JP2015102752A - Electrophotographic photoreceptor, process cartridge, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor in which a deterioration in electrical characteristics is suppressed even after repeated use.SOLUTION: There is provided an electrophotographic photoreceptor including a layer composed of a cured film of a composition containing a compound represented by the following general formula (I), where F represents a charge transport sub unit; Rand Reach independently represent a hydrogen atom, alkyl group, alkoxyalkyl group, or aralkyl group; and n represents an integer of 1 or more and 4 or less.

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an image forming apparatus.

An electrophotographic image forming apparatus generally has the following configuration and process.
That is, the surface of the electrophotographic photosensitive member is charged to a predetermined polarity and potential by a charging unit, and the surface of the electrophotographic photosensitive member after charging is selectively neutralized by image exposure to form an electrostatic latent image, The toner is attached to the electrostatic latent image by the developing means, whereby the latent image is developed as a toner image, and the toner image is transferred to a transfer medium by the transfer means, and discharged as an image formed product. .

The following materials have been proposed for the material system of the protective layer (outermost surface layer) of the electrophotographic photosensitive member.
Patent Document 1 proposes an organic-inorganic hybrid material.
Patent Document 2 proposes a cured product of a tri- or higher functional radical polymerizable monomer having no charge transporting structure and a radical polymerizable compound having a charge transporting structure.
Patent Document 3 proposes a method in which a hole transporting compound having two or more chain polymerizable functional groups in the same molecule is polymerized or crosslinked using heat or light.
Patent Documents 4 and 5 propose a radiation cross-linked material composed of a radiation cross-linking agent and a charge transport material.
Patent Documents 6, 7, 8, and 9 propose an acrylate compound containing a radically polymerizable group having a specific branched structure.

  As another aspect of the outermost surface layer of the electrophotographic photosensitive member, for example, Patent Document 10 proposes a conductive powder dispersed in a phenol resin.

JP 2000-019749 A JP 2005-234546 A JP 2000-66424 A Japanese Patent Laid-Open No. 2004-240079 JP 2007-156081 A JP 2006-178285 A JP 2006-316011 A JP 2008-304702 A JP 2007-17933 A Japanese Patent No. 3287678

  An object of the present invention is to provide an electrophotographic photosensitive member in which deterioration of electrical characteristics is suppressed even after repeated use.

The above problem is solved by the following means. That is,
The invention according to claim 1 is an electrophotographic photosensitive member provided with a layer comprising a cured film of a composition containing a compound represented by the following general formula (I).

[In General Formula (I), F represents a charge transporting subunit, R ¹ and R ² each independently represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, or an aralkyl group, and n is 1 or more and 4 The following integers are shown. ]

  The invention according to claim 2 is the electrophotographic photoreceptor according to claim 1, wherein the compound represented by the general formula (I) is a compound represented by the following general formula (II).

[In General Formula (II), Ar ^{1 to} Ar ⁴ each independently represents an aryl group, Ar ⁵ represents an aryl group or an arylene group, and D represents a group represented by General Formula (III). k represents 0 or 1, c1 to c5 each independently represents an integer of 0 or more and 2 or less, and all of c1 to c5 do not simultaneously become 0. The sum of c1 to c5 is an integer of 1 or more and 4 or less.
In general formula (III), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkoxyalkyl group, or an aralkyl group. ]

  A third aspect of the present invention is the electrophotographic photosensitive member according to the first or second aspect, wherein the layer is provided as an outermost surface layer.

  The invention according to claim 4 is the electrophotographic photosensitive member according to any one of claims 1 to 3, wherein the layer further contains a thermal radical generator or a derivative thereof.

  A fifth aspect of the present invention is a process cartridge that includes the electrophotographic photosensitive member according to any one of the first to fourth aspects and is detachable from an image forming apparatus.

  The invention according to claim 6 is the electrophotographic photosensitive member according to any one of claims 1 to 4, charging means for charging the surface of the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member. An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the toner, and a developing means for developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image. And a transfer means for transferring the toner image onto the surface of the recording medium.

According to the invention which concerns on Claim 1, 2, or 3, even if it uses repeatedly, compared with the case where the layer which consists of a cured film of the composition containing the compound (Ref CT-1) used by the comparative example is provided, it is an electrical property. An electrophotographic photosensitive member in which deterioration of the toner is suppressed is obtained.
According to the fourth aspect of the present invention, an electrophotographic photosensitive member can be obtained in which deterioration of electrical characteristics is further suppressed as compared with a case where the layer does not contain a thermal radical generator or a derivative thereof.

  According to the inventions according to claims 5 and 6, it is used repeatedly as compared with the case where an electrophotographic photoreceptor provided with a layer comprising a cured film of a composition containing the compound (Ref CT-1) used in the comparative example is not applied. Even in this case, a process cartridge and an image forming apparatus in which deterioration of image quality is suppressed are provided.

1 is a schematic partial cross-sectional view showing an electrophotographic photosensitive member according to an embodiment. 1 is a schematic partial cross-sectional view showing an electrophotographic photosensitive member according to an embodiment. 1 is a schematic partial cross-sectional view showing an electrophotographic photosensitive member according to an embodiment. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment. It is a schematic block diagram which shows the image forming apparatus which concerns on other embodiment. It is IR spectrum of exemplary compound CTM-27. (A) thru | or (C) are explanatory drawings which respectively show the reference | standard of ghost evaluation.

  Hereinafter, embodiments of the electrophotographic photosensitive member, the process cartridge, and the image forming apparatus of the present invention will be described in detail.

<Electrophotographic photoreceptor>
The electrophotographic photoreceptor according to the exemplary embodiment includes a layer formed of a cured film of a composition containing a compound represented by the following general formula (I) (hereinafter sometimes simply referred to as “specific cured layer”). Electrophotographic photosensitive member.

[Compound represented by formula (I)]
First, the compound represented by the following general formula (I) will be described.
The compound represented by the general formula (I) is a charge transport material since it has a charge transporting subunit, and further has a chain transfer functional group in the molecule. It may be referred to as “material”.

In the general formula (I), F represents a charge transporting subunit, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkoxyalkyl group, or an aralkyl group, and n is 1 or more and 4 The following integers are shown.
Hereinafter, in the general formula (I), a structure other than F (that is, a structure in parentheses) may be referred to as a “polymerizable site” as appropriate.

As a result of detailed studies by the present inventors, the charge transport material having a chain-polymerizable reactive group may deteriorate the charge transport performance of the resulting cured film when the degree of cure, that is, the number of reaction sites is increased. It has become clear.
The cause of this is not necessarily clear, but at this stage, if the number of reaction sites in the charge transport material having a chain-polymerizable reactive group is increased, the charge transport sites (charge transport properties) can be increased when cured (polymerized or crosslinked). This is presumed to be caused by distortion in the subunit.
On the other hand, in the compound represented by the general formula (I) in this embodiment, a site containing a chain polymerizable reactive group (the polymerizable site, a group represented by the general formula (III)) has a charge transport property. A branched structure in which a charge transporting site (charge transporting subunit) is bonded with one bond and a linking group having the one bond is bonded to two chain polymerizable reactive groups. It is what you have. With such a structure, while maintaining a high degree of curing and the number of reactive sites, the presence of the structure of a linking group containing this branched structure makes it possible to form a charge transporting subunit when cured (polymerized or crosslinked). It is considered that a cured film that hardly causes distortion and has both a high degree of curing and excellent charge transport performance can be obtained.
As a result, the layer formed of the cured film of the composition containing the compound represented by the general formula (I) is considered to have excellent mechanical strength and charge transport performance (electrical characteristics).
In addition, Patent Documents 6 to 9 disclose electrophotographic photoreceptors using a compound having a similar branched structure between a chain-polymerizable reactive group and a charge transporting site. In addition, isomers are easily generated, and a charge-transporting group is introduced into the structure responsible for charge-transporting (charge-transporting site) via an oxygen atom with high electronegativity. There is a tendency that the electronic state of the structure responsible for the property changes, and as a result, the charge transporting property is lowered.

The charge transporting subunit represented by F in the general formula (I) may be a subunit derived from a compound having charge transporting performance. Specifically, specifically, a phthalocyanine compound, porphyrin Compounds, azobenzene compounds, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, quinone compounds, fluorenone compounds, etc. Examples include subunits derived from compounds having charge transport performance.
Among these, subunits derived from triarylamine compounds (compounds containing a triarylamine skeleton) that are excellent in terms of charge mobility, oxidation stability, and the like are preferable.

R ¹ and R ² in the general formula (I) each independently represent a hydrogen atom, an alkyl group, an alkoxyalkyl group, or an aralkyl group.
Examples of the alkyl group represented by R ¹ and R ² include a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, and a butyl group. Of these, a methyl group and an ethyl group are preferable from the viewpoint of solubility and compatibility.
Please delete it because it is not realistic.

As the alkoxyalkyl group represented by R ¹ and R ² , —X—O—R ³ (X represents an alkylene group having 1 to 3 carbon atoms, and R ³ represents an alkyl group having 1 to 3 carbon atoms) And an alkoxyalkyl group having 2 to 10 carbon atoms in total. Specific examples of the alkoxyalkyl group include —CH ₂ —O—CH ₃ , —CH ₂ —O—C ₂ H ₅ , —CH ₂ —O—C ₄ H ₉ , — (CH ₂ ) ₂ —O—. CH ₃ , — (CH ₂ ) ₂ —O—C ₂ H ₅ , — (CH ₂ ) ₂ —O—C ₄ H ₉ , — (CH ₂ ) ₃ —O—C ₄ H ₉ may be mentioned. Among these, —CH ₂ —O—CH ₃ and —CH ₂ —O—C ₂ H ₅ are preferable from the viewpoint of reactivity.

The aralkyl group represented by R ¹ and R ² is represented by —Y—Ar (Y represents an alkylene group having 1 to 3 carbon atoms, and Ar represents an aryl group having 6 to 15 carbon atoms). An aralkyl group having 7 to 10 carbon atoms in total is preferable.
Specific examples such aralkyl _{groups, -CH 2 -C 6 H 5,} - (CH 2) 2 -C 6 H 5, -CH 2 -C 6 H 5 -CH 3, - (CH 2) 2 -C ₆ H ₅ —CH ₃ may be mentioned. Among these, —CH ₂ —C ₆ H ₅ and — (CH ₂ ) ₂ —C ₆ H ₅ are preferable from the viewpoint of reactivity and solubility.

R ¹ and R ^{2 in} general formula (I) may be the same or different.
From the viewpoint of ease of production, R ¹ and R ² in parentheses (polymerizable site) in the general formula (I) are either the same or one is a hydrogen atom. It is preferable.
Moreover, when n is 2 or more and 4 or less, all of the plurality of polymerizable sites may be the same or different from each other. Preferably they are the same.

In addition, the polymerizable moiety in the general formula (I) is directly bonded to the aryl group constituting the charge transporting subunit represented by F.
By adopting such a structure, even when it is polyfunctionalized and cured, it is difficult to reduce the charge transport performance of the charge transporting subunit.

In the present embodiment, as a particularly desirable compound represented by the general formula (I), a charge derived from a triarylamine-based compound (compound containing a triarylamine skeleton) as F in the general formula (I). Those having transportable subunits can be mentioned.
Specifically, it is desirable that the compound represented by the general formula (I) is a compound represented by the following general formula (II).

In the general formula (II), Ar ^{1 to} Ar ⁴ each independently represent a substituted or unsubstituted aryl group, Ar ⁵ represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted arylene group, and D Represents a group represented by the general formula (III). k represents 0 or 1, c1 to c5 each independently represents an integer of 0 to 2, and all of c1 to c5 do not simultaneously become 0. The sum total of c1 to c5 is an integer of 1 to 4.
In the general formula (III), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkoxyalkyl group, or an aralkyl group.
^{R 1} and ^{R 2} in the general formula (III) has the same meaning as ^{R 1} and ^{R 2} in Formula (I), preferred examples are also the same preferred combination.
When D is 2 or more and 4 or less, a plurality of groups represented by the general formula (III) may all be the same or different.

In general formula (II), the substituted or unsubstituted aryl groups represented by Ar ^{1 to} Ar ⁴ may be the same or different.
Here, as a substituent in the substituted aryl group, other than “D”, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, Examples thereof include a substituted phenyl group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom.
Ar ^{1 to} Ar ⁴ are preferably any one of the following structural formulas (1) to (7). In addition, the following structural formulas (1) to (7) collectively indicate “— (D) _C1 ” to “— (D) _C4 ” that can be connected to each Ar ^{1 to} Ar ^4. _C ".

