JP2001356503A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having excellent durability against blade cleaning, generating no pressure mark by the blade at the blade cleaning, and having high compatibility with a charge transfer agent and good electric characteristics. SOLUTION: The electrophotographic photoreceptor has a photosensitive layer consisting of a binder resin containing at least a charge generating agent and a charge transfer agent on a conductive substrate. The binder resin contains polycarbonate resin consisting of repeating structural units expressed by formulas [1], [2] and [3]. The weight content ratio of the repeating structural unit expressed by formula [1] to the sum of the repeating structural units expressed by formulas [2] and [3] ranges from 45:55 to 10:90 and the weight content ratio of the structural unit expressed by formula [2] to the structural unit expressed by formula [3] ranges from 50:50 to 90:10. The sum of the repeating structural units expressed by formulas [1], [2] and [3] to the whole amount of the binder resin is >=50 wt.%.

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 used in an image forming apparatus such as an electrostatic copying machine, a facsimile, a laser beam printer, etc., and more particularly, to an organic electrophotographic photosensitive member having excellent durability. About the body.

[0002]

2. Description of the Related Art In the above-mentioned image forming apparatus, various photosensitive members having sensitivity in a wavelength region of a light source used in the image forming apparatus are used. One is an inorganic photoreceptor using an inorganic material such as selenium for the photosensitive layer, and the other is an organic photoreceptor (OPC) using an organic material for the photosensitive layer. Of these, it is easier to manufacture than organic photoreceptors and inorganic photoreceptors, and there are a variety of photoreceptor materials such as charge transport agents, charge generators, binder resins, etc. In recent years, extensive research has been conducted.

An organic photoreceptor has a so-called laminated type photoreceptor having a laminated structure of a charge generating layer containing a charge generating agent and a charge transporting layer containing a charge transporting agent, and a charge generating agent and a charge transporting agent. Is dispersed in a single photosensitive layer, that is, a so-called single-layer type photosensitive member. Of these, the multilayer photoconductor occupies a wide market scale.

On the other hand, a single-layer type photoreceptor has a simple layer structure and is excellent in productivity, can suppress the occurrence of film defects in the photosensitive layer, and can improve optical characteristics because there are few interfaces between layers. By using an electron transporting agent and a hole transporting agent together as a charge transporting agent, one photoreceptor can be used for both a positively charged type and a negatively charged type. It is in the limelight because it has the advantage of generating less ozone.

[0005] The electrophotographic photosensitive member is used in a repetitive process of charging, exposing, developing, transferring, cleaning, and removing electricity in the image forming process. The electrostatic latent image formed by the charge exposure is developed with toner, which is a fine powder. Further, the developed toner is transferred to a transfer material such as paper in a transfer process, but 100% of the toner is not transferred, and a part thereof remains on the photoconductor. Unless the remaining toner is removed, a high-quality image free from dirt or the like cannot be obtained in the repetitive process. Therefore, cleaning of the remaining toner is required.

A typical cleaning process uses a fur brush, a magnetic brush, a blade, or the like. However, from the viewpoint of cleaning accuracy and rationalization of the apparatus configuration, the blade-shaped resin plate is in direct contact with the photosensitive member. In general, blade cleaning for performing cleaning is selected.

[0007] Blade cleaning, while high in accuracy, increases the mechanical load on the photoreceptor, resulting in an increase in the amount of abrasion of the photoconductive layer, a reduction in surface potential, a deterioration in sensitivity, and the like. It is difficult to obtain a high-quality image.
To improve the abrasion resistance of the photoreceptor, Japanese Patent Application Laid-Open No.
254664 and JP-A-1-273046 describe bisphenol C (hereinafter referred to as bis) as a binder resin for a photoreceptor.
-C type) polycarbonate resins have been proposed.

[0008]

The bis-C type polycarbonate resin has very low abrasion resistance, but has a low glass transition temperature (hereinafter abbreviated as Tg). When used in an image forming apparatus having a high temperature, the photosensitive layer is deformed (blade indentation) due to the pressure of the cleaning blade pressing portion, causing a problem that an image defect occurs. In addition, the bis-C type polycarbonate resin has low compatibility with the charge transporting agent, and as a result, there has been a problem in that electrical characteristics such as poor photosensitivity of the photoreceptor are deteriorated.

