Orange toner and toner cartridge for storing the same, orange developer and process cartridge for storing the same, color toner set, and image forming apparatus

1. An orange toner comprising a binder resin and a coloring agent, wherein

the binder resin contains a polyester resin having a dodecenyl succinic acid structure;

the coloring agent contains C.I. Pigment Orange 38 in a content of from about 5% by mass to about 18% by mass relative to the whole mass of the toner; and

the toner is satisfying the following formulae (a) to (c):

0.05 mg/L≦(Na ion amount)≦0.3 mg/L  (a)

0.3 mg/L≦(NH 4 ion amount)≦1.0 mg/L  (b)

1.0≦(NH 4 ion amount)/(Na ion amount)≦5.0  (c)

wherein each of Na ion amount and NH 4 ion amount is a value detected by weighing 0.5 g of the toner, adding the toner to 100 g of ion-exchanged water at 30±1° C. dispersing it for 30 minutes by an ultrasonic disperser, filtering the dispersion and then analyzing the filtrate by ion chromatography.

2. The orange toner according to claim 1 , wherein the toner further contains a hydrocarbon based wax having a melting temperature of about 60° C. or higher and lower than 100° C.; and the binder resin contains a crystalline polyester resin in a content of from about 1% by mass to about 10% by mass in the binder resin component, and the melting temperature of the hydrocarbon based wax is higher than a melting temperature of the crystalline polyester resin.

3. A color toner set comprising a yellow toner containing C.I. Pigment Yellow 74; a magenta toner containing C.I. Pigment Red 238 or 269; and the orange toner according to claim 2 .

4. An orange developer comprising the orange toner according to claim 2 ; and a carrier.

5. The orange toner according to claim 2 , wherein the hydrocarbon based wax has a melting temperature of 80° C. to 95° C.

6. The orange toner according to claim 2 , wherein the crystalline polyester resin is present in a content from about 2% by mass to about 8% by mass of the binder resin component.

7. The orange toner according to claim 1 , wherein the toner is one prepared in an aqueous medium.

8. The orange toner according to claim 1 , wherein a dispersion diameter of the coloring agent particles in the toner is in the range of from about 30 nm to about 300 nm.

9. The orange toner according to claim 1 , wherein a content of the dodecenyl succinic acid structure is in the range of from about 3 mol % to about 30 mol % based on 100 mol % of the whole of acid-derived components of the polyester resin.

10. The orange toner according to claim 1 , wherein a ratio of mol % of the dodecenyl succinic acid structure in the toner to the content of C.I. Pigment Orange 38 in the toner is in the range of from about 3/1 to about 1/12.

11. The orange toner according to claim 1 , wherein a ratio of mol % of the dodecenyl succinic acid structure in the toner to the content of C.I. Pigment Orange 38 in the toner is in the range of from about 2/1 to about 1/9.

12. A color toner set comprising a yellow toner containing C.I. Pigment Yellow 74; a magenta toner containing C.I. Pigment Red 238 or 269; and the orange toner according to claim 1 .

13. An orange developer comprising the orange toner according to claim 1 ; and a carrier.