JPS6059589B2 - electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor in which a photosensitive layer comprising a combination of a carrier generation phase and a carrier transport phase is provided on a conductive support.

In general, it is difficult for substances that absorb visible light to generate carriers to form a film on their own, with the exception of a small number of substances such as amorphous selenium. It has a lack of holding power.

On the contrary, materials that have excellent film-forming ability and can retain a charge of 500 V or more for a long time with a thickness of about 10 microns generally have the disadvantage of not having sufficient photoconductivity due to absorption of visible light. have. For this reason,
Recently, photosensitive layers have been developed by combining a carrier generation phase made of a substance that absorbs visible light and generates charge carriers, and a carrier transport phase that transports either positive or negative charge carriers or both of the charge carriers generated in this carrier generation phase. It was proposed to configure the

In this way, by separating the generation and transport of charge carriers into separate phases, the range of material selection is widened.
It has become possible to enhance or improve various properties required for electrophotographic process J tin, such as charge retention, surface strength, sensitivity to visible light, and stability during repeated use. Conventionally, such photoreceptors include:
The following are known:

(1) Carrier generation phase layer (hereinafter simply referred to as 1 carrier generation layer).

) is composed of amorphous selenium, and the carrier transport phase layer (
Hereinafter, it will simply be referred to as the 1 carrier transport layer. ) is poly N-vinylcarbazole (hereinafter referred to as RpvKJ).

) having a photosensitive layer formed and laminated (2)
) The carrier generation layer is composed of amorphous selenium, and the carrier transport layer is composed of 2,4,7-trinylo-9-fluorenone (
Hereafter referred to as RTNFJ.

) having a laminated photosensitive layer (3)
) A photosensitive layer in which the carrier generation layer is composed of a perylene derivative and the carrier transport layer is composed of an oxadiazole derivative (US Pat. No. 38718)
(4) A photosensitive layer in which the carrier generation layer is composed of chlordian blue or methylscarillium and the carrier transport layer is composed of a pyrazoline derivative (Japanese Patent Laid-Open No. 51-90827) (Refer to the publication) (5) A photosensitive layer having a photosensitive layer in which phthalocyanine constituting a carrier generation phase is dispersed in a carrier transport phase containing PVK (6) A structure in which a carrier generation phase is constituted in a carrier transport phase containing NF Electrophotographic photoreceptors having a photosensitive layer having a two-phase structure are known, such as those having a photosensitive layer having a phthalocyanine dispersed therein. To date, no excellent electrophotographic photoreceptor has been known that has the following characteristics and is stable against environmental changes.

For example, when PVK is used to construct a carrier transport layer, the coating film shrinks significantly during the drying process.
For this reason, there is a drawback that the formed photosensitive layer peels off from the conductive support. Furthermore, when TNF or an oxadiazole derivative is dissolved in a solvent together with a resin binder to form a carrier transport phase or carrier transport layer, there is a drawback that crystal precipitation of the above-mentioned compound often occurs. Further, in a photoreceptor having a two-layer structure, a carrier generation layer is formed using an organic pigment such as chlordian blue or scarillium, and a carrier transport layer is formed using a pyrazoline derivative having various substituents or PVK.

According to Merz's research on the injection efficiency of positive-sign carriers (holes) from the carrier generation layer to the carrier transport layer, the injection efficiency was the lowest when PVK was used as the material for the carrier transport layer, and the injection efficiency was the lowest when PVK was used as the material for the carrier transport layer. In some cases, the injection efficiency varies greatly depending on the type of substituent, and it is said that the lower the ionization potential of the carrier transport substance relative to the carrier generation layer, the higher the injection efficiency. However, for the carrier generation layer made of amorphous selenium, PVK
can constitute a good carrier transport layer.

