JPH1195462A - Electrophotographic photoreceptor, process cartridge and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor capable of thinning its photosensitive layer because of superior durability and therefore giving a high grade image having superior gradation reproducibility and to provide a process cartridge and an electrophotographic device both having the photoreceptor. SOLUTION: The electrophotographic photoreceptor has an electric charge transport layer contg. one or more reaction products of a compd. represented by the formula R<1> m -M-(OR<2> )n , wherein M is Si, Al, Ti or Zr, R<1> and R<2> are H, alkyl, cycloalkyl, aryl, halogen or -CF3 , (m) is an integer and (n) is an integer of >=1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photoreceptor,
And a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member. Such electrophotographic apparatuses include black-and-white, mono-color or full-color electrophotographic copying machines, printers, and various other recording devices.

[0002]

2. Description of the Related Art Among image forming apparatuses, there is a laser beam printer employing an electrophotographic system as a high-speed and low-noise printer. A typical application is binary recording in which images such as characters and figures are formed by applying or not applying a laser beam to a photoconductor. In general, printing of characters and figures does not require a halftone, so that the structure of the printer can be simplified.

However, there is a printer capable of expressing halftones even with such a binary recording system. As such a printer, a printer employing a dither method, a density pattern method, or the like is well known. However, as is well known, high resolution cannot be obtained with a printer employing a dither method, a density pattern method, or the like. Therefore, in recent years, a method (PWM method) of forming a halftone in each pixel with high resolution without lowering the recording density has been proposed. In this method, a halftone pixel is formed by modulating a laser beam irradiation time by an image signal. According to this method, a high-resolution and high-gradation image can be formed. A color image forming apparatus requiring high gradation is particularly suitable. That is, according to this method, the area gradation of the dot formed by the beam spot can be performed for each pixel, and the halftone can be expressed without lowering the resolution.

However, even in this PWM method, if the image density is further increased, the pixels become relatively small with respect to the exposure spot diameter, so that it is not possible to sufficiently obtain gradation by exposure time modulation. There is.

Therefore, in order to improve the resolution while maintaining the gradation, it is necessary to reduce the diameter of the exposure spot. For that purpose, for example, when a scanning optical system using a laser is used, it is necessary to shorten the wavelength of the laser light or to increase the NA of the f-θ lens, but such a method is required. When using a laser, it is unavoidable to increase the size and cost of the apparatus due to the use of expensive lasers, the enlargement of lenses and scanners, and the increase in mechanical precision required due to the decrease in the depth of focus.

[0006] Further, even in a solid-state scanner such as an LED array or a liquid crystal shutter array, an increase in the price of the scanner itself, an increase in mounting accuracy, and an increase in the cost of an electric drive circuit are inevitable.

Further, even when the light spot is miniaturized as described above, it is difficult to obtain good gradation reproducibility in the electrophotographic system, and the gradation is reproduced in a pseudo manner by electrical processing. It was just doing.

[0008] In spite of the above-mentioned problems, the resolution and gradation required of an image forming apparatus (electrophotographic apparatus) using an electrophotographic method have been increasing in recent years.

Under such circumstances, attempts have been made to improve the resolution and gradation by reducing the particle size of the toner used for development, and to improve the uniformity of the development conditions.

However, even if such improvements are made, the reproducibility of gradation data such as full-color image data of 256 gradations of 400 to 600 lines recognizable by the naked eye and the high resolution of binary images such as characters. Image reproduction was not enough.

For such a situation, Japanese Patent Laid-Open Publication No.
If a photoreceptor having characteristics such that the sensitivity is low at a low exposure amount and the sensitivity increases as the exposure amount increases, as described in JP-A No. 9454 and JP-A No. 1-172863, the strength can be improved. It has been found that it is possible to remove the low exposure amount portion of the irradiation spot having a distribution and obtain the same effect as reducing the irradiation spot diameter. That is, in an electrophotographic apparatus in which an irradiation spot having an intensity distribution is scanned with respect to such a photoreceptor, a high resolution equal to or smaller than the irradiation spot diameter can be stably obtained. However, even when such a photoconductor is used, it has been difficult to stably reproduce 256 gradations by PWM of 400 dpi.

