| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a battery separator comprising a polymeric porous film of low electrical resistance with a thin skin layer. SOLUTION: This method for producing the separator for battery comprises the steps of coating the surface of a substrate with a polymer solution with a polymeric material dissolved therein and exposing the thus coated substrate to a liquid sparingly soluble for the polymeric material to deposit the polymeric material onto the surface of the substrate; wherein the contact angle between the substrate and the liquid sparingly soluble for the polymeric material is designed to be≤80°in view of the finding that as for the mechanism of generating the skin layer, if the wettability of such a liquid with a substrate to form a polymeric porous film on its surface is poor, the liquid is hard to intrude to the substrate side and the deposition of a polymer existing nearby is delayed, resulting in getting coarse in the structure of the polymeric porous film and thus forming a slightly porous skin layer. COPYRIGHT: (C)2003,JPO |
