JP6432244B2 - Electrophotographic photosensitive member, process cartridge, and image forming apparatus - Google Patents

Description

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

As an electrophotographic photoreceptor, it has been proposed to provide a protective layer on the surface from the viewpoint of improving strength. As a material system for forming the protective layer, for example, an organic-inorganic hybrid material (see, for example, Patent Document 1) or a film obtained by applying and curing a liquid containing a photocurable acrylic monomer (see, for example, Patent Document 2) A mixture of a monomer having a carbon-carbon double bond, a charge transport material having a carbon-carbon double bond, and a binder resin by heat or light energy, and carbon of the charge transport material. A film formed by reacting with a carbon double bond (for example, see Patent Document 3) is disclosed.
Further, a film made of a compound obtained by polymerizing a hole transporting compound having two or more chain polymerizable functional groups in the same molecule is disclosed (for example, see Patent Document 4). In addition, a technique of using a polymer of a charge transport material having a chain polymerizable functional group for a protective layer is disclosed (for example, see Patent Document 5).

On the other hand, since the acrylic material used for forming the protective layer is strongly affected by the curing conditions, curing atmosphere, etc., for example, a film formed by heating after irradiation with radiation in a vacuum or an inert gas. (For example, refer patent document 6), the technique which uses the film | membrane (for example refer patent document 7) heat-hardened in inert gas for a protective layer or a photosensitive layer is disclosed.
Moreover, the crosslinked body of the charge transportable compound by which the styrene skeleton was connected as a chain polymerizable group is disclosed (for example, refer patent documents 8-12). It is disclosed that cyclic polysilane or cyclic polysiloxane is added to the surface of the photoconductor in order to maintain cleaning properties even if the surface of the photoconductor is worn (see, for example, Patent Document 13 and Patent Document 14).

  In addition, an electrophotographic photosensitive member containing a resin obtained by polymerizing and curing a bifunctional or higher functional photoionic polymerizable compound in the surface layer (see, for example, Patent Document 15), a cyclic polysiloxane having a molecular weight of 1,000 or more. An electrophotographic photoreceptor (for example, see Patent Document 16) contained in the photosensitive layer is disclosed.

JP 2000-019749 A JP-A-5-40360 JP-A-5-216249 JP 2000-206715 A JP 2001-175016 A Japanese Patent Laid-Open No. 2004-12986 Japanese Patent Laid-Open No. 7-72640 Japanese Patent No. 2546739 Japanese Patent No. 2852464 JP 2013-044818 A JP 2013-060572 A JP 2013-061640 A Japanese Patent No. 4214113 Japanese Patent No. 4322468 Japanese Patent No. 2790382 JP 2010-185955 A

  The object of the present invention is to repeatedly form an image over a long period of time compared to the case where the outermost surface layer is composed of a cured film of a composition containing a cyclic silicon-containing compound and a charge transport material having an alkoxysilyl group. However, it is an object of the present invention to provide an electrophotographic photosensitive member that suppresses a difference in image quality caused by a difference between the worn state of the electrophotographic photosensitive member and the worn state of the cleaning blade.

The above problem is solved by the following means. That is,
The invention according to < 1 >
A conductive substrate, and a photosensitive layer provided on the conductive substrate,
The outermost surface layer has at least one selected from cyclic silicon-containing compounds represented by the following general formula (X) and the following general formula (Y), and a charge having at least one chain polymerizable functional group in one molecule An electrophotographic photosensitive member comprising a cured film of a composition containing a transport material.

(In General Formula (X), A ¹ and A ² may be the same or different and each independently represents a hydrogen atom or a monovalent organic group, and x represents an integer of 4 or more and 12 or less. A certain A ¹ and A ² may be the same or different.

(In General Formula (Y), B ¹ and B ² may be the same or different, and each independently represents a hydrogen atom or a monovalent organic group, and y represents an integer of 2 or more and 6 or less. B ¹ and B ² may be the same or different.)

The invention according to < 2 >
A ¹ and A ² in the general formula (X) and B ¹ and B ² in the general formula (Y) are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, Or it is an electrophotographic photoreceptor as described in < 1 > which shows a substituted or unsubstituted aralkyl group.

The invention according to < 3 >
The electrophotographic photosensitive member according to < 1 > or < 2 > , wherein x in the general formula (X) represents an integer of 4 or more and 10 or less.

The invention according to < 4 >
The electrophotographic photosensitive member according to any one of < 1 > to < 3 > , wherein y in the general formula (Y) represents an integer of 3 to 6.

The invention according to < 5 >
The electrophotographic photosensitive member according to any one of < 1 > to < 4 > , wherein at least one of the chain polymerizable functional groups is an acryloyl group, a methacryloyl group, or a vinylphenyl group.

The invention according to < 6 >
The electrophotographic photosensitive material according to any one of < 1 > to < 5 > , wherein the charge transport material is at least one selected from compounds represented by the following general formula (I) and the following general formula (II). Is the body.

(In general formula (I), F represents a charge transporting skeleton. L represents an alkylene group, an alkenylene group, —C (═O) —, —N (R) —, —S—, and —O—). And R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and m represents an integer of 1 or more and 8 or less.)

(In general formula (II), F represents a charge transporting skeleton. L ′ represents a trivalent or tetravalent group derived from an alkane or alkene, an alkylene group, an alkenylene group, —C (═O )-, -N (R)-, -S-, and -O-, and represents an (n + 1) -valent linking group containing two or more selected from the group consisting of -O-, where R represents a hydrogen atom, an alkyl group, an aryl A group or an aralkyl group, m ′ represents an integer of 1 to 6, and n represents an integer of 2 to 3.

The invention according to < 7 >
A conductive substrate, and a photosensitive layer provided on the conductive substrate,
The outermost surface layer is a cyclic silicon-containing compound represented by the following general formula (X), and at least one selected from charge transport materials represented by the following general formula (I) and the following general formula (II): It is an electrophotographic photosensitive member composed of a cured film of the contained composition.

(In General Formula (X), A ¹ and A ² may be the same or different and each independently represents a hydrogen atom or a monovalent organic group, and x represents an integer of 4 or more and 12 or less. A certain A ¹ and A ² may be the same or different.

(In general formula (I), F represents a charge transporting skeleton. L represents an alkylene group, an alkenylene group, —C (═O) —, —N (R) —, —S—, and —O—). And R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and m represents an integer of 1 or more and 8 or less.)

(In general formula (II), F represents a charge transporting skeleton. L ′ represents a trivalent or tetravalent group derived from an alkane or alkene, an alkylene group, an alkenylene group, —C (═O )-, -N (R)-, -S-, and -O-, and represents an (n + 1) -valent linking group containing two or more selected from the group consisting of -O-, where R represents a hydrogen atom, an alkyl group, an aryl A group or an aralkyl group, m ′ represents an integer of 1 to 6, and n represents an integer of 2 to 3.

The invention according to < 8 >
< 1 > The electrophotographic photoreceptor according to any one of < 7 > ,
It is a process cartridge that can be attached to and detached from the image forming apparatus.

The invention according to < 9 >
< 1 >- < 7 > electrophotographic photoreceptor according to any one of the above,
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.

According to the invention according to < 1 > , < 2 > , < 3 > , < 4 > , or < 5 > , the outermost surface layer comprises a cyclic silicon-containing compound and a charge transport material having an alkoxysilyl group. Compared to the case where it is composed of a cured film of the composition that contains it, even when images are formed repeatedly over a long period of time, the difference in image quality that occurs due to the difference in the wear state of the electrophotographic photoreceptor and the wear state of the cleaning blade An electrophotographic photoreceptor that suppresses the above is provided.

According to the invention according to < 6 >, the wear state of the electrophotographic photosensitive member and the wear state of the cleaning blade even when repeated image formation is performed over a long period of time as compared with the case where a charge transport material having an acryloyl group or a methacryloyl group is applied. There is provided an electrophotographic photosensitive member that suppresses the difference in image quality caused by the difference between the two.

According to the invention according to < 7 > , an electrophotographic photoreceptor can be used even when repeated image formation is performed over a long period of time as compared with the case where the cyclic silicon-containing compound represented by the general formula (Y) is applied as the cyclic silicon-containing compound. There is provided an electrophotographic photosensitive member that suppresses a difference in image quality caused by a difference between the wear state of the toner and the wear state of the cleaning blade.

According to the invention according to < 8 > or < 9 > , an electron whose outermost surface layer is composed of a cured film of a composition containing a cyclic silicon-containing compound and a charge transport material having an alkoxysilyl group. Process cartridge that suppresses the difference in image quality caused by the difference between the wear state of the electrophotographic photoreceptor and the wear state of the cleaning blade even when image formation is repeated over a long period of time compared to the case where a photographic photoreceptor is applied Alternatively, an image forming apparatus is provided.

1 is a schematic partial cross-sectional view illustrating an example of a layer configuration of an electrophotographic photoreceptor according to an exemplary embodiment. FIG. 6 is a schematic partial cross-sectional view illustrating another example of the layer configuration of the electrophotographic photosensitive member according to the exemplary embodiment. FIG. 6 is a schematic partial cross-sectional view illustrating another example of the layer configuration of the electrophotographic photosensitive member according to the exemplary embodiment. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows another example of the image forming apparatus which concerns on this embodiment. It is a figure which shows the image pattern used for image quality evaluation.

  Hereinafter, the present embodiment which is an example of the present invention will be described.

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor according to the exemplary embodiment (hereinafter sometimes simply referred to as “photoreceptor”) includes a conductive substrate and a photosensitive layer provided on the conductive substrate, and the outermost surface layer is a surface layer. , At least one selected from cyclic silicon-containing compounds represented by the general formula (X) and the general formula (Y) (hereinafter sometimes referred to as “specific cyclic silicon-containing compound”), and within one molecule It comprises a cured film of a composition containing a charge transport material having at least one chain-polymerizable functional group (hereinafter sometimes referred to as “specific chain-polymerizable charge transport material”).

  Here, in the conventional photoreceptor, it is known that a cyclic silicon-containing compound is contained in the outermost surface layer composed of a non-cured film or a cured film for the purpose of improving wear resistance and cleaning properties. ing. However, even if the outermost surface layer contains a cyclic silicon-containing compound, if it is repeatedly used (image formation) for a long period of time, the wear resistance of the photoreceptor tends to decrease. Specifically, when the outermost surface layer is composed of a non-cured film, the substrate strength is insufficient in the first place, so that the wear resistance of the photoreceptor is likely to be lowered. On the other hand, when the outermost surface layer is composed of a cured film obtained by condensing a siloxane compound together with a cyclic silicon-containing compound, unreacted silanol remains on the outermost surface layer, or cyclic silicon is formed by an acid catalyst necessary for condensation. The chemical stability of the substrate tends to be insufficient due to decomposition of the contained compound. As a result, when images are formed repeatedly over a long period of time, the wear resistance of the photoreceptor tends to decrease.

  On the other hand, for the purpose of improving the wear resistance of the photoreceptor for a longer period, a photoreceptor having an outermost surface layer formed of a cured film cured by chain polymerization is known. When this photoreceptor is used, the wear resistance of the photoreceptor is improved over a long period of time. However, it has been found that the wear resistance of the cleaning blade for cleaning the photoconductor tends to be lowered while the wear resistance of the photoconductor is improved. That is, when the same image is repeatedly formed, there is a difference in the wear state of the photoconductor and the wear state of the cleaning blade between the portion corresponding to the image forming area of the photoconductor and the portion corresponding to the non-image forming area of the photoconductor. It has been found that image quality differences are likely to occur.

Therefore, in the present embodiment, the outermost surface layer is composed of a cured film of a composition containing a specific cyclic silicon-containing compound and a specific chain polymerizable charge transport material. As a result, even when images are repeatedly formed over a long period of time, the difference in image quality caused by the difference between the worn state of the photoreceptor and the worn state of the cleaning blade is suppressed.
Although this reason is not certain, it is thought to be due to the following reasons.
Since the outermost surface layer of the present embodiment is composed of a cured film obtained by chain polymerization of the composition containing the specific chain polymerizable charge transport material, the outermost surface layer is likely to be a strong and chemically stable substrate. . On the other hand, the specific cyclic silicon-containing compound is dispersed in this strong and chemically stable substrate, so that it is difficult to be decomposed when cured, and the lubricity and repellency of the cyclic silicon-containing compound in the outermost surface layer. The original functions of aqueous and releasability are likely to be expressed. As a result, not only the wear resistance of the photoconductor is improved, but also the wear resistance of the cleaning blade is improved, so that both the wear resistance of the photoconductor and the wear resistance of the cleaning blade can be achieved. As a result, even if image formation is repeated over a long period of time, a difference between the wear state of the photoconductor and the wear state of the cleaning blade hardly occurs, and the difference in image quality is suppressed.

Hereinafter, the electrophotographic photoreceptor according to the exemplary embodiment will be described in detail with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of the electrophotographic photosensitive member according to the present embodiment. 2 and 3 are schematic cross-sectional views showing other examples of the electrophotographic photosensitive member according to this embodiment.

  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 7A, the charge generation layer 2 and the charge transport layer 3 constitute a photosensitive layer.

An 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.
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, the charge transport layer 3 and the charge generation layer 2 constitute a photosensitive layer.

  The electrophotographic photoreceptor 7C shown in FIG. 3 contains a charge generation material and a charge transport material in the same layer (single layer type photosensitive layer 6). The electrophotographic photoreceptor 7C shown in FIG. 3 has a structure in which an undercoat layer 1 is provided on a conductive substrate 4, and a single-layer type photosensitive layer 6 and a protective layer 5 are sequentially formed thereon. .

In the electrophotographic photoreceptors 7A, 7B and 7C shown in FIGS. 1, 2 and 3, the protective layer 5 is the outermost surface layer disposed on the side farthest from the conductive substrate 4. In this embodiment, the outermost surface layer (protective layer 5) is composed of a cured film of a composition containing a specific cyclic silicon-containing compound and a specific chain polymerizable charge transport material.
In the electrophotographic photosensitive member shown in FIGS. 1, 2, and 3, the undercoat layer 1 may or may not be provided.

  Hereinafter, each element of the electrophotographic photoreceptor 7A shown in FIG. 1 will be described as a representative example. Note that. Reference numerals will be 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.

  Examples of roughening methods include wet honing by suspending an abrasive in water and spraying the conductive substrate, centerless grinding in which the conductive substrate is pressed against a rotating grindstone, and grinding is performed continuously. And anodizing treatment.

  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 an amino group-containing silane coupling agent is more 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 and 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, but 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. In particular, the binder resin is preferably a polycarbonate resin, and specifically, a polycarbonate copolymer having a solubility parameter calculated by the Feders method of 11.40 or more and 11.75 or less. 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 the outermost surface layer of the photoreceptor, and is composed of a cured film of a composition containing a specific cyclic silicon-containing compound and a specific chain polymerizable charge transport material. That is, the protective layer (outermost surface layer) includes a specific cyclic silicon-containing compound and a polymer or a crosslinked product of a specific chain-polymerizable charge transport material.

