JP3248627B2 - Electrophotographic photoreceptor, electrophotographic apparatus and apparatus unit having the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor,
More specifically, the present invention relates to an electrophotographic photoreceptor having a low molecular weight organic photoconductive compound that provides improved electrophotographic properties.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic photoreceptor, an inorganic photoreceptor having a photosensitive layer containing selenium, zinc oxide, cadmium or the like as a main component has been widely used. Although these have some basic properties, they have problems such as difficulty in film formation, poor plasticity, and high production cost. Furthermore, inorganic photoconductive materials are generally highly toxic, and have great restrictions on production and handling.

On the other hand, an organic photoreceptor containing an organic photoconductive compound as a main component has attracted attention in recent years because it has many advantages such as compensating the above-mentioned disadvantages of the inorganic photoreceptor, and many proposals have been made so far. or that have been put into practical use.

As such an organic photoreceptor, poly-N
-An electrophotographic photoreceptor having a charge transfer complex formed from a photoconductive polymer represented by vinyl carbazole and a Lewis acid such as 2,4,7-trinitro-9-fluorenone as a main component has been proposed. I have. These organic photoconductive polymers are superior to inorganic photoconductive polymers in terms of lightness, film-forming properties, etc., but are inferior in terms of sensitivity, durability, stability due to environmental changes, etc. And it is not always satisfactory.

On the other hand, a function-separated type electrophotographic photoreceptor in which a charge generation function and a charge transport function are respectively assigned to different substances brings a remarkable improvement in sensitivity and durability, which have been regarded as disadvantages of conventional organic photoreceptors. Was. Such a function-separated type photoreceptor has an advantage that a material selection range of a charge generation material and a charge transport material is wide, and an electrophotographic photoreceptor having arbitrary characteristics can be relatively easily prepared.

Various azo pigments are used as the charge generating material,
Known are polycyclic quinone pigments, cyanine dyes, squaric acid dyes, and pyrylium salt dyes. Among them, many structures of azo pigments have been proposed from the viewpoints of high light resistance, high charge generation ability, easy material synthesis, and the like.

On the other hand, examples of the charge transport material include pyrazoline compounds disclosed in JP-B-52-4188 and JP-B-55-188.
Hydrazone compounds disclosed in JP-A-42380 and JP-A-55-52063, triphenylamine compounds disclosed in JP-B-58-32372 and JP-A-61-132950, JP-A-54-151955 and JP-A-54-151955 A stilbene compound disclosed in Japanese Patent Application Laid-Open No. 58-198043 is known.

These charge transport materials are required to (1) be stable to light and heat (2) be stable to ozone, NOx, nitric acid, etc. generated by corona discharge ( 3) High charge transport ability (4)
High compatibility with organic solvents and binders; (5) easy and inexpensive production.

With the recent demand for higher durability of the electrophotographic photosensitive member, a protective layer is provided on the photosensitive layer in order to improve durability, and the photosensitive member is stored for a long time by a copying machine or a laser beam printer. As a result, cracks may occur in the charge transport layer, or phenomena such as crystallization and phase separation of the charge transport material may occur, resulting in image defects.

In a reversal developing system corresponding to recent digitization, since the primary charging and the transfer charging have opposite polarities, a so-called transfer memory having a different chargeability depending on the presence or absence of transfer occurs, and it is very easy to appear as density unevenness on an image. Has become.

However, a conventional electrophotographic photosensitive member using a charge transporting substance using a low-molecular organic compound satisfies some of the above problems and requirements, but none of them satisfy all of them at a high level. .

[0012]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an organic photoconductive compound which sufficiently satisfies the characteristics required for the above-described charge transporting material, thereby providing various types of conventional photoreceptors. It is to eliminate the disadvantages.

That is, first, it is an object of the present invention to provide an electrophotographic photosensitive member having a high sensitivity and capable of stably maintaining a potential upon repeated use.

Second, even if a protective layer is provided on the photosensitive layer, or the photosensitive member is stored for a long period of time by a copying machine, a laser beam printer, or the like, cracks occur in the charge transport layer, and crystallization of the charge transport material occurs. There is no need to provide an electrophotographic photoreceptor.

