Patent ID: 8329056

Claim:
An anisotropic rare earth-iron based resin bonded magnet comprising: [1] a continuous phase including: (1) a spherical Sm 2 Fe 17 N 3 based magnetic material where an average particle size and an average aspect ratio AR ave of the magnetic material are 1 to 10 μm and 0.8 or more, respectively, in a condition that AR is b/a when the maximum diameter of a particle image is “a” while the maximum diameter perpendicular to the “a” is “b”, and mechanical milling is not applied after an Sm—Fe alloy is nitrided, the spherical Sm 2 Fe 17 N 3 based magnetic material being covered with epoxy oligomer that is solid at a room temperature; and (2) a linear polymer that has an active hydrogen group in which to react to the oligomer; and [2] a discontinuous phase being defined by an Nd 2 Fe 14 B based magnetic material where an average particle size and an average aspect ratio AR ave of the magnetic material are 50 to 150 μm and 0.65 or more, respectively, the Nd 2 Fe 14 B based magnetic material being covered with epoxy oligomer that is solid at a room temperature, the anisotropic rare earth-iron based resin bonded magnet further satisfying the following: [3] a volume fraction of void in the material including continuous and discontinuous phases is 5% or less; and [4] the material including continuous phase and discontinuous phase having a crosslinking agent with an average particle size of 10 μm or less is compacted into a specific shape through a magnetic field press at 50 MPa or less.