Carrier for two-component developer, two-component developer, image forming method, and image forming apparatus
A carrier for a two-component developer includes magnetic particles, and a resin coating layer that covers the magnetic particles. The resin coating layer contains metal boride particles having a volume average primary particle diameter of from about 300 nm to about 2,500 nm.
1. A carrier for a two-component developer comprising:
magnetic particles, and a resin coating layer that covers the magnetic particles,
wherein the resin coating layer contains metal boride particles having a volume average primary particle diameter of from about 300 nm to about 2,500 nm, the metal boride being a compound selected from the group consisting of dimetal monoboride, pentametal triboride, trimetal tetraboride, dimetal triboride, dimetal pentaboride, metal tetraboride, metal hexaboride, and metal dodecaboride.
2. The carrier for a two-component developer according to claim 1 , wherein the resin coating layer contains a resin selected from a cyclohexyl methacrylate homopolymer or a cyclohexyl methacrylate copolymer.
3. The carrier for a two-component developer according to claim 1 , wherein a volume electric resistance of the magnetic particles is within a range of from about 10 5 Ω·cm to about 10 9.5 Ω·cm.
4. The carrier for a two-component developer according to claim 1 , wherein a volume electric resistance of the magnetic particles is within a range of from about 10 7 Ω·cm to about 10 9 Ω·cm.
5. The carrier for a two-component developer according to claim 1 , wherein the volume average primary particle diameter of the metal boride particles is within a range of from about 500 nm to about 2,200 nm.
6. The carrier for a two-component developer according to claim 1 , wherein the resin coating layer contains a conductive material.
7. The carrier for a two-component developer according to claim 6 , wherein the conductive material is a white conductive material.
8. The carrier for a two-component developer according to claim 1 , wherein an amount of the metal boride particles is within a range of from about 0.1% by weight to about 30% by weight to the total weight of the resin coating layer.
9. The carrier for a two-component developer according to claim 1 , wherein a volume electric resistance of the carrier is within a range of from about 1×10 7 Ω·cm to about 1×10 15 Ω·cm.
10. A two-component developer containing:
the carrier for a two-component developer according to claim 1 and a toner.
11. The two-component developer according to claim 10 ,
wherein a volume average particle diameter distribution index GSDv of the toner expressed by the following Equation (1) is 1.21 or less:
GSDv ={( D 84v )/( D 16v )} 0.5 (1)
wherein, D 84v is a volume particle diameter at a cumulant of 84% and D 16v is a volume particle diameter at a cumulant of 16% when a volume cumulative distribution curve is drawn from the smaller particle diameter side with respect to the divided particle diameter ranges.
12. The two-component developer according to claim 10 , wherein the resin coating layer of the carrier for a two-component developer contains a resin selected from a cyclohexyl methacrylate homopolymer or a cyclohexyl methacrylate copolymer.
13. The two-component developer according to claim 10 , wherein a shape factor SF1 of the toner is within a range of from about 110 to about 140.
14. An image forming method comprising:
charging an image holding member;
forming an electrostatic latent image on the surface of the image holding member;
developing the electrostatic latent image formed on the surface of the image holding member with an electrostatic charge image developer to form a toner image; and
transferring the toner image formed on the surface of the image holding member to the surface of a transfer medium,
wherein the electrostatic charge image developer is the two-component developer according to claim 10 .
15. The image forming method according to claim 14 ,
wherein a volume average particle diameter distribution index GSDv of the toner for electrostatic charge image development expressed by the following Equation (1) is 1.21 or less:
GSDv ={( D 84v )/( D 16v )} 0.5 (1)
wherein, D 84v is a volume particle diameter at a cumulant of 84% and D 16v is a volume particle diameter at a cumulant of 16% when a volume cumulative distribution curve is drawn from the smaller particle diameter side with respect to the divided particle diameter ranges.
16. An image forming apparatus comprising:
an image holding member;
a charging unit that charges the image holding member;
an exposure unit that exposes the charged image holding member to form an electrostatic latent image on the image holding member;
a developing unit that develops the electrostatic latent image with a developer to form a toner image; and
a transfer unit that transfers the toner image from the image holding member to a transfer medium,
wherein the electrostatic charge image developer is the two-component developer according to claim 10 .
17. The image forming apparatus according to claim 16 ,
wherein a volume average particle diameter distribution index GSDv of the toner for electrostatic charge image development expressed by the following Equation (1) is 1.21 or less:
GSDv ={( D 84v )/( D 16v )} 0.5 (1)
wherein, D 84v is a volume particle diameter at a cumulant of 84% and D 16v is a volume particle diameter at a cumulant of 16% when a volume cumulative distribution curve is drawn from the smaller particle diameter side with respect to the divided particle diameter ranges.