Rare-earth permanent magnet and method for manufacturing rare-earth permanent magnet

A manufacturing method of a rare-earth permanent magnet comprising, in order, steps of:

• milling magnet material into magnet powder;
• mixing the magnet powder with a binder to obtain a mixture;
• forming the mixture into a formed body;
• calcining the formed body in a non-oxidizing atmosphere, wherein during the calcining, the formed body is held at a temperature in a range of 200 degrees Celsius to 900 degrees Celsius and the non-oxidizing atmosphere is always pressurized at 0.5 MPa to 15 MPa so that a residual oxygen content contained in the formed body after sintering is 5000 ppm or less;
• and
• holding the calcined formed body at a sintering temperature so as to sinter the calcined formed body,
• wherein the binder consists of a resin that is made of a polymer or a copolymer consisting essentially of one or more kinds of monomers expressed with a general formula (1):
• wherein R1 and R2 represent a hydrogen atom, a lower alkyl group, a phenyl group or a vinyl group.

A manufacturing method of a rare-earth permanent magnet comprising, in order, steps of:

• milling magnet material into magnet powder;
• mixing the magnet powder with a binder to obtain a mixture;
• forming the mixture into a formed body;
• calcining the formed body in a non-oxidizing atmosphere, wherein during the calcining, the non-oxidizing atmosphere is pressurized to 0.5 MPa to 15 MPa while the formed body is concurrently held at a temperature in a range of 200 degrees Celsius to 900 degrees Celsius for several hours so that a residual oxygen content contained in the formed body after sintering is 5000 ppm or less;
• and
• holding the calcined formed body at a sintering temperature so as to sinter the calcined formed body,
• wherein the binder consists of a resin that is made of a polymer or a copolymer consisting essentially of one or more kinds of monomers expressed with a general formula (1):
• wherein R1 and R2 represent a hydrogen atom, a lower alkyl group, a phenyl group or a vinyl group.