JP3124974B2 - Electrophotographic photoreceptor and cleaning method - Google Patents

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 and a method for cleaning the same.

[0002]

2. Description of the Related Art In recent years, an electrophotographic photosensitive member using an organic photosensitive material having advantages such as low cost, productivity and no pollution has begun to spread.

[0003] Organic electrophotographic photoreceptors include a photoconductive resin represented by polyvinyl carbazole (PVK), P
VK-TNF (2,4,7-trinitrofluorenone)
A charge-transfer complex represented by, for example, a pigment-dispersed type represented by a phthalocyanine-binder, and a function-separated type photoreceptor using a combination of a charge-generating substance and a charge-transfer substance have attracted attention.

When such a function-separated high-sensitivity photosensitive member is used in a Carlson type copying machine or printer,
After the surface of the photoconductor is charged, an electrostatic latent image is formed by exposure, the electrostatic latent image is developed with charged colored powder (toner), and then the visible image is transferred and fixed on paper or the like. At the same time, the photoreceptor is subjected to removal of the adhered toner, charge elimination, and surface cleaning (cleaning), and is repeatedly used for a long time.

Accordingly, the electrophotographic photoreceptor has not only electrophotographic characteristics such as good chargeability and sensitivity and low dark decay, but also abrasion resistance and abrasion resistance in repeated use. Is also required to be stable in terms of mechanical durability and humidity resistance and resistance to deterioration due to ultraviolet rays and the like in corona discharge light emission.

However, in a conventional electrophotographic photosensitive member in which a charge generation layer and a charge transfer layer are sequentially laminated on a support, the charge transfer layer is formed by binding a low-molecular charge transfer substance with a high-molecular resin binder. Therefore, it is not always sufficient to achieve both mechanical strength characteristics and electrophotographic characteristics. For a highly sensitive composition or resin binder type, the cleaning brush and / or cleaning blade may be rubbed when the photoconductor is repeatedly used. Scratches on the photoreceptor surface,
Electrophotographic properties such as low surface sensitivity and low residual sensitivity were not obtained with a composition or a resin binder type having high abrasion resistance due to abrasion of the surface.

[0007] To solve the above-mentioned disadvantage, for example,
In order to improve the occurrence of abrasion on the outermost charge transfer layer (CTL-2) described in JP-A-7955 and JP-A-61-17945, a silicone resin having dimethylpolysiloxane and a polycarbonate resin are used. Spray-coat with a solvent that can elute the charge transfer material (CTM).
In order to improve the generation of scratches due to friction and the corona resistance of CTM described in JP-A-60-12551, the CTL is multi-layered, and the amount of CTM in the deepest charge transfer layer (CTL-1) is adjusted from CTL-2. JP-A-60-12
No. 552 discloses a single layer of a thermoplastic polyester carbonate between CGL and CTL or a thermosetting polyester carbonate having CGM or CTM added between CGL and CTL in order to improve the adhesion between the CGL and the CTL. An intermediate layer is provided. JP-A-60-87331
In order to improve the generation of scratches due to friction and the corona resistance of CTM described in Japanese Patent Application Laid-Open No. 60-143346, CTL is divided into two layers via a charge-transferable intermediate layer.
CTM / R of TL-2 is smaller than CTL-1. In order to improve the abrasion resistance described in JP-A-62-272282, a protective layer made of a polycarbonate resin, polytetrafluoroethylene and CTM (hydrazone compound) is provided on CTL. JP-A-2-16024
In order to improve the mechanical strength and the penetration of ozone into the photosensitive layer described in JP-A-7, the CTL is multi-layered to improve the CT of CTL-1.
M / R is larger than that of CTL-2 and CTL-
The second resin binder comprises a specific polycarbonate. For the purpose of improving the durability described in JP-A-2-161449, a protective layer containing polyetherimide as a main component was provided. To reduce the residual potential and increase the sensitivity in repeated use described in JP-A-2-178672, CTL and C
There has been proposed a photoreceptor provided with an intermediate layer between the GL and the GL to promote separation and injection of carriers by containing an amine compound. These proposals do not sufficiently satisfy both sensitivity and durability, and in recent years, there is an increasing demand for durability while maintaining high sensitivity.

