JP6175404B2 - Electrophotographic photoreceptor - Google Patents

Description

  The present invention relates to an electrophotographic photoreceptor.

  The electrophotographic photoreceptor provided in the electrophotographic image forming apparatus includes an inorganic photoreceptor having a photosensitive layer made of an inorganic material such as selenium and amorphous silicon, and an organic material such as a binder resin, a charge generating agent, and a charge transporting agent. An organic photoreceptor having a photosensitive layer containing the material as a main component of the photoreceptor material is used. It is known that such an organic photoreceptor is easy to manufacture as compared to an inorganic photoreceptor, and there are various options for the photoreceptor material constituting the photosensitive layer, and the degree of freedom in structural design is high. It is preferably used.

  As such an electrophotographic photoreceptor, for example, an electrophotographic photoreceptor using a p-terphenyl compound having a specific structure is proposed in order to satisfy the photoreceptor characteristics of the photosensitive layer and improve sensitivity and durability. (Patent Document 1).

JP 2011-177872 A

  However, a photoreceptor having a p-terphenyl compound having a specific structure as described in Patent Document 1 has a problem in that electrical characteristics are inferior. In addition, with the recent increase in the speed of printers and multi-function machines, there is a demand for a photoconductor having higher wear resistance. However, the photoconductor described in Patent Document 1 has a problem in terms of wear resistance. is there.

  An object of the present invention is to provide an electrophotographic photoreceptor having excellent electrical characteristics and high wear resistance.

An electrophotographic photosensitive member according to the present invention is an electrophotographic photosensitive member having a conductive substrate and a photosensitive layer formed directly or via an undercoat layer on the conductive substrate, wherein the photosensitive layer comprises: A charge generating layer containing at least a charge generating agent; and a charge transporting layer containing at least a hole transporting agent, an electron transporting agent, and a binder resin , wherein the hole transporting agent comprises the following (HTM-5): It contains the compound shown by this.

  According to the present invention, since the hole transport agent containing the para-terphenyl derivative represented by the general formula (I) or the general formula (II) is used for the photosensitive layer, the electrical characteristics are excellent and high. An electrophotographic photosensitive member having wear resistance can be provided.

  Hereinafter, although the embodiment concerning the present invention is described, the present invention is not limited to these.

  An electrophotographic photoreceptor (hereinafter also simply referred to as “photoreceptor”) according to an embodiment of the present invention is formed on a conductive substrate and directly or via an undercoat layer (intermediate layer) on the conductive substrate. The photosensitive layer contains at least a charge generating agent, a hole transporting agent, and a binder resin.

  In this embodiment, the hole transport agent contains a para-terphenyl derivative represented by the general formula (I) or the general formula (II).

≪Electrophotographic photoreceptor (photoreceptor) ≫
If the electrophotographic photoreceptor according to the exemplary embodiment satisfies the above-described configuration, that is, the hole transport agent in the photosensitive layer is para-terphenyl represented by the above general formula (I) or general formula (II). Others are not particularly limited as long as they contain a derivative. For example, the photosensitive layer is a so-called single-layer type photosensitive member in which a charge generating agent, a charge transporting agent such as a hole transporting agent or an electron transporting agent, and a binder resin are contained in the same layer. Also good. Further, the photosensitive layer includes at least two layers of a charge generation layer containing a charge generation agent and a binder resin, and a charge transport layer containing a charge transfer agent such as a hole transfer agent and an electron transfer agent and a binder resin. May be a so-called laminated type photoreceptor.

  In the case where a binder resin is used for the charge generation layer, the binder resin is called a base resin, and the binder resin used for the charge transport layer is called a binder resin, similar to the binder resin used for the single-layer photoconductor described above. .

  The single-layer type photoreceptor includes a conductive substrate and a layer containing a charge generating agent, a charge transport agent, and a binder resin in the same layer as a photosensitive layer on the conductive substrate. is there. The single-layer type photoreceptor may include the photosensitive layer directly on the conductive substrate as long as it includes the conductive substrate and the photosensitive layer, or the conductive substrate and the photosensitive layer. An intermediate layer as an undercoat layer may be provided between the photosensitive layer and the photosensitive layer. The photosensitive layer may be exposed as an outermost layer, or a protective layer may be provided on the photosensitive layer.

