Magnetic particles for charging, process for producing the magnetic particles, and charging member, process cartridge and image-forming apparatus which have the magnetic particles
US6405007B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 2000 |
| Grant date | Jun 11, 2002 |
| Priority date | — |
| Expiry date | Jun 12, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2221/183
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Magnetic particles for charging an image-bearing member electrostatically. The charging magnetic particles have magnetic particles, first surface coat layers containing a first surface coating agent and covering the surfaces of the magnetic particles and second surface coat layers containing a second surface coating agent and covering the first surface coat layers. The charging magnetic particles contain magnetic particles for charging which have a maximum chord length of 5 &mgr;m or larger, and the magnetic particles for charging which have a maximum chord length of 5 &mgr;m or larger having a minor-axis length/major-axis length standard deviation of 0.08 or more. Also, a process for producing the charging magnetic particles is disclosed together with a charging member, a process cartridge and an image forming apparatus which make use of the charging magnetic particles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.