JP3500481B2 - Electrophotographic photoreceptor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated type electrophotographic photoreceptor used in a copying machine, a printer or the like using an electrophotographic process.

[0002]

2. Description of the Related Art Since the electrophotographic process uses the visualization of a latent image by electrostatic force as a basic principle, the electrophotographic photosensitive member used in the process has good chargeability and rapid surface irradiation by light irradiation. Potential decay is required.
The properties required for these processes are reduced to high dark resistance, which is a specific physical property value, good quantum efficiency for charge carrier generation, and high charge mobility.

In order to satisfy these physical property values, a photoconductor composed of an inorganic compound such as selenium, a selenium-tellurium alloy or an arsenic-selenium alloy has been adopted and has been used in many copying machines. However, these materials have strong toxicity, are difficult to handle because they are used in an amorphous state, and have drawbacks such as high cost because they need to be vacuum-deposited to a film thickness of several tens of μm. Was not satisfied enough.

In order to improve these drawbacks, electrophotographic photoconductors (OPC) using organic materials have been actively developed and put into practical use. Most of the practically used OPCs are of a function separation type in which a layer having a charge generation function (CGL) and a layer having a charge transport function (CTL) are laminated on a conductive substrate. The range of choice of materials has expanded, and characteristics such as electrophotographic sensitivity, repeatability, and mechanical strength have improved. The laminated OPC currently in practical use uses a donor compound having a hole transfer property as the CTL, and is therefore used in the negative charging process.

However, negative charging is more unstable in corona discharge than positive charging, and generates ozone, nitrogen oxides, etc. about 10 times as much as in positive charging, resulting in physical deterioration such as adsorption on the surface of the photoreceptor. It is easy to cause chemical deterioration, and it becomes a problem in terms of environmental pollution. Still another problem is that the toner of positive polarity is required for developing the negative charging photoreceptor, but the toner of positive polarity is difficult to manufacture in view of the triboelectrification series with respect to the ferromagnetic carrier particles, and it is high in two components. In the resistance magnetic brush development method, the negatively charged toner / developer is more stable, and the degree of freedom in selection and use conditions is greater. From this point as well, the applicable range is wide and advantageous for the positively charged type photoreceptor.

There are several methods for making OPC positively charged. Typical examples are 1) a charge generating layer (CGL) and a charge transporting layer (CT) having an electron transporting ability on a conductive substrate.
L) sequentially stacked (forward layer), 2) a charge transport layer (CTL) having a hole transporting capability and a charge generation layer (CGL) sequentially stacked on a conductive substrate (reverse layer), 3) The charge-generating substance is dispersed in a binder together with the charge-transporting substance as needed (single layer). Although there are advantages and disadvantages, respectively, the forward layer type of 1) is advantageous for high sensitivity and high durability. However, the forward layer type requires an electron transporting material exhibiting high mobility, and currently has the drawbacks of low sensitivity, large residual potential, and poor practicality. For example, JP-A-63-150293, 63-150274,
Various electron transport materials have been proposed in Japanese Patent Laid-Open No. 2-97958 and the like, but in reality, practical properties have not been obtained.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a laminate for use in a positive charging process which is excellent in charging property and sensitivity, and which is excellent in stability of electrostatic characteristics when the copying process is repeated, and in which a small amount of ozone is generated. Type electrophotographic photoreceptor.

[0008]

Means for Solving the Problems The inventors of the present invention have made extensive studies on positive charging of OPC, and paid attention to a laminated type photoreceptor having a forward layer which is considered to be advantageous for high sensitivity and high durability. C
By using at least one kind of the same binder for GL and CTL and further containing an acceptor compound having a specific electron-transporting ability in CGL and CTL, the problem of positively charged OPC of the forward layer can be solved. The inventors have found that the drawbacks such as the lack of a practical level of sensitivity, the large residual potential, and the poor stability of repeated potential are eliminated, and the present invention has been completed.

