Electrostatic image developing toner and image forming method

Patent metadata

Field	Value
Publication number	US-10585368-B2
Application number	US-201816194631-A
Country	US
Kind code	B2
Filing date	Nov 19, 2018
Priority date	Jan 10, 2018
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

Provided is an electrostatic image developing toner containing toner mother particles having external additives on a surface of the mother particle, wherein the external additives contains calcium titanate particles having an average primary particle size in the range of 50 to 150 nm, and alumina particles; and an average primary particle size of the alumina particles is less than the average primary particle size of the calcium titanate particles.

First claim

What is claimed is:

1. An electrostatic image developing toner comprising:
toner mother particles having external additives on a surface of the mother particle;
wherein the external additives contain calcium titanate particles having an average primary particle size in the range of 50 to 150 nm, and alumina particles; and an average primary particle size of the alumina particles is less than the average primary particle size of the calcium titanate particles;
wherein the calcium titanate particles are surface-modified with either a silane compound or a silicone oil;
wherein the average primary particle size of the alumina particles is in the range of 6 to 25 nm; and
wherein the alumina particles are surface-modified with either a silane compound or a silicone oil, and the surface-modified alumina particles have a degree of hydrophobicity of 40 to 70.

2. The electrostatic image developing toner described in claim 1 ,
wherein the average primary particle size of the alumina particles is in the range of 10 to 20 nm.

3. The electrostatic image developing toner described in claim 1 ,
wherein the toner mother particles contain a vinyl resin.

4. An image forming method comprising a step of forming an image on a substrate using the electrostatic image developing toner described in claim 1 .

Assignees

• Konica Minolta Inc

Inventors

• Ueda Junya
• Obara Shinya
• Takahashi Takuya
• Sakurada Ikuko
• Uchino Satoshi

Classifications

• G03G9/0819

  characterised by the dimensions of the particles · CPC title

• G03G9/09708 Primary

  Inorganic compounds · CPC title

• G03G9/0831

  Chemical composition of the magnetic components · CPC title

• G03G9/09716

  treated with organic compounds · CPC title

• G03G9/0833

  Oxides · CPC title