In this way, a carrier transporting substance that is effective against a specific carrier-generating substance is not always effective against other carrier-generating substances, and a carrier-generating substance that is effective against a specific carrier-generating substance is not always effective against other carrier-generating substances. However, it cannot be said that it is always effective for other carrier transport substances. If the combination of these two substances is inappropriate, not only will the electrophotographic sensitivity become low, but also the discharge efficiency will be poor especially at low electrolytes, so the so-called residual potential will increase, and in the worst case, repeated use will cause damage. Potential accumulates in the area, making it practically unusable for electrophotographic purposes. In this way, there is no legal way to select a suitable combination of the constituent substances of the carrier generation phase and the constituent substances of the carrier transport phase, and it is necessary to practically determine an advantageous combination from among many substance groups. .

An object of the present invention is to provide an electrophotographic photoreceptor that does not have the drawbacks of conventional electrophotographic photoreceptors as described above, has very high sensitivity to visible light, and can therefore always form clear images. shall be. Another object of the present invention is to provide an electrophotographic photoreceptor that has high sensitivity, high mechanical strength, and extremely low residual potential, and can therefore be used repeatedly. The present invention will be explained below with reference to the drawings.

In the present invention, as shown in FIG. 1, a carrier generation layer 2 containing a carrier generation substance described later as a main component is formed on a conductive support 1, and a carrier generation layer 2 containing a carrier generation substance described below as a main component is formed on this carrier generation layer 2. A carrier transport layer 3 containing a carrier transport substance as a main component is laminated to form a photosensitive layer 4. The carrier generation layer 2 and the carrier transport layer 3 constitute a photosensitive layer 4.

Here, as the material of the conductive support 1, for example, a sheet of metal such as aluminum, nickel, copper, zinc, palladium, silver, indium, tin, platinum, gold, stainless steel, brass, etc. can be used. For example, as shown in FIG. 2, the insulating substrate 1A
The conductive support 1 can also be configured by providing a conductive layer 1B thereon.

In this case, the substrate 1A is suitably flexible, such as paper or a plastic sheet, and has sufficient strength against stress such as bending and tension. The conductive layer 1B can also be provided by laminating metal sheets, vacuum depositing metal, or by other methods. The carrier generation layer 2 may be made of a carrier generation substance alone, which will be described later, or a suitable binder resin added thereto, or a substance with high mobility for carriers of specific or non-specific polarity, that is, a carrier transport substance. It can be formed by adding .

Specific forming methods include a method in which a carrier-generating substance is vacuum-deposited on the support, and a method in which a carrier-generating substance dissolved or dispersed in a suitable solvent is coated and dried.

In this latter method, a binder resin or a carrier transport substance may be added, and in this case, the ratio of carrier generating substance: binder resin: carrier transport substance is 1:0 to 100: by weight. The ratio is preferably 0 to 50, particularly 1:0 to 10:0 to 50.

Examples of the binder resin used here include polyethylene one, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, Addition polymer resins such as melamine resins, polyaddition resins, polycondensation resins, and copolymer resins containing two or more repeating units of these resins, such as vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate copolymer resins, Examples include vinyl acetate-maleic anhydride copolymer resin.

The binder resin is not limited to these, and all resins commonly used for such purposes can be used. As the carrier transporting substance having high mobility for carriers of specific or non-specific polarity that can be added to the carrier generation layer, specific carrier transporting substances described below, which are used in the structure of the carrier transporting layer 3 etc. in the present invention, may be used. Although it may be used in part or in whole, other carrier transport materials may be used in consideration of the performance as an electrophotographic photoreceptor. Furthermore, this carrier generation layer may contain a residual potential lowering agent, a fatigue reducing agent, and the like, if necessary.

The thickness of the carrier generation layer 2 formed as described above is preferably 0.005 to 20 microns, particularly preferably 0.1 to 5 microns. The carrier transport layer 3 is formed by applying a coating solution obtained by dissolving or dispersing a hydrazone derivative described below as a carrier transport substance in an appropriate solvent together with an appropriate binder resin or other additives as necessary. It can be formed by a drying method or other methods. Examples of the binder resin used here include: For example, addition polymer resins such as polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, polymer Addition type resins, polycondensation type resins, and copolymer resins containing two or more of the repeating units of these resins, such as vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, etc. can be mentioned.