[0009]

According to the present invention, the following inventions are provided. (1) Only a charge generating substance, an acceptor compound (A) having an electron transporting ability, and a binder are formed on a conductive substrate.
A charge generation layer (CGL), and a charge transport layer (CTL) consisting only of an acceptor compound (B) having an electron transporting ability and a binder are sequentially laminated. CGL) and the charge transport layer (CT)
In L), at least one kind of the same binder is contained, and the acceptor compound (A) having the electron transporting ability is prepared from at least one of the compounds represented by the following general formulas (I) to (III). An electrophotographic photoreceptor, which is a selected compound.

[Chemical 8] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ ,
R ² , R ⁴ and R ⁵ are each a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted A sulfonyl group of
R ¹ and R ² , R ⁴ selected from a substituent group consisting of a substituted or unsubstituted sulfonamide group, a substituted or unsubstituted carbamoyl group, a halogen atom, a cyano group and a nitro group.
And R ⁵ may form a ring with each other. R ³ represents a single bond, a sulfone group, a sulfoxide group or a sulfur atom, and r ¹
Is a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted carbamoyl group, a halogen atom, a cyano group or a nitro group. It was selected from the group. r ¹ may combine with another atom to form a ring. l is 1 to 4
Represents the integer. )

[Chemical 9] (In the formula, R ⁶ and R ⁷ are hydrogen atoms, unsubstituted alkyl
Group, unsubstituted phenyl group, alkyl-substituted phenyl group, cal
Bonate ester-substituted phenyl group, halogen-substituted phenyl
Group or an atom or group selected from cyano-substituted phenyl groups
You R ⁸ is an unsubstituted alkyl group, a halogenated alkyl
Group, alkyl ether group, cycloalkyl substituted alkyl
Group, cycloalkylcarboxylic acid ester substituted alkyl
Group, carboxylic acid ester group, phenyl group, alkyl substitution
Phenyl group, halogenated alkyl-substituted phenyl group, halo
Gen-substituted phenyl group, carboxylic acid ester-substituted phenyl
Group, cyano-substituted phenyl group, nitro-substituted phenyl group
Represents a selected group. )

[Chemical 10] (In the formula, R ⁶ and R ⁷ are a hydrogen atom, an unsubstituted alkyl group,
Unsubstituted phenyl group, alkyl-substituted phenyl group, halogen
Substituted phenyl group, carboxylic acid ester substituted phenyl group,
Represents an atom or group selected from halogen-substituted phenyl groups
You R ⁸ is an unsubstituted alkyl group, an unsubstituted phenyl group,
To halogenated alkyl group, alkyl ether group, cyclo
Xyl-substituted alkyl group, cyclohexylcarboxylic acid ester
Ter-substituted alkyl group, carboxylic acid ester group, alkyl
A substituted phenyl group, a halogenated alkyl-substituted phenyl group,
Cyano-substituted phenyl group, nitro-substituted phenyl group, halogen
Group-substituted phenyl group, carboxylic acid ester-substituted phenyl group
Represents a group selected from ) (2) At least one of the compounds represented by formula (I)
Species following general formula (I _{A) ~} are those selected from at least one compound represented by (I _{C) (1)} The electrophotographic photoreceptor according.

[Chemical 11] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ ,
r ² and r ³ are each independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted alkoxycarbonyl group, a halogen atom, a cyano group and a nitro group. Is. r ¹ may combine with another atom to form a ring. l is 1 to 4
Represents the integer. )

