JPH05188631A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To prevent decrease in picture qualities caused by repeated use for a long period and to prevent deterioration of a photosensitive body due to an ionic oxidizing agent such as NO2<->, NO3<->, etc., by forming an ion trapping layer between a charge generating layer and a surface protective layer. CONSTITUTION:This electrophotographic sensitive material consists of a conductive base body 1 and a charge transfer layer(CTL) 2, charge generating layer(CGL) 3, ion trapping layer 4 for anions, and surface protective layer (OCL) 5 successively formed on the base body 1. Namely, by providing the ion trapping layer 4 between CGL 3 and OCL 5, oxidative aions such as NO2<->, NO3<->, etc., transmitting through OCL 5 are prevented from intruding and oxidization deterioration of CGL 3 can be prevented. These anions are strong anions so that if these anions intrude into CGL 3, negative spacial charges are accumulated to cause deterioration of electrostatic characteristics even when oxidization deterioration of CGL 3 is not caused. However, by preventing anions from intruding by the ion trapping layer 4, accumulation of negative spacial charges can be prevented.

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 more particularly, to an improvement for preventing deterioration of image quality over time in a function-separated layered photosensitive member and improving durability.

[0002]

2. Description of the Related Art As one type of photoconductor used in electrophotography, there is a function-separated laminated photoconductor, for example, one in which a charge generation layer (CGL) and a charge transport layer (CTL) are sequentially laminated on a conductive substrate. On the contrary, a charge transport layer (C
It is known that a TL) and a charge generation layer (CGL) are sequentially stacked. Among these laminated photoreceptors, the latter one has the advantage that positive charging with less generation of ozone is possible, but since the charge generation layer is located on the outermost surface, it also has a mechanical (physical) meaning. There is a drawback that the printing durability is inferior also in the chemical sense. For the purpose of preventing this, a surface protective layer (OCL) is generally provided on the charge generation layer.

Japanese Unexamined Patent Publication (Kokai) No. 2-139574 describes blending a hindered amine as a light resistance stabilizer in the surface protective layer of the above-mentioned laminated photoreceptor. Further, JP-A-2-149855 describes that an antioxidant is blended in the charge transport layer and the surface protective layer of the laminated photoreceptor. Further, in JP-A-60-212770, although the layer structure and function are different from those of the above-mentioned laminated photoreceptor,
A laminate comprising a transparent base film, a transparent conductive layer, a photoconductive layer, an intermediate layer and a surface layer, which contains colloidal silica powder in the intermediate layer is described.

[0004]

The former two proposals are to prevent the photo-deterioration and the oxidative deterioration caused during exposure or charging by adding a light stabilizer or an antioxidant to the surface protective layer. The latter proposal aims to provide a highly stable and highly durable photoreceptor by improving the adhesion and adhesion between the surface layer and the photoconductive layer and preventing delamination. Is. However, in these conventional proposals, when the function separation type laminated photoreceptor, particularly the laminated photoreceptor in which the charge transport layer and the charge generation layer are provided in this order on the conductive substrate, is repeatedly charged and exposed, an image of an image gradually increases. It was found that deterioration of the image quality over time, such as white spots, could not be avoided.

According to the research conducted by the present inventors, when charging a photoreceptor, NOx (NO _x ) in which oxygen and nitrogen react with active oxygen molecules such as ozone (O ₃ ) and singlet oxygen (O ₂ ¹ ). ) Is generated. The antioxidant effectively acts on O ₃ , O ₂ ¹ and radical oxidants that attack from the surface of the surface protective layer (OCL), effectively preventing chemical deterioration and electrostatic characteristics of the photoconductor. Can be prevented. However, NO _x is water and the reaction was to produce nitrite ions in the air (NO ₂ ^-) and nitrate ion (NO ₃ ^-) with respect to the ionic oxidizing agents such as, the effect of the antioxidant It was low, and it was still insufficient to prevent deterioration due to repeated use of the photoreceptor, particularly deterioration in image quality.

Therefore, an object of the present invention is to prevent deterioration of image quality over time due to repeated use of a laminated photoreceptor comprising a conductive substrate, a charge transport layer, a charge generating layer and a surface protective layer. Another object of the present invention is to provide an organic laminated photoreceptor in which deterioration of the photoreceptor due to an ionic oxidant such as NO ₂ ⁻ or NO ₃ ⁻ is effectively prevented.

