Dry type developer for electrophotography
US4980258A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1989 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Nov 14, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/09741
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention relates to the positively chargeable black toner particles which comprise binder resins, carbonblack as a main colorant, quaternary anmonium salt of the following formula (I) as a charge control agent and .beta.-form Cu-phthalocyanine as a stabilizing agent for chargeability of toner particles without being affected by the change of environmental conditions. ##STR1## Wherein R.sub.1 is C.sub.1 -C.sub.8 alkyl or benzyl, R.sub.2 and R.sub.3 are each C.sub.1 -C.sub.18 alkyl, R is C.sub.1 -C.sub.118 alkyl or benzyl, X is hydroxy or amino, and Y is hydoroxy or hydrogen; (c) .beta.-form Cu-phthalocyanine; and (d) carbonblack. The present invention further relates to the two component dry-type developer composed by the improved above said positively chargeable toner particles and the carrier particles coated with silicone polylmers which have the strong durability without being changed to a supent carrier particles for a use of long time period.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.