[Chemical 12] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ is water.
Elemental atom, halogen atom, unsubstituted alkyl group, nitro
Group, alkyl ether group, carboxylic acid ester group, halo
Genated alkyl group, alkyl ether-substituted phenyl group,
A benzyl substituent, or an atom selected from a benzyl group or
Represents a group. l represents an integer of 1 to 4. R ⁹ and R ¹⁰ are
Hydrogen atom, nitro group, cyano group, unsubstituted alkyl group,
Halogen-substituted alkyl group, alkyl ether group, unsubstituted
Phenyl group, nitro-substituted phenyl group, benzyl-substituted phenyl group
Nyl group, alkyl-substituted phenyl group, halogenated alkyl
Substituted phenyl group, cyano-substituted phenyl group, alkyl ether
Ter-substituted phenyl groups, benzyl-substituted phenyl groups,
Rubonate ester substituent Atom or atom selected from phenyl group
Represents a group. )

[Chemical 13] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ is
Hydrogen atom, halogen atom, unsubstituted alkyl group, nitro
Group, alkyl ether group, carboxylic acid ester group, halo
Genated alkyl group, alkyl ether-substituted phenyl group,
A benzyl substituent, or an atom selected from a benzyl group or
Represents a group. l represents an integer of 1 to 4. R ¹¹ ,
R ¹² , R ¹³ , and R ¹⁴ are a halogen atom, a nitro group,
Unsubstituted alkyl group, unsubstituted phenyl group, carboxylic acid
Ester-substituted phenyl group, halogen-substituted phenyl group,
Toro-substituted phenyl group, benzyl-substituted phenyl group, alkyl
-Substituted phenyl group, halogenated alkyl-substituted phenyl
Group, nitro-substituted phenyl group, cyano-substituted phenyl group,
Ruby ether substituted phenyl group, benzyl substituted phenyl
Group, dialkylaminosulfonyl group, alkylphenyl
Aminosulfonyl group, ethylbenzylaminosulfonyl
Group, alkylaminosulfinyl group, dialkylcarbamo
Ile group, group represented by the following structural formula

[Chemical 14] Represents an atom or group selected from (3) The charge generation layer (CGL) and the charge transport layer (CT)
The electrophotographic photosensitive member according to (1), wherein the same binder contained in L) is polycarbonate.

Further, according to the present invention, a preferred embodiment, at least one of said general formula (I) with at least one the following general formula are compounds represented (I _A) ~ compounds represented by (I _C) There is provided the electrophotographic photoreceptor as described above, which is selected from species.

[Chemical 4] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ ,
r ² and r ³ are each independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted alkoxycarbonyl group, a halogen atom, a cyano group and a nitro group. is there. r ¹ may combine with another atom to form a ring. l represents an integer of 1 to 4. )

[Chemical 5] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ is selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted alkoxycarbonyl group, a cyano group and a nitro group. .R ⁹ is .r ¹ are those that good .l also form a ring with another atom represents an integer of 1 to 4, R ¹⁰ is a hydrogen atom, a substituted or unsubstituted alkyl Represents a group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alkoxycarbonyl group, a cyano group, a nitro group, a halogen atom, etc.)

[Chemical 6] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ is a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted alkoxycarbonyl group, a halogen atom, a cyano group or a nitro group. Selected from the group: r ¹ may combine with another atom to form a ring, l represents an integer of 1 to 4, R ¹¹ ,
R ¹² , R ¹³ , and R ¹⁴ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alkoxycarbonyl group, a cyano group, a nitro group, a halogen atom, or the like. Represents )

Hereinafter, the above-mentioned general formula (I _A ) used in the present invention,
(I _B), shows a typical example of (I _C), the compound of formula (II) and (III).

[0012]

[Table 1- (1)]

[0013]

[Table 1- (2)]

[0014]

[Table 1- (3)]

[0015]

[Table 1- (4)]

[0016]

[Table 1- (5)]

[0017]

[Table 1- (6)]

[0018]

[Table 1- (7)]

[0019]

[Table 1- (8)]

[0020]

[Table 1- (9)]

[0021]

[Table 1- (10)]

[0022]

[Table 1- (11)]

[0023]

[Table 1- (12)]

[0024]

[Table 1- (13)]

[0025]

[Table 1- (14)]

[0026]

[Table 2- (1)]

