| 摘要 |
PROBLEM TO BE SOLVED: To provide a method or the like for producing a porous film made of PVDF, having excellent water permeation performance and blocking performance to a micro pathogen, and not only having extremely high chemical resistance capable of suppressing the coarsening of pores to chemical washing or the like but also stably holding the blocking performance to the micro pathogen for a long period.SOLUTION: In a method for producing a porous film, a film forming raw liquid containing at least a polyvinylidene fluoride resin and a solvent is discharged and is brought into contact with a congealing liquid containing at least a nonsolvent to produce the porous film by a nonsolvent induced phase separation method. A discharge temperature of the film forming raw liquid is not less than a melting point of the polyvinylidene fluoride resin, and less than a decomposition temperature of the polyvinylidene fluoride resin, and a temperature of the congealing liquid is higher than a solidification temperature of the film forming raw liquid. |
