JPS63208857A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a sensitive body causing no rise of residual potential and having stable electrical characteristics by incorporating a specified azo pigment into an intermediate layer on an electrically conductive substrate. CONSTITUTION:This electrophotographic sensitive body has an intermediate layer contg. at least one kind of azo pigment represented by formula I. In the formula, X is an arom. ring such as benzene or naphthalene, a hetero ring such as indole, carbazole or benzofuran, or a substituted product thereof, Ar1 is an arom. ring such as benzene or naphthalene, a hetero ring such as dibenzofuran or a substituted product thereof, each of Ar2 and Ar3 is an arom. ring such as benzene or naphthalene or a substituted product thereof, each of R1 and R3 is H atom, lower alkyl, phenyl group or a substituted product thereof and R2 is lower alkyl, carboxyl group or ester thereof. The sensitive body causes no rise of residual potential, has stable electrical characteristics independently of a change in environmental conditions such as temp. and humidity and gives a copied image of high reliability without forming a spotted abnormal image or causing ground stain.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an improvement in an electrophotographic photoreceptor in which an intermediate layer, a charge generation layer, and a charge transfer layer are successively laminated on a conductive substrate.

[Prior art]

A photoreceptor formed from a charge generation layer and a charge transfer layer is provided on a conductive substrate, and then a corona is applied to the photoreceptor.

After being uniformly charged with a charger and exposed for one image to form an electrostatic latent image corresponding to optical information on the surface of the photoreceptor, when developed with a developer containing charged and colored particles (toner), a speckled image is formed. Abnormal images occur. When the charge polarity of the toner is opposite to the charge polarity of the photoreceptor (regular development), the toner adhesion area of one image (in the case of black-and-white development, the area corresponding to the so-called black solid area) is coated with a few . Approximately 1 ■ patchy white spots (
If the charge polarity of the toner is the same as the charge polarity (reverse development), a 0.1 to several am. Some degree of spot-like abnormal images, so-called background stains, occur.

These spot-like abnormal images occur when the image formation process of charging, exposure, development, and transfer is repeated on the photoreceptor, and as the image formation process is repeated, the density of the spots increases and their size tends to increase. be. Furthermore, depending on the photoreceptor, the problem may occur from the beginning of image formation.

These spot-like abnormal images significantly impair copy quality and print quality in electrophotographic copiers, printers, and facsimile machines.

This abnormal image occurs because when the photoreceptor is charged with a corona or charger, charges are locally injected from the chargeable substrate into the photosensitive layer, resulting in the existence of local low potential areas on the surface of the photosensitive layer, which prevents development. This is based on the fact that non-uniformity occurs. Therefore, it has been proposed to provide an intermediate layer between the conductive layer and the charge generation layer for the purpose of preventing charge injection.

For example, JP-A Nos. 47-6341, 4g-3544 and 48-12034 have cellulose sulfate resin intermediate layers;
No. 58-30757, No. 58-63945, 58
-95351, 58-98739 and 60-66
No. 258 has a nylon resin intermediate layer, as disclosed in JP-A-48-2.
No. 6141 has a vinyl acetate resin intermediate layer, which was disclosed in Japanese Patent Application Laid-open No. 49
No. 69332 and No. 52-10138 disclose a maleic acid resin intermediate layer, and JP-A-58-103155 discloses a polyvinyl alcohol resin intermediate layer.

A photoreceptor using such an intermediate layer has fewer abnormal images in the form of a single spot than a photoreceptor without an intermediate layer, and the intermediate layer is effective. However, the intermediate layer reduces the sensitivity of the photoreceptor, and as the image forming process is repeated, the residual potential gradually increases. In addition, the resin intermediate layer is easily affected by moisture in the air, and the residual potential becomes particularly high at low temperatures and low humidity. There was a problem in that it caused dirt.

〔the purpose〕

The present invention has no increase in residual potential and exhibits stable electrical characteristics even when the environment such as temperature and humidity fluctuates.

An object of the present invention is to provide a photoreceptor for electrophotography that does not cause spot-like abnormal images or background stains.

〔composition〕

According to the present invention, in an electrophotographic photoreceptor in which an intermediate layer, a charge generation layer, and a charge transfer layer are sequentially laminated on a conductive substrate, the intermediate layer is made of an azo pigment represented by the following general formula (1). Provided is an electrophotographic photoreceptor characterized by being made of a thermosetting resin containing at least one type of thermosetting resin.