A third object of the present invention is to provide an electrophotographic photosensitive member in which transfer memory hardly occurs even in a reversal developing system.

A fourth object of the present invention is to provide a novel organic photoconductive compound which can be easily produced and can be provided at low cost.

[0017]

Means for Solving the Problems The present inventors have intensively studied the organic photoconductive compound which provides the above-described electrophotographic photoreceptor having high sensitivity, high durability and free from image defects, and reached the present invention.

That is, the present invention provides an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer comprises at least two arylamine compounds represented by the following general formula [1].
Or more, and at least one of them has a melting point of 120.
An electrophotographic photoreceptor, wherein the temperature is below

[0019]

Embedded image

(Wherein, Ar ¹ , Ar ² and Ar ³ each represent an alkyl group, an aralkyl group, an aromatic ring group, a heterocyclic group,
An aromatic or heterocyclic group which may have an alkoxy group, an aryloxy group, a halogen atom, an alkylthio group, an arylthio group or a hydroxyl group but has no amino group . ).

In the general formula [1], Ar ¹ , Ar ² and Ar ³ each represent an alkyl group, an aralkyl group, an aromatic ring group, a heterocyclic group, an alkoxy group, an aryloxy group, a halogen atom, an alkylthio group, an arylthio group or Although it may have a hydroxyl group, a phenyl group having no amino group , a naphthyl group, anthryl group, a pyrenyl group, a fluorenyl group, a carbazolyl group, a dibenzofuryl group, a dibenzothiophenyl group, or an aromatic ring group or an amino group. It represents a heterocyclic group such as a pyridyl group, a thienyl group, a furyl group, and a quinolyl group that does not have .

The groups which Ar ¹ , Ar ² and Ar ³ may have include alkyl groups such as methyl, ethyl, propyl and butyl, benzyl, phenethyl and naphthylmethyl. Aralkyl group, phenyl group, naphthyl group, anthryl group, aromatic ring group such as pyrenyl group, pyridyl group, thienyl group, quinolyl group, heterocyclic group such as furyl group,
Methoxy group, ethoxy group, alkoxy group such as propoxy group, phenoxy group, aryloxy group such as naphthoxy group, fluorine, chlorine, bromine, halogen atom group such as iodine,
Examples thereof include an alkylthio group such as a methylthio group and an ethylthio group, an arylthio group such as a phenylthio group and a naphthylthio group, and a hydroxyl group.

According to the detailed studies by the present inventors, it is found that the melting point is extremely effective for any of cracks in the photosensitive layer that causes image defects, crystallization of the charge transport material, and transfer memory in the reversal development system. Is a general formula [1] in which is less than 120 ° C.
Is preferably 5% to 95%, particularly preferably 10% to 90%, of all the charge transporting substances in the photosensitive layer.

The typical examples of the compounds represented by the general formula [1] are shown below. However, they are not represented by these compounds.

[0025]

Embedded image

[0026]

Embedded image

[0027]

Embedded image

[0028]

Embedded image

[0029]

Embedded image

[0030]

Embedded image

[0031]

Embedded image

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

The photoreceptor of the present invention is suitable for a charge transport material comprising at least two arylamine compounds represented by the above general formula [1] (at least one of which has a melting point of 120 ° C. or less). And various charge generating substances.

Examples of the structure of the photosensitive layer include the following. (1) Layer containing charge generation material / layer containing charge transport material (2) Layer containing charge transport material / layer containing charge generation material (3) Layer containing charge generation material and charge transport material (4) Layer containing charge generation material / layer containing charge generation material and charge transport material

Since the arylamine compound represented by the general formula [1] of the present invention has a high hole-transporting ability, it can be used as a charge-transporting substance in the photosensitive layer of the above-mentioned embodiment. When the form of the photosensitive layer is (1), negative charge is preferable, and when the form is (2), positive charge is preferable. (3), (4)
In the case of, either positive or negative charging can be used.

