JPS61200544A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having superior sensitivity, repetition characteristics and durability by forming a photosensitive layer contg. a specified hydrazone compound on an electrically conductive support. CONSTITUTION:A single photosensitive layer contg. one or more kinds of hydrazone compounds represented by the formula as a charge transferring substance as well as a charge generating substance is formed on an electrically conductive support. In the formula, each of R1 and R2 is H, halogen, (substituted) alkyl or alkoxy, R3 is alkyl, aralkyl or aryl, R4 is (substituted) alkyl or alkoxy, each of R5 and R6 is alkyl, aralkyl or aryl, and R5 and R6 may form a heterocyclic ring. A laminate type photosensitive layer consisting of a charge transferring layer contg. the hydrazone compounds and a charge generating layer may be formed. An electrophotographic sensitive body having high photosensitivity and superior durability is obtd. The sensitive body undergoes little change in the charge retentivity and sensitivity at low to high temp. and low to high humidity.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an electrophotographic photoreceptor, and more specifically, the present invention relates to an electrophotographic photoreceptor, and more specifically, a photoconductive layer formed on a conductive support has a ,
By containing a novel hydrazone compound, an electrophotographic photoreceptor having excellent photosensitivity and durability is provided.

(Prior art) Electrophotography has already been developed by Carlson in US Patent No. 2.297,
As disclosed in No. 691, this photographic method is a clever combination of electrostatic phenomena and photoconductive phenomena, in which two surfaces of a photoconductive photoreceptor are uniformly charged by corona discharge etc. in a dark place. After that, the optical image is converted into an electrostatic latent image using photoconductivity,
This is one of the image forming methods in which colored charged powder (toner) is attached to this to turn it into a visible image.

The basic electrical and photoelectric properties required of a photoreceptor in such electrophotography are that it can be charged to an appropriate potential in a dark place, that this potential can be maintained for an appropriate amount of time, and that it can be charged quickly by light irradiation. For example, the electric charge can be dissipated.

In such photoreceptors, amorphous selenium,
Inorganic photoconductive materials such as cadmium sulfide and zinc oxide have been widely used. Although these inorganic materials satisfy the above conditions, they also have some drawbacks. For example, cadmium sulfide or zinc oxide is used as a photoreceptor by dispersing it in a resin as a binder.

Since it has mechanical defects such as smoothness, flexibility, hardness, tensile strength, and abrasion resistance, it cannot withstand repeated use as it is. Furthermore, when using cadmium sulfide, consideration must also be given to hygiene issues.

In addition, amorphous selenium must be manufactured by vapor deposition, which not only increases manufacturing costs but also has no flexibility and is difficult to process into a belt shape.
It has drawbacks such as the toxicity of selenium and its sensitivity to heat and mechanical shock, so care must be taken when handling it.

In recent years, in order to eliminate the drawbacks of these inorganic photoreceptors,
Research on organic photoreceptors is progressing, and organic photoreceptors.

Easy to form a film, easy to manufacture, lightweight.

1 to have many advantages of flexibility, 1 spectral sensitivity, and versatility.
Various organic photoreceptors have been proposed, and some are in practical use.

For example, poly-N-vinylcarbazole and 2.4°7-
Photoreceptor consisting of dolinitrofluorene-9-one (US Pat. No. 3,484,237), poly-N-vinylcarbazole sensitized with biryllium base dye (Japanese Patent Publication No. 1983-25658), dye Photoreceptor whose main component is a eutectic complex consisting of
Publication No.) etc.

Additionally, an electrophotographic photoreceptor has been proposed that combines a substance that generates electric charge when exposed to light (called a charge-generating substance) and a substance that can transport the generated electric charge (called a charge-transporting substance). . For example, U.S. Patent No. 3.791.
No. 826 describes a photoreceptor in which a charge transport layer is provided on a charge generation layer, and U.S. Pat. No. 3,764,315 describes a photoreceptor in which a charge generation material is dispersed in a charge transport material A photoreceptor with a This kind of charge generation and charge transport.

By sharing the functions with different substances,
In other words, by the combination of a charge generating substance and a charge transporting substance,
Its properties are better and a useful photoreceptor is provided.

Until now, many charge generating substances useful in this type of photoreceptor have been known. On the other hand, various materials have been proposed as charge transport materials.

