US 11,796,931 B2
Toner, method for manufacturing toner, developer, toner accommodating unit, image forming apparatus, and image forming method
Akio Takei, Shizuoka (JP); Takahiro Honda, Shizuoka (JP); Tsukiko Takahashi, Shizuoka (JP); and Tsuneyasu Nagatomo, Shizuoka (JP)
Assigned to RICOH COMPANY, LTD., Tokyo (JP)
Filed by RICOH COMPANY, LTD., Tokyo (JP)
Filed on Oct. 1, 2020, as Appl. No. 17/60,289.
Claims priority of application No. 2019-191349 (JP), filed on Oct. 18, 2019.
Prior Publication US 2021/0116830 A1, Apr. 22, 2021
Int. Cl. G03G 9/083 (2006.01); G03G 9/087 (2006.01); G03G 9/08 (2006.01); G03G 9/09 (2006.01); G03G 15/16 (2006.01)
CPC G03G 9/08773 (2013.01) [G03G 9/0804 (2013.01); G03G 9/0827 (2013.01); G03G 9/0832 (2013.01); G03G 9/0833 (2013.01); G03G 9/08711 (2013.01); G03G 9/09 (2013.01); G03G 15/163 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A toner, comprising:
colored particles each comprising:
a core containing a crystalline resin, a non-crystalline resin, and a colorant; and
a shell layer on a surface of the core, the shell layer containing a resin and having a thickness of from 30 to 130 nm; and
external additives present on surfaces of the colored particles,
wherein the external additives comprise a metal oxide selected from the group consisting of one or more of an aluminum oxide, a zinc oxide, a cerium oxide, and a zirconium oxide,
and a silicon compound,
wherein an electronegativity X(A) of the metal oxide and an electronegativity X(Si) of the silicon compound satisfy a relation 0.5≤X(A)/X(Si)≤0.8,
wherein a proportion of an amount of the metal oxide directly adhered to the surfaces of the colored particles to a total amount of the metal oxide present on the colored particles is from 60% to 90% by mass.