| abstract |
PROBLEM TO BE SOLVED: To provide a filter material capable of realizing a high filtration rate with respect to fine particles and a manufacturing method thereof even though the pore diameter is moderately large and the resistance to ventilation or liquid passage is extremely low. SOLUTION: A polymer solution is applied to a porous support such as a non-woven fabric, the polymer solution layer is gradually gelled, and then the solvent of the polymer solution is removed, so that the skin layer is not provided. A filter material having a three-dimensional structure in which fibrous polymers are intertwined in a web shape is obtained. In the porous filter material (or three-dimensional structure), the BET specific surface area caused by the polymer is 1 m 2 / g or more, and the water permeation rate at 25 ° C. of the filter material is 1 × 10 −3 kg / sec · N or more. The trapping rate of latex particles having a particle diameter of 5 μm is 20% by weight or more. In the bubble point test method defined in JIS K3832, the minimum pressure at which bubbles are continuously generated is 0.05 to 1.5 MPa. [Selection] Figure 1 |