JPH1138665A - Electrophotographic photoreceptor and its manufacture and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having sufficient mechanical strength without deteriorating the optoelectronic characteristics of the photoreceptor and image quality and high durability against uses for a long period under strong external stresses, and to provide its manufacture and an image forming device. SOLUTION: The electrophotographic photoreceptor is provided on an electrically conductive substrate with a photosensitive layer and a surface protective layer containing a 3-dimensionally cross-linked polymer of an isocyanate compound having >=3 functional groups and a charge transfer compound represented by the formula, in which Y is an H or halogen atom or a 1-5C alkyl, such alkoxy or phenyl group each optionally halogenated, or a phenyl group having halogen atom, an optionally halogenated 1-5C alkyl or such alkoxy group; T is an optionally branched 1-10C divalent aliphatic group; and (n) is 0 or 1.

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 applicable to a wide range of fields such as a copying machine, a printer, and a facsimile, a method of manufacturing the same, and an image forming apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, an electrophotographic apparatus such as a plain paper copier (PPC), a laser printer, an LED printer, a liquid crystal printer, etc. has a rotating drum type or the like photosensitive member which is charged, exposed and developed through an image forming process. Is formed and transferred to a transfer material and then fixed to obtain a copy. As the photoreceptor used for these, an inorganic photoreceptor such as selenium, arsenic-selenium, cadmium sulfide, zinc oxide, a-Si or the like is used. In particular, research and development has been active, and among them, the so-called function-separated type photoconductor in which a charge generation layer and a charge transport layer are stacked is superior in terms of electrophotographic characteristics such as sensitivity, chargeability and repetition stability. Therefore, various proposals have been made and put to practical use.

However, the characteristics required for the electrophotographic photoreceptor, especially the durability, are becoming severer year by year, and the wear and damage of the surface layer due to repeated use, especially the surface layer which is remarkably increased by use under contact charging. For the problems such as wear and scratches of the surface layer and oxidative deterioration of the surface layer due to oxidizing gas such as ozone generated from the corona charger, techniques required for improving durability have been continuously studied. As a method for solving these problems of the surface layer, there has been proposed a method of forming a surface protective layer mainly containing a cross-linkable curable resin such as an organic polysiloxane on the charge transporting layer (Japanese Patent Laid-Open No. 54-1979). 148537).

[0004]

However, if the surface protective layer is composed of only a cross-linkable curable resin, the surface protective layer becomes an insulating layer, which sacrifices the photoelectric characteristics of the photoreceptor. Specifically, when the surface protective layer becomes an insulating layer, the bright portion potential at the time of exposure increases, so that the development potential margin becomes narrower or the residual potential after static elimination increases, so that especially long-term repeated printing is performed. Sometimes, there is a problem that the image density is reduced.

As a method for improving these photoelectric characteristics,
A method has been proposed in which a conductive metal oxide fine powder is dispersed in a surface protective layer as a resistance control material (Japanese Patent Application Laid-Open No. 57-1).
No. 28344). This method suppresses the deterioration of the photoreceptor photoelectric characteristics and significantly improves the above-mentioned problem. However, since the resistance value of the metal oxide used as the conductive fine powder greatly depends on the humidity of the environment, it is particularly high temperature and high temperature. There has been an essential problem that the surface resistance of the photoreceptor is reduced under humidity, the electrostatic latent image is blurred, and the image quality is greatly reduced.

As another method for improving the photoelectric characteristics, there has been proposed a method in which a charge transporting material is dispersed in a binder resin, and then the binder resin is cured to form a surface protective layer (Japanese Patent Laid-Open No. Hei. No. 4-15659).
This method eliminates the dependence of the surface resistance of the photoreceptor on humidity and eliminates the problem of image quality.However, since a low molecular weight component called a charge transporting substance is added, the curing reaction of the binder resin is inhibited, and the surface protective layer is formed. The mechanical strength decreases. Therefore,
Even if a cross-linkable curable resin having high mechanical strength is used alone, a large decrease in mechanical strength of the surface protective layer cannot be avoided since it contains a low molecular weight component as a charge transporting substance essential for improving photoelectric properties. .

Therefore, a method has been proposed in which a charge transport material having a functional group is used to interact with or react with a binder resin to improve the mechanical strength of the surface layer (Japanese Patent Application Laid-Open No. Hei 6 (1996) -1994). -202354,
JP-A-5-323630). This method can initially obtain sufficient mechanical strength without deteriorating the photoelectric characteristics of the photoreceptor, but when used under a contact charging system or a scorotron charging system for a long period of time, the above-mentioned surface protection The layer has a sharp decrease in mechanical strength. The cause is strong external stress, such as the breaking of the resin bond of the surface protective layer due to the application of the AC voltage in contact charging, and the ozone generated by scorotron charging, which oxidizes and decomposes the charge transport material. It is considered something.

Further, when the surface protective layer as described above is employed, even if the mechanical strength is mainly improved, the charge generation material and the charge transport material constituting the photosensitive layer are caused by the photocurrent repeatedly flowing through the photosensitive layer. The problem of deterioration due to fatigue occurs. This is a problem that appears more prominently as the printing durability of the photoreceptor improves and the number of sheets that are repeatedly printed increases.
It is necessary to use a charge generating substance and a charge transporting substance that are stable against photocurrent.

Therefore, the present invention solves the above problem,
An electrophotographic photoreceptor that maintains sufficient mechanical strength without deteriorating the photoelectric characteristics and image quality of the photoreceptor, and exhibits high durability and excellent image quality even when used for a long period of time under strong external stress. And a method of manufacturing the same, and an image forming apparatus using the same.

[0010]

The present invention has made it possible to solve the above problems by employing the following constitution. (1) In an electrophotographic photosensitive member having a photosensitive layer and a surface protective layer on a conductive support, the surface protective layer comprises a charge-transporting compound represented by the following structural formula (I) and three or more functional groups. A photoconductor for electrophotography, comprising a three-dimensionally cross-linked polymer of a compound containing at least the above isocyanate compound.

[0011]

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(Wherein, Y represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom, and 1 to 5 carbon atoms which may be substituted with a halogen atom. An alkoxy group, a phenyl group, or a halogen atom as a substituent, or an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom, or a halogen atom as a substituent. Carbon number 1
Represents a phenyl group having an alkoxy group in the range of from 5 to 5, T represents an optionally branched divalent aliphatic group having a carbon number of 1 to 10, and n represents 0 or 1. )

(2) The electrophotographic photoreceptor according to claim 1, wherein the crosslinked polymer of the surface protective layer has a urethane bond content ratio A defined by the following formula of 1.5 or more.

