IP Library › Granted Patent US 11,256,188
Granted Patent B2
US 11,256,188 · App. 16/959,478 · Granted Feb 22, 2022

Toner, toner stored unit, and image forming apparatus

Inventors: Akihiro Kaneko (Shizuoka, JP); Kazumi Suzuki (Shizuoka, JP); Hisashi Nakajima (Shizuoka, JP); Yoshitaka Yamauchi (Shizuoka, JP); Kohtaroh Ogino (Shizuoka, JP); Teruyuki Suzuki (Shizuoka, JP); Namie Suzuki (Shizuoka, JP)
Assignee: RICOH COMPANY, LTD.
G03G9/0819G03G9/0827G03G9/08755G03G9/09725G03G15/0865
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Quick Facts
Patent No.
US 11,256,188
App. No.
16/959,478
Granted
Feb 22, 2022
Kind
B2
Abstract

Provided is a toner including toner particles, each toner particle includes: a base particle including a binder resin; and external additive particles, wherein the external additive particles include particles each having an equivalent circle diameter of 10 nm or greater, a volume average particle diameter of the particles each having an equivalent circle diameter of 10 nm or greater is 80 nm or greater but 140 nm or less, and a ratio (circumscribed circle area/particle area) of a circumscribed circle area of the particle having an equivalent circle diameter of 10 nm or greater to a particle area of the particle having an equivalent circle diameter of 10 nm or greater is 1.60 or greater but 2.60 or less.

Claims (23)

1. A toner, comprising:

toner particles, wherein each toner particle includes:

a base particle including a hinder resin; and

external additive particles,

wherein the external additive particles include particles each having an equivalent circle diameter of 10 nm or greater,

a volume average particle diameter of the particles each having an equivalent circle diameter of 10 nm or greater is 90 nm or greater but 130 nm or less, wherein the volume average particle diameter is calculated as a volume-weighted average of the equivalent circle diameter of the particles, and

a ratio (circumscribed circle area/particle area) of a circumscribed circle area of the particle having an equivalent circle diameter of 10 nm or greater to a particle area of the particle having an equivalent circle diameter of 10 nm or greater is 1.65 or greater hut 2.00 or less.

2. The toner according to claim 1 , wherein the particle having an equivalent circle diameter of 10 nm or greater is an aggregate.

3. The toner according to claim 1 , wherein the particle having an equivalent circle diameter of 10 nm or greater is an inorganic particle.

4. The toner according to claim 3 , wherein the inorganic particle is at least one selected from the group consisting of silica, titanium oxide, strontium titanate, and alumina.

5. The toner according to claim 4 , wherein the silica is fumed silica.

6. A toner stored unit comprising:

a unit; and

the toner according to claim 1 stored in the unit.

7. An image forming apparatus comprising:

an electrostatic latent image bearer;

an electrostatic latent image forming unit configured to form an electrostatic latent image on the electrostatic latent image bearer;

a developing unit configured to develop the electrostatic latent image formed on the electrostatic latent image bearer with a toner to form a toner image where the developing unit includes the toner;

a transferring unit configured to transfer the toner image formed on the electrostatic latent image bearer to a surface of a recording medium; and

a fixing unit configured to fix the transferred toner image onto the surface of the recording medium,

wherein the toner is the toner according to claim 1 .

8. The image forming apparatus according to claim 7 ,

wherein the image forming apparatus does not include a lubricant applying unit configured to apply a lubricant onto the electrostatic latent image bearer.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 1, 2020
From: KANEKO, AKIHIRO; SUZUKI, KAZUMI; NAKAJIMA, HISASHI; YAMAUCHI, YOSHITAKA; OGINO, KOHTAROH; SUZUKI, TERUYUKI; SUZUKI, NAMIE
To: RICOH COMPANY, LTD.
Reel/Frame 053097/0855 →
Priority Claims (1)
JP JP2018-006251 · Jan 18, 2018 · national
Continuity (1)
Related Publication 20210072656A1 · Mar 11, 2021
Cited By (1)
US 12,366,788