JPH07160021A - Electrophotograpic photoreceptor - Google Patents

Abstract

PURPOSE:To provide a lamination type electrophotographic sensitive body or photoreceptor for positive electrification having high sensitivity, low residual potential, and good image characteristic by containing a specific compound as a charge carrying substance in the photosensitive layer. CONSTITUTION:A photosensitive layer contains a compound as a charge carrying substance shown in the formula. In the formula, R1, R2 indicate an alkyl group capable of having substituent, a vinyl group capable of having substituent, an ester group capable of having substituent, an acyl group capable of having stubstituent, and an amido group capable of having substituent. X1, X2 indicate a nitro group, a cyano group, and a halogen atom. Following symbols indicate: (m) is an integer of 0-2, (n) is an integer of 0-1, (p) is an integer of 0-4, (q) is an integer of 0-1. Y1, Y2 indicate a cyano group, an ester group capable of having substituent, an acyl group capable of having substituent, a nitro group, a halogen atom, a phenyl group capable of having substituent, and a hydrogen atom.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photosensitive member for forming an electrostatic latent image. More specifically, it relates to an electrophotographic photoreceptor having a layer containing a compound having an electron transporting ability.

[0002]

2. Description of the Related Art Conventionally, electrophotographic photoreceptors using organic photoconductors have been variously studied because of their advantages such as pollution-free, high productivity and low cost. It has been put to practical use as a photoconductor. These electrophotographic photoreceptors include a laminated type and a single layer type, but a photoreceptor using an organic photoconductor generally has a charge generation layer that generates a charge by light irradiation and a charge that transports the generated charge. It has a laminated structure consisting of a transport layer. In this case, as the charge transport material used in the charge transport layer, a polymer material such as poly-N-vinylcarbazole or a low molecular weight compound such as pyrazoline, hydrazone or triphenylamine derivative is used.

However, since all of these charge-transporting substances have a hole-transporting ability, most of the developing systems adopting a negative charge on the surface of the photoconductor are adopted.
For this reason, the toner that has been conventionally used in high-speed machines cannot be used, and there are few high-quality toners at present. Further, when the surface of the photoconductor is negatively charged as described above, there is a problem that not only the ozone is generated due to the reaction with oxygen in the air at the time of charging to harm the environment but also the surface of the photoconductor is deteriorated.

On the other hand, a positive charging laminated photoreceptor having a charge transport layer on the lower side and a charge generation layer on the upper side has been developed by reversing the layer structure of the photosensitive layer of the laminated photoreceptor. Since the charging potential is low and the printing durability is poor, a protective layer is further provided on the charge generation layer.

[0005]

In order to solve the above problems, a photoconductor in which a charge transport material having an electron transporting property is used in a charge transport layer and the surface of the photoconductor is positively charged. Should be configured. 2,4,7-Trinitro-9-fluorenone is known as such an electron-transporting material, but its solubility is poor and it is not possible to obtain practical sensitivity by combining it with an existing charge-generating substance. It was In addition, 2, 4,
As a result of improved studies on 7-trinitro-9-fluorenone, in recent years, an electron transporting substance having a solubilizing group introduced into an electron acceptor structure has been proposed. For example, Japanese Patent Laid-Open No. 1-206349
No. 2-135362, No. 2-214866, No. 3-290666 and “Japan Hardcopy '92” Proceedings, 173, (1992). However, in the present situation, when any of the compounds is combined with an existing charge generating substance to form a photoreceptor, the sensitivity is still insufficient in practical use, and a good image cannot be obtained.

In view of the above problems, it is an object of the present invention to provide an electrophotographic photosensitive member using a charge transporting substance having an electron transporting ability.

Another object of the present invention is to provide a laminate type electrophotographic photoreceptor for positive charging, which has excellent electrophotographic performance, that is, high sensitivity, low residual potential and good image characteristics.

[0008]

As a result of research, the present inventors have found that the object of the present invention can be achieved by any of the following electrophotographic photoreceptors. That is, (1) an electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, wherein the photosensitive layer contains a compound represented by the following general formula [A].

[0009]

[Chemical 7]

R ₁ and R ₂ each have an alkyl group which may have a substituent, a vinyl group which may have a substituent, an ester group which may have a substituent, and a substituent which may have a substituent. It represents a good acyl group or an amide group which may have a substituent.

