JP3961475B2 - C / C composite plate - Google Patents

Description

  The present invention relates to a C / C composite plate having high flexibility and high conductivity.

  Carbon fiber reinforced carbon composite material, so-called C / C composite (hereinafter abbreviated as C / C), is a composite material that uses carbon fiber as an aggregate and carbon as a matrix, and has excellent heat resistance, chemical resistance, and friction characteristics. It is used for rocket nozzles and aircraft brake discs and pads because of its excellent strength, high strength and light weight. This C / C includes a flexible one and a conductive one.

  However, the conventional C / C has a high flexibility and a low conductivity, and a high conductivity has a low flexibility and has either high flexibility or high conductivity. It could only be prepared.

  Accordingly, an object of the present invention is to provide a C / C plate having both high flexibility and high conductivity.

In order to achieve the above object, according to the present invention, two or more UD prepregs each having a carbon fiber aligned in a plane in one direction as an aggregate and a graphitized substance as a matrix are stacked at 2000 ° C. or higher. A heat-treated C / C plate having a thickness of 0.18 to 0.19 mm, a flexural modulus of 59 GPa to 63 GPa, and a specific resistance of 17 μΩ · m to 18 μΩ · m A highly conductive C / C plate is provided.

Here, the weight per unit of the UD prepreg is preferably 90 g / m ² or more.

  Moreover, it is preferable that the tensile elasticity modulus of the said carbon fiber is 200 GPa or more.

  Furthermore, it is preferable that two or more UD prepregs are stacked by vacuum pack molding.

  Since this invention is comprised as mentioned above, the C / C plate which has high flexibility and high electroconductivity can be provided.

  Next, an embodiment will be described. The base material constituting the C / C plate of the present invention is a unidirectionally oriented material in which carbon fibers are aligned in a plane in one direction. As the material to be graphitized, a thermosetting resin such as an amino resin, a phenol resin, a furan resin, an epoxy resin or a polyimide resin, or a thermoplastic material such as tar or pitch can be used. As a method for producing the C / C plate, for example, the carbon fiber is prepreg by a method such as impregnation and coating of the graphitizing substance, and is formed into a molded body by lamination pressure molding or the like. This compact is graphitized by a heat treatment at 2000 ° C. or higher to form a C / C plate.

  As the graphitizing substance used in the present invention, in detail, natural product adhesives such as gelatin, albumin and cellulose, vinyl acetate, acrylic, tar, pitch and other thermoplastic resins, amino resins, phenol resins, epoxy resins , Thermosetting resins such as polyimide resins, rubber adhesives such as polychloroprene and nitrile rubber, instant adhesives such as cyanoacrylate, synthetic water-soluble resins such as polyvinyl alcohol and isobutene-maleic anhydride polymer, synthesis Emulsion adhesives such as rubber latex, polyvinyl acetate, and polyvinyl chloride can be used alone or in combination.

The C / C plate according to the embodiment of the present invention is composed of two UD prepregs, each of which has a carbon fiber aligned in a plane in one direction as an aggregate and a graphitized substance as a matrix. is a C / C plates made of heat-treated at 2200 ° C. or more, 0.18 or more 0.19 mm or less, flexural modulus 63 GPa and not more than 59GPa, resistivity or 17μΩ · m 18 μΩ · m or less of It has high flexibility and high electrical conductivity.

The basis weight of one UD prepreg is preferably 90 g / m ² or more. This is because if the thickness is less than 90 g / m ² , the thickness per sheet becomes thin, making the production difficult.

  The carbon fiber preferably has a tensile modulus of 200 GPa or more. It is known that the electrical resistance of carbon fibers decreases with an increase in tensile elastic modulus, and in the present invention, it is necessary to have high electrical conductivity. is there. When the tensile elastic modulus of the carbon fiber is less than 200 GPa, the electric resistance of the carbon fiber is high, so that the specific resistance of the C / C plate is high, which is not preferable.

The two UD prepregs are preferably stacked by vacuum bag molding. According to the vacuum bag forming, the stacked UD prepregs can be pressed uniformly, and a C / C plate displaced substantially uniformly at any part can be formed.
Note that the UD prepreg is not limited to two sheets, and three or more UD prepregs may be stacked to form a C / C plate.

  With the above configuration, a highly flexible and highly conductive C / C plate can be provided.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited only to these Examples.

Unidirectional orientation in which ^two UD prepregs (carbon fiber tensile elastic modulus 230 GPa, weight per unit weight 100 g / m ² ) coated with epoxy resin are stacked in a vacuum bag, and the carbon fibers are aligned in a plane. A molded body of the material was produced. Furthermore, it heat-processed at 2200 degreeC and graphitized, and the C / C plate was obtained.
After the heat treatment, it was processed into a test piece having a width of 5 mm and a length (fiber direction) of 60 mm, and this was used as a sample of Example 1. The size of the test piece is the same in the following examples and comparative examples.

