JP2003167368A - Electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent electrophotographic photoreceptor giving a stable image of high image quality even after repeated use and not causing a curling-up of a cleaning blade. <P>SOLUTION: In the electrophotographic photoreceptor having a photosensitive layer on an electrically conductive support, is characterized in that a layer forming the surface of the electrophotographic photoreceptor has the barium salt of a long-chain carboxylic acid. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member (hereinafter, also simply referred to as a photosensitive member), and more specifically, it reduces abrasion of the photosensitive member surface and toner adhesion to the photosensitive member surface, and prevents the cleaning blade from turning over. The present invention relates to an excellent photoconductor.

[0002]

2. Description of the Related Art In recent years, the frequency of use of copying machines and printers utilizing electrophotography has increased more and more with the development of electronic equipment. However, repeated use causes problems such as deterioration of image quality and curling of a cleaning blade. is doing.

These problems occur due to wear of the surface of the photoconductor, adhesion of toner to the surface of the photoconductor, deterioration of slipperiness between the surface of the photoconductor and the cleaning blade, and the like.

In order to prevent such wear of the surface of the photoconductor, maintain the cleaning property of the toner, and maintain a certain slip property between the surface of the photoconductor and the cleaning blade,
A method of adding a metal soap to a layer forming the surface of the photoconductor has been attempted for the purpose of lowering the surface energy of the surface of the photoconductor (JP-A-62-279342, Japanese Patent Publication No. 8-3).
639 gazette, Unexamined-Japanese-Patent No. 2000-89495). A representative metal soap is long-chain zinc carboxylate, which is also described in the examples of the aforementioned patents.

However, the photoreceptor using zinc stearate typified by the long-chain zinc carboxylate has good slipperiness and does not cause a problem in the initial stage of use, but the good slipperiness gradually disappears as the use is continued. The above problem may occur.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above problems, and its object is to:
An object of the present invention is to provide an excellent photoreceptor in which a high-quality and stable image can be obtained even when it is repeatedly used, and the cleaning blade does not turn over.

[0007]

The object of the present invention can be achieved by adopting one of the following configurations.

1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the layer forming the surface of the electrophotographic photoreceptor has barium long-chain carboxylate.

2. The long-chain barium carboxylate is a compound represented by the following general formula: 1
The electrophotographic photosensitive member according to the item.

General formula (RCOO) ₂ Ba (In the formula, R represents an alkyl group, an alkenyl group or an aryl group having 10 or more carbon atoms.) 3. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the layer forming the surface of the electrophotographic photoreceptor comprises barium long-chain carboxylate and a polycarbonate resin.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

As a result of earnest efforts to solve the above problems, the inventor has found that the above problems can be greatly improved by adding barium long-chain carboxylate to the layer forming the surface of the photoreceptor.

Long-chain barium carboxylate has a high melting point. For example, barium stearate has a melting point around 275 ° C.,
It is in a solid state at the drying temperature (about 110 ° C.) at the time of producing the photoconductor, and uniformly exists in the entire layer forming the surface of the photoconductor without bleeding out on the surface of the layer. Therefore, it has been found that the slipperiness can be maintained for a long time even if the surface of the layer is depleted by a cleaning blade or a developer.

On the other hand, long-chain zinc carboxylate has a low melting point,
For example, the melting point of zinc stearate is around 120 ° C., and the drying temperature (about 110 ° C.) when manufacturing the photoreceptor
However, zinc stearate tends to bleed out to the surface of the layer forming the surface of the photoreceptor when heated and dried at the drying temperature. For this reason, the slipperiness of the surface of the photoreceptor is excellent in the initial stage of use, but when the layer containing zinc stearate which is worn down by the cleaning blade or the developer disappears, good slipperiness cannot be maintained, and the above-mentioned problems occur. I presume.

The long-chain barium carboxylate according to the present invention is
The barium carboxylate is characterized by being an alkyl group, an alkenyl group, or an aryl group having 10 or more carbon atoms.