X ₁ and X ₂ represent a nitro group, a cyano group and a halogen atom.

M is an integer of 0 to 2, n is an integer of 0 to 1, p
Represents an integer of 0 to 4, and q represents an integer of 0 to 1.

Y ₁ and Y ₂ are a cyano group, an ester group which may have a substituent, an acyl group which may have a substituent, a nitro group, a halogen atom and a phenyl which may have a substituent. Represents a hydrogen atom.

(2) An electrophotographic photosensitive member characterized in that the compound represented by the general formula [A] is a compound represented by the following general formula [a].

[0015]

[Chemical 8]

Y ₁ and Y ₂ are the same as in the general formula [A]. R represents an alkyl group which may be substituted.

(3) In an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support, the photosensitive layer has the following general formula [B].
An electrophotographic photoreceptor containing a compound represented by:

[0018]

[Chemical 9]

R is an alkyl group which may have a substituent,
It represents a phenyl group which may have a substituent, a condensed polycyclic group which may have a substituent, or a heterocyclic group which may have a substituent.

X ₁ and X ₂ are nitro group, cyano group, halogen atom, -OCOCF ₃ , -CH (CN) ₂ , -CF ₃ , -CH = C (CN) ₂ ,
It represents an electron withdrawing group such as -CH-CH-NO _2.

M is an integer of 0 to 4, and n is an integer of 0 to 1.

(4) An electrophotographic photosensitive member characterized in that the compound represented by the general formula [B] is a compound represented by the following general formula [b].

[0023]

[Chemical 10]

X ₁ , X ₂ , m and n are the same as in the general formula [B].
R ₁ and R ₂ are alkyl groups having 1 to 4 carbon atoms, R ₃ is an alkyl group, nitro group, acyl group, ester group, vinyl group, CF ₃
Represents

(5) In an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support, the photosensitive layer has the following general formula [C].
An electrophotographic photoreceptor containing a compound represented by:

[0026]

[Chemical 11]

Q ₂ represents phenylene or naphthylene which may be substituted.

Q ₃ is an oxygen atom, a sulfur atom, an alkylene which may have a substituent, a single bond, a vinylene which may have a substituent, a phenylene which may have a substituent, or --NR ₃
− Represents a selenium atom.

Y ₁ and Y ₂ are nitro group, cyano group, halogen atom, -OCOCF ₃ , -CH (CN) ₂ , -CF ₃ , -CH = C (CN) ₂ ,
It represents an electron withdrawing group such as -CH-CH-NO _2.

N and m represent integers of 1 to 4.

(6) An electrophotographic photoreceptor, wherein the compound represented by the general formula [C] is a compound represented by the following general formula [c].

[0032]

[Chemical 12]

X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈
Represents a nitro group, a cyano group, CF ₃ , Y represents an alkyl group,
Represents a halogen atom. Further, m represents an integer of 1 to 4.

The high performance of the charge transport material of the present invention is
It seems that the long-term compatibility with the binder is kept stable as compared with the conventional charge transport material.

Next, specific examples of the compounds represented by the above general formula and synthetic examples thereof will be shown.

(A) Compound represented by the general formula [A]: Exemplified compound:

[0037]

[Chemical 13]

[0038]

[Chemical 14]

[0039]

[Chemical 15]

: Synthesis example:

[0041]

[Chemical 16]

According to the above scheme, exemplary compound K-1
Was synthesized. That is, Aldrich 7-oxo-7H-benzo [e] pyrimidine-4-carboxylic acid 5.0 g and Kanto Kagaku 1-
Octanol 18.5 ml, toluene 100 ml and concentrated sulfuric acid 2 drops 300
It was put in a four-ml flask of ml, equipped with an ester tube, a Dimroth, a thermometer, and a ball, and heated and stirred under an argon stream for 10 hours.

Thereafter, 200 ml of toluene was added, and the mixture was thoroughly washed with water to neutrality, the toluene layer was dried over Na ₂ SO ₄ , and the toluene was distilled off under reduced pressure to obtain 6.1 g of crude crystals of 2 (light brown). This was recrystallized with ethanol, and 2 was converted into a light brown spherical crystal by 5.1.
g (1.73%) was obtained.

Next, 2: 5.0 g, 3.0 g of bis (trimethylsilyl) -carbodiimide manufactured by Tokyo Chemical Industry Co., Ltd., 0.2 g of cesium fluoride and 75 ml of acetonitrile were placed in a 200 ml four-headed flask, and under a nitrogen stream at room temperature for 30 hours. Stir.

