发明授权
US5672423A Magnetic recording medium having an underlayer containing three different powders 失效
具有含有三种不同粉末的底层的磁记录介质

Magnetic recording medium having an underlayer containing three
different powders
摘要:
A magnetic recording medium containing a support having thereon in order, a non-magnetic layer unit and a magnetic layer unit, said magnetic recording medium having been produced by providing a non-magnetic layer unit containing at least one non-magnetic layer and comprising a non-magnetic powder dispersed in a binder on a non-magnetic support followed by providing, while the non-magnetic layer is still wet, a magnetic layer unit containing at least one magnetic layer and comprising a ferromagnetic powder dispersed in a binder on the non-magnetic layer, wherein the mean thickness of the magnetic layer is 1.0 .mu.m or less and the non-magnetic powder in the non-magnetic layer comprises (A) a tabular non-magnetic powder having a tabular size of from 0.01 to 0.3 .mu.m and an aspect ratio of from 3 to 20, or an acicular non-magnetic powder having a long axis of from 0.05 to 0.25 .mu.m and an aspect ratio of from 3 to 15, (B) a carbon black powder having a mean particle size of from 0.01 to 0.04 .mu.m and (C) a powder component having a larger mean particle size than the mean particle size of either powders (A) or (B).
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