JPS6298357A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the titled body having good properties of a sensitivity, a repeating property and a durability by incorporating a specific hydrazone compd. to a photosensitive layer. CONSTITUTION:The titled body contains the hydrazone compd. shown by the formula wherein R1 and R2 are each independently a (unsubstd.) substd. aryl group, at least one of R3 and R4 groups is a residue of a heterocyclic ring or an alkyl or an aryl group, (n) is 0 or 1. The hydrazone compd. of the electrostatic charge transfer substance may be incorporated to the same layer to that of the electrostatic charge generating substance to form a monolayer type photosensitive body, or may be incorporated so as to be a two layer structure composed of the 1st layer contg. the charge generating layer and the 2nd layer contg. the hydrazone compd. Thus, as the hydrazone compd. is used to the titled body, the photosensitive layer having a high sensitivity, a low degradation property and a high electrostatic charge holding property is obtd.

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 5 and durability is provided.

(Prior Art) The electrophotographic method has already been published by Carlson in US Patent No. 2.297.
As revealed in No. 691, this photographic method is a clever combination of electrostatic phenomena and optical electrostatic phenomena.

After uniformly charging two surfaces of a photoconductive photoreceptor in a dark place by corona discharge, etc., the photoconductivity is used to convert the optical image into an electrostatic latent image, and colored powder (1- This is one of the image forming methods in which a visible image is created by attaching a colorant (colorant) to 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 substances satisfy the above conditions, they also have some drawbacks. For example, cadmium sulfide and zinc oxide are used as photoreceptors after being dispersed 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 the manufacturing cost but also has no flexibility and is difficult to process into a heald 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.

Flexibility 1 9 Because it has many advantages of polymorphism in spectral sensitivity
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.

Furthermore, an electrophotographic photoreceptor has been proposed that combines a substance that generates electric charge when exposed to light (called a charge ordering 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 By separating the functions of this type of charge generation and charge transport using different substances, that is, by combining a charge generation material and a charge transport material, the characteristics can be improved and a useful photoreceptor can be produced. 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. Until now, 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 U.S. Pat. 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 that is excellent in strength, 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 by discovering 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 novel structure of 1 to razone derivatives.

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 -C formula (1) as a charge transport substance.

An electrophotographic photoreceptor comprising a photosensitive layer containing at least one compound represented by the following general formula (1).

General Formula [I] However, in Formula 2, R, and R2 each independently represent an optionally substituted group. At least one of R, and R4 is a heterocyclic residue, and when it is not a heterocyclic residue, it is an alkyl group, an aralkyl group, or an aryl group. , is 0 or 1.

R1 or R2 is a group that may have one or more substituents, and examples of the substituents include a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, an arylalkoxy group, an aralkyl group, It is a methylenedioxy group or a substituent represented by the following general formula (n).

General formula (n) R3 N (In the formula, R2, R, are each independently an alkyl group, an aralkyl group, or an aryl group that may have a substituent.) To further explain the substituents, an alkyl group and is a methyl group, an ethyl group, a linear or branched propyl group, a butyl group, a pentyl group, and a hexyl group.

Substituents such as heptyl, octyl, and stearyl groups; alkoxy groups include methoxy and ethoxy groups.

Substituents such as propoxy group, butoxy group, hexyloxy group, benzyloxy group; Aryloxy group refers to substituents such as phenoxy group and naphthyloxy group; arylalkoxy group refers to benzyloxy group, phenethyloxy group. Substituents such as; Arafrekyl group refers to benzyl group, phenethyl group, cinnamyl group, henzhydryl group,
Substituents such as trityl group and naphthylmethyl, and aryol group are phenyl groups.

Substituents and heterocyclic residues such as naphthyl group, anthryl group, pyrenyl group, acenaphthyl group, and fluorenyl group are:
Substituents such as pyridyl, benzothiazolyl, and phthalazinyl groups.

The compound of the present invention represented by the general formula (1) can be produced, for example, by the method shown below.

This is a method of reacting an aldehyde represented by the following formula -C ([[) with hydrazine represented by general formula (IV) or a mineral acid salt thereof in an organic solvent.

General formula (Ill) (In the formula, R+, Rz or A are the same as in general formula (1))
General formula (rV) (In the formula, R3 or R4 is the same as in general formula (1)) As the solvent, a wide range of non-reactive organic solvents can be used, but alcohols such as methanol and ethanol, and dimethylformamide are preferable. , dioxane, etc. can be used alone or in combination.

