| 摘要 |
PURPOSE:To execute the color conversion and to attain high resolution by using an extrusion molding magnet of a rare earth resin coupling type which consists of rare earth magnet powder and a specific thermosetting resin, and also, in which the content of magnetic powder is specified, as a magnet roller. CONSTITUTION:A magnetic material roller 8 is an extrusion molding magnet of a rare earth resin coupling type which consists of rare earth magnetic powder consisting of a transition metal mainly composed of a rare earth element and cobalt, and a thermosetting resin having thermoplasticity in a temperature area of a hardening temperature or below from 50 deg.C, and also, in which the content of the magnetic powder is 50 - 80 volume %. Accordingly, a small sized and light weight magnetic material roller 8 in which wall thickness of a magnetic formed body is thin can be constituted, and also, since the magnetic performance of the magnet is improved, the magnetic flux density on the surface of a developer carrying member 7 can be raised. In such a way, by decreasing the content of the magnetic material in a developer 11, and making a particle size of the magnetic material small, the color conversion and the high resolution can be attained. |