The current situation is that it is difficult to say that the situation is necessarily satisfactory.

The basic properties of an excellent charge transport material are:

When charged, it must be able to maintain a sufficient potential, it must be able to sufficiently transmit light of an effective wavelength to generate charges from the charge-generating substance, and it must also be able to sufficiently hold the electric charge generated by the charge-generating substance. It has the ability to promptly transport. In addition, as for the practically required properties, it can be used alone or dissolved in a binder.

It is necessary to be able to form a uniform film and to not cause deterioration or change in electrostatic properties under harsh environmental conditions due to temperature, humidity, ozone, NOx, etc. generated during corona discharge. So far, as charge transport materials of this type, polyphenyl compounds such as triphenyl have been classified by chemical structural formula, U.S. Pat. No. 3.717.462, U.S. Pat. 55-52
064, diarylalkane compounds described in U.S. Pat. No. 3,820,989, U.S. Pat. No. 3,189.4.
2,5-bis(P-diethylaminophenyl)-1,3,4-oxadiazole described in No. 77, pyrazoline compounds described in U.S. Patent No. 3'837.851, etc. is a relatively excellent charge transport material that has been proposed in recent years. However, the current situation is that these charge transport materials do not satisfy all of the above conditions.

(Problems to be Solved by the Invention) The present invention provides an electrophotographic photoreceptor having excellent sensitivity, repeatability, durability, and the like.

[Structure of the invention]

(Means for Solving the Problem) As a result of intensive research, the present inventors discovered that a hydrazone compound with a specific structure is a truly useful charge transport material for electrophotographic photoreceptors, and further discovered that The present invention was completed based on the discovery that an electrophotographic photoreceptor using a charge transporting material has excellent properties.

That is, the present invention provides an electrophotographic photoreceptor having excellent properties using a hydrazone derivative having a novel structure.

An object of the present invention is to provide an electrophotographic photoreceptor that contains a novel charge transporting substance, exhibits high sensitivity and low residual potential, and has high charge transport efficiency, so that copying speed is high. Another object of the present invention is to use it as a photoreceptor for repetitive transfer type electrophotography in which charging, exposure, development, and transfer steps are repeated.

To provide an electrophotographic photoreceptor with excellent durability and environmental friendliness, which has little fatigue deterioration due to repeated use, maintains stable characteristics under various harsh environments such as high temperature rather than low temperature, and high humidity than low humidity. It is in.

This object of the present invention can be achieved by containing at least one compound represented by the following general formula (I).

General formula (1) (In the formula, +R1 or R2 is each independently a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group that may have a substituent. RJ is an alkyl group, an aralkyl group, or an aryl group.・Rq- is an alkyl group or an alkoxy group that may have a substituent.R1
or R6 is each independently an alkyl group, an aralkyl group or an aryl group;

R1 and RJ may form a heterocyclic residue. ) To further explain the substituents, the above substituents R1, R2,
Of Rj, R←, R, or R6, the alkyl group refers to a methyl group, ethyl group, linear or branched propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, stearyl group. Among R7, Rλ or R≠, an alkoxy group means a substituent such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, a benzyloxy group; Among RJ, Rj or R6 Aralkyl group refers to substituents such as benzyl group, phenethyl group, cinnamyl group, benzhydryl group, trityl group, and naphthylmethyl group; aryl group refers to phenyl group, anthonyl group, hrenyl group,
substituents such as an acenaphthynyl group and a fluorenyl group; substituents such as a piperidino group and a morpholino group when R1 and R6 form a heterocyclic residue;

The compound of the present invention represented by the general formula [I] can be produced, for example, by the method shown below.

One method is to react hydrazine represented by the following general formula (IF) or its mineral acid salt with an aldehyde represented by the general formula (I[[) in an organic solvent.

General formula (II) (In the formula, R5 or R6 is the same as in general formula (1).

) General formula (I[I) R ((In the formula, R,, Rs, RJ or Rq is the same as in general formula [I].) As the solvent, a wide range of non-reactive solvents can be used. However, preferably alcohols such as methanol and ethanol, dimethylformamide, etc. can be used alone or in combination.

In another method, hydrazine represented by the following general formula (IV) or a mineral acid salt thereof is reacted in an organic solvent represented by the above general formula (III).