[0007]

According to the present invention, a charge transport layer, a charge generating layer, an ion trap layer for anions and a surface protective layer are laminated in this order on a conductive substrate. An electrophotographic photoreceptor is provided.
In the present invention, as the ion trap layer for anions, an organopolysiloxane having a silanol group, particularly an organopolysiloxane containing a silanol group at a concentration of 5 mmol / 100 g resin or more, polyvinyl alcohol, an ethylene-vinyl alcohol copolymer is used. Hydroxyl group-containing polymers such as and high nitrile resins are preferably used.

[0008]

In FIG. 1 showing the sectional structure of the laminated photoreceptor of the present invention, the laminated photoreceptor comprises a conductive substrate 1, a charge transport layer (CTL) 2 sequentially provided on the conductive substrate, and a charge generation layer. (CGL) 3, an ion trap layer 4 for anions, and a surface protective layer (OCL) 5. In the present invention, the above-mentioned CTL / CGL / OCL type laminated photoreceptor is targeted because it is capable of positive charging with less generation of ozone. However, in this type of laminated photoreceptor, CGL is present in a portion close to the surface of the photoreceptor, so that it is very susceptible to the effects of oxidants and ions that permeate OCL.

In the photoreceptor of the present invention, CGL3 and OCL5
An ion trap layer 4 for anions is provided between
The character is a remarkable feature. That is, this ion tiger
By providing the top layer 4 between CGL and OCL,
NO that has passed through OCL ₂ ^-, NO₃ ^-Oxidation of etc.
This layer blocks the ionic anion and effectively prevents oxidative deterioration of CGL
Can be prevented. The anion is a strong anion.
When it enters CGL, it causes oxidative deterioration of CGL.
In the absence of this, negative space charge buildup will occur, which results in static
Although it causes deterioration of electrical characteristics, the ion trap layer causes
By blocking the invasion of the nions, the negative space charge is stored.
The product can be effectively prevented.

Further, since the ion trap layer for anions is provided between CGL and OCL, CGL and OCL
The above-mentioned anionic oxidant is effectively blocked without interfering with the original function of CL, and the ion trap layer is protected by OCL, so the blocking action of the anionic oxidant is used for a long time. There is an advantage that it is continuously and stably expressed. Further, in general, the resins constituting the anion trap layer used in the present invention tend to have increased permeability to anions due to moisture absorption, but by providing a surface protective layer (OCL) on the anion trap layer, moisture absorption can be prevented. There is also an advantage that it can be prevented and the anion blocking property can be improved.

[0011]

In a preferred embodiment the ion trap layer present invention a preferred embodiment of the invention, as an ion trap layer, using an organopolysiloxane having a silanol group. That is, a usual organopolysiloxane has almost no blocking property against anions, but it has a silanol group, that is,

[Chemical 1] Organopolysiloxanes containing groups NO ₂ ^-, NO ₃
^- superior exceptionally in barrier properties against anions such.
The concentration of silanol groups in the organopolysiloxane is generally in the range of 5 mmol / 100 g resin or more, particularly 30 to 300 mmol / 100 g resin,
Desirable for the purpose of the present invention, when the silanol group concentration is lower than the above range, the barrier property against ions tends to be unsatisfactory, while when the silanol group concentration is higher than the above range, the denseness and mechanical properties of the film as the ion trap layer are high. Strength tends to decrease.

Examples of the silane used for forming the silanol group-containing organopolysiloxane include those represented by the formula:

[Chemical 2] In the formula, R is a monovalent hydrocarbon group having up to 5 carbon atoms, R ¹ is a hydrolyzable monovalent group such as an alkoxy group having 4 or less carbon atoms or a halogen atom, and n is 2 to 4 Is the number of. One or a combination of two or more of the silanes represented by Examples of the monovalent hydrocarbon group include an alkyl group such as a methyl group, an ethyl group and a propyl group, an alkenyl group such as a vinyl group, a phenyl group, a tolyl group and an aryl group such as an ethylphenyl group. These silanes can be used to form silanol group-containing organopolysiloxanes in the form of dimers, trimers, tetramers or other linear or cyclic oligomers.