[0014]

A = x / y

(Where x represents the absorbance of the infrared absorption peak at 1720 to 1740 cm ^-1 based on the CO stretching vibration of the urethane bond, and y represents 29 based on the CH ₂ stretching vibration.)
It represents the absorbance of the infrared absorption peak at 37 cm ^-1 . )

(3) The surface protective layer is formed of the structural formula (I)
Wherein the charge transporting compound represented by the formula (2), a compound having two or more hydroxy groups, and a compound obtained by three-dimensionally cross-linking and polymerizing an isocyanate compound having three or more functional groups. The electrophotographic photosensitive member according to 2) or 2).

(4) The electrophotographic photoreceptor according to (3), wherein the compound having two or more hydroxy groups is a glycol compound and / or a bisphenol compound.

(5) The isocyanate compound having three or more functional groups is a buret-modified form of hexamethylene diisocyanate represented by the following structural formula (II) or hexamethylene represented by the following structural formula (III) The electrophotographic photoreceptor according to any one of the above (1) to (4), which is a modified isocyanurate of diisocyanate.

[0019]

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[0020]

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(6) The electrophotographic photoconductor according to any one of (1) to (5), wherein the photosensitive layer contains hydroxygallium phthalocyanine and / or chlorogallium phthalocyanine.

(7) The photosensitive layer contains a benzidine-based compound represented by the following structural formula (IV) and / or a triphenylamine-based compound represented by the following structural formula (V). The electrophotographic photoreceptor according to any one of the above (1) to (5).

[0023]

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(Wherein, R ₁ and R ₁ ′ may be the same or different and each have a hydrogen atom, a halogen atom, and a carbon number of 1 to 5).
R ₂ , R ₂ ′, R ₃ , R ₃ ′ may be the same or different, and represent a hydrogen atom, a halogen atom, An alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an amino group substituted with an alkyl group having 1 to 2 carbon atoms, wherein p and q are 0-2
Means an integer in the range )

[0025]

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(Wherein, R ₄ represents a hydrogen atom or a methyl group, r represents 1 or 2. Ar ₁ and Ar ₂ represent a substituted or unsubstituted aryl group, and the substituent is a halogen atom, An alkyl group having 1 to 5 carbon atoms, and 1 carbon atom
Represents a substituted amino group substituted with an alkoxy group having a range of 5 to 5 or an alkyl group having 1 to 3 carbon atoms. )

(8) The method for producing an electrophotographic photosensitive member in which a photosensitive layer and a surface protective layer are formed on a conductive support, wherein the charge transporting compound represented by the structural formula (I) and the number of functional groups are After applying a coating solution containing three or more isocyanate compounds on the photosensitive layer, the compound is heated to 3
A method for producing an electrophotographic photoreceptor, which comprises carrying out a three-dimensional cross-linking polymerization.

(9) The crosslinked polymer of the surface protective layer,
(8) The method for producing an electrophotographic photosensitive member according to the above (8), wherein the urethane bond content ratio A defined in (2) is 1.5 or more.

(10) A coating liquid containing the charge transporting compound represented by the structural formula (I), a compound having two or more hydroxy groups, and an isocyanate compound having three or more functional groups, The electrophotographic photoreceptor according to (8) or (9), wherein after coating on the photosensitive layer, the compound is heated and three-dimensionally crosslinked and polymerized to form the surface protective layer. Manufacturing method.

(11) As the compound having two or more hydroxy groups, a glycol compound and / or a bisphenol compound is used.
(9) The method for producing an electrophotographic photosensitive member according to (9).

(12) As the isocyanate compound having three or more functional groups, a buret-modified form of hexamethylene diisocyanate represented by the structural formula (II) or a hexene represented by the structural formula (III) described above The method for producing an electrophotographic photosensitive member according to any one of the above (8) to (11), wherein a modified isocyanurate of methylene diisocyanate is used.

(13) An image forming apparatus comprising a charging unit, an image forming unit by exposure, a developing unit and a transferring unit around an electrophotographic photosensitive member, according to any one of the above (1) to (7) An image forming apparatus using the electrophotographic photosensitive member of (1).

(14) The image forming apparatus according to the above (13), wherein a charging means of a contact charging type is employed as the charging means.

(15) The image forming apparatus according to (14), wherein a means for applying a voltage having an AC component is provided as means for applying a voltage to the charging means.

The present invention relates to an electrophotographic photoreceptor having a photosensitive layer and a surface protective layer on a conductive support, wherein the surface protective layer has a three-dimensional network structure formed of a cross-linkable curable binding material, The above-mentioned problem can be solved by directly bonding a charge transporting compound into the compound. The photosensitive layer of the invention may be a single layer, or may have a laminated structure of a charge generation layer and a charge transport layer.

The surface protective layer of the present invention is obtained by mixing a charge transporting compound having a plurality of hydroxy groups at the terminal and a compound having three or more isocyanate groups, and reacting the hydroxy group and the isocyanate group with each other to form a surface protective layer. By forming the surface protective layer cross-linked in a three-dimensional manner, it is possible to provide a photoreceptor having mechanical strength and excellent durability while maintaining the photoelectric characteristics of the photoreceptor. In particular, by using the compound represented by the above structural formula (I) as the charge transporting substance to be blended in the surface protective layer, it is possible to ensure excellent photoelectric properties, image quality, abrasion resistance, and scratch resistance. .

The charge transporting compound having a plurality of hydroxy groups is subjected to a polyaddition reaction with a polyisocyanate compound having at least three isocyanate groups, and the crosslinked polymer has a urethane bond content ratio (A = x / y) of 1. By setting it to 5 or more, it became possible to easily form a three-dimensional network structure with a high crosslinking density. Due to such a high-density cross-linking structure, mechanical strength is maintained even if the bond of the binder resin is partially cut by strong external stress such as ozone generated by AC voltage application or scorotron charging in contact charging. It is considered that the rapid decrease in Further, the charge transporting compound represented by the structural formula (I) has excellent compatibility with many isocyanate compounds, so that the charge transporting compound can be uniformly introduced into a network structure, and And excellent photoelectric characteristics.

Since the conventional charge transport layer is formed by dissolving a low molecular weight charge transport material in a binder resin, it was not possible to add too much charge transport material in order to increase mechanical strength. . However, since the surface protective layer of the present invention incorporates a three-dimensional structure in the form of a bond, it is possible to introduce more charge transporting substances than the conventional charge transporting layer, thereby facilitating the maintenance of the photoelectric characteristics of the photoreceptor. .

Since the three-dimensionally crosslinked polymer compound is generally insoluble in any solvent,
As in the conventional layer formation, apply a solution dissolved in a solvent,
It cannot be dried to form a film. However, the surface protective layer can be formed by mixing a compound before crosslinking or dissolving in a solvent to apply and form a film, and then causing a crosslinking polymerization reaction by heating or the like. vice versa,
Polymeric charge transporting materials with low crosslink density can be coated and deposited by dissolving them in a solvent, but these have low mechanical strength due to low crosslink density and do not have sufficient abrasion resistance . In particular, there is a problem that abrasion increases in an electrophotographic image forming apparatus using a contact charging method.

