JP6327981B2 - Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus - Google Patents

Description

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

  As an electrophotographic photosensitive member mounted on an electrophotographic apparatus, there is an electrophotographic photosensitive member containing an organic photoconductive substance (charge generating substance), and extensive studies have been made so far. In recent years, for the purpose of extending the life and image quality of an electrophotographic photosensitive member, it has been required to improve the image flow as the mechanical durability (abrasion resistance) of the electrophotographic photosensitive member is improved. .

  The image flow is a phenomenon in which the output image is blurred due to the electrostatic latent image being blurred. This is considered to be caused by the fact that the discharge product generated by charging remains on the surface of the electrophotographic photosensitive member, thereby altering the constituent material of the surface of the electrophotographic photosensitive member.

  As a means for suppressing this image flow, a method of attaching or containing a urea compound to the surface layer of the electrophotographic photoreceptor can be mentioned. Patent Document 1 describes a method for suppressing image flow by attaching a long-chain alkyl group-containing urea compound to the outermost surface layer of an electrophotographic photosensitive member. Further, Patent Document 2 proposes that image flow is suppressed by including a urea compound having two or more urea sites in the surface layer of the electrophotographic photosensitive member.

Japanese Patent No. 3805142 JP2013-08014A

  However, as a result of the study by the present inventors, the urea compound described in Patent Document 1 is not sufficiently effective in suppressing the image flow of the electrophotographic photosensitive member, and has a streak-like shape during image formation in a low-temperature and low-humidity environment. An image defect occurred. Although the urea compound described in Patent Document 2 has an effect of suppressing image flow, it has been found that there is room for improvement in terms of suppressing streak-like image defects during image formation in a low-temperature and low-humidity environment.

  An object of the present invention is to provide an electrophotographic photosensitive member having a protective layer that suppresses image flow and suppresses streak-like image defects during image formation in a low-temperature and low-humidity environment. is there. Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

（式（１）〜（３）中、Ｒ^１１、Ｒ^１３、Ｒ^２１、Ｒ^２４、Ｒ^３１、Ｒ^３２、Ｒ^３４は、それぞれ独立に、アルキル基を示す。Ｒ^１２、Ｒ^２２、Ｒ^２３、Ｒ^３３は、それぞれ独立に、アルキレン基を示す。Ａｒ^２３、Ａｒ^３２は、それぞれ独立に、置換もしくは無置換のアリーレン基を示す。Ａｒ^１１〜Ａｒ^１４、Ａｒ^２１、Ａｒ^２２、Ａｒ^２４、Ａｒ^２５、Ａｒ^３１、Ａｒ^３３、Ａｒ^３４は、それぞれ独立に、置換もしくは無置換のアリール基を示す。該置換アリーレン基の置換基としては、アルキル基、アルコキシ基、または、ハロゲン原子である。該置換アリール基の置換基としては、アルキル基、アルコキシ基、またはハロゲン原子である。） The above object is achieved by the present invention described below.
The present invention relates to an electrophotographic photoreceptor having a support, a charge generation layer formed on the support, a charge transport layer formed on the charge generation layer, and a protective layer formed on the charge transport layer. In
The protective layer is
A curable resin;
At least one compound selected from the group consisting of a compound represented by the following formula (1), a compound represented by the following formula (2), and a compound represented by the following formula (3);
The present invention relates to an electrophotographic photosensitive member containing

(In the formulas (1) to (3), R ¹¹ , R ¹³ , R ²¹ , R ²⁴ , R ³¹ , R ³² , R ³⁴ each independently represents an alkyl group. R ¹² , R ²² , R ^23. , R ³³ each independently represents an alkylene group, Ar ²³ and Ar ³² each independently represent a substituted or unsubstituted arylene group, Ar ^{11 to} Ar ¹⁴ , Ar ²¹ , Ar ²² , Ar ²⁴ , Ar ²⁵ , Ar ³¹ , Ar ³³ , and Ar ³⁴ each independently represents a substituted or unsubstituted aryl group, and the substituent of the substituted arylene group is an alkyl group, an alkoxy group, or a halogen atom. (The substituent of the substituted aryl group is an alkyl group, an alkoxy group, or a halogen atom.)

  The present invention also provides a process in which the electrophotographic photosensitive member and at least one means selected from the group consisting of a charging means, a developing means, and a cleaning means are integrally supported and detachable from the main body of the electrophotographic apparatus. To provide a cartridge.

  Another object of the present invention is to provide an electrophotographic apparatus having the electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit, and a transfer unit.

  According to the present invention, in an electrophotographic photosensitive member having a protective layer, an electrophotographic photosensitive member that suppresses image flow and suppresses streak-like image defects at the time of image formation in a low-temperature and low-humidity environment is provided. it can. In addition, according to the present invention, a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member can be provided.

It is a figure which shows an example of the laminated constitution of the electrophotographic photoreceptor of this invention. 1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having the electrophotographic photosensitive member of the present invention.

  As described above, the electrophotographic photosensitive member of the present invention is formed on a support, a charge generation layer formed on the support, a charge transport layer formed on the charge generation layer, and a charge transport layer. A protective layer. The protective layer is at least selected from the group consisting of a curable resin, a compound represented by the formula (1), a compound represented by the formula (2), and a compound represented by the formula (3). 1 type of compound is contained, It is characterized by the above-mentioned. The compounds represented by the formula (1), formula (2) and formula (3) are urea compounds.

  The present inventors presume the reason why the electrophotographic photosensitive member of the present invention suppresses streak-like image defects during image formation in a low temperature and low humidity environment as follows.

  In the urea compound described in JP2013-08014A, it is presumed that the aryl or arylene group of the nitrogen atom of the urea site forms an ion pair with nitric acid derived from the discharge product. Thus, image flow is suppressed. However, the nitrogen atom in the urea moiety has an aryl group or an arylene group, and the urea molecule has a rigid structure. As a result, it is presumed that the molecules of the urea compound are easily stacked and easily aggregated, and are less likely to be uniformly present in the film. In particular, it is presumed that in a low temperature and low humidity environment, the molecules are less likely to move, more easily aggregate, and are less likely to exist uniformly in the film. Therefore, it is presumed that streak-like image defects are likely to occur in a low temperature and low humidity environment.