As described above, an image which can be normally discriminated by the naked eye is about 400 dpi and has about 256 gradations. In this case, the minimum resolution area is about 16 μm ² and 5000 d
This corresponds to a resolution of pi or higher. In order to realize such high resolution, it is necessary to reduce the spot area of the light beam, but simply reducing the spot area cannot achieve the high image quality as described above.

In consideration of such problems, in an electrophotographic apparatus in which a latent image is formed by irradiating a light beam, the product of the film thickness of the photosensitive layer of the photosensitive member and the irradiated spot area and the gradation It was found that there was a certain relationship between reproducibility, and the product of the spot area and the thickness of the photosensitive layer of the photosensitive member was 2
400dpi by a 0000Myuemu ³ or less, 256
It is possible to obtain an extremely excellent image quality for realizing the gradation (see FIGS. 6 and 7).

This is presumably because, in the conventional electrophotographic apparatus, the conditions of the latent image formed on the photoreceptor and the development conditions are not sufficient despite the miniaturization of the light spot area. That is, the development in which the image information given by the light spot is degraded due to the diffusion of the optical carrier for forming the latent image while traveling through the photosensitive layer, and the potential potential generated by the formed latent image It is considered that the phenomenon that the contrast is reduced by the space existing up to the conductive support occurs, and the image information given by the light spot at the beginning is greatly deteriorated, so that the image quality is reduced. .

As described above, by setting the product of the spot area of the light beam and the film thickness of the photosensitive layer of the photosensitive member to 20,000 μm ³ or less, favorable results can be obtained without causing the above-described carrier diffusion and deterioration in developability. This enables image formation.

On the other hand, with respect to the photoreceptor, an electrophotographic photoreceptor using an organic photoconductive material has a function separation structure in which a charge generation layer and a charge transport layer are laminated in order to satisfy both electrical and mechanical properties. It is often used as a type photoreceptor. As a matter of course, the electrophotographic photoreceptor is required to have sensitivity, electrical characteristics, and even optical characteristics according to the applied electrophotographic process. In particular, in the case of an electrophotographic photoreceptor that is repeatedly used, an external electrical and mechanical force such as corona charging, direct charging, image exposure, toner development, transfer process and surface cleaning is directly applied to the photoreceptor surface layer. Also, durability for them is required. Specifically, durability against electrical deterioration due to ozone or nitrogen oxides during charging, and mechanical deterioration such that the surface is worn or scratched due to discharge during charging and rubbing of a cleaning member. Is required.

Since the surface of an electrophotographic photosensitive member is generally a thin film composed of a charge transporting material and a resin layer, of the above-mentioned disadvantages, mechanical deterioration is largely caused by the resin layer, and selection of this resin layer is very important. become.

[0018]

Conventionally, polycarbonate Z or the like has been used as a resin for the charge transport layer. However, organic materials have insufficient mechanical strength, and therefore have durability against abrasion and scratches due to cleaning. There was a drawback that it was inferior. In addition, there is a problem that it is deteriorated by discharge at the time of charging.

In order to cope with this problem, conventionally, the thickness of the charge transport layer needs to be as thick as about 20 to 30 μm, and the durability is improved by providing a surface protective layer on the surface of the charge transport layer. Ways to improve have been taken. Therefore, it has been difficult to obtain sufficient durability with a thin charge transport layer made of an organic material and having high gradation reproducibility.

It is an object of the present invention to provide an electrophotographic apparatus capable of forming a thin photosensitive layer because of less wear due to abrasion and scratches and having excellent durability, thereby obtaining a high-quality image having excellent gradation reproducibility. An object of the present invention is to provide a photoconductor, a process cartridge having the electrophotographic photoconductor, and an electrophotographic apparatus.

[0021]

That is, the present invention provides an electrophotographic photosensitive member having a photosensitive layer having a charge generating layer and a charge transport layer on a conductive support, wherein the charge transport layer has the following formula (1) An electrophotographic photoreceptor comprising at least one reaction product of the compound represented by the formula (1).

