Positively chargeable magnetic toner, image forming process image forming apparatus, apparatus unit and facsimile apparatus
US5213933A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | May 28, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/09741
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A positively chargeable magnetic toner comprises positively chargeable magnetic toner particles having at least a binder resin, a magnetic substance and a charge controlling agent; wherein the binder resin contains (A) a vinyl polymer having carboxyl groups, acid anhydride groups, partial esters thereof or mixtures of the groups and having and an acid value of 5 to 30, and (B) a copolymer obtained by polymerizing at least a diolefin monomer and a vinyl monomer; and wherein the charge controlling agent contains (C) a quaternary ammonium salt and (D) a nigrosine dye or a triphenylmethane dye, the ratio by weight among the components (A), (B), (C) and (D) being within the range of (A):(B):(C):(D)=80 to 30:70 to 20:2.0 to 0.5: 2.0 to 0.1 relative to 100 parts of the total weight of the components (A) and (B). The present invention also provides an image forming process, an image forming apparatus and a facsimile apparatus, all of which use the positively chargeable magnetic toner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.