Process cartridge and electrophotographic apparatus
A process cartridge that can suppress production of a banding image attributed to contact rotation of an electrophotographic photosensitive member and a charging member and output a high-quality image is provided. The charging member includes an electro-conductive substrate and an electroconductive resin layer, the resin layer contains a binder, a conductive fine particle, and a bowl-shaped resin particle having an opening, and the surface of the charging member has a concavity derived from the opening of the bowl-shaped resin particle and a protrusion derived from the edge of the opening thereof. The electrophotographic photosensitive member includes a support and a photosensitive layer, and the surface layer in the photosensitive member contains a specific resin (α), a specific resin (β), and a specific compound (γ).
1. A process cartridge comprising:
a charging member; and
an electrophotographic photosensitive member which is electrically charged upon being brought into contact with the charging member, wherein:
the charging member comprises
an electro-conductive substrate and
an electroconductive resin layer formed on the electro-conductive substrate;
the electroconductive resin layer comprises
a binder,
a conductive fine particle, and
a bowl-shaped resin particle which has an opening; and
the surface of the charging member has
a concavity derived from the opening of the bowl-shaped resin particle, and
a protrusion derived from an edge of the opening of the bowl-shaped resin particle;
and wherein:
the electrophotographic photosensitive member comprises
a support and
a photosensitive layer formed on the support, and
a surface layer of the electrophotographic photosensitive member comprises the following resin (α), resin (β), and compound (γ):
resin (α): polycarbonate resins having no siloxane structure at a terminal;
resin (β): at least one resin selected from the group consisting of polycarbonate resins having a siloxane structure at a terminal, polyester resins having a siloxane structure at a terminal, and acrylic resins having a siloxane structure at a terminal; and
compound (γ): at least one compound selected from the group consisting of methyl benzoate, ethyl benzoate, benzyl acetate, ethyl 3-ethoxypropionate, and diethylene glycol ethyl methyl ether,
wherein the resin (α) is a polycarbonate resin A having a repeating structural unit represented by the following formula (A):
wherein R 21 to R 24 each independently represent a hydrogen atom or a methyl group; X 1 represents a single bond, a cyclohexylidene group, or a divalent group having a structure represented by the following formula (C):
wherein R 41 and R 42 each independently represent a hydrogen atom, a methyl group, or a phenyl group.
2. The process cartridge according to claim 1 , wherein the polycarbonate resin A is a polymer having only one kind of repeating structural unit selected from repeating structural units represented by the following formulas (A-1) to (A-8) or a polymer having a combination of two or more kinds of repeating structural units represented by the following formulas (A-1) to (A-8):
3. The process cartridge according to claim 1 , wherein the resin (β) is a polyester resin B′ having a repeating structural unit represented by the following formula (B′) and a terminal structure represented by the following formula (D):
wherein R 35 to R 38 each independently represent a hydrogen atom or a methyl group; X 4 represents a single bond, a cyclohexylidene group, or a divalent group having a structure represented by the following formula (C′); Y 2 represents a m-phenylene group, a p-phenylene group, or a divalent group in which two p-phenylene groups are bonded via an oxygen atom:
wherein R 43 and R 44 each independently represent a hydrogen atom, a methyl group, or a phenyl group,
wherein a and b represent a repetition number of the structure unit within the brackets, an average value of a is 20 or more and 100 or less, and an average value of b is 1 or more and 10 or less.
4. The process cartridge according to claim 1 , wherein the bowl-shaped resin particle is a particle having a resin shell, an opening derived from the partial lack of the shell, and a spherical concavity.
5. The process cartridge according to claim 4 , wherein an electroconductive resin layer is formed along an inner wall of the spherical concavity of the bowl-shaped resin particle.