(However, in Formula 1 (1), A is.

A group represented by X, Ar1, Ar, , Ar
, , R1, R2, R, are as follows.

X; an aromatic ring such as a benzene ring or a naphthalene ring, a hetero ring such as an indole ring, a carbazole ring, or a benzofuran ring, or a substituted product thereof.

Ar1: An aromatic ring such as a benzene ring or a naphthalene ring, a hetero ring such as dibenzofuran, or a substituted product thereof; Ar3: An aromatic ring such as a benzene ring or a naphthalene ring or a substituted product thereof.

RtvRa: hydrogen, a lower alkyl group, a phenyl group, or a substituted product thereof; R1: a lower alkyl group, a carboxyl group, or an ester thereof) The present inventors have found that the present inventors can suppress the occurrence of spot-like abnormal images by increasing the charging property, and As a result of intensive studies on developing an electrophotographic photoreceptor that has a low residual potential and does not cause background smearing, we found that the intermediate layer contains a thermosetting resin containing at least one azo pigment represented by the general formula (1). The inventors have now discovered that an electrophotographic photoreceptor suitable for the above purpose can be obtained when the above-mentioned method is used, and the present invention has been completed.

In conventional electrophotographic photoreceptors, by increasing the thickness of the intermediate layer, the charging performance can be increased and the generation of spot-like abnormal images can be suppressed, but due to repeated charging and exposure, the residual potential increases significantly. .

Dirt appears on the skin. On the other hand, if the thickness of the intermediate layer is made thinner, it is possible to suppress the increase in the residual potential, but in this case, the charging property decreases and a spot-like abnormal image occurs. No material has been found that simultaneously satisfies these two characteristics.

In addition, the conventional photoreceptor has the drawback that the residual potential increases significantly under low temperature and low humidity conditions, and the photoreceptor characteristics fluctuate due to environmental changes.However, the electrophotographic photoreceptor according to the present invention As shown, even if the environment changes, it is possible to provide a good copy image without spotty white spots or background stains.

The present invention will be explained in more detail below.

The electrophotographic photoreceptor according to the present invention is formed by sequentially laminating an intermediate layer, an IT charge generation layer, and a charge transfer layer on a conductive substrate.

The purpose of the conductive substrate is to supply charges of opposite polarity to the charged charges to the substrate side.

It is possible to use materials that have an electrical resistance of 10" Ωc11 or less and that can withstand the film formation conditions of the intermediate layer, charge generation, and charge transfer layer. Examples of these include AΩ, Ni,
Vacuum deposition,
Afi, by sputtering, spray painting, etc.
Ni, Cr, Zn, stainless steel, carbon, SnO,
Examples include those coated with an electrically conductive substance such as In or O□ and subjected to conductive treatment.

The intermediate layer may contain a disazo pigment represented by the above general formula (1) in a dispersed state in a binding resin. Examples of the binding resin include polyester resin, polystyrene resin, polycarbonate resin, polyacrylate resin, and polyvinyl butyral. resin, thermoplastic resin such as polyvinyl acetate resin, ethyl cellulose resin, polysulfone resin, polyvinyl carbazole resin, etc. can be used, but when overcoating the charge generation layer and charge transport layer on the intermediate layer, May melt and cause coating defects. For this reason, it is more preferable to use a thermosetting resin as shown below as the binder resin.

The thermosetting resin is, for example, active hydrogen (-〇■ group, -N) I
.

It is obtained by thermally polymerizing a compound containing a plurality of hydrogen groups such as -NH group and a compound containing a plurality of isocyanate groups and/or a compound containing a plurality of epoxy groups. Compounds containing multiple active hydrogens include:
Examples of the compound include polyvinyl butyral, phenoxy resin, phenol resin, polyamide, acrylic resin containing active hydrogen such as hydroxyethyl methacrylate group, and examples of the compound containing a plurality of isocyanate groups.

Examples include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and their prepolymers, and compounds containing multiple epoxy groups include bisphenol A.
Examples include molded epoxy resin.

In the present invention, the bisazo pigment represented by the general formula (I) is used, and its content is from 3 parts by weight to 100 parts by weight, preferably 5 parts by weight, based on 10 parts by weight of the resin.
50 parts by weight.

