Toner for developing electrostatic charge image, electrostatic charge image developer, toner cartridge, developer cartridge, process cartridge, image forming apparatus, and image forming method

1. A toner for developing an electrostatic charge image comprising:

toner particles containing a colorant, a binder resin, and a release agent; and

an external additive that contains inorganic particles having hydrophobization-treated surfaces and a fluorine atom-containing oil on the hydrophobization-treated surfaces,

wherein

an amount of the fluorine atom-containing oil is from 7% to 30% by weight with respect to a total weight of the external additive,

a weight ratio of the hydrophobization treatment agent to the fluorine atom-containing oil is in a range of 1:30 to 50:1,

the inorganic particles are treated with the fluorine atom-containing oil prior to incorporation of the external additive into the toner, and

the fluorine atom-containing oil is selected from perfluoropolyether, polyhexafluoropropylene epoxide, polychlorotrifluoroethylene, polytetrafluoroethylene, and perfluorocarbon.

2. The toner for developing an electrostatic charge image according to claim 1 , wherein an amount of the hydrophobization treatment agent in the hydrophobization treatment is in a range of 1 part by weight to 50 parts by weight with respect to 100 parts by weight of the inorganic particles.

3. The toner for developing an electrostatic charge image according to claim 1 , wherein a volume average primary particle diameter of the inorganic particles is in a range of 3 nm to 500 nm.

4. The toner for developing an electrostatic charge image according to claim 1 , wherein a volume average primary particle diameter of the inorganic particles is in a range of 7 nm to 300 nm.

5. The toner for developing an electrostatic charge image according to claim 1 , wherein a content of the inorganic particles is in a range of 0.3% by weight to 10% by weight with respect to the total weight of the toner.

6. The toner for developing an electrostatic charge image according to claim 1 , wherein the toner particles contain a crystalline polyester resin in a range of 2% by weight to 30% by weight with respect to a weight of the toner particles.

7. An electrostatic charge image developer comprising:

the toner according to claim 1 ; and

a carrier.

8. A toner cartridge containing the toner according to claim 1 .

9. A developer cartridge containing the developer according to claim 7 .

10. A process cartridge for an image forming apparatus, having a developer holding member that holds and transports an electrostatic charge image developer,

wherein the developer is the electrostatic charge image developer according to claim 7 .

11. An image forming apparatus comprising:

an image holding member;

a charging unit that charges a surface of the image holding member;

a latent image forming unit that forms an electrostatic latent image on the surface of the image holding member;

a developing unit that contains the electrostatic charge image developer according to claim 7 and develops the electrostatic latent image formed on the surface of the image holding member using the developer to form a toner image; and

a transfer unit that transfers the developed toner image onto a transfer medium.

12. An image forming method comprising:

charging a surface of 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 using a developer to form a toner image; and

transferring the developed toner image onto a transfer medium,

wherein the developer is the electrostatic charge image developer according to claim 7 .