Patent ID: 6833173
Filing Date: 2004-12-21
Classification: G11B,Y10T

Abstract:
A floppy disk comprising a base material and, sequentially formed on both surfaces of said base material, a metal seed layer, a primer layer, a magnetic layer, a protective layer, and a lubricant layer,wherein said base material comprises a nonmagnetic flexible support member with a thickness in the range of 30-150 &mgr;m and formed on both surfaces of said nonmagnetic flexible support member a heat-resistant macromolecular flattening layer, wherein said heat-resistant macromolecular flattening layer comprises at least one type of silicone resin, polyimide resin, polyamideimide resin or polyamide resin, wherein the linear expansion coefficient of the seed layer (ESE) and the linear expansion coefficient of the primer layer (EUL) satisfy a relation of: |ESEâˆ’EUL|/EUL<0.3, and the tensile strength of the seed layer (SSE) and the tensile strength of the primer layer (SUL) satisfy a relation of: SSE/SUL>1, wherein the seed layer contains at least one metal selected from the group consisting of Ta, Mo, W, V, Zr, Cr, Rh, Hf, Nb, Mn, Ni, Al, and Ru, or an alloy of these elements.