[0008] The scratches and abrasion on the surface of the photoreceptor due to the rubbing of the cleaning brush and the cleaning blade when the photoreceptor is repeatedly used include the material and shape of the cleaning blade and the cleaning brush, the conditions of contact with the surface of the photoreceptor, and the like. In connection with the cleaning of the photoreceptor, a report relating to the prevention of defective cleaning of the developer (for example,
Roughening the surface of the electrophotographic photosensitive member disclosed in
JP-A-2-162, in which fine powder is interposed between a cleaning blade and a photosensitive layer disclosed in JP-A-101488.
Japanese Patent Application Laid-Open Nos. Sho 57-82842 and Sho 62-628, in which a thin portion is provided at the end of a cleaning blade disclosed in
No. 272,282, the photosensitive layer and the protective layer contain a fluorine-based compound, etc.), but the scratches and abrasion on the surface of the photosensitive member are reduced by the rubbing of the cleaning brush or the cleaning blade when the photosensitive member is repeatedly used. There are few reports (for example, Japanese Unexamined Patent Publication No. Hei 3-20768) that the electrophotographic photoreceptor having a specific molecular weight bisphenol Z-type polycarbonate is cleaned with a cleaning blade of a specific shape and material. Not in.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances of the prior art, and a first object of the present invention is to maintain high sensitivity even when repeatedly used and to have good abrasion resistance. An object of the present invention is to provide an electrophotographic photosensitive member. A second object of the present invention is to provide a cleaning method for reducing scratches and abrasion on the surface of a photoreceptor caused by rubbing of a cleaning brush or a cleaning blade without causing problems such as defective cleaning of a developer even when used repeatedly. is there.

[0010]

According to the present invention, there is provided an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the product of the tensile strength at break (σ) and the elongation (ε) of the photosensitive layer of the photosensitive member is zero. .
An electrophotographic photoreceptor characterized by being at least 4 kg / mm ² .

It has been found that the mechanical properties of the photosensitive layer are involved in the scratches and abrasion on the surface of the photosensitive member due to the rubbing of the cleaning brush or the cleaning blade when the photosensitive member is repeatedly used. The effect of elongation is large, and the product of the tensile breaking strength of the photosensitive layer of the photoreceptor and the elongation is more preferably 0.4 kg / mm ² or more.
When it was 5 kg / mm ² or more, it was found that the scratch resistance and abrasion resistance were excellent, and the present invention was reached.

[0012] The tensile strength at break referred to herein is the stress required for a sample to break when a tensile break test is performed, and the elongation is the elongation of the sample before the test breaks in the same test. It is the ratio of the growth divided by the length.

In the present invention, the relationship between the surface friction coefficient (μ) of the photosensitive layer and the above-mentioned σ and ε may be represented by the following formula I.

[0014] ε · σ / μ ≧ 0.3kg / mm 2 ... I Result went further consideration, the surface coefficient of friction scratch resistance in addition to the photosensitive layer of the tensile breaking strength and elongation, abrasion resistance It has been found that there is an effect, and when the photosensitive layer has the photosensitive layer within the range of the above formula I, it is more preferable that ε · σ / μ ≧ 0.4 kg.
/ Scratch resistance when having a photosensitive layer in the range of / mm ² ,
It was found that the wear resistance was extremely excellent. The surface friction coefficient referred to herein is such that a thin layer of developer is provided on the electrophotographic photosensitive member, and then the cleaning blade is brought into contact with the electrophotographic photosensitive member to rotate the electrophotographic photosensitive member. The torque was detected by a torque meter, and the tangential and normal forces at the cleaning blade contact position were calculated from the torque, and the tangential force was divided by the normal force.

If the conductive support used in the present invention is soft, a hazard which is likely to be unevenly applied to the outermost surface layer of the cleaning brush or the cleaning blade is easily applied. It is desirable to use.

The hard cylinder referred to here has a thickness of 0.5
mm, cylindrical shape, Al, Ni, Cr, Zn,
The surface of an electrically insulating metal such as stainless steel or the like, or an organic insulating material such as polyester, polyimide, phenolic resin, or nylon resin, is vacuum-evaporated, sputtered, spray-painted, or the like by a method such as Al, Ni, Cr, Zn,
It refers to a material which is coated with an electrically conductive material such as stainless steel, carbon, SnO ₂ , In ₂ O _{3 and the} like and subjected to a conductive treatment.

The present invention also relates to the electrophotographic photoreceptor described above.
The cleaning method is characterized in that cleaning is performed by contacting a cleaning blade having a rebound resilience of at least 70% and preferably at least 40%. The rebound resilience is measured according to JIS K 6301 rebound resilience test. The rebound resilience of the cleaning blade is related to the wear resistance. If it exceeds 70%, the wear resistance is inferior, and if it is less than 30%, the cleaning blade is liable to chip, resulting in poor cleaning. The rebound resilience has a temperature dependence, but the rebound resilience described in the present invention is 23 ° C.
It is the value in. The ambient temperature in a copying machine or the like when using the cleaning blade of the present invention is preferably 10 to 60C.

The material of the cleaning blade used in the present invention is a urethane resin, the hardness is 60 to 80 °, the contact angle to the photoreceptor is 10 to 170 °, and the contact pressure to the photoreceptor is 10 The thickness is preferably 50 g / cm, and the shape may be plate-like, and a treatment such as providing a thin portion at an end may be performed as necessary.

