Infrared absorbent, electrophotographic toner, and image forming apparatus using electrophotographic toner

1. A method for forming a modified infrared absorbent having a light absorption peak in the infrared region and a crystallinity of from 20 to 80%, the method comprising:

adjusting the crystallinity of an original infrared absorbent that is at least one of a metal naphthalocyanine compound, an aminium compound and an immonium salt compound, by applying pressure to the original infrared absorbent or dissolving the original infrared absorbent in a solvent and precipitating the modified infrared absorbent while controlling a deposition speed thereof.

2. The method for forming a modified infrared absorbent according to claim 1 , wherein the light absorption peak is in a range of from 750 to 2000 nm.

3. The method for forming a modified infrared absorbent according to claim 1 , wherein the crystallinity is from 30 to 70%.

4. The method for forming a modified infrared absorbent according to claim 1 , wherein the crystallinity is from 40 to 65%.

5. The method for forming a modified infrared absorbent according to claim 1 , wherein the metal naphthalocyanine compound includes a metal selected from the group consisting of vanadium, aluminum, titanium, and silane.

6. The method for forming a modified infrared absorbent according to claim 1 , wherein the crystallinity of the original infrared absorbent is adjusted by applying pressure to the original infrared absorbent.

7. A method of forming an electrophotographic toner including forming a modified infrared absorbent having a light absorption peak in the infrared region and a crystallinity of from 20 to 80%, the method comprising:

adjusting the crystallinity of an original infrared absorbent that is at least one of a metal naphthalocyanine compound, an aminium compound and an immonium salt compound, by applying pressure to the original infrared absorbent or dissolving the original infrared absorbent in a solvent and precipitating the modified infrared absorbent while controlling a deposition speed thereof.

8. The method of forming an electrophotographic toner according to claim 7 , wherein the toner is a color toner for flash fusing.

9. The method of forming an electrophotographic toner according to claim 7 , wherein the toner is an invisible toner.

10. The method of forming an electrophotographic toner according to claim 7 , wherein the amount of the modified infrared absorbent in the toner is from 0.05 to 5 parts by mass with respect to 100 parts by mass of the toner.

11. The method of forming an electrophotographic toner according to claim 7 , wherein the crystallinity of the original infrared absorbent is adjusted by applying pressure to the original infrared absorbent.

12. A method for forming a toner image on a recording medium with an electrophotographic toner including forming a modified infrared absorbent having a light absorption peak in the infrared region and a crystallinity of from 20 to 80%, the method comprising:

adjusting the crystallinity of an original infrared absorbent that is at least one of a metal naphthalocyanine compound, an aminium compound and an immonium salt compound, by applying pressure to the original infrared absorbent or dissolving the original infrared absorbent in a solvent and precipitating the modified infrared absorbent while controlling a deposition speed thereof; and

fixing the toner image on the recording medium.

13. The method for forming a toner image on a recording medium according to claim 12 , wherein the fixing unit performs flash fusing, which optically fixes the toner image with a flash lamp.

14. The method for forming a toner image on a recording medium according to claim 13 , wherein the fixing unit comprises a plurality of the fusing flashs, and performs a delayed light emission flash fusing using the plurality of the flash lamps which emit light at a time interval.

15. The method for forming a toner image on a recording medium according to claim 14 , wherein the time interval of flashing between each flash lamp is in a range of from 0.1 to 20 msec.

16. The method for forming a toner image on a recording medium according to claim 15 , wherein the emitted light energy of the flash lamp is in a range of from 1.0 to 7.0 J/cm 2 .

17. The method for forming a toner image on a recording medium according to claim 15 , wherein the emitted light energy of the flash lamp is in a range of from 2.0 to 5.0 J/cm 2 .

18. The method for forming a toner image on a recording medium according to claim 12 , wherein the crystallinity of the original infrared absorbent is adjusted by applying pressure to the original infrared absorbent.