Control process of expansion properties of thermally expansible graphite-sulfuric acid particles and their use.

摘要

Process for regulating the expansion properties of thermally expandable sulfuric acid-graphite particles (I) comprises washing (I), obtained by reacting graphite particles with sulfuric acid in the presence of an oxidant, with an aqueous wash liquor (II) containing compounds that influence the expansion properties, until (II) separated from washed (I) has pH 2-8, preferably 3-7; and then drying.