Kaneka Corporation

Shuhei Wakahara

Yasushi Nishikawa

Mutsuaki Murakami

Yusuke Ohta

In order to obtain a graphite film having an excellent thermal diffusivity, a high density, and excellent flatness without flaws, recesses and wrinkles on the surface, the process for producing a graphite film according to the present invention comprises the graphitization step for a raw material film made of a polymer film and/or a carbonized polymer film and/or the post-planar pressurization step for the film in this order to prepare a graphite film, wherein the graphitization step is a step of thermally treating two or more stacked raw material films at a highest temperature of 2,000&#xb0; C. and includes a method of electrically heating the raw material films themselves and/or a method of thermally treating the films while applying pressure to the films planarly, and the post-planar pressurization step includes a method of planarly pressurizing the one raw material film or the multiple stacked raw material films after graphitization by single-plate press or vacuum press.

Process for producing graphite film and graphite film produced thereby

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.

Graphite film and graphite composite film

A graphite film excelling in heat conductivity, especially, a graphite film of high heat conductivity that even when its thickness is large, would not suffer damage by heat treatment. There is provided a process for producing a graphite film, including graphitizing a raw material film of a polymer film and/or carbonized polymer film, characterized by including (i) holding the raw film in a vessel capable of direct passage of current through voltage application and (ii) applying voltage to the vessel to thereby induce electrification so that graphitization is carried out. There is further provided a process for producing a graphite film, characterized by including the step of holding the raw material film in vessel (A) being electrifiable, subsequently holding the resultant vessel (A) in vessel (B) being electrifiable and effecting current passage through the whole so that graphitization is carried out.

Method for producing graphite film and graphite film produced by the method

Method for producing graphite film, and graphite film produced by the method

A graphite film having excellent thermal conductivity, surface hardness, surface adhesion and appearance can be obtained. Further, a thick graphite film in which each of such properties is excellent can be obtained. There is provided a process for producing a graphite film in which a polymer film is thermally treated at a temperature of 2,000&#xb0; C. or more, the process comprising the step of bringing a polymer film into contact with a substance containing a metal during graphitization treatment. When a polymer film having a high plane orientation is used as a raw material and the raw material is brought into contact with a metal to thermally treat the material, a problem of separation of graphite from the surface can be solved which has not been solved by the prior art, and furthermore a graphite can be obtained having excellent thermal conductivity, surface hardness, density and surface adhesion.

Process for producing graphite film

A graphite film having excellent thermal conductivity, surface hardness, surface adhesion and appearance can be obtained. Further, a thick graphite film in which each of such properties is excellent can be obtained. There is provided a process for producing a graphite film in which a polymer film is thermally treated at a temperature of 2,000&#xb0; C. or more, the process comprising the step of bringing a polymer film into contact with a substance containing a metal during graphitization treatment. When a polymer film having a high plane orientation is used as a raw material and the raw material is brought into contact with a metal to thermally treat the material, a problem of separation of graphite from the surface can be solved which has not been solved by the prior art, and furthermore a graphite can be obtained having excellent thermal conductivity, surface hardness, density and surface adhesion. An effect that cannot be expected in the prior art can be achieved by bringing a polymer film having a high plane orientation into contact with a metal to thermally treat the film.

Growing community of inventors

Settsu, Japan

Shuhei Wakahara