Porous ferrite core material for electrophotographic developer, resin-coated ferrite carrier and electrophotographic developer using the ferrite carrier
US-9201329-B2 · Dec 1, 2015 · US
Carrier core material and electrophotographic carrier using same and electrophotographic developer
US10915034B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-10915034-B2 |
| Application number | US-201816491365-A |
| Country | US |
| Kind code | B2 |
| Filing date | Mar 15, 2018 |
| Priority date | Mar 31, 2017 |
| Publication date | Feb 9, 2021 |
| Grant date | Feb 9, 2021 |
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- Title
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Abstract
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A carrier core material is represented by a composition formula M X Fe 3-X O 4 (where M is at least one type of metal element selected from Mg, Mn, Ca, Ti, Cu, Zn and Ni, 0<X<1), in which part of M and/or Fe is substituted with Sr and formed of ferrite particles, and in the carrier core material, a Sr content is equal to or more than 2500 ppm but equal to or less than 12000 ppm, the amount of Sr eluted with pure water at a temperature of 25° C. is equal to or less than 50 ppm, an apparent density is equal to or more than 1.85 g/cm 3 but equal to or less than 2.25 g/cm 3 and magnetization σ 1k when a magnetic field of 79.58×10 3 A/m (1000 oersteds) is applied is equal to or more than 63 Am 2 /kg but equal to or less than 75 Am 2 /kg.
First claim
Opening claim text (preview).
The invention claimed is: 1. A carrier core material which is represented by a composition formula M X Fe 3-X O 4 , wherein M is Mn and 0<X<1, in which part of M and/or Fe is substituted with Sr and which is formed of ferrite particles, wherein a Sr content is equal to or more than 2500 ppm but equal to or less than 12000 ppm, an amount of Sr eluted with pure water at a temperature of 25° C. is equal to or less than 50 ppm, an apparent density is equal to or more than 1.85 g/cm 3 but equal to or less than 2.25 g/cm 3 and magnetization σ 1k when a magnetic field of 79.58×10 3 A/m (1000 oersteds) is applied is equal to or more than 63 Am 2 /kg but equal to or less than 75 Am 2 /kg. 2. The carrier core material according to claim 1 , wherein the carrier core material contains a compound represented by SrFe 12 O 19 . 3. An electrophotographic development carrier, wherein a surface of the carrier core material according to claim 1 is coated with a resin. 4. An electrophotographic developer comprising: the electrophotographic development carrier according to claim 3 ; and a toner. 5. The carrier core material according to claim 1 , wherein 0.5<X<1.
Assignees
Inventors
Classifications
with non-ferrous metal oxide, e.g. MgO-Fe2O3 · CPC title
Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability · CPC title
- G03G9/1075Primary
Structural characteristics of the carrier particles, e.g. shape or crystallographic structure · CPC title
Solid density · CPC title
Micrometer sized, i.e. from 1-100 micrometer · CPC title
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- What does patent US10915034B2 cover?
- A carrier core material is represented by a composition formula M X Fe 3-X O 4 (where M is at least one type of metal element selected from Mg, Mn, Ca, Ti, Cu, Zn and Ni, 0<X<1), in which part of M and/or Fe is substituted with Sr and formed of ferrite particles, and in the carrier core material, a Sr content is equal to or more than 2500 ppm but equal to or less than 12000 ppm, the amount of …
- Who is the assignee on this patent?
- Dowa Electronics Materials Co Ltd, Dowa Ip Creation Co Ltd
- What technology area does this patent fall under?
- Primary CPC classification G03G9/1075. Mapped technology areas include Physics.
- When was this patent published?
- Publication date Tue Feb 09 2021 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 8 related publications on this page (citations in our corpus or others sharing the same primary CPC).