JP2010210913A - Electrophotographic photoreceptor and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having high sensitivity. <P>SOLUTION: The electrophotographic photoreceptor has a photosensitive layer containing an electron transport agent, a charge generator, and a binder resin, formed on a conductive base, and the electron transport agent is a compound expressed by general formula (1), wherein R1 to R4 are identical or different and each represents an hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 20 carbon atoms and m, n, o, and p are identical or different and each represents an integer of 1 to 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member used in an image forming apparatus such as a copying machine, a facsimile machine, a printer, and a multifunction machine.

  In the image forming apparatus described above, various photoreceptors having sensitivity in the wavelength region of the light source used in the apparatus are used. One is an inorganic photoreceptor using an inorganic material such as selenium for the photosensitive layer, and the other is an organic photoreceptor using an organic material for the photosensitive layer. Organic photoconductors are easier to manufacture than inorganic photoconductors, and have a wide range of material options such as charge generators, charge transport agents (electron transport agents / hole transport agents), binder resins, etc. Due to its high degree, it has been used in recent years.

  The organic photoconductor includes a so-called laminated photoconductor comprising a charge generating layer containing a charge generating agent and a charge transporting layer containing a charge transporting agent, and a single layer comprising a charge generating agent and a charge transporting agent. And so-called single-layer type photoreceptors.

  Generally, 3,5-dimethyl-3 ', 5'-di-t-butyldiphenoquinone is used as the electron transporting agent contained as a charge transporting agent in these organic photoreceptors. However, sufficient sensitivity cannot be obtained with a photoreceptor containing this electron transport agent.

    On the other hand, Patent Document 1 discloses a perylenequinone derivative as a compound that can improve the photosensitivity by reducing the residual potential of the electrophotographic photosensitive member, and is particularly suitable as a single-layer type photosensitive member. Yes.

JP 2005-173292 A

However, the electrophotographic photoreceptor using the perylenequinone derivative still has a problem that the photosensitivity is still insufficient. Therefore, the present inventors have discovered the fact that the sensitivity characteristics of the electrophotographic photoreceptor are excellent by using a compound having a specific structure as an electron transport agent, and have completed the present invention.

  That is, an object of the present invention is to solve the above-described technical problems and provide an electrophotographic photoreceptor excellent in sensitivity characteristics and an image forming apparatus provided with such an electrophotographic photoreceptor.

  As a result of intensive studies to solve the above problems, the present inventors have used a compound having a specific structure represented by the following general formula (1) as an electron transport agent, thereby improving the sensitivity of the electrophotographic photoreceptor. A new fact that it can be improved has been found, and the present invention has been completed.

  That is, the electrophotographic photoreceptor in the present invention is an electrophotographic photoreceptor in which a photosensitive layer containing at least an electron transport agent, a charge generating agent, and a binder resin is provided on a conductive substrate. And a compound represented by the following general formula (1).

[In Formula (1), R _{1 to} R ₄ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 20 carbon atoms. . m, n, o, and p are the same or different and represent an integer of 1 to 5. ]
Further, in constituting the electrophotographic photosensitive member of the present invention, it is preferable that the addition amount of the electron transport agent is set to a value within a range of 10 to 100 parts by weight with respect to 100 parts by weight of the binder resin.
In constituting the electrophotographic photosensitive member of the present invention, the photosensitive layer is preferably a single layer type.
Another aspect of the present invention is an image forming apparatus including any one of the electrophotographic photosensitive members described above, and a charging unit, an exposing unit, a developing unit, and a transfer unit arranged around the electrophotographic photosensitive member. .

The electrophotographic photoreceptor of the present invention uses the compound represented by the general formula (1), which is excellent in compatibility with a binder resin and the like and exhibits high charge mobility, as an electron transport agent, so that the residual potential is effectively reduced. In addition to being able to obtain high sensitivity, a good image can be obtained.
In addition, according to the electrophotographic photosensitive member of the present invention, by limiting the amount of the electron transport agent added to a predetermined range, crystallization of the electron transport agent can be effectively prevented, and an electron having excellent sensitivity characteristics can be obtained. A photographic photoreceptor can be obtained.
In addition, according to the electrophotographic photosensitive member of the present invention, by specifying the photosensitive layer as a single layer type, an electrophotographic photosensitive member having excellent sensitivity characteristics can be obtained even though the configuration and manufacture are easy. it can.
In addition, according to the image forming apparatus provided with the electrophotographic photosensitive member of the present invention, the image forming apparatus having an excellent sensitivity characteristic and capable of forming a clear image by including the electrophotographic photosensitive member containing the specific electron transport agent. Can be obtained.

(A)-(b) is a figure provided in order to demonstrate a single layer type electrophotographic photoreceptor. (A)-(c) is a figure provided in order to demonstrate a laminated electrophotographic photoreceptor. FIG. 2 is a diagram for explaining an image forming apparatus including an electrophotographic photosensitive member.

Hereinafter, embodiments of the electrophotographic photosensitive member and the image forming apparatus of the present invention will be specifically described with reference to the drawings as appropriate.
[First Embodiment] The first embodiment is an electrophotographic photosensitive member provided with a photosensitive layer containing a binder resin, an electron transport agent, and a charge generating agent, and the electron transport agent is An electrophotographic photoreceptor containing a compound represented by the general formula (1).
Here, the electrophotographic photosensitive member includes a single layer type and a laminated type, and the electrophotographic photosensitive member of the present invention is applicable to both. However, it can be used for both positive and negative chargeability, has a simple structure and is easy to manufacture, and can suppress film defects when forming a photosensitive layer, so that there are few interfaces between layers and optical characteristics can be improved. For these reasons, it is more preferable to apply to a single layer type. Next, a single layer type electrophotographic photosensitive member and a multilayer type electrophotographic photosensitive member will be described in detail.
1. Single Layer Type Electrophotographic Photoreceptor (1) Basic Configuration As shown in FIG. 1A, a single layer type electrophotographic photosensitive member 10 is constituted by providing a single photosensitive layer 14 on a conductive substrate 12. can do.

In addition, as shown in FIG. 1B, the single layer type electrophotographic photosensitive member has an intermediate layer 16 formed between the conductive substrate 12 and the photosensitive layer 14 as long as the characteristics of the photosensitive member are not impaired. The single-layer type electrophotographic photoreceptor 10 ′ may be used.
(2) Substrate As the conductive substrate 12 illustrated in FIG. 1, various materials having conductivity can be used. For example, a substrate formed of a metal such as iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass, or the above-described metal Examples include a substrate made of a vapor-deposited or laminated plastic material, or a glass substrate coated with aluminum iodide, alumite, tin oxide, indium oxide, or the like.

  That is, it is only necessary that the substrate itself has conductivity or the surface of the substrate has conductivity. Further, it is preferable that the substrate has sufficient mechanical strength when used.

The shape of the substrate may be any of a sheet shape and a drum shape according to the structure of the image forming apparatus to be used.
(3) Intermediate Layer Further, as shown in FIG. 1B, an intermediate layer 16 containing a predetermined binder resin may be provided on the conductive substrate 12.

  The reason for this is to improve the adhesion between the conductive substrate and the photosensitive layer, and by adding a predetermined fine powder in this intermediate layer, to scatter incident light and suppress the generation of interference fringes, This is because charge injection from the substrate to the photosensitive layer during non-exposure that causes fogging and black spots can be suppressed. The fine powder is not particularly limited as long as it has light scattering properties and dispersibility. Inorganic pigments such as alumina, calcium carbonate, barium sulfate and the like, fluorine resin particles, benzoguanamine resin particles, styrene resin particles, and the like can be used.

In addition, it is preferable that the film thickness of an intermediate | middle layer shall be a value within the range of 0.1-50 micrometers.
(4) Photosensitive layer The photosensitive layer contains at least an electron transport agent, a charge generator, and a binder resin.
(4) -1 Charge generator As the charge generator to be contained in the photosensitive layer, a conventionally known charge generator can be used. Examples of such charge generating agents include phthalocyanine pigments such as oxotitanyl phthalocyanine, perylene pigments, bisazo pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaraine pigments, trisazo pigments, indigo pigments, azurenium pigments, cyanine Examples thereof include organic photoconductors such as pigments, pyrylium pigments, ansanthrone pigments, triphenylmethane pigments, selenium pigments, toluidine pigments, pyrazoline pigments, and quinacridone pigments.
Among the charge generating agents described above, in particular, when used in a digital optical image forming apparatus such as a laser beam printer or a facsimile provided with a light source such as a semiconductor laser, a photosensitive material having sensitivity in a wavelength region of 700 nm or more. Therefore, it is preferable that at least one of metal-free phthalocyanine, titanyl phthalocyanine, hydroxygallium phthalocyanine, and chlorogallium phthalocyanine is contained.
Moreover, it is preferable to make the addition amount of a charge generator into the value within the range of 0.2-40 weight part with respect to 100 weight part of binder resin.

The reason for this is that when the added amount of the plurality of charge generating agents is less than 0.2 parts by weight, the effect of increasing the quantum yield becomes insufficient, and the sensitivity, electrical characteristics, stability, etc. of the electrophotographic photosensitive member are reduced. This is because it cannot be improved.
On the other hand, when the added amount of the plurality of charge generating agents exceeds 40 parts by weight, the effect of increasing the extinction coefficient for light having a wavelength in the infrared or near infrared region becomes insufficient, and the sensitivity of the photoconductor. This is because characteristics, electrical characteristics, stability, and the like may not be improved.

Therefore, it is more preferable to set the addition amount of the charge generating agent to a value within the range of 0.5 to 20 parts by weight.
(4) -2 Electron Transfer Agent The electron transfer agent is a compound represented by the following general formula (1).

[In the formula _(1), R 1 ~R ₄ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 20 carbon atoms. m, n, o, and p are the same or different and represent an integer of 1 to 5. ]
The compound represented by the general formula (1) has a broad aromatic electron cloud. Therefore, an electrophotographic photoreceptor using the compound represented by the general formula (1) as an electron transport agent can obtain excellent sensitivity characteristics.
In the general formula (1), examples of the alkyl group represented by R _{1 to} R ₄ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, pentyl, isopentyl, neopentyl, And groups such as hexyl. Examples of the aryl group in R _{1 to} R ₄ include groups such as phenyl, naphthyl, tolyl, xylyl, anthryl, phenanthryl. Examples of the alkoxy group in R _{1 to} R ₄ include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, s-butoxy, t-butoxy, pentyloxy, isopentyloxy, neopentyloxy, hexyloxy and the like. Can be mentioned.
In said general formula (1), m, n, o, p represents the integer of 1-5. When m is an integer of 2 to 5, a plurality of R ₁ may be different substituents. When n is an integer of 2 to 5, a plurality of R ₂ may be different substituents. When o is an integer of 2 to 5, a plurality of R ₃ may be different substituents. When p is an integer of 2 to 5, a plurality of R ₄ may be different substituents.
In general formula (1), the C1-C6 alkyl group may have a substituent and an amino group etc. are mentioned as a substituent. The aryl group having 6 to 20 carbon atoms may have a substituent, and examples of the substituent include an alkyl group, an alkoxy group, a halogen group, a carboxy group, and an ester group.

In the compound of the general formula (1), a synthesis method in the case where R _{1 to} R ₄ are hydrogen atoms will be described based on the following chemical reaction formula (1).
The following compound (A-1) (8.16 g, 0.05 mol), the following compound (A-2) (41.6 g, 0.2 mol), boron tetrafluoride (12 g) in diethyl ether solution and 200 ml of chloroform were added. The reaction vessel was placed and heated to reflux for 5 hours.
The reaction solution was cooled, poured into water, and extracted with chloroform. The obtained organic layer was dried with a desiccant, the solvent was distilled off, and the residue was recrystallized with ethanol to obtain the desired product (A-3).
Next, the obtained compound (A-3) (12.2 g, 0.022 mol), P (Si (CH ₃ ) ₃ ) ₃ (27.5 g, 0.11 mol) and 100 ml of acetonitrile were placed in a reaction vessel, and heated. Refluxing was performed for 5 hours. After cooling the reaction solution, the solvent was distilled off, and the residue was purified by column chromatography to obtain the desired product (1-1).

Moreover, it is also preferable to use together the compound represented by the said General formula (1) and a conventionally well-known electron transport agent.
Examples of such electron transporting agents include diphenoquinone derivatives, benzoquinone derivatives, anthraquinone derivatives, malononitrile derivatives, thiopyran derivatives, trinitrothioxanthone derivatives, fluorenone derivatives, anthracene derivatives, acridine derivatives, anthraquinone derivatives, succinic anhydride, maleic anhydride And various compounds having an electron accepting property such as dibromomaleic anhydride, and one kind or a mixture of two or more kinds may be used.
The addition amount of the electron transfer agent is preferably set to a value in the range of 10 to 100 parts by weight with respect to 100 parts by weight of the binder resin.

The reason for this is that when the added amount of the plurality of electron transfer agents is less than 10 parts by weight, the sensitivity is lowered and a practical problem may occur.
On the other hand, when the added amount of the plurality of electron transfer agents exceeds 100 parts by weight, the electron transfer agent is likely to be crystallized, and an appropriate film as a photoreceptor may not be formed.

Therefore, it is more preferable to set the addition amount of the electron transfer agent to a value within the range of 20 to 80 parts by weight.
(4) -3 Hole transport agent The electrophotographic photoreceptor of the present invention preferably contains a hole transport agent. Examples of the hole transport agent suitable for the electrophotographic photoreceptor of the present invention include various hole transport agents conventionally used for photoreceptors.

Examples of such hole transporting agents include benzidine derivatives, phenylenediamine derivatives, naphthylenediamine derivatives, phenanthrylenediamine derivatives, oxadiazole compounds, styryl compounds, carbazole compounds, organic polysilane compounds, pyrazoline compounds, Nitrogen-containing cyclic compounds such as hydrazone compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, triazole compounds, and condensed polycyclic compounds Is mentioned.
The amount of the hole transport agent added is preferably set to a value within the range of 10 to 150 parts by weight with respect to 100 parts by weight of the binder resin.
The reason for this is that when the added amount of the hole transport agent is less than 10 parts by weight, the sensitivity is lowered and a practical problem may occur.
On the other hand, when the added amount of the hole transport agent exceeds 150 parts by weight, the hole transport agent is likely to be crystallized, and an appropriate film as a photoreceptor may not be formed.
Therefore, the amount of the hole transport agent added is more preferably set to a value within the range of 20 to 100 parts by weight, and further preferably set to a value within the range of 30 to 80 parts by weight.
(4) -4 Binder resin
As the binder resin, various resins conventionally used for the photosensitive layer can be used.
For example, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene resin, ethylene-vinyl acetate copolymer, chlorination Polyethylene resin, polyvinyl chloride resin, polypropylene resin, ionomer resin, vinyl chloride-vinyl acetate copolymer, polyester resin, alkyd resin, polyamide resin, polyurethane resin, polycarbonate resin, polyarylate resin, polysulfone resin, diallyl phthalate resin, ketone Thermoplastic resins such as resin, polyvinyl butyral resin, polyether resin, polyester resin; silicone resin, epoxy resin, phenol resin, urea resin, melamine resin, other crosslinkable thermosetting resins; epoxy acrylic Over bets, urethane - alone or in combinations of two or more such photocurable resin such as acrylate.

In particular, a polycarbonate resin is a preferable binder resin because it is excellent not only in transparency and heat resistance but also in mechanical properties and compatibility with a hole transport agent.
(4) -5 Additive
In the photosensitive layer, in addition to the above-mentioned components, various conventionally known additives such as an antioxidant, a radical scavenger, a singlet quencher, and an ultraviolet absorber are provided as long as the electrophotographic characteristics are not adversely affected. Deterioration preventing agents such as, softeners, plasticizers, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, acceptors, donors, and the like can be blended.
In order to improve the sensitivity of the photosensitive layer, a known sensitizer such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generator.
The film thickness of the photosensitive layer is preferably set to a value in the range of 5 to 100 μm.

  The single layer type electrophotographic photosensitive member can be produced, for example, by the following procedure. First, a coating solution for a photosensitive layer is prepared by containing a charge generating agent, an electron transporting agent having a specific structure, a binder resin, a hole transporting agent and the like in a solvent. The coating solution thus obtained is applied onto a conductive substrate (aluminum tube) using a coating method such as a dip coating method, a spray coating method, a bead coating method, a blade coating method, or a roller coating method. Apply. Thereafter, for example, the photosensitive layer having a predetermined thickness can be formed by drying with hot air under conditions of 100 ° C. for 40 minutes.

In addition, various organic solvents can be used as a solvent for preparing the dispersion, for example, alcohols such as methanol, ethanol, isopropanol and butanol; aliphatic hydrocarbons such as n-hexane, octane and cyclohexane. Aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride and chlorobenzene; dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, 1,3- Ethers such as dioxolane and 1,4-dioxane; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and methyl acetate; dimethylformaldehyde; Methylformamide, dimethyl sulfoxide, and the like. These solvents are used alone or in admixture of two or more.
2. Laminated electrophotographic photoreceptor The electrophotographic photoreceptor of the present invention may be configured as a laminated electrophotographic photoreceptor.

That is, as shown in FIG. 2 (a), the electrophotographic photosensitive member of the present invention is provided with a charge generation layer 24 containing a charge generating agent or the like on a conductive substrate 12, and a charge transporting agent or the like is further provided thereon. Alternatively, the multilayer electrophotographic photosensitive member 20 provided with the charge transport layer 22 may be configured.
In contrast to the above structure, as shown in FIG. 4B, the charge transport layer 22 may be formed on the substrate 12, and the charge generation layer 24 may be formed thereon.
Further, as shown in FIG. 4C, it is also preferable to form an intermediate layer 25 on the substrate 12.

  In the charge transport layer 22, both a hole transport agent and an electron transport agent may be used. The content of the electron transport agent in the charge transport layer 22 is preferably set to a value within the range of 10 to 100 parts by weight with respect to 100 parts by weight of the binder resin of the charge transport layer.

  The substrate and organic material used in the multilayer electrophotographic photosensitive member can be basically the same as in the case of the single-layer electrophotographic photosensitive member.

  Furthermore, the content of the charge generating agent is preferably set to a value within the range of 5 to 1000 parts by weight with respect to 100 parts by weight of the binder resin of the charge generating layer.

  The film thickness of the charge transport layer is preferably a value in the range of 5 to 50 μm, and the film thickness of the charge generation layer is preferably a value in the range of 0.1 to 5 μm.

Second Embodiment The second embodiment includes the electrophotographic photosensitive member of the first embodiment (hereinafter sometimes simply referred to as a photosensitive member), and around the electrophotographic photosensitive member. An image forming apparatus is characterized in that a charging unit, an exposure unit, a developing unit, and a transfer unit are arranged to form an image.
In this example of the image forming apparatus, the case where a single layer type electrophotographic photosensitive member is used as the electrophotographic photosensitive member will be described.
1. Configuration of Image Forming Apparatus (1) In carrying out the image forming method of the second embodiment, a copying machine 30 as an image forming apparatus as shown in FIG. 3 can be suitably used.
The copying machine 30 includes an image forming unit 31, a paper discharge unit 32, an image reading unit 33, and a document feeding unit 34.
The image forming unit 31 further includes an image forming unit 31a and a paper feeding unit 31b.
In the illustrated example, the document feeding unit 34 includes a document placing tray 34a, a document feeding mechanism 34b, and a document discharge tray 34c, and the document placed on the document placing tray 34a. Is fed to the image reading position P by the document feeding mechanism 34b and then discharged to the document discharge tray 34c.
Then, when the original is sent to the original reading position P, the image reading unit 33 reads the image on the original using the light from the light source 33a.
That is, an image signal corresponding to the image on the document is formed using an optical element 33b such as a CCD.

On the other hand, recording sheets (hereinafter simply referred to as “sheets”) S stacked on the sheet feeding unit 31b are sent one by one to the image forming unit 31a.
The image forming unit 31a is provided with a photosensitive drum 41 having an electrophotographic photosensitive member. Further, around the photosensitive drum 41, a charger 42 as a charging unit and an exposure unit as an exposure unit. 43, a developing device 44 as a developing means, and a transfer roller 45 as a transferring means are arranged along the rotation direction of the photosensitive drum 41.
Among these components, the photosensitive drum 41 is rotationally driven in the direction indicated by the solid line arrow in the drawing, and the surface thereof is uniformly charged by the charger 42.
Thereafter, an exposure process is performed on the photosensitive drum 41 by the exposure device 43 based on the above-described image signal, and an electrostatic latent image is formed on the surface of the photosensitive drum 41.
Based on the electrostatic latent image, the developing unit 44 attaches toner and develops it, thereby forming a toner image on the surface of the photosensitive drum 41.
The toner image is transferred as a transfer image onto the sheet S conveyed to the nip portion between the photosensitive drum 41 and the transfer roller 45.
Next, the sheet S to which the transferred image is transferred is conveyed to the fixing unit 47 and a fixing process is performed.
The paper S after fixing is sent to the paper discharge unit 32. However, when performing post-processing (for example, stapling processing), the paper S is sent to the intermediate tray 32a and then subjected to post-processing. Is called.
Thereafter, the sheet S is discharged to a discharge tray portion (not shown) provided on the side surface of the image forming apparatus.
On the other hand, when no post-processing is performed, the sheet S is discharged to a discharge tray 32b provided below the intermediate tray 32a.
The intermediate tray 32a and the paper discharge tray 32b are configured as a so-called in-body paper discharge unit.

  After the transfer is performed as described above, residual toner remaining on the photosensitive drum 41 is removed by the developing unit 44.

  Next, the electrophotographic photoreceptor of the present invention will be described with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.
As the electron transporting agent in the examples, the compound (1-1) obtained by the synthesis method described above was used.
The electron transport agent used in the comparative examples, the charge generating agent, the binder resin and the hole transport agent used in the examples and comparative examples are as follows.
<Electron transport agent used in comparative example>

    <Charge generator>

<Binder resin>

<Hole transport agent>

[Examples 1-2]
[Comparative Examples 1-2]
<Production of electrophotographic photoreceptor>
The combinations shown in Table 1 were used for the electron transport agent, charge generator, binder resin, and hole transport agent. That is, 100 parts by weight of a binder resin (Resin-1: bisphenol Z-type polycarbonate resin having a viscosity average molecular weight of 50,000), 50 parts by weight of a hole transporting agent (H-1) with respect to 800 parts by weight of tetrahydrofuran as a solvent. 3 parts by weight of the charge generating agent (X—H ₂ Pc or Y—TiOPc) shown in Table 1 and 50 parts by weight of the electron transporting agent (1-1 or ET-1) shown in Table 1 were added. This mixture was mixed and dispersed with an ultrasonic disperser for 1 hour to prepare a dispersion for a single-layer type photosensitive layer. Next, the obtained dispersion is applied on a conductive base material (aluminum tube) by dip coating, dried with hot air at 100 ° C. for 30 minutes, and electrophotographic having a single-layer type photosensitive layer having a thickness of 30 μm. A photoreceptor was obtained.

Next, the sensitivity characteristics of the electrophotographic photosensitive member obtained above were evaluated as follows. That is, the electrophotographic photosensitive member is charged to 700 V using a drum sensitivity tester (manufactured by GENTEC), and then monochromatic light having a wavelength of 780 nm extracted from the light of the halogen lamp using a bandpass filter (half-color) Value width: 20 nm, light quantity: 1.5 μJ / cm ² ) was exposed [irradiation time: 0.08 seconds (80 msec)]. Then, the surface potential (residual potential) at the time when 0.33 seconds (330 msec) had elapsed from the start of exposure was measured and used as the sensitivity. The results are shown in Table 1.

  From Table 1, the electrophotographic photoreceptors of Examples 1 and 2 using the compound represented by the general formula (1) as the electron transport agent are electrophotographic photoreceptors using (ET-1) as the electron transport agent. 10-15V sensitivity was a good result.

10: Single layer type electrophotographic photosensitive member 12: Conductive substrate 14: Photosensitive layer 16: Intermediate layer 20: Multilayer type electrophotographic photosensitive member 22: Charge transport layer 24: Charge generation layer 25: Intermediate layer 30: Copying machine 31: Image forming unit 31a: Image forming unit 31b: Paper feeding unit 32: Paper discharge unit 33: Image reading unit 34: Document feeding unit 41: Photoconductor drum 42: Charger 43: Exposure unit 44: Developer 45: Transfer roller

Claims (4)

An electrophotographic photosensitive member in which a photosensitive layer containing at least an electron transport agent, a charge generator and a binder resin is provided on a conductive substrate,
The electrophotographic photoreceptor, wherein the electron transfer agent is a compound represented by the following general formula (1).

[In Formula (1), R _{1 to} R ₄ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 20 carbon atoms. . m, n, o, and p are the same or different and represent an integer of 1 to 5. ]   2. The electrophotographic photosensitive member according to claim 1, wherein the addition amount of the electron transfer agent is set to a value within a range of 10 to 100 parts by weight with respect to 100 parts by weight of the binder resin.   The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer is a single layer type. An image forming apparatus in which a charging unit, an exposure unit, a developing unit, and a transfer unit are arranged around the electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is according to any one of claims 1 to 3. An image forming apparatus which is an electrophotographic photosensitive member.