Surface-treated rare earth-based magnetic particles, resin composition for bonded magnets comprising the earth-based magnetic particles and bonded magnet comprising the earth-based magnetic particles

摘要

The present invention relates to surface-treated rare earth-based magnetic particles comprising rare-earth-based magnetic particles, a first coating layer comprising a phosphoric acid compound which is formed on a surface of the respective magnetic particles and a second coating layer in the form of a composite coating film comprising a silicon compound and a phosphoric acid compound which is formed on a surface of the first coating layer, wherein an amount of Fe eluted from the rare earth-based magnetic particles is not more than 10 mg/L; a resin composition for bonded magnets comprising the above surface-treated rare earth-based magnetic particles and a resin; and a bonded magnet comprising the above surface-treated rare earth-based magnetic particles.