[0022] _{^{R 1 m -M- (OR 2)}} n (1) ( wherein, M represents Si, Al, Ti or Zr, R ¹
And R ² represent a hydrogen atom, an alkyl group, a cyclic alkyl group, an aryl group, a halogen atom or —CF ₃ , m represents an integer, and n represents an integer of n ≧ 1. Further, the present invention is a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

In the present invention, in order to solve the problem of mechanical strength of an electrophotographic photosensitive member having a conventionally used organic resin as a charge transporting layer, the charge transporting layer has the formula (1). By including at least one or more reaction products of the compound (1), high durability can be provided. Preferably, the thickness of the charge transport layer is small (the product of the thickness of the photosensitive layer and the spot area of the light beam is 20).
000 μm ³ or less), it is possible to form a good image without causing the diffusion of the carrier and the deterioration of the developing property at the time of forming the latent image.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION In the formula (1), R ¹ and R ²
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a t-butyl group, and a hexyl group.Examples of the cyclic alkyl group include a cyclopentyl group and a cyclohexyl group. Examples of the aryl group include a phenyl group and a naphthyl group, and examples of the halogen atom include chlorine, fluorine, and bromine. These alkyl group, cyclic alkyl group and aryl group may further have a substituent such as an alkyl group, an aryl group and a halogen atom.

What is important in the present invention is that the compound of the formula (1) is prepared by mixing the compound of the formula (1) in the form of a monomer, oligomer or polymer having a reactive functional group with a charge transporting material and then mixing with a solvent or other resin. A polymerization reaction and a cross-linking reaction are caused together with the drying process using the applied coating liquid.
According to this method, the charge transporting material can be uniformly dispersed, and the dispersion state of the reaction product of the compound of the formula (1) can be controlled even when the compound of the formula (1) is mixed with another resin.

The reaction that occurs during coating and drying is as follows: M = Si
Can be expressed as follows.

[0027]

Embedded image

As the catalyst used in this reaction, various acids,
Examples thereof include metal salts, bases and alkoxides of organic acids, and an organic solvent is used as a solvent. When R ¹ is halogen, a catalyst may not be used.

The reaction product obtained by this reaction is composed of the following units.

[0030]

Embedded image

Next, the structure of the electrophotographic photosensitive member of the present invention will be described.

The conductive support may be any conductive material, and may be a metal such as aluminum and stainless steel, or a metal provided with a conductive layer, plastic, paper, or the like. And the like.

When the image input is a laser beam such as LBP, a conductive layer may be provided for the purpose of preventing interference fringes due to scattering or covering a scratch on the support. This can be formed by dispersing conductive powder such as carbon black and metal particles in a binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, more preferably 10 to 30 μm.
It is.

An intermediate layer having an adhesive function is provided thereon. Examples of the material for the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are applied by dissolving in an appropriate solvent. The thickness of the intermediate layer is preferably from 0.1 to 5 μm, more preferably from 0.3 to 1 μm.

On the intermediate layer, a coating liquid in which a charge generating material such as a phthalocyanine pigment, an azo pigment and an anthrone pigment is dispersed in a binder resin in which the charge generating material is dissolved in a solvent is applied and dried to form a charge generating layer. . As the binder resin used herein, for example, a polyester resin, a polyacryl resin, a polyvinyl carbazole resin, a phenoxy resin, a polycarbonate resin, a polystyrene resin, a polyvinyl acetate resin, a polysulfone resin, a polyarylate resin, a vinylidene chloride resin, an acrylonitrile copolymer, and a polyvinyl benzal Resins and the like are mainly used. The ratio of the binder resin to the pigment is preferably 1/1 to 10/1, more preferably 1.5 / 1 to 3/1.
It is.

The charge transport layer is formed by applying a coating material in which a charge transport material and a binder resin are dissolved in a solvent and then drying the coating material. Examples of the charge transporting material used include various triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, triallylmethane compounds, and thiazole compounds.

The compound of the formula (1) used in the present invention is
One kind may be used, or two or more kinds may be mixed at an arbitrary ratio. Further, the compound of the formula (1) can be used alone as a binder or mixed with another organic resin. In this case, the same resin as that used in the charge generation layer can be used as the organic resin.

FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.

In FIG. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate around a shaft 2 in a direction of an arrow at a predetermined peripheral speed. The photoreceptor 1 rotates during the rotation process.
The peripheral surface thereof is uniformly charged with a predetermined positive or negative potential by the primary charging unit 3 and then receives image exposure light 4 from an image exposure unit (not shown) such as slit exposure or laser beam scanning exposure. Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then transferred to developing means 5
The toner-developed image developed by the toner image is transferred from a paper supply unit (not shown) between the photoconductor 1 and the transfer unit 6 in synchronization with the rotation of the photoconductor 1 and fed to a transfer material 7 fed therefrom. The image is sequentially transferred by the transfer unit 6.

The transfer material 7 having undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing, thereby being printed out of the apparatus as a copy.

The surface of the photoreceptor 1 after the image is transferred is cleaned by removing the untransferred toner by the cleaning means 9, and the pre-exposure light 10 from the pre-exposure means (not shown).
Is used for image formation repeatedly after the charge removal processing. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not necessarily required.

In the present invention, a plurality of components such as the above-described electrophotographic photosensitive member 1, primary charging means 3, developing means 5 and cleaning means 9 are integrally connected as a process cartridge. The process cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photoreceptor 1 to form a cartridge, which can be attached to and detached from the apparatus main body using a guide unit such as a rail 12 of the apparatus main body. The process cartridge 11 can be used.

When the electrophotographic apparatus is a copying machine or a printer, the image exposure light 4 is reflected or transmitted from the original, or the original is read by a sensor and converted into a signal, and the exposure is performed according to the signal. Laser beam scanning,
Light emitted by driving the LED array, driving the liquid crystal shutter array, and the like.

The electrophotographic photosensitive member of the present invention can be used not only for an electrophotographic copying machine but also for a laser beam printer,
It can be widely used in electrophotographic applications such as RT printers, LED printers, liquid crystal printers, and laser plate making.

Hereinafter, the present invention will be described with reference to examples.

<Example of preparation of preparation liquid> Equimolar mixture of tetraethyl silicate and phenyltriethyl silicate 2
0 parts by weight, 10 parts by weight of ion-exchanged water, and 2N hydrochloric acid 0.1 part by weight.
A solution composed of 15 parts by weight and 65 parts by weight of methanol was mixed and stirred for one day to prepare a liquid mixture 1. In the same manner as in the preparation liquid 1, the following preparation liquids 2 and 3 were prepared.

[0048]

Example 1 A 30φ, 260 aluminum cylinder was used as a support, and a coating composed of the following materials was applied on the support by a dipping method.
The film was thermally cured for 0 minute to form a conductive layer having a thickness of 15 μm.

Conductive pigment: tin oxide-coated titanium oxide 10 parts (parts by weight, hereinafter the same) Resistance adjusting pigment: titanium oxide 10 parts Binder resin: phenol resin 10 parts Leveling agent: Silicone oil: 0.001 part Solvent: methanol / methyl cellosolve = 1/1: 20 parts

Next, N-methoxylated nylon 3
And a solution of 3 parts of copolymerized nylon in 65 parts of methanol and 30 parts of n-butanol were applied by a dipping method to form a 0.5 μm intermediate layer. Next, CuKα characteristic X
The Bragg angle 2θ ± 0.2 ° in the line diffraction is 9.0
Oxytitanium phthalocyanine (TiOP) having strong peaks at °, 14.2 °, 23.9 ° and 27.1 °.
c) 4 parts and polyvinyl butyral (trade name: SREC B
M-2, manufactured by Sekisui Chemical Co., Ltd.) and 80 parts of cyclohexanone were dispersed in a sand mill using φ1 glass beads for 4 hours, and 115 parts of methyl ethyl ketone was added to obtain a charge generation layer dispersion. This was applied on the intermediate layer by an immersion method to form a charge generation layer having a thickness of 0.3 μm.

Next, 25 parts of an amine compound having the following structural formula

[0053]

Embedded image And 100 parts of Preparation 1 shown in Table 1 were mixed.

