| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing flaky phthalic anhydride which does not clog the hopper of a weighing apparatus while when packed into a bag and which does not cause such a situation that a specified amount of it can not be packed into a bag. SOLUTION: This method for producing flaky phthalic anhydride comprises distilling crude phthalic anhydride obtained by the oxidation of naphthalene, cooling and solidifying the resultant molten phthalic anhydride on a rotating drum flaker, and scraping the solidified phthalic anhydride, provided the crude phthalic anhydride is distilled so that the benzoic acid content in the molten phthalic anhydride is higher than 1,000 ppm but not higher than 5,000 ppm.
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