Patent · US Expired

Single component toner for improved magnetic image character recognition

US6696212B2 · kind B2 · utility

5Cited by
40References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 27, 2001
Grant dateFeb 24, 2004
Priority date
Expiry dateMar 27, 2021

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G9/09716
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

Magnetic toner particles are disclosed. The magnetic toner particles contain at least one polymeric binder and at least one magnetic additive, wherein the surface of the toner particle contains particles of positively chargeable inorganic fine powder particles. The inorganic fine powder particles have a mean volume average particle size of from about 0.5 to about 7 &mgr;m, and a cleaning ratio of from about 0.1 to about 5.0 and a cleaning ratio being the volume fraction of particles between 0 and 1.0 &mgr;m, divided by the volume fraction of particles greater than 1.0 &mgr;m; and the toner particles having on the surface thereof a flowability improving agent having a BET surface area of at least about 30 m2/g. Methods of forming electrostatic images are further disclosed. Also, images formed from the magnetic toner particles are further disclosed and have excellent character void frequency, total void area, and suitable magnetic signal strengths. Developers containing the magnetic toner particles of the present invention are also disclosed.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.