This paint was applied on the above-mentioned charge generation layer by a dipping method and dried at 120 ° C. for 2 hours to form a charge transport layer having a thickness of 25 μm.

The gradation reproducibility of the image of the electrophotographic photosensitive member produced as described above was evaluated using the following electrophotographic image forming apparatus. Table 2 shows the results.

FIG. 2 shows an electrophotographic apparatus showing an embodiment of the present invention, and will be briefly described.

First, the original G is set on the original table 30 with the side to be copied facing downward. Next, copying is started by pressing the copy button. Document illumination lamp, short focus lens array and CCD sensor integrated unit 2
9 scans the original while irradiating the original, and the irradiated scanning light is imaged by the short-focus lens array and
It is incident on the D sensor. The CCD sensor includes a light receiving unit, a transfer unit, and an output unit. The light signal is converted into an electric signal in the CCD light receiving section, and is sequentially transferred to the output section in synchronization with the clock pulse in the transfer section. The output section converts the charge signal into a voltage signal, and amplifies and reduces the impedance to output. The analog signal obtained in this manner is converted into a digital signal, and further converted into a digital signal for performing image processing for optimizing resolution and gradation according to the characteristics of the image and outputting the digital signal. Sent to the department. When outputting from a computer or the like, resolution, gradation reproduction method, and the like are selected, processed and converted so as to obtain a desired image, and sent to a printer unit. The printer unit receives the image signal and forms an electrostatic latent image as follows. Photosensitive drum 2 of the present invention
1 is driven to rotate at a predetermined peripheral speed around a center support shaft,
In the rotation process, the charger 23 receives a predetermined positive or negative uniform charging process of a predetermined voltage, and emits light of the solid-state laser element which is turned on and off in response to an image signal on the uniformly charged surface. An electrostatic latent image corresponding to a document image is sequentially formed on the surface of the photosensitive drum 21 by scanning with a rotating polygon mirror rotating at high speed.

FIG. 3 shows a schematic mechanism of a laser scanning section 300 for scanning a laser beam in the above-mentioned apparatus. When a laser beam is scanned by the laser scanning unit 300, the laser beam emitted from the solid-state laser element 302 is first emitted by a light-emitting signal generator 301 based on an input image signal to a collimator lens system 303.
Is converted into a substantially parallel light beam, and is further scanned in the direction of the arrow c by the rotating polygon mirror 304 which rotates in the direction of the arrow b, and the fθ lens groups 305a, 305b and 305c
As a result, a spot-like image is formed on the surface to be scanned 306 such as a photosensitive drum. By such scanning of the laser beam, an exposure distribution for one scan of an image is formed on the surface to be scanned 306. If the surface to be scanned 306 is scrolled by a predetermined amount perpendicularly to the scanning direction, the scanned surface is scanned. An exposure distribution according to the image signal is obtained on the surface 306.

In this embodiment, since the multi-value recording by the area gradation of one pixel is performed by using the laser PWM method (pulse width modulation), the PWM method will be briefly described.

FIG. 4 is a circuit block diagram showing one example of the pulse width modulation circuit, and FIG. 5 is a timing chart showing the operation of the pulse width modulation circuit.

In FIG. 4, reference numeral 401 denotes a TTL latch circuit for latching an 8-bit digital image signal;
A high-speed level converter 403 for converting the L logic level to the ECL logic level, and a high-speed D / A converter 403 for converting the ECL logic level to an analog signal. 404 is PWM
ECL comparator for generating signal, 405 is ECL comparator
A level converter for converting the logic level to a TTL logic level, a clock oscillator 406 for oscillating the clock signal 2f, a reference numeral 407 for generating a substantially ideal triangular wave signal in synchronization with the clock signal 2f, and a reference numeral 408 for the clock signal 2f Is a 分 frequency divider that generates the image clock signal f by dividing the frequency by １ ／. Thus, the clock signal 2f has a cycle twice as long as the image clock signal f. In order to operate the circuit at high speed, ECL is used everywhere.
A logic circuit is provided.

