Electrophotographic photosensitive body, processing box and image forming device

Abstract

The present invention provides an electrophotographic photoreceptor, a processing box and an image forming device with excellent photosensitivity and suppressed residual potential. The electrophotographic photoreceptor of the present invention comprises: a conductive substrate, an undercoat layer arranged on the conductive substrate, and a photosensitive layer arranged on the undercoat layer, wherein the undercoat layer contains titanate metal compound particles, an electron transporting compound and a binding resin.

Description

Technical Field

[0001] The present invention relates to an electrophotographic photosensitive body, a process cartridge and an image forming device. Background Art

[0002] Patent Document 1 discloses an electrophotographic photoreceptor in which an intermediate layer and a photosensitive layer are sequentially provided on a conductive support, and the intermediate layer contains a polyolefin resin and a benzimidazole-based compound.

[0003] Patent Document 2 discloses an electrophotographic photoreceptor having an undercoat layer and a photosensitive layer sequentially provided on a conductive support, wherein the undercoat layer contains an olefin resin and a benzimidazole compound, wherein the olefin resin contains a compound having at least one of a carboxylic acid group and a carboxylic anhydride group as a constituent component.

[0004] Patent Document 3 discloses an electrophotographic photoreceptor including a support, a conductive layer, and a photosensitive layer in this order, wherein the conductive layer contains strontium titanate particles or barium titanate particles coated with a coating layer containing a conductive material, and a binder.

[0005] Patent document 4 discloses an electronic photographic photoreceptor, which is obtained by stacking an intermediate layer and an organic photosensitive layer in sequence on a conductive substrate, and the intermediate layer is obtained by coating a coating liquid for forming the intermediate layer and thermally curing it, and has a thickness of more than 10 μm and less than 50 μm. The coating liquid for forming the intermediate layer is formed by dissolving or dispersing a blocked isocyanate compound, a resin having an active hydrogen-containing group capable of reacting with the isocyanate group in the blocked isocyanate compound, inorganic oxide microparticles, and an electron transport agent in an aqueous medium.

[0006] [Prior art literature]

[0007] [Patent Document]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2011-095665

[0009] [Patent Document 2] Japanese Patent Application Publication No. 2009-288621

[0010] [Patent Document 3] Japanese Patent Publication No. 2018-141972

[0011] [Patent Document 4] Japanese Patent Application Publication No. 2010-122440 Summary of the invention

[0012] [Problems to be solved by the invention]

[0013] The present disclosure aims to provide an electrophotographic photoreceptor having excellent photosensitivity and suppressed residual potential, compared with a case where an undercoat layer does not contain metal titanate compound particles but contains an electron-transporting compound.

[0014] [Technical means to solve the problem]

[0015] Specific means for solving the above-mentioned problems include the following embodiments.

[0016] [1] An electrophotographic photoreceptor comprising: a conductive substrate; an undercoat layer disposed on the conductive substrate and containing titanate metal compound particles, an electron transporting compound, and a binder resin; and a photosensitive layer disposed on the undercoat layer.

[0017] [2] The electrophotographic photoreceptor according to [1], wherein the electron transport compound contains at least one perinone compound selected from the group consisting of compounds represented by the following general formula (1) and compounds represented by the following general formula (2).

[0018] [Chemistry 1]

[0019]

[0020] In the general formula (1), R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 and R 18 R each independently represents a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group or a halogen atom. 11 With R 12 , R 12 With R 13 and R 13 With R 14 They can independently link with each other to form a ring. 15 With R 16 , R 16 With R 17 and R 17 With R 18 They can independently link with each other to form a ring.

[0021] In the general formula (2), R 21 , R 22 , R 23 , R 24 , R 25 , R 26 , R27 and R 28 R each independently represents a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group or a halogen atom. 21 With R 22 , R 22 With R 23 and R 23 With R 24 They can independently link with each other to form a ring. 25 With R 26 , R 26 With R 27 and R 27 With R 28 They can independently link with each other to form a ring.