  On the other hand, the urea compound used in the present invention has an alkylene group or an aralkylene group between the urea sites. As a result, the rigidity of the urea molecule is relaxed and it is difficult to agglomerate, and it is assumed that the urea molecule exists uniformly in the film. Therefore, it is presumed that streak-like image defects are suppressed in a low temperature and low humidity environment.

  JP-A-58-65438 discloses an electrophotographic photoreceptor provided with a layer of a photoconductive composition containing a urea compound. However, a streak-like image in a low-temperature and low-humidity environment is disclosed. There is no suggestion about the suppression of defects and the effect of image flow suppression.

前記式（１）〜（３）中、Ｒ^１１、Ｒ^１３、Ｒ^２１、Ｒ^２４、Ｒ^３１、Ｒ^３２、Ｒ^３４は、それぞれ独立に、アルキル基を示す。Ｒ^１２、Ｒ^２２、Ｒ^２３、Ｒ^３３は、それぞれ独立に、アルキレン基を示す。Ａｒ^２３、Ａｒ^３２は、それぞれ独立に、置換もしくは無置換のアリーレン基を示す。Ａｒ^１１〜Ａｒ^１４、Ａｒ^２１、Ａｒ^２２、Ａｒ^２４、Ａｒ^２５、Ａｒ^３１、Ａｒ^３３、Ａｒ^３４は、それぞれ独立に、置換もしくは無置換のアリール基を示す。 The protective layer of the electrophotographic photoreceptor of the present invention contains at least one compound selected from the group consisting of compounds represented by the following formulas (1), (2), and (3).

In said formula (1)-(3), R < ¹¹ >, R <^13> , R <^21> , R <^24> , R < ^{31 >} , R ^{< 32>} , R ^<34 > shows an alkyl group each independently. R ¹² , R ²² , R ²³ and R ³³ each independently represents an alkylene group. Ar ²³ and Ar ³² each independently represent a substituted or unsubstituted arylene group. Ar ^{11 to} Ar ¹⁴ , Ar ²¹ , Ar ²² , Ar ²⁴ , Ar ²⁵ , Ar ³¹ , Ar ³³ , Ar ³⁴ each independently represents a substituted or unsubstituted aryl group.

Examples of the arylene group for Ar ²³ and Ar ³² include a phenylene group, a biphenylene group, a fluorenylene group, and a naphthylene group. The substituent for the substituted arylene group is an alkyl group, an alkoxy group, or a halogen atom.

  Examples of the alkyl group include a methyl group, an ethyl group, and an n-propyl group. Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

Examples of the aryl group for Ar ^{11 to} Ar ¹⁴ , Ar ²¹ , Ar ²² , Ar ²⁴ , Ar ²⁵ , Ar ³¹ , Ar ³³ , Ar ³⁴ include a phenyl group, a naphthyl group, and an anthryl group. The substituent for the substituted aryl group is an alkyl group, an alkoxy group, or a halogen atom. Examples of the alkyl group include a methyl group, an ethyl group, and an n-propyl group. Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

From the viewpoint of suppressing streak-like image defects due to aggregation caused by the interaction between urea compounds and obtaining an excellent image flow suppression effect, Ar ^{11 to} Ar ¹⁴ , Ar ^{21 of} the above formulas (1) to (3), Ar ²² , Ar ²⁴ , Ar ²⁵ , Ar ³¹ , Ar ³³ , Ar ³⁴ are each independently a substituted or unsubstituted phenyl group, and Ar ²³ , Ar ^{32 in} the above formulas (1) to (3) are Each independently represents a substituted or unsubstituted phenylene group, and the substituted phenyl group and the substituent of the substituted phenylene group are preferably a methyl group, an ethyl group, an n-propyl group, or a methoxy group.

In said formula (1)-(3), R < ¹¹ >, R <^13> , R <^21> , R <^24> , R < ^{31 >} , R ^{< 32>} , R ^<34 > shows an alkyl group each independently. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. Among these, R ¹¹ , R ¹³ , R ²¹ , R ²⁴ , R ³¹ , R and R ¹¹ , R ¹³ , R ²¹ , R ²⁴ , R ³¹ , R are preferable from the viewpoint of suppressing streak-like image defects due to aggregation caused by interaction between urea compounds and obtaining an excellent image flow suppression effect. ³² and R ³⁴ are each independently preferably any one of a methyl group, an ethyl group, and an n-propyl group.

In said formula (1)-(3), R < ¹² >, R < ²² >, R ^{< 23>} , R ^<33 > shows an alkylene group each independently. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and a hexylene group. Among these, R ¹² , R ²² , R ²³ , and R ³³ are each independently selected from the group consisting of a methylene group, an ethylene group, and a propylene group from the viewpoint of suppressing streak-like image defects due to aggregation caused by the interaction between urea compounds. Any group is preferred.

  The urea compound used in the present invention represented by the above formula (1), formula (2) and formula (3) may contain only one type in the protective layer of the electrophotographic photoreceptor, or two or more types. You may make it contain. From the viewpoint of the effect of the present invention, the content of the urea compound of the present invention is preferably 0.1% by mass or more and 50% by mass or less with respect to the total mass of the surface layer of the electrophotographic photosensitive member. More preferably, it is 0.1 mass% or more and 10 mass% or less.

Said urea compound is compoundable using the synthesis method described in the following literature, for example.
-Photochem. Photobiol. Sci. , 2002, 1, P30-37
・ Transactions of the Farad Society, 34, 1938, P783-786
Tetrahedron Letters, 39, (1998), P6267-6270
Bulletin of the Chemical Society of Japan, vol. 47 (4), 1974, P935-937.

Specific examples of the urea compound used in the present invention are listed below, but the present invention is not limited to these.

  Among these, exemplary compounds (1-1) to (1-6), (2-3) to (2-5), and (3-1) to (3-3) are preferable.

  As shown in FIG. 1, the electrophotographic photosensitive member of the present invention includes a support, a charge generation layer formed on the support, a charge transport layer formed on the charge generation layer, and a charge transport layer. It has the formed protective layer.

  In FIG. 1, a charge generation layer 102 is formed on a support 101, a charge transport layer 103 is formed on the charge generation layer, and a protective layer 104 is formed on the charge transport layer. A conductive layer and an undercoat layer may be provided between the support 101 and the charge generation layer 102 as necessary.