  Next, the multilayer photoreceptor includes a conductive substrate, a charge generation layer containing a charge generating agent and a base resin as a photosensitive layer on the conductive substrate, and a charge containing a charge transport agent and a binder resin. And a layer obtained by laminating at least two layers with a transport layer. The laminated photoreceptor is not particularly limited as long as it includes the conductive substrate and a photosensitive layer in which the charge generation layer and the charge transport layer are laminated. Specifically, the multilayer photoreceptor may be a laminate in which the charge generation layer and the charge transport layer are laminated in this order on the conductive substrate, or the charge on the conductive substrate. It may be formed by laminating the transport layer and the charge generation layer in this order. The photosensitive layer may be directly provided on the conductive substrate, or an intermediate layer may be provided between the conductive substrate and the photosensitive layer. An intermediate layer as an undercoat layer may be provided between the charge transport layer and the charge generation layer. The photosensitive layer may be exposed as an outermost layer, or a protective layer may be provided on the photosensitive layer.

  In addition, if the photoreceptor satisfies the above-described configuration, that is, the para-terphenyl derivative represented by the general formula (I) or the general formula (II) is contained in the hole transport agent in the photosensitive layer. With such a photoreceptor, a photoreceptor excellent in electrical characteristics and wear resistance can be obtained. Examples of the structure of the photoreceptor include the single-layer photoreceptor and the multilayer photoreceptor as described above.

[Conductive substrate]
The conductive substrate is not particularly limited as long as it can be used as a conductive substrate of an electrophotographic photosensitive member, and examples thereof include those having at least a surface portion made of a conductive material. Specifically, it may be made of a conductive material, or may be a plastic material or the like whose surface is covered with a conductive material. Examples of the conductive material include aluminum, iron, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass. Moreover, as a material which has electroconductivity, the material which has the said electroconductivity may be used by 1 type, and may be used as an alloy etc., for example, combining 2 or more types. Among the above, the conductive substrate is preferably made of aluminum or an aluminum alloy, and an electrophotographic photosensitive member capable of forming a more suitable image can be provided. This is considered to be due to good charge transfer from the photosensitive layer to the conductive substrate.

  The shape of the conductive substrate is not particularly limited, and may be a sheet shape or a drum shape according to the structure of the image forming apparatus to be applied.

(Photosensitive layer)
The single-layer photoreceptor has one photosensitive layer containing at least a charge generating agent, a hole transport agent, and a binder resin, and the charge generating layer containing at least a charge generating agent as the photosensitive layer of the laminated photoreceptor. And a charge transport layer containing at least a hole transport agent and a binder resin. The hole transport agent in the present embodiment contains a para-terphenyl derivative represented by the following general formula (I) or (II).

(Binder resin)
As described above, the binder resin used for the photosensitive member includes a binder resin used for the photosensitive layer of the single-layer photosensitive member or the charge transporting layer of the laminated photosensitive member, and a base resin when used for the charge generation layer of the laminated photosensitive member. .

  The binder resin is not particularly limited as long as it can be used as a binder resin contained in the photosensitive layer of the single-layer type photoreceptor and the charge transport layer of the multilayer type photoreceptor, but the following general formula (III) or A polycarbonate resin having any one of the skeletons represented by (IV) or a polyarylate resin having any one of the skeletons represented by the following general formula (V) or (VI) is preferable.

〔式中、Ｒ_１及びＲ_２は、同一又は異なって、メチル基又は水素原子を示す。〕

[Wherein, R ₁ and R ₂ are the same or different and each represents a methyl group or a hydrogen atom. ]

〔式中、Ｒ_３は、メチル基又は水素原子を示し、Ｒ_４及びＲ_５は、同一又は異なって、水素原子又は炭素数１〜４のアルキル基を示す。ｎ、ｐ及びｑは整数を示す。〕

[Wherein, R ₃ represents a methyl group or a hydrogen atom, and R ₄ and R ₅ are the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n, p and q represent integers. ]

  A polycarbonate resin having any one of the skeletons represented by the general formula (III) or (IV) or a polyarylate resin having any one of the skeletons represented by the general formula (V) or (VI) can be produced in various ways. It can be manufactured by a method.

