Carrier
A carrier which is capable of avoiding excess blocking of the carrier particles at the time of forming a covering layer and is excellent in durability, a developer containing the carrier, and a developer container containing the developer, as well as an image forming method and a process cartridge which use the developer are provided. A carrier including at least a core material particle and a covering layer, a surface of the core material particle being covered with the covering layer, wherein the covering layer contains a condensate which is obtained by condensation of a silicone resin having at least one of a silanol group and a functional group which can be converted to the silanol group by hydrolysis, using a titanium diisopropoxy bis(ethylaceto-acetate) catalyst.
1. A carrier comprising:
a core material particle, and
a covering layer,
a surface of the core material particle being covered with the covering layer,
wherein the covering layer contains a condensate which is obtained by condensation of a silicone resin having at least one of a silanol group and a functional group which can be converted to the silanol group by hydrolysis, the condensation caused by titanium diisopropoxy bis(ethylaceto-acetate) which is incorporated in the silicone resin.
2. The carrier according to claim 1 , wherein the silicone resin is cured by a crosslinking agent represented by the following formula:
wherein R 1 , R 2 , and R 3 each represent one of CH 3 and C 2 H 5 .
3. The carrier according to claim 1 , wherein the amount of titanium diisopropoxy bis(ethylaceto-acetate) is 0.5 parts by mass to 20 parts by mass per 100 parts by mass of the silicone resin and a crosslinking agent.
4. The carrier according to claim 1 , wherein the covering layer further contains a conductive particle.
5. The carrier according to claim 1 , wherein the covering layer further contains a silane coupling agent.
6. The carrier according to claim 1 , wherein the covering layer further contains an acrylic resin.
7. The carrier according to claim 1 , wherein the carrier has a specific volume resistance of 1×10 9 Ω·cm to 1×10 17 Ω·cm.
8. The carrier according to claim 1 , wherein the covering layer has an average thickness of 0.05 μm to 4 μm.
9. The carrier according to claim 1 , wherein the core material particle has a weight average particle diameter of 20 μm to 65 μm.
10. The carrier according to claim 1 , wherein the magnetization of the carrier in a magnetic field of 1 kOe is 40 Am 2 /kg to 90 Am 2 /kg.
11. A developer comprising:
the carrier according to claim 1 , and
a toner.
12. The developer according to claim 11 , wherein the toner is a color toner used in polychromatic image formation.
13. An image forming method comprising:
forming a latent electrostatic image on a latent electrostatic image bearing member,
developing the latent electrostatic image formed on the latent electrostatic image bearing member with the developer according to claim 11 to form a toner image,
transferring the toner image formed on the latent electrostatic image bearing member to a recording medium, and
fixing the toner image transferred onto the recording medium.