  As described above, the protective layer of the electrophotographic photoreceptor of the present invention includes at least one compound selected from the group consisting of the compounds represented by the formula (1), formula (2), and formula (3), and curing. Contains a functional resin. The curable resin is a cured product of a resin obtained by polymerizing a compound having a reactive functional group and three-dimensionally crosslinking and curing.

  Examples of the compound having a reactive functional group used in the protective layer of the electrophotographic photoreceptor of the present invention include an olefin compound (a compound having only one double bond C = C) and a halogenated olefin compound (double A compound having only one bond C = C and having halogen X (X is F, Cl, Br or I), a diene compound (a compound having two or more double bonds C = C), an acetylene compound (Compounds having one or more triple bonds C≡C), styrene compounds (C═CAr (where Ar is an aromatic ring or aromatic heterocyclic ring) structure), vinyl compounds (vinyl group C═C— Compound), acrylic acid compound (C═C—CO—Z (where Z is O, S or N) or C═C—CN structure), cyclic ether compound (having —O— bond in the ring) Cyclic compound Or a lactone compound (a cyclic compound having a —CO—O— bond in the ring), a lactam compound (a cyclic compound having a —NH—CO— bond in the ring), a cyclic amine compound (having a —NH— bond in the ring) Cyclic compounds), cyclic sulfide compounds (cyclic compounds having an S atom in the ring), cyclic carbonate compounds (cyclic compounds having an —O—CO—O— bond in the ring), cyclic acid anhydrides (—CO in the ring) A cyclic compound having a —O—CO— bond), a cyclic imino ether compound (a cyclic compound having a —N═C—O— bond in the ring), and an amino acid-N-carboxylic acid anhydride (—O—CO in the ring). A cyclic compound having —N═C—CO— bond) and a cyclic imide compound (cyclic ring having —CO—NH—CO— bond, —NH—CO—O— bond or —NH—CO—NH— bond in the ring) Compound) and ring Phosphorus-containing compounds (cyclic compounds having a P atom in the ring), cyclic silicon-containing compounds (cyclic compounds having a Si atom in the ring), cyclic olefin compounds (cyclic compounds in which the ring is composed of carbon or carbon multiple bonds), phenol Compounds (compounds having an aromatic hydroxyl structure), melamine / urea compounds (melamines or urea derivatives), diamine compounds (including diamine derivatives and polyamines), dicarboxylic acid compounds (dicarboxylic acid (ester) derivatives), Oxycarboxylic acid compounds (oxycarboxylic acid (ester) derivatives), aminocarboxylic acid compounds (aminocarboxylic acid (ester) derivatives), diol compounds (polyols having two or more free OH groups), diisocyanate compounds ( Iso (thio) cyanate derivatives) and sulfur-containing compounds (including Sulfur (S) monomers), phosphorus-containing compounds (phosphorus-containing (P) monomers), aromatic ether compounds (compounds in which aromatic hydrocarbon groups are bonded with oxygen), dihalogen compounds (other than acid halides) Compounds having a plurality of carbon-halogen bonds), aldehyde compounds (compounds having an aldehyde group), diketone compounds, carbonic acid derivative compounds, aniline derivative compounds, silicon compounds, and the like.

  The compound having a reactive functional group is preferably a hole transporting compound having a reactive functional group from the viewpoint of electrical characteristics.

Further, the hole transporting compound is a hole transporting compound having an acryloyl group or a methacryloyl group from the viewpoint of film strength and electrical characteristics, and is preferably a compound represented by the following formula (4). In one embodiment of the present invention, preferably, the curable resin is a cured product obtained by polymerizing a hole transport compound having an acryloyl group or a methacryloyl group.

In formula (4), P ₁ is a group represented by the following formula (5) or (6). a represents an integer of 1 to 4. P ₁ may be the same or different.

Here, “P1 may be the same or different” means that, for example, when a = 3, all three functional groups P ₁ directly bonded to the hole transporting group A may be the same. It means that one can be the same and one can be different.

A in the above formula (4) represents a hole transport group. The hydrogen adduct (hole transporting compound) obtained by replacing the bonding site of A with P ₁ with a hydrogen atom is preferably a compound represented by the following formula (7) or the following formula (8).

式（７）中、Ｒ^４１、Ｒ^４２およびＲ^４３は、フェニル基、または置換基として炭素数１から６のアルキル基を有するフェニル基を示す。
Ｒ^４１、Ｒ^４２およびＲ^４３はそれぞれ同一であっても異なっていてもよい。炭素数１から６のアルキル基としては、メチル基、エチル基、プロビル基、ブチル基、ヘキシル基などが挙げられる。

In formula (7), R ⁴¹ , R ⁴² and R ⁴³ represent a phenyl group or a phenyl group having an alkyl group having 1 to 6 carbon atoms as a substituent.
R ⁴¹ , R ⁴² and R ⁴³ may be the same or different. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a provir group, a butyl group, and a hexyl group.

式（８）中、Ｒ^５１、Ｒ^５２、Ｒ^５３およびＲ^５４は、フェニル基、または置換基として炭素数１から６のアルキル基を有するフェニル基を示す。
Ｒ^５１、Ｒ^５２、Ｒ^５３およびＲ^５４はそれぞれ同一であっても異なっていてもよい。
炭素数１から６のアルキル基としては、メチル基、エチル基、プロピル基、ブチル基、ヘキシル基などが挙げられる。

In formula (8), R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ represent a phenyl group or a phenyl group having an alkyl group having 1 to 6 carbon atoms as a substituent.
R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may be the same or different.
Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group.

Although the preferable example of the positive hole transport compound shown by General formula (4) below is given, this invention is not limited to these.

According to another aspect of the present invention, the curable resin used for the protective layer is a cured product obtained by polymerizing a hole transporting compound having a reactive functional group from the viewpoint of film strength and electrical characteristics. In addition, the structure in which the reactive functional group of the hole transporting compound is replaced with a hydrogen atom is also preferably a structure represented by the following general formula (9).

In formula (9), R ^{61 to} R ⁶⁶ are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group. R ⁶⁷ is a group derived by removing six hydrogen atoms from a substituted or unsubstituted arene, and is a group having at least one polycyclic structure containing 12 or more sp2 carbon atoms.

n represents an integer of 1 to 10, and when n is 2 to 10, the partial structures represented by the following formula (10) in the above formula (9) may be the same or different.

