| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nonwoven fabric exhibiting heat resistance, mechanical strength and thermal dimensional stability in an application of being exposed to high-temperature environment, having very large surface area and exhibiting high filter performance. <P>SOLUTION: The nonwoven fabric comprises a fiber of a polyimide obtained by polycondensing at least aromatic tetracarboxylic acids and an aromatic diamine having a benzoxazole structure, having 0.001-1 μm fiber diameter, and is obtained through a step of subjecting a polyamic acid obtained by polycondensing at least the aromatic tetracarboxylic acids and the aromatic diamine having the benzoxazole structure to charge spinning to form a polyimide precursor nonwoven fabric, and a step of subjecting the group of the polyimide precursor fiber to imidation treatment. <P>COPYRIGHT: (C)2008,JPO&INPIT |