The circuit operation having such a configuration will be described with reference to the timing chart of FIG. The signal (a) shows the clock signal 2f and the signal (b) shows the image clock signal f, which are related to the special image signal shown in the figure. Also,
Even inside the triangular wave generator, the clock signal 2f is once frequency-divided by に to generate the triangular wave signal (c) in order to keep the duty ratio of the triangular wave signal at 50%. Further, this triangular wave signal (c) is converted into an ECL level to become a triangular wave signal (d).

On the other hand, the image signal is from 00h (white) to FFh
It changes at 256 gradation levels up to (black). The symbol 'h' indicates hexadecimal notation. And the image signal (e) is D / A for some image signal values.
The converted ECL voltage level is shown. For example, the first
The pixel indicates a black pixel level FFh, the second pixel indicates a halftone level 80h, the third pixel indicates a halftone level 40h, and the fourth pixel indicates a halftone level 20h. The comparator compares the triangular wave signal (d) with the image signal (e) to generate PWM signals such as pulse widths T, t2, t3 and t4 corresponding to the pixel density to be formed.
Then, this PWM signal is converted into a TTL level of 0 V or 5 V, becomes a PWM signal (f), and is input to the laser driver circuit 409. The P thus obtained
By changing the exposure time per pixel corresponding to the WM signal value, it is possible to obtain a maximum of 256 gradations per pixel. Reference numeral 500 denotes a laser beam scanning exposure.

In this embodiment, the gradation control by the PWM method is used. However, an area gradation method such as a dither method or laser light intensity modulation can be used, and furthermore, these methods may be combined.

The electrostatic latent image formed on the photosensitive drum 21 is developed by the developing device 24, and the formed toner image is electrostatically transferred onto a transfer material by the transfer charger 27. Thereafter, the transfer material is electrostatically separated by the separation charger 28, conveyed to the fixing device 26, and thermally fixed to output an image.

On the other hand, the surface of the photosensitive drum 21 after the transfer of the toner image is subjected to removal of adhered contaminants such as untransferred toner by the cleaner 25 and is repeatedly used for image formation.

The above-described electrophotographic image forming apparatus uses a semiconductor laser to expose a photosensitive member by a polygonal scanning optical system. However, an LED printer is used as a solid-state scanner having no mechanical driving unit such as a polygon. A head is used. LED printer heads are generally linearly integrated with light-emitting diodes, and some have a resolution of 400 dpi or more. Since there is no driving part, the size is advantageous for miniaturization. The spot light from the LED printer head is imaged on the photoreceptor by the converging rod lens array. At this time, the resolution in the main scanning direction is determined by the integration degree of the LED printer head, and is 400 dpi, that is, 63.
Although a resolution higher than 5 μm is used, the sub-scanning direction is determined by the light condensing performance of the rod lens array and the moving speed of the photoconductor.

Although the light emission intensity distribution of the LED has a more rectangular distribution than the Gaussian distribution, the area of a portion having 1 / e ² of the peak intensity may be considered.

The gradation reproducibility in the present invention is 400 dp.
When the irradiation amount of the light beam is linearly changed by 256 gradations at the resolution of i, the image density is defined by a portion proportional to the irradiation amount. FIG. 7 shows a schematic diagram of the measurement of gradation reproducibility in the present invention.

The image forming apparatus used in the present invention is 680 m
m, 35 mW semiconductor laser is used. The spot system on the photoconductor is 1 / e ² in the sub-scanning direction, 63.5 μm corresponding to 400 lines, and the spot diameter of 1 / e ^{2 in the} main scanning direction is 25.
μm (see FIG. 6). The gradation reproducibility was measured by the above-described apparatus and method.

Further, the easiness of scraping of the photosensitive member at the time of durability was evaluated using NP-6030 manufactured by Canon. Changes in the film thickness of the photoreceptor after 10,000 sheets of durability were shown. Table 2 shows the results.

Example 2 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the thickness of the charge transport layer of the photosensitive member used in Example 1 was 9 μm. Table 2 shows the results.
Shown in

Example 3 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that Preparation Liquid 2 was used instead of Preparation Liquid 1 in Table 1 used in Example 2. Table 2 shows the results.

Example 4 An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that Preparation Liquid 3 was used instead of Preparation Liquid 1 in Table 1 used in Example 2. Table 2 shows the results.

