Toner, developer, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9377707-B2
Application number	US-201514631136-A
Country	US
Kind code	B2
Filing date	Feb 25, 2015
Priority date	Mar 10, 2014
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A toner including a crystalline polyester and an amorphous polyester is provided. When the binder resin is extracted from the toner with tetrahydrofuran to obtain an extracted solution, and the extracted solution is heated to remove the tetrahydrofuran and obtain a deposit, the deposit contains spherical domains of the crystalline polyester having an average particle diameter of 7.0 μm or less.

First claim

What is claimed is:

1. A toner, comprising:
a binder resin, including
a crystalline polyester; and
an amorphous polyester,

wherein when the binder resin is extracted from the toner with tetrahydrofuran to obtain an extracted solution, and the extracted solution is heated to remove the tetrahydrofuran and obtain a deposit, the deposit contains spherical domains of the crystalline polyester having an average particle diameter of 7.0 μm or less.

2. The toner according to claim 1 , wherein domains of the crystalline polyester in the toner have an average size of 150 nm or less.

3. The toner according to claim 1 , wherein the deposit has a thermomechanical analysis compressive deformation ratio of 3.0% or less at 200 mN under a temperature of 40° C. and a relative humidity of 80%.

4. The toner according to claim 1 , wherein the binder resin includes the crystalline polyester in an amount of from 1% to 20% by weight based on total weight of the binder resin.

5. The toner according to claim 1 , wherein the amorphous polyester has a weight average molecular weight of from 10,000 to 35,000, a glass transition temperature of from 50° C. to 80° C., and a softening temperature of from 130° C. to 180° C.

6. The toner according to claim 1 , wherein the crystalline polyester has a melting point of from 60° C. to 120° C. and a weight average molecular weight of from 10,000 to 35,000.

7. A developer, comprising:
the toner according to claim 1 ; and
a carrier.

8. An image forming apparatus, comprising:
an electrostatic latent image bearer;
an image forming device to form an electrostatic latent image on the electrostatic latent image bearer; and
a developing device to develop the electrostatic latent image into a visible image with the toner according to claim 1 .

Assignees

• Miyakoshi Ryo
• Asahina Daisuke
• Moriya Yoshihiro
• Sekiguchi Satoyuki
• Hirokawa Yuya
• Ricoh Co Ltd

Inventors

• Miyakoshi Ryo
• Asahina Daisuke
• Moriya Yoshihiro
• Sekiguchi Satoyuki
• Hirokawa Yuya

Classifications

• G03G9/08797

  characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature · CPC title

• G03G9/08795

  characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants · CPC title

• G03G9/08755 Primary

  Polyesters · CPC title