IP Library › Granted Patent US 12,306,580
Granted Patent B2
US 12,306,580 · App. 17/400,226 · Granted May 20, 2025

Toner and production method thereof, and toner stored unit, image forming apparatus, and image forming method

Inventors: Hiroshi Yamada (Shizuoka, JP); Akinori Saitoh (Shizuoka, JP); Akio Takei (Shizuoka, JP); Yasuo Kamada (Shizuoka, JP); Toma Takebayashi (Shizuoka, JP)
Assignee: Ricoh Company, Ltd.
G03G9/08726G03G9/0802G03G9/0819G03G9/08711G03G9/08782G03G9/09G03G9/09321G03G15/0896
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Quick Facts
Patent No.
US 12,306,580
App. No.
17/400,226
Granted
May 20, 2025
Kind
B2
Abstract

A toner includes toner particles, each including: a toner base particle including a binder resin, a colorant, and wax; and resin particles on a surface of the toner base particle, wherein Formulae 1 to 3 below are satisfied, where M is a volume average primary particle diameter (nm) of the resin particles, and L is a distance (nm) between the resin particles present next to one another on the surface of the toner base particle: M<L;   (Formula 1) 5 (nm)< M ≤60 (nm); and  (Formula 2) 0.40≤[ M (nm)/ L (nm)]<0.90.  (Formula 3)

Claims (67)

1. A toner, comprising:

toner particles, each comprising:

a toner base particle including a binder resin, a colorant, and wax; and

resin particles on a surface of the toner base particle,

wherein Formulae 1 to 3 below are satisfied, where M is a volume average primary particle diameter (nm) of the resin particles, and L is a distance (nm) between the resin particles present next to one another on the surface of the toner base particle:

M<L;   (Formula 1)

5 (nm)< M ≤60 (nm); and  (Formula 2)

0.40≤[ M (nm)/ L (nm)]<0.90;  (Formula 3)

wherein the resin particles each include a core resin and a shell resin covering at least part of a surface of the core resin.

2. The toner according to claim 1 ,

wherein Formula 1, Formula 2-1, and Formula 3-1 below are satisfied:

M<L;   (Formula 1)

10 (nm)< M ≤50 (nm); and  (Formula 2-1)

0.50≤[ M (nm)/ L (nm)]<0.80.  (Formula 3-1)

3. The toner according to claim 1 ,

wherein Formula 1, Formula 2-2, Formula 3-2, and Formula 4 below are satisfied:

M<L;   (Formula 1)

10 (nm)< M;   (Formula 2-2)

0.60≤[ M (nm)/ L (nm)]<0.70; and  (Formula 3-2)

L< 35 (nm).  (Formula 4)

4. The toner according to claim 1 ,

wherein the resin particles each include a resin including a vinyl-based unit, and the resin including a vinyl-based unit includes methacrylic acid.

5. The toner according to claim 1 ,

wherein the shell resin contains a styrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer.

6. A toner, comprising:

toner particles, each comprising:

a toner base particle including a binder resin, a colorant, and wax; and

resin particles on a surface of the toner base particle,

wherein M<L is satisfied, where M is a volume average primary particle diameter (nm) of the resin particles, and L is a distance (nm) between the resin particles present next to one another on the surface of the toner base particle, and

wherein an amount of methacrylic acid detected by pyrolysis gas chromatography of the toner is 1.0 mg/g or greater but 4.0 mg/g or less relative to a total amount of the toner;

wherein the resin particles each include a core resin and a shell resin covering at least part of a surface of the core resin.

7. The toner according to claim 6 ,

wherein the resin particles each include a resin including a vinyl-based unit, and the resin including a vinyl-based unit includes methacrylic acid.

8. The toner according to claim 6 ,

wherein the shell resin contains a styrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer.

9. A toner stored unit, comprising:

a unit; and

the toner according to claim 1 stored in the unit.

10. An image forming apparatus, comprising:

the toner stored unit according to claim 9 .

11. A toner stored unit, comprising:

a unit; and

the toner according to claim 6 stored in the unit.

12. An image forming apparatus, comprising:

the toner stored unit according to claim 11 .

13. An image forming method, comprising:

forming an electrostatic latent image on an electrostatic latent image bearer;

developing the electrostatic latent image formed on the electrostatic latent image with a toner to form a toner image;

transferring the toner image formed on the electrostatic latent image bearer to a medium; and

fixing the transferred toner image on the medium,

wherein the toner is the toner according to claim 1 .

14. An image forming method, comprising:

forming an electrostatic latent image on an electrostatic latent image bearer;

developing the electrostatic latent image formed on the electrostatic latent image bearer with a toner to form a toner image;

transferring the toner image formed on the electrostatic latent image bearer to a medium; and

fixing the transferred toner image on the medium,

wherein the toner is the toner according to claim 6 .

15. A method for producing a toner, the method comprising:

depositing resin particles on surfaces of toner base particles to form composite particles; and

removing at least part of the resin particles from the composite particles,

wherein the toner is the toner according to claim 1 , and

wherein the removing is washing the composite particles with a basic aqueous solution.

16. A method for producing a toner, the method comprising:

depositing resin particles on surfaces of toner base particles to form composite particles; and

removing at least part of the resin particles from the composite particles,

wherein the toner is the toner according to claim 6 , and

wherein the removing is washing the composite particles with a basic aqueous solution.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 20, 2021
From: YAMADA, HIROSHI; SAITOH, AKINORI; TAKEI, AKIO; KAMADA, YASUO; TAKEBAYASHI, TOMA
To: RICOH COMPANY, LTD.
Reel/Frame 057245/0489 →
Priority Claims (3)
JP 2020-137006 · Aug 14, 2020 · national
JP 2021-048048 · Mar 23, 2021 · national
JP 2021-127199 · Aug 3, 2021 · national
Continuity (1)
Related Publication 20220050395A1 · Feb 17, 2022
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