[0040]

Embodiments of the present invention will be described below in detail. The photosensitive layer of the present invention may be a so-called single-layer type photoreceptor or a laminated type photoreceptor comprising a charge generation layer and a charge transport layer. The stacking order of the charge generation layer and the charge transport layer in the stacked photoreceptor may be either order. However, since the surface protective layer of the present invention mainly has a hole transport property, the charge generation layer, the charge transport layer, and the surface protection layer The most excellent characteristics are obtained in the case of a negatively charged laminated photoreceptor laminated in the order of layers.

FIGS. 1 to 4 are schematic cross-sectional views of the electrophotographic photoreceptor of the present invention. The photoreceptor of FIG. 1 comprises a conductive support 3 on which a charge generation layer 1 and a charge transport layer 2 are formed. And a surface protective layer 5. In the photoreceptor of FIG. 2, after providing an undercoat layer 4 on a conductive support 3, a photosensitive layer including a charge generation layer 1 and a charge transport layer 2 and a surface protection layer 5
Are laminated. The photoconductor of FIG. 3 is obtained by laminating a photoconductive layer 6 and a surface protective layer 5 on a conductive support 3. The photoreceptor of FIG. 4 has a structure in which an undercoat layer 4 is provided on a conductive support 3 and then a photoconductive layer 6 and a surface protective layer 5 are laminated.

The surface protective layer according to the present invention may have the above-mentioned structural formula (I)
And the isocyanate compound having a functional group number of 3 or more is reacted with each other, and the crosslinked polymer has a urethane bond content ratio (A = x /
When y) is 1.5 or more, the film is crosslinked in a network to form a film. If the urethane bond content ratio A is less than 1.5, the required mechanical strength cannot be obtained,
Wear increases. In addition, a more preferable range of the urethane bond content ratio A is 1.5 to 3.0.

Tables 1 and 2 show specific examples of the above-mentioned hydroxy group-containing charge transporting compound. Tables 3 and 4 show specific examples of T in Tables 1 and 2 of the structural formula (I).

[0044]

[Table 1]

[0045]

[Table 2]

[0046]

[Table 3]

[0047]

[Table 4]

As a constituent of the surface protective layer of the present invention, a glycol compound or a bisphenol compound can be added as required. These compounds form a crosslinked structure by replacing a part of the compound of the structural formula (I). Compounds having these hydroxy groups include:
It has two or more hydroxy groups in the molecule and can be freely selected from those polymerizable with isocyanate, for example,
Examples include ethylene glycol, propylene glycol, butanediol, and polyethylene glycol. Examples of other compounds having a hydroxy group include various polymers and oligomers having a reactive hydroxy group, such as acrylic polyols and oligomers thereof, and polyester polyols and oligomers thereof. On the other hand, specific examples of the bisphenol compound are shown in Tables 5 and 6.

[0049]

[Table 5]

[0050]

[Table 6]

In order to form a three-dimensional network structure by crosslinking, it is necessary to use an isocyanate compound having three or more functional groups, that is, a compound having three or more reactive isocyanate groups. Thereby, the surface protective layer can have a high-density crosslinked structure. As the isocyanate compound having three or more isocyanate groups, it is more preferable to use a derivative obtained from an isocyanate monomer or a modified polyisocyanate such as a prepolymer. Examples thereof include an adduct modified product obtained by adding an isocyanate to a polyol having 3 or more functional groups, a buret modified product obtained by modifying a compound having a urea bond with an isocyanate compound, an allophanate modified product obtained by adding an isocyanate to a urethane group, and an isocyanurate modified product The carbodiimide modified product can be used.

In particular, a buret-modified hexamethylene diisocyanate represented by the structural formula (II) or
The modified hexamethylene diisocyanate and isocyanurate represented by the structural formula (III) are particularly excellent in mechanical strength and electrical properties of the completed protective layer.

In addition, although it is contained in the modified polyisocyanate, a blocked isocyanate using a blocking agent such as an oxime can be preferably used in order to temporarily mask the activity of the isocyanate group. This is preferable from the viewpoint of extending the pot life of the coating liquid.

The isocyanate compounds which can be used together with the isocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, tolidine diisocyanate, 1,6-hexamethylene diisocyanate, xylene diisocyanate, and lysine isocyanate. , Tetramethyl xylene diisocyanate, 1,
3,6-hexamethylene triisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-
Isocyanate methyl octane, triphenylmethane triisocyanate, tris (isocyanate phenyl)
Common isocyanate monomers such as thiophosphate may be mentioned.

In order to form the surface protective layer of the present invention,
A compound having a hydroxy group-containing charge transporting compound represented by the structural formula (I), an isocyanate compound having 3 or more functional groups, and optionally another hydroxy group-containing compound, an additive, a solvent and the like. Mix to create a coating solution,
After this coating solution is applied on the photosensitive layer, it is heated to cause cross-linking polymerization to form a film to form a surface protective layer.

The mixing ratio of the coating solution is such that the ratio of (the number of reactive hydroxy groups) :( the number of reactive isocyanate groups) is in the range of 2: 1 to 1: 2, and 1.5: 1 to 1: 1. It is desirable to formulate so as to be in the range of 0.5, more preferably in the range of 1.2: 1 to 1: 1.2. In particular, if an excess hydroxyl group remains beyond this mixing ratio, the hydrophilicity of the surface of the protective layer increases, and image characteristics under high temperature and high humidity deteriorate. Therefore, care must be taken including reaction conditions. Care must be taken because the isocyanate compound is deactivated by moisture in the air and the like, and the number of reacting isocyanates may decrease. In this case, it is effective to prepare the isocyanate groups so that the number thereof is slightly excessive.

The crosslinking reaction temperature is 80 to 170 ° C.
Preferably, the range of 100 to 150 ° C. is appropriate. If the crosslinking reaction temperature is lower than 80 ° C., a desired urethane bond content ratio cannot be obtained, and if it exceeds 170 ° C., damage to a layer below the protective layer may occur. The crosslinking reaction time is
Although it varies depending on the material, it is about 1 to 5 hours. If it is shorter than 1 hour, a desired urethane bond content ratio may not be obtained. If it exceeds 5 hours, a desired urethane bond content ratio is obtained. Since the urethane bond content ratio hardly changes even if it is further extended, the upper limit is set to 5 hours from the viewpoint of production efficiency.

