| 摘要 |
PROBLEM TO BE SOLVED: To provide a support for ferromagnetic metal thin-film magnetic recording medium with excellent dimensional stability, electromagnetic conversion characteristics and running durability, and which has little dimensional change due to a change of environment such as temperature and humidity when particularly used for the ferromagnetic metal thin-film magnetic recording medium. SOLUTION: The support for ferromagnetic metal thin-film magnetic recording medium is provided with a layer (M layer) made of metal or alloy on at least one surface of a polyester film, and has a side A with a surface roughness Ra of 0.5 to 5 nm and a side B with a surface roughness Ra of 5 to 20 nm. The M layer is provided only at the side B or at both sides, so that a thickness Ta of the M layer at the side A and a thickness Tb of the M layer at the side B satisfy Ta/Tb<1, and further, a sum of Young's modulus in a longitudinal direction and a width direction falls between 13 and 22 GPa, Young's modulus Em in the longitudinal direction falls between 6.5 and 11 GPa, and a ratio Em/Et between Young's modulus Em in the longitudinal direction and Young's modulus Et in the width direction falls between 0.5 and 1.0. COPYRIGHT: (C)2009,JPO&INPIT |