Dispersion methods for disazo pigments in resin include ball mill,
Ultrasonic methods, three rolls, sand gliders, attritors, impellers, stone mills, etc. can be used.

To disperse a disazo pigment in a thermoplastic resin, it is sufficient to add the pigment to an organic solvent solution of the resin and disperse it by grinding and mixing using the above dispersion means. However, when dispersing it in a thermosetting resin, first disazo After the pigment is dispersed in an organic solvent solution of a compound containing active hydrogen, a compound containing a plurality of isocyanate groups and/or a compound containing a plurality of epoxy resins is added. This is to avoid thermal polymerization in the dispersion step, since the pouring and dispersion steps involve heat generation. The intermediate layer is formed on the conductive substrate by a conventionally known coating method such as roll coating, dip coating, spray coating, or blade coating at a temperature of 50°C to 0°C. Heat polymerized to a film thickness of 0.1μ
The intermediate layer has a thickness of m-10 μm (preferably 0.5 μm-5 μI).

Next, specific examples of the compound represented by the general formula (1) used in the present invention are shown below.

Table-1 Azo pigment for intermediate layer -A ・ ・ ・ ・ ・ ・ (Summer) A charge generation layer is a layer whose purpose is to generate and separate charges by image exposure. uses organic dyes and pigments, crystalline selenium, or arsenic selenide as a charge-generating substance, and organic pigments include phthalocyanine pigments, disazo pigments, trisazo pigments, perylene pigments, squalic base dyes, and azulenium salt dyes. , quinone-based fused polycyclic compounds, etc. Specific examples of disazo pigments and trisazo pigments are shown below.

I! 1LII! IQ-1-Δ--- Face JLh--1Δ-1-Face J [Almost-1-Δ--1 and 1-
1 person 1 1 and 5 - 1" L - 1 face J ``h --" Shi - 1 1 and 1
-One face, one face J
-One piece-- N○2 11LMU! Q---8111 face 4 [correct -11---face] L
Corner -8- Face 4 [Then -118111 face] 'Nu
-11111 face” L corner
-11---Face] "Limbs -1" Sea face JL & -11---shin spots)
Distribute and use according to the method. Examples of resins for dispersing these organic dyes and pigments include condensation resins such as polyamide, polyurethane, polyester, epoxy resin, polycarbonate, and polyether, as well as polystyrene, polyacrylate, polymethacrylate, poly-N-vinylcarbazole, and polyvinyl. Examples include polymers and copolymers such as butyral, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, etc., and insulation and adhesive properties are required. Disperse using the same dispersion method as above.

A film is formed on the intermediate layer in the same manner as the intermediate layer and dried to form a charge generation layer having a thickness of 0.05 μm to several μm. The content of the organic dye and pigment is preferably 60% by weight and 100% by weight.

The purpose of the charge transfer layer provided on the charge generation layer is to retain the charged charges on its surface, and also to move the charges generated and separated in the charge generation layer by exposure and combine them with the held charges. This is the layer where In order to achieve the purpose of retaining electrical charges, high electrical resistance is required.
In addition, in order to achieve the purpose of obtaining a high surface potential using the retained charges, it is required that the dielectric constant be small and the charge mobility be good. In order to satisfy these requirements, an organic charge transfer layer containing an organic charge transfer substance as an active ingredient is used. Examples of organic charge transfer substances include:
Poly-N-vinylcarbazole compounds, pyrazoline compounds, α-phenylstyrene bene compounds, hydrazone compounds, diarylmethane compounds, 1-liphenylamine compounds, divinylbenzene compounds, fluorine compounds, anthracene compounds Conventionally known compounds such as oxadiazole compounds, diaminocarbazole compounds, and the like can be used.

These organic charge transfer substances other than polymers such as polyvinylcarbazole are used by being blended with the same resin as shown as the binder for the charge generation layer described above. However, it is not necessary that the resin used in the charge generation layer and the resin used in the charge transfer layer be the same. Furthermore, a plasticizer is added to these as necessary. Examples of such plasticizers include halogenated paraffins, dimethylnaphthalene, dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, and copolymers of polymers such as polyester. A charge transfer substance, the above-mentioned binder resin, and silicone oil (as a leveling agent during film formation) were dissolved in an organic solvent, and a film was formed and dried in the same manner as the intermediate layer and charge generation layer to form a peritoneal layer of 5 μm. A charge transfer layer with a thickness of 100 μm is formed on the charge generation layer. The charge transfer material to resin binder ratio is 218 to 8/2 weight ratio, and the amount of silicone oil to resin binder is o, ooi weight percent.