The content of the charge transporting compound in the surface protective layer depends on the molecular weight of the hydroxy group-containing compound and the molecular weight of the isocyanate compound. In order to maintain the electrical characteristics of the photoreceptor and also to provide mechanical strength, the content of the charge transporting compound in the entire surface protective layer should be 5 to 90
% By weight, preferably in the range of 25 to 75% by weight. Since the surface protective layer of the present invention incorporates the charge transporting compound in the network structure, the amount of the charge transporting compound is larger than that of the charge transporting layer in which the ordinary low molecular weight charge transporting substance is dispersed. Can be introduced.

The surface protective layer of the present invention may contain various binder resins in order to improve its film formability and flexibility. As such a binder resin, various polymers such as polycarbonate, polyester, polyacryl, polyvinyl alcohol, and polyamide can be used. However, in order to maintain the mechanical strength and the photoelectric characteristics, the content of these binder resins in the surface protective layer is preferably set to 60% by weight or less.

For crosslinking polymerization of the surface protective layer of the present invention,
After coating on the photosensitive layer, heating may be performed. The reaction between the hydroxy group and the isocyanate group depends on the reactivity between the compounds used, but generally does not require a catalyst or the like, and only requires heating. When a solvent is used at the time of coating, heat treatment can be performed simultaneously with or subsequent to the drying step.

When it is desired to accelerate the crosslinking reaction, organometallic compounds such as dibutyltin dilaurate, inorganic metal compounds, monoamines, diamines, triamines,
Catalysts such as cyclic amines, alcohol amines and ether amines may be added according to a conventional method.

Examples of the conductive support used in the photoreceptor of the present invention include metals such as aluminum, nickel, chromium, and stainless steel; and aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, and oxides. Examples include a plastic film provided with a thin film of indium, ITO, or the like, or paper or a plastic film coated or impregnated with a conductivity imparting agent. These conductive supports are used in an appropriate shape such as a drum shape, a sheet shape, and a plate shape, but are not limited thereto. In addition, the surface of the conductive support can be subjected to various kinds of processing as necessary, as long as the image quality is not affected. For example, surface oxidation treatment, chemical treatment, coloring treatment, and the like, and irregular reflection treatment such as graining can be performed.

An undercoat layer may be provided between the conductive support and the photosensitive layer. The undercoat layer is an adhesive layer that prevents charge injection from the conductive support into the photosensitive layer when the photosensitive layer having a laminated structure is charged, and that integrally adheres and holds the photosensitive layer to the conductive support. Is effective in preventing the reflection of light from the conductive support in some cases.

The binder resin used for the undercoat layer is polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, polyimide resin, Vinylidene resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, water-soluble polyester resin, nitrile cellulose, casein, gelatin,
Known materials such as polyglutamic acid, starch, starthiacetate, amino starch, polyacrylic acid, polyacrylamide, zirconium chelate compound, titanyl chelate compound, titanyl alkoxide compound, organic titanyl compound, and silane coupling agent can be used. Can be used alone or in combination of two or more.

Further, fine particles such as titanium oxide, silicon oxide, zirconium oxide, barium titanate, and silicone resin can be blended in the undercoat layer. The thickness of the undercoat layer is 0.01 to 10 μm, preferably 0.05 to
A range of 2 μm is appropriate. The coating method of the undercoat layer includes a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method,
Bead coating method, air knife coating method,
An ordinary method such as a curtain coating method can be used.

The charge generating layer of the photoreceptor contains a charge generating material and a binder resin. As a charge generation material,
Amorphous selenium, crystalline selenium-tellurium alloy, selenium-arsenic alloy, other selenium compounds, selenium alloys, inorganic photoconductive materials such as zinc oxide and titanium oxide, phthalocyanine, squarylium, anthantrone, perylene And organic pigments and dyes such as azo, anthraquinone, pyrene, pyrylium salts and thiapyrylium salts.

Among them, phthalocyanine compounds are preferable from the viewpoint of photosensitivity of the photoreceptor.
Preference is given to titanyl phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine and the like.

In particular, gallium phthalocyanine having strong diffraction peaks at least at 6.8 °, 12.8 °, 15.8 ° and 26 ° in the Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum by CuKα. , CuK
Bragg angle (2θ) in X-ray diffraction spectrum by α
± 0.2 °) at least 7.5 °, 9.9 °, 12.
5 °, 16.3 °, 18.6 °, 25.1 ° and 28.
Hydroxygallium phthalocyanine having a specific crystal form having a strong diffraction peak at 3 °, or a Bragg angle of 7.4 ° in the X-ray diffraction spectrum by CuKα, 1
Chlorogallium phthalocyanine having a specific crystal form having strong diffraction peaks at 6.6 °, 25.5 ° and 28.3 ° has high charge generation efficiency with respect to a wide range of light from visible light to near infrared light. Is particularly preferred. Phthalocyanine crystals having these specific crystal forms are synthesized as follows.

Synthesis Example 1 30 parts of 1,3-diiminoisoindoline and 9.1 parts of gallium trichloride were converted to quinoline 23
After putting in 0 parts and reacting at 200 ° C. for 3 hours, the product was separated by filtration, washed with acetone and methanol, and the obtained wet cake was dried to obtain 28 parts of chlorogallium phthalocyanine crystal. Then, 3 parts of the chlorogallium phthalocyanine crystal was placed in an automatic mortar (manufactured by Yamato Kagaku KK, L
ab Mill UT-21) for 3 hours.
0.5 parts thereof was milled with 60 parts of glass beads (1 mmφ) in 20 parts of benzyl alcohol at room temperature for 24 hours, and the glass beads were separated by filtration.
By washing with 0 parts and drying, the Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum was 7.4.
A chlorogallium phthalocyanine crystal having strong diffraction peaks at °, 16.6 °, 25.5 °, and 28.3 ° was obtained.

(Synthesis Example 2) 3 parts of the chlorogallium phthalocyanine crystal obtained in Synthesis Example 1 was dissolved in 60 parts of concentrated sulfuric acid at 0 ° C., and the above solution was added dropwise to 450 parts of 5 ° C. distilled water to recrystallize the crystal. Was deposited. This was washed with distilled water, diluted ammonia water and the like, and then dried to obtain 2.5 parts of a hydroxygallium phthalocyanine crystal. The crystals were dry-pulverized for 5.5 hours in the automatic mortar used in Synthesis Example 1, and 0.5 part of the crystal was dimethylformamide (15 parts) and glass beads (1 mmφ)
After milling at room temperature together with 0 parts for 24 hours, the glass beads were separated by filtration, washed with 10 parts of methanol and dried, so that the Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum was 7%. .5 °, 9.9 °, 12.
5 °, 16.3 °, 18.6 °, 25.1 °, 28.3
A hydroxygallium phthalocyanine crystal having a strong diffraction peak at ° was obtained.