Particularly, in a single-layer type photoreceptor, a hole transporting agent and an electron transporting agent are often used in combination as a charge transporting agent, and the content ratio of the charge transporting agent to the binder resin is large. The compatibility of the charge transport agent is important. When the compatibility is poor, the photosensitivity is deteriorated as described above, and not only the charging of the drum surface is likely to be non-uniform, but also the problem that the crystal of the charge transporting agent is precipitated on the photoreceptor surface occurs. is there.

It is an object of the present invention to provide an electrophotographic photosensitive member having excellent durability even when used in an image forming apparatus having blade cleaning. In particular, it has excellent durability, and has a high Tg and no defect of blade indentation.
An object of the present invention is to provide a single-layer electrophotographic photoreceptor having high compatibility with a charge transporting agent and excellent electric characteristics.

[0011]

Means for Solving the Problems and Effects of the Invention As a result of intensive studies to solve the above problems, the present inventors have found that a conductive substrate contains at least a charge generating agent and a charge transporting agent. A photosensitive layer made of a binder resin,
The binder resin contains a polycarbonate resin composed of a repeating structural unit represented by Formula [1], Formula [2] and Formula [3], and a repeating structural unit represented by Formula [1]; The weight content ratio of the sum of the repeating structural units represented by the formula [3] is in the range of 45:55 to 10:90, and the repeating structural unit represented by the formula [2] and the structural unit represented by the formula [3] The weight content ratio is 50:50 to 90:10, and the sum of the repeating structural units represented by the formulas [1], [2], and [3] is 50 wt% based on the total amount of the binder resin. The electrophotographic photoreceptor characterized by the above is found to have extremely good abrasion resistance, and has no problem in compatibility with Tg and a charge transport agent.
The present invention has been completed.

Formula [1];

Embedded image Formula [2];

Embedded image (In the formula [2], R ¹ and R ² are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and Z may have a substituent and has 5 to 7 carbon atoms. It represents a cycloalkylidene group.) Formula [3];

Embedded image (In the formula [3], R ³ and R ⁴ are different from each other and are a hydrogen atom,
It represents an alkyl group having 1 to 3 carbon atoms. )

That is, the electrophotographic photoreceptor according to the present invention is characterized by containing, as a binder resin, a polycarbonate resin having a repeating structural unit represented by the formulas [1], [2] and [3]. Features.

The repeating structural unit represented by the above formula [3] exhibits abrasion resistance equal to or higher than that of the bis-C type polycarbonate resin, and has a high compatibility with the charge transport agent due to its asymmetric structure. . In addition, as in the repeating structural unit represented by the formula [2], Tg is increased by having a cyclic cycloalkylidene structure. That is, by containing both of them at the same time as the bis-C type polycarbonate represented by the formula [1], excellent abrasion resistance is obtained, and
It is possible to simultaneously solve the above-mentioned problems of compatibility with the charge transport agent and Tg.

[0015]

Next, the electrophotographic photosensitive member according to the present invention will be described in detail.

[Binder Resin] The binder resin used in the electrophotographic photoreceptor of the present invention is represented by the following formulas [1], [2],
It is characterized by containing a polycarbonate resin comprising a repeating structural unit represented by the formula [3].

The content of the binder resin is represented by the following formula:
Of the structural units represented by [1], [2] and [3], any two types of structural units are copolymerized and other resins are blended, or the formula [1] , Equation [2], Equation [3]
May be copolymerized, or all the structural units may be blended.

However, the weight content ratio of the sum of the repeating structural unit represented by the formula [1] and the repeating structural units represented by the formulas [2] and [3] is in the range of 45:55 to 10:90. And the weight content ratio of the repeating structural unit represented by the formula [2] to the structural unit represented by the formula [3] is 50:50 to 90:10.
It is necessary that the sum of the repeating structural units represented by the formulas [1], [2] and [3] is not less than 50 wt% with respect to the total amount of the binder resin.

When the content of the repeating structural units represented by the formulas [1], [2] and [3] is outside the above range, phenomena such as deterioration of abrasion resistance, Tg and sensitivity of the photoreceptor are caused. Occurs.

If the sum of the repeating structural units represented by the formulas [1], [2], and [3] is 50 wt% or more with respect to the total amount of the binder resin, it has been conventionally used for the photosensitive layer. Various resins can be used. For example, a polycarbonate resin other than the repeating structural units represented by the formulas [1], [2] and [3], a polyester resin,
Polyarylate resin, styrene-butadiene copolymer,
Styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene, ethylene-vinyl acetate copolymer, chlorinated polyethylene, polyvinyl chloride, polypropylene, ionomer, Vinyl chloride-vinyl acetate copolymer, alkyd resin, polyamide, polyurethane, polysulfone, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, thermoplastic resin such as polyether resin, silicone resin, epoxy resin, phenol resin, urea resin, Resins such as a melamine resin, other crosslinkable thermosetting resins, photo-curable resins such as epoxy acrylate and urethane-acrylate can be used. These binder resins can be used alone or as a blend or copolymer of two or more.

The weight average molecular weight of the above binder resin is 5,000 to 200,000, and more preferably 15,000 to 1
00,000 is preferred.

[Charge Generator] Examples of the charge generator used in the electrophotographic photoreceptor of the present invention include metal-free phthalocyanine (PCH ₂ ), oxotitanyl phthalocyanine (PcTiO), perylene pigments, bisazo pigments, and diazo pigments. Ketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaraine pigments, trisazo pigments, indigo pigments, azurenium pigments, cyanine pigments, pyrylium pigments, anthanthrone pigments, triphenylmethane pigments, sulene pigments, toluidine pigments Conventionally known charge generators such as organic photoconductors such as pigments, pyrazoline pigments and quinacridone pigments, and inorganic photoconductive materials such as selenium, selenium-tellurium, selenium-arsenic, cadmium sulfide, and amorphous silicon are exemplified.

The above-described charge generating agents can be used alone or in combination of two or more so as to have an absorption wavelength in a desired region.

Among the charge generating agents exemplified above, particularly, a digital optical image forming apparatus such as a laser beam printer or a facsimile using a light source such as a semiconductor laser includes:
Since a photoconductor having a sensitivity in a wavelength region of 700 nm or more is required, for example, a metal-free phthalocyanine (PC
H ₂ ), oxotitanyl phthalocyanine (PcTiO)
And the like. Phthalosinine pigments such as The crystal form of the phthalocyanine pigment is not particularly limited, and various types can be used.

[Charge Transport Agent] As the charge transport agent used in the electrophotographic photoreceptor of the present invention, conventionally known electron transport agents,
And a hole transport agent. Whether to use an electron transporting agent or a hole transporting agent is appropriately selected and used depending on the layer structure of the photoreceptor, the chargeability of the photosensitive layer, and the like.

In particular, in a single-layer type photoreceptor, it is preferable that an electron transporting agent and a hole transporting agent are blended and contained in the photosensitive layer.

As the electron transporting agent usable in the electrophotographic photoreceptor of the present invention, in addition to diphenoquinone derivatives and benzoquinone derivatives, anthraquinone derivatives, malononitrile derivatives, thiopyran derivatives, trinitrothioxanthone derivatives, 3,4,5,7- Tetranitro-9-fluorenone derivative, dinitroanthracene derivative, dinitroacridine derivative, nitroantaraquinone derivative, dinitroanthraquinone derivative, tetracyanoethylene,
Various compounds having electron-accepting properties, such as 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, dinitroanthraquinone, succinic anhydride, maleic anhydride, and dibromomaleic anhydride, may be mentioned. Can be In particular, a quinone derivative represented by the formula [4] is preferably used.

In the present invention, the electron transporting agent may be used alone or in combination of two or more.

Examples of the hole transporting agent usable in the electrophotographic photoreceptor of the present invention include N, N, N ', N'-tetraphenylbenzidine derivatives, N, N, N', N'-tetraphenylphenylenediamine Derivatives, N, N, N ',
N′-tetraphenylnaphthylenediamine derivative, N,
N, N ', N'-tetraphenylphenanthrylenediamine derivative, 2,5-di (4-methylaminophenyl)
Oxadiazole compounds such as -1,3,4-oxadiazole, styryl compounds such as 9- (4-diethylaminostyryl) anthracene, carbazole compounds such as polyvinylcarbazole, organic polysilane compounds,
Pyrazoline compounds such as -phenyl-3- (p-dimethylaminophenyl) pyrazoline, hydrazone compounds,
Examples include nitrogen-containing cyclic compounds such as indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, triazole compounds, and condensed polycyclic compounds. In particular, a stilbene derivative represented by the formula [5] is preferably used.

In the present invention, only one type of hole transporting agent may be used, or two or more types may be blended and used.

When the photosensitive layer is a single layer, the thickness of the photosensitive layer is 5
To 100 μm, and more preferably about 10 to 50 μm.
The charge generating agent is 0.1 to 5 with respect to the total weight of the binder resin.
It is preferable to contain 0 wt%, more preferably 0.5 to 30 wt%. The electron transporting agent is preferably contained in an amount of 5 to 100% by weight, more preferably 10 to 80% by weight based on the total weight of the binder resin. The hole transport agent is 5 to 500 wt%, and more preferably 25 to 200 wt%, based on the total binder resin weight.
It is preferable to include them. When the electron transporting agent and the hole transporting agent are used by blending, the total amount of the electron transporting agent and the hole transporting agent is 20 to 50 with respect to the total binder resin.
The content is preferably 0 wt%, more preferably 30 to 200 wt%.

When the photosensitive layer has a laminated structure, the thickness of the charge generation layer is preferably about 0.01 to 5 μm, more preferably about 0.1 to 3 μm, and the thickness of the charge transport layer is 2 to 100 μm, more preferably 5 to 100 μm. About 50 μm is preferable. The charge generation layer contains the charge generation material in an amount of 0.1 to 50 wt.
%, More preferably 0.5 to 30 wt%, and the charge transport layer contains the charge transport material in an amount of 20 to 500 wt% based on the entire binder resin.
%, More preferably 30 to 200 wt%.

In the photosensitive layer, in addition to the above components, various conventionally known additives such as an antioxidant, a radical scavenger, a singlet quencher, Deterioration inhibitors such as UV absorbers, softeners,
Plasticizers, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, acceptors, donors, and the like can be added. Also, in order to improve the sensitivity of the photosensitive layer, for example,
Known sensitizers such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generator.

A barrier layer may be formed between the support and the photosensitive layer as long as the characteristics of the photosensitive member are not impaired.
Further, a protective layer may be formed on the surface of the photoreceptor.

As the support on which the photosensitive layer is formed, various conductive materials can be used.
Iron, aluminum, copper, tin, platinum, silver, vanadium,
Molybdenum, chromium, cadmium, titanium, nickel,
Examples of the material include simple metals such as palladium, indium, stainless steel, and brass; plastic materials on which the above metals are deposited or laminated; glass coated with aluminum iodide, tin oxide, indium oxide, and the like.

The shape of the support may be sheet-like or drum-like depending on the structure of the image forming apparatus to be used, and the support itself has conductivity or the surface of the support has What is necessary is just to have electroconductivity. The support preferably has a sufficient mechanical strength when used.

When the photosensitive layer is formed by a coating method, the above-described charge generating agent, charge transporting agent, binder resin, etc., together with a suitable solvent, may be used in a known manner, for example, a roll mill, a ball mill, an attritor, a paint coater. A dispersion may be prepared by dispersion blending using an acre, an ultrasonic disperser, or the like, and the dispersion may be applied by a known means and dried.

Various organic solvents can be used as a solvent for preparing the above-mentioned dispersion liquid, for example, alcohols such as methanol, ethanol, isopropanol and butanol, and aliphatic solvents such as n-hexane, octane and cyclohexane. Hydrocarbons, aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated hydrocarbons such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride, and chlorobenzene; dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether. Ethers, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and methyl acetate, dimethylformaldehyde, dimethylformamide, dimethyls Rufoxide and the like. These solvents are used alone or as a blend of two or more.

Further, in order to improve the dispersibility of the charge generating agent, the charge transporting agent and the like and the smoothness of the surface of the photosensitive layer, a surfactant, a leveling agent and the like may be used.

[0040]

The present invention will be described below with reference to examples and comparative examples. Note that the following embodiments are merely examples embodying the present invention, and do not limit the technical scope of the present invention.

Examples 1 to 10 Comparative Examples 1 to 8 Titanyl phthalocyanine (PcTiO) 1.0 as a charge generating agent
20 parts by weight of a compound (ETM-1) represented by the formula [4] as an electron transporting agent, 40 parts by weight of a compound (HTM-1) represented by the formula [5] as a hole transporting agent, and a compound represented by the formula: A bis-C type polycarbonate resin (Resin-1) having a weight average molecular weight of 50,000 of the repeating structural unit represented by [1], a formula [2], a formula
A binder resin having a weight average molecular weight of 50,000 (Resin-2) obtained by copolymerizing the repeating structural unit represented by [3]
And a bis-Z type polycarbonate resin in 800 parts by weight of tetrahydrofuran,
The mixture was dispersed or dissolved in a ball mill for 24 hours to prepare a coating solution for a single-layer photosensitive layer. Then, this coating solution is applied by dip coating onto an aluminum tube as a support, and dried with hot air at 110 ° C. for 30 minutes to obtain a single-layer photoreceptor having a single photosensitive layer having a thickness of 27 μm. Was prepared.

<ETM-1>

Embedded image

<HTM-1>

Embedded image

<Resin-1 (bis-C type polycarbonate)>

Embedded image

<Resin-2>

Embedded image

<Bis-Z type polycarbonate>

Embedded image

[Examples 11 to 20] [Comparative Examples 9 to 16] As the binder resin, three types of polycarbonate resins having repeating structural units represented by the formulas [1], [2] and [3] (Res)
A single-layer type photoreceptor was prepared in the same manner as in Examples 1 to 10, except that a resin blended with in-1, Resin-3, Resin-4 (weight average molecular weight: 50,000) was used.

<Resin-3>

Embedded image

<Resin-4>

Embedded image

The following evaluation tests were carried out on the single-layer type photoreceptors of each of the examples and comparative examples prepared above.

[Abrasion Resistance Evaluation Test] The electrophotographic photoreceptors of each of the above Examples and Comparative Examples were replaced with a digital copier (“Creag” manufactured by Kyocera Mita Corporation) having blade cleaning means.
e7340 ”), a printing test of 50,000 sheets of A4 size paper was performed, and the film thickness of the photosensitive layer before and after the printing test was measured.
The amount of change in film thickness was calculated. The smaller the change in film thickness, the better the abrasion resistance. Regarding the amount of change in film thickness, see 3.
0 μm or less was considered acceptable, and 3.0 μm or more was unacceptable.

[Electrical Characteristics Evaluation Test] Using a drum sensitivity tester manufactured by GENTEC, an applied voltage was applied to the surface of the electrophotographic photosensitive member of each of the examples and comparative examples before the printing test, and the surface was brought to +700 V. Charged. Then, monochromatic light having a wavelength of 780 nm (half-width 20 nm, extracted from white light of a halogen lamp as an exposure light source using a bandpass filter).
Exposure at a light intensity of 8 μJ / cm ² )
The surface potential at the point of time when seconds passed was measured as residual potential (V _L ). The lower the residual potential _{VL, the} higher the sensitivity of the photoconductor. Regarding V _L , a value of 100 V or less was acceptable, and a value of more than 100 V was not acceptable.

[Tg Evaluation Test] The photosensitive layers of the electrophotographic photosensitive members of Examples and Comparative Examples were peeled and collected, and the Tg of the photosensitive layers was measured by differential thermal analysis. Regarding Tg, 60 ° C. or higher was acceptable, and Tg was lower than 60 ° C.

[Blade Indentation Evaluation Test] The electrophotographic photoreceptor of each of Examples and Comparative Examples was made by Kyocera Mita Co., Ltd., under the condition that a cleaning blade was constantly pressed against the surface of the photoreceptor.
50% cartridge, humidity 45%, temperature 60
At 48 ° C. for 48 hours in a dark place constant temperature bath.
At 50, an image was displayed. X (impossible) when the portion where the cleaning blade was in contact with the image became black streaks, and ○ (acceptable) when the portion did not become an image black streak.

The evaluation results are shown in Tables 1 and 2. In addition, FIG.
3. Formula [1], Formula [2], Formula
Three types of polycarbonate resin having a repeating structural unit represented by [3] (Resin-1, Resin-3, Resin-
4. In the case of using a resin blended with all (weight average molecular weight: 50,000) (Examples 11 to 20, Comparative Examples 9-1)
The result of 6) was graphed.

[0056]

[Table 1]

[0057]

[Table 2]

FIG. 1 shows Resin-1 (bis-C type polycarbonate), Resin-3, Resin-4.
, Resin-1, Resin-3, Resin-4 when the content of is 90 wt.
The relationship between the Resin-1 content in the sample and the amount of wear, sensitivity, and Tg was shown. As shown in the figure, the Resin-1 content is 10 wt.
%, The wear amount becomes 3.0 μm or more and 45 wt%.
As the content increases, the sensitivity is greater than 100 V,
Further, Tg was less than 60 ° C.

FIG. 2 shows Resin-1 (bis-C type polycarbonate), Resin-3 and Resin-4.
Is 90 wt with respect to all binder resins, and Resin-1, Resin-3, Resin-4
Resin-1 content is 45 wt%, Resin-
When the content of 3 and Resin-4 is 55 wt%,
The relationship between the content ratio of Resin-3 in Resin-3 and Resin-4 and the amount of wear, sensitivity, and Tg was shown. From the figure,
When the content ratio of Resin-3 is more than 0.9, the abrasion amount becomes 3.0 μm or more, and when it is less than 0.5, the sensitivity becomes more than 100 V or the Tg becomes less than 60 ° C.

FIG. 3 shows Resin-1 (bis-C type polycarbonate), Resin-3, Resin-4.
Resin-1 content is 45 wt%, Resin-
3 and Resin-4 content is 55 wt%, and R
When the content ratio of Resin-3 in Resin-3 and Resin-4 is 0.9, Re with respect to all binder resins
The relationship between the content ratio of sin-1, Resin-3, and Resin-4 and the amount of wear, sensitivity, and Tg was shown. As shown in the figure, when the content ratio is less than 0.5, the wear amount becomes 3 μm or more.

From the above, the binder resin is represented by the formula [1],
It contains a polycarbonate resin composed of the repeating units represented by the formulas [2] and [3], and comprises a repeating unit represented by the formula [1] and a repeating unit represented by the formulas [2] and [3] And the weight content ratio of the repeating structural unit represented by the formula [2] and the structural unit represented by the formula [3] is 50:50 to 50:50 to 10:90.
90:10, and the sum of the repeating structural units represented by the formulas [1], [2], and [3] is 50 wt% or more with respect to the total amount of the binder resin. It is clear that the electrophotographic photoreceptor is excellent in abrasion resistance, high in Tg, free from blade indentation, and good in sensitivity.

[0062]

According to the present invention, it is possible to obtain an electrophotographic photoreceptor having excellent abrasion resistance, high Tg, free from indentation of the blade and good sensitivity.

[0063]

[Brief description of the drawings]

As the binder resin, three types of polycarbonate resin having repeating structural units represented by the formulas [1], [2] and [3] (R
esin-1, Resin-3, Resin-4, all of which have a weight average molecular weight of 50,000) (Examples 11 to 20, Comparative Examples 9 to 16).

FIG. 1 shows the case where the content of Resin-1 (bis-C type polycarbonate), Resin-3 and Resin-4 is 90 wt.
-1, Resin-3, Resin in Resin-4
1 shows the relationship among the content, wear amount, sensitivity, and Tg.

FIG. 2 shows that the content of Resin-1 (bis-C type polycarbonate), Resin-3 and Resin-4 is 90 wt.
1. Resin-3 in Resin-3, Resin-4
1 content 45 wt%, Resin-3 and Resin-
4, the content of Resin-3 in Resin-3 and Resin-4 is 55 wt%,
The relationship between sensitivity and Tg was shown.

FIG. 3 Resin in Resin-1 (bis-C type polycarbonate), Resin-3, Resin-4
-1 content 45 wt%, Resin-3 and Resin
When the content of Resin-3 is 55 wt% and the content ratio of Resin-3 in Resin-3 and Resin-4 is 0.9, Resin-1 and R with respect to all binder resins are used.
The relationship between the content ratio of esin-3 and Resin-4 and the amount of wear, sensitivity, and Tg was shown.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ayako Yashima 1-2-28 Tamazo, Chuo-ku, Osaka City Inside Kyocera Mita Corporation (72) Inventor Kyoichi Nakamura 1-2-28 Tamazo, Chuo-ku, Osaka City Kyocera Mita (72) Inventor Eiichi Miyamoto 1-2-28 Tamazo, Chuo-ku, Osaka-shi F-term in Kyocera Mita Corporation (reference) 2H068 AA13 AA19 AA20 AA21 AA31 BA13 BA14 BA39 BB20 BB21 BB26 BB53 BB54

Claims (8)

[Claims] 1. A photosensitive layer comprising a binder resin containing at least a charge-generating agent and a charge-transporting agent on a conductive substrate, wherein the binder resin is represented by the formulas [1], [2] and [3]. ] And a weight ratio of the sum of the repeating structural units represented by the formula [1] and the repeating structural units represented by the formulas [2] and [3] is 45. : 55 to 10: 90,
The weight content ratio of the repeating structural unit represented by the formula [2] to the structural unit represented by the formula [3] is 50:50 to 90:10, and the formula [1] is based on the total amount of the binder resin. Wherein the sum of the repeating structural units represented by formulas [2] and [3] is 50 wt% or more. Formula [1]; Formula [2]; (In the formula [2], R ¹ and R ² are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and Z may have a substituent and has 5 to 7 carbon atoms. It represents a cycloalkylidene group.) Formula [3]; (In the formula [3], R ³ and R ⁴ are different from each other and are a hydrogen atom,
It represents an alkyl group having 1 to 3 carbon atoms. ) 2. The method according to claim 1, wherein the binder resin has the formula [1], the formula [2],
2. The electrophotographic photoreceptor according to claim 1, wherein any two of the structural units represented by the formula [3] are copolymerized and another resin is blended. 3. The method according to claim 1, wherein the binder resin has the formula [1], the formula [2],
2. The electrophotographic photosensitive member according to claim 1, wherein all the structural units represented by the formula [3] are copolymerized or all the structural units are blended. 4. The electrophotographic photosensitive member according to claim 1, wherein in the formula [2], Z is cyclohexylidene. 5. The electrophotographic photosensitive member according to claim 1, wherein said photosensitive layer is a single layer type. 6. The electrophotographic photosensitive member according to claim 1, wherein said charge generating agent contains a phthalosinin-based pigment. 7. The single-layer electron according to claim 5, wherein the charge transporting agent contains an electron transporting agent represented by the formula [4] or a hole transporting agent represented by the formula [5]. Photoreceptor. Formula [4]; (In formula [4], R ⁵ represents a halogen atom, an optionally substituted alkyl group or an aryl group, and R ⁶ represents an optionally substituted alkyl group or an aryl group, or a group :. .R ^6a showing a -O-R ^6a may have a substituent, an alkyl group or an aryl group) formula [5]; embedded image (In the formula [5], R ⁷ and R ⁹ are the same or different and each may be an alkyl group which may have a substituent, an aryl group which may have a substituent, or an aralkyl which may have a substituent. R ⁸ and R ¹⁰ are the same or different and represent a hydrogen atom or an alkyl or alkoxy group which may have a substituent, provided that the substitution positions of R ⁸ and R ¹⁰ are para R ⁸ and R ¹⁰ are hydrogen atoms.) 8. An electrophotographic photoconductor according to claim 1, wherein the electrophotographic photoconductor is used in an image forming apparatus for collecting untransferred toner by a blade cleaning means.