〔effect〕

Since the electrophotographic photoreceptor of the present invention uses a thermosetting resin containing at least one kind of azo pigment represented by the general formula (1) as the intermediate layer, there is no increase in residual potential;
Furthermore, it exhibits stable electrical characteristics even when the environment such as temperature and humidity fluctuates, and provides highly reliable copied images that do not cause spot-like abnormal images or background stains.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 10+ of 1/2 volume in a 12cmφ glass pot
Put a mmφ alumina sintered ball, add 120g of the following resin liquid A, and 0.5g/azo pigment (azo pigment No. for intermediate layer).
(1)-1) and 100 g of methyl ethyl ketone were added and mixed for 72 hours. After 220 g of methyl ethyl ketone was added and mixed for 24 hours, 27 g of the following TDI solution and 240 g of methyl ethyl ketone were added to 420 g of this dispersion to prepare an intermediate layer coating solution.

[Resin liquid A]

Cyclohexanone 92 parts by weight (TD
Solution I] Tolylene diisocyanate 10 parts by weight Methyl ethyl ketone 90 parts by weight Next, φ15
c■ In a glass pot, add 1/2 the volume of a stainless steel pole of φlc■, 400g of cyclohexanone, and 25g
Azo pigment (Nol) for charge generation material was added and 48
Mixed for an hour.

After adding an additional 408 g of cyclohexanone and mixing for another 24 hours, 800 g of the dispersion solution was taken out.
While stirring, 800 g of tetrahydrofuran was added dropwise to obtain a charge generation layer coating solution.

The above intermediate layer coating solution was applied by dip coating onto an aluminum drum of 2 mm wall thickness and 80φ x 340+U+, and then heated and cured at 130° C. for 1 hour to form an intermediate layer with a thickness of 2 μI. The aluminum drum on which the intermediate layer was formed was immersed in the above charge generation layer coating solution and pulled up at a speed of 15 m+s/sec to perform dip coating, followed by drying at 130° C. for 10 minutes to form a charge generation layer. Further, the charge transfer layer coating solution shown below was applied on top of this by dip coating, and then coated at 130°C.
After drying for a while, a charge transport layer having a thickness of 20 μm was formed.

[Charge transfer layer coating liquid (composed of the following composition)] α-
Phenylstilbene-based charge transfer substance Compound below) (Part name, Panlite C1400: Kaito) Tetrahydrofuran 80 parts by weight The photoreceptor drum thus prepared was modified to have negative polarity for charging, transfer charger, and developing bias. When the image was evaluated by installing it in an FT4060 (a copying machine made by Ricoh) and developing it with a developer designed for the FT8030 (a copying machine made by Ricoh), a clear image was obtained with no speckled white spots in the solid black areas. .

Further, the photoreceptor was subjected to forced fatigue by repeating exposure and charging 1000 times, and then developed and evaluated the image. As a result, an image was obtained with no speckled white spots or stains on the background.

In addition, this photoreceptor was subjected to initial image, charging and exposure cycles 1000 times in the same manner as above in an environment of 10° C. and 15% RH.
When the images were evaluated after repeated use, it was found that there were no mottled white spots and no background stains.

Comparative Example 1 The charge generation layer and charge transfer layer liquid shown in Example 1 were coated in the same manner as in Example 1 without providing an intermediate layer on an aluminum drum having a wall thickness of 2 m and a length of 80φ x 340 mm. A photoreceptor was created.

Comparative Example 2 A photoreceptor was prepared in the same manner as in Example 1, except that the following resin liquid B was used in place of the intermediate layer in Example 1 and was dip-coated and cured by heating at 130°C for 1 hour to form a 2μ-intermediate layer. It was created.

[Resin liquid B]

Tolylene diisocyanate (TDI) 14.5 parts by weight Cyclohexane 552 parts by weight Methyl ethyl ketone 130 parts by weight Example 2 The azo pigment for the intermediate layer No. (I)-2 exemplified in Table 1 was used as the azo pigment for the intermediate layer of Example 1. A photoreceptor was produced in the same manner as in Example 1 except that

Example 3 A photoreceptor was produced in the same manner as in Example 1, except that the azo pigment for intermediate layer No. (I)-21 exemplified in Table 1 was used as the azo pigment for intermediate layer of Example 1.

