POROUS SHEET AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To enable the high speed and stable running of a magnetic tape in a case adapted, for example, to a slide sheet for a magnetic tape cassette by improviding sliding properties. SOLUTION: A porous sheet 11 is composed of a thermoplastic resin like ultra-high mol.wt. polyethylene and has a large number of voids and emossed patterns 19 are formed on at least the single surface of the sheet 11. An antistatic agent may be contained in the porous sheet 11. This porous sheet 11 is obtained by sintering a thermoplastic resin powder to mold the same into a sheet having a large number of pores and forming enbossed patterns 19 to at least the single surface of this sheet.