[0027]

[Table 2- (2)]

[0028]

[Table 2- (3)]

[0029]

[Table 2- (4)]

[0030]

[Table 2- (5)]

[0031]

[Table 2- (6)]

[0032]

[Table 2- (7)]

[0033]

[Table 3- (1)]

[0034]

[Table 3- (2)]

[0035]

[Table 3- (3)]

[0036]

[Table 3- (4)]

[0037]

[Table 3- (5)]

[0038]

[Table 3- (6)]

The electrophotographic photosensitive member of the present invention has the structure shown in FIG. 1 and can be manufactured by sequentially laminating CGL and CTL on a conductive substrate. In the CGL, the charge-generating substance and the specific acceptor compound (A) having a larger reduction potential than the acceptor compound (B) used in the CTL and the same binder as that used in the CTL are essential components. A binder containing at least one kind is contained. The specific acceptor compound (B) having an electron transporting property and a binder are contained in the CTL as essential components. Further, in CGL and CTL, polycarbonate Z is particularly used as the same binder.

In recent years, various electron transport materials have been proposed aiming at the development of positively charged OPC. When a forward layer type laminated photoreceptor is used, the initial light decay is relatively fast but the residual potential is very large. Not practical. (For example, Polymer
Preprints, Japan Vol. 37, N
O. 3 1988 Tanaka et al.) One of the reasons is
It is said that the electron mobility of the electron-transporting material that has been announced largely depends on the electric field strength, and it is difficult to move in a low electric field. This depends on the molecular structure of the electron transport material and is an essential problem of the material. It is also considered that many electron transporting materials have poor compatibility with the binder as compared with the hole transporting material. (For example, J
apan Hardcopy 92 "paper collection 1992
Kobayashi and others)

The present inventors effectively inject the conduction carriers (electrons) generated in CGL into CTL, and further
By taking measures to increase the generation efficiency of conductive carriers in the GL, there are drawbacks such as low sensitivity, high residual potential, and poor stability in repeated potential, which have been problems in the conventional forward layer type positive charging photoreceptor. I found that it can be resolved. That is, in the forward layer structure, the charge generating substance in the CGL and the CTL
By making a condition in which the electron-transporting substance therein easily contacts with the CGL / CTL interface, the conduction carriers (electrons) are smoothly injected into the CTL, and further, the specific acceptor compound (A It has been found that the above problem can be solved by promoting the extraction of electrons out of the conduction carriers generated in the charge generating substance, increasing the practical number of free electrons, and eliminating the above-mentioned problems. The charge conductivity σ is expressed by the following equation. σ = ne μ (n: number of conductive carriers e: elementary charge μ:
Mobility) Of these, the mobility μ is the molecular structure of the electron transport material, CTL
It greatly depends on the dispersion state in the inside. The molecular structure of the electron transport material is a problem associated with the molecular design and synthesis technology, but the molecular dispersion of the electron transport material in CTL can be achieved by appropriately selecting the binder, and the electron mobility Can be improved. In addition, the number of conductive carriers n is basically the absorption coefficient of the charge generating substance, the aggregation state,
Although depending on the trap or the like, the n number can be increased by allowing the specific acceptor compound (A) having an action of extracting an electron to exist in the vicinity of the charge generating substance.

The present invention is basically based on the above findings. As described above, many known electron-transporting materials have poor compatibility with the binder, so that only a small amount can be added to the CTL, or the electron-transporting material often precipitates as crystals in the CTL. The present inventors have found that Polycarbonate Z has good compatibility with many electron transporting materials, and the above problems can be solved by using Polycarbonate Z as a binder for electron transporting materials. Perhaps Polycarbonate Z is an amorphous polymer, so it seems that the compatibility is good. Furthermore, in the present invention, the polycarbonate Z is also contained in CGL. When CGL containing Polycarbonate Z is applied, dried and then CTL with Polycarbonate Z as a binder is laminated on CGL, a part of the electron-transporting substance in CTL migrates into CGL due to good compatibility, and the charge is transferred. The contact between the generating substance and the electron transport material is improved, and conduction electrons generated in the charge generating substance are smoothly injected into the electron transport material, CTL. Also,
In the present invention, the specific acceptor compound (electron transport material) (A) is also contained in CGL. The acceptor compound originally has a function of withdrawing electrons, and withdraws conduction electrons generated in the charge generating substance before recombination with holes, thereby increasing the number of conduction electrons.