Further, in the electrophotographic photoreceptor of the present invention, a protective layer or an insulating layer may be provided on the surface of the photosensitive layer for improving adhesion and controlling charge injection. The configuration of the photoreceptor of the present invention is not limited to the above basic configuration.

The configuration (1) is particularly preferable among the above configurations, and will be described in more detail below.

Examples of the conductive support in the present invention include the following forms. (1) Aluminum, aluminum alloy, stainless steel,
Plates or drums made of metal such as copper. (2) Aluminum, palladium, or the like on a non-conductive support such as glass, resin, paper, or the conductive support of (1).
A thin film formed by depositing or laminating metals such as rhodium, gold and platinum. (3) Depositing or applying a layer of a conductive compound such as a conductive polymer, tin oxide, or indium oxide on a non-conductive support such as glass, resin, paper, or the conductive support of (1). What was formed by

Examples of the effective charge generating substance used in the present invention include the following substances. These charge generating substances may be used alone or in combination of two or more. (1) Azo pigments such as monoazo, bisazo and trisazo (2) Phthalocyanine pigments such as metal phthalocyanine and non-metal phthalocyanine (3) Indigo pigments such as indigo and thioindigo (4) Perylene anhydride, perylene imide and the like Novelylene pigments (5) Polycyclic quinone pigments such as anthraquinone and pyrenequinone (6) Squarylium dyes (7) Pyrylium salts and thiopyrylium salts (8) Triphenylmethane dyes (9) Selenium, amorphous silicon, etc. Inorganic substances

The layer containing the charge generating substance, that is, the charge generating layer, can be formed by dispersing the above-described charge generating substance in an appropriate binder, and applying the resultant to a conductive support. it can. Further, it can also be formed by forming a thin film on a conductive support by a dry method such as vapor deposition, sputtering, or CVD.

The binder can be selected from a wide range of binder resins, for example, polycarbonate resin, polyester resin, polyarylate resin, butyral resin, polystyrene resin, polyvinyl acetal resin, diallyl phthalate resin, acrylic resin, methacrylic resin. , Vinyl acetate resin, phenol resin, silicone resin, polysulfone resin, styrene-butadiene copolymer resin, alkyd resin, epoxy resin, urea resin, vinyl chloride-vinyl acetate copolymer resin, but are not limited thereto. Not something. These may be used alone or as a copolymer in one kind or as a mixture of two or more kinds.

The resin contained in the charge generation layer is preferably at most 80% by weight, more preferably at most 40% by weight. The thickness of the charge generation layer is 5 μm or less, particularly 0.01 μm to 2 μm.
It is preferable to form a thin film layer having a thickness of μm.

Various sensitizers may be added to the charge generation layer.

The layer containing the charge transporting material, that is, the charge transporting layer, has at least two kinds of arylamine compounds represented by the general formula [1] (at least one kind having a melting point of 120 ° C. or less) and a suitable adhesive property. It can be formed in combination with a resin. Here, examples of the binder resin used in the charge transport layer include those used in the charge generation layer, and further include photoconductive polymers such as polyvinyl carbazole and polyvinyl anthracene.

The mixing ratio of the binder and the arylamine compound of the general formula [1] is preferably 10 to 500 parts by weight of the arylamine compound per 100 parts by weight of the binder.

The charge transport layer is electrically connected to the above-described charge generation layer, and has a function of receiving charge carriers injected from the charge generation layer in the presence of an electric field and transporting these charge carriers to the surface. have. Since the charge transport layer has a limit to transport charge carriers, it cannot be made thicker than necessary.
The range is preferably from m to 40 µm, particularly preferably from 10 µm to 30 µm.

Further, an antioxidant, an ultraviolet absorber, a plasticizer, or a known charge transport substance can be added to the charge transport layer as needed.

In forming such a charge transport layer, an appropriate organic solvent is used, and a coating method such as dip coating, spray coating, spinner coating, roller coating, Meyer bar coating, blade coating, etc. Can be performed.