[0022] [3] The electrophotographic photoreceptor according to [1] or [2], wherein the metal titanate compound particles include at least one selected from the group consisting of strontium titanate particles, barium titanate particles, calcium titanate particles, and magnesium titanate particles.

[0023] [4] The electrophotographic photoreceptor according to any one of [1] to [3], wherein the metal titanate compound particles have an average primary particle size of 30 nm or more and 1 μm or less.

[0024] [5] The electrophotographic photoreceptor according to any one of [1] to [4], wherein the total content of the metal titanate compound particles contained in the undercoat layer is 5 mass % or more and 100 mass % or less relative to the total content of the electron transporting compound contained in the undercoat layer.

[0025] [6] The electrophotographic photoreceptor according to any one of [1] to [5], wherein the total content of the metal titanate compound particles is 5% by mass or more and 40% by mass or less relative to the total solid content of the undercoat layer.

[0026] [7] The electrophotographic photoreceptor according to any one of [1] to [6], wherein the total content of the electron transport compound is 30% by mass or more relative to the total solid content of the undercoat layer.

[0027] [8] The electrophotographic photoreceptor according to any one of [1] to [7], wherein the binder resin contains polyurethane.

[0028] [9] A process cartridge comprising the electrophotographic photoreceptor according to any one of [1] to [8], wherein the process cartridge is detachably provided in an image forming apparatus.

[0029]

[10] An image forming device, comprising: an electrophotographic photoreceptor according to any one of [1] to [8]; a charging mechanism for charging the surface of the electrophotographic photoreceptor; an electrostatic latent image forming mechanism for forming an electrostatic latent image on the charged surface of the electrophotographic photoreceptor; a developing mechanism for developing the electrostatic latent image formed on the surface of the electrophotographic photoreceptor using a developer containing toner to form a toner image; and a transfer mechanism for transferring the toner image to the surface of a recording medium.

[0030] [Effects of the Invention]

[0031] According to the invention of [1], [3], [4], [6], [7] or [8], there is provided an electrophotographic photoreceptor having excellent photosensitivity and suppressed residual potential compared to a case where the undercoat layer does not contain titanate metal compound particles but contains an electron transporting compound.

[0032] According to the invention of [2], an electrophotographic photoreceptor is provided which has excellent photosensitivity and suppressed residual potential compared with a case where the undercoat layer contains metal titanate compound particles and contains no perinone compound but an imide compound.

[0033] According to the invention of [5], an electrophotographic photoreceptor is provided, which has excellent photosensitivity and suppressed residual potential compared with a case where the total content of the metal titanate compound particles contained in the undercoat layer is less than 10 mass % relative to the total content of the electron transporting compound contained in the undercoat layer.

[0034] According to the invention of [9], there is provided a process cartridge including an electrophotographic photoreceptor having excellent photosensitivity and suppressed residual potential compared with a case where the undercoat layer does not contain metal titanate compound particles but contains an electron transporting compound.

[0035] According to the invention of

[10] , there is provided an image forming apparatus including an electrophotographic photoreceptor having excellent photosensitivity and suppressed residual potential compared to a case where the undercoat layer does not contain metal titanate compound particles but contains an electron transporting compound. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic partial cross-sectional view showing an example of the layer structure of the electrophotographic photoreceptor according to the present embodiment.

[0037] Figure 2 This is a schematic diagram showing the configuration of an example of the image forming apparatus according to the present embodiment.

[0038] Figure 3 This is a schematic diagram showing the configuration of another example of the image forming apparatus according to the present embodiment.

[0039] Figure 4 This is a schematic diagram of an image formed for evaluating image quality in the embodiment.

[0040] [Explanation of Symbols]

[0041] 1: Base coating

[0042] 2: Charge generation layer

[0043] 3: Charge transfer layer

[0044] 4: Conductive substrate

[0045] 5: Photosensitive layer

[0046] 7A: Electrophotographic photoreceptor

[0047] 7: Electrophotographic photoreceptor

[0048] 8: Live device

[0049] 9: Exposure device

[0050] 11: Development device

[0051] 13: Cleaning device

[0052] 14: Lubricant

[0053] 40: Transfer device

[0054] 50: Intermediate transfer body

[0055] 100: Image forming device

[0056] 120: Image forming device

[0057] 131: Cleaning scraper

[0058] 132: Fibrous member (roller)

[0059] 133: Fibrous member (flat brush shape)

[0060] 300: Processing box DETAILED DESCRIPTION

[0061] Hereinafter, embodiments of the present disclosure will be described. These descriptions and examples are intended to illustrate the embodiments and do not limit the scope of the embodiments.