―Specific cyclic silicon-containing compounds―
The protective layer (outermost surface layer) contains a specific cyclic silicon-containing compound. Specifically, the protective layer includes a cyclic polysilane compound represented by the following general formula (X) (hereinafter also referred to as “specific cyclic polysilane compound”) and a cyclic polysilane compound represented by the following general formula (Y). It contains at least one selected from siloxane compounds (hereinafter sometimes referred to as “specific cyclic siloxane compounds”).

In general formula (X), A ¹ and A ² may be the same or different and each independently represents a hydrogen atom or a monovalent organic group, and x represents an integer of 4 or more and 12 or less. A plurality of A ¹ and A ² may be different from each other.

In general formula (Y), B ¹ and B ² may be the same or different, and each independently represents a hydrogen atom or a monovalent organic group, and y represents an integer of 2 or more and 6 or less. A plurality of B ¹ and B ² may be different from each other.

Here, the specific cyclic polysilane compound represented by the general formula (X) will be described.
A ¹ and A ² in the general formula (X) are a hydrogen atom or a monovalent organic group. The number of carbon atoms of the monovalent organic group represented by A ¹ and A ² in the general formula (X) is not particularly limited as long as the electrophotographic characteristics are not impaired, but is preferably 1 or more and 20 or less, more preferably 1 or more and 10 or less. preferable. By setting the number of carbon atoms of A ¹ and A ² to 1 or more and 20 or less, compatibility with other components in the coating liquid for forming the protective layer and in the protective layer is easily improved.

Examples of the monovalent organic group include a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted aralkyl group.
Examples of the alkyl group include alkyl groups having 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms). The alkyl group may be linear, branched or cyclic, but is preferably linear or branched. Examples of the substituent substituted on the alkyl group include a halogen atom (for example, a fluorine atom), an alkoxy group and the like. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, fluoroalkyl group, 2-methoxyethyl group, 2-phenoxyethyl group and the like.
Examples of the aryl group include aryl groups having 5 to 12 carbon atoms (preferably 6 to 10 carbon atoms). Examples of the substituent substituted on the aryl group include a halogen atom (for example, a fluorine atom), a linear or branched alkyl group, and an alkoxy group. Specific examples of the aryl group include phenyl group, methylphenyl group (tolyl group), dimethylphenyl group, naphthyl group, biphenyl group, methoxyphenyl group, pentafluorophenyl group, (trifluoromethyl) phenyl group and the like.
Examples of the aralkyl group include aralkyl groups having 6 to 20 carbon atoms (preferably 7 to 14 carbon atoms). Examples of the substituent substituted on the aralkyl group include a halogen atom (for example, a fluorine atom), a linear or branched alkyl group, and an alkoxy group. Specific examples of the aralkyl group include benzyl group, methylbenzyl group, dimethylbenzyl group, phenylethyl group, methylphenylethyl group, phenylpropyl group, phenylbutyl group and the like.

Also, compatibility with the other components in the composition for forming the protective layer (hereinafter sometimes referred to as “coating liquid for forming the protective layer”) and other components in the protective layer, stability, and lubricity. From the viewpoint of enhancing, A ¹ and A ² in the general formula (X) are each independently a substituted or unsubstituted alkyl group (specifically, for example, a linear or branched unsubstituted alkyl group, A linear or branched fluoroalkyl group), a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group. Furthermore, it is more preferably a linear unsubstituted alkyl group, a linear fluoroalkyl group, or a substituted or unsubstituted aryl group. In particular, from the viewpoint of compound stability, at least one of A ¹ and A ² is preferably a substituted or unsubstituted aryl group. The alkyl group is preferably a methyl group or a fluoromethyl group, and the aryl group is preferably a phenyl group or a tolyl group.

Further, x in the general formula (X) is an integer of 4 or more and 12 or less, and from the viewpoint of easily holding the specific cyclic polysilane compound in the protective layer in the protective layer forming coating solution, 4 It is preferably 10 or less and more preferably 5 or more and 8 or less.
The x repeating units in the general formula (X) are not necessarily the same, and a specific cyclic polysilane compound may be constituted by two or more repeating units in which A ¹ and A ² are different. Moreover, when there are two or more repeating units, the specific cyclic polysilane compound may be either a block copolymer or a random copolymer.

  As a method for producing a specific cyclic polysilane compound, various known methods can be used. In order to produce these specific cyclic polysilane compounds, for example, a method of dehalogenating polycondensation of halosilanes using magnesium as a reducing agent from a silicon-containing monomer having a specific structural unit (“magnesium reduction method”, WO 98 No. 29,476, etc.); a method of dehalogenating polycondensation of halosilanes in the presence of an alkali metal (“Kipping method”, J. Am. Chem. Soc., 110, 124 (1988), Macromolecules, 23, 3423 ( 1990) and the like; a method of dehalogenating polycondensation of halosilanes by electrode reduction (J. Chem. Soc., Chem. Commun., 1161 (1990), J. Chem. Soc., Chem. Commun. 897 (1992)). In the presence of a metal catalyst A method of dehydrogenating polycondensation of gins (JP-A-4-334551 etc.); a method by anionic polymerization of disilene crosslinked with biphenyl (Macromolecules, 23, 4494 (1990), etc.); ring opening of cyclic silanes And a method such as a method by polymerization. Further details are described in paragraphs [0116] to [0117] of Japanese Patent No. 4214113.

  Specific examples of the specific cyclic polysilane compound include octamethylcyclotetrasilane, octa (trifluoromethyl) cyclotetrasilane, octaphenylcyclotetrasilane, 1,2,3,4-tetramethyl-1,2,3. , 4-tetraphenylcyclotetrasilane, decamethylcyclopentasilane, deca (trifluoromethyl) cyclopentasilane, decaphenylcyclopentasilane, deca (p-tolyl) cyclopentasilane, 1,2,3,4,5 -Pentamethyl-1,2,3,4,5-pentaphenylcyclopentasilane ((methyl, phenyl) cyclopentasilane), dodecamethylcyclohexasilane, dodeca (trifluoromethyl) cyclohexasilane, dodecaphenylcyclohexasilane, 1,2,3,4,5,6-hexa Tyl-1,2,3,4,5,6-hexaphenylcyclohexasilane, tridecamethylcycloheptasilane, trideca (trifluoromethyl) cycloheptasilane, tridecaphenylcycloheptasilane, 1,2,3,4 Examples include 5,6,7-heptamethyl-1,2,3,4,5,6,7-heptaphenylcycloheptasilane, hexadecaphenylcyclooctasilane, and the like. These specific cyclic polysilane compounds may be used alone or in combination of two or more.

Next, the specific cyclic siloxane compound represented by the general formula (Y) will be described.
B ¹ and B ² in the general formula (Y) are a hydrogen atom or a monovalent organic group. The number of carbon atoms of the monovalent organic group represented by B ¹ and B ² in the general formula (Y) is not particularly limited as long as the electrophotographic characteristics are not impaired, but is preferably 1 or more and 20 or less, and preferably 1 or more and 10 or less. More preferred. By setting the number of carbon atoms of B ¹ and B ² to 1 or more and 20 or less, compatibility with other components in the coating liquid for forming the protective layer and in the protective layer is easily improved.

Examples of the monovalent organic group include a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted aralkyl group.
Preferred examples and specific examples of the alkyl group, aryl group and aralkyl group are the same as those exemplified for A ¹ and A ² in the general formula (X).

In addition, from the viewpoint of enhancing the compatibility with the other components in the protective layer-forming coating solution and the protective layer, stability, and lubricity, B ¹ and B ² in the general formula (Y) are respectively Independently, a substituted or unsubstituted alkyl group (specifically, for example, a linear or branched unsubstituted alkyl group), a linear or branched fluoroalkyl group, a substituted or unsubstituted aryl group Or a substituted or unsubstituted aralkyl group. Furthermore, a linear unsubstituted alkyl group and a linear fluoroalkyl group are more preferable. The alkyl group is preferably a methyl group or a fluoromethyl group, and the aryl group is preferably a phenyl group or a tolyl group.

Y in the general formula (Y) is an integer of 2 or more and 6 or less, and 3 or more and 5 from the viewpoint of easily maintaining the specific cyclic siloxane compound in the protective layer forming coating solution and in the protective layer. The following is preferred.
The y repeating units in the general formula (Y) are not necessarily the same, and a specific cyclic siloxane compound may be composed of two or more repeating units different in B ¹ and B ² . When the number of repeating units is 2 or more, the specific cyclic siloxane compound may be either a block copolymer or a random copolymer.

  As a method for producing a specific cyclic siloxane compound, various known methods can be used. These specific cyclic siloxane compounds are produced by hydrolytic polycondensation of the corresponding dihalosilane compound, alkoxysilane, or cyclic silazane compound; the cyclic siloxane compound is produced by directly oxidizing the dihalosilane compound with a sulfoxide compound. And a method of obtaining a new cyclic siloxane by reacting a chain siloxane containing a silanol group with a cyclic siloxane using an alkali catalyst.

  Specific examples of the specific cyclic siloxane compound include cyclo (dimethylsiloxane) s such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane; 5-trimethyl-1,3,5-triphenylcyclotrisiloxane ((methyl, phenyl) cyclotrisiloxane), 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclotetrasiloxane , 1,3,5,7,9-pentamethyl-1,3,5,7,9-pentaphenylcyclopentasiloxane and other cyclo (methylphenylsiloxane) s; hexaphenylcyclotrisiloxane, dodecaphenylcyclohexasiloxane, etc. Of cyclo (diphenylsiloxane) s; - (3,3,3-trifluoropropyl) fluorine-containing cyclosiloxane such as octamethylcyclotetrasiloxane (hexa (trifluoromethyl) cyclotrisiloxane); and the like. In addition to the above compounds, a specific cyclic siloxane compound can be synthesized and used according to a conventional method (for example, the method described in Experimental Chemical Steels 4th Edition, Volume 27, 373). These specific cyclic siloxane compounds may be used alone or in combination of two or more.

  Among the specific cyclic silicon-containing compounds, it is preferable to use a specific cyclic polysilane compound from the viewpoint of making it difficult to cause a difference between the wear state of the photoreceptor and the wear state of the cleaning blade and suppressing the difference in image quality.

  Moreover, the upper limit of the molecular weight of the specific cyclic silicon-containing compound is preferably less than 1500. By setting the molecular weight to less than 1500, the function as a lubricant is hardly lowered. The upper limit of the molecular weight is more preferably less than 1200, and even more preferably less than 1000. The lower limit of the molecular weight is preferably 150 or more, more preferably 180 or more, and even more preferably 200 or more. By setting the molecular weight to 150 or more, volatilization and sublimation hardly occur at the time of drying after the coating liquid for forming the protective layer is applied, and the amount added in the substantial protective layer is hardly lowered. As a result, the original functions of lubricity, water repellency and releasability possessed by the cyclic silicon-containing compound are easily exhibited.

  The content of the specific cyclic silicon-containing compound is preferably 1% by mass or more and 40% by mass or less, and preferably 2% by mass or more and 30% by mass or less, based on the total solid content in the protective layer forming coating solution (composition). Is more preferable. By setting the content to 1% by mass or more, the original functions of lubricity, water repellency and releasability possessed by the cyclic silicon-containing compound are easily expressed. Moreover, by setting the content to 40% by mass or less, the content of the curing component is hardly lowered, and sufficient film strength is easily obtained.

-Specific chain polymerizable charge transport material-
The specific chain polymerizable charge transport material is selected from known materials as long as it is a compound having a charge transport skeleton and at least one chain polymerizable functional group in one molecule. Here, the chain-polymerizable functional group may be a functional group capable of radical polymerization, for example, a functional group having a group containing at least a carbon double bond. Specifically, the chain polymerizable functional group is at least one selected from acryloyl group, methacryloyl group, vinylphenyl group (styryl group), allyl group, vinyl group, vinyl ether group, allyl group, and derivatives thereof. (Especially, a group which these groups have at the terminal). Among these, acryloyl group, methacryloyl group, and vinylphenyl group (styryl group) are preferable from the viewpoint of chain polymerization reactivity and mechanical strength of the obtained cured film, and further, vinylphenyl group ( Most preferred is a styryl group.
The vinyl phenyl group (styryl group) is most preferable because it has excellent charge transport performance, has few polar groups that hinder carrier transport such as -OH and -NH-, and has π electrons effective for carrier transport. It is considered that the electrical characteristics can be maintained over a long period of time because it has the property of being submerged and less likely to adhere moisture than the acryloyl group and methacryloyl group.

  The charge transporting skeleton is not particularly limited as long as it is a known structure in an electrophotographic photosensitive member. For example, nitrogen-containing hole transport such as triarylamine compounds, benzidine compounds, and hydrazone compounds is possible. And a structure that is conjugated to a nitrogen atom. Among these, a triarylamine skeleton is preferable.

  The specific chain polymerizable charge transport material is represented by the general formula (I) and the general formula (II) from the viewpoint of dispersibility of the specific silicon-containing compound in the protective layer (cured film) and the suppression of image quality difference. It is preferably at least one selected from the chain polymerizable compounds shown.

  In particular, the chain polymerizable compounds represented by the general formula (I) and the general formula (II) tend to have improved electrical characteristics and mechanical strength. The reason for this is not clear, but is thought to be as follows.

A cured film of a composition containing at least one selected from a specific chain polymerizable charge transport material (a film containing a polymer or a crosslinked product of a specific chain polymerizable charge transport material) as a protective layer (outermost surface layer) When it has, it is thought that a protective layer has the outstanding electrical property and mechanical strength. Further, it is considered that the protective layer is made thicker (for example, 10 μm or more).
This is because the specific chain polymerizable charge transport material itself is excellent in charge transport performance, and as described above, there are few polar groups that hinder carrier transport such as —OH and —NH—, and π which is effective for carrier transport. This is presumably because the vinyl phenyl group having electrons is connected to the material by polymerization, so that residual strain is suppressed and formation of a structural trap for trapping charges is suppressed.
In addition, since a specific chain polymerizable charge transport material has a property of being more hydrophobic and less likely to get moisture than an acrylic material, it is considered that electric characteristics are maintained over a long period of time.

In general formula (I), F represents a charge transporting skeleton.
L represents a divalent linking group containing two or more selected from the group consisting of an alkylene group, an alkenylene group, -C (= O)-, -N (R)-, -S-, and -O-. Show. R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group.
m represents an integer of 1 or more and 8 or less.

In general formula (II), F represents a charge transporting skeleton.
L ′ represents a trivalent or tetravalent group derived from an alkane or alkene, and an alkylene group, alkenylene group, —C (═O) —, —N (R) —, —S—, and —O—. And an (n + 1) -valent linking group containing two or more selected from the group consisting of: R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group. The trivalent or tetravalent group derived from alkane or alkene means a group obtained by removing three or four hydrogen atoms from alkane or alkene. The same applies hereinafter.
m ′ represents an integer of 1 to 6. n represents an integer of 2 or more and 3 or less.

