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 method for producing a filmy graphite comprising the step of heat-treating a polyimide film having a thickness of 25 μm or more and 50 μm or less at 3,000° C. or lower, wherein the filmy graphite has a ratio of electrical resistance at 77 K to that at room temperature of 0.8 or less.
2. The method according to claim 1 , wherein the filmy graphite has an electrical conductivity of 20,000 S/cm or more.
3. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film at 3,000° C. or lower, wherein the filmy graphite has a thickness of 10.6 μm or more and 20 μm or less, and has a ratio of electrical resistance at 77 K to that at room temperature of 0.8 or less.
4. The method according to claim 3 , wherein the filmy graphite has an electrical conductivity of 20,000 S/cm or more.
5. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film having a thickness of 25 μm or more and 50 μm or less at 3,000° C. or lower, wherein the filmy graphite has a ratio of electrical resistance at 4 K to that at room temperature of 0.4 or less.
6. The method according to claim 5 , wherein the filmy graphite has an electrical conductivity of 20,000 S/cm or more.
7. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film at 3,000° C. or lower, wherein the filmy graphite has a thickness of 10.6 μm or more and 20 μm or less, and has a ratio of electrical resistance at 4 K to that at room temperature of 0.4 or less.
8. The method according to claim 7 , wherein the filmy graphite has an electrical conductivity of 20,000 S/cm or more.
9. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film having a thickness of 25 μm or more and 50 μm or less at 2,800° C. or lower, wherein the filmy graphite has a ratio of electrical resistance at 77 K to that at room temperature of 0.9 or less.
10. The method according to claim 9 , wherein the filmy graphite has an electrical conductivity of 13,000 S/cm or more.
11. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film at 2,800° C. or lower, wherein the filmy graphite has a thickness of 10.3 μm or more and 21 μm or less, and has a ratio of electrical resistance at 77 K to that at room temperature of 0.9 or less.
12. The method according to claim 11 , wherein the filmy graphite has an electrical conductivity of 13,000 S/cm or more.
13. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film having a thickness of 25 μm or more and 50 μm or less at 2,800° C. or lower, wherein the filmy graphite has a ratio of electrical resistance at 4 K to that at room temperature of 0.75 or less.
14. The method according to claim 13 , wherein the filmy graphite has an electrical conductivity of 13,000 S/cm or more.
15. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film at 2,800° C. or lower, wherein the filmy graphite has a thickness of 10.3 μm or more and 21 μm or less, and has a ratio of electrical resistance at 4 K to that at room temperature of 0.75 or less.
16. The method according to claim 15 , wherein the filmy graphite has an electrical conductivity of 13,000 S/cm or more.
17. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film having a thickness of 12.5 μm or more and 25 μm or less at 3,000° C. or lower, wherein the filmy graphite has a thermal conductivity of 1,767 W/m·K or more.
18. The method according to claim 17 , wherein the filmy graphite has an electrical conductivity of 20,000 S/cm or more.
19. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film at 3,000° C. or lower, wherein the filmy graphite has a thickness of 4.9 μm or more and 10.6 μm or less, and has a thermal conductivity of 1,767 W/m·K or more.
20. The method according to claim 19 , wherein the filmy graphite has an electrical conductivity of 20,000 S/cm or more.
21. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film having a thickness of 12.5 μm or more and 25 μm or less at 2,800° C. or lower, wherein the filmy graphite has a thermal conductivity of 1,481 W/m·K or more.
22. The method according to claim 21 , wherein the filmy graphite has an electrical conductivity of 13,500 S/cm or more.
23. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film at 2,800° C. or lower, wherein the filmy graphite has a thickness of 5.0 μm or more and 10.3 μm or less, and has a thermal conductivity of 1,481 W/m·K or more.
24. The method according to claim 23 , wherein the filmy graphite has an electrical conductivity of 13,500 S/cm or more.
25. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film having a thickness of 25 μm or more and 50 μm or less at 3,000° C. or lower, wherein the filmy graphite has a thermal conductivity of 1,760 W/m·K or more.
26. The method according to claim 25 , wherein the filmy graphite has an electrical conductivity of 20,000 S/cm or more.
27. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film at 3,000° C. or lower, wherein the filmy graphite has a thickness of 0.6 μm or more and 20 μm or less, and has a thermal conductivity of 1,760 W/m·K or more.
28. The method according to claim 27 , wherein the filmy graphite has an electrical conductivity of 20,000 S/cm or more.
29. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film having a thickness of 25 μm or more and 50 μm or less at 2,800° C. or lower, wherein the filmy graphite has a thermal conductivity of 1,398 W/m·K or more, and an electrical conductivity of 13,0000 S/cm or more.
30. A method for producing a filmy graphite comprising the step of heat-treating a polyimide film at 2,800° C. or lower, wherein the filmy graphite has a thickness of 10.3 μm or more and 21 μm or less, and has a thermal conductivity of 1,398 W/m·K or more.
31. The method according to claim 30 , wherein the filmy graphite has an electrical conductivity of 13,000 S/cm or more.