Carrier for electrostatic image development, electrostatic image developer, and process cartridge
A carrier for electrostatic image development includes: a core material; and a coating resin layer that contains inorganic particles and covers the core material. The content of the inorganic particles is 10% by mass or more and 60% by mass or less based on the total mass of the coating resin layer. The volume average diameter D (μm) of the inorganic particles and the thickness T (μm) of the coating resin layer satisfy the following relational expression (1): 0.007≤D/T≤0.24.
1. A carrier for electrostatic image development, comprising:
a core material; and
a coating resin layer that contains inorganic particles and covers the core material,
wherein a content of the inorganic particles is 10% by mass or more and 60% by mass or less based on a total mass of the coating resin layer, and
wherein a volume average diameter D (μm) of the inorganic particles and a thickness T (μm) of the coating resin layer satisfy the following relational expression (1):
0.007 ≤D/T≤ 0.24.
2. The carrier for electrostatic image development according to claim 1 ,
wherein the volume average diameter D of the inorganic particles is more than 1 nm and 80 nm or less.
3. The carrier for electrostatic image development according to claim 1 ,
wherein the surface roughness Ra of the carrier is more than 0.1 μm and less than 0.9 μm.
4. The carrier for electrostatic image development according to claim 1 ,
wherein the inorganic particles include silica particles.
5. The carrier for electrostatic image development according to claim 4 ,
wherein the silica particles include silica particles subjected to hydrophobic treatment.
6. The carrier for electrostatic image development according to claim 5 ,
wherein a treatment agent for the hydrophobic treatment is at least one of hexamethyldisilazane (HMDS) and dimethylpolysiloxane (PDMS).
7. The carrier for electrostatic image development according to claim 1 ,
wherein the coating resin layer contains an alicyclic (meth)acrylic resin.
8. The carrier for electrostatic image development according to claim 7 ,
wherein the alicyclic (meth)acrylic resin contains cyclohexyl (meth)acrylate as a monomer component.
9. The carrier for electrostatic image development according to claim 1 ,
wherein the volume average diameter D (μm) of the inorganic particles and a surface roughness Ra (μm) of the carrier satisfy the following relational expression (2):
0.003 <D/Ra< 0.50.
10. The carrier for electrostatic image development according to claim 1 ,
wherein the surface roughness Ra of the core material is 0.5 μm or more and 1.5 μm or less.
11. An electrostatic image developer comprising:
a toner for electrostatic image development: and
the carrier for electrostatic image development according to claim 1 .
12. A process cartridge detachably attached to an image forming apparatus, the process cartridge comprising:
an image holding member; and
a developing device that contains the electrostatic image developer according to claim 11 and develops, as a toner image, an electrostatic image formed on a surface of the image holding member using the electrostatic image developer.