| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a purification method for easily obtaining color-reduced 2,2', 3,3'-biphenyltetracarboxylic dianhydride powder in simple operations, to provide color-reduced 2,2', 3,3'-biphenyltetracarboxylic dianhydride powder, and to provide a polyimide using the same and having improved light transparency. <P>SOLUTION: The 2,2', 3,3'-biphenyltetracarboxylic dianhydride powder is characterized in that the light transmittance in wavelength of 400 nm for a solution obtained by dissolving the 2,2', 3,3'-biphenyltetracarboxylic dianhydride powder in a 2N aqueous sodium hydroxide solution as a solvent in a concentration of 10 mass% is ≥80%. <P>COPYRIGHT: (C)2013,JPO&INPIT |