Specific compounds include stearic acid
Rium (C₁₈H₃₅O₂)₂Ba, barium palmitate
(C₁₆H₃₁O₂)₂Ba, barium myristate (C₁₄H
₂₇O₂)₂Ba, barium oleate (C₁₈H₃₃O₂)₂B
a, barium laurate (C_{1 2}H_{twenty three}O₂)₂Ba, Behen
Barium acid (C_{twenty two}H₄₃O₂)₂Ba, ricinoleic acid Baliu
Mu (C₁₇H₃₂(OH) COO)₂Ba, naphthoic acid burr
Umm (C_TenH₇COO) ₂Ba etc. can be mentioned
However, it is not limited thereto. Among these
Is barium stearate or barium palmitate
Is preferred.

As the long-chain barium carboxylate, a commercially available product prepared by a known method can be used.

Barium carboxylate having an alkyl group, an alkenyl group or an aryl group having less than 10 carbon atoms is
It is not preferable because it easily bleeds out on the surface of the layer.

The long-chain barium carboxylate according to the present invention is
Since it is intended to reduce the wear of the surface of the photoconductor, reduce the adhesion of toner to the surface of the photoconductor, and improve the slipperiness between the surface of the photoconductor and the cleaning blade, the layer forming the surface of the photoconductor is It is characterized by being added.

The layer forming the surface of the photoconductor is a charge transport layer in a normal negative charge function separation type photoconductor, and a charge generation layer in a positive charge function separation type photoconductor. It is also possible to further provide a protective layer on the charge transport layer or the charge generating layer in order to further extend the durability. In this case, the protective layer serves as a layer forming the surface of the photoreceptor. As the layer forming the surface of the photoconductor, a protective layer is preferable because high durability is easily obtained.

Next, the layers forming the surface of the photoreceptor will be described in detail. FIG. 1 is a sectional view showing an example of the layer structure of the photoconductor of the present invention.

In FIG. 1, 50 is a photoreceptor, 1 is a conductive support, 2 is an intermediate layer, 3 is a charge generation layer, 4 is a charge transport layer, 5
Represents a protective layer, 6 represents a binder resin, and 7 represents barium long-chain carboxylate.

FIG. 1A shows a photoconductor in which the layer forming the surface of the photoconductor comprises a charge transport layer having a long-chain barium carboxylate, a binder resin and a charge transport substance.

FIG. 1B shows a photoconductor in which the layer forming the surface of the photoconductor comprises a charge generating layer having a long-chain barium carboxylate, a binder resin and a charge generating substance.

FIG. 1C shows a photoconductor in which the layer forming the surface of the photoconductor comprises a protective layer containing long-chain barium carboxylate and a binder resin.

The charge-transporting layer forming the surface of the photoreceptor is prepared by dispersing or dissolving long-chain barium carboxylate, a binder resin and a charge-transporting substance in a coating solvent to prepare a coating solution, and forming the coating solution on the charge-generating layer. It is preferably formed by coating.

The binder resin used in the charge transport layer is mechanically strong and has good compatibility with the charge transport material, for example, polycarbonate resin, polyester resin, polystyrene resin, methacrylic resin, acrylic resin, polyvinyl chloride. Resin, polyvinylidene chloride resin, polyvinyl butyral resin, polyvinyl acetate resin,
Styrene-butadiene resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-maleic anhydride copolymer resin, urethane resin, silicone resin, epoxy resin, silicone-alkyd resin, phenol resin, polysilane resin, polyvinylcarbazole, etc. Of these, polycarbonate is preferred.

The polycarbonate resin is a binder resin represented by the following general formula (P).

[0029]

[Chemical 1]

In the formula, n represents an integer of 1 or more. In the above general formula (P), Ar represents an organic group, and not only bisphenol A condensate (P1) and Z condensate (P2) but also biphenyl condensate (for example, P3 in the case of a partial structural unit), polysiloxane Block copolymerized (eg P
4) and grafted ones (for example, P5), and copolymers thereof and those having a substituent such as a fluorinated alkyl group. In addition, m represents an integer of 1 or more. These are disclosed in, for example, JP-A-6-220181, JP-A-7-76619, JP-A-8-225639, JP-A-9-216944, and JP-A-11-17.
2003, JP-A-2000-171989, JP-A-2001-56606, and the like.

The coating solvent for preparing the coating liquid for the charge transport layer is not particularly limited as long as it dissolves the binder resin and the charge transport substance and disperses or dissolves the barium long-chain carboxylate. Specifically, N, N-dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2- Trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, tetrahydrofuran, dioxolane, dioxane,
Methanol, ethanol, butanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide,
Methyl cellosolve and the like can be mentioned, and among these, dichloromethane, 1,2-dichloroethane, methyl ethyl ketone and the like are preferably used. Further, these solvents can be used alone or as a mixed solvent of two or more kinds.

As the charge-transporting substance, known substances can be used, for example, triphenylamine derivative, oxazole derivative, oxadiazole derivative, thiazole derivative, thiadiazole derivative, triazole derivative, imidazole derivative, imidazoline derivative, bisimidazoline. Derivatives, styryl compounds, hydrazone compounds, benzidine compounds, pyrazoline derivatives, stilbene compounds, amine 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-vinyl anthracene and the like can be mentioned. The following compounds can be mentioned as typical ones.

[0033]

[Chemical 2]

[0034]

[Chemical 3]

[0035]

[Chemical 4]

[0036]

[Chemical 5]

[0037]

[Chemical 6]

[0038]

[Chemical 7]

The charge generating layer forming the surface of the photosensitive member is prepared by dispersing or dissolving long-chain barium carboxylate, a binder resin and a charge generating substance in a coating solvent to prepare a coating solution, and forming the coating solution on the charge transporting layer. It is preferably formed by coating.

As the binder resin used in the charge generation layer, the same binder resin as in the charge transport layer can be used.

The coating solvent for preparing the coating liquid for the charge generation layer is not particularly limited as long as it dissolves the binder resin and disperses or dissolves the charge generation substance and barium long-chain carboxylate. Specifically, the same material as the charge transport layer can be used.

As the charge generating substance, known substances can be used, for example, phthalocyanine pigment, polycyclic quinone pigment, azo pigment, perylene pigment, indigo pigment, quinacridone pigment, azurenium pigment, squarylium dye, cyanine dye, pyrylium. Examples thereof include dyes, thiopyrylium dyes, xanthene dyes, triphenylmethane dyes and styryl dyes.

The protective layer forming the surface of the photosensitive member comprises barium long-chain carboxylate and a binder resin dispersed in a coating solvent,
Alternatively, it is preferably formed by dissolving and preparing a coating solution, and coating the coating solution on the charge transport layer or the charge generating layer.
The charge transport compound may be added to the protective layer for the purpose of ensuring potential characteristics.

As the binder resin used in the protective layer, for example, a commonly known organic polymer such as polycarbonate or polyester, or an inorganic polymer containing a siloxane bond can be used, and among these, the polycarbonate resin is preferable.

The polycarbonate resin is a binder resin represented by the general formula (P).

The coating solvent for preparing the coating liquid for the protective layer is not particularly limited as long as it dissolves the binder resin and disperses or dissolves the barium long-chain carboxylate. Specifically, methanol is used. , Ethanol, butanol, isopropanol, ethyl acetate, butyl acetate, dimethylsulfoxide, methyl cellosolve, methylene chloride, ethylene chloride, tetrahydrofuran or chlorobenzene. When using chlorobenzene as a coating solvent, unlike other solvents, long-chain barium carboxylate is applied in a state of being almost dissolved, and fine crystals are precipitated as the solvent evaporates.

When a solvent having a low solubility for long-chain barium carboxylate is used, it is necessary to uniformly disperse the long-chain barium carboxylate in the coating solution. As a method for dispersing the long-chain barium carboxylate in the coating liquid, an ultrasonic disperser, a sand mill, a ball mill or the like can be used.

The mixing ratio (mass) of the long-chain barium carboxylate and the binder resin in the layer forming the surface is preferably 1 to 40 mass% with respect to the binder resin. If it is less than 1% by mass, the effect of improving the slipperiness is small, and if it exceeds 40% by mass, the potential characteristics and the film strength may be deteriorated.

The mixing ratio (mass) of the charge transport material and the binder resin in the charge transport layer forming the surface is 3: 1.
˜1: 3 is preferred. The thickness of the charge transport layer is 5 to 50.
μm is preferable, and 10 to 40 μm is more preferable.

The mixing ratio (mass) of the charge generating substance and the binder resin in the charge generating layer forming the surface is 10:
1 to 1:10 is preferable. The film thickness of the charge generation layer is 0.
5 to 2.0 μm is preferable, and 0.7 to 1.0 μm is more preferable.

The thickness of the protective layer composed of long-chain barium carboxylate and a binder resin is preferably 0.1 to 10 μm, more preferably 0.5 to 5.0 μm.

Next, the conductive support used in the present invention will be described. As the conductive support, 1) a metal plate such as an aluminum plate or a stainless plate, 2) a support such as paper or a plastic film,
A thin metal layer such as aluminum, palladium, or gold provided by lamination or vapor deposition 3) On a support such as paper or plastic film,
Examples thereof include those in which a layer of a conductive compound such as a conductive polymer, indium oxide, or tin oxide is provided by coating or vapor deposition.

Materials for the conductive support used in the present invention are mainly aluminum, copper, brass, steel,
A metal material such as stainless steel or other plastic material molded into a belt shape or a drum shape is used. Among them, aluminum, which is excellent in cost and workability, is preferably used, and a thin-walled cylindrical aluminum element tube that is usually extruded or pultruded is often used.

The roughened state of the conductive support is preferably a ten-point average surface roughness Rz of more than 0.3 μm and not more than 2.5 μm. More preferably, it is 0.6 μm or more and 2.0 μm or less. Ten-point average surface roughness Rz is 0.3
When the thickness is less than μm, the adhesiveness is insufficient, and when a laser light source is used as an exposure light source, moire occurs in the image, which is not practical. If Rz is larger than 2.5 μm,
This causes a problem that processing streaks appear in the image.

As a method for roughening the surface of the conductive support, in the case of a metal base pipe made of aluminum or the like, a metal base pipe is mirror-polished on the metal surface and then finely grooved with a diamond cutting tool, or sand blasting. A method of roughening the surface is preferable, but the present invention is not limited to these methods.

The conductive support may have a drum shape, a sheet shape, or a belt shape, and it is preferable that the shape is optimal for the electrophotographic apparatus to which it is applied.

Next, a method for producing the photoconductor of the present invention will be described. As a method for applying the coating liquid for the photoreceptor, a coating processing method such as dip coating, spray coating, or circular amount regulation type coating is used, but since the coating processing of the protective layer does not dissolve the lower layer film as much as possible, In order to achieve uniform coating processing, it is preferable to use a coating processing method such as spray coating or circular amount regulation type (a circular slide hopper type is a typical example) coating. The spray coating is described in detail, for example, in JP-A-3-90250 and JP-A-3-269238, and the circular amount regulation coating is described in detail in JP-A-58-189061. ing.

The photoreceptor of the present invention is coated and processed to
It is preferably 0 ° C. or higher, and more preferably dried by heating at a temperature of 60 to 200 ° C. By this heat drying, the residual coating solvent can be reduced, and when the curable resin layer is used, it can be sufficiently cured.

In the present invention, it is preferable to provide an intermediate layer having a barrier function between the conductive support and the layer thereabove (charge generation layer or charge transport layer).

The material for the intermediate layer is, for example, polycarbonate, polystyrene, acryl, polyvinyl chloride, polyvinyl butyral, polyamide or the like, or so-called obtained by condensing a metal hydroxide such as zirconia, titanium or silane. Ceramics can be mentioned. The thickness of the intermediate layer is preferably 0.1 to 10 μm,
0.1-5 micrometers is more preferable.

Next, an image forming apparatus having the photoconductor of the present invention will be described. FIG. 2 is a sectional view showing an example of the image forming apparatus of the present invention.

In FIG. 2, reference numeral 50 designates a photosensitive drum (photosensitive member) which is an image bearing member and is grounded and driven and rotated clockwise. Reference numeral 52 denotes a scorotron charger as a charging means, which uniformly applies a uniform charge to the peripheral surface of the photosensitive drum 50 by corona discharge. Prior to the charging by the charger 52, in order to eliminate the history of the photosensitive member in the pre-image formation, the pre-charging pre-exposure unit 51 using a light emitting diode or the like may be used to remove the charge on the peripheral surface of the photosensitive member.

After the photosensitive member is uniformly charged, an image exposing device 53 as an image exposing means performs image exposure based on an image signal. The image exposure device 53 in this figure uses a laser diode (not shown) as an exposure light source. Rotating polygon mirror 5
Scanning on the photosensitive drum is performed by the light whose optical path is bent by the reflection mirror 532 through the 31, f.theta.
An electrostatic latent image is formed.

The electrostatic latent image is then developed by the developing device 54. A developing device 54 containing a developer composed of toner and carrier is provided on the periphery of the photosensitive drum 50.
Development is performed by a developing sleeve 541 that has a magnet built therein and holds a developer and rotates. Inside the developing device 54, the developer agitating and conveying members 544 and 543 and the conveying amount regulating member 5 are provided.
The developer is agitated and conveyed to be supplied to the developing sleeve 541, and the supply amount thereof is controlled by the conveyance amount regulating member 542. The developer carrying amount is generally in the range of ^{20 to} 200 mg / cm ² , although it varies depending on the linear velocity of the applied photoreceptor and the developer specific gravity.

The developer is, for example, a carrier in which an insulating resin is coated around the above-mentioned ferrite core, a coloring agent such as carbon black and a charge control agent mainly composed of the above-mentioned styrene acrylic resin, and a charge control agent of the present invention. Colored particles consisting of low molecular weight polyolefin, and toner externally added with silica, titanium oxide, etc., the developer is transported to the developing zone with the layer thickness regulated by the transport amount regulating member, and development is carried out. . At this time, normally, a DC bias is applied between the photosensitive drum 50 and the developing sleeve 541, and if necessary, an AC bias voltage is applied to develop. Further, the developer is developed in a state of being in contact with or non-contacting with the photoreceptor. The potential sensor 547 measures the potential of the photoconductor.
Is provided above the developing position as shown in FIG.

After the image formation, the recording paper P is fed to the transfer area by the rotation operation of the paper feed roller 57 when the transfer timing is adjusted.

In the transfer area, a transfer electrode (transfer device) 58 is provided on the peripheral surface of the photosensitive drum 50 in synchronization with the transfer timing.
Are pressed against each other, and the fed recording paper P is nipped and transferred.

Next, the recording paper P is de-charged by a separating electrode (separator) 59 which is brought into pressure contact with the transfer roller almost at the same time, separated by the peripheral surface of the photosensitive drum 50, and conveyed to the fixing device 60, where it is heated by a heat roller. The toner is fused by heating and pressurizing the pressure roller 601 and the pressure roller 602, and then the toner is discharged to the outside of the apparatus through the paper discharge roller 61. The transfer electrode 58 and the separation electrode 59 are withdrawn from the peripheral surface of the photoconductor drum 50 after the recording paper P has passed and are prepared for the next toner image formation.

On the other hand, after the recording paper P is separated, the photosensitive drum 50 is removed and cleaned by pressing the blade 621 of the cleaning device (cleaning means) 62 to remove the residual toner.
The pre-charging pre-exposure unit 51 again removes electricity and the charger 52 charges, and the next image forming process starts.

Reference numeral 70 denotes a removable process cartridge in which a photoconductor, a charger, a transfer device, a separator and a cleaning device are integrated.

The photoconductor of the present invention is applicable to general electrophotographic apparatuses such as electrophotographic copying machines, laser printers, LED printers and liquid crystal shutter type printers.
Display, recording, light printing using electrophotographic technology,
It can be widely applied to devices such as plate making and facsimile.

[0072]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

A photoconductor was prepared as follows. << Photoreceptor 1 >><Conductive Support 1> A drum-shaped aluminum conductive support (aluminum tube) was washed to obtain “conductive support 1”. <Intermediate Layer 1> The following materials were dissolved to prepare a coating solution for the intermediate layer. This coating solution is applied onto the above-mentioned "conductive support 1" by a dip coating method and dried at 110 ° C for 30 minutes to give a film thickness of 0.8.
A μm “middle layer 1” was formed.

Diisopropoxytitanium (methylacetoacetate) 140 g γ-methacryloxypropyltrimethoxysilane 60 g Isopropyl alcohol 2000 ml Ethyl alcohol 500 ml <Charge generation layer 1> The following materials were mixed and mixed with a sand mill 1
Dispersion and dissolution were carried out for 0 hours to prepare a charge generation layer coating solution.
This coating solution was applied onto the "intermediate layer 1" by a dip coating method and dried at 95 ° C for 30 minutes to form a "charge generation layer 1" having a film thickness of 0.5 µm.

Y-type titanyl phthalocyanine 20 g Silicone-modified butyral resin 100 g “X41-1222 solid content 10 mass%” (manufactured by Shin-Etsu Chemical Co., Ltd.) t-butyl acetate 880 ml methoxymethylpentanone 130 ml <Charge transport layer 1> It melt | dissolved and prepared the charge transport layer coating liquid. This coating solution is applied onto the “charge generation layer 1” by a dip coating method and dried at 95 ° C. for 30 minutes to give a film thickness of 15
The “charge transport layer 1” having a thickness of μm was formed.

Charge Transport Material (Exemplified Compound S-3) 100 g Bisphenol Z-type Polycarbonate (P2 Type) “Iupilon Z300” (manufactured by Mitsubishi Gas Chemical Co., Inc.) 150 g 1,2-dichloroethane 1000 ml <Protective Layer 1> The mixture was mixed, dispersed by a sand mill for 10 hours, and dissolved to prepare a coating liquid for protective layer. This coating solution was applied onto the “charge transport layer 1” by a circular amount control type coating method, and dried by heating at 110 ° C. for 1 hour to give a film thickness of 2 μm.
"Protective layer 1" was formed to prepare "photoreceptor 1".

Bisphenol Z-type polycarbonate resin (P2 type) "Upilon Z300" (manufactured by Mitsubishi Gas Chemical Co., Inc.) 150 g Charge-transporting substance (exemplary compound S-3) 100 g Barium stearate 30 g 1,2-Dichloroethane 1000 ml << Photoreceptor 2 A “photoreceptor 2” was prepared in the same manner as the “photoreceptor 1” except that barium stearate used in the “protective layer 1” of the “photoreceptor 1” was replaced with barium palmitate.

<< Photoreceptor 3 >>"Protective Layer 1" of "Photoreceptor 1"
Bisphenol Z type polycarbonate resin (P
2 type) was replaced with polycarbonate resin (copolymer of P1 type 90% by mass, P3 type 9% by mass, P4 type 1% by mass) "G-400" (manufactured by Idemitsu Kosan Co., Ltd.). "Photoreceptor 3" was prepared in the same manner as in ".

<< Photoreceptor 4 >>"Protective Layer 1" of "Photoreceptor 1"
"Photoreceptor 4" was prepared in the same manner as "Photoreceptor 1" except that 1,2-dichloroethane used in 1 was replaced with chlorobenze.

<< Photoreceptor 5 >>"Protective Layer 1" of "Photoreceptor 1"
A “photoreceptor 5” was prepared in the same manner as the “photoreceptor 1” except that the barium stearate used in 1 was replaced with zinc stearate.

<< Photoreceptor 6 >>"Protective Layer 1" of "Photoreceptor 1"
A “photoreceptor 6” was prepared in the same manner as the “photoreceptor 1” except that the barium stearate used in 1 was replaced with calcium stearate.

<< Photoreceptor 7 >>"Protective Layer 1" of "Photoreceptor 1"
A “photoreceptor 7” was prepared in the same manner as the “photoreceptor 1” except that the barium stearate used in 1 was replaced with magnesium stearate.

<< Photoreceptor 8 >>"Protective Layer 1" of "Photoreceptor 1"
A “photoreceptor 8” was prepared in the same manner as the “photoreceptor 1” except that the barium stearate used in 1 was removed.

The melting points of the carboxylic acid compounds used in the examples were as follows. Barium stearate mp 275 ° C Barium palmitate Decomposed at 200 ° C or higher Zinc stearate mp 140 ° C Calcium stearate mp 155 ° C Magnesium stearate mp 130 ° C As can be seen from the above, the melting points of barium stearate and barium palmitate are as good as those of other stearic acid compounds. High. <Evaluation of Photoreceptor> First, “photoreceptor 1 to
8 ”was evaluated for the tactile sensation on the surface of the photoconductor.

Table 1 shows the tactile evaluation results.

[0086]

[Table 1]

Next, the "photoreceptors 1 to 1 prepared in the examples are described.
8 "is sequentially installed in the copying machine" Konica 7050 "(manufactured by Konica Corporation), and normal temperature and humidity (23 ° C, 55% RH).
Under these conditions, 100,000 sheets were printed.

The photoconductors were evaluated by the potential characteristics (non-exposed part potential and exposed part potential) of each photoconductor after printing and the amount of film thickness loss of the photoconductor.

The image evaluation of the printed image was performed visually with respect to the image density, stain and blurring of fine lines of the image after printing 100,000 sheets.

The evaluation of the cleaning blade flipping is 1
It was determined whether or not the cleaning blade was turned over during the printing of 0,000 sheets.

The potential characteristics of the unexposed portion potential (Vh) and the exposed portion potential (Vi) were measured by attaching a potential measuring device to the inside of the "Konica 7050" machine.

The evaluation results are shown in Table 2.

[0093]

[Table 2]

From the evaluation results, the "photoreceptors 1 to 4" of the present invention provided with the protective layer containing barium stearate and barium palmitate had a smooth feel, a small amount of film thickness loss of the photoreceptor, and an image. The cleaning blade was also good, and the cleaning blade was not turned up.

On the other hand, the "photoreceptor 5" to which zinc stearate was added had a fine line and was slightly unclear, and the amount of film thickness loss was large as compared with the "photoreceptors 1 to 4" of the present invention.
The cleaning blade has also been turned over when printing nearly 0,000 sheets. It is considered that this is because the initial feel of the photoconductor had a sticky feel, and zinc stearate bleeded out significantly to the surface, and was consumed immediately due to the wear of the surface.

The "photoreceptor 6" and "photoreceptor 7" to which calcium stearate and magnesium stearate were added had a rough feel rather than slipping the surface, and a decrease in image density and image stains due to an increase in the potential of the exposed area. Has occurred. It is considered that this is because calcium stearate or magnesium stearate was partially dissolved in the solvent, and calcium stearate or magnesium stearate was deposited as large crystals during the evaporation of the solvent, resulting in non-uniformity of the entire layer.

The "photoreceptor 8" prepared as a blank to which barium stearate was not added had a large amount of wear of the photoconductor, and the cleaning blade was curled.

[0098]

As demonstrated in the examples, the photoconductor of the present invention has an excellent effect that a high quality and stable image can be obtained even if it is repeatedly used and that the cleaning blade does not turn up.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a layer structure of a photoconductor of the present invention.

FIG. 2 is a sectional view showing an example of an image forming apparatus using the photoconductor of the present invention.

[Explanation of symbols]

50 photoconductor drum (or photoconductor) 51 Pre-charge exposure unit 52 Charger 53 Image exposure device 54 Developer 541 Development sleeve 543,544 developer stirring and conveying member 547 potential sensor 57 Paper Feed Roller 58 transfer electrode (transfer device) 59 Separation electrode (separator) 60 fixing device 61 Paper ejection roller 62 cleaning device 70 Process cartridge

Claims (3)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the layer forming the surface of the electrophotographic photoreceptor has barium long-chain carboxylate. 2. The barium long-chain carboxylate is a compound represented by the following general formula: 1.
The electrophotographic photosensitive member according to 1. Formula (RCOO) ₂ Ba (wherein, R represents a number of 10 or more alkyl groups, alkenyl group or an aryl group having a carbon.) 3. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein a layer forming a surface of the electrophotographic photoreceptor comprises barium long-chain carboxylate and a polycarbonate resin. Photoconductor.