JPH039364A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To neutralize electric charge in a zone having transfer voltage directly applied and to prevent fogging on both sides of a copying paper, even if it is large in size, by incorporating not only a positive hole transfer material but also an electron transfer material in a charge transfer layer. CONSTITUTION:An undercoat layer 2, a charge generating layer 3, and the charge transfer layer 4 are successively laminated on a conductive substrate 1 in this order, and the charge transfer layer 4 has a function of transferring carriers generated in the charge generating layer 3 to the surface of the photosensitive body, and it is a resin layer containing the positive hole transfer material and the electron transfer material, thus permitting the charge on the zone to which transfer voltage is directly applied to be neutralized, consequently, positive charge due to the transfer voltage not to remain on the surface of the photosensitive body after transferring a toner image to a small-sized paper, accordingly, fogging not to occur on both sides of the transfer paper, even if it is large in size.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Application Field) The present invention relates to an electrophotographic photoreceptor used in an electrophotographic apparatus of a type that forms an electrostatic latent image on the surface of the photoreceptor.

(Prior art) In an electrophotographic device, the role played by a photoreceptor is to maintain corona discharge for a certain period of time and neutralize the surface charge by one of the electron/hole pairs generated in the photoreceptor due to image exposure. It is about making peace.

At this time, an electrostatic latent image is formed on the surface of the photoreceptor.

In the case of laser printers, color copying machines, etc., this electrostatic latent image is reversely developed and visualized by attaching a powder called toner that has the same sign of charge as the surface charge on the photoreceptor. A toner image is transferred onto the transfer paper by applying an electric charge of opposite sign to the front surface from the back side of the transfer paper.

In such electrophotographic apparatuses, organic photoreceptors (hereinafter referred to as OPc) using organic photoconductors have recently been used. Compared to inorganic photoreceptors, OPC has a wide range of versatility and is widely used because spectral sensitivity can be obtained by selecting materials.

(Problem to be Solved by the Invention) However, in the case of reversal development as described above, if a larger transfer paper is passed after passing a small transfer paper, for example, A
If you pass the A3 transfer paper after passing the 4 transfer paper,
There is a drawback that a fogging phenomenon occurs at both ends of the larger size A3 transfer paper. It is common practice to perform continuous transfer using transfer papers of different sizes, and it is desired to solve these drawbacks.

The present invention has been made in view of these circumstances, and provides an electronic photograph that provides clear images over a long period of time without causing fogging even when transfer paper of different sizes is passed successively. The purpose is to provide a photoreceptor.

[Structure of the Invention] (Means for Solving the Problems) The electrophotographic photoreceptor of the present invention has a charge generation layer and a charge transport layer 2, and the charge transport layer comprises a hole charge transport material and an electron transport material. It is characterized by consisting of a resin layer in which material is dispersed.

(Function) When reversal development is performed using a conventional OPC photoreceptor, when a small transfer paper is passed through and then a larger transfer paper is passed through, a fogging phenomenon occurs at both ends of the larger size transfer paper. It has been found that the area where such a fogging phenomenon occurs is an area where a transfer voltage is directly applied to the photoreceptor during transfer to a small transfer paper. This is because the charge on the side to which the OPC has no sensitivity is not removed even by light irradiation.

In the photoreceptor of the present invention, the electron transport layer contains not only a genuine plate transport material but also an electron transport material, thereby neutralizing the electric charge in the area to which a direct transfer voltage is applied. As a result, no positive charge remains on the surface of the photoreceptor after being transferred to a small-sized transfer paper due to the direct application of the transfer voltage, and therefore, no positive charge remains on the surface of the photoreceptor after being transferred to a larger-sized transfer paper. No fog will occur at either end, even if the

(Example) Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a sectional view showing an example of the photoreceptor of the present invention.

In FIG. 1, a subbing layer 2 is provided on a substrate 1,
A charge generation layer 3 and a charge transport layer 4 are sequentially provided on the undercoat layer 2.

The base body 1 usually consists of a drum made of aluminum. The undercoat layer 2 is formed in order to suppress the flow of charges between the substrate 1 and the charge generation layer 3, thereby increasing the charge retention function of the surface of the photoreceptor and increasing the charging ability of the photoreceptor. It is usually formed from synthetic resins such as butyral, acetal, phenol, polycarbonate, polyester, cellulose, and polyurethane.

The charge generation layer 3 generates carriers when irradiated with light, and carriers of one polarity travel within the charge transport layer 3 and neutralize the charges on the surface of the photoreceptor, and the carriers of the other polarity travel within the charge transport layer 3 and neutralize the charges on the surface of the photoreceptor. The polar ones reach the substrate 1. The charge generation layer 3 is
It is composed of a resin layer containing a charge generating material. Examples of the charge generating agent include τ-type metal-free phthalocyanine, X-type phthalocyanine, azo pigment, etc., and examples of the resin layer include phenoxy resin, polycarbonate resin, butyral resin, etc. can be used. The amount of charge generating material in the resin layer is preferably 0.6 to 1 to 1 part resin.

