JPH0147404B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pyrolytic carbonide having high electrical conductivity. More specifically, it provides a highly conductive carbon-based heat-treated product obtained by thermally decomposing an unsaturated compound having a halogen atom on the carbon adjacent to the carbon-carbon double bond. Conventionally, regarding the production of highly conductive pyrolytic carbon,
Many pyrolytic carbons of hydrocarbon compounds are known. For example, it is known that charcoal can be obtained by thermally decomposing relatively low-boiling hydrocarbon compounds such as methane, propane, propylene, and benzene as raw materials at a thermal decomposition temperature of 1200°C to 2200°C. In addition to this gas phase pyrolysis of hydrocarbon compounds,
Gas phase thermal decomposition of halogen-containing compounds is also known as a method using other organic compounds as raw materials. Already, Journal of the Chemical Society of Japan 494 (1979), 1690
(1979), 1,2-dichloroethylene was
It is known that pyrolysis occurs at a temperature of 1100°C, and pyrolytic carbon is produced on graphite substrates at a relatively low temperature compared to hydrocarbon compounds. However, the pyrolytic carbon obtained by this method does not necessarily exhibit high electrical conductivity. The present inventors extensively studied methods for obtaining products that undergo gas phase pyrolysis easily at low temperatures and have high electrical conductivity, and as a result, they discovered a method that is even better than conventional techniques and arrived at the present invention. That is,
When an unsaturated compound having a halogen atom on the carbon adjacent to a double bond is used, thermal decomposition products can be obtained at lower temperatures than conventional hydrocarbon compounds, and a homogeneous deposit can be obtained on the substrate. They have found that they are easier to use and, more importantly, have higher electrical conductivity. That is, an object of the present invention is to provide a highly conductive carbon-based heat-treated product obtained by thermally decomposing an unsaturated compound having at least one halogen atom in the carbon adjacent to a double bond, and a method for producing the same. be. The unsaturated compound having a halogen atom on the carbon adjacent to the double bond used in the present invention is generally an organic compound having at least one halogen atom, and in the case of an aliphatic compound, the compound has a halogen atom, and in the case of an aliphatic compound, the halogen atom is present at the allylic position; Those containing halogen are preferred. Here, the halogen atom is preferably chlorine, bromine, or iodine. That is, compounds in which a halogen atom is substituted on the carbon adjacent to an aromatic ring; for example, benzyl chloride, benzyl bromide,
Benzyl iodide, benzylidene dibromide, p
-xylylene dichloride, p-xylylene dibromide, O-xylylene dichloride, O-xylylene dibromide, p-xylylene dibromide,
α-chloromethylnaphthalene, aliphatic compounds in which the carbon adjacent to the double bond is substituted with a halogen atom; e.g. allyl chloride, allyl bromide, allyl iodide, 1,4-dibromo-2-butene,
It may be 1,4-dichloro-2-butene, or an alicyclic or heterocyclic compound, such as 3,6-dichloro-1-cyclohexene, 1-chloromethylcyclopentene, 1-chloromethylnorbornadiene, etc. . Thermal decomposition can be carried out at temperatures above 500°C under an inert atmosphere. Although deposition on a specific substrate is not required, homogeneous pyrolysis product deposition is generally observed in the presence of a suitable substrate. The molded body base material can be powder, spherical, irregularly shaped, fibrous, sheet, tape, tubular, or any other shape, and the molded body can be deposited thereon. In addition, heat-resistant base materials used for the purpose of the present invention include quartz glass, alumina,
Silicon nitride, silicon carbide, boron nitride, carbon materials, etc. are preferred, but they are not particularly affected by the base material. The thermal decomposition temperature is generally 500°C or higher.
Among them, thermal decomposition can be easily carried out at temperatures of 600℃ to 1000℃, but even higher temperatures such as 2000℃ to 2500℃ can be carried out.
