FLUORORESIN MICROPOROUS FILM, METHOD FOR PRODUCING SAME, AND FILTER ELEMENT USING FLUORORESIN MICROPOROUS FILM

摘要

Provided are a fluororesin microporous film which has a narrow pore size distribution and a smaller difference between the mean flow pore size and maximum pore size, a method for producing the same, and a filter element using said fluororesin microporous film. This fluororesin microporous film is a porous film obtained by molding fluororesin particles, which are constructed such that the amount of heat of fusion of the fluororesin on the outer surface is lower than the amount of heat of fusion of polytetrafluoroethylene on the inside, into a film with a predetermined shape and dimensions, heating the obtained film to above the fusion point thereof to sinter the fluororesin particles, then stretching the film.