US 12,228,881 B2
Toner, developer, process cartridge, image forming apparatus, and image forming method
Shoki Matsuda, Kanagawa (JP); Keisuke Tada, Shizuoka (JP); and Yasuyuki Sanui, Shizuoka (JP)
Assigned to RICOH COMPANY, LTD., Tokyo (JP)
Filed by Shoki Matsuda, Kanagawa (JP); Keisuke Tada, Shizuoka (JP); and Yasuyuki Sanui, Shizuoka (JP)
Filed on Dec. 12, 2023, as Appl. No. 18/536,261.
Claims priority of application No. 2022-200189 (JP), filed on Dec. 15, 2022.
Prior Publication US 2024/0210847 A1, Jun. 27, 2024
Int. Cl. G03G 9/08 (2006.01); G03G 9/09 (2006.01); G03G 15/08 (2006.01); G03G 15/16 (2006.01); G03G 21/00 (2006.01); G03G 21/18 (2006.01)
CPC G03G 9/0821 (2013.01) [G03G 9/09 (2013.01); G03G 15/08 (2013.01); G03G 15/1605 (2013.01); G03G 21/1807 (2013.01); G03G 21/0011 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A yellow toner, comprising:
a binder resin; and
a pigment,
wherein in a case where an intensity of a Raman spectrum of each toner particle at a wavenumber λ, at which a total intensity obtained by summing up Raman spectrums of toner particles that occur in a wavenumber range of 950 cm−1 or greater and 3,250 cm−1 or less in Raman spectroscopy of the yellow toner is maximum, is normalized to 1, and when a distribution is generated for 300 or more toner particles regarding a Localization Coefficient (LC) that is calculated according to a formula (3) below based on a CHc rate defined by a formula (1) below and a CHs rate defined by a formula (2) below where In represents an integrated intensity of a Raman spectrum of a center portion of each toner particle that occurs in a wavenumber range of 2,750 cm−1 or greater and 3,250 cm−1 or less and an integrated intensity of a Raman spectrum of a surface portion of each toner particle that occurs in the wavenumber range of 2,750 cm−1 or greater and 3,250 cm−1 or less, and Iave represents an average value of the In, a percentage by number of toner particles having the LC that deviates from a median of the distribution of the LC by an absolute value of 25.0% or greater is 1.0% by number or greater and 25.0% by number or less,

OG Complex Work Unit Math
where Inc represents the integrated intensity of the Raman spectrum of the center portion of an n-th toner particle in the wavenumber range of 2,750 cm−1 or greater and 3,250 cm−1 or less,
Ins represents the integrated intensity of the Raman spectrum of the surface portion of the n-th toner particle in the wavenumber range of 2,750 cm−1 or greater and 3,250 cm−1 or less, and
Iave represents the average value of the In of the toner particles including their center portions and surface portions.