[0062] In the present disclosure, a numerical range expressed using “to” indicates a range including the numerical values ​​described before and after “to” as the minimum value and the maximum value, respectively.

[0063] In the numerical ranges recorded in the present disclosure, the upper limit or lower limit of one numerical range can be replaced by the upper limit or lower limit of another numerical range. In addition, in the numerical ranges recorded in the present disclosure, the upper limit or lower limit of the numerical range can also be replaced by the value shown in the embodiment.

[0064] In the present disclosure, the term "process" refers not only to an independent process but also to a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved.

[0065] In the present disclosure, each component may contain a plurality of corresponding substances. In the present disclosure, when the amount of each component in the composition is mentioned, when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, it refers to the total amount of the plurality of substances present in the composition.

[0066] In the present disclosure, the main component refers to a major component. For example, in a mixture of multiple components, the main component refers to a component that accounts for 30% by mass or more of the total mass of the mixture.

[0067] In the present disclosure, the electrophotographic photoreceptor is also simply referred to as a photoreceptor.

[0068] <Electronic Photographic Photoreceptor>

[0069] The photoreceptor of this embodiment includes a conductive substrate, an undercoat layer disposed on the conductive substrate, and a photosensitive layer disposed on the undercoat layer.

[0070] Figure 1 An example of the layer structure of the photoreceptor according to the present embodiment is schematically shown. Figure 1 The photoreceptor 7A shown has a structure in which an undercoat layer 1, a charge generating layer 2, and a charge transporting layer 3 are sequentially stacked on a conductive substrate 4. The charge generating layer 2 and the charge transporting layer 3 constitute a photosensitive layer 5. The photoreceptor 7A may also have a layer structure in which a protective layer is further provided on the charge transporting layer 3.

[0071] The photoreceptor of this embodiment can be Figure 1 The photosensitive layer may be a functional separation type in which the charge generating layer 2 and the charge transporting layer 3 are separated, as in the photosensitive layer 7A shown in the figure, or may be a single-layer type photosensitive layer in which the charge generating layer 2 and the charge transporting layer 3 are integrated.

[0072] In the photoreceptor of the present embodiment, the undercoat layer contains metal titanate compound particles, an electron transporting compound, and a binder resin.

[0073] In the photoreceptor of this embodiment, the undercoat layer contains the metal titanate compound particles and the electron transporting compound, so that the photoreceptor has excellent photosensitivity and suppressed residual potential. The following mechanism is presumed as the reason for this.

[0074] The dielectric constant of the undercoat layer increases by containing metal titanate compound particles as a strong dielectric. If the dielectric constant of the undercoat layer increases, the voltage applied to the photosensitive layer during charging increases, so it is speculated that the photosensitivity of the photoreceptor is excellent. However, if the voltage applied to the photosensitive layer during charging increases, the potential on the surface of the photoreceptor is difficult to decay after the charge removal, and the electron transport compound is contained in the place where the potential on the surface of the photoreceptor is difficult to decay, and the potential on the surface of the photoreceptor is easy to decay. Therefore, it is speculated that in the photoreceptor of this embodiment, the undercoat layer contains metal titanate compound particles and electron transport compounds, and the photosensitivity is excellent and the residual potential is suppressed.

[0075] The electron transporting compound is preferably at least one violacetone compound selected from the group consisting of compounds represented by the general formula (1) and compounds represented by the general formula (2) described below. In the present disclosure, the compound represented by the general formula (1) is also referred to as the violacetone compound (1), and the compound represented by the general formula (2) is also referred to as the violacetone compound (2).

