Global Patent Index - EP 0488742 A1

EP 0488742 A1 19920603 - Electrophotographic toner for negative charging.

Title (en)

Electrophotographic toner for negative charging.

Title (de)

Elektrophotographischer Toner zum negativen Aufladen.

Title (fr)

Toner électrophotographique pour charger négativement.

Publication

EP 0488742 A1 19920603 (EN)

Application

EP 91311033 A 19911128

Priority

JP 32836190 A 19901128

Abstract (en)

An electrophotographic toner for negative charging comprises a polyester resin as fixing resin and a quaternary ammonium salt having an oxyacid anion as a charge-controlling assistant in combination with a charge-controlling agent for negative charging and a colorant. The quaternary ammonium salt used as the assistant is incompatible with the 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 of lowly charged toner particles which are easily scattered is effectively prevented.

IPC 1-7

G03G 9/097

IPC 8 full level

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

CPC (source: EP)

G03G 9/097 (2013.01); G03G 9/09783 (2013.01)

Citation (search report)

  • [Y] FR 2592184 A1 19870626 - RICOH KK [JP]
  • [Y] EP 0227874 A1 19870708 - ORIENT CHEMICAL IND [JP]
  • [A] EP 0284000 A2 19880928 - HODOGAYA CHEMICAL CO LTD [JP]
  • [X] PATENT ABSTRACTS OF JAPAN, vol. 15, no. 23 (P-1155)18 January 1991 ( MITSUBISHI KASEI CORP. ) 29 October 199& JP-A-2 264 970
  • [A] PATENT ABSTRACTS OF JAPAN ,vol. 10, no. 305 (P-507)(2361) 17 October 1986 ( FUJITSU LTD. ) 6 June 1986,;& JP-A-61 118 761
  • [A] PATENT ABSTRACTS OF JAPAN ,vol. 14, no. 245 (P-1052)(4188) 24 May 1990 ( CANON INC. ) 5 March 1990,:& JP-A-2 064 558

Designated contracting state (EPC)

DE ES FR GB IT

DOCDB simple family (publication)

EP 0488742 A1 19920603; EP 0488742 B1 19960110; DE 69116323 D1 19960222; DE 69116323 T2 19960905; ES 2084785 T3 19960516; JP 2609356 B2 19970514; JP H04195148 A 19920715

DOCDB simple family (application)

EP 91311033 A 19911128; DE 69116323 T 19911128; ES 91311033 T 19911128; JP 32836190 A 19901128