In this reaction, acid 1. Small amounts of reaction promoters such as organic or inorganic acids such as p-toluenesulfonic acid can be used.

The aldehyde, which is a raw material for synthesis, is produced, for example, according to the known reaction described below.

(The following is a blank space) h2 Representative examples of the two hydrazone compounds obtained by such a synthesis method and used in the present invention are listed below.

[Hydrazone compound]

(The following is a blank space) 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 charge generating substances used in the present invention include the following.

Inorganic compounds include selenium, selenium alloys, and CdS.

Although inorganic light-semi-containing materials such as ZnO, CdSe, and amorphous silicon can also be used, it is preferable to use organic charge-generating materials. Examples of organic charge generating substances include 5, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azo dyes such as monoazo dyes and disazo dyes, 2 indigo pigments,
Dyes and pigments such as quinacridone pigments, indanthrene pigments, xanthine dyes, benzimidazotyl pigments, perylene pigments, squarisocumetone dyes, or electron-donating materials such as eutectic complexes formed from biryllium salt dyes and polycarbonate resins, and polyvinylcarbazole. Examples include charge transfer complexes consisting of a chemical substance and an electron-accepting substance such as TNF, but it is particularly preferable to use a phthalocyanine pigment.

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. In addition, two photoreceptors 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 two hydrazone compounds according to the present invention and a binder.

In addition, the hydrazone compound according to the present invention has a binding agent of 10
Preferably, the amount of the charge transport material is 10 to 300 parts by weight per 0 parts 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 or conductive particles on which indium oxide, tin oxide, etc. are vapor-deposited or laminated 1 For example, carbon blanks,
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. 2. 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 750 parts m or more, so a gallium-aluminum lamp is used. Laser light such as a Muharion 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.

A diethyl ether solution of methylmagnesium iodide is prepared from 4 parts of magnesium, 20 parts of methyl iodide, and 180 parts of diethyl ether, and this solution is dissolved in 180 parts of benzene. After gradually adding 21.8 parts of benzophenone to this solution, the mixture was stirred at room temperature for 3 hours. Next, 300 parts of a saturated ammonium chloride aqueous solution is added, and the mixture is further stirred for 2 hours. After separating the organic layer, it was washed with water, and the solvent was distilled off under reduced pressure.

17 parts of 1.1-diphenylethylene are obtained.

Next, 28 parts of phosphorus oxychloride was added to 33 parts of dimethylformamide at 15 to 20°C, and then at the same temperature.

Add 16 parts of 1,1-diphenylethylene obtained by the above method and stir at 40°C to 50°C for 3 hours. After cooling the reaction solution, it is poured into 1000 parts of ice water. Next, after neutralizing with sodium hydroxide and adjusting the pH to 9 to 10, 15 parts of 3.3-diphenylacrolein are obtained by cooling, filtering, washing with water, and drying.

1 part of 3,3-diphenylacrolein in 90 parts of ethanol
5 parts and 1-butyl-1-benzothiazolylhydrazine 1
7 parts and 2 parts of acetic acid as a catalyst to 70-80"C.
Stir for 2 hours. The reaction solution is cooled, the precipitated crystals are filtered, and then dried to obtain 27 parts of compound (1). 20 parts of pure product are obtained by recrystallization from acetonitrile.

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

A tetrahydrofuran solution of 4-diethylaminomagnesium bromide is prepared by dissolving 4 parts of magnesium and 32 parts of 4-bromodiethylaniline in 80 parts of tetrahydrofuran. Add 4-methoxyacetophenone 21 to this solution.
A solution prepared by dissolving 1 part in 80 parts of benzene is added dropwise. Next, stirring under reflux is performed for 7 hours. After cooling the reaction solution, 400 parts of a saturated ammonium chloride aqueous solution is added, and the mixture is further stirred for 2 hours. After separating the organic layer, the organic layer was washed with water and the solvent was distilled off under reduced pressure to obtain 1-(4-methoxyphenyl)-1-
28 parts of (4-diethylaminophenyl)-ethylene are obtained.

Next, 25 parts of phosphorus oxychloride was added to 29 parts of dimethylformamide at 15 to 20°C, and then at the same temperature.

