Process cartridge
A process cartridge that is detachable from a main body of an electrophotographic apparatus, in which a surface protective layer of an electrophotographic photosensitive member contains an electroconductive particle; the content of the electroconductive particle is 20.0 to 70.0% by volume of the surface protective layer; the surface protective layer has a volume resistivity of 1.0×10 9 to 1.0×10 14 Ω·cm; a toner particle has at least one multivalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron; and a total content of the multivalent metal elements in the toner particle, as measured by coupled induction plasma atomic emission spectrometry (ICP-AES), is 0.10 to 1.25 μmol/g.
1. A process cartridge that is detachable from a main body of an electrophotographic apparatus, the process cartridge comprising:
an electrophotographic photosensitive member; and
a development unit that comprises a toner storage portion accommodating toner and is configured to supply the toner to a surface of the electrophotographic photosensitive member;
the electrophotographic photosensitive member comprising an electroconductive support, with a photosensitive layer and a surface protective layer formed thereon in this order;
the toner comprising an external additive, and a toner particle comprising a binder resin and at least one multivalent metal element selected from the group consisting of aluminum, magnesium, calcium and iron; and
the surface protective layer comprising an electroconductive particle, the electroconductive particle comprising a niobium atoms-containing titanium oxide particle, wherein
the niobium atoms-containing titanium oxide particle comprises 2.6 to 10.0% by mass of niobium atoms,
a content of the electroconductive particle is 20.0 to 70.0% by volume of a total volume of the surface protective layer,
the surface protective layer has a volume resistivity of 1.0×10 9 to 1.0×10 14 Ω·cm, and
a total content of the multivalent metal elements in the toner particle is 0.10 to 1.25 μmol/g as measured by coupled induction plasma atomic emission spectrometry (ICP-AES).
2. The process cartridge according to claim 1 , wherein, with respect to the multivalent metal elements contained in the toner particle,
a content of aluminum is 0.50 μmol/g or less;
a content of magnesium is 0.80 μmol/g or less;
a content of calcium is 0.90 μmol/g or less and
a content of iron is 1.25 μmol/g or less.
3. The process cartridge according to claim 1 , wherein the toner particle comprises 0.10 to 0.32 μmol/g of aluminum as the multivalent metal element.
4. The process cartridge according to claim 1 , wherein the toner particle comprises a wax that is an ester compound.
5. The process cartridge according to claim 1 , wherein a carboxy group is present in a molecular chain constituting the binder resin, and the carboxy group and the multivalent metal element form a coordination bond and are present in the toner particle.
6. The process cartridge according to claim 1 , wherein the toner particle is an emulsion aggregation toner particle.
7. The process cartridge according to claim 1 , wherein in the electrophotographic photosensitive member, a content of the electroconductive particle is 40.0 to 70.0% by volume of the surface protective layer, and
the surface protective layer has a volume resistivity of 1.0×10 10 1.0×10 14 Ω·cm.