Filmy graphite and process for producing the same
View Patent ↗A process for producing a filmy graphite includes the steps of forming a polyimide film having a birefringence of 0.12 or more and heat-treating the polyimide film at 2,400° C. or higher.
1. A process for producing a filmy graphite comprising the steps of: forming a polyimide film having a thickness of 75 μm or less and a birefringence of 0.12 or more; and heat-treating the polyimide film at 2,700° C. or higher,
wherein the filmy graphite has an electrical conductivity of 9,200 S/cm or more.
2. A process for producing a filmy graphite comprising the steps of:
forming a polyimide film having a thickness of 75 μm or less and a mean coefficient of linear expansion of less than 2.5×10 −5 /° C. in a range of 100° C. to 200° C., the mean coefficient of linear expansion being in a planar direction of the film; and
heat-treating the polyimide film at 2,400° C. or higher,
wherein the filmy graphite has an electrical conductivity of 12,000 S/cm or more.
3. A process for producing a filmy graphite comprising the steps of:
forming a polyimide film having a thickness of 75 μm or less and a mean coefficient of linear expansion of less than 2.5×10 −5 /° C. in a range of 100° C. to 200° C., the mean coefficient of linear expansion being in a planar direction of the film, and having a birefringence of 0.12 or more; and
heat-treating the polyimide film at 2,400° C. or higher,
wherein the filmy graphite has an electrical conductivity of 12,000 S/cm or more.
4. A process for producing a filmy graphite comprising the steps of: forming a polyimide film having a thickness of 100 μm or less and a birefringence of 0.12 or more; and heat-treating the polyimide film at 2,700° C. or higher,
wherein the filmy graphite has an electrical conductivity of 8,000 S/cm or more.
5. The process for producing a filmy graphite according to claim 4 , wherein the filmy graphite has an electrical conductivity of 9,300 S/cm or more.
6. The process for producing a filmy graphite according to claim 4 , wherein the filmy graphite has an electrical conductivity of 9,700 S/cm or more.
7. A process for producing a filmy graphite comprising the steps of: forming a polyimide film having a thickness of 50 μm or less and a mean coefficient of linear expansion of less than 2.5×10 −5 /° C. in a range of 100° C. to 200° C. birefringence of 0.12 or more; and heat-treating the polyimide film at 2,400° C. or higher, wherein the filmy graphite has an electrical conductivity of 16,000 S/cm or more.
8. A process for producing a filmy graphite comprising the steps of: forming a polyimide film having a thickness of 200 μm or less and a birefringence of 0.12 or more; and heat-treating the polyimide film at 2,700° C. or higher, wherein the filmy graphite has an electrical conductivity of 9,800 S/cm or more.