In the structural formula (1), R ⁹ is a phenyl group substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. , An unsubstituted phenyl group, and an aralkyl group having 7 to 10 carbon atoms.
In the structural formulas (2) and (3), R ^{10 to} R ¹² are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or 1 or more carbon atoms. 1 type selected from the group consisting of a phenyl group substituted with 4 or less alkoxy groups, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms and a halogen atom. T represents an integer of 1 or more and 3 or less. In the structural formula (7), Ar represents a substituted or unsubstituted arylene group.
Here, as Ar in Formula (7), what is represented by following Structural formula (8) or (9) is desirable.

In the structural formulas (8) and (9), R ¹³ and R ¹⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or 1 or more carbon atoms. 1 represents one selected from the group consisting of a phenyl group substituted with 4 or less alkoxy groups, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom, and t is an integer of 1 to 3 Represents.
In the structural formula (7), Z ′ represents a divalent organic linking group, and is preferably represented by any one of the following structural formulas (10) to (17). S represents 0 or 1 respectively.

In the structural formulas (10) to (17), R ¹⁵ and R ¹⁶ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or 1 or more carbon atoms. 1 represents one selected from the group consisting of a phenyl group substituted with 4 or less alkoxy groups, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom, and W represents a divalent group. , Q and r each independently represents an integer of 1 to 10, and t represents an integer of 1 to 3 respectively.
W in the structural formulas (16) to (17) is preferably any one of divalent groups represented by the following (18) to (26). However, in formula (25), u represents an integer of 0 or more and 3 or less.

Ar ⁵ in the general formula (II) is a substituted or unsubstituted aryl group when k is 0, and examples of the aryl group include the aryl groups exemplified in the description of Ar ^{1 to} Ar ^4. It is done. When k is 1, Ar ⁵ is a substituted or unsubstituted arylene group. The arylene group includes an arylene group obtained by removing one hydrogen atom from the aryl group exemplified in the description of Ar ^{1 to} Ar ^4. Is mentioned.
Further, the substituent in the substituted arylene group is the same as the substituents other than “D” in the substituted aryl group in the description of Ar ^{1 to} Ar ⁴ .

In the general formula (II), c1 to c5 each independently represents an integer of 0 to 2, and all of c1 to c5 do not become 0 at the same time.
Moreover, the sum total of c1 thru | or c5 in general formula (II) is an integer of 1-4. That is, in the compound represented by the general formula (II), the group represented by the general formula (III) represented by “D” is included in the range of 1 or more and 4 or less.

Specific examples of the compound represented by the general formula (I) are shown below. In addition, the compound represented with general formula (I) is not limited at all by these.
In the following specific examples, first, a specific example of the charge transporting subunit (skeleton excluding the polymerizable moiety) represented by F in the general formula (I) and the polymerizable moiety (general formula (III) Specific examples of the group represented) are exemplified. These may be in any combination.
Moreover, it described in Table 1 about the example of these combinations, and this was made into the exemplary compound of the compound represented by general formula (I).
In the following specific examples, “*” means a linking site. Here, in the exemplary compounds described in Table 1, compound No. CTM-1 is a specific example of a charge transporting subunit represented by F (described as “skeleton” in Table 1): (1) -1 and the polymerizable moiety (represented by the general formula (III)) And a specific example of (functional group) in Table 1): (III) -1 and a compound linked by “*”. Specifically, CTM-1 shows the following structure.

Next, a method for synthesizing the compound represented by the general formula (I) will be described.
For the synthesis of the compound represented by the general formula (I), those used for the synthesis and reaction of the following general charge transport materials can be applied. Specifically, the methods listed in the examples can be used.
First, the precursor alcohol compound is condensed with the corresponding methacrylic acid or a halide of methacrylic acid, or when the precursor alcohol compound has a benzyl alcohol structure, a methacrylic acid having a hydroxyl group such as hydroxyethyl methacrylate. It can be synthesized by dehydrating etherification with an acid derivative.

[Layer structure of electrophotographic photosensitive member]
The electrophotographic photoreceptor according to the exemplary embodiment includes a layer (specific cured layer) made of a cured film of a composition containing the compound represented by the general formula (I).
Since the compound represented by the general formula (I) is a compound having a chain-polymerizable reactive group, the specific cured layer is a reaction product obtained by reacting the compound represented by the general formula (I) ( It is a layer containing one or both of a polymer and a crosslinked product.
As described above, since the compound represented by the general formula (I) can form a specific cured layer excellent in both mechanical strength and charge transport performance, an electrophotographic photoreceptor to which the specific cured layer is applied. It is considered that deterioration of electrical characteristics is suppressed even after repeated use, and as a result, stable images can be continuously obtained.
In particular, this specific hardened layer may have high mechanical strength, and is preferably applied to the outermost surface layer of the electrophotographic photosensitive member. As a result, it is considered that stable images can be continuously obtained.

The specific cured layer is composed of a cured film obtained by reacting a composition containing the compound represented by the general formula (I) with energy such as heat, light, or electron beam (polymerization reaction or crosslinking reaction). is there.
That is, the specific hardened layer is prepared by preparing a composition containing the compound represented by the general formula (I) and other components as necessary, and using the composition such as heat, light, and electron beam. It is obtained by polymerizing (curing) with energy.

As content of the reaction product (one or both of a polymer and a crosslinked body) of the compound represented by the general formula (I) in the specific cured layer according to the present embodiment, the charge corresponding to the use of the specific cured layer What is necessary is just to set based on transport performance, Generally, if it sets in the range of 5 mass% or more and 100 mass% or less (desirably 40 mass% or more and 100 mass% or less) in a specific hardened layer. Good.
In addition, in the specific hardened layer according to the present embodiment, in addition to the reaction product of the compound represented by the general formula (I), the compound itself represented by the general formula (I) (unreacted state) is contained. May be.

The specific cured layer in the electrophotographic photoreceptor according to the exemplary embodiment has a functional number of a chain-polymerizable functional group in the compound represented by the general formula (I), that is, the polymerizable site (general formula (III) You may adjust the intensity | strength of a specific hardening layer, without reducing charge transport performance by using together what differs in the number of group represented).
Specifically, the compound represented by the above general formula (I) includes a compound having two or more functional groups and the number of functional groups for the purpose of adjusting the strength of the specific cured layer without reducing the charge transport performance. May be used in combination with a smaller compound.
In the case of such combined use, the content of the compound having 2 or more functional groups is 5% by mass to 95% by mass (preferably 10% by mass to 90% by mass) of the total content of the compound represented by the general formula (I). (Mass% or less) may be set.

  The electrophotographic photoreceptor according to the present embodiment includes the specific cured layer according to the present embodiment, and the specific cured layer may be any of the outermost surface layer and a layer other than the outermost surface layer. As described above, the outermost surface layer is preferable because it is excellent in both mechanical strength and charge transport performance.

Here, the outermost surface layer forms the uppermost surface of the electrophotographic photosensitive member itself, and is desirably provided as a layer functioning as a protective layer or a layer functioning as a charge transport layer.
In the case where the outermost surface layer is a layer functioning as a protective layer, there is a mode in which the photosensitive layer and the outermost surface layer have a protective layer on the conductive substrate, and the protective layer is composed of the specific hardened layer described above. .
On the other hand, when the outermost surface layer is a layer that functions as a charge transport layer, it has a charge generation layer on the conductive substrate and a charge transport layer as the outermost surface layer, and the charge transport layer is composed of the specific hardened layer described above. The form which is made is mentioned.
When the above-mentioned specific hardened layer constitutes a layer other than the outermost surface layer, a protective layer is provided on the photosensitive layer as well as a photosensitive layer including the charge generation layer and the outermost surface layer on the conductive substrate. And the form by which this electric charge transport layer is comprised with the specific hardening layer mentioned above is mentioned.

Hereinafter, the electrophotographic photoreceptor according to the exemplary embodiment in the case where the above-described specific hardened layer is a layer functioning as a protective layer which is the outermost surface layer will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.
FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the electrophotographic photosensitive member according to the embodiment. 2 to 3 are schematic sectional views showing electrophotographic photosensitive members according to other embodiments.

  An electrophotographic photoreceptor 7A shown in FIG. 1 is a so-called function-separated photoreceptor (or laminated photoreceptor), and an undercoat layer 1 is provided on a conductive substrate 4, on which a charge generation layer 2 and a charge are formed. The transport layer 3 and the protective layer 5 have a structure formed sequentially. In the electrophotographic photoreceptor 7 </ b> A, the charge generation layer 2 and the charge transport layer 3 constitute a photosensitive layer.

  The electrophotographic photoreceptor 7B shown in FIG. 2 is a function-separated type photoreceptor in which the functions are separated into the charge generation layer 2 and the charge transport layer 3 like the electrophotographic photoreceptor 7A shown in FIG. Further, the electrophotographic photoreceptor 7C shown in FIG. 3 contains the charge generation material and the charge transport material in the same layer (single layer type photosensitive layer 6 (charge generation / charge transport layer)).

In the electrophotographic photoreceptor 7B shown in FIG. 2, a structure in which an undercoat layer 1 is provided on a conductive substrate 4, and a charge transport layer 3, a charge generation layer 2, and a protective layer 5 are sequentially formed thereon. It is what has. In the electrophotographic photoreceptor 7B, a photosensitive layer is constituted by the charge transport layer 3 and the charge generation layer 2.
Further, the electrophotographic photoreceptor 7C shown in FIG. 3 has a structure in which the undercoat layer 1 is provided on the conductive substrate 4, and the single-layer type photosensitive layer 6 and the protective layer 5 are sequentially formed thereon. It is.

In the electrophotographic photoreceptors 7A to 7C shown in FIGS. 1 to 3, the protective layer 5 is the outermost surface layer disposed on the side farthest from the conductive substrate 2, and the outermost surface layer is It is the structure comprised by the specific hardening layer mentioned above.
In the electrophotographic photoreceptor shown in FIGS. 1 to 3, the undercoat layer 1 may or may not be provided.

  Hereinafter, each element will be described based on the electrophotographic photosensitive member 7A shown in FIG. 1 as a representative example. Note that the reference numerals are omitted.

(Conductive substrate)
Examples of the conductive substrate include metal plates (eg, aluminum, copper, zinc, chromium, nickel, molybdenum, vanadium, indium, gold, platinum, etc.) or alloys (stainless steel, etc.), metal drums, metal belts, etc. Is mentioned. In addition, as the conductive substrate, for example, paper, resin film, belt, etc. coated, vapor-deposited or laminated with a conductive compound (for example, conductive polymer, indium oxide, etc.), metal (for example, aluminum, palladium, gold, etc.) or an alloy, etc. Also mentioned. Here, “conductive” means that the volume resistivity is less than 10 ¹³ Ωcm.

  When the electrophotographic photosensitive member is used in a laser printer, the surface of the conductive substrate has a center line average roughness Ra of 0.04 μm or more and 0.5 μm for the purpose of suppressing interference fringes generated when laser light is irradiated. The surface is preferably roughened below. When non-interfering light is used as a light source, roughening for preventing interference fringes is not particularly required, but it is suitable for extending the life because it suppresses generation of defects due to irregularities on the surface of the conductive substrate.

  As a roughening method, for example, wet honing performed by suspending an abrasive in water and spraying it on a support, centerless grinding in which a conductive substrate is pressed against a rotating grindstone, and grinding is continuously performed, Anodizing treatment etc. are mentioned.

  As a roughening method, without roughening the surface of the conductive substrate, conductive or semiconductive powder is dispersed in the resin to form a layer on the surface of the conductive substrate. The method of roughening by the particle | grains disperse | distributed in a layer is also mentioned.

  In the roughening treatment by anodic oxidation, a metal (for example, aluminum) conductive substrate is used as an anode, and an oxide film is formed on the surface of the conductive substrate by anodizing in an electrolyte solution. Examples of the electrolyte solution include a sulfuric acid solution and an oxalic acid solution. However, the porous anodic oxide film formed by anodic oxidation is chemically active as it is, easily contaminated, and has a large resistance fluctuation due to the environment. Therefore, the pores of the oxide film are blocked by the volume expansion due to the hydration reaction in pressurized water vapor or boiling water (a metal salt such as nickel may be added) against the porous anodic oxide film, and more stable hydration oxidation It is preferable to perform a sealing treatment for changing to a product.

  The thickness of the anodized film is preferably, for example, 0.3 μm or more and 15 μm or less. When this film thickness is within the above range, the barrier property against implantation tends to be exhibited, and the increase in residual potential due to repeated use tends to be suppressed.

