JP6946845B2 - Electrophotographic photosensitive member, manufacturing method of electrophotographic photosensitive member and image forming apparatus - Google Patents

Description

The present invention relates to an electrophotographic photosensitive member, a method for producing an electrophotographic photosensitive member, and an image forming apparatus. The present invention particularly relates to an electrophotographic photosensitive member having excellent memory resistance and abrasion resistance and having difficulty in image flow, a method for producing an electrophotographic photosensitive member, and an image forming apparatus.

Conventionally, the surface of an electrophotographic photosensitive member is charged and then exposed to form an electrostatic latent image on the electrophotographic photosensitive member, and the formed electrostatic latent image is developed with a developing agent and transferred. As a result, an electrophotographic image forming apparatus for forming an image on paper is provided.

Generally, an electrophotographic photosensitive member (hereinafter, also referred to as a photosensitive member) is configured by laminating an intermediate layer, a charge generation layer, a charge transport layer, a surface protection layer, and the like on a conductive support. Further, in the process of forming an electrophotographic image using such a photoconductor, the surface resistance is lowered and image flow is generated due to the influence of discharge products such as ozone and nitrogen oxides generated at the band electrode. There's a problem.
As a countermeasure against this, it is empirically known to add an antioxidant (see, for example, Patent Document 1 and Patent Document 2), but when the amount of the antioxidant added is increased, the residual potential rises and the like. Due to problems, it was difficult to achieve both image flow countermeasures and potential performance.

Further, in recent years, the surface protective layer of the photoconductor has been actively studied for the purpose of achieving both high image quality (improvement of memory resistance) and long life (improvement of wear resistance). It is known that the surface is a layer formed of a curable binder resin.
However, in such a surface protective layer, by-products derived from the polymerization initiator used when forming the surface protective layer may remain, so that the discharge products are easily adsorbed and the image flow. Was more likely to occur. As described above, it has been difficult to achieve both prevention of image flow and improvement of memory resistance.

Japanese Unexamined Patent Publication No. 2008-58779 JP-A-2010-237241

The present invention has been made in view of the above problems and situations, and the problems to be solved are an electrophotographic photosensitive member having excellent memory resistance and abrasion resistance and having difficulty in image flow, and a method for manufacturing an electrophotographic photosensitive member. And to provide an image forming apparatus.

As a result of investigating the causes of the above problems in order to solve the above problems, the present inventors have formed an amino ether structure in at least one of a plurality of layers formed on the conductive support of the electrophotographic photosensitive member. We have found that it is possible to provide an electrophotographic photosensitive member having excellent memory resistance and abrasion resistance and having difficulty in image flow by containing the hindered amine compound, and have reached the present invention.
That is, the problem according to the present invention is solved by the following means.

［一般式（１）中、Ｙは水素原子以外の任意の構造を表す。Ｚは、有機基を表す。ただし、Ｙ及びＺは、Ｎ−ＣＨ _３ 結合及びＮ−Ｈ結合を有さない。］ 1. 1. An electrophotographic photosensitive member having a plurality of layers including at least a photosensitive layer on a conductive support.
The plurality of layers have a surface protective layer on the surface side of the photosensitive layer.
An electrophotographic photosensitive member , wherein the surface protective layer contains a hindered amine compound having an amino ether structure represented by the following general formula (1).

[In the general formula (1), Y represents an arbitrary structure other than a hydrogen atom. Z represents an organic group. However, Y and Z _{do not have N—CH 3} bond and N—H bond. ]

2. The electrophotographic photosensitive member according to item 1, wherein the organic group represented by Z in the general formula (1) is an alkyl group having 8 or more carbon atoms or a cycloalkyl group having 4 or more carbon atoms.

3. 3. The first or second item, wherein the content of the hindered amine compound is in the range of 2 to 15 parts by mass with respect to 100 parts by mass of the binder resin of the layer containing the hindered amine compound. Electrophotographic photosensitive member.

4 . The item according to any one of items 1 to 3 , wherein the surface protective layer is a cured product of a composition containing the hindered amine compound, a polymerizable compound for a binder, and a charge transporting agent. Electrophotographic photosensitive member.

5 . The electrophotographic photosensitive member according to Item 4 , wherein the electrophotographic photosensitive member contains conductive fine particles as the charge transporting agent.

6 . A method for producing an electrophotographic photosensitive member according to item 4 or 5, wherein the electrophotographic photosensitive member is produced.
Production of an electrophotographic photosensitive member, which comprises a step of curing a composition containing a polymerization initiator having an acylphosphine oxide structure or an O-acyloxime structure to form the surface protective layer. Method.

7 . An image forming apparatus comprising the electrophotographic photosensitive member according to any one of items 1 to 5.

According to the present invention, an electrophotographic photosensitive member having excellent memory resistance and abrasion resistance and having difficulty in image flow, a method for producing an electrophotographic photosensitive member, and an image forming apparatus provided with the electrophotographic photosensitive member are provided. Can be done.

Although the expression mechanism or action mechanism of the effect of the present invention has not been clarified, it is inferred as follows.
So far, as antioxidants for preventing image flow, hindered amine compounds and hindered phenol compounds have been studied.
However, when the hindered amine compound has a structure having an N—H bond or an N—CH ₃ bond, it is likely to trap holes and reduce the potential performance because of its strong basicity.
On the other hand, since the hindered phenol compound has low basicity, it is possible to suppress a decrease in potential performance, but the effect on preventing image flow is small.
On the other hand, the hindered amine compound used in the present invention has an amino ether structure. It is considered that the hindered amine compound was relatively weak in basicity and was less likely to trap holes in charge transport, so that it was possible to prevent a decrease in potential performance. Furthermore, when a photosensitive layer was actually formed using a hindered amine compound having an amino ether structure, it was found that it was also excellent in abrasion resistance. It is presumed that this is because the compatibility with the binder resin is high.

Therefore, by forming the layer constituting the surface of the electrophotographic photosensitive member by using the hindered amine compound having the amino ether structure according to the present invention, the electrophotographic photosensitive member is excellent in memory resistance and abrasion resistance and is difficult to image flow. It is probable that he was able to obtain a body.

Schematic cross-sectional view showing an example of the electrophotographic photosensitive member of the present invention. Schematic configuration diagram showing an example of an image forming apparatus including the electrophotographic photosensitive member of the present invention.

The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member having a plurality of layers including at least a photosensitive layer on a conductive support, and hindered amine having an aminoether structure in at least one of the plurality of layers. It is characterized by containing a compound. This feature is a technical feature common to or corresponding to the following embodiments.

In an embodiment of the present invention, from the viewpoint of effectively obtaining the effects of the present invention, the organic group constituting the aminoether structure of the hindered amine compound is an alkyl group having 8 or more carbon atoms or a cycloalkyl group having 4 or more carbon atoms. Is preferable.

In an embodiment of the present invention, from the viewpoint of effectively obtaining the effects of the present invention, the content of the hindered amine compound is 2 to 15 parts by mass with respect to 100 parts by mass of the binder resin of the layer containing the hindered amine compound. It is preferably within the range.

In an embodiment of the present invention, from the viewpoint of improving wear resistance, the plurality of layers have a surface protective layer on the surface side of the photosensitive layer, and the surface protective layer contains the hindered amine compound. Is preferable.

In an embodiment of the present invention, from the viewpoint of effectively obtaining the effects of the present invention, the surface protective layer is a cured product of a composition containing the hindered amine compound, a polymerizable compound for a binder, and a charge transporting agent. Is preferable.

In an embodiment of the present invention, it is preferable to contain conductive fine particles as the charge transporting agent from the viewpoint of improving wear resistance.

As a method for producing an electrophotographic photosensitive member of the present invention, from the viewpoint of improving abrasion resistance, the composition containing a polymerization initiator having an acylphosphine oxide structure or an O-acyloxime structure is cured. It is preferable to have a step of forming the surface protective layer.

Further, the electrophotographic photosensitive member of the present invention can be suitably provided in an image forming apparatus.

Hereinafter, the components of the present invention and the forms and modes for carrying out the present invention will be described in detail. In the present application, "~" is used to mean that the numerical values described before and after the value are included as the lower limit value and the upper limit value. Further, in the following description, when a compound is listed by giving a specific example, the stereoisomer of the compound is also included.

[Electrophotophotoreceptor]
The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member having a plurality of layers including at least a photosensitive layer on a conductive support, and hindered amine having an aminoether structure in at least one of the plurality of layers. It contains a compound.

<< Hindered amine compound having an amino ether structure >>
The "hindered amine compound having an amino ether structure" of the present invention refers to a hindered amine compound having an amino ether (-NOZ) structure as represented by the following general formula (1). However, the amino ether (-NOZ) structure referred to in the present invention does not include those having an amino ester (-NOCO-) structure.

In the general formula (1), Y represents an arbitrary structure other than a hydrogen atom. For Y, any structure can be selected as long as the effect of the present invention is not impaired.
Further, Z represents an organic group constituting the aminoether (-NOZ) structure of the hindered amine compound according to the present invention. Any organic group can be selected for Z as long as it does not inhibit the effect of the present invention, but an alkyl group having 8 or more carbon atoms or a cycloalkyl group having 4 or more carbon atoms is effective for the effect of the present invention. It is preferable from the viewpoint of obtaining. The upper limit of these carbon atoms is not particularly limited as long as the effect of the present invention is not impaired, but from the viewpoint of effectively obtaining the effect of the present invention, an alkyl group having 6 or less carbon atoms or a cycloalkyl having 11 or less carbon atoms It is preferably a group.

