Polymer coated carrier particles for electrophotographic developers
US6245474A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 2000 |
| Grant date | Jun 12, 2001 |
| Priority date | — |
| Expiry date | Mar 7, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/1134
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A coated carrier having a core particle coated with a mixture of an electronegative insulating polymer comprising a polyvinylidenefluoride polymer or copolymer and an electropositive conductive polymer comprising a polymethyl methacrylate polymer or copolymer with a conductive material dispersed therein is made by powder coating. The coated carrier has unique properties, including a conductivity of from 1.1.times.10.sup.-14 to 1.0.times.10.sup.-8 mho-cm.sup.-1, a triboelectric charging value of from 12 to 20 and an average particle diameter of from 65 to 75, rendering the coated carrier ideal for use in a developer to be used in a magnetic brush type development apparatus. The powder coating method includes mixing the core particle and the mixture of negatively charging polymer and conductive polymer until the mixture of negatively charging polymer and conductive polymer adheres to the core particle, heating the mixture of the core particle and the mixture of negatively charging polymer and conductive polymer until the mixture of negatively charging polymer and conductive polymer melts and fuses to the core particle, and cooling the coated core obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.