| 摘要 |
There are disclosed a composition for resin magnets which comprises a thermoplastic resin and magnetic powders and which, when determined in a heated molten state, has specific viscosity characteristics characterized in that the almost linear line which is obtained by taking etaR/etaO as ordinate and gamma as abscissa has a slope of at most 0.02, preferably at most 0.01 within a specific temperature range in which etaO falls within the range of from 2.0x106 to 1.0x107 dyne/cm2, wherein etaR denotes shear stress (dyne/cm2), etaO denotes yield stress (dyne/cm2) and gamma denotes shear rate (S-1); a magnetic member which is produced by the use of the above composition for resin magnets; and a process for efficiently producing the magnetic member from the composition by an extrusion molding in a magnetic field under specific temperature and pressure conditions. The above composition for resin magnets has specific viscosity characteristics, and thereby enables to readily afford a magnetic member having a strong magnetic force such as magnet rollers and magnet pieces. Accordingly, the magnetic member is well suited for use in the field of electrophographic equipment and electrostatic recording equipment such as copying machinery, facsimile machinery and printers.
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