Examples of the hindered amine compound having an amino ether (-NOZ) structure represented by the above general formula (1) include Tinuvin 123 (hereinafter compound A5), Tinuvin 152 (hereinafter compound A7) and Tinuvin NOR manufactured by BASF Japan Co., Ltd. Examples thereof include 371 FF, Tinuvin XT850 FF, Tinuvin XT855 FF, Flamestab NOR 116 FF (compound A1 below), and ADEKA STAB LA-81 (compound A4 below) manufactured by ADEKA Corporation.
Hereinafter, specific examples of the hindered amine compound having an amino ether (-NOZ) structure according to the present invention will be shown, but the present invention is not limited thereto. In addition, "*" in the chemical structural formula represented by R of the following compound A1 indicates the bonding portion with a nitrogen atom.

The electrophotographic photosensitive member of the present invention has a plurality of layers including at least a photosensitive layer on a conductive support, and a hindered amine compound having the above amino ether structure as an antioxidant in at least one of the plurality of layers. Contains. Since the hindered amine compound has a relatively weak basicity and is less likely to trap holes in charge transport, it is considered that the hindered amine compound can prevent deterioration of potential performance while obtaining an effect of preventing image flow as an antioxidant. Furthermore, it was found that the layer formed by using the hindered amine compound having the amino ether structure was also excellent in wear resistance. It is presumed that this is because the compatibility with the binder resin is high.

From the viewpoint of effectively obtaining the effects of the present invention, the content of the hindered amine compound having an amino ether structure according to the present invention is 2 to 15 with respect to 100 parts by mass of the binder resin of the layer containing the hindered amine compound. It is preferably within the range of parts by mass.

<< Layer structure on the surface of electrophotographic photosensitive member >>
The electrophotographic photosensitive member of the present invention has a plurality of layers including at least a photosensitive layer on a conductive support.
Here, the photosensitive layer has both a function of absorbing light to generate electric charges and a function of transporting electric charges. The layer structure of the photosensitive layer may be a single-layer structure containing a charge generating substance and a charge transporting substance, or a charge generating layer containing the charge generating substance and a charge transporting layer containing the charge transporting substance. It may have a laminated structure. Further, if necessary, an intermediate layer may be provided between the conductive support and the photosensitive layer. The layer structure of the photosensitive layer is not particularly limited, and specific layer structures including the surface protective layer and the intermediate layer are shown below, for example.

(1) Layer structure in which a photosensitive layer composed of a charge generating layer and a charge transporting layer and a surface protective layer are sequentially laminated on a conductive support (2) A charge transporting substance and a charge generating substance on the conductive support Layer structure in which a single photosensitive layer and a surface protective layer containing a substance are sequentially laminated (3) An intermediate layer, a photosensitive layer composed of an intermediate layer, a charge generating layer and a charge transport layer, and surface protection on a conductive support. Layer structure in which layers are sequentially laminated (4) Layer structure in which an intermediate layer, a single photosensitive layer containing a charge transporting substance and a charge generating substance, and a surface protective layer are sequentially laminated on a conductive support.

The electrophotographic photosensitive member of the present invention may have any of the above-mentioned layer configurations (1) to (4), and among these, the one having the above-mentioned (3) layer configuration is particularly preferable.

Further, FIG. 1 is a cross-sectional view showing an example of the layer structure of the electrophotographic photosensitive member of the present invention.
As shown in FIG. 1, the electrophotographic photosensitive member 200 of the present invention is configured by sequentially laminating, for example, an intermediate layer 202, a photosensitive layer 203, and a surface protective layer 204 on a conductive support 201. From the viewpoint of improving wear resistance, the surface protective layer 204 preferably contains conductive fine particles 205 as a charge transport agent.
The photosensitive layer 203 is composed of a charge generation layer 203a and a charge transport layer 203b.
The electrophotographic photosensitive member 200 according to the present invention does not necessarily have to be provided with the surface protective layer 204, and may have a layer structure in which the surface protective layer 204 is not provided.

The electrophotographic photosensitive member of the present invention is an organic photosensitive member, and the organic photoconductor expresses at least one of a charge generation function and a charge transport function, which are indispensable for the configuration of the electrophotographic photosensitive member, by the organic compound. It means an electrophotographic photosensitive member, and includes a photosensitive member composed of a known organic charge generating substance or an organic charge transporting substance, and a photosensitive member composed of a polymer complex having a charge generating function and a charge transporting function.

Further, the effect of the present invention can be obtained if the hindered amine compound having an amino ether structure according to the present invention is contained in at least one of a plurality of layers formed on the conductive support.
In the following description, an example of the embodiment in which the hindered amine compound having an amino ether structure is contained in the surface protective layer will be described, but it may be contained in a layer other than the surface protective layer. For example, the hindered amine compound may be contained in the charge transport layer, or may be contained in both the charge transport layer and the surface protection layer.

《Surface protection layer》
In an embodiment of the present invention, it is not always necessary to provide the surface protective layer 204, but from the viewpoint of effectively obtaining the effect of the present invention, a plurality of layers formed on the conductive support 201 are formed on the photosensitive layer 203. It is preferable that the surface protective layer 204 is provided on the surface side of the above, and the surface protective layer 204 contains a hindered amine compound having an amino ether structure according to the present invention.
Further, it is the present invention that the surface protective layer according to the present invention is a cured product of a composition containing a hindered amine compound having an amino ether structure according to the present invention, a polymerizable compound for a binder, a charge transport agent and the like. It is preferable from the viewpoint of effectively obtaining the effect. Further, from the viewpoint of improving the wear resistance and suppressing the fluctuation of the surface roughness, the surface protective layer according to the present invention preferably further contains inorganic particles in the above composition. Further, when forming the surface protective layer, it is preferable to cure the composition containing the polymerization initiator to form the surface protective layer.
Hereinafter, regarding [1] polymerization initiator, [2] polymerizable compound for binder, [3] charge transporter, [4] inorganic particles, and [5] other additives, which are materials for forming the surface protective layer. It will be explained in order.

[1] Polymerization Initiator As the polymerization initiator according to the present invention, for example, a single-molecule-based polymerization initiator having an acylphosphine oxide structure or an O-acyloxime structure is used from the viewpoint of improving wear resistance. Is preferable. These may be used alone or in combination of two or more. In the present invention, the single-molecule-based polymerization initiator means one in which one molecule functions as a polymerization initiator by itself, and the two-molecule-based polymerization initiator is a polymerization initiator only when two or more molecules are prepared. It means something that functions as.

Specific examples of the polymerization initiator having an acylphosphine oxide structure are shown below.

Of the compound PI-1 Irgacure 819 (manufactured by BASF Japan) and the compound PI-2 Irgacure TPO (manufactured by BASF Japan), Irgacure 819 (manufactured by BASF Japan) is the one. Is preferable.

Examples of the polymerization initiator having an O-acyloxime structure include PBG-304 (compound PI-3 below) manufactured by Changzhou Strong Electronics New Materials Co., Ltd. and Irgacure OXE02 (compound PI-4 below) manufactured by BASF Japan Ltd. And so on. Specific examples of these will be shown below, but the polymerization initiator having an O-acyloxime structure according to the present invention is not limited thereto.

Further, in the present invention, as the polymerization initiator having an O-acyloxime structure, a polymerization initiator having a structure represented by the following general formula (4) is preferable.

In the general formula (4), R ₁₁ and R ₁₂ each independently have a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, and an alkyl group which may have a substituent. Represents an aryl group that may have 3 to 6 cycloalkyl groups or substituents.
R ₁₃ may have a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, an alkoxy group having 1 to 6 carbon atoms which may have a substituent, and a substituent. Represents a carbonyl group that may have a good aryl group, halogeno group, cyano group, nitro group, hydroxy group, or substituent.
Specific examples of the alkyl group, cycloalkyl group, aryl group and alkoxy group in the general formula (4) include alkyl groups listed as substituents represented by _{R 1} and R _{2 in the general formula (2) described later.} , Cycloalkyl group and alkoxy group, and the aromatic hydrocarbon ring group represented by _{R 3 and R 4} in the general formula (2) described later. Further, specific examples of the substituent in the general formula (4) are the same as those represented by _{R 1} and R _{2 in the general formula (2) described later.}

Specific examples of the compound having the structure represented by the general formula (4) are shown below.

Examples of commercially available polymerization initiators having an O-acyloxime structure include O-acyloxym having a disulfide structure in the compound, in addition to Irgacure OXE01 (manufactured by BASF Japan Ltd.) of the above-exemplified compound B-1. Examples thereof include PBG-305 and PBG-329 (both manufactured by Changzhou Powerful Electronics New Materials Co., Ltd.), which are system initiators.

Further, the polymerization initiator according to the present invention is not limited to the above-mentioned single molecule polymerization initiator, and a bimolecular polymerization initiator can also be used. Examples of the bimolecular polymerization initiator include a combination of a compound having a hexaarylbisimidazole structure and a thiol compound.

Specific examples of compounds having a hexaarylbisimidazole structure used as a bimolecular polymerization initiator are shown below.

Specific examples of the thiol compound used as the bimolecular polymerization initiator are shown below.

The addition ratio of the polymerization initiator according to the present invention is preferably in the range of 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable compound for a binder, and is in the range of 0.5 to 10 parts by mass. It is more preferable to be inside. Further, in addition to the above-mentioned polymerization initiator, other known polymerization initiators may be further contained.

[2] Polymerizable Compound for Binder As the polymerizable compound for a binder according to the present invention, a monomer having a radically polymerizable functional group and polymerizing (curing) with a radical polymerization initiator to form a binder resin of a photoconductor is used. It is preferably used. Examples of the binder resin include polystyrene and polyacrylate. The polymerizable compound for a binder according to the present invention does not include the charge transport agent according to the present invention.

