Electrophotographic photoreceptor, process cartridge, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-11099492-B2
Application number	US-202016744210-A
Country	US
Kind code	B2
Filing date	Jan 16, 2020
Priority date	Sep 24, 2019
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer disposed on the conductive substrate. An outermost surface layer of the electrophotographic photoreceptor contains a fluorine-containing resin particle and a fluorine-based graft polymer having a fluorinated alkyl group. A ratio of an amount of a fluorine-based graft polymer separated from the fluorine-containing resin particle to a total amount of the fluorine-based graft polymer in the outermost surface layer is 15% or less.

First claim

What is claimed is:

1. An electrophotographic photoreceptor comprising:
a conductive substrate; and
a photosensitive layer disposed on the conductive substrate, wherein
an outermost surface layer of the electrophotographic photoreceptor contains a fluorine-containing resin particle and a fluorine-based graft polymer having a fluorinated alkyl group, and
a ratio of an amount of a fluorine-based graft polymer separated from the fluorine-containing resin particle to a total amount of the fluorine-based graft polymer in the outermost surface layer is 15% by mass or less,
wherein the fluorine-based graft polymer has a weight-average molecular weight of 116,000 or more and 200,000 or less.

2. The electrophotographic photoreceptor according to claim 1 , wherein
the fluorine-based graft polymer includes a structural unit A having a fluorinated alkyl group having 2 to 8 carbon atoms and a structural unit B having a graft chain, and
in an infrared absorption spectrum of the fluorine-based graft polymer, a ratio (S 2 /S 1 ) of a peak area S 2 in a wavenumber range of from 1,020 cm −1 to 1,308 cm −1 to a peak area S 1 in a wavenumber range of from 1,673 cm −1 to 1,779 cm −1 is 2.7 or more and 4.8 or less.

3. The electrophotographic photoreceptor according to claim 2 , wherein, in the infrared absorption spectrum of the fluorine-based graft polymer, the ratio (S 2 /S 1 ) of the peak area S 2 in the wavenumber range of from 1,020 cm −1 to 1,308 cm −1 to the peak area S 1 in the wavenumber range of from 1,673 cm −1 to 1,779 cm −1 is 2.9 or more and 3.9 or less.

4. The electrophotographic photoreceptor according to claim 3 , wherein the fluorine-based graft polymer is a binary copolymer constituted by a structural unit represented by general formula (FA) and a structural unit represented by general formula (FB),

in the general formulae (FA) and (FB),
R F1 , R F2 , R F3 , and R F4 each independently represent a hydrogen atom or an alkyl group;
X F1 represents an alkylene chain, a halogen-substituted alkylene chain, —S—, —O—, —NH—, or a single bond;
Y F1 represents an alkylene chain, a halogen-substituted alkylene chain, —(C fx H 2fx-1 (OH))—, or a single bond;
Q F1 represents —O— or —NH—;
fl and fin each represent a content by mass of a structural unit enclosed in parentheses relative to the total structural units of the fluorine-based graft polymer;
fn is a number of structural units enclosed in parentheses and represents an integer of 1 or more;
fp, fq, fr, and fs each independently represent an integer of 0 or 1 or more;
ft represents an integer of 1 or more and 7 or less; and
fx represents an integer of 1 or more.

5. The electrophotographic photoreceptor according to claim 3 , wherein a content of the fluorine-based graft polymer is 1% by mass or more and 10% by mass or less relative to the fluorine-containing resin particle.

6. The electrophotographic photoreceptor according to claim 3 , wherein
the outermost surface layer contains a dispersant-carrying particle formed of the fluorine-containing resin particle having a surface to which the fluorine-based graft polymer adheres, and
a content of perfluorooctanoic acid in the dispersant-carrying particle is 0 ppb or more and 25 ppb or less relative to a total mass of the fluorine-containing resin particle.

