| 摘要 |
PURPOSE:To obtain the subject porous film or sheet by extracting filler and/or ethylene-propylene rubber (containing polyethylene) from film or sheet comprising specific soft polypropylene optionally containing filler. CONSTITUTION:(A) 90-40wt.% soft homopolypropylene is mixed with 10-60wt.% organic filler having 3-30mum particle diameter or inorganic filler having 0.1-30mum particle diameter and formed to film or sheet, then the filler on at least the surface is extracted with solvent, or (B) soft blocked polypropylene is optionally mixed with the filler and formed to film or sheet, then ethylenepropylene rubber (containing polyethylene) and/or the filler on at least the surface layer is extracted with a solvent to afford the aimed porous film or sheet containing fine pores having 0.1-100mum pore diameter in a range of 2-85% of the surface area. |
