JPH07304720A - Benzofluorene compound and electrophotographic photoreceptor containing the same - Google Patents

Abstract

PURPOSE:To obtain a new benzofluorene compound, useful as a charge transport substance for electrophotographic photoreceptors and capable of providing the highly durable electrophotographic photoreceptors with a high sensitivity. CONSTITUTION:This benzofluorene compound is expressed by formula I [R is a (substituted)alkyl, a halogen, a (substituted)alkoxycarbonyl. cyano or nitro; (n) is 0-5]. The compound expressed by formula I is obtained by reacting a benzofluorenone compound expressed by formula II with an amine compound expressed by formula III in the presence of an acidic catalyst. The compound expressed by formula I is useful as an acceptorlike compound used in an electrophotographic photoreceptor which is prepared by forming a photosensitive layer containing a charge generation substance and a charge transport substance on an electrically conductive substrate. The compound expressed by formula I as this charge transport substance is good in compatibility especially with a binder resin and has high performances.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel benzofluorene compound useful as an acceptor compound used in an electrophotographic photoreceptor, and an electrophotographic photoreceptor containing the benzofluorene compound.

[0002]

2. Description of the Related Art Conventionally, as a photosensitive layer of an electrophotographic photoreceptor,
Inorganic photoconductive substances such as selenium, selenium-tellurium alloy, and zinc oxide have been widely used, but in recent years, research on electrophotographic photoreceptors using organic photoconductive substances has progressed, and some of them have been put to practical use. ing. Here, most of the photoconductors that have been put into practical use are laminated electrophotographic photoconductors that are composed of a photoconductive layer having a charge-generating layer and a charge-transporting layer, and a photoconductive layer made of an inorganic photoconductive material. The electrophotographic photoconductor is actively designed, which is improved in terms of sensitivity and photoconductor life, which are inferior to those of the human body, and is low in cost, and takes advantage of organic photoconductive substances such as safety and versatility. It became so.

This type of laminated electrophotographic photosensitive member is generally a charge generating layer made of a charge generating substance such as a pigment and a dye, and a charge transporting layer made of a charge transporting substance such as hydrazone and pyrazoline on a conductive support. Are sequentially formed. Due to the property of the electron transporting charge transport material, they are of the hole transfer type and have sensitivity when negatively charged on the surface of the photoreceptor. However, with negative charging, the corona discharge used during charging is more unstable than with positive charging, and ozone, nitrogen oxides, etc., which are about 10 times as much as during positive charging, are generated, and physical contact such as adsorption on the surface of the photoconductor occurs. It is easy to cause deterioration and chemical deterioration.
There is a problem of making the environment worse. Yet another issue is
A positive polarity toner is required for developing the negative charging photoreceptor, but the positive polarity toner is difficult to manufacture in view of the triboelectrification series for the ferromagnetic carrier particles, and the two-component high resistance magnetic brush development method is used. In this case, the negatively charged toner / developer is more stable, and the degree of freedom in selection and use conditions is greater, and in this respect as well, the applicable range of the positively charged type photoreceptor is wide and advantageous.

Therefore, it has been proposed to use a photoconductor using an organic photoconductive material with a positive charge. For example, when a charge transport layer is laminated on the charge generation layer to form a photoreceptor, the charge transport layer has a large electron transport ability, for example, 2,
Although 4,7-trinitro-9-fluorenone and the like are used, there is a problem that the substance has carcinogenicity and is extremely unsuitable for occupational health.

Further, as a charge transport material, Japanese Patent Laid-Open No.
-69657 discloses a fluorenidene methane compound, and JP-A-61-233750 discloses an anthraquinodimethane and anthrone derivatives, both of which have a problem in repeatability. 5-
No. 25136 uses a naphthalene dicarboxylic acid imide compound, and JP-A No. 5-25174 uses a naphthalene tetracarboxylic acid diimide compound. However, both of them have insufficient sensitivity, and moreover, they are used with a binder resin. There are problems that need to be improved, such as poor compatibility.

Further, as a positively charged photoreceptor, US Pat.
Japanese Patent No. 615,414 discloses that thiapyrylium salt (charge generating substance) is contained so as to form a eutectic complex with polycarbonate (binder resin). However, this known photoconductor has a drawback that a memory phenomenon is large and a ghost is likely to occur.