As the polymerizable compound for the binder, it is preferable to use a crosslinkable polymerizable compound from the viewpoint of maintaining high durability. Specific examples of the crosslinkable polymerizable compound include a polymerizable compound having two or more radically polymerizable functional groups (hereinafter, also referred to as “polyfunctional radically polymerizable compound”).

A compound having one radically polymerizable functional group (hereinafter, also referred to as “monofunctional radically polymerizable compound”) can be used in combination with the above polyfunctional radically polymerizable compound. When a monofunctional radical polymerizable compound is used, the ratio thereof is preferably 20% by mass or less based on the total amount of the monomers for forming the binder resin.
Examples of the radically polymerizable functional group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group and the like.

Since the polyfunctional radically polymerizable compound can be cured with a small amount of light or in a short time, the radically polymerizable functional group is an acryloyl group (CH ₂ = CHCO−) or a methacryloyl group (CH ₂ = CCH ₃ CO−). It is particularly preferable that it is an acrylic monomer having two or more) or an oligomer thereof. Therefore, as the resin, an acrylic resin formed of an acrylic monomer or an oligomer thereof is preferable.

In the present invention, the polyfunctional radical polymerizable compound may be used alone or in combination of two or more. Further, these polyfunctional radically polymerizable compounds may be used as oligomers, although monomers may be used.

Specific examples of the polyfunctional radically polymerizable compound are shown below.

In the chemical formulas showing the above exemplified compounds M1 to M14, R represents an acryloyl group (CH ₂ = CHCO−) and R ′ represents a methacryloyl group (CH ₂ = CCH ₃ CO−).

[3] Charge Transport Agent The charge transport agent referred to in the present invention refers to a compound having a function of transporting charge carriers.

Further, it is preferable that the charge transport agent according to the present invention is a compound having a maximum absorption wavelength within the range of 405 ± 50 nm in the spectral absorption spectrum from the viewpoint of effectively obtaining the effect of the present invention. Here, in the present invention, the maximum absorption wavelength of the charge transport agent is ^{the absorption wavelength of a solution obtained by dissolving the charge transport agent in tetrahydrofuran at a concentration of 1.0 × 10-5} mol / L, which is a normal absorption spectrophotometer. Refers to the maximum point of the absorption peak when measured at 25 ° C. The maximum absorption wavelength is not necessarily the maximum absorption wavelength, and a plurality of maximum points may exist.

The addition ratio of the charge transporting agent according to the present invention is preferably in the range of 10 to 100 parts by mass with respect to 100 parts by mass of the polymerizable compound for a binder, and is preferably in the range of 20 to 60 parts by mass. Is more preferable.

[3.1] Compound having a structure represented by the general formula (2) The charge transporting agent according to the present invention is preferably a compound having a structure represented by the following general formula (2).

In the above general formula (2), R ₁ and R ₂ each independently represent a substituent, _{and at least one of R 1} and R ₂ is methacryloyloxy linked by an alkylene group having 1 to 5 carbon atoms. Represents a group or acryloyloxy group. m and n each independently represent an integer of 0 to 5. However, both m and n do not represent 0. R ₃ and R ₄ each independently represent a hydrogen atom or a substituted or unsubstituted aromatic ring group.

In the general formula (2) _{, examples of the substituent represented by R 1} and R ₂ include an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a (t) butyl group, a pentyl group and a hexyl). Group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, benzyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyloxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group. Group, dodecyloxy group, etc.), acryloyloxy group, methacryloyloxy group, cycloalkyl group (eg, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), Any group selected from an alkynyl group (eg, propargyl group, etc.) can be mentioned. Among them, for example, an alkyl group, an alkoxy group, an acryloyloxy group, a methacryloyloxy group and the like are preferable.
In addition, these substituents may be further substituted with the above-mentioned substituents, or they may be condensed with each other to further form a ring. Moreover, the specific examples in parentheses in these substituents are not limited to these. Further, when m in the general formula (2) represents an integer of 2 to 5, the _{substituents represented by R 1} may be different from each other, and n in the general formula (2) is an integer of 2 to 5. The same applies to the case of representing.

In the general formula (2), _{at least one of R 1} and R ₂ represents a methacryloyloxy group or an acryloyloxy group linked by an alkylene group having 1 to 5 carbon atoms, and among them, it is linked by a methylene group. It preferably represents a methacryloyloxy group or an acryloyloxy group.

In the general formula (2) _{, examples of the aromatic ring group represented by R 3} and R ₄ include a phenyl group, a p-chlorophenyl group, a mesityl group, a trill group, a xsilyl group, a naphthyl group, an anthryl group and an azulenyl group. , Acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group and other aromatic hydrocarbon ring groups (also referred to as aryl groups), pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group. Group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazole-1-yl group, etc.), oxazolyl group, benzoxazolyl group, Thiazolyl group, isooxazolyl group, isothiazolyl group, frazayl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (above One of the carbon atoms constituting the carboline ring of the carborinyl group is replaced with a nitrogen atom.), An aromatic heterocyclic group such as a quinoxalinyl group, a pyridadinyl group, a triazinyl group, a quinazolinyl group, a phthalazinyl group and the like can be mentioned. Further, these groups may be further _{substituted with the substituents represented by R 1} and R ₂ , or they may be condensed with each other to further form a ring.

Further, the compound having the structure represented by the general formula (2) is more preferably a compound having the structure represented by the following general formula (3).

In the above general formula (3), R ₅ represents a substituent, and at least one represents a methacryloyloxy group or an acryloyloxy group linked by an alkylene group having 1 to 5 carbon atoms. m represents an integer of 1-5. R _{6 to} R ₉ each independently represent a hydrogen atom or a substituted or unsubstituted aromatic ring group.

In the general formula (3), examples of the _{substituent represented by R 5} include the same substituents represented by R ₁ and R _{2 in the general formula (2).}
In the general formula (3), the _{substituted or unsubstituted aromatic ring group represented by R 6 to} R ₉ is a substituted or unsubstituted aromatic ring group represented by _{R 3} and R ₄ in the above general formula (2). The same as the group ring group can be mentioned.

[3.2] Specific Examples Specific examples of the compound having the structure represented by the above general formula (2) or (3) are shown below, but the present invention is not limited thereto.

Further, specific examples of the charge transporting agent according to the present invention and which does not have the structure represented by the above general formula (2) or (3) are shown below, but the present invention is not limited thereto.

[3.3] Synthesis Example An example of synthesis of a compound having a structure represented by the general formula (2) or (3) will be described below by taking the above compound RCTM-27 as an example, but the present invention is limited thereto. It is not something that is done.
Compound RCTM-27 can be synthesized according to steps A to D below.

(Step A)
First, 2.5 g of t-BuOK and 150 mL of DMF (N, N-dimethylformamide) were added to a 100 mL flask equipped with an argon gas introduction device and a stirrer in the same manner as in paragraph 0073 of JP-A-2000-2758787. The atmosphere was argon gas. To this, 5.0 g of compound (1) and 9.0 g of compound (2) were added, and the mixture was stirred at room temperature for 1 hour. The stirred solution is added to a large excess of water, extracted with toluene, the extract is washed with water, dried over sodium sulfate, concentrated and then column purified to obtain 10.6 g of compound (3). Obtained.

(Step B)
Next, in the same manner as in paragraph 0171 of JP2013-254136A, 0.37 g (1.6 mmol) of palladium acetate and tri-tert-butylphosphine 1. 33 g (6.6 mmol) was added and stirred at room temperature for 30 minutes. Next, 3.51 g (32.8 mmol) of compound (4), 7.9 g (22 mmol) of compound (3) and 20 mL of toluene, and 6.29 g (65.5 mmol) of sodium-tert-butoxide were added, and the mixture was refluxed for 2 hours. .. After allowing to cool, 100 mL of water was added and the mixture was stirred for 10 minutes, and the organic layer was washed with water until the aqueous layer became neutral. After drying the organic layer with sodium sulfate, toluene was distilled off.

(Step C)
Next, in the same manner as in paragraph 0072 of JP-A-2000-2758787, a 100 mL flask equipped with a thermometer, a dropping funnel, an argon gas introduction device and a stirrer was brought into an argon gas atmosphere, which was obtained in step B. 7 g of compound (5), 50 mL of toluene and 3 g of phosphoryl chloride were added. While stirring at room temperature, 2 g of DMF was slowly added dropwise, and then the temperature was raised to about 80 ° C. and the mixture was stirred for 16 hours. The stirred solution was added to warm water at about 70 ° C. and then cooled. This was extracted with toluene, and the extract was washed with water until the pH of the water reached 7. After drying over sodium sulfate, the mixture was concentrated, and column purification gave 5 g of compound (6).

(Step D)
Next, 35.1 g of compound (6) and 100 mL of ethanol were added to the flask and stirred in the same manner as in paragraph 0068 of JP-A-2000-2758787. After gradually adding 1.9 g of sodium borohydride to this, the liquid temperature was maintained at 40 to 60 ° C., and the mixture was stirred for about 2 hours. Next, the reaction solution was gradually added to about 300 mL of water and stirred to precipitate crystals. After filtration, the mixture was thoroughly washed with water and dried to obtain compound (7). The yield was 33 g.

Next, compound (7) dissolved in 50 mL of dichloromethane, 2 equivalents of triethylamine, and a catalytic amount of DMAP (dimethylaminopyridine) are ice-cooled and cooled to 0 ° C. 1.5 equivalents of acrylic chloride is slowly added thereto, and then the temperature is gradually raised and the mixture is stirred for 24 hours. This solution is added to 100 mL of water, extracted with dichloromethane and washed with saturated aqueous sodium hydrogen carbonate solution. Then, it is extracted with a dichloromethane solution and washed with a saturated aqueous sodium hydrogen carbonate solution. The organic layer is dried over magnesium sulfate and the solvent is distilled off. The mixture is column-purified with a solution of ethyl acetate: hexane = 3: 1 to obtain compound RCTM-27, which is a methacrylate monomer.

