| abstract |
PROBLEM TO BE SOLVED: To be able to be manufactured in a small number of steps, to have a small anisotropy in the in-plane direction of the film, to have a small pore diameter, and to be a through-hole, so that the collection efficiency of fine particles is high, Provide a porous film for a filter that has a relatively large filtration amount, has good wettability to water and oil, and has excellent mechanical strength, has excellent durability, is light in weight, and is not bulky. . SOLUTION: This is a porous polyamide film having fine through holes, having a porous structure, a porosity of 15 to 85%, a pore diameter of 0.01 to 5 µm, and a film thickness of 10 to 50 µm, and a film. Has a structure in which a layer made of microporous material and a layer having relatively large voids or openings are stacked in the cross-sectional direction, and the two layers are connected to each other by through micropores. I do. |