Therefore, a charge generating layer containing a charge generating substance that generates holes and electrons upon irradiation with light is used as an upper layer (surface layer), and a charge transporting layer containing a charge transporting substance having hole transporting ability is used as a lower layer. A method of using a photoreceptor having a laminated photosensitive layer for positive charging can be considered. However, since the layer containing the charge generating substance is formed as the surface layer in the photoconductor for positive charging, it is vulnerable to external effects such as short-wavelength light irradiation such as ultraviolet light, corona discharge, humidity, mechanical friction, etc. during light irradiation. Since such a charge-generating substance is present in the vicinity of the surface layer, electrophotographic performance is deteriorated during storage of the photoconductor and during image formation, resulting in a problem that the image is deteriorated.

In the conventional negative charging photoreceptor having the charge transport layer as the surface layer, the influence of the various external actions is small, and rather the charge transport layer also has the action of protecting the lower charge generating layer. There is. Therefore, for example, it is possible to provide a thin protective layer made of an insulating and transparent resin to protect the layer containing the charge generating substance from an external action, but the charge generated during light irradiation is blocked by the protective layer. Photosensitivity is impaired, and it is not easy to manufacture. Although various attempts have been made to obtain a photoconductor for positive charging, there are many problems to be solved in terms of photosensitivity, mechanical strength, memory phenomenon, industrial hygiene, and the like.

[0009]

The object of the present invention is to provide a novel benzofluorene compound useful as an acceptor compound used in an electrophotographic photoreceptor, and a photosensitive material containing a charge generating substance and a charge transporting substance on a conductive support. An electrophotographic photosensitive member provided with a layer, which uses, as the charge-transporting substance, a high-performance benzofluorene compound having particularly good compatibility with a binder resin and having high sensitivity and durability. Is to provide.

[0010]

The inventors of the present invention have conducted research to solve the above-mentioned problems, and as a result, found a specific group of compounds and completed the present invention. That is, the present invention provides a benzofluorene compound represented by the following general formula (I),

[Chemical 1] (In the formula, R represents a group selected from a substituted or unsubstituted alkyl group, a halogen atom, a substituted or unsubstituted alkoxycarbonyl group, a cyano group, and a nitro group, which may be the same or different. Further, according to the present invention, in an electrophotographic photoreceptor having an electroconductive support and a photosensitive layer formed thereon as an essential component, the following general formula is contained in the photosensitive layer. Provided is an electrophotographic photoreceptor containing at least one kind of benzofluorene compound represented by the formula (I),

[Chemical 1] (In the formula, R represents a group selected from a substituted or unsubstituted alkyl group, a halogen atom, a substituted or unsubstituted alkoxycarbonyl group, a cyano group, and a nitro group, and n represents an integer of 0 to 5. According to the present invention, the photosensitive layer is composed of two layers of a charge generating layer and a charge transporting layer, and the charge transporting layer contains at least one kind of benzofluorene compound represented by the general formula (I). According to the present invention, the photosensitive layer is composed of a single layer containing a charge-generating substance and a charge-transporting substance. There is provided the electrophotographic photosensitive member characterized by containing at least one kind of the benzofluorene compound represented by the general formula (I).

In the benzofluorene compound represented by the general formula (I) of the present invention, R is a substituted or unsubstituted alkyl group, a halogen atom, a substituted or unsubstituted alkoxycarbonyl group, a cyano group, Represents a group selected from a nitro group. Specific examples of the substituted or unsubstituted alkyl group include a methyl group, an ethyl group, an n-propyl group, and an iso- group.
Examples thereof include alkyl groups such as propyl group, n-butyl group, sec-butyl group and t-butyl group, and substituted alkyl groups such as trifluoromethyl group. Among these groups, methyl group, ethyl group, iso group -Propyl group and trifluoromethyl group are preferable because of excellent compatibility with the binder resin. Further, specific examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom. Further, specific examples of the alkoxy group of the alkoxycarbonyl group include methoxy group, ethoxy group, n-propyloxy group and iso-
Alkoxy groups such as propyloxy group, n-butyloxy group, iso-butyloxy group, n-hexyloxy group, n-octyloxy group, and n-decyloxy group are exemplified, and the phenyl group is a substituent of the alkoxy group,
Examples thereof include an alkoxy group such as a methoxy group or an ethoxy group, a halogen atom such as a fluorine atom and a chlorine atom, among which an alkyl group having 4 to 8 carbon atoms, and 2
A -methoxyethoxy group or a 2-ethoxyethoxy group is preferable in terms of excellent compatibility with the binder resin.
Specific examples of the benzofluorene compound of the general formula (I) of the present invention are shown in Table 1 in relation to the following general formula (I), but not limited thereto.