As the charge generating substance used in the present invention, bisazo dye, trisazo dye, phthalocyanine dye, quinacridone dye, perylene dye, polycyclic quinone dye, indigo dye, cyanine dye, pyrylium dye, bisbenzimidazole dye, indus Organic compounds such as ron dye, triarylmethane dye, thiazine dye, oxazine dye, squarylium dye, anthraquinone dye, xentene dye, amorphous selenium, trigonal selenium, selenium-arsenic alloy, selenium-tellurium alloy, cadmium sulfide, sulfur Examples thereof include inorganic compounds such as cadmium selenide, zinc oxide, and amorphous silicon.

Examples of the electron transport material used in the present invention include quinone compounds, vinylidene dinitrile compounds of quinone compounds, fluorenone compounds, vinylidene dinitrile compounds of fluorenone compounds, π-electron compounds having a nitrile group, Π having a carboxylic acid ester group
Examples thereof include electronic compounds and π-electron compounds having a cyano group.

Polycarbonate, especially polycarbonate Z (manufactured by PC-Z Teijin Kasei Co., Ltd.) is most suitable as the binder used in the present invention, and other amorphous polymers such as polyethylene resin and polypropylene resin, Acrylic resin, methacrylic resin, polystyrene, vinyl chloride resin, vinyl acetate resin, bisphenol A type polycarbonate, polyester resin, phenoxy resin, polyurethane resin, polyvinyl butyral resin, vinylidene fluoride resin, silicone resin, fibrous resin, phenol resin, Examples thereof include addition polymerization resins such as melamine resins, alkyd resins, and epoxy resins, polyaddition resins, polycondensation resins, and copolymer resins containing two or more of these repeating units.

As the conductive substrate used in the present invention,
Metal plates such as aluminum, nickel, copper, stainless steel,
Examples thereof include a metal drum or metal foil, a plastic film coated with a thin film of aluminum, tin oxide, copper iodide, or the like, or glass. In the present invention, the composition of CGL is 100 to 4 parts by weight of the charge generating substance, and the binder is 100 to 4 parts by weight.
00 parts by weight, preferably 25 to 100 parts by weight, and the acceptor compound is 0 to 200 parts by weight, preferably 1
It is 0 to 100 parts by weight. The thickness of CGL is 0.0
It is 5 to 10 μm, preferably 0.1 to 2 μm. Further, the composition of CTL is 25 to 400 parts by weight, preferably 50 to 200 parts by weight, with respect to 100 parts by weight of the binder, and the acceptor compound (electron transporting substance). Also, CT
The film thickness of L is 5 to 60 μm, preferably 10 to 30 μm.

Further, in the electrophotographic photoreceptor of the present invention, an undercoat layer may be provided between the conductive substrate and CGL for the purpose of improving charging property, adhesiveness and the like. As these materials, in addition to the binder material, polyamide resin, polyvinyl alcohol, polyvinylpyrrolidone, casein polyimide and the like can be used. In addition, silicon oil such as phenylmethyl siloxane or dimethyl siloxane is used for the purpose of improving the surface properties and coating properties of CTL.
It can be contained in.

In the electrophotographic photoreceptor of the present invention, a predetermined material is dissolved in an organic solvent or dispersed by a ball mill, ultrasonic wave, homomixer or the like to obtain a coating solution, which is a depping coater, a blade coater, a spray coater, a kiss coater, It is prepared by coating on a conductive substrate with a gravure coater, spin coater or the like and drying.