Example 4 A photoreceptor was produced in the same manner as in Example 1, except that the azo pigment for intermediate layer No. (I)-8 exemplified in Table 1 was used as the azo pigment for intermediate layer of Example 1.

Example 5 The same intermediate layer coating solution as in Example 1 was dip-coated on an aluminum drum with a wall thickness of 2 mm and a length of 80 φ x 340 m.
The material was cured by heating at 30° C. for 1 hour to form an intermediate layer having a thickness of 2 μm.

In addition, put a 10 m diameter agate ball with 1/2 volume in a glass pot with a diameter of 15 cm, and add 400 g of resin liquid C below and 25 g of azo pigment (No. 3) for charge generation material.
9) was added and mixed for 48 hours. Further, 580 g of resin liquid C was added and mixed for another 24 hours, and then 710 g of methyl ethyl ketone was added dropwise to 950 g of the dispersion solution taken out while stirring to obtain a charge generation layer coating solution.

The aluminum drum provided with the above-mentioned intermediate layer was immersed in this charge generation layer coating solution, pulled up at a speed of 6■■/second to coat, and then heated and dried at 130°C for 10 minutes to form a charge generation layer. did.

Next, the charge transfer layer coating solution shown in Example 1 was applied by dip coating in the same manner as in Example 1 to provide a charge transfer layer of 20 μm to prepare a photoreceptor.

[Resin liquid C]

Cyclohexane 970 parts by weight Example 6 Example 5 except that the intermediate layer azo pigment No. (1)-15 illustrated in Table 1 was used instead of the intermediate layer azo pigment of Example 5.
A photoreceptor similar to that was created.

Comparative Example 3 A photoreceptor was prepared in the same manner as in Example 5, except that instead of the intermediate layer in Example 5, the following resin liquid (D) was applied and heated at 130° C. for 10 minutes to form a 2 μm thick intermediate layer. Created.

[Resin liquid D]

Nylon resin (Toshisha 1B) 8 parts by weight Methanol 60 parts Butanol 32 parts by weight The photoreceptor thus prepared was tested at room temperature and humidity (22°C to 25°C) using the modified copying test apparatus shown in Example 1. °C, 50% R1 (-6
Image evaluation was performed in the same manner as in Example 1 under a low temperature, low humidity (10° C., 15% RH) environment.

The results are shown in Tables 2 and 3.6 It can be seen that the photoreceptor of the present invention provides stable copied images free from spotty white spots and background smearing despite environmental changes.

The meaning of each symbol in the table is as follows.

0; Abnormal images do not occur Δ; Abnormal images occur, but the degree is slight and there is no substantial problem.
5% to 65% Procedural Amendment (Voluntary) R. 77, 1988 Director General of the Patent Office Kunio Ogawa 1. Indication of the case 1988 Patent Application No. 43607 2. Name of the invention Photoreceptor for electrophotography 3 , Relationship with the case of the person making the amendment Patent applicant Address 1-3-6 Nakamagome, Ota-ku, Tokyo Name Name
(674) Rico Co., Ltd. - Representative Hama 1
) Hiro 4, Agent 〒151 "Claims" and "Detailed Description of the Invention" in the specification
Column 8, Contents of amendment The following amendments will be made in the specification of the application.

(1) The scope of patent claims will be corrected as shown in the attached sheet.

(2) On page 2, line 19, "a photoreceptor is provided, and then on the photoreceptor" is corrected to "a photoreceptor is provided with a photoreceptor layer."

(3) Correct "Corona, Charger" in lines 17 to 20 of page 2 to "Corona Charger."

(4) Correct "charged" in the second line of page 3 to "charged."

(5) "Several nm - about 0.1 mn" on page 3, line 7,
Correct it to "rO, lim - about several meters".

(6) Change “Corona, Charger” in the first line of page 4 to “
Corrected to ``Corona Charger.''

(7) Correct "cellulose sulfate" in line 4 and line 9 to "cellulose nitrate."

(8) Page 4, line 15, “Unexamined Japanese Patent Publication No. 58-103155J
I am correcting ``Unexamined Japanese Patent Publication No. 58-105155J.

(9) “The middle class” in page 5, line 15, “to the middle class”
I will correct it.