General formula (IV) H2N-NH-R5 (In the formula, R5 is the same as in general formula (1).) Thereafter, a compound represented by the following general formula (V) and a solvent, preferably under basic conditions. By reacting, 9 compounds of the present invention can be obtained.

General formula (V) R(-X (In the formula, X represents a negative group such as a halogen atom.

Further, Rlf is the same as in general formula [I]. ) As the solvent, a wide range of non-reactive solvents can be used, but preferably protic solvents such as water and alcohols, aprotic polar solvents such as dimethyl sulfoxide and dimethyl formamide, and ketones such as acetone and methyl ethyl ketone. ,benzene.

Aromatic hydrocarbons such as toluene and xylene, ethers such as tetrahydrofuran and dioxane, dichloromethane,
Chlorinated hydrocarbons such as 1,2-dichloroethane or amines such as pyridine and triethylamine can be used alone or in combination.

Bases include sodium hydroxide and potassium hydroxide.

Potassium carbonate, sodium methylate, sodium hydride, etc. are used.

Representative examples of the compounds of the present invention obtained by such synthetic methods are listed below.

[Hydrazone compound]

These compounds can be used alone or in combination of two or more.

The photoreceptor of the present invention contains the above-mentioned hydrazone compounds, and photoreceptors with various characteristics can be obtained depending on how these hydrazone compounds are applied. For example, a hydrazone compound as a charge transporting substance is provided on a conductive support substrate in the same layer as a charge generating substance, which is usually referred to as a single-layer photoreceptor, or a first layer mainly containing a charge generating substance. and.

It can be used in a structure commonly called a laminated type photoreceptor, which is formed by laminating two second layers mainly containing a charge transporting substance on a conductive support substrate.

These configurations are appropriately selected depending on the polarity of the photoreceptor used. Further, examples of the charge generating substance used in the present invention include the following.

Inorganic compounds include selenium, selenium alloys, and CdS.

Although inorganic optical semiconductors such as ZNO, CdSe, and amorphous silicon can also be used, it is preferable to use organic charge-generating substances. Examples of organic charge generating substances include phthalocyanine pigments such as gold mud phthalocyanine and metal-free phthalocyanine, azo dyes such as monoazo dyes and disazo dyes, indigo pigments, quinacridone pigments, indanthrene pigments, xanthine dyes, and benzimidazoles. Pigments, dyes and pigments such as perylene pigments and squalic menane dyes, eutectic complexes formed from pyrylium salt dyes and polycarbonate resins, and charge transfer complexes formed from electron-donating substances such as polyvinylcarbazole and electron-accepting substances such as TNF. Among them, it is particularly preferable to use phthalocyanine pigments.

Since the hydrazone compound in the present invention does not have film-forming ability by itself, a binder resin is used to form it as a photosensitive layer. Further, since charge generating substances cannot form a film by themselves except for polymeric resins such as polyvinylcarbazole, a binder may be used as necessary.

The binder preferably used in the present invention is a highly electrically insulating film-forming polymer or copolymer. These high molecular weight polymers and copolymers are 1
Binders preferably used in the present invention include phenolic resin, polyester resin, vinyl acetate resin, polycarbonate resin, polypeptide resin, cellulose resin, polyurethane resin, polyvinylpyrrolidone, polyethylene oxide, polyvinyl chloride resin, starch, and polyvinyl alcohol. .

Acrylic copolymer resin, methacrylic copolymer resin.

silicone resin, polyacrylonitrile copolymer resin,
Polyacrylamide, polyvinyl butyral.

Examples include polyvinyl carbazole and polyvinylidene chloride resin. These polymer binders may be used alone or in combination of two or more, but the binders that can be used in the present invention are not limited to these. Further, in the photoreceptor of the present invention, a charge generation layer containing a charge generation substance as a main component is provided on the conductive support via an intermediate layer if necessary, and adjacent to the charge generation layer the charge generation layer containing a charge transport substance as a main component is provided. A stacked structure including a charge transport material may also be used. Also, if such a laminated structure is used.

Which of the charge generation layer and the charge transport layer is to be used as the upper layer is determined depending on whether the chargeability is positive or negative.

Generally, when negatively charged, it is advantageous in terms of characteristics to have a charge transport layer as an upper layer. Further, in one photoreceptor of the present invention.