This may be done at temperatures around ℃. The pyrolysis products mainly consist of carbon, and are characterized by the fact that carbon-based decomposition products are deposited more easily at lower temperatures than conventional pyrolysis products. This is thought to be related to the fact that halogen or hydrogen halide is easily eliminated due to allyl coexistence. The heating method for thermal decomposition can be a direct heating method or an external indirect heating method in which the surface of the substrate is indirectly heated by axial radiation from the outer periphery of the substrate. The latter external indirect heating method is preferred from the viewpoint of homogeneity of the carbon-based coating deposited on the substrate. The raw materials can be introduced into the furnace by any method, but it is necessary to do so in the absence of reactive substances such as oxygen. The halogen-substituted compound may be introduced into the heating section as it is, or may be accompanied by an inert atmospheric gas such as argon, nitrogen, hydrogen, etc. The pyrolysis products produced in this way generally have high electrical conductivity, and are characterized by particularly exhibiting a value of 500 S/cm or more. The highly conductive pyrolytic carbon used in the present invention is characterized by its high conductivity, and uses that exhibit this characteristic can be considered. In particular, quartz glass, which is an insulating material,
One of the effects can be found in the ability to impart conductivity to ceramics and the like. The present invention will be described in detail below with reference to Examples, but the present invention is not limited thereto. Example 1 A quartz glass furnace core tube (30 mmφ x 700 mmL) is inserted into a resistance wire heating type horizontal tubular electric furnace (450 mmL), and a glass container for storing and supplying raw materials is placed at the end of one furnace core tube. The device was set up so that inert glass could be introduced above it. A quartz plate (2cm x 5cm) is placed inside the furnace core tube in the center of the electric furnace.
was placed as a base material. p-xylylene dichloride
2gr was used as a raw material, placed in the glass container mentioned above, nitrogen gas was passed through at 100ml per minute, and the temperature inside the electric furnace was raised to 950°C. Furthermore, a ribbon heater for heating the raw material is wrapped around the part of the quartz glass furnace core tube exposed from the electric furnace, and then p-xylylene dichloride is heated to 150°C with the ribbon heater and poured into the furnace core tube in the gas phase to heat it. I did the disassembly. After continuous thermal decomposition for 1 hour, it was cooled to room temperature and a sample was taken out. A homogeneous, silvery-white, shiny deposit of pyrolytic carbon had formed on the quartz plate. The electrical conductivity of this pyrolysis deposit was 1170 S/cm (room temperature). In the same manner, O-xylylene dichloride, p-xylylene dibromide, and allyl chloride were thermally decomposed at an oven temperature of 950°C. In each case, a homogeneous silvery white shiny pyrolytic carbon deposit was obtained on the quartz plate. The conductivity (room temperature) of each was measured: 940S/cm, 1050S/cm, 815S/cm
It was hot. Comparative Example 1 Same as Example 1, p-diiodobenzene, p-
Dichlorobenzene, 1,2-dichloroethylene (trans), and benzene were thermally decomposed at a furnace temperature of 950°C. Benzene produces only a small amount of soot,
No homogeneous pyrolytic carbon deposits were obtained.
When we measured the conductivity of each, we found that the former three
The conductivity was 405S/cm, 420S/cm, and 350S/cm, which were all lower than that of the present invention. Example 2 Using the same equipment as in Example 1, p-xylylene dichloride was heated at different thermal decomposition temperatures of 950°C, 700°C, and 600°C.
℃ and used a quartz plate as the base material for thermal decomposition. The electrical conductivity of the obtained pyrolysis deposits is 950.
℃; 1060S/cm (0.7μ), 700℃; 860S/cm
(0.5μ), 600°C; 510S/cm (0.2μ). The value in parentheses indicates the thickness of the deposit. When 1,2-dichloroethylene was thermally decomposed at 600°C under the same conditions, the conductivity was 35S/cm. Example 3 Using the same equipment as in Example 1, p-xylylene dichloride was thermally decomposed at 900° C. by changing the base materials to alumina fiber, quartz wool, and carbon fiber, respectively. A homogeneous coating was obtained on each fiber. The measurement results of electrical conductivity are shown in Table 1. Here, the film thickness was measured using an electron micrograph. Carbon fibers having an electrical conductivity of 400 S/cm were used as the base material. All of the coated fibers showed similar electrical conductivity and were able to impart high electrical conductivity. 【table】

Claims (1)

[Claims] 1 Highly conductive carbon-based heat treatment obtained by thermally decomposing an unsaturated organic compound having at least one halogen atom on the carbon adjacent to a carbon-carbon double bond at a temperature of at least 500°C or higher in an inert atmosphere thing.