Patent · US Expired

Magnetic carrier particles

US4879198A · kind A · utility

9Cited by

6References

13Claims

0Family size

Assignee

Agfa-Gevaert NV · BE

Inventors

Serge Tavernier · Lint, BE
Joannes J. Van Beek · Ravels, BE
Pierre L. van Daele · Wilrijk, BE

Key dates

Filing date	Apr 7, 1988
Grant date	Nov 7, 1989
Priority date	—
Expiry date	Apr 7, 2008

Classification

Technology area (CPC G)Physics
CPC primaryG03G9/107
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A particulate material suited for serving as carrier particles for finely-divided toner particles in magnetic brush toner-carrier development of electrostatic charge patterns, said carrier particles comprising finely divided magnetite powder dispersed in a resin binder, characterized in that said magnetite powder is a mixture of magnetites wherein one type (A) of the magnetite has an oil absorption number in the range of 10 to 20 g/100 g pigment and another type (B) of the magnetite has an oil absorption number in the range of 20 to 40 g/100 g pigment. The binder contains hydrophilic functional groups and has an acid number in the range of 5 to 50 KOH/g.

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