US 7,371,495 B2
Toner
Shuitsu Sato, Tokyo (Japan)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan); and Toshiba Tec Kabushiki Kaisha, Tokyo (Japan)
Filed on Mar. 15, 2005, as Appl. No. 11/79,197.
Prior Publication US 2006/0210900 A1, Sep. 21, 2006
Int. Cl. G03G 9/08 (2006.01)
U.S. Cl. 430—108.1  [430/108.23; 430/108.3; 430/108.4; 430/108.6; 430/111.4] 20 Claims
 
1. A toner, comprising: (1) toner particles comprising a polyester resin as a principal component, a colorant, and a charge control agent; (2) externally added inorganic fine particles; and (3) externally added metal-containing organic fine particles;
the toner having a volume-average diameter of 4 to 10 μm, containing the charge control agent at 0.1 to 1.5%, and having an acid value of 2 to 33 mg KOH/g;
the charge control agent exhibiting a number-basis isolation percentage of at most 10% with respect to the toner particles; and
the charge control agent, the inorganic fine particles and organic fine particles exhibiting number-basis isolation percentages from the toner particles satisfying a relationship shown below: 30%>inorganic fine particles>organic fine particles>charge control agent>0%.