| 摘要 |
PURPOSE:To obtain the title membrane suitable for use in batteries, because it has no defects such as fisheyes on its fine pore surface, and shows excellent uniformity in its pore size, by adding a specific organic solid to the polyolefin and controlling the cooling temperature in a prescribed range. CONSTITUTION:A blend of (A) a polyolefin and (B) an organic solid which melts at 35-100 deg.C, has a molecular weight of 200-1,000 and includes dipolar or polar groups is melt-extruded, solidified by cooling it down to a temperature between the melting point of component B and the melting and crystallizing temperature, then subjected to the extraction of component B to give the subject membrane. |