[3.4] Other Charge Transporting Agents In addition to the above-mentioned charge transporting agents, as the charge transporting agent contained in the surface protective layer, a charge transporting agent contained in the surface protective layer of a conventionally known electrophotographic photosensitive member. May be used. Specifically, for example, known charge transporting agents described in JP-A-2015-230437, JP-A-2016-143021, JP-A-2017-116628, and the like can be used.
Further, the surface protective layer preferably contains conductive fine particles known as a charge transporting agent from the viewpoint of improving wear resistance. The conductive fine particles will be described later in "[4] Inorganic particles".

[4] Inorganic Particles The surface protective layer of the present invention preferably contains inorganic particles, and more preferably contains metal oxide particles as the inorganic particles.
As the metal oxide particles, metal oxide fine particles including a transition metal are preferable. For example, silica (silicon dioxide), magnesium oxide, zinc oxide, lead oxide, aluminum oxide, tantalum oxide, indium oxide, bismuth oxide, yttrium oxide, cobalt oxide, copper oxide, manganese oxide, selenium oxide, iron oxide, zirconium oxide, Examples thereof include metal oxide fine particles such as germanium oxide, tin oxide, titanium oxide, niobium oxide, molybdenum oxide, and vanadium oxide. Of these, any of tin oxide fine particles, titanium oxide fine particles, zinc oxide fine particles, and alumina fine particles is preferable because the wear resistance of the surface protective layer can be improved.

Further, it is preferable to use conductive fine particles among the metal oxide fine particles. Since the conductive metal oxide fine particles also have a function of transporting electrons or holes, they can be used as a charge transporting agent while also obtaining the effect of improving the wear resistance.
Examples of the conductive fine particles that can also be used as a charge transport agent include tin oxide, zinc oxide, titanium oxide and the like.

The metal oxide particles are preferably produced by a known method, for example, a general production method such as a vapor phase method, a chlorine method, a sulfuric acid method, a plasma method, or an electrolysis method.

The number average primary particle size of the metal oxide particles is, for example, preferably in the range of 1 to 300 nm, and particularly preferably in the range of 3 to 100 nm.

The addition ratio of the metal oxide particles is preferably in the range of 1 to 250 parts by mass, and preferably in the range of 10 to 200 parts by mass with respect to 100 parts by mass of the polymerizable compound for a binder. More preferred.

[4.1] Method for measuring particle size of metal oxide particles The particle size of the metal oxide particles (number average primary particle size) is measured by taking a 10000 times magnified photograph with a scanning electron microscope (manufactured by JEOL Ltd.). , Automatic image processing and analysis device "LUZEX AP (LUZEX® AP)" (manufactured by JEOL Ltd.) software Ver. Using 1.32, binarization is performed, the horizontal ferret diameter is calculated for each, and the average value is calculated as the number average primary particle size. Here, the horizontal ferret diameter refers to the length of the side of the circumscribed rectangle when the image of the metal oxide particles is binarized, parallel to the x-axis.

[4.2] Surface Modification In the present invention, the metal oxide particles preferably have a reactive organic group. That is, from the viewpoint of dispersibility and abrasion resistance of the photoconductor, it is preferable that the surface is surface-modified with a surface modifier having a reactive organic group.

As the surface modifier, a surface modifier that reacts with a hydroxy group or the like existing on the surface of the metal oxide particles before the surface modification may be used, and as such a surface modifier, a silane coupling agent or a titanium cup may be used. Ring agents and the like can be mentioned.
Further, in the present invention, for the purpose of further increasing the hardness of the surface protective layer, it is preferable to use a surface modifier having a reactive organic group, and it is preferable to use one in which the reactive organic group is a radically polymerizable functional group. More preferred. By using a surface modifier having a radically polymerizable functional group, a strong protective film can be formed because it reacts with a polymerizable compound for a binder and a charge transport agent contained in the surface protective layer.
As the surface modifier having a radically polymerizable functional group, it is preferable to use a silane coupling agent having an acryloyl group or a methacryloyl group, and the surface modifier having such a radically polymerizable functional group is described below. Known compounds are exemplified.

S-1: CH ₂ = CHSi (CH ₃ ) (OCH ₃ ) ₂
S-2: CH ₂ = CHSi (OCH ₃ ) ₃
S-3: CH ₂ = CHSiCl ₃
S-4: CH ₂ = CHCOO (CH ₂ ) ₂ Si (CH ₃ ) (OCH ₃ ) ₂
S-5: CH ₂ = CHCOO (CH ₂ ) ₂ Si (OCH ₃ ) ₃
S-6: CH ₂ = CHCOO (CH ₂ ) ₂ Si (OC ₂ H ₅ ) (OCH ₃ ) ₂
S-7: CH ₂ = CHCOO (CH ₂ ) ₃ Si (OCH ₃ ) ₃
S-8: CH ₂ = CHCOO (CH ₂ ) ₂ Si (CH ₃ ) Cl ₂
S-9: CH ₂ = CHCOO (CH ₂ ) ₂ SiCl ₃
S-10: CH ₂ = CHCOO (CH ₂ ) ₃ Si (CH ₃ ) Cl ₂
S-11: CH ₂ = CHCOO (CH ₂ ) ₃ SiCl ₃
S-12: CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₂ Si (CH ₃ ) (OCH ₃ ) ₂
S-13: CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₂ Si (OCH ₃ ) ₃
S-14: CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₃ Si (CH ₃ ) (OCH ₃ ) ₂
S-15: CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₃ Si (OCH ₃ ) ₃
S-16: CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₂ Si (CH ₃ ) Cl ₂
S-17: CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₂ SiCl ₃
S-18: CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₃ Si (CH ₃ ) Cl ₂
S-19: CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₃ SiCl ₃
S-20: CH ₂ = CHSi (C ₂ H ₅ ) (OCH ₃ ) ₂
S-21: CH ₂ = C (CH ₃ ) Si (OCH ₃ ) ₃
S-22: CH ₂ = C (CH ₃ ) Si (OC ₂ H ₅ ) ₃
S-23: CH ₂ = CHSi (OCH ₃ ) ₃
S-24: CH ₂ = C (CH ₃ ) Si (CH ₃ ) (OCH ₃ ) ₂
S-25: CH ₂ = CHSi (CH ₃ ) Cl ₂
S-26: CH ₂ = CHCOOSi (OCH ₃ ) ₃
S-27: CH ₂ = CHCOOSi (OC ₂ H ₅ ) ₃
S-28: CH ₂ = C (CH ₃ ) COOSi (OCH ₃ ) ₃
S-29: CH ₂ = C (CH ₃ ) COOSi (OC ₂ H ₅ ) ₃
S-30: CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃
S-31: CH ₂ = CHCOO (CH ₂ ) ₂ Si (CH ₃ ) ₂ (OCH ₃ )
S-32: CH ₂ = CHCOO (CH ₂ ) ₂ Si (CH ₃ ) (OCOCH ₃ ) ₂
S-33: CH ₂ = CHCOO (CH ₂ ) ₂ Si (CH ₃ ) (ONHCH ₃ ) ₂
S-34: CH ₂ = CHCOO (CH ₂ ) ₂ Si (CH ₃ ) (OC ₆ H ₅ ) ₂
S-35: CH ₂ = CHCOO (CH ₂ ) ₂ Si (C ₁₀ H ₂₁ ) (OCH ₃ ) ₂
S-36: CH ₂ = CHCOO (CH ₂ ) ₂ Si (CH ₂ C ₆ H ₅ ) (OCH ₃ ) ₂

As the surface modifier, a silane compound having a reactive organic group capable of conducting a radical polymerization reaction can be used in addition to the above S-1 to S-36. These surface modifiers can be used alone or in admixture of two or more.

The amount of the surface modifier used is not particularly limited, but is preferably in the range of 0.1 to 100 parts by mass with respect to 100 parts by mass of the metal oxide particles before modification.

[4.3] Method for surface modification of metal oxide particles Specifically, surface modification of metal oxide particles is a slurry (suspension of solid particles) containing the metal oxide particles before modification and a surface modifier. By wet pulverizing the metal oxide particles, the surface modification of the particles is promoted at the same time as the metal oxide particles are refined, and then the solvent is removed and the particles are pulverized.

The slurry is preferably a mixture of 0.1 to 100 parts by mass of the surface modifier and 50 to 5000 parts by mass of the solvent with respect to 100 parts by mass of the metal oxide particles before modification.

Further, as an apparatus used for wet pulverization of a slurry, a wet media dispersion type apparatus can be mentioned.
The wet media dispersion type device is a device in which beads are filled as media in a container, and a stirring disk mounted perpendicular to the rotation axis is rotated at high speed to crush and crush and disperse agglomerated particles of metal oxide particles. It is an apparatus having a process, and there is no problem as long as the structure is such that the metal oxide particles can be sufficiently dispersed and the surface can be modified when the surface modification is performed on the metal oxide particles. , Continuous type, batch type, etc. can be used. Specifically, a sand mill, an ultra visco mill, a pearl mill, a Glen mill, a dyno mill, an agitator mill, a dynamic mill and the like can be used. In these dispersion-type devices, fine pulverization and dispersion are performed by impact crushing, friction, shearing, shear stress, etc. using a pulverizing medium (media) such as balls and beads.

As the beads used in the wet media dispersion type apparatus, for example, balls made of glass, alumina, zircon, zirconia, steel, flint stone or the like can be used, and in particular, beads made of zirconia or zircon can be used. preferable. The size of the beads is usually about 1 to 2 mm in diameter, but in the present invention, for example, beads having a diameter of about 0.1 to 1.0 mm are preferably used.

