Electrophotographic photoreceptor and image forming apparatus including the same

Abstract

An electrophotographic photoreceptor of high durability capable of providing stable excellent electrical characteristics over a prolonged period of time, which electrophotographic photoreceptor excels in mechanical strength. Photosensitive layer (14) of electrophotographic photoreceptor (1) comprises a polyarylate resin having structural units, for example, those of aforementioned formula (1-3) and an enamine compound represented by, for example, aforementioned formula (2-1). By virtue of these, electrophotographic photoreceptor (1) of excellent mechanical strength and favorable electrical characteristics can be realized.

Description

technical field [0001] The present invention relates to an electrophotographic photoreceptor, a process cartridge having the electrophotographic photoreceptor, and an electrophotographic apparatus, and more particularly, to an electrophotographic photoreceptor having a photosensitive layer containing a specific resin and a specific charge-transporting substance , a process cartridge with an electrophotographic photoreceptor, and an electrophotographic apparatus. [0002] The present invention also relates to an electrophotographic photoreceptor used in electrophotographic image forming apparatuses such as copiers, printers, and facsimile apparatuses, and an image forming apparatus having the electrophotographic photoreceptor, and more particularly, to an electrophotographic photoreceptor having a specific resin and An electrophotographic photoreceptor of a photosensitive layer of a specific charge transport substance, and an image forming apparatus having the electrophotograph...

AI Technical Summary

Problems solved by technology

The problem that the practical organic photoreceptor has when it is repeatedly used is that it is easy to cause property changes such as a decrease in charge potential and an increase in residual potential due to film reduction of the photosensitive layer, electrical changes, and chemical changes.

Polyarylate-based resins have a similar structure to polycarbonate resins, but differ in properties from photoreceptors using these resins

It is known that a photoreceptor using a polyarylate system is excellent in mechanical strength, but when a polyarylate-based resin is used as a binder resin for a charge transport layer, it has the following disadvantages: Depending on the structure of the charge transport substance used , it is easy to cause property changes such as a decrease in the potential retention rate and an increase in the residual potential

[0041] (1) Poor solubility, only showing good solubility in some halogen organic solvents such as dichloromethane and 1,2-dichloroethane

Due to the low boiling point of these halogen-based organic solvents, if a coating solution prepared from these solvents is used to manufacture a photoreceptor, the evaporation rate of the solvent is too fast, and the coating film is prone to white turbidity due to the heat of vaporization.

In addition, halogen-based organic solvents such as dichloromethane and 1,2-dichloroethane are highly toxic and have a large impact on operators and the global environment due to the destruction of the ozone layer, and the management of the manufacturing process becomes complicated.

[0042] (2) In addition to the aforementioned halogen organic solvents, although they are partially soluble in tetrahydrofuran, dioxane, cyclohexanone or their mixed solvents, the coating liquid prepared with these solvents will condense within a few days after preparation. Gelling, etc., poor storage stability

In particular, when a photoreceptor is produced by dip coating, the coating liquid in the coating tank will gel, which hinders the production of the photoreceptor.

[0043] (3) Due to the strong intermolecular attraction of the resin itself, the formed coating film has poor adhesion and is prone to cracks at the interface with other layers

Therefore, tailing (tailing) of the coating film occurs to reduce productivity

In addition, when used as a photoreceptor, the toner adheres to the convex part and remains without being removed, which easily causes image defects due to so-called poor cleaning.

[0045] (5) Due to the lack of mechanical strength of the resin itself, the photosensitive layer using bisphenol A polycarbonate resin is prone to scratches on its surface due to the friction of charging rollers, magnetic brushes or cleaning shovels, and gradually wears away.

However, even if the high charge mobility enamine compound used in the photoreceptor described in the aforementioned JP-A-2-51162, JP-A-6-43674 or JP-A-10-69107 is used, in a low temperature environment Sufficient photoresponsiveness cannot be obtained

In addition, although the photoreceptor described in Japanese Unexamined Publication No. 7-134430 has a high charge transport ability by containing polysilane, there is a problem that the photoreceptor using polysilane has weak resistance to exposure, and the photoreceptor using polysilane has a weak resistance to exposure. In the light, the various properties of the photoreceptor are reduced

[0057] In addition, although the aforementioned corona discharge and gap discharge are used in the charging of the photoreceptor, there is a problem that the organic photoreceptor is decomposed and deteriorated by active gases such as ozone and NOx generated by these discharges. , so that the surface of the photosensitive layer is easy to deteriorate, and after repeated use, the electrical characteristics such as chargeability, sensitivity and responsiveness will be reduced, and the image quality will be deteriorated

[0060] The technique described in the aforementioned Japanese Patent Laid-Open No. 10-10761 cannot prevent the generation of defects by itself, so it cannot avoid the dielectric breakdown of the photosensitive layer.

In addition, since the charge transport layer is formed in this technology, the process of applying the coating liquid and the drying process must be repeated, and the production efficiency is poor.

[0061] In addition, the sensitivity and responsiveness of the photoreceptor described in JP-A-2001-56595 are not sufficient, and image defects such as background contamination and lowered image density occur when electrophotography is performed at high speed.

[0062] In addition, in order to form the charge-transporting layer of the photoreceptor in the technique described in JP-A-2001-166502, it is necessary to polymerize the hole-transporting compound by radiation or the like, so it is difficult to manufacture it with existing manufacturing equipment.

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