Image forming method

Abstract

Disclosed is an electrophotographic image forming method which comprises steps of forming a toner image on an image support, fixing the toner image on the image support in a fixing nip section of a fixing device employing a contact heating system and the toner contains a first releasing agent, a dynamic viscosity of the first releasing agent is 4-20 mm2/sec; and a fixing temperature in the fixing nip section of the fixing device is 75-100° C. higher than a melting point of the first releasing agent.

Description

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic view of a fixing device which may be employed for the invention.

FIG. 2 is a schematic view of an example of a heating roller which may be employed for a fixing device of FIG. 1.

FIG. 3 is a schematic view of another model of a fixing device which may be employed for the invention.

FIG. 4 is a schematic view of an image forming apparatus which may be employed for the invention.

Claims

1. An image forming method comprising the steps of forming a toner image on an image support,fixing the toner image on the image support in a fixing nip section of a fixing device employing a contact heating system, whereinthe toner contains a first releasing agent,a dynamic viscosity of the first releasing agent is 4-20 mm2/sec; anda fixing temperature in the fixing nip section of the fixing device is 75-100° C. higher than a melting point of the first releasing agent.

2. The image forming method of claim 1, wherein the melting point of the releasing agent is 50-100° C.

3. The image forming method of claim 1, wherein the dynamic viscosity of the first releasing agent is 8-15 mm2/sec.

4. The image forming method of claim 1, wherein the toner contains a second releasing agent which has a dynamic viscosity of 8-15 mm2/sec.

5. The image forming method of claim 1, wherein the transport rate in the fixing nip section is 230-500 mm/sec.

6. The image forming method of claim 5, wherein the transport rate in the fixing nip section is 230-400 mm/sec.

7. The image forming method of claim 1, wherein the first releasing agent is Fischer-Tropsch wax, paraffin wax, microcrystalline wax or mono-ester wax.

8. The image forming method of claim 7, wherein the first releasing agent is microcrystalline wax.

9. The image forming method of claim 8, wherein the microcrystalline wax has a weight average molecular weight of 600-800.

10. The image forming method of claim 9, wherein the microcrystalline wax has a number average molecular weight of 300-1,000.

11. The image forming method of claim 10, wherein the microcrystalline wax has a number average molecular weight of 400-800.

12. The image forming method of claim 10, wherein the microcrystalline wax has a ratio of the weight average molecular weight to the number average molecular weight (Mw/Mn) of 1.01-1.20.