Various materials such as stainless steel, nylon, and ceramic can be used for the inner wall of the disk or container used in the wet media dispersion device, but in the present invention, the disk or the inner wall of the container is made of ceramic such as zirconia or silicon carbide. It is preferably a disk or an inner wall of a container.

[5] Other Additives The surface protective layer according to the present invention may contain other components in addition to a polymerizable compound for a binder (binder resin), a charge transport agent, a polymerization initiator and inorganic particles. It is good, for example, various antioxidants and various lubricant particles such as fluorine atom-containing resin particles can be added. Examples of the fluorine atom-containing resin particles include ethylene tetrafluoride resin, ethylene trifluoride resin, ethylene hexafluoride propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride dichloride resin, and the like. It is preferable to appropriately select one or more of these copolymers, but ethylene tetrafluoride resin and vinylidene fluoride resin are particularly preferable.

《Conductive support》
The conductive support may be any as long as it has conductivity. For example, a metal such as aluminum, copper, chromium, nickel, zinc, stainless steel, which is formed into a drum or a sheet, or a metal foil such as aluminum or copper is used. Examples thereof include those laminated on a plastic film, aluminum, indium oxide, tin oxide and the like vapor-deposited on the plastic film, metal, plastic film or paper provided with a conductive layer by applying a conductive substance alone or together with a binder resin. ..

《Middle layer》
In the electrophotographic photosensitive member of the present invention, an intermediate layer having a barrier function and an adhesive function can be provided between the conductive support and the photosensitive layer. It is preferable to provide an intermediate layer in consideration of various failure preventions.

Such an intermediate layer contains, for example, a binder resin (hereinafter, also referred to as "binder resin for an intermediate layer") and, if necessary, conductive particles or metal oxide particles.

Examples of the binder resin for the intermediate layer include casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide resin, polyurethane resin, gelatin and the like. Of these, alcohol-soluble polyamide resins are preferred.

The intermediate layer can contain various conductive particles and metal oxide particles for the purpose of adjusting resistance. For example, various metal oxide particles such as alumina, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, and bismuth oxide can be used. Further, ultrafine particles such as tin-doped indium oxide, antimony-doped tin oxide or zirconium oxide can be used.
The number average primary particle size of such metal oxide particles is, for example, preferably 0.3 μm or less, and more preferably 0.1 μm or less. The number average primary particle size of the metal oxide particles can be measured by the same method as the method for measuring the number average primary particle size of the metal oxide particles contained in the surface protective layer.
These metal oxide particles may be used alone or in combination of two or more. When two or more kinds are mixed, it may take the form of a solid solution or a fusion.
The content ratio of the conductive particles or the metal oxide particles is preferably in the range of 20 to 400 parts by mass, preferably in the range of 50 to 350 parts by mass with respect to 100 parts by mass of the binder resin for the intermediate layer. Is more preferable.

The thickness of the intermediate layer is preferably in the range of 0.1 to 15 μm, more preferably in the range of 0.3 to 10 μm, for example.

《Charge generation layer》
The charge generation layer contains a charge generation substance and a binder resin (hereinafter, also referred to as “binder resin for charge generation layer”).

Examples of the charge generating substance include azo raw materials such as Sudan Red and Diane Blue, quinone pigments such as pyrenequinone and antoanthrocyanine, quinocianin pigments, perylene pigments, indigo pigments such as indigo or thioindigo, and many such as pyranthron and diphthaloylpyrene. Examples thereof include, but are not limited to, ring quinone pigments and phthalocyanine pigments. Among these, polycyclic quinone pigments and titanyl phthalocyanine pigments are preferable.
These charge generating substances may be used alone or in combination of two or more.

As the binder resin for the charge generation layer, known resins can be used, for example, polystyrene resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, etc. Polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, or copolymer resin containing two or more of these resins (for example, vinyl chloride-vinyl acetate copolymer resin, chloride) Vinyl-vinyl acetate-maleic anhydride copolymer resin), poly-vinylcarbazole resin and the like, but are not limited thereto. Among these, polyvinyl butyral resin is preferable.

The content ratio of the charge generating substance in the charge generating layer is preferably in the range of 1 to 600 parts by mass with respect to 100 parts by mass of the binder resin for the charge generating layer, and is in the range of 50 to 500 parts by mass. More preferably.

The thickness of the charge generating layer varies depending on the characteristics of the charge generating substance, the characteristics of the binder resin for the charge generating layer, the content ratio, etc., but is preferably in the range of 0.01 to 5 μm, preferably 0.05 to 0.05. More preferably, it is within the range of 3 μm.

《Charge transport layer》
The charge transport layer contains a charge transport substance and a binder resin (hereinafter, also referred to as “binder resin for charge transport layer”).

Examples of the charge-transporting substance in the charge-transporting layer include triphenylamine derivatives, hydrazone compounds, styryl compounds, benzidine compounds, and butadiene compounds.

As the binder resin for the charge transport layer, known resins can be used, for example, polycarbonate resin, polyacrylate resin, polyester resin, polystyrene resin, styrene-acrylic nitrile copolymer resin, polymethacrylic acid ester resin, styrene-methacryl. Examples thereof include acid ester copolymer resin, but polycarbonate resin is preferable. Further, BPA (bisphenol A) type, BPZ (bisphenol Z) type, dimethyl BPA type, BPA-dimethyl BPA copolymer type polycarbonate resin and the like are preferable in terms of crack resistance, abrasion resistance and charging characteristics.

The content ratio of the charge transporting substance in the charge transport layer is preferably in the range of 10 to 500 parts by mass with respect to 100 parts by mass of the binder resin for the charge transport layer, and is in the range of 20 to 250 parts by mass. Is more preferable.

The thickness of the charge transport layer varies depending on the characteristics of the charge transport material, the characteristics of the binder resin for the charge transport layer, the content ratio, etc., but is preferably in the range of 5 to 40 μm, preferably in the range of 10 to 30 μm. Is more preferable.

For example, an antioxidant, an electron conductive agent, a stabilizer, a silicone oil, or the like may be added to the charge transport layer. It is preferable that the antioxidant is disclosed in JP-A-2000-305291, and the electron conductive agent is disclosed in JP-A-50-137543, JP-A-58-76483, and the like.

[Manufacturing method of electrophotographic photosensitive member]
As a method for producing an electrophotographic photosensitive member of the present invention, a composition containing a hindered amine compound having an amino ether structure, a polymerizable compound for a binder, a charge transport agent and a polymerization initiator according to the present invention is cured to form a surface protective layer. It is preferable to have a step of forming the above. Further, the polymerization initiator contained in the composition is preferably a compound having an acylphosphine oxide structure or an O-acyloxime structure. As a curing method, a method such as ultraviolet curing, thermosetting, or electron beam curing can be appropriately used depending on the type of the polymerizable compound for the binder. Further, in the following description of the embodiment of the method for producing the electrophotographic photosensitive member, the method of ultraviolet curing among these will be described with specific examples.

As a method for producing an electrophotographic photosensitive member of the present invention, for example, it can be produced by going through the following steps.
Step (1): A step of forming an intermediate layer by applying a coating liquid for forming an intermediate layer to the outer peripheral surface of the conductive support and drying it. Step (2): An intermediate formed on the conductive support. Step of forming a charge generation layer by applying a coating liquid for forming a charge generation layer to the outer peripheral surface of the layer and drying it Step (3): A charge transport layer on the outer peripheral surface of the charge generation layer formed on the intermediate layer. Step of forming a charge transport layer by applying a coating liquid for forming and drying Step (4): A coating liquid for forming a surface protective layer is applied to the outer peripheral surface of the charge transport layer formed on the charge generating layer. A step of forming a surface protective layer by applying the coating to form a coating film and irradiating the coating film with ultraviolet rays to cure the coating film. Each step will be described below.

(Step (1): Formation of intermediate layer)
For the intermediate layer, a binder resin for the intermediate layer is dissolved in a solvent to prepare a coating liquid (hereinafter, also referred to as “coating liquid for forming the intermediate layer”), and conductive particles and metal oxide particles are added as necessary. After the dispersion, the coating liquid can be applied onto the conductive support to a certain layer thickness to form a coating film, and the coating film can be dried to form the coating film.

As a means for dispersing the conductive particles and the metal oxide particles in the coating liquid for forming the intermediate layer, for example, an ultrasonic disperser, a ball mill, a sand mill, a homomixer and the like can be used, but the present invention is limited thereto. It's not a thing.

Known methods for applying the coating liquid for forming the intermediate layer include, for example, a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, a slide hopper method, and a circular slide hopper method. The method can be mentioned.

The method for drying the coating film can be appropriately selected depending on the type of solvent, layer thickness and the like, but heat drying is preferable.

The solvent used in the intermediate layer forming step may be any solvent that satisfactorily disperses conductive particles and metal oxide particles and dissolves the binder resin for the intermediate layer. Specifically, for example, alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, t-butanol, and sec-butanol are used for the solubility and coating performance of the binder resin. It is preferable because it is excellent in. In addition, benzyl alcohol, toluene, dichloromethane, cyclohexanone, tetrahydrofuran and the like can be mentioned as co-solvents that can be used in combination with the above solvents to obtain preferable effects in order to improve storage stability and particle dispersibility.

The concentration of the binder resin for the intermediate layer in the coating liquid for forming the intermediate layer is appropriately selected according to the layer thickness of the intermediate layer and the production rate.

(Step (2): Formation of charge generation layer)
For the charge generation layer, a coating liquid (hereinafter, also referred to as “coating liquid for forming a charge generation layer”) is prepared by dispersing a charge generation substance in a solution in which a binder resin for the charge generation layer is dissolved in a solvent. , The coating liquid can be formed by applying the coating liquid on the intermediate layer to a certain layer thickness to form a coating film, and drying the coating film.