  In addition, you may add resin other than the said polycarbonate resin or polyarylate resin to the binder resin in this embodiment in the range which does not impair the effect of this invention. Examples of other resins include styrene resins, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, styrene-acrylic acid copolymers, acrylic copolymers, polyethylene resins, Ethylene-vinyl acetate copolymer, chlorinated polyethylene resin, polyvinyl chloride resin, polypropylene resin, ionomer, vinyl chloride-vinyl acetate copolymer, polyester resin, alkyd resin, polyamide resin, polyurethane resin, polysulfone resin, diallyl phthalate resin , Ketone resins, polyvinyl butyral resins, polyether resins, polyester resins, silicone resins, epoxy resins, phenol resins, urea resins, melamine resins, other crosslinkable thermosetting resins, and epoxy acrylic resins. Over preparative resin, urethane - photocurable resins such as acrylate copolymer resin. These may be used alone or in combination of two or more.

  The base resin is not particularly limited as long as it can be used as a binder resin contained in the charge generation layer of the multilayer photoreceptor. Specifically, for example, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene resin, ethylene-vinyl acetate copolymer. Polymer, chlorinated polyethylene resin, polyvinyl chloride resin, polypropylene resin, ionomer resin, vinyl chloride-vinyl acetate copolymer, alkyd resin, polyamide resin, polyurethane resin, polysulfone resin, diallyl phthalate resin, ketone resin, polyvinyl acetal resin , Polyvinyl butyral resin, polyether resin, silicone resin, epoxy resin, phenol resin, urea resin, melamine resin, epoxy acrylate resin, urethane-acrylate resin, and the like. Moreover, as said base resin, each said illustrated base resin may be used independently, and may be used in combination of 2 or more type.

  The base resin is exemplified by the same resin as the binder resin, but a resin different from the binder resin is usually selected for the same photoreceptor. This is due to the following. When producing a laminated photoreceptor, usually, a charge generation layer and a charge transport layer are formed in this order, so that a charge transport layer forming coating solution is applied to the charge generation layer. Therefore, the charge generation layer is required not to be dissolved in the solvent of the charge transport layer forming coating solution. For this reason, as the base resin, which is the binder resin contained in the charge generation layer, a resin different from the binder resin is usually selected for the same photoreceptor.

(Charge generator)
The charge generator is not particularly limited as long as it can be used as a charge generator for an electrophotographic photosensitive member. For example, X-type metal-free phthalocyanine (x-H2Pc), Y-type oxotitanyl phthalocyanine (Y -TiOPc), perylene pigment, bisazo pigment, dithioketopyrrolopyrrole pigment, metal-free naphthalocyanine pigment, metal naphthalocyanine pigment, squaraine pigment, trisazo pigment, indigo pigment, azulenium pigment, cyanine pigment, selenium, selenium-tellurium, selenium -Powders of inorganic photoconductive materials such as arsenic, cadmium sulfide and amorphous silicon, pyrylium salts, ansanthrone pigments, triphenylmethane pigments, selenium pigments, toluidine pigments, pyrazoline pigments, quinacridone pigments, etc. .

  In addition, each of the charge generation agents may be used alone or in combination of two or more so that the charge generation agent has an absorption wavelength in a desired region. Furthermore, among the above charge generating agents, digital optical image forming apparatuses such as laser beam printers and facsimiles using a light source such as a semiconductor laser, in particular, require a photoreceptor having sensitivity in a wavelength region of 700 nm or more. Therefore, for example, metal-free phthalocyanines such as X-type metal-free phthalocyanine (x-H2Pc) and phthalocyanine-based pigments such as oxotitanyl phthalocyanine such as Y-type oxotitanyl phthalocyanine (Y-TiOPc) are preferably used. The crystal form of the phthalocyanine pigment is not particularly limited, and various types can be used.