  In general formulas (I) and (II), F represents a charge transporting skeleton, that is, a structure having charge transporting properties. Specifically, phthalocyanine compounds, porphyrin compounds, azobenzene compounds, triarylamine compounds Examples thereof include structures having charge transporting properties such as compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, quinone compounds, and fluorenone compounds.

In general formula (I), examples of the linking group represented by L include:
A divalent linking group in which —C (═O) —O— is interposed in the alkylene group,
A divalent linking group in which —C (═O) —N (R) — is interposed in an alkylene group,
A divalent linking group in which —C (═O) —S— is interposed in the alkylene group,
A divalent linking group in which -O- is interposed in the alkylene group,
A divalent linking group in which -N (R)-is interposed in the alkylene group,
A divalent linking group in which -S- is interposed in the alkylene group,
Is mentioned.
The linking group represented by L is an alkylene group, -C (= O) -O-, -C (= O) -N (R)-, -C (= O) -S-, -O. Two groups of-or -S- may be present.

Specific examples of the linking group represented by L in the general formula (I) include:
* — (CH ₂ ) _p —C (═O) —O— (CH ₂ ) _q —,
_{* - (CH 2) p -O} -C (= O) - (CH 2) r -C (= O) -O- (CH 2) q -,
* — (CH ₂ ) _p —C (═O) —N (R) — (CH ₂ ) _q —,
_{* - (CH 2) p -C} (= O) -S- (CH 2) q -,
_{* - (CH 2) p -O-} (CH 2) q -,
_{* - (CH 2) p -N} (R) - (CH 2) q -,
_{* - (CH 2) p -S-} (CH 2) q -,
_{* - (CH 2) p -O-} (CH 2) r -O- (CH 2) q -
Etc.
Here, in the linking group represented by L, p represents 0 or an integer of 1 to 6 (preferably 1 to 5). q represents an integer of 1 to 6 (preferably 1 to 5). r represents an integer of 1 to 6 (preferably 1 to 5).
In the linking group represented by L, “*” represents a site linked to F.

On the other hand, in the general formula (II), as the linking group represented by L ′, for example,
A (n + 1) -valent linking group in which —C (═O) —O— is interposed in a branched alkylene group,
A (n + 1) -valent linking group in which -C (= O) -N (R)-is interposed in a branched alkylene group;
A (n + 1) -valent linking group in which —C (═O) —S— is interposed in a branched alkylene group;
(N + 1) -valent linking group in which —O— is interposed in a branched alkylene group,
A (n + 1) -valent linking group in which -N (R)-is interposed in a branched alkylene group;
A (n + 1) -valent linking group in which -S- is interposed in a branched alkylene group;
Is mentioned.
The linkage represented by L ′ is —C (═O) —O—, —C (═O) —N (R) —, —C (═O) — in the branched alkylene group. Two groups of S-, -O-, or -S- may intervene.

In the general formula (II), as the linking group represented by L ′, for example,
* — (CH ₂ ) _p —CH [C (═O) —O— (CH ₂ ) _q —] ₂ ,
* — (CH ₂ ) _p —CH═C [C (═O) —O— (CH ₂ ) _q —] ₂ ,
_{* - (CH 2) p -CH} [C (= O) -N (R) - (CH 2) q -] 2,
_{* - (CH 2) p -CH} [C (= O) -S- (CH 2) q -] 2,
* — (CH ₂ ) _p —CH [(CH ₂ ) _r —O— (CH ₂ ) _q —] ₂ ,
_{* - (CH 2) p -CH} = C [(CH 2) r -O- (CH 2) q -] 2,
_{* - (CH 2) p -CH} [(CH 2) r -N (R) - (CH 2) q -] 2,
_{* - (CH 2) p -CH} [(CH 2) r -S- (CH 2) q -] 2,

* — (CH ₂ ) _p —O—C [(CH ₂ ) _r —O— (CH ₂ ) _q —] ₃
* — (CH ₂ ) _p —C (═O) —O—C [(CH ₂ ) _r —O— (CH ₂ ) _q —] ₃
Etc.
Here, in the linking group represented by L ′, p represents 0 or an integer of 1 to 6 (preferably 1 to 5). q represents an integer of 1 to 6 (preferably 1 to 5). r represents an integer of 1 to 6 (preferably 1 to 5). s represents an integer of 1 to 6 (preferably 1 to 5).
In the linking group represented by L ′, “*” represents a site linked to F.

Among these, in the general formula (II), as the linking group represented by L ′,
* — (CH ₂ ) _p —CH [C (═O) —O— (CH ₂ ) _q —] ₂ ,
* — (CH ₂ ) _p —CH═C [C (═O) —O— (CH ₂ ) _q —] ₂ ,
* — (CH ₂ ) _p —CH [(CH ₂ ) _r —O— (CH ₂ ) _q —] ₂ ,
_{* - (CH 2) p -CH} = C [(CH 2) r -O- (CH 2) q -] 2,
Is good.
Specifically, the group connected to the charge transporting skeleton represented by F of the chain polymerizable compound represented by the general formula (II) (corresponding to the group represented by the general formula (IIA-a)) is represented by the following general formula: It may be a group represented by (IIA-a1), the following general formula (IIA-a2), the following general formula (IIA-a3), or the following general formula (IIA-a4).

In general formula (IIA-a1) or (IIA-a2), ^Xk1 represents a divalent linking group. kq1 represents an integer of 0 or 1. X ^k2 represents a divalent linking group. kq2 represents an integer of 0 or 1.
Here, the divalent linking group represented by X ^k1 and X ^k2 is, for example, — (CH ₂ ) _p — (wherein p represents an integer of 1 to 6 (preferably 1 to 5))). Can be mentioned. Examples of the divalent linking group also include an alkyleneoxy group.

In general formula (IIA-a3) or (IIA-a4), ^Xk3 represents a divalent linking group. kq3 represents an integer of 0 or 1. X ^k4 represents a trivalent linking group. kq4 represents an integer of 0 or 1.
Here, the divalent linking group represented by X ^k3 and X ^k4 is, for example, — (CH ₂ ) _p — (wherein p represents an integer of 1 to 6 (preferably 1 to 5))). Can be mentioned. Examples of the divalent linking group also include an alkyleneoxy group.

In general formulas (I) and (II), in the linking group represented by L or L ′, the alkyl group represented by R of “—N (R) —” has 1 to 5 carbon atoms (preferably 1 4 or less) linear and branched alkyl groups, and specific examples include a methyl group, an ethyl group, a propyl group, and a butyl group.
Examples of the aryl group represented by R in “—N (R) —” include aryl groups having 6 to 15 carbon atoms (preferably 6 to 12 carbon atoms). Specific examples include phenyl groups and toluyl groups. Group, xylidyl group, naphthyl group and the like.
Examples of the aralkyl group include aralkyl groups having 7 to 15 carbon atoms (preferably 7 to 14 carbon atoms). Specific examples include a benzyl group, a phenethyl group, and a biphenylmethylene group.

In general formulas (I) and (II), m preferably represents an integer of 1 to 6.
m ′ preferably represents an integer of 1 to 6.
n preferably represents an integer of 2 or more and 3 or less.

Next, suitable compounds of the chain polymerizable compounds represented by the general formulas (I) and (II) will be described.
As the chain polymerizable compound represented by the general formulas (I) and (II), a chain polymerizable compound having a charge transporting skeleton (structure having a charge transporting property) derived from a triarylamine compound as F is preferable.
Specifically, as the chain polymerizable compound represented by the general formula (I), the general formula (Ia), the general formula (Ib), the general formula (Ic), and the general formula (I- Preference is given to at least one compound selected from the group consisting of chain-polymerizable compounds represented by d).
On the other hand, as the chain polymerizable compound represented by the general formula (II), the chain polymerizable compound represented by the general formula (II-a) is preferable.

-Chain polymerizable compound represented by general formula (Ia) The chain polymerizable compound represented by general formula (Ia) will be described.
When the chain polymerizable compound represented by the general formula (Ia) is applied as the specific chain polymerizable charge transport material, it is easy to suppress deterioration of electrical characteristics due to environmental changes. The reason is not clear, but is thought to be as follows.
First, since the chain-polymerizable compound having a (meth) acryl group that has been used conventionally has a strong hydrophilicity of a (meth) acryl group with respect to a skeleton portion that expresses charge transport performance during polymerization. It is considered that a certain kind of layer separation state is formed, which hinders hopping conduction. For this reason, a charge transporting film containing a polymer of a chain polymerizable compound having a (meth) acrylic group or a crosslinked product has a reduced efficiency of charge transport, and further has a reduced environmental stability due to partial adsorption of moisture, etc. It is thought to do.
In contrast, the chain-polymerizable compound represented by the general formula (Ia) has a vinyl-based chain-polymerizable group that is not strongly hydrophilic, and further has a single skeleton that exhibits charge transport performance. The skeletons are connected by a flexible linking group that does not have a conjugated bond such as an aromatic ring or a conjugated double bond. Since it has such a structure, it is considered that efficient charge transport performance and high strength can be achieved, and formation of a layer separation state during polymerization is suppressed. As a result, the protective layer (outermost surface layer) containing the polymer or crosslinked product of the chain polymerizable compound represented by the general formula (Ia) is excellent in both charge transport performance and mechanical strength, It is thought that the environment dependence (temperature and humidity dependence) of the charge transport performance can be reduced.
From the above, it is considered that when the chain polymerizable compound represented by the general formula (Ia) is applied, deterioration of electrical characteristics due to environmental changes is easily suppressed.

In the general formula (Ia), Ar ^{a1 to} Ar ^a4 each independently represent a substituted or unsubstituted aryl group. Ar ^a5 and Ar ^a6 each independently represent a substituted or unsubstituted arylene group. Xa represents a divalent linking group formed by combining groups selected from an alkylene group, -O-, -S-, and an ester. Da represents a group represented by the following general formula (IA-a). ac1 to ac4 each independently represents an integer of 0 or more and 2 or less. However, the total number of Da is 1 or 2.

In the general formula ^{(IA-a), L} a _{is, * - (CH 2) an} -O-CH 2 - is represented by the divalent linking group linked to the group represented by ^Ar a1 ^{to Ar a4} at * Indicates. an represents an integer of 1 or 2.

Details of the general formula (Ia) will be described below.
In general formula (Ia), the substituted or unsubstituted aryl groups represented by Ar ^{a1 to} Ar ^a4 may be the same or different.
Here, as a substituent in the substituted aryl group, other than “Da”, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and 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.

In general formula (Ia), Ar ^{a1 to} Ar ^a4 are preferably any one of the following structural formulas (1) to (7).
Incidentally, the following structural formula (1) to (7) ^can be coupled to each of Ar a1 ^{to Ar a4} were generically indicates - - _{"(Da) ac4"} "-" _{(Da) ac1} "- (D ) _C ”.

In the structural formulas (1) to (7), R ¹¹ is 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. And a phenyl group, an unsubstituted phenyl group, and an aralkyl group having 7 to 10 carbon atoms. R ¹² and R ¹³ 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 a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms. 1 group selected from the group consisting of an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom. R ¹⁴ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms, an unsubstituted phenyl group, 1 type chosen from the group which consists of a C7-C10 aralkyl group and a halogen atom is shown. Ar represents a substituted or unsubstituted arylene group. s represents 0 or 1. t represents an integer of 0 or more and 3 or less. Z ′ represents a divalent organic linking group.

  Here, in the formula (7), Ar is preferably one represented by the following structural formula (8) or (9).

In structural formulas (8) and (9), R ¹⁵ and R ¹⁶ are each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. Represents one selected from the group consisting of a phenyl group substituted with a group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom, and t1 and t2 each represent an integer of 0 to 3 Show.

  In the formula (7), Z ′ is preferably one represented by any of the following structural formulas (10) to (17).

In Structural Formulas (10) to (17), R ¹⁷ and R ¹⁸ are each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. 1 type selected from the group consisting of a phenyl group substituted with a group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom. W represents a divalent group. q1 and r1 each independently represents an integer of 1 or more and 10 or less. t3 and t4 each represent an integer of 0 or more and 3 or less.

  In the structural formulas (16) to (17), W is preferably any one of divalent groups represented by the following structural formulas (18) to (26). However, in Formula (25), u shows the integer of 0-3.

In the general formula (Ia), in the substituted or unsubstituted arylene group represented by Ar ^a5 and Ar ^a6 , the arylene group is a target position from the aryl group exemplified in the description of Ar ^{a1 to} Ar ^a4. And an arylene group in which one hydrogen atom is removed.
Moreover, as a substituent in a substituted arylene group, it is the same as that of what is mentioned as substituents other than "Da" in a substituted aryl group by description of Ar < ^a1 > -Ar < ^a4 >.

In general formula (Ia), the divalent linking group represented by Xa is an alkylene group or a divalent group formed by combining alkylene groups, —O—, —S—, and groups selected from esters. Thus, the linking group does not contain a conjugated bond such as an aromatic ring or a conjugated double bond.
Specifically, examples of the divalent linking group represented by Xa include an alkylene group having 1 to 10 carbon atoms, and an alkylene group having 1 to 10 carbon atoms and —O—, —S—, and —O. A divalent group formed by combining a group selected from —C (═O) — and —C (═O) —O— is also included.
When the divalent linking group represented by Xa is an alkylene group, the alkylene group may have a substituent such as alkyl, alkoxy, halogen, etc., and two of these substituents are bonded to each other, A structure such as a divalent linking group represented by Structural Formula (26) described as a specific example of W in Structural Formulas (16) to (17) may be used.

-Chain-polymerizable compound represented by general formula (Ib) The chain-polymerizable compound represented by general formula (Ib) will be described.
When the chain polymerizable compound represented by the general formula (Ib) is applied as a specific chain polymerizable charge transport material, wear of the protective layer (outermost surface layer) is suppressed and generation of density unevenness of the image is suppressed. It becomes easy to be done. The reason is not clear, but is thought to be as follows.
First, the bulky charge transport skeleton and the polymerization site (styryl group) are structurally close, and if it is rigid, the polymerization sites will not move easily, and residual strain due to the curing reaction tends to remain, and the charge transport skeleton is distorted. As a result, a change in the level of HOMO (the highest occupied orbit) that leads to carrier transport occurs, and as a result, the energy distribution is likely to be widened (energy disorder: σ is large).
On the other hand, through a methylene group and an ether group, flexibility is obtained in the molecular structure, and a small σ is easily obtained. Further, the methylene group and the ether group are compared with an ester group, an amide group, etc. The dipole moment (dipole moment) is small, and this effect also contributes to the reduction of σ and is considered to improve the electrical characteristics. In addition, it is considered that the flexibility of the molecular structure increases the degree of freedom of movement of the reaction site (reaction site), and the reaction rate also improves, resulting in a strong film. A structure in which a flexible connecting chain is interposed between the polymerization sites is preferable.
For this reason, it is considered that the chain polymerizable compound represented by the general formula (Ib) increases the molecular weight of the molecule itself due to the curing reaction, makes the center of gravity difficult to move, and has a high degree of freedom of the styryl group. As a result, the protective layer (outermost surface layer) containing a polymer or a crosslinked product of the chain polymerizable compound represented by the general formula (Ib) is considered to have excellent electrical properties and high strength.
From the above, it is considered that when the chain-polymerizable compound represented by the general formula (Ib) is applied, wear of the protective layer (outermost surface layer) is suppressed and occurrence of density unevenness of the image is easily suppressed.

