IP Library Granted Patent US 11,561,483
Granted Patent B2
US 11,561,483 · App. 16/945,098 · Granted Jan 24, 2023

Electrostatic charge image developing carrier, electrostatic charge image developer, and image forming apparatus

Inventors: Kazutsuna Sasaki (Minamiashigara, JP); Yasuo Kadokura (Minamiashigara, JP); Shintaro Anno (Minamiashigara, JP); Satoshi Miura (Minamiashigara, JP); Jumpei Iwasaki (Minamiashigara, JP)
Assignee: FUJIFILM Business Innovation Corp.
G03G9/1131G03G9/0819G03G9/1075G03G9/1139G03G15/08
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Quick Facts
Patent No.
US 11,561,483
App. No.
16/945,098
Granted
Jan 24, 2023
Kind
B2
Abstract

An electrostatic charge image developing carrier includes: magnetic particles; and a resin layer coating the magnetic particles and containing inorganic particles, in which an exposed area ratio of the magnetic particles is 0.1% or more and 4.0% or less, an average particle diameter of the inorganic particles is 5 nm or more and 90 nm or less, and a ratio B/A of a surface area B of the electrostatic charge image developing carrier to a plan view area A of the electrostatic charge image developing carrier is 1.020 or more and 1.100 or less when a surface of the electrostatic charge image developing carrier is three-dimensionally analyzed.

Claims (26)

1. An electrostatic charge image developing carrier comprising:

magnetic particles; and

an acrylate resin layer coating the magnetic particles and containing silica particles,

wherein an exposed area ratio of the magnetic particles is 0.1% or more and 4.0% or less,

wherein an average particle diameter of the silica particles is 5 nm or more and 90 nm or less, and

wherein a ratio B/A of a surface area B of the electrostatic charge image developing carrier to a plan view area A of the electrostatic charge image developing carrier is 1.020 or more and 1.100 or less when a surface of the electrostatic charge image developing carrier is three-dimensionally analyzed.

2. The electrostatic charge image developing carrier according to claim 1 , wherein the ratio B/A is 1.040 or more and 1.080 or less.

3. The electrostatic charge image developing carrier according to claim 1 , wherein the average particle diameter of the silica particles is 5 nm or more and 70 nm or less.

4. The electrostatic charge image developing carrier according to claim 1 , wherein the exposed area ratio of the magnetic particles is 0.3% or more and 3.5% or less.

5. The electrostatic charge image developing carrier according to claim 1 , wherein an average thickness of the resin layer is 0.6 μm or more and 1.4 μm or less.

6. The electrostatic charge image developing carrier according to claim 5 , wherein the average thickness of the resin layer is 0.8 μm or more and 1.2 μm or less.

7. The electrostatic charge image developing carrier according to claim 1 , wherein an amount of toluene in the electrostatic charge image developing carrier is 100 ppm or less.

8. The electrostatic charge image developing carrier according to claim 7 , wherein the amount of toluene in the electrostatic charge image developing carrier is 20 ppm or less.

9. An electrostatic charge image developer comprising:

the electrostatic charge image developing carrier according to claim 1 ; and

an electrostatic charge image developing toner.

10. An image forming apparatus comprising:

an image carrier;

a charging unit configured to charge a surface of the image carrier;

an electrostatic charge image forming unit configured to form an electrostatic charge image on the surface of the charged image carrier;

a developing unit configured to develop the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer according to claim 9 ;

a transfer unit configured to transfer the toner image onto a surface of a recording medium; and

a fixing unit configured to fix the transferred toner image onto the surface of the recording medium.

11. The electrostatic charge image developing carrier according to claim 1 ,

wherein a volume average particle diameter of the magnetic particles is 15 μm or more and 100 μm or less.

12. The electrostatic charge image developing carrier according to claim 1 , wherein the electrostatic charge image developing carrier is a resin-coated carrier.

Assignments (2)
CHANGE OF NAME Recorded Apr 29, 2021
From: FUJI XEROX CO., LTD.
To: FUJIFILM BUSINESS INNOVATION CORP.
Reel/Frame 056092/0913 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 31, 2020
From: SASAKI, KAZUTSUNA; KADOKURA, YASUO; ANNO, SHINTARO; MIURA, SATOSHI; IWASAKI, JUMPEI
To: FUJI XEROX CO., LTD.
Reel/Frame 053372/0867 →
Priority Claims (1)
JP JP2020-034175 · Feb 28, 2020 · national
Continuity (1)
Related Publication 20210271180A1 · Sep 2, 2021