Comparative Example 1 Example 1 was repeated except that the binder resin of the charge transport layer was changed to polycarbonate Z.
An electrophotographic photoreceptor was prepared in the same manner as described above and evaluated in the same manner. Table 2 shows the results.

Comparative Example 2 Example 2 was repeated except that the binder resin of the charge transport layer was made of polycarbonate Z.
An electrophotographic photoreceptor was prepared in the same manner as described above and evaluated in the same manner. Table 2 shows the results.

Example 5 An electrophotographic photoreceptor of the present invention was prepared in the same manner as in Example 1, except that the aluminum cylinder was changed to one having an outer diameter of 30 mm and a length of 260 mm. The obtained electrophotographic photosensitive member was mounted on a reversal-developed electrophotographic printer, and charged, exposed, developed, and transferred.
The cleaning process was repeated with a 6 second cycle.
The electrophotographic properties of this photoreceptor were evaluated under low temperature and low humidity (15 ° C., 15% RH) and high temperature and high humidity (30 ° C., 85% RH) environments. As a result, as shown in Table 3, this photoconductor can form a large difference between the dark portion potential (V _D ) and the bright portion potential (V _L ) at both low temperature and low humidity and high temperature and high humidity. As a result, sufficient contrast could be obtained. Further, when images were continuously output on 5000 sheets of recording paper, in either environment, both the dark portion potential and the bright portion potential hardly changed, and extremely excellent image quality free of unnecessary black spot images and fog was obtained. Images were also obtained stably.

Comparative Example 3 Example 5 was repeated except that the binder resin of the charge transport layer was changed to polycarbonate Z.
An electrophotographic photoreceptor was prepared in the same manner as described above and evaluated in the same manner. Table 3 shows the results.

[0079] Sharpness (μm) = Photoreceptor thickness before endurance−Photoreceptor thickness after endurance 400 dpi Gradation: ○ 256 gradations are reproduced. Δ 128 to less than 256 tones.

[0080]

[0081]

As described above, the electrophotographic photoreceptor of the present invention has less wear due to abrasion and scratches during continuous image formation by repeated charging and exposure, and has excellent durability. An electrophotographic photosensitive member capable of obtaining high image quality output having tone reproducibility, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member have been made possible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first example of an electrophotographic apparatus of the present invention.

FIG. 2 is a schematic configuration diagram of a second example of the electrophotographic apparatus of the present invention.

FIG. 3 is a schematic diagram of a laser beam scanning unit of the second apparatus example.

FIG. 4 is a circuit block diagram of a pulse width modulation circuit for controlling a laser beam of the second device example.

FIG. 5 is a timing chart showing an operation of a pulse width modulation circuit for controlling laser light in the second device example.

FIG. 6 is a schematic diagram showing a product of a spot area of a light beam and a film thickness of a photosensitive layer in the electrophotographic photosensitive member of the present invention.

FIG. 7 is a schematic diagram illustrating a relationship between a light irradiation amount and an image density in a method of measuring gradation reproducibility.

Claims (4)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer having a charge generation layer and a charge transport layer on a conductive support, wherein the charge transport layer is at least one kind of a compound represented by the following formula (1). An electrophotographic photoreceptor comprising the reaction product of _{^{R 1 m -M- (OR 2)}} n (1) ( wherein, M represents Si, Al, Ti or Zr, R ¹
And R ² represent a hydrogen atom, an alkyl group, a cyclic alkyl group, an aryl group, a halogen atom or —CF ₃ , m represents an integer, and n represents an integer of n ≧ 1. ) 2. The electrophotography according to claim 1, wherein a product of a spot area of a light beam for forming a latent image on the electrophotographic photoconductor and a film thickness of a photosensitive layer of the electrophotographic photoconductor is 20,000 μm ³ or less. Photoconductor. 3. The electrophotographic photoreceptor according to claim 1 or 2, and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means are integrally supported and detachably attached to an electrophotographic apparatus main body. A process cartridge, characterized in that: 4. An electrophotographic apparatus comprising: the electrophotographic photoreceptor according to claim 1; a charging unit; an image exposing unit; a developing unit; and a transfer unit.