CPC C22C 38/02 (2013.01) [B22F 1/102 (2022.01); B22F 1/16 (2022.01); B22F 3/02 (2013.01); B22F 3/24 (2013.01); C22C 38/06 (2013.01); H01F 1/14766 (2013.01); H01F 1/14791 (2013.01); H01F 1/26 (2013.01); H01F 41/02 (2013.01); H01F 41/0246 (2013.01); H01F 41/04 (2013.01); B22F 2003/248 (2013.01); B22F 2301/35 (2013.01); B22F 2998/10 (2013.01); C22C 2202/02 (2013.01)] | 17 Claims |
1. A method for producing a coated magnetic powder in which particle surfaces of a soft magnetic powder are coated with a silicone resin, the method comprising:
preparing a silicone emulsion by adding a silicone resin into water containing a surfactant with stirring, the silicone emulsion consisting of the silicone resin, the surfactant and the water;
applying the silicone emulsion onto particle surfaces of a soft magnetic powder; and
drying the soft magnetic powder after the silicone emulsion is applied,
wherein the surfactant is a nonionic surfactant having a polyoxyethylene structure and has a weight-average molecular weight in an inclusive range of 300 or more through 700 or less, and an average particle size of particles of the silicone resin dispersed in the silicone emulsion is 200 nm or more,
the silicone resin is dimethyl silicone resin or methyl phenyl silicone resin.
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