JPH03129357A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide a high sensitivity and excellent repetitive characteristics and to prevent the deterioration against the exposure to light by incorporating specific bisazo compds. as the charge generating material of a charge generating layer into this layer and incorporating specific hydrazone compd. as the charge transfer material of a charge transfer layer into this layer. CONSTITUTION:This photosensitiv body has a photosensitive layer 4 which contains at least one kind of the bisazo compds. expressed by formula I as the charge generating material of the charge generating layer 2 and at least one kind of the hydrazone compds. expressed by formula II as the charge transfer material of the charge transfer layer 3. In the formulas I and II, R1 denotes a halogen atom, an alkyl group or the like, R2 denotes an alkyl group which may be substd.; R3 denotes a hydrogen atom, cyano group, etc.; R4 denotes a hydrogen atom, halogen atom, etc.; A denotes an aryl group, heterocyclic group which may be substd.; R5 denotes an alkyl group, aryl group which may be substd.; R6 denotes a hydrogen atom, halogen atom, etc.; n denotes 0 or 1. The photosensitive body which has the high sensitivity and excellent repetitive characteristics and is less deteriorated in the electrophotographic characteristics against the exposure of light is obtd. in this way.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electrophotographic photoreceptor, and in particular, it is composed of a charge generation layer and a charge transport layer containing an organic material, and is suitable for use in electrophotographic printers, copying machines, etc. The present invention relates to a laminated electrophotographic photoreceptor that is used.

[Conventional technology]

Conventionally, photosensitive materials for electrophotographic photoreceptors (hereinafter also referred to as photoreceptors) include inorganic photoconductive substances such as selenium or selenium alloys, or inorganic photoconductive substances such as zinc oxide or cadmium sulfide in a resin binder. Dispersed, PoI
Organic photoconductive substances such as J-N-vinylcarbazole or polyvinylanthracene, phthalocyanine compounds, or bisazo compounds dispersed in a resin binder or vacuum-deposited are used. ing.

The photoreceptor also has the ability to retain surface charge in the dark.

It is necessary to have the function of receiving light and generating a charge, and also the function of receiving light and transporting a charge, but a so-called single-layer photoreceptor that has both these functions in two layers, and a function that mainly performs charge generation. There is a so-called laminated photoreceptor in which functionally separated layers are laminated, including a layer contributing to surface charge in the dark and a layer contributing to charge transport during light reception. For example, the Carlson method is applied to image formation by electrophotography using these photoreceptors. Image formation in this method involves charging the photoconductor in a dark place by corona discharge, forming an electrostatic latent image such as text or pictures on the original on the surface of the charged photoconductor, and forming an electrostatic latent image on the surface of the charged photoconductor. After the toner image has been transferred, the photoreceptor is subjected to static electricity removal, removal of residual toner, photostatic static removal, etc. before being reused. be done.

In recent years, electrophotographic photoreceptors using organic materials have been put into practical use due to their advantages such as flexibility, thermal stability, and film-forming properties. For example, poly-N-vinylcarbazole and 2.
4.7-) A photoreceptor consisting of linitrofluorene-9-one (described in U.S. Pat. No. 3,484,237), a photoreceptor containing an organic pigment as a main component (Japanese Patent Laid-Open No. 37,543/1989)
(described in Japanese Unexamined Patent Publication No. 10785/1983), and a photoreceptor whose main component is a eutectic complex consisting of a dye and a resin (described in Japanese Patent Application Laid-open No. 10785/1985).

[Problem to be solved by the invention]

However, although organic materials have many advantages that inorganic materials do not have, the current situation is that organic materials that fully satisfy all of the characteristics required of electrophotographic photoreceptors have not been obtained, and are highly sensitive and repeatable. A photoreceptor with excellent characteristics is strongly desired.