Thereafter, 500 ml of toluene was added and the mixture was washed with water to neutrality, the toluene layer was dried over Na ₂ SO ₄ , and toluene was distilled off under reduced pressure to obtain 3.4 g of crude crystals with a yield of 64%. The crude crystals were subjected to column purification, and from the eluate of toluene-ethyl acetate = 9: 1, one spot on TLC, to obtain 2.0 g of Exemplified Compound K-1 as light brown crystals in a yield of 38%. Melting point is 137-138
℃ . In FD-mass spectrum, a peak was observed at m / z = 412, and the elemental analysis value was in agreement with the calculated value. Therefore, the structure of Exemplified Compound K-1 was confirmed.

Elemental analysis data C H N measured value 72.79 (%) 5.92 13.41 calculated value 72.80 5.86 13.58 (B) compound represented by general formula [B]: exemplified compound:

[0047]

[Chemical 17]

[0048]

[Chemical 18]

[0049]

[Chemical 19]

[0050]

[Chemical 20]

[0051]

[Chemical 21]

: Synthesis example:

[0053]

[Chemical formula 22]

According to a known method, from 50 g of 7-oxo-7H-benzo [e] pyrimidine-4-carboxylic acid manufactured by Aldrich,
Intermediate 5: 12.3 g was synthesized. The known method is the method described in the following document, and 1 → 2 is described in Ber. 9
Regarding 6 .1387 (1963), 2 → 3, J. Med, Chem. 13 .26.
(1970), about 3 → 4 is, Monatsh.Chem. 32 .315 (196
7), for the 4 → 5, Journal of the Chemical Society of Japan, it was 1.127 the (1973) as a reference.

Next, 5:10 g of the intermediate and 10 of chlorobenzene were used.
0 ml, 22 g of zinc chloride and 6.3 g of 2,6-xylidine were placed in a four-headed flask and stirred and refluxed for 24 hours. Then, remove chlorobenzene by steam distillation, add toluene, wash with water,
Dry over anhydrous sodium sulfate, evaporate the solvent and red crystal.
7.6 g was obtained. The crystals were recrystallized from 75 ml of ethyl acetate to obtain 5.7 g of Exemplified compound K-1. Melting point is 145-146 ° C
Met. The structure has the same FD mass spectrum,
It was confirmed that the following elemental analysis values were in agreement.

Elemental analysis data C H N measured value 78.71 (%) 4.25 16.91 calculated value 78.82 4.16 17.02 (C) compound represented by general formula [C]: exemplified compound:

[0057]

[Chemical formula 23]

[0058]

[Chemical formula 24]

[0059]

[Chemical 25]

[0060]

[Chemical formula 26]

[0061]

[Chemical 27]

[0062]

[Chemical 28]

[0063]

[Chemical 29]

[0064]

[Chemical 30]

: Synthesis example:

[0066]

[Chemical 31]

According to the above scheme, exemplary compound K-1
Was synthesized. That is, 15 g of 2,4,7-trinitrofluorenone manufactured by Kanto Kagaku Co., 20 ml of toluene, 11 g of phosphorus pentachloride and 0.15 g of phosphorus oxychloride were placed in a 200 ml four-headed flask and the internal temperature was 90 to 1
The mixture was heated and stirred at 00 ° C for 39 hours.

Thereafter, 200 ml of toluene was added, and the mixture was thoroughly washed with water to neutrality, the toluene layer was dried over Na ₂ SO ₄ , and the toluene was distilled off under reduced pressure to obtain 10.5 g of crude crystals. This was purified by a silica gel chromatogram and recrystallized from 200 ml of ethanol to obtain 2 as yellow crystals of 7.8 g. The structure was confirmed by FD mass spectrum.

Next, 2: 7.0 g and 4,4 'manufactured by Aldrich
-Methylenebis (2,6-dimethylaniline) 2.0 g, zinc chloride 10.5 g and o-dichlorobenzene 80 ml are put into a 200 ml four-headed flask, an ester tube and a thermometer are attached, nitrogen gas is introduced, and the mixture is stirred for 55 hours. Refluxed.