[0076] If at least one of the purple ketone compound (1) and the purple ketone compound (2) is used as the main electron transport material of the undercoat layer, the potential on the surface of the photoreceptor becomes easier to decay and the residual potential is further suppressed compared to the undercoat layer using other electron transport compounds (such as the imide compound (A), the imide compound (B) or the imide compound (C) described later) as the main electron transport material. It is speculated that the reason is that compared with other electron transport compounds, holes are more likely to diffuse and move from the purple ketone compound (1) or the purple ketone compound (2) to the charge generating material (such as phthalocyanine pigment) contained in the photosensitive layer.

[0077] Hereinafter, each layer of the photoreceptor according to the present embodiment will be described in detail.

[0078] [Base coating]

[0079] The undercoat layer contains metal titanate compound particles, an electron transporting compound, and a binder resin. The undercoat layer may also contain particles other than the metal titanate compound particles and other additives.

[0080] -Metal Titanate Compound Particles-

[0081] In the present embodiment, the undercoat layer contains at least one type of metal titanate compound particles.

[0082] Examples of the metal constituting the metal titanate compound particles include strontium, barium, calcium, magnesium, and lead.

[0083] The metal titanate compound particles contained in the undercoat layer are preferably n-type semiconductors, and more preferably have a perovskite type crystal structure.

[0084] Examples of the perovskite-type metal titanate compound particles include strontium titanate particles, barium titanate particles, calcium titanate particles, and magnesium titanate particles.

[0085] The undercoat layer may contain only one type of metal titanate compound particles, or may contain two or more types.

[0086] From the viewpoint of dispersibility in the undercoat layer, the average primary particle size of the metal titanate compound particles contained in the undercoat layer is preferably greater than or equal to 30 nm and less than or equal to 1 μm, more preferably greater than or equal to 50 nm and less than or equal to 600 nm, further preferably greater than or equal to 60 nm and less than or equal to 400 nm, and further more preferably greater than or equal to 80 nm and less than or equal to 300 nm.

[0087] The average primary particle size of the titanate metal compound particles contained in the undercoat layer is obtained by measuring the long diameters of 100 titanate metal compound particles randomly selected during observation using a scanning electron microscope (SEM), and averaging the 100 long diameters. The sample provided for SEM observation is the titanate metal compound particles used as the material of the undercoat layer, or the titanate metal compound particles extracted from the undercoat layer. There is no limitation on the method of extracting the titanate metal compound particles from the undercoat layer, for example, the method of heating the undercoat layer to about 800°C to eliminate the binding resin and extract the titanate metal compound particles; the method of immersing the undercoat layer in an organic solvent, dissolving the binding resin using the organic solvent, and extracting the titanate metal compound particles, etc.

[0088] From the viewpoint of achieving both high photosensitivity and suppression of residual potential, the total content of titanate metal compound particles contained in the undercoat layer is preferably greater than 5 mass % and less than 100 mass %, more preferably greater than 7 mass % and less than 50 mass %, and further preferably greater than 10 mass % and less than 35 mass %, relative to the total content of electron-transporting compounds contained in the undercoat layer.

[0089] From the viewpoint of achieving both high photosensitivity and suppression of residual potential, the total content of the titanate metal compound particles is preferably 5% by mass or more and 40% by mass or less, more preferably 7% by mass or more and 30% by mass or less, and further preferably 10% by mass or more and 20% by mass or less, relative to the total solid content of the primer layer.

[0090] -Electron transporting compounds-

[0091] The primer layer contains an electron transport compound. Examples of the electron transport compound include quinone compounds such as p-benzoquinone, chloranil, bromoquinone, and anthraquinone; tetracyanoquinodimethane compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone; xanthone compounds; benzophenone compounds; cyanovinyl compounds; vinyl compounds; imide compounds; and perinone compounds. The electron transport compound may be used alone or in combination of two or more.

[0092] From the viewpoint of controlling the volume resistivity of the primer layer to be within the desired range, the total content of the electron transport compound is preferably 30 mass % or more, more preferably 30 mass % or more and 90 mass % or less, further preferably 40 mass % or more and 80 mass % or less, further more preferably 45 mass % or more and 75 mass % or less, and further preferably 50 mass % or more and 70 mass % or less, relative to the total solid content of the primer layer.