[0049]

EXAMPLES The present invention will be described below with reference to examples, but the embodiments of the present invention are not limited thereby.

Example 1 0.6 g of X-type metal-free phthalocyanine (Fastogen Blue 8120BS manufactured by Dainippon Ink and Chemicals, Inc.) was added to 10 parts of Polycarbonate Z.
After ball milling with 6 g of a wt% tetrahydrofuran solution, 0.3 g of the acceptor compound (Compound No. 1) and 5.4 g of tetrahydrofuran, 62.7 g of tetrahydrofuran was added and stirred to prepare a 2 wt% coating solution, and aluminum was used. Was applied onto a 75 μm thick polyester film vapor-deposited to a thickness of 1000 Å by a doctor blade, and CGL having a film thickness after drying of 0.5 μm was provided. Next, 6 g of a diphenoquinone compound, which is an electron transporting material represented by the following structural formula 7, polycarbonate 9 g, silicon oil (KF50 manufactured by Shin-Etsu Chemical Co., Ltd.) 0.009
g was dissolved in 85 g of tetrahydrofuran to prepare a coating solution, which was coated on CGL with a doctor blade, and CTL having a film thickness after drying of 20 μm was laminated to prepare an electrophotographic photoreceptor.

[Chemical 7] Compound No. Compounds Nos. 1 and 7 were dissolved in acetonitrile, and the reduction potential Ered was measured with respect to the reference electrode SCE. 1 is -0.60V,
The diphenoquinone compound of Chemical formula 5 was -0.45 V, and the compound No. It can be seen that 1 has a weaker electron affinity.

Example 2 The acceptor compound (Compound No. 1) was replaced with Compound No. An electrophotographic photoconductor was produced under the same conditions as in Example 1 except that 18 was used. Compound No. When 18 was dissolved in acetonitrile and the reduction potential was measured, it was -0.52 V (vs SCE).

Example 3 The acceptor compound (Compound No. 1) was replaced with Compound No. An electrophotographic photosensitive member was produced under the same conditions as in Example 1 except that 53 was used. Compound No. When 53 was dissolved in acetonitrile and the reduction potential was measured, it was -0.73V (vs SCE).

Example 4 The acceptor compound (Compound No. 1) was replaced with Compound No. An electrophotographic photoconductor was produced under the same conditions as in Example 1 except that 89 was used. Compound No. When 89 was dissolved in acetonitrile and the reduction potential was measured, it was -0.55 V (vs SCE).

Example 5 The acceptor compound (Compound No. 1) was replaced with Compound No. An electrophotographic photoconductor was produced under the same conditions as in Example 1 except that II-53 was used instead. Compound No. When II-53 was dissolved in acetonitrile and the reduction potential was measured, it was -0.96 V (vsSCE).

Example 6 Compound (Compound No. I) was replaced with compound No. An electrophotographic photoconductor was produced under the same conditions as in Example except that II-65 was used instead. Compound No. II-6
When 5 was dissolved in acetonitrile and the reduction potential was measured, it was −0.96V (vs SCE).

Example 7 The compound (Compound No. I) was replaced with the compound No. An electrophotographic photoreceptor was prepared under the same conditions as in Example 1 except that II-70 was used. Compound No. II-
When 70 was dissolved in acetonitrile and the reduction potential was measured, it was −0.96 V (vs SCE).

Example 8 The compound (Compound No. I) was replaced with the compound No. An electrophotographic photosensitive member was produced under the same conditions as in Example 1 except that III-34 was used instead. Compound No. II
When I-34 was dissolved in acetonitrile and the reduction potential was measured, it was -0.55 V (vs SCE).

Comparative Example 1 An electrophotographic photoreceptor was prepared under the same conditions as in Example 1 except that the benzoxa (thia) zole compound was not added to CGL.