  A C / C plate was produced in the same manner as in Example 1 except that the heat treatment temperature was 2000 ° C. This was processed into the same test piece as in Example 1 to obtain a sample of Example 2.

Comparative Example 1

  A C / C plate was produced in the same manner as in Example 1 except that the heat treatment temperature was 1000 ° C. This was processed into a test piece similar to that of Example 1 to obtain a sample of Comparative Example 1.

Comparative Example 2

A C / C plate was produced in the same manner as in Example 2, except that a UD prepreg (carbon fiber tensile elastic modulus 230 GPa, basis weight 150 g / m ² ) to which an epoxy resin was attached was used. This was processed into a test piece similar to that of Example 1 to obtain a sample of Comparative Example 2.

Comparative Example 3

A C / C plate was produced in the same manner as in Example 1, except that a UD prepreg (carbon fiber tensile elastic modulus 380 GPa, weight per unit area 90 g / m ² ) to which an epoxy resin was attached was used. This was processed into the same test piece as in Example 1 to obtain a sample of Comparative Example 3.

Comparative Example 4

A C / C plate was produced in the same manner as in Example 1, except that a UD prepreg (carbon fiber tensile elastic modulus 55 GPa, basis weight 100 g / m ² ) impregnated with an epoxy resin was used. This was processed into the same test piece as in Example 1 to obtain a sample of Comparative Example 4.

Comparative Example 5

  A C / C plate was produced in the same manner as in Example 1 except that only one UD prepreg was used. This was processed into the same test piece as in Example 1 to obtain a sample of Comparative Example 5.

  About the said Examples 1, 2 and Comparative Examples 1-5, the measurement of thickness, a bending elastic modulus, a specific resistance, and evaluation of the C / C plate surface appearance were performed. The bending elastic modulus was calculated from the amount of deflection at that time when a 10 g weight was suspended from the tip of a test piece protruding from a 45 mm fulcrum. The specific resistance was measured by the voltage drop method. These measurement results are shown in Table 1.

  From Table 1, it can be seen that the samples of Examples 1 and 2 can realize both functions of flexibility and high conductivity at high values. In contrast, the sample of Comparative Example 1 has a high specific resistance value and poor conductivity, the sample of Comparative Example 2 is thick and lacks flexibility, and the sample of Comparative Example 3 has a large flexural modulus and flexibility. It can be seen that the sample of chipping and comparative example 4 has a high specific resistance value and poor conductivity. In the sample of Comparative Example 5, cracks occurred along the fiber direction during the heat treatment, and the flexural modulus and specific resistance could not be measured.

  Thus, according to this example, it was confirmed that a C / C plate having flexibility and high conductivity could be provided.

This C / C plate can be used for an electric heating device for a traveling body of a wire or a strip product. In this energization heating device, a low temperature side electrode wheel and a high temperature side electrode wheel that rotate in contact with the wire are arranged upstream and downstream of the traveling body, the traveling body from the low temperature side electrode wheel, and the high temperature side electrode from the traveling body. By energizing the ring, the wire rod and the strip-shaped product are energized and overheated. Specifically, the electrode wheel of the energization heating device is formed by vegetating the C / C plate of the above-described embodiment at an interval on the outer periphery of a rotatable and current collecting wheel. When these C / C plates come into contact with the traveling body, the C / C plates are highly flexible and highly conductive, so that they can be bent in the traveling direction of the traveling body and increase the current density. it can. Moreover, since many C / C plates are contacting the traveling body, the number of C / C plates which are contacting the traveling body is ensured, and generation | occurrence | production of a spark is also suppressed.

Claims (4)

A C / C composite plate made of carbon fiber aligned in a plane in one direction, aggregated, and two UD prepregs with a graphitized substance as a matrix, and heat treated at 2000 ° C or higher. There 0.18 or 0.19 mm less, flexural modulus less 63 GPa or more 59GPa, resistivity 17μΩ · m or 18 [mu] [Omega] · m or less of a high flexibility, high conductivity of the C / C composite plate. ^2. The C / C composite plate according to claim 1, wherein the weight per unit of the UD prepreg is 90 g / m ² or more.   The C / C composite plate according to claim 1 or 2, wherein the carbon fiber has a tensile modulus of 200 GPa or more. The two sheets of the UD prepreg, C / C composite plate according to claim 1, which is superimposed by a vacuum bag molding.