Although the preferable example of the hole transportable compound shown by Formula (9) below is given, it is not limited to these.

  Next, the configuration of the electrophotographic photosensitive member used in the present invention will be described.

[Support]
Examples of the support (conductive support) of the electrophotographic photosensitive member of the present invention include metals or alloys such as aluminum, stainless steel, and nickel. In addition, a material in which a thin film of a metal such as aluminum or copper or a conductive material such as indium oxide or tin oxide is formed on an insulating support of a polyester resin or a polycarbonate resin. A resin impregnated with conductive particles such as carbon black, tin oxide particles and titanium oxide particles, or a plastic having a conductive binder resin can also be used. Examples of the shape of the support include a cylindrical shape and a sheet, but a cylindrical shape is preferable. In order to suppress interference fringes, it is preferable that the surface of the support is moderately roughened. Specifically, it is preferable to use a support that has been subjected to cutting treatment, roughening treatment, and alumite treatment.

  In the electrophotographic photoreceptor of the present invention, a conductive layer may be provided between the support and the photosensitive layer or the undercoat layer. The conductive layer can be formed by applying a conductive layer coating solution having conductive particles and a resin on a support to form a coating film, and then drying the coating film. The conductive layer contains a powder containing conductive particles. Examples of the conductive particles include powders of metals and alloys such as carbon black, acetylene black, aluminum, zinc, copper, chromium, nickel and silver, and metal oxide powders such as tin oxide and ITO. Further, rough particles may be included to suppress interference fringes.

  Examples of the resin used for the conductive layer include acrylic resin, alkyd resin, epoxy resin, phenol resin, butyral resin, polyacetal resin, polyurethane, polyester, polycarbonate, and melamine resin.

  Examples of the solvent used for the conductive layer coating solution include ether solvents, alcohol solvents, ketone solvents, and aromatic hydrocarbon solvents. The thickness of the conductive layer is preferably 0.2 μm or more and 40 μm or less, and more preferably 5 μm or more and 40 μm or less.

  In the electrophotographic photosensitive member of the present invention, an undercoat layer may be provided between the support or the conductive layer and the charge generation layer. The undercoat layer can be formed by applying a coating solution for an undercoat layer containing a resin on a support or a conductive layer to form a coating film, and drying or curing the coating film.

  As the resin used for the undercoat layer, polyvinyl alcohol resin, poly-N-vinylimidazole resin, polyethylene oxide resin, ethyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide resin, N-methoxymethylated 6 nylon, co-polymer Examples thereof include polymerized nylon. Moreover, the above-mentioned electroconductive particle can also be contained in the undercoat layer.

  Examples of the solvent for the undercoat layer coating liquid include ether solvents, alcohol solvents, ketone solvents, and aromatic hydrocarbon solvents. The thickness of the undercoat layer is preferably 0.05 μm or more and 40 μm or less, and more preferably 0.4 to 20 μm. The undercoat layer may contain semiconductive particles, an electron transport material, or an electron accepting material.

(Charge generation layer)
In the electrophotographic photoreceptor of the present invention, a charge generation layer is formed on the support, the conductive layer or the undercoat layer.

  Examples of charge generating materials used in the electrophotographic photoreceptor of the present invention include pyrylium, thiapyrylium dyes, phthalocyanine compounds, anthanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, azo pigments, indigo pigments, quinacridone pigments, quinocyanine pigments, and the like. Can be mentioned. Among these, gallium phthalocyanine is preferable. Furthermore, from the viewpoint of high sensitivity, hydroxygallium phthalocyanine crystals having peaks at 7.4 ° ± 0.3 ° and 28.2 ° ± 0.3 ° of the Bragg angle 2θ in CuKα characteristic X-ray diffraction are more preferable.

  As the binder resin used for the charge generation layer, polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, polyvinyl alcohol resin, polyvinyl acetal resin, polyvinyl benzal resin, polycarbonate resin, polyester resin, Examples include polysulfone resin, polyphenylene oxide, polyurethane resin, cellulose resin, phenol resin, melamine resin, silicon resin, and epoxy resin. These can be used singly or in combination of two or more as a mixture or copolymer.

  The charge generation layer can be formed by applying a charge generation layer coating solution obtained by dispersing a charge generation material together with a binder resin and a solvent to form a coating film, and then drying the coating film. The charge generation layer may be a vapor generation film of a charge generation material.

  In the charge generation layer, the ratio of the charge generation material to the binder resin is preferably 0.3 parts by mass or more and 4 parts by mass or less for the binder resin with respect to 1 part by mass of the charge generation material. Examples of the dispersion method include a method using a homogenizer, an ultrasonic wave, a ball mill, a sand mill, an attritor, and a roll mill.

  Examples of the solvent used in the charge generation layer coating solution include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents. The thickness of the charge generation layer is preferably from 0.01 μm to 5 μm, and more preferably from 0.1 μm to 1 μm. Various sensitizers, antioxidants, ultraviolet absorbers, plasticizers and the like can be added as necessary.

(Charge transport layer)
A charge transport layer is formed on the charge generation layer. The charge transport layer is formed by forming a coating film of a coating solution for a charge transport layer obtained by dissolving a charge transport material and a binder resin in a solvent on the charge generation layer and drying the coating film. be able to.

  Examples of the charge transport material used for the charge transport layer include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, triallylmethane compounds, and the like. In the present invention, the ratio of the charge transport material is preferably 30% by mass to 70% by mass with respect to the total mass of the charge transport layer.

  The binder resin used for the charge transport layer includes polyvinyl butyral resin, polyarylate resin, polycarbonate resin, polyester resin, phenoxy resin, polyvinyl acetate resin, acrylic resin, polyacrylamide resin, polyamide resin, polyvinyl pyridine, and cellulose resin. , Urethane resin, epoxy resin, agarose resin, casein, polyvinyl alcohol resin, polyvinylpyrrolidone and the like.

  Examples of the solvent used in the charge transport layer coating solution include ether solvents, alcohol solvents, ketone solvents, and aromatic hydrocarbon solvents. The thickness of the charge transport layer is preferably 5 μm or more and 40 μm or less.

[Protective layer]
The structure of the protective layer of the electrophotographic photosensitive member of the present invention is as described above.

