Developer for developing electrostatic latent images
US4311779A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 1979 |
| Grant date | Jan 19, 1982 |
| Priority date | — |
| Expiry date | Nov 28, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/105
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Disclosed is a one-component type magnetic developer which comprises a binder medium and 45 to 65% by weight, based on the total developer, of fine particles of a magnetic material dispersed in the binder medium, the binder medium comprising a homopolymer of an aromatic vinyl monomer or a copolymer of (a) at least one aromatic vinyl monomer with (b) at least one mono- or di-ethylenically unsaturated monomer other than the aromatic vinyl monomer and having a weight average molecular weight of 75,000 to 150,000, wherein the electrostatic capacity as determined under conditions of an electrode spacing of 0.65 mm, an electrode sectional area of 1.43 cm.sup.2 and an electrode load of 105 g/cm.sup.2 is 7.8 to 11.7 PF (picofarad), the dielectric constant is 4 to 6 as determined under the above conditions and the electric resistance is at least 5.times.10.sup.13 .OMEGA.-cm as determined under the above conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.