IMAGE FORMING METHOD AND IMAGE FORMING APPARATUS

Abstract

An image forming method including forming an image of a toner on a receiving material; and fixing the toner image on the receiving upon application of heat and pressure thereto, wherein the weight average particle diameter (D4) of the toner is from 2.0 to 4.5 μm, the pressure (P) is not greater than 15 N/cm2, P×D4 is not less than 30 N/cm2·μm, the melt viscosity (Gw110) of the toner at 110° C. is from 3,000 to 40,000 Pa·s, the melt viscosity (Gw140) of the toner at 140° C. is from 100 to 1,000 Pa·s, and the ratio Gw110/Gw140 is not less than 30.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the detailed description when considered in connection with the accompanying drawings in which like reference characters designate like corresponding parts throughout and wherein:

FIGS. 1 and 2 are schematic views illustrating the cross sections of background fixing devices, which can also be used for the image forming apparatus of the present invention;

FIG. 3 is a schematic view illustrating an example (a full color image forming apparatus) of the image forming apparatus of the present invention;

FIGS. 4 and 5 are schematic views illustrating fixing devices for use in the image forming apparatus of the present invention;

FIG. 6 is a schematic view illustrating a toner preparation apparatus for use in preparing the toner for use in the image forming apparatus of the present invention;

FIG. 7 is an enlarged view illustrating the nozzle of the toner preparation apparatus illustrated in FIG. 7;

FIG. 8 is a graph for explaining how to determine the granularity of an image;

FIG. 9 is a graph illustrating the relationship among the fixing pressure, the weight average particle diameter of toners and the qualities of the toners; and

FIGS. 10A and 10B are graphs illustrating the relationships among melt viscosities (Gw110 and Gw140) of toners provided in Examples and Comparative Examples, the ratio of Gw110/Gw140) of the toners and image and the qualities of the toners.

Claims

1. An image forming method comprising forming an image of a toner on a receiving material; andfixing the toner image on the receiving material upon application of heat and pressure thereto,wherein the following relationships (1) to (6) are satisfied: 2.0 μm≦D4≦4.5 μm  (1),P≦15N/cm2  (2),P×D4≧30N/cm2·μm  (3),3,000 Pa·s≦Gw110≦40,000 Pa·s  (4),100 Pa·s≦Gw140≦1,000 Pa·s  (5), andGw110/Gw140≧30  (6),

2. The image forming method according to claim 1, wherein the toner satisfies the following relationship: D4/Dn≦1.25,

3. The image forming method according to claim 1, wherein the toner has a glass transition temperature of from 40 to 55° C.

4. The image forming method according to claim 1, wherein the toner includes a binder resin including at least a crystalline polyester resin.

5. The image forming method according to claim 1, wherein the crystalline polyester resin has a melting point of from 80 to 130° C.

6. The image forming method according to claim 1, wherein the toner includes a release agent having a melting point of from 60 to 80° C.

7. The image forming method according to claim 1, wherein the toner includes a binder resin and a release agent, and wherein a weight ratio (R/B) of the release agent (R) and the binder resin (B) in the toner is from 0.03 to 0.10.

8. An image forming apparatus comprising: an image bearing member configured to bear a toner image thereon;a transfer device configured to transfer the toner image onto a receiving material; anda fixing device configured to fix the toner image on the receiving material upon application of heat and pressure thereto,wherein following relationships (1) to (6) are satisfied: 2.0 μm≦D4≦4.5 μm  (1),P≦15N/cm2  (2),P×D4≧30N/cm2·μm  (3),3,000 Pa·s≦Gw110≦40,000 Pa·s  (4),100 Pa·s≦Gw140≦1,000 Pa·s  (5), andGw110/Gw140≧30  (6),