Toner and method for producing the same and developer

1. A toner comprising:

base particles produced by dissolving and/or dispersing a toner material in an organic solvent so as to prepare a toner material solution, and emulsifying and/or dispersing the toner material solution in an aqueous medium,

wherein

the toner material comprises a binder resin and a releasing agent,

the binder resin comprises a polyester resin, and

the releasing agent consists of a hydrocarbon wax which is modified with a carboxylic acid or carboxylic anhydride, and

wherein the releasing agent has a dispersion diameter of 0.05 μm to 0.5 μm, an acid value of 1 mg KOH/g to 100 mg KOH/g and a melting point of 50° C. to 90° C.

2. The toner according to claim 1 , wherein the releasing agent has an acid value of 3 mg KOH/g to 20 mg KOH/g.

3. The toner according to claim 1 , wherein the polyester resin has an acid value of 5 mg KOH/g to 40 mg KOH/g.

4. The toner according to claim 1 , wherein the releasing agent consists of a paraffin wax modified with a carboxylic acid or carboxylic anhydride.

5. The toner according to claim 1 , wherein the carboxylic anhydride is maleic anhydride.

6. The toner according to claim 1 , wherein the releasing agent has a melt viscosity at 120° C. of 1.0 mPa·s to 20 mPa·s.

7. The toner according to claim 1 , wherein the base particles have a volume average particle diameter of 3.0 μm to less than 6.0 μm.

8. The toner according to claim 1 , wherein the base particles have a ratio of a volume average particle diameter to a number average particle diameter of 1.00 to 1.15.

9. The toner according to claim 1 , wherein the mass ratio of the releasing agent relative to the base particles is 1% to 20%.

10. The toner according to claim 1 , wherein the binder resin further comprises a polyester resin having a functional group reactive with an active hydrogen group, and wherein the polyester resin having a functional group reactive with an active hydrogen group and an active hydrogen group-containing compound are reacted in the aqueous medium.

11. A method for producing a toner according to claim 1 , comprising:

dissolving and/or dispersing the toner material in an organic solvent so as to prepare a toner material solution; and

emulsifying and/or dispersing the toner material solution in an aqueous medium so as to prepare the base particles.

12. The method for producing a toner according to claim 11 , wherein the organic solvent has a solubility parameter of 8 cal 1/2 ·m −3/2 to 9.8 cal 1/2 ·m 3/2 .

13. The method for producing a toner according to claim 11 , wherein the step of dissolving and/or dispersing the toner material in the organic solvent so as to prepare the toner material solution comprises:

heating and dissolving the binder resin and the releasing agent in the organic solvent so as to prepare a solution in which the binder resin and the releasing agent are dissolved; and

cooling the solution.

14. A developer comprising:

a toner,

wherein the toner comprises base particles produced by dissolving and/or dispersing a toner material in an organic solvent so as to prepare a toner material solution, and emulsifying and/or dispersing the toner material solution in an aqueous medium, and wherein

the toner material comprises a binder resin and a releasing agent,

the binder resin comprises a polyester resin, and

the releasing agent consists of a hydrocarbon wax which is modified with a carboxylic acid or carboxylic anhydride, and

wherein the releasing agent has a dispersion diameter of 0.05 μm to 0.5 μm, an acid value of 1 mg KOH/g to 100 mg KOH/g and a melting point of 50° C. to 90° C.

15. The developer according to claim 14 , further comprising a carrier.