[0093] -Purple ketone compound (1), purple ketone compound (2)-

[0094] The primer layer preferably contains at least one of a peroxide compound (1) and a peroxide compound (2). The peroxide compound (1) is a compound represented by the following general formula (1). The peroxide compound (2) is a compound represented by the following general formula (2).

[0095] [Chemistry 2]

[0096]

[0097] In the general formula (1), R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 and R 18 R each independently represents a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group or a halogen atom. 11 With R 12 , R 12 With R 13 and R 13 With R 14 They can independently link with each other to form a ring. 15 With R 16 , R 16 With R 17 and R 17 With R 18 They can independently link with each other to form a ring.

[0098] In the general formula (2), R 21 , R 22 , R 23 , R 24 , R 25 , R 26 , R 27 and R 28 R each independently represents a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group or a halogen atom. 21 With R 22 , R 22 With R 23 and R 23 With R 24 They can independently link with each other to form a ring. 25 With R 26 , R 26 With R 27 and R 27 With R 28 They can independently link with each other to form a ring.

[0099] In the general formula (1), R 11 ~R 18 Examples of the alkyl group represented by include substituted or unsubstituted alkyl groups.

[0100] In the general formula (1), R 11 ~R 18 The unsubstituted alkyl group represented may include a straight-chain alkyl group having 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), a branched alkyl group having 3 to 20 carbon atoms (preferably 3 to 10 carbon atoms), and a cyclic alkyl group having 3 to 20 carbon atoms (preferably 3 to 10 carbon atoms).

[0101] Examples of the straight-chain alkyl group having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, tridecyl, n-tetradecyl, n-pentadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, and n-eicosyl.

[0102] Examples of the branched alkyl group having 3 to 20 carbon atoms include isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, sec-hexyl, tert-hexyl, isoheptyl, sec-heptyl, tert-heptyl, isooctyl, sec-octyl, tert-octyl, isononyl, sec-nonyl, tert-nonyl, isodecyl, sec-decyl, tert-decyl, isododecyl, sec-dodecyl, tert-dodecyl, tert-tetradecyl, and tert-pentadecyl.

[0103] Examples of the cyclic alkyl group having 3 to 20 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and polycyclic (e.g., bicyclic, tricyclic, spirocyclic) alkyl groups formed by linking these monocyclic alkyl groups.

[0104] Among the above, the unsubstituted alkyl group is preferably a linear alkyl group such as a methyl group or an ethyl group.

[0105] Examples of the substituent in the alkyl group include an alkoxy group, a hydroxy group, a carboxyl group, a nitro group, and a halogen atom (a fluorine atom, a bromine atom, an iodine atom, etc.).

[0106] Examples of the alkoxy group that replaces the hydrogen atom in the alkyl group include the following: 11 ~R 18 The same groups as the unsubstituted alkoxy groups represented by .

[0107] In the general formula (1), R 11 ~R 18 Examples of the alkoxy group represented by include substituted or unsubstituted alkoxy groups.

[0108] In the general formula (1), R 11 ~R 18 Examples of the unsubstituted alkoxy group represented by the above-mentioned group include linear, branched or cyclic alkoxy groups having 1 to 10 (preferably 1 to 6, more preferably 1 to 4) carbon atoms.

[0109] Specific examples of the linear alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, an n-pentyloxy group, an n-hexyloxy group, an n-heptyloxy group, an n-octyloxy group, an n-nonyloxy group, and an n-decyloxy group.

[0110] Specific examples of the branched alkoxy group include isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, isopentyloxy, neopentyloxy, tert-pentyloxy, isohexyloxy, sec-hexyloxy, tert-hexyloxy, isoheptyloxy, sec-heptyloxy, tert-heptyloxy, isooctyloxy, sec-octyloxy, tert-octyloxy, isononyloxy, sec-nonyloxy, tert-nonyloxy, isodecyloxy, sec-decyloxy, and tert-decyloxy.

