Process cartridge and process cartridge set

Patent metadata

Field	Value
Publication number	US-12510839-B2
Application number	US-202418961214-A
Country	US
Kind code	B2
Filing date	Nov 26, 2024
Priority date	Dec 1, 2023
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

A process cartridge includes a charging unit, (I) wherein the charging unit includes a conductive member, wherein the conductive member includes a conductive layer disposed on an outer surface of a support, the conductive layer has a matrix-domain structure including a matrix and a plurality of domains, the matrix contains a first rubber, the domains contain a second rubber, and (II) wherein the toner includes agglomerates containing silica fine particles and binding components on surfaces of the toner particles, and wherein a relationship of Dms<Ag is satisfied, where Dms is an arithmetic mean of distances between adjacent domains at the outer surface of the conductive roller, and Ag is an arithmetic mean of Feret diameters of the agglomerates.

First claim

What is claimed is:

1 . A process cartridge comprising:
toner; a toner accommodation unit configured to accommodate the toner; an electrophotographic photosensitive member; a charging unit configured to charge a surface of the electrophotographic photosensitive member; a cleaning unit configured to remove residual toner from a region upstream of the charging unit; and a developing unit configured to develop an electrostatic latent image formed on the surface of the electrophotographic photosensitive member with toner to form a toner image on the surface of the electrophotographic photosensitive member, (I) wherein the charging unit includes a conductive member disposed to contact the electrophotographic photosensitive member, wherein the cleaning unit includes a cleaning blade disposed to contact the electrophotographic photosensitive member, wherein the conductive member includes a support having a conductive outer surface and a conductive layer disposed on the outer surface of the support, the conductive layer has a matrix-domain structure including a matrix and a plurality of domains dispersed in the matrix, the matrix contains a first rubber, the domains contain a second rubber, and a surface of the conductive member has a surface roughness Ra of 2.00 μm or less, and wherein G1 and G2 both fall within a range of 1.0 N/mm 2 or more and 10.0 N/mm 2 or less, and an absolute value of a difference between G1 and G2 is 0.1 N/mm 2 or more and 7.0 N/mm 2 or less, where G1 is a Martens hardness of the matrix measured at the outer surface of the conductive member under a load of 1 mN, and G2 is a Martens hardness of the domains measured at the outer surface of the conductive member under a load of 1 mN, and (II) wherein the toner includes at least toner particles, with agglomerates containing silica fine particles and binding components on surfaces of the toner particles, wherein CI is 1% by number or more and 15% by number or less, where CI (% by number) is a ratio by number of toner particles with the agglomerates, wherein CI, Ca, and Cb satisfy the following inequalities (1) and (2):

0.9
≤

Ca
/
CI

≤
1.

,

and
⁢

inequality

(
1
)

0.01
≤

Cb
/
CI

≤
0.1

,
inequality

(
2
)

where Ca (% by number) is the ratio by number of toner particles with the agglomerates in the toner after processed under the following ultrasonic condition A, and Cb (% by number) is the ratio by number of toner particles with the agglomerates in the toner after processed under the following ultrasonic condition B:
ultrasonic condition A: an output frequency of 30 kHz, an output power of 0.75 W, and an irradiation time of 300 s, and
ultrasonic condition B: an output frequency of 30 kHz, an output power of 35 W, and an irradiation time of 300 s, and
wherein a relationship of Dms<Ag is satisfied, where Dms is an arithmetic mean of distances between adjacent domains at the outer surface of the conductive roller, and Ag is an arithmetic mean of Feret diameters of the agglomerates.

2 . The process cartridge according to claim 1 , wherein an area ratio of the binding components of an agglomerate on a surface of a toner particle with the agglomerate, observed under a scanning electron microscope is 5% or more and 50% or less with respect to the entire agglomerate.

3 . The process cartridge according to claim 1 , wherein the Martens hardnesses G1 and G2 satisfy a relationship of G1<G2.

4 . The process cartridge according to claim 1 , wherein the arithmetic mean Dms of distances between the adjacent domains is 200 nm or more and 2000 nm or less.

5 . The process cartridge according to claim 1 , wherein the arithmetic mean Ag of the Feret diameters of the agglomerates is 1000 nm or more and 8000 nm or less.

6 . The process cartridge according to claim 1 , wherein the domains contain an electron conductive agent.

7 . The process cartridge according to claim 1 , wherein the matrix has a volume resistivity higher than 1.00×10 12 Ω·cm and lower than or equal to 1.00×10 17 Ω·cm.

8 . The process cartridge according to claim 1 , wherein the toner contains a layered composite compound as an external additive.

9 . The process cartridge according to claim 8 , wherein the layered composite compound contains fluorine.

10 . The process cartridge according to claim 8 , wherein the layered composite compound is hydrotalcite.

11 . A process cartridge set comprising:
a first cartridge and a second cartridge configured to be detachably attached to a main body of an electrophotographic apparatus, (I) wherein the first cartridge includes a charging unit configured to charge a surface of an electrophotographic photosensitive member, a cleaning unit configured to remove residual toner from a region upstream of the charging unit, and a first frame configured to support the charging unit and the cleaning unit, and wherein the second cartridge includes a toner container configured to accommodate toner with which an electrostatic latent image formed on the surface of the electrophotographic photosensitive member is developed to form a toner image on the surface of the electrophotographic photosensitive member, (II) wherein the charging unit includes a conductive member disposed to contact the electrophotographic photosensitive member, wherein the cleaning unit includes a cleaning blade disposed to contact the electrophotographic photosensitive member, wherein the conductive member includes a support having a conductive outer surface and a conductive layer disposed on the outer surface of the support, the conductive layer has a matrix-domain structure including a matrix and a plurality of domains dispersed in the matrix, the matrix contains a first rubber, the domains contain a second rubber, and a surface of the conductive member has a surface roughness Ra of 2.00 μm or less, and wherein G1 and G2 both fall within a range of 1.0 N/mm 2 or more and 10.0 N/mm 2 or less, and an absolute value of a difference between G1 and G2 is 0.1 N/mm 2 or more and 7.0 N/mm 2 or less, where G1 is a Martens hardness of the matrix measured at the outer surface of the conductive member under a load of 1 mN, and G2 is a Martens hardness of the domains measured at the outer surface of the conductive member under a load of 1 mN, and (III) wherein the toner includes a

Assignees

• Canon Kk

Inventors

• Kototani Shohei
• Nozaki Dai
• Uno Masashi
• Ookubo Kenji
• Kikuchi Yuichi

Classifications

• G03G15/0258

  provided with means for the maintenance of the charging apparatus, e.g. cleaning devices, ozone removing devices G03G15/0225, G03G15/0291 takes precedence · CPC title

• G03G9/08773

  Polymers having silicon in the main chain, with or without sulfur, oxygen, nitrogen or carbon only · CPC title

• G03G9/0825

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

• G03G9/1139

  Inorganic components of coatings · CPC title

• G03G21/1828 Primary

  Prevention of damage or soiling, e.g. mechanical abrasion (G03G21/1839 takes precedence) · CPC title