof, and its applications are immeasurable.

Since the carbon of the present invention mainly uses a double bond or a hydrocarbon material having a double bond, such as acetylene or ethylene, as its raw material, bonds can be created even with low electrical energy. However, if you provide an auxiliary microwave of 1KW or more, it is possible to make it from propane gas. This has many industrial applications because the raw materials used are inexpensive and the energy required does not require high temperatures.

In the present invention, the carbon mainly formed exhibited an amorphous structure when electromagnetic energy was weakly applied. However, when the electromagnetic energy output was increased to 500 W or more, a microcrystalline structure with a size of 5 to 200 Å was obtained. This microcrystalline structure was even stronger.

In the above, carbon is described as the main component, but it contains 0.01 to 10 mol% of hydrogen, and further contains 3 mol% or less of impurities of valence, valence, or valence, and on average It is also possible to provide P or N type conductivity while having 2.6 to 4.5 eV.

In the present invention, there is no surface to be formed, or a thread-like material is used as the substrate. However, it goes without saying that by using a plate shape or the like, it can be used as a protective film for reinforcing mechanical strength.

The core used in the present invention is an organic fiber. However, when this core is made of glass and its surface is coated with a film of carbon, the refractive index of carbon increases to 2.3~
2.6, it is extremely effective in reducing optical signal loss on the surface of SiO ₂ fibers for optical communications. In this case, we believe that the industrial value of the fiber communication cable is extremely great because it is a cylindrical coating made of carbon, which is an inexpensive material that has high strength, especially tensile strength.

Furthermore, metals such as copper or ceramics may be used as the core for providing this fibrous shape, and thin metal wires can improve their processing strength and have excellent electrical insulation properties, so they have excellent heat resistance. It is ideal as a conducting wire with

[Brief explanation of drawings]

FIG. 1 shows an outline of an apparatus for producing carbon according to the present invention.

Claims (1)

[Scope of Claims] 1. A carbon-coated fiber characterized in that carbon having an optical energy band gap width of 2.0 eV or more is provided in a cylindrical shape on the surface of a material having a fiber as a core. 2. The carbon-coated fiber according to claim 1, characterized in that the carbon is provided in a cylindrical shape on the surface of a core made of an organic material or its carbonized fiber, glass, thin ceramic wire, or thin metal wire. 3. The carbon-coated fiber according to claim 2, wherein the carbon having a cylindrical shape has a thickness of 30μ or less.