# US 12,222,676 B2 · Preparing method of electrostatic charge image developing toner, electrostatic charge image developing toner, and electrostatic charge image developer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,222,676 B2 - Document ID: US12222676B2 - Status: Granted - Kind: B2 - Application number: 17/459,010 - Filed: 2021-08-27 - Published: 2022-09-22 - Granted: 2025-02-11 - Earliest claimed: 2021-03-19 - Assignees: FUJIFILM Business Innovation Corp. - Applicants: FUJIFILM Business Innovation Corp. - Inventors: Yoshimasa Fujihara; Daisuke Noguchi; Kazuhiko Nakamura; Hiroshi Nakazawa - Web page: https://patentgrep.com/patent/US12222676B2 ## CPC - G03G 9/0804: {whereby the components are brought together in a liquid dispersing medium} - G03G 9/0819: {characterised by the dimensions of the particles} - G03G 9/09392: {Preparation thereof} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## 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 (m2) of the binder resin particles at a start of the aggregating is 1.5×1010 or more and 2.5×1013 or less. ## Claims ### Claim 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 (m2) of the binder resin particles at a start of the aggregating is 1.5×1010 or more and 2.5×1013 or less. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 1) 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. ### Claim 4 (depends on 2) 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. ### Claim 5 (depends on 1) 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. ### Claim 6 (depends on 2) 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. ### Claim 7 (depends on 3) 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. ### Claim 8 (depends on 4) 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. ### Claim 9 (depends on 5) 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. ### Claim 10 (depends on 6) 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. ### Claim 11 (depends on 7) 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. ### Claim 12 (depends on 9) 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. ### Claim 13 (depends on 5) 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. ### Claim 14 (depends on 13) 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/m3 in the stopping. ### Claim 15 (depends on 13) 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/m3 in the stopping. ### Claim 16 (depends on 1) 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. ### Claim 17 (depends on 1) 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. ### Claim 18 (depends on 1) 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.