As a means for dispersing the charge generating substance in the coating liquid for forming the charge generating layer, for example, an ultrasonic disperser, a ball mill, a sand mill, a homomixer and the like can be used, but the means is not limited thereto.

Known methods for applying the coating liquid for forming a charge generation layer include, for example, a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, a slide hopper method, and a circular slide hopper method. Method can be mentioned.

The method for drying the coating film can be appropriately selected depending on the type of solvent, layer thickness and the like, but heat drying is preferable.

Examples of the solvent used for forming the charge generation layer include toluene, xylene, dichloromethane, 1,2-dichloroethane, methyl ethyl ketone, cyclohexane, ethyl acetate, t-butyl acetate, methanol, ethanol, propanol, butanol, methyl cellosolve, 4 −methoxy-4-methyl-2-pentanone, ethyl cellosolve, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, pyridine, diethylamine and the like can be mentioned, but are not limited thereto.

(Step (3): Formation of charge transport layer)
For the charge transport layer, a coating liquid in which a binder resin for the charge transport layer and a charge transport substance are dissolved in a solvent (hereinafter, also referred to as “coating liquid for forming a charge transport layer”) is prepared, and the coating liquid is charged. It can be formed by applying a certain layer thickness on the layer to form a coating film, and then drying the coating film.

Known methods for applying the coating liquid for forming a charge transport layer include, for example, a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, a slide hopper method, and a circular slide hopper method. Method can be mentioned.

The method for drying the coating film can be appropriately selected depending on the type of solvent, layer thickness and the like, but heat drying is preferable.

Examples of the solvent used for forming the charge transport layer include toluene, xylene, dichloromethane, 1,2-dichloroethane, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, methanol, ethanol, propanol, butanol, tetrahydrofuran, 1,4-. Examples thereof include, but are not limited to, dioxane, 1,3-dioxolane, pyridine, diethylamine and the like.

(Step (4): Formation of surface protective layer)
The surface protective layer can be formed by irradiating a composition containing a hindered amine compound having an amino ether structure according to the present invention, a polymerizable compound for a binder, a charge transport agent and a polymerization initiator with ultraviolet rays to cure the surface protective layer.

Specifically, first, for example, a hindered amine compound having an amino ether structure according to the present invention, a polymerizable compound for a binder, a composition containing a charge transport agent and a polymerization initiator, inorganic particles and other components as required. Is added to a known solvent to prepare a coating liquid (hereinafter, also referred to as “coating liquid for forming a surface protective layer”). Then, the coating liquid for forming the surface protective layer is applied to the outer peripheral surface of the charge transport layer formed in the step (3) to form a coating film, the coating film is dried, and the coating film is irradiated with ultraviolet rays. A surface protective layer can be formed by curing the polymerizable compound for a binder inside.

In the curing treatment of the surface protective layer, the coating film is irradiated with ultraviolet rays to generate radicals, the polymerizable compound for a binder is polymerized with a charge transporter having a radically polymerizable functional group, and is intermolecular and intramolecular. It is preferable that the polymerizable compound for a binder is formed as a cross-linked curable resin by forming a cross-linked bond by a cross-linking reaction and curing the compound.

In the coating liquid for forming a surface protective layer, the hindered amine compound having an amino ether structure according to the present invention is preferably in the range of 2 to 15 parts by mass with respect to 100 parts by mass of the polymerizable compound for a binder.
Further, the inorganic particles are preferably contained in the range of 5 to 60 parts by mass, more preferably in the range of 10 to 60 parts by mass with respect to 100 parts by mass of the polymerizable compound for a binder.
Further, the charge transport agent is preferably contained in the range of 5 to 75 parts by mass, more preferably in the range of 5 to 50 parts by mass with respect to 100 parts by mass of the polymerizable compound for a binder.
The polymerization initiator is preferably contained in the range of 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the polymerizable compound for a binder. Is inside.

As a means for dispersing the inorganic particles and the charge transporting agent in the coating liquid for forming the surface protective layer, for example, an ultrasonic disperser, a ball mill, a sand mill, a homomixer and the like can be used, but the means is limited thereto. is not it.

As the solvent used for forming the surface protective layer, any hindered amine compound having an amino ether structure according to the present invention, a polymerizable compound for a binder, a charge transporter, a polymerization initiator, inorganic particles and the like can be dissolved or dispersed. Can also be used. For example, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, t-butanol, sec-butanol, benzyl alcohol, toluene, xylene, dichloromethane, methyl ethyl ketone, cyclohexane, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve. , Tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, pyridine, diethylamine and the like, but are not limited thereto.

Known methods for applying the coating liquid for forming the surface protective layer include, for example, a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, a slide hopper method, and a circular slide hopper method. Method can be mentioned.

The coating film may be cured without being dried, but it is preferable that the coating film is naturally dried or heat-dried and then cured.

The drying conditions can be appropriately selected depending on the type of solvent, layer thickness and the like. The drying temperature is preferably in the range of room temperature (25 ° C.) to 180 ° C., and particularly preferably in the range of 80 to 140 ° C. The drying time is preferably 1 to 200 minutes, particularly preferably 5 to 100 minutes.

As the ultraviolet light source, any light source that generates ultraviolet rays can be used without limitation. For example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a flash (pulse) xenon, or the like can be used.
The irradiation conditions vary depending on individual lamps, for example, the dose of ultraviolet ray is within the range of normal 5~500mJ / cm ^2, preferably in the range of 5 to 100 mJ / cm ^2.
The power of the lamp is preferably in the range of 0.1 to 5 kW, particularly preferably in the range of 0.5 to 3 kW.

The irradiation time for obtaining the required irradiation amount of ultraviolet rays is, for example, preferably 0.1 seconds to 10 minutes, and more preferably 0.1 seconds to 5 minutes from the viewpoint of work efficiency.

In the step of forming the surface protective layer, drying can be performed before and after irradiation with ultraviolet rays and during irradiation with ultraviolet rays, and the timing of drying can be appropriately selected by combining these.

<< Image forming device >>
The image forming apparatus of the present invention includes the above-mentioned electrophotographic photosensitive member. The image forming apparatus of the present invention further includes a first charging means for charging the surface of the electrophotographic photosensitive member, and an exposure means for irradiating the surface of the electrophotographic photosensitive member with light to form an electrostatic latent image. A developing means that develops an electrostatic latent image with toner to form a toner image, a transfer means that transfers the toner image to paper, and a second charge that charges the surface of the electrophotographic photosensitive member after transferring the toner image to paper. It is preferable to provide means and cleaning means for removing residual toner on the electrophotographic photosensitive member.

FIG. 2 is a schematic configuration diagram showing an example of the image forming apparatus of the present invention.
The image forming apparatus 100 is referred to as a tandem type color image forming apparatus, and includes four sets of image forming units 10Y, 10M, 10C, 10Bk, an endless belt-shaped intermediate transfer unit 7, a paper feeding means 21, a fixing means 24, and the like. It has. A document image reading device SC is arranged above the device main body A of the image forming device 100.

The image forming unit 10Y for forming a yellow image is sequentially arranged around the drum-shaped photoconductor 1Y along the rotation direction of the photoconductor 1Y, the first charging means 2Y, the exposure means 3Y, and the developing means 4Y. It has a primary transfer roller 5Y, a second charging means 9Y, and a cleaning means 6Y. The image forming unit 10M for forming a magenta color image is sequentially arranged around the drum-shaped photoconductor 1M along the rotation direction of the photoconductor 1M, the first charging means 2M, the exposure means 3M, the developing means 4M, and the like. It has a primary transfer roller 5M, a second charging means 9M and a cleaning means 6M. The image forming unit 10C for forming a cyan image is sequentially arranged around the drum-shaped photoconductor 1C along the rotation direction of the photoconductor 1C, the first charging means 2C, the exposure means 3C, the developing means 4C, and the like. It has a primary transfer roller 5C, a second charging means 9C, and a cleaning means 6C. The image forming unit 10Bk for forming a black image is sequentially arranged around the drum-shaped photoconductor 1Bk along the rotation direction of the photoconductor 1Bk, that is, the first charging means 2Bk, the exposure means 3Bk, the developing means 4Bk, and the primary transfer. It has a roller 5Bk, a second charging means 9Bk, and a cleaning means 6Bk. As the photoconductors 1Y, 1M, 1C, and 1Bk, the electrophotographic photosensitive member of the present invention described above is used.

The image forming units 10Y, 10M, 10C, and 10Bk are similarly configured except that the colors of the toner images formed on the photoconductors 1Y, 1M, 1C, and 1Bk are different. Therefore, the image forming unit 10Y will be described in detail as an example, and the description of the image forming units 10M, 10C, and 10Bk will be omitted.

The image forming unit 10Y arranges the first charging means 2Y, the exposure means 3Y, the developing means 4Y, the primary transfer roller 5Y, the second charging means 9Y, and the cleaning means 6Y around the photoconductor 1Y which is an image forming body. A yellow (Y) toner image is formed on the photoconductor 1Y. Further, in the present embodiment, at least the photoconductor 1Y, the first charging means 2Y, the developing means 4Y, the second charging means 9Y, and the cleaning means 6Y are integrally provided in the image forming unit 10Y.

The first charging means 2Y is a means for giving a uniform potential to the photoconductor 1Y, and for example, a corona discharge type charger is used.

The exposure means 3Y exposes the photoconductor 1Y to which a uniform potential is applied by the first charging means 2Y based on the image signal (yellow) to form an electrostatic latent image corresponding to the yellow image. It is a means. As the exposure means 3Y, for example, one composed of LEDs and imaging elements in which light emitting elements are arranged in an array in the axial direction of the photoconductor 1Y, or a laser optical system is used.

The developing means 4Y comprises, for example, a developing sleeve having a built-in magnet and rotating while holding a developer, and a voltage applying device for applying a DC and / or AC bias voltage between the photoconductor 1Y and the developing sleeve. be.

The primary transfer roller 5Y is a means for transferring the toner image formed on the photoconductor 1Y to the endless belt-shaped intermediate transfer body 70. The primary transfer roller 5Y is arranged in contact with the intermediate transfer body 70.

The second charging means 9Y is a static removing means for charging (eliminating) the surface of the photoconductor 1Y after transferring the toner image to the intermediate transfer body 70, and is provided as a pre-cleaning member. As the second charging means 9Y, for example, a corona discharge type charger is used.
According to the image forming apparatus 100 of the present invention, in addition to the electrophotographic photosensitive member of the present invention, the second charging means 9Y is provided, so that a sufficient long life and high image quality of the photoconductor can be obtained. Can be done. Further, since the image forming apparatus 100 includes the electrophotographic photosensitive member of the present invention, sufficient exposure is provided even under image forming conditions in which the second charging means 9Y is not provided or the second charging means 9Y is not used. It is possible to obtain a long life of the body and high image quality.

The cleaning means 6Y is composed of a cleaning blade and a brush roller provided on the upstream side of the cleaning blade.

The endless belt-shaped intermediate transfer unit 7 has a semi-conductive endless belt-shaped second image carrier that is wound by a plurality of rollers 71, 72, 73, 74 and supported rotatably. Has an intermediate transcript 70 of. In the endless belt-shaped intermediate transfer body unit 7, a cleaning means 6b for removing toner is arranged on the intermediate transfer body 70.

Further, the housing 8 is composed of the image forming units 10Y, 10M, 10C, 10Bk and the endless belt-shaped intermediate transfer unit 7. The housing 8 is configured to be able to be pulled out from the device main body A via the support rails 82L and 82R.

The fixing means 24 is, for example, a heat roller fixing composed of a heating roller provided with a heating source inside and a pressure roller provided in a state of being pressure-contacted so as to form a fixing nip portion on the heating roller. There is a method.

In the above-described embodiment, the image forming apparatus 100 is a color laser printer, but a monochrome laser printer, a copier, a multifunction device, or the like may be used. Further, the exposure light source may be a light source other than the laser, for example, an LED light source or the like.

<< Image formation method >>
The image forming method according to the present invention can be carried out as follows using the above-mentioned image forming apparatus 100 including the electrophotographic photosensitive member of the present invention.

That is, first, the surface of the photoconductors 1Y, 1M, 1C, and 1Bk is discharged by the first charging means 2Y, 2M, 2C, and 2Bk to be negatively charged. Next, the surface of the photoconductors 1Y, 1M, 1C, and 1Bk is exposed by the exposure means 3Y, 3M, 3C, and 3Bk based on the image signal to form an electrostatic latent image. Next, toner is applied to the surfaces of the photoconductors 1Y, 1M, 1C, and 1Bk by the developing means 4Y, 4M, 4C, and 4Bk for development, and a toner image is formed.

Next, the toner images of each color formed on the photoconductors 1Y, 1M, 1C, and 1Bk are sequentially transferred (primary transfer) onto the rotating intermediate transfer body 70 by the primary transfer rollers 5Y, 5M, 5C, and 5Bk. A color image is formed on the intermediate transfer member 70.

Then, the surfaces of the photoconductors 1Y, 1M, 1C and 1Bk are statically eliminated by the second charging means 9Y, 9M, 9C and 9Bk. Then, the toner remaining on the surface of the photoconductors 1Y, 1M, 1C, and 1Bk is removed by the cleaning means 6Y, 6M, 6C, and 6Bk. Then, in preparation for the next image forming process, the photoconductors 1Y, 1M, 1C, and 1Bk are negatively charged by the charging means 2Y, 2M, 2C, and 2Bk.

On the other hand, the paper P is fed from the paper cassette 20 by the paper feeding means 21, and is conveyed to the secondary transfer unit 5b via the plurality of intermediate rollers 22A, 22B, 22C, 22D, and the resist roller 23. Then, the color image is transferred (secondary transfer) on the paper P by the secondary transfer unit 5b.

The paper P to which the color image is transferred in this way is fixed by the fixing means 24, sandwiched by the paper ejection roller 25, ejected to the outside of the apparatus, and placed on the paper ejection tray 26. Further, after the paper P is separated from the intermediate transfer body 70, the residual toner on the intermediate transfer body 70 is removed by the cleaning means 6b.
As described above, an image can be formed on the paper P.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, the indication of "parts" or "%" is used, but unless otherwise specified, it indicates "parts by mass" or "% by mass".

The structural formulas of the compounds used in the examples are shown below. In addition, "*" in the chemical structural formula represented by R of the following compound A1 indicates the bonding portion with a nitrogen atom.
The maximum absorption wavelength (nm) of the following charge transport agent used for forming the surface protective layer is the absorption wavelength of the solution dissolved in ^{tetrahydrofuran at a concentration of 1.0 × 10-5 mol / L.} It is the maximum point of the absorption peak when measured at 25 ° C. with a photometer (manufactured by Hitachi High-Tech Science, UH4150), and the results are shown in Table I.
Further, in the following compounds M1 and M2, R represents an acryloyl group (CH ₂ = CHCO−) and R ′ represents a methacryloyl group (CH ₂ = CCH ₃ CO−).

[Preparation of electrophotographic photosensitive member]
<< Preparation of electrophotographic photosensitive member 101 >>
(Preparation of conductive support)
First, the surface of a cylindrical aluminum support having a diameter of 60 mm was cut to prepare a conductive support.

(Formation of intermediate layer)
The dispersion having the following composition was diluted 1.5 times with the same mixed solvent, allowed to stand overnight, and then filtered using a Rigimesh 5 μm filter manufactured by Nippon Paul Co., Ltd. to prepare a coating liquid for forming an intermediate layer.
Binder resin for intermediate layer: Polyamide resin CM8000 (manufactured by Toray Industries, Inc.)
100 parts by mass Metal oxide particles: Titanium oxide SMT500SAS (manufactured by TAYCA)
120 parts by mass Metal oxide particles: Titanium oxide SMT150MK (manufactured by TAYCA)
155 parts by mass Solvent: Ethanol / n-PrOH / tetrahydrofuran (volume ratio 60:20:20)
1290 parts by mass The prepared coating liquid for forming an intermediate layer was dispersed in a batch system for 5 hours using a sand mill as a disperser. Next, the coating liquid for forming an intermediate layer after dispersion was applied onto the conductive support by a dip coating method to form an intermediate layer having a layer thickness of 2 μm after drying.

(Formation of charge generation layer)
The following components were mixed and dispersed for 10 hours using a sand mill to prepare a coating liquid for forming a charge generation layer. The prepared coating liquid for forming a charge generating layer was applied onto the intermediate layer by a dip coating method to form a charge generating layer having a layer thickness of 0.3 μm after drying.
Charge generator: Titanyl phthalocyanine pigment (titanyl phthalocyanine pigment having a maximum diffraction peak at at least 27.3 ° in Cu-Kα characteristic X-ray diffraction spectrum measurement)
20 parts by mass Binder resin for charge generation layer: Polyvinyl butyral resin # 6000-C (manufactured by Denka)
10 parts by mass Solvent: t-butyl acetate 700 parts by mass Solvent: 4-methoxy-4-methyl-2-pentanone 300 parts by mass

(Formation of charge transport layer)
The following components were mixed and dissolved to prepare a coating liquid for forming a charge transport layer. The prepared coating liquid for forming a charge transport layer was applied onto the charge generation layer by a dip coating method to form a charge transport layer having a layer thickness of 20 μm after drying. As a result, a photosensitive layer composed of a charge generating layer and a charge transporting layer was formed. In this way, the electrophotographic photosensitive member 101 was produced.
Charge transport agent: 225 parts by mass of the above compound CTM-1 Binder resin for charge transport layer: Polycarbonate (Iupizeta FPC6535A: manufactured by Mitsubishi Gas Chemical Company, Inc.)
300 parts by mass Additive: Flamestab NOR116 FF (Compound A1, manufactured by BASF Japan Ltd.)
6 parts by mass Solvent: tetrahydrofuran 1600 parts by mass Solvent: Toluene 400 parts by mass Leveling agent: Silicone oil (KF-54: manufactured by Shin-Etsu Chemical Co., Ltd.)
1 part by mass

<< Preparation of electrophotographic photosensitive member 102 >>
The intermediate layer to the charge transport layer were prepared in the same manner as the electrophotographic photosensitive member 101.
(Formation of surface protective layer)
The following components were mixed and stirred to sufficiently dissolve and disperse to prepare a coating liquid for forming a surface protective layer. The prepared coating liquid for forming a surface protective layer is applied onto the photosensitive layer using a circular slide hopper coating machine, irradiated with ultraviolet rays (wavelength: 365 nm) for 1 minute using a mercury xenon lamp, and then dried at 80 ° C. for 70 minutes. went. As a result, a surface protective layer having a layer thickness of 3.0 μm after drying was formed. In this way, the electrophotographic photosensitive member 102 was produced.
Radical polymerizable compound: 100 parts by mass of the above-exemplified compound M1 Charge transport agent: 43 parts by mass of the above compound CTM-2 Additive: Flamestab NOR116 FF (Compound A1, manufactured by BASF Japan Ltd.)
15 parts by mass Polymerization initiator: Irgacure 819 (Compound PI-1, manufactured by BASF Japan Ltd.)
10 parts by mass Solvent: 2-butanol 160 parts by mass Solvent: 2-methyltetrahydrofuran 160 parts by mass

<< Preparation of electrophotographic photosensitive member 103 >>
In the preparation of the electrophotographic photosensitive member 101, the same applies to the photosensitive layer except that the additive contained in the coating liquid for forming the charge transport layer is changed to BHT (di-tert-butylhydroxytoluene: the above compound C1). Was produced.

