Toner, two-component developer, and image-forming apparatus

Patent metadata

Field	Value
Publication number	US-12025951-B2
Application number	US-202117405936-A
Country	US
Kind code	B2
Filing date	Aug 18, 2021
Priority date	Sep 2, 2020
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

The toner has a toner matrix particle containing a crystalline polyester resin. Associated silica including two or more of primary particles is present on the surface of the toner matrix particle. The coverage with associated silica onto the toner matrix particle is 1% or more to 30% or less, and the adherence strength of associated silica to the toner matrix particle is 20% or more to 90% or less.

First claim

What is claimed is:

1. A toner having a toner matrix particle comprising a crystalline polyester resin,
wherein associated silica is present on a surface of the toner matrix particle, and the associated silica is obtained by adding a tetraalkyl ammonium hydroxide compound as an association-promoting additive to a silica sol so as to bond two or more silica particles in the silica sol,
a coverage with the associated silica onto the toner matrix particle is 1.6% or more to 13% or less, and
an adherence strength of the associated silica to the toner matrix particle is 45% or more to 75% or less.

2. The toner according to claim 1 ,
wherein the associated silica is hydrophobized with hexamethyldisilazane.

3. The toner according to claim 1 ,
wherein an average particle diameter of the associated silica is 10 nm or more to 200 nm or less.

4. A two-component developer comprising the toner according to claim 1 and a carrier.

5. An image-forming apparatus using the two-component developer according to claim 4 .

6. The image-forming apparatus according to claim 5 , further comprising a photoconductive drum,
wherein a difference between a Solubility Parameter (SP) value of a surface of the photoconductive drum and an SP value of the crystalline polyester resin is 1.5 or more.

7. The image-forming apparatus according to claim 6 ,
wherein a resin forming the surface of the photoconductive drum is polytetrafluoroethylene.

8. The toner according to claim 1 ,
wherein a number of the two or more silica particles that are obtained from the silica sol and are contained in each particle of the associated silica is less than or equal to 20.

Assignees

• Sharp Kk

Inventors

• Maeda Hiroki

Classifications

• G03G9/09725

  Silicon-oxides; Silicates · CPC title

• G03G9/0825

  characterised by their structure; characterised by non-homogenuous distribution of components (microcapsular toners G03G9/093) · CPC title

• G03G9/0819

  characterised by the dimensions of the particles · CPC title

• G03G15/75 Primary

  Details relating to xerographic drum, band or plate, e.g. replacing, testing (electrographic recording members per se G03G5/00) · CPC title

• G03G5/0596

  Macromolecular compounds characterised by their physical properties · CPC title