PROCESS FOR PRODUCING TONER

• US 20130108955A1
• Filed: 10/18/2012
• Published: 05/02/2013
• Est. Priority Date: 10/28/2011
• Status: Abandoned Application

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Shibata, Takaho, Kato, Masayoshi, Chimoto, Yuya, Ida, Hayato, Hirasa, Takashi
• Application Number:
  US13/655,256
• Publication Number:
  US 20130108955A1
• Time in Patent Office: Days
• US Class Current: 430/137.14
• CPC Class Codes: G03G 9/0804 whereby the components are brought together in a liquid dispersing medium
• CPC Class Codes: G03G 9/08795 characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants

Abstract

An object of the present invention is to provide a process of producing a toner according to an emulsion aggregation process in which the temperature and treatment time in the fusion process can be reduced, and a toner having a small particle diameter, a sharp particle size distribution, and a properly controlled average circularity can be efficiently produced simply with a small amount of energy. The process includes aggregating a resin fine particles and a colorant fine particles by adding an aggregating agent containing a divalent or higher-valent metal ion, and fusing the resin fine particles and the colorant fine particles to obtain a toner particle by adding a chelating agent and a monovalent metal salt to the aggregate particle dispersion liquid obtained in the aggregation process, and heating the liquid to a temperature of not less than glass transition temperature of the resin.

Claims

1. A process for producing a toner, comprising the steps of:

(I) mixing

an aqueous dispersion liquid in which resin fine particles each containing a resin having an acidic polar group are dispersed, with

an aqueous dispersion liquid in which colorant fine particles each containing a colorant are dispersed, to obtain a mixed dispersion liquid containing the resin fine particles and the colorant fine particles;

(II) aggregating the resin fine particles and the colorant fine particles to form aggregate particles by adding an aggregating agent containing a divalent or higher-valent metal ion to the mixed dispersion liquid; and

(III) fusing the resin fine particles and the colorant fine particles in the aggregate particles by

(a) adding a chelating agent to a dispersion liquid of the aggregate particles, and then adding a monovalent water-soluble metal salt thereto, and

(b) heating at a temperature of not less than a glass transition temperature of the resin having an acidic polar group.

2. The process for producing a toner according to claim 1, wherein the monovalent water-soluble metal salt is a neutral salt.

3. The process for producing a toner according to claim 1, wherein the monovalent water-soluble metal salt is selected from the group consisting of sodium chloride, sodium sulfate, potassium chloride, and sodium carbonate.

4. The process for producing a toner according to claim 1, wherein the chelating agent is a metal salt of a trivalent or higher-valent carboxylic acid.

5. The process for producing a toner according to claim 1, wherein the resin having an acidic polar group is a polyester resin.

6. The process for producing a toner according to claim 1, wherein the acidic polar group is selected from the group consisting of a carboxyl group, a sulfonic acid group, a phosphonic acid group, and a sulfinic acid group.

7. The process for producing a toner according to claim 1, wherein an acid value of the resin having an acidic polar group is 5 to 50 mgKOH/g.