The present invention has been made in view of the above-mentioned points, and its object is to use a new organic material as a charge generating substance and an N charge transporting substance, and to produce an electrophotographic photocopy machine with high sensitivity and excellent repeatability, and which does not deteriorate when exposed to light. The purpose is to provide a photoreceptor.

[Means to solve the problem]

According to the present invention, the above-mentioned objects are as follows: 1) A laminated photoreceptor having a charge generation layer and a charge transport layer on a conductive substrate, in which a bisazo compound represented by the general formula (I) is used as a charge generation substance in the charge generation layer. and a photosensitive layer containing at least one hydrazone compound represented by the general formula (II) as a charge transport substance of the charge transport layer, [in formulas (I) and (II), R5 is , halogen atom, alkyl group, alkoxy group, R2 is an optionally substituted alkyl group, R3 is a hydrogen atom, cyano group, carbamoyl group, carboxyl group, ester group, acyl group, R1 is hydrogen atom 1 halogen atom, nitro group , an alkyl group, an alkoxy group, A is an optionally substituted aryl group, a heterocyclic group, R
3 is an optionally substituted alkyl group, aryl group, R6
represents a hydrogen atom, a hydrogen atom, an optionally substituted alkyl group, or an aryl group, and n represents 0 or l. 2) A laminated photoreceptor having a charge generation layer and a charge transport layer on a conductive substrate, containing at least one bisazo compound represented by the general formula (I) as a charge generation substance in the charge generation layer. and contains at least one hydrazone compound represented by the general formula (n) and at least one pyrazole compound represented by the -fi formula (III) as a charge transport substance of the charge transport layer, ^9 [Formula (I ), (Kyuichi R1 is a halogen atom, an alkyl group, an alkoxy group, R2 is an optionally substituted alkyl group, R3 is a hydrogen atom, a cyano group, a carbamoyl group, a carboxyl group, an ester group, an acyl group, hydrogen atom,
halogen atom, nitro group, alkyl group, alkoxy group, A is an optionally substituted aryl group 1 heterocyclic group, R5
is an optionally substituted alkyl group or aryl group, R8 is a hydrogen atom, a halogen atom, an optionally substituted alkyl group or an aryl group, and n is 0 or 1.

In formula (III), E is an optionally substituted heterocyclic group, an aromatic fused polycyclic group, R7 is a hydrogen atom, an optionally substituted alkyl group, R6 is a hydrogen atom, an optionally substituted alkyl group, phenyl group, tolyl Lp-dimethylaminophenyl group or p-diethylaminophenyl group; R9 represents a hydrogen atom or an alkyl group which may be substituted with i; 3) In a laminated photoreceptor having a charge generation layer and a charge transport layer on a conductive substrate, at least one of polycyclic non-compounds represented by the general formula (rV) is used as a charge generation substance in the charge generation layer. Contains a kind of charge ring.

At least one hydrazone compound represented by the general formula (ff) and the general formula (II
9 [In the formula (■), D represents a halogen atom, a nido group, a cyano group, an acyl group, a carboxyl group, and m represents an integer of 0 to 4, containing at least one pyrazole compound represented by I) In formula (n), A is an optionally substituted aryl group or heterocyclic group, R5 is an optionally substituted alkyl group or aryl group, R6 is a hydrogen atom, a halogen atom, or an optionally substituted Good alkyl group, aryl group, n represents O or l, in formula (III), E is an optionally substituted heterocyclic group, aromatic condensed polyester, R, is a hydrogen atom, optionally substituted alkyl group, R8 represents a hydrogen atom, an optionally substituted alkyl group, phenyl group, tolyl group, p-dimethylaminophenyl group or p-diethylaminophenyl group, and Rs represents a hydrogen atom or an optionally substituted alkyl group. ].

General formula (I), (II), ([1), (r
Specific examples of the compound represented by V) are as follows.