  Furthermore, various additives can be added to the protective layer. Additives include degradation inhibitors such as antioxidants and UV absorbers, lubricants such as polytetrafluoroethylene (PTFE) resin fine particles and fluorocarbons, and polymerization control agents such as polymerization reaction initiators and polymerization reaction terminators. Is mentioned.

  In addition, a charge transport material can be added. Examples of the charge transport material include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triallylmethane compounds.

  The thickness of the protective layer is preferably from 0.1 μm to 15 μm. Further, it is more preferably 0.5 μm or more and 10 μm or less.

  Examples of the solvent used in the coating solution for the protective layer include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, aliphatic halogenated hydrocarbon solvents, aromatic hydrocarbon solvents, and the like. . From the viewpoint of not dissolving the lower charge transport layer, an alcohol solvent is preferred.

  Means for forming the protective layer are as follows. A protective layer is formed by forming a coating film of a coating solution for a protective layer containing a polymerizable monomer or oligomer that forms the urea compound and the curable resin on the charge transport layer, and polymerizing and drying the coating film. Preferably, a protective layer is formed by forming a coating film using the above urea compound and a coating solution for a protective layer containing a hole transporting compound having a chain polymerizable functional group, and polymerizing and drying the coating film. It is.

  Polymerization of the hole transporting compound having a reactive functional group can be performed using heat, light (such as ultraviolet rays), or radiation (such as an electron beam).

  The surface of the protective layer may be subjected to surface processing using an abrasive sheet, a shape transfer mold member, glass beads, zirconia beads, or the like. Moreover, you may form an unevenness | corrugation in the surface using the constituent material of a coating liquid.

  When applying the coating liquid for each of the above layers, a coating method such as a dip coating method (dipping method), a spray coating method, a spinner coating method, a bead coating method, a blade coating method, or a beam coating method can be used.

  FIG. 2 shows an example of a schematic configuration of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention.

  In FIG. 2, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member, which is rotationally driven with a predetermined peripheral speed (process speed) in the direction of an arrow about the shaft 2. In the rotation process, the electrophotographic photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by a charging unit (primary charging unit) 3. Next, the exposure light 4 intensity-modulated in response to a time-series electric digital image signal of target image information output from an exposure means (not shown) such as slit exposure or laser beam scanning exposure is received. In this way, electrostatic latent images corresponding to target image information are sequentially formed on the surface of the electrophotographic photosensitive member 1.

  The formed electrostatic latent image is then visualized as a toner image by regular development or reversal development with toner contained in the developing means 5. The toner image formed and supported on the surface of the electrophotographic photosensitive member 1 is sequentially transferred onto the transfer material 7 by the transfer means 6. Here, the transfer material 7 is taken out from a sheet feeding unit (not shown) in synchronization with the rotation of the electrophotographic photosensitive member 1 and fed between the electrophotographic photosensitive member 1 and the transfer means 6. Further, a bias voltage having a polarity opposite to the charge held in the toner is applied to the transfer means 6 from a bias power source (not shown). The transfer means may be an intermediate transfer type transfer means having a primary transfer member, an intermediate transfer member, and a secondary transfer member.

  The transfer material 7 that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member, conveyed to the fixing means 8, and subjected to a fixing process of the toner image, whereby an electrophotographic image forming product (print, copy) is obtained. Printed out of the device.

  The surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is cleaned by removing the deposits such as transfer residual toner by the cleaning means 9. The transfer residual toner can be collected by a developing device or the like. Further, if necessary, the charge is removed by pre-exposure light 10 from a pre-exposure means (not shown) and then repeatedly used for image formation. Note that when the charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not necessarily required.

  In the present invention, a plurality of components such as the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, the transfer unit 6, and the cleaning unit 9 may be housed in a container to form a process cartridge. The process cartridge may be detachably attached to an electrophotographic apparatus main body such as a copying machine or a laser beam printer. For example, at least one means selected from the group consisting of charging means 3, developing means 5, and cleaning means 9 is integrally supported together with the electrophotographic photosensitive member 1 to form a cartridge. Then, the process cartridge 11 can be detachably attached to the main body of the electrophotographic apparatus using guide means 12 such as a rail of the main body of the electrophotographic apparatus.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the examples, “part” means “part by mass”.

<Example 1>
An aluminum cylinder having a diameter of 30 mm, a length of 357.5 mm, and a wall thickness of 1 mm was used as a support (conductive support).

Next, 100 parts of zinc oxide particles (specific surface area: 19 m ² / g, powder resistance: 4.7 × 10 ⁶ Ω · cm) as a metal oxide are stirred and mixed with 500 parts of toluene, and this is mixed with a silane coupling agent. (Compound name: N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, trade name: KBM602, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.8 part was added and stirred for 6 hours. Thereafter, toluene was distilled off under reduced pressure, followed by heating and drying at 130 ° C. for 6 hours to obtain surface-treated zinc oxide particles.

  Next, 15 parts of butyral resin (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) and 15 parts of blocked isocyanate (trade name: Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as polyol resin were added to methyl ethyl ketone 73. It was dissolved in a mixed solution of 5 parts and 73.5 parts of 1-butanol. To this solution, 80.8 parts of the surface-treated zinc oxide particles and 0.81 part of a compound represented by 2,3,4-trihydroxybenzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) were added. The dispersion was carried out for 3 hours in an atmosphere of 23 ± 3 ° C. by a sand mill using 8 mm glass beads. After dispersion, 0.01 parts of silicone oil (trade name: SH28PA, manufactured by Toray Dow Corning Silicone), crosslinked polymethyl methacrylate (PMMA) particles (trade name: TECHPOLYMER SSX-103, manufactured by Sekisui Plastics Co., Ltd.) 5.6 parts of an average primary particle size of 3.0 μm) was added and stirred to prepare an undercoat layer coating solution.

  This undercoat layer coating solution was dip-coated on the support, and the resulting coating film was dried at 160 ° C. for 30 minutes to form an undercoat layer having a thickness of 18 μm.