However, the binder resin is not limited to these, and all resins commonly used for such purposes can be used. The blending ratio of the binder resin and the carrier transport substance is preferably 10 to 50 parts by weight of the carrier transport substance per 10 parts by weight of the binder resin, and when polycarbonate is used as the binder resin, 10 parts by weight of the carrier transport substance. It is preferable to use 20 to 10 parts per rut of carrier transport material since excellent electrophotographic properties can be obtained.

The thickness of this carrier transport layer 3 is between 2 and 100 microns, preferably between 5 and 30 microns. In the present invention, the carrier generating substance contained in the carrier generating layer 2 as its main component is selected from compounds represented by the following general formulas [A], [B] and [C].

General formula [A] General formula [B] General formula [C] In the above formula, represents an integer from 0 to 6.

Specific examples of compounds of the anthoanthrone pigment represented by the general formula [A] are as follows. Specific compound examples of the dibenzpyrenequinone pigment represented by the general formula [B] are as follows; Specific compound examples of the pyranthrone pigment represented by the general formula [C] are as follows. be. In the present invention, the carrier transport material contained in the carrier transport layer 3 as a main component is selected from hydrazone derivatives represented by the following general formula [P]. (In the formula, R1 is an alkyl group, phenyl group or benzyl group, R2 is an alkyl group, phenyl group or benzyl group, R is a hydrogen atom or an alkyl group, R4 is a hydrogen atom or an alkyl group, R5 is hydrogen an atom or an alkoxy group, l represents a hydrogen atom, an alkyl group, or an alkoxy group, R7 represents a hydrogen atom or an alkyl group, R8 represents a hydrogen atom, an alkyl group, an alkoxy group, a dialkylamino group, or a heterocyclic group, n represents 1 when R3 is a hydrogen atom, and represents 1 or O when R3 is an alkyl group.

) Representative specific examples of the hydrazone derivative represented by the general formula [P] are as follows.

The above-mentioned hydrazone derivatives may be used not only one type, but also a mixture of two or more types, and further a mixture of one or more of the hydrazone derivatives and one or more other carrier transport substances. You can also do it. In the last case, there is a possibility that the hydrazone derivative and the other carrier transport substance can form a charge transfer complex, thereby causing a specific sign of carrier movement in the carrier transport layer. It becomes possible to control the degree arbitrarily,
It also becomes possible to effectively eliminate internal traps. Furthermore, this carrier transport layer may contain a suitable plasticizer, residual potential lowering agent, fatigue reducing agent, and others as required. Since the electrophotographic photoreceptor of the present invention has the above-mentioned structure, as is clear from the Examples and Comparative Examples described later, it has extremely high sensitivity compared to conventional photoreceptors having two photosensitive layers. Since its maximum spectral sensitivity is in the central part of the visible light region, the color sensitivity is poor, and as a result, it is possible to form a copied image with extremely good resolution and gradation reproducibility. Further, the electrophotographic photoreceptor of the present invention includes:
It has high charge retention and surface strength, and has an extremely low residual potential, so it exhibits stable performance even after repeated use and does not accumulate charge. Note that during the formation of the carrier generation layer 2 and the carrier transport layer 3, shrinkage of the film body or crystallization of the contained substance does not occur, and therefore problems of peeling and clouding do not occur.

In the present invention, as shown in FIG. 3, an intermediate layer 5 is provided on a conductive support 1, a carrier generation layer 2 is formed thereon, and a carrier transport layer 3 is formed thereon. It's okay.

This intermediate layer 5 prevents the injection of free carriers from the conductive support 1 to the photosensitive layer 4 when the photosensitive layer 4 is charged, and also holds the photosensitive layer 4 integrally bonded to the conductive support 1. Acts as an adhesive layer that binds. Materials for this intermediate layer 5 include metal oxides such as aluminum oxide and indium oxide, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, and polycarbonate. Polymer materials such as resins, silicone resins, melamine resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins can be used. Further, as shown in FIG. 4, a carrier transport layer 3 is formed on the conductive support 1 with or without the intermediate layer 5, and a carrier generation layer 2 is formed thereon. Layer 4 may also be configured.

Further, as shown in FIG. 5, the photosensitive layer 4 is formed by dispersing the above-mentioned carrier-generating substance 21 in the carrier-transporting phase 31 containing the above-mentioned hydrazone derivative to form a carrier-generating phase. You can also do that.

In this case, 0.1 to 10 parts of the carrier generating substance is added to 10 parts of the material forming the carrier transport phase 31.
It may be dispersed in a proportion of 0 parts by weight, preferably 1 to 50 parts by weight. If the proportion of the carrier-generating substance is too small, the sensitivity of the photoreceptor will be reduced, and if the proportion is too large, the strength of the photosensitive layer 4 will generally be reduced. As described above, various mechanical configurations can be employed in the present invention, but those skilled in the art will not be able to determine which polarity to charge the photosensitive layer 4 in the electrophotographic process in addition to such mechanical configurations. You can choose the one you like.

Examples of the present invention will be described below, but the present invention is not limited thereto.

Example 1 Polyethylene terephthalate with a thickness of 100 microns. An exemplary carrier-generating substance [A3] (anthorone pigment 1 monolite red 2Y C.I-N
O. 593OO) was evaporated and deposited for 3 minutes at an evaporation source temperature of 350 DEG C. in a vacuum atmosphere of 2 to 3.times.10@-4 TOrr' to form a carrier generation layer with a thickness of about 0.5 micron.

Next, 7.5 g of the exemplified hydrazone derivative [P1] and 10 g of polycarbonate resin 1 Panlite L-1250J (manufactured by Teijin Chemicals) were dissolved in 100 ml of tetrahydrofuran, and this solution was poured onto the carrier generation layer using a doctor blade. A carrier transport layer having a thickness of about 10 microns was formed by coating the carrier and drying it at a temperature of 70° C. for 1 hour, thereby producing an electrophotographic photoreceptor of the present invention.

This is referred to as one sample L. This sample 1 was attached to an electrostatic copying paper tester SP-428 model (manufactured by Kawaguchi Electric Seisakusho),
A charging operation was performed for 5 seconds with the voltage applied to the discharge electrode of the charger set to 1, and the charging potential VO (V) on the surface of the photosensitive layer immediately after this charging operation and this charging potential VO were 112
The half-reduced exposure amount Ell2(Ix
．． sec) was measured.

The results are shown in Table 1. Examples 2 to 4 In each of these Examples, hydrazone derivatives [P2] and [Pl] were used instead of the exemplified hydrazone derivative [Pl] as carrier transport substances.
A total of three types of electrophotographic photoreceptors of the present invention were produced in the same manner as in Example 1, except that Samples No. 4] and P9 were used.

These were designated as 1 sample 2J-1 sample 4J, and the charging potential VO and half-decreased exposure amount ElI2 of each were measured in the same manner as sample 1. The results are shown in Table 1. RCTM represents a carrier transport material, and RCTL represents a carrier transport layer.

Examples 5 to 7 In each of these Examples, the carrier-generating substance was exemplified substance [A2] (Anthrone pigment 1 Indanthrene Priliant Orange GKyo C●■・NO.593
O5), [B3] (Dibenzpyrenequinone pigment 1 Indanthrene Golden Yellow RKJC.I.NO59
lO5) and [C4] (pyranthrone pigment "Paliogen Red 33340J), respectively, as exemplified substances [A3]
A thickness of 0.
A carrier generation layer of 5 microns was formed, and a carrier transport layer was formed in the same manner as in Example 1 using the exemplified hydrazone derivative [P1] as a carrier transport material, so that a total of 3 microns was formed.
Separate electrophotographic photoreceptors of the present invention were prepared, and these were divided into 7 samples and 5
1 sample 7. J, and in the same manner as Sample 1, each charging potential VO and half-decreased exposure amount Ell2 were measured.

The results are shown in Table 2. RCGMJ indicates a carrier generating substance.

Example 8 Vinyl chloride-vinyl acetate-maleic anhydride copolymer 1 Esletsuha E-10 (manufactured by Sekisui Chemical Co., Ltd.) was applied to a conductive support made by vapor-depositing aluminum on a substrate made of polyethylene terephthalate with a thickness of 100 microns. Example material [A3] is prepared as a carrier-generating substance in a solution of 3 g of polycarbonate resin dissolved in 100 ml of 1,2-dikuyama rhethane.
The dispersion obtained by adding 3g of and carrying out ultrasonic dispersion,
A carrier generation layer having a thickness of 2 microns was formed by coating on the intermediate layer by a wire spray coating method and drying.