6. A process cartridge comprising:
a charging member; and
an electrophotographic photosensitive member which is electrically charged upon being brought into contact with the charging member, wherein:
the charging member comprises
an electro-conductive substrate and
an electroconductive resin layer formed on the electro-conductive substrate;
the electroconductive resin layer comprises
a binder,
a conductive fine particle, and
a bowl-shaped resin particle which has an opening; and
the surface of the charging member has
a concavity derived from the opening of the bowl-shaped resin particle, and
a protrusion derived from an edge of the opening of the bowl-shaped resin particle;
and wherein:
the electrophotographic photosensitive member comprises
a support and
a photosensitive layer formed on the support, and
a surface layer of the electrophotographic photosensitive member comprises the following resin (α), resin (β), and compound (γ):
resin (α): at least one resin selected from the group consisting of polycarbonate resins having no siloxane structure at a terminal and polyester resins having no siloxane structure at a terminal;
resin (β): polycarbonate resins having a siloxane structure at a terminal, polyester resins having a siloxane structure at a terminal, and
compound (γ): at least one compound selected from the group consisting of methyl benzoate, ethyl benzoate, benzyl acetate, ethyl 3-ethoxypropionate, and diethylene glycol ethyl methyl ether,
wherein the resin (β) is a polycarbonate resin A′ having a repeating structural unit represented by the following formula (A′) and a terminal structure represented by the following formula (D):
wherein R 25 to R 28 each independently represent a hydrogen atom or a methyl group; X 3 represents a single bond, a cyclohexylidene group, or a divalent group having a structure represented by the following formula (C′):
wherein R 43 and R 44 each independently represent a hydrogen atom, a methyl group, or a phenyl group,
wherein a and b represent a repetition number of the structure unit within the brackets, an average value of a is 20 or more and 100 or less, and an average value of b is 1 or more and 10 or less.
7. The process cartridge according to claim 6 , wherein the resin (α) is a polyester resin B having a repeating structural unit represented by the following formula (B):
wherein R 31 to R 34 each independently represent a hydrogen atom or a methyl group; X 2 represents a single bond, a cyclohexylidene group, or a divalent group having a structure represented by the following formula (C); Y 1 represents a m-phenylene group, a p-phenylene group, or a divalent group in which two p-phenylene groups are bonded via an oxygen atom.
wherein R 41 and R 42 each independently represent a hydrogen atom, a methyl group, or a phenyl group.
8. The process cartridge according to claim 7 , wherein the polyester resin B is a polymer having only one kind of repeating structural unit selected from repeating structural units represented by the following formulas (B-1) to (B-9) or a polymer having a combination of two or more kinds of repeating structural units represented by the following formulas (B-1) to (B-9):
9. The process cartridge according to claim 6 , wherein the bowl-shaped resin particle is a particle having a resin shell, an opening derived from the partial lack of the shell, and a spherical concavity.
10. The process cartridge according to claim 9 , wherein an electroconductive resin layer is formed along an inner wall of the spherical concavity of the bowl-shaped resin particle.
11. An electrophotographic apparatus comprising a process cartridge, wherein,
a process cartridge comprises:
a charging member; and
an electrophotographic photosensitive member which is electrically charged upon being brought into contact with the charging member,
wherein:
the charging member comprises
an electro-conductive substrate and
an electroconductive resin layer formed on the electro-conductive substrate;
the electroconductive resin layer comprises
a binder,
a conductive fine particle, and
a bowl-shaped resin particle which has an opening; and
the surface of the charging member has
a concavity derived from the opening of the bowl-shaped resin particle, and
a protrusion derived from an edge of the opening of the bowl-shaped resin particle;
and wherein:
the electrophotographic photosensitive member comprises
a support and
a photosensitive layer formed on the support, and
a surface layer of the electrophotographic photosensitive member comprises the following resin (α), resin (β), and compound (γ):
resin (α): polycarbonate resins having no siloxane structure at a terminal;
resin (β): at least one resin selected from the group consisting of polycarbonate resins having a siloxane structure at a terminal, polyester resins having a siloxane structure at a terminal, and acrylic resins having a siloxane structure at a terminal; and
compound (γ): at least one compound selected from the group consisting of methyl benzoate, ethyl benzoate, benzyl acetate, ethyl 3-ethoxypropionate, and diethylene glycol ethyl methyl ether,
wherein the resin (α) is a polycarbonate resin A having a repeating structural unit represented by the following formula (A):
wherein R 21 to R 24 each independently represent a hydrogen atom or a methyl group; X 1 represents a single bond, a cyclohexylidene group, or a divalent group having a structure represented by the following formula (C):
wherein R 41 and R 42 each independently represent a hydrogen atom, a methyl group, or a phenyl group.