Image forming apparatus, image forming method and process cartridge

Abstract

Provided are image forming apparatuses, image forming methods, and process cartridges using a toner that is excellent in low temperature fixing ability, hot offset resistance, and storage stability, and also generate less odor, and thus that can provide high quality images with superior fixing ability, far from tone change with time, and less likely to occur abnormal images such as density-drop and background smear. The image forming apparatuses comprise a latent electrostatic image bearing member, a charging unit, an exposing unit, a developing unit, a transfer unit, and a fixing unit, wherein the toner comprises a binder resin and a colorant, the binder resin comprises a polyester resin prepared by condensation polymerization between an alcohol component that contains an aliphatic polyvalent alcohol and a carboxylic acid component that contains (meth)acrylic acid-modified rosin.

Description

technical field [0001] The present invention relates to image forming apparatuses, image forming methods, and process cartridges of electrophotographic methods such as copiers, electrostatic printing, printers, facsimile machines, and electrostatic recording. Background technique [0002] At present, various methods are known for image formation by electrophotography. Generally, the surface of an electrostatic latent image carrier (hereinafter also referred to as "photoreceptor", "electrophotographic photoreceptor", or "image carrier") is charged, and then The surface of the charged latent electrostatic image carrier is exposed to form an electrostatic latent image. Next, the latent electrostatic image is developed with toner to form a visible image on the latent electrostatic image carrier. The visible image is transferred directly or through an intermediate transfer body to a recording medium, and then the transferred transfer image is fixed by heat, pressure, or both, th...

AI Technical Summary

Problems solved by technology

[0018] However, in the method of blending a low-molecular-weight resin and a high-molecular-weight resin in the above-mentioned Japanese Patent Application Laid-Open No. 2-82267, there is a disadvantage that the presence of a high-molecular-weight component causes pulverization in the resin production process, or the use of The crushability of the binder resin in the production process of the crushed toner is deteriorated

On the other hand, in the method of using only low-molecular-weight resin, not only the offset resistance and storability are poor, but also the pulverization is too good, so there is a problem that the resin is fused during the pulverization, which worsens the productivity.

[0019] On the other hand, if the softening point of the binder resin for toner is lowered in order to improve the low-temperature fixability, it will inevitably be accompanied by a lowering of the glass transition temperature, so that the toner will be aggregated, and as a result, the storability will be deteriorated.

[0020] In addition, although the rosins used in the above-mentioned JP-A-4-70765 and JP-A-4-307557 are effective for improving low-temperature fixing properties, they also have the disadvantage of easily generating an odor depending on the type of rosin.

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