| 摘要 |
PROBLEM TO BE SOLVED: To provide a rolled item of a fine porous membrane made of a polyolefin that is excellent in workability when a manufactured article such as a cell separator or the like is fabricated and that has high strength, is produced at a low cost and is excellent in thickness stability so as to allow for a high winding speed during the winding process in the subsequent step of slitting and rewinding using the rolled item. SOLUTION: The rolled item of the fine porous membrane made of a polyolefin is a rolled item produced by winding the fine porous membrane made of a polyolefin around a tube, wherein the relation among a maximum outer diameter D (mm), a minimum outer diameter d (mm) and a wound length L (m) of the rolled item including the fine porous membrane satisfies the formula represented by 0.01≤(D<SP>2</SP>-d<SP>2</SP>)/L≤0.5. COPYRIGHT: (C)2004,JPO |