The present invention further provides a cleaning method, wherein the cleaning is performed by bringing the cleaning blade into contact with the electrophotographic photosensitive member with a cleaning brush made of an acrylic resin or a polyester resin.

By using such a cleaning blade and a cleaning brush together during the cleaning, the burden of cleaning applied only to the cleaning blade can be shared by the cleaning brush, whereby the cleaning of the electrophotographic photosensitive member can be performed. Since the contact pressure of the blade can be reduced, wear resistance can be increased. However, if the material of the cleaning brush is other than an acrylic resin or a polyester resin, the cleaning effect is inferior because the cleaning ability is inferior. Therefore, the material of the cleaning brush is preferably an acrylic resin or a polyester resin.

The photosensitive layer in the present invention is preferably a laminated type comprising a charge generation layer and a charge transfer layer.

The charge generation layer is composed of only the charge generation material or a resin layer in which the charge generation material is dispersed or dissolved.

As the charge generating material, for example, CI Pigment Blue 25 @ CI (color index) 2
1180｝, CI Pigment Red 41 (CI21
100), CI Acid Red 52 (CI4510)
0), CI Basic Red 3 (CI4521)
0), a phthalocyanine pigment having a porphyrin skeleton, an azulhenium salt pigment, a squaric salt pigment, an anthansangthrone pigment, an azo pigment having a carbazole skeleton (described in JP-A-53-95033), and a stilbene skeleton Azo pigments (JP-A-53-1382)
No. 29), azo pigments having a triphenylamine skeleton (described in JP-A-53-13247),
Azo pigments having a dibenzothiophene skeleton (JP-A-54
No. 21728), an azo pigment having an oxadiazole skeleton (described in JP-A-54-12742), and an azo pigment having a fluorenone skeleton (described in JP-A-54-12742).
No. 22834), an azo pigment having a bisstilbene skeleton (described in JP-A-54-17733), and an azo pigment having a distyryloxadiazole skeleton (described in JP-A-54-2129) , A trisazo pigment having a distyrylcarbazole skeleton (JP-A-54
No. 17734), a trisazo pigment having a carbazole skeleton (described in JP-A-57-195767), and C-I-Bad Brown 5 (CI7321).
And organic pigments such as indigo pigments such as C.I. Bad Die (CI73030) and perylene pigments such as Argall Scarlet B and Indulens Scarlet R (manufactured by Bayer).

Among these charge generating materials, azo pigments are particularly preferred, and among the azo pigments, the following disazo pigments or trisazo pigments are most preferred.

Specific examples of the azo pigment are shown below.

[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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[0041]

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[0042]

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The thickness of the charge generation layer is suitably about 0.05 to 2 μm, and preferably 0.1 to 1 μm.

The charge generating layer is formed by dispersing or dissolving a charge generating material in a suitable solvent together with a resin binder, and coating and drying the dispersion on a substrate or an undercoat layer.

As such a resin binder, polystyrene, styrene-butadiene copolymer, styrene-
Acrylonitrile copolymer, styrene-maleic anhydride copolymer, polyester, polyarylate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyacrylate, polycarbonate, cellulose acetate resin, Ethyl cellulose resin, polyvinyl butyral, polyvinyl acetal, polyvinyl formal, phenoxy resin, polyvinyl pyridine, poly-N-vinyl carbazole, acrylic resin,
Thermoplastic or thermosetting resins such as silicone resin, nitrile rubber, chloroprene rubber, butadiene rubber, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin. These binder materials are used alone or in combination.

As the solvent, benzene, toluene, xylene, methylene chloride, dichloroethane, monochlorobenzene, dichlorobenzene, ethyl alcohol, methyl alcohol, butyl alcohol, isopropyl alcohol, ethyl acetate, butyl acetate, methyl ethyl ketone, dioxane, tetrahydrofuran, cyclohexane , Methyl cellosolve, ethyl cellosolve and the like, and these solvents can be used alone or in combination.

The charge transfer layer can be formed by dissolving or dispersing the charge transfer material and the resin binder in an appropriate solvent, and applying and drying the solution. If necessary, a plasticizer, a leveling agent, a material for enhancing abrasion resistance and the like can be added.

Examples of the charge transfer material include poly-N-carbazole and its derivatives, poly-γ-carbazolylethylglutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, imidazole There are derivatives, triphenylamine derivatives, and compounds represented by the following formula.

(1) (described in JP-A-55-154955 and JP-A-55-156954)

[0050]

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In the formula, R ₁ is a methyl group, an ethyl group, 2-
R ₂ represents a methyl group, an ethyl group, a benzyl group, or a phenyl group; R ₃ represents hydrogen, chlorine, bromine, a carbon atom of 1;
Represents an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, a dialkylamino group, or a nitro group. (2) (described in JP-A-55-52063)

[0052]

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In the formula, Ar represents a naphthalene ring, an anthracene ring, a styryl group, or a substituted product thereof, or a pyridine ring, a furan ring, or a thiophene ring, and R represents an alkyl group or a benzyl group. (Described in JP-A-56-81850)

[0054]

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Wherein R ₁ is an alkyl group, a benzyl group,
R ₂ represents hydrogen, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group, a diaralkylamino group or a diarylamino group, and n is an integer of 1 to 4 And when n is 2 or more, R ₂ may be the same or different. R ₂ represents hydrogen or a methoxy group. (4) (described in JP-B-51-10983)

[0056]

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In the formula, R ₁ represents an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group or a heterocyclic group; R ₂ and R ₃ may be the same or different; Represents an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a chloroalkyl group, a substituted or unsubstituted aralkyl group, and R ₂ and R ₃ may be bonded to each other to form a nitrogen-containing heterocyclic ring; . R ₄ may be the same or different and include hydrogen, an alkyl group having 1 to 4 carbon atoms,
Represents an alkoxy group or a halogen (5) (described in JP-A-51-94829)

[0058]

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In the formula, R represents hydrogen or a halogen atom, and Ar represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group or carbazolyl group. (6) (JP-A-52-128373) Described)

[0060]

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In the formula, R ₁ is hydrogen, halogen, cyano, alkoxy having 1 to 4 carbons, or 1 to 4 carbons.
Ar represents an alkyl group of

[0062]

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R ₂ represents an alkyl group having 1 to 4 carbon atoms, and R ₃ represents hydrogen, halogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a dialkylamino group. Wherein n is 1 or 2, and when n is 2, R ₃ may be the same or different, and R ₄ and R ₅ are hydrogen, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, Or a substituted or unsubstituted benzyl group. (7) (described in JP-A-56-29245)

[0064]

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In the formula, R represents a carbazolyl group, a pyridyl group, a phenyl group, an indolyl group, a furyl group, or a substituted or unsubstituted phenyl group, styryl group,
A naphthyl group or an anthryl group, wherein these substituents are a dialkylamino group, an alkyl group, an alkoxy group,
Represents a group selected from the group consisting of a carboxy group or an ester thereof, a halogen atom, a cyano group, an aralkylamino group, an N-alkyl-N-aralkylamino group, an amino group, a nitro group, and an acetylamino group. (Described in JP-A-58-58552)

[0066]

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In the formula, R ₁ represents a lower alkyl group or a benzyl group, and R ₂ represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, an amino group,
Alternatively, it represents an amino group substituted by a lower alkyl group or a benzyl group, and n represents an integer of 1 or 2. (9) (described in JP-A-57-73075)

[0068]

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In the formula, R ₁ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and R ₂ and R ₃
Represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and R ₄ represents a hydrogen atom,
Represents a lower alkyl group or a substituted or unsubstituted phenyl group, and Ar represents a phenyl group or a naphthyl group. (10) (described in JP-A-58-198043)

[0070]

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In the formula, n is an integer of 0 or 1, R ₁ is a hydrogen atom, an alkyl group including a substituted alkyl group, or a substituted or unsubstituted phenyl group, and Ar ₁ is a substituted or unsubstituted aryl group Wherein R ₅ represents an alkyl group containing a substituted alkyl group, or a substituted or unsubstituted aryl group;

[0072]

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Or a 9-anthryl group or a substituted or unsubstituted carbazolyl group, wherein R ₂ is a hydrogen atom, an alkyl group, an alkoxyl group, a halogen atom, or

[0074]

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(However, R ₃ and R ₄ represent an alkyl group containing a substituted alkyl group or a substituted or unsubstituted aryl group, R ₃ and R ₄ may be the same or different, and R ₄ represents a ring. May be formed), and m is 0,
An integer of 1, 2 or 3, and when m is 2 or more, R
₂ may be the same or different. When n is 0,
A and R ₁ may form a ring together. (11) (described in JP-A-49-105537)

[0076]

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Wherein R ₁ , R ₂ and R ₃ represent hydrogen, a lower alkyl group, a lower alkoxy group, a dialkylamino group, or a halogen atom, and n represents 0 or 1. (12) (See Japanese Patent Application Laid-Open No. 52-139066)

[0078]

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In the formula, R ₁ and R ₂ represent an alkyl group containing a substituted alkyl group, or a substituted or unsubstituted aryl group, and A represents a substituted amino group, or a substituted or unsubstituted aryl group or allyl group. (13) (described in JP-A-52-139065)

[0080]

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Wherein X is a hydrogen atom, a lower alkyl group,
Or a halogen atom, R represents an alkyl group containing a substituted alkyl group, or a substituted or unsubstituted aryl group, and A represents a substituted amino group, a substituted or unsubstituted aryl group, or an allyl group. Compounds represented by 1) include, for example, 9-ethylcarbazole-3-aldehyde-1-methyl-1-methyl
Phenylhydrazone, 9-ethylcarbazole-3-aldehyde-1-benzyl-1-phenylhydrazone, 9
-Ethylcarbazole-3-aldehyde-1,1-diphenylhydrazone.

Compounds represented by the general formula (2) include, for example, 4-diethylaminostyryl-β-aldehyde-
There are 1-methyl-1-phenylhydrazone, 4-methoxynaphthalene-1-aldehyde-1-benzyl-1-phenylhydrazone and the like.

The compound represented by the general formula (3) includes, for example, 4-methoxybenzaldehyde-1-methyl-1
-Phenylhydrazone, 2,4-dimethoxybenzaldehyde-1-benzyl-1-phenylhydrazone, 4-
Diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-methoxybenzaldehyde-1-benzyl-1- (4-methoxy) phenylhydrazone, 4-
Diphenylaminobenzaldehyde-1-benzyl-1
-Phenylhydrazone, 4-dibenzylaminobenzaldehyde-1,1-diphenylhydrazone and the like.

Compounds represented by the general formula (4) include, for example, 1,1-bis (4-dibenzylaminophenyl)
There are propane, tris (4-diethylaminophenyl) methane, 1,1-bis (4-dibenzylaminophenyl) propane, 2-2′-dimethyl-4,4′-bis (diethylamino) -triphenylmethane and the like.

The compound represented by the general formula (5) includes, for example, 9- (4-diethylaminostyryl) anthracene, 9-bromo-10- (4-diethylaminostyryl) anthracene and the like.

Examples of the compound represented by the general formula (6) include 9- (4-dimethylaminobenzylidene) fluorene and 3- (9-fluorenylidene) -9-ethylcarbazole.

The compounds represented by the general formula (7) include, for example, 1,2-bis (4-diethylaminostyryl) benzene, 1,2-bis (2,4-dimethoxystyryl)
There is benzene.

Compounds represented by the general formula (8) include, for example, 3-styryl-9-ethylcarbazole,
(4-methoxystyryl) -9-ethylcarbazole and the like.

The compounds represented by the general formula (9) include, for example, 4-diphenylaminostilbene, 4-dibenzylaminostilbene, 4-ditolylaminostilbene,
1- (4-diphenylaminostyryl) naphthalene, 1
-(4-diethylaminostyryl) naphthalene and the like.

The compound represented by the general formula (10) includes
For example, 4′-diphenylamino-α-phenylstilbene, 4′-N, N-bis (4-methylphenyl) amino-α-phenylstilbene and the like are available.

Compounds represented by the general formula (11) include:
For example, 1-phenyl-3- (4-diethylaminostyryl) -5- (4-diethylaminophenyl) pyrazoline, 1-phenyl-3- (4-dimethylaminostyryl) -5- (4-dimethylaminophenyl) pyrazoline and the like There is.

Compounds represented by the general formula (12) include:
For example, 2,5-bis (4-diethylaminophenyl)
-1,3,4-oxadiazole, 2-N, N-diphenylamino-5- (4-diethylaminophenyl)-
1,3,4-oxadiazole, 2- (4-dimethylaminophenyl) -5- (4-diethylaminophenyl)
-1,3,4-oxadiazole and the like.

Compounds represented by the general formula (13) include:
For example, 2-N, N-diphenylamino-5 (N-ethylcarbazol-3-yl) -1,3,4-oxadiazole, 2- (4-diethylaminophenyl) -5
(N-ethylcarbazol-3-yl) -1,3,4-
Oxadiazole and the like.

Further examples of the charge transfer material are listed below.

(14) (described in JP-B-58-323772)

[0096]

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In the formula, R ₁ represents a lower alkyl group, a lower alkoxy group, or a halogen atom, n represents an integer of 0 to 4, R ₂ and R ₃ may be the same or different, and a hydrogen atom , A lower alkyl group, a lower alkoxy group, or a halogen atom. ｝ (15) (described in Japanese Patent Application No. Hei 1-280763)

[0098]

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Wherein R ₁ , R ₃ and R ₄ are a hydrogen atom,
R ₂ represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted aryl group, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom, or a substituted or unsubstituted aryl group; Or an unsubstituted alkyl group or halogen.
However, the case where all of R ₁ , R ₂ , R ₃ and R ₄ are hydrogen atoms is excluded. K, l, m and n are 1, 2, 3
Or R is an integer of 4, and when each is an integer of 2, 3 or 4, the above R ₁ , R ₂ , R ₃ and R ₄ may be the same or different. 77839)

[0100]

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In the formula, Ar represents a condensed polycyclic hydrocarbon group having 18 or less carbon atoms, R ₁ and R ₂ represent a hydrogen atom,
A halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, or a substituted or unsubstituted phenyl group, which may be the same or different. (17) (described in Japanese Patent Application No. 62-98394) CH-Ar-CH = CH-A wherein Ar represents a substituted or unsubstituted aromatic hydrocarbon group;

[0102]

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(Where Ar ′ represents a substituted or unsubstituted aromatic hydrocarbon group, and R ₁ and R ₂ are a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group). (18) (described in Japanese Patent Application No. 2-94812)

[0104]

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In the formula, Ar represents an aromatic hydrocarbon group, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, or an aryl group. n is 0 or 1, m is 1 or 2, and when n = 0 and m = 1, Ar and R may form a ring together. In the benzidine compound represented by the general formula (14), Is, for example, N, N′-diphenyl-bis (3-methylphenyl)-{1,1′-biphenyl} -4,4′-diamine, 3,3′-dimethyl-N, N, N ′, N And '-tetrakis (4-methylphenyl)-{1,1'-biphenyl} -4,4'-diamine.

The biphenylamine compound represented by the general formula (15) includes, for example, 4′-methoxy-N, N-diphenyl- {1,1′-biphenyl} -4-amine,
4'-methyl-N, N-bis (4-methylphenyl)-
{1,1′-biphenyl} -4-amine, 4′-methoxy-N, N-bis (4-methylphenyl)-{1,1 ′
-Biphenyl} -4-amine and the like.

Examples of the triarylamine compound represented by the general formula (16) include 1-N, N-diphenylaminopyrene, 1-N, N-pis (p-tolylamino) pyrene and the like.

The diolefin aromatic compound represented by the general formula (17) includes, for example, 1,4-bis (4-N, N
-Diphenylamino) styrylbenzene, 1,4-bis {4-N, N-bis (p-tolyl) amino} styrylbenzene and the like.

Examples of the stilpyrene compound represented by the general formula (18) include 1- (4-N, N-diphenylamino) styrylpyrene and 1- {4-N, N-bis (p-
(Tolyl) aminostilpyrene and the like.

In particular, a substance that transports negative charges, that is, electrons, may be used for the electrophotographic photosensitive member. Examples of the electron transport material include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,
7-trinitro-9-fluorene, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8- Trinitro-indeno 4H-indeno {1,2-b} thiophen-4-one, 1,3,7
-Trinitrodibenzothiophene-5,5-dioxide and the like. Examples of the resin binder for the charge transfer layer in which the above charge transfer agent is compatible or dispersed include polycarbonate, polyarylate, polyacrylate, polyester, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene-anhydride. Maleic acid copolymer, polyvinyl chloride, polyvinyl acetate,
Vinyl chloride-vinyl acetate copolymer, polyvinylidene chloride, phenoxy resin, cellulose acetate, ethyl cellulose, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, silicone resin, epoxy resin, melamine resin, urethane resin, phenol Thermoplastic or thermosetting resins such as resin and alkyd resin. These may be used alone or as a mixture.

As the solvent at this time, tetrahydrofuran, dioxane, cyclohexane, toluene, monochlorobenzene, dichloroethane, methylene chloride and the like can be used. The solvent may be used alone or in combination of two or more.

Further, a plasticizer or a leveling agent may be added as required. As the plasticizer, for example, halogenated paraffin, dimethyl naphthalene, dibutyl phthalate,
Examples thereof include polymers and copolymers such as dioctyl phthalate, tricresyl phosphate, and polyester.

Examples of the leveling agent include silicone oil and perfluoro group-containing oligomers or polymers.

The thickness of the charge transfer layer is 5 to 100 μm, preferably 10 to 50 μm.

Further, in the present invention, an intermediate layer of polyamide, polyvinyl alcohol, polyvinyl acetal, polyacrylic acid, polyhydroxymethacrylate, epoxy resin or the like, or a resin and a white pigment such as zinc oxide are provided between the support and the photosensitive layer. , Magnesium oxide, barium sulfate, and lithopone.

The film thickness of the intermediate layer or the white pigment layer is 0.05
The thickness is suitably from 10 to 10 μm, preferably from 0.2 to 5 μm.

[0117]

The present invention will be specifically described below with reference to examples and comparative examples.

Example 1 Two 80 mmφ aluminum cylinders were prepared. On this 80 mmφ aluminum cylinder, a polyamide (CM8000, manufactured by Toray Industries, Inc.) was formed as a subbing layer of about 0.2 μm, and the following azo pigment The cyclohexanone dispersion of (1) is dip-coated and dried by heating to about 0.1 μm.
m of the charge generation layer was formed.