Examples of the binder resin for the charge generation layer include polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal resin, polycarbonate resin,
Polyester resin, acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer, silicone resin, phenol resin, poly-N-vinyl carbazole resin and the like can be mentioned. It is not limited.
These binder resins can be used alone or in combination of two or more.

The compounding ratio of the charge generation material to the binder resin in the charge generation layer is preferably in the range of 10: 1 to 1:10 by weight. Further, the thickness of the charge generation layer used in the present invention is suitably in the range of 0.1 to 5 μm, preferably 0.2 to 2.0 μm. As a method for applying the charge generation layer, a usual method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like can be used.

Further, as a solvent used for forming the charge generating layer, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-acetate -Ordinary organic solvents such as -butyl, dioxane, tetrahydrofuran, methylene chloride, chloroform and the like can be used alone or in combination of two or more.

The charge transport layer in the laminated photoreceptor is formed containing at least a charge transport material and a binder resin. Examples of the charge transport material include quinone-based compounds such as p-benzoquinone, chloranil, bromanyl, and anthraquinone, tetracyanoquinodimethane-based compounds, and 2,4,7-
Fluorenone compounds such as trinitrofluorenone, xanthone compounds, benzophenone compounds, cyanovinyl compounds, electron-withdrawing substances such as ethylene compounds, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds , Stilbene compounds, anthracene compounds, hydrazone compounds and the like. These charge transport materials can be used alone or in combination of two or more.

In particular, the benzidine compound represented by the structural formula (IV) and the triphenylamine compound represented by the structural formula (V) have high charge (hole) transport ability and excellent stability. Therefore, it can be particularly preferably used. Table 7 shows specific examples of the benzidine-based compound.
Table 8 shows specific examples of the above triphenylamine compounds.
10 to 10.

[0076]

[Table 7]

[0077]

[Table 8]

[0078]

[Table 9]

[0079]

[Table 10]

Examples of the binder resin for the charge transport layer include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin,
Styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicon-alkyd resin, phenol-formaldehyde resin, Known resins such as styrene-acrylic resin, styrene-alkyd resin, poly-N-vinylcarbazole, and polysilane can be used. Particularly, a preferred binder resin is a polycarbonate resin.

An antioxidant may be added to the charge transport layer in order to prevent deterioration due to oxidizing gas such as ozone generated in the corona charger. Since the charge transport layer is not the outermost layer, it does not come into direct contact with the oxidizing gas.However, these oxidizing gases may penetrate through the surface protective layer and penetrate into the charge transport layer. belongs to. As the antioxidant, hindered phenol-based or hindered amine-based antioxidants are desirable, and organic sulfur-based antioxidants, phosphite-based antioxidants, dithiocarbamate-based antioxidants, thiourea-based antioxidants, and benzimidazole-based antioxidants A known antioxidant such as an antioxidant may be used. The amount of the antioxidant added to the charge transport layer is
It is preferably at most 15% by weight of the charge transport layer, more preferably at most 10% by weight.

Solvents used for forming the charge transport layer include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, and halogens such as methylene chloride, chloroform and ethylene chloride. Aliphatic hydrocarbons, tetrahydrofuran,
Ordinary organic solvents such as cyclic or linear ethers such as ethyl ether and dioxane can be used alone or in combination of two or more. The method for applying the charge transport layer can be the same as that for the charge generation layer. The thickness of the charge transport layer is 5 to 50 μm, preferably 10 to 40 μm.
A range of μm is suitable.

When a single-layer type photosensitive layer is formed, it is formed by containing the above-mentioned charge generating substance and a binder resin. As the binder resin, those similar to the binder resins used for the charge generation layer and the charge transport layer can be used.
The content of the charge generating substance in the single-layer type photosensitive layer is 10 to 85.
% By weight, preferably in the range of 20 to 50% by weight.

A charge transporting material may be added to the single-layer type photosensitive layer as needed. The addition amount is preferably in the range of 5 to 50% by weight. Further, if necessary, an antioxidant may be added to the single-layer type photosensitive layer for the same reason as in the case of the charge transport layer. The addition amount is 15% by weight or less, preferably 1%.
0% by weight or less is preferred.

The electrophotographic photoreceptor of the present invention can be used in an image forming apparatus using a non-contact charging system such as scorotron charging, and has excellent photoelectric characteristics and durability, particularly, ozone resistance. Further, when applied to an image forming apparatus using a contact charging system such as a charging roll as a charging unit,
Very strong durability against photoreceptor abrasion, which is noticeable due to contact charging.

FIG. 5 is a conceptual diagram showing an example of the image forming apparatus of the present invention. Electrophotographic photosensitive drum 1, power supply 2, contact charger 3 using charging rolls as charging means, laser exposure optical system 4, developing device 5 using magnetic one-component toner, transfer corotron 6, cleaning blade 7, transfer material 8
It has a fixing roll 9 and an LED 10 for static elimination.

The shape of the conductive member for performing the contact charging may be any of a brush shape, a blade shape, a pin electrode shape, a roller shape and the like, but a roller shape member is particularly preferable. Usually, the roller-shaped member is composed of a resistance layer, an elastic layer supporting them and a core material from the outside. Further, a protective layer can be provided outside the resistance layer as needed. As the material of the core of the conductive member, conductive iron, copper, brass, stainless steel, aluminum, nickel or the like is used. In addition, a resin molded article or the like in which conductive particles or the like are dispersed can also be used.

The material of the elastic layer of the conductive member is a material having conductivity or semi-conductivity. Generally, a material in which conductive particles or semi-conductive particles are dispersed in a rubber material can be used. Rubber materials include EPDM, polybutadiene, natural rubber, polyisobutylene, SBR, CR, NBR, silicone rubber, urethane rubber, epichlorohydrin rubber, S
BS, thermoplastic elastomer, norbornene rubber, fluorosilicone rubber, ethylene oxide rubber and the like are used.

Examples of the conductive particles or semiconductive particles include metals such as carbon black, zinc, aluminum, copper, iron, nickel, chromium and titanium, and ZnO-Al
₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —Sn
_{O 2, ZnO-TiO 2,} MgO-Al 2 O 3, FeO
_{-TiO 2, TiO 2, SnO 2} , Sb 2 O 3, In 2
Metal oxides such as O ₃ , ZnO, and MgO can be used, and these materials may be used alone or in combination of two or more.

The resistance layer and the protective layer of the conductive member are formed by dispersing conductive particles or semiconductive particles in a binder resin and controlling the resistance. The resistivity is 10 ³ to 10 ¹⁴ Ωc.
m, preferably 10 ⁵ to 10 ¹² Ωcm, and more preferably 10 ⁷ to 10 ¹² Ωcm. The resistance layer and the protective layer of the conductive member have a thickness of 0.01 to 1000 μm.
m, preferably in the range of 0.1 to 500 μm, more preferably 0.5 to 100 μm.

