| 摘要 |
PURPOSE:To provide a separator for battery which is inexpensive and is well applicable to an alkaline battery as well, by causing a pore forming agent to be impregnated into a granular porous powder having specified size pores, mixing the resulting mass with polyethylene resin having a melt index of 1 or less, and removing the pore forming agent after forming. CONSTITUTION:A pore forming agent is impregnated into a granular porous resin powder having a pore radius of 100 to 2000 angstrom, a pore volume of 0.1 to 2.0ml/g, and a maximum granule diameter which is 60% or less of the sheet thickness. The resulting mass is mixed with polyethylene resin having a melt index of 1 or less. The mixture is formed into a sheet by heating and fusing, and then the pore forming agent is removed. At this time, using a ribbonlike blade type blender 1, the mixing is performed by means of a screw 2b until the pore forming agent is mixed uniformly with the granular resin powder. The mixture thus obtained is heated using a two-axle type resin extruder 2 and is extruded from a die 2C. The extruded mass is formed using a calender roller 3 and is thereby formed into a sheet, and then is immersed into N-hexane to extract the pore forming agent. Thus, the product thus obtained is inexpensive and can well be used for an alkaline battery. |