Next, 4 parts of a crystalline gallium phthalocyanine crystal (charge generation material) having peaks at 7.4 ° and 28.1 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction, the above formula (1) -1) 0.04 part of a compound (manufactured by Sigma-Aldrich) and 0.04 part of a compound represented by the following formula (A) in 100 parts of cyclohexanone with a polyvinyl butyral resin (trade name: ESREC BX-1, 2 parts of Sekisui Chemical Co., Ltd.) was added to the dissolved solution. Thereafter, dispersion treatment was performed for 1 hour in an atmosphere of 23 ± 3 ° C. in a sand mill apparatus using glass beads having a diameter of 1 mm. After dispersion treatment, 100 parts of ethyl acetate was added to prepare a coating solution for a charge generation layer. The charge generation layer coating solution was dip-coated on the undercoat layer, and the resulting coating film was dried at 90 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.21 μm.

Next, 30 parts of a compound represented by the following formula (B) (charge transporting substance), 60 parts of a compound represented by the following formula (C) (charge transporting substance), 10 parts of a compound represented by the following formula (D), polycarbonate 100 parts of resin (trade name: Iupilon Z400, manufactured by Mitsubishi Engineering Plastics Co., Ltd., bisphenol Z type polycarbonate), 0.02 part of polycarbonate (viscosity average molecular weight Mv: 20000) represented by the following formula (E) are mixed. A charge transport layer coating solution was prepared by dissolving in a mixed solvent of 600 parts of xylene and 200 parts of dimethoxymethane. The charge transport layer coating solution was dip coated on the charge generation layer to form a coating film, and the resulting coating film was dried at 100 ° C. for 30 minutes to form a charge transport layer having a thickness of 18 μm. .

  Next, 97 parts of the formula (4-5) and 3 parts of the formula (1-1) are dissolved in 100 parts of n-propyl alcohol, and 1,1,2,2,3,3,4- A coating solution for a protective layer was prepared by adding 100 parts of heptafluorocyclopentane (trade name: Zeorora H, manufactured by Nippon Zeon Co., Ltd.).

  This protective layer coating solution was dip-coated on the charge transport layer, and the resulting coating film was dried at 50 ° C. for 5 minutes. After drying, under a nitrogen atmosphere, the coating film was cured by irradiating the coating film with an electron beam for 1.6 seconds under conditions of an acceleration voltage of 70 kV and an absorbed dose of 5000 Gy while rotating the cylinder. Thereafter, heat treatment was performed for 25 seconds in a nitrogen atmosphere under conditions where the coating film reached 130 ° C. The oxygen concentration from the electron beam irradiation to the heat treatment for 25 seconds was 18 ppm. Next, in the air, a heat treatment was performed for 12 minutes under the condition that the coating film became 110 ° C., thereby forming a protective layer having a film thickness of 5 μm.

  Thus, an electrophotographic photosensitive member having an undercoat layer, a charge generation layer, a charge transport layer, and a protective layer in this order on the support was produced.

<Example 2>
In Example 1, the electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-4). Manufactured.

<Example 3>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the formula (4-5) was changed to the formula (4-13) to prepare a coating solution for a protective layer.

<Example 4>
In Example 1, the electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (2-2). Manufactured.

<Example 5>
In Example 4, the same procedure as in Example 1 was carried out except that the protective layer coating solution was prepared by changing the formula (4-5) to 90 parts and the formula (2-2) to 10 parts. A photographic photoreceptor was produced.

<Example 6>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating solution for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (2-5). Manufactured.

<Example 7>
In Example 1, the electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (3-1). Manufactured.

<Example 8>
In Example 1, a protective layer coating solution was prepared by dissolving 99 parts of the formula (9-5) and 1 part of the formula (1-1) in 200 parts of tetrahydrofuran. did.

  This protective layer coating solution was dip-coated on the charge transport layer, and the resulting coating film was dried at 50 ° C. for 5 minutes. After drying, under a nitrogen atmosphere, the coating film was cured by irradiating the coating film with an electron beam for 1.6 seconds under conditions of an acceleration voltage of 70 kV and an absorbed dose of 5000 Gy while rotating the cylinder. Thereafter, heat treatment was performed for 25 seconds in a nitrogen atmosphere under conditions where the coating film reached 130 ° C. The oxygen concentration from the electron beam irradiation to the heat treatment for 25 seconds was 18 ppm. Next, in the air, a heat treatment was performed for 12 minutes under the condition that the coating film became 110 ° C., thereby forming a protective layer having a film thickness of 5 μm.

  Thus, an electrophotographic photosensitive member having an undercoat layer, a charge generation layer, a charge transport layer, and a protective layer in this order on the support was produced.

<Example 9>
In Example 8, an electrophotographic photosensitive member was produced in the same manner as in Example 8, except that the protective layer coating solution was prepared by changing the formula (9-5) to the formula (9-8).

<Example 10>
In Example 8, the electrophotographic photoreceptor was prepared in the same manner as in Example 8, except that the coating solution for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (2-2). Manufactured.

<Example 11>
In Example 8, an electrophotographic photosensitive member was prepared in the same manner as in Example 8, except that a coating solution for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (3-1). Manufactured.

<Example 12>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-7). Manufactured.

<Example 13>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating solution for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-9). Manufactured.

<Example 14>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-10). Manufactured.

<Example 15>
In Example 1, the electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (2-6). Manufactured.

<Example 16>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (2-7). Manufactured.

<Example 17>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (3-4). Manufactured.

<Example 18>
In Example 8, an electrophotographic photosensitive member was prepared in the same manner as in Example 8, except that a coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-7). Manufactured.

<Example 19>
In Example 8, the formula (9-5) was changed to the formula (9-3), and the formula (1-1) was changed to the compound represented by the formula (1-9) to obtain a coating solution for a protective layer. An electrophotographic photosensitive member was produced in the same manner as in Example 8 except that was prepared.

<Example 20>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-11). Manufactured.

<Example 21>
In Example 1, the electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-12). Manufactured.

<Example 22>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-13). Manufactured.

<Example 23>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-14). Manufactured.

<Example 24>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating solution for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (2-8). Manufactured.

<Example 25>
In Example 1, the electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (2-9). Manufactured.

<Example 26>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (3-5). Manufactured.

<Example 27>
In Example 19, an electrophotographic photosensitive member was prepared in the same manner as in Example 19 except that the protective layer coating solution was prepared by changing the formula (1-1) to the compound represented by the formula (1-11). Manufactured.

<Example 28>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-17). Manufactured.

<Example 29>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (1-18). Manufactured.

<Example 30>
In Example 1, the electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that the coating solution for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (2-11). Manufactured.

<Example 31>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (2-13). Manufactured.

<Example 32>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for protective layer was prepared by changing the formula (1-1) to the compound represented by the formula (3-6). Manufactured.

<Example 33>
In Example 19, an electrophotographic photosensitive member was prepared in the same manner as in Example 19 except that the protective layer coating solution was prepared by changing the formula (1-1) to the compound represented by the formula (1-17). Manufactured.

<Example 34>
In Example 1, the coating solution for the protective layer was trimethylolpropane triacrylate (trade name: TMPTA, manufactured by Daicel Cytec Co., Ltd.) (having an acryloyl group which is a polymerizable functional group, and had a charge transport structure. 48.5 parts, 48.5 parts of the compound represented by the formula (4-8) and 3 parts of the compound represented by the formula (1-1) were dissolved in 25 parts of n-propanol. A protective layer coating solution was prepared by adding 25 parts of 1,1,2,2,3,3,4-heptafluorocyclopentane (trade name: Zeolora H, manufactured by Nippon Zeon Co., Ltd.). This protective layer coating solution is dip coated on the charge transport layer, and the resulting coating film is heat-treated for 5 minutes at 50 ° C., and then using a metal halide lamp, under the condition of irradiation intensity: 500 mW / cm ² . The coating film was irradiated with ultraviolet rays for 20 seconds, and heat-treated for 30 minutes under the condition that the coating film reached 130 ° C., thereby forming a protective layer having a thickness of 5 μm. Except for these, an electrophotographic photosensitive member was produced in the same manner as in Example 1.

<Example 35>
In Example 1, the protective layer coating liquid was prepared by adding 97 parts of the compound represented by the formula (4-5), 3 parts of the compound represented by the formula (1-1), and polytetrafluoroethylene particles (trade name: Lubron). L2, manufactured by Daikin Co., Ltd.) and a resin having a structural unit represented by the following formula (A1) and a structural unit represented by the following formula (A2) (weight average molecular weight: 130,000, copolymerization ratio ( 1 part of A1) / (A2) = 1/1 (molar ratio)) is added to 100 parts of n-propanol and 1,1,2,2,3,3,4-heptafluorocyclopentane (trade name: Zeolora H, In addition to 100 parts of the mixed solvent (manufactured by Nippon Zeon Co., Ltd.), an electrophotography was carried out in the same manner as in Example 1 except that this was changed to a coating solution for the protective layer obtained by dispersion treatment with an ultrahigh pressure disperser. A photoreceptor was manufactured.

<Example 36>
In the same manner as in Example 1, an undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution were prepared and applied. Next, compound 1 shown by 50 parts of resol type phenolic resin (trade name: PL-4804, containing amine compound other than ammonia, manufactured by Gunei Chemical Co., Ltd.) and 150 parts of ethanol and exemplified compound (1-1) .5 parts was dissolved to prepare a protective layer coating solution. This protective layer coating solution was dip-coated on the charge transport layer, and this coated film was heat-treated at 150 ° C. for 60 minutes to form a protective layer having a thickness of 5.1 μm.

<Comparative example 1>
In Example 1, except that the formula (4-5) was changed to the formula (4-7) and a coating solution for a protective layer was prepared without adding the exemplified compound (1-1). In the same manner as in Example 1, an electrophotographic photosensitive member was produced.

<Comparative example 2>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the exemplified compound (1-1) was changed to a compound represented by the following formula (F) to prepare a coating solution for a protective layer. Manufactured.

<Comparative Example 3>
In Example 1, the formula (4-5) was changed to the formula (4-7), and the exemplified compound (1-1) was changed to a compound represented by the following formula (I) to obtain a coating solution for a protective layer. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that it was prepared.

<Comparative example 4>
In Example 1, the formula (4-5) was changed to the formula (4-7) and the exemplified compound (1-1) was changed to the compound represented by the formula (J) to obtain a protective layer coating solution. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that it was prepared.

<Comparative Example 5>
In Example 1, the formula (4-5) was changed to the formula (4-7) and the exemplified compound (1-1) was changed to the compound represented by the formula (L) to obtain a coating solution for a protective layer. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that it was prepared.

<Comparative Example 6>
In Example 36, an electrophotographic photosensitive member was produced in the same manner as in Example 36, except that the protective layer coating solution was prepared without adding the exemplified compound (1-1).

<Reference example>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the protective layer was not provided.

(Evaluation method)
The evaluation methods for the electrophotographic photoreceptors of Examples 1 to 36, Comparative Examples 1 to 9, and Reference Example are as follows.

(Image flow evaluation)
A copying machine (trade name: GP-405, manufactured by Canon Inc.), which is an electrophotographic apparatus, was used as an evaluation apparatus. As a modification point, the charging roller of the process cartridge for the copying machine has been changed to a corona charger (a corona charger for copying machine GP-55 (trade name) manufactured by Canon Inc.), and the outside of the copying machine. Modified to supply power to the corona charger. Further, the drum cartridge of GP-405 was modified so that a corona charger could be mounted, and a charger for an electrophotographic copying machine GP-55 (manufactured by Canon Inc.) was mounted as a corona charger. The heater for the electrophotographic photosensitive member (drum heater (cassette heater)) was always turned off during the evaluation.

  A high voltage power supply control system (Model 615-3, manufactured by Trek) was used as a power source for supplying power for the corona charger from the outside of the copying machine. The amount of current flowing through the corona wire of the corona charger is adjusted to 500 μA, and the initial dark portion potential (Vd) of the electrophotographic photosensitive member is about −700 (V) and the initial bright portion potential (Vl) is about −−. The constant current control scorotron grid applied voltage and the exposure light quantity conditions of the exposure apparatus were set so as to be 200 (V).

