Electrophotographic toner, and image forming method and apparatus using the toner

A full color image forming apparatus comprising:

• an image bearing member having an electrostatic latent image thereon;
• a yellow, magenta and cyan developer which comprise a yellow, magenta, and cyan toner, respectively;
• a yellow developing device which develops the latent image with the developer to form a yellow toner image;
• a magenta developing device which develops the latent image with the developer to form a magenta toner image;
• a cyan developing device which develops the latent image with the developer to form a cyan toner image;
• a transfer device which transfers the yellow, magenta, and cyan toner image onto a receiving material to form a full color image on the receiving material;
• and
• a fixing device, comprising:
• at least one selected from the group consisting of a belt and an endless belt;
• and
• a heating element,
• wherein the full color toner image is fixed while being contacted with said belt, said endless belt, or both,
• wherein each of the yellow, magenta and cyan toner comprises a resin and a colorant, said colorant comprising an average major particle diameter not greater than about 0.5 μm, and wherein the following relationships are satisfied:
• Ta≦100 (° C.), and (Tb−Ta)≧7.0 (° C.)
• wherein Ta represents a temperature at which the toner has a melt viscosity of 50,000 Pa·sec, and Tb represents a temperature at which the toner has a melt viscosity of 5,000 Pa·sec.

An image forming method, comprising:

• forming a toner image on a receiving material;
• and
• contacting the toner image with at least one selected from the croup consisting of a belt or an endless belt while heating the toner image with a heating element, to fix the toner image,
• wherein the toner comprises a resin and a colorant, said colorant comprising an average major particle diameter not greater than about 0.5 μm, and wherein the following relationships are satisfied:
• Ta≦100 (° C.), and (Tb−Ta)≧7.0 (° C.)
• wherein Ta represents a temperature at which the toner has a melt viscosity of 50,000 Pa·sec, and Tb represents a temperature at which the toner has a melt viscosity of 5,000 Pa·sec.

A full color image forming method comprising:

• forming a full color image, comprising a yellow toner, a magenta toner, and a cyan toner, on a receiving material;
• and
• contacting the color toner image with at least one selected from the group consisting of a belt and an endless belt while heating the toner image with a heating element,
• wherein each of said yellow, magenta and cyan toner comprises a resin and a colorant, said colorant compring an average major particle diameter not greater than about 0.5 μm, wherein the following relationships are satisfied:
• Ta≦100 (° C.), and (Tb−Ta)≧7.0 (° C.)
• wherein Ta represents a temperature at which the toner has a melt viscosity of 50,000 Pa·sec, and Tb represents a temperature at which the toner has a melt viscosity of 5,000 Pa·sec.