JPH0547823B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an electrophotographic photoreceptor, and particularly to improvements in organic photoconductive electrophotographic photoreceptors. [Prior Art] In an electrophotographic copying machine using the Carlson method,
After the surface of the photoreceptor is charged, an electrostatic latent image is formed by exposure, the electrostatic latent image is developed with toner, and the visible image is then transferred and fixed onto paper or the like. On the other hand, the photoreceptor is subjected to removal of adhering toner, neutralization of static electricity, and surface cleaning, and is used repeatedly over a long period of time. Therefore, as an electrophotographic photoreceptor, it not only has electrophotographic properties such as good charging characteristics and sensitivity, and low dark decay, but also physical properties such as printing durability, abrasion resistance, and moisture resistance after repeated use. It is also required to have good properties and resistance to ozone generated during corona discharge, ultraviolet rays during exposure, etc. (environmental resistance). Conventionally, inorganic photoreceptors having a photoreceptor layer containing an inorganic photoconductive substance such as selenium, zinc oxide, or cadmium sulfide as a main component have been widely used as electrophotographic photoreceptors. On the other hand, the use of various organic photoconductive substances as materials for photoreceptor layers of electrophotographic photoreceptors has been actively researched and developed in recent years. For example, in Japanese Patent Publication No. 50-10496, poly-N-vinylcarbazole and 2,4,7-trinitro-9
- An organic photoreceptor having a photoreceptor layer containing fluorenone is described. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability. In order to improve these drawbacks, attempts have been made to develop organic photoreceptors with high sensitivity and durability by assigning charge generation and charge transport functions to different materials in the photoreceptor layer. being done. In such so-called function-separated type electrophotographic photoreceptors, substances that exhibit each function can be selected from a wide range of materials, so it is relatively easy to produce electrophotographic photoreceptors with arbitrary characteristics. Is possible. Many substances have been proposed as charge-generating substances that are effective for such functionally separated electrophotographic photoreceptors. An example of using an inorganic substance is amorphous selenium, as described in Japanese Patent Publication No. 43-16198. This is combined with an organic charge transport material. In addition, many electrophotographic photoreceptors using organic dyes or organic pigments as charge-generating substances have been proposed.
For example, those having a photoreceptor layer containing a bisazo compound are disclosed in JP-A-47-37543 and JP-A-55-22834.
No. 54-79632, No. 56-116040, etc. By the way, known photoreceptors using organic photoconductive substances are generally used for negative charging. The reason for this is that when negative charging is used, the mobility of holes among the charges is large, which is advantageous in terms of photosensitivity and the like. However, a problem with such negative charging is that ozone is likely to be generated in the atmosphere during negative charging by the charger, which worsens the environmental conditions. Furthermore, a positive polarity toner is required for development of a negatively charged photoreceptor, but it is difficult to manufacture a positive polarity toner in view of the triboelectrification series with respect to ferromagnetic charged particles. Therefore, positively charged photoreceptors using organic photoconductive substances are used, for example, positively charged photoreceptors in which a charge transport layer is laminated on a charge generation layer and the charge transport layer is formed of a material with a high electron transport ability. is proposed. However, if the charge transport layer contains, for example, trinitrofluorenone, problems may arise, such as that the substance is carcinogenic. On the other hand,
A positively charged photoreceptor in which a charge generation layer is laminated on a charge transport layer with a high hole transport ability is considered, but with this mechanism, the charge generation layer on the surface side needs to be extremely thin, and printing durability etc. This is not a practical layer structure. In addition, as a positively charged photoreceptor, U.S. Patent No. 3615414
No. 1 shows a product containing thiapyrylium salt (charge generating substance) so as to form a complex with polycarbonate (binder resin). However, this photoreceptor has disadvantages in that the memory phenomenon is large and ghosts are likely to occur. Also US patent
No. 3357989 discloses a photoreceptor containing phthalocyanine, but the characteristics of phthalocyanine change depending on the crystal type, the crystal type must be strictly controlled, and short wavelength sensitivity is insufficient. In addition, the memory phenomenon is large, making it unsuitable for copying machines that use light sources in the visible wavelength range. Various attempts have been made to obtain positively charged photoreceptors, but all require improvements in terms of photosensitivity, memory phenomenon, occupational hygiene, etc., and durability such as ultraviolet resistance and ozone oxidation resistance. There are many problems. Therefore, from a functional standpoint, a laminated structure in which the upper layer (surface layer) is a charge generation layer containing a charge generation substance that generates holes and electrons when irradiated with light, and the lower layer is a charge transport layer containing a charge transport substance having a hole transport function. It is conceivable to make the photoreceptor a basic type of photoreceptor with both positive and negative charges, and to supplement what is lacking. In addition, in such a photoreceptor, if a charge generating substance having, for example, an electron-withdrawing group is used in the structure, the movement of electrons to cancel the positive charge on the surface of the photoreceptor becomes faster, and high sensitivity characteristics can be obtained. It is conceivable that However, since the positively charged photoreceptor is formed with a layer containing a charge generating substance as a surface layer, it is vulnerable to external effects such as light irradiation, especially short wave light irradiation such as ultraviolet light, corona discharge, humidity, ozone oxidation, and mechanical friction. As a result, the electrophotographic performance deteriorates during the storage of the photoreceptor and during the image formation process, resulting in a decrease in image quality. In a negatively charged photoreceptor having a conventional charge transport layer as a surface layer, the effects of the various external effects described above are extremely small, and rather the charge transport layer has the effect of protecting the underlying charge generation layer. Therefore, it is conceivable to provide a thin protective layer made of an insulating and transparent resin to protect the layer containing the charge-generating substance from external effects, but the charge generated during light irradiation may be blocked by the protective layer. The light irradiation effect will be lost, and if the protective layer that serves as the surface layer is thick, it will cause a decrease in sensitivity and will have little UV blocking effect. You can't just leave it to others. [Objective of the Invention] The object of the present invention is to provide an organic material that can be applied to positive and negative charging, has good sensitivity, has excellent environmental resistance, and has particularly good UV resistance, oxidation resistance, and durable physical properties. The present invention provides a photoconductive electrophotographic photoreceptor. [Structure and Effects of the Invention] The object of the present invention is to reduce the number of layers containing a charge-generating substance (marked as CGM) and a layer containing a charge-transporting substance (marked as CTM) on a conductive support. This is achieved by an electrophotographic photoreceptor characterized by containing a compound represented by the following general formula. general formula In the formula, R represents hydrogen or a halogen atom,
R ₁ represents an amino, alkyl, arylamino, alkoxy, phenyloxy, nitro group or a halogen atom, and the alkyl group may have a substituent. R ₂ represents each group of amino, alkyl, arylamino, alkoxy and phenyloxy. The photoreceptor layer provided on the conductive support according to the present invention may have a single layer structure in which CTM and CGM are mixed together, or may have a multilayer structure in which a layer containing CTM is a lower layer and a layer containing CGM is an upper layer. Alternatively, the configuration may be reversed. Also, if necessary, a protective layer (marked as OCL)
may be provided. The compound according to the present invention is added to at least one of the above layers, but is preferably added to the surface layer of the photoreceptor layer. In addition, it may be most concentrated on the surface layer and gradually decrease toward the inside. The present invention will be explained in detail below. In the electrophotographic process based on the Carlson process, a light source that generates ultraviolet rays is generally used for image exposure, erasing exposure, pre-transfer exposure, cleaning exposure, etc. Repeated irradiation with energetic ultraviolet light is sufficient to cleave the organic compound molecules used in the photoreceptor. In other words, the CGM that forms the photoreceptor,
CTM or a binder causes radical dissociation, loses its original molecular structure, and deteriorates, leading to deterioration of the photoreceptor. Specifically, it causes a decrease in sensitivity, an increase in residual potential, etc., and the occurrence of fogging. Image quality deteriorates. The combined deterioration induced and derived from ultraviolet rays or ultraviolet rays and ozone on the photoreceptor is caused by various exposure treatments and corona discharge that are repeatedly applied, but it can also be caused by singlet oxygen generated by exposure. It is thought that it can be strengthened. In addition, the layer structure of the photoreceptor, CGM
Although the degree of composite deterioration caused by ultraviolet rays and the like varies depending on the type of photoconductive material and the type of CTM, CTM is more susceptible to deterioration, and the effect is particularly large when an organic photoconductive substance is used. As a result of intensive studies on improving the composite deterioration (particularly potential drop) of the photoreceptor, the present inventors found that a specific quinone compound represented by the above general formula in the photoreceptor layer not only significantly prevents the composite deterioration. It has been found that this also contributes to improvements in other electrophotographic properties and physical properties. The stabilization mechanism of the compound according to the present invention, that is, a compound generally regarded as an ultraviolet absorber, against organic substances is that the decomposition energy possessed by ultraviolet rays (sometimes referred to as UV) is absorbed by the vibrational energy within the UV absorber. This is thought to be due to the transformation.
The energy of this vibration is released as thermal energy from the UV absorber, but the thermal energy is already insufficient to degrade the organic material, and the photoreceptor is protected from harm caused by repeated UV irradiation. Seem. Typical specific examples of the compounds of the present invention are shown below, but the compounds used in the present invention are not limited thereto.

[Table] The amount of the compound represented by the above general formula used in the present invention (hereinafter referred to as the compound of the present invention) varies depending on the layer structure of the photoreceptor, the type of CTM, etc. 0.1 to 100
It is used in a range of % by weight, preferably 1 to 50% by weight, particularly preferably 5 to 25% by weight. Next, the structure of the photoreceptor of the present invention will be explained with reference to the drawings. The photoreceptor of the present invention is, for example, as shown in FIG. 1, on a support 1 (a conductive support or a sheet with a conductive layer provided thereon) and a charge generation layer (containing CGM 5 and optionally a binder resin). Hereinafter referred to as CGL) 2 is the lower layer, and CTM 6 and a charge transport layer (hereinafter referred to as CGL) containing a binder resin as required.
A photoreceptor layer 4 having a laminated structure with CTL 3 as the upper layer and CTL 3 as the upper layer, as shown in FIG. 4, and as shown in FIG. 3, a photoreceptor layer 4 of a single layer structure containing CGM, CTM and, if necessary, a binder resin is provided on the support 1. In addition, the upper layer CGL has the same layer configuration as shown in Figure 2.
Both CGM and CTM may be included, a protective layer (OCL) may be provided on top of the layer, and an intermediate layer may be provided between the support and the photoreceptor layer. An example is shown in FIG. That is, the intermediate layer 7 is provided on the support 1, and CTL3, CGM5, and CTM6b containing the CTM6a binder resin are provided on the intermediate layer 7.
This photoreceptor has a photoreceptor layer 4 in which CGL 2 and CGL 2 containing a binder resin are laminated, and is further provided with an OCL 8 whose main component is a binder. The compound of the present invention comprises CGL, which constitutes a photoreceptor,
It may be contained in any of the CTL, single-layer structure photoreceptor layer, or OCL, or may be contained in multiple layers.
The effects of the present invention are more clearly exhibited when
This is a photoreceptor with a laminated structure in which CGL is an upper layer and CTL is a lower layer. Next, as the CGM suitable for the present invention, both inorganic pigments and organic pigments can be used as long as they absorb visible light and generate free charges. Amorphous selenium, trigonal selenium, selenium-arsenic alloy, selenium-tellurium alloy, cadmium sulfide,
In addition to inorganic pigments such as cadmium selenide, cadmium selenide sulfide, mercury sulfide, lead oxide, and lead sulfide, organic pigments such as those shown in the following representative examples are used. (1) Azo pigments such as monoazo pigments, polyazo pigments, metal complex azo pigments, pyrazolone azo pigments, stilbene azo and thiazole azo pigments (2) Perylene pigments such as perylenic anhydride and perylenic acid imide (3) Anthraquinone derivatives , anthraquinone or polycyclic quinone pigments such as anthrone derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives, violanthrone derivatives and isoviolanthrone derivatives (4) Indigoid pigments such as indigo derivatives and thioindigo derivatives (5) Metal phthalocyanines and phthalocyanine pigments such as metal-free phthalocyanine (6) Carbonium pigments such as diphenylmethane pigments, triphenylmethane pigments, xanthene pigments and acridine pigments (7) Quinoneimine pigments such as azine pigments, oxazine pigments and thiazine pigments (8) Methine pigments such as cyanine pigments and azomethine pigments (9) Quinoline pigments (10) Nitro pigments (11) Nitroso pigments (12) Benzoquinone and naphthoquinone pigments (13) Naphthalimide pigments (14) Bisbenzimidazole derivatives Perinone pigments such as Azo pigments used in the present invention include:
For example, there are compounds shown in the following exemplified structural compound groups [] to [], and several examples of individual preferable specific compounds in the exemplified structural compound groups are also listed. For a complete list of preferred specific compounds, see Japanese Patent Application No. 195881/1983.

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[Table] Furthermore, the following exemplary structural compound groups [] to [] consisting of polycyclic quinone pigments can be most preferably used as CGM.

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[Table] Next, CTMs that can be used in the present invention are not particularly limited, but include, for example, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolol derivatives, imidazolidine derivatives, imidazolidine derivatives, styryl compounds, hydrazone compounds, pyrazoline derivatives,
Oxazolone derivatives, benzothiazole derivatives,
benzimidazole derivatives, quinazoline derivatives,
Benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N
-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, etc. However, in addition to having an excellent ability to transport holes generated during light irradiation to the support side, those suitable for combination with the above-mentioned CGM are preferably used.
As the CTM, for example, a still compound represented by the following exemplified structural compound group [] or [] is used. Several examples of individual specific compounds in the group of exemplified structural compounds are listed below, and for the complete details, reference is made to Japanese Patent Application No. 195881/1981.

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[Table] In addition, the following exemplified structural compound group as CTM [
] to [ ] can also be used. For the complete details of each specific compound, reference is made to Japanese Patent Application No. 195881/1983.

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[Table] In addition, the following exemplified structural compound group as CTM [
] Amino derivatives represented by the following can also be used.
For details, please refer to Japanese Patent Application No. 195881/1983.

〔Example〕

EXAMPLES The present invention will be explained below with reference to Examples, but the embodiments of the present invention are not limited thereby. Example 1 A conductive support consisting of a polyester film laminated with aluminum foil and an aluminum drum was coated with a layer of vinyl chloride-vinyl acetate-maleic anhydride copolymer (Eslec MF-10, manufactured by Sekisui Chemical Co., Ltd.). An intermediate layer with a thickness of 0.1 μm was formed. Next, CTM (-75)/polycarbonate resin (Panlite L-1250, manufactured by Teijin Chemicals) = 75/100
A 1,2-dichloroethane solution containing 15.5% by weight (weight ratio) was dip-coated onto the intermediate layer and dried to obtain a CTL with a thickness of 15 μm. Next, 4,10-dibromoanthrone (-3)/panlite L- was sublimed as CGM.
1250 = 50/100 (weight ratio) was ground in a ball mill for 24 hours, 1,2-dichloroethane was added to make it 9% by weight, and the mixture was further dispersed in a ball mill for 24 hours.
CTM (-75) to 75 against Panlite L-1250
Weight% and compound (1) of the present invention relative to CTM
Added 10% by weight. Monochlorobenzene was added to this dispersion to adjust the ratio of monochlorobenzene/1,2-dichloroethane to 3/7 (volume ratio), and the thickness was adjusted by spray coating onto CTL.
A photoreceptor 1 of the present invention having a photoreceptor layer having a laminated structure was obtained by forming a CGL of 5 μm. Comparative example (1)′ In place of compound (1) in Example 1, 2,5-
A comparative photoreceptor (1)' was obtained in the same manner as in Example 1 except that dichloro-p-benzoquinone (compound (A)) was added. Comparative Example (1)″ In place of compound (1) in Example 1, 2,6-
Comparative photoreceptor (1)'' was obtained in the same manner as in Example 1, except that dichloro-p-benzoquinone (compound (B)) was added. Comparative Example (1) Compound 1 in CGL was removed. A comparative photoreceptor (1) was obtained in the same manner as in Example 1 except for that.Example 2 Compound (2) was used in place of compound (1) in Example 1.
Photoreceptor 2 was prepared in the same manner as in Example 1 except that
I got it. Example 3 A thermosetting acrylic-melamine-epoxy (1:1:1) resin was placed on a photoreceptor (same as the photoreceptor of Comparative Example 1) obtained by removing compound (1) from the CGL of Example 1.
Spray coating with a coating solution obtained by dissolving 1.55 parts by weight and 0.155 parts by weight of the compound (1) of the present invention in 100 parts by weight of a mixed solvent of monomacrolobenzene/1,1,2-trichloroethane (1/1 volume ratio). , dried to form a 1 μm thick OCL, and photoreceptor 3 of the present invention.
I got it. Example 4 A silicone hard coat primer PH91 was applied onto the photoconductor obtained by removing compound (1) from the CGL of Example 1.
(manufactured by Toshiba Silicon Co., Ltd.) to a thickness of 0.1 μm, and on top of that, silicone hard coat Tossguard 510 (manufactured by Toshiba Silicon Co., Ltd.) and compound (1) are applied to the resin.
A solution added in an amount of 10 parts by weight per 100 parts by weight was spray applied and dried to form a 1 μm OCL, thereby obtaining a photoreceptor 4 of the present invention. Example 5 An intermediate layer exactly the same as in Example 1 was formed on a conductive support consisting of a polyester film laminated with aluminum foil and an aluminum drum. Next, as a coating liquid for CTL, 8% by weight of butyral resin (Eslec BX-1, manufactured by Sekisui Chemical Co., Ltd.),
A solution obtained by dissolving 6% by weight of CTM (-75) in methyl ethyl ketone was applied onto the intermediate layer and dried to form a 10 μm thick CTL. Next, apply 0.2 g of CGM (-7) to a paint conditioner (Paint Conditioner, manufactured by Red Devil).
Grind for 30 minutes, and add polycarbonate resin (Panlite L-1250, mentioned above) to this in a mixed solvent of 1,2-dichloroethane/1,1,2-trichloroethane.
After adding 8.3g of a solution dissolved to a concentration of 0.5% by weight and dispersing for 3 minutes, polycarbonate resin, CTM (-75) and Compound 1 were added to this, respectively.
Solution 19.1 obtained by dissolving in a mixed solvent of 1,2-dichloroethane/1,1,2-trichloroethane to give 3.3% by weight, 2.6% by weight and 0.26% by weight
g was added and the mixture was further dispersed for 30 minutes. The thus obtained dispersion was spray-coated onto the CTL and dried to form an OGL having a thickness of 5 μm, thereby obtaining a photoreceptor 5 according to an embodiment of the present invention having a photoreceptor layer having a laminated structure. Comparative example (2') In place of compound (1) in Example 5, 2,5-
A comparative photoreceptor (2') was obtained in the same manner as in Example 5, except that dichloro-p-benzoquinone (compound (A)) was added. Comparative example (2″) Instead of compound (1) in Example 5, 2,6-
A comparative photoreceptor (2″) was obtained in the same manner as in Example 5, except that dichloro-p-benzoquinone (compound (B)) was added.Comparative Example 2 Compound (1) in CGL was removed. A comparative photoreceptor (2) was obtained in the same manner as in Example 5 except for that.Example 6 Compound (2) was used in place of compound (1) in Example 5.
Photoreceptor 6 of the present invention was obtained in the same manner as in Example 5 except that . Example 7 OCL containing the compound (1) used in Example 3 was provided on a photoreceptor (same as the photoreceptor of Comparative Example 2) obtained by removing compound (1) from the CGL of Example 5, and the present invention A photoreceptor (7) was obtained. Example 8 Compound (1) used in Example 7 is contained on a photoreceptor obtained by removing compound (1) from the CGL of Example 5.
An OCL was provided to obtain a photoreceptor (8) of the present invention. Example 9 An intermediate layer exactly the same as in Example 1 was formed on a polyester film laminated with aluminum foil and an aluminum drum. Next, 40 g of sublimed 4,10-dibromoanthrone (-3) was milled at 40 rpm in a porcelain ball mill.
Grind for 24 hours with Panlite L-1250, (mentioned above)
20 g and 1,300 ml of 1,2-dichloroethane were added and dispersed for an additional 24 hours to obtain a CGL coating solution. This was applied onto the intermediate layer to form a CGL with a film thickness of 1 μm. Next, CTM (-61) 7.5g, Panlite L-
A solution of 125010 g and Compound 1 0.75 g dissolved in 80 ml of 1,2-dichloroethane was applied to the above CGL to form a CTL having a film thickness of 15 μm, thereby producing photoreceptor 9 of the present invention. Comparative example (3') In place of compound (1) in Example 9, 2,5-
A comparative photoreceptor (3') was obtained in the same manner as in Example 9 except that dichloro-p-benzoquinone (compound (A)) was added. Comparative example (3″) Instead of compound (1) in Example 9, 2,6-
A comparative photoreceptor (3″) was obtained in the same manner as in Example 9 except that dichloro-p-benzoquinone (compound (B)) was added.Comparative Example (3) Compound (1) in CTL was A comparative photoreceptor (3) was obtained in the same manner as in Example 9 except for the above.Example 10 On a conductive support consisting of a polyester film laminated with aluminum foil and an aluminum drum, Example 1 and A completely similar intermediate layer was formed. Then, bisazo compound (-7) was used as CGL.
A dispersion of 1.5 g of 1,2-dichloroethane/monoethanolamine (1000/1 volume ratio) mixed solvent (100 ml of 1,2-dichloroethane/monoethanolamine (1000/1 volume ratio) mixed solvent for 8 hours using a ball mill) was coated onto the above intermediate layer, thoroughly dried, and a 0.3 g thick layer was formed. CGL was established. Then styryl compound (−43) as CTM
11.25g, Panlite L-1250 (above) 15g and compound (1) 1.25g in 100ml of 1,2-dichloroethane
The photoreceptor (10) of the present invention is coated with a solution dissolved in the above CGL and dried sufficiently to form a 15 μm thick CTL.
It was created. Comparative example (4') In place of compound (1) in Example 10, 2,5-
A comparative photoreceptor (4') was obtained in the same manner as in Example 10, except that dichloro-p-benzoquinone (compound (A)) was added. Comparative example (4″) Instead of compound (1) in Example 10, 2,6-
A comparative photoreceptor (4″) was obtained in the same manner as in Example 10, except that dichloro-p-benzoquinone (compound (B)) was added. Comparative Example (4) Compound (1) in CTL was Example 10 except that
A comparative photoreceptor (4) was prepared in the same manner as described above. Regarding the UV resistance of the above Example Samples 1 to 10 and Comparative Example Samples (1) to (4), a 20,000-time photographic test for chargeability and a quantitative measurement of sensitivity change due to UV exposure were conducted. In the charging property live-action test, a sample photoreceptor drum was attached to a modified experimental machine U-Bix2812MR (manufactured by Konishiroku Photo Industry Co., Ltd.), and the sample photoreceptor drum was charged positively or negatively, and each process including image exposure of the photoreceptor was carried out. The unit cycle consisting of and fixing is repeated 20,000 times, and the positive and negative charging potentials at the beginning of the live-action test are ±V ₀ , and the positive and negative charges after 20,000 times are
Let the negative charging potential be ±V ₁ . Sensitivity changes due to UV exposure can be determined by irradiating ultraviolet rays of known intensity onto a photoreceptor sheet made from cut sample film, and before and after the irradiation, the potential of the photoreceptor, which has been charged to + or -600V, is adjusted to ±100V, respectively. It was determined using an exposure amount of E ⁶⁰⁰ ₁₀₀ that gives up to . The sensitivity S of the photoreceptor is defined as the relationship E ⁶⁰⁰ ₁₀₀ ∝1/S, and the smaller E ⁶⁰⁰ ₁₀₀ is, the greater the sensitivity S is, and a sharper image can be obtained. If the sensitivities before and after UV exposure are respectively S ₀ and S ₁ , then the reciprocal ratio R _S ; (1/S ₁ )/(1/S ₀ )=S ₀ /S ₁ is
It represents UV resistance, and the larger R _S is, the more UV resistance there is. UV irradiation is done using a mercury lamp for physical and chemical use SHL-100UV-
2 (manufactured by Toshiba Corporation) to 30 cm of the sample photoreceptor sheet.
Placed at a distance that blocks other electromagnetic waves and reduces UV intensity.
Irradiation was performed at 1500 cd/m ² for 100 minutes, and the sensitivity was measured using an electrostatic tester (Kawaguchi Electric Seisakusho; Model SP-428). These results are shown in Table 1.

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[Table] Note: Sample numbers in parentheses are comparative samples. As is clear from Table 1, by adding the compound of the present invention, the potential drop due to corona charging under ultraviolet irradiation is significantly improved. . Furthermore, it can be seen that there is almost no decrease in sensitivity due to the addition of the compound of the present invention.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views of the photoreceptor of the present invention. 1... Support, 2... Charge generation layer (CGL), 3
...Charge transport layer (CTL), 4...Photosensitive layer, 5...
Charge generating material (CGM), 6... Charge transporting material (CTM), 7... Intermediate layer, 8... Protective layer (OCL).

Claims (1)

[Scope of Claims] 1. In an electrophotographic photoreceptor having at least a layer containing a charge-generating substance and a layer containing a charge-transporting substance on a conductive support, a compound represented by the following general formula: An electrophotographic photoreceptor characterized by containing. general formula [In the formula, R represents hydrogen or a halogen atom,
R ₁ represents an amino, alkyl, arylamino, alkoxy, phenyloxy, nitro group or a halogen atom, and the alkyl group may have a substituent. R ₂ represents each group of amino, alkyl, arylamino, alkoxy and phenyloxy. ]