| 摘要 |
PROBLEM TO BE SOLVED: To provide a method wherein high-purity a-BPDA (2,3,3',4'-biphenyltetracarboxylic acid dianhydride) suitable for producing a polyimide is produced with good productivity. SOLUTION: 2,3,3',4'-Biphenyltetracarboxylic acid is kept in a molten state at≥200°C temperature (a heater 19) under the flow of an inert gas (an introduction pipe 12 and a discharge pipe 13) in a reactor 10 having at least one reaction vessel 11. The melt is stirred (a stirrer 14), heated and dehydrated to produce the 2,3,3',4'-biphenyltetracarboxylic acid dianhydride. COPYRIGHT: (C)2009,JPO&INPIT
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