Toner production process and toner

• US 8,697,327 B2
• Filed: 05/19/2010
• Issued: 04/15/2014
• Est. Priority Date: 05/28/2009
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Shibata, Takaho, Kato, Masayoshi, Higashi, Ryuji, Toyoda, Takayuki, Natori, Ryo, Chimoto, Yuya
• Primary Examiner(s): VAJDA, PETER L
• Application Number:
  US13/264,136
• Publication Number:
  US 20120040285A1
• Time in Patent Office: 1,427 Days
• Field of Search: 430/110.1, 430/110.2, 430/137.11, 430/137.14
• 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 9/08759 Polyethers
• CPC Class Codes: G03G 9/08791 characterised by the presence of specified groups or side chains
• CPC Class Codes: G03G 9/093 Encapsulated toner particles
• CPC Class Codes: G03G 9/09328 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: G03G 9/09371 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: G03G 9/09392 Preparation thereof

Abstract

A process for producing a core-shell toner is provided in which the toner has core particles containing at least a binder resin (1), a colorant and a release agent and shell layers which contain at least a resin (2) and with which the core particles are covered; and the process including the steps of (A) mixing a binder resin-(1) dispersion, a colorant dispersion and a release agent dispersion, (B) adding to a mixed dispersion thus obtained an agglomerating agent to effect agglomeration, (C) adding to core agglomerated particles thus formed a mixture prepared by mixing the resin-(2) dispersion and a metal salt to make the resin (2) adhere to the surfaces of the core agglomerated particles, and (D) heating core-shell agglomerated particles thus formed to a temperature not lower than the glass transition temperatures of the binder resin (1) and resin (2) to effect fusion thereof.

Claims

1. A process for producing a core-shell toner having core particles which contain at least a resin (1), a colorant and a release agent and shell layers which contain at least a resin (2) and with which the core particles are covered;

the process comprising;

providing a resin (1) dispersion in which at least the resin (1) stands dispersed in a dispersion medium;

providing a colorant dispersion in which at least the colorant stands dispersed in a dispersion medium;

providing a release agent dispersion in which at least the release agent stands dispersed in a dispersion medium;

mixing at least the resin (1) dispersion, the colorant dispersion and the release agent dispersion, to obtain a mixed dispersion;

adding an agglomerating agent to the mixed dispersion to make the resin (1), the colorant and the release agent agglomerate to form core agglomerated particles;

providing a resin (2) dispersion in which at least the resin (2) stands dispersed in a dispersion medium;

loading a metal salt into the resin (2) dispersion in order to electrostatically neutralize the resin (2) dispersion;

adding the metal salt loaded resin dispersion to a dispersion in which the core agglomerated particles stand dispersed, to make the resin (2) adhere to the surfaces of the core agglomerated particles to form core-shell agglomerated particles; and

heating the core-shell agglomerated particles to a temperature not lower than the glass transition temperature of the resin (1) and resin (2) to effect fusion thereof.

2. The process for producing a core-shell toner according to claim 1, wherein the resin (1) has at least a carboxyl group as an acid group.

3. The process for producing a core-shell toner according to claim 1, wherein the resin (2) has at least a sulfonic acid group as an acid group.

4. The process for producing a core-shell toner according to claim 1, wherein the metal salt is a divalent or more polyvalent metal salt.

5. The process for producing a core-shell toner according to claim 1, wherein the metal salt is a divalent metal salt.

6. The process for producing a core-shell toner according to claim 1, wherein the resin (1) is a polyester resin.

7. The process for producing a core-shell toner according to claim 1, wherein the resin (2) is a polyester resin.

8. The process for producing a core-shell toner according to claim 1, wherein glass transition temperature Tg1 of the resin (1) and glass transition temperature Tg2 of the resin (2) satisfy the following expression:

30°

C.<

Tg1<

60°

C.<

Tg2<

80°

C.

9. A toner obtained by the process for producing a core-shell toner according to claim 1.