Carrier, developer, image forming method, and process cartridge
A carrier is provided that includes a core particle and a coating layer coating the core particle. The coating layer includes a resin and chargeable inorganic fine particles, and has voids. The resin has an average film thickness of 0.10 μm or larger and smaller than 0.45 μm. The coating layer has a porosity of 0.1% or higher and lower than 2.8%, when the porosity expressed by the following equation: Porosity [%]= S 1/ S 2×100 where, on a cross section of the coating layer, S1 represents a cross sectional area of the voids and S2 represents a cross sectional area of the resin.
1. A carrier comprising:
a core particle; and,
a coating layer coating the core particle,
the coating layer comprising a resin, chargeable inorganic fine particles and a defoaming agent, and having voids,
the resin having an average film thickness of 0.10 μm or larger and smaller than 0.45 μm,
the coating layer having a porosity of 0.1% or higher and lower than 2.8%, the porosity expressed by the following equation:
Porosity [%]= S 1/ S 2×100
where, on a cross section of the coating layer, S1 represents a cross sectional area of the voids and S2 represents a cross sectional area of the resin.
2. The carrier according to claim 1 , wherein the chargeable inorganic fine particles comprise at least one selected from the group consisting of barium sulfate, magnesium oxide, magnesium hydroxide, and hydrotalcite.
3. The carrier according to claim 1 , wherein
the chargeable inorganic fine particles comprise barium sulfate, and
an amount of barium exposed to a surface of the coating layer is 0.1 atomic % or more.
4. A developer comprising:
a toner; and
the carrier according to claim 1 .
5. An image forming method comprising:
forming an electrostatic latent image on an electrostatic latent image bearer;
developing the electrostatic latent image formed on the electrostatic latent image bearer using the developer according to claim 4 to form a toner image;
transferring the toner image formed on the electrostatic latent image bearer to a recording medium; and
fixing the toner image to the recording medium.
6. A process cartridge comprising:
an electrostatic latent image bearer;
a charging device configured to charge a surface of the electrostatic latent image bearer;
a developing device accommodating the developer according to claim 4 , the developing device configured to develop an electrostatic latent image formed on the electrostatic latent image bearer using the developer; and
a cleaning device configured to clean the electrostatic latent image bearer.
7. The carrier according to claim 1 , wherein the coating layer contains conductive particles, the conductive particles including base particles and a conductive component provided on the surfaces on the base particles.
8. The carrier according to claim 7 , wherein the base particles comprise aluminum oxide or titanium oxide, and the conductive component comprises a compound in which tin oxide is doped with any of tungsten, indium, and phosphorus, or an oxide thereof.
9. The carrier according to claim 1 , wherein the coating layer contains a dispersing agent.
10. The carrier according to claim 9 , wherein the dispersing agent comprises a phosphate-based surfactant.