PROCESS, TONER, PROCESS CARTRIDGE AND APPARATUS FOR DEVELOPING A TONER IMAGE

Abstract

A process includes developing toner images on a photoconductor, transferring to an intermediate transfer belt and a transferring-and-fixing roller. The toner images are transferred to and fixed to a paper simultaneously while the paper moves between the transferring-and-fixing roller and a pressure roller which is pressed against the transferring-and-fixing roller. After transfer process to the paper, residual toner particles remaining on the transferring-and-fixing roller are removed by a cleaning roller. In order to achieve a cleanability from the transferring-and-fixing roller and prevent the intermediate belt from becoming too high temperature, the elastic modulus of the toner particles measured when the toner particles are heated is greater than the elastic modulus of the toner particles when cooled in a temperature range where the glass transition temperature and 10° C. lower than the melting temperature of the toner particles.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross section of an embodiment of an image forming apparatus.

FIG. 2 shows one example of the transferring-and-fixing roller contacts a cleaning roller.

FIG. 3 shows a cross section of another embodiment of an image forming apparatus.

FIG. 4 shows a cross section of another embodiment of an image forming apparatus.

FIG. 5 shows one embodiment of how the transferring-and-fixing belt contacts a cleaning roller.

FIG. 6 shows an example of the relation between the temperature of toner particles and the storage elastic modulus of toner particles.

FIG. 7 shows the relation between the temperature of conventional toner particles and the storage elastic modulus of conventional toner particles.

FIG. 8 shows a test image used in experiments.

Claims

1. Toner particles having a storage elastic modulus when heated (Gr) in a temperature range that is from 10° C. lower than the temperature at which the toner particles begin to flow (Tm) to the glass transition temperature (Tg) of the toner particles, that is greater than a storage elastic modulus when cooled (Gl) in the same temperature range.

2. The toner particles of claim 1, comprising: a crystalline polyester resin, anda plasticizer.

3. The toner particles of claim 1, comprising: a crystalline polyester resin, anda plasticizer;wherein the crystalline polyester resin and the plasticizer are present as separate particles in the toner particles.

4. The toner particles of claim 3, wherein the plasticizer and the crystalline polyester resin are soluble in one another when heated above the melting temperature of the crystalline polyester resin.

5. A developer comprising the toner particles of claim 1.

6. An image present on a recording medium, wherein the image is formed by developing and fixing a toner image comprising the toner particles of claim 1 on the recording medium.

7. A process cartridge configured to be detachable from a main body of an image forming apparatus, comprising: a latent image carrier;at least one of a charger, a developing device and a cleaner; andthe toner particles of claim 1.

8. An image forming process, comprising: forming a toner image on a photoconductor;transferring the toner image onto an intermediate transfer body;transferring the toner image from the intermediate transfer body to a transferring-and-fixing body;transferring the toner image from the transferring-and-fixing body to a recording medium and fixing the toner image on the recording medium by simultaneously heating the recording medium with the transferring-and-fixing body, and pressing the recording medium against the transferring-and-fixing body;wherein the transferring and fixing is carried out at a temperature range T that is 10° C. less than the temperature at which the toner particles of the toner image begin to flow, and the glass transition temperature of the toner particles, andwherein the toner has a storage elastic modulus when heated that is greater than the storage elastic modulus when cooled at the temperature range T that the transferring and fixing is carried out.

9. The process according to claim 8, further comprising: after the transferring and fixing, cleaning residual toner particles from the transferring-and-fixing body with a cleaning body.

10. The process of claim 8, wherein the toner particles of the toner image comprise a crystalline polyester resin and a plasticizer.

11. The process of claim 8, wherein during the transferring and fixing, the resin and the plasticizer dissolve in one another.

12. An image forming apparatus, comprising: toner particles;a latent image carrier configured to carry latent images;a developing device configured to develop latent images on the latent image carrier to toner images with the toner particles;an intermediate transfer body to which toner images on the latent image carrier are transferred;a transferring-and-fixing body to which toner images are transferred from the intermediate transfer body;a heater configured to heat toner images on the transferring-and-fixing body;a pressure body configured to be pressed against the transferring-and-fixing body;a cleaner for the transferring-and-fixing body configured to remove the toner particles from the transferring-and-fixing body;wherein the toner images on the transferring-and-fixing body heated by the heater are transferred to and fixed to a recording medium simultaneously while the recording medium moves through between the transferring-and-fixing body and the pressure body, the toner particles are removed by the cleaner from the transferring-and-fixing body after the toner images are transferred to and fixed to the recording medium simultaneously, and a following relation is satisfied within a range of temperature not smaller than Tg and smaller than TL,wherein the following relationship is met: Gr>Glwherein Gr is a storage elastic modulus of the toner particles measured when the toner particles are heated in a temperature range T, Gl is a storage elastic modulus of the toner particles measured when toner particles are cooled in the temperature range T, wherein the temperature range T is a range from a temperature TL that is 10° C. lower than a temperature Tm that is a flow starting temperature of the toner particles, to a temperature Tg that is a glass transition temperature of the toner particles.

