Electrophotographic photoreceptor, process cartridge, and image forming apparatus
View Patent ↗An electrophotographic photoreceptor includes a conductive substrate, and at least a photosensitive layer on the conductive substrate, a layer located at a surface of the photosensitive layer side of the electrophotographic photoreceptor contains fluorine containing resin particles and a fluoro graft polymer having a fluoroalkyl group having 1 to 7 carbon atoms, and an area for a polystyrene equivalent molecular weight of 700,000 or more is from about 5% to about 20% of the total area in a gel permeation chromatography (GPC) chart for the fluoro graft polymer.
1. An electrophotographic photoreceptor comprising:
a conductive substrate,
at least a photosensitive layer on the conductive substrate, and
a surface layer located at a surface of the photosensitive layer side of the electrophotographic photoreceptor,
wherein
the surface layer contains fluorine containing resin particles and a fluoro graft polymer having a fluoroalkyl group having 1 to 7 carbon atoms,
the fluoro graft polymer having a fluoroalkyl group having 1 to 7 carbon atoms has a molecular distribution such that an area in a gel permeation chromatography (GPC) chart of the fluoro graft polymer for a polystyrene equivalent molecular weight of 700,000 or more is about 5% to about 20% of a total area in the GPC chart of the fluoro graft polymer,
a maximum peak in the GPC chart of the fluoro graft polymer is present in a range where a polystyrene equivalent molecular weight is from about 50,000 to about 150,000, and
the fluorine content in the fluoro graft polymer is from about 10% by weight to about 30% by weight with respect to a weight of the fluoro graft polymer.
2. The electrophotographic photoreceptor of claim 1 , wherein the content of the fluoro graft polymer is from about 0.5% by weight to about 5.0% by weight based on the content of the fluorine containing resin particles.
3. The electrophotographic photoreceptor of claim 1 , wherein the fluoro graft polymer is a fluoroalkyl group-containing copolymer containing repeating units represented by the following structural formulae A and B:
wherein
l, m and n each independently represent a positive number of 1 or more;
p, q, r and s each independently represent 0 or a positive number of 1 or more;
t represents 0 or a positive number of 6 or less;
R 1 , R 2 , R 3 and R 4 each independently represent a hydrogen atom or an alkyl group;
X represents an alkylene group, a halogen-substituted alkylene group, —S—, —O—, —NH— or a single bond;
Y represents an alkylene group, a halogen-substituted alkylene group, —(C z H 2z-1 (OH))— or a single bond; and
z represents a positive number of 1 or more.
4. A process cartridge which is attachable to and detachable from an image forming apparatus, and comprises an electrophotographic photoreceptor, the electrophotographic photoreceptor comprising:
a conductive substrate,
at least a photosensitive layer on the conductive substrate, and
a surface layer located at a surface of the photosensitive layer side of the electrophotographic photoreceptor,
wherein
the surface layer contains fluorine containing resin particles and a fluoro graft polymer having a fluoroalkyl group having 1 to 7 carbon atoms,
the fluoro graft polymer having a fluoroalkyl group having 1 to 7 carbon atoms has a molecular distribution such that an area in a gel permeation chromatography (GPC) chart of the fluoro graft polymer for a polystyrene equivalent molecular weight of 700,000 or more is about 5% to about 20% of a total area in the GPC chart of the fluoro graft polymer,
a maximum peak in the GPC chart of the fluoro graft polymer is present in a range where a polystyrene equivalent molecular weight is from about 50,000 to about 150,000, and
the fluorine content in the fluoro graft polymer is from about 10% by weight to about 30% by weight with respect to a weight of the fluoro graft polymer.
5. The process cartridge of claim 4 , wherein the content of the fluoro graft polymer is from about 0.5% by weight to about 5.0% by weight based on the content of the fluorine containing resin particles.
6. The process cartridge of claim 4 , wherein the fluoro graft polymer is a fluoroalkyl group-containing copolymer containing repeating units represented by the following structural formulae A and B:
wherein
l, m and n each independently represent a positive number of 1 or more;
p, q, r and s each independently represent 0 or a positive number of 1 or more;
t represents 0 or a positive number of 6 or less;
R 1 , R 2 , R 3 and R 4 each independently represent a hydrogen atom or an alkyl group;
X represents an alkylene group, a halogen-substituted alkylene group, —S—, —O—, —NH— or a single bond;
Y represents an alkylene group, a halogen-substituted alkylene group, —(C z H 2z-1 (OH))— or a single bond; and
z represents a positive number of 1 or more.
7. An image forming apparatus comprising:
an electrophotographic photoreceptor comprising:
a conductive substrate,
at least a photosensitive layer on the conductive substrate, and
a surface layer located at a surface of the photosensitive layer side of the electrophotographic photoreceptor,
wherein
the surface layer contains fluorine containing resin particles and a fluoro graft polymer having a fluoroalkyl group having 1 to 7 carbon atoms,
the fluoro graft polymer having a fluoroalkyl group having 1 to 7 carbon atoms has a molecular distribution such that an area in a gel permeation chromatography (GPC) chart of the fluoro graft polymer for a polystyrene equivalent molecular weight of 700,000 or more is about 5% to about 20% of a total area in the GPC chart of the fluoro graft polymer,
a maximum peak in the GPC chart of the fluoro graft polymer is present in a range where a polystyrene equivalent molecular weight is from about 50,000 to about 150,000, and
the fluorine content in the fluoro graft polymer is from about 10% by weight to about 30% by weight with respect to a weight of the fluoro graft polymer;
a developing unit that develops an electrostatic latent image formed on the electrophotographic photoreceptor by an electrostatic latent image developer to form a toner image;
a transfer unit that transfers the toner image formed on the electrophotographic photoreceptor to a transfer receiving body; and
a fixing unit that fixes the toner image transferred to the transfer receiving body.
8. The image forming apparatus of claim 7 , wherein the content of the fluoro graft polymer is from about 0.5% by weight to about 5.0% by weight based on the content of the fluorine containing resin particles.
9. The image forming apparatus of claim 7 , wherein the fluoro graft polymer is a fluoroalkyl group-containing copolymer containing repeating units represented by the following structural formulae A and B:
wherein
l, m and n each independently represent a positive number of 1 or more;
p, q, r and s each independently represent 0 or a positive number of 1 or more;
t represents 0 or a positive number of 6 or less;
R 1 , R 2 , R 3 and R 4 each independently represent a hydrogen atom or an alkyl group;
X represents an alkylene group, a halogen-substituted alkylene group, —S—, —O—, —NH— or a single bond;
Y represents an alkylene group, a halogen-substituted alkylene group, —(C z H 2z-1 (OH))— or a single bond; and
z represents a positive number of 1 or more.