In the post-treatment, o-dichlorobenzene was removed by steam distillation, 200 ml of toluene was added, the mixture was washed with water to neutrality, dried over anhydrous sodium sulfate and distilled under reduced pressure to obtain 7.3 g of residue.
Obtained. This was purified by silica gel chromatogram, recrystallized with acetone, and red crystals of the target exemplified compound 5.
6 g was obtained with a yield of 83%. The structure was confirmed by FD mass spectrum. The melting point was 201-202 ° C. The elemental analysis values also agreed well.

Elemental analysis data C H N measured value 55.25 (%) 2.31 15.51 calculated value 55.32 2.25 15.64 In the electrophotographic photosensitive member of the present invention, examples of the conductive support include metal pipes, metal plates, metal sheets and metal foils. ,
A conductive polymer film, a polymer film provided with a vapor deposition layer of a metal such as Al, a polymer film coated with a metal oxide, a quaternary ammonium salt, or the like, or paper is used.

In the electrophotographic photosensitive member of the present invention, a photosensitive layer is provided on the conductive support, but the photosensitive layer may have a single layer structure or a laminated structure in which the charge generating layer and the charge transporting layer are functionally separated. It may be one. An adhesive layer may be provided between the conductive support and the photosensitive layer.

As shown in FIGS. 1 (a) and 1 (b), the photoconductor of the present invention comprises a charge generating substance (CG) on a conductive support 1.
M) as the main component of the charge generation layer (CGL) 2 and the charge transport material (CTM) as the main component of the charge transport layer (C)
A photosensitive layer 4 composed of a laminate with TL) 3 is provided. The photosensitive layer 4 may be provided via an intermediate layer 5 provided on the conductive support 1, as shown in FIGS. Thus, when the photosensitive layer 4 has a two-layer structure, a photoreceptor having the most excellent electrophotographic characteristics can be obtained. In addition, in the present invention, as shown in FIGS.
The photosensitive layer 4 in which the particulate CGM 7 is dispersed in the layer 6 containing as a main component may be provided directly on the conductive support 1 or via the intermediate layer 5.

Further, a protective layer (OCL) may be provided on the photosensitive layer 4 if necessary.

CGL which constitutes the photosensitive layer 4 having a two-layer structure
2, CTL3 can be formed by the following method depending on the characteristics of CTM and CGM, directly on the conductive support 1 which is the lower layer surface, or on the intermediate layer such as an adhesive layer or a barrier layer if necessary. it can.

(1) Vapor deposition method (2) Coating method a) Method of applying a solution coating in which CGM and CTM are dissolved in a suitable solvent b) CGM and CTM are finely dispersed in a dispersion medium by a ball mill, homomixer or the like. A method of applying a dispersion coating material obtained by mixing and dispersing it into particles and, if necessary, a binder.

Examples of the vapor deposition method include a vacuum vapor deposition method, a sputtering method, an ion plating method, a CVD method and the like, and a paint coating method includes a dipping method, a spray method, an air doctor method, a doctor blade method and a reverse method. An appropriate method is selected according to the physical properties of the coating material such as the roll method.

The adhesive layer is formed of a resin alone, is applied with a low resistance compound such as tin oxide, indium oxide or titanium oxide dispersed in resin, or is applied with aluminum oxide, zinc oxide, silicon oxide or the like. The vapor deposition film of
The resin used for the adhesive layer is not particularly limited, and examples thereof include vinylidene chloride-vinyl chloride copolymer, water-soluble polyvinyl butyral resin, alcohol-soluble polyamide resin, vinyl acetate-based resin, polyvinyl alcohol, nitrocellulose, and polyimide resin. To be

The thickness of the binder layer is preferably about 0.01 to 10 μm, and particularly preferably 0.01 to 1 μm.

When the photosensitive layer is a single layer, the compound represented by the above formulas [A] to [C] is contained as a sensitizer in the photosensitive layer composed of a known material such as polyvinylcarbazole. Or a photosensitive layer containing a known charge generating substance containing the compounds represented by the above formulas [A] to [C] as an electron transporting substance.

On the other hand, when the photosensitive layer is a laminated type,
The charge generation layer may be obtained by vapor deposition of a charge generation substance on a conductive support, or may be formed by applying a coating liquid containing a charge generation substance and a binder resin as main components.

Any known charge generating substance and binder resin can be used.

