| abstract |
A method for producing a micro-porous film of a thermoplastic resin, wherein a thermoplastic resin and a solvent for forming a film are together molten and kneaded to form a solution, the solution is extruded from a die and then cooled to prepare a gelated product, the residue of the above solvent for film forming is removed from the gelated product by using a solvent for cleaning, and the solvent for cleaning is removed, which comprises using, as the solvent for cleaning, a solvent having (a) a surface tension at 25°C of 24 mN/m or less, (b) a boiling point under atmospheric pressure of 100°C or lower, and (c) a solubility into water at 16°C of 600 ppm (on mass basis) or less, and further comprises removing the residue of the above solvent for cleaning from the product after the above cleaning by the use of warm water. |