[0012]

[Table 1- (1)]

[0013]

[Table 1- (2)]

The compounds represented by the general formula (I) are
Generally, as shown in Table 2 below, it can be obtained by reacting a benzofluorenone compound (II) with an amine compound (III) under an acidic catalyst. Examples of the acidic catalyst used include organic acids such as acetic acid, trifluoroacetic acid, or trifluoroborate, and acidic inorganic substances such as zinc chloride, iron chloride, titanium tetrachloride, or aluminum chloride. The reaction solvent can be usually a solvent-free solvent, a halogen-based solvent such as dichloromethane, chloroform, or 1,2-dichloroethane, carbon disulfide, or an aromatic solvent such as chlorobenzene or nitrobenzene. The reaction temperature is 0 to 150 ° C, preferably 0 to 100 ° C.

[0015]

[Table 2]

The benzofluorene compound of the present invention is not only useful as an acceptor compound for an electrophotographic photoreceptor, but also can be suitably used in the electronic field as an electronic device such as a solar cell and an organic EL device.

Next, the structure of the photoconductor of the present invention will be described with reference to the drawings. As the photoconductor, for example, as shown in FIG.
A support 1 (a conductive support or a sheet on which a conductive layer is provided) has a charge generating substance and a layer (charge generating layer) 2 containing a binder resin as necessary as a lower layer, and needs a charge transporting substance. According to the above, a photosensitive layer 4 having a laminated structure having a layer (charge transport layer) 3 containing a binder resin as an upper layer is provided,
As shown in FIG. 2, a protective layer 5 is provided on the photosensitive layer 4 of FIG. 1, and as shown in FIG. 3, a charge generating substance, a charge transporting substance and, if necessary, a binder resin are contained on a support. The protective layer may be provided on the upper layer of the single-layered photosensitive layer 6 shown in FIG. 3, and an intermediate layer may be provided between the support and the photosensitive layer. Layers may be provided.

The charge generating substance used in the present invention includes:
If it absorbs visible light and generates free charge,
Both inorganic and organic substances can be used. For example, amorphous selenium, trigonal selenium, selenium-
Arsenic alloy, selenium-tellurium alloy, cadmium sulfide, cadmium selenide, cadmium sulphide selenide, titanium oxide,
Inorganic substances such as zinc oxide, zinc sulfide, and amorphous silicon, or bisazo dyes, polyazo dyes, triarylmethane dyes, thiazine dyes, oxazine dyes, xanthene dyes, cyanine dyes, styryl dyes, pyrylium dyes Organic substances such as dyes, quinacridone dyes, indigo dyes, perylene dyes, polycyclic quinone dyes, bisbenzimidazole dyes, indanthrone dyes, squarylium dyes, anthraquinone dyes, and phthalocyanine dyes. To be

Examples of the binder resin usable in the photoreceptor layer in the present invention include polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin,
Vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicon resin, addition resin such as melamine resin, polyaddition resin, polycondensation resin, and repetition of these resins Copolymer resins containing two or more units, such as vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, and other insulating resins, as well as poly-N-vinylcarbazole. Polymer organic semiconductors such as

As the conductive support for supporting the photosensitive layer, a metal plate of aluminum, nickel or the like, a metal drum or a metal foil, a plastic film deposited with aluminum, tin oxide, indium oxide or the like or a conductive substance is used. A coated paper, a film such as a plastic, or a drum can be used.

In the case where the photosensitive layer of the electrophotographic photosensitive member according to the present invention is formed with a laminated structure of a charge generating layer and a charge transporting layer, that is, in the case of FIGS. 1 and 2, the charge transporting layer of the present invention is
A charge-transporting substance, which is dissolved or dispersed in a suitable solvent alone or together with a suitable binder resin, is applied onto a charge-generating layer (a specific forming method will be described later) provided on the support and dried. Set up by the method. Examples of the solvent used in the charge transport layer include N, N-dimethylformamide, toluene, xylene, monochlorobenzene, 1,2-dichloroethane, dichloromethane,
Examples include 1,1,1-trichloroethane, 1,1,2-trichloroethylene, tetrahydrofuran, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate and the like. In the charge transport layer, the ratio of the charge transport material contained in the binder resin is 100%.
It is preferable that the charge transport material is 20 to 200 parts by weight with respect to parts by weight. The thickness of the charge transport layer is preferably 5 to
The thickness is 50 μm, particularly preferably 5 to 30 μm.

