| 摘要 |
<p>PURPOSE:To make fluorinated carbon hard to be desorbed from a resin-coated layer and to eliminate growth of a picture image failure due to fixed smears by adding and containing fluorinated carbon grains with a specified quietness density in the resin coated layer. CONSTITUTION:On the surface of core material grains, a resin coated layer is formed in a dry method. As the core material grains, magnetic substance grains are favourably used. The size of the magnetic substance grain is within a range of 45-75mum for its weight average grain diameter, favourably within a range of 50-70mum. As a coating resin, styrene-acryl copolymer resin is favourably used. It is favourable that a volume average grain diameter of a coated resin grain is 1.0-7.0mum. In the resin coated layer, fluorinated carbon grains quietness density of which is within a range of 0.01-0.10g/cc are added and contained. It is favorable that proportion of fluorinated carbon to be added and container is within a range of 5.0-20.0weight%.</p> |