7. The electrophotographic photoreceptor according to claim 2 , wherein the fluorine-based graft polymer is a binary copolymer constituted by a structural unit represented by general formula (FA) and a structural unit represented by general formula (FB),

in the general formulae (FA) and (FB),
R F1 , R F2 , R F3 , and R F4 each independently represent a hydrogen atom or an alkyl group;
X F1 represents an alkylene chain, a halogen-substituted alkylene chain, —S—, —O—, —NH—, or a single bond;
Y F1 represents an alkylene chain, a halogen-substituted alkylene chain, —(C fx H 2fx-1 (OH))—, or a single bond;
Q F1 represents —O— or —NH—;
fl and fin each represent a content by mass of a structural unit enclosed in parentheses relative to the total structural units of the fluorine-based graft polymer;
fn is a number of structural units enclosed in parentheses and represents an integer of 1 or more;
fp, fq, fr, and fs each independently represent an integer of 0 or 1 or more;
ft represents an integer of 1 or more and 7 or less; and
fx represents an integer of 1 or more.

8. The electrophotographic photoreceptor according to claim 2 , wherein a content of the fluorine-based graft polymer is 1% by mass or more and 10% by mass or less relative to the fluorine-containing resin particle.

9. The electrophotographic photoreceptor according to claim 2 , wherein
the outermost surface layer contains a dispersant-carrying particle formed of the fluorine-containing resin particle having a surface to which the fluorine-based graft polymer adheres, and
a content of perfluorooctanoic acid in the dispersant-carrying particle is 0 ppb or more and 25 ppb or less relative to a total mass of the fluorine-containing resin particle.

10. The electrophotographic photoreceptor according to claim 1 , wherein the fluorine-based graft polymer is a binary copolymer constituted by a structural unit represented by general formula (FA) and a structural unit represented by general formula (FB),

in the general formulae (FA) and (FB),
R F1 , R F2 , R F3 , and R F4 each independently represent a hydrogen atom or an alkyl group;
X F1 represents an alkylene chain, a halogen-substituted alkylene chain, —S—, —O—, —NH—, or a single bond;
Y F1 represents an alkylene chain, a halogen-substituted alkylene chain, —(C fx H 2fx-1 (OH))—, or a single bond;
Q F1 represents —O— or —NH—;
fl and fin each represent a content by mass of a structural unit enclosed in parentheses relative to the total structural units of the fluorine-based graft polymer;
fn is a number of structural units enclosed in parentheses and represents an integer of 1 or more;
fp, fq, fr, and fs each independently represent an integer of 0 or 1 or more;
ft represents an integer of 1 or more and 7 or less; and
fx represents an integer of 1 or more.

11. The electrophotographic photoreceptor according to claim 1 , wherein a content of the fluorine-based graft polymer is 1% by mass or more and 10% by mass or less relative to the fluorine-containing resin particle.

12. The electrophotographic photoreceptor according to claim 1 , wherein
the outermost surface layer contains a dispersant-carrying particle formed of the fluorine-containing resin particle having a surface to which the fluorine-based graft polymer adheres, and
a content of perfluorooctanoic acid in the dispersant-carrying particle is 0 ppb or more and 25 ppb or less relative to a total mass of the fluorine-containing resin particle.

13. A process cartridge detachably attachable to an image forming apparatus, the process cartridge comprising:
the electrophotographic photoreceptor according to claim 1 .

14. An image forming apparatus comprising:
the electrophotographic photoreceptor according to claim 1 ;
a

Assignees

• Fujifilm Business Innovation Corp

Inventors

• Kusano Keisuke
• Yamada Wataru
• Iwasaki Masahiro
• Fujii Ryosuke
• Okazaki Yuto
• FUKUI Taisuke

Classifications

• G03G15/75

  Details relating to xerographic drum, band or plate, e.g. replacing, testing (electrographic recording members per se G03G5/00) · CPC title

• G03G5/0539 Primary

  Halogenated polymers · CPC title

• G03G5/14795

  Macromolecular compounds characterised by their physical properties · CPC title

• G03G5/14791

  Macromolecular compounds characterised by their structure, e.g. block polymers, reticulated polymers, or by their chemical properties, e.g. by molecular weight or acidity · CPC title

• G03G5/14786

  Macromolecular compounds characterised by specific side-chain substituents or end groups · CPC title