US 12,032,332 B2
Magenta toner, developer, toner accommodating unit, image forming apparatus, and image forming method
Hiyori Fujino, Shizuoka (JP); Keisuke Tada, Shizuoka (JP); Shoki Matsuda, Shizuoka (JP); Fumihiko Chimoto, Shizuoka (JP); Takashi Okano, Shizuoka (JP); and Ayumi Satoh, Shizuoka (JP)
Assigned to Ricoh Company, Ltd., Tokyo (JP)
Filed by RICOH COMPANY, LTD., Tokyo (JP)
Filed on Feb. 12, 2021, as Appl. No. 17/174,382.
Claims priority of application No. 2020-041916 (JP), filed on Mar. 11, 2020; and application No. 2020-105407 (JP), filed on Jun. 18, 2020.
Prior Publication US 2021/0286279 A1, Sep. 16, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. G03G 9/087 (2006.01); G03G 9/09 (2006.01); G03G 15/08 (2006.01); G03G 15/20 (2006.01)
CPC G03G 9/08755 (2013.01) [G03G 9/0906 (2013.01); G03G 9/0926 (2013.01); G03G 15/0865 (2013.01); G03G 15/2064 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A magenta toner comprising:
toner particles each comprising:
a binder resin that comprises a polestar resin;
a magenta colorant, and
a release agent,
wherein from 1.0% to 25.0% by number of the toner particles have a CH rate of 25.0% or more in absolute value,
wherein the CH rate is calculated from the following formula (1):
CH rate(%)=[(In−Iave)/Iave]×100  Formula (1)
where, in a Raman spectrum of each toner particle, In represents an integrated intensity within a wavenumber region of from 2,750 to 3,250 cm when an intensity at a wavenumber λ within a wavenumber region of from 1,200 to 3,250 cm−1 is [s] normalized to 1, where a total intensity of all the toner particles is maximum at the wavenumber λ; and Iave represents an average of the In.