In the general formula (Ib), Ar ^{b1 to} Ar ^b4 each independently represent a substituted or unsubstituted aryl group. Ar ^b5 represents a substituted or unsubstituted aryl group or a substituted or unsubstituted arylene group. Db represents a group represented by the following general formula (IA-b). bc1 to bc5 each independently represent an integer of 0 or more and 2 or less. bk represents 0 or 1. However, the total number of Db is 1 or 2.

In General Formula (IA-b), L ^b includes a group represented by * — (CH ₂ ) _bn —O—, and is a divalent linking group linked to a group represented by Ar ^{b1 to} Ar ^b5 at *. Indicates. bn represents an integer of 3 to 6.

Hereinafter, the details of the general formula (Ib) will be described.
In general formula (Ib), the substituted or unsubstituted aryl group represented by Ar ^{b1 to} Ar ^b4 is the substituted or unsubstituted aryl group represented by Ar ^{a1 to} Ar ^a4 in general formula (Ia). It is the same.
Ar ^b5 represents a substituted or unsubstituted aryl group when bk is 0, and examples of the substituted or unsubstituted aryl group include substituted or unsubstituted Ar ^{a1 to} Ar ^a4 in the general formula (Ia) Same as unsubstituted aryl group.
Ar ^b5 represents a substituted or unsubstituted arylene group when bk is 1, and the substituted or unsubstituted arylene group includes a substituent represented by Ar ^a5 and Ar ^a6 in the general formula (Ia) or The same as the unsubstituted arylene group.

Next, the details of the general formula (IA-b) will be described.
In the general formula (IA-b), examples of the divalent linking group represented by ^{L b,} for example,
* — (CH ₂ ) _bp —O—,
* — (CH ₂ ) _bp —O— (CH ₂ ) _bq —O—
Etc.
Here, in the linking group represented by L ^b, bp represents an integer of 3 to 6 (preferably 3 to 5). bq represents an integer of 1 to 6 (preferably 1 to 5).
Incidentally, in the linking group represented by ^{L b, "*"} represents a site connecting to a group represented by Ar b1 ^{to Ar b5.}

-Chain-polymerizable compound represented by general formula (Ic) The chain-polymerizable compound represented by general formula (Ic) will be described.
When the chain polymerizable compound represented by the general formula (Ic) is applied as a specific chain polymerizable charge transporting material, scratches are hardly generated on the surface even when used repeatedly, and image quality deterioration is easily suppressed. The reason is not clear, but is thought to be as follows.
First, when forming the outermost surface layer containing a polymer or cross-linked polymer of a specific chain polymerizable charge transport material, film shrinkage accompanying the polymerization reaction or cross-linking reaction, and around the charge transport structure and the chain polymerizable group. Aggregation of structures is thought to occur. Therefore, when the surface of the electrophotographic photosensitive member is subjected to a mechanical load by repeated use, the film itself is worn or the chemical structure in the molecule is cut, so that the film contraction and aggregation state change, and the electrophotographic photosensitive member changes. It is considered that the electrical characteristics of the image change and cause image quality degradation.
On the other hand, since the chain polymerizable compound represented by the general formula (Ic) has a styrene skeleton as the chain polymerizable group, it has good compatibility with the aryl group which is the main skeleton of the charge transport material, and the film It is thought that aggregation of charge transport structures and chain polymerizable group peripheral structures due to shrinkage, polymerization reaction or crosslinking reaction is suppressed. As a result, in the electrophotographic photosensitive member having a protective layer (outermost surface layer) containing a polymer or a crosslinked product of the chain polymerizable compound represented by the general formula (Ic), image quality deterioration due to repeated use is suppressed. Conceivable.
In addition, the chain polymerizable compound represented by the general formula (Ic) includes a charge transporting skeleton and a styrene skeleton, a specific group such as —C (═O) —, —N (R) —, and —S—. It is thought that the interaction between the specific group and the nitrogen atom in the charge transporting skeleton, the interaction between the specific groups, and the like occur by linking via a linking group containing The strength of the protective layer (outermost surface layer) containing a polymer or a crosslinked product of the chain polymerizable compound represented by -c) is considered to be further improved.
From the above, it is considered that when the chain polymerizable compound represented by the general formula (Ic) is applied, scratches are hardly generated on the surface even when used repeatedly, and image quality deterioration is easily suppressed.
Note that specific groups such as -C (= O)-, -N (R)-, and -S- are attributed to the polarity and hydrophilicity, causing the charge transportability and image quality deterioration under high humidity conditions. However, since the chain-polymerizable compound represented by the general formula (Ic) has a styrene skeleton having higher hydrophobicity than (meth) acryl as a chain-polymerizable group, the charge transportability is deteriorated and the previous cycle is reduced. It is considered that image quality deterioration such as an afterimage phenomenon (ghost) due to the history of the image hardly occurs.

In the general formula (Ic), Ar ^{c1 to} Ar ^c4 each independently represent a substituted or unsubstituted aryl group. Ar ^c5 represents a substituted or unsubstituted aryl group or a substituted or unsubstituted arylene group. Dc represents a group represented by the following general formula (IA-c). cc1 to cc5 each independently represents an integer of 0 or more and 2 or less. ck represents 0 or 1. However, the total number of Dc is 1 or more and 8 or less.

In the general formula (IA-c), ^{L C} is, -C (= O) -, - N (R) -, - S-, and, -C (= O) - and -O -, - N (R )-Or -S- represents a divalent linking group containing one or more groups selected from the group consisting of groups. R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group.

Details of the general formula (Ic) will be described below.
In general formula (Ic), the substituted or unsubstituted aryl group represented by Ar ^{c1 to} Ar ^c4 is a substituted or unsubstituted aryl group represented by Ar ^{a1 to} Ar ^a4 in general formula (Ia). It is the same.
Ar ^c5 represents a substituted or unsubstituted aryl group when ck is 0, and examples of the substituted or unsubstituted aryl group include a substituted group represented by Ar ^{a1 to} Ar ^a4 in formula (Ia) or Same as unsubstituted aryl group.
Ar ^c5 represents a substituted or unsubstituted arylene group when ck is 1, and the substituted or unsubstituted arylene group includes a substituent represented by Ar ^a5 and Ar ^a6 in formula (Ia) or The same as the unsubstituted arylene group.
The total number of Dc is preferably 2 or more, more preferably 4 or more, from the viewpoint of obtaining a protective layer (outermost surface layer) with higher strength. In general, if the number of chain polymerizable groups in one molecule is too large, as the polymerization (crosslinking) reaction proceeds, the molecules become difficult to move and the chain polymerization reactivity decreases, and the proportion of unreacted chain polymerizable groups increases. Therefore, the total number of Dc is preferably 7 or less, more preferably 6 or less.

Next, the details of the general formula (IA-c) will be described.
In the general formula (IA-c), ^examples of the divalent linking group represented by L ^c include —C (═O) —, —N (R) —, —S—, and —C (═O) —. And a divalent linking group containing a group in which —O—, —N (R) —, or —S— is combined (hereinafter referred to as “specific linking group”).
Here, the specific linking group includes, for example, —C (═O) —, —N (R) —, and —S— from the viewpoint of the balance between the strength and polarity (hydrophobicity) of the protective layer (outermost surface layer). , -C (= O) -O-, -C (= O) -N (R)-, -C (= O) -S-, -O-C (= O) -O-, -O-C (═O) —N (R) — is preferred, preferably —N (R) —, —S—, —C (═O) —O—, —C (═O) —N (H) —, — C (= O) -O-, more preferably -C (= O) -O-.
The divalent linking group represented by L ^c includes, for example, a specific linking group, a saturated hydrocarbon (including any of linear, branched, and cyclic) or aromatic hydrocarbon residues, and an oxygen atom. And a divalent linking group formed by combining a specific linking group, a linear saturated hydrocarbon residue, and an oxygen atom. The linking group is preferable.
The total number of carbon atoms contained in the divalent linking group represented by L ^c is, for example, from 1 to 20 in terms of the density of the styrene skeleton in the molecule and chain polymerization reactivity, and preferably from 2 to 10 It is as follows.

Specific examples of the divalent linking group represented by L ^c in the general formula (IA-c) include, for example,
_{* - (CH 2) cp -C} (= O) -O- (CH 2) cq -,
* — (CH ₂ ) _cp —O—C (═O) — (CH ₂ ) _cr —C (═O) —O— (CH ₂ ) _cq —,
* — (CH ₂ ) _cp —C (═O) —N (R) — (CH ₂ ) _cq —,
_{* - (CH 2) cp -C} (= O) -S- (CH 2) cq -,
_{* - (CH 2) cp -N} (R) - (CH 2) cq -,
_{* - (CH 2) cp -S-} (CH 2) cq -,
Etc.
Here, in the linking group represented by ^{L c,} cp is 0, or 1 to 6 (preferably 1 to 5) represents an integer of. cq represents an integer of 1 to 6 (preferably 1 to 5). cr represents an integer of 1 to 6 (preferably 1 to 5).
In the linking group represented by L ^c , “*” represents a site linked to the group represented by Ar ^{c1 to} Ar ^c5 .

Among these, in the general formula (IA-c), the divalent linking group represented by ^{_{L c, * - (CH 2}} ) cp -C (= O) -O-CH 2 - is preferred. That is, the group represented by the general formula (IA-c) is preferably a group represented by the following general formula (IA-c1). However, in general formula (IA-c1), cp1 shows the integer of 0-4.

-Chain-polymerizable compound represented by the general formula (Id) The chain-polymerizable compound represented by the general formula (Id) will be described.
When the chain polymerizable compound represented by the general formula (Id) is applied as a specific chain polymerizable charge transport material, wear of the protective layer (outermost surface layer) is suppressed and generation of density unevenness of the image is suppressed. It becomes easy to be done. Although the reason is not certain, it is thought that it is due to the same reason as the chain polymerizable compound represented by the general formula (Ib).
In particular, the chain polymerizable compound represented by the general formula (Id) has a higher total number of Dd of 3 or more and 8 or less than the general formula (Ib). It is considered that (crosslinked network) is easily formed and wear of the protective layer (outermost surface layer) is more easily suppressed.

In the general formula (Id), Ar ^{d1 to} Ar ^d4 each independently represent a substituted or unsubstituted aryl group. Ar ^d5 represents a substituted or unsubstituted aryl group or a substituted or unsubstituted arylene group. Dd represents a group represented by the following general formula (IA-d). dc1 to dc5 each independently represents an integer of 0 or more and 2 or less. dk represents 0 or 1. However, the total number of Dd is 3 or more and 8 or less.

In General Formula (IA-d), L ^d includes a group represented by * — (CH ₂ ) _dn —O—, and represents a divalent linking group that is coupled to Ar ^{d1 to} Ar ^d5 by *. Show. dn represents an integer of 1 to 6.

Details of the general formula (Id) will be described below.
In general formula (Id), the substituted or unsubstituted aryl group represented by Ar ^{d1 to} Ar ^d4 is the substituted or unsubstituted aryl group represented by Ar ^{a1 to} Ar ^a4 in general formula (Ia). It is the same.
Ar ^d5 represents a substituted or unsubstituted aryl group when dk is 0, and examples of the substituted or unsubstituted aryl group include substituted or unsubstituted Ar ^{a1 to} Ar ^a4 in the general formula (Ia) Same as unsubstituted aryl group.
Ar ^d5 represents a substituted or unsubstituted arylene group when dk is 1, and the substituted or unsubstituted arylene group includes a substituent represented by Ar ^a5 and Ar ^a6 in the general formula (Ia) or The same as the unsubstituted arylene group.
The total number of Dd is preferably 4 or more from the viewpoint of obtaining a protective layer (outermost surface layer) with higher strength.

Next, the details of the general formula (IA-d) will be described.
In the general formula (IA-d), examples of the divalent linking group represented by L ^d include:
* — (CH ₂ ) _dp —O—,
_{* - (CH 2) dp -O-} (CH 2) dq -O-
Etc.
Here, in the linking group represented by L ^d , dp represents an integer of 1 to 6 (preferably 1 to 5). dq represents an integer of 1 to 6 (preferably 1 to 5).
In the linking group represented by L ^d , “*” represents a site linked to the group represented by Ar ^{d1 to} Ar ^d5 .

-Chain-polymerizable compound represented by general formula (II-a) The chain-polymerizable compound represented by general formula (II-a) will be described.
When a chain-polymerizable compound represented by the general formula (II) (particularly the general formula (II-a)) is applied as a specific chain-polymerizable charge transport material, deterioration of electrical characteristics is suppressed even when used repeatedly over a long period of time. It becomes easy to be done. The reason is not clear, but is thought to be as follows.
First, the chain-polymerizable compound represented by the general formula (II) (particularly the general formula (II-a)) has two or three chain-polymerizable reactivities from a charge transporting skeleton through one linking group. It is a compound having a group (styrene group).
For this reason, the chain polymerizable compound represented by the general formula (II) (particularly the general formula (II-a)) is polymerized or crosslinked due to the presence of this linking group while maintaining a high degree of curing and the number of crosslinking sites. In this case, it is difficult to generate distortion in the charge transporting skeleton, and it is considered that it is easy to realize both a high degree of curing and excellent charge transport performance.
In addition, conventionally used charge transporting compounds having a (meth) acryl group are likely to be distorted as described above, and the reactive sites are highly hydrophilic and the charge transporting sites are highly hydrophobic. Therefore, while it is easy to perform microscopic phase separation (microphase separation), the chain polymerizable compound represented by the general formula (II) (particularly the general formula (II-a)) has a styrene group as a reactive group. In addition, the structure has a linking group that hardly causes distortion in the charge transporting skeleton when cured (crosslinked), and both the reactive site and the charge transporting site are hydrophobic. Since phase separation is difficult to occur, it is considered that efficient charge transport performance and high strength can be achieved. As a result, the protective layer (outermost surface layer) containing a polymer or a crosslinked product of the chain polymerizable compound represented by the general formula (II) (particularly the general formula (II-a)) is excellent in mechanical strength, It is considered that the charge transport performance (electrical characteristics) is more excellent.
From the above, it is considered that when the chain polymerizable compound represented by the general formula (II) (particularly, the general formula (II-a)) is applied, the deterioration of the electrical characteristics is easily suppressed even when used repeatedly over a long period of time.