On this carrier generation layer, a carrier transport layer having a thickness of 10 microns was formed in the same manner as in Example 1 using an exemplary hydrazone derivative [Pll] as a carrier transport substance, thereby producing an electrophotographic photoreceptor of the present invention. .

When one sample was 8J and measurements were carried out in the same manner as sample 1, VO=-945 (V), Ell2=2.8
(Ix.sec). Example 9 Using an exemplary hydrazone derivative [P9] as a carrier transport substance, 7.
5g of polycarbonate resin and 10g of polycarbonate resin were dissolved in 100ml of 1,2-dichloroethane, 1.5g of exemplified substance [A3] was added as a carrier generating substance to the resulting solution, and ultrasonic dispersion was performed to obtain this dispersion. The same intermediate layer was provided on the same conductive support as in Example 8 and was coated by the same method and dried at a temperature of 70° C. for 1 hour to form a photosensitive layer of the present invention having a thickness of 13 microns. An electrophotographic photoreceptor was produced.

This is assumed to be 9J for one sample. The photosensitive layer of Sample 9 has a structure in which a carrier generating substance 21 is dispersed in a carrier transporting phase 31, as shown in FIG. This sample 9
When measurements were carried out in the same manner as for sample 1, V
O=-927(V), Ell2=5.1(Ix●Sec
).

When each of Samples 1 to 9 obtained in each of the above Examples was attached to an electronic copying machine RU-BiX2OOORJ (manufactured by Konishiroku Photo Industry Co., Ltd.) and a photocopying test was conducted, it was found that the image density was sufficient. , and a good copy image without fog could be obtained.

Comparative Example 1 Chlordiane blue was used as a carrier generating substance,
0.5g of it was made of ethylenediamine, n-butylamine, and tetrahydrofuran, the weight ratio of which was 1.2:
A carrier was prepared by dissolving the solution in 75 g of a mixed solvent of 1.0:2.2 and coating it on the same conductive support as in Example 8 so that the amount of adhesion after drying was 0.2 g/d. A generation layer was formed.

On this carrier generation layer, a carrier transport layer having a thickness of 10 microns was formed in the same manner as in Example 1 using the illustrated hydrazone derivative [P1] as a carrier transport substance, thereby producing a comparative electrophotographic photoreceptor. This was used as a comparison sample, and measurements were carried out in the same manner as sample 1, and VO=
-783 (V), Ell2 = 4.9 (Ix.sec), which was lower than the electrophotographic photoreceptor of the present invention. Comparative Example 2 An electrophotographic photoreceptor was produced in the same manner as Comparative Example 1, except that methylscalyllium was used instead of chlordian blue as a carrier generating substance.

This was used as 1 Comparative Sample 2J, and measurements were carried out in the same manner as Sample 1. As a result, ■O=-735 (V) and Ell2-ni 4.4 (IX●Sec). As is clear from the above, when a substance other than the compound of the present invention is used as a carrier-generating substance, excellent sensitivity characteristics can be obtained even when the hydrazone derivative used in the present invention is used as a carrier-transporting substance. I can't.

Comparative Example 3 Carrier transport with a thickness of 11 microns using 1,1-bis(4-N,N-diethylamino-2-methylphenyl)-1-phenylmethane instead of the exemplified hydrazone derivative [Pl] as a carrier transport material An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the layers were formed.

When this was used as 1 comparative sample 2J and measurements were performed in the same manner as sample 1, VO = -638 (V), E1'2 = 2
．． 5 (Ix-Sec). Next, each of Sample 1 and Comparative Sample 3 was installed in an electronic copying machine RU-BlX2OOORJ, and a continuous copying test was carried out. The measurement was performed using 1D Model J (manufactured by Monroe Electronics Inc.).

