Patent · US Expired

Bipolar liquid electrostatic developer

US4985329A · kind A · utility

7Cited by

16References

22Claims

0Family size

Assignee

E.I. DU PONT DE NEMOURS AND COMPANY · US

Inventors

Lyla M. El-Sayed · West Chester, US
Sanford M. Marcus · Wilmington, US
Torence J. Trout · Yorklyn, US

Key dates

Filing date	Dec 30, 1988
Grant date	Jan 15, 1991
Priority date	—
Expiry date	Dec 30, 2008

Classification

Technology area (CPC G)Physics
CPC primaryG03G9/12
WIPO fieldOptics
WIPO sectorInstruments

Abstract

Bipolar liquid electrostatic developer consisting essentially of at least one charge director in a nonpolar liquid having dispersed therein two toner particles having opposite charge polarity which comprise at least one thermoplastic copolymer resin. The particle average by area size is less than 10 .mu.m. The ratio of the two toner particles is 5 to 95 and 95 to 5. A process of simultaneous transfer of such developer is included. The developer is useful in copying.

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