Comparative Example 2 An electrophotographic photoconductor was produced under the same conditions as in Example 1 except that the binder of CGL was changed from Polycarbonate Z to a polyester resin (manufactured by Byron 200 Toyobo Co., Ltd.). .

[0060]

The electrophotographic photosensitive member thus produced was used as an electrostatic copying paper tester (SP-42) manufactured by Kawaguchi Electric Co., Ltd.
8), corona discharge was performed at −6 KV for 20 seconds to charge the surface potential V _S (V), and then dark decay was performed for 20 seconds. It was necessary for the surface potential V ₀ at that time to become 1/2. The exposure amount E _1/2 (lux · sec) and the surface potential (V) after 30 seconds of light irradiation were measured. The results are shown in Table 4.

[0062]

[Table 4]

[0063]

According to the present invention, as is clear from comparison with Comparative Example 1, CGL contains the benzoxa (thia) zole compound (I) of the present invention or maleinimide (II) or (III). By doing so, it can be seen that the residual potential is low and there is an effect of improving the sensitivity. Further, according to the present invention, as is clear from comparison with Comparative Example 2, CGL and CT
It can be seen that the use of Polycarbonate Z as a binder with L has a low residual potential and an effect of improving sensitivity.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an electrophotographic photoreceptor according to the present invention.

[Explanation of symbols] 1 Charge transport layer 2 Charge generation layer 3 Conductive substrate

