Kaneka Corporation

Yusuke Ohta

Yasushi Nishikawa

Takashi Inada

Makoto Mishiro

Satoshi Katayama

Makoto Kutsumizu

Shuhei Wakahara

Yusuke Kato

Naoshi Marutani

Keisuke Inaba

Motoaki Kobayashi

A graphite film has a higher degree of thermal diffusion property in one in-plane direction and a method produces the graphite film. The graphite film includes a first axial direction, which is a direction having the highest thermal diffusivity in a film surface, and a second axial direction orthogonal to the first axial direction in the film surface. A value obtained by dividing the thermal diffusivity in the first axial direction by a thermal diffusivity in the second axial direction is not less than 1.020 and not more than 1.300.

Graphite film and manufacturing method thereof

A rolled graphite sheet includes a rod-shaped body and a graphite sheet having a length of 1 m or more and a width shorter than the length. The graphite sheet is wound around the rod-shaped body and is rolled in a length direction. When a length direction-end of the graphite sheet is pulled with a force of 1.5 N/cm in a direction parallel to a tangent of a cross-sectional circle of the rolled graphite sheet while fixing the rod-shaped body, the end moves 5 mm or less in the direction parallel to the tangent of the circle.

Rolled graphite sheet

It is possible to obtain a graphite film with its shape controlled, by performing a sag controlling step of controlling temperatures of a polymer film at both widthwise ends and a temperature of the polymer film in a widthwise middle portion within a temperature range from a starting temperature of thermal decomposition of the polymer film to a sag controlling temperature of the polymer film.

Graphite film and method for producing graphite film

When a raw material graphite film bad in flatness is laminated onto another material, creases and other defects may be caused. In particular, when a graphite film having a large area is laminated, defects such as creases may be often caused. In order to solve such defects, a flatness correction treatment step is performed wherein a raw material graphite film is subjected to heat treatment up to 2000&#xb0; C. or higher while a pressure is applied thereto. This flatness correction treatment gives a graphite film good in flatness. Furthermore, when the flatness of the raw material graphite film is corrected by use of a thermal expansion of a core, a graphite film small in sagging can be obtained.

Method for improving the flatness of graphite film, graphite film, and method for producing same

Use of highly oriented graphite including graphite layers placed on top of one another and containing only a small amount of water allows for production of an electronic device that includes, as an element, highly oriented graphite in which no delamination occurs, that is highly reliable in use, and that has a good heat dissipation capability.

Highly oriented graphite

In order to prevent positional displacement of a graphite sheet laminate during production of a resin molded product obtained by integrally molding the graphite sheet laminate and a resin, the present invention uses a graphite sheet laminate having a structure in which a first fixing layer having a modulus of elasticity of not less than 7.0&#xd7;10Pa and not more than 5.0&#xd7;10Pa at 250&#xb0; C. is in contact with a graphite sheet on at least one of principal surfaces of the graphite sheet.

Method for producing resin molded body and graphite sheet laminate

There has been a problem that wrinkles easily occur on a carbonaceous film produced by the use of a continuous production method and on a graphite film obtained by heat-treating the carbonaceous film. In the present invention, heating treatment is carried out on a polymeric film while applying pressure to the polymeric film in the film thickness direction with the use of a continuous carbonization apparatus. This makes it possible to obtain a carbonaceous film and a graphite film in which wrinkling is reduced.

Method for manufacturing carbonaceous film and method for manufacturing graphite film

Provided is a long and large-area graphite film having improved thermal diffusivity and flex resistance, and accompanied by ameliorated ruffling. According to a method for producing a graphite film, in which graphitization of a heat-treated film consisting of a carbonized polymer film is carried out in a state being wrapped around an internal core, the method being characterized in that a heat treatment is executed by controlling distance(s) between the internal core and the film, and/or between the layers of the film, a graphite film accompanied by significantly ameliorated ruffling can be obtained.

Method for producing graphite film

Graphite film

A graphite film showing an extremely low average tearing force is more likely to suffer from various kinds of defects, such as splitting, winding deviation, wrinkling, and poor dimensional accuracy, in a step of producing the graphite film and in a step of processing the graphite film. However, these defects can be prevented by using a graphite film that satisfies the following requirements: 1) having an average tearing force of not more than 0.08 N as determined by Trouser tear method in accordance with JIS K7128; and 2) having sag of not less than 5 mm and not greater than 80 mm as determined by a method of film windability evaluation in accordance with JIS C2151.

Method for producing graphite film, method for rewinding same, and method for producing graphite composite film and graphite die-cutting product

A graphite film which is low in graphite dust generation can be produced by properly selecting acid dianhydride and diamine which constitute a polyimide film, which polyimide film is a raw material of the graphite film. Specifically, the graphite film which is low in graphite dust generation can be obtained if (1) the acid dianhydride is PMDA and the diamine has a molar ratio of ODA/PDA in a range of 100:0 to 80:20, or (2) the acid dianhydride has a molar ratio of PMDA/BPDA in a range of 80:20 to 50:50, and the diamine has a molar ratio of ODA/PDA in a range of 30:70 to 90:10.

Graphite film and process for producing graphite film

There is provided a graphite composite film including a graphite film and a metal layer formed on a surface of the graphite film, in which peeling-off of the metal layer from the graphite film is suppressed. More specifically, the graphite composite film includes a graphite film and a metal layer formed on at least one side of the graphite film, wherein the graphite film has a plurality of through holes formed therein, a metal layer is formed also inside the through holes so as to be connected to the metal layer formed on a surface of the graphite film, the metal layer inside the through holes is formed continuously from the one side to an opposite side of the graphite film, and a distance between outer diameters of the through holes is 0.6 mm or less and a ratio of an area of metal inside the through holes to an area of the graphite composite film is 1.4% or more.

Graphite composite film

An object of the present invention is to provide a graphite film, and a graphite composite film both having an excellent thermal diffusivity which can sufficiently manage heat dissipation of electronic instruments, precision instruments and the like, along with an excellent flex resistance which can withstand application to bent portions. Means for Resolution of the present invention is a graphite film exhibiting the number of reciprocal foldings being 10,000 times or more as measured using a rectangular strip test piece having a width of 15 mm until the test piece breaks in a MIT folding endurance test under conditions of: a curvature radius R of the bending clamp being 2 mm; a left-and-right bending angle being 135&#xb0;; a bending rate being 90 times/min; and a load being 0.98 N.

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Settsu, Japan

Yusuke Ohta