Electrostatic charge image developing toner, method for producing electrostatic charge image developing toner, electrostatic charge image developer, toner cartridge, process cartridge, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-12197169-B2
Application number	US-202117404729-A
Country	US
Kind code	B2
Filing date	Aug 17, 2021
Priority date	May 21, 2021
Publication date	Jan 14, 2025
Grant date	Jan 14, 2025

Abstract

An electrostatic charge image developing toner includes a toner particle, and the toner particle includes: a core particle containing a large-diameter particle having a number average particle diameter of 1 μm or more; and a shell layer that includes at least two resin layers each containing an amorphous resin and covers a surface of the core particles, and an outermost layer of the at least two resin layers is a resin layer being made of the amorphous resin.

First claim

What is claimed is:

1. An electrostatic charge image developing toner comprising:
a toner particle including:
a core particle that contains a light-emitting particle having a number average particle diameter of 1 μm or more; and
a shell layer that covers a surface of the core particle and includes at least three resin layers each containing an amorphous resin,

wherein the at least three resin layers include:
an innermost layer consisting of the amorphous resin,
an outermost layer consisting of the amorphous resin, and
an intermediate layer that is a layer other than the innermost layer and the outermost layer of the at least three resin layers, and that includes a resin layer containing the amorphous resin, a releasing agent, and a crystalline resin.

2. The electrostatic charge image developing toner according to claim 1 ,
wherein the core particle consists of one light-emitting particle being the light-emitting particle.

3. The electrostatic charge image developing toner according to claim 1 ,
wherein the core particle contains at least two light-emitting particles each being the light-emitting particle, and an amorphous resin.

4. The electrostatic charge image developing toner according to claim 3 ,
wherein a content of the light-emitting particles relative to a whole of the core particle is 50 mass % or more.

5. The electrostatic charge image developing toner according to claim 1 ,
wherein a content of a resin single particle in the electrostatic charge image developing toner is equal to or less than 80% by number of a whole of the electrostatic charge image developing toner, the resin single particle containing an amorphous resin and not containing the light-emitting particle.

6. A method for producing an electrostatic charge image developing toner, comprising:
preparing a core particle dispersion liquid in which a core particle containing a large-diameter particle having a number average particle diameter of 1 μm or more is dispersed;
performing an operation of adding an amorphous resin particle to the core particle dispersion liquid and aggregating the core particle and the amorphous resin particle such that the amorphous resin particle adheres to the core particle, thereby forming a resin particle layer on a surface of the core particle;
repeating the operation at least one time, wherein only the amorphous resin particle is added as a particle added in the last operation, thereby forming an aggregated particle including at least two resin particle layers on the surface of the core particle, an outermost layer of the at least two resin particle layers consisting of the amorphous resin particle; and
heating an aggregated particle dispersion liquid in which the aggregated particle is dispersed to fuse and coalesce the aggregated particle, thereby forming a toner particle.

7. The method for producing an electrostatic charge image developing toner according to claim 6 ,
wherein the particle added in the forming of the resin particle layer is only the amorphous resin particle, and
in the forming of the aggregated particle, the operation is further repeated at least two times in the repeating of the operation, and the particle added in at least one time of the operation excluding the last operation includes the amorphous resin particle and at least one selected from the group consisting of releasing agent particles, crystalline resin particles and colorant particles, and the aggregated particle including at least three resin particle layers is formed on the surface of the core particle, and an innermost layer of the at least three resin particle layers consists of the amorphous resin particle, and an intermediate layer that is a layer other than the outermost layer and the innermost layer of the at least three resin particle layers includes the amorphous resin particle and at least one selected from the group consisting of the releasing agent particles, the crystalline resin particles, and the colorant particles.

8. The method for producing an electrostatic charge image developing toner according to claim 6 ,
wherein the large-diameter particle includes at least one selected from the group consisting of scaly particles and light-emitting particles.

9. The method for producing an electrostatic charge image developing toner according to claim 6 ,
wherein the core particle consists of one large-diameter particle being the large-diameter particle.

10. The method for producing an electrostatic charge image developing toner according to claim 6 ,
wherein the core particle contains at least two large-diameter particles each being the large-diameter particle, and an amorphous resin.

11. The method for producing an electrostatic charge image developing toner according to claim 10 ,
wherein a content of the large-diameter particles relative to a whole of the core particle is 50 mass % or more.

12. The method for producing an electrostatic charge image developing toner according to claim 6 ,
wherein in all operations in the forming of the resin particle layer and in the repeating of the operation, an aggregating agent is added to the core particle dispersion liquid in addition to the amorphous resin particle.

13. The method for producing an electrostatic charge image developing toner according to claim 6 ,
wherein an aggregation temperature in each operation in the repeating of the operation is higher than an aggregation temperature in an operation immediately preceding the each operation.

14. The method for producing an electrostatic charge image developing toner according to claim 6 ,
wherein an addition amount of the amorphous resin particle in each operation in the repeating of the operation is larger than an addition amount of the amorphous resin particle in an operation immediately preceding the each operation.

15. The electrostatic charge image developing toner according to claim 5 ,
wherein the electrostatic charge image developing toner does not contain the resin single particle.

16. The electrostatic charge image developing toner according to claim 1 ,
wherein the intermediate layer includes a colorant.

Assignees

• Fujifilm Business Innovation Corp

Inventors

• Nakamura Yukiaki
• Noguchi Daisuke
• Takahashi Masaru
• Nakamura Kazuhiko

Classifications

• G03G9/09371

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• G03G9/09328

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• G03G9/08782

  Waxes · CPC title

• G03G9/08728

  Polymers of esters · CPC title

• G03G9/0804

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