Patent · US Expired

Toner for developing electrostatic image containing hydrophobized inorganic fine powder

US5827632A · kind A · utility

43Cited by
9References
21Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 12, 1997
Grant dateOct 27, 1998
Priority date
Expiry dateAug 12, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G9/09725
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A toner for developing electrostatic images includes (a) toner particles having a weight-average particle size of 1-9 .mu.m, (b) hydrophobized inorganic fine powder having an average particle size of 10-90 nm and (c) hydrophobized silicon compound fine powder. The hydrophobized silicon compound fine powder has an average particle size of 30-120 nm, and a particle size distribution such that it contains 15-45% by number of particles having sizes of 5-30 nm, 30-70% by number of particles having sizes of 30-60 nm and 5-45% by number of particles having sizes of at least 60 nm. The hydrophobized silicon compound fine powder having a broad particle size distribution including coarse particles functions to prevent the embedding of the hydrophobized inorganic fine powder (functioning as a flowability improver) from being embedded at the toner particle surfaces, whereby the toner is allowed to exhibit stable performances even in a continuous image formation on a large number of sheets.

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