Suitable examples of the "Chemical Formula 2" silanes include, but are not limited to, monomethyltriethoxysilane, dimethyltriethoxysilane, trimethylethoxysilane,
Examples thereof include ethyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, vinyltrimethoxysilane, ethylsilicate and dimethyldichlorosilane. Among these, 2- to 4-functional alkoxysilanes are preferable, and those having trifunctional alkoxysilane as a main component are particularly preferable.

The concentration of silanol groups in the organopolysiloxane can be set to a desired value by adjusting the concentration of hydrolyzable groups in the silane of Chemical formula 2 and controlling the degree of condensation thereof. .. That is, a hydrolyzable group such as an alkoxy group in silane is first hydrolyzed to a silanol group and then condensed to a siloxane repeating unit.
Silanol groups can be left in the organopolysiloxane by gently performing this condensation.
For example, in the case of trialkoxysilane, the heat treatment at 400 ° C. or higher almost eliminates the residual silanol group, but by treating this at a temperature of 150 to 200 ° C., the silanol group is left at a predetermined concentration to give a predetermined concentration. An ion trap layer can be formed. Needless to say, this heat treatment condition cannot be unconditionally specified because it changes depending on the use or non-use of the silanol condensation catalyst, but in short, the condition that the silanol group of the above-mentioned concentration remains may be selected.

In another preferred embodiment of the present invention, polyvinyl alcohol
Water such as alcohol and ethylene-vinyl alcohol copolymer
An acid group-containing polymer is used. These polymers are
Permeability to other polymers is significantly lower than other polymers
Not NO₂ ^-, NO₃ ^-Shielding against anions such as
Excellent in cutting performance. As polyvinyl alcohol,
Average degree of polymerization (P) is 1000 to 60,000, especially 20
00 to 30,000 and saponification degree of 80 to 99.8
%, Especially in the range of 90 to 99.5% is suitable
It As the ethylene-vinyl alcohol copolymer,
Tylene content of 15 to 60% by weight, especially 20 to 50
Weight% and saponification degree of 90 to 99.5% are suitable.
ing.

In addition to the above, known oxygen barrier resins such as high nitrile resin, oxygen barrier polyamide, oxygen barrier polyester and the like can be used as the ion trap layer. However, vinylidene chloride resins are not suitable for the ion trap layer of the present invention because they have poor light resistance.

In the present invention, the thickness of the ion trap layer varies depending on the type of material, but is generally 0.0.
The thickness is preferably 1 to 2 μm, particularly 0.05 to 0.5 μm. The ion trap layer is formed by preparing a solution or dispersion of the above-mentioned resin or resin precursor,
It can be carried out by applying this solution or dispersion, drying it, and heat treating it if necessary.

As the solvent for preparing the coating solution, for example, in addition to water, alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; aliphatic hydrocarbons such as n-hexane, octane and cyclohexane; benzene and toluene , Aromatic hydrocarbons such as xylene; halogenated hydrocarbons such as dichloromethane, dichloroethane, carbon tetrachloride, chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether; acetone, Ketones such as methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and methyl acetate; dimethylformamide; dimethyl sulfoxide and the like,
Various solvents are used alone or in combination of two or more.

Laminated Photoreceptor In the present invention, the composition, constitution and preparation method of each layer of the laminated photoreceptor other than the ion trap layer are known per se. The positively chargeable laminate type photosensitive layer is formed by first coating the charge transporting layer on a conductive substrate using a charge transporting layer coating liquid containing a charge transporting material, a binder resin, and optionally a solvent. A charge generation layer is formed by applying a charge generation layer coating liquid containing a charge generation material, a binder resin, and a solvent, if necessary, onto the charge transport layer.

