Kanegafuchi Kagaku Kogyo Kabushiki Kaisha

Toshiaki Ishimaru

Yasushi Kakehashi

Shogo Miki

Yasunori Matsunari

A machine part used as a magnet roll for developing and a process for producing the same. The machine part constitutes a member of a developing machine for an electrophotographic process such as a copier and facsimile, and a laser printer as well. The machine part comprises a shaft having a resin-bonded magnet layer provided on the outer periphery thereof. The composite molding of a resin-bonded magnet is produced by molding and establishing a composition for a thermoplastic resin-bonded magnet comprising from 35 to 60 % by volume of a thermoplastic resin and from 40 to 65 % by volume of a hard ferrite powder into a cylinder of uniform thickness on the outer periphery of a shaft, obtained is a thin resin-bonded magnet layer having a surface roughness of 5 .mu.m or less and free of seams which have generated during molding, the thin resin-bonded magnet layer further having provided on the surface a plurality of magnetic poles at a small spacing.

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Mooka, Japan

Toshiaki Ishimaru