Next, the charge generation layer is formed by vacuum-depositing the charge generation substance on a conductive support, or by coating or drying a solution obtained by dissolving or dispersing it in a suitable solvent alone or with a suitable binder resin. It can be formed in the same manner as the charge transport layer. The charge generation layer is preferably provided by the following method. That is, the charge generating substance is made into fine particles in a dispersion medium by a ball mill, a homomixer or the like, and when a dispersion liquid obtained by mixing and dispersing a binder resin is applied, when the particles are dispersed under the action of ultrasonic waves, Uniform dispersion is possible.

When the charge generating layer is formed by dispersing the charge generating substance, the charge generating substance preferably has an average particle size of 2 μm or less, preferably 1 μm or less. That is, if the particle size is too large, the dispersion in the layer becomes poor, and the particles partially project on the surface and the surface smoothness deteriorates. Toner filming phenomenon tends to occur due to particles adhering. However, if the above-mentioned particle size is too small, it tends to agglomerate rather, the resistance of the layer increases, the crystal defects increase and the sensitivity and repeatability deteriorate, or there is a limit on miniaturization, so the average particle The lower limit of the diameter is 0.
The thickness is preferably 01 μm. In the charge generation layer, the proportion of the charge generation substance contained in the binder resin is preferably 20 to 200 parts by weight with respect to 100 parts by weight of the binder resin. The thickness of the charge generation layer formed as described above is preferably 0.05 to 10 μm, particularly preferably 0.1 to 5 μm.

Next, in the case where the photosensitive layer of the electrophotographic photosensitive member of the present invention is formed in a single layer structure, that is, in the case of FIG. A dissolved or dispersed solution is coated on the support and dried to form the charge transporting layer and the charge generating layer in the case of the laminated structure. The ratio of the charge generating substance and the charge transporting substance contained in the binder resin depends on the binder resin 1
It is preferable that the charge generating substance is 20 to 200 parts by weight and the charge transporting substance is 20 to 200 parts by weight with respect to 00 parts by weight. The film thickness of the single-layer photosensitive member is 7 to 50 μm, more preferably 10 to 30 μm.

Further, the intermediate layer functions as an adhesive layer or a barrier layer, and in addition to the above binder resin, for example, polyvinyl alcohol, ethyl cellulose,
Resins such as carboxymethyl cellulose, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, casein, N-alkoxymethyl nylon as they are, or those in which tin oxide or indium is dispersed, A deposited film of aluminum oxide, zinc oxide, silicon oxide, or the like is used. The thickness of the intermediate layer is preferably 1 μm or less.

Further, as the material used for the protective layer, it is suitable to use the above-mentioned resin as it is or to disperse a low resistance substance such as tin oxide or indium oxide. An organic plasma-polymerized film can also be used, and the organic plasma-polymerized film may optionally contain oxygen, nitrogen, halogen, and Group III or Group V atoms in the periodic table.

[0027]

EXAMPLES The present invention will be described below with reference to examples, but the embodiments of the present invention are not limited thereto. In the examples, "parts" means "parts by weight" unless otherwise specified.

Synthesis Example 1 1,4-dicyano-2,3-benzofluorenone (I
I) 5.61 g in 150 ml of methylene chloride under ice cooling,
With stirring, 11.38 g of titanium tetrachloride was added dropwise over 10 minutes. Next, under the same conditions, 8.11 g of o-isopropylaniline was added dropwise over 50 minutes, and the mixture was added at room temperature to 4
Reacted for hours. After the reaction, the reaction mixture was poured onto ice, extracted with methylene chloride, and washed twice with water. After drying the methylene chloride solution over anhydrous magnesium sulfate, the methylene chloride was distilled off, and the residue was subjected to column chromatography using toluene as a developing solvent, and the obtained crude target product was recrystallized from butanol. To obtain 5.46 g of pure target product. Melting point: 235.0 to 236.0 ° C. Further, an infrared absorption spectrum diagram of this product is shown in FIG.

Synthetic Examples 2 to 5 In the same manner as in Synthetic Example 1, the compound Nos. 9, 1
Compounds 4, 21, 33 and 34 were obtained. Table 3 shows the melting points and elemental analysis results.