1-(4-methoxyphenyl)-1-(4-diethylaminophenyl)-ethylene 2 obtained by the above method
Add 2 parts and stir at 40°C to 50°C for 3 hours. After cooling the reaction solution, it is poured into 1000 parts of ice water. Next, after neutralizing with sodium hydroxide and adjusting the pH to 9 to 10, 3-(4-methoxyphenyll-3-(4-diethylaminophenyl)- 20 parts of acrolein are obtained.

3-(4-methoxyphenyl)-3 in 90 parts of ethanol
-(4-diethylaminophenyl)-acrolein 19
1 part, 12 parts of 1-ethyl-1-(1-phthalazinyl)hydrazine, and 2 parts of acetic acid as a catalyst, and heated to 70-80°C.
Stir for 2 hours. The reaction solution is cooled, the precipitated crystals are filtered, and then dried to obtain 23 parts of compound (b). 18 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 dissolved solution was poured into 5,000 parts of water to precipitate a composition of copper phthalocyanine and tetranitrocopper phthalocyanine, which was then filtered through two mouths, 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 Narita Pharmaceutical Co., Ltd., Takerank 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 at 110°C. Place in the heated oven for 1 hour.

It was used as an electrophotographic photoreceptor. +5.7KV for the sample thus obtained, corona gap 10mm, 10m
A corona discharge was applied at a charging speed of /min, and 10 seconds after the discharge stopped, a tungsten light source of 2854 was used to
Expose with an illuminance of Lux. The potential just before exposure at this time is 5
The amount of light required to reduce the sensitivity by 0% was defined as the sensitivity. The sample measured in this way had a maximum surface charge of 1630 V.
, dark decay rate 17%, sensitivity 4.6 Lux.

The 5eC1 residual potential was 23 V, which was sufficient for practical use in both chargeability and sensitivity, and no induction was observed in the 2 surface potential attenuation during charging exposure, and a 3-curve light attenuation 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 detailed intermediate color density, there is no change in sensitivity, and there is no scratch on the photoreceptor. However, a clear image with no such 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 1.5 parts of the same phthalocyanine 4OS and dinitrometal-free fluorocyanine are dissolved in 100 parts of 98% concentrated sulfuric acid with thorough stirring. The dissolved liquid was poured into 1000 parts of water to precipitate the phthalocyanine composition, and then filtered 9 times.
Wash with water and dry at 120°C under reduced pressure. Add 1 part of this composition and 3 parts of compound (3) to polycarbonate resin.
Panlite L-1250) 4 parts and tetrahydrofuran 1
This solution was sprayed onto an aluminum cylinder to a thickness of 10 μm, and then dried to obtain 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 way has a maximum surface charge L
t590 parts, sensitivity 4. I Lux, sec, and its light attenuation curve shows three curves with no induction, and even in repeated photo-photographing tests with positive charging by a copying machine, there was no gradation in the initial and final images after 10,000 copies. The image quality was excellent, and there was no change in sensitivity (clear images were obtained).

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 without induction, the maximum surface potential at this time is 610 V, and the dark attenuation rate is 16%.
, sensitivity 3.9 Lux, sec, residual potential 21V, 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.

A composition consisting of 32 parts of thermosetting acrylic resin, 8 parts of melamine resin, and 50 parts of butyl acetate:cellosolve acetate (1:1) was kneaded for 24 hours in a ball mill to prepare a photoconductive paint. It was coated on an aluminum support to a thickness of about 1 μm and cured to form a charge generation 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 -710V, and the sensitivity was 3.
9 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), (11) or (12) respectively,
When tested in the same manner as in Example 7, both chargeability and sensitivity were of sufficient value for practical use as in Example 7, and no induction was observed in the two-surface pattern attenuation during charging exposure.
Furthermore, the repeatability was also good.

Example 12 98 parts of tetrahydrofuran was added to 2 parts of Guianpoule (CI21180), and the mixture was crushed and mixed in a ball mill to obtain a charge-generating pigment coating 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 0° C. for 30 minutes to form a charge generating layer with a thickness of 10 μm. When this photoreceptor was corona charged at -6.5 KV for 0.2 seconds, the surface potential was -76 OV, and the sensitivity E'A was 4.4 L.
It was ux, sec.

〔Effect of the invention〕

The present invention has the above-mentioned configuration, and when using it, there are two points.
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.▼ However, in the formula, R_1 and R_2 are each independently an aryl group that may have a substituent. R_3, R_
At least one of 4 is a heterocyclic residue, and when it is not a heterocyclic residue, it is an alkyl group, an aralkyl group, or an aryl group. _n is 0 or 1.