In the general formula (II-a), Ar ^{k1 to} Ar ^k4 each independently represents a substituted or unsubstituted aryl group. Ar ^k5 represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted arylene group. Dk represents a group represented by the following general formula (IIA-a). kc1 to kc5 each independently represents an integer of 0 or more and 2 or less. kk represents 0 or 1. However, the total number of Dk is 1 or more and 8 or less.

In the general formula (IIA-a), L ^k represents a trivalent or tetravalent group derived from an alkane or alkene, an alkylene group, an alkenylene group, -C (= O)-, -N (R)- A (kn + 1) -valent linking group containing two or more selected from the group consisting of, -S-, and -O-. R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group. kn represents an integer of 2 or more and 3 or less.

Hereinafter, the details of the general formula (II-a) will be described.
In general formula (II-a), the substituted or unsubstituted aryl group represented by Ar ^{k1 to} Ar ^k4 is the substituted or unsubstituted aryl group represented by Ar ^{a1 to} Ar ^a4 in general formula (Ia). It is the same.
Ar ^k5 represents a substituted or unsubstituted aryl group when kk is 0. ^Examples of the substituted or unsubstituted aryl group include substituted or unsubstituted Ar ^{a1 to} Ar ^a4 in the general formula (Ia) Same as unsubstituted aryl group.
Ar ^k5 represents a substituted or unsubstituted arylene group when kk is 1, and the substituted or unsubstituted arylene group includes a substituent represented by Ar ^a5 and Ar ^a6 in the general formula (Ia) or The same as the unsubstituted arylene group.
The total number of Dk is preferably 2 or more, more preferably 4 or more, from the viewpoint of obtaining a protective layer (outermost surface layer) with higher strength. In general, if the number of chain polymerizable functional groups in one molecule is too large, as the polymerization (crosslinking) reaction proceeds, the molecule becomes difficult to move and the chain polymerization reactivity decreases, and the ratio of unreacted chain polymerizable groups decreases. Since it increases, the total number of Dc is preferably 7 or less, and more preferably 6 or less.

Next, the detail of general formula (IIA-a) is demonstrated.
In the general formula (IIA-a), the (kn + 1) -valent linking group ^represented by L ^k is, for example, the same as the (n + 1) -valent linking group represented by L ′ in the general formula (II).

Specific examples of specific chain polymerizable charge transport materials are shown below.
Specifically, the charge transporting skeleton F of the general formulas (I) and (II) (for example, a portion corresponding to the skeleton excluding Da in the general formula (Ia) and Dk of the general formula (II-a)). Together with specific examples of functional groups linked to the charge transporting skeleton F (for example, a site corresponding to Da in the general formula (Ia) or Dk in the general formula (II-a)). Specific examples of the chain polymerizable compound represented by (II) and (II) are shown below, but are not limited thereto.
In the specific examples of the charge transporting skeleton F in the general formulas (I) and (II), the “*” part means that the “*” part of the functional group linked to the charge transporting skeleton F is linked. To do.
That is, for example, the exemplary compound (Ib) -1 is shown as a specific example of the charge transporting skeleton F: (M1) -1, and a specific example of the functional group: (R2) -1. The typical structure shows the following structure.

  First, specific examples of the charge transporting skeleton F are shown below.

  Next, specific examples of the functional group linked to the charge transporting skeleton F are shown.

  Next, specific examples of the compound represented by the general formula (I), specifically, the general formula (Ia) are shown.

Next, specific examples of the compound represented by the general formula (I), specifically, the general formula (Ib) are shown.

  Next, specific examples of the compound represented by the general formula (I), specifically, the general formula (Ic) are shown.

  Next, specific examples of the compound represented by the general formula (I), specifically, the general formula (Id) will be shown.

  Next, specific examples of the compound represented by the general formula (II), specifically, the general formula (II-a) are shown.

A specific chain polymerizable charge transport material (particularly, a chain polymerizable compound represented by the general formula (I)) is synthesized, for example, as follows.
That is, a specific chain polymerizable charge transport material is synthesized by etherification with a carboxylic acid or alcohol as a precursor and a corresponding chloromethylstyrene or the like.

  An example of the synthesis route of the exemplary compound (Id) -22 of a specific chain polymerizable charge transport material is shown below.

The arylamine compound carboxylic acid is an ester group of an arylamine compound, for example, as described in Experimental Chemistry Course, 4th edition, volume 20, p. As described in No. 51 and the like, it can be obtained by hydrolysis using a basic catalyst (NaOH, K ₂ CO ₃ etc.) and an acidic catalyst (eg phosphoric acid, sulfuric acid etc.).
In this case, various solvents can be used, and it is preferable to use alcohols such as methanol, ethanol, ethylene glycol, or a mixture of water.
Furthermore, when the solubility of the arylamine compound is low, methylene chloride, chloroform, toluene, dimethyl sulfoxide, ether, tetrahydrofuran or the like may be added.
Although there is no restriction | limiting in particular in the quantity of a solvent, For example, it is 1 mass part or more and 100 mass parts or less with respect to 1 mass part of arylamine compounds containing an ester group, Preferably it is used by 2 mass parts or more and 50 mass parts or less. Good.
The reaction temperature is set, for example, in the range from room temperature (for example, 25 ° C.) to the boiling point of the solvent, and is preferably 50 ° C. or higher in view of the reaction rate.
Although there is no restriction | limiting in particular about the quantity of a catalyst, For example, 0.001 mass part or more and 1 mass part or less with respect to 1 mass part of arylamine compounds containing an ester group, Preferably it is 0.01 mass part or more and 0.5 It is good to use below mass parts.
When hydrolysis is performed with a basic catalyst after the hydrolysis reaction, the generated salt is neutralized with an acid (for example, hydrochloric acid or the like) and released. Furthermore, after washing thoroughly with water, use after drying, or if necessary, recrystallize and purify with an appropriate solvent such as methanol, ethanol, toluene, ethyl acetate, acetone, etc. Also good.

  The alcohol form of the arylamine compound may be prepared by reacting the ester group of the arylamine compound with, for example, Experimental Chemistry Course, 4th edition, volume 20, p. As described in No. 10 and the like, it is synthesized by reducing to the corresponding alcohol using lithium aluminum hydride, sodium borohydride or the like.

  For example, when a chain polymerizable functional group is introduced by an ester bond, normal esterification in which an arylamine compound carboxylic acid and hydroxymethylstyrene are subjected to dehydration condensation with an acid catalyst, an arylamine compound carboxylic acid, and a methyl halide are used. A method of condensing styrene with a base such as pyridine, piperidine, triethylamine, dimethylaminopyridine, trimethylamine, DBU, sodium hydride, sodium hydroxide, potassium hydroxide can be used, but a method using halogenated methylstyrene Is preferable because by-products are suppressed.

The halogenated methylstyrene is preferably added in an amount of 1 equivalent or more, preferably 1.2 equivalents or more, more preferably 1.5 equivalents or more with respect to the acid of the arylamine compound carboxylic acid. It is preferably used in an amount of from 8 equivalents to 2.0 equivalents, preferably from 1.0 equivalents to 1.5 equivalents.
Solvents include aprotic polar solvents such as N-methylpyrrolidone, dimethyl sulfoxide, N, N-dimethylformamide; ketone solvents such as acetone and methyl ethyl ketone; ether solvents such as diethyl ether and tetrahydrofuran; toluene, chlorobenzene, 1 -Aromatic solvents such as chloronaphthalene; and the like are effective, and ranges from 1 part by weight to 100 parts by weight, preferably from 2 parts by weight to 50 parts by weight with respect to 1 part by weight of the arylamine compound carboxylic acid. It is good to be used in.
The reaction temperature is not particularly limited. After completion of the reaction, the reaction solution is poured into water, extracted with a solvent such as toluene, hexane, or ethyl acetate, washed with water, and further purified using an adsorbent such as activated carbon, silica gel, porous alumina, or activated clay if necessary. May be.

In addition, when introduced by an ether bond, arylamine compound alcohol and halogenated methylstyrene are converted into bases such as pyridine, piperidine, triethylamine, dimethylaminopyridine, trimethylamine, DBU, sodium hydride, sodium hydroxide, potassium hydroxide, etc. It is preferable to use a method of condensing with.
The halogenated methylstyrene is preferably added in an amount of 1 equivalent or more, preferably 1.2 equivalents or more, more preferably 1.5 equivalents or more with respect to the alcohol of the arylamine compound alcohol. It is 8 to 2.0 equivalents, preferably 1.0 to 1.5 equivalents.
Solvents include aprotic polar solvents such as N-methylpyrrolidone, dimethyl sulfoxide, N, N-dimethylformamide ; ketone solvents such as acetone and methyl ethyl ketone ; ether solvents such as diethyl ether and tetrahydrofuran ; toluene, chlorobenzene, 1 -Aromatic solvents such as chloronaphthalene ; etc. are effective, and in the range of 1 to 100 parts by weight, preferably 2 to 50 parts by weight with respect to 1 part by weight of the arylamine compound alcohol. It is good to use.
The reaction temperature is not particularly limited. After completion of the reaction, the reaction solution is poured into water, extracted with a solvent such as toluene, hexane, or ethyl acetate, washed with water, and further purified using an adsorbent such as activated carbon, silica gel, porous alumina, or activated clay if necessary. May be.

Specific chain-polymerizable charge transport materials (especially chain-polymerizable compounds represented by the general formula (II)) include, for example, the following general charge transport material synthesis methods (formylation, esterification, etherification, hydrogenation) ) And synthesized.
-Formylation: Aromatic compounds with electron donating groups-Heterocyclic compounds-Reactions suitable for introducing formyl groups into alkenes. In general, DMF and phosphorus oxytrichloride are used, and the reaction temperature is often from room temperature (for example, 25 ° C.) to about 100 ° C.
Esterification: A condensation reaction between an organic acid and a compound containing a hydroxyl group such as alcohol or phenol. It is preferable to use a method of biasing the equilibrium toward the ester side by coexisting a dehydrating agent or removing water out of the system.
Etherification: A Williamson synthesis method in which an alkoxide and an organic halogen compound are condensed is common.
-Hydrogenation: A method in which hydrogen is reacted with an unsaturated bond using various catalysts.

  As specific chain polymerizable charge transport materials, in addition to the chain polymerizable compounds represented by the general formula (I) and the general formula (II), paragraphs [0110] to [0153] of JP2012-163893A. , Compounds described in paragraphs [0055] to [0082] of Japanese Patent No. 4365960, compounds described in paragraphs [0040] to [0043] of Japanese Patent No. 4429340, and JP2013-195762A And compounds described in paragraphs [0161] to [0166] of the publication.

  The content of the specific chain polymerizable charge transport material is, for example, preferably 40% by mass or more and 95% by mass or less, and preferably 50% by mass or more and 95% by mass or less, based on the total solid content in the coating liquid for forming the protective layer. It is.

-Resin particles-
The film constituting the protective layer (outermost surface layer) may contain resin particles.
Examples of the resin particles include polycarbonate resin particles such as bisphenol A type or bisphenol Z type; acrylic resin, methacrylic resin, polyarylate resin, polyester resin, polyvinyl chloride resin, polystyrene resin, acrylonitrile-styrene copolymer resin, Acrylonitrile-butadiene copolymer resin, polyvinyl acetate resin, polyvinyl formal resin, polysulfone resin, styrene-acrylic copolymer, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate- Insulating resin particles such as maleic anhydride resin, silicone resin, phenol-formaldehyde resin, polyacrylamide resin, polyamide resin, chlorine rubber; polyvinylcarbazole, polyvinylidene And particles of organic photoconductive polymers such as luanthracene and polyvinylpyrene.
These resin particles may be hollow particles. The resin particles may be used alone or in combination of two or more.

Moreover, the film | membrane which comprises a protective layer (outermost surface layer) may contain a fluorine-containing resin particle as a resin particle.
Examples of the fluorine-containing resin particles include fluoroolefin homopolymers, two or more types of copolymers, and copolymer particles of one or more types of fluoroolefins and non-fluorinated monomers.

  Examples of the fluoroolefin include perhaloolefins such as tetrafluoroethylene (TFE), perfluorovinyl ether, hexafluoropropylene (HFP), and chlorotrifluoroethylene (CTFE); vinylidene fluoride (VdF), trifluoroethylene, and fluoride. Non-perfluoroolefins such as vinyl; and the like.

  On the other hand, non-fluorine monomers include, for example, hydrocarbon olefins such as ethylene, propylene, and butene; alkyl vinyl ethers such as cyclohexyl vinyl ether (CHVE), ethyl vinyl ether (EVE), butyl vinyl ether, and methyl vinyl ether; polyoxyethylene allyl ether (POEAE), alkenyl vinyl ethers such as ethyl allyl ether; organosilicon compounds having reactive α, β-unsaturated groups such as vinyltrimethoxysilane (VSi), vinyltriethoxysilane, vinyltris (methoxyethoxy) silane; acrylic acid Acrylic esters such as methyl and ethyl acrylate; methacrylates such as methyl methacrylate and ethyl methacrylate; vinyl acetate, vinyl benzoate, (Trade name, vinyl ester manufactured by Shell) and the like.

  Among these, those having a high fluorination rate are preferable, such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer (PFA). ), Ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and the like are preferable. Among these, PTFE, FEP, and PFA are particularly preferable.

As the fluorine-containing resin particles, for example, particles (fluorine resin aqueous dispersion) produced by a method such as emulsion polymerization of a fluorine-based monomer may be used as they are, or may be used after thoroughly washing with water and drying. Good.
The average particle size of the fluorine-containing resin particles is preferably 0.01 μm or more and 100 μm or less, and particularly preferably 0.03 μm or more and 5 μm or less.
In addition, the average particle diameter of the said fluorine-containing resin particle means the value measured using laser diffraction type particle size distribution measuring device LA-700 (made by Horiba Seisakusho).

  As the fluorine-containing resin particles, commercially available ones may be used. For example, as PTFE particles, Fullon L173JE (Asahi Glass Co., Ltd.), Taniion THV-221AZ, Taniion 9205 (Sumitomo 3M), Lubron L2, Lubron And L5 (manufactured by Daikin).

  The fluorine-containing resin particles may be irradiated with laser light having an oscillation wavelength in the ultraviolet region. The laser beam irradiated to the fluorine-containing resin particles is not particularly limited, and examples thereof include an excimer laser. As the excimer laser light, an ultraviolet laser light having a wavelength of 400 nm or less, particularly 193 nm or more and 308 nm or less is suitable. In particular, KrF excimer laser light (wavelength: 248 nm) and ArF excimer laser light (wavelength: 193 nm) are preferred. Excimer laser light irradiation is usually performed in the air at room temperature (25 ° C.), but may be performed in an oxygen atmosphere.

The irradiation conditions of excimer laser light depend on the type of fluororesin and the required degree of surface modification, but general irradiation conditions are as follows.
Fluence: 50 mJ / cm ² / pulse or more Incident energy: 0.1 J / cm ² or more Shot number: 100 or less

Particularly suitable irradiation conditions for particularly suitable KrF excimer laser light and ArF excimer laser light are as follows.
KrF
Fluence: 100 mJ / cm ² / pulse or more 500 mJ / cm ² / pulse or less incident energy: 0.2 J / cm ² or more 2.0 J / cm ² or less number of shots: 1 to 20

ArF
Fluence: 50 mJ / cm ² / pulse or more 150 mJ / cm ² / pulse or less incident energy: 0.1 J / cm ² or more 1.0 J / cm ² or less number of shots: 1 to 20

  The content of the fluorine-containing resin particles is preferably 1% by mass or more and 20% by mass or less, and more preferably 1% by mass or more and 12% by mass or less with respect to the total solid content of the protective layer (outermost surface layer).

-Fluorine-containing dispersant-
The film constituting the protective layer (outermost surface layer) may contain a fluorine-containing dispersant together with the fluorine-containing resin particles.
Since the fluorine-containing dispersant is used to disperse the fluorine-containing resin particles in the protective layer (outermost surface layer), it preferably has a surface active action, that is, has a hydrophilic group in the molecule. A substance having a hydrophobic group is preferable.

Examples of the fluorine-containing dispersant include resins obtained by polymerizing the following reactive monomers (hereinafter referred to as “specific resins”). Specifically, a random or block copolymer of an acrylate having a perfluoroalkyl group and a monomer having no fluorine, a methacrylate homopolymer, and an acrylate having the perfluoroalkyl group, and not having the fluorine Examples thereof include random or block copolymers of monomers and random or block copolymers of methacrylate and monomers not containing fluorine. Examples of the acrylate having a perfluoroalkyl group include 2,2,2-trifluoroethyl methacrylate and 2,2,3,3,3-pentafluoropropyl methacrylate.
Moreover, as a monomer which does not have fluorine, for example, 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 Le acrylate, phenoxy polyethylene glycol methacrylate, hydroxyethyl o- phenylphenol acrylate, o- phenylphenol glycidyl ether acrylate. Also, block or branch polymers disclosed in US Pat. No. 5,637,142 and Patent No. 4,251,662 can be used. In addition, a fluorine-type surfactant is mentioned. Specific examples of the fluorosurfactant include Surflon S-611, Surflon S-385 (manufactured by AGC Seimi Chemical Co., Ltd.), Aftergent 730FL, Aftergent 750FL (manufactured by Neos), PF-636, and PF-6520 (Kitamura). Chemical Co., Ltd.), Megafac EXP, TF-1507, Megafac EXP, TF-1535 (manufactured by DIC), FC-4430, FC-4432 (manufactured by 3M), and the like.
The weight average molecular weight of the specific resin is preferably 100 or more and 50000 or less.

  The content of the fluorine-containing dispersant is preferably 0.1% by mass or more and 1% by mass or less, and more preferably 0.2% by mass or more and 0.5% by mass or less with respect to the total solid content of the protective layer (outermost surface layer). preferable.

  As a method of attaching the fluorine-containing dispersant to the surface of the fluorine-containing resin particles, the fluorine-containing dispersant may be attached directly to the surface of the fluorine-containing resin particles, or first, the above monomer is added to the fluorine-containing resin particles. The specific resin may be formed on the surface of the fluorine-containing resin particles by polymerizing after adsorbing on the surface.

  The fluorine-containing dispersant may be used in combination with other surfactants. However, the amount is preferably as small as possible, and the content of the other surfactant is preferably 0 part by mass or more and 0.1 part by mass or less, preferably 0 part by mass with respect to 1 part by mass of the fluorine-containing resin particles. It is 0.05 parts by mass or less, more preferably 0 parts by mass or more and 0.03 parts by mass or less.

Other surfactants are preferably nonionic surfactants, such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyls. Examples thereof include esters, glycerin esters, fluorosurfactants and derivatives thereof.
Specific examples of polyoxyethylenes include, for example, Emulgen 707 (manufactured by Kao Corporation), NAROACTY CL-70, NAROACTY CL-85 (manufactured by Sanyo Chemical Industries), Leocor TD-120 (manufactured by Lion Corporation), and the like. It is done.

-Compound having an unsaturated bond-
The film constituting the protective layer (outermost surface layer) may be used in combination with a compound having an unsaturated bond in addition to the specific chain polymerizable charge transport material according to the present embodiment. In this case, the protective layer includes a polymer or a crosslinked product of a specific chain polymerizable charge transport material and a compound having an unsaturated bond.
As a compound which has an unsaturated bond, any of a monomer, an oligomer, and a polymer may be sufficient. Examples of the compound having an unsaturated bond include those having no charge transporting skeleton.

Examples of the compound having an unsaturated bond include those having no charge transporting skeleton as follows.
Monofunctional monomers include, for example, 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, methoxy polyethylene glycol acrylate, methoxy polyethylene glycol methacrylate, phenoxy polyethylene glycol acrylate The Roh carboxymethyl polyethylene glycol methacrylate, hydroxyethyl o- phenylphenol acrylate, o- phenylphenol glycidyl ether acrylate, styrene, and the like.

Examples of the bifunctional monomer include diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,6-hexanediol di (meth). Examples thereof include acrylate, divinylbenzene, diallyl phthalate and the like.
Examples of the trifunctional monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, aliphatic tri (meth) acrylate, trivinylcyclohexane, and the like.
Examples of the tetrafunctional monomer include pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and aliphatic tetra (meth) acrylate.
Examples of the pentafunctional or higher monomer include dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like, as well as (meth) acrylate having a polyester skeleton, a urethane skeleton, and a phosphazene skeleton.

  Among the compounds having an unsaturated bond, examples of reactive polymers include, for example, JP-A-5-216249, JP-A-5-323630, JP-A-11-52603, and JP-A-2000-264961. And those disclosed in Japanese Patent Laid-Open No. 2005-2291.

When using a compound having an unsaturated bond that does not have a charge transporting skeleton, it is used alone or as a mixture of two or more.
The content of the compound having an unsaturated bond having no charge transporting skeleton is preferably 60% by mass or less, and preferably 55% by mass, based on the total solid content in the coating liquid for forming the protective layer. Hereinafter, it is more preferably 50% by mass or less.

-Non-reactive charge transport material-
The film constituting the protective layer (outermost surface layer) may be used in combination with a non-reactive charge transport material. Here, the non-reactive charge transport material refers to a charge transport material having a charge transport skeleton and no reactive group. When a non-reactive charge transport material is used for the protective layer (outermost surface layer), the concentration of the charge transport component is increased, which is effective for further improving the electrical characteristics. Further, a non-reactive charge transport material may be added to reduce the crosslink density and adjust the strength.

As the non-reactive charge transport material, a known charge transport material may be used. Specifically, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds. Anthracene compounds, hydrazone compounds and the like are used.
Among these, those having a triphenylamine skeleton are preferable from the viewpoint of charge mobility and compatibility.

  The non-reactive charge transport material is preferably used in an amount of 0% by mass to 30% by mass, more preferably 1% by mass to 25% by mass, based on the total solid content in the protective layer forming coating solution. More preferably, it is 5 mass% or more and 25 mass% or less.

-Other additives-
The film constituting the protective layer (outermost surface layer) is further mixed with other coupling agents, especially fluorine-containing coupling agents, for the purpose of adjusting the film formability, flexibility, lubricity, and adhesion. May be used. As this compound, various silane coupling agents and commercially available silicone hard coat agents are used. Moreover, you may use the silicon compound and fluorine-containing compound which have a radically polymerizable group.

As silane coupling agents, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxy Silane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) -3-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxysilane , Dimethyldimethoxysilane, and the like.
As commercially available hard coat agents, KP-85, X-40-9740, X-8239 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), AY42-440, AY42-441, AY49-208 (above, made by Toray Dow Corning) ) And the like.

  In order to impart water repellency and the like, (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (hepta) 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 amount according to the purpose, the amount of the fluorine-containing compound is 0.25 times or less by mass with respect to the compound containing no fluorine from the viewpoint of the film forming property of the protective layer. It is preferable. Furthermore, you may mix the reactive fluorine compound etc. which are disclosed by Unexamined-Japanese-Patent No. 2001-166510 etc.
Examples of the silicon compound and the fluorine-containing compound having a radical polymerizable group include compounds described in JP-A No. 2007-11005.

It is preferable to add a deterioration inhibitor to the film constituting the protective layer (outermost surface layer). As the deterioration inhibitor, hindered phenols or hindered amines are preferable, organic sulfur antioxidants, phosphite antioxidants, dithiocarbamate antioxidants, thiourea antioxidants, benzimidazole antioxidants. You may use well-known antioxidants, such as an agent.
The amount of the deterioration inhibitor added is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total amount of the total solid content of the protective layer.

Examples of the hindered phenol antioxidant include Irganox 1076, Irganox 1010, Irganox 1098, Irganox 245, Irganox 1330, Irganox 3114, Irganox 1076 (manufactured by Ciba Japan), 3, 5 -Di-t-butyl-4-hydroxybiphenyl and the like.
Examples of the hindered amine antioxidant include Sanol LS2626, Sanol LS765, Sanol LS770, Sanol LS744 (Sanyo Lifetech Co., Ltd.), Tinuvin 144, Tinuvin 622LD (above, manufactured by Ciba Japan), Mark LA57, Mark LA67, Mark LA62, Mark LA68, Mark LA63 (manufactured by Adeka Co., Ltd.), and thioethers include Sumilizer TPS and Sumitizer TP-D (manufactured by Sumitomo Chemical Co., Ltd.), and phosphites include Mark 2112, Mark PEP-8, Mark PEP-24G, Mark PEP-36, Mark 329K, Mark HP-10 (manufactured by Adeka) and the like.

Conductive particles, organic or inorganic particles may be added to the film constituting the protective layer (outermost surface layer).
An example of such 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 preferably silica having an average particle diameter of 1 nm to 100 nm, more preferably 10 nm to 30 nm, in an acidic or alkaline aqueous dispersion, or an organic solvent such as alcohol, ketone, or ester. It is selected from those dispersed in. As the particles, commercially available particles may be used.

  The solid content of the colloidal silica in the protective layer is not particularly limited, but is 0.1% by mass or more and 20% by mass or less, preferably 0.1% by mass based on the total solid content of the protective layer. % Or more and 15% by mass or less.

The silicone particles used as the silicon-containing particles may be selected from silicone resin particles, silicone rubber particles, and silicone surface-treated silica particles, and commercially available particles may be used.
These silicone particles are spherical, and the average particle diameter is preferably 1 nm to 500 nm, more preferably 10 nm to 100 nm.
The content of the silicone particles in the protective layer is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, based on the total solid content of the protective layer. .

Other particles include ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —SnO ₂ , ZnO ₂ —TiO ₂ , ZnO—TiO ₂ , MgO—Al ₂ O ₃ , FeO. Examples thereof include semiconductive metal oxides such as —TiO ₂ , TiO ₂ , SnO ₂ , In ₂ O ₃ , ZnO, and MgO. Furthermore, various known dispersing materials may be used to disperse the particles.

Oil such as silicone oil may be added to the film constituting the protective layer (outermost surface layer).
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 And reactive silicone oils such as siloxane and phenol-modified polysiloxane.

Metal, metal oxide, carbon black, or the like may be added to the film constituting the protective layer (outermost surface layer). 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 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 are used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed or mixed by solid solution or fusion. The average particle size of the conductive particles is preferably 0.3 μm or less, particularly preferably 0.1 μm or less.

  In order to improve the wettability of the coating film, a silicone-containing oligomer, a fluorine-containing acrylic polymer, a silicone-containing polymer, or the like may be added to the film constituting the protective layer (outermost surface layer).

-Composition-
The composition used to form the protective layer is preferably prepared as a protective layer-forming coating solution obtained by dissolving or dispersing each component in a solvent.
Examples of the solvent for the protective layer-forming coating solution include methyl ethyl ketone, methyl isobutyl ketone, diisopropyl ketone, diisobutyl ketone, ethyl n butyl ketone, di n propyl ketone, methyl n amyl ketone, methyl n butyl ketone, diethyl ketone, methyl n propyl ketone, and the like. Ketones of: isopropyl acetate, isobutyl acetate, ethyl acetate, npropyl acetate, nbutyl acetate, ethyl isovalerate, isoamyl acetate, isopropyl butyrate, isoamyl propionate, butyl butyrate, amyl acetate, butyl propionate, ethyl propionate, Examples thereof include single solvents or mixed solvents such as esters such as methyl acetate, methyl propionate, and allyl acetate. Also, 0% by mass or more and 50% by mass or less of an ether solvent (for example, diethyl ether, dioxane, diisopropyl ether, cyclopentyl methyl ether, tetrahydrofuran, etc.), an alkylene glycol solvent (for example, 1-methoxy-2-propanol, 1-ethoxy- 2-propanol, ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether acetate, etc.) may be mixed and used.

  In addition, when a coating liquid for forming a protective layer is obtained by reacting the above-mentioned components, each component may be simply mixed and dissolved, but is preferably room temperature (20 ° C.) or higher and 100 ° C. or lower, more preferably 30 ° C. Heating is performed at 80 ° C. or lower, preferably 10 minutes or longer and 100 hours or shorter, more preferably 1 hour or longer and 50 hours or shorter. In this case, it is also preferable to irradiate ultrasonic waves.

-Formation of protective layer-
The coating solution for forming the protective layer is formed on the surface to be coated (charge transport layer) by 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, a curtain coating method, It is applied by a normal method such as an ink jet coating method or a push-up coating method.
Thereafter, light, electron beam or heat is applied to the obtained coating film to cause radical polymerization, thereby curing the coating film.

As the curing method, heat, light, radiation or the like is used. When curing with heat and light, a polymerization initiator is not necessarily required, but a photocuring catalyst or a thermal polymerization initiator may be used. Known photocuring catalysts and thermal polymerization initiators are used as the photocuring catalyst and the thermal polymerization initiator. The radiation is preferably an electron beam.
By adjusting the curing method so that the reaction does not proceed too quickly, the mechanical strength and electrical properties of the protective layer (outermost surface layer) are improved, and the occurrence of film unevenness and wrinkles is also suppressed. The polymerization is preferably performed under conditions where radical generation occurs relatively slowly. From this point, thermal polymerization that allows easy adjustment of the polymerization rate is preferred. That is, the composition for forming the cured film constituting the protective layer (outermost surface layer) preferably contains a thermal radical generator or a derivative thereof.

