US 2024/0033979 A1 · FERRITE PARTICLES FOR BONDED MAGNETS, RESIN COMPOSITION FOR BONDED MAGNETS, AND MOLDED PRODUCT USING THE SAME

Abstract

The present invention relates to ferrite particles for bonded magnets and a resin composition for bonded magnets which can provide a bonded magnet molded product capable of realizing a high magnetic force and a complicated multipolar waveform owing to such a feature that the ferrite particles are readily and highly oriented against an external magnetic field in a flowing resin upon injection molding, as well as a bonded magnet molded product obtained by injection-molding the above composition. According to the present invention, there are provided ferrite particles for bonded magnets which have a crystallite size of not less than 500 nm as measured in an oriented state by XRD, and an average particle diameter of not less than 1.30 μm as measured by Fisher method; a resin composition for bonded magnets; and a molded product obtained by injection-molding the composition.

Claims17

Dependent claims

A process for producing ferrite particles for bonded magnets comprising:

blending and mixing raw material particles at a predetermined mixing ratio to provide mixed raw material particles;
molding the mixed raw material particles by compressing and granulating the mixed raw material particles to provide a molded product;
calcining the molded product at a temperature of 900 to 1250° C. in atmospheric air to provide calcined particles;
subjecting the calcined particles to a pulverization step and washing with water;
and then
subjecting the resulting particles to annealing heat treatment at a temperature of 700 to 1100° C. in atmospheric air thereby providing the ferrite particles;
wherein the ferrite particles have a crystallite size of not less than 500 nm as measured in an oriented state by XRD, and an average particle diameter of not less than 1.30 μm as measured by Fisher method.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application

18/379,809Filed 13 Oct 2023

Priority

JP 2013-0780733 Apr 2013

Published

1 Feb 2024

Term ends

Not estimatedThe source records don’t support an estimate.

Classification14 codes

B29C 45/0001
Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor: characterised…
C01G 49/0036
Mixed oxides or hydroxides,: containing one alkaline earth metal, magnesium or lead
H01F 1/11
Non-metallic substances, e.g. ferrites , e.g. [O6] ferrites with hexagonal structure: in the form of particles
B29K 2505/12
Transition metals: iron

Ferrite particles for bonded magnets, resin composition for bonded magnets, and molded product using the same

Life of this patent

Ferrite particles for bonded magnets, resin composition for bonded magnets, and molded product using the same

Life of this patent

Abstract

Claims17