As the binder resin for the resistance layer and the protective layer of the conductive member, acrylic resin, cellulose resin, polyamide resin, methoxymethylated nylon, ethoxymethylated nylon, polyurethane resin, polycarbonate resin, polyester resin, polyethylene resin, Polyvinyl resin,
Polyarylate resin, polythiophene resin, PFA, F
Polyolefin resins such as EP and PET, and styrene butadiene resins are used. As the conductive particles or semiconductive particles, the same carbon black, metal, metal oxide, and the like as the elastic layer are used.

If necessary, antioxidants such as hindered phenol and hindered amine, fillers such as clay and kaolin, and lubricants such as silicone oil can be added. Means for forming these layers include blade coating, Meyer bar coating,
Spray coating, dip coating, bead coating, air knife coating, curtain coating, and the like can be used.

When the photosensitive member is charged using these conductive members, a voltage is applied to the conductive members, and the applied voltage is preferably a DC voltage with an AC voltage superimposed thereon.
It is difficult to obtain uniform charging only with a DC voltage. As for the voltage range, the DC voltage is preferably in the range of 50 to 2000 V, positive or negative, depending on the required photoconductor charging potential.
The range of 0 to 1500 V is more preferable. The AC voltage to be superimposed has a peak-to-peak voltage in the range of 400 to 1800 V, preferably in the range of 800 to 1600 V, and more preferably 1 to 800 V.
A range of 200 to 1600 V is suitable. The frequency of the AC voltage is in the range of 50 to 20,000 Hz, preferably 100
It is in the range of ２０００2000 Hz.

[0094]

【Example】

Example 1 10 parts of a zirconium compound (manufactured by Matsumoto Pharmaceutical Co., Ltd., Organotics ZC540) and 1 part of a silane compound (manufactured by Nippon Unicar, A1110), 40 parts of isopropanol and 20 parts of butanol on an aluminum pipe (outer diameter: 40 mm) Was applied by a dip coating method and dried by heating at 150 ° C. for 10 minutes to form an undercoat layer having a thickness of 0.1 μm.

One part of X-type metal-free phthalocyanine crystal and 1 part of polyvinyl butyral (Eslec BM-S, manufactured by Sekisui Chemical Co., Ltd.) were mixed with 100 parts of cyclohexanone,
A coating solution was prepared by dispersing with glass beads for 1 hour in a sand mill, dip-coated on the undercoat layer,
For 10 minutes to form a charge generation layer having a thickness of about 0.15 μm.

Next, 2 parts of the exemplified compound (IV-27) of the structural formula (IV) shown in Table 7 and 3 parts of the polymer compound (viscosity average molecular weight: 39000) represented by the following structural formula (a) were added to chlorobenzene. Dissolve in 20 parts to prepare a coating solution, apply on the charge generating layer by dip coating,
By heating at 40 ° C. for 40 minutes, a charge transport layer having a thickness of 20 μm was formed.

[0097]

Embedded image

Further, 1 part of the exemplified compound (I-12) represented by the structural formula (I) shown in Table 1 and 2 parts of the modified buret solution (solid content: 67% by weight) represented by the structural formula (II) were used. A coating solution is prepared by dissolving in 50 parts of cyclohexanone, and is coated on the charge transport layer by a spray coating method.
After drying for 0 minutes, it is heated at 150 ° C. for 60 minutes, and the film thickness is 4 μm.
Was formed. The mixing ratio of this coating solution is such that [the total number of moles of the OH groups of the exemplified compound (I-12)]: [the total number of moles of the isocyanate groups of the structural formula (II)] is about 45:
It was prepared to be 55.

Example 2 A charge generation layer and a charge transport layer were laminated on a conductive substrate in the same manner as in Example 1. And
1 part of the exemplified compound (I-12) used in Example 1 and 2 parts of the modified isocyanurate represented by the structural formula (III) were dissolved in 50 parts of cyclohexanone to prepare a coating solution, and the charge transport was performed. It is applied on the layer by spray coating, dried at room temperature for 10 minutes, and then heated at 150 ° C. for 60 minutes to form
A μm surface protective layer was formed. The mixing ratio of this coating solution is such that [total mole number of OH groups of Exemplified Compound (I-12)]: [total mole number of isocyanate groups of structural formula (III)] is about 4
It was prepared to be 5:55.

Example 3 Example 1 was repeated except that the heating and drying were performed by heating at 150 ° C. for 30 minutes and drying.
A photoreceptor was produced in the same manner as described above.

Example 4 In Example 1, the mixture ratio of the exemplified compound (I-12) and the modified burette solution represented by the structural formula (II) (solid content: 67% by weight) was changed. O
A photoconductor was prepared in the same manner as in Example 1, except that [total number of moles of H group]: [total number of moles of isocyanate group] was approximately 65:35.

Comparative Example 1 In Example 1, the thickness of the charge transport layer was changed from 20 μm of Example 1 to 24 μm.
A photoreceptor was produced in exactly the same manner as in Example 1 except that the surface protective layer was omitted.

Comparative Example 2 A charge generation layer and a charge transport layer were laminated on a conductive substrate in the same manner as in Example 1. And
2 parts of a compound represented by the following structural formula (b) in place of the exemplified compound (I-12) of Example 1, a modified polyisocyanate solution represented by the above structural formula (II) (solid content: 67% by weight)
A coating solution was prepared by dissolving 4.5 parts in 50 parts of cyclohexanone, applied on the charge transport layer by a spray coating method, dried at room temperature for 10 minutes, and then heated at 150 ° C. for 60 minutes to form a film. A 4 μm surface protection layer was formed. The mixing ratio used here is the same as in Example 1 [total number of moles of OH groups of Exemplified Compound (I-12)]: [total number of moles of isocyanate groups of structural formula (II)] is about 45:55. It was prepared as follows.

[0104]

Embedded image

(Test Method) The electrophotographic photoreceptors of Examples 1 and 2 and Comparative Examples 1 and 2 obtained as described above were mounted on an XP-11 remodeled machine manufactured by Fuji Xerox (about 11 sheets of A4 per minute per minute). Then, the following experiment was performed. The XP-11 remodeling machine includes a contact charger using a charging roll as shown in FIG. 1, an exposure optical system having a semiconductor laser, a developing device having a magnetic one-component toner, a corotron for transfer, and an LE for discharging.
D, an electrophotographic printer having a cleaning blade and a fixing roll.

After evaluating the initial image quality using this device,
A continuous printing test of 50,000 sheets was performed, and the image quality after the test was evaluated again. Also, the amount of decrease in film thickness before and after the continuous test of 50,000 sheets was measured, and the wear resistance was evaluated. The results are shown in Table 11 below. The charging was performed by applying a charging voltage obtained by superimposing DC -550 V and AC 1.5 kVpp (800 Hz) on the charging roll.