In the case of a laminated structure consisting of separate layers of a charge generation layer and a charge transport layer, the charge generation layer may be formed directly on the conductive support or, if necessary, with an intermediate layer such as an adhesive layer or a barrier layer provided thereon. ■ Apply vacuum evaporation, ■ Apply a solution of the charge-generating substance dissolved in an appropriate solvent, or ■ Minimize the charge-generating substance in a dispersion solvent using a ball mill, attritor, etc., and add a polymer binder as necessary. It can be provided by a method such as coating a dispersion obtained by mixing and dispersing with. The polymer binder used at this time may be the same as that used for the charge transport layer.

Alternatively, it may be a single photosensitive layer comprising the hydrazone compound according to the present invention and a binder.

In addition, 9 the hydrazone compound according to the present invention is a binder 10
Preferably, the amount of the charge transport material is 10 to 300 M parts per 0 part by weight. However, the present invention is not limited only to this range. The thickness of this photosensitive layer is determined by the required photosensitivity and durability, as well as the mixing ratio of the charge generating substance and the charge transporting substance to the binder. , the thickness of the photosensitive layer on the supporting conductive substrate is 50 microns or less.

Preferably, the thickness is about 7 to 30 microns, which is suitable from the viewpoint of flexibility of the film.

The photosensitive layer can also be coated with a layer that serves as a protective layer, if necessary.

The support used in the electrophotographic photoreceptor of the present invention includes:

Any material may be used as long as it is imparted with electrical conductivity, and any type of electrically conductive layer conventionally used may be used. Specifically, aluminum and copper.

Metals such as stainless steel and brass, aluminum, plastics on which indium oxide, tin oxide, etc. are vapor-deposited or laminated, or conductive particles 1 For example, carbon black,
Examples include plastics in which tin particles and aluminum particles are dispersed. Also, regarding its shape, it can be sheet-like or cylinder-like.

Other items are also acceptable. 9 When using the electrophotographic photoreceptor according to the present invention, the light source is usually a halogen lamp or the like, and when the charge generating substance is phthalocyanine, the sensitivity is as high as 750 nm or more.
Laser light such as a gallium-aluminum-arsenic semiconductor laser (oscillation wavelength: 780 nm) can also be used.

Next, the present invention will be explained in more detail with reference to synthesis examples and examples, but the present invention is not limited to the following examples. In the following examples, "parts" refer to parts by weight.

Synthesis example 1 A synthesis example of compound (1) of the present invention will be shown.

After adding 31 parts of phosphorus oxychloride to 73 parts of dimethylformamide at 15-20°C, N-ethyl-N-(
28 parts of 1-naphthyl)methyl-m-toluidine are added and stirred at 50-60°C for 3 hours.

After the reaction solution was cooled, it was poured into 2000 parts of ice water.

Next, after neutralizing with sodium hydroxide and adjusting the pH to 9 to 10, the mixture is cooled, filtered, washed with water, and dried to obtain 27 parts of aldehyde having the structure shown below.

Next, 24 parts of the above aldehyde and 1,
19 parts of 1-diphenylhydrazine hydrochloride and 2 parts of acetic acid as a catalyst are added and stirred at 70-80°C for 2 hours. After cooling the reaction solution and filtering the precipitated crystals, they are suspended in aqueous ammonia, filtered, washed with water, and dried to obtain 30 parts of compound (1).

24 parts of pure product are obtained by recrystallization from acetonitrile.

Synthesis example 2 A synthesis example of compound (5) of the present invention will be shown.

After adding 34 parts of phosphorus oxychloride to 80 parts of dimethylformamide at 15-20°C, N-octyl-N-
Add 46 parts of (1-(7-ethoxy)naphthyl)methyl-m-anisidine and stir at 50-60°C for 3 hours.

After the reaction solution was cooled, it was poured into 2000 parts of ice water. Next, after neutralizing with sodium hydroxide to adjust the pH to 9 to 10, the mixture is cooled, filtered, washed with water, and dried to obtain 44 parts of aldehyde having the structure shown below.

Next, 40 parts of the above aldehyde, 11 parts of phenylhydrazine, and 1 part of p-toluenesulfonic acid as a catalyst are added to 108 parts of ethanol, and the mixture is stirred at 70 to 80°C for 3 hours. By cooling the reaction solution and filtering and drying the precipitated crystals, 39 parts of hydrazone having the following structure is obtained.