911-1 Compound function 1l-2 N1911-3 911-4 [2H5 Compound function o-1 Use! ! -8 Entrance 11-9 柟II-10 绝■-15 Hz 嘘I+-19 [Operation] By using the above-mentioned materials, a photoreceptor with high sensitivity and excellent repeatability, or a photoconductor with high sensitivity and excellent repeatability.
It becomes possible to obtain a photoreceptor that does not deteriorate due to dew.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

′! Figure J1 and Figure 2 are conceptual cross-sectional views showing one embodiment of the photoreceptor of the present invention, in which 1 is a conductive substrate, 2 is a charge generation layer, and 3 is a conductive substrate.
4 is a charge transport layer, 4 is a photosensitive layer, and 5 is a surface coating layer. The photosensitive layer is a functionally separated type in which a charge generation layer and a charge transport layer are separated. The photosensitive layer in FIG. 1 has a charge generation layer and a charge transport layer laminated in this order, and the photosensitive layer in FIG. 2 has a charge transport layer and a charge generation layer laminated in that order, contrary to FIG.

The conductive substrate 1 serves as an electrode for the photoreceptor and at the same time serves as a support for the other layers, and may be cylindrical, plate-shaped, or film-shaped, and may be made of aluminum, stainless steel cape, or nickel nat. It may also be made of metal, glass, resin, or the like, which has been subjected to conductive treatment.

The charge generation layer 2 is formed by vacuum-depositing an organic photoconductive material and coating a material in which particles of the organic photoconductive material are dispersed in a resin binder, and generates charges by receiving light. In addition to the high charge generation efficiency, the ability to inject the generated charges into the charge transport layer 3 is also important, and it is desirable that the charge is less dependent on the electric field and can be easily injected even in a low electric field.

Since the charge generation layer only needs to have a charge generation function, its thickness is determined by the light absorption coefficient of the charge generation substance and is generally 5.
It is 1 μm or less, preferably 1 μm or less. The charge generation layer is mainly composed of a charge generation substance, and a charge transport substance or the like may be added thereto. As the resin binder, polycarbonate, polyester, polyamide, polyurethane, epoxy 2 silicone resin, polymers and copolymers of methacrylic acid ester, etc. can be used in appropriate combinations.

The charge transport layer 3 is a coating film made of a material in which an organic charge transport substance is dispersed in a resin binder, and in the dark, it serves as an insulating layer to retain the charge on the photoreceptor, and when receiving light, it is injected from the charge generation layer. Demonstrates the function of transporting electric charge. As a resin binder, polycarbonate, polyester,
polyamide.

Polyurethane, epoxy, silicone resin, methacrylic acid ester polymers and copolymers, etc. are used, but in addition to mechanical, chemical, and electrical stability and adhesion, compatibility with the charge transport substance is important. be.

In order to maintain a practically effective surface potential, the thickness of the charge transport layer is preferably in the range of 3 to 35 μm, more preferably 10 to 28 μm.

The surface coating layer 5 has excellent durability against mechanical stress,
Furthermore, it is composed of a chemically stable substance, has the function of accepting and retaining the charge of corona discharge in the dark, and has the ability to transmit the light to which the charge generation layer is sensitive, so that it is not exposed to light when exposed to light. It is necessary for the surface charges to be neutralized and eliminated by the injection of the generated charges. Furthermore, as described above, it is desirable that the coating material be as transparent as possible in the wavelength region where the charge generating substance absorbs maximum light.

As the coating material for the surface coating layer, modified silicone resins include acrylic modified silicone resin, epoxy modified silicone resin, and alkyd modified silicone resin.

Polyester modified silicone resin, urethane modified silicone resin, and silicone resin as a hard coating agent can be used. These modified silicone resins can be used alone, but for the purpose of improving durability, 5ins
, T! A mixed material with a condensate of a metal alkoxy compound that can form a film mainly composed of Os, fniL, or ZrL is suitable.

The thickness of the coating layer itself depends on the composition of the coating layer, but
It can be set arbitrarily within a range that does not cause adverse effects such as an increase in residual potential when used repeatedly and continuously.

Examples of the present invention will be described below.

Example 1 1 part by weight of a bisazo compound represented by the above compound hr-i as a charge generating substance, 1 part by weight of diallyl phthalate resin (trade name: DAP, manufactured by Osaka Soda) as a binder resin, and 150 parts by weight of methyl ethyl ketone. Mix, 3
The mixture was kneaded using a time mixer to prepare a coating solution to prepare a coating solution for the charge generation layer. Next, 1 part by weight of a hydrazone compound represented by the compound hn-2 as a charge transport substance and 1 part by weight of a polycarbonate resin (trade name Panlite L-1225, manufactured by Teijin Chemical Co., Ltd.) as a binder resin were added to 6 parts by weight of dichloromethane. A coating liquid for a charge transport layer was prepared by dissolving in parts by weight. Next, a charge generation layer (I μl 11) and a charge transport layer (I 6 μm) were coated with the prepared coating liquids in this order on a polyester terephthalate film on which aluminum had been vapor-deposited, thereby producing a negatively charged photoreceptor.

Example 2 A photoreceptor was produced in the same manner as in Example 1, except that the charge transport material in Example 1 was replaced with a hydrazone compound represented by Compound 1n-3.

Example 3 A photoreceptor was prepared in the same manner as in Example 1 except that the charge transport material in Example 1 was replaced with a hydrazone compound represented by the compound kIr-5.

Example 4 A photoreceptor was produced in the same manner as in Example 1 except that the charge transport material in Example 1 was replaced with a hydrazone compound represented by the compound Nllll-8.

Example 5 A photoreceptor was produced in the same manner as in Example 1 except that the charge transport material in Example 1 was replaced with a hydrazone compound represented by the compound kII-9.

Example 6 A photoreceptor was produced in the same manner as in Example 1 except that the charge generating substance in Example 1 was replaced with a bisazo compound represented by the compound kl-2.

Example 7 A photoreceptor was produced in the same manner as in Example 2 except that the charge generating substance in Example 2 was replaced with a bisazo compound represented by the compound kl-2.

Example 8 The charge generating substance of Example 3 was replaced with the above compound! i'o, r
A photoreceptor was produced in the same manner as in Example 3 except that the bisazo compound represented by -2 was used.

Example 9 A photoreceptor was produced in the same manner as in Example 4 except that the charge generating substance in Example 4 was replaced with a bisazo compound represented by the compound NαI-2.

Example 10 A photoreceptor was produced in the same manner as in Example 5, except that the charge generating biological material in Example 5 was changed to the bisazo compound represented by the compound kl-2.

Example 11 A photoreceptor was produced in the same manner as in Example 1 except that the charge generating substance in Example 1 was replaced with a bisazo compound represented by the compound NαN-6.

Example I2 A photoreceptor was produced in the same manner as in Example 2 except that the charge generating substance in Example 2 was replaced with the bisazo compound represented by Compound N (L12).

Example 13 A photoreceptor was produced in the same manner as in Example 3, except that the charge generating substance in Example 3 was replaced with a bisazo compound represented by the compound hI-6.

Example 14 A photoreceptor was produced in the same manner as in Example 4 except that the charge generating substance in Example 4 was replaced with a bisazo compound represented by the compound kl-6.

Example 15 A photoreceptor was produced in the same manner as in Example 5 except that the charge generating substance in Example 5 was replaced with a bisazo compound represented by the compound NαI-6.

Comparative Example 1 A photoreceptor was prepared in the same manner as in Example 1 except that the charge transport substance in Example 1 was changed to 1-phenyl-3-(p-diethylaminostyrirne-5-(para-diethylaminophenyl)-2-pyrazoline (ASPP)). Created.

Comparative Example 2 A photoreceptor was produced in the same manner as in Example 1 except that the charge transport material in Example 1 was changed to p-diethylaminobenzaldehyde-diphenylhydrazone (ABPH).

Comparative Example 3 A photoreceptor was produced in the same manner as in Comparative Example 1 except that the charge generating substance in Comparative Example 1 was changed to ε-type copper phthalocyanine.

Comparative Example 4 A photoreceptor was produced in the same manner as in Comparative Example 3 except that the charge transport material in Comparative Example 3 was changed to p-diethylaminobenzaldehyde-diphenylhydrazone (ABPH).

The electrophotographic properties of the photoreceptor thus obtained were measured using an electrostatic recording paper tester RSP-428J manufactured by Kawaguchi Electric.

The surface potential V, (Pol)) of the photoreceptor is -6, OkV in the dark.
This is the initial surface potential when corona discharge is performed for 10 seconds to negatively charge the surface of the photoreceptor, and the surface potential V is the surface potential when the photoreceptor surface is then held in the dark for 2 seconds with corona discharge stopped.
(volts), and then the illuminance 2 on the photoreceptor surface.
The time (seconds) required for vd to be halved after irradiation with 1ux white light was determined as the half-attenuation exposure amount El/□ (Lux·seconds). Further, the surface potential when the surface of the photoreceptor was irradiated with 21 ux white light for 10 seconds was defined as the residual potential V (volt).

Table 1 (Part 1) Table (Part 2) As seen in Table 1, Examples 1-15 are the same as Comparative Examples 1 to 1.
Although the surface potential is the same as in Example 4, the residual potential and half-attenuation exposure amount are clearly improved, and the superiority of the combination of the bisazo compound and hydrazone compound of the present invention is clear.

Example 16 1 part by weight of the bisazo compound represented by the above compound Nα1-8 as a charge generating substance, 2 parts by weight of diallyl phthalate resin (trade name: DAP, manufactured by Osaka Soda) as a binder resin, and 300 parts by weight of methyl ethyl ketone. The mixture was mixed and kneaded using a blender for 3 hours to prepare a coating solution to prepare a coating solution for the charge generation layer.

Next, 1 part by weight of a hydrazone compound represented by Compound 1n-2 as a charge transport substance and 1.5 parts by weight of a polyarylate resin (trade name U-polymer U-100A: Unitika lff1) as a binder resin were added in dichloromethane. A coating liquid for a charge transport layer was prepared by dissolving 9 parts by weight. Next, a charge transport layer (I 7 μm) and a charge generation layer (I μm) were placed on the polyester terephthalate film on which aluminum was vapor-deposited.
The coating liquids prepared respectively were applied in this order to prepare a positively charging photoreceptor.

Example 17 A photoreceptor was produced in the same manner as in Example I6 except that the charge transport material in Example 16 was replaced with a hydrazone compound represented by the compound kn-3.

Example 18 A photoreceptor was produced in the same manner as in Example 16 except that the charge transport material in Example 16 was replaced with a hydrazone compound represented by the compound NQII-5.

Implementation f! 419 A photoreceptor was prepared in the same manner as in Example I6 except that the charge transport material in Example 16 was replaced with a hydrazone compound represented by the compound NαIf-8.

Example 20 The charge transport material of Example 16 was added to the compound N(LI[-
In place of the hydrazone compound shown in 9, Practical Example 16
A photoreceptor was prepared in the same manner as described above.

Comparative Example 5 The charge transport material of Example 16 was converted into 1-phenyl-3-(p-
A photoreceptor was prepared in the same manner as in Example 16 except that diethylaminostyryl)-5-(varadiethylaminophenyl)-2-pyrazoline (AsPP) was used.

Comparative Example 6 A photoreceptor was produced in the same manner as in Example 16 except that the charge transport material in Example 16 was changed to p-diethylaminobenzaldehyde-diphenylhydrazone (ABPI()).