(lO) "Characterized by being made of a thermosetting resin containing at least one kind of azo pigment" on page 5, lines 16 to 17.

Corrected to "Characterized by containing at least one kind of azo pigment."

(11) In line 6 of page 7, "as a middle class" is corrected to "to a middle class."

(12) Delete “Using thermosetting resin” from lines 7 to 8 of page 7.

(13) Correct "conductive substrate" in line 8 of page 8 to "conductive substrate."

(14) Correct “and” in line 18 of page 8 to “and”.

(15) The structural formula of pigment No. (1)-18 on page 14 is corrected as follows.

(16) The structural formula of pigment No. 17 on page 21 is corrected as follows.

(17) Page 40, line 2, “Simulation 5prsJ It,
[w! 4 Thickness 5 μm J Ir:, I will correct it.

(18) On page 40, line 7, "as a middle class" is corrected to "to a middle class."

(19) Delete “Using thermosetting resin” on page 40, line 9.

(20) RO, 5g/azo pigment” at the end of page 40,
Corrected to ``rlo, 5g of azo pigment''.

(20) Change “Add /” to “Add /” on page 41, line 5.
I will correct it.

(22) "Cyclohexane" in line 8 from the bottom of page 44 will be corrected to "cyclohexanone."

(23) “Cyclohexane” in line 12 from the bottom of page 46
is corrected to "cyclohexanone".

(24) “Nylon resin (manufactured by Toshisha)” at the end of page 46
"Nylon resin (Toshisha! 11cM-8000)
Correct to J.

(25) "Substantially" in lines 13 and 14 of page 47 is corrected to "substantially."

``Claims (1) An electrophotographic photoreceptor comprising an intermediate layer, a charge generation layer, and a charge transfer layer sequentially laminated on a conductive substrate.

An electrophotographic photoreceptor characterized in that the intermediate layer contains at least one azo pigment represented by the following general formula (1).

(However, in formula (1), A is a group represented by X, Ar1. At2, A
r, , R2, R3 are as follows.

X; an aromatic ring such as a benzene ring or a naphthalene ring, a hetero ring such as an indole ring, a carbazole ring, or a benzofuran ring, or a substituted product thereof.

Ar1; aromatic ring such as a benzene ring or naphthalene ring, hetero ring such as dibenzofuran, or a substituted product thereof; Ar;
+Art; aromatic ring such as a benzene ring or naphthalene ring, or a substituent thereof; R11R:l; hydrogen, a lower alkyl group, a phenyl group, or a substituent thereof; R2; a lower alkyl group, a carboxyl group, or an ester thereof)" Procedure Written amendment (spontaneous) May 18, 1988 Kunio Ogawa, Commissioner of the Patent Office 1, Indication of the case, Patent Application No. 43607 of 1988, 2, Name of the invention: Photoreceptor for electrophotography 3, Person making the amendment Case Relationship with Patent Applicant Address 1-3-6 Nakamagome, Ota-ku, Tokyo Name Name
(674) Rico Co., Ltd. - Representative Hama 1
) Hiro 4, Agent 151 Address 1-58-10-5 Yoyogi, Shibuya-ku, Tokyo
Date of amendment order Voluntary action 8. Contents of amendment The following amendments will be made to the specification of this application.

(1) The structural formula of pigment No. (1)-9 on page 13 is corrected as follows.

"

Claims (1)

[Claims] (1) In an electrophotographic photoreceptor in which an intermediate layer, a charge generation layer, and a charge transfer layer are sequentially laminated on a conductive substrate, the intermediate layer contains at least one azo pigment represented by the following general formula (I). An electrophotographic photoreceptor comprising a thermosetting resin containing seeds. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (However, in formula (I), A is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, a group represented by X, Ar_1, Ar_2, A
r_3, R_1, R_2, and R_3 are as follows. X; an aromatic ring such as a benzene ring or a naphthalene ring, a hetero ring such as an indole ring, a carbazole ring, or a benzofuran ring, or a substituted product thereof. Ar_1; Aromatic ring such as benzene ring or naphthalene ring, hetero ring such as dibenzofuran, or substituted product thereof; Ar_2, Ar_3; Aromatic ring such as benzene ring or naphthalene ring, or substituted product thereof; R_1, R_3; Hydrogen, lower alkyl group, phenyl group or a substituted product thereof, R_2; lower alkyl group, carboxyl group or ester thereof)