A part of the surface protective layer of the obtained photoreceptor was peeled off, and the infrared absorption spectrum was measured by transmission to obtain FT-I.
An R spectrophotometer (manufactured by Perkin-Elmer, 1640) was used to measure the absorbance at 1720 to 1740 cm ⁻¹ based on the CO stretching vibration based on the measurement results.
And the absorbance y at 2937 cm ^-1 based on the stretching vibration of CH ₂ , and the urethane bond ratio A was calculated according to the above equation. The results are shown in Table 11.

[0108]

[Table 11]

(Evaluation) As is clear from Table 11, the photosensitive members of Examples 1 and 2 had good initial image characteristics.
In addition, good image quality characteristics were maintained after printing 50,000 sheets.
In addition, the good image quality characteristics were maintained after printing 50,000 sheets because the three-dimensional cross-linking structure was sufficiently formed, the abrasion loss of the photoreceptor was small at 0.31 μm and 0.40 μm, and at the same time, This is due to the fact that it is not easily scratched. Also, since the charge transporting material structure is included in the crosslinked structure in the surface protective layer, it is considered that the photoelectric characteristics of the photoreceptor are good and the characteristics are less deteriorated by continuous printing.

The photoreceptor of Example 3 did not have sufficient heating conditions, and the photoreceptor of Comparative Example 2 did not sufficiently form a three-dimensional cross-linked structure due to the composition ratio. After copying 10,000 or 15,000 sheets, a streak-like scratch was generated on the surface due to contact with the developer or paper, which appeared as an image defect.

The photoreceptor of Comparative Example 1 had a large decrease in film thickness before and after the continuous test of 50,000 sheets of 10.5 μm, so that the photoelectric characteristics changed and the initial image quality was good. In the subsequent image quality, the surface potential did not sufficiently decrease, resulting in a decrease in image density. Further, on the surface of the photoreceptor, a number of streak-like scratches due to contact with a developer or paper were observed, which appeared as image defects.

In the photoreceptor of Comparative Example 2, although the amount of decrease in film thickness before and after the continuous test of 50,000 sheets was as small as 0.25 μm, the image density decreased after printing 10,000 sheets, and almost Images could not be obtained. This is presumably due to the fact that the surface protective layer had a urethane bond ratio of 1.7, but had no charge transporting property, resulting in an increase in the light portion potential (decrease in photoelectric characteristics).

[Examples 5 to 8] In Example 5, instead of Example Compound (I-12) shown in Table 1 used for the surface protective layer, Example Compound (I-12) shown in Table 1 was used in Example 5. −
In Example 6, the compound (I-) described in Table 1 was used.
7) was prepared in Example 7 by the exemplified compound (I-
7) and Example 8 (I-1) shown in Table 1 in Example 8.
A photoreceptor was produced in exactly the same manner as in Example 1 except that each of 0) was used. The mixing ratio of the coating solution was adjusted so that [total mole number of OH groups of Exemplified Compound (I)]: [total mole number of isocyanate groups of Structural Formula (II)] was about 45:55.

The photosensitive members of Examples 5 to 8 were evaluated in the same manner as in Example 1, and the results are shown in Table 12 below. As is clear from Table 12, the photoreceptors of Examples 3 to 6 have urethane bond content ratios A between 1.6 and 1.8, and the amount of decrease in film thickness before and after the continuous test of 50,000 sheets is as follows. It was as small as 0.34 to 0.65 μm, had good initial image characteristics, and maintained good image quality characteristics even after printing 50,000 sheets.

Example 9 A charge generation layer and a charge transport layer were laminated on a conductive substrate in the same manner as in Example 1. And
1 part of Exemplified Compound (I-12) used in Example 1, 1,4
-0.5 part of butanediol and 4 parts of the isocyanurate-modified compound represented by the structural formula (III) are dissolved in 70 parts of cyclohexanone to prepare a coating solution, and spray coating is performed on the charge transport layer. And dried at room temperature for 10 minutes, and then heated at 150 ° C. for 60 minutes to form a surface protective layer having a thickness of 4 μm. The mixing ratio of this coating solution was adjusted such that [total mole number of OH groups of Exemplified Compound (I-12)]: [total mole number of isocyanate groups of structural formula (III)] was about 45:55. .

This photosensitive member was evaluated in the same manner as in Example 1, and
The results are shown in Table 12 below. As is clear from Table 12, the photoreceptor of Example 7 had a urethane bond content ratio A of 1.6, a small decrease in film thickness before and after the continuous test of 50,000 sheets of 0.60 μm, and an initial image. The characteristics are good,
In addition, good image quality characteristics were maintained after printing 50,000 sheets.

[0117]

[Table 12]

Example 10 An undercoat layer was formed on an aluminum pipe (outer diameter: 30 mm) in the same manner as in Example 1. On the other hand, the coating solution was prepared by adding a part of the chlorogallium phthalocyanine having a specific crystal form obtained in Synthesis Example 1 to polyvinyl butyral (Slec BM-S, manufactured by Sekisui Chemical Co., Ltd.)
And 100 parts of n-butyl acetate, and treated with a glass shaker for 1 hour in a paint shaker to disperse.
Prepared. This coating solution was dip-coated on the undercoat layer and dried by heating at 100 ° C. for 10 minutes to form a film having a thickness of about 0.15.
A μm charge generation layer was formed.

Next, 2 parts of the exemplified compound (IV-27) of Structural Formula (IV) shown in Table 7 and 1 part of the exemplified compound (V-28) of Structural Formula (V) shown in Table 9 were prepared. A coating solution is prepared by dissolving 3 parts of a polymer compound having a repeating structural unit represented by the formula (a) (viscosity average molecular weight: 39000) in 12 parts of chlorobenzene, and dip coating the coating solution on the charge generation layer. And dried at 110 ° C. for 40 minutes to form a film having a thickness of 20 μm.
m of the charge transport layer was formed. Further, a 5 μm-thick surface protective layer was formed thereon in the same manner as in Example 1 to obtain an electrophotographic photosensitive member of Example 10.

Example 11 Example 10 was repeated in the same manner as in Example 10, except that hydroxygallium phthalocyanine having a specific crystal form obtained in Synthesis Example 2 was used instead of chlorogallium phthalocyanine. 11
Was obtained.

The photoreceptors of Examples 10 to 11 were subjected to an Abl manufactured by Fuji Xerox Co., Ltd.
e 1321 and was subjected to the same printing durability test as in Example 1. The results are shown in Table 13 below. The above-described remodeling machine is an electrophotographic image forming apparatus having the same configuration as that of FIG. 1, but does not have a charge removing LED. The printing speed of this remodeled machine is 30 sheets of A4 width per minute, which is higher than the XP-11 remodeled machine used in Example 1 (about 11 sheets of A4 width per minute). 1KH
z, increased to 1.8 kVpp. For this reason, the abrasion amount after printing 50,000 sheets is large, but there was no problem in the sensory evaluation by visual observation for both image density and resolution.

