Nanofiber structure

Abstract

A transparent soluble polyimide resin was dissolved in N,N-dimethyacetamide, and a sample solution whose concentration was 10 weight percent was produced. This sample solution is put in a container CNT which is attached to an apparatus shown in FIG. 1 , whereby a nanofiber structure was produced. The produced polyimide nanofiber structure acquired the excellent water resistance, air permeability and moisture permeability while maintaining the physical properties inherent in a polyimide, such as high heat resistance and insulation. Further, when a nanofiber structure is produced in a similar manner from a different polyimide resin, the nanofiber structure maintains excellent adhesiveness.

1 . A nanofiber structure comprising:
 a polyimide resin having a structure in which   (1) a void ratio thereof is 75% or more, and   (2) an average pore diameter distribution thereof is 0.5-2.0 μm.   
     
     
         2 . The nanofiber structure according to  claim 1 , wherein a formation of nanofibers is carried out by an electrospray deposition method. 
     
     
         3 . The nanofiber structure according to  claim 1 , wherein a nanofiber structure is not changed even if heated at 400° C. for 16 hours. 
     
     
         4 . The nanofiber structure according to  claim 1 , wherein an air permeability thereof is 4.55 cc/cm2/s or more in a JIS-L1096 air permeability A method (Frazier method), or 1.68 s/300 cc or less by a JIS-P8117 Gurley testing machine. 
     
     
         5 . The nanofiber structure according to  claim 1 , wherein a moisture permeation resistance (RET) thereof in a ISO11092 method is 3.0 (m2 and Pa/W) or less. 
     
     
         6 . The nanofiber structure according to  claim 1 , wherein a water resistance thereof is 0.01 or more MPa by JIS-L1092 water-penetration-test B method (high-pressure water method). 
     
     
         7 . The nanofiber structure according to  claim 1 , wherein a thermal conductivity thereof is within a range of 0.04-0.05 W/mK. 
     
     
         8 . The nanofiber structure according to  claim 1 , wherein the nanofiber structure has an adhesiveness.