NON-MAGNETIC PARTICLE POWDER FOR NON-MAGNETIC BASE LAYER OF MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide acicular hematite particle powder suitable for non-magnetic particle powder for a non-magnetic base layer of a magnetic recording medium having improved surface smoothness. SOLUTION: The acicular hematite particle powder suitable for the non- magnetic particle powder for the non-magnetic base layer is mixed acicular hematite particle powder of large particle size acicular hematite particle powder having 0.10-0.30μm average major axis and an aspect ratio of 3.0-9.5 and small particle size acicular hematite particle powder having a ratio of the average major axis to the major axis of the large particle size acicular hematite particle powder of 0.10-0.83 and an aspect ratio of 3.0-9.5. The mixing ratio of the large particle size acicular hematite particle powder to the small particle size acicular hematite particle powder is 20:80-40:60 in volume.