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yumi Ichikawa 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) Reference JP-A-61-2157 (JP, A) JP-A-SHO 58-120261 (JP, A) JP 8-286402 (JP, A) JP 8-245601 (JP, A) JP 8-234467 (JP, A) JP 8-231502 (JP, A) JP-A-7-175233 (JP, A) JP-A-7-104495 (JP, A) JP-A-6-345742 (JP, A) JP-A-6-31974 (JP, A) JP-A-5 -45901 (JP, A) JP-A-4-360148 (JP, A) JP-A-2-136861 (JP, A) JP-A-1-106067 (JP, A) (58) Fields investigated (Int.Cl) . ⁷ , DB name) G03G 5/00 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. A charge generating substance, an acceptor compound (A) having an electron transporting ability, and a binder only on a conductive substrate.
A charge generation layer (CGL) composed of (1) and a charge transport layer (CTL) composed of only an acceptor compound (B) having an electron transporting ability and a binder are sequentially laminated. (CGL) and the charge transport layer (C
TL) contains at least one kind of the same binder, and the acceptor compound (A) having the electron transporting ability is prepared from at least one of the compounds represented by the following general formulas (I) to (III). An electrophotographic photoreceptor, which is a selected compound. [Chemical 1] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ ,
R ² , R ⁴ and R ⁵ are each a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted A sulfonyl group of
R ¹ and R ² , R ⁴ selected from a substituent group consisting of a substituted or unsubstituted sulfonamide group, a substituted or unsubstituted carbamoyl group, a halogen atom, a cyano group and a nitro group.
And R ⁵ may form a ring with each other. R ³ represents a single bond, a sulfone group, a sulfoxide group or a sulfur atom, and r ¹
Is a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted carbamoyl group, a halogen atom, a cyano group or a nitro group. It was selected from the group. r ¹ may combine with another atom to form a ring. l is 1 to 4
Represents the integer. ) [Chemical 2] (In the formula, R ⁶ and R ⁷ are hydrogen atoms, unsubstituted alkyl
Group, unsubstituted phenyl group, alkyl-substituted phenyl group, cal
Bonate ester-substituted phenyl group, halogen-substituted phenyl
Group or an atom or group selected from cyano-substituted phenyl groups
You R ⁸ is an unsubstituted alkyl group, a halogenated alkyl
Group, alkyl ether group, cycloalkyl substituted alkyl
Group, cycloalkylcarboxylic acid ester substituted alkyl
Group, carboxylic acid ester group, phenyl group, alkyl substitution
Phenyl group, halogenated alkyl-substituted phenyl group, halo
Gen-substituted phenyl group, carboxylic acid ester-substituted phenyl
Group, cyano-substituted phenyl group, nitro-substituted phenyl group
Represents a selected group. ) [Chemical 3] (In the formula, R ⁶ and R ⁷ are a hydrogen atom, an unsubstituted alkyl group,
Unsubstituted phenyl group, alkyl-substituted phenyl group, halogen
Substituted phenyl group, carboxylic acid ester substituted phenyl group,
Represents an atom or group selected from halogen-substituted phenyl groups
You R ⁸ is an unsubstituted alkyl group, an unsubstituted phenyl group,
To halogenated alkyl group, alkyl ether group, cyclo
Xyl-substituted alkyl group, cyclohexylcarboxylic acid ester
Ter-substituted alkyl group, carboxylic acid ester group, alkyl
A substituted phenyl group, a halogenated alkyl-substituted phenyl group,
Cyano-substituted phenyl group, nitro-substituted phenyl group, halogen
Group-substituted phenyl group, carboxylic acid ester-substituted phenyl group
Represents a group selected from ) 2. A method according to claim 1, wherein at least one compound represented by the general formula (I) are those selected from at least one compound represented by the following general formula _{(I A) ~ (I C} ) Electrophotographic photoconductor. [Chemical 4] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ ,
r ² and r ³ are each independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted alkoxycarbonyl group, a halogen atom, a cyano group and a nitro group. Is. r1 may combine with another atom to form a ring. l is 1 to 4
Represents the integer. ) [Chemical 5] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ is water.
Elemental atom, halogen atom, unsubstituted alkyl group, nitro
Group, alkyl ether group, carboxylic acid ester group, halo
Genated alkyl group, alkyl ether-substituted phenyl group,
A benzyl substituent, or an atom selected from a benzyl group or
Represents a group. l represents an integer of 1 to 4. R ⁹ and R ¹⁰ are
Hydrogen atom, nitro group, cyano group, unsubstituted alkyl group,
Halogen-substituted alkyl group, alkyl ether group, unsubstituted
Phenyl group, nitro-substituted phenyl group, benzyl-substituted phenyl group
Nyl group, alkyl-substituted phenyl group, halogenated alkyl
Substituted phenyl group, cyano-substituted phenyl group, alkyl ether
Ter-substituted phenyl groups, benzyl-substituted phenyl groups,
Rubonate ester substituent Atom or atom selected from phenyl group
Represents a group. ) [Chemical 6] (In the formula, X represents an oxygen atom or a sulfur atom. R ¹ is
Hydrogen atom, halogen atom, unsubstituted alkyl group, nitro
Group, alkyl ether group, carboxylic acid ester group, halo
Genated alkyl group, alkyl ether-substituted phenyl group,
A benzyl substituent, or an atom selected from a benzyl group or
Represents a group. l represents an integer of 1 to 4. R ¹¹ ,
R ¹² , R ¹³ , and R ¹⁴ are a halogen atom, a nitro group,
Unsubstituted alkyl group, unsubstituted phenyl group, carboxylic acid
Ester-substituted phenyl group, halogen-substituted phenyl group,
Toro-substituted phenyl group, benzyl-substituted phenyl group, alkyl
-Substituted phenyl group, halogenated alkyl-substituted phenyl
Group, nitro-substituted phenyl group, cyano-substituted phenyl group,
Ruby ether substituted phenyl group, benzyl substituted phenyl
Group, dialkylaminosulfonyl group, alkylphenyl
Aminosulfonyl group, ethylbenzylaminosulfonyl
Group, alkylaminosulfinyl group, dialkylcarbamo
Ile group, a group represented by the following structural formula : Represents an atom or group selected from ) 3. The electrophotographic photosensitive member according to claim 1, wherein the same binder contained in the charge generation layer (CGL) and the charge transport layer (CTL) is polycarbonate.