US 11,249,407 B2Granted

Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

AssigneeCanon Kabushiki Kaisha

InventorsKaname Watariguchi, Tomohito Ishida, Masataka Kawahara, Michiyo Sekiya, Kohei Makisumi

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Abstract

The electrophotographic photosensitive member has: a cylindrical support; a charge generating layer formed on the cylindrical support; and a charge transport layer formed on the charge generating layer, the charge generating layer contains a hydroxygallium phthalocyanine crystal having a particular CuKα characteristic X-ray diffraction peak, a titanyl phthalocyanine crystal having a particular CuKα characteristic X-ray diffraction peak or a chlorogallium phthalocyanine crystal having a particular spectral absorption spectrum as a charge generating material, and in the charge generating layer, with respect to the film thickness of the charge generating layer, when a region from the central position of an image forming area to the end position of the image forming area is divided in the axial direction of the cylindrical support into five equal regions and the average film thickness of the charge generating layer in each region satisfies a specific condition.

Claims6

Dependent claims

An electrophotographic photosensitive member, comprising in this order:

a cylindrical support;
a conductive layer that contains a binder resin and a metal oxide fine particle, the metal oxide fine particle having a core material containing titanium oxide and an enveloping layer covering the core material that contains niobium or tantalum-doped titanium oxide;
a charge generating layer that contains a hydroxygallium phthalocyanine crystal as a charge generating material, the hydroxygallium phthalocyanine crystal having strong peaks at Bragg angle 2θ of 7.4°±0.3° and 28.2°±0.3° in CuKα characteristic X-ray diffraction;
and
a charge transport layer, wherein
d1<d2<d3<d4<d5 where in the charge generating layer, when a region from a central position of an image forming area to an end position of the image forming area is divided in an axial direction of the cylindrical support into five equal regions, d1, d2, d3, d4 and d5 are respectively average film thicknesses of the charge generating layer in each region in order from the central part,
the hydroxygallium phthalocyanine crystal contains 0.4 to 3.0% by mass of a compound having a structure represented by formula (A1)
where R0 represents a methyl group, a propyl group or a vinyl group,
1
-
e
-
2
⁢
β
⁢
⁢
d
6
1
-
e
-
2
⁢
β
⁢
⁢
d
0
≥
1.2
(
E
⁢
⁢
1
)
where β (nm−1) is an absorption coefficient of the charge generating layer, d0 is a film thickness of the charge generating layer at the central position of the image forming area and d6 is a film thickness of the charge generating layer at the end position of the image forming area, and
a film thickness of the charge generating layer for all Y, where 0≤Y≤Ymax, is between d−0.2Δ and d+0.2Δ with respect to d=d(Y) calculated with expression (E2)
d
⁡
(
Y
)
=
d
0
+
Δ
⁡
(
1
-
βΔ
)
⁢
Y
2
Y
max
2
+
βΔ
2
⁢
Y
4
Y
max
4
(
E
⁢
⁢
2
)
where Y (mm) is a distance in the charge generating layer from the central position of the image forming area in the axial direction of the cylindrical support, Ymax is a value of Y at the end position of the image forming area, and Δ=d6−d0.

75 more elements

A process cartridge integrally supporting an electrophotographic photosensitive member and at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit, the process cartridge being removably attached to a main body of an electrophotographic apparatus, the electrophotographic photosensitive member comprising in this order:

a cylindrical support;
a conductive layer that contains a binder resin and a metal oxide fine particle, the metal oxide fine particle having a core material containing titanium oxide and an enveloping layer covering the core material that contains niobium or tantalum-doped titanium oxide;
a charge generating layer that contains a hydroxygallium phthalocyanine crystal as a charge generating material, the hydroxygallium phthalocyanine crystal having strong peaks at Bragg angle 2θ of 7.4°±0.3° and 28.2°±0.3° in CuKα characteristic X-ray diffraction;
and
a charge transport layer, wherein
d1<d2<d3<d4<d5 where in the charge generating layer, when a region from a central position of an image forming area to an end position of the image forming area is divided in an axial direction of the cylindrical support into five equal regions, d1, d2, d3, d4 and d5 are respectively average film thicknesses of the charge generating layer in each region in order from the central part,
the hydroxygallium phthalocyanine crystal contains 0.4 to 3.0% by mass of a compound having a structure represented by formula (A1)
where R0 represents a methyl group, a propyl group or a vinyl group,
1
-
e
-
2
⁢
β
⁢
⁢
d
6
1
-
e
-
2
⁢
β
⁢
⁢
d
0
≥
1.2
(
E
⁢
⁢
1
)
where β (nm−1) is an absorption coefficient of the charge generating layer, d0 is a film thickness of the charge generating layer at the central position of the image forming area and d6 is a film thickness of the charge generating layer at the end position of the image forming area, and
a film thickness of the charge generating layer for all Y, where 0≤Y≤Ymax, is between d−0.2Δ and d+0.2Δ with respect to d=d(Y) calculated with expression (E2)
d
⁡
(
Y
)
=
d
0
+
Δ
⁡
(
1
-
βΔ
)
⁢
Y
2
Y
max
2
+
βΔ
2
⁢
Y
4
Y
max
4
(
E
⁢
⁢
2
)
where Y (mm) is a distance in the charge generating layer from the central position of the image forming area in the axial direction of the cylindrical support, Ymax is a value of Y at the end position of the image forming area, and Δ=d6−d0.

75 more elements

An electrophotographic apparatus having an electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit and a transfer unit, the electrophotographic photosensitive member comprising in this order:

a cylindrical support;
a conductive layer that contains a binder resin and a metal oxide fine particle, the metal oxide fine particle having a core material containing titanium oxide and an enveloping layer covering the core material that contains niobium or tantalum-doped titanium oxide;
a charge generating layer that contains a hydroxygallium phthalocyanine crystal as a charge generating material, the hydroxygallium phthalocyanine crystal having strong peaks at Bragg angle 2θ of 7.4°±0.3° and 28.2°±0.3° in CuKα characteristic X-ray diffraction;
and
a charge transport layer, wherein
d1<d2<d3<d4<d5 where in the charge generating layer, when a region from a central position of an image forming area to an end position of the image forming area is divided in an axial direction of the cylindrical support into five equal regions, d1, d2, d3, d4 and d5 are respectively average film thicknesses of the charge generating layer in each region in order from the central part,
the hydroxygallium phthalocyanine crystal contains 0.4 to 3.0% by mass of a compound having a structure represented by formula (A1)
where R0 represents a methyl group, a propyl group or a vinyl group,
1
-
e
-
2
⁢
β
⁢
⁢
d
6
1
-
e
-
2
⁢
β
⁢
⁢
d
0
≥
1.2
(
E
⁢
⁢
1
)
where β (nm−1) is an absorption coefficient of the charge generating layer, d0 is a film thickness of the charge generating layer at the central position of the image forming area and d6 is a film thickness of the charge generating layer at the end position of the image forming area, and
a film thickness of the charge generating layer for all Y, where 0≤Y≤Ymax, is between d−0.2Δ and d+0.2Δ with respect to d=d(Y) calculated with expression (E2)
d
⁡
(
Y
)
=
d
0
+
Δ
⁡
(
1
-
βΔ
)
⁢
Y
2
Y
max
2
+
βΔ
2
⁢
Y
4
Y
max
4
(
E
⁢
⁢
2
)
where Y (mm) is a distance in the charge generating layer from the central position of the image forming area in the axial direction of the cylindrical support, Ymax is a value of Y at the end position of the image forming area, and Δ=d6−d0.

75 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/905,427Filed 18 Jun 2020
Priority: JP JP2019-11781625 Jun 2019
Published: US 2020/0409281 A131 Dec 2020
Granted: 15 Feb 2022
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

G03G 5/0696
Dyes: phthalocyanines
C09B 67/0002
Post-treatment of organic pigments or dyes: grinding; Milling with solid grinding or milling assistants
C09B 67/0019
Influencing the physical properties by treatment with an acid, H2SO4: of phthalocyanines
C09B 67/0026
Crystal modifications; Special X-ray patterns: of phthalocyanine pigments