| 摘要 |
PURPOSE:To form a thermally expandable graphite having no change with time on the acidity thereof and not damaging the stability of aqueous emulsion products or aqueous latex products on the addition of the graphite to the products. CONSTITUTION:The thermally expandable graphite contains an alkali metal in a molar ratio of >=1 to sulfuric acid radical (free sulfuric acid) except sulfuric acid forming interlaminar compounds contained in the thermally expandable graphite. The expandable graphite is obtained by the following method. In a method comprising the treatment of graphite with a mixture of concentrated sulfuric acid and an oxidizing agent, the washing of the treated graphite with water and the drying of the washed graphite, the treated graphite is washed until the amount of free sulfuric acid becomes <=1mol/kg based on the solid content of the graphite to be washed, neutralized with an aqueous solution of an alkali metal compound so as to give a mol ratio of the alkali metal of >=2 based on the free sulfuric acid and subsequently drying the neutralized graphite. |