13. The image forming apparatus according to claim 12, wherein following relations are satisfied. tf−30° C.>tc° C.Gl(tc)/Gr(tf)<10wherein tf is the temperature of the toner particles when the toner particles on the transferring-and-fixing body are transferred to the recording medium and tc is the temperature of the toner particles when the toner particles on the transferring-and-fixing body are removed by the cleaning body, Gr(tf) is the value of Gr measured at the temperature tf, and Gl(tc) is the value of Gl measured at the temperature tc.

14. The image forming apparatus according to claim 12, wherein following relations are satisfied. 5×102 [Pa]<Gr(tf)<1×104 [Pa]1×103 [Pa]<Gl(tc)<5×104 [Pa].

15. The image forming apparatus according to claim 12, further comprising: a cooler configured to cool the transferring-and-fixing body disposed at upstream of a position F2 and at downstream of a position F3 in the rotating direction of the transferring-and-fixing body,wherein the position F2 is a position at which toner images on the latent image carrier are transferred to the intermediate transfer body, and the position F3 is a position at which toner images on the intermediate transfer body are transferred to the transferring-and-fixing body.

16. The image forming apparatus according to claim 12, wherein the cleaner includes a cleaning roller.

17. The image forming apparatus according to claim 16, wherein fine convexes and concaves are present on the surface of the cleaning roller.

18. The image forming apparatus according to claim 17, wherein a widthwise length of the cleaning roller is greater than a widthwise length of the intermediate transfer body.

19. The image forming apparatus according to claim 12, wherein the toner particles comprise a plasticizer which is compatible with resin of toner particles when heated.

20. The image forming apparatus according to claim 12, wherein the toner particles comprise a crystalline polyester resin which is compatible with resin of toner particles when heated.

21. The image forming apparatus according to claim 12, wherein the toner particles are produced by suspension polymerization method in which the toner particles are obtained by at least one of emulsifying and dispersing at solution and/or dispersion liquid of a toner component in an aqueous medium followed by granulating to form the toner particles.

22. An image forming apparatus comprising: toner particles;a latent image carrier configured to carry latent images;a developing device configured to develop latent images on the latent image carrier to toner images with the toner particles;an intermediate transfer body to which toner images on the latent image carrier are transferred;a heater configured to heat toner images on the intermediate transfer body;a pressure body configured to be pressed against intermediate transfer body;a cleaner for the intermediate transfer body configured to remove the toner particles from the intermediate transfer body;wherein the toner images on the intermediate transfer body heated by the heater are transferred to and fixed to a recording medium simultaneously while the recording medium moves through between the intermediate transfer body and the pressure body, the toner particles are removed by the cleaner from the intermediate transfer body after the toner images are transferred to and fixed to the recording medium simultaneously, and a following relation is satisfied within a range of temperature not smaller than Tg and smaller than TL: Gr>Glwherein Gr is a storage elastic modulus of the toner particles measured when the toner particles are heated in a temperature range T, Gl is a storage elastic modulus of the toner particles measured when toner particles are cooled in the temperature range T, wherein the temperature range T is a range from a temperature TL that is 10° C. lower than a temperature Tm that is a flow starting temperature of the toner particles, to a temperature Tg that is a glass transition temperature of the toner particles.

23. The image forming apparatus according to claim 22, wherein following relations are satisfied. tf−30° C.>tc° C.Gl(tc)/Gr(tf)<10wherein tf is the temperature of the toner particles when the toner particles on the transferring-and-fixing body are transferred to the recording medium and tc is the temperature of the toner particles when the toner particles on the transferring-and-fixing body are removed by the cleaning body, Gr(tf) is the value of Gr measured at the temperature tf, and Gl(tc) is the value of Gl measured at the temperature tc.

24. The image forming apparatus according to claim 22, wherein following relations are satisfied. 5×102 [Pa]<Gr(tf)<1×104 [Pa]1×103 [Pa]<Gl(tc)<5×104 [Pa].

25. The image forming apparatus according to claim 22, further comprising: a cooler configured to cool the transferring-and-fixing body disposed at upstream of a position F2 and at downstream of a position F3 in the rotating direction of the transferring-and-fixing body,wherein the position F2 is a position at which toner images on the latent image carrier are transferred to the intermediate transfer body, and the position F3 is a position at which toner images on the intermediate transfer body are transferred to the transferring-and-fixing body.

26. The image forming apparatus according to claim 22, wherein the cleaner includes a cleaning roller.

27. The image forming apparatus according to claim 26, wherein fine convexes and concaves are present on the surface of the cleaning roller.

28. The image forming apparatus according to claim 27, wherein a widthwise length of the cleaning roller is greater than a widthwise length of the intermediate transfer body.

29. The image forming apparatus according to claim 22, wherein the toner particles comprise a plasticizer which is compatible with resin of toner particles when heated.

30. The image forming apparatus according to claim 22, wherein the toner particles comprise a crystalline polyester resin which is compatible with resin of toner particles when heated.

31. The image forming apparatus according to claim 22, wherein the toner particles are produced by suspension polymerization method in which the toner particles are obtained by at least one of emulsifying and dispersing at solution and/or dispersion liquid of a toner component in an aqueous medium followed by granulating to form the toner particles.