Magnetic coated carrier, two-component type developer and developing method
US5766814A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1997 |
| Grant date | Jun 16, 1998 |
| Priority date | — |
| Expiry date | Apr 7, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/10884
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A magnetic coated carrier suitable for constituting a two-component type developer for use in electrophotography is composed of magnetic coated carrier particles comprising magnetic carrier core particles and a resinous surface coated layer coating the magnetic carrier core particles. The carrier is suitably constituted so as to satisfy the condition of: (a) the magnetic carrier core particles has a resistivity of at least 1.times.10.sup.10 ohm.cm, and the magnetic coated carrier has a resistivity of at least 1.times.10.sup.12 ohm.cm, (b) the magnetic coated carrier has a number-average particle size of 1-100 .mu.m and has such a particle size distribution that particles having particle sizes of at most a half of the number-average particle size occupy an accumulative percentage of at most 20% by number, (c) the magnetic coated carrier has a shape factor SF-1 of 100-130, (d) the magnetic coated carrier has a magnetization at 1 kilo-oersted of 40-250 emu/cm.sup.3, and (e) the resinous surface coating layer comprises a coating resin composition which in turn comprises a straight silicone resin and a coupling agent. The straight silicone resin includes trifunctional silicon and difunc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.