FIG. 1 shows a schematic configuration example of a general transfer type electrophotographic apparatus using the electrophotographic photosensitive member of the present invention.

In FIG. 1, reference numeral 1 denotes a drum type photosensitive member of the present invention as an image carrier, which is driven to rotate around an axis 1a in a direction of an arrow at a predetermined peripheral speed. The photoreceptor 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by a charging means 2 during the rotation process, and then, in an exposure section 3, a light image exposure L (slit exposure / Laser beam scanning exposure). As a result, an electrostatic latent image corresponding to the exposure image is sequentially formed on the peripheral surface of the photoconductor.

The electrostatic latent image is then developed with toner by the developing means 4, and the developed toner image is transferred by the transfer means 5 between the photosensitive member 1 and the transfer means 5 from a paper feeding unit (not shown). The transfer material P is sequentially transferred onto the surface of the transfer material P which is synchronously taken out and fed.

The transfer material P having undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing to be printed out outside the machine as a copy.

The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the untransferred toner by the cleaning means 6, and further subjected to a charge removal treatment by the pre-exposure means 7 to be used repeatedly for image formation.

As the uniform charging means 2 for the photosensitive member 1, a corona charging device is generally widely used. Transfer device 5
Also, corona transfer means are generally widely used. As an electrophotographic apparatus, a plurality of components such as the above-described photoreceptor, developing means, and cleaning means are integrally connected as an apparatus unit, and this unit is configured to be detachable from the apparatus body. May be. For example, photoconductor 1
The cleaning unit 6 and the cleaning unit 6 may be integrated into one device unit, and may be configured to be detachable using a guide unit such as a rail of the device body. At this time, the above-described device unit may be provided with a charging unit and / or a developing unit.

In the case where the electrophotographic apparatus is used as a copying machine or a printer, the light image exposure L is a signal reflected from or transmitted from the original, or a read signal of the original. , Or by driving a liquid crystal shutter array.

When used as a facsimile printer, the light image exposure L is an exposure for printing received data. FIG. 2 is a block diagram showing an example of this case.

The controller 11 controls the image reading section 10 and the printer 19. The whole controller 11 is CP
It is controlled by U17. The read data from the image reading unit 10 is transmitted to the partner station through the transmission circuit 13. Data received from the partner station is sent to the printer 19 through the receiving circuit 12. The image memory 16 stores predetermined image data. The printer controller 18 controls a printer 19. 14 is a telephone.

The image information received from the line 15 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 12, then decoded by the CPU 17, and sequentially stored in the image memory 16. Is stored. When the image information of at least one page is stored in the memory 16, the image of the page is recorded. The CPU 17 reads one page of image information from the memory 16 and sends the decoded one page of image information to the printer controller 18. Upon receiving the image information of one page from the CPU 17, the printer controller 18 controls the printer 19 to record the image information of the page.

The CPU 17 receives the next page during recording by the printer 19.

As described above, image reception and recording are performed.

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,
RT printer, LED printer, LCD printer,
It can be widely used in electrophotographic applications such as laser plate making.

According to the present invention, it is possible to provide a high-sensitivity electrophotographic photosensitive member, and has an advantage that a change in a light portion potential and a dark portion potential upon repeated charging and exposure is small.

Further, cracks may occur in the charge transport layer,
It is possible to provide an electrophotographic photoreceptor that does not cause crystallization and phase separation of the charge transport material and has no image defects.

Further, it is possible to provide an electrophotographic photosensitive member in which transfer memory hardly occurs even in a reversal developing system.

[0067]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.

Example (1) A coating solution was prepared by dispersing 15 g of a bisazo pigment represented by the following structural formula together with a solution of 7.5 g of butyral resin (butyralization degree: 63 mol%) in 280 ml of cyclohexanone using a sand mill for 24 hours. did.

[0069]

Embedded image

This coating solution was applied on an aluminum sheet with a Meyer bar so that the film thickness after drying was 0.15 μm to form a charge generation layer.