The charge transport layer 4 has a function of transporting carriers generated within the charge generation layer 3 to the surface of the photoreceptor. The charge transport layer 4 is
It is composed of a resin layer containing a hole charge transporting material and an electron transporting material. For example, 1. ]-Bis(
p-diethylaminophenyl) = 4.4-diethyl-1
, 3-butadiene, 4-diedylamino-2-methylbenzaldehyde-1,1-diphenylhydrazone, etc. Examples of the electron transport material include tetracyanodimethane, 2,4,7-dolinitrofluorene, or its conductor. Polycarbonate, phenol resin, phenoxy resin, etc. can be used for the resin layer. The hole charge transporting material and the electron transporting material in the resin layer are
In contrast, the hole charge transport material is 0.5 to 1, and the electron transport material is 0.
．． 1 to 0.4 is preferred.

FIG. 2 schematically shows an image forming apparatus equipped with the photoreceptor shown in FIG. 1 described above. Around the photosensitive drum 11, there are a charger] 2, an exposure light source 13, a developer] 4, a transfer device] 5
, a cleaner 16, and a static eliminator]7 are arranged.

The image forming operation using the apparatus shown in FIG. 2 is as follows. First, the surface of the photosensitive drum 1 is uniformly charged by the charger 12, and then a predetermined image is exposed from the exposure light source 13 to form an electrostatic latent image. Next, developer is supplied from the developing device 14 to the surface of the photosensitive drum 11 to develop the electrostatic latent image. Thereafter, the developer image on the photoreceptor drum 11 is transferred to the transfer device 15.
The developer remaining on the photoreceptor drum 11 after the transfer is removed from the surface of the photoreceptor by the cleaner 16, and finally the charge is removed from the photoreceptor surface by the static eliminator 17, and the image forming operation is completed. .

Hereinafter, one test example of the present invention will be explained.

Test example [By immersing an aluminum shield with a diameter of 3 (Lsm) in 1.1.2-trichloroethane for 1 to 10 minutes and then steam cleaning,
Cutting oil was removed from the surface of the aluminum tube. Then,
After ultrasonic cleaning, alcohol-soluble nylon (K-80: manufactured by Toshi Co., Ltd.) is applied to the surface to form a 0.1 μm undercoat layer.1. Ta.

Next, a charge generating material consisting of a τ-type metal-free phthalocyanine (τ-H2PC: manufactured by Toyo Ingi Co., Ltd.) represented by the following general formula (1) and a phenoxy resin represented by the following general formula (2) (manufactured by P K HHHVCC Company) were used. )]:1 solution to form a charge generation layer with a thickness of 0.2 μm.

Thereafter, a hole charge transporting material made of 1,1-bis(p-diethylaminophenyl)-4゜4-diethyl-1,3-butadiene (manufactured by Anan Perfumery Co., Ltd.) represented by the following general formula (3), tetra Electron transport material consisting of cyanoquinodimethane and bisphenol Z type car recarbonate (manufactured by Banjin Kasei Co., Ltd.) represented by the following general formula (4) in a ratio of 1:1:
A charge transport layer having a thickness of about 20 μm was formed by immersing the photoreceptor in a solution of 7, thereby obtaining an OPC photoreceptor as shown in FIG. In addition,
In the above operation, drying is performed after the coating step.

n-82~123 When this OPC photoreceptor was installed in the copying machine shown in Fig. 2 and copies were made on transfer paper, even when the images were transferred successively from A4 transfer paper to 83 transfer paper, the result was that of A3. No fogging was observed at both ends of the transfer paper, and a clear copy image was obtained.

On the other hand, an OPC photoreceptor was manufactured in the same manner as described above except that it did not contain the electron transporting material, and when it was loaded into the copying machine shown in Fig. 2 and copied onto transfer paper, it was found that When the images were continuously transferred from 83 to 83 transfer paper, a fogging phenomenon was observed at both ends of the 83 transfer paper.

[Effects of the Invention] As explained above, in the photoreceptor of the present invention, the charge transport layer contains not only a hole transport material but also an electron transport material. Neutralize the charge in the region where iJ is applied.

-'2''- As a result, there is no residual positive charge that is transferred to the transfer paper with small →noise and that a direct transfer 'rf voltage is applied to the subsequent surface of the sensitive body. Therefore, even if the image is transferred to a larger size transfer paper, fog will not occur at both ends (-).

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention (a diagram of a photoconductor shown in FIG. 1), and FIG. It is a diagram showing the I invasion of the device.''...Substrate, 2...Undercoat layer 13...Charge generation layer., 1...Charge transport layer.

Claims (1)

[Claims] An electrophotographic photoreceptor comprising a charge generation layer and a charge transport layer, the charge transport layer comprising a resin layer in which a hole charge transport material and an electron transport material are dispersed.