Examples of the charge transport material include chloranil, tetracyanoethylene, fluorenone compounds such as 2,4,7-trinitro-9-fluorenone, and nitration compounds such as 2,4,8-trinitrothioxanthone and dinitroanthracene. N, N-diethylaminobenzaldehyde, N, N-diphenylhydrazone, N-methyl-3-
Carbazolyl aldehyde, hydrazone compounds such as N, N-diphenylhydrazone, oxadiazole compounds such as 2,5-di (4-dimethylaminophenyl) -1,3,4-oxadiazole, 9- ( Styryl compounds such as 4-diethylaminostyryl) anthracene, carbazole compounds such as N-ethylcarbazole, pyrazoline compounds such as 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline, 2- (p-diethylaminophenyl) -4- (p-dimethylaminophenyl) -5
Oxazole compounds such as (2-chlorophenyl) oxazole, isoxazole compounds, thiazole compounds such as 2- (p-diethylaminostyryl) -6-diethylaminobenzothiazole, triphenylamine,
Amine derivatives such as 4,4′-bis [N- (3-methylphenyl) -N-phenylamino] diphenyl, stilbene compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, indole compounds,
Examples include nitrogen-containing cyclic compounds such as triazole compounds, condensed polycyclic compounds, succinic anhydride, maleic anhydride, dibromomaleic anhydride, poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, and ethylcarbazole-formaldehyde resin. To be done. The photoconductive polymer such as poly-N-vinylcarbazole is
It can also be used as a binder resin described later. These charge transport materials may be used alone or in combination of two or more.

As the charge generating material, various conventionally known materials such as selenium, selenium-tellurium, amorphous silicon, pyrylium salts, azo compounds, disazo compounds, trisazo compounds, anthanthrone compounds, phthalocyanine are used. Compounds, indigo compounds, triphenylmethane compounds, slene compounds, toluidine compounds, pyrazoline compounds, perylene compounds,
Examples include quinacridone compounds, and these may be used alone or in combination of two or more. As the binder resin (binder), a styrene-based polymer, a styrene-butadiene copolymer, a styrene-acrylonitrile copolymer, a styrene-maleic acid copolymer, an acrylic polymer, a styrene-acrylic copolymer, ethylene -Vinyl acetate copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyester, alkyd resin, polyamide, polyurethane, epoxy resin, polycarbonate,
In addition to polyarylate, polysulfone, diallyl phthalate resin, silicone resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin and the like, epoxy acrylate, photo-curable resin such as urethane acrylate and the like, various polymers are exemplified, These may be used alone or in combination of two or more.

When forming the charge transport layer, the ratio of the charge transport material to the binder resin may be appropriately selected. Usually, 30 to 50 parts by weight of binder resin or the like is added to 100 parts by weight of the charge transport material.
Used 0 parts by weight. The charge transport layer may be formed to have an appropriate thickness. Usually, it is formed to a film thickness of about 2 to 100 μm. When forming the charge generation layer, a binder resin may be used together, and the charge generation material is directly formed on the charge transport layer by using a film forming method such as vapor deposition or sputtering without using the binder resin. You may. When the charge generating layer is formed using the binder resin, the binder resin is usually used in an amount of 1 to 300 parts by weight based on 100 parts by weight of the charge generating material. The charge generation layer may be formed to have an appropriate thickness. Normally, the film thickness is 0.
It is formed to have a thickness of about 01 to 5 μm.

In the preparation of the coating liquid for the charge generating layer and the coating liquid for the charge transporting layer, an appropriate organic solvent is added as necessary in order to improve the coating property depending on the kind of the resin contained in each layer. It can be used and can be appropriately selected and used from the above-mentioned solvents used in the preparation of the protective layer coating liquid. The photosensitive layer may contain various additives such as terphenyl, halonaphthoquinones, acenaphthylene, and other conventionally known sensitizers, plasticizers, ultraviolet absorbers, deterioration inhibitors such as antioxidants, and the like. .. Further, an intermediate layer for facilitating charge transfer between the charge generation layer and the charge transport layer may be formed between the layers. Also in the preparation of the coating liquid for the charge generating layer or the coating liquid for the charge transporting layer, the above-mentioned conventional conventional mixing means and coating method used in the preparation of the coating liquid for the protective layer can be used.

The conductive base material on which the photosensitive layer including the charge transport layer and the charge generation layer is laminated is aluminum, aluminum alloy, copper, tin, platinum, gold,
A simple substance of metal such as silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass, and a glass substrate on which a film of these listed metals or a metal oxide thereof is formed by vapor deposition or the like. An example is a plastic substrate. The conductive substrate may have a sheet shape or a drum shape. After the above-described ion trap layer is formed on the photosensitive layer made of CTL / CGL thus formed, a surface protective layer (OCL) is formed.

As the surface protective layer, a resin having excellent chemical stability and thermal stability, abrasion resistance and mechanical properties, particularly a thermosetting resin is used. This resin is not particularly limited as long as it is a resin that is cured by light or heat. For example, thermosetting acrylic resin, silicone resin, epoxy resin,
Urethane resin, phenol resin, polyester, melamine resin and the like can be mentioned. Incidentally, the surface protection resin,
In order to maintain good chargeability, its electric resistance value is
^{1.0 × 10 - 8 ~5.0 × 10} - 8 Ω - 1 cm - 1 preferably has ^{2.0 × 10 - 8 ~4.0 × 10} - 8 Ω
^{- 1} cm ^{- 1} ones are more preferable. Further, in order to improve coatability and prevent cracks from occurring in the protective layer, the protective layer may contain less than 50% by weight of a thermoplastic resin. As such a thermoplastic resin, a conventionally known thermoplastic resin such as vinyl chloride resin, vinyl acetate resin, polypropylene or methacrylic resin can be used.

The thickness of the protective coating layer varies depending on the resin, but is generally 0.1 to 10 μm, and particularly 0.5 to 5 μm.
The range of μm is suitable. The coating of the surface protective layer can also be carried out by preparing a solution or dispersion of the above resin, coating the solution, drying it, and optionally baking it. The solvent used is appropriately selected from those exemplified above, but it is preferable to select a solvent that does not mix the ion trap layer and the surface protective layer.

In the present invention, the surface protective layer may contain a compounding agent known per se. For example, sterically hindered phenols, 2,6-di-t-butyl-p-cresol,
2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'-thiobis (3-methyl-6-
t-butylphenol), 4,4′-butylidenebis (3-methyl-6-t-butylphenol), stearyl-β (3,5-di-4-butyl-4-hydroxyphenyl) propionate, 1,1,3- Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl)
0.5 to 20 parts by weight of an antioxidant such as benzene and tetrakis (methylene-3 (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate) methane per 100 parts by weight of the resin. Can be included.
Also, hindered amines, especially formulas

[0028]

[Chemical 3]

[0029]

[Chemical 4] Or

[0030]

[Chemical 5] However, in the above “Chemical Formula 3”, “Chemical Formula 4” and “Chemical Formula 5”, R _{1 to} R ₄ are each independently an alkyl group having 1 to 4 carbon atoms, R ₅ is a hydrogen atom or an alkyl group, and R ₆ is a hydrogen atom or An alkyl group,
R represents a group represented by the following general formula "Chemical Formula 6". However, in the general formula “Chemical Formula 6”, R _{11 to} R ₁₄ each independently represent an alkyl group having 1 to 4 carbon atoms, and R ₁₅ represents a hydrogen atom or an alkyl group.

[0031]

[Chemical 6] The hindered amine represented by the formula (1) can be contained as a light stabilizer in an amount of 0.5 to 20 parts by weight per 100 parts by weight of the resin.

[0032]

The present invention will be described in more detail with reference to the following examples. Example 1 p-Diethylaminobenzaldehyde diphenylhydrazone [100 parts by weight] and polyarylate resin [100 parts by weight] were dissolved in dichloromethane [900 parts by weight], and this solution was applied onto a 100 μm thick aluminum tube by dip coating. Then, it was dried at 100 ° C. to form a carrier transport layer. At this time, the coating conditions were set so that the film thickness after drying was about 22 μm. Next, dibromoansanthuron [100 parts by weight] and polyvinyl butyral [50 parts by weight] are stirred and mixed in n-butyl alcohol [3500 parts by weight], and a dispersion liquid is applied onto the carrier transport layer by dip coating. The carrier-generating layer was dried at ℃. At this time, the coating conditions were set so that the film thickness after drying was 0.3 μm.

Subsequently, a solution of ethyl silicate [100 parts by weight], acetic acid [50 parts by weight] and isopropyl alcohol [2000 parts by weight] was prepared, and dip-coated on the carrier generating layer at 120 ° C. It heat-processed and it was set as the ion trap layer. At this time, the film thickness after drying was 0.
The coating conditions were set to be 1 μm. Finally, a commercially available silicon-based hard coat agent (NSC-made by Nippon Seika Co., Ltd.)
1272) on the ion trap layer by dip coating / heat treatment (120) so that the film thickness after drying becomes 2.5 μm.
℃) and used as an overcoat layer. The positive charging type photoconductor thus produced is used as a plain paper copying machine DC-3 manufactured by Mita Kogyo Co., Ltd.
It was mounted on 285, and a printing durability test was performed on 200,000 sheets of A4 size paper, but no defects occurred and good images were obtained until the end.

<< Comparative Example 1 >> For comparison, a photosensitive member was prepared from the above-mentioned << Example 1 >> from which the ion trap layer was removed, and a printing durability test was conducted in the same manner. At the time of 1,000 sheets, the image density was remarkably reduced in the central portion of the copy, compared to the surroundings, and an image with white spots was generated.

<< Embodiment 2 >> Of the above << Embodiment 1 >>,
An ion trap layer was formed by using a 2.5 wt% polyvinyl alcohol / methyl alcohol solution instead of a solution consisting of ethyl silicate [100 parts by weight], acetic acid [50 parts by weight] and isopropyl alcohol [2000 parts by weight]. A photoconductor was prepared. This photoconductor was mounted on a plain paper copier DC-3285 manufactured by Mita Kogyo Co., Ltd., and a printing durability test was performed on 200,000 sheets of A4 size paper, but no problems occurred and good images were obtained until the end. Was obtained.

<< Embodiment 3 >> Of the above << Embodiment 1 >>,
An ion trap was prepared by using a 2.0 wt% ethylene-vinyl alcohol copolymer / isopropyl alcohol solution instead of a solution consisting of ethyl silicate [100 parts by weight], acetic acid [50 parts by weight] and isopropyl alcohol [2000 parts by weight]. A photoconductor having a layer formed was prepared.
This photoconductor is a plain paper copying machine DC-3285 manufactured by Mita Kogyo Co., Ltd.
Then, a printing durability test of 200,000 sheets of A4 size paper was carried out, and no defects occurred until the end, and good images were obtained.

<< Embodiment 4 >> Of the above << Embodiment 1 >>,
Instead of a solution consisting of ethyl silicate [100 parts by weight], acetic acid [50 parts by weight] and isopropyl alcohol [2000 parts by weight], 3.2 wt% high nitrile resin /
A photoreceptor having an ion trap layer formed using a methyl alcohol solution was prepared. This photoconductor was attached to a plain paper copier DC-3285 manufactured by Mita Kogyo Co., Ltd., and a printing durability test was performed on 200,000 sheets of A4 size paper.
Good images were obtained without any problems.

[0038]

According to the present invention, in a laminated photoreceptor comprising a conductive substrate, a charge transport layer, a charge generation layer and a surface protection layer, an ion trap layer is provided between the charge generation layer and the surface protection layer. by the, NO ₂ ^-, NO ₃ ^- from entering the charge generation layer of the oxidizing agent anion prevented that occurs with the charging or the like, significantly improved electrostatic repetitive characteristics, image characteristics and their temporal retention It became possible to do.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a sectional structure of an electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 1 Base 2 Charge Transport Layer 3 Charge Generation Layer 4 Ion Trap Layer 5 Surface Protection Layer

Claims (5)

[Claims] 1. An electrophotographic photoreceptor comprising a charge transport layer, a charge generation layer, an ion trap layer and a surface protection layer, which are laminated in this order on a conductive substrate. 2. The electrophotographic photosensitive member according to claim 1, wherein the ion trap layer comprises an organopolysiloxane having a silanol group. 3. The electrophotographic photoreceptor according to claim 1, wherein the organopolysiloxane comprises silanol groups at a concentration of 5 mmol / 100 g resin or more. 4. The electrophotographic photosensitive member according to claim 1, wherein the ion trap layer is made of polyvinyl alcohol or an ethylene-vinyl alcohol copolymer. 5. The electrophotographic photosensitive member according to claim 1, wherein the ion trap layer is a high nitrile resin.