Next, add 2 parts of sodium hydride to 70 parts of dimethylformamide.
38 parts of the above hydrazone are added at the same temperature. Then 12 parts of butyl bromide are added dropwise.

After stirring at the same temperature for 3 hours, the mixture was poured into 1200 parts of ice water. Compound (6) 37 is obtained by filtering, washing with water, and drying.
part is obtained. 30 parts of pure product are obtained by recrystallization from ethyl acetate.

Synthesis example 3 A synthesis example of the compound (11) of the present invention will be shown.

N-ethyl-N-(1-naphthyl)methyl- of Synthesis Example 1
m-) N-methyl-N-1- in place of 28 parts of luidine
(5-butoxy)naphthyl methyl-m-anisidine 3
By using 5 parts, aldehyde 3 having the following structure
Three copies are obtained.

Next, 30 parts of the above aldehyde was added to 96 parts of ethanol and 1.
19 parts of I-diphenylhydrazine hydrochloride and 2 parts of acetic acid as a catalyst are added and stirred at 70-80°C for 2 hours. After cooling the reaction solution and filtering the precipitated crystals, they are suspended in aqueous ammonia, filtered, washed with water, and dried to obtain 34 parts of compound (11). 27 parts of pure product are obtained by recrystallization from acetonitrile.

Example 1 40 parts of copper phthalocyanine and 0.5 parts of tetranitrocopper phthalocyanine are dissolved in 500 parts of 98% concentrated sulfuric acid with thorough stirring. The molten liquid was poured into 5000 parts of water to precipitate a composition of copper phthalocyanine and tetranitrocopper phthalocyanine, which was then filtered once, washed with water, and dried at 120° C. under reduced pressure.

Next, 1 part of this composition, 2.5 parts of compound (1), acrylic polyol (manufactured by Takeda Pharmaceutical Co., Ltd., Takelac A-70
2) A composition consisting of 3.6 parts, 0.5 parts of epoxy resin (manufactured by Shell Chemical Co., Ltd., Epon 1007), 1.2 parts of methyl ethyl ketone, and 1.2 parts of cellosolve acetate was kneaded in a magnetic ball mill for 48 hours. A photoconductive composition is obtained.

Next, this photoconductive composition was roll coated onto the aluminum of a laminate film of 5 micron thick aluminum foil and 75 micron polyester film to a dry film thickness of 8 microns, and uniformly heated to 110°C. Every hour during the opening hours.

It was used as an electrophotographic photoreceptor. +5.7KV for the sample thus obtained, corner gap 10m+, 10
A corona discharge was applied at a charging speed of m/min, and 10 seconds after the discharge stopped, a 2854 tungsten light source was used to
Expose with an illuminance of 0 Lux. The amount of light irradiation required for the potential immediately before exposure to decrease by 50% at this time was defined as the sensitivity.

The sample measured in this way had a maximum surface charge of 610
V, dark decay rate 13%, sensitivity 3.7 Lux.

The SeC+ residual potential was 20 V, and both chargeability and sensitivity were values sufficient for practical use, and no induction was observed in 1 surface potential decay during charging exposure, and a 5-curve light decay curve was shown. In addition, this photoconductor was positively charged with a copying machine for 10
I made 000 copies in a row.

The resulting image has excellent gradation. 1. Even when copying an ordinary photograph as an original, a beautiful image can be obtained in terms of detail intermediate color density, and there is no change in sensitivity. 4. Furthermore, although there were scratches on the photoreceptor, a clear image without any scratches was obtained in the copied image.

Examples 2 to 4 In Example 1, compound (2) was used instead of compound (1).
, (5) or (9), respectively, Example 1
When tested in the same manner as in Example 1, both chargeability and sensitivity were sufficient for practical use.

No induction was observed in the 2-surface potential decay upon charging exposure, and the repeatability was also good.