[0119]

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Next, the charge-transfer substance (D) represented by the following structural formula (2) and the binder resin (R) represented by the following structural formula (3) having a viscosity average molecular weight of 50,000 were combined with D / R = 5 / 10
(Weight ratio), the solid content was adjusted to 15% (solvent: methylene chloride solution), and then silicone oil (KF-
50, manufactured by Shin-Etsu Silicone Co., Ltd.) and a charge transfer layer coating solution (solvent: methylene chloride solution) to which 0.2% (R ratio) was added, dip-coated on the charge generation layer and dried by heating to obtain a charge of about 22 μm. A moving layer was formed to prepare an electrophotographic photoreceptor (one was a sample for a tensile break test, and the other was a sample for a copy test).

[0121]

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The photosensitive layer was peeled off from the electrophotographic photosensitive member,
Dumbbell punching No.2 type (described in JIS K-6301)
This was used as a sample for a tensile breaking test.

The sample for tensile breaking test was mounted on a universal tensile compression tester (Model TCM-200CR, manufactured by Minebea), and a tensile breaking test was performed at a pulling speed of 5 mm / min to determine tensile breaking strength and elongation.

Next, the above-mentioned electrophotographic photosensitive member was mounted on a copying machine having the following specifications by a usual Carlson process, and a 100,000-sheet copy test was carried out. It was measured with a meter.

(Copier specifications) Cleaning blade Material: Polyurethane resin Rebound resilience: 48% Hardness: 70 ° Contact angle: 15 ° Contact pressure: 20 g / cm Cleaning brush Material: Acrylic resin Copy speed: 30 Sheets / min Example 2 An electrophotographic photoreceptor and a sample for a tensile break test were prepared and evaluated in the same manner as in Example 1 except that the charge transfer material was changed to that shown by the following structural formula (4). Was.

[0126]

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Example 3 An electrophotographic photosensitive member and a sample for a tensile test were prepared in the same manner as in Example 1 except that the binder resin was changed to that represented by the following structural formula (5) (viscosity average molecular weight: 60,000). The same evaluation was performed.

[0128]

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Comparative Example 1 The charge transfer material was represented by the following structural formula (6), the binder resin was represented by the following structural formula (7) (viscosity average molecular weight: 20,000), and D / R = 9. An electrophotographic photoreceptor and a sample for a tensile break test were prepared and evaluated in the same manner as in Example 1 except that the ratio was changed to / 10.

[0130]

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Table 1 shows the above results.

[0132]

[Table 1]

Example 4 Two 80 mmφ aluminum cylinders were prepared, and the following intermediate layer coating solution was applied by dip coating and heat drying on the aluminum cylinder to provide an intermediate layer of about 3 μm.

(Coating Liquid for Intermediate Layer) Alkyd resin (Beccolite M-6401, manufactured by Dai Nippon Ink) 3 parts by weight Melamine resin (Super Beckamine G-821, manufactured by Dai Nippon Ink) 2 parts by weight TiO ₂ (CR-EL, manufactured by Ishihara Sangyo Co., Ltd.) After dispersing a liquid consisting of 30 parts by weight of methyl ethyl ketone 15 parts by weight for 24 hours, methyl ethyl ketone /
It was diluted with 11/9 parts by weight of isopropyl alcohol to obtain a coating liquid for an intermediate layer.

Next, a cyclohexanone dispersion of the following azo pigment (8) was dip-coated and dried by heating to a thickness of about 0.1.
A μm charge generation layer was formed.

[0136]

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Next, a charge transfer material (D) represented by the following structural formula (9) and a binder resin (R) having a viscosity average molecular weight of 50,000 represented by the following structural formula (10) were combined with D / R = 5 /
10 (weight ratio) and a solid content concentration of 15% (solvent: methylene chloride solution).
F-50, manufactured by Shin-Etsu Silicone Co., Ltd.) 1.0% (R ratio)
Added coating solution for charge transfer layer (solvent: methylene chloride solution)
Dip coating on the charge generation layer and drying by heating
To form an electrophotographic photoreceptor (1).
The book is a sample for a tensile break test, and the other is a sample for a copy test.)

[0138]

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The photosensitive layer was peeled off from the electrophotographic photosensitive member,
Dumbbell punching No.2 type (described in JIS K-6301)
This was used as a sample for a tensile breaking test.

The sample for tensile breaking test was attached to a universal tensile compression tester (Model TCM-200CR, manufactured by Minebea), and a tensile breaking test was performed at a pulling speed of 5 mm / min to determine tensile breaking strength and elongation.

Next, the above electrophotographic photosensitive member was mounted on a copying machine having the following specifications by a normal Carlson process, and a 100,000 copy test was carried out. It was measured with a meter.

(Copier specifications) Cleaning blade Material: Polyurethane resin Rebound resilience: 55% Contact angle: 100 ° Contact pressure: 40 g / cm Cleaning brush Material: Polyester resin Copy speed: 60 sheets / min. After removing the charger, developing device, transfer device, and cleaning brush from the copier of the above specifications, installing the electrophotographic photoreceptor before the copy test on a modified machine equipped with a torque meter, and then applying the developer thinner on the electrophotographic photoreceptor. The electrophotographic photosensitive member was rotated by contacting only the cleaning blade without providing the layer and exposing and passing the paper, and the surface friction coefficient was determined from the detected torque.