[Table 3]

Example 1 5 parts of a bisazo dye represented by the following structural formula (P-1), butyral resin (Denka butyral resin # 3000-2:
Denki Kagaku Kogyo) 2.5 parts, and tetrahydrofuran 9
2.5 parts were dispersed in a ball mill for 12 hours, and then tetrahydrofuran was added so that the concentration of the dispersion liquid was 2% by weight and redispersed to prepare a coating liquid. The prepared dispersion liquid was cast and coated on a 100 μm-thick polyester film on which aluminum was vapor-deposited by a doctor blade to form a charge generation layer having a film thickness after drying of 1.0 μm.

[Chemical 2] On the charge generation layer thus obtained, the compound No. 9 parts of a benzofluorene compound, 9 parts of a polycarbonate resin (K-1300: manufactured by Teijin Chemicals), 0.002 parts of methylphenylsilicone (KF50-100 cps: manufactured by Shin-Etsu Chemical Co., Ltd.), and 94 parts of tetrahydrofuran as a coating solution. A multilayer electrophotographic photosensitive member (aluminum electrode / charge-generating layer / charge-transporting layer) which is prepared and cast-coated with a doctor blade to form a charge-transporting layer having a dried film thickness of 20.0 μm ( Photoconductor No. 1)
It was created.

Examples 2 to 5 The benzofluorene compound used in Example 1 (Compound N
o. In the same manner as in Example 1 except that the benzofluorene compounds shown in Table 4 were used instead of 9), the laminated electrophotographic photosensitive member No. 2-5 were created.

Example 6 Charge generation was performed in the same manner as in Example 1 except that 6 parts of the trisazo dye represented by the following structural formula (P-2) was used instead of 5 parts of the bisazo dye used in Example 1. Layers were formed.

[Chemical 3] On the charge generation layer thus obtained, the compound No. 9 parts of benzofluorene compound, 9 parts of polycarbonate resin (K-1300: manufactured by Teijin Kasei), 0.002 parts of methylphenylsilicone (KF50-100 cps: manufactured by Shin-Etsu Chemical), and 94 parts of tetrahydrofuran were prepared. In the same manner as in Example 1, a charge transport layer having a film thickness after drying of 20.0 μm was formed, and a laminated electrophotographic photoreceptor (aluminum electrode / charge generation layer / charge transport layer (photoreceptor No. .6) was created.

Examples 7 to 10 Benzofluorene compounds used in Example 6 (Compound N
o. In the same manner as in Example 6 except that the benzofluorene compound shown in Table 4 was used instead of 9), the laminated electrophotographic photosensitive member No. 7-10 were created.

Example 11 5 parts of x-type metal-free phthalocyanine (P-3), polyvinyl butyral resin (S-Rex BLS: Sekisui Chemical Co., Ltd.) 5
Parts and 90 parts of tetrahydrofuran in a ball mill 1
Dispersion was carried out for 2 hours, and then tetrahydrofuran was added so as to have a dispersion liquid concentration of 2% by weight, which was then positively dispersed to prepare a coating liquid. The coating liquid thus prepared was cast and coated on a 100 μm-thick polyester film vapor-deposited on aluminum with a doctor blade to form a charge generation layer having a film thickness after drying of 0.5 μm. On the charge generation layer thus obtained, the compound No. 9 parts of benzofluorene compound, 10 parts of polycarbonate resin (K-1300: manufactured by Teijin Chemicals), and 94 parts of tetrahydrofuran were prepared to prepare a coating solution, which was cast-coated with a doctor blade to obtain a film thickness after drying. Of 20.0 μm was formed, and a laminated electrophotographic photosensitive member (photoreceptor No. 11) composed of an aluminum electrode / charge generation layer / charge transfer layer was formed.

Examples 12 to 15 Benzofluorene compounds used in Example 11 (Compound N
o. In the same manner as in Example 11 except that the benzofluorene compound shown in Table 4 was used instead of 9), the laminated electrophotographic photosensitive member No. 12-15 were created.

The electrophotographic photosensitive member obtained as described above was subjected to +6 KV corona charging using an electrostatic copying paper tester (SP-428: Kawaguchi Denki Seisakusho), and after being positively charged, for 20 seconds. The sample was left in a dark place, the surface potential Vo at that time was measured, and then light was irradiated using a tungsten lamp so that the illuminance on the surface was 40 lux, and the half-exposure amount E1 / 2 (lux · sec) was measured. The results are shown in Table 4.