After the electrophotographic photosensitive member produced in each example is mounted on a process cartridge and mounted on the evaluation apparatus, an image with an image ratio of 3% is placed on A4 vertical size paper in an environment of a temperature of 35 ° C. and a humidity of 85% RH. Output 5000 sheets. Thereafter, the power supply to the evaluation apparatus was stopped and suspended for 2 days. Power supply to the evaluation device is started again after a two-day pause, and a character image (E character image) in which a halftone image and the letter E of the alphabet (font type: Times, font size 6 points) are repeated on A4 vertical size paper ) Was output.
Rank 5: No image defects are observed in both the lattice image and the E character image Rank 4: Some lattice images are hazy, but no image defect is observed in the E character image Rank 3: Some lattice images are hazy The E character image is partially thin Rank 2: The lattice image is partially lost, and the E character image is entirely thin Rank 1: The lattice image is entirely disappeared, and the E character image is thin

(Striped image evaluation)
The obtained electrophotographic photosensitive member is mounted on a black station of a modified machine of an electrophotographic apparatus (trade name: iR-ADV C5051) manufactured by Canon Inc. in an environment of a temperature of 0 ° C. and a humidity of 5% RH. After output, a solid black image was output and image evaluation was performed. Even during output, after 1000 sheets, 5000 sheets, and 10000 sheets were output, a solid black image was output and image evaluation was performed. The drum cycle speed was set to 0.25 seconds and the total discharge current amount in the charging process was set to 100 μA by modifying the apparatus.
The evaluation results are shown in Table 1.
Rank 3: No image defect is observed Rank 2: One or two stripe-like image defects are found Rank 1: Three or more stripe-like image defects are seen

(Abrasion evaluation)
The obtained electrophotographic photoreceptor is mounted on a black station of a modified machine of an electrophotographic apparatus (trade name: iR-ADV C5051) manufactured by Canon Inc. in an environment of a temperature of 23 ° C. and a humidity of 50% RH, and 100000 sheets After output, the amount of abrasion of the electrophotographic photosensitive member was measured. The drum cycle speed was set to 0.25 seconds and the total discharge current amount in the charging process was set to 100 μA by modifying the apparatus.

DESCRIPTION OF SYMBOLS 101 Conductive support body 102 Charge generation layer 103 Charge transport layer 104 Protective layer 1 Electrophotographic photoreceptor 2 Axis 3 Charging means 4 Exposure light 5 Development means 6 Transfer means 7 Transfer material 8 Fixing means 9 Cleaning means 10 Pre-exposure light 11 Process Cartridge 12 guide means

Claims (9)

In an electrophotographic photosensitive member having a support, a charge generation layer formed on the support, a charge transport layer formed on the charge generation layer, and a protective layer formed on the charge transport layer,
The protective layer is
A curable resin;
At least one urea compound selected from the group consisting of a compound represented by the following formula (1), a compound represented by the following formula (2), and a compound represented by the following formula (3);
An electrophotographic photosensitive member comprising:

(In the formulas (1) to (3), R ¹¹ , R ¹³ , R ²¹ , R ²⁴ , R ³¹ , R ³² , R ³⁴ each independently represents an alkyl group. R ¹² , R ²² , R ^23. , R ³³ each independently represents an alkylene group, Ar ²³ and Ar ³² each independently represent a substituted or unsubstituted arylene group, Ar ^{11 to} Ar ¹⁴ , Ar ²¹ , Ar ²² , Ar ²⁴ , Ar ²⁵ , Ar ³¹ , Ar ³³ , and Ar ³⁴ each independently represents a substituted or unsubstituted aryl group, and the substituent of the substituted arylene group is an alkyl group, an alkoxy group, or a halogen atom. (The substituent of the substituted aryl group is an alkyl group, an alkoxy group, or a halogen atom.) In the above formulas (1) to (3), Ar ^{11 to} Ar ¹⁴ , Ar ²¹ , Ar ²² , Ar ²⁴ , Ar ²⁵ , Ar ³¹ , Ar ³³ , Ar ³⁴ are each independently a substituted or unsubstituted phenyl group. In the formulas (1) to (3), Ar ²³ and Ar ³² are each independently a substituted or unsubstituted phenylene group, and the substituted phenyl group and the substituent of the substituted phenylene group are each a methyl group The electrophotographic photosensitive member according to claim 1, which is an ethyl group, an n-propyl group, or a methoxy group. In the formulas (1) to (3), R ¹¹ , R ¹³ , R ²¹ , R ²⁴ , R ³¹ , R ³² , and R ³⁴ are each independently any one of a methyl group, an ethyl group, and an n-propyl group. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is a group. The R ¹² , R ²² , R ²³ , and R ^{33 in the} formulas (1) to (3) are each independently any one of a methylene group, an ethylene group, and a propylene group. The electrophotographic photosensitive member according to any one of 1 to 3. The curable resin is a cured product obtained by polymerizing a hole transporting compound having an acryloyl group or a methacryloyl group,
The hole transporting compound is represented by the following general formula (4):

(In the formula (4), A represents a hole transporting group. P ₁ is a group represented by the following general formula (5) or (6).

a represents an integer of 1 to 4. P ₁ may be the same or different. )
The hydrogen adduct obtained by replacing the bonding site of P with P ₁ with a hydrogen atom is represented by the following formula (7) or the following formula (8): 2. The electrophotographic photosensitive member according to item 1.

(In the formula (7), R ⁴¹ , R ⁴² and R ⁴³ represent a phenyl group or a phenyl group having an alkyl group having 1 to 6 carbon atoms as a substituent. Further, R ⁴¹ , R ⁴² and R ⁴³ represent Each may be the same or different.)

(In the formula (8), R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ represent a phenyl group or a phenyl group having an alkyl group having 1 to 6 carbon atoms as a substituent, and R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may be the same or different.) The curable resin is a cured product obtained by polymerizing a hole transporting compound having a reactive functional group,
5. The electron according to claim 1, wherein the structure in which the reactive functional group of the hole transporting compound is replaced with a hydrogen atom is a structure represented by the following formula (9): Photoconductor.

(In Formula (9), R ^{61 to} R ⁶⁶ are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group. R ⁶⁷ is substituted or unsubstituted. It is a group derived by removing 6 hydrogen atoms from a substituted arene, and is a group having at least one polycyclic structure containing 12 or more sp2 carbon atoms.
n represents an integer of 1 to 10, and when n is 2 to 10, the partial structures represented by the following formula (10) in the above formula (9) may be the same or different. )

  7. The electrophotographic photosensitive member according to claim 1, wherein the content of the urea compound in the protective layer is 0.1% by mass or more and 50% by mass or less.   An electrophotographic apparatus main body integrally supporting the electrophotographic photosensitive member according to any one of claims 1 to 7 and at least one means selected from the group consisting of a charging means, a developing means, and a cleaning means. The process cartridge is detachable.   An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an exposure unit, a developing unit, and a transfer unit.

Images