Example 5 40 parts of copper phthalocyanine and 165 parts of dinitrometal-free phthalocyanine are dissolved in 100 parts of 98% concentrated sulfuric acid with thorough stirring. Pour the molten liquid into 1000 parts of water,
After the phthalocyanine composition is precipitated, it is filtered 9 times, washed with water, and dried at 120° C. under reduced pressure. 1 part of this composition and 3 parts of compound (3) were dispersed in a ball mill along with 4 parts of polycarbonate resin (Kijin Panlite L-1250) and 10 parts of tetrahydrofuran, and the liquid was sprayed into an aluminum cylinder with a thickness of 10 μm. After coating, it was dried to prepare an electrophotographic photoreceptor. The electrophotographic properties of the thus obtained sample were measured in the same manner as in Example 1. The sample measured in this manner had a maximum surface charge amount of 590 parts, a sensitivity of 3.5 Lux, sec, and its light attenuation curve showed 3 curves without inductidin, and in a repeated photo-photographing test using positive charging using a copying machine. too,
After making 10,000 copies, clear images with excellent gradation and no change in sensitivity were obtained both in the initial and final images.

Example 6 2 parts of compound (8) for 1 part of ε-type copper phthalocyanine,
Disperse 0.8 parts of triphenylmethane, 4 parts of acrylic resin, and 20 parts of cellosolve acetate in a ball mill,
Thereafter, the samples were measured in the same manner as in Example 1.

The obtained light attenuation curve is 3 curves with no induction, the maximum surface potential at this time is 570 V, and the dark attenuation rate is 18%.
, sensitivity 3.5 Lux, sec, residual potential 15V, and also in live photography tests.

The same results as in Example 1 were obtained.

Example 7 10 parts of copper phthalocyanine obtained in Example 1.

Thermosetting acrylic resin 32 parts, melamine resin 8 parts and butyl acetate (cellosolve acetate) (1:1) 50
A photoconductive coating material was prepared by kneading the composition consisting of the following parts in a ball mill for 24 hours, and this coating material was coated on an aluminum support to a thickness of about 1 .mu.m and cured to form a charge generating layer.

Next, polycarbonate resin (Panlite L-1250
) and 3 parts of polyester resin (manufactured by Gutdeyer) were mixed with tetrahydrofuran and 100 parts of toluene solvent. The weight ratio of solvents is 9:1.

9 parts of compound (1) were added together with 0.02 part of silicone oil. This liquid was applied onto the charge generation layer to a thickness of about 15μ and dried at 80° C. to form a charge transport layer to obtain a laminated photoreceptor.

When this photoreceptor was corona charged at -6.5KV for 0.2 seconds, the surface potential was -760■, and the sensitivity was 3,
8 Lux, sec, and was an extremely highly sensitive photoreceptor.

Examples 8 to 11 In Example 7, compound (4) was used instead of compound (1).
, (6), (7), or (11) were tested in the same manner as in Example 7. As in Example 7, both chargeability and sensitivity were sufficient for practical use, and 1. No induction was observed in surface potential decay, and the repeatability was also good. Example 12 98 parts of tetrahydrofuran was added to 2 parts of Diane Blue (CI21180), and the mixture was crushed and mixed in a ball mill to form a charge-generating pigment coating. Get the liquid. This was applied using a doctor blade onto a polyester film on which aluminum had been vapor-deposited, and air-dried to form a charge generation layer with a thickness of 0.5 μm. Next, a charge transport layer forming coating liquid obtained by mixing 2 parts of compound (5), 2 parts of polycarbonate (Panlite L) and 45 parts of tetrahydrofuran was applied onto the charge generation layer using a doctor blade.
A photoreceptor of the present invention was prepared by drying at .degree. C. for 30 minutes to form a charge generating layer with a thickness of 10 .mu.m. This photoreceptor is -6
, the surface potential when 5KV corona charging was performed for 0.2 seconds was -780■, and the sensitivity E% was 3.7 Lux,
It was sec.

〔Effect of the invention〕

The present invention has the above configuration, and when using it,
High sensitivity even in positive and negative charging, and
There is little deterioration of the photoconductor due to repeated use.

In addition, in practical use, it has excellent characteristics such as charge retention ability from low to high temperatures and from low humidity to high humidity, environmental friendliness with respect to sensitivity changes, and durability.

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor characterized by having a photosensitive layer containing at least one compound represented by the following general formula [I]. General formula [I] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_1 or R_2 are each independently a hydrogen atom, a halogen atom, or an alkyl group or alkoxy group that may have a substituent. R_3 is an alkyl group, an aralkyl group, or an aryl group.R_4 is an alkyl group or an alkoxy group that may have a substituent.R_5 or R_6 is each independently an alkyl group, an aralkyl group, or an aryl group, and R_5 and R_
6 may form a heterocyclic residue. )