[0122]

[Table 13]

[0123]

According to the present invention, since the charge transporting substance is incorporated into the three-dimensional crosslinked structure of the surface protective layer of the electrophotographic photosensitive member by adopting the above-mentioned constitution, good photoelectric characteristics and excellent abrasion resistance can be obtained. Also, it is possible to provide an electrophotographic photoreceptor having high durability against external stresses such as application of an alternating voltage and a discharge gas, and an image forming apparatus using the photoreceptor has a good durability even after printing a large number of sheets. Image quality can be maintained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an electrophotographic photoreceptor of the present invention, in which a photosensitive layer has a laminated structure.

FIG. 2 is a schematic sectional view of another electrophotographic photosensitive member of the present invention, in which a photosensitive layer has a laminated structure.

FIG. 3 is a schematic sectional view of still another electrophotographic photoreceptor of the present invention, in which a photosensitive layer has a single-layer structure.

FIG. 4 is a schematic sectional view of still another electrophotographic photoreceptor of the present invention, in which a photosensitive layer has a single-layer structure.

FIG. 5 is a conceptual diagram of the electrophotographic printer used in Example 1.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G03G 15/02 102 G03G 15/02 102 (72) Inventor Seiwa Shimokazu 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd. (72 ) Inventor Fumio Kojima 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd.

Claims (15)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer and a surface protective layer on a conductive support, wherein the surface protective layer comprises a charge-transporting compound represented by the following structural formula (I) and a number of functional groups. Wherein a compound containing at least three isocyanate compounds is cross-linked and polymerized three-dimensionally. Embedded image (Wherein, Y represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom, and 1 to 5 carbon atoms which may be substituted with a halogen atom.
An alkoxy group, a phenyl group, or a halogen atom as a substituent, or an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom, or a halogen atom as a substituent. Represents a phenyl group having an alkoxy group having 1 to 5 carbon atoms, and T is a divalent aliphatic group which may be branched and has 1 to 10 carbon atoms;
Represents 0 or 1. ) 2. The electrophotographic photoconductor according to claim 1, wherein the urethane bond content ratio A defined by the following formula of the crosslinked polymer of the surface protective layer is 1.5 or more. A = x / y (where x is 17 based on the CO stretching vibration of a urethane bond)
Y represents the absorbance of the infrared absorption peak at 20 to 1740 cm ^-1 , and y represents the absorbance of the infrared absorption peak at 2937 cm ^-1 based on CH ₂ stretching vibration. ) 3. The three-dimensional charge-transporting compound represented by the structural formula (I), a compound having two or more hydroxy groups, and an isocyanate compound having three or more functional groups, wherein the surface protective layer has a three-dimensional structure. 3. The electrophotographic photoconductor according to claim 1, wherein the electrophotographic photoconductor is formed by cross-linking polymerization. 4. The electrophotographic photoreceptor according to claim 3, wherein said compound having two or more hydroxy groups is a glycol compound and / or a bisphenol compound. 5. The method according to claim 1, wherein the isocyanate compound having three or more functional groups is a buret modified form of hexamethylene diisocyanate represented by the following structural formula (II) or a hexamethylene diisocyanate represented by the following structural formula (III): The electrophotographic photoreceptor according to any one of claims 1 to 4, wherein the electrophotographic photoreceptor is a modified isocyanurate. Embedded image Embedded image 6. The photosensitive layer according to claim 1, wherein said photosensitive layer contains hydroxygallium phthalocyanine and / or chlorogallium phthalocyanine.
13. The electrophotographic photoreceptor according to item 6. 7. The photosensitive layer contains a benzidine-based compound represented by the following structural formula (IV) and / or a triphenylamine-based compound represented by the following structural formula (V). The electrophotographic photosensitive member according to any one of claims 1 to 5, wherein Embedded image (Wherein R ₁ and R ₁ ′ may be the same or different,
Represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms, even if R ₂ , R ₂ ′, R ₃ and R ₃ ′ are the same. They may be different and have a hydrogen atom, a halogen atom, a carbon number of 1 to 5
Represents an alkyl group, an alkoxy group having 1 to 5 carbon atoms, or an amino group substituted with an alkyl group having 1 to 2 carbon atoms, and p and q represent 0 to 2 Means an integer. ) (Wherein, R ₄ represents a hydrogen atom or a methyl group, r represents 1 or 2. Ar ₁ and Ar ₂ represent a substituted or unsubstituted aryl group, and the substituent has a halogen atom and a carbon number of Represents an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a substituted amino group substituted with an alkyl group having 1 to 3 carbon atoms.) 8. A method for producing an electrophotographic photosensitive member, comprising forming a photosensitive layer and a surface protective layer on a conductive support, wherein the charge transporting compound represented by the structural formula (I) according to claim 1, and After applying a coating liquid containing an isocyanate compound having three or more functional groups onto the photosensitive layer, the compound is heated and three-dimensionally crosslinked and polymerized to form a surface protective layer. A method for manufacturing a photoreceptor. 9. The method for producing an electrophotographic photosensitive member according to claim 8, wherein the urethane bond content ratio A defined in claim 2 of the crosslinked polymer of the surface protective layer is 1.5 or more. Method. 10. A coating solution containing a charge transporting compound represented by the structural formula (I), a compound having two or more hydroxy groups, and an isocyanate compound having three or more functional groups, The method for producing an electrophotographic photoreceptor according to claim 8, wherein the surface protective layer is formed by applying the compound onto the layer and then heating the compound to cross-link and polymerize the compound three-dimensionally. 11. The method according to claim 1, wherein the compound having two or more hydroxy groups is a glycol compound and / or a bisphenol compound.
0. The method for producing an electrophotographic photosensitive member according to item 0. 12. The buret modified form of hexamethylene diisocyanate represented by the structural formula (II) according to claim 5, or the structural formula (III) according to the same as the isocyanate compound having three or more functional groups. The method for producing an electrophotographic photosensitive member according to any one of claims 8 to 11, wherein a modified isocyanurate of hexamethylene diisocyanate is used. 13. The image forming apparatus according to claim 1, further comprising a charging unit, an image forming unit by exposure, a developing unit, and a transferring unit around the electrophotographic photosensitive member. An image forming apparatus using a body. 14. The image forming apparatus according to claim 13, wherein a contact charging type charging unit is used as said charging unit. 15. The image forming apparatus according to claim 14, wherein a means for applying a voltage having an AC component is provided as means for applying a voltage to said charging means.