For example, as the charge generating substance, an inorganic semiconductor such as Te-Se, an organic semiconductor such as polyvinylcarbazole, a bisazo compound, a trisazo compound, a metal-free phthalocyanine compound, a metal phthalocyanine compound,
Organic pigments such as pyrylium compounds, squarylium compounds, cyanine compounds, perylene compounds and polycyclic quinone compounds can be used. Among them, preferable charge generating substances include, for example, Y-type titanyl phthalocyanine pigments having an X-ray diffraction peak at 27.2 ° in JP-A-64-17066,
A having an X-ray diffraction peak at 26.3 ° in JP-A-62-67094
Type titanyl phthalocyanine pigment, B type titanyl phthalocyanine pigment having an X-ray diffraction peak at 28.7 ° of JP-A-61-239248, metal-free phthalocyanine pigment of JP-B-49-4338, and copper phthalocyanine of JP-A-57-163239. Pigments, vanadyl phthalocyanine pigments of JP-A-57-148747, perylene pigments of JP-A-49-128734, condensed polycyclic pigments of JP-A-47-18544, bisazo pigments of JP-A-1-150145, etc. is there. As the binder resin, polystyrene, silicone resin, polycarbonate resin, acrylic resin, methacrylic resin, polyester, vinyl polymer, cellulose resin, butyral resin, silicone modified butyral resin, alkyd resin and the like can be used.

The thickness of the charge generation layer is preferably about 0.01 to 10 μm, and particularly preferably 0.05 to 2 μm.

A charge transport layer is formed on the charge generation layer. The charge transport layer comprises a compound represented by the above general formulas [A] to [C] and a binder resin,
A coating solution containing the compounds represented by the above general formulas [A] to [C], a binder resin, and a suitable solvent as main components is applied onto the charge generation layer by an applicator, a bar coater, a dip coater, or the like. Formed by. In this case, the mixing ratio of various compounds and the binder resin is preferably 1: 100 to 100: 1, and particularly preferably 1:20 to 20: 1.

As the charge transport material and the binder resin used in the charge transport layer, any known materials can be used. For example, as the binder resin, acrylonitrile
-Butadiene copolymer, styrene-butadiene copolymer,
Vinyltoluene-styrene copolymer, styrene-modified alkyd resin, silicone-modified alkyd resin, soybean oil-modified alkyd resin, vinylidene chloride-vinyl chloride resin,
Polyvinyl butyral, nitrated polystyrene, polymethylstyrene, polyisoprene, polyester, phenol resin, Kent resin, polyamide, polycarbonate, polythiocarbonate, polyacrylate, polyhaloacrylate, vinyl acetate resin, polystyrene, polyallyl ether, polyvinyl Acrylate, polysulfone, polymethacrylate, etc. may be mentioned. Among them, biphenyl Z type polycarbonate is particularly preferable. Further, an electron-donating substance may be added to the charge transport layer to produce a bipolar photoreceptor.

Further, an antioxidant or a radical trap agent may be added to the charge transport layer.

The thickness of the charge transport layer is preferably 2 to 100 μm, particularly preferably 5 to 50 μm.

In the electrophotographic photosensitive member of the present invention,
A barrier layer may be provided on the conductive support. The barrier layer is
It is effective in preventing the injection of unnecessary charges from the conductive support and has the effect of improving the image quality. Materials for forming the barrier layer include metal oxide such as aluminum oxide, acrylic resin, phenol resin, polyester resin, polyurethane and the like. The barrier layer may be provided on the adhesive layer or may be provided on the upper side.

[0090]

EXAMPLES Next, the present invention will be specifically described by way of examples. In addition, "parts" in the present examples means "parts by weight".

(I) Sensitivity Evaluation Evaluation 1 Examples 1 to 30 A 0.5 μm-thick intermediate layer made of a polyamide resin “CM8000” (manufactured by Toray Industries, Inc.) was provided on a PET film on which aluminum was vapor-deposited. 32 "Perylene pigment G-
1: 1 part, polyvinyl butyral resin "ESREC BL
S "(manufactured by Sekisui Chemical Co., Ltd.) and 50 parts of methyl ethyl ketone as a dispersion medium dispersed in a sand mill were applied using a wire bar to form a charge generation layer having a thickness of 0.3 μm. Next, 1 part of the exemplified compounds shown in Tables 1 to 3 and 1.5 parts of a polycarbonate resin "Iupilon Z-200" (manufactured by Mitsubishi Gas Chemical Co., Inc.) are dissolved in 10 parts of THF, and blade-coated on the charge generation layer to form a charge having a thickness of 20 μm. A transport layer was formed.

Comparative Example 1 A comparative sample was prepared in the same manner as in Example 1 except that the comparative compound 1 shown in "Chemical Formula 32" was used in place of the exemplified compound.

Electrophotographic Photosensitive Samples Obtained in Example 1 and Comparative Example 1 Electrostatic Copy Paper Testing Apparatus EPA
Using -8100 (manufactured by Kawaguchi Denki Co., Ltd.), it was charged to +800 V and exposed to 10 lux of white light, and the exposure amount until the surface potential was halved was determined and used as the sensitivity. The results are shown in Tables 1 to 3.

(II) Durability Evaluation Examples 31 to 60 A 0.5 μm-thick intermediate layer made of polyamide resin “X-1874M” (manufactured by Daicel Hüls) was provided on a PET film on which aluminum was vapor-deposited. 1 part of pigment X type metal-free phthalocyanine (manufactured by Dainippon Ink and Chemicals, Inc.), 0.4 part of polyvinyl butyral resin "ESREC BX-1" (manufactured by Sekisui Chemical Co., Ltd.), and methyl isopropyl ketone 50 as a dispersion medium.
The liquid in which the parts were dispersed using a sand mill was applied using a wire bar to form a charge generation layer having a thickness of 0.3 μm. Then, 1 part of the exemplified compounds of Tables 4 to 6 and 1.5 parts of a polycarbonate resin "Iupilon Z-200" (manufactured by Mitsubishi Gas Chemical Co., Inc.) were added to THF.
Dissolve in 10 parts and apply a blade onto the charge generation layer to obtain a film thickness of 20
A μm charge transport layer was formed.

Comparative Example 2 A comparative sample was prepared in the same manner as in Example 31 except that the comparative compound 2 shown in "Chemical Formula 32" was used in place of the exemplified compound.

Evaluation 2 The electrophotographic photoreceptor samples obtained in Examples 31 to 60 and Comparative Example (2) were measured with the following actual measurement values after initial copying and after copying 10,000 sheets with a U-BIX1017 remodeling machine manufactured by Konica Corporation. evaluated. The results are shown in Tables 4-6.

Vb: Black part potential, Vw: White part potential,
Vr: Residual potential (III) Image quality evaluation Examples 61 to 90 A 0.5 μm thick intermediate layer made of polyamide resin “CM8000” (manufactured by Toray Industries, Inc.) was provided on a cylindrical aluminum substrate, and a Bragg in X-ray diffraction was provided thereon. Angle 2θ 9.5 °, 24.1 °, 27.
A liquid in which 1 part of titanyl phthalocyanine having a peak at 2 °, 0.5 part of silicone-butyral resin and 50 parts of methyl isopropyl ketone as a dispersion medium were dispersed using a sand mill was dip-coated to form a charge generation layer having a thickness of 0.3 μm.

Next, 1 part of the exemplified compounds shown in Tables 7 to 9 and 1.5 parts of polycarbonate resin "Iupilon Z-200" (manufactured by Mitsubishi Gas Chemical Co., Inc.) were dissolved in 10 parts of THF, and dip-coated on the charge generation layer to form a film thickness. A 20 μm charge transport layer was formed.

Comparative Example 3 A comparative sample was prepared in the same manner as in Example 61 except that Comparative Compound 3 shown in "Chemical Formula 32" was used in place of the exemplified compound.

Evaluation 3 The electrophotographic photoreceptor samples obtained in Examples 61 to 90 and Comparative Example 3 were imaged by a digital copying machine "Konica 9028" modified by Konica Corp. (charged polarity: positive, reverse development). I put it out. These samples were then placed at low temperature (10
(° C.) environment was left for 1 month, and then images were reproduced again under the same conditions. The black spots on the white background portion of these copied images were evaluated. The results are shown in Tables 7-10.

The black spots were evaluated by measuring the size and number of the black spots using an image analysis device "Omnicon 300 type" (manufactured by Shimadzu Corporation), and the black spots with a diameter of 0.05 mm or more were 1 cm ²
It was performed by judging how many there are. The criteria for evaluating the black spots are as shown below. It should be noted that if the result of the black spot determination is ⊚ and ◯, it is practical, but Δ is not suitable for practical use, and if it is ×, it is not suitable for practical use.

