Electrostatic charge image developing toner, electrostatic charge image developer, and toner cartridge

1. An electrostatic charge image developing toner comprising:

toner particles containing:

a binder resin containing a polyester resin forming a sea part of a sea-island structure and a surface layer of the toner particles, and a vinyl resin forming an island part of the sea-island structure,

a first release agent existing in the sea part in a domain state, and

a second release agent existing in the island part in a domain state,

wherein:

when a cross-sectional area of the second release agent is set to A1 and a cross-sectional area of the first release agent is set to B1 in a cross section of the toner particles, a relationship of 0.2≦A1/B1≦0.8 is satisfied, and

the first release agent and the second release agent are each paraffin wax.

2. The electrostatic charge image developing toner according to claim 1 , wherein 60% or more of the polyester resin exists in the surface layer of the toner particles.

3. The electrostatic charge image developing toner according to claim 1 , wherein a glass transition temperature (Tg) of the polyester resin is from 50° C. to 80° C.

4. The electrostatic charge image developing toner according to claim 1 , wherein a weight average molecular weight (Mw) of the polyester resin is from 5,000 to 1,000,000.

5. The electrostatic charge image developing toner according to claim 1 , wherein a number average molecular weight (Mn) of the polyester resin is from 2,000 to 100,000.

6. The electrostatic charge image developing toner according to claim 1 , wherein a molecular weight distribution Mw/Mn of the polyester resin is from 1.5 to 100.

7. The electrostatic charge image developing toner according to claim 1 , further comprising fumaric acid as an acid component constituting the polyester resin.

8. The electrostatic charge image developing toner according to claim 1 , further comprising acrylic acid as a monomer constituting the vinyl resin.

9. The electrostatic charge image developing toner according to claim 1 , wherein a content of the binder resin is from 40% by weight to 95% by based on the total amount of the toner particles.

10. The electrostatic charge image developing toner according to claim 1 , wherein a mass ratio of the polyester resin to the vinyl resin (polyester resin: vinyl resin) is from 98:2 to 60:40.

11. The electrostatic charge image developing toner according to claim 1 , wherein the first release agent the second release agent each have a melting temperature of from 50° C. to 110° C.

12. The electrostatic charge image developing toner according to claim 11 , wherein a total content of the first release agent and release agent is from 1% by weight to 20% by weight based on the total amount of the toner particles.

13. The electrostatic charge image developing toner according to claim 1 , wherein a volume particle diameter (D50v) of the toner particles is from 2 μm to 10 μm.

14. The electrostatic charge image developing toner according to claim 1 , wherein a shape factor SF1 of the toner particles is from 110 to 150.

15. An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1 .

16. The electrostatic charge image developer according to claim 15 , wherein the electrostatic charge image developer contains a resin-coated carrier.

17. The electrostatic charge image developer according to claim 16 , wherein a resin of the resin-coated carrier is styrene acrylic resin.

18. A toner cartridge that accommodates the electrostatic charge image developing toner according to claim 1 , and is detachable from an image forming apparatus.

19. The electrostatic charge image developing toner according to claim 1 , wherein the vinyl resin is homopolymer or a copolymer of one or more monomers selected from the group consisting of (meth)acrylic ester compounds, ethylenic unsaturated nitrile compounds, and vinyl ether compounds.