Toner and developer using the toner

1. A toner comprising:

a binder resin, comprising at least one polyester resin in an amount of from 50 to 100% by weight; and

a colorant, having the following formula (I):

wherein the toner has a shape factor SF-1 of from 120 to 150 and a shape factor SF-2 of from 125 to 180;

wherein the toner is manufactured by a method using an aqueous medium;

wherein the method using an aqueous medium is a dissolution suspension method;

wherein the dissolution suspension method comprises:

dissolving or dispersing at least a polymer capable of reacting with an active hydrogen, which is a precursor of the binder resin, and the colorant, in an organic solvent to prepare a toner constituent mixture liquid,

dispersing the toner constituent mixture liquid in an aqueous medium while subjecting the polymer to a reaction with a compound having an active hydrogen, to prepare a dispersion including toner particles, and

removing the organic solvent from the dispersion, followed by washing and drying; and

wherein the binder resin comprises a modified polyester resin and an unmodified polyester resin, and the polymer capable of reacting with an active hydrogen is a precursor of the modified polyester resin, and

wherein a weight ratio of the modified polyester resin to the unmodified polyester resin is from 5/95 to 75/25.

2. The toner according to claim 1 , further comprising a rosin resin present on at least a surface of the colorant.

3. The toner according to claim 1 , wherein the dissolution suspension method further comprises

dispersing the toner constituent mixture liquid in an aqueous medium containing a particulate resin while subjecting the polymer to a reaction with a compound having an active hydrogen, to prepare a dispersion including toner particles, on a surface of which the particulate resin is present.

4. The toner according to claim 3 , wherein the particulate resin has a volume average particle diameter of from 5 to 500 nm.

5. The toner according to claim 1 , wherein a weight ratio of the colorant to the organic solvent is from 5/95 to 50/50.

6. The toner according to claim 1 , further comprising a release agent.

7. The toner according to claim 6 , wherein the release agent has a melting point of from 40 to 160° C.

8. The toner according to claim 1 , wherein the toner has a volume average particle diameter (Dv) of from 3.0 to 8.0 μm, and a ratio (Dv/Dn) between the volume average particle diameter (Dv) and a number average particle diameter (Dn) of from 1.00 to 1.30.

9. A developer, comprising the toner according to claim 1 , and a carrier.

10. A toner comprising:

a binder resin, comprising at least one polyester resin in an amount of from 50 to 100% by weight; and

a colorant, having the following formula (I):

wherein the toner has a shape factor SF-1 of from 120 to 150 and a shape factor SF-2 of from 125 to 180;

wherein the toner is manufactured by a method using an aqueous medium;

wherein the method using an aqueous medium is a dissolution suspension method;

wherein the dissolution suspension method comprises:

dissolving or dispersing at least a polymer capable of reacting with an active hydrogen, which is a precursor of the binder resin, and the colorant, in an organic solvent to prepare a toner constituent mixture liquid,

dispersing the toner constituent mixture liquid in an aqueous medium while subjecting the polymer to a reaction with a compound having an active hydrogen, to prepare a dispersion including toner particles, and

removing the organic solvent from the dispersion, followed by washing and drying;

wherein the binder resin comprises a modified polyester resin and an unmodified polyester resin, and the polymer capable of reacting with an active hydrogen is a precursor of the modified polyester resin, and

wherein a weight ratio of the modified polyester resin to the unmodified polyester resin is from 5/95 to 75/25; and

wherein the modified polyester resin and the unmodified polyester resin, independently, have an acid value of from 0 to 30 mgKOH/g.

11. The toner according to claim 10 , further comprising a rosin resin present on at least a surface of the colorant.

12. The toner according to claim 10 , wherein the dissolution suspension method further comprises

dispersing the toner constituent mixture liquid in an aqueous medium containing a particulate resin while subjecting the polymer to a reaction with a compound having an active hydrogen, to prepare a dispersion including toner particles, on a surface of which the particulate resin is present.

13. The toner according to claim 12 , wherein the particulate resin has a volume average particle diameter of from 5 to 500 nm.

14. The toner according to claim 10 , wherein a weight ratio of the colorant to the organic solvent is from 5/95 to 50/50.

15. The toner according to claim 10 , further comprising a release agent.

16. The toner according to claim 15 , wherein the release agent has a melting point of from 40 to 160° C.

17. The toner according to claim 10 , wherein the toner has a volume average particle diameter (Dv) of from 3.0 to 8.0 μm, and a ratio (Dv/Dn) between the volume average particle diameter (Dv) and a number average particle diameter (Dn) of from 1.00 to 1.30.

18. A developer, comprising the toner according to claim 10 and a carrier.