Number of black spots having a diameter of 0.05 mm or more (pieces / cm ² ) Black spot determination 0 ◎ 1-3 ○ 4-10 △ 11 or more ×

[0103]

[Chemical 32]

[0104]

[Table 1]

[0105]

[Table 2]

[0106]

[Table 3]

[0107]

[Table 4]

[0108]

[Table 5]

[0109]

[Table 6]

[0110]

[Table 7]

[0111]

[Table 8]

[0112]

[Table 9]

As is clear from the above tables, the electrophotographic photosensitive member using the charge transporting material of the present invention has higher sensitivity and repeatability than the conventional charge photographic photosensitive member using the charge transporting material. The characteristics of the photoconductor during use are stable, and
It can be seen that the occurrence of image defects is extremely small even after storage at low temperature.

[0114]

The compound of the present invention has an electron transporting ability and is practical, that is, high sensitivity, low residual potential, good image retention,
A positive charging photoreceptor can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an exemplary embodiment of a photoconductor of the present invention.

[Explanation of symbols]

 1 Conductive Support 2 Charge Generation Layer (CGL) 3 Charge Transport Layer (CTL) 4 Photosensitive Layer 5 Intermediate Layer 6 Layer Containing Charge Transport Material 7 Charge Generation Material

Claims (6)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, wherein the photosensitive layer contains a compound represented by the following general formula [A]. [Chemical 1] R ₁ and R ₂ are each an alkyl group which may have a substituent, a vinyl group which may have a substituent, an ester group which may have a substituent, an acyl group which may have a substituent. , Represents an amide group which may have a substituent. X ₁ and X ₂ represent a nitro group, a cyano group and a halogen atom. m is an integer from 0 to 2 and n is 0
1 is an integer, p is an integer of 0 to 4, and q is an integer of 0 to 1. Y ₁ and Y ₂ are a cyano group, an ester group which may have a substituent, an acyl group which may have a substituent, a nitro group, a halogen atom, a phenyl group which may have a substituent, hydrogen Represents an atom. 2. The electrophotographic photosensitive member according to claim 1, wherein the compound represented by the general formula [A] is a compound represented by the following general formula [a]. [Chemical 2] Y ₁ and Y ₂ are the same as in the general formula [A]. R represents an alkyl group which may be substituted. 3. An electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, wherein the photosensitive layer contains a compound represented by the following general formula [B]. [Chemical 3] R represents an alkyl group which may have a substituent, a phenyl group which may have a substituent, a condensed polycyclic group which may have a substituent, or a heterocyclic group which may have a substituent. Represent X ₁ , X
₂ is a nitro group, a cyano group, a halogen atom, -OCOCF ₃ ,
It represents an electron-withdrawing group of —CH (CN) ₂ , —CF ₃ , —CH═C (CN) ₂ , and —CH—CH—NO ₂ . m represents an integer of 0 to 4, and n represents an integer of 0 to 1. 4. The electrophotographic photosensitive member according to claim 3, wherein the compound represented by the general formula [B] is a compound represented by the following general formula [b]. [Chemical 4] X ₁ , X ₂ , m and n are the same as those in the general formula [B]. R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and R ₃ represents an alkyl group, a nitro group, an acyl group, an ester group, a vinyl group and CF ₃ . 5. An electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, wherein the photosensitive layer contains a compound represented by the following general formula [C]. [Chemical 5] Q ₂ represents phenylene or naphthylene which may be substituted. Q ₃ represents an oxygen atom, a sulfur atom, an optionally substituted alkylene, a single bond, an optionally substituted vinylene, an optionally substituted phenylene, —NR ₃ — or a selenium atom. Y ₁ ,
Y ₂ is a nitro group, a cyano group, a halogen atom, —OCOC
_{F 3, -CH (CN) 2} , -CF 3, -CH = C (CN) 2, -CH-CH-NO 2
Represents an electron-withdrawing group such as. n and m represent the integer of 1-4. 6. The electrophotographic photosensitive member according to claim 5, wherein the compound represented by the general formula [C] is a compound represented by the following general formula [c]. [Chemical 6] X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , and X ₈ are nitro groups,
Represents a cyano group, CF ₃ . Y represents an alkyl group or a halogen atom, and m is an integer of 1 to 4.