[0037]

[Table 4]

Example 16 Bisazo dye 0.08 represented by the structural formula (P-1)
g, a 10 wt% tetrahydrofuran solution of a polycarbonate resin (PC-Z: manufactured by Teijin Chemicals), 0.6 g of a compound represented by the following structural formula (D-1), compound No. 1 in Table 1. 0.32 g of the benzofluorene compound of 9 and 0.3 g of a 1 wt% tetrahydrofuran solution of silicon oil (KF50: manufactured by Shin-Etsu Chemical Co., Ltd.) were weighed in a ball mill pot and ball-milled for 24 hours to prepare a coating solution. The coating solution thus prepared was cast and coated on a 100 μm thick polyester film on which aluminum was vapor-deposited by a doctor blade, and a single layer type electrophotographic photosensitive member (photosensitive member No. 16) having a film thickness after drying of about 15 μm was formed. Created.

[Chemical 5]

Examples 17 to 20 Benzofluorene compounds used in Example 16 (Compound N
o. Single-layer electrophotographic photosensitive member N was prepared in the same manner as in Example 16 except that the compounds shown in Table 5 were used instead of 9).
o. 17-20 were created.

Comparative Example 1 A single-layer type electrophotographic photosensitive member was prepared in the same manner as in Example 16 except that the acceptor compound of the present invention was not added.

The electrophotographic photosensitive member obtained as described above was subjected to a corona charging of +6 KV by using an electrostatic copying paper test device (SP-428: Kawaguchi Denki Seisakusho).
After being positively charged, it is left in a dark place for 20 seconds, the surface potential Vo at that time is measured, and then light irradiation is performed using a tungsten lamp so that the illuminance on the surface becomes 40 lux. .Sec) and the surface potential Vr 30 seconds after light irradiation. Next, Vo, E1 / 2, and Vr were measured after the above operation was repeated 5000 times. The results are shown in Table 5.

[0042]

[Table 5]

[0043]

The benzofluorene compound according to the present invention can be produced in a high yield by a relatively simple operation,
Moreover, it has excellent solubility or dispersibility in the binder resin. Further, the benzofluorene compound of the present invention has excellent properties as an acceptor compound, and the electrophotographic photoreceptor using the benzofluorene compound has high sensitivity and high durability.

[Brief description of drawings]

FIG. 1 is a sectional view of a laminated electrophotographic photosensitive member according to the present invention.

FIG. 2 is a cross-sectional view of a laminated electrophotographic photosensitive member provided with a protective layer according to the present invention.

FIG. 3 is a sectional view of a single-layer type electrophotographic photosensitive member according to the present invention.

FIG. 4 is an infrared absorption spectrum diagram of the benzofluorene compound of the present invention obtained in Synthesis Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Support body 2 ... Charge generation layer 3 ... Charge transport layer 4 ... Photosensitive layer (laminated structure) 5 ... Protective layer 6 ... Photosensitive layer (single layer structure)

Claims (4)

[Claims] 1. A benzofluorene compound represented by the following general formula (I): [Chemical 1] (In the formula, R represents a group selected from a substituted or unsubstituted alkyl group, a halogen atom, a substituted or unsubstituted alkoxycarbonyl group, a cyano group, and a nitro group, which may be the same or different. It represents an integer of 0 to 5.) 2. An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer formed thereon as an essential component, wherein a benzofluorene compound represented by the following general formula (I) is contained in the photosensitive layer. An electrophotographic photoreceptor containing at least one kind. [Chemical 1] (In the formula, R represents a group selected from a substituted or unsubstituted alkyl group, a halogen atom, a substituted or unsubstituted alkoxycarbonyl group, a cyano group, and a nitro group, and n represents an integer of 0 to 5. ) 3. The photosensitive layer is composed of two layers, a charge generation layer and a charge transport layer, and the charge transport layer contains at least one benzofluorene compound represented by the general formula (I). The electrophotographic photosensitive member according to claim 2, which is characterized in that. 4. The photosensitive layer is composed of a single layer containing a charge generating substance and a charge transporting substance, and contains at least one of the benzofluorene compounds represented by the general formula (I) as the charge transporting substance. The electrophotographic photosensitive member according to claim 2, wherein