| abstract |
[Problem] To be applied to a heat-resistant nonwoven fabric having a high shape retention without significantly lowering its tensile strength even when placed in an atmosphere of 200 ° C. or higher, and to have a heat resistance Provided is a novel polyimide resin binder which can be used in the form of an aqueous solution when mixed with fibers, and a heat-resistant nonwoven fabric using the same. A polyimide obtained from a water-soluble polyimide precursor containing 1,2-dimethylimidazole and / or 1-methyl-2-ethylimidazole is used as a binder resin for a fiber made of a heat-resistant resin. Heat resistant non-woven fabric. |