AROMATIC POLYAMIDE POROUS FILM, PROCESS FOR PRODUCING THE SAME AND SECONDARY BATTERY

摘要

An aromatic polyamide porous film that excels in thin-film forming capability and can easily express stable porous characteristics even after use at high temperature for a prolonged period of time. There is provided an aromatic polyamide porous film consisting of a porous film composed mainly of an aromatic polyamide, characterized in that on at least one major surface thereof, when the range of section area S µm² is measured by means of an atomic force microscope, the section area at a depth of 10 nm from the top surface, S(10) µm², and the section area at a depth of 20 nm from the top surface, S(20) µm², simultaneously satisfy the relationships: 0.01=S(10)/S=0.3, and 5=S(20)/S(10)=20.