US 11,823,823 B2 · Ferrite particles for bonded magnets, resin composition for bonded magnets, and molded product using the same

Abstract

According to the present invention, there are provided ferrite particles for bonded magnets and a resin composition for bonded magnets which are capable of producing a bonded magnet molded product having a good tensile elongation and exhibiting excellent magnetic properties, as well as a bonded magnet molded product such as a rotor which is obtained by using the resin composition. The present invention relates to ferrite particles for bonded magnets having a bulk density of not less than 0.5 g/cm3 and less than 0.6 g/cm3 and a degree of compaction of not less than 65%, a resin composition for bonded magnets using the ferrite particles, and a molded product obtained by using the ferrite particles and the resin composition.

Claims4

Dependent claims

A process for producing ferrite particles comprising:

(a) blending and mixing raw material particles at a predetermined mixing ratio;
(b) calcining the resulting mixed raw material particles from (a) at a temperature of 900 to 1250° C. in atmospheric air;
(c) subjecting the particles obtained from (b) to pulverization and washing with water;
(d) subjecting the resulting particles from (c) to annealing heat treatment at a temperature of 700 to 1100° C. in atmospheric air;
(e) subjecting the obtained particles from (d) to compaction and grinding;
and
(f) subjecting the obtained particles from (e) to deaggregation treatments, wherein the ferrite particles have an average particle diameter of 0.9 to 2.0 μm.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application

17/984,519Filed 10 Nov 2022 · continuation

Priority

JP 2013-2073052 Oct 2013

Published

US 2023/0078224 A116 Mar 2023

Granted

21 Nov 2023

Term ends

Not estimatedThe source records don’t support an estimate.

Classification32 codes

H01F 1/0306
Characterised by unspecified or heterogeneous hardness or specially adapted for magnetic hardness transitions: metals or alloys, e.g. LAVES phase…
C01G 49/0036
Mixed oxides or hydroxides,: containing one alkaline earth metal, magnesium or lead
C01G 49/0063
Mixed oxides or hydroxides,: containing zinc
C01G 49/009
Compounds of iron: compounds containing iron, with or without oxygen or hydrogen, and containing two or more other elements

Family

PCT/JP2014/076066Parent of this continuation · filed 30 Sep 2014

US 2023/0078224 A1Pre-grant publication · published 16 Mar 2023

Application15/025,599Parent of this continuation

US 2016/0217892 A1Published application

US 11,823,823 B2This patent

From the US filing history. Foreign family members aren’t listed.

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

Claims4