| 摘要 |
PROBLEM TO BE SOLVED: To solve such problems that a conventional highly oriented graphite obtained by carrying out heating pressurization treatment of a laminate of polyimide films synthesized from pyromellitic dianhydride and 4, 4'-diaminodiphenyl ether (4,4'-oxydianiline) is inferior in radioactive ray reflectiveness and heat conductivity since the locking characteristic (orientation) is greater than 0.45, so that it is inadequate for a high performance radioactive ray optical element, or a high heat conductivity body. SOLUTION: In a radioactive ray optical element, or a high heat conductivity body, a highly oriented graphite is used wherein the thickness obtained by carrying out the heating pressurization treatment of a laminate of polyimide films having high birefringence is not less than 0.1 mm and not greater than 6 mm, and the locking characteristic is not greater than 0.44. Further, in a method of producing the highly oriented graphite, the laminate of the polyimide films having high birefringence is heat-pressed. Yet further, increasing the thickness of the raw materials and pressurizing even during carbonization make the quality high. COPYRIGHT: (C)2011,JPO&INPIT |
