Toner and method for its preparation

• US 9,005,866 B2
• Filed: 05/31/2011
• Issued: 04/14/2015
• Est. Priority Date: 08/31/2010
• Status: Active Grant

• Current Assignee: ICMI (China) Limited
• Original Assignee: ICMI (China) Limited
• Inventors: Cheng, Lanlan, Zhang, Xiushan, Tang, Fugen
• Primary Examiner(s): VAJDA, PETER L
• Application Number:
  US13/820,014
• Publication Number:
  US 20130316281A1
• Time in Patent Office: 1,414 Days
• Field of Search: 430/137.14, 430/110.1
• US Class Current: 430/137.14
• CPC Class Codes: G03G 9/0825 characterised by their structure; characterised by non-homogenuous distribution of components microcapsular toners G03G9/093
• CPC Class Codes: G03G 9/0827 characterised by their shape, e.g. degree of sphericity
• CPC Class Codes: G03G 9/093 Encapsulated toner particles
• CPC Class Codes: G03G 9/09307 specified by the shell material
• CPC Class Codes: G03G 9/09314 Macromolecular compounds
• CPC Class Codes: G03G 9/0935 specified by the core material
• CPC Class Codes: G03G 9/09392 Preparation thereof

Abstract

Disclosed are a toner and a preparation method thereof. The toner of the invention has honeycomb-shaped core-shell structured particles. The honeycomb-shaped core-shell structured particles comprise two or more core layers. Each core layer is completely covered by a shell layer.

Claims

1. A method for preparing a toner having honeycomb-shaped core-shell structured particles which comprise two or more core layers, each of which is completely covered by a shell layer, said method comprising:

(a) dispersing a core-forming binding resin, a colorant, and a dispersant in an organic solvent to form an oil phase dispersing liquid, adding water to the oil phase dispersing liquid to emulsify and form a mixture emulsion;

(b) under shearing, adding a coagulating agent to the resultant emulsion from step (a) to form a dispersion of the coagulated core particles;

(c) to the resultant dispersion from step (b), adding a shell-forming binding resin dispersion which contain shell-forming binding resin particles, wherein the shell-forming binding resin particles form shells surrounding the coagulated core particles and yield coagulated core-shell structured particles dispersion;

(d) to the coagulated core-shell structured particles dispersion from step (c), adding a coagulating agent to merge the coagulated core-shell structured particles into honeycomb-shaped, core-shell structured toner particles, wherein the sphericity of the toner particles is controlled by controlling the coagulating time; and

(e) precipitating, washing, filtrating, and vacuum-drying of the toner particles from step (d) to yield honeycomb-shaped, core-shell structured toner particles having two or more core layers, each of which is covered by a shell layer.

2. The method of claim 1, wherein in step (a), the mixture emulsion is prepared by dispersing 1 to 10 parts of a colorant, 0.5 to 20 parts of a wax, 100 to 200 parts of a binding resin and 0 to 2 parts of an emulsifier in 50 to 150 parts of an organic solvent;

agitating the above mixture at 3000 to 10000 rpm for about one hour to form an oil phase dispersing liquid, remaining the temperature at about 30°

C., and then adding 100 to 200 parts of deionized water to emulsify the mixture and form a mixture emulsion.

3. The method of claim 1, wherein in step (b), the average particle diameter of the coagulated core particles is within the range of 1 μ

m to 5 μ

m.

4. The method of claim 3, wherein in step (a), the mixture emulsion is prepared by dispersing 1 to 10 parts of a colorant, 0.5 to 20 parts of a wax, 100 to 200 parts of a binding resin and 0 to 2 parts of an emulsifier in 50 to 150 parts of an organic solvent;

agitating the above mixture at 3000 to 10000 rpm for about one hour to form an oil phase dispersing liquid, remaining the temperature at about 30°

C., and then adding 100 to 200 parts of deionized water to emulsify the mixture and form a mixture emulsion.

5. The method of claim 3, wherein in step (c), the average diameter of the shell-forming particles in the shell-forming particles dispersion is less than or equal to 1 μ

m.

6. The method of claim 5, wherein in step (a), the mixture emulsion is prepared by dispersing 1 to 10 parts of a colorant, 0.5 to 20 parts of a wax, 100 to 200 parts of a binding resin and 0 to 2 parts of an emulsifier in 50 to 150 parts of an organic solvent;

agitating the above mixture at 3000 to 10000 rpm for about one hour to form an oil phase dispersing liquid, remaining the temperature at about 30°

C., and then adding 100 to 200 parts of deionized water to emulsify the mixture and form a mixture emulsion.

7. The method of claim 3, wherein step (d) is performed at an ambient temperature.