Process for producing 2, 3, 3′, 4′,-biphenyltetracarboxylic dianhydride
2,3,3′,4′-biphenyltetracarboxylic acid is heat-dehydrated in a molten state at a temperature not lower than 200° C. in a flow of an inert gas in a reactor having at least one reaction vessel by stirring the molten material to produce 2,3,3′,4′-biphenyltetracarboxylic dianhydride. Thus obtained 2,3,3...
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Zusammenfassung: | 2,3,3′,4′-biphenyltetracarboxylic acid is heat-dehydrated in a molten state at a temperature not lower than 200° C. in a flow of an inert gas in a reactor having at least one reaction vessel by stirring the molten material to produce 2,3,3′,4′-biphenyltetracarboxylic dianhydride. Thus obtained 2,3,3′,4′-biphenyltetracarboxylic dianhydride in the molten state is subsequently cooled and solidified in an inert gas or dry air, or cooled and solidified in the ambient air at a temperature of 40° C. or lower or 100° C. or higher. |
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