JPH01276147A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve electrophotographic characteristics and mechanical durability and to obtain a stable image having high quality by incorporating lubricant powder, a charge transfer material having a specific oxidation potential and specific compd. into the surface layer of the photosensitive body. CONSTITUTION:The lubricant powder, for example, tetrafluoroethylene resin powder, the charge transfer material having >=0.6V oxidation potential and the compd. expressed by formula I (X1, X2, X3 denote -H or -CH3; X4, X5 denote C(CH3)2CH2CH3) are incorporated into the surface layer of the photosensitive body having a photosensitive layer on a conductive base body. The slipperiness and wear resistance of the surface layer are improved by the addition of the lubricant powder and the durability to corona products is improved by the use of the charge transfer material having the high oxidation potential, by which the photographic characteristics are stabilized. A pause memory is prevented by the compd. expressed by formula I. The physical characteristics and mechanical durability of the electrophotograph are thereby improved and the high-quality image is obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a highly durable product that can be widely used in electrophotographic application fields such as electrophotographic copying machines, laser beam printers, CRT printers, and electrophotographic engraving systems. The present invention relates to an electrophotographic photoreceptor.

[Conventional technology]

In recent years, various organic photoconductive materials have been developed as photoconductive materials for electrophotographic photoconductors, and in particular, functionally separated photoconductors with a layered charge generation layer and charge transport layer have already been put into practical use and installed in copying machines and printers. There is. However, one major drawback of these photoreceptors has been that they generally have low durability.

Durability is broadly divided into durability of electrophotographic physical properties such as sensitivity, residual potential, charging ability, and image blur, and mechanical durability such as abrasion and scratches on the surface of the photoconductor due to rubbing. is a major factor in determining the lifespan of

Among these, the durability of electrophotographic physical properties, especially image blur, is caused by the deterioration of charge transport substances contained in the surface layer of the photoreceptor due to active substances such as ozone and No generated from the corona charger. It has been known. It is also known that mechanical durability is caused by physical contact and rubbing of paper, cleaning members such as blades/rollers, toner, etc. against the photosensitive layer.

In order to increase the durability of electrophotographic physical properties, it is important to use a charge transport material that is resistant to deterioration by active substances such as ozone and No. It is well known that a charge transport material with a high oxidation potential is selected. It is being In addition, in order to improve mechanical durability, it is necessary to increase the lubricity of the surface and reduce friction (to withstand rubbing by paper and cleaning materials), and to prevent toner filming and fusing, etc. It is important to improve the mold releasability of
-25746 publication, JP-A-56-25749 publication,
As described in JP-A No. 61-123850, it is known to incorporate lubricants such as fluororesin powder, fluorinated graphite, and polyolefin resin powder into the surface layer.

Furthermore, according to Japanese Unexamined Patent Publication No. 63-30850, it is proposed to combine the above measures, and thereby,
It has become clear that the durability is improved and the life of the photoreceptor is greatly extended.

[Problem that the invention seeks to solve]

However, as the life of the photoreceptor has been greatly extended, it has been found that a new problem, the photoreceptor pause memory phenomenon, is likely to occur.

The dormant memory phenomenon is basically a deterioration phenomenon caused by corona products, but after copying is completed, the rotation of the photoreceptor stops and the charging ability of the part that stops directly under the corona charger decreases. In the case of normal development, the image density decreases in that area and white spots appear on the image, whereas in the case of reverse development, the image density increases and black streaks appear on the image. This phenomenon tends to occur after the photoreceptor is used for a long period of time (and becomes more noticeable as the life of the photoreceptor is extended by the above measures.

By improving the intake/exhaust mechanism of the image forming apparatus main body and the shape of the charger, some improvement can be seen in this phenomenon, but it is not perfect, especially in small copying devices and copying devices with cartridge-type photoreceptors. The current situation is that this is a problem.

That is, an object of the present invention is to provide a photoreceptor that has the above-mentioned electrophotographic physical durability and mechanical durability and does not cause the pause memory phenomenon when used in an actual image forming apparatus.

Another object of the present invention is to provide a photoreceptor that can always produce stable, high-quality images with little potential fluctuation.

[Means for solving problems]

As a result of extensive studies in accordance with the above objective, the present inventors have developed a surface layer containing a lubricant powder, a charge transport substance having an oxidation potential of 0.6 V or more, and a compound represented by the general formula (I). It has been found that the photoreceptor having the above-mentioned photoreceptor has performance that meets the above-mentioned requirements.

That is, the present invention provides an electrophotographic photoreceptor having a photosensitive layer on a conductive support, in which the surface layer comprises a lubricant powder, a charge transporting substance having an oxidation potential of 0.6 V or more, and general formula (1). However, X, , X2 and X3 are -H or -〇H
3CH3ζ-C-CH2C1 (indicates 3) This is an electrophotographic photoreceptor characterized by containing a compound represented by CH3.

In the present invention, by adding lubricant powder, the mechanical properties such as the slipperiness and abrasion resistance of the surface layer and the releasability against deposits are improved. By using a potential charge transport material, it improves resistance to corona products, prevents negative effects associated with charge transport material deterioration such as decreased sensitivity, increased residual potential, and image blurring, and stabilizes electrophotographic properties. It measures the Furthermore, in the present invention, the compound of the general formula (I) is used to prevent the photoreceptor stop memory phenomenon that newly occurs due to the extension of the photoreceptor life by these means.

Examples of the lubricant powder used in the present invention include tetrafluoroethylene resin, trifluorochloride ethylene resin, hexafluoroethylene propylene resin, niphthodichloride ethylene resin, vinylidene fluoride resin, and copolymers thereof. Examples include fluorine-based resin powder, polyolefin-based resin powder such as polyethylene, polypropylene, polyhexene, and their copolymers, and even fluorinated graphite powder, and two or more types may be combined. Among these, tetrafluoroethylene resin and vinylidene fluoride resin are preferred from the viewpoint of slipperiness, abrasion resistance, and mold releasability.

As the charge transport substance having an oxidation potential of 0.6 V or more used in the present invention, hydrazone compounds, stilbene compounds,
It is selected from carbazole compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, triarylmethane compounds, polyarylalkanes, and the like. Further, two or more types of charge transport materials may be used in combination.

The higher the oxidation potential, the better the durability performance, and especially when the oxidation potential is 0.7V or more, the effect becomes more remarkable.

Examples of the compound represented by the general formula (1) used in the present invention include the following.

These compounds are one of the phenol derivatives known as radical scavengers or antioxidants for plastics, rubber, etc. Two or more of these compounds may be used in combination.

In the present invention, the surface layer is a charge transport layer when the photosensitive layer has a structure in which a charge generation layer and a charge transport layer are laminated in this order on a conductive support; In the case of a structure in which a charge generation layer is laminated, it is the charge generation layer containing a charge transport substance, and in the case of a single layer structure in which a charge generation substance and a charge transport substance are mixed in the same layer, it is this single layer. .

Charge transport materials generally have a low molecular weight and cannot be used to form a film by themselves, so a resin having film-forming properties is used as a binder to form a photosensitive layer in which lubricant powder is dispersed. The binder resin may be any polymeric compound that has film-forming properties, but polymethacrylic acid ester, polycarbonate, polyarylate, polyester, and polysulfone are recommended because they have a certain degree of hardness even when used alone and do not interfere with carrier transport. etc. are preferable. The content of the lubricant powder is suitably 1 to 30% by weight, particularly preferably 2 to 20% by weight, based on the material constituting the surface layer of the photosensitive layer.

If the content is less than 1% by weight, the surface modification effect due to dispersion of the lubricant powder will not be sufficient, while if it exceeds 30% by weight, the light transmittance will decrease and carrier mobility will also decrease.

The amount of the compound represented by the general formula (I) added is 0.1% by weight based on 100 parts by weight of the material constituting the surface layer of the photosensitive layer.
~30% by weight is appropriate, particularly 0.2% by weight ~10% by weight.
Weight percent is preferred. If the amount added is less than 0.1% by weight, the effect of preventing sleep memory will not be sufficient, and if it exceeds 30% by weight, the residual potential will tend to increase.

When producing the electrophotographic photoreceptor of the present invention, the conductive support may be one that itself has conductivity, such as aluminum, aluminum alloy, stainless steel, etc. In addition, aluminum, aluminum alloy, stainless steel, etc. can be used.
Plastics having a layer formed by vacuum deposition of indium oxide, tin oxide, indium oxide-tin oxide alloy, etc., supports in which conductive particles are coated on plastics or the above-mentioned conductive supports together with a suitable binder, conductive Supports made of plastic or paper impregnated with conductive particles, plastics containing conductive polymers, etc. can be used.

A subbing layer having barrier and adhesive functions can also be provided between the conductive support and the photosensitive layer. The subbing layer is casein, polyvinyl alcohol, nitrocellulose, and ethylene-acrylic acid copolymer.

Polyvinyl butyral, phenolic resin, polyamide (
It can be formed from nylon 6, nylon 66, nylon 610° copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin, aluminum oxide, etc.

The thickness of the subbing layer is 0.1 to 40 μm, preferably 0.3 to 40 μm.
3 μm is appropriate.

As a charge generating substance, selenium-tellurium, pyrylium, thiopyrylium dyes, phthalocyanine pigments, anthoanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, azo pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanine ,
Quinocyanine and the like can be used, and it is also possible to use a mixture of various charge generating substances in order to obtain an appropriate spectral sensitivity.

As a method for dispersing the lubricant powder, general dispersion means such as a homogenizer, an ultrasonic wave, a ball mill, a vibration mill, a sand mill, an attritor, and a roll mill can be used. The lubricant powder is added to the binder dissolved in a suitable solvent, and then dispersed by the above-mentioned dispersion method. A surface layer coating liquid containing a lubricant can be obtained by mixing an appropriate amount of this with a solution in which a binder, a charge transport substance, and a compound represented by the general formula (D) are dissolved in a solvent.

Coating can be performed using a coating method such as a dip coating method, a spray coating method, a Meyer bar coating method, or a blade coating method. For drying, it is preferable to dry to the touch at room temperature and then heat dry. Heat drying can be performed at 30° C. to 300° C. for a period of 5 minutes to 2 hours, either stationary or with ventilation.

The oxidation potential in the present invention is determined by using a saturated calomel electrode as a reference electrode and a 0.0. Using an IN (n-Bu)4N+Cl0-4 acetonitrile solution as an electrolyte, the potential of the working electrode was swept with a potential sweeper, and the peak position of the obtained current-potential curve was directly determined as the value of the oxidation potential.

In detail, the sample is 0.1N (n-Bu) N” (
5-10 m in the electrolyte of J'σ4 acetonitrile solution.
Dissolve to a concentration of mo1%. Then, a voltage is applied to this sample solution, and a current change is measured when the voltage is changed linearly from a low potential to obtain a current-potential curve. The potential value corresponding to the first inflection point of the current value in this current-potential curve was defined as the oxidation potential in the present invention.

Example 1 An 80 φ x 360 mm aluminum cylinder was used as a conductive support, and a 5% methanol solution of polyamide resin (trade name: Amilan CM-8000, manufactured by Toshi) was coated on it by dipping method, and a 1 μm thick layer was coated on the conductive support. Created a pull layer.

Next, 10 parts (parts by weight, the same applies hereinafter) of a disazo pigment with the following structural formula, 6 parts of polyvinyl butyral resin (trade name: Eslec BXL, manufactured by Tanesui Kagaku ■), and 100 parts of cyclohexanone were mixed in a sand mill using lφ glass beads. The mixture was dispersed for 20 hours. Add 5% of tetrahydrofuran to this dispersion.
Add 0 to 100 parts (appropriately) and apply on the undercoat layer, 1
A charge generation layer having a thickness of 0.15 μm was formed by drying at 00° C. for 5 minutes.

Next, as polyolefin-based lubricant powder, polyethylene resin powder (trade name Frozen 13142 manufactured by Seitetsu Kagaku),
As a charge transport substance, the oxidation potential of the following structural formula is 0.67 (
A compound of V), a compound having the following structural formula (IRGANOX1330: manufactured by Ciba Geigy, Japan), and a bisphenol Z type polycarbonate resin (manufactured by Banjin Kasei) as a fixing agent binder were prepared. First, 20 parts of the polycarbonate resin, 20 parts of the above charge transporting substance, and 0.2 parts of the above-mentioned dormant memory countermeasure compound were dissolved in 100 parts of monochlorobenzene, 6 parts of the above polyethylene resin powder was added thereto, and the mixture was heated in a stainless steel ball mill. The mixture was dispersed for 50 hours, and 20 parts of dichloroethane was further added to prepare a charge transport layer coating solution. Applying this liquid on the generation layer,
A charge transport layer having a thickness of 20 μm was formed by drying with hot air at 100° C. for 90 minutes, thereby producing photoreceptor 1.

Comparative Example 1 Photoreceptor 2 was produced in the same manner as in Example 1, except that a compound having the following structural formula and an oxidation potential of 0.54 (V) was used as the charge transport material.

Comparative Example 2 Photoreceptor 3 was produced in the same manner as in Example 1 except that polyethylene resin powder was not added as the lubricant powder.

Comparative Example 3 Photoreceptor 4 was produced in the same manner as in Example 1, except that no compound for counteracting sleep memory was added.

For the above photoconductor, the blade penetration fil, Omm,
Table 1 shows the results of a 100,000-sheet durability evaluation conducted on a Canon copier NP-3525 modified to have a cleaning roller relative speed of 106%.

Table 1 In Table 1, potential fluctuation refers to the dark potential (VD
) is -650V, and the bright area potential (VL) is -150V.

The residual potential (VR) at that time was set to -10V, and 10
The figure shows the change in absolute value after running for 10,000 sheets.

In addition, the pause memory is expressed by the change in image density between the area immediately below the corona charger and other areas, or the change in potential (VO) 10 hours after the rotation of the photoreceptor is stopped after 10,000 sheets have been used. .

From Table 1, the photoreceptor of Example 1 exhibits high practical durability, with small potential fluctuations and small abrasion of the surface layer even after being used for 10,000 sheets, and no pause memory occurred. On the other hand, comparative example 1
The one using a charge transport material with a low oxidation potential has a large potential fluctuation, and the one of Comparative Example 2 without a lubricant has very large abrasion of the surface layer, and the potential fluctuation occurs accordingly.

In addition, scratches have also occurred on the surface of the photoreceptor, which are also visible on the image. Furthermore, in the photoconductor of Comparative Example 3 to which no compound for preventing pause memory was added, potential fluctuations,
Although it is excellent in terms of scratching as in Example 1, a pause memory of as much as 90V is generated, which is clearly visible in the image.

Example 2 An 80φ x 360mm aluminum cylinder was used as a conductive support, and polyamide resin (trade name:
A 5% methanol solution of Ami 920M-8000 (manufactured by Toshi) was applied by dipping to form a 0.5 μm thick undercoat layer.

Next, 10 parts of a trisazo pigment having the following structural formula, 6 parts of polyvinyl butyral resin (trade name: Eslec BL-5, manufactured by Sekisui Chemical Co., Ltd.), and 50 parts of cyclohexanone were dispersed in a sand mill apparatus using glass beads. Add 100 parts of methyl ethyl ketone to this dispersion and apply it on the undercoat layer.
A charge generation layer having a thickness of 0.2 μm was formed.

Next, a tetrafluoroethylene resin powder (trade name: Nilburon L-2 manufactured by Daikin Industries, Ltd.) was used as a fluororesin powder, and a compound of the following structural formula (oxidation potential: 0.81) was used as a charge transport material.
(V)), the compounds shown in Table 2 as compounds for counteracting dormant memory, and bisphenol Z-type polycarbonate resin (manufactured by Kijin Kasei Co., Ltd.) as a fixing agent binder were prepared.

Hereinafter, a photoreceptor was manufactured using the compounds listed in Table 2 in the same manner as in Example 1 using 20 parts of a charge transport material and 20 parts of a fixing agent binder. The amount of the fluororesin powder added is 2 parts, and the amount of the compound for preventing sleep memory is 0.
2 parts, but for compound NO,1, it is 0.05 parts (equivalent to 0.125% by weight based on 100 parts by weight of the surface layer constituent material), 0.1 part (equivalent to 0.25% by weight), 0.
There are five levels: 5 parts (equivalent to 1.25% by weight), 1.0 parts (equivalent to 2.5% by weight), and 4.0 parts (equivalent to 100% by weight).

Table 3 shows the results of evaluating the above photoreceptors. For the evaluation, we used an image scan reversal development type laser beam printer equipped with a semiconductor laser with an oscillation wavelength of 780 nm, a cleaning blade with a penetration depth of 1.0 mm, and a two-component developer consisting of toner and carrier. . In the table above, the potential fluctuation is defined as the change in absolute value after the dark area potential is set to -600V, the bright area potential is -150V, and the residual potential is -110V at the initial stage of durability. This is what is shown. Regarding the pause memory, the measurement method is the same as in Example 1, but since reversal development is used, the change in image density appears in the direction of increasing density, contrary to Example 1.

As can be seen from Table 3, the system to which the compound having the structure described in the present invention is added is clearly more effective in preventing pause memory than additives having other structures, and has less negative effects such as potential fluctuations.

Example 3 An aluminum cylinder of 80 φ x 360 mm was used as a conductive support, and polyamide resin (trade name:
A 5% methanol solution of Amiran CM-8000 (manufactured by Toshi) was applied by dipping to provide a 1 μm thick undercoat layer. Next, add 10 parts of a disazo pigment having the following structural formula to 6 parts of polyvinyl butyral resin (trade name: Eslec BL-3. manufactured by Sekisui Chemical).
1 part and 50 parts of cyclohexanone were dispersed using a sand mill apparatus using glass beads. Add 100 parts of methyl ethyl ketone to this dispersion and apply it on the undercoat layer to 0.2μ
A charge generation layer having a thickness of m was formed.

Next, fluorinated graphite (manufactured by Daikin Industries) was used as a fluorinated carbon-based powder, and Example 1 was used as a compound for countermeasures against dormant memory.
The same compound as above, the compound shown in Table 4 as a charge transport substance, and a bisphenol Z type polycarbonate resin (manufactured by Kijin Kasei) as a fixing agent binder were prepared.

Table 4 (continued from Table 4) Photoreceptors were manufactured using the charge transport materials listed in Table 4 in the same manner as in Example 1 using 20 parts of the charge transport material and 20 parts of the binder. The amount of fluorinated graphite powder added is 2
%, and the amount of the compound for resting memory is 0.2
Department.

The above photoreceptors were evaluated in the same manner as in Example 1, and the results are shown in Table 5.

As is clear from Table 5, the oxidation potential of the charge transport substance is 0.6.
It can be seen that although those with a lower oxidation potential of 0.6 (V) are superior in terms of rest memory, the potential fluctuations are larger than those using oxidation potentials higher than 0.6 (V).

Example 4 An 80 φ x 360 mm aluminum cylinder was used as a conductive support, and a 5% methanol solution of polyamide resin (trade name: Amilan CM-8000 manufactured by Toshi) was applied by dipping to the conductive support, and a 1 μm thick undercoating was applied. Layers were provided. Next, 10 parts of a disazo pigment having the following structural formula, 6 parts of polyvinyl butyral resin (trade name: Eslec BXL, manufactured by Sekisui Chemical Co., Ltd.) and 100 parts of cyclohexanone were dispersed for 20 hours in a sand mill apparatus using glass beads.

50 to 100 parts of tetrahydrofuran was added to this dispersion, which was coated on the undercoat layer, and dried at 100°C for 5 minutes to form a charge generation layer with a thickness of 0.15 μm.

Next, a tetrafluoroethylene resin powder (trade name: Lublon L-2 manufactured by Daikin Industries) was used as a fluororesin powder, and a compound of the following structural formula (oxidation potential 0.66) was used as a charge transport material.
(V)), the same compound as in Example 1 was prepared as a compound for dealing with dormant memory, and a bisphenol Z type polycarbonate resin (manufactured by Kijin Kasei Co., Ltd.) was prepared as a fixing agent binder. Hereinafter, in the same manner as in Example 1 using 20 parts of a charge transport substance and 20 parts of a binder, the amount of tetrafluoroethylene resin powder added was adjusted to 1% by weight relative to the surface layer constituent material (charge transport substance + binder). .0% by weight, 10.0% by weight.

Photoreceptors were manufactured with three levels of 30% by weight.

The above photoreceptors were evaluated in the same manner as in Example 1, and the results are shown in Table 6.

Table 6 Example 5 In the same manner as in Example 4, layers up to the undercoat layer were coated on the conductive support. Next, 15 parts of the charge transport material used in Example 1,
A solution prepared by dissolving 10 parts of polycarbonate Z resin in 50 parts of dichloromethane and 10 parts of monochlorobenzene was applied onto the undercoat layer to form a charge transport layer with a thickness of 15 μm. Next, 4 parts of the disazo pigment used in Example 1, 10 parts of polycarbonate Z resin, and 50 parts of cyclohexanone were added to 1φ
Dispersion was carried out for 20 hours using a sand mill device using glass beads to form charge generation layer dispersion 1.

Next, a tetrafluoroethylene resin powder, a fluorine-based acrylic oligomer as a dispersant, the above-mentioned hydrazone compound, and polycarbonate Z resin were prepared. First, 10 parts of polycarbonate resin and 4 parts of hydrazone compound.

0.15 parts of fluorine-based acrylic oligomer is dissolved in 10 parts of dichloromethane and 40 parts of monochlorobenzene.

Next, 1.5 parts of tetrafluoroethylene resin powder was added to this and dispersed in a stainless steel ball mill for 40 hours.

Further, 0.3 part of the additive used in Example 1 was added to this liquid to prepare charge transport layer liquid 1. This charge generation layer dispersion 1
A coating material prepared by mixing the sample and Charge Transport Layer Liquid 1 was applied onto the charge transport layer to form a charge generation layer having a thickness of 5 μm, thereby producing a photoreceptor.

The copying machine used in Example 1 was modified so that it could be positively charged, and this photoconductor was evaluated in the same manner as in Example 1, but even after 100,000 copies, potential fluctuations, photoconductor scraping, and pause memory were small and high. A quality copy was obtained.

Comparative Example 4 As a comparative example of Example 5, a photoreceptor without additives was manufactured and the same evaluation was performed. After 10,000 sheets, a pause memory appeared on the image, and electrically, △Vd was -160V. Thick (varied.

Example 6 An aluminum cylinder of 80φ×36Qmm was prepared as a conductive support.

On the other hand, 100 parts of conductive powder coated with tin oxide containing 10% antimony oxide so as to be 75% by weight relative to titanium oxide was mixed with 100 parts of resol type phenolic resin, 30 parts of methanol, and 100 parts of methyl cellosolve. It was added to the solution and dispersed well using a ball mill to form a paint. This coating material was dip-coated onto a conductive support and cured by heating at 140° C. for 30 minutes to form a conductive undercoat layer of 20 μm.

On top of this, 1 part of polyamide resin (6-66-610 to 124 element nylon copolymer) and 3 parts of 8-nylon resin (methoxymethylated 6 nylon methoxylation rate 30%) were added to 50 parts of methanol and 40 parts of phthanol. A coating solution dissolved in a solvent was applied by dipping, and after drying at 70° C. for 10 minutes, a 0.5 μm thick undercoat layer was formed.

Next, 10 parts of a disazo pigment having the following structural formula, 6 parts of polyvinylbenzal resin, and 50 parts of cyclohexanone were dispersed for 20 hours in a sand mill apparatus using glass beads (Dispersion 1).

Next, 10 parts of trisazo pigment having the following structural formula, 6 parts of polyvinylbenzal resin, and 50 parts of cyclohexanone were dispersed for 20 hours in a sand mill using glass beads (
Dispersion 2).

30 parts of this dispersion 1 and 10 parts of dispersion 2 were mixed, further 50 to 60 parts of tetrahydrofuran were added, and the mixture was coated on the undercoat layer and dried at 100°C for 5 minutes to form a charge generation layer with a thickness of 0.25 μm. was formed.

Next, tetrafluoroethylene resin powder was used as the fluororesin powder, and a fluorine-based acrylic oligomer was used as the dispersion aid.A compound of the following structural formula (oxidation potential: 0.8
1V), the same compound as in Example 1 was prepared as a compound for preventing sleep memory, and bisphenol Z type polycarbonate resin was prepared as a fixing agent binder. A photoreceptor was manufactured in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 7.

Table 7 Similar to Example 1, this photoconductor shows potential fluctuation 1 even after 100,000 sheets
There is little abrasion of the surface layer, no pause memory occurs, and it shows high durability in practical use.

〔Effect of the invention〕

As described above, according to the electrophotographic photoreceptor of the present invention containing a lubricant powder, a charge transport substance having an oxidation potential of 0.6 V or more, and a compound having a specific structure, the electrophotographic photoreceptor has electrophotographic physical properties and mechanical properties. It has excellent durability and allows you to always obtain stable, high-quality images.

Claims (5)

[Claims] (1) In an electrophotographic photoreceptor having a photosensitive layer on a conductive support, the surface layer includes a lubricant powder, a charge transport substance with an oxidation potential of 0.6 V or more, and a general formula (I) ▲Mathematical formula, chemical formula , tables, etc.▼ ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼ [However, X_1, X_2 and X_3 indicate -H or -CH_3, and X_4 and X_5 are ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ show. ] An electrophotographic photoreceptor comprising a compound represented by the following. (2) The electrophotography according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer, and the charge transport layer is coated on the charge generation layer. Photoreceptor. (3) Electrophotography according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer, and the charge generation layer is coated on the charge transport layer. Photoreceptor. (4) The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer is a single layer containing a charge-generating substance and a charge-transporting substance. (5) The electrophotographic photoreceptor according to claim 1, wherein the lubricant powder is a fluororesin powder, a polyolefin powder, or a fluorocarbon powder.