Magnetite particles, magnetic iron oxide particles, process for the production of the same and magnetic toner using the same
US5858532A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1997 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | Mar 7, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2998
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Magnetite particles of the present invention have an average particle diameter of 0.05 to 0.50 .mu.m, each of the magnetite particles having a plurality of mountain-shaped protrusions with unsharpened crests on a surface of each magnetite particle, and the number of the mountain-shaped protrusions formed on the surface of each magnetite particle being in the range of 2 to 30 when viewed in projected plan; magnetic iron oxide particles for magnetic toner comprising not less than 60%, in number, of the said magnetite particles; and a magnetic toner comprising the said magnetic iron oxide particles and a binder resin. The magnetite particles of the present invention are free from the falling-off from toner particles. The toner particles of the present invention shows a good fluidity and produces visual images having a higher definition upon development of electrostatic latent images.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.