[0111] Specific examples of the cyclic alkoxy group include a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, a cycloheptyloxy group, a cyclooctyloxy group, a cyclononyloxy group, and a cyclodecyloxy group.

[0112] Among these, as the unsubstituted alkoxy group, a linear alkoxy group is preferred.

[0113] Examples of the substituent in the alkoxy group include an aryl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a hydroxyl group, a carboxyl group, a nitro group, and a halogen atom (a fluorine atom, a bromine atom, an iodine atom, etc.).

[0114] Examples of the aryl group that replaces the hydrogen atom in the alkoxy group include the following: 11 ~R 18 The same groups are used as the unsubstituted aryl groups represented.

[0115] Examples of the alkoxycarbonyl group that replaces the hydrogen atom in the alkoxy group include the following: 11 ~R 18 The same groups as those represented by the unsubstituted alkoxycarbonyl group.

[0116] Examples of the aryloxycarbonyl group that replaces the hydrogen atom in the alkoxy group include the following: 11 ~R 18 The same groups as the unsubstituted aryloxycarbonyl groups represented.

[0117] In the general formula (1), R 11 ~R 18 Examples of the aralkyl group represented by include substituted or unsubstituted aralkyl groups.

[0118] In the general formula (1), R 11 ~R 18 The unsubstituted aralkyl group represented is preferably an aralkyl group having 7 to 30 carbon atoms, more preferably an aralkyl group having 7 to 16 carbon atoms, and still more preferably an aralkyl group having 7 to 12 carbon atoms.

[0119] Examples of the unsubstituted aralkyl group having 7 to 30 carbon atoms include benzyl, phenylethyl, phenylpropyl, 4-phenylbutyl, phenylpentyl, phenylhexyl, phenylheptyl, phenyloctyl, phenylnonyl, naphthylmethyl, naphthylethyl, anthracenylmethyl, and phenyl-cyclopentylmethyl.

[0120] Examples of the substituent in the aralkyl group include an alkoxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, and a halogen atom (a fluorine atom, a bromine atom, an iodine atom, etc.).

[0121] Examples of the alkoxy group that replaces the hydrogen atom in the aralkyl group include the following: 11 ~R 18 The same groups as the unsubstituted alkoxy groups represented by .

[0122] Examples of the alkoxycarbonyl group that replaces the hydrogen atom in the aralkyl group include the following: 11 ~R 18 The same groups as those represented by the unsubstituted alkoxycarbonyl group.

[0123] Examples of the aryloxycarbonyl group that replaces the hydrogen atom in the aralkyl group include the following: 11 ~R 18 The same groups as the unsubstituted aryloxycarbonyl groups represented.

[0124] In the general formula (1), R 11 ~R 18 Examples of the aryl group represented by include substituted or unsubstituted aryl groups.

[0125] In the general formula (1), R 11 ~R 18 The unsubstituted aryl group represented by is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 14 carbon atoms, and still more preferably an aryl group having 6 to 10 carbon atoms.

[0126] Examples of the aryl group having 6 to 30 carbon atoms include phenyl, biphenyl, 1-naphthyl, 2-naphthyl, 9-anthryl, 9-phenanthryl, 1-pyrenyl, 5-naphthyl, 1-indenyl, 2-azulenyl, 9-fluorenyl, biphenylenyl, indacenyl, fluoranthenyl, acenaphthylenyl, aceanthrylenyl, phenalenyl, fluorenyl, anthracenyl, bianthracenyl, teranthracenyl, quarteranthracenyl, anthraquinolyl, phenanthryl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, pleiadenyl, picenyl, perylenyl, pentaphenyl, pentaphenyl, tetraphenylenyl, hexaphenyl, hexacenyl, rubicenyl, coronenyl, etc. Among the above, phenyl is preferred.

[0127] Examples of the substituent in the aryl group include an alkyl group, an alkoxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, and a halogen atom (a fluorine atom, a bromine atom, an iodine atom, etc.).