The conductive substrate may be treated with an acidic treatment liquid or boehmite treatment.
The treatment with the acidic treatment liquid is performed as follows, for example. First, an acidic treatment liquid containing phosphoric acid, chromic acid and hydrofluoric acid is prepared. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is, for example, in the range of 10% by mass to 11% by mass of phosphoric acid, in the range of 3% by mass to 5% by mass of chromic acid, The concentration of these acids is preferably in the range of 13.5% by mass or more and 18% by mass or less. The treatment temperature is preferably 42 ° C. or higher and 48 ° C. or lower, for example. The film thickness is preferably from 0.3 μm to 15 μm.

  The boehmite treatment is performed, for example, by immersing in pure water of 90 ° C. or higher and 100 ° C. or lower for 5 minutes to 60 minutes, or by contacting with heated steam of 90 ° C. or higher and 120 ° C. or lower for 5 minutes to 60 minutes. The film thickness is preferably 0.1 μm or more and 5 μm or less. This may be further anodized using an electrolyte solution with low film solubility such as adipic acid, boric acid, borate, phosphate, phthalate, maleate, benzoate, tartrate, citrate, etc. Good.

(Undercoat layer)
The undercoat layer is, for example, a layer containing inorganic particles and a binder resin.

Examples of the inorganic particles include inorganic particles having a powder resistance (volume resistivity) of 10 ² Ωcm or more and 10 ¹¹ Ωcm or less.
Among these, as the inorganic particles having the resistance value, for example, metal oxide particles such as tin oxide particles, titanium oxide particles, zinc oxide particles, and zirconium oxide particles are preferable, and zinc oxide particles are particularly preferable.

The specific surface area of the inorganic particles by the BET method is preferably 10 m ² / g or more, for example.
The volume average particle diameter of the inorganic particles is, for example, preferably from 50 nm to 2000 nm (preferably from 60 nm to 1000 nm).

  For example, the content of the inorganic particles is preferably 10% by mass or more and 80% by mass or less, and more preferably 40% by mass or more and 80% by mass or less with respect to the binder resin.

  The inorganic particles may be subjected to a surface treatment. Two or more inorganic particles having different surface treatments or particles having different particle diameters may be mixed and used.

  Examples of the surface treatment agent include a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, and a surfactant. In particular, a silane coupling agent is preferable, and a silane coupling agent having an amino group is preferable.

  Examples of the silane coupling agent having an amino group include 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, and N-2- (aminoethyl) -3-amino. Examples include, but are not limited to, propylmethyldimethoxysilane, N, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, and the like.

  Two or more silane coupling agents may be used in combination. For example, a silane coupling agent having an amino group and another silane coupling agent may be used in combination. Other silane coupling agents include, for example, vinyltrimethoxysilane, 3-methacryloxypropyl-tris (2-methoxyethoxy) silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycol. Sidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- ( Aminoethyl) -3-aminopropylmethyldimethoxysilane, N, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, and the like, but are not limited thereto. It is not a thing.

  The surface treatment method using the surface treatment agent may be any method as long as it is a known method, and may be either a dry method or a wet method.

  The treatment amount of the surface treatment agent is preferably 0.5% by mass or more and 10% by mass or less with respect to the inorganic particles, for example.

  Here, the undercoat layer may contain an electron-accepting compound (acceptor compound) together with the inorganic particles from the viewpoint of enhancing the long-term stability of the electric characteristics and the carrier blocking property.

Examples of the electron accepting compound include quinone compounds such as chloranil and bromoanil; tetracyanoquinodimethane compounds; 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, and the like. 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4- Oxadiazole compounds such as oxadiazole and 2,5-bis (4-diethylaminophenyl) -1,3,4 oxadiazole; xanthone compounds; thiophene compounds; 3,3 ′, 5,5 ′ tetra- electron transporting substances such as diphenoquinone compounds such as t-butyldiphenoquinone;
In particular, the electron-accepting compound is preferably a compound having an anthraquinone structure. As the compound having an anthraquinone structure, for example, a hydroxyanthraquinone compound, an aminoanthraquinone compound, an aminohydroxyanthraquinone compound, and the like are preferable, and specifically, for example, anthraquinone, alizarin, quinizarin, anthralfin, and purpurin are preferable.

  The electron-accepting compound may be dispersed and included in the undercoat layer together with the inorganic particles, or may be included in a state of being attached to the surface of the inorganic particles.

  Examples of the method for attaching the electron accepting compound to the surface of the inorganic particles include a dry method or a wet method.

  In the dry method, for example, while stirring inorganic particles with a mixer having a large shearing force or the like, an electron-accepting compound dissolved directly or in an organic solvent is dropped and sprayed with dry air or nitrogen gas. It is a method of adhering to the surface of inorganic particles. When the electron-accepting compound is dropped or sprayed, it is preferably performed at a temperature not higher than the boiling point of the solvent. After dropping or spraying the electron-accepting compound, baking may be performed at 100 ° C. or higher. The baking is not particularly limited as long as it is a temperature and time for obtaining electrophotographic characteristics.

  In the wet method, for example, an electron-accepting compound is added while dispersing inorganic particles in a solvent by stirring, ultrasonic waves, a sand mill, an attritor, a ball mill, etc., and after stirring or dispersing, the solvent is removed to remove electrons. This is a method of attaching a receptive compound to the surface of inorganic particles. The solvent removal method is distilled off by filtration or distillation, for example. After removing the solvent, baking may be performed at 100 ° C. or higher. The baking is not particularly limited as long as it is a temperature and time for obtaining electrophotographic characteristics. In the wet method, the water content of the inorganic particles may be removed before adding the electron-accepting compound. Examples thereof include a method of removing while stirring and heating in a solvent, and a method of removing by azeotropic distillation with a solvent. Can be mentioned.

  The attachment of the electron-accepting compound may be performed before or after the surface treatment with the surface treatment agent is performed on the inorganic particles, or may be performed simultaneously with the attachment of the electron-accepting compound and the surface treatment with the surface treatment agent.

  The content of the electron-accepting compound is, for example, from 0.01% by mass to 20% by mass with respect to the inorganic particles, and preferably from 0.01% by mass to 10% by mass.

Examples of the binder resin used for the undercoat layer include acetal resins (eg, polyvinyl butyral), polyvinyl alcohol resins, polyvinyl acetal resins, casein resins, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, and unsaturated polyesters. Resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, urea resin, phenol resin, phenol-formaldehyde resin, melamine resin, Known polymer compounds such as urethane resin, alkyd resin, epoxy resin; zirconium chelate compound; titanium chelate compound; aluminum chelate compound; titanium alkoxide compound ; Organic titanium compounds; known materials silane coupling agent, and the like.
Examples of the binder resin used for the undercoat layer include a charge transport resin having a charge transport group, a conductive resin (for example, polyaniline) and the like.

Among these, as the binder resin used for the undercoat layer, a resin insoluble in the upper coating solvent is preferable, and in particular, a urea resin, a phenol resin, a phenol-formaldehyde resin, a melamine resin, a urethane resin, and an unsaturated polyester. Thermosetting resins such as resins, alkyd resins, and epoxy resins; at least one resin selected from the group consisting of polyamide resins, polyester resins, polyether resins, methacrylic resins, acrylic resins, polyvinyl alcohol resins, and polyvinyl acetal resins; Resins obtained by reaction with curing agents are preferred.
When these binder resins are used in combination of two or more, the mixing ratio is set as necessary.

The undercoat layer may contain various additives for improving electrical characteristics, improving environmental stability, and improving image quality.
Additives include known materials such as electron transport pigments such as polycyclic condensation systems and azo systems, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, and silane coupling agents. It is done. The silane coupling agent is used for the surface treatment of the inorganic particles as described above, but may be further added to the undercoat layer as an additive.

  Examples of the silane coupling agent as the additive include vinyltrimethoxysilane, 3-methacryloxypropyl-tris (2-methoxyethoxy) silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3- Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (Aminoethyl) -3-aminopropylmethylmethoxysilane, N, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, 3-chloropropyltrimethoxysilane and the like can be mentioned.

  Examples of the zirconium chelate compound include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, Zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of the titanium chelate compound include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, and titanium lactate ammonium salt. , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  These additives may be used alone or as a mixture or polycondensate of a plurality of compounds.

The undercoat layer preferably has a Vickers hardness of 35 or more.
The surface roughness (ten-point average roughness) of the undercoat layer is adjusted from 1 / 4n (n is the refractive index of the upper layer) to 1 / 2λ of the exposure laser wavelength λ used to suppress moire images. It should be done.
Resin particles or the like may be added to the undercoat layer for adjusting the surface roughness. Examples of the resin particles include silicone resin particles and cross-linked polymethyl methacrylate resin particles. Further, the surface of the undercoat layer may be polished for adjusting the surface roughness. Examples of the polishing method include buffing, sandblasting, wet honing, and grinding.

  There is no particular limitation on the formation of the undercoat layer, and a well-known formation method is used. For example, a coating film for forming an undercoat layer in which the above components are added to a solvent is formed, and the coating film is dried. And heating as necessary.

Solvents for preparing the coating solution for forming the undercoat layer include known organic solvents such as alcohol solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, ketone solvents, ketone alcohol solvents, ether solvents. Examples include solvents and ester solvents.
Specific examples of these solvents include methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, Examples include ordinary organic solvents such as n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene.

  Examples of the dispersion method of the inorganic particles when preparing the coating liquid for forming the undercoat layer include known methods such as a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker.

  Examples of the method for applying the coating liquid for forming the undercoat layer onto the conductive substrate include, for example, a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method. The usual methods, such as these, are mentioned.

  The thickness of the undercoat layer is, for example, preferably set in the range of 15 μm or more, more preferably 20 μm or more and 50 μm or less.

(Middle layer)
Although illustration is omitted, an intermediate layer may be further provided between the undercoat layer and the photosensitive layer.
An intermediate | middle layer is a layer containing resin, for example. Examples of the resin used for the intermediate layer include an acetal resin (for example, polyvinyl butyral), polyvinyl alcohol resin, polyvinyl acetal resin, casein resin, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, Polymer compounds such as polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin, and the like can be given.
The intermediate layer may be a layer containing an organometallic compound. Examples of the organometallic compound used for the intermediate layer include organometallic compounds containing metal atoms such as zirconium, titanium, aluminum, manganese, and silicon.
The compounds used for these intermediate layers may be used alone or as a mixture or polycondensate of a plurality of compounds.

  Among these, the intermediate layer is preferably a layer containing an organometallic compound containing a zirconium atom or a silicon atom.

The formation of the intermediate layer is not particularly limited, and a well-known formation method is used. For example, a coating film of an intermediate layer forming coating solution in which the above components are added to a solvent is formed, and the coating film is dried and necessary. It is performed by heating according to.
As the coating method for forming the intermediate layer, usual methods such as a dip coating method, a push-up coating method, a wire bar coating method, a spray coating method, a blade coating method, a knife coating method, and a curtain coating method are used.

  For example, the thickness of the intermediate layer is preferably set in a range of 0.1 μm to 3 μm. An intermediate layer may be used as the undercoat layer.

(Charge generation layer)
The charge generation layer is, for example, a layer containing a charge generation material and a binder resin. The charge generation layer may be a vapor deposition layer of a charge generation material. The vapor-deposited layer of the charge generation material is suitable when an incoherent light source such as an LED (Light Emitting Diode) or an organic EL (Electro-Luminescence) image array is used.

  Examples of the charge generating material include azo pigments such as bisazo and trisazo; fused aromatic pigments such as dibromoanthanthrone; perylene pigments; pyrrolopyrrole pigments; phthalocyanine pigments; zinc oxide;

  Among these, in order to cope with near-infrared laser exposure, it is preferable to use a metal phthalocyanine pigment or a metal-free phthalocyanine pigment as the charge generation material. Specifically, for example, hydroxygallium phthalocyanine disclosed in JP-A-5-263007, JP-A-5-279591, etc .; chlorogallium phthalocyanine disclosed in JP-A-5-98181; More preferred are dichlorotin phthalocyanines disclosed in JP-A No. 140472, JP-A No. 5-140473 and the like; and titanyl phthalocyanine disclosed in JP-A No. 4-189873.

  On the other hand, in order to cope with laser exposure in the near-ultraviolet region, as the charge generation material, condensed aromatic pigments such as dibromoanthanthrone; thioindigo pigments; porphyrazine compounds; zinc oxide; trigonal selenium; Bisazo pigments and the like disclosed in 2004-78147 and JP-A-2005-181992 are preferred.