Next, as the charge transporting substance, the above-mentioned Compound No. (3) 8 g, (4) 2 g, and 12.5 g of a polycarbonate resin (weight average molecular weight 25,000) were dissolved in 80 g of monochlorobenzene, and this solution was applied on the previous charge generating layer with a Meyer bar, and then dried. A charge transport layer having a thickness of 20 μm was provided to form a two-layer electrophotographic photosensitive member.

The electrophotographic photoreceptor thus prepared was used as an electrostatic copying paper tester Model-SP manufactured by Kawaguchi Electric Co., Ltd.
Using -428, corona charging was performed in a static manner at -5 kV, and after holding in a dark place for 1 second, exposure was performed at an illuminance of 20 Lux to check charging characteristics.

The charging characteristics include surface potential (V ₀ ) and 1
The exposure amount (E _1/5 ) required to attenuate the potential (V ₁ ) after dark decay for 2 seconds to 1/5 was measured.

Further, in order to measure the fluctuations in the light portion potential and the dark portion potential when the photoreceptor is repeatedly used, the photoconductor prepared in this embodiment was replaced with a PPC copier NP-382 manufactured by Canon Inc.
Paste 5 of the photosensitive drum cylinder performs 3,000 sheet copying in the aircraft, the initial and variation △ V _L and the dark potential of the light portion potential after 3,000 sheet copying (V _L) (V _D )
The variation △ V _D was measured. The initial V _D and V _L were set to be -700 V and -200 V, respectively.

As a test for accelerating the cracking of the photosensitive layer, finger oil was adhered to the surface of the electrophotographic photosensitive member prepared as described above, and left standing at normal temperature and pressure for 8 hours to determine whether the photosensitive layer had cracks. Was observed.

As a test for accelerating the crystallization of the charge transport material, finger oil was adhered to the surface of the electrophotographic photosensitive member prepared as described above, and left at 45 ° C. for 4 days to cause crystallization of the charge transport material. It was observed whether or not.

Examples (2) to ( 9 ) and Comparative Examples (1) to
(13) In this example and the comparative example, the charge transport material No. 1 used in the example (1) was used. Instead of (3), (4),
An electrophotographic photosensitive member was prepared in the same manner as in Example (1) except that the compounds shown in Tables 1 and 2 below were used. The electrophotographic characteristics of each photoconductor, cracks in the photoconductive layer and crystallization of the charge transporting substance were evaluated by the same method as in Example (1).

The results of Examples (1) to ( 9 ) are shown in Table 1 below, and the results of Comparative Examples (1) to (13) are shown in Table 2 below.

[0079]

[Table 1]

[0080]

[Table 2]

As is clear from Tables 1 and 2, the Examples of the present invention are extremely superior to Comparative Examples without cracking of the photosensitive layer and crystallization of the charge transport material.

Example ( 10 ) 5 g of N-methoxymethylated 6 nylon resin (weight average molecular weight 35,000) and alcohol-soluble copolymerized nylon resin (weight average molecular weight 30,000) were placed on an aluminum substrate.
A solution in which 10 g was dissolved in 90 g of methanol was applied by a Meyer bar, and an undercoat layer having a thickness of 1 μm after drying was provided.

Next, 5 g of titanyloxyphthalocyanine was added to a solution prepared by dissolving 4 g of phenoxy resin in 180 g of cyclohexanone, and dispersed in a ball mill for 48 hours. A charge generation layer having a thickness of 0.15 μm after coating and drying was formed by a blade coating method on the undercoat layer prepared above with the dispersion.

Next, the exemplified compound No. (3) 3 g and no. (27) 7 g of a polycarbonate Z-type resin (weight average molecular weight 85,000) dissolved in 12.0 g of monochlorobenzene 75 g, applied on the previously formed charge generating layer by a blade coating method, and dried to obtain a film thickness. 18
A μm charge transport layer was formed.

The photoreceptor thus produced is applied with -5 kV
Was subjected to corona discharge. At this time, the surface potential (initial potential V ₀ ) was measured. Further, the surface potential of this photoconductor after leaving it in a dark place for 1 second was measured. The sensitivity is the exposure amount (E _1/6 : necessary to attenuate the potential V ₁ after dark attenuation to _1/6).
μJ / cm ² ). At this time, a ternary semiconductor laser of gallium / aluminum / arsenic is used as a light source (output: 5 mW; oscillation wavelength: 780 nm).
Was used.

Next, the photosensitive member was attached to a laser beam printer (a modified LBP-SX made by Canon), which is an electrophotographic printer of a reversal development type equipped with a semiconductor laser as described above, and primary charging was performed when the transfer current was OFF. Assuming that the voltage is V _d1 and the primary charging voltage when the transfer current is ON is V _d2 ,
The so-called transfer memory (V _d1 -V _d2 ) was measured, and then an image forming test was performed. The conditions are as follows. Surface potential after primary charging; -700 v, surface potential after image exposure; -150 v (exposure amount 1.0 μJ / cm ² ), transfer potential +700 v, developing polarity; negative polarity, process speed;
47 mm / sec, developing condition (developing bias); -45
0 v, scan method after image exposure; image scan, exposure before primary charging; 8.0 Lux · sec red overall exposure, and image formation was performed by line scanning with a laser beam according to character signals and image signals. Good prints were obtained.

The photoreceptor prepared in the same manner as above
The evaluation of the cracks in the photosensitive layer and the crystallization of the charge transport material was carried out in the same manner as in Example (1). Table 3 shows the results.

Examples ( 11 ) to ( 14 ) The above-mentioned exemplified compound No. 1 used in Example ( 10 ) was used.
(3) 3 g and no. (27) Table 4 below instead of 7g
An electrophotographic photoreceptor was prepared in the same manner as in Example ( 10 ) except that the compound shown in ( 1 ) was used.

Then, the electrophotographic characteristics of each photoconductor, the transfer memory, the cracks in the photoconductive layer, and the crystallization of the charge transporting substance were evaluated by the same methods as in Example ( 10 ).
The results are shown in Table 3 below.

Comparative Examples (14) to (24) The charge transport material No. 1 used in Example ( 10 ) was used.
An electrophotographic photoreceptor was prepared in the same manner as in Example ( 10 ) except that the compounds shown in Table 3 below were used instead of (3) and (27).

Further, (A) to (C) represented by the following structural formulas
An electrophotographic photoreceptor was prepared in the same manner as in Example ( 10 ), except that the compound of No. was used as shown in Table 3 below.

[0092]

Embedded image

Then, the electrophotographic characteristics of each photoconductor, the transfer memory, the cracks in the photoconductive layer, and the crystallization of the charge transporting substance were evaluated by the same method as in Example ( 10 ).
The results are shown in Table 3 below.

[0094]

[Table 3]

[0095]

[Table 4]

[0096] By a similar method as in Example (15) to (18) above except for using the mixing ratio of the charge transporting substance used in Example (10) in the ratio shown in Table 4 below Example (10) An electrophotographic photoreceptor was prepared.

Then, the electrophotographic characteristics of each photoconductor, transfer memory, cracks in the photoconductive layer and crystallization of the charge transporting substance were evaluated by the same methods as in Example ( 10 ).
The results are shown in Table 4 below.

[0098]

[Table 5]

Example ( 19 ) 3 g of 4- (4-dimethylaminophenol) -2,6-diphenylthiapyrylium perchlorate and the above-described charge transporting material No. (3) 2 g and No. (27) 3 g of a copolymerized polyester resin (weight average molecular weight 49,00
The mixture was mixed with 100 g of a solution of 0) in toluene (50 parts by weight) -dioxane (50 parts by weight) and dispersed in a ball mill for 24 hours. This dispersion was applied to an aluminum sheet with a Meyer bar and dried at 110 ° C. for 1 hour to form a 14 μm photosensitive layer. The initial characteristics of the photoreceptor thus prepared were measured in the same manner as in Example (1). This result is shown.

V ₀ = −700 (V) V ₁ = −695 (V) E _1/5 = 3.0 (lux.sec)

When the accelerated test for cracking and crystallization of the photosensitive layer was carried out in the same manner as in Example (1), no cracking was observed even after 4 hours, and no crystallization was observed even after 4 days. Not at all.

Example ( 20 ) 5 g of N-methoxymethylated 6 nylon resin (weight average molecular weight 30,000) and alcohol-soluble copolymerized nylon resin (weight average molecular weight 25,000) were placed on a glass substrate.
A solution in which 10 g was dissolved in a mixed solution of 50 g of methanol and 50 g of butanol was applied by dip coating, and an undercoat layer having a dried film thickness of 1 μm was provided.

Next, the exemplified compound No. (18) 5 g and No. (39) 5 g of bisphenol A type polycarbonate resin (weight average molecular weight 25,000) 12 g was added to monochlorobenzene (25 parts by weight) -dichloromethane (7
5 parts by weight) dissolved in 90 g of the solution, applied on the undercoat layer prepared above with a Meyer bar, and dried to a thickness of 16 μm.
Was formed.

Next, an acrylic monomer 60 having the following structural formula
g, ultrafine tin oxide particles 3 having an average particle size of 400 ° before dispersion
0 g, 2 g of 2-methylthioxanthone as a photoinitiator,
300 g of methylcellosolve was dispersed in a sand mill for 96 hours.

[0105]

Embedded image

Using this dispersion, a film was formed on the above-mentioned photosensitive layer by a beam coating method and dried, and then light-cured with a high-pressure mercury lamp at a light intensity of 8 mW / cm ² for 30 seconds to protect 3 μm. Layers were provided. While irradiating the thus obtained photosensitive layer with light from the back surface at an angle of 15 °, the occurrence of cracks and the crystallization of the charge transport material were observed with a transmission microscope.

The results are shown in Table 5 below.

Examples ( 21 ) and ( 22 ) and Comparative Example (2)
5) to (28) In this example and the comparative example, the aforementioned example ( 20 )
The charge transport material No. used in A photosensitive layer was formed in the same manner as in Example ( 20 ) except that the compounds shown in Table 5 below were used instead of (18) and (39). Then, the cracks in the photosensitive layers and the crystallization of the charge transporting material were evaluated by the same method as in Example ( 20 ).

The results are shown in Table 5 below.

[0110]

[Table 6]

[0111]

As described above, the electrophotographic photoreceptor containing at least two kinds of the arylamine compounds of the present invention has high sensitivity, and has a bright portion potential and a dark portion potential upon continuous image formation by repeated charging and exposure. Fluctuation is small and the durability is excellent. Furthermore, even in the reversal development system, it was possible to simultaneously provide an electrophotographic photoreceptor in which transfer memory is extremely small and cracks in the photosensitive layer that cause image defects and crystallization of the charge transport material are extremely unlikely to occur.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a general transfer type electrophotographic apparatus.

FIG. 2 is a block diagram of a facsimile using the electrophotographic apparatus as a printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging means 3 Exposure part 4 Developing means 5 Transfer means 6 Cleaning means 7 Pre-exposure means 8 Image fixing means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Tetsuro Kanamaru, 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Takakazu Tanaka 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon (56) References JP-A-2-178668 (JP, A) JP-A-3-51854 (JP, A) JP-A-3-196049 (JP, A) JP-A-3-181951 (JP, A A)

Claims (3)

(57) [Claims] 1. An electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer contains at least two or more arylamine compounds represented by the following general formula [1], and An electrophotographic photosensitive member having a melting point of 120 ° C. or less, (Wherein, Ar ¹ , Ar ² and Ar ³ each have an alkyl group, an aralkyl group, an aromatic ring group, a heterocyclic group, an alkoxy group, an aryloxy group, a halogen atom, an alkylthio group, an arylthio group or a hydroxyl group. Is good ,
An aromatic ring group or a heterocyclic group having no amino group is shown. ). 2. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1 . 3. An electrophotographic photoreceptor according to claim 1 , and at least one means selected from the group consisting of a developing means and a cleaning means, which are integrally connected,
An apparatus unit, which is detachable from an electrophotographic apparatus body.