Patent ID: 6565962
Filing Date: 2003-05-20
Classification: B29C,B29K,C08G,C08J,Y10T

Abstract:
A polyimide porous film obtained by drying and imidizing a polyimide precursor porous film which is substantially homogeneous on both sides, the polyimide porous film having pores on both sides wherein the pores all satisfy the following conditions 1) to 4):1) The difference in the mean pore size of both sides is less than 200% based on the smaller average value of the mean pore size. 2) The coefficient of variation for the pore size on each side is smaller than 70%. 3) The coefficient of variation for the pore centroid distance on each side is smaller than 50%. 4) The mean pore size on each side is 0.05-5 &mgr;m.