(Formation of surface protective layer)
The following components were mixed and stirred to sufficiently dissolve and disperse to prepare a coating liquid for forming a surface protective layer. The prepared coating liquid for forming a surface protective layer is applied onto the photosensitive layer using a circular slide hopper coating machine, irradiated with ultraviolet rays (wavelength: 365 nm) for 1 minute using a mercury xenon lamp, and then dried at 80 ° C. for 70 minutes. went. As a result, a surface protective layer having a layer thickness of 3.0 μm after drying was formed. In this way, the electrophotographic photosensitive member 103 was produced.
Radical polymerizable compound: 100 parts by mass of the above-exemplified compound M1 Tin oxide particles (number average primary particle size: 20 nm) 150 parts by mass Additive: Flamestab NOR116 FF (Compound A1, manufactured by BASF Japan Ltd.)
6 parts by mass Polymerization initiator: Irgacure 819 (Compound PI-1, manufactured by BASF Japan Ltd.)
10 parts by mass Solvent: 2-butanol 160 parts by mass Solvent: 2-methyltetrahydrofuran 160 parts by mass

<< Preparation of electrophotographic photosensitive member 104 >>
In the preparation of the electrophotographic photosensitive member 103, the coating liquid for forming the charge transport layer was prepared in the same manner, and the surface protective layer was prepared as follows.
(Formation of surface protective layer)
The following components were mixed and stirred to sufficiently dissolve and disperse to prepare a coating liquid for forming a surface protective layer. The prepared coating liquid for forming a surface protective layer is applied onto the photosensitive layer using a circular slide hopper coating machine, irradiated with ultraviolet rays (wavelength: 365 nm) for 1 minute using a mercury xenon lamp, and then dried at 80 ° C. for 70 minutes. went. As a result, a surface protective layer having a layer thickness of 3.0 μm after drying was formed. In this way, the electrophotographic photosensitive member 104 was produced.
Radical polymerizable compound: 100 parts by mass of the above-exemplified compound M1 Tin oxide particles (number average primary particle size: 20 nm) 150 parts by mass Charge transporter: 20 parts by mass of the above compound CTM-2 Additive: Flamestab NOR116 FF (the above compound A1, Made by BASF Japan)
6 parts by mass Polymerization initiator: Irgacure 819 (Compound PI-1, manufactured by BASF Japan Ltd.)
10 parts by mass Solvent: 2-butanol 160 parts by mass Solvent: 2-methyltetrahydrofuran 160 parts by mass

<< Preparation of electrophotographic photosensitive member 105-126 >>
In the preparation of the electrophotographic photosensitive member 104, the electrophotographic photosensitive members 105-120 and 122-126 were prepared in the same manner except that the changes were made as described in Table I below.
Further, the electrophotographic photosensitive member 121 did not add the additive Flamestab NOR116 FF (Compound A1, manufactured by BASF Japan Ltd.) when forming the charge transport layer in the production of the electrophotographic photosensitive member 101. It was produced in the same manner except for the above.
In Table I, the polymerization initiator PI-1 is Irgacure 819 (manufactured by BASF Japan), PI-2 is Irgacure TPO (manufactured by BASF Japan), and PI-3 is PBG-304 (Joshu Powerful Electronic New Materials Stock). B-1 is Irgacure OXE01 (manufactured by BASF Japan Ltd.).
In Table I, the amount of the polymerization initiator added indicates the amount (parts by mass) of the polymerization initiator added to the coating liquid for forming the surface protective layer used when forming the surface protective layer.
Further, as shown in Table I, two kinds of polymerization initiators are added to the coating liquids for forming the surface protective layer of the electrophotographic photosensitive members 105-114, 117, 119 and 123-126.
Further, in the electrophotographic photosensitive members 105-116, 118, 119, 122, 123, 126, the inorganic particles shown in Table I are added to the coating liquid for forming the surface protective layer instead of the tin oxide particles which are conductive fine particles. doing.
In addition, Table II shows the types of organic groups (Z) and the number of carbon atoms constituting the amino ether (-NOZ) structure for compounds A1 to A6, which are hindered amine compounds having an amino ether structure contained in the additive. Is shown.

[Evaluation method of photoconductor]
The electrophotographic photosensitive members 101 to 126 produced as described above were evaluated as follows. As an evaluation machine, "bizhub PRESS C1070" manufactured by Konica Minolta Co., Ltd. was used, and each photoconductor was mounted on the evaluation machine for evaluation. In an environment of 23 ° C. and 50% RH, a durability test was conducted in which a character image with an image area ratio of 6% was printed in A4 horizontal feed on both sides of 400,000 sheets in succession, and the following evaluation was performed during or after the durability test. rice field.

(1) Evaluation of memory resistance After the durability test, 10 images in which solid black and solid white are mixed are continuously printed, and then a uniform halftone image (relative reflection density 0.4 with a Macbeth densitometer). ) Is printed, and it is determined whether or not the history of the solid black portion and the solid white portion appears in the halftone image (memory generation) or not (no memory generation).
⊚: No memory generated (good)
◯: The memory can be visually recognized only at the boundary between the solid black part and the solid white part at the time of printing (there is virtually no problem).
X: A clear memory is generated in addition to the boundary between the solid black part and the solid white part at the time of printing (there is a problem in practice).

(2) Evaluation of Abrasion Resistance (α Value) The layer thickness of the layer formed on the conductive support before and after the durability test was measured, and the amount of layer thickness wear was calculated and evaluated.
The layer thickness of the layer formed on the conductive support is measured at 10 random locations in the uniform layer thickness portion (excluding the layer thickness variation portion at the tip and rear ends of the coating by creating a layer thickness profile). Then, it was calculated from the average value.
The layer thickness measuring instrument is an eddy current type layer thickness measuring instrument EDDY560C (manufactured by HELMUT FISCHER GmbH CO), and the layer thickness difference of the photosensitive layer before and after the live-action test is defined as the layer thickness depletion amount. The amount of wear per 100 krot (100,000 rpm) is shown in Table III below as the α value. If it is 0.20 μm or less, it can be said that the level satisfies the standard in the present invention.

(3) Evaluation of image flow After the durability test, 5000 sheets of character images having an image area ratio of 5% were continuously printed in A4 horizontal feed under an environment of 10 ° C. and 15% RH, and then the main power supply of the actual machine was immediately stopped. Immediately after turning on the power 12 hours after stopping and making it possible to print, a halftone image (relative reflection density 0.4 with a Macbeth densitometer) and a 6dot grid image on the entire surface of A3 are displayed on the entire surface of A3 acid-free paper. Printed. The state of the printed image was observed and the following evaluation was performed.
⊚: In the halftone image and the lattice image, a thin band-like density decrease in the long axis direction of the photoconductor is not observed (no image blurring: good).
◯: A thin band-like density decrease in the long axis direction of the photoconductor is observed only in the halftone image (no problem in practical use).
X: In the halftone image and the grid image, a thin band-like density decrease in the long axis direction of the photoconductor was observed (image blurring occurred), and the grid image was defective or the line width was narrowed entirely in the grid image. (There is a problem in practical use).

As shown in Table III, it was found that the electrophotographic photosensitive member of the present invention has excellent memory resistance and abrasion resistance, and it is difficult for the image to flow. On the other hand, the electrophotographic photosensitive member of the comparative example was inferior in any of the items.

100 Image forming apparatus 1Y, 1M, 1C, 1Bk, 200 Electrophotographic photosensitive member 201 Conductive support 202 Intermediate layer 203 Photosensitive layer 203a Charge generation layer 203b Charge transport layer 204 Surface protection layer 205 Conductive fine particles

Claims (7)

An electrophotographic photosensitive member having a plurality of layers including at least a photosensitive layer on a conductive support.
The plurality of layers have a surface protective layer on the surface side of the photosensitive layer.
An electrophotographic photosensitive member , wherein the surface protective layer contains a hindered amine compound having an amino ether structure represented by the following general formula (1).

[In the general formula (1), Y represents an arbitrary structure other than a hydrogen atom. Z represents an organic group. However, Y and Z _{do not have N—CH 3} bond and N—H bond. ] The electrophotographic photosensitive member according to claim 1, wherein the organic group represented by Z in the general formula (1) is an alkyl group having 8 or more carbon atoms or a cycloalkyl group having 4 or more carbon atoms. The first or second aspect of the present invention, wherein the content of the hindered amine compound is in the range of 2 to 15 parts by mass with respect to 100 parts by mass of the binder resin of the layer containing the hindered amine compound. Electrophotographic photosensitive member. The invention according to any one of claims 1 to 3 , wherein the surface protective layer is a cured product of a composition containing the hindered amine compound, a polymerizable compound for a binder, and a charge transporting agent. Electrophotographic photosensitive member. The electrophotographic photosensitive member according to claim 4 , wherein the electrophotographic photosensitive member contains conductive fine particles as the charge transport agent. A method for producing an electrophotographic photosensitive member according to claim 4 or 5, wherein the electrophotographic photosensitive member is produced.
Production of an electrophotographic photosensitive member, which comprises a step of curing a composition containing a polymerization initiator having an acylphosphine oxide structure or an O-acyloxime structure to form the surface protective layer. Method. An image forming apparatus comprising the electrophotographic photosensitive member according to any one of claims 1 to 5.

Images