Example 5 0.1% (based on R) of a fluorine-based compound (Defenser MCF312, manufactured by Dainippon Ink) in the above-mentioned coating solution for the charge transfer layer.
A sample was prepared and evaluated in the same manner as in Example 4 except that the ratio was added.

Example 6 A sample was prepared and evaluated in the same manner as in Example 4 except that the binder resin was changed to the one represented by the following structural formula (11).

[0145]

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Example 7 A binder resin having a viscosity average molecular weight of 50,000 represented by the following structural formula (12) and a resin represented by the following structural formula (13) were mixed at a ratio of 9/1 (weight ratio). A sample was prepared and evaluated in the same manner as in Example 4 except that the sample was replaced with a sample.

[0147]

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Comparative Example 2 A charge transfer material was replaced with one represented by the following structural formula (14).
A sample was prepared and evaluated in the same manner as in Example 4, except that the binder resin was changed to a resin having the viscosity average molecular weight of 20,000 represented by the structural formula (3).

[0149]

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Comparative Example 3 The charge transfer material was changed to that represented by the following structural formula (15).
A sample was prepared and evaluated in the same manner as in Example 4, except that D / R was changed to 10/5.

[0151]

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Table 2 shows the evaluation results of Examples 4 to 7 and Comparative Examples 2 and 3.

[0153]

[Table 2]

Comparative Example 4 A copy test was performed in the same manner as in Example 4 except that the cleaning blade was changed to a cleaning blade having a rebound resilience of 20%. When about 80,000 sheets were tested, the cleaning blade was chipped, resulting in poor cleaning of the image. Black streaks occurred.

Comparative Example 5 A copy test was performed in the same manner as in Example 4 except that the cleaning blade was changed to a rebound resilience of 80%. After the copy test of 100,000 sheets, the film thickness was reduced by 7.1 μm. Fogging had occurred.

Comparative Example 6 A copy test was carried out in the same manner as in Example 4 except that the aluminum cylinder was changed to a paper tube on which aluminum was vapor-deposited. As a result, the film thickness was reduced by 5.0 μm after the 100,000-sheet copy test. Further, film thickness unevenness occurred, and the image was non-uniform.

Comparative Example 7 A copy test was performed in the same manner as in Example 4 except that the cleaning brush was changed to a styrene resin brush. At the very early stage, a background stain due to poor cleaning occurred on the image. When a copying test was performed while changing the contact pressure of the cleaning blade to 60 g / cm, the film thickness was reduced by 6.5 μm after the 100,000-sheet copying test, and fogging occurred in the image.

[0158]

The electrophotographic photoreceptor of the present invention can maintain high sensitivity even when repeatedly used, has good abrasion resistance, and does not cause problems such as poor cleaning during cleaning. This can be performed with almost no scratches or wear on the surface of the photoreceptor due to the rubbing of the cleaning brush or the cleaning blade.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshiaki Kawasaki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-3-20768 (JP, A) JP-A Heihei JP-A-3-63651 (JP, A) JP-A-3-65444 (JP, A) JP-A-3-179909 (JP, A) JP-A-5-35156 (JP, A) JP-A-54-3545 (JP, A) A) JP-A-56-113186 (JP, A) JP-A-1-99056 (JP, A) JP-A-2-233765 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) G03G 5 / 047,5 / 10

Claims (5)

(57) [Claims] 1. An electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the product of the tensile strength at break (σ) and the elongation (ε) of the photosensitive layer of the photosensitive member is 0.4 kg / mm ² or more. An electrophotographic photoreceptor, characterized in that: 2. The electrophotographic photosensitive member according to claim 1, wherein the relationship between the surface friction coefficient (μ) of the photosensitive layer and σ, ε is represented by the following formula I. ε · σ / μ ≧ 0.3 kg / mm ² … I 3. The electrophotographic photosensitive member according to claim 1, wherein the conductive support is a hard cylinder. 4. An electrophotographic photosensitive member in which the product of the tensile strength at break (σ) and the elongation (ε) of the photosensitive layer on the conductive support is 0.4 kg / mm ² or more is 30% or more and 70% or less. A cleaning method for an electrophotographic photoreceptor, wherein the cleaning is performed by bringing a cleaning blade having a rebound resilience into contact with the cleaning blade. 5. The method for cleaning an electrophotographic photosensitive member according to claim 4, wherein a cleaning blade having a rebound resilience of 30% or more and 70% or less is brought into contact with a cleaning brush made of an acrylic resin or a polyester resin.