Hereinafter, electron beam curing, photocuring, and thermal curing will be described.
-Electron beam curing When an electron beam is used, the acceleration voltage is preferably 300 KV or less, and optimally 150 KV or less. The dose is preferably in the range of 1 Mrad to 100 Mrad, more preferably in the range of 3 Mrad to 50 Mrad. When the acceleration voltage is 300 KV or less, damage caused by electron beam irradiation on the characteristics of the photoreceptor is suppressed. Further, when the dose is 1 Mrad or more, crosslinking is sufficiently performed, and when the dose is 100 Mrad or less, deterioration of the photoreceptor is suppressed.

  Irradiation is performed in an inert gas atmosphere such as nitrogen or argon at an oxygen concentration of 1000 ppm, preferably 500 ppm or less, and may be further heated to 50 ° C. or higher and 150 ° C. or lower during or after irradiation.

-Photocuring As a light source, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, etc. are used, A suitable wavelength may be selected using filters, such as a band pass filter. Irradiation time, the light intensity is selected freely, for example, the illuminance (365 nm) is 300 mW / cm ² or more, preferably 1000 mW / cm ² or less, for example, the case of irradiation with UV light of 600 mW / cm ^2, 5 seconds or more 360 What is necessary is just to irradiate for less than a second.

  Irradiation is performed under an inert gas atmosphere such as nitrogen or argon, preferably at an oxygen concentration of 1000 ppm or less, more preferably 500 ppm or less, and may be further heated to 50 ° C. or more and 150 ° C. or less during or after the irradiation.

Examples of the photocuring catalyst include intramolecular cleavage types such as benzyl ketal, alkylphenone, aminoalkylphenone, phosphine oxide, titanocene, and oxime.
More specifically, examples of the benzyl ketal system include 2,2-dimethoxy-1,2-diphenylethane-1-one.

Examples of the alkylphenone series include 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl]. 2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl- Examples include propan-1-one, acetophenone, and 2-phenyl-2- (p-toluenesulfonyloxy) acetophenone.
Examples of aminoalkylphenones include p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1 -Butanone and the like.
Examples of the phosphinoxide include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide.
Examples of the titanocene include bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium.
Examples of oxime compounds include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl)- 9H-carbazol-3-yl]-, 1- (O-acetyloxime) and the like.

Examples of the hydrogen abstraction type include benzophenone series, thioxanthone series, benzyl series, and Michler ketone series.
More specifically, examples of the benzophenone series include 2-benzoylbenzoic acid, 2-chlorobenzophenone, 4,4′-dichlorobenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, p, p′-bisdiethylaminobenzophenone, and the like. Can be mentioned.
Examples of the thioxanthone series include 2,4-diethylthioxanthen-9-one, 2-chlorothioxanthone, and 2-isopropylthioxanthone.
Examples of the benzyl type include benzyl, (±) -camphorquinone, p-anisyl and the like.

  These photopolymerization initiators are used alone or in combination of two or more.

-Thermosetting Thermal polymerization initiators include thermal radical generators or derivatives thereof. Specifically, for example, V-30, V-40, V-59, V601, V65, V-70, VF- Azo initiators such as 096, VE-073, Vam-110, Vam-111 (manufactured by Wako Pure Chemical Industries, Ltd.), OTazo-15, OTazo-30, AIBN, AMBN, ADVN, ACVA (Otsuka Chemical); Perhexa HC, Perhexa C, Perhexa V, Perhexa 22, Perhexa MC, Perbutyl H, Parkmill H, Parkmill P, Permenta H, Perocta H, Perbutyl C, Perbutyl D, Perhexyl D, Parroyl IB, Parroyl 355, Parroyl L, Parroyl SA , Nyper BW, Nyper BMT-K40 / M, Parroyl IPP, Parro Il NPP, Parroyl TCP, Parroyl OPP, Parroyl SBP, Park Mill 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 25Z, perbutyl A, perhexyl Z, perbutyl ZT, perbutyl Z (manufactured by NOF Chemical), Kayaketal AM-C55, Trigonox 36-C75, Laurox, Perkadox L-W75, Parkadox CH-50L, Trigonox TMBH, Kayacumen H, Kayabutyl H-70, Percadox BC-FF, Kaya Hexa AD, Parkadox 14, Kayabuchi C, Kayabutyl D, Kayahexa YD-E85, Parkadox 12-XL25, Parkadox 12-EB20, Trigonox 22-N70, Trigonox 22-70E, Trigonox D-T50, Trigonox 423-C70, Kayaester CND-C70, Kayaester CND-W50, Trigonox 23-C70, Trigonox 23-W50N, Trigonox 257-C70, Kaya ester P-70, Kaya ester TMPO-70, Trigonox 121, Kaya ester O, Kaya ester HTP-65W, Kaya ester AN, Trigonox 42 , Trigonox F-C50, Kaya Butyl B, Kaya Carbon EH-C70, Kaya Carbon EH-W60, Kaya Carbon I-20, Kaya Carbon BIC-75, Trigonok 117, Kayalen 6-70 (manufactured by Kayaku Akzo), Lupelox 610, Lupelox 188, Lupelox 844, Lupelox 259, Lupelox 10, Lupelox 701, Lupelox 11, Lupelox 26, Lupelox 80, Lupelox 7, Lupelox P, Lupelox P, Lupelox 546, Lupelox 554, Lupelox 575, Lupelox TANPO, Lupelox 555, Lupelox 570, Lupelox TAP, Lupelox TBIC, Lupelox TBEC, Lupelox JW, Lupelox TAIC, Lupelox DC, Lupelox DC, Lupelox DC , Lupelox 220, Lupelox 230, Lupelox 23 3, Lupelox 531 (manufactured by Arkema Yoshitomi) and the like.

  Among these, when an azo polymerization initiator having a molecular weight of 250 or more is used, the reaction proceeds without unevenness at a low temperature, so that a high-strength film with suppressed unevenness can be formed. More preferably, the molecular weight of the azo polymerization initiator is 250 or more, and more preferably 300 or more.

  The heating is performed under an inert gas atmosphere such as nitrogen or argon, and the oxygen concentration is preferably 1000 ppm or less, more preferably 500 ppm or less, preferably 50 ° C. or more and 170 ° C. or less, more preferably 70 ° C. or more and 150 ° C. or less. Preferably it is 10 minutes or more and 120 minutes or less, More preferably, 15 minutes or more and 100 minutes or less are heated.

The total content of the photocuring catalyst or the thermal polymerization initiator is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.1% by mass with respect to the total solid content in the solution for forming the protective layer. The range of 8% by mass or less is more preferable, and the range of 0.1% by mass or more and 5% by mass or less is particularly preferable.
In this embodiment, if the reaction proceeds too quickly, the structure of the coating film is difficult to be relaxed by crosslinking, and the generation of radicals is relatively slow because it tends to cause film unevenness and wrinkles. The curing method is adopted.
In particular, by combining a specific chain polymerizable charge transport material and curing by heat, the structure relaxation of the coating film is promoted, and a high protective layer (outermost surface layer) excellent in surface properties is easily obtained.

  The thickness of the protective layer is, for example, preferably set in the range of 3 μm to 40 μm, more preferably 5 μm to 35 μm.

  The structure of each layer in the function-separated type photosensitive layer has been described with reference to the electrophotographic photoreceptor shown in FIG. 1, but this structure is also applied to each layer in the function-separated type electrophotographic photoreceptor shown in FIG. Can be adopted. Further, in the case of the single-layer type photosensitive layer of the electrophotographic photosensitive member shown in FIG.

That is, the single-layer type photosensitive layer (charge generation / charge transport layer) includes a charge generation material, a charge transport material, and, if necessary, a binder resin and other known additives. Is good. These materials are the same as those described in the charge generation material 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 electrophotographic photosensitive member according to the present embodiment, the mode in which the outermost surface layer is the protective layer has been described, but a layer configuration without the protective layer may be employed.
In the case of a layer structure without a protective layer, in the electrophotographic photoreceptor shown in FIG. 1, the charge transport layer located on the outermost surface in the layer structure becomes the outermost surface layer. And the electric charge transport layer used as the said outermost surface layer is comprised with the cured film of the said specific composition.
In the case of a layer structure without a protective layer, in the electrophotographic photoreceptor shown in FIG. 3, the single-layer type photosensitive layer located on the outermost surface in the layer structure is the outermost surface layer. And the single layer type photosensitive layer used as the said outermost surface layer is comprised with the cured film of the said specific composition. However, a charge generating material is blended in the composition.
The film thickness of the charge transport layer and single-layer type photosensitive layer that are the outermost surface layers is, for example, preferably from 7 μm to 70 μm, and preferably from 10 μm to 60 μm.

[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 member 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. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

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.

  In FIG. 4, as an image forming apparatus, 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 shape) for assisting cleaning are shown. Examples are provided, but these are 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.

-Developer-
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.

Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail in detail, this embodiment is not limited to the following examples. Unless otherwise specified, “parts” and “%” represent “parts by mass” and “mass%”.
<Example 1>
-Production of undercoat layer-
100 parts by mass of zinc oxide (average particle size 70 nm: manufactured by Teica: specific surface area value 15 m 2 / g) is stirred and mixed with 500 parts by mass of toluene, and 1.3 parts by mass of a silane coupling agent (KBM503: manufactured by Shin-Etsu Chemical Co., Ltd.) 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.) Manufactured): 15 parts by mass and 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 are mixed, and dispersion is performed for 2 hours with a sand mill using glass beads having a diameter of 1 mmφ. A liquid was obtained. 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 undercoat layer forming coating solution was applied onto an aluminum substrate by a dip coating method, followed by drying and curing at 170 ° C. for 40 minutes to obtain an undercoat layer having a thickness of 20 μm.

-Fabrication of charge generation layer-
Bragg angles (2θ ± 0.2 °) of X-ray diffraction spectrum using Cukα characteristic X-ray as a charge generation material are at least 7.3 °, 16.0 °, 24.9 °, 28.0 ° 15 parts by mass of hydroxygallium phthalocyanine (CGM-1) having a diffraction peak at 10 parts by mass, vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) as binder resin, and 200 parts by mass of n-butyl acetate The mixture of parts 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 0.2 μm.

-Preparation of charge transport layer-
Next, 45 parts by mass of N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine (TPD) and bisphenol as a binder resin Z polycarbonate resin (hereinafter referred to as “PCZ500”, viscosity average molecular weight: 50,000): 55 parts by mass was added to tetrahydrofuran (THF) / toluene mixed solvent (mass ratio 70/30): 800 parts by mass, and dissolved. A coating solution for a charge transport layer was obtained. This charge transport layer 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 20 μm.

-Formation of protective layer (outermost surface layer)-
As a specific chain polymerizable charge transport material, exemplary compound (A-1): 95 parts by mass is dissolved in tetrahydrofuran (THF) / toluene mixed solvent (mass ratio 60/40): 150 parts by mass, and as an initiator, After dissolving 2 parts by mass of OTazo15 (manufactured by Otsuka Chemical Co., Ltd.), the specific compound (X-1): 3 parts by mass (parts converted in terms of solid content) is dispersed as the specific cyclic silica-containing compound, and the protective layer A forming coating solution was obtained. This coating solution for forming a protective layer was applied onto the charge transport layer and heated at 150 ° C. for 40 minutes in an atmosphere having an oxygen concentration of 100 ppm to form a protective layer having a thickness of 7 μm.
Through the above steps, an electrophotographic photosensitive member was obtained.

<Examples 2 to 26, Comparative Examples 1, 2, and 4>
According to Table 1 and Table 2, each electrophotography was performed in the same manner as in Example 1 except that the type and amount of the charge transport material (A or AC) and the silicon-containing compound (X, Y, or YC) were changed. A photoreceptor was obtained.

<Comparative Example 3>
An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the protective layer and the charge transport layer were prepared. The charge transport layer was produced according to the following procedure. The charge transport layer is the outermost surface layer.
Benzidine compound (AC-2): 45 parts by mass and, as a binder resin, PCZ500: 52 parts by mass were added to tetrahydrofuran (THF) / toluene mixed solvent (mass ratio 70/30): 800 parts by mass, and then dissolved. As a specific cyclic silica-containing compound, exemplary compound (X-1): 3 parts by mass (parts converted in terms of solid content only) was dispersed to obtain a coating solution for forming a charge transport layer. This charge transport layer forming 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 23 μm.

<Long-term output evaluation>
The electrophotographic photosensitive member obtained in each example is mounted on Doccentre-IV C2260 manufactured by Fuji Xerox Co., Ltd., and is printed on A4 paper with a solid image density of 100% under an environment of normal temperature and humidity (20 ° C., 50% RH). 300,000 images having a painted image portion and a non-image portion having an image density of 0% were continuously output. Then, the evaluation shown below was performed. For image formation, Fuji Xerox P paper (A4 size, landscape feed) was used. The evaluation results are shown in Tables 1 and 2.

-Evaluation of wear condition of photoconductor-
After outputting 300,000 sheets, a portion (hereinafter referred to as “image portion”) corresponding to an image forming region (solid image portion having an image density of 100%) of the photosensitive member, and a non-image forming region (image density 0) of the photosensitive member. % Of the non-image portion) (hereinafter referred to as “non-image portion”) was visually observed on the surface of the photoreceptor and evaluated according to the following evaluation criteria. A + indicates the best characteristics.
A +: Scratches are not confirmed even by microscopic observation.
A: Although scratches are not visually confirmed, small scratches are confirmed by microscopic observation.
B: Scratches are partially generated.
C: Scratches are generated on the entire surface.

−Evaluation of wear state (chip) of cleaning blade−
After forming 300,000 images, one solid image with an image density of 30% was output on A4 paper. The output solid image having an image density of 30% was visually observed for the presence or absence of streaks in the image area and the non-image area, and evaluated according to the following evaluation criteria. A + indicates the best characteristics.
A +: No streaks due to chipping of cleaning blade A: Three or less minor streaks due to chipping of cleaning blade B: Three or more streaks due to chipping of cleaning blade are generated C: 10 or more clear streaks are generated due to chipping of the cleaning blade

-Image quality evaluation-
After outputting 300,000 sheets, the image pattern shown in FIG. 6 was output on A4 paper. About the output image pattern, the deterioration degree of the image quality in an image part and a non-image part was observed visually, and the following evaluation criteria evaluated. A ++ indicates the best characteristics.
A ++: Best (deterioration is hardly seen in all output image patterns)
A +: Change is confirmed in the enlarged image in some of the plurality of output image patterns. A: Good (change is not visually confirmed, but change is confirmed in the enlarged image)
B: Image quality degradation can be confirmed, but acceptable level C: Image quality degradation has occurred, causing a problem

From the results shown in Tables 1 and 2, in the image quality evaluation, in this example, compared with the comparative example, the part corresponding to the image forming area (image part) and the part corresponding to the non-image area (non-image part) of the photoconductor. ), Good image quality was obtained, and the difference in the degree of image quality degradation was small. Further, in this example, better results were obtained in the evaluation of the wear state of the photoconductor after continuous output and the wear state of the cleaning blade than in the comparative example.
As a result, when the photoconductor of this embodiment is applied, even when images are repeatedly formed over a long period of time, a difference in image quality caused by a difference between the wear state of the photoconductor and the wear state of the cleaning blade is suppressed. I found out.
Specifically, Examples 3 and 4 in which the outermost surface layer contains a specific chain-polymerizable charge transport material having a vinylphenyl group are compared with Comparative Example 1 in which the charge transport material having an alkoxysilyl group is contained. Good image quality was obtained in both the image area and the non-image area, and the difference in the degree of image quality deterioration was reduced.
In addition, Example 7 in which the outermost surface layer contains a specific chain-polymerizable charge transport material and a specific cyclic silicon-containing compound is compared with Comparative Example 2 that does not contain a specific cyclic silicon-containing compound. Good image quality was obtained in both areas, and the difference in the degree of image quality degradation was small.
In addition, Example 7 in which the outermost surface layer is composed of a cured film of a composition containing a specific chain-polymerizable charge transport material is composed of a non-cured film of a composition containing a non-reactive charge transport material. Compared to Comparative Example 3, good image quality was obtained in both the image area and the non-image area, and the difference in the degree of image quality degradation was small.
Further, in Example 21, in which the outermost surface layer contains a specific cyclic siloxane compound (octamethylcyclotetrasiloxane), a better image quality was obtained in the image portion than in Comparative Example 4 containing acyclic decamethyltetrasiloxane. As a result, the difference in image quality degradation between the image portion and the non-image portion is reduced.
Further, among Examples in which the outermost surface layer contains a specific cyclic silicon-containing compound, Examples 12 to 16 containing a specific cyclic polysilane compound are compared with Examples 17 to 23 containing a specific cyclic siloxane compound. As a result, better image quality was obtained in both the image area and the non-image area, and the difference in the degree of deterioration of the image quality became smaller.
Further, Example 24 in which the addition amount of the specific cyclic polysilane compound in the outermost surface layer is 5 parts and Example 25 which is 3 parts are more continuous than Example 26 in which the addition amount is 1.5 parts. In the evaluation of the wear state of the photoreceptor after the output and the wear state of the cleaning blade, good results were obtained in the image area.

The details of the abbreviations in the table are shown below.
[Specific Chain Polymerizable Charge Transport Material (A)]
A-1: Charge transport material represented by the following structural formula

A-2: Exemplary compound (Ic) -15
A-3: Exemplary compound (Ib) -32
A-4: Exemplary compound (II) -8
A-5: Specific chain polymerizable charge transport material represented by the following structural formula

A-6: Exemplary compound (Ic) -43
A-7: Exemplified compound (Id) -20
A-8: exemplary compound (II) -58
A-9: Exemplified compound (Id) -22
A-10: Exemplified compound (Id) -28
A-11: exemplary compound (II) -56
A-12: exemplary compound (II) -50

(Charge transport material for comparative example)
AC-1: charge transport material represented by the following structural formula

AC-2: Charge transport material (benzidine compound) represented by the following structural formula

[Specific cyclic silicon-containing compound]
(Specific cyclic polysilane compound (X))
(X-1): Decaphenylcyclopentasilane (X-2): (Methyl, phenyl) cyclopentasilane (X-3): Decamethylcyclopentasilane (X-4): Deca (p- (Tolyl) cyclopentasilane. (X-5): dodecaphenylcyclohexasilane. (X-6): hexadecaphenylcyclooctasilane.

(Specific cyclic siloxane compound (Y))
(Y-1): hexamethylcyclotrisiloxane (Y-2): (methyl, phenyl) cyclotrisiloxane (Y-3): hexaphenylcyclotrisiloxane (Y-4): hexa (trifluoro (Methyl) cyclotrisiloxane (Y-5): octamethylcyclotetrasiloxane (Y-6): (methyl, phenyl) cyclotetrasiloxane (Y-7): dodecaphenylcyclohexasiloxane

(Siloxane compound for comparative example (YC))
(YC-1): Decamethyltetrasiloxane

—Synthesis of Exemplary Compound (Ic) -15—
In a 500 ml three-necked flask, 68.3 g of 4,4′-bis (2-methoxycarbonylethyl) diphenylamine, 46.4 g of 4-iodoxylene, 30.4 g of potassium carbonate, 1.5 g of copper sulfate pentahydrate, 50 ml of n-tridecane Was added, and the system was stirred for 20 hours while heating at 220 ° C. while flowing nitrogen. Thereafter, the temperature was lowered to room temperature, and 200 ml of toluene and 150 ml of water were added to carry out a liquid separation operation. The toluene layer was collected, 20 g of sodium sulfate was added and stirred for 10 minutes, and then sodium sulfate was filtered. The crude product obtained by evaporating toluene under reduced pressure was purified by silica gel column chromatography using toluene / ethyl acetate as an eluent to obtain 65.1 g of (Ic) -15a (yield 73%).
59.4 g of (Ic) -15a and 450 ml of tetrahydrofuran were added to a 3 L three-necked flask, and an aqueous solution in which 11.7 g of sodium hydroxide was dissolved in 450 ml of water was added thereto, followed by stirring at 60 ° C. for 3 hours. Thereafter, the reaction solution was added dropwise to 1 L of water / 60 ml of concentrated hydrochloric acid, and the precipitated solid was collected by suction filtration. Further, 50 ml of an acetone / water mixed solvent (volume ratio 40/60) was added to this solid and stirred in a suspended state, then collected by suction filtration, dried in vacuo for 10 hours, and 46 of (Ic) -15b was obtained. 0.2 g was obtained (yield 83%).
To a 500 ml three-necked flask, 29.2 g of (Ic) -15b, 23.5 g of 4-chloromethylstyrene, 21.3 g of potassium carbonate, 0.17 g of nitrobenzene, 175 ml of DMF (N, N-dimethylformamide) were added, The system was stirred for 3 hours with nitrogen flowing and heated to 75 ° C. Thereafter, the temperature was lowered to room temperature, and 200 ml of ethyl acetate / 200 ml of water was added to the reaction solution to carry out a liquid separation operation. The ethyl acetate layer was collected, 10 g of sodium sulfate was added and stirred for 10 minutes, and then the sodium sulfate was filtered. The crude product obtained by distilling off ethyl acetate under reduced pressure was purified by silica gel column chromatography using toluene / ethyl acetate as an eluent to obtain 36.4 g of Exemplified Compound (Ic) -15 (yield 80%). .

—Synthesis of Exemplary Compound (Ic) -43—
In a 500 ml three-necked flask, 68.3 g of 4,4′-bis (2-methoxycarbonylethyl) diphenylamine, 43.4 g of 4,4′-diiodo 3,3′-dimethyl-1,1′-biphenyl, 30.4 g of potassium carbonate, Copper sulfate pentahydrate (1.5 g) and n-tridecane (50 ml) were added, and the system was stirred for 20 hours while heating at 220 ° C. with nitrogen flow. Thereafter, the temperature was lowered to room temperature, and 200 ml of toluene and 150 ml of water were added to carry out a liquid separation operation. The toluene layer was collected, 10 g of sodium sulfate was added and stirred for 10 minutes, and then the sodium sulfate was filtered. The crude product obtained by evaporating toluene under reduced pressure was purified by silica gel column chromatography using toluene / ethyl acetate as an eluent to obtain 56.0 g of (Ic) -43a (yield 65%).
To a 3 L three-necked flask, 43.1 g of (Ic) -43a and 350 ml of tetrahydrofuran were added, an aqueous solution in which 8.8 g of sodium hydroxide was dissolved in 350 ml of water was added, and the mixture was stirred for 5 hours while heating to 60 ° C. did. Thereafter, the reaction solution was added dropwise to 1 L of water / 40 ml of concentrated hydrochloric acid, and the precipitated solid was collected by suction filtration. The solid was further added with 50 ml of an acetone / water mixed solvent (volume ratio 40/60), stirred in a suspended state, collected by suction filtration, dried in vacuo for 10 hours, and (Ic) -43b was replaced with 36. 0.6 g was obtained (yield 91%).
To a 500 ml three-necked flask, 28.2 g of (Ic) -43b, 23.5 g of 4-chloromethylstyrene, 21.3 g of potassium carbonate, 0.09 g of nitrobenzene, 175 ml of DMF (N, N-dimethylformamide) were added, The system was stirred for 5 hours while flowing nitrogen and heating to 75 ° C. Thereafter, the temperature was lowered to room temperature, and 200 ml of ethyl acetate / 200 ml of water was added to the reaction solution to carry out a liquid separation operation. The ethyl acetate layer was collected, 10 g of sodium sulfate was added and stirred for 10 minutes, and then the sodium sulfate was filtered. The crude product obtained by distilling off ethyl acetate under reduced pressure was purified by silica gel column chromatography using toluene / ethyl acetate as an eluent to obtain 37.8 g of Exemplified Compound (Ic) -43 (yield 85%). .

  Other exemplary compounds were also synthesized according to the above synthesis.

1 subbing layer, 2 charge generation layer, 3 charge transport layer, 4 conductive support, 5 protective layer, 6 single-layer type photosensitive layer (charge generation / charge transport layer), 7A, 7B, 7C, 7 electrophotographic photosensitive layer Body, 8 charging device, 9 exposure device, 11 developing device, 13 cleaning device, 14 lubricant, 40 transfer device, 50 intermediate transfer body, 100, 120 image forming device, 300 process cartridge

Claims (14)

A conductive substrate, and a photosensitive layer provided on the conductive substrate,
The outermost surface layer has at least one selected from cyclic silicon-containing compounds represented by the following general formula (X) and the following general formula (Y), and a charge having at least one chain polymerizable functional group in one molecule An electrophotographic photoreceptor comprising a cured film of a composition containing a transport material.


(In General Formula (X), A ¹ and A ² may be the same or different and each independently represents a hydrogen atom or a monovalent organic group, and x represents an integer of 4 or more and 12 or less. A certain A ¹ and A ² may be the same or different.


(In General Formula (Y), B ¹ and B ² may be the same or different, and each independently represents a hydrogen atom or a monovalent organic group, and y represents an integer of 2 or more and 4 or less. B ¹ and B ² may be the same or different.) A ¹ and A ² in the general formula (X) and B ¹ and B ² in the general formula (Y) are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member represents a substituted or unsubstituted aralkyl group.   The electrophotographic photosensitive member according to claim 1, wherein x in the general formula (X) represents an integer of 4 or more and 10 or less. The electrophotographic photoreceptor according to claim 1, wherein y in the general formula (Y) represents an integer of 3 or more and 4 or less.   The electrophotographic photoreceptor according to claim 1, wherein at least one of the chain polymerizable functional groups is an acryloyl group, a methacryloyl group, or a vinylphenyl group. The electrophotographic photosensitive material according to any one of claims 1 to 5, wherein the charge transport material is at least one selected from the compounds represented by the following general formula (I) and the following general formula (II). body.


(In general formula (I), F represents a charge transporting skeleton. L represents an alkylene group, an alkenylene group, —C (═O) —, —N (R) —, —S—, and —O—). And R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and m represents an integer of 1 or more and 8 or less.)


(In general formula (II), F represents a charge transporting skeleton. L ′ represents a trivalent or tetravalent group derived from an alkane or alkene, an alkylene group, an alkenylene group, —C (═O )-, -N (R)-, -S-, and -O-, and represents an (n + 1) -valent linking group containing two or more selected from the group consisting of -O-, where R represents a hydrogen atom, an alkyl group, an aryl A group or an aralkyl group, m ′ represents an integer of 1 to 6, and n represents an integer of 2 to 3. A conductive substrate, and a photosensitive layer provided on the conductive substrate,
The outermost surface layer has at least one selected from cyclic silicon-containing compounds represented by the following general formula (X) and the following general formula (Y), and a charge having at least one chain polymerizable functional group in one molecule A charge transport material, wherein the charge transport material is a cured film of a composition that is at least one selected from the charge transport materials represented by the following general formula (I) and the following general formula (II): Electrophotographic photoreceptor.


(In general formula (X), A ¹ And A ² May be the same or different and each independently represents a hydrogen atom or a monovalent organic group, and x represents an integer of 4 or more and 12 or less. Multiple A ¹ And A ² May be the same or different. )


(In general formula (Y), B ¹ And B ² May be the same or different and each independently represents a hydrogen atom or a monovalent organic group, and y represents an integer of 2 or more and 6 or less. Multiple B ¹ And B ² May be the same or different. )


(In general formula (I), F represents a charge transporting skeleton. L represents an alkylene group, an alkenylene group, —C (═O) —, —N (R) —, —S—, and —O—). And R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and m represents an integer of 1 or more and 8 or less.)


(In general formula (II), F represents a charge transporting skeleton. L ′ represents a trivalent or tetravalent group derived from an alkane or alkene, an alkylene group, an alkenylene group, —C (═O )-, -N (R)-, -S-, and -O-, and represents an (n + 1) -valent linking group containing two or more selected from the group consisting of -O-, where R represents a hydrogen atom, an alkyl group, an aryl A group or an aralkyl group, m ′ represents an integer of 1 to 6, and n represents an integer of 2 to 3. A in the general formula (X) ¹ And A ² And B in the general formula (Y) ¹ And B ² The electrophotographic photoreceptor according to claim 7, wherein each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group. The electrophotographic photosensitive member according to claim 7 or 8, wherein x in the general formula (X) represents an integer of 4 or more and 10 or less. The electrophotographic photoreceptor according to any one of claims 7 to 9, wherein y in the general formula (Y) represents an integer of 3 to 6. The electrophotographic photosensitive member according to claim 7, wherein at least one of the chain polymerizable functional groups is an acryloyl group, a methacryloyl group, or a vinylphenyl group. A conductive substrate, and a photosensitive layer provided on the conductive substrate,
The outermost surface layer is a cyclic silicon-containing compound represented by the following general formula (X), and at least one selected from charge transport materials represented by the following general formula (I) and the following general formula (II): An electrophotographic photosensitive member comprising a cured film of a composition containing the same.


(In General Formula (X), A ¹ and A ² may be the same or different and each independently represents a hydrogen atom or a monovalent organic group, and x represents an integer of 4 or more and 12 or less. A certain A ¹ and A ² may be the same or different.


(In general formula (I), F represents a charge transporting skeleton. L represents an alkylene group, an alkenylene group, —C (═O) —, —N (R) —, —S—, and —O—). And R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and m represents an integer of 1 or more and 8 or less.)


(In general formula (II), F represents a charge transporting skeleton. L ′ represents a trivalent or tetravalent group derived from an alkane or alkene, an alkylene group, an alkenylene group, —C (═O )-, -N (R)-, -S-, and -O-, and represents an (n + 1) -valent linking group containing two or more selected from the group consisting of -O-, where R represents a hydrogen atom, an alkyl group, an aryl A group or an aralkyl group, m ′ represents an integer of 1 to 6, and n represents an integer of 2 to 3. The electrophotographic photosensitive member according to any one of claims 1 to 12 ,
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 12 ,
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: