JP2001350282A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor with practically extremely high performance which is further improved in the initial electric characteristics as well as shows sufficient stability against irradiation with external light. SOLUTION: In the electrophotographic photoreceptor having a photosensitive layer containing a charge generating material and a charge transfer material on a conductive supporting body, the charge transfer material contains an arylamine compound having such wavelength in the range from 350 to 450 nm that the transmittance is 50%, and contains a compound expressed by general formula (1). The proportion of the compound expressed by general formula (1) is 2 to 25 wt.% to 100 wt.% of the arylamine compound. In formula (1), each of R3 and R4 is an alkyl group, aralkyl group or aryl group which may have substituents, each of X and Y is independently a hydrogen atom, alkyl group, alkoxy group or dialkylamino group and m is 0 or 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member. More specifically, the present invention relates to a high-sensitivity and high-performance electrophotographic photosensitive member having a photosensitive layer containing an organic photoconductive substance.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive substances such as selenium, cadmium sulfide, and zinc oxide have been widely used for a photosensitive layer of an electrophotographic photosensitive member. However, selenium and cadmium sulfide need to be recovered as poisons, selenium crystallizes due to heat and therefore has poor heat resistance, cadmium sulfide and zinc oxide have poor moisture resistance, and zinc oxide has no printing durability. It has drawbacks and efforts to develop new photoreceptors are ongoing. Recently, studies have been made on the use of organic photoconductive materials for the photosensitive layer of an electrophotographic photoreceptor, and some of them have been put to practical use. Organic photoconductive materials have advantages over inorganic ones, such as being lighter, easier to form films, easier to manufacture photoconductors, and capable of manufacturing transparent photoconductors depending on the type. Have.

Electrophotographic photoreceptors using these organic photoconductive compounds are often used as function-separated type photoreceptors in which a charge transport layer and a charge generation layer are laminated. This is because it is easy to design an electrophotographic photosensitive member that satisfies both electrical and mechanical characteristics. Here, the electrical and mechanical properties to be satisfied by the electrophotographic photoreceptor include not only having an initially excellent performance but also having a sufficient durability when used repeatedly. .

[0004] In an electrophotographic process of a so-called reversal development system in which toner is adhered to an exposed portion of an electrophotographic photoreceptor, initially excellent performance means optimum sensitivity and electrical characteristics matching the electrophotographic process to be used. Sufficient durability when used repeatedly means that it is added directly to the surface of the electrophotographic photosensitive member during repeated use, by corona or direct charging, image exposure, toner development, transfer process, surface cleaning, etc. It has durability against deterioration due to electrical and mechanical external forces.

However, the durability desired for the electrophotographic photosensitive member is not limited to the durability required when used in an electrophotographic process, such as the durability during repeated use described above. Even when taken out of the electrophotographic process, that is, outside the electrophotographic apparatus, it is necessary to have sufficient durability to withstand actual use. Specifically, the electrophotographic photoreceptor may be temporarily exposed to external light during the assembly of the electrophotographic apparatus. In some cases, the photoreceptor is exposed to external light by being extracted, but the electrophotographic photoreceptor is required to have sufficient durability against irradiation of such external light.

In other words, an electrophotographic photoreceptor needs to have sufficient photosensitivity in response to light irradiated in an electrophotographic process, but must be stable when exposed to external light. Must meet two conflicting performances.

[0007]

As one means for satisfying the above-mentioned various properties, there is a method using a charge transporting material having excellent electric and mechanical properties. Such a charge transport material is disclosed in JP-B-56-13.
It has been known that the arylamine compound described in Japanese Patent No. 939 has excellent initial electric properties and sufficient durability when used repeatedly in an electrophotographic process. Also, recently, Japanese Patent Application Laid-Open No.
The arylamine compound described in JP-A No. 9 also has excellent initial electrical properties and sufficient durability when repeatedly used in an electrophotographic process.

However, electrophotographic photoreceptors using these arylamine compounds do not have sufficient durability against the external light, and have the following problems. That is,
When the electrophotographic photosensitive member is taken out of the electrophotographic device at the time of assembling the electrophotographic device or in the market, the electrophotographic photosensitive member may be strongly irradiated with external light. After receiving such external light irradiation, when the electrophotographic photoreceptor is used again in the electrophotographic process, the exposure potential of the portion irradiated with the external light sharply rises and corresponds to the irradiated portion. On a printed image, there occurs a problem that the image density is reduced in the electrophotographic process of reversal development, and the image density is increased in the electrophotographic process of forward development.

The problem of potential rise due to the external light irradiation is as follows.
Although it is not always a problem because it is not a phenomenon directly caused in the electrophotographic process, it is practically impossible to put the electrophotographic photosensitive member under external light, so it is practically possible to use electrophotographic photosensitive materials. This is a technical issue that cannot be ignored when trying to gain body.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above-mentioned circumstances, and as a result, by using a specific electron transport material together, the performance of the arylamine compound has been further improved. As a result, the present invention has been found that a photosensitive member free from potential rise due to external light can be obtained.

That is, the gist of the present invention, that is, the first gist of the present invention is to provide an electrophotographic photosensitive member having a photosensitive layer containing a charge generating substance and a charge transporting substance on a conductive support. The transport substance contains an arylamine compound having a wavelength at which the transmittance becomes 50% in a range of 350 to 450 nm and a compound represented by the following general formula (1). An electrophotographic photoreceptor, wherein the content is 2 to 25% by weight based on 100% by weight of the arylamine compound.

[0012]

Embedded image (In the general formula (1), R ₃ and R ₄ represent an alkyl group, an aralkyl group or an aryl group which may have a substituent,
X and Y each independently represent a hydrogen atom, an alkyl group, an alkoxy group or a dialkylamino group, and m represents 0 or 1. A second aspect of the present invention is to provide an electrophotographic photosensitive member having a photosensitive layer containing a charge generating substance and a charge transporting substance on a conductive support, wherein the charge transporting substance is represented by the following general formula (2) And a compound represented by the general formula (1), wherein the content of the compound represented by the general formula (1) is the arylamine compound 1
2 to 25% by weight with respect to 00% by weight.

[0013]

Embedded image (In the general formula (2), X is a divalent residue which may have a substituent, Ar is an aryl group which may have a substituent,
R represents an optionally substituted aryl, alkyl, fused polycyclic or heterocyclic ring).

A third aspect of the present invention resides in an electrophotographic method characterized in that an electrostatic latent image is formed on the electrophotographic photosensitive member with light of 500 nm or more. Further, a fourth gist of the present invention resides in a process cartridge including the electrophotographic photosensitive member.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. <Conductive Support> As the conductive support on which the photosensitive layer is formed, any of those used for known electrophotographic photosensitive members can be used. Specifically, for example, aluminum, aluminum alloy, stainless steel, copper, a drum made of a metal material such as nickel, a laminate of these sheets or a metal foil of these, a deposited material, or aluminum on the surface,
Examples thereof include an insulating support such as a polyester film and paper provided with a conductive layer such as copper, palladium, tin oxide, and indium oxide. Further, a plastic film, a plastic drum, paper, a paper tube, and the like, which are subjected to a conductive treatment by applying a conductive substance such as metal powder, carbon black, copper iodide, and a polymer electrolyte together with an appropriate binder, may be mentioned. Further, a plastic sheet or drum containing a conductive substance such as a metal powder, carbon black, or carbon fiber to become conductive may be used. Further, plastic films and belts which have been subjected to conductive treatment with a conductive metal oxide such as tin oxide or indium oxide may be used.

Among them, an endless pipe made of metal such as aluminum is a preferable support. <Barrier Layer> In the present invention, a known barrier layer which is generally used may be provided between the conductive support and the photosensitive layer. As the barrier layer, for example, an anodized aluminum film, aluminum oxide, inorganic layers such as aluminum hydroxide, polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, polyamide and other resins. The organic layer used is used. When the organic layer is used as the barrier layer, it may be used alone or in a state where a metal oxide such as titania, alumina, silica and zirconium oxide or a fine metal powder such as copper, silver and aluminum is dispersed.

In the case of an organic layer, the above-mentioned resin is dissolved or dispersed alone or together with the above-mentioned metal oxide / metal fine powder in a solvent, and a wire bar, a doctor blade, a film applicator, It can be formed by coating with an application method such as immersion or spraying and drying. The thickness of these barrier layers can be appropriately set, but is 0.05 to 20 μm, preferably 0.1 to 20 μm.
Preferably, it is used in the range of 10 to 10 μm.

<Photosensitive Layer> (1) Charge Transport Material A photosensitive layer containing a charge generating material and a charge transport material is formed on the barrier layer. The photosensitive layer in the invention is a single-layer type containing a charge transport material and a charge generation material in the same layer, even if the charge transport layer contains a charge transport material, and the charge generation layer contains a charge generation material. It may be a separate stacked type, but in any case, it requires the use of a specific charge transporting material as described in detail below.

In the present invention, it is necessary to use the following specific arylamine compound as a charge transporting material in combination with a compound represented by the following general formula (1). As the charge transporting material to be used, first, the transmittance 5
The wavelength at which 0% is reached is 350 to 450 nm, preferably 35.
Arylamine compounds at 0-400 nm are mentioned.

Here, in the present invention, the term "arylamine compound having a transmittance of 50% at a wavelength of 350 to 450 nm" is defined as a 5% by weight solution of the arylamine compound in toluene as a solvent. When the transmittance of the solution is measured with a spectrophotometer, the arylamine compound has a wavelength at which the transmittance becomes 50% in the range of 350 to 450 nm.

Further, as the arylamine compound used in the present invention, a charge transport material represented by the following general formula (2) can be used.

[0022]

Embedded image In the general formula (2), X is a divalent residue which may have a substituent, Ar is an aryl group which may have a substituent, R
Represents an optionally substituted aryl, alkyl, fused polycyclic, or heterocyclic ring.

In the general formula (2), a more preferred structure is that X is a divalent organic residue which may have a substituent, A
r is a phenyl group which may have a substituent, and R is a phenyl group or a naphthyl group which may have a substituent.
More preferably, X is a methylene group which may have a substituent, Ar is a phenyl group which may have a substituent, R is a paratolyl group which may have a substituent, Alternatively, X is the following general formula (3), Ar is a phenyl group which may have a substituent, and R is a paratolyl group which may have a substituent.

[0024]

Embedded image —O—X ₁ —O— (3) In the general formula (3), X ₁ is optionally substituted 2
Represents a monovalent hydrocarbon residue. Such substituents include
For example, a methyl group, an ethyl group, an isopropyl group, an alkyl group having 1 to 10 carbon atoms such as a t-butyl group, a methoxy group, an alkoxy group having 1 to 5 carbon atoms such as an ethoxy group,
Examples include a phenyl group, a cyclohexyl group, and a hydroxyl group. Specific examples of such compounds include, for example, Table-1
No. 1 to 21 are mentioned.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

[0029]

[Table 5]

[0030]

[Table 6] Here, among the compounds in Table 1, No. 2, No.
7, no. For each 13, 5 in toluene solvent
The transmittance of the solution in which the weight% was dissolved was measured. The results are shown in FIGS. Here, the measurement of transmittance is
The measurement was performed using a spectrophotometer U-3210 manufactured by Hitachi, Ltd. From the results of FIG. 1 and FIG. 2 and No. The wavelength at which the transmittance of the compound of No. 7 is 50% is around 380 nm. It was around 390 nm for 13 compounds. That is, it can be seen that some of the arylamine compounds having the structure of the general formula (2) have a wavelength at which the transmittance becomes 50% in the range of 350 to 450 nm depending on the selected structure.

Further, in the present invention, a compound represented by the following general formula (1) is used in combination with the arylamine compound as a charge transporting substance.

[0032]

Embedded image In the general formula (1), R3 and R4 represent an alkyl group, an aralkyl group or an aryl group which may have a substituent,
X and Y each independently represent a hydrogen atom, an alkyl group, an alkoxy group or a dialkylamino group, and m represents 0 or 1.

Specific examples of such compounds include, for example, No. 1 in Table 2. Structures 1 to 4 are mentioned.

[0034]

[Table 7] In the present invention, the quantitative ratio of the above-mentioned arylamine compound to the compound represented by the general formula (1) is such that the compound represented by the general formula (1) is 2 to 25 with respect to 100% by weight of the arylamine compound. % By weight, preferably 2 to 20% by weight in the photosensitive layer.

(2) Laminated Type Photosensitive Layer Charge Generating Layer In the case of the laminated type, a charge transporting layer may be laminated on the charge generating layer, or a charge generating layer may be laminated on the charge transporting layer. First, the charge generation layer will be described. A charge generation layer is preferably formed on the barrier layer. The charge generation layer can also be formed by depositing a charge generation material, but the charge generation material and, if necessary, other organic photoconductive compounds, dyes, electron-withdrawing compounds, etc. are dissolved in a solvent together with a binder resin. Alternatively, it can be formed by applying a known coating method such as a wire bar, a doctor blade, a film applicator, immersion, spraying or the like, dispersing and applying the obtained coating liquid, and drying.

As the charge generating substance, inorganic photoconductive particles such as selenium, selenium-tellurium alloy, selenium-arsenic alloy, cadmium sulfide, amorphous silicon, metal-free phthalocyanine, metal-containing phthalocyanine, perinone pigment,
Organic photoconductive particles such as thioindigo, cycridone, perylene pigment, anthraquinone pigment, azo pigment, bisazo pigment, trisazo pigment, tetrakis azo pigment, and cyanine pigment. Further, various organic pigments and dyes such as polycyclic quinone, pyrylium salt, thiopyrylium salt, indigo, anthantrone and pyranthrone can be used. Among them, metals such as metal-free phthalocyanines, copper, indium chloride, gallium chloride, tin, oxytitanium, zinc, and vanadium, or oxides thereof, phthalocyanines with coordinated chlorides, azo such as monoazo, bisazo, trisazo, and polyazos Pigments and perylene pigments are preferred.

As the binder resin, polyester,
Examples include polyvinyl acetate, polycarbonate, polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral, phenoxy, epoxy, urethane, cellulose ester, and cellulose ether. Further, polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinyl alcohol, and ethyl vinyl ether, polyamide, and silicon resin may be used. These binder resins are used alone or in a blend. The charge generation layer can be formed as a dispersion layer in which the charge generation material and other additives are bound to the binder resin.

In this case, the charge generating substance is used in an amount of usually 20 to 2,000 parts by weight, preferably 30 to 500 parts by weight, more preferably 33 to 500 parts by weight, based on 100 parts by weight of the binder resin. The thickness of the charge generation layer is usually 0.05 to 5 μm, preferably 0.1 to 2 μm.
m, more preferably 0.15 to 0.8 μm. Further, the charge generation layer may contain various additives such as a leveling agent, an antioxidant, and a sensitizer for improving coating properties.

Charge Transport Layer In the case of a laminated type, a charge transport layer mainly composed of two kinds of charge transport materials used in the present invention and a binder resin is formed on the charge generation layer. As the binder resin, for example, polyester, polymethyl methacrylate,
Polystyrene, vinyl polymers such as polyvinyl chloride, and copolymers thereof, polycarbonate, polyester, polyester carbonate, polysulfone, polyimide,
Polymers such as phenoxy, epoxy and silicone resins, and copolymers thereof, and partially cross-linked cured products thereof can also be used. Further, two or more kinds of the binder resins may be blended and used. The ratio of the binder resin to the charge transporting material is in the range of 30 to 90 parts by weight, preferably 40 to 70 parts by weight, based on 100 parts by weight of the binder resin. The charge transport layer may contain various additives such as an antioxidant and a sensitizer as needed.
The thickness of the charge transport layer is 10 to 60 μm, preferably 10 to 60 μm.
It is good to use with a thickness of 45 μm, more preferably 25 to 40 μm.

As a method for forming the charge transport layer, a coating solution obtained by dissolving or dispersing a substance to be contained in the layer in a solvent is coated with a known coating method such as a wire bar, a doctor blade, a film applicator, immersion, and a spray. It can be formed by coating by a method and drying. (3) Single-Layer Photoconductor Next, the case where the photosensitive layer is of a single-layer type will be described. When a single-layer photosensitive layer is provided by a casting method, a function-separation type layer composed of a charge generating substance and a charge transporting substance is often used. That is, the above-mentioned materials can be used as the charge generating substance and the charge transporting substance.

The single-layer photosensitive layer can be formed by dissolving or dispersing a charge generating substance, a charge transporting substance, and a binder resin in a suitable solvent, coating and drying. If necessary, a plasticizer, a leveling agent, an antioxidant, an electron transporting agent and the like can be added. As the binder resin, in addition to using the binder resin described above for the laminated charge transport layer as it is, a mixture of the binder resin described above for the laminated charge generation layer may be used.

The single-layer type photosensitive layer is obtained by dispersing a charge generating substance, a charge transporting substance and a binder resin in a ball mill, an attritor, a sand mill or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane or butanone. It can be formed by appropriately diluting and applying. The coating can be performed using a known coating method such as a wire bar, a doctor blade, a film applicator, and dipping or spraying. A photoreceptor in which a charge transporting substance is added to an amorphous complex formed from a beryllium-based dye or bisphenol A-based polycarbonate can also be formed from a suitable solvent by a similar coating method. The thickness of the single-layer photoreceptor is suitably about 5 to 100 μm.

<Electrophotographic Photoreceptor> The electrophotographic photoreceptor of the present invention is provided with at least a photosensitive layer on a conductive support and, if necessary, a barrier layer and a photosensitive layer on the conductive support as described above. However, needless to say, an intermediate layer, a transparent insulating layer, and a surface protective layer may be further provided as necessary.

For example, a conventionally known overcoat layer mainly composed of, for example, a thermoplastic or thermosetting polymer may be used as the outermost surface layer. The electrophotographic photoreceptor thus obtained is a photoreceptor that maintains excellent printing durability over a long period of time, and is suitable for electrophotographic fields such as copying machines, printers, fax machines, and plate making machines.

<Electrophotographic Apparatus and Electrophotographic Method> An electrophotographic apparatus such as a copying machine or a printer using the electrophotographic photosensitive member of the present invention includes at least respective processes of charging, exposure, development, and transfer. Any of the commonly used methods may be used. As the charging method (charging device), for example, any of corotron or scorotron charging using corona discharge, contact charging using a conductive roller, a brush, a film, or the like may be used.
Among them, in the charging method using corona discharge, scorotron charging is often used in order to keep the dark area potential constant.

In the present invention, the exposure is usually performed at a wavelength of 5
A laser beam such as He-Ne, a halogen lamp, a fluorescent lamp, an exposure device that emits LED light, or the like is used. A laser beam is preferably used, and particularly, 530 to 850 nm. Is preferred. Specifically, a laser beam around 532 nm, around 635 nm, around 650 nm, around 780 nm, or around 830 nm can be mentioned.

As a developing method, a general method of developing by contacting or non-contacting a magnetic or non-magnetic one-component developer, a two-component developer or the like is used. As a transfer method, any of a method using corona discharge, a method using a transfer roller or a transfer belt, and the like may be used. The transfer may be performed directly on paper or an OHP film, or may be once transferred onto an intermediate transfer body (belt or drum shape) and then transferred onto paper or an OHP film.

Usually, after the transfer, a fixing process of fixing the developer on paper or the like is used, and as a fixing means, generally used heat fixing, pressure fixing and the like can be used. In addition to these processes, a process such as cleaning and static elimination that is generally used may be provided. Further, the electrophotographic photoreceptor of the present invention can be used as an electrophotographic photoreceptor for a detachable process cartridge, which is particularly frequently exposed to external light. The process cartridge is one device (part) that includes an electrophotographic photosensitive member and includes other charging means, exposure means, developing means, transfer means, cleaning means, and static elimination means. Although there are many shapes and the like of such a process cartridge, a general example is shown in FIG. In FIG. 4, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate around an axis 2 at a predetermined peripheral speed in a direction indicated by an arrow. In the rotation process, the photosensitive member 1 is uniformly charged around the periphery thereof by the primary charging means 3 at a predetermined positive or negative potential, and then is subjected to image exposure means (not shown) such as slit exposure or laser beam scanning exposure. It receives image exposure light 4 having a wavelength of 500 nm or more. Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then
And the developed toner developed image is taken out from a paper feeding unit (not shown) between the photosensitive member 1 and the transfer means 6 in synchronization with the rotation of the photosensitive member 1. The transfer means 6 is transferred to the transfer material 7 fed and fed.
Is sequentially transferred by electrostatic force. The transfer material 7 to which the image has been transferred is separated from the photoreceptor surface, and is
And the image is fixed and printed out of the apparatus 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 unit 9, and is further neutralized by the neutralizing light 10 from the neutralizing unit (not shown). used. Depending on the selected electrophotographic process, static elimination 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 is configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer.

[0051]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Example 1 The experiment was performed using an electrophotographic photosensitive member having an undercoat layer between the conductive support and the photosensitive layer. As the undercoat layer, a layer containing titanium oxide whose surface is coated with a silicon compound and a polyamide resin was used. The specific forming method is as follows. That is, the titanium oxide surface-treated with methyl hydrogen polysiloxane used in the experiment was first manufactured by Ishihara Sangyo Co., Ltd. under the product name TTO-55N (crystal rutile 1)
(The following particle diameter: 0.03 to 0.05 μm), and methylhydrogenpolysiloxane was uniformly applied to the surface at 3% by weight. The thus obtained methyl hydrogen polysiloxane treated titania was dispersed in a ball mill for 16 hours together with a mixed alcohol (methanol / 1-propanol = 7/3). Next, the obtained titanium oxide dispersion liquid is
Mixed alcohol (methanol / 1-propanol = 70 /) of a random copolymer polyamide having the following structure produced by the production method described in the example of JP-A-31870
30) Added to solution. Finally, a dispersion having a solid content concentration of 16% by weight with a titanium oxide / nylon ratio of 3/1 (weight ratio) was prepared.

[0052]

Embedded image An undercoat layer was provided on an aluminum-deposited surface of this dispersion liquid on a polyester film so that the film thickness after drying with a bar coater was 1.3 μm. Black angle (2θ ± 0.2 °) in powder X-ray diffraction spectrum
It shows the maximum diffraction peak at 27.3 °, and 7.4 ° and 9.7
10 parts by weight of a crystalline Y-type oxytitanium phthalocyanine having diffraction peaks at .degree. And 24.2.degree. Were added to 200 parts by weight of 4-methoxy-4-methylpentanone-2, and pulverized and dispersed by a sand-mill. Then, a pigment dispersion preliminary liquid was prepared. Polyvinyl butyral (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name "Denka Butyral"# 6)
000C) was mixed with 5 parts by weight of a 10% methanol solution to prepare a dispersion.

Then, a charge generation layer was provided on the undercoat layer of the dispersion by a bar coater so that the film thickness after drying was 0.4 μm. On the charge generation layer, No. 1 in Table 1 manufactured by the manufacturing method disclosed in Japanese Patent Publication No. 56-13939. 7 of the arylamine compound (charge transporting substance 1) in an amount of 49 parts by weight and
No. in Table 2 manufactured by the manufacturing method disclosed in JP-A-33391. Compound 2 (Charge transporting substance 2)
1 part by weight and dibutylhydroxytoluene (BHT)
8 parts by weight, 100 parts by weight of the following polycarbonate resin (monomer molar ratio: 1: 1) having two repeating structural units produced by the production method described in Examples of JP-A-3-221962.

[0054]

Embedded image Was dissolved in 687 parts by weight of a mixed solution of tetrahydrofuran and toluene, and applied by a film applicator, and a charge transport layer was provided so that the film thickness after drying was 25 μm. The photoconductor formed in this manner is referred to as photoconductor A.

Example 2 In Example 1, No. 1 in Table 1 was used. 48 parts by weight of the arylamine compound (charge transporting substance 1) of No. 7 and No. 7 in Table 2 above. A photoconductor was prepared by the same way as that of Example 1 except that the charge transport layer was provided using the charge transport layer coating solution containing 2 parts by weight of the compound (charge transport material 2). The photoconductor formed in this manner is referred to as photoconductor B.

Example 3 In Example 1, No. 1 in Table 1 was used. No. 7 of the arylamine compound (charge transporting substance 1) and 45 parts by weight of No. 7 in Table 2 above. A photoconductor was prepared by the same way as that of Example 1 except that a charge transport layer was provided using a charge transport layer coating solution containing 5 parts by weight of compound 2 (charge transport material 2). The photoconductor formed in this manner is referred to as photoconductor C.

Comparative Example 1 In Example 1, no. A photoconductor was prepared by the same way as that of Example 1 except that a charge transport layer was provided using a charge transport layer coating solution containing 50 parts by weight of an arylamine compound (charge transport material 1) alone. The photoconductor formed in this manner is referred to as photoconductor D.

Comparative Example 2 In Example 1, no. 40 parts by weight of the arylamine compound (charge transporting substance 1) of No. 7 and No. 7 in Table 2 above. A photoconductor was prepared by the same way as that of Example 1 except that a charge transport layer was provided using a charge transport layer coating solution containing 10 parts by weight of compound (charge transport material 2).
The photoconductor formed in this manner is referred to as photoconductor E.

Comparative Example 3 In Example 1, no. 30 parts by weight of the arylamine compound (charge-transporting substance 1) of No. 7 and No. 7 in Table 2 above. A photoconductor was prepared by the same way as that of Example 1 except that a charge transport layer was provided using a charge transport layer coating solution containing 20 parts by weight of compound (charge transport material 2).
The photoconductor formed in this manner is referred to as photoconductor F.

Comparative Example 4 7 except that the charge transport layer was provided using a charge transport layer coating solution containing 45 parts by weight of the arylamine compound (charge transport material 1) and 5 parts by weight of the compound of the following structural formula (charge transport material 3). A photoconductor was prepared in the same manner as in Example 1. The photoconductor formed in this manner is referred to as photoconductor G.

[0061]

Embedded image Example 4 An arylamine compound was prepared in the same manner as in Example 1 except that
No. 13 in Table 1 manufactured by the manufacturing method disclosed in JP-A-13939. A photoconductor was prepared by the same way as that of Example 1 except that compound 2 was used (charge transport material 4). The photoconductor formed in this manner is referred to as photoconductor H.

Example 5 In Example 2, the arylamine compound was replaced with the compound shown in Table 1
No. in A photoconductor was prepared by the same way as that of Example 2 except that compound 2 (charge transport material 4) was used. The photoconductor formed in this manner is referred to as photoconductor I. Example 6 In Example 3, the arylamine compound was replaced with the above-mentioned Table-1
No. in A photoconductor was prepared by the same way as that of Example 3 except that compound 2 (charge transport material 4) was used. The photoreceptor thus produced is referred to as photoreceptor J.

Comparative Example 5 In Comparative Example 1, the arylamine compound was replaced by
No. in A photoconductor was prepared by the same way as that of Comparative Example 1 except that compound 2 (charge transport material 4) was used. The photoconductor formed in this manner is referred to as photoconductor K. Comparative Example 6 In Comparative Example 2, the arylamine compound was replaced with the above-mentioned Table-1
No. in A photoconductor was prepared by the same way as that of Comparative Example 2 except that the compound of Example 2 (charge transport material 4) was used. The photoconductor formed in this manner is referred to as photoconductor L.

Comparative Example 7 In Comparative Example 3, the arylamine compound
No. in A photoconductor was prepared by the same way as that of Comparative Example-3 except that the compound of No. 2 (charge transport material 4) was used. The photoconductor formed in this manner is referred to as photoconductor M. Comparative Example 8 In Comparative Example 4, the arylamine compound was replaced with the above-mentioned Table-1
No. in A photoconductor was prepared by the same way as that of Comparative Example-4 except that the compound of No. 2 (charge transport material 4) was used. The photoconductor formed in this manner is referred to as photoconductor N.

Example 7 In Example 1, the arylamine compound was prepared by the method described in
No. in the above-mentioned Table-1 manufactured by the manufacturing method disclosed in JP-A-119489. A photoconductor was prepared by the same way as that of Example 1 except that compound 13 (charge transport material 5) was used. The photoconductor formed in this manner is referred to as photoconductor O.

Example 8 In Example 2, the arylamine compound was replaced with the compound shown in Table 1
No. in A photoconductor was prepared by the same way as that of Example 2 except that compound 13 (charge transport material 5) was used. The photoconductor formed in this manner is referred to as photoconductor P. Example 9 In Example 3, the arylamine compound was replaced with the compound shown in Table 1 above.
No. in A photoconductor was prepared by the same way as that of Example 3 except that compound 13 (charge transport material 5) was used. The photoconductor formed in this manner is referred to as photoconductor Q.

Comparative Example 9 In Comparative Example 1, the arylamine compound was replaced by
No. in A photoconductor was prepared by the same way as that of Comparative Example 1 except that the compound of Example 13 (charge transport material 5) was used. The photoreceptor thus prepared is referred to as photoreceptor R. Comparative Example 10 In Comparative Example 2, the arylamine compound was replaced with the above-mentioned Table-1
No. in A photoconductor was prepared by the same way as that of Comparative Example 2 except that the compound of No. 13 (charge transport material 5) was used. The photoconductor formed in this manner is referred to as photoconductor S.

Comparative Example 11 In Comparative Example 3, the arylamine compound was replaced with No. 1 in Table 1 above. A photoconductor was prepared by the same way as that of Comparative Example 3 except that the compound of Example 13 was used (charge transport material 5). The photoconductor formed in this manner is referred to as photoconductor T. Comparative Example 12 In Comparative Example 4, the arylamine compound was replaced with the above-mentioned Table-1
No. in A photoconductor was prepared by the same way as that of Comparative Example 4 except that the compound of No. 13 (charge transport material 5) was used. The photoconductor formed in this manner is referred to as photoconductor U. <Evaluation of Photoreceptor> The electrophotographic photoreceptors having the photosensitive layers obtained in Examples 1 to 9 and Comparative Examples 1 to 12 were mounted on a photoreceptor characteristic measuring device, and were subjected to a temperature of 25 ° C. and a relative humidity of 50% (NN
Environment). The measurement items were 780 nm after being charged so that the surface potential became -700 V.
Is the exposure potential (VL1) when irradiated with light (0.45 μJ / cm ² ). Table 3 shows the results. In Table 3, "Den 1", "Den 2", "Den 3", "Den 4",
“Electricity 5” represents charge transport material 1, charge transport material 2, charge transport material 3, charge transport material 4, and charge transport material 5, respectively.
Is represented.

[0069]

[Table 8] From this result, the charge transport material 2, the charge transport material 4, and the charge transport material 5 (100 parts by weight) were compared with the charge transport material 2
It can be seen that the addition of 2 parts by weight or more improves the initial electrical properties. However, it is almost the same at 25 parts by weight,
It can be seen that when the content is about 7 parts by weight, it worsens. Therefore, the optimal addition amount of the charge transport material 2 is
It can be said that it is in the range of 2 to 25 parts by weight with respect to 4, 5 (100 parts by weight).

The durability of each of the photoconductors D and C was evaluated by repeating the electrophotographic process of charging, exposing, and removing static electricity 30,000 times. Table-4
The dark part potential (Vo) and the exposure potential (VL2) before and after repeated use are shown. Here, VL2 refers to an exposure potential when 780 nm light is irradiated at 0.2 μJ / cm ² . still,
In Table-4, "Electricity 1" and "Electricity 2" refer to the charge transport material 1 and the charge transport material 2, respectively.

[0071]

[Table 9] From the results in Table 4, it can be seen that the decrease in Vo and the increase in VL of the photoconductor are almost the same regardless of the presence or absence of the charge transport material 2. That is, it is understood that the durability as an electrophotographic photosensitive member is not impaired by the addition of the compound.

Next, the effects of external light irradiation on the photoconductors D, C, G, K, J, N, R, Q and U were measured. did. Specifically, after measuring the exposure potential (VL3) before and after irradiating a 3000 lux fluorescent lamp for 5 minutes, charging was performed 190 times.
VL3 after repeated exposure was measured. As a measuring device for measuring VL3, a model EPA-8100 manufactured by Kawaguchi Electric Works, Ltd. was used.
The surface potential at the time of irradiating the light of cm ² for 0.2 seconds is VL3
And The results are shown in Table-5. In the table, the numbers shown in parentheses are differences from before irradiation (VL3), and “Den 1”, “Den 2”, “Den 3”, “Den 4”, and “Den 5” are respectively The charge transport material 1, the charge transport material 2, the charge transport material 3, the charge transport material 4, and the charge transport material 5 are shown.

[0073]

[Table 10] For an electrophotographic photoreceptor that is resistant to external light irradiation, VL3 needs to be stable even in repeated electrophotographic processes after irradiation. In this regard, an electrophotographic photoreceptor (photoreceptors D, K, and R) composed of the charge transport material 1, the charge transport material 4, and the charge transport material 5 alone
It can be seen that VL3 rises sharply by repeated use about 190 times. This phenomenon appears in a printed image as a density increase in forward development and a density decrease in reverse development. On the other hand, in photoconductor C, photoconductor J, and photoconductor Q, VL3 hardly fluctuates even after repeating 190 times, and the stability to external light is greatly improved by the addition of the charge transport material 2. I understand.

When the charge transport material 3 is added to the charge transport material 1 or the charge transport material 5 (photoreceptor G, photoreceptor U),
The results are almost the same as those of the charge transport material 1 or the charge transport material 5 alone (photoconductor D and photoconductor R), and it can be seen that the stability to external light is not improved at all even if added. On the other hand, in the case of the charge transporting substance 4, it can be seen that the potential increase after repeated use of the photoreceptor N is more suppressed than that of the photoreceptor K, and the stability to external light is improved by the addition. Potential rise is observed,
It can be said that the degree of suppression is not sufficient. That is, even in the photoconductor N, a density increase in forward development and a density decrease in reversal development appear in a printed image.

In order to investigate the cause of the improvement in the stability to external light, the transmittance of a toluene solution in which each of the charge transport material 1, the charge transport material 2, and the charge transport material 3 was dissolved at 5% by weight was measured. The results are shown in FIG. As a result of the measurement, the wavelength at which the transmittance of the charge transport material 2 became 50% was around 490 nm. This is because charge transport materials 1 and 4 (both around 380 nm) and charge transport material 5 (3
(Around 90 nm). from this result,
The improvement in stability against external light by adding the charge transport material 2 is because the charge transport material 2 has the charge transport materials 1, 4,.
Since the absorption extends to the longer wavelength side than that of 5, the external light irradiated to the photoreceptor is absorbed, and the amount of irradiation on the charge transport materials 1, 4 and 5 is reduced (the charge transport material 2 is It is presumed that it is expressed by performing such a role). However, the wavelength at which the transmittance of the charge transport material 3 becomes 50% is around 520 nm, and the charge transport material 3 extends to a longer wavelength side than that of the charge transport material 2 (see FIG. 3). The addition of the substance 3 hardly improves the stability against external light. Therefore, the above presumption is not always appropriate, and it is considered that the stability of the present invention with respect to external light is improved due to some other factors.

The addition of the charge transport material 3 also deteriorates the initial electrical characteristics (VL1), and it can be said that the addition of the charge transport material 3 simply deteriorates the electrophotographic characteristics. Therefore, although the reason is not clear, in the present invention, in order to exhibit the effect of improving the stability to the external light, the above specific arylamine compound is represented by the above-mentioned general formula (1). It is understood that it is necessary to use a compound having a specific structure.

[0077]

According to the present invention, a specific arylamine compound is used as a charge transport material in a photosensitive layer, and a charge transport material having a specific structure is contained in the photosensitive layer at a predetermined ratio, whereby the charge transport material is prepared. It is possible to obtain a practically extremely high performance electrophotographic photoreceptor which further improves the initial electric characteristics of the photoreceptor and has sufficient stability against external light irradiation.

[Brief description of the drawings]

FIG. 1 shows the arylamine compound No. 1 in Table 1. 2 and N
o. 7 is a graph showing the transmittance of No. 7;

FIG. 2 shows arylamine compound Nos. 13 is a graph showing the transmittance of No. 13.

FIG. 3 is a graph showing the transmittance of charge transport materials 1 to 3 used in Examples.

FIG. 4 is a schematic view illustrating a process cartridge.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrophotographic photoreceptor 2 axis 3 primary charging means 4 image exposure light having wavelength of 500 nm or more 5 developing means 6 transfer means 7 transfer material 8 image fixing means 9 cleaning means 10 charge removing light

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Rinko 1000 Kamoshita-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Corporation Yokohama Research Laboratory F-term (reference) 2H068 AA19 AA20 BA05 BA13 BA39 FA27 FB07 FC05 2H076 AB02 DA37

Claims (9)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer containing a charge generating substance and a charge transporting substance on a conductive support, wherein the charge transporting substance has a transmittance of 50% in a range of 350 to 450 nm. An arylamine compound having a wavelength and a compound represented by the following general formula (1) are contained, and the content of the compound represented by the general formula (1) is 2 to 100% by weight of the arylamine compound. An electrophotographic photoreceptor comprising 25% by weight. Embedded image (In the general formula (1), R ₃ and R ₄ represent an alkyl group, an aralkyl group or an aryl group which may have a substituent,
X and Y each independently represent a hydrogen atom, an alkyl group, an alkoxy group or a dialkylamino group, and m represents 0 or 1. ) 2. An electrophotographic photosensitive member having a photosensitive layer containing a charge generating substance and a charge transporting substance on a conductive support, wherein the charge transporting substance is an arylamine represented by the following general formula (2). A compound and a compound represented by the general formula (1) are contained, and the content of the compound represented by the general formula (1) is 2 to 25% by weight based on 100% by weight of the arylamine compound. An electrophotographic photoreceptor, comprising: Embedded image (In the general formula (2), X is a divalent residue which may have a substituent, Ar is an aryl group which may have a substituent,
R represents an optionally substituted aryl, alkyl, fused polycyclic or heterocyclic ring). 3. The arylamine compound represented by the general formula (2), wherein X is a divalent organic residue optionally having a substituent, and Ar is a phenyl group optionally having a substituent. 3. The electrophotographic photosensitive member according to claim 2, wherein R is a phenyl group or a naphthyl group which may have a substituent. 4. An arylamine compound represented by the general formula (2), wherein X is a methylene group which may have a substituent,
The electrophotographic photoreceptor according to claim 3, wherein Ar is a phenyl group which may have a substituent, and R is a paratolyl group which may have a substituent. 5. The arylamine compound represented by the general formula (2), wherein X is a group represented by the general formula (3), Ar is a phenyl group which may have a substituent, and R is a substituent. The electrophotographic photoreceptor according to claim 3, which is a paratolyl group optionally having Embedded image —O—X ₁ —O— (3) (In the general formula (3), X ₁ represents a divalent hydrocarbon residue which may have a substituent.) 6. The electrophotographic photoreceptor according to claim 1, wherein the charge generation substance is oxytitanium phthalocyanine. 7. An electrophotographic method comprising forming an electrostatic latent image on the electrophotographic photosensitive member according to claim 1 with light having a wavelength of 500 nm or more. 8. The electrophotographic method according to claim 7, wherein the light for forming the electrostatic latent image is a laser beam. 9. A process cartridge comprising the electrophotographic photosensitive member according to claim 1.