  The above-described charge generation material may also be used in the case of using an incoherent light source such as an LED having a central wavelength of light emission of 450 nm to 780 nm and an organic EL image array. However, from the viewpoint of resolution, the photosensitive layer is 20 μm or less. When the thin film is used, the electric field strength in the photosensitive layer is increased, and a charge reduction due to charge injection from the base material, so-called image defects called black spots are likely to occur. This becomes conspicuous when a charge generating material that easily generates a dark current is used in a p-type semiconductor such as trigonal selenium or a phthalocyanine pigment.

On the other hand, when an n-type semiconductor such as a condensed ring aromatic pigment, perylene pigment, azo pigment or the like is used as the charge generation material, dark current hardly occurs and even a thin film can suppress image defects called black spots. . Examples of the n-type charge generation material include compounds (CG-1) to (CG-27) described in paragraphs [0288] to [0291] of JP2012-155282A. It is not limited.
The n-type determination is performed by using a time-of-flight method that is usually used, and is determined by the polarity of the flowing photocurrent, and an n-type is more likely to flow electrons as carriers than holes.

The binder resin used for the charge generation layer is selected from a wide range of insulating resins, and the binder resin is selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinyl anthracene, polyvinyl pyrene, and polysilane. You may choose.
As the binder resin, for example, polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol and aromatic divalent carboxylic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, Examples thereof include polyamide resin, acrylic resin, polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, and the like. Here, “insulating” means that the volume resistivity is 10 ¹³ Ωcm or more.
These binder resins are used singly or in combination of two or more.

  The mixing ratio of the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10 by mass ratio.

  In addition, the charge generation layer may contain a known additive.

  The formation of the charge generation layer is not particularly limited, and a known formation method is used. For example, a coating film of a charge generation layer forming coating solution in which the above components are added to a solvent is formed, and the coating film is dried. And heating as necessary. The charge generation layer may be formed by vapor deposition of a charge generation material. Formation of the charge generation layer by vapor deposition is particularly suitable when a condensed ring aromatic pigment or perylene pigment is used as the charge generation material.

  Solvents for preparing the charge generation layer forming coating solution include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-acetate. -Butyl, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene and the like. These solvents are used alone or in combination of two or more.

Examples of a method for dispersing particles (for example, a charge generation material) in a coating solution for forming a charge generation layer include, for example, a media disperser such as a ball mill, a vibrating ball mill, an attritor, a sand mill, a horizontal sand mill, a stirring, an ultrasonic disperser, etc. Medialess dispersers such as roll mills and high-pressure homogenizers are used. Examples of the high-pressure homogenizer include a collision method in which a dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision in a high pressure state, and a penetration method in which a fine flow path is dispersed in a high pressure state.
In this dispersion, it is effective that the average particle size of the charge generation material in the coating solution for forming the charge generation layer is 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less. .

  Examples of methods for applying the charge generation layer forming coating solution on the undercoat layer (or on the intermediate layer) include blade coating, wire bar coating, spray coating, dip coating, bead coating, and air knife coating. And usual methods such as a curtain coating method.

  The film thickness of the charge generation layer is, for example, preferably set in the range of 0.1 μm to 5.0 μm, more preferably 0.2 μm to 2.0 μm.

(Charge transport layer)
The charge transport layer is, for example, a layer containing a charge transport material and a binder resin. The charge transport layer may be a layer containing a polymer charge transport material.

  Examples of charge transport materials include quinone compounds such as p-benzoquinone, chloranil, bromanyl and anthraquinone; tetracyanoquinodimethane compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone; xanthone compounds; benzophenone compounds A cyanovinyl compound; an electron transporting compound such as an ethylene compound; Examples of the charge transporting material include hole transporting compounds such as triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, and hydrazone compounds. These charge transport materials may be used alone or in combination of two or more, but are not limited thereto.

  As the charge transport material, from the viewpoint of charge mobility, a triarylamine derivative represented by the following structural formula (a-1) and a benzidine derivative represented by the following structural formula (a-2) are preferable.

In Structural Formula (a-1), Ar ^T1 , Ar ^T2 , and Ar ^T3 are each independently a substituted or unsubstituted aryl group, —C ₆ H ₄ —C (R ^T4 ) ═C (R ^T5 ) (R ^T6), or _{-C 6 H 4 -CH = CH-} CH = C (R T7) shows the ^{(R T8).} R ^T4 , R ^T5 , R ^T6 , R ^T7 , and R ^T8 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.
Examples of the substituent for each group include a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. Examples of the substituent of each group also include a substituted amino group substituted with an alkyl group having 1 to 3 carbon atoms.

In Structural Formula (a-2), R ^T91 and R ^T92 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. R ^T101 , R ^T102 , R ^T111 and R ^T112 are each independently ^substituted with a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 2 carbon atoms. A substituted amino group, a substituted or unsubstituted aryl group, —C (R ^T12 ) ═C (R ^T13 ) (R ^T14 ), or —CH═CH— ^CH═C (R ^T15 ) (R ^T16 ), R ^T12 , R ^T13 , R ^T14 , R ^T15 and R ^T16 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Tm1, Tm2, Tn1, and Tn2 each independently represent an integer of 0 or more and 2 or less.
Examples of the substituent for each group include a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. Examples of the substituent of each group also include a substituted amino group substituted with an alkyl group having 1 to 3 carbon atoms.

Here, among the triarylamine derivative represented by the structural formula (a-1) and the benzidine derivative represented by the structural formula (a-2), in particular, “—C ₆ H ₄ —CH═CH—CH═ Triarylamine derivatives having “C (R ^T7 ) (R ^T8 )” and benzidine derivatives having “—CH═CH— ^CH═C (R ^T15 ) (R ^T16 )” are preferable from the viewpoint of charge mobility.

  As the polymer charge transporting material, known materials having charge transporting properties such as poly-N-vinylcarbazole and polysilane are used. In particular, polyester-based polymer charge transport materials disclosed in JP-A-8-176293, JP-A-8-208820 and the like are particularly preferable. The polymer charge transport material may be used alone or in combination with a binder resin.

The binder resin used for the charge transport layer is polycarbonate resin, polyester resin, polyarylate resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, Vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N -Vinylcarbazole, polysilane, etc. are mentioned. Among these, as the binder resin, a polycarbonate resin or a polyarylate resin is preferable. These binder resins are used alone or in combination of two or more.
The mixing ratio of the charge transport material and the binder resin is preferably 10: 1 to 1: 5 by mass ratio.

  In addition, the charge transport layer may contain a known additive.

  The formation of the charge transport layer is not particularly limited, and a known formation method is used. For example, a coating film of a charge transport layer forming coating solution in which the above components are added to a solvent is formed, and the coating film is dried. This is done by heating as necessary.

  Solvents for preparing the coating solution for forming the charge transport layer include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene; ketones such as acetone and 2-butanone; methylene chloride, chloroform and ethylene chloride. Halogenated aliphatic hydrocarbons: Usual organic solvents such as cyclic or linear ethers such as tetrahydrofuran and ethyl ether. These solvents are used alone or in combination of two or more.

  Coating methods for applying the charge transport layer forming coating solution on the charge generation layer include blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain A usual method such as a coating method may be mentioned.

  The thickness of the charge transport layer is, for example, preferably set in the range of 5 μm to 50 μm, more preferably 10 μm to 30 μm.

(Protective layer)
The protective layer is obtained by applying the above-described specific hardened layer, and is obtained using the compound represented by the general formula (I).
In forming this protective layer, a composition containing the compound represented by formula (I) is used as a protective layer-forming coating solution.
The total content of the compound represented by the general formula (I) in the coating solution for forming the protective layer is preferably, for example, 40% by mass or more with respect to the total solid content excluding the solvent of the coating solution for forming the protective layer. More preferably, it is 50% by mass or more, and still more preferably 60% by mass or more.
By setting it as this range, it is excellent in an electrical property and the thickening of a cured film is implement | achieved.

Moreover, in this embodiment, you may use together the compound represented with general formula (I), and the well-known charge transport material (non-reactive charge transport material) which does not have a reactive group. A known charge transport material that does not have a reactive group is effective because it does not have a reactive group that does not carry charge transport, and therefore increases the component concentration of the charge transport material and further improves electrical characteristics.
As this known charge transporting material, those mentioned as the charge transporting material constituting the above-mentioned charge transporting layer are used.

  When the compound represented by the general formula (I) and a known charge transport material (non-reactive charge transport material) are used in combination, the compound represented by the general formula (I) in the total charge transport material is 50% by mass or more. It is desirable that it is contained, and it is more desirable that it is contained by 60% by mass or more.

  Furthermore, in the present embodiment, the compound represented by the general formula (I) and the compound represented by the general formula (I) are within a range that does not hinder the expression of the effect of the compound represented by the general formula (I). A known charge transport material having a reactive group other than the compound may be used in combination.

Hereinafter, other components contained in the coating liquid for forming the protective layer will be described.
The charge transporting composition used for forming the protective layer may contain the following surfactant from the viewpoint of ensuring film forming properties.

Examples of the surfactant include (A) a structure formed by polymerizing an acrylic monomer having a fluorine atom, (B) a structure having a carbon-carbon double bond and a fluorine atom, (C) an alkylene oxide structure, and (D) carbon. -A surfactant containing in the molecule thereof one or more types of structures having a carbon triple bond and a hydroxyl group.
This surfactant needs to contain 1 or more types of the structure of (A) thru | or (D) in the molecule | numerator, and may contain 2 or more types.

  Hereinafter, the structures (A) to (D) and the surfactant having the structure will be described.

(A) Structure formed by polymerizing an acrylic monomer having a fluorine atom (A) The structure formed by polymerizing an acrylic monomer having a fluorine atom is not particularly limited, but an acrylic monomer having a fluoroalkyl group is polymerized. The structure is preferably a structure obtained by polymerizing an acrylic monomer having a perfluoroalkyl group.

  Specific examples of the surfactant having the structure (A) include Polyflow KL-600 (manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF-351, EF-352, EF-801, EF-802, and EF- 601 (manufactured by JEMCO).

(B) Structure having a carbon-carbon double bond and a fluorine atom (B) The structure having a carbon-carbon double bond and a fluorine atom is not particularly limited, but in the following structural formulas (B1) and (B2) It is desirable that the group be at least one of them.

As the surfactant having the structure (B), a compound having a group represented by at least one of the structural formulas (B1) and (B2) in the side chain of the acrylic polymer, or the following structural formulas (B3) to (B3) to The compound represented by any one of (B5) is desirable.
When the surfactant having the structure (B) is a compound having at least one of the structural formulas (B1) and (B2) in the side chain of the acrylic polymer, the acrylic structure and the other components in the composition A uniform outermost surface layer can be formed because of the familiarity.
In addition, when the surfactant having the structure (B) is a compound represented by any one of the structural formulas (B3) to (B5), it tends to prevent repelling during coating. Defects can be suppressed.

In the structural formulas (B3) to (B5), v and w each independently represent an integer of 1 or more, R ′ represents a hydrogen atom or a monovalent organic group, and Rf each independently represents a structural formula (B1). Or represents the group shown by (B2).
In the structural formulas (B3) to (B5), examples of the monovalent organic group represented by R ′ include an alkyl group having 1 to 30 carbon atoms or a hydroxyalkyl group having 1 to 30 carbon atoms.

The following are mentioned as a commercial item of surfactant which has the structure of (B).
For example, as a compound represented by any one of structural formulas (B3) to (B5), the following are possible: 100, 100C, 110, 140A, 150, 150CH, AK, 501, 250, 251, 222F, FTX-218, 300, 310, 400 SW, 212M, 245M, 290M, FTX-207S, FTX-211S, FTX-220S, FTX-230S, FTX-209F, FTX-213F, FTX-222F, FTX-233F, FTX-245F, FTX- 208G, FTX-218G, FTX-230G, FTX-240G, FTX-204D, FTX-280D, FTX-212D, FTX-216D, FTX-218D, FTX-220D, FTX-222D (manufactured by Neos), etc. .
Moreover, as a compound which has at least one of Structural formula (B1) and (B2) in the side chain of an acrylic polymer, KB-L82, KB-L85, KB-L97, KB-L109, KB-L110, KB-F2L , KB-F2M, KB-F2S, KB-F3M, KB-FaM (manufactured by Neos), and the like.

