Toner, toner housing unit, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9977367-B2
Application number	US-201615340647-A
Country	US
Kind code	B2
Filing date	Nov 1, 2016
Priority date	Nov 26, 2015
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A toner includes a toner base particle including a binder resin; a release agent; and an inorganic fine particle, and an external additive. The inorganic fine particle is silica having an average abundance ratio at the surface of the toner base particle of from 70% to 90%. The toner base particle has a BET specific surface area of from 1.0 m 2 /g to 2.5 m 2 /g after the external additive is removed from the toner.

First claim

What is claimed is:

1. A toner, comprising:
a toner base particle; and
an external additive,
wherein the toner base particle comprises a binder resin, a release agent, and an inorganic fine particle,
the inorganic fine particle is silica,
an average abundance ratio of the inorganic fine particle at the surface of the toner base particle is from 70% to 90%, and
the toner base particle has a BET specific surface area of from 1.0 m 2 /g to 2.5 m 2 /g after the external additive is removed from the toner.

2. The toner of claim 1 , wherein the silica is an organosol synthesized by a wet method.

3. The toner of claim 1 , wherein the toner base particle has the BET specific surface area of from 1.1 m 2 /g to 2.0 m 2 /g after the external additive is removed from the toner.

4. The toner of claim 1 , wherein the toner base particle has a surface Si quantity of from 10% by atom to 30% by atom when measured by XPS.

5. The toner of claim 1 , wherein the inorganic fine particle detected from a transmission electron microscope photograph of a torn surface of the toner base particle has an average primary particle diameter of from 10 nm to 50 nm.

6. The toner of claim 1 , wherein an amount of the release agent abstracted with n-hexane from 1.0 g of the toner is from 5 mg to 30 mg.

7. The toner of claim 1 , wherein the toner has an average circularity of from 0.970 to 0.985.

8. The toner of claim 1 , wherein a volume-basis particle diameter distribution of the toner has a first peak and a second peak, and a volume-basis particle diameter of the second peak is 1.21 to 1.31 times of a volume-basis particle diameter of the first peak.

9. The toner of claim 1 , wherein at least a part of the inorganic fine particle is not exposed on the surface of the toner base particle.

10. The toner of claim 1 , wherein the toner has an average circularity of from 0.975 to 0.985.

11. The toner of claim 1 , wherein the toner has an average circularity of from 0.977 to 0.985.

12. The toner of claim 1 , wherein the inorganic fine particle is included in the toner base particle in an amount of from 10 parts by mass to 25 parts by mass per 100 parts by mass of the toner base particles.

13. The toner of claim 1 , wherein the inorganic fine particle is included in the toner base particle in an amount of from 15 parts by mass to 20 parts by mass per 100 parts by mass of the toner base particles.

14. A toner housing unit, containing the toner according to claim 1 .

15. An image forming apparatus, comprising:
a toner housing unit containing the toner of claim 1 ;
an electrostatic latent image bearer;
an electrostatic latent image former configured to form an electrostatic latent image on the electrostatic latent image bearer;
an image developer configured to develop the electrostatic latent image with the toner to form a visible image;
a transferer configured to transfer the visible image onto a recording medium; and
a fixer configured to fix the visible image on the recording medium.

Assignees

• Kojima Satoshi
• Takahashi Satoshi
• Moritani Tatsuru
• Aoai Shosuke
• Yamaguchi Tatsuki
• Ricoh Co Ltd

Inventors

• Kojima Satoshi
• Takahashi Satoshi
• Moritani Tatsuru
• Aoai Shosuke
• Yamaguchi Tatsuki

Classifications

• G03G9/087

  Binders for toner particles · CPC title

• B29B9/10

  by moulding the material, i.e. treating it in the molten state · CPC title

• B29B2009/125

  Micropellets, microgranules, microparticles · CPC title

• G03G9/0825

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

• B29B9/12

  characterised by structure or composition · CPC title