The results are shown in Table 3. As judged from the results in Table 3, when an arylalkane compound other than the hydrazone derivative of the present invention is used as a carrier transporting substance as in Comparative Sample 3, the carrier generating substance is similar to that of the present invention. However, it is clear that the repeatability is inferior.

That is, the potential of the background portion of the image increases significantly due to continuous copying a large number of times, and the resulting copied image has a large amount of fog and cannot be put to practical use. Comparative example 4
~8 Exemplary hydrazone derivative [P1
) Electrophotographic photoreceptors 1 comparative sample 4 to 0 comparative sample 9 were prepared in the same manner as in Example 1, except that the following materials were used in place of Summer.

The results are shown in Table 4. Comparative sample 4: N-ethylcarbazole Comparative sample 5: Anthracene Comparative sample 6: Fluorenone Comparative sample 7: 2,4,7-trinitro 9-fluorene
Fluorenone Comparative Sample 8: 2,4,5,7-Tetranitroph Fluorenone Comparative Sample 9: Polyvinylcarbazole As a result, even when the carrier-generating substance used in the present invention is used, when the carrier-transporting substance is not a specific one, a large It is clear that an electrophotographic photoreceptor with sensitivity cannot be obtained.

As is clear from the above explanation, even when the carrier transporting substance used in the present invention is used, when a carrier generating substance other than that used in the present invention is used as a carrier generating substance, and the carrier used in the present invention Even when a generating substance is used, if a carrier transporting substance other than that used in the present invention is used as a carrier transporting substance, the resulting electrophotographic photoreceptor will have extremely low sensitivity, and sufficient characteristics may not be obtained. I can't.

However, as in the present invention, by combining a specific carrier-generating substance and a specific carrier-transporting substance,
It is possible to obtain an excellent electrophotographic photoreceptor having a high sensitivity that was previously unexpected.

[Brief explanation of drawings]

FIG. 1 is an explanatory enlarged sectional view showing an example of the structure of the electrophotographic photoreceptor of the present invention, FIG. 2 is an explanatory enlarged sectional view showing a modified example of the conductive support, and FIGS. 3 and 4 are respectively FIG. 5 is an explanatory enlarged cross-sectional view showing still another example of the structure of the present invention. FIG. 1... Conductive support, 2... Carrier generation layer, 3... Carrier transport layer, 4...
・Photosensitive layer, 5...Intermediate layer, 21...
Carrier generating substance, 31...Carrier transport phase.

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor comprising a photosensitive layer comprising a combination of a carrier generation phase and a carrier transport phase provided on a conductive support, wherein the carrier generation phase has the following general formula [A] andanthrone pigment represented by the following general formula [B], and a dibenzpyrenequinone pigment represented by the following general formula [C]
The carrier transport phase contains as a main component at least one selected from the group consisting of pyranthrone pigments represented by the following, and the carrier transport phase contains a hydrazone derivative represented by the following general formula [P] as a main component. Electrophotographic photoreceptor. General formula [A] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ General formula [B] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ General formula [C] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, represents a halogen atom, a nitro group, a cyano group, an acyl group, or a carboxyl group, n represents an integer of 0 to 4, and m represents an integer of 0 to 6.) General formula [P] ▲ Numerical formula, chemical formula, There are tables etc.▼ (In the formula, R_1 is an alkyl group, phenyl group or benzyl group, R_2 is an alkyl group, phenyl group or benzyl group, R_3 is a hydrogen atom or an alkyl group, R_4 is a hydrogen atom or an alkyl group, R_5 is a hydrogen atom or an alkoxy group, R_6 is a hydrogen atom, an alkyl group, or an alkoxy group, R
_7 represents a hydrogen atom or an alkyl group, R_8 represents a hydrogen atom, an alkyl group, an alkoxy group, a dialkylamino group, or a heterocyclic group, n is 1 when R_3 is a hydrogen atom, and when R_3 is an alkyl group, In some cases, it represents 1 or 0. )2 The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer is constituted by a laminate of a layer of the carrier generation phase and a layer of the carrier transport phase. 3. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer is configured such that the carrier generation phase is dispersed in a carrier transport phase.