  In the case of an image forming apparatus using a short wavelength laser light source of 350 to 550 nm, an santhrone pigment or a perylene pigment is used as the charge generating agent.

(Charge transport agent)
Examples of the charge transfer agent generally include a hole transfer agent and an electron transfer agent.

  The hole transport agent in the present embodiment contains a para-terphenyl derivative represented by the following general formula (I) or general formula (II).

〔式中、Ｒ_１及びＲ_２は、同一又は異なって、水素原子又は置換基を有してもよいアリール基を示す。Ｒ_３〜Ｒ_７は、同一又は異なって、水素原子、アルキル基、アルコキシ基又は置換基を有してもよいアリール基を示す。また、Ｒ_３〜Ｒ_７は互いに隣接する基同士が結合して環を形成してもよい。〕

[Wherein, R ₁ and R ₂ are the same or different and each represents a hydrogen atom or an aryl group which may have a substituent. R _{3 to} R ₇ are the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group which may have a substituent. Moreover, R < ₃ > -R < ₇ > may mutually adjoin groups and may form a ring. ]

〔式中、Ｒ_１１及びＲ_１２は、同一又は異なって、水素原子又は置換基を有してもよいアリール基を示す。Ｒ_１３〜Ｒ_１７は、同一又は異なって、水素原子、アルキル基、アルコキシ基又は置換基を有してもよいアリール基を示す。また、Ｒ_１３〜Ｒ_１７は互いに隣接する基同士が結合して環を形成してもよい。〕

[Wherein, R ₁₁ and R ₁₂ are the same or different and each represents a hydrogen atom or an aryl group which may have a substituent. R _{13 to} R ₁₇ are the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group which may have a substituent. R _{13 to} R ₁₇ may be bonded to each other to form a ring. ]

  The alkyl group herein may be linear or branched. For example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl , Pentyl, neopentyl, isopentyl, n-hexyl, 2-methylpentyl, heptyl, octyl and the like. Carbon number of an alkyl group becomes like this. Preferably it is 2-8, More preferably, it is 2-6.

  Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, t-butoxy group, n-pentoxy group, n-hexoxy group, n -Heptoxy group, n-octoxy group, etc. are mentioned. Carbon number of an alkoxy group becomes like this. Preferably it is 2-8, More preferably, it is 2-6. This is fine.

In the present embodiment, R _{3 to} R ₇ in the general formula (I) are preferably an alkyl group having 2 or more carbon atoms or an alkoxy group having 2 or more carbon atoms, and R ₁₃ to R ₇ in the general formula (II). R ₁₇ is preferably an alkyl group having 2 or more carbon atoms or an alkoxy group having 2 or more carbon atoms.

R ₃ in the general formula (I) is preferably an alkyl group or an alkoxy group, particularly preferably an alkyl group having 2 or more carbon atoms or an alkoxy group having 2 or more carbon atoms. R ₁₃ in the general formula (II) is preferably an alkyl group or an alkoxy group, particularly preferably an alkyl group having 2 or more carbon atoms or an alkoxy group having 2 or more carbon atoms.

  Examples of the aryl group include a phenyl group, a naphthyl group, a biphenylyl group, a benzyl group, a tolyl group, and a xylyl group. The aryl group may have a substituent, and the number of substituents may be 1 or more, preferably 1 to 3. Examples of the substituent include a methyl group, an ethyl group, a propyl group, and an isopropyl group.

  The para-terphenyl derivative represented by the general formula (I) or the general formula (II) can be produced by various production methods. The para-terphenyl derivative represented by the following formula (HTM-1) can be produced, for example, as follows.

(First coupling reaction)
In the presence of a catalyst containing an phosphine compound and a palladium compound, an aryl halide (AH-1) is added to 1 mol of the amine compound (Amine-1) so as to have a value within the range of 1 to 2 mol. Then, the mixture is stirred at 80 to 140 ° C. for 1 to 8 hours, and the resulting reaction solution is extracted with toluene or the like to obtain a diarylamine compound (DAA-1).

