Interdispersed three-phase ferrite composite and electrographic magnetic carrier particles therefrom
US5104761A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1990 |
| Grant date | Apr 14, 1992 |
| Priority date | — |
| Expiry date | Sep 14, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/42
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Disclosed is an interdispersed three-phase ferrite composite which comprises from about 0.1 mole to about 1.0 mole of a spinel phase having the general formula MFe.sub.2 O.sub.4 where M is at least one element that forms a spinel ferrite and is selected from the group consisting of cobalt, manganese, iron and mixtures thereof, to about 2.5 moles of a magnetoplumbite phase having the general formula PO.6Fe.sub.2 O.sub.3 where P is selected from the group consisting of strontium, barium, calcium, lead and mixtures thereof and, as a third phase, from about 0.02 to about 2.0 percent by weight, based on the combined weight of the spinel phase and the magnetoplumbite phase, of TiO.sub.2 or SiO.sub.2. Also disclosed are carrier particles formed from magnetized particles of the composite which optionally can be polymerically coated, an electrostatic charged toner particles mixed with oppositely charged carrier particles formed from magnetized, and optionally polymerically coated, particles of the composite, and a method of developing an electrostatic image by contacting the image with a two-component dry developer composition described above.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.