Comparative Example 7 A photoreceptor was produced in the same manner as in Comparative Example 5 except that the charge generating substance in Comparative Example 5 was changed to ε-type copper phthalocyanine.

Comparative Example 8 A photoreceptor was produced in the same manner as in Comparative Example 7 except that the charge transport material in Comparative Example 7 was changed to p-diethylaminobenzaldehyde-diphenylhydrazone (ABPH>).

The electrophotographic properties of the photoreceptor thus obtained were measured using an electrostatic recording paper tester rSP-428J manufactured by Kawaguchi Electric.

The surface potential V of the photoreceptor (volts) is +5.Qk in the dark.
This is the initial surface potential when the surface of the photoreceptor is negatively charged by performing a corona discharge of V for 10 seconds, and the surface potential when the photoreceptor surface is then held in the dark for 2 seconds with corona discharge stopped.
, (volts), and then irradiate the surface of the photoreceptor with white light with an illuminance of 2 Lux to find the time (seconds) until V becomes half, and find the half-attenuation exposure amount El, □ (Lux・seconds) Further, the surface potential when the surface of the photoreceptor was irradiated with 2 Lux of white light for 10 seconds was defined as the residual potential V, (volt).

Table 2 As seen in Table 2, Examples 16 to 20 are Comparative Example 3
Although the surface potential is the same as in Samples 4 to 4, the residual potential and half-attenuation exposure amount are clearly improved, and the superiority of the combination of the bisazo compound and hydrazone compound of the present invention is clear.

Example 21 1 part by weight of a bisazo compound represented by the above compound FJa I-1 as a charge generating substance, and 1 part by weight of diallyl phthalate resin (trade name DAP: manufactured by Osaka Soda) as a binder resin.
parts by weight were mixed with 150 parts by weight of methyl ethyl ketone and kneaded for 3 hours using a mixer to prepare a coating solution to prepare a coating solution for the charge generation layer.

Next, 1 part by weight of a hydrazone compound represented by the compound Nαn-2 was used as a charge transport substance, and a polycarbonate resin (trade name: Panlite L-1225:
(manufactured by Ondai Kasei) was dissolved in 6 parts by weight of dichloromethane to prepare a coating liquid for a charge transport layer. Next, a charge generation layer (I μm) and a charge transport layer (I 6 μm) were coated with the prepared coating liquids in this order on a polyester terephthalate film on which aluminum had been vapor-deposited, thereby producing a negatively charged photoreceptor.

Example 22 A photoreceptor was prepared in the same manner as in Example 21, except that the compound lll-1 was added to the charge transport layer of Example 21 in an amount of 0.7% by weight based on the compound Ir-5.

Example 23 A photoreceptor was prepared in the same manner as in Example 21, except that 1.5% by weight of Compound I-1 of the charge transport layer of Example 21 was added to Compound n-5.

Example 24 A photoreceptor was prepared in the same manner as in Example 21 by adding the compound I [I-1 in an amount of 5% by weight based on the compound 11-5 to the charge transport layer of Example 21.

Example 25 A photoreceptor was prepared in the same manner as in Example 21, except that the compound m-1 was added to the charge transport layer of Example 21 in an amount of 10% by weight based on the compound 11-5.

The electrophotographic characteristics of the photoreceptor thus obtained were measured using an electrostatic recording paper tester rSP-428 manufactured by Kawaguchi Electric.

For evaluation, the photoreceptor was exposed to -6,0 kv corona discharge in a dark place at 10
After the test was performed for a second, the test was performed at a potential vr when white light was irradiated with a light intensity of 3 Lux -5 ac. Next, expose to 5QQjuz's fluorescent lamp for 24 hours, leave it in a dark place for 24 hours, and measure V in the same way as above. ! vr due to dew
The change ΔV, (increase) was measured.

As seen in Table 3, Example 2 compared to Example 21.
2 to 25 have a small Δ■, and the addition of the pyrazole compound is effective against light exposure. However, in Example 24, deterioration of the sensitivity characteristics and dark decay characteristics was observed, and in Example 25, these characteristics deteriorated significantly.

Example 26 1 part by weight of a polycyclic quinone compound represented by the compound NIIV-1 was used as a charge generating substance, and a vinyl chloride copolymer resin (trade name MR-110, manufactured by Nippon Zeon Corporation) was used as a binder resin. A coating solution for the charge generation layer was prepared by mixing with 100 parts by weight of methyl ethyl ketone and kneading in a blender for 3 hours to prepare a coating solution for the charge generation layer.Next, 1 weight of the hydrazone compound represented by the above compound Na1I2 was added as a charge transport substance. A coating liquid for a charge transport layer was prepared by dissolving 1 part by weight of a polycarbonate resin (trade name: Panrye L-1225, manufactured by Ondai Kasei) as a binder resin in 6 parts by weight of dichloromethane. Next, a charge generation layer (I μm) and a charge transport layer (I 6 μm) were coated with the prepared coating liquids in this order on a polyester film on which aluminum had been vapor-deposited, thereby producing a negatively charged photoreceptor.

Example 27 0.5% by weight of the compound 1-1 based on the compound 11-5 was added to the charge transport layer of Example 26.
A photoreceptor was prepared in the same manner as described above.

Example 28 A photoreceptor was prepared in the same manner as in Example 26 by adding the compound 11-1 to the charge transport layer of Example 26 in an amount of 2% by weight based on the compound 1-5.

Example 29 A photoreceptor was prepared in the same manner as in Example 26 by adding the compound 1-1 to the charge transport layer of Example 26 in an amount of 6% by weight based on the compound n-5.

Example 30 The compound lll-1 was added to the charge transport layer of Example 26 in an amount of 15% by weight based on the compound 11-5, and Example 2
A photoreceptor was prepared in the same manner as in Example 6.

Example 31 A photoreceptor was prepared in the same manner as in Example 26 by adding the compound 1-1 to the charge transport layer of Example 26 in an amount of 22% by weight based on the compound 11-5.

The electrophotographic characteristics of the photoreceptor thus obtained were measured using an electrostatic recording paper tester RSP-428J manufactured by Kawaguchi Electric.

The evaluation is -6 for the photoreceptor in the dark, and 10 for OkV corona discharge.
After performing the test for a few seconds, the test was performed at a potential Vr when white light was irradiated with a light intensity of 3 lux-sec. Next, 5QQjuz's fluorescent light II was applied for 24 hours, then left in a dark place for 24 hours, and V was measured in the same manner as above to determine the Vr due to light exposure.
The change ΔV, (increase) was measured.

Addition of compounds listed in Table 1 is effective. However, in Example 29, the sensitivity characteristics and dark decay characteristics deteriorated, and in Example 30, these characteristics deteriorated significantly.

〔Effect of the invention〕

By using a compound represented by the general formula (I) as a charge-generating substance and a hydrazone compound represented by the above-mentioned general formula (formerly) as a charge-transporting substance, it can be used as an electrophotographic photoreceptor for copying machines in both positive and negative charging. It is also possible to obtain a photoreceptor with high sensitivity and excellent repeatability.Furthermore, a bisazo compound represented by the general formula (I) above is used as a charge generating substance, and a bisazo compound represented by the above general formula (II) is used as a charge transporting substance.
) and the above general formula (III)
By using the pyrazole compound represented by the formula, it is possible to obtain a photoreceptor whose electrophotographic properties are less likely to deteriorate when exposed to light. Further, as a charge generating substance, the general formula (IV
), and by using a hydrazone compound represented by the above-mentioned formula (n) and a pyrazole compound represented by the above general formula (III) as charge transporting substances, electrons are suppressed against light exposure. A photoreceptor with less deterioration of photographic properties can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a conceptual sectional view showing an embodiment of the photoreceptor of the present invention, and FIG. 2 is a conceptual sectional view showing an embodiment of the photoreceptor having a configuration opposite to that of FIG. 1. Conductive substrate, 2. Charge-generating 1 layer, 3. Charge wheel diagram.

Claims (1)

[Scope of Claims] 1) In a laminated photoreceptor having a charge generation layer and a charge transport layer on a conductive substrate, at least a bisazo compound represented by the general formula (I) is used as a charge generation substance in the charge generation layer. 1. A photoreceptor for electrophotography, comprising a photosensitive layer containing at least one hydrazone compound represented by general formula (II) as a charge transport material in a charge transport layer. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) [In formulas (I) and (II), R_1 is a halogen atom, alkyl group, or alkoxy group, R_2 is an optionally substituted alkyl group, R_3 is Hydrogen atom, cyano group, carbamoyl group, carboxyl group, ester group, acyl group, R_4 is a hydrogen atom, halogen atom, nitro group, alkyl group, alkoxy group, A is an optionally substituted aryl group, heterocyclic group,
R_5 is an optionally substituted alkyl group, aryl group, R
_6 represents a hydrogen atom, a halogen atom, an optionally substituted alkyl group, or an aryl group; n represents 0 or 1; 2) A laminated photoreceptor having a charge generation layer and a charge transport layer on a conductive substrate, containing at least one bisazo compound represented by the general formula (I) as a charge generation substance in the charge generation layer. and containing at least one hydrazone compound represented by the general formula (II) and at least one pyrazole compound represented by the general formula (III) as a charge transport substance of the charge transport layer. Photoreceptor. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) [Formula In (I) and (II), R_1 is a halogen atom, an alkyl group, an alkoxy group, R_2 is an optionally substituted alkyl group, R_3 is a hydrogen atom, a cyano group, a carbamoyl group, a carboxyl group, an ester group, an acyl group, R_4 is a hydrogen atom, a halogen atom, a nitro group, an alkyl group, an alkoxy group, A is an optionally substituted aryl group, a heterocyclic group,
R_5 is an optionally substituted alkyl group, aryl group, R
_6 represents a hydrogen atom, a halogen atom, an optionally substituted alkyl group, or an aryl group; n represents 0 or 1; In formula (III), E is an optionally substituted heterocyclic group, an aromatic fused polycyclic group, R_7 is a hydrogen atom, an optionally substituted alkyl group, R_8 is a hydrogen atom, an optionally substituted alkyl group, Phenyl group, tolyl group, p-dimethylaminophenyl group or p-diethylaminophenyl group, R_9 represents a hydrogen atom or an optionally substituted alkyl group. 3) In a laminated photoreceptor having a charge generation layer and a charge transport layer on a conductive substrate, at least one polycyclic quinone compound represented by the general formula (IV) is used as a charge generation substance in the charge generation layer. and at least one of the hydrazone compounds represented by the general formula (II) and at least one pyrazole compound represented by the general formula (III) as the charge transport substance of the charge transport layer. Photoreceptor for electrophotography. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(IV) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) [Formula In (IV), D represents a halogen atom, a nitro group, a cyano group, an acyl group, or a carboxyl group, m represents an integer of 0 to 4, and in formula (II), A represents an optionally substituted aryl group. , heterocyclic group, R_5 is an optionally substituted alkyl group, aryl group, R_6 is a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an aryl group, n represents 0 or 1, and the formula ( In III), E is an optionally substituted heterocyclic group, an aromatic condensed polycyclic group, R_7 is a hydrogen atom, an optionally substituted alkyl group, R_8 is a hydrogen atom, an optionally substituted alkyl group, a phenyl group , tolyl group, p-dimethylaminophenyl group or p-diethylaminophenyl group,
R_9 represents a hydrogen atom or an optionally substituted alkyl group. ]