(Second coupling reaction)
Next, an aryl halide is added to 1 mol of the diarylamine compound (DAA-1) so as to have a value within the range of 1 to 2 mol, and in the presence of a catalyst containing a phosphine compound and a palladium compound. Stirring at 80 to 140 ° C. for 1 to 8 hours, and then subjecting the resulting reaction solution to extraction treatment with toluene or the like to obtain a compound having a triarylamine structure (HTM-1). it can.

  In addition, you may add hole transport agents other than the said compound to the hole transport agent in this embodiment in the range which does not impair the effect of this invention. Examples of other hole transporting agents include benzidine derivatives, oxadiazole compounds such as 2,5-di (4-methylaminophenyl) -1,3,4-oxadiazole, and 9- (4-diethylamino). Styryl) styryl compounds such as anthracene, carbazole compounds such as polyvinyl carbazole, organic polysilane compounds, pyrazoline compounds such as 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline, hydrazone compounds, triphenylamine compounds , Nitrogen-containing cyclic compounds such as indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, triazole compounds, and condensed polycyclic compounds. . Among these, triphenylamine compounds and benzidine derivatives are preferable, and benzidine derivatives are more preferable. Moreover, these may be used independently and may be used in combination of 2 or more type.

  Here, the weight ratio (hole transport agent / binder resin) of the hole transport agent (total weight of the hole transport agent) and the binder resin (total weight of the binder resin) in the photosensitive layer in the present embodiment is From the viewpoint of wear resistance, it is preferably 0.55 or less, particularly preferably 0.45 or less.

  The electron transporting agent is not particularly limited as long as it can be used as an electron transporting agent contained in the photosensitive layer of the electrophotographic photosensitive member, but a compound having a ketone structure or a dicyanomethylene structure is preferable.

  Examples of the compound having a ketone structure or dicyanomethylene structure include compounds represented by the following general formula.

〔式中、Ｒ_１〜Ｒ_６は、同一又は異なって、置換基を有してもよい炭素数１〜８のアルキル基もしくは炭素数６〜１２のアリール基、又はハロゲン原子を示す。

[Wherein, R _{1 to} R ₆ are the same or different and each represents an optionally substituted alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 12 carbon atoms, or a halogen atom.

  The alkyl group having 1 to 8 carbon atoms here may be linear or branched. For example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec -Butyl, tert-butyl, pentyl, neopentyl, isopentyl, n-hexyl, 2-methylpentyl, heptyl, octyl and the like. Carbon number of an alkyl group becomes like this. Preferably it is 1-6, More preferably, it is 1-4. The number of substituents may be one or more, and is preferably 1 to 3. Examples of the substituent include a methyl group, an ethyl group, a propyl group, and an isopropyl group.

  Moreover, as said C6-C12 aryl group, a phenyl group, a naphthyl group, etc. are mentioned, for example. The aryl group may have a substituent, and the number of substituents may be 1 or more, preferably 1 to 3. Examples of the substituent include a methyl group, an ethyl group, a propyl group, and an isopropyl group.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

(Additive)
The photoreceptor may contain various additives other than the charge generator, the charge transport agent, and the binder resin as long as they do not adversely affect the electrophotographic characteristics and wear resistance. Examples of the additives include antioxidants, radical scavengers, singlet quenchers, deterioration inhibitors such as ultraviolet absorbers, softeners, plasticizers, surface modifiers, extenders, thickeners, dispersions. Stabilizers, waxes, acceptors, donors, surfactants, leveling agents and the like can be mentioned. Further, in order to improve the sensitivity of the photosensitive layer, for example, a sensitizer such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generator.

≪Method for producing electrophotographic photosensitive member≫
Next, a method for producing an electrophotographic photoreceptor will be described.

  First, a method for producing the single layer type photoreceptor will be described.

  The single-layer photoreceptor is a coating in which the charge generator, the charge transport agent (hole transport agent, electron transport agent), the binder resin, and various additives as necessary are dissolved or dispersed in a solvent. It can be produced by applying the liquid onto the conductive substrate by coating or the like and drying it. Although it does not specifically limit as said coating method, For example, the dip coating method etc. are mentioned.

  In the single-layer type photoreceptor, each content of the charge generator, the charge transport agent, and the binder resin is appropriately selected, and the content of the charge generator is 100 parts by mass of the binder resin. It is preferable that it is 0.1-50 mass parts, and it is more preferable that it is 0.5-30 mass parts. Moreover, it is preferable that it is 5-100 mass parts with respect to 100 mass parts of binder resin, and, as for content of the said electron transport agent, it is more preferable that it is 10-80 mass parts. Moreover, it is preferable that it is 5-500 mass parts with respect to 100 mass parts of binder resin, and, as for content of the said hole transport agent, it is more preferable that it is 25-200 mass parts. Furthermore, the total amount of the hole transporting agent and the electron transporting agent, that is, the content of the charge transporting agent is preferably 20 to 500 parts by weight, and 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin. It is more preferable that

  In addition, the thickness of the photosensitive layer of the single-layer type photoreceptor is not particularly limited as long as it can sufficiently function as a photosensitive layer, and is preferably 5 to 100 μm, and more preferably 10 to 50 μm.

  Next, a method for producing the laminated photoreceptor will be described.

  The laminated photoreceptor can be manufactured by the following method.

  Specifically, first, a charge generation layer forming coating solution in which the charge generator, the base resin, and various additives as necessary are dissolved or dispersed in a solvent, the charge transport agent, a binder resin, and If necessary, a charge transport layer forming coating solution in which various additives and the like are dissolved or dispersed in a solvent is prepared. Then, the charge generation layer is formed by applying one of the coating liquid for forming the charge generation layer and the coating liquid for forming the charge transport layer onto the conductive substrate by coating or the like, and drying. And any one of the charge transport layers is formed. Thereafter, the other coating liquid is applied onto the conductive substrate on which the charge generation layer or the charge transport layer is formed, and dried to form the other layer. In this way, the multilayer photoreceptor can be manufactured. Although it does not specifically limit as said coating method, For example, the dip coating method etc. are mentioned.

  In the multilayer photoconductor, the contents of the charge generator, the charge transport agent, the base resin, and the binder resin are appropriately selected and are not particularly limited. The content of the charge generator is the charge The amount is preferably 5 to 1000 parts by mass and more preferably 30 to 500 parts by mass with respect to 100 parts by mass of the base resin constituting the generation layer.

  Moreover, it is preferable that it is 10-500 mass parts with respect to 100 mass parts of binder resin which comprises the said charge transport layer, and, as for content of the said charge transport agent, it is more preferable that it is 25-100 mass parts.

  Further, the thickness of each layer of the charge generation layer and the charge transport layer is not particularly limited as long as it can sufficiently function as each layer. The thickness of the charge generation layer is preferably 0.01 to 5 μm, and more preferably 0.1 to 3 μm. The thickness of the charge transport layer is preferably 2 to 100 μm, and more preferably 5 to 50 μm.

  Further, the solvent contained in the coating solution is not particularly limited as long as it can dissolve or disperse the above-described components. For example, alcohols such as methanol, ethanol, isopropanol, butanol, n-hexane, octane, Aliphatic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene (for example, o-xylene), halogenated hydrocarbons such as dichloromethane, dichloroethane, carbon tetrachloride, and chlorobenzene, 1,4-dioxane, Ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and methyl acetate, dimethyl Le formaldehyde, dimethylformamide, dimethyl sulfoxide and the like. Among these, toluene, 1,4-dioxane, and o-xylene are particularly preferable. As these solvents, the solvents exemplified above may be used alone, or two or more kinds may be used in combination.

  The electrophotographic photosensitive member can be used as an image carrier of an electrophotographic image forming apparatus. The image forming apparatus is not particularly limited as long as it is an electrophotographic system. The electrophotographic photoreceptor can be used as an image carrier of an image forming apparatus, for example.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited at all by the Example.

(Synthesis of hole transport agent)
The compounds represented by the following formulas (HTM-1) to (HTM-9) were synthesized according to the synthesis of the hole transport agent described above. Moreover, the compound shown by (HTM-8) and (HTM-9) was synthesize | combined as a hole transport agent used by a comparative example, respectively.

[Synthesis of binder resin]
Binder resins represented by the following formulas (R-1) to (R-4) were respectively synthesized.

(Synthesis of electron transport agent)
Electron transport agents represented by the following formulas (ETM-1) to (ETM-11) were respectively synthesized.

[Example 1]
(Underlayer)
After surface treatment with alumina and silica, 2 parts by mass of titanium oxide (manufactured by Teika, prototype SMT-A (number average primary particle size 10 nm)) surface-treated with methylhydrogenpolysiloxane while being wet-dispersed, Disperse 1 part by mass of 6,12,66,610-quaternary copolymer polyamide resin (manufactured by Toray Industries, Inc., Amilan CM8000), 10 parts by mass of methanol, 1 part by mass of butanol and 1 part by mass of toluene for 5 hours using a bead mill. The undercoat layer coating solution was prepared. The obtained coating solution for the undercoat layer is filtered through a 5 micron filter, and then applied on a drum-like support made of aluminum (diameter 30 mm, total length 246 mm) as a conductive support by dip coating. Then, heat treatment was performed at 130 ° C. for 30 minutes to form an undercoat layer having a thickness of 2 μm.

(Charge generation layer)
1.5 parts by mass of titanyl phthalocyanine, 1 part by mass of polyvinyl acetal resin (Sekisui Chemical Co., Ltd., ESREC BX-5) as a binder resin, 40 parts by mass of propylene glycol monomethyl ether and 40 parts by mass of tetrahydrofuran as a dispersion medium For 2 hours to prepare a charge generation layer coating solution. The obtained coating solution for charge generation layer was filtered with a 3 micron filter, and then applied on the undercoat layer produced above by the dip coating method and dried at 50 ° C. for 5 minutes. A 3 μm charge generation layer was formed.

(Charge transport layer)
45 parts by mass of the compound represented by the above formula (HTM-1) as a hole transporting agent, 0.5 parts by mass of Irganox 1010 as an additive, and 2 parts by mass of the compound represented by the above formula (ETM-1) as an electron transporting agent. Parts, 0.1 part by weight of dimethyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., KF-96-100CS) as a leveling agent, 100 parts by weight of the polycarbonate resin (R-1, viscosity average molecular weight 50,500) as a binder resin, and solvent A charge transport layer coating solution was prepared by mixing and dissolving 500 parts by mass of tetrahydrofuran and 200 parts by mass of toluene. The resulting charge transport layer coating solution was filtered through a 3 micron filter, and then applied onto the charge generation layer and dried at 120 ° C. for 40 minutes to form a charge transport layer having a thickness of 20 μm. In this way, a multilayer electrophotographic photosensitive member was produced in which an undercoat layer, a charge generation layer, and a charge transport layer were sequentially formed on a conductive support.

[Examples 2 to 6, Comparative Examples 1 and 2]
Instead of the compound represented by the above formula (HTM-1) as the hole transporting agent, the compounds represented by the formulas (HTM-2) to (HTM-8) shown in Table 1 and Table 2 below were used, respectively. According to Example 1, a multilayer electrophotographic photosensitive member was produced in which an undercoat layer, a charge generation layer, and a charge transport layer were sequentially formed on a conductive support.

[Examples 7 to 9]
Instead of the polycarbonate resin represented by the above formula (R-1) as the binder resin, the polycarbonate resin represented by the formula (R-2) shown in Table 1 below, or the formula (R-3), (R-4) A laminated electrophotographic photoreceptor in which an undercoat layer, a charge generation layer, and a charge transport layer are sequentially formed on a conductive support in the same manner as in Example 1 except that the polyarylate resin shown is used. Produced.

[Examples 10 to 19]
In place of the compounds represented by the above formula (ETM-1) as the electron transfer agent, except that the compounds represented by the formulas (ETM-2) to (ETM-11) shown in Table 1 and Table 2 below were used, respectively. In accordance with Example 1, a multilayer electrophotographic photosensitive member was produced in which an undercoat layer, a charge generation layer, and a charge transport layer were sequentially formed on a conductive support.

[Examples 20-22, 24]
According to Example 1 except that the weight ratio of the hole transport agent represented by the above formula (HTM-1) and the polycarbonate resin represented by (R-1) was changed to the values shown in Table 2 below. Thus, a multilayer electrophotographic photosensitive member was produced in which an undercoat layer, a charge generation layer, and a charge transport layer were sequentially formed on a conductive support.

Example 23
A laminated electrophotographic photosensitive member in which an undercoat layer, a charge generation layer, and a charge transport layer are sequentially formed on a conductive support is prepared in the same manner as in Example 1 except that no electron transport agent is blended. did.

≪Evaluation≫
Various evaluations were performed using the electrophotographic photoreceptors of Examples and Comparative Examples according to the following criteria. These results are shown together in Tables 1 and 2 above.

(Electrical characteristics evaluation)
The produced electrophotographic photosensitive member was measured for chargeability and sensitivity under the following conditions using an electrical property tester (manufactured by GENTEC).
Measurement environment: 10 ° C x 15%
Charging: Number of revolutions: 31 rpm Drum inflow current: Surface potential at −10 μA (V ₀ )
Sensitivity: When charged at 450 V Exposure wavelength: 780 nm Exposure amount: 0.20 J / cm ²
Surface potential (V _L ) after 40 msec after exposure

(Abrasion evaluation test)
Wear evaluation was performed using the coating solutions for charge transport layers prepared for the electrophotographic photoreceptors of Examples and Comparative Examples.

  First, the prepared charge transport layer coating solution was applied to a PP (polypropylene) sheet (thickness 0.3 mm) wound around a φ78 aluminum pipe, dried at 120 ° C. for 40 minutes, and evaluated for wear with a film thickness of 30 μm. A sheet was prepared.

  The charge transport layer was peeled off from this PP sheet and attached to Wheel S-36 (manufactured by Taber) to prepare a sample. Using a rotary abrasion tester (manufactured by Toyo Seiki Co., Ltd.), this sample was subjected to a 1000 rotation wear test at a wear wheel C-10 (Taber), a load of 500 gf, and a rotation speed of 60 rpm. Abrasion was evaluated by weight change (wear loss).

  From the result of the said Table 1 and Table 2, since Examples 1-24 contain the compound shown by the said Formula (HTM-1)-(HTM-6) as a hole transport agent, the said Formula (HTM-7) ) Or (HTM-8), it was excellent in electrical characteristics as compared with Comparative Examples 1 and 2 containing a compound represented by (HTM-8). Examples 1 to 24 were not crystallized, had a good drum appearance, and were excellent in wear resistance.

  In addition, since Examples 1 to 23 had an HTM / binder resin ratio of 0.55 or less, the wear resistance was further superior to Example 24 in which the HTM / binder resin ratio was 0.65. .

  The electrophotographic photosensitive member of the present invention can be used, for example, as an image carrier of an image forming apparatus.

Claims (4)

An electrophotographic photosensitive member having a conductive substrate and a photosensitive layer formed directly or via an undercoat layer on the conductive substrate, wherein the photosensitive layer contains at least a charge generating agent. And a charge transport layer containing at least a hole transport agent, an electron transport agent, and a binder resin , wherein the hole transport agent contains a compound represented by the following (HTM-5): An electrophotographic photoreceptor.

The electrophotographic photosensitive member according to claim 1, wherein the binder resin is a resin having a skeleton represented by the following formula (R-3) .

The electron transport agent, the following (ETM-4), (ETM -5), is either (ETM-6), the electrophotographic photosensitive member according to claim 1 or 2.

The electrophotographic photosensitive member according to any one of claims 1 to 3 , wherein a weight ratio of the hole transport agent to the binder resin (hole transport agent / binder resin) in the charge transport layer is 0.55 or less. body.