Global Patent Index - EP 0488744 A1

EP 0488744 A1 19920603 - Electrophotographic toner for negative charging.

Title (en)

Electrophotographic toner for negative charging.

Title (de)

Elektrophotographischer Toner für Negativaufladung.

Title (fr)

Toneur électrophotographique pour charger négativement.

Publication

EP 0488744 A1 19920603 (EN)

Application

EP 91311035 A 19911128

Priority

JP 32836390 A 19901128

Abstract (en)

An electrophotographic toner for negative charging comprises an acrylamide copolymer containing sulfonic acid groups as a charge-controlling agent for negative charging and a quaternary ammonium salt having an oxyacid anion as a charge-controlling assistant, a fixing resin and a colorant. The quaternary ammonium salt used as the assistant is incompatible with a fixing resin but dispersible therein. The toner provides a sharp distribution of the charge quantity so that formation of highly charged toner particles which do not contribute to development and lowly charged toner particles which are easily scattered is effectively prevented.

IPC 1-7

G03G 9/087; G03G 9/097

IPC 8 full level

G03G 9/08 (2006.01); G03G 9/087 (2006.01); G03G 9/09 (2006.01); G03G 9/097 (2006.01)

CPC (source: EP)

G03G 9/08726 (2013.01); G03G 9/09741 (2013.01); G03G 9/0975 (2013.01)

Citation (search report)

Designated contracting state (EPC)

DE ES FR GB IT

DOCDB simple family (publication)

EP 0488744 A1 19920603; EP 0488744 B1 19960717; DE 69120908 D1 19960822; DE 69120908 T2 19961128; ES 2091884 T3 19961116; JP 2609358 B2 19970514; JP H04195166 A 19920715

DOCDB simple family (application)

EP 91311035 A 19911128; DE 69120908 T 19911128; ES 91311035 T 19911128; JP 32836390 A 19901128