[0128] Examples of the alkyl group that replaces the hydrogen atom in the aryl group include the following:11 ~R 18 The same groups as the unsubstituted alkyl groups represented.

[0129] Examples of the alkoxy group that replaces the hydrogen atom in the aryl group include the following: 11 ~R 18 The same groups as the unsubstituted alkoxy groups represented by .

[0130] Examples of the alkoxycarbonyl group that replaces the hydrogen atom in the aryl group include the following: 11 ~R 18 The same groups as those represented by the unsubstituted alkoxycarbonyl group.

[0131] Examples of the aryloxycarbonyl group that replaces the hydrogen atom in the aryl group include the following: 11 ~R 18 The same groups as the unsubstituted aryloxycarbonyl groups represented.

[0132] In the general formula (1), R 11 ~R 18 The aryloxy group (—O—Ar, where Ar represents an aryl group) represented by the formula (hereinafter referred to as “aryloxy”) may be a substituted or unsubstituted aryloxy group.

[0133] In the general formula (1), R 11 ~R 18 The unsubstituted aryloxy group represented by is preferably an aryloxy group having 6 to 30 carbon atoms, more preferably an aryloxy group having 6 to 14 carbon atoms, and still more preferably an aryloxy group having 6 to 10 carbon atoms.

[0134] Examples of the aryloxy group having 6 to 30 carbon atoms include phenyloxy (phenoxy), biphenyloxy, 1-naphthyloxy, 2-naphthyloxy, 9-anthryloxy, 9-phenanthryloxy, 1-pyrenyloxy, 5-naphthyloxy, 1-indenyloxy, 2-azulyloxy, 9-fluorenyloxy, biphenyleneoxy, dicyclopentadienylphenyloxy, fluoranthenyloxy, acenaphthyloxy, vinylanthryloxy, propenylnaphthyloxy, fluorenyloxy, anthracenyloxy, bianthryloxy, tertianthryloxy, bianthryloxy, anthraquinoneyloxy, phenanthryloxy, triphenyleneoxy, pyrenyloxy, The following are examples of the present invention: 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 6

[0135] Examples of the substituent in the aryloxy group include an alkyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, and a halogen atom (a fluorine atom, a bromine atom, an iodine atom, etc.).

[0136] Examples of the alkyl group that replaces the hydrogen atom in the aryloxy group include the following: 11 ~R 18 The same groups as the unsubstituted alkyl groups represented.

[0137] Examples of the alkoxycarbonyl group that replaces the hydrogen atom in the aryloxy group include the following: 11 ~R 18 The same groups as those represented by the unsubstituted alkoxycarbonyl group.

[0138] Examples of the aryloxycarbonyl group that replaces the hydrogen atom in the aryloxy group include the following: 11 ~R 18 The same groups as the unsubstituted aryloxycarbonyl groups represented.

[0139] In the general formula (1), R 11 ~R 18 Examples of the alkoxycarbonyl group (—CO—OR, where R represents an alkyl group) represented by the group include substituted or unsubstituted alkoxycarbonyl groups.

[0140] In the general formula (1), R 11 ~R 18 The number of carbon atoms in the alkyl chain of the unsubstituted alkoxycarbonyl group represented is preferably 1 or more and 20 or less, more preferably 1 or more and 15 or less, and even more preferably 1 or more and 10 or less.

[0141] Examples of the alkoxycarbonyl group having an alkyl chain with a carbon number of 1 to 20 include methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, n-butoxycarbonyl, sec-butoxycarbonyl, tert-butoxycarbonyl, pentaoxycarbonyl, hexaoxycarbonyl, heptaoxycarbonyl, octaoxycarbonyl, nonaoxycarbonyl, decaoxycarbonyl, dodecaoxycarbonyl, tridecaoxycarbonyl, tetradecaoxycarbonyl, pentadecyloxycarbonyl, hexadecyloxycarbonyl, heptadecaoxycarbonyl, octadecyloxycarbonyl, icosyloxycarbonyl and the like.

[0142] Examples of the substituent in the alkoxycarbonyl group include an aryl group, a hydroxyl group, and a halogen atom (a fluorine atom, a bromine atom