-(C) alkylene oxide structure (C) As an alkylene oxide structure, an alkylene oxide and a polyalkylene oxide are included. Specific examples of the alkylene oxide include ethylene oxide and propylene oxide, and the alkylene oxide may be a polyalkylene oxide having a repeating number of 2 to 10,000.
Examples of the surfactant (C) having an alkylene oxide structure include polyethylene glycol, polyether antifoaming agent, and polyether-modified silicone oil.
The polyethylene glycol preferably has an average molecular weight of 2000 or less, and the polyethylene glycol having an average molecular weight of 2000 or less includes polyethylene glycol 2000 (average molecular weight 2000), polyethylene glycol 600 (average molecular weight 600), polyethylene glycol 400 (average molecular weight). 400), polyethylene glycol 200 (average molecular weight 200), and the like.
In addition, PE-M, PE-L (above, manufactured by Wako Pure Chemical Industries, Ltd.), antifoam No. 1. Antifoaming agent No. 1 Polyether antifoaming agents such as 5 (above, manufactured by Kao Corporation) are also suitable examples.

(C) As the surfactant containing a fluorine atom in the molecule in addition to the alkylene oxide structure, those having an alkylene oxide or polyalkylene oxide in the side chain of the polymer having a fluorine atom, and alkylene oxide or polyalkylene oxide Examples thereof include those in which the terminal is substituted with a substituent containing a fluorine atom.
(C) Specifically, as a surfactant containing a fluorine atom in the molecule in addition to the alkylene oxide structure, for example, MegaFac F-443, F-444, F-445, F-446 (above, manufactured by DIC Corporation) ), 250, 251, 222F (manufactured by Neos), POLY FOX PF636, PF6320, PF6520, PF656 (manufactured by Kitamura Chemical Co., Ltd.).

  (C) Specific examples of the surfactant containing a silicone structure in the molecule in addition to the alkylene oxide structure include KF351 (A), KF352 (A), KF353 (A), KF354 (A), KF355 (A ), KF615 (A), KF618, KF945 (A), KF6004 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), TSF4440, TSF4445, TSF4450, TSF4446, TSF4452, TSF4453, TSF4460 (above, Momentive Performance Materials Japan) BYK-300, 302, 306, 307, 310, 315, 320, 322, 323, 325, 330, 331, 333, 337, 341, 344, 345, 346, 347, 348, 370, 375, 377 , 378, UV3500, V3510, UV3570, etc. (manufactured by BYK Japan KK), and the like.

-(D) Structure having a carbon-carbon triple bond and a hydroxyl group (D) The structure having a carbon-carbon triple bond and a hydroxyl group is not particularly limited, and examples of the surfactant having this structure include the following compounds. It is done.
(D) Examples of the surfactant having a structure having a carbon-carbon triple bond and a hydroxyl group include compounds having a triple bond and a hydroxyl group in the molecule. Specifically, for example, 2-propyn-1-ol, 1-butyn-3-ol, 2-butyn-1-ol, 3-butyn-1-ol, 1-pentyn-3-ol, 2-pentyn-1-ol, 3-pentyn-1-ol, 4- Pentyn-1-ol, 4-pentyn-2-ol, 1-hexyn-3-ol, 2-hexyn-1-ol, 3-hexyn-1-ol, 5-hexyn-1-ol, 5-hexyne- 3-ol, 1-heptin-3-ol, 2-heptin-1-ol, 3-heptin-1-ol, 4-heptin-2-ol, 5-heptin-3-ol, 1-octin-3- All, 1-o Chin-3-ol, 3-octyn-1-ol, 3-nonin-1-ol, 2-decyn-1-ol, 3-decyn-1-ol, 10-undecin-1-ol, 3-methyl- 1-butyn-3-ol, 3-methyl-1-penten-4-in-3-ol, 3-methyl-1-pentyn-3-ol, 5-methyl-1-hexyn-3-ol, 3- Ethyl-1-pentyn-3-ol, 3-ethyl-1-heptin-3-ol, 4-ethyl-1-octin-3-ol, 3,4-dimethyl-1-pentyn-3-ol, 3, 5-dimethyl-1-hexyn-3-ol, 3,6-dimethyl-1-heptin-3-ol, 2,2,8,8-tetramethyl-3,6-nonadiin-5-ol, 4,6 -Nonadecadiin-1-ol, 10,12-pe Tacosadin-1-ol, 2-butyne-1,4-diol, 3-hexyne-2,5-diol, 2,4-hexadiyne-1,6-diol, 2,5-dimethyl-3-hexyne-2, 5-diol, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, (+)-1,6-bis (2-Chlorophenyl) -1,6-diphenyl-2,4-hexadiyne-1,6-diol, (-)-1,6-bis (2-chlorophenyl) -1,6-diphenyl-2,4-hexadiyne -1,6-diol, 2-butyne-1,4-diol bis (2-hydroxyethyl), 1,4-diacetoxy-2-butyne, 4-diethylamino-2-butyn-1-ol, 1,1- Diphenyl-2-propyne 1-ol, 1-ethynyl-1-cyclohexanol, 9-ethynyl-9-fluorenol, 2,4-hexadiindiyl-1,6-bis (4-phenylazobenzenesulfonate), 2-hydroxy-3- Butyric acid, 2-hydroxy-3-butynoic acid ethyl ester, 2-methyl-4-phenyl-3-butyn-2-ol, methylpropargyl ether, 5-phenyl-4-pentyn-1-ol, 1- Examples include phenyl-1-propyn-3-ol, 1-phenyl-2-propyne-1-ol, 4-trimethylsilyl-3-butyn-2-ol, and 3-trimethylsilyl-2-propyn-1-ol.
Moreover, the compound (For example, Surfynol 400 series (made by Shin-Etsu Chemical Co., Ltd.)) etc. which alkylene oxides, such as ethylene oxide, added to a part or all of the hydroxyl group of said compound are mentioned.

  (D) As the surfactant having a structure having a carbon-carbon triple bond and a hydroxyl group, a compound represented by any one of the following general formulas (D1) and (D2) is desirable.

In the general formulas (D1) and (D2), R ^a , R ^b , R ^c , and R ^d each independently represent a monovalent organic group, and x, y, and z are each independently An integer of 1 or more is shown.
Among the compounds represented by the general formula (D1) or (D2), those in which R ^a , R ^b , R ^c and R ^d are alkyl groups are preferable. More preferably, at least one of R ^a and R ^b and at least one of R ^c and R ^d are branched alkyl groups. Furthermore, z is preferably 1 or more and 10 or less. x and y are each preferably 1 or more and 500 or less.

  Surfinol 400 series (made by Shin-Etsu Chemical Co., Ltd.) is mentioned as a commercial item of the compound shown by general formula (D1) or (D2).

  The surfactants having the structures (A) to (D) described above may be used singly or in combination of two or more. In the case of using a mixture of a plurality of types, a surfactant having a structure different from the surfactant having the structure of (A) to (D) may be used in combination as long as the effect is not impaired.

Examples of the surfactant that can be used in combination include the following surfactants having a fluorine atom and surfactants having a silicone structure.
That is, as the surfactant having a fluorine atom that can be used in combination with the surfactant having the structure of (A) to (D), perfluoroalkylsulfonic acid (for example, perfluorobutanesulfonic acid, perfluorooctanesulfonic acid, etc.) ), Perfluoroalkyl carboxylic acids (for example, perfluorobutane carboxylic acid, perfluoro octane carboxylic acid, etc.), and perfluoroalkyl group-containing phosphate esters. Perfluoroalkylsulfonic acids and perfluoroalkylcarboxylic acids may be salts thereof and amide-modified products thereof.
Examples of commercially available perfluoroalkyl sulfonic acids include Megafac F-114 (manufactured by DIC), F-top EF-101, EF102, EF-103, EF-104, EF-105, EF-112, and EF-. 121, EF-122A, EF-122B, EF-122C, EF-123A (above, manufactured by JEMCO), FT 100, 100C, 110, 140A, 150, 150CH, AK, 501 (above, made by Neos) ) And the like.
Examples of commercially available perfluoroalkyl carboxylic acids include Megafac F-410 (manufactured by DIC), F-top EF-201, EF-204 (manufactured by JEMCO).
Commercial products of perfluoroalkyl group-containing phosphates include MegaFac F-493, F-494 (above, manufactured by DIC), EFTOP EF-123A, EF-123B, EF-125M, EF-132, (above , Manufactured by JEMCO).

  In addition, the surfactant having a fluorine atom that can be used in combination with the surfactant having the structure of (A) to (D) is not limited to the above, and for example, a fluorine atom-containing betaine structure compound (for example, Factent 400SW, Neos) and surfactants having amphoteric ion groups (for example, Footent SW (manufactured by Neos)) are also preferably used.

  Examples of the surfactant having a silicone structure that can be used in combination with the surfactant having the structure of (A) to (D) include general silicone oils such as dimethyl silicone, methylphenyl silicone, diphenyl silicone, and derivatives thereof. Can be mentioned.

The content of the surfactant is desirably 0.01% by mass or more and 1% by mass or less, more desirably 0.02% by mass or more and 0.000% by mass or more with respect to the charge transporting composition (total solid content excluding the solvent). 5% by mass or less. When the content of the surfactant is less than 0.01% by mass, the coating film defect preventing effect tends to be insufficient. Further, when the content of the surfactant exceeds 1% by mass, the strength of the cured film obtained by separation of the surfactant and the curing component (a compound represented by the general formula (I), other monomers, oligomers, etc.) is obtained. Tend to decrease.
Further, the surfactant having the structure of (A) to (D) is preferably contained in an amount of 1% by mass or more, more preferably 10% by mass or more.

To the coating solution for forming the protective layer, radical polymerizable monomers and oligomers that do not have charge transport performance are added for the purpose of controlling the viscosity, film strength, elasticity, smoothness, and cleaning properties of the coating solution. May be.
Examples of the monofunctional radical polymerizable monomer include isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, lauryl acrylate, stearyl acrylate, isobornyl acrylate, cyclohexyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, ethyl carbitol acrylate, phenoxyethyl acrylate, 2-hydroxy acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, methoxypolyethylene glycol acrylate, methoxypolyethylene glycol methacrylate , Phenoxypolyethyleneglycol Lumpur acrylate, phenoxy polyethylene glycol methacrylate, hydroxyethyl o- phenylphenol acrylate, and the like o- phenylphenol glycidyl ether acrylate.

  Examples of the bifunctional radical polymerizable monomer include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 2-n-butyl-2-ethyl- 1,3-propanediol diacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, dioxane glycol diacrylate, polytetramethylene glycol diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, tricyclodecane Examples include methanol diacrylate and tricyclodecane methanol dimethacrylate.

  Examples of the tri- or more functional radical polymerizable monomer include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol acrylate, trimethylolpropane EO-added triacrylate, glycerin PO-added triacrylate, and trisacryloyloxyethylphosphine. Fate, pentaerythritol tetraacrylate, ethoxylated isocyanuric triacrylate.

  Moreover, as a radically polymerizable oligomer, an epoxy acrylate type, a urethane acrylate type, and a polyester acrylate type oligomer are mentioned, for example.

  The radically polymerizable monomer or oligomer having no charge transport performance is desirably contained in an amount of 0% by mass or more and 50% by mass or less, based on the total solid content excluding the solvent of the protective layer forming coating solution. The content is more preferably 40% by mass or less, and further preferably 0% by mass or more and 30% by mass or less.

Moreover, it is desirable to add a thermal radical generator to the coating solution for forming the protective layer. That is, it is desirable that the protective layer contains a thermal radical generator or a derivative thereof.
Here, the “derivative of the thermal radical generator” means a reaction residue of the thermal radical generator after generating radicals by heat, or a radical active species of the thermal radical generator bonded to the polymerization terminal. .

Here, the cured film (crosslinked film) constituting the protective layer is obtained by curing the protective layer-forming coating liquid containing the above components by various methods such as heat, light, and electron beam. Thermosetting is desirable in order to balance properties such as electrical properties and mechanical strength of the film. Usually, when curing a general acrylic paint or the like, an electron beam that can be cured without a catalyst and photopolymerization that can be cured in a short time are preferably used. However, in the electrophotographic photosensitive member, since the photosensitive layer which is the surface of the outermost layer contains a photosensitive material, it is difficult to damage the photosensitive material, and in order to improve the surface properties of the obtained cured film, It is desirable to perform thermosetting that allows the reaction to proceed.
Therefore, thermosetting may be performed without a catalyst, but it is desirable to use the thermal radical generator as a catalyst. Thereby, it becomes easy to suppress generation | occurrence | production of the ghost by repeated use.
The thermal radical generator is not particularly limited, but is preferably one having a 10-hour half-life temperature of 40 ° C. or higher and 110 ° C. or lower in order to suppress damage of the photosensitive material in the photosensitive layer during the formation of the protective layer.

Commercially available products of thermal radical generators include V-30 (10-hour half-life temperature: 104 ° C.), V-40 (same: 88 ° C.), V-59 (same: 67 ° C.), V-601 (same as above: 66 ° C), V-65 (same: 51 ° C), V-70 (same: 30 ° C), VF-096 (same: 96 ° C), Vam-110 (same: 111 ° C), Vam-111 (same: 111 ° C), VE-073 (same as above: 73 ° C) (manufactured by Wako Pure Chemical Industries, Ltd.), OT _AZO- 15 (same as 61 ° C), OT _AZO- 30 (same as 57 ° C), AIBN (same as 65) ° C), AMBN (same: 67 ° C), ADVN (same: 52 ° C), ACVA (same: 68 ° C) (above, manufactured by Otsuka Chemical Co., Ltd.);
Pertetra A, Perhexa HC, Perhexa C, Perhexa V, Perhexa 22, Perhexa MC, Perbutyl H, Park Mill H, Park Mill P, Permenta H, Per Octa H, Perbutyl C, Perbutyl D, Perhexyl D, Parroyl IB, Parroyl 355, Parroyl L , Parroyl SA, Niper BW, Niper BMT-K40 / M, Parroyl IPP, Parroyl NPP, Parroyl TCP, Parroyl OPP, Parroyl SBP, Parkmill ND, Perocta ND, Perhexyl ND, Perbutyl ND, Perbutyl NHP, Perhexyl PV, Perbutyl PV, Perhexa 250, Perocta O, Perhexyl O, Perbutyl O, Perbutyl L, Perbutyl 355, Perhexyl I, Perbutyl I, Perbutyl E, Perhexa 5Z, perbutyl A, perhexyl Z, perbutyl ZT, perbutyl Z (manufactured by NOF Chemical Co., Ltd.), Kayaketal AM-C55, Trigonox 36-C75, Laurox, Parkardox L-W75, Percadox CH-50L, Trigonox TMBH, Kayakumen H, Kayabutyl H-70, Percadox BC-FF, Kaya Hexa AD, Parka Dox 14, Kaya Butyl C, Kaya Butyl D, Kaya Hexa YD-E85, Perkadox 12-XL25, Perkadox 12-EB20, Trigonox 22-N70, Trigonox 22-70E, Trigonox DT50, Trigonox 423-C70, Kayaester CND-C70, Kayaester CND-W50, Trigonox 23-C70, Trigonox 23-W5 N, Trigonox 257-C70, Kayaester P-70, Kayaester TMPO-70, Trigonox 121, Kayaester O, Kayaester HTP-65W, Kayaester AN, Trigonox42, Trigonox F-C50, Kayabutyl B, Kayacarboxyl EH- C70, Kaya-Carbon EH-W60, Kaya-Carbon I-20, Kaya-Carbon BIC-75, Trigonox 117, Kayalen 6-70 (manufactured by Kayaku Akzo), Luperox LP (same: 64 ° C.), Ruperox 610 (same: 37 ° C. ), Lupelox 188 (same: 38 ° C), Lupelox 844 (same: 44 ° C), Lupelox 259 (same: 46 ° C), Lupelox 10 (same: 48 ° C), Lupelox 701 (same: 53 ° C), Lupelox 11 ( Same: 58 ℃) Rox 26 (same: 77 ° C), Lupelox 80 (same: 82 ° C), Lupelox 7 (same: 102 ° C), Lupelox 270 (same: 102 ° C), Lupelox P (same: 104 ° C), Lupelox 546 (same: 46 ° C), Lupelox 554 (same: 55 ° C), Lupelox 575 (same: 75 ° C), Lupelox TANPO (same: 96 ° C), Lupelox 555 (same: 100 ° C), Lupelox 570 (same: 96 ° C), Lupelox TAP (same as above: 100 ° C.), Luperox TBIC (same as above: 99 ° C.), Luperlocks TBEC (same as above: 100 ° C.), Luperlocks JW (same as above: 100 ° C.), Lupelox TAIC (same as above: 96 ° C.), Lupelox TAEC (same as 99) ° C), Luperox DC (same as 117 ° C), Luperox 101 (same as 120 ° C) Lupelox F (same as 116 ° C), Lupelox DI (same as 129 ° C), Lupelox 130 (same as 131 ° C), Lupelox 220 (same as 107 ° C), Lupelox 230 (same as 109 ° C), Lupelox 233 (same as above) : 114 ° C.), Ruperox 531 (same as 93 ° C.) (above, manufactured by Arkema Yoshitomi).

  The thermal radical generator is contained in an amount of 0.001% by mass to 10% by mass with respect to the reactive compound (compound represented by the general formula (I) + other reactive compound) in the coating liquid for forming the protective layer. It is more desirable to contain 0.01 mass% or more and 5 mass% or less, and it is still more desirable to contain 0.1 mass% or more and 3 mass% or less.

  In addition, in order to effectively suppress oxidation by the discharge generated gas by adding it to the coating liquid for forming the protective layer so that the discharge generated gas is not excessively adsorbed, a phenol resin, a melamine resin, a benzoguanamine resin, etc. Other thermosetting resins may be added.

In addition, a coupling agent, a hard coat agent, and a fluorine-containing compound are added to the coating solution for forming the protective layer for the purpose of adjusting the film formability, flexibility, lubricity, and adhesiveness of the film. May be. Specifically, various silane coupling agents and commercially available silicone hard coat agents are used as these additives.
As the silane coupling agent, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane and the like are used.
Moreover, as a commercially available hard coat agent, KP-85, X-40-9740, X-8239 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), AY42-440, AY42-441, AY49-208 (above, Toray Dow Corning) Etc.) are used.
Further, (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (hepta) for imparting water repellency and the like. Fluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyl Fluorine-containing compounds such as triethoxysilane may be added.
Although the silane coupling agent is used in an arbitrary amount, the amount of the fluorine-containing compound is desirably 0.25 times or less by mass with respect to the compound not containing fluorine. If this amount is exceeded, there may be a problem with the film formability of the crosslinked film.

In addition, the protective layer forming coating solution is thermoplastic for the purpose of particle dispersibility and viscosity control as well as discharge gas resistance, mechanical strength, scratch resistance, torque reduction, wear amount control, extended pot life, etc. of the protective layer. Resin may be added.
Examples of the thermoplastic resin include polyvinyl butyral resin, polyvinyl formal resin, polyvinyl acetal resin such as partially acetalized polyvinyl acetal resin in which a part of butyral is modified with formal, acetoacetal or the like (for example, ESREC B, K manufactured by Sekisui Chemical Co., Ltd.) ), Polyamide resin, cellulose resin, polyvinylphenol resin and the like. In particular, polyvinyl acetal resin and polyvinyl phenol resin are desirable in terms of electrical characteristics. The resin preferably has a weight average molecular weight of 2,000 to 100,000, and more preferably 5,000 to 50,000. If the molecular weight of the resin is less than 2,000, the effect due to the addition of the resin tends to be insufficient, and if it exceeds 100,000, the solubility is reduced and the addition amount is limited. It tends to cause defects. The amount of the resin added is preferably 1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and further preferably 5% by mass or more and 20% by mass or less. If the addition amount of the resin is less than 1% by mass, the effect of the addition of the resin tends to be insufficient. Image blur is likely to occur.

It is desirable to add an antioxidant to the protective layer forming coating solution for the purpose of preventing deterioration due to an oxidizing gas such as ozone generated by the charging device of the protective layer. This is because when the mechanical strength of the surface of the photosensitive member is increased and the photosensitive member has a long life, the photosensitive member comes into contact with the oxidizing gas for a long time, and therefore, stronger oxidation resistance is required than before.
Antioxidants are preferably hindered phenols or hindered amines, organic sulfur antioxidants, phosphite antioxidants, dithiocarbamate antioxidants, thiourea antioxidants, benzimidazole antioxidants. , Etc., may be used. The addition amount of the antioxidant is preferably 20% by mass or less, and more preferably 10% by mass or less.
Examples of the hindered phenol antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butylhydroquinone, N, N′-hexamethylene bis (3,5-di). -T-butyl-4-hydroxyhydrocinnamide, 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 2,4-bis [(octylthio) methyl] -o-cresol, 2,6-di-t-butyl-4-ethylphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol) 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 2,5-di-t-amylhydroquinone, 2-t-butyl-6- (3-butyl-2-hydro Xyl-5-methylbenzyl) -4-methylphenyl acrylate, 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), and the like.

Further, various particles may be added to the protective layer forming coating solution for the purpose of lowering the residual potential of the protective layer or improving the strength.
An example of the particles is silicon-containing particles. The silicon-containing particles are particles containing silicon as a constituent element, and specific examples include colloidal silica and silicone particles. The colloidal silica used as the silicon-containing particles is obtained by dispersing silica having an average particle diameter of 1 nm or more and 100 nm or less, preferably 10 nm or more and 30 nm or less in an organic solvent such as an acidic or alkaline aqueous dispersion, alcohol, ketone, or ester. A commercially available product may be used. The solid content of the colloidal silica in the protective layer is not particularly limited, but from the viewpoint of film forming properties, electrical properties, and strength, the charge transporting composition (total solid content mass excluding solvent) And 0.1 mass% or more and 50 mass% or less, desirably 0.1 mass% or more and 30 mass% or less.
The silicone particles used as the silicon-containing particles are selected from silicone resin particles, silicone rubber particles, and silicone surface-treated silica particles, and those commercially available are generally used. These silicone particles are spherical, and the average particle size is desirably 1 nm or more and 500 nm or less, and more desirably 10 nm or more and 100 nm or less. Silicone particles are small particles that are chemically inert and excellent in dispersibility in resin, and since the content required to obtain more sufficient properties is low, the electron does not hinder the crosslinking reaction. The surface properties of the photographic photoreceptor are improved. In other words, it is improved in lubricity and water repellency on the surface of the electrophotographic photosensitive member in a state of being taken in without a variation in a strong cross-linked structure, and has good wear resistance and contamination resistance adhesion over a long period of time. Maintained.
The content of the silicone particles in the protective layer is desirably 0.1% by mass or more and 30% by mass or less, more desirably 0.5% by mass with respect to the charge transporting composition (total solid content excluding the solvent). It is 10 mass% or less.

Other particles include fluorine-based particles such as ethylene tetrafluoride, ethylene trifluoride, propylene hexafluoride, vinyl fluoride, vinylidene fluoride, and “8th Polymer Material Forum Lecture Proceedings p89”. As shown, particles made of a resin obtained by copolymerizing a fluororesin and a monomer having a hydroxyl group, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —SnO ₂ , ZnO ₂ —TiO ₂ , ZnO Examples thereof include semiconductive metal oxides such as —TiO ₂ , MgO—Al ₂ O ₃ , FeO—TiO ₂ , TiO ₂ , SnO ₂ , In ₂ O ₃ , ZnO, and MgO. For the same purpose, an oil such as silicone oil may be added. Silicone oils include silicone oils such as dimethylpolysiloxane, diphenylpolysiloxane, and phenylmethylsiloxane; amino-modified polysiloxane, epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, methacryl-modified polysiloxane, mercapto-modified poly Reactive silicone oils such as siloxane and phenol-modified polysiloxane; cyclic dimethylcyclosiloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane; 1,3,5- Trimethyl-1.3.5-triphenylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclo Cyclic methylphenylcyclosiloxanes such as trasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-pentaphenylcyclopentasiloxane; cyclic phenylcyclosiloxanes such as hexaphenylcyclotrisiloxane Fluorine-containing cyclosiloxanes such as (3,3,3-trifluoropropyl) methylcyclotrisiloxane; hydrosilyl group-containing cyclosiloxanes such as methylhydrosiloxane mixtures, pentamethylcyclopentasiloxane, and phenylhydrocyclosiloxane; penta And vinyl group-containing cyclosiloxanes such as vinylpentamethylcyclopentasiloxane.

  Moreover, you may add a metal, a metal oxide, carbon black, etc. to the coating liquid for protective layer formation. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver, and stainless steel, or those obtained by depositing these metals on the surface of the resin particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony and tantalum-doped tin oxide, and antimony-doped zirconium oxide. . These may be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion. The average particle diameter of the conductive particles is preferably 0.3 μm or less, particularly preferably 0.1 μm or less, from the viewpoint of the transparency of the protective layer.

The coating solution for forming the protective layer may be solvent-free, and if necessary, alcohols such as methanol, ethanol, propanol, butanol, cyclopentanol, and cyclohexanol; ketones such as acetone and methyl ethyl ketone; tetrahydrofuran , Ethers such as diethyl ether, dioxane and cyclopentyl methyl ether, and ester solvents such as ethyl acetate and butyl acetate may be contained.
Such solvents can be used singly or in combination of two or more, but preferably have a boiling point of 130 degrees or less. As a solvent,

The coating liquid for forming the protective layer is formed on the charge transport layer by a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method. The film is obtained by applying and polymerizing (curing), for example, by heating at a temperature of 100 ° C. to 170 ° C. as necessary. As a result, a protective layer made of this film is obtained.
The oxygen concentration during the polymerization (curing) of the coating liquid for forming the protective layer is desirably 1% or less, more desirably 1000 ppm or less, and even more desirably 500 ppm or less.

(Single layer type photosensitive layer)
As described above, the example of the function separation type has been described as the electrophotographic photosensitive member. However, the electrophotographic photosensitive member according to the present embodiment may include a single-layer type photosensitive layer shown in FIG.
Here, the single-layer type photosensitive layer (charge generation / charge transport layer) is a layer including, for example, a charge generation material, a charge transport material, and, if necessary, a binder resin and other well-known additives. is there. Note that these materials are the same as those described for the charge generation layer and the charge transport layer.
In the single-layer type photosensitive layer, the content of the charge generating material is preferably 10% by mass or more and 85% by mass or less, and preferably 20% by mass or more and 50% by mass or less with respect to the total solid content. In the single-layer type photosensitive layer, the content of the charge transport material is preferably 5% by mass or more and 50% by mass or less based on the total solid content.
The method for forming the single-layer type photosensitive layer is the same as the method for forming the charge generation layer and the charge transport layer.
The film thickness of the single-layer type photosensitive layer is, for example, from 5 μm to 50 μm, and preferably from 10 μm to 40 μm.

In the present embodiment, the embodiment in which the outermost surface layer made of the specific hardened layer described above is a protective layer has been described. However, in the case of a layer configuration without a protective layer, the charge transport located on the outermost surface in the layer configuration. A layer may be the outermost surface layer, and a specific cured layer containing a polymer of the compound represented by the general formula (I) may be applied to the layer.
Moreover, even if there is a protective layer, the above-mentioned specific hardened layer may be applied as the charge transport layer below it.

<Image forming apparatus and process cartridge>
The image forming apparatus according to the present embodiment includes an electrophotographic photosensitive member, a charging unit that charges the surface of the electrophotographic photosensitive member, and an electrostatic latent image formation that forms an electrostatic latent image on the surface of the charged electrophotographic photosensitive member. Means, developing means for developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image, and transfer means for transferring the toner image to the surface of the recording medium; Is provided. The electrophotographic photosensitive member according to the present embodiment is applied as the electrophotographic photosensitive member.

  The image forming apparatus according to the present embodiment includes an apparatus having fixing means for fixing a toner image transferred to the surface of a recording medium; direct transfer for directly transferring the toner image formed on the surface of the electrophotographic photosensitive member to the recording medium Type apparatus; intermediate transfer in which the toner image formed on the surface of the electrophotographic photosensitive member is primarily transferred onto the surface of the intermediate transfer member, and the toner image transferred onto the surface of the intermediate transfer member is secondarily transferred onto the surface of the recording medium. Type apparatus; apparatus provided with cleaning means for cleaning the surface of the electrophotographic photosensitive member after the toner image is transferred and before charging; after the toner image is transferred, the surface of the image carrier is irradiated with a charge-removing light before charging. A known image forming apparatus, such as an apparatus provided with a static elimination means for removing electricity; an apparatus provided with an electrophotographic photosensitive member heating member for increasing the temperature of the electrophotographic photosensitive member and reducing the relative temperature is applied.

  In the case of an intermediate transfer type apparatus, the transfer means includes, for example, an intermediate transfer body on which a toner image is transferred onto the surface, and a primary transfer that primarily transfers the toner image formed on the surface of the image holding body onto the surface of the intermediate transfer body. And a secondary transfer unit that secondarily transfers the toner image transferred onto the surface of the intermediate transfer body onto the surface of the recording medium.

  The image forming apparatus according to the present embodiment may be either a dry developing type image forming apparatus or a wet developing type (developing type using a liquid developer).

  Note that in the image forming apparatus according to the present embodiment, for example, the portion including the electrophotographic photosensitive member may have a cartridge structure (process cartridge) that is detachable from the image forming apparatus. As the process cartridge, for example, a process cartridge including the electrophotographic photosensitive member according to this embodiment is preferably used. In addition to the electrophotographic photosensitive member, the process cartridge may include at least one selected from the group consisting of a charging unit, an electrostatic latent image forming unit, a developing unit, and a transfer unit.

  Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

FIG. 4 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present embodiment.
As shown in FIG. 4, the image forming apparatus 100 according to the present embodiment includes a process cartridge 300 including an electrophotographic photosensitive member 7, an exposure device 9 (an example of an electrostatic latent image forming unit), and a transfer device 40 (primary. Transfer device) and an intermediate transfer member 50. In the image forming apparatus 100, the exposure device 9 is disposed at a position where the electrophotographic photosensitive member 7 can be exposed from the opening of the process cartridge 300, and the transfer device 40 is interposed between the electrophotographic photosensitive member via the intermediate transfer member 50. 7, and a part of the intermediate transfer member 50 is disposed in contact with the electrophotographic photosensitive member 7. Although not shown, it also has a secondary transfer device that transfers the toner image transferred to the intermediate transfer member 50 to a recording medium (for example, paper). The intermediate transfer member 50, the transfer device 40 (primary transfer device), and the secondary transfer device (not shown) correspond to an example of a transfer unit.

  In the process cartridge 300 in FIG. 4, an electrophotographic photosensitive member 7, a charging device 8 (an example of a charging unit), a developing device 11 (an example of a developing unit), and a cleaning device 13 (an example of a cleaning unit) are integrated in a housing. I support it. The cleaning device 13 includes a cleaning blade (an example of a cleaning member) 131, and the cleaning blade 131 is disposed so as to contact the surface of the electrophotographic photosensitive member 7. The cleaning member may be a conductive or insulating fibrous member instead of the cleaning blade 131, and may be used alone or in combination with the cleaning blade 131.

  FIG. 4 shows a fibrous member 132 (roll shape) for supplying the lubricant 14 to the surface of the electrophotographic photosensitive member 7 and a fibrous member 133 (flat brush) for assisting cleaning in the image forming apparatus 100. Examples are provided, but these are members arranged as necessary.

  Hereinafter, each configuration of the image forming apparatus according to the present embodiment will be described.

-Charging device-
As the charging device 8, for example, a contact type charger using a conductive or semiconductive charging roller, a charging brush, a charging film, a charging rubber blade, a charging tube or the like is used. Further, a non-contact type roller charger, a known charger such as a scorotron charger using a corona discharge or a corotron charger may be used.

-Exposure device-
Examples of the exposure device 9 include optical system devices that expose the surface of the electrophotographic photoreceptor 7 with light such as semiconductor laser light, LED light, and liquid crystal shutter light in a predetermined image-like manner. The wavelength of the light source is set within the spectral sensitivity region of the electrophotographic photosensitive member. As the wavelength of the semiconductor laser, near infrared having an oscillation wavelength near 780 nm is the mainstream. However, the present invention is not limited to this wavelength, and an oscillation wavelength laser in the 600 nm range or a laser having an oscillation wavelength of 400 nm to 450 nm as a blue laser may be used. In addition, a surface-emitting type laser light source that can output a multi-beam is also effective for color image formation.

-Development device-
Examples of the developing device 11 include a general developing device that performs development by bringing a developer into contact or non-contact with the developer. The developing device 11 is not particularly limited as long as it has the functions described above, and is selected according to the purpose. For example, a known developing device having a function of attaching a one-component developer or a two-component developer to the electrophotographic photosensitive member 7 using a brush, a roller, or the like can be used. Among these, those using a developing roller holding the developer on the surface are preferable.

  The developer used in the developing device 11 may be a one-component developer including a toner alone or a two-component developer including a toner and a carrier. Further, the developer may be magnetic or non-magnetic. A well-known thing is applied for these developers.

-Cleaning device-
As the cleaning device 13, a cleaning blade type device including a cleaning blade 131 is used.
In addition to the cleaning blade method, a fur brush cleaning method and a simultaneous development cleaning method may be employed.

-Transfer device-
As the transfer device 40, for example, a contact transfer charger using a belt, a roller, a film, a rubber blade, etc., or a known transfer charger such as a scorotron transfer charger using a corona discharge or a corotron transfer charger. Can be mentioned.

-Intermediate transfer member-
As the intermediate transfer member 50, a belt-like member (intermediate transfer belt) containing polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber or the like having semiconductivity is used. Further, as the form of the intermediate transfer member, a drum-like member may be used in addition to the belt-like member.

FIG. 5 is a schematic configuration diagram illustrating another example of the image forming apparatus according to the present embodiment.
An image forming apparatus 120 shown in FIG. 5 is a tandem multicolor image forming apparatus equipped with four process cartridges 300. In the image forming apparatus 120, four process cartridges 300 are arranged in parallel on the intermediate transfer member 50, and one electrophotographic photosensitive member is used for one color. The image forming apparatus 120 has the same configuration as that of the image forming apparatus 100 except that it is a tandem system.

The image forming apparatus and the process cartridge according to the present embodiment are not limited to the above configuration, and other well-known image forming apparatuses and process cartridges may be applied as long as the electrophotographic photosensitive member according to the present embodiment is included. May be.
As described above, since the electrophotographic photosensitive member according to the present embodiment suppresses deterioration of electrical characteristics even after repeated use, the process cartridge and the image forming apparatus provided with the electrophotographic photosensitive member have long been used. A stable image can be provided.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

[Synthesis Example 1: Synthesis of CTM-27]
The exemplary compound CTM-27 was synthesized according to the following scheme.

  While adding 25.0 g of the above compound (1), 250 ml of toluene, 22.0 g of acrylic acid, 1.0 g of toluenesulfonic acid, and 0.3 g of nitrobenzene to a three-necked flask, remove the generated water with a Dean-Stark trap. Heated to reflux for hours. Then, it cooled to room temperature, toluene 250ml was added, the organic layer was wash | cleaned 3 times with distilled water 250ml, and the solvent was distilled off under pressure reduction after drying with anhydrous sodium sulfate. Thereafter, the residue was purified by column chromatography (adsorbent: silica gel, solvent: toluene / ethyl acetate = 10/1) to obtain 23.3 g of oily CTM-27. The IR spectrum of CTM-27 is shown in FIG.

[Example 1]
(Preparation of electrophotographic photoreceptor)
-Production of undercoat layer-
Zinc oxide: (average particle diameter 70 nm: manufactured by Teica Co., Ltd .: specific surface area value 15 m ² / g) 100 parts by mass was stirred and mixed with 500 parts by mass of toluene, and a silane coupling agent (KBM503: manufactured by Shin-Etsu Chemical Co., Ltd.) 1.3 Part by mass was added and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 120 ° C. for 3 hours to obtain zinc oxide surface-treated with a silane coupling agent.
110 parts by mass of surface-treated zinc oxide was stirred and mixed with 500 parts by mass of tetrahydrofuran, a solution prepared by dissolving 0.6 parts by mass of alizarin in 50 parts by mass of tetrahydrofuran was added, and the mixture was stirred at 50 ° C. for 5 hours. . Then, the zinc oxide to which alizarin was imparted by filtration under reduced pressure was filtered off, and further dried at 60 ° C. under reduced pressure to obtain zinc oxide to which alizarin was imparted.

Zinc oxide provided with this alizarin: 60 parts by mass, curing agent (blocked isocyanate Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.): 13.5 parts by mass, butyral resin (ESREC BM-1, Sekisui Chemical Co., Ltd.) ): 15 parts by mass of 38 parts by mass of methyl ethyl ketone mixed with 85 parts by mass of methyl ethyl ketone: 25 parts by mass of methyl ethyl ketone were mixed, and dispersion was performed for 2 hours with a sand mill using glass beads having a diameter of 1 mmφ. Got.
Dioctyltin dilaurate: 0.005 parts by mass and silicone resin particles (Tospearl 145, manufactured by GE Toshiba Silicone): 40 parts by mass were added as catalysts to the obtained dispersion to obtain a coating liquid for forming an undercoat layer. . This coating solution was applied on an aluminum substrate by a dip coating method, followed by drying and curing at 175 ° C. for 40 minutes to obtain an undercoat layer having a thickness of 22 μm.

-Fabrication of charge generation layer-
Bragg angles (2θ ± 0.2 °) of X-ray diffraction spectrum using Cukα characteristic X-ray as a charge generating material are at least 7.3 °, 16.0 °, 24.9 °, 28.0 ° A mixture consisting of 15 parts by mass of hydroxygallium phthalocyanine having a diffraction peak, 10 parts by mass of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) as a binder resin, and 200 parts by mass of n-butyl acetate. The mixture was dispersed for 4 hours in a sand mill using glass beads having a diameter of 1 mmφ. To the obtained dispersion, 175 parts by mass of n-butyl acetate and 180 parts by mass of methyl ethyl ketone were added and stirred to obtain a coating solution for forming a charge generation layer. This charge generation layer forming coating solution was dip coated on the undercoat layer and dried at room temperature (25 ° C.) to form a charge generation layer having a thickness of 0.15 μm.

-Preparation of charge transport layer-
48 parts by mass of N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine (hereinafter referred to as “TPD”) and bisphenol Z 52 parts by mass of a polycarbonate resin (hereinafter referred to as “PCZ500”, viscosity average molecular weight: 50,000) was added to 800 parts by mass of chlorobenzene and dissolved to obtain a coating solution for forming a charge transport layer. This coating solution was applied onto the charge generation layer and dried at 130 ° C. for 45 minutes to form a charge transport layer having a thickness of 22 μm.

-Production of protective layer-
20 parts by mass of the compound represented by the general formula (I) (the exemplified compound CTM-4) is dissolved in 15 parts by mass of stabilizer-free tetrahydrofuran (THF) and 15 parts by mass of cyclopentyl methyl ether, and further, initiator V -601 (made by Wako Pure Chemical Industries, Ltd.) 0.8 mass part was dissolved, and the coating liquid for protective layer formation was obtained. This coating solution was applied onto the charge transport layer and heated at 155 ° C. for 40 minutes in an atmosphere having an oxygen concentration of about 80 ppm to form a protective layer having a thickness of 7 μm.
An electrophotographic photoreceptor was obtained by the method as described above. This photoreceptor is referred to as a photoreceptor 1.

[Evaluation]
(1) Measurement of charging potential (surface potential) and residual potential The obtained electrophotographic photosensitive member was subjected to the following steps (A) to (C) at high temperature and high humidity (28 ° C., 67% RH).
(A): Step of charging the electrophotographic photosensitive member with a scorotron charger with a grid applied voltage of −700 V (B): 10.0 erg / cm ² of light using a semiconductor laser with a wavelength of 780 nm one second after step (A) Exposure step (C) for irradiating with 50.0 erg / cm ² of red LED light 3 seconds after step (A) At this time, the above steps were repeated 100 kcycle using a laser printer remodeling scanner .

Initial and 100 kcycle VH (surface potential of the photoreceptor after charging in step (A)), VL (surface potential of the photoreceptor after exposure in step (B)), and VRP (step ( The surface potential (residual potential) of the photoconductor after being neutralized in C) was measured, and the initial VH, VL, and VRP, and the variations ΔVH, ΔVL, and ΔVRP from the initial stage were obtained.
In addition, the surface potential meter MODEL344 (made by Trek Japan) was used for the measurement of the surface potential (residual potential).

The evaluation index is as follows.
(VL evaluation index)
A: -240V or more B: -280V or more and less than -240V C: -300V or more and less than -280V D: -300V or less (VRP evaluation index)
A: -130 V or more B: -150 V or more and less than -130 V C: -170 V or more and less than -150 V D: less than -170 V (evaluation index of ΔVH, ΔVL, and ΔVRP)
A: 10 V or less B: Greater than 10 V and 20 V or less C: Greater than 20 V and 30 V or less D: Greater than 30 V

(2) Evaluation of initial image quality: evaluation of ghost, evaluation of graininess of 20% halftone image The produced electrophotographic photosensitive member was mounted on “Docu Center-IV C5575 (K color)” manufactured by Fuji Xerox Co., In an environment of 67% RH, evaluation of ghost (test 1) and evaluation of graininess of 20% halftone image (test 1) were performed as follows.
For this evaluation, Fuji Xerox P paper (A4 size, short direction feed) was used.

-Evaluation of ghost-
The ghost output a chart of a pattern having G and a black area shown in FIG. 7A, and visually evaluated the appearance of the letter G in the black area.
A: Good or slight as shown in FIG.
B: Slightly conspicuous as shown in FIG. 7B. C: It is clearly confirmed as shown in FIG. 7C.

-Evaluation of graininess of 20% halftone image-
As for graininess, a black solid image of 20% halftone was output, and the uniformity of the obtained solid image was visually evaluated.
A: Good.
B: Slightly inferior in uniformity.
C: Clearly inferior in uniformity.

(3) Image quality evaluation after output test: evaluation of ghost, evaluation of graininess of 20% halftone image The produced electrophotographic photosensitive member is mounted on “Docu Center-IV C5575 (K color)” manufactured by Fuji Xerox Co., Ltd. A 10,000% output test of 15% halftone was performed in an environment of ℃ and 67% RH.
Thereafter, under the environment of 28 ° C. and 67% RH, the ghost was evaluated (test 2) and the graininess of the 20% halftone image was evaluated in the same manner as described above.

(4) Initial surface observation (2) Initial image quality evaluation: The surface of the electrophotographic photosensitive member at the time of ghost evaluation was observed, and surface observation (test 1) was performed as follows.

-Surface observation-
The surface of the electrophotographic photosensitive member was observed and evaluated as follows.
A: Even if it is magnified 20 times, both scratches and adhesion are not visible.
B: Deposits are observed when magnified 20 times. C: Slight scratches are observed when magnified 20 times. D: Slight scratches or deposits are observed even with the naked eye.
E: Scratches or deposits are clearly seen even with the naked eye.

(5) Surface observation after output test (3) Image quality evaluation after output test: The surface of the electrophotographic photosensitive member at the time of ghost evaluation was observed, and surface observation (test 2) was performed in the same manner as described above.

The results evaluated as described above are summarized in Table 4 below.
(6)

[Examples 2 to 24, Comparative Examples 1 and 2]
(Preparation of electrophotographic photoreceptor)
The charge transport layer was prepared in the same manner as in Example 1, and the composition of the material used for forming the protective layer was changed as shown in Table 2 below to obtain a coating liquid for forming a protective layer. Each coating solution was applied onto the charge transport layer and heated at 155 ° C. for 40 minutes in an atmosphere having an oxygen concentration of about 80 ppm to form a protective layer having a thickness of 7 μm.
The non-reactive charge transport materials listed in Table 2 were as follows.
CTM-A: N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine CTM-B: N, N′-bis (3 4-dimethylphenyl) -biphenyl-4-amine Further, as the additive described in Table 2, Lubron L-2 (manufactured by Daikin), which is PTFE particles (fluorine-based particles), was used. In the case of using this additive, 5% by mass of GF-300 (manufactured by Toa Gosei Co., Ltd.) was added as a dispersant to Lubron L-2.
Here, in Comparative Example 1, the structure of Ref CT-1 used as a charge transport material having a chain polymerizable reactive group is shown below.

  An electrophotographic photoreceptor was obtained by the method as described above. This photoreceptor is referred to as photoreceptors 2 to 24 and comparative photoreceptors 1 and 2.

[Evaluation]
Each of the obtained photoreceptors was evaluated in the same manner as in Example 1. The results are shown in Table 3.

From the above results, it can be seen that the present example is superior to Comparative Examples 1 and 2 in VL and VRP, and the amounts of fluctuation ΔVH, ΔVL, and ΔVRP from the initial stage are also excellent.
In addition, compared with Comparative Examples 1 and 2, the present example was excellent in ghost at the initial stage and after the print test, and good results were obtained in the surface observation after the print test.

[Example 25, Comparative Example 3]
The charge transport layer was prepared in the same manner as in Example 1, and the composition of the material used for forming the protective layer was changed as shown in Table 2 to obtain a protective layer forming coating solution. Each coating solution was applied onto the charge transport layer and heated at 155 ° C. for 40 minutes in an atmosphere having an oxygen concentration of about 80 ppm to form a protective layer having a thickness of 7 μm.
Here, the structure of Ref CT-2 used as a charge transport material having a chain polymerizable reactive group in Comparative Example 3 is shown below.

  An electrophotographic photoreceptor was obtained by the method as described above. This photosensitive member is referred to as a photosensitive member 25 and a comparative photosensitive member 3.

[Evaluation]
Evaluation similar to Example 1 was performed for the photoconductor 25 of Example 25 and the comparative photoconductor 3 of Comparative Example 3. The results are shown in Table 3.
In the photoreceptor 25 of Example 25, a coating solution for forming a protective layer containing PTFE particles was used. The dispersion state of the PTFE particles in this coating solution was uniform. Further, the surface of the protective layer obtained with this coating solution was also a glossy surface with excellent image uniformity, as is apparent from the evaluation results of the graininess shown in Table 3.
On the other hand, in the comparative photoreceptor 3 of Comparative Example 3, when the dispersion state of the PTFE particles in the protective layer forming coating solution was confirmed, partial aggregation was observed. Further, the surface of the protective layer obtained with this coating solution was slightly inferior in image uniformity to that of Example 25.

Regarding the difference in image uniformity (graininess) as described above, the following effects are presumed.
That is, the compound represented by the general formula (I) is a compound having an ester bond. This ester bond has a high polarity, and in the case of the compound represented by the general formula (I), it is presumed that the ester bond effectively contributes to the dispersibility of the PTFE particles coexisting in the coating solution.
When the coating liquid (dispersion) is not a uniform liquid (when the dispersibility of PTFE particles is low), aggregation of PTFE particles is promoted during curing, and the surface of the protective layer is considered to be rough. Although this can be avoided by changing the solvent of the coating solution, the solvent selected to increase the dispersibility of the PTFE particles is likely to damage the underlying charge transport layer, As a result, the range of selection of the solvent is limited, and the design freedom of the coating liquid may be reduced.
On the other hand, if the compound represented by the general formula (1) is used, the dispersibility of the PTFE particles can be improved due to the structure thereof. Will be expensive.

DESCRIPTION OF SYMBOLS 1 Undercoat layer, 2 Charge generation layer, 3 Charge transport layer, 4 Conductive substrate, 5 Protective layer, 6 Single layer type photosensitive layer, 7A, 7B, 7C, 7 Electrophotographic photoreceptor, 8 Charging device, 9 Exposure device , 11 Developing device, 13 Cleaning device, 14 Lubricant, 40 Transfer device, 50 Intermediate transfer member, 100 Image forming device, 120 Image forming device, 300 Process cartridge

Claims (6)

An electrophotographic photosensitive member provided with a layer comprising a cured film of a composition containing a compound represented by the following general formula (I).

[In General Formula (I), F represents a charge transporting subunit, R ¹ and R ² each independently represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, or an aralkyl group, and n is 1 or more and 4 The following integers are shown. ] The electrophotographic photosensitive member according to claim 1, wherein the compound represented by the general formula (I) is a compound represented by the following general formula (II).

[In General Formula (II), Ar ^{1 to} Ar ⁴ each independently represents an aryl group, Ar ⁵ represents an aryl group or an arylene group, and D represents a group represented by General Formula (III). k represents 0 or 1, c1 to c5 each independently represents an integer of 0 or more and 2 or less, and all of c1 to c5 do not simultaneously become 0. The sum of c1 to c5 is an integer of 1 or more and 4 or less.
In general formula (III), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkoxyalkyl group, or an aralkyl group. ]   The electrophotographic photosensitive member according to claim 1, wherein the layer is provided as an outermost surface layer.   The electrophotographic photosensitive member according to claim 1, wherein the layer further contains a thermal radical generator or a derivative thereof. The electrophotographic photosensitive member according to any one of claims 1 to 4, comprising:
A process cartridge that can be attached to and detached from an image forming apparatus. The electrophotographic photosensitive member according to any one of claims 1 to 4,
Charging means for charging the surface of the electrophotographic photosensitive member;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image;
Transfer means for transferring the toner image to the surface of the recording medium;
An image forming apparatus comprising: