| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing an expanded graphite utilizable as an adsorbent for oils, an adsorbent, etc., for gaskets, packing sheets and volatile organic compounds(VOCs). SOLUTION: Graphite is brought into contact with SO3 gas generated from fuming sulfuric acid or sulfuric anhydride to produce an SO3-graphite intercalation compound. The SO3 gas condensed in an excessive amount in the SO3- graphite intercalation compound is desorbed from the graphite intercalation compound. An energy is applied to the SO3-graphite intercalation compound to expand the graphite. The amount of the acid used is reduced as compared with that of the prior art and the amount of wastes is reduced. Furthermore, the concentration of sulfur remaining in the expanded graphite can be reduced to thereby moderate the corrosion of metals when producing gaskets or packing sheets using the expanded graphite. |
