Rare earth bonded magnet
View Patent ↗A rare earth bonded magnet is provided which is produced such that a mixture which comprises: a rare earth magnet powder; a resin binder comprising a thermosetting resin; an organic phosphorus compound; and a coupling agent is compress-molded, heated and cured, wherein the organic phosphorus compound and the coupling agent are represented by the following respective chemical formulas (structural formulas):
1. A rare earth bonded magnet produced such that a mixture, which comprises:
a rare earth magnet powder;
a resin binder comprising a thermosetting resin;
an organic phosphorus compound; and
a coupling agent,
is compress-molded, heated and cured,
wherein the organic phosphorus compound is an organophosphate ester compound defined by a formula below:
where: R 1 and R 2 are an organic group of at least one kind including a hydrocarbon group; when R 1 and R 2 have two or more kinds of organic groups, the organic groups can be either identical to or different from one another; and the hydrocarbon group is one of an alkyl group and aryl group with a carbon number of 3 to 18 which can be either straight-chained, branched or cyclic in formation, and
wherein the coupling agent is defined by a formula below:
where: R 3 , R 4 and R 5 are an organic group of at least one kind including a hydrocarbon group; M is one element selected from Si, Ti and Zr; when R 3 , R 4 and R 5 have two or more kinds of organic groups, the organic groups can be either identical to or different from one another; n is an integer which corresponds to a number of coupling hands of M and which ranges from 1 to 3; and the hydrocarbon group is one of an alkyl group and aryl group with a carbon number of 3 to 18 which can be either straight-chained, branched or cyclic in formation.
2. The rare earth bonded magnet according to claim 1 , wherein a content of the thermosetting resin is 0.5 to 6 weight % with respect to the rare earth magnet powder.
3. The rare earth bonded magnet according to claim 1 , wherein a content of the organophosphate ester compound is 0.01 to 2 weight % with respect to the rare earth magnet powder.
4. The rare earth bonded magnet according to claim 1 , wherein a content of the coupling agent is 0.01 to 2 weight % with respect to the rare earth magnet powder.
5. The rare earth bonded magnet according to claim 1 , wherein a total content of the thermosetting resin, the organophosphate ester compound and the coupling agent in the mixture is 0.6 to 10 weight %.
6. A rare earth bonded magnet produced such that a mixture, which comprises:
a rare earth magnet powder;
a resin binder comprising a thermosetting resin;
an organic phosphorus compound; and
a coupling agent,
is compress-molded, heated and cured,
wherein the organic phosphorus compound is an organophosphate ester compound defined by a formula below:
where: R 1 and R 2 are an organic group of at least one kind including a hydrocarbon group; when R 1 and R 2 have two or more kinds of organic groups, the organic groups can be either identical to or different from one another; and the hydrocarbon group is one of an alkyl group and aryl group with a carbon number of 3 to 18 which can be either straight-chained, branched or cyclic in formation, and
wherein the coupling agent is defined by a formula below:
where: R 3 and R 4 are an organic group of at least one kind including a hydrocarbon group; M is one element selected from Si, Ti and Zr; when R 3 and R 4 have two or more kinds of organic groups, the organic groups can be either identical to or different from one another; n is an integer which corresponds to a number of coupling hands of M and which ranges from 1 to 3; and the hydrocarbon group is one of an alkyl group and aryl group with a carbon number of 3 to 18 which can be either straight-chained, branched or cyclic in formation.
7. The rare earth bonded magnet according to claim 6 , wherein a content of the thermosetting resin is 0.5 to 6 weight % with respect to the rare earth magnet powder.
8. The rare earth bonded magnet according to claim 6 , wherein a content of the organophosphate ester compound is 0.01 to 2 weight % with respect to the rare earth magnet powder.
9. The rare earth bonded magnet according to claim 6 , wherein a content of the coupling agent is 0.01 to 2 weight % with respect to the rare earth magnet powder.
10. The rare earth bonded magnet according to claim 6 , wherein a total content of the thermosetting resin, the organophosphate ester compound and the coupling agent in the mixture is 0.6 to 10 weight %.