| 摘要 |
PURPOSE:To improve the electrical and thermal conductivity and strengh of the title material by treating the vapor-growth graphite fibers with a mixed soln. of a strong mineral acid, potassium chlorate, chromic acid, etc., and treating the obtained fibers alone or the mixture with expandable graphite under specified conditions. CONSTITUTION:A mixed soln. of fuming nitric acid or concd. sulfuric acid and nitric acid, potassium chlorate, chromic acid, potassium permanganate, perchloric acid, hydrogen peroxide, etc., is prepared. The vapor-growth graphite fibers are treated with the mixed soln., and thermally expandable vapor-growth graphite fibers are obtained. The fibers alone or the mixture with thermally expandable graphite are treated at 400-1700 deg.C, and compacted to a density of >=0.9. As a result, the sheet material having <=700muOMEGA.cm electrical resistivity in the sheet plane direction, >=120kcal/m.hr. deg.C thermal conductivity, <=10,000muOMEGA.cm electrical resistivity in the sheet thickness direction, >=10kcal/ m.hr. deg.C thermal conductivity, and >=40kg/cm<2> tensile strength is obtained. |
