Preparing method of electrostatic charge image developing toner, electrostatic charge image developing toner, and electrostatic charge image developer

Patent metadata

Field	Value
Publication number	US-12222676-B2
Application number	US-202117459010-A
Country	US
Kind code	B2
Filing date	Aug 27, 2021
Priority date	Mar 19, 2021
Publication date	Feb 11, 2025
Grant date	Feb 11, 2025

Abstract

A preparing method of an electrostatic charge image developing toner includes:
aggregating binder resin particles in a dispersion containing the binder resin particles to form aggregated particles; and coalescing the aggregated particles by heating a dispersion containing the aggregated particles to form toner particles, in which the aggregating includes adding a divalent or higher valent metal salt compound to the dispersion containing the binder resin particles, and the preparing method satisfies the following Requirement (1), Requirement (1): a ratio M/S of a total metal ion amount M (mol) generated from the divalent or higher valent metal salt compound to a total surface area S (m 2 ) of the binder resin particles at a start of the aggregating is 1.5×10 10 or more and 2.5×10 13 or less.

First claim

What is claimed is:

1. A preparing method of an electrostatic charge image developing toner, the method comprising:
aggregating binder resin particles in a dispersion containing the binder resin particles to form aggregated particles; and
coalescing the aggregated particles by heating a dispersion containing the aggregated particles to form toner particles, wherein
the aggregating includes adding a divalent or higher valent metal salt compound to the dispersion containing the binder resin particles, and
the preparing method satisfies the following Requirement (1),
Requirement (1): a ratio M/S of a total metal ion amount M (mol) generated from the divalent or higher valent metal salt compound to a total surface area S (m 2 ) of the binder resin particles at a start of the aggregating is 1.5×10 10 or more and 2.5×10 13 or less.

2. The preparing method of an electrostatic charge image developing toner according to claim 1 , wherein
a volume average particle diameter of the binder resin particles at the start of the aggregating is 30 nm or more and 460 nm or less.

3. The preparing method of an electrostatic charge image developing toner according to claim 1 , wherein
a total weight of the binder resin particles at the start of the aggregating is 50% by weight or more and 90% by weight or less with respect to a total amount of the toner particles formed in the coalescing.

4. The preparing method of an electrostatic charge image developing toner according to claim 2 , wherein
a total weight of the binder resin particles at the start of the aggregating is 50% by weight or more and 90% by weight or less with respect to a total amount of the toner particles formed in the coalescing.

5. The preparing method of an electrostatic charge image developing toner according to claim 1 , further comprising:
stopping growth of the aggregated particles by adding a chelating agent that chelates metal ions generated from the divalent or higher valent metal salt compound to the dispersion containing the aggregated particles, wherein
the preparing method satisfies the following Requirement (2),
Requirement (2): a ratio C/M of a total amount C (mol) of the chelating agent to the total metal ion amount M (mol) generated from the divalent or higher valent metal salt compound is 0.2 or more and 3.0 or less.

6. The preparing method of an electrostatic charge image developing toner according to claim 2 , further comprising:
stopping growth of the aggregated particles by adding a chelating agent that chelates metal ions generated from the divalent or higher valent metal salt compound to the dispersion containing the aggregated particles, wherein
the preparing method satisfies the following Requirement (2),
Requirement (2): a ratio C/M of a total amount C (mol) of the chelating agent to the total metal ion amount M (mol) generated from the divalent or higher valent metal salt compound is 0.2 or more and 3.0 or less.

7. The preparing method of an electrostatic charge image developing toner according to claim 3 , further comprising:
stopping growth of the aggregated particles by adding a chelating agent that chelates metal ions generated from the divalent or higher valent metal salt compound to the dispersion containing the aggregated particles, wherein
the preparing method satisfies the following Requirement (2),
Requirement (2): a ratio C/M of a total amount C (mol) of the chelating agent to the total metal ion amount M (mol) generated from the divalent or higher valent metal salt compound is 0.2 or more and 3.0 or less.

8. The preparing method of an electrostatic charge image developing toner according to claim 4 , further comprising:
stopping growth of the aggregated particles by adding a chelating agent that chelates metal ions generated from the divalent or higher valent metal salt compound to the dispersion containing the aggregated particles, wherein
the preparing method satisfies the following Requirement (2),
Requirement (2): a ratio C/M of a total amount C (mol) of the chelating agent to the total metal ion amount M (mol) generated from the divalent or higher valent metal salt compound is 0.2 or more and 3.0 or less.

9. The preparing method of an electrostatic charge image developing toner according to claim 5 , wherein
the stopping includes adding at least one aqueous solution selected from the group consisting of an aqueous solution of an alkali metal hydroxide and an aqueous solution of an alkaline earth metal hydroxide to the dispersion containing the aggregated particles.

10. The preparing method of an electrostatic charge image developing toner according to claim 6 , wherein
the stopping includes adding at least one aqueous solution selected from the group consisting of an aqueous solution of an alkali metal hydroxide and an aqueous solution of an alkaline earth metal hydroxide to the dispersion containing the aggregated particles.

11. The preparing method of an electrostatic charge image developing toner according to claim 7 , wherein
the stopping includes adding at least one aqueous solution selected from the group consisting of an aqueous solution of an alkali metal hydroxide and an aqueous solution of an alkaline earth metal hydroxide to the dispersion containing the aggregated particles.

12. The preparing method of an electrostatic charge image developing toner according to claim 9 , wherein
a pH of the dispersion containing the aggregated particles does not exceed 9 in the stopping.

13. The preparing method of an electrostatic charge image developing toner according to claim 5 , wherein
the stopping includes reducing a required stirring power per unit volume stepwise or continuously while stirring the dispersion containing the aggregated particles.

14. The preparing method of an electrostatic charge image developing toner according to claim 13 , wherein
the required stirring power per unit volume is not less than 0.1 kW/m 3 in the stopping.

15. The preparing method of an electrostatic charge image developing toner according to claim 13 , wherein
the required stirring power per unit volume does not exceed 3.5 kW/m 3 in the stopping.

16. The preparing method of an electrostatic charge image developing toner according to claim 1 , wherein
the dispersion containing the binder resin particles further contains release agent particles, and
in the aggregating, the release agent particles are further aggregated to form the aggregated particles.

17. The preparing method of an electrostatic charge image developing toner according to claim 1 , wherein
the dispersion containing the binder resin particles further contains coloring agent particles, and
in the aggregating, the coloring agent particles are further aggregated to form the aggregated particles.

18. The preparing method of an electrostatic charge image developing toner according to claim 1 , further comprising:
after the aggregating, second aggregating of further mixing the dispersion containing the aggregated particles and a dispersion containing resin particles to be a shell layer and aggregating the resin particles to be the shell layer on surfaces of the aggregated particles to form second aggregated particles, wherein
in the coalescing, a dispersion containing the second aggregated particles is heated and the second aggregated particles are coalesced to form toner particles.

Assignees

• Fujifilm Business Innovation Corp

Inventors

• FUJIHARA Yoshimasa
• Noguchi Daisuke
• Nakamura Kazuhiko
• Nakazawa Hiroshi

Classifications

• G03G9/0819

  characterised by the dimensions of the particles · CPC title

• G03G9/09392

  Preparation thereof · CPC title

• G03G9/0804 Primary

  whereby the components are brought together in a liquid dispersing medium · CPC title