JP6232928B2 - Electrophotographic photosensitive member and image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member and an image forming apparatus including the electrophotographic photosensitive member.

  In electrophotographic printers and multifunction machines, a photoreceptor is used as an image carrier. Examples of the photoreceptor include an organic photoreceptor, a selenium photoreceptor, and an amorphous silicon photoreceptor. Among them, the organic photoreceptor has advantages such as relatively little influence on the environment, easy film formation, and easy manufacture, and is currently used in many image forming apparatuses.

  In general, the organic photoreceptor includes a conductive substrate and a photosensitive layer provided directly or indirectly on the conductive substrate. The photosensitive layer contains a charge transport material, a charge generation material, and a binder resin (binder resin) that binds these materials. An organic photoreceptor is referred to as a laminated photoreceptor when a charge transport material and a charge generation material are formed in separate layers and perform both charge generation and charge transport functions. Are formed of the same layer, it is called a single-layer type photoreceptor.

Examples of the charge transporting material that can be applied to single-layered and laminated organic photoconductors and that transport holes include amine stilbene derivatives disclosed in Patent Document 1. The amine stilbene derivative exhibits excellent sensitivity characteristics (electrical characteristics) and can reduce the residual potential (V _L ).

JP 2006-008670 A

  However, in order to exhibit characteristics such as sensitivity characteristics (electrical characteristics) and durability required for the image carrier as a whole of the photoreceptor, not only the performance of the charge transport material alone but also the charge generation material and the binder resin. In addition to the significant contribution of properties, their compatibility (characteristics resulting from the combination of various components) is also an important factor. Even when the amine stilbene derivative disclosed in Patent Document 1 is used as a charge transport material, it is required to improve the wear resistance of the entire photoreceptor while maintaining excellent sensitivity characteristics (electrical characteristics). Yes.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an electrophotographic photosensitive member capable of imparting abrasion resistance while maintaining excellent sensitivity characteristics (electrical characteristics) as a whole photosensitive member. An object is to provide an image forming apparatus.

  The electrophotographic photoreceptor according to the present invention has a photosensitive layer containing a charge generator, a hole transport agent, and a binder resin. In the electrophotographic photoreceptor according to the present invention, the hole transport agent contains an amine stilbene derivative represented by the general formula (1), and the binder resin contains a polycarbonate resin represented by the general formula (2).

ここで、一般式（１）中、Ｒ₁〜Ｒ₁₄は、それぞれ独立した水素原子、ハロゲン原子、炭素数１〜２０のアルキル基、炭素数１〜２０のハロゲン化アルキル基、炭素数１〜２０のアルコキシ基、メチル基にて置換又は非置換の炭素数６〜２０のアリール基、あるいは、メチル基にて置換又は非置換のアミノ基であり、繰り返し数ａ〜ｄはそれぞれ独立した０〜４の整数である。ただし、Ａ及びＢ、あるいはいずれか一方が、メチル基にて置換又は非置換の炭素数６〜２０のアリール基であり、Ｃ及びＤ、あるいはいずれか一方が、メチル基にて置換又は非置換の炭素数６〜２０のアリール基であり、Ａ、Ｂ、Ｃ及びＤのうちアリール基でないものは、水素原子である。

Here, in general formula (1), R < ₁ > -R < ₁₄ > is respectively independently a hydrogen atom, a halogen atom, a C1-C20 alkyl group, a C1-C20 halogenated alkyl group, C1-C1 An alkoxy group having 20 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms substituted or unsubstituted with a methyl group, or an amino group substituted or unsubstituted with a methyl group; It is an integer of 4. However, A and B, or any one is a C6-C20 aryl group substituted or unsubstituted by the methyl group, and C and D, or any one is substituted or unsubstituted by the methyl group The aryl group having 6 to 20 carbon atoms of A, B, C and D which is not an aryl group is a hydrogen atom.

ここで、一般式（２）中、 Ｒ₂₃〜Ｒ₂₅は水素原子もしくは炭素数１〜４のアルキル基であるが、少なくともＲ₂₃〜Ｒ₂₅の内いずれか一つはアルキル基である。また、ｐ＋ｑ＝１００で、ｐ≧３５である。そして、ｎは２又は３である。

Here, in the general formula (2), R ₂₃ ~R ₂₅ is an alkyl group having 1 to 4 carbon hydrogen atom or atoms, and any one of at least R ₂₃ to R ₂₅ is an alkyl group. Further, p + q = 100 and p ≧ 35. N is 2 or 3.

  An image forming apparatus according to the present invention includes an image carrier, a charger that charges the surface of the image carrier, and the surface of the image carrier charged by the charger to expose an electrostatic latent image on the surface. A developing unit that develops the toner image as the image carrier, and a transfer unit that transfers the toner image from the image carrier to a transfer target. In the image forming apparatus according to the present invention, the image carrier is the above-described electrophotographic photosensitive member.

  According to the present invention, in an electrophotographic photoreceptor, excellent sensitivity characteristics (electrical characteristics) can be maintained and wear resistance can be improved.

It is a schematic sectional drawing which shows the structure of the single layer type electrophotographic photosensitive member in embodiment of this invention. It is a schematic sectional drawing which shows the structure of the laminated electrophotographic photoreceptor in embodiment of this invention. 1 is a schematic diagram illustrating a configuration of an image forming apparatus including an electrophotographic photosensitive member according to an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to these.

[Embodiment 1]
The photosensitive layer of the single-layer or multi-layer electrophotographic photoreceptor (hereinafter referred to as “photoreceptor”) according to the present embodiment contains a charge generating agent, a hole transporting agent, and a binder resin. Yes.

  The hole transport agent is a kind of charge transport material, and an amine stilbene derivative represented by the general formula (1) is used.

ここで、Ｒ₁〜Ｒ₁₄は、それぞれ独立した水素原子、ハロゲン原子、炭素数１〜２０のアルキル基、炭素数１〜２０のハロゲン化アルキル基、炭素数１〜２０のアルコキシ基、メチル基にて置換又は非置換の炭素数６〜２０のアリール基、あるいは、メチル基にて置換又は非置換のアミノ基であり、繰り返し数ａ〜ｄはそれぞれ独立した０〜４の整数である。ただし、Ａ及びＢ、あるいはいずれか一方が、メチル基にて置換又は非置換の炭素数６〜２０のアリール基であり、Ｃ及びＤ、あるいはいずれか一方が、メチル基にて置換又は非置換の炭素数６〜２０のアリール基であり、Ａ、Ｂ、Ｃ及びＤのうちアリール基でないものは、水素原子である。

Here, R _{1 to} R ₁₄ are each independently an hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a methyl group. Substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a methyl group substituted or unsubstituted amino group, and the repeating numbers a to d are each independently an integer of 0 to 4. However, A and B, or any one is a C6-C20 aryl group substituted or unsubstituted by the methyl group, and C and D, or any one is substituted or unsubstituted by the methyl group The aryl group having 6 to 20 carbon atoms of A, B, C and D which is not an aryl group is a hydrogen atom.

  Moreover, polycarbonate resin represented by General formula (2) is used for binder resin.

ここで、一般式（２）中、 Ｒ₂₃〜Ｒ₂₅は水素原子もしくは炭素数１〜４のアルキル基であるが、少なくともＲ₂₃〜Ｒ₂₅の内いずれか一つはアルキル基である。また、ｐ＋ｑ＝１００で、ｐ≧３５である。そして、ｎは２又は３である。

Here, in the general formula (2), R ₂₃ ~R ₂₅ is an alkyl group having 1 to 4 carbon hydrogen atom or atoms, and any one of at least R ₂₃ to R ₂₅ is an alkyl group. Further, p + q = 100 and p ≧ 35. N is 2 or 3.

  Since the photoreceptor according to the present embodiment contains the amine stilbene derivative represented by the general formula (1) and the polycarbonate resin represented by the general formula (2), the photoreceptor has sensitivity characteristics (electrical characteristics). Excellent wear resistance. Accordingly, an image forming apparatus provided with such a photoreceptor has durability and can form high-quality images over a long period of time.

  If the photoreceptor satisfies the above-described configuration, that is, an amine stilbene derivative represented by the general formula (1) as a hole transport agent, and a polycarbonate resin represented by the general formula (2) as a binder resin Others are not particularly limited as long as they are contained in the photosensitive layer.

  Specifically, the photoreceptor according to the present embodiment may be a so-called single-layer photoreceptor as shown in FIG. The single-layer type photoreceptor has a photosensitive layer, and the photosensitive layer contains at least a charge generator, a hole transport agent, and a binder resin called a binder resin in the same layer.

  FIG. 1 is a schematic cross-sectional view showing the structure of a single-layer electrophotographic photoreceptor 10 (hereinafter referred to as “single-layer photoreceptor 10”) in an embodiment of the present invention.

  As shown in FIG. 1A, the single-layer type photoreceptor 10 includes a conductive substrate 11 and a photosensitive layer 12 provided on the conductive substrate 11. The photosensitive layer 12 contains a charge generator, a hole transport agent, an electron transport agent, and a binder resin in the same layer.

  The single layer type photoreceptor 10 is not particularly limited as long as it includes the conductive substrate 11 and the photosensitive layer 12. Specifically, for example, as shown in FIG. 1A, the photosensitive layer 12 may be directly provided on the conductive substrate 11, or as shown in FIG. An undercoat layer 13 may be provided between the photosensitive layer 12.

  Further, the photoreceptor according to the present embodiment may be a so-called multilayer photoreceptor as shown in FIG. The multilayer photoreceptor has a photosensitive layer, and the photosensitive layer includes at least a charge generation layer containing a binder resin called a charge generator and a base resin, a hole transport agent, and a binder used for the single-layer photoreceptor described above. Similar to the resin, at least a charge transport layer containing a binder resin is laminated.

  FIG. 2 is a schematic cross-sectional view showing the structure of a laminated electrophotographic photoreceptor 20 (hereinafter referred to as “laminated photoreceptor 20”) in an embodiment of the present invention.

  As shown in FIG. 2A, the multilayer photoconductor 20 includes a conductive substrate 21 and a photosensitive layer 22 provided on the conductive substrate 21. Further, the photosensitive layer 22 includes a charge generation layer 22a and a charge transport layer 22b, and the charge generation layer 22a and the charge transport layer 22b are laminated. The charge generation layer 22a contains a charge generation agent and a base resin. The charge transport layer 22b contains a hole transport agent and a binder resin.

  Further, the multilayer photoreceptor 20 is not particularly limited as long as it includes the conductive substrate 21 and the photosensitive layer 22. Specifically, as shown in FIG. 2A, the multilayer photoconductor 20 may be one in which a charge generation layer 22a and a charge transport layer 22b are stacked in this order on a conductive substrate 21. Alternatively, although not shown here, the multilayer photoreceptor 20 may be formed by laminating a charge transport layer 22b and a charge generation layer 22a in this order on a conductive substrate 21. Further, the photosensitive layer 22 may be provided directly on the conductive substrate 21, or an undercoat layer 23 is provided between the conductive substrate 21 and the photosensitive layer 22, as shown in FIG. Also good. Alternatively, although not shown here, the multilayer photoreceptor 20 may be provided with an intermediate layer between the charge transport layer 22b and the charge generation layer 22a.

  In the photoreceptor according to this embodiment, the polycarbonate resin represented by the general formula (2) is contained in the above-described binder resin, whether it is a single-layer photoreceptor or a laminated photoreceptor. . In addition, the photoreceptor in this embodiment may further include a protective layer on the surface side of the photosensitive layer. However, in order to prevent the occurrence of image flow and to suppress the manufacturing cost, it is preferable that the photosensitive layer according to the present embodiment has the photosensitive layer as the outermost layer.

  Hereinafter, with reference to FIGS. 1 and 2, each component of the photoconductor according to the present exemplary embodiment will be described in detail.

[Conductive substrate]
In the present embodiment, the conductive substrates 11 and 21 are not particularly limited as long as at least the surface portion has conductivity. The conductive bases 11 and 21 may be made of, for example, a conductive material, or may be a plastic material or a glass surface coated or vapor-deposited with a conductive material. Good. Here, examples of the conductive material include metals such as aluminum, iron, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass, Or an alloy thereof may be mentioned. These electrically conductive materials may be used alone or in combination of two or more. Of the exemplified conductive substrates, those made of aluminum or an aluminum alloy are preferably used. In this case, a photoreceptor capable of forming a more suitable image can be provided. This is considered to be due to the good charge transfer from the photosensitive layers 12 and 22 to the conductive substrates 11 and 21.

  The shape of the conductive substrates 11 and 21 is not particularly limited. For example, a sheet shape or a drum shape may be used according to the structure of the image forming apparatus to be applied.

  Further, it is desirable that the conductive substrates 11 and 21 have sufficient mechanical strength when used.

[Photosensitive layer]
As described with reference to FIG. 1, the single-layer type photoreceptor 10 includes the photosensitive layer 12. The photosensitive layer 12 contains a charge generating agent, a hole transport agent, and a binder resin in the same layer. Further, as described with reference to FIG. 2, the multilayer photoreceptor 20 includes a photosensitive layer 22. The photosensitive layer 22 has a charge generation layer 22a containing a charge generation agent, and a charge transport layer 22b containing a hole transfer agent and a binder resin.

  Further, in both the single layer type photoreceptor 10 and the multilayer photoreceptor 20, an electron transport agent and an additive may be contained in the photosensitive layer as necessary.

(Charge generator)
The charge generator is not particularly limited as long as it can be used as a charge generator for a photoreceptor. Specifically, for example, X-type metal-free phthalocyanine (x-H ₂ Pc), 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-arsenic, cadmium sulfide, amorphous silicon inorganic photoconductive material powder, pyrylium salt, ansanthrone pigment , Triphenylmethane pigments, selenium pigments, toluidine pigments, pyrazoline pigments, or quinacridone pigments.

In addition, as the charge generating agent, each of the above-described charge generating agents may be used alone or in combination of two or more thereof so as to have an absorption wavelength in a desired region. Further, for example, a laser beam printer using a light source of a semiconductor laser or a digital optical image forming apparatus of a facsimile requires a photosensitive member having a sensitivity in a wavelength region of 700 nm or more. A phthalocyanine pigment of phthalocyanine (x-H ₂ Pc) or Y-type oxotitanyl phthalocyanine (Y-TiOPc) is preferably used. In addition, it does not specifically limit about the crystal form of a phthalocyanine pigment, A various thing is used.

  Further, when the image forming apparatus includes a short wavelength laser light source of 350 nm or more and 550 nm or less, an sanslon pigment or a perylene pigment is preferably used as the charge generating agent.

  Of the charge generating agents described above, it is more preferable to use phthalocyanine pigments (CGM-1 to CGM-4) represented by general formulas (3) to (6).

(Hole transport agent)
The hole transport agent includes an amine stilbene derivative represented by the general formula (1).

Here, R _{1 to} R ₁₄ are each independently an hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a methyl group. Substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a methyl group substituted or unsubstituted amino group, and the repeating numbers a to d are each independently an integer of 0 to 4. However, A and B, or any one is a C6-C20 aryl group substituted or unsubstituted by the methyl group, and C and D, or any one is substituted or unsubstituted by the methyl group The aryl group having 6 to 20 carbon atoms of A, B, C and D which is not an aryl group is a hydrogen atom.

  The amine stilbene derivative represented by the general formula (1) is obtained by introducing a predetermined ethenyl group and a predetermined substituent into the ortho position, meta position, or para position of phenyl in the phenylamino group at the molecular end. Since an obstacle occurs, it is difficult to crystallize, and compatibility with the binder resin and solubility in the solvent can be improved.

  Therefore, by using such an amine stilbene derivative as a hole transport agent in the photoreceptor according to the present embodiment, such an amine stilbene derivative can be uniformly dispersed in the photosensitive layer, and excellent sensitivity characteristics and A durable photoreceptor can be provided.

  In addition, if it is an amine stilbene derivative having a predetermined ethenyl group at the ortho position and meta position of phenyl in the phenylamino group at the molecular end, there is also an advantage that it is easier to produce through reaction with an iodobenzene derivative or the like. .

  Further, the hole transport agent according to the present invention may contain an amine stilbene derivative represented by the general formula (1 ′). As a result, an electrophotographic photoreceptor excellent in sensitivity characteristics and durability can be provided.

ここで、前記一般式（１’）中、Ａ〜Ｄ、Ｒ₁〜Ｒ₁₄および繰り返し数ａ〜ｄは、前記一般式（１）の内容と同様である。

Here, in the general formula (1 ′), A to D, R _{1 to} R ₁₄ and the number of repetitions a to d are the same as the contents of the general formula (1).

  That is, in the amine stilbene derivative represented by the general formula (1 ′), a steric hindrance occurs when a predetermined ethenyl group and a predetermined substituent are introduced at the phenyl para-position of the phenylamino group at the molecular end. The compatibility with the binder resin and the solubility in the solvent can be improved.

  Moreover, if it is a compound which has a predetermined ethenyl group in the phenyl para-position in the phenylamino group of a molecular terminal, there also exists an advantage that it is easier to manufacture via reactions, such as formylation.

More specifically, according to the amine stilbene derivative of the present invention, R ₂ , R ₆ , R ₉ and R _{13 in} the general formula (1) and the general formula (1 ′) are substituted or substituted with 1 to 10 carbon atoms. By being an unsubstituted alkyl group, it is possible to further improve the compatibility with the binder resin and the solubility in the solvent, increase the charge mobility, and more effectively prevent crystallization in the binder resin. be able to.

  Therefore, by using an amine stilbene derivative having such a substituent as a charge transfer agent (hole transfer agent), a photoreceptor having further excellent sensitivity characteristics and durability can be provided. In addition, since such a substituent is relatively easy to introduce, a predetermined amine stilbene derivative can be produced in a relatively high yield.

  Further, according to the amine stilbene derivative of the present invention, A and B in the general formula (1) and the general formula (1 ′), or any one of them is substituted or unsubstituted with 6 to 20 carbon atoms. C and D, or any one of them is a C6-C20 aryl group substituted or unsubstituted by a methyl group, and A, B, C and D are not aryl groups. By being a hydrogen atom, intramolecular conjugation spreads and charge mobility can be increased.

  Therefore, by using such an amine stilbene derivative as a charge transporting agent (hole transporting agent), a photoreceptor having excellent sensitivity characteristics can be provided. In addition, since such a structure is relatively easy to introduce, a predetermined amine stilbene derivative can be produced in a relatively high yield.

  Of the amine stilbene derivatives represented by the general formula (1) described above, specifically, HTM-1 to HTM-6 represented by the general formulas (7) to (12) are more preferably used.

(Electron transfer agent)
As the charge transport agent, in addition to the hole transport agent, if necessary, the photosensitive layer may contain an electron transport agent. In particular, the single-layer type photoreceptor 10 is used for imparting bipolar characteristics by transporting electrons. On the other hand, in the case of the multilayer photoreceptor 20, an electron transport agent may be included in the charge generation layer.

  Examples of the electron transport agent include naphthoquinone compounds, diphenoquinone compounds, anthraquinone compounds, azoquinone compounds, nitroantharaquinone compounds, quinone compounds of dinitroanthraquinone compounds, malononitrile compounds, thiopyran compounds, and trinitro. Thioxanthone compound, 3,4,5,7-tetranitro-9-fluorenone compound, dinitroanthracene compound, dinitroacridine compound, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroanthracene, Examples include dinitroacridine, succinic anhydride, maleic anhydride, and dibromomaleic anhydride. These electron transfer agents are used alone or in combination of two or more.

  Of the electron transfer agents described above, specifically, ETM-1 to ETM-8 represented by the general formulas (13) to (20) are more preferably used.

(Binder resin)
As the binder resin used for the photoreceptor, as described above, the binder resin used for the photosensitive layer 12 of the single-layer photoreceptor 10 or the charge transport layer 22b of the multilayer photoreceptor 20, and the charge generation of the multilayer photoreceptor 20 are performed. And a base resin for a charge generation layer when used for the layer 22a.

  As described above, the binder resin can be used for the photosensitive layer 12 of the single-layer type photoreceptor 10 or the charge transport layer 22b of the multilayer photoreceptor 20, and a polycarbonate resin represented by the general formula (2) is used. Contains.

  The charge generation layer base resin is not particularly limited as long as it is a binder resin for the charge generation layer that can be used for the charge generation layer 22a of the multilayer photoconductor 20 as described above.

  Specific examples of the base resin for charge generation layer include styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene resin, Ethylene-vinyl acetate copolymer, 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, or urethane-acrylate resin. Butyral is preferably used. The charge generation layer base resin used for the charge generation layer may be used alone or in combination of two or more.

(Binder resin)
The binder resin includes a polycarbonate resin represented by the general formula (2). The polycarbonate resin is a polycarbonate copolymer composed of a repeating structural unit represented by the general formula (2-1) and a repeating structural unit represented by the general formula (2-2).

  According to the polycarbonate resin represented by the general formula (2) as the binder resin, when p + q = 100 and p ≧ 35, the wear resistance of the photoreceptor is improved. In order to improve other characteristics of the photosensitive member, for example, sensitivity characteristics (electrical characteristics) and mechanical characteristics, the upper limit of p is more preferably 65 or less.

Moreover, in the repeating unit represented by General Formula (2-1) and General Formula (2-2), preferably at least one of R _{23 to} R ₂₅ is an alkyl group having 1 to 4 carbon atoms. is there. More preferably, one of R ₂₃ to R ₂₅ is a methyl group.

The reason is that by replacing R _{23 to} R ₂₅ with an alkyl group, solubility in non-halogen solvents and compatibility with amine stilbene derivatives can be improved, and good sensitivity characteristics (electrical characteristics) ) And achieving wear resistance.

  On the other hand, as the chain length, branching property and quantity of the alkyl substituent increase, the entanglement between the molecules tends to decrease and the packing property of the molecules tends to decrease, which may adversely affect the wear resistance. Therefore, it is preferable that the alkyl substituent has a small carbon number of 1 to 4.

  In the polycarbonate resin described above, the aromatic ring of the repeating unit is substituted with an alkyl group having an appropriate quantity and an appropriate chain length, thereby imparting excellent sensitivity characteristics (electrical characteristics) and abrasion resistance to the photoreceptor. be able to.

  In addition, there is a quaternary carbon between two phenylene groups in the repeating unit represented by the general formula (2-2), and the quaternary carbon is usually substituted with a methyl group and an ethyl group. In comparison with the secondary carbon, a portion having a relatively low polarity exists as a relatively repeating structural unit itself. Thereby, the hole transport agent represented by the general formula (1) is likely to be collected in the vicinity of the repeating structural unit represented by the general formula (2). As a result, the compatibility between the polycarbonate resin and the amine stilbene derivative is improved, whereby the film strength is increased and the wear resistance is improved. In addition, the dispersibility of the hole transport agent in the charge transport layer is increased, and a photoreceptor that exhibits stable photosensitivity can be obtained.

  By using the hole transport agent containing the amine stilbene derivative represented by the general formula (1) and the binder resin containing the polycarbonate represented by the general formula (2) in combination, both of them are excellent. Each of the properties can be maintained, and the amine stilbene derivative exhibits good compatibility with the polycarbonate resin represented by the general formula (2). Thereby, film | membrane intensity | strength improves and abrasion resistance can improve. The charge transport layer 22b maintains good sensitivity characteristics (electrical characteristics).

  The molecular weight of the binder resin (polycarbonate resin) is preferably 30,000 or more, more preferably 40,000 or more and 60,000 or less in terms of viscosity average molecular weight. If the molecular weight of the binder resin is too low, the effect of enhancing the wear resistance of the binder resin cannot be sufficiently exhibited, and the charge transport layer tends to be easily worn. Further, if the molecular weight of the binder resin is too high, it is difficult to dissolve in the non-halogen polar and non-polar mixed solvent, and it becomes difficult to prepare a coating solution for the charge transport layer. Tend to be difficult.

  The structure of the polycarbonate is not particularly limited. For example, a random copolymer in which the repeating structural unit represented by the general formula (2-1) and the repeating structural unit represented by the general formula (2-2) are randomly copolymerized. Polymer, alternating copolymer obtained by alternately copolymerizing both repeating structural units, one or more repeating structural units represented by general formula (2-1) and one or more general formulas (2-2) A cyclic copolymer obtained by cyclic copolymerization with a repeating structural unit represented by the formula (2), or a block composed of a repeating structural unit represented by a plurality of general formulas (2-1) and a plurality of general formulas (2- It may be a block copolymer obtained by copolymerization with a block composed of repeating structural units represented by 2).

  The method for producing the binder resin is not particularly limited as long as the polycarbonate resin having the structure described above can be produced. Examples of these production methods include a method of interfacial polycondensation of a diol compound and phosgene for constituting a repeating structural unit of a polycarbonate resin, a so-called phosgene method, and a method of transesterifying a diol compound and diphenyl carbonate. It is done. More specifically, for example, the diol compound represented by the general formula (2-3) and the general formula (2-4) so that the diol compound represented by the general formula (2-3) is 40 mol% or more. And a method obtained by interfacial condensation polymerization of phosgene with a mixture obtained by mixing the diol compounds represented by formula (1).

  In addition, although polycarbonate resin may be used independently as binder resin in this embodiment, you may add resin other than polycarbonate resin in the range which does not impair the effect of this invention. Specific examples of other resins that can be blended with the polycarbonate resin include styrene resins, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, and styrene-acrylic acid copolymers. Polymer, acrylic copolymer, polyethylene resin, 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, polyarylate resin, polysulfone resin, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin, thermoplastic resin such as polyester resin, silicone resin, epoxy resin, phenol resin, urine Resins, melamine resins, and other crosslinkable thermosetting resin, or epoxy acrylate resins, urethane - photocurable resins such as acrylate copolymer resin. These may be used alone or in combination of two or more.

(Additive)
The photoreceptor in the exemplary embodiment may contain various additives as long as the electrophotographic characteristics are not adversely affected with respect to any of the charge generation layer, the charge transport layer, the intermediate layer, and the protective layer. Examples of additives include antioxidants, radical scavengers, singlet quenchers, deterioration inhibitors such as UV absorbers, softeners, plasticizers, surface modifiers, extenders, thickeners, and dispersion stabilizers. Agents, waxes, acceptors, donors, surfactants, or leveling agents. Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidinone, and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds.

  In order to improve the sensitivity of the charge generation layer, the charge generation layer may contain a sensitizer such as terphenyl, halonaphthoquinones, or acenaphthylene.

  In addition, in order to improve the crack resistance of the charge transport layer, the charge transport layer is made of, for example, one type of biphenyl derivatives represented by chemical formulas (BP-1) to (BP-20) as a plasticizer. You may contain individually or in combination of 2 or more types.

[Underlayer]
As described with reference to FIGS. 1 and 2, the photoreceptor according to this embodiment may have an undercoat layer between the conductive substrate and the charge generation layer. By interposing an undercoat layer between the conductive substrate and the charge generation layer, insulation is suppressed to the extent that leakage is suppressed, and a smooth current is passed when the photosensitive member is exposed to suppress an increase in resistance. Can do. The undercoat layer may contain inorganic particles and a binder resin for the undercoat layer.

  Examples of the inorganic particles include metals (aluminum, iron, or copper), metal oxides (titanium oxide, alumina, zirconium oxide, tin oxide, or zinc oxide), and nonmetal oxides (silica). These inorganic particles are used alone or in combination of two or more.

  The binder resin for the undercoat layer is not particularly limited as long as it can be used as the binder resin for forming the undercoat layer. For example, one of the charge generation layer base resins exemplified in the description of the charge generation layer may be used alone, or two or more may be used in combination.

[Method for producing photoreceptor]
First, with reference to FIG. 1, the manufacturing method of the single layer type photoreceptor 10 is demonstrated.

  The single-layer type photoreceptor 10 is manufactured by applying a coating solution onto the conductive substrate 11 and drying it. This coating solution is produced by dissolving or dispersing a charge generator, a charge transport agent, a binder resin, and various additives as required in a solvent.

  In the single-layer type photoreceptor 10, the contents of the charge generator, the charge transport agent, and the binder resin are appropriately selected and are not particularly limited. Specifically, for example, the content of the charge generating agent is preferably 0.1 parts by mass or more and 50 parts by mass or less, and 0.5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the binder resin. It is more preferable that In addition, the content of the electron transport agent is preferably 5 parts by mass or more and 100 parts by mass or less, and more preferably 10 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the binder resin. Moreover, it is preferable that they are 5 mass parts or more and 500 mass parts or less with respect to 100 mass parts of binder resins, and, as for content of a hole transport agent, it is more preferable that they are 25 mass parts or more and 200 mass parts or less. Furthermore, the total amount of the hole transport agent and the electron transport agent, that is, the content of the charge transport agent is preferably 20 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the binder resin, and 30 parts by mass. More preferably, it is 200 parts by mass or less.

  Further, the thickness of the photosensitive layer 12 of the single-layer type photoreceptor 10 is not particularly limited as long as it can sufficiently function as the photosensitive layer 12. Specifically, it is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.

  Next, a method for manufacturing the laminated photoreceptor 20 will be described.

  Specifically, for example, first, a charge generation layer forming coating solution is prepared. The coating solution for forming a charge generation layer is prepared by dissolving or dispersing a charge generation agent, a base resin, and various additives as required in a solvent.

  The charge transport layer forming coating solution is also prepared by dissolving or dispersing various additives in a solvent as required. Then, either one of the charge generation layer forming coating liquid and the charge transport layer forming coating liquid is applied onto the conductive substrate and dried, so that either the charge generation layer 22a or the charge transport layer 22b is applied. One is formed. Thereafter, the other coating solution is applied to the charge generation layer 22a or the charge transport layer 22b formed on the conductive substrate 21 and dried, and then the other layer is formed to manufacture the multilayer photoreceptor 20. Can do.

  In the multilayer photoconductor 20, 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. Specifically, for example, the content of the charge generation agent is preferably 5 parts by mass or more and 1000 parts by mass or less, and 30 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the base resin constituting the charge generation layer 22a. It is more preferable that the amount is not more than part by mass.

  The content of the charge transport agent is preferably 10 parts by mass or more and 500 parts by mass or less, and 25 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the binder resin constituting the charge transport layer 22b. It is more preferable.

  In addition, the thickness of each layer of the charge generation layer 22a and the charge transport layer 22b is not particularly limited as long as it can sufficiently function as each layer. Specifically, the thickness of the charge generation layer 22a is preferably 0.01 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 3 μm or less. The thickness of the charge transport layer 22b is specifically preferably 2 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

  In addition, the solvent contained in the coating solution is not particularly limited as long as each component can be dissolved or dispersed. Specifically, for example, alcohols such as methanol, ethanol, isopropanol and butanol, aliphatic hydrocarbons such as n-hexane, octane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, dichloromethane , Halogenated hydrocarbons such as dichloroethane, carbon tetrachloride or chlorobenzene, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ketones such as acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, acetic acid Examples include esters such as methyl, or dimethylformaldehyde, dimethylformamide, and dimethyl sulfoxide. As these solvents, the exemplified solvents may be used alone, or two or more kinds may be used in combination. In order to improve the safety and health of workers in the process of manufacturing the photoreceptor, it is preferable to use a non-halogen solvent.

  The manufacturing method of the single layer type photoreceptor 10 and the multilayer type photoreceptor 20 has been described above. In either the single layer type photoreceptor 10 or the multilayer type photoreceptor 20, the coating solution is prepared by mixing and dispersing each component. For example, the method of preparing using a bead mill, a roll mill, a bowl mill, an attritor, a paint shaker, or an ultrasonic disperser is mentioned.

  In order to improve the dispersibility of each component and the smoothness of the surface of the photosensitive layer, a surfactant, a leveling agent and the like may be added to the coating solution.

  The coating method is not particularly limited as long as the coating solution can be uniformly coated on the conductive substrate. For example, a dip coating method, a spray coating method, a spin coating method, or a bar coating method can be used.

  The drying method is not particularly limited as long as the solvent in the charge generation layer coating solution evaporates to form the charge generation layer. For example, the method of heat-processing (hot-air drying) on 40 degreeC or more and 150 degrees C or less for 3 minutes or more and 120 minutes or less conditions using a high temperature drier and a vacuum dryer is mentioned.

  The photoreceptor according to the exemplary embodiment 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. Specifically, the photoconductor according to the exemplary embodiment can be used as, for example, an image carrier of an image forming apparatus described later.

[Embodiment 2]
[Image forming apparatus]
The image forming apparatus according to this embodiment includes an image carrier, a charger that charges the surface of the image carrier, an exposure device, a developer that develops an electrostatic latent image as a toner image, and a toner image as an image carrier. A transfer device for transferring from the body to the transfer target. The exposure device exposes the surface of the image carrier charged by the charger to form an electrostatic latent image on the surface. In the image forming apparatus according to the present embodiment, the image carrier is the above-described photoconductor. That is, the image forming apparatus according to the present embodiment is not particularly limited as long as it is an electrophotographic image forming apparatus and uses an image carrier as a photoconductor.

  The image forming apparatus according to the present exemplary embodiment preferably includes a contact charging type charger from the viewpoint that generation of gas such as ozone can be suppressed.

  Further, as the image forming apparatus of the present embodiment, a tandem type color image forming apparatus using a plurality of color toners is used. More specifically, the image forming apparatus according to the present exemplary embodiment includes a photoconductor that is a plurality of image carriers, and a plurality of developing devices that include developing rollers. The photoconductors are provided side by side in predetermined directions in order to form toner images of different colors of toner on the respective surfaces. The plurality of developing devices are arranged to face the respective photoconductors, carry and carry toner on the surface, and supply the conveyed toner to the surface of each photoconductor.

  Hereinafter, an example of the image forming apparatus according to the present embodiment will be described with reference to FIG.

  FIG. 3 is a schematic diagram illustrating a configuration of an image forming apparatus including the photosensitive member according to the embodiment of the present invention. In FIG. 3, the image forming apparatus is a tandem color printer 1. The color printer 1 has a box-shaped device main body 1a. In the apparatus main body 1a, a paper feeding unit 2, an image forming unit 3, and a fixing unit 4 are provided. The paper feed unit 2 feeds the paper P. The image forming unit 3 transfers the toner image based on the image data to the paper P while conveying the paper P fed from the paper feeding unit 2. The fixing unit 4 fixes the unfixed toner image transferred on the paper P by the image forming unit 3 to the paper P. Further, a paper discharge unit 5 is provided on the upper surface of the device main body 1a. The paper discharge unit 5 discharges the paper P fixed by the fixing unit 4.

  The image forming unit 3 includes an image forming unit 7, an intermediate transfer belt 31, and a secondary transfer roller 32. A toner image based on image data transmitted from a computer or the like by the image forming unit 7 is primarily transferred to the intermediate transfer belt 31. The secondary transfer roller 32 secondarily transfers the toner image on the intermediate transfer belt 31 onto the paper P sent from the paper feed cassette 121.

  The image forming unit 7 includes a black unit 7K, a yellow unit 7Y, a cyan unit 7C, and a magenta unit 7M that are sequentially arranged from the upstream side to the downstream side. In each of the units 7K, 7Y, 7C, and 7M, a photosensitive drum 37 as an image carrier is disposed at the center position so as to be rotatable in the arrow (clockwise) direction. Around each photosensitive drum 37, a charger 39, an exposure device 38, a developing device 71, a cleaning device (not shown), and a static eliminator as a static eliminator are arranged in order from the upstream side in the rotation direction. . As the photosensitive drum 37, the above-described electrophotographic photosensitive member is used.

  Here, in the image forming apparatus according to the present embodiment, a contact charging type charger is used as the charger 39, but the peripheral surface of the photosensitive drum 37 rotated in the direction of the arrow is uniformly charged. If so, a non-contact charging type charger may be used. As the contact charging type charger 39, for example, a device that charges the peripheral surface (surface) of the photosensitive drum 37 while the charging roller and the charging brush are in contact with the photosensitive drum 37 (that is, a contact type charging roller and charging). And a charger equipped with a brush).

  Examples of the contact-type charging roller include a roller having at least a surface portion made of resin and rotating in accordance with the rotation of the photosensitive drum 37 while being in contact with the photosensitive drum 37. More specifically, for example, the charging roller includes a cored bar that is rotatably supported, a resin layer formed on the cored bar, and a voltage applying unit that applies a voltage to the cored bar. The charger having such a charging roller can apply a voltage to the cored bar by voltage applying means, and can charge the surface of the photosensitive drum 37 that is in contact with the resin layer.

  A charger equipped with such a contact-type charging roller has a tendency that the wear amount of the outermost layer tends to be large when an organic photoreceptor is used as an image carrier. However, when an electrophotographic photosensitive member having a charge transport layer as the outermost layer is used as an image carrier, the outermost layer (a charge transport layer in the case of a laminated type and a photosensitive layer in the case of a single layer type) is worn. A product having high durability such as a small amount is obtained. As a result, it is easy to manufacture and has the durability of low wear while taking advantage of the advantages of organic photoconductors with various options for organic materials constituting the photosensitive layer and high degree of freedom in structural design. High photoreceptor.

  Moreover, although resin which comprises the resin layer of a charging roller is not specifically limited, For example, a silicone resin, a urethane resin, or a silicone modified resin is mentioned. This resin layer may contain an inorganic filler.

  Moreover, it is preferable that the voltage applied by the voltage applying means is only a DC voltage. By doing so, when an electrophotographic photosensitive member having a charge transport layer (in the case of a multilayer type) or a photosensitive layer (in the case of a single layer type) as an outermost layer is used as an image carrier, the wear amount of the outermost layer is reduced. can do. Specifically, when the direct current voltage is applied to the charging roller only when the alternating voltage or the superimposed voltage obtained by superimposing the alternating current voltage on the direct current voltage is applied to the charging roller, the charge transport layer which is the outermost layer is more The amount of wear can be reduced.

  In addition, when an AC voltage is applied, the potential of the surface (circumferential surface) of the image carrier due to charging tends to be uniform, but in an image forming apparatus equipped with a contact charging type charger, only a DC voltage is applied. Can be charged evenly. Therefore, in the image forming apparatus, a suitable image can be formed by applying only a DC voltage to the charging roller, and further, the wear amount of the photosensitive layer can be reduced.

  The exposure device 38 is a so-called laser scanning unit. Laser light based on image data input from a personal computer (PC) as a host device is applied to the peripheral surface of the photosensitive drum 37 uniformly charged by the charger 39. Irradiation forms an electrostatic latent image on the photosensitive drum 37 based on the image data. The developing device 71 supplies toner to the peripheral surface of the photosensitive drum 37 on which the electrostatic latent image is formed, thereby forming a toner image based on the image data. The toner image is primarily transferred to the intermediate transfer belt 31. The cleaning device cleans the toner remaining on the peripheral surface of the photosensitive drum 37 after the primary transfer of the toner image to the intermediate transfer belt 31 is completed. The static eliminator neutralizes the peripheral surface of the photosensitive drum 37 after the primary transfer is completed. The peripheral surface of the photosensitive drum 37 cleaned by the cleaning device and the static eliminator is directed to the charger 39 for a new charging process, and the charging process is performed for a new image formation.

  The intermediate transfer belt 31 is an endless belt-like rotating body, and includes a driving roller 33, a driven roller 34, a backup roller 35, and 1 so that the surface (contact surface) side abuts on the peripheral surface of each photosensitive drum 37. It is stretched over a plurality of rollers such as the next transfer roller 36. The intermediate transfer belt 31 is configured to rotate endlessly by a plurality of rollers in a state where the intermediate transfer belt 31 is pressed against the photosensitive drum 37 by a primary transfer roller 36 disposed to face each photosensitive drum 37. The driving roller 33 is rotationally driven by a driving source such as a stepping motor, and provides a driving force for rotating the intermediate transfer belt 31 endlessly. The driven roller 34, the backup roller 35, and the primary transfer roller 36 are rotatably provided, and are driven to rotate with the endless rotation of the intermediate transfer belt 31 by the driving roller 33. The rollers 34, 35, and 36 are driven to rotate via the intermediate transfer belt 31 in accordance with the main rotation of the driving roller 33 and support the intermediate transfer belt 31.

  The primary transfer roller 36 applies a primary transfer bias (a polarity opposite to the toner charging polarity) to the intermediate transfer belt 31. Thus, the toner image formed on each photoconductive drum 37 circulates in the direction of the arrow (counterclockwise) by driving the drive roller 33 between each photoconductive drum 37 and the primary transfer roller 36. Overlaid on the intermediate transfer belt 31 and sequentially transferred (primary transfer).

  The secondary transfer roller 32 applies a secondary transfer bias having a polarity opposite to that of the toner image to the paper P. As a result, the toner image primarily transferred onto the intermediate transfer belt 31 is transferred to the paper P between the secondary transfer roller 32 and the backup roller 35, and the color unfixed toner image is transferred to the paper P. .

  The fixing unit 4 performs a fixing process on the transfer image transferred to the paper P by the image forming unit 3. The fixing unit 4 includes a heating roller 41 and a pressure roller 42. The heating roller 41 is heated by an energized heating element. The pressure roller 42 is disposed so as to face the heating roller 41, and the circumferential surface thereof is pressed against the circumferential surface of the heating roller 41.

  Then, the transfer image transferred to the paper P by the secondary transfer roller 32 in the image forming unit 3 is applied to the paper P by a fixing process by heating when the paper P passes between the heating roller 41 and the pressure roller 42. It is fixed. Then, the fixed sheet P is discharged to the discharge unit 5. Further, in the image forming apparatus (color printer 1) of the present embodiment, a transport roller 6 is disposed at an appropriate position between the fixing unit 4 and the paper discharge unit 5.

  The paper discharge unit 5 is formed by recessing the top of the apparatus main body 1a of the color printer 1, and a paper discharge tray 51 for receiving the discharged paper P is formed at the bottom of the recess.

  The image forming apparatus (color printer 1) of this embodiment forms an image on the paper P by the image forming operation as described above. In the image forming apparatus of the present embodiment, the photoconductor described in the first embodiment is used as the image carrier. Accordingly, particularly when the image forming apparatus includes a contact-type charger, the amount of wear of the charge transport layer can be remarkably suppressed, and a suitable image can be obtained without replacing the image carrier for a long period of time. Can be formed.

  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.

[Preparation of multilayer photoconductor]
[Example 1]
(Formation of undercoat layer)

  First, an undercoat layer coating solution was prepared. Specifically, after surface treatment with alumina and silica, titanium oxide surface-treated with methyl hydrogen polysiloxane while being wet-dispersed (manufactured by Teika, prototype SMT-A, number average primary particle size 10 nm) (2 parts by mass) ), 6,12,66,610 quaternary copolymerized polyamide resin Amilan (manufactured by Toray, product number: CM8000) (1 part by mass), methanol (10 parts by mass), butanol (1 part by mass) and toluene (1 part by mass) Part) was mixed using a bead mill and dispersed for 5 hours.

  Next, an undercoat layer was formed. Specifically, the obtained undercoat layer coating solution was filtered through a 5 μm filter, and then applied as a conductive support to an aluminum drum-shaped support having a diameter of 30 mm and a total length of 246 mm by a dip coating method. Heat treatment was performed at 130 ° C. for 30 minutes to form an undercoat layer having a thickness of 1 μm.

(Formation of charge generation layer)
Next, a coating solution for the charge generation layer was prepared. Specifically, CGM-2 (1.5 parts by mass), polyvinyl acetal resin (Sekisui Chemical Co., Ltd., product number: ESREC BX-5) (1 part by mass) as a binder resin, and propylene glycol monomethyl as a dispersion medium Ether (40 parts by mass) and tetrahydrofuran (40 parts by mass) were mixed and dispersed with a bead mill for 2 hours. Next, after filtering the obtained coating liquid with a 3 μm filter, it was applied on the undercoat layer prepared above by the dip coating method and dried at 50 ° C. for 10 minutes to obtain a charge having a film thickness of 0.3 μm. A generation layer was formed.

(Formation of charge transport layer)
Next, a charge transport layer coating solution was prepared. Specifically, the above-described amine stilbene compound HTM-1 (45 parts by mass) as a hole transport agent, BHT (0.5 parts by mass) as an additive, metaterphenyl (3 parts by mass), electrons Acceptor compound ETM-1 (1 part by mass), polycarbonate resin (Resin-1, viscosity average molecular weight 50, 100) (100 parts by mass) as a binder resin, tetrahydrofuran (420 parts by mass) as a solvent, toluene ( 210 parts by mass) were mixed and dissolved. The composition of Resin-1 is represented by general formula (21).

  The prepared charge transport layer coating solution is applied onto the charge generation layer in the same manner as the charge generation layer coating solution, and dried at 120 ° C. for 40 minutes to form a charge transport layer having a thickness of 20 μm. A photographic photoreceptor was prepared.

[Example 2]
The method for forming the charge transport layer in Example 2 is the same as that in Example 1 except that HTM-2 is used instead of HTM-1 as the hole transport agent.

[Example 3]
The method for forming the charge transport layer in Example 3 is the same as that in Example 1 except that HTM-3 is used instead of HTM-1 as the hole transport agent.

[Example 4]
The method for forming the charge transport layer in Example 4 is the same as that in Example 1 except that HTM-4 is used instead of HTM-1 as the hole transport agent.

[Example 5]
The method for forming the charge transport layer in Example 5 is the same as that in Example 1 except that HTM-5 is used instead of HTM-1 as the hole transport agent.

[Example 6]
The method for forming the charge transport layer in Example 6 is the same as that in Example 1 except that HTM-6 is used instead of HTM-1 as the hole transport agent.

[Example 7]
The method for forming the charge transport layer in Example 7 is the same as that in Example 1 except that Resin-2 (viscosity average molecular weight 50,300) is used instead of Resin-1 as the binder resin. The composition of Resin-2 is represented by the general formula (22).

[Example 8]
The method for forming the charge transport layer in Example 8 is the same as that in Example 1 except that Resin-3 (viscosity average molecular weight 50,200) is used instead of Resin-1 as the binder resin. The composition of Resin-3 is represented by the general formula (23).

[Example 9]
The method for forming the charge transport layer in Example 9 is the same as that in Example 1 except that Resin-4 (viscosity average molecular weight 50,200) is used instead of Resin-1 as the binder resin. The composition of Resin-4 is represented by the general formula (24).

[Comparative Example 1]
The method for forming the charge transport layer in Comparative Example 1 is the same as in Example 1 except that Resin-5 (viscosity average molecular weight 50,300) is used instead of Resin-1 as the binder resin. The composition of Resin-5 is represented by the general formula (25).

[Comparative Example 2]
The method for forming the charge transport layer in Comparative Example 2 is the same as that of Comparative Example 1 except that HTM-2 is used instead of HTM-1 as the hole transport agent.

[Comparative Example 3]
The method for forming the charge transport layer in Comparative Example 3 is the same as that of Comparative Example 1 except that HTM-3 is used instead of HTM-1 as the hole transport agent.

[Comparative Example 4]
The method for forming the charge transport layer in Comparative Example 4 is the same as that of Comparative Example 1 except that HTM-4 is used instead of HTM-1 as the hole transport agent.

[Comparative Example 5]
The method for forming the charge transport layer in Comparative Example 5 is the same as that of Comparative Example 1 except that HTM-5 was used instead of HTM-1 as the hole transport agent.

[Comparative Example 6]
The method for forming the charge transport layer in Comparative Example 6 is the same as that of Comparative Example 1 except that HTM-6 is used instead of HTM-1 as the hole transport agent.

[Comparative Example 7]
The method for forming the charge transport layer in Comparative Example 7 is the same as in Example 1 except that Resin-6 is used instead of Resin-1 as the binder resin.

[Comparative Example 8]
The method for forming the charge transport layer in Comparative Example 8 is the same as in Example 1 except that Resin-7 was used instead of Resin-1 as the binder resin.

[Comparative Example 9]
The method for forming the charge transport layer in Comparative Example 9 is the same as in Example 1 except that Resin-8 is used instead of Resin-1 as the binder resin.

[Comparative Example 10]
The method for forming the charge transport layer in Comparative Example 10 is the same as in Example 1 except that Resin-9 is used instead of Resin-1 as the binder resin.

[Comparative Example 11]
The method for forming the charge transport layer in Comparative Example 11 is the same as in Example 1 except that Resin-10 is used instead of Resin-1 as the binder resin.

[Production of single layer type photoreceptor]
[Example 10]
The production method of the single layer type photoreceptor in Example 10 is as follows: amine stilbene compound HTM-1 (50 parts by mass) as a hole transport agent, ETM-2 (20 parts by mass) as an electron transport agent, and charge generation. X-type metal-free phthalocyanine CGM-1 (3 parts by mass) as an agent and a polycarbonate resin copolymer Resin-1 (100 parts by mass) as a binder resin with respect to tetrahydrofuran (800 parts by mass) as a solvent Added. Subsequently, it mixed and dispersed using the ultrasonic disperser, and the coating liquid for single layer type photoreceptor layers was prepared. The obtained coating solution was applied onto a conductive substrate (aluminum base tube) and dried with hot air at 100 ° C. for 30 minutes to obtain a single-layer electrophotographic photosensitive member having a film thickness of 25 μm.

[Example 11]
The production method of the single layer type photoreceptor in Example 11 is the same as that of Example 10 except that ETM-2 is used instead of ETM-1 as the charge generating agent.

[Example 12]
The production method of the single layer type photoreceptor in Example 12 used ETM-2 instead of ETM-1 as the charge generating agent, and HTM-2 instead of HTM-1 as the hole transporting agent. Example 10 is the same as Example 10 except that is used.

[Example 13]
The production method of the single layer type photoreceptor in Example 13 used ETM-2 instead of ETM-1 as the charge generating agent, and HTM-3 instead of HTM-1 as the hole transporting agent. Example 10 is the same as Example 10 except that is used.

[Example 14]
The production method of the single layer type photoreceptor in Example 14 used ETM-2 instead of ETM-1 as the charge generating agent, and HTM-4 instead of HTM-1 as the hole transporting agent. Example 10 is the same as Example 10 except that is used.

[Example 15]
In the production method of the single layer type photoreceptor in Example 15, ETM-2 was used instead of ETM-1 as a charge generating agent, and HTM-5 was used instead of HTM-1 as a hole transporting agent. Example 10 is the same as Example 10 except that is used.

[Example 16]
In the production method of the single layer type photoreceptor in Example 16, ETM-2 was used instead of ETM-1 as a charge generating agent, and HTM-6 was used instead of HTM-1 as a hole transporting agent. Example 10 is the same as Example 10 except that is used.

[Example 17]
The production method of the single layer type photoreceptor in Example 17 used Resin-2 instead of Resin-1 as the binder resin, and used ETM-2 instead of ETM-1 as the charge generating agent. Other than that, this example is the same as Example 10.

[Example 18]
The production method of the single layer type photoreceptor in Example 18 used Resin-3 instead of Resin-1 as the binder resin, and used ETM-2 instead of ETM-1 as the charge generating agent. Other than that, this example is the same as Example 10.

[Example 19]
The production method of the single layer type photoreceptor in Example 19 used Resin-4 instead of Resin-1 as the binder resin, and used ETM-2 instead of ETM-1 as the charge generating agent. Other than that, this example is the same as Example 10.

[Example 20]
The production method of the single layer type photoreceptor in Example 20 was that Resin-4 was used instead of Resin-1 as the binder resin, ETM-2 was used instead of ETM-1 as the charge generating agent, and The same as Example 10, except that CGM-2 and PY128 were used instead of CGM-1 as the charge generating agent. PY-128 is represented by the general formula (31).

[Example 21]
The production method of the single layer type photoreceptor in Example 21 used ETM-2 instead of ETM-1 as an electron transport agent, and used CGM-2 + PY128 instead of CGM-1 as a charge generating agent, Moreover, it is the same as that of Example 10 except having used HTM-2 instead of HTM-1 as a charge transport agent.

[Example 22]
The production method of the single layer type photoreceptor in Example 22 used ETM-2 instead of ETM-1 as an electron transport agent, and used CGM-2 + PY128 instead of CGM-1 as a charge generating agent, Moreover, it is the same as that of Example 10 except having used HTM-3 instead of HTM-1 as a charge transport agent.

[Example 23]
The production method of the single layer type photoreceptor in Example 23 used ETM-2 instead of ETM-1 as an electron transport agent, and used CGM-2 + PY128 instead of CGM-1 as a charge generator. Moreover, it is the same as that of Example 10 except having used HTM-4 instead of HTM-1 as a charge transport agent.

[Example 24]
The production method of the single layer type photoreceptor in Example 24 used ETM-2 instead of ETM-1 as an electron transport agent, and used CGM-2 + PY128 instead of CGM-1 as a charge generating agent, Moreover, it is the same as that of Example 10 except having used HTM-5 instead of HTM-1 as a charge transport agent.

[Example 25]
The method for producing a single-layer type photoreceptor in Example 25 uses ETM-2 instead of ETM-1 as an electron transport agent, and uses CGM-2 + PY128 instead of CGM-1 as a charge generator. Moreover, it is the same as that of Example 10 except having used HTM-6 instead of HTM-1 as a charge transport agent.

[Example 26]
The production method of the single layer type photoreceptor in Example 26 used ETM-3 instead of ETM-1 as an electron transport agent, and CGM-2 + PY128 instead of CGM-1 as a charge generator. Except for this, this is the same as Example 10.

[Example 27]
The production method of the single layer type photoreceptor in Example 27 used ETM-4 instead of ETM-1 as an electron transport agent, and CGM-2 + PY128 instead of CGM-1 as a charge generator. Except for this, this is the same as Example 10.

[Example 28]
The production method of the single-layer type photoreceptor in Example 28 used ETM-5 instead of ETM-1 as an electron transport agent, and CGM-2 + PY128 instead of CGM-1 as a charge generator. Except for this, this is the same as Example 10.

[Example 29]
The production method of the single layer type photoreceptor in Example 29 used ETM-6 instead of ETM-1 as an electron transport agent, and CGM-2 + PY128 instead of CGM-1 as a charge generator. Except for this, this is the same as Example 10.

[Example 30]
The production method of the single layer type photoreceptor in Example 30 used ETM-7 instead of ETM-1 as an electron transport agent, and CGM-2 + PY128 instead of CGM-1 as a charge generator. Except for this, this is the same as Example 10.

[Example 31]
The production method of the single layer type photoreceptor in Example 31 used ETM-8 instead of ETM-1 as an electron transport agent, and CGM-2 + PY128 instead of CGM-1 as a charge generator. Except for this, this is the same as Example 10.

[Example 32]
The production method of the single layer type photoreceptor in Example 32 used ETM-2 instead of ETM-1 as the electron transport agent, and CGM-3 instead of CGM-1 as the charge generating agent. Except for this, this is the same as Example 10.

[Example 33]
The production method of the single layer type photoreceptor in Example 33 used ETM-2 instead of ETM-1 as an electron transport agent and CGM-4 instead of CGM-1 as a charge generating agent. Except for this, this is the same as Example 10.

[Comparative Example 12]
The production method of the single layer type photoreceptor in Comparative Example 12 is the same as that in Example 10 except that Resin-5 is used instead of Resin-1 as the binder resin.

[Comparative Example 13]
The production method of the single layer type photoreceptor in Comparative Example 13 used HTM-2 instead of HTM-1 as the hole transport agent, and Resin-5 instead of Resin-1 as the binder resin. Except for the above, this is the same as Example 10.

[Comparative Example 14]
The production method of the single layer type photoreceptor in Comparative Example 14 used HTM-3 instead of HTM-1 as the hole transport agent, and Resin-5 instead of Resin-1 as the binder resin. Except for this, this is the same as Example 10.

[Comparative Example 15]
The production method of the single layer type photoreceptor in Comparative Example 15 used HTM-4 instead of HTM-1 as the hole transport agent, and Resin-5 instead of Resin-1 as the binder resin. Except for this, this is the same as Example 10.

[Comparative Example 16]
The production method of the single layer type photoreceptor in Comparative Example 16 used HTM-5 instead of HTM-1 as the hole transport agent, and Resin-5 instead of Resin-1 as the binder resin. Except for this, this is the same as Example 10.

[Comparative Example 17]
The production method of the single layer type photoreceptor in Comparative Example 17 used HTM-6 instead of HTM-1 as the hole transport agent, and Resin-6 instead of Resin-1 as the binder resin. Except for this, this is the same as Example 10.

[Comparative Example 18]
The production method of the single layer type photoreceptor in Comparative Example 18 is the same as Example 10 except that Resin-6 was used instead of Resin-1 as the binder resin.

[Comparative Example 19]
The production method of the single layer type photoreceptor in Comparative Example 19 is the same as Example 10 except that Resin-7 was used instead of Resin-1 as the binder resin.

[Comparative Example 20]
The production method of the single layer type photoreceptor in Comparative Example 20 is the same as that in Example 10 except that Resin-8 was used instead of Resin-1 as the binder resin.

[Comparative Example 21]
The production method of the single layer type photoreceptor in Comparative Example 21 is the same as that in Example 10 except that Resin-9 was used instead of Resin-1 as the binder resin.

[Comparative Example 22]
The manufacturing method of the single layer type photoreceptor in Comparative Example 22 is the same as that in Example 10 except that Resin-10 is used instead of Resin-1 as the binder resin.

[Performance evaluation of photoconductor]
(Sensitivity characteristics evaluation (electrical characteristics evaluation))

Each of the produced laminated type photoreceptor and single layer type photoreceptor is charged with a sensitivity characteristic (electrical characteristic) tester under the following conditions: charging ability (surface potential V ₀ ) and sensitivity characteristic (residual potential V _L ). Was measured. The temperature of the measurement environment was 10 ° C. and the humidity was 20%.

(Measurement conditions for multilayer photoconductor)
Using a drum sensitivity tester, the rotation speed was 31 rpm and the potential was measured in a state of being charged to −600 V to obtain the initial surface potential (V _o ). Next, monochromatic light with a wavelength of 780 nm (half-value width: 20 nm, exposure amount: 0.26 μJ / cm ² ) extracted from the light of the halogen lamp using a hand pulse filter was irradiated on the surface of the photoreceptor. After the irradiation, the surface potential after 50 msec was measured and set as the residual potential (V _L ).

(Measurement conditions for single-layer photoconductor)
Using a drum sensitivity tester, the potential was measured in a state of being charged to 700 V to obtain an initial surface potential (V _o ). Next, the surface of the photoreceptor was irradiated with monochromatic light (half-value width: 20 nm, light amount: 1.5 μJ / cm ² ) having a wavelength of 780 nm extracted from the light of the halogen lamp using a hand pulse filter. After the irradiation, the surface potential after 100 msec was measured and set as the residual potential (V _L ).

[Abrasion resistance (wear loss)]
(Common to single-layer and multi-layer photoreceptors)
The prepared charge transport layer coating solution or single layer coating solution is applied to a PP sheet (thickness 0.3 mm) wound around a φ78 aluminum pipe, dried at 120 ° C. for 40 minutes, and evaluated for wear with a thickness of 30 μm. A sheet was prepared.

  The CT layer was peeled off from this PP sheet and attached to a wheel S-36 (manufactured by Taber) to prepare a sample. The prepared sample was subjected to a 1000 rotation wear test using a rotary abrasion tester (manufactured by Toyo Seiki Co., Ltd.) with a wear wheel C-10 (Taber Co., Ltd.), a load of 500 gf, and a rotation speed of 60 rpm. Abrasion loss (mg / 1000 revolutions), which is a change in the weight of the sample, was measured to evaluate the wear resistance.

  Table 1 shows the results of the sensitivity characteristic evaluation (electric characteristic evaluation) and the wear evaluation test of the above-described laminated type photoconductor, and the materials of the photosensitive layer. Table 2 shows the results of the sensitivity characteristic evaluation (electric characteristic evaluation) and the wear evaluation test of the single-layer type photoreceptor described above, and each material of the photosensitive layer.

According to Tables 1 and 2, a laminate containing an amine stilbene derivative represented by the general formula (1) as a charge transporting agent (hole transporting agent) and a polycarbonate resin represented by the general formula (2) as a binder resin Type photoreceptors (Examples 1 to 9) and single-layer type photoreceptors (Examples 10 to 33) have a low residual potential (V _L ) in sensitivity characteristic evaluation (electrical characteristic evaluation), and 1000 in the wear resistance test. It was found that wear loss per revolution was small. Therefore, according to the multilayer photoreceptor and the single-layer photoreceptor according to the present invention, it is possible to improve the wear resistance while maintaining excellent sensitivity characteristics (electrical characteristics).

  The electrophotographic photosensitive member according to the present invention can be applied to an image forming apparatus such as a multifunction peripheral.

DESCRIPTION OF SYMBOLS 10 Single layer type photoreceptor 11 Conductive base | substrate 12 Photosensitive layer 13 Undercoat layer 20 Laminated type photoreceptor 21 Conductive base | substrate 22 Photosensitive layer 22a Charge generation layer 22b Charge transport layer 23 Undercoat layer

Claims (6)

An electrophotographic photoreceptor having a photosensitive layer containing a charge generator, a hole transport agent, and a binder resin,
An electrophotographic photoreceptor in which the hole transport agent contains an amine stilbene derivative represented by the chemical formula (11) or the chemical formula (12), and the binder resin contains a polycarbonate resin represented by the general formula (2). .

(In the general formula (2) , R ₂₃ and R ₂₄ are hydrogen atoms. R ₂₅ is a methyl group. Also, p + q = 100, and p / q is 60/40 to 65/35.) , N is 3. ) The electrophotographic photosensitive member according to claim 1, wherein the binder resin contains a polycarbonate resin represented by the formula (22).

The electrophotographic photosensitive member according to claim 1, wherein the charge generating agent contains PY-128 represented by Formula (26).

The photosensitive layer includes a charge generation layer and a charge transport layer,
The charge generation layer contains the charge generation agent;
The charge transport layer contains the hole transport agent, the binder resin, and an electron transport agent;
The electron transfer agent is represented by Formula (13), Formula (14), Formula (15), Formula (16), Formula (17), Formula (18), Formula (19), or Formula (20). The electrophotographic photosensitive member according to any one of claims 1 to 3.

  The electrophotographic photosensitive member according to claim 4, wherein the content of the electron transport agent is 1 part by mass with respect to 100 parts by mass of the binder resin. An image carrier;
A charger for charging the surface of the image carrier;
An exposure device that exposes the surface of the image carrier charged by the charger to form an electrostatic latent image on the surface;
A developing device for developing the toner image as the image carrier;
A transfer device for transferring the toner image from the image carrier to a transfer target;
An image forming apparatus comprising:
An image forming apparatus, wherein the image carrier is the electrophotographic photosensitive member according to claim 1.

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