MAGNET COMPOUND FOR COMPRESSION MOLDING, LONG MAGNET COMPACT, MAGNET ROLLER, DEVELOPER CARRIER, DEVELOPING APPARATUS, AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a magnet compound for compression molding capable of providing a compression molded magnet which has high strength and a high magnetic force when it is molded into a long one, and in which there is reduced the variation of a magnetic force in a magnet compact and among coupling resin lots.

SOLUTION: In the magnet compound 3 for compression molding including magnetic powder 1 and coupling resin particles 2, a ratio of a volume average grain size of the coupling resin particles 1 and a number average grain size is 1.1 to 1.3 or less. The volume average grain size of the coupling resin particles 2 is preferably 3 to 7 μm, and a fine powder content rate is preferably 10% or less in the magnet compound 3 for compression molding. Moreover, the compounding ratio of the coupling resin particles 2 is preferably 4 to 10 wt.%. Further, the magnetic powder 1 contained in the magnet compound 3 for compression molding is composed of wany magnetic powder with 100 to 200 μm average grain size, and the bulk density of the magnet compound 3 is 3.2 to 3.9 g/cm3for compression molding.

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