| 摘要 |
<p>Disclosed are polyimide short fibers having extremely high heat resistance, suitable for non-woven fabrics and paper, and having many branches. Specifically disclosed are polyimide short fibers having many branches, which are produced by beating and loosening a specific foamed polyimide material. The foamed material preferably comprises a polyimide produced using 2,3,3',4'-biphenyltetracarboxylic acid as an aromatic tetracarboxylic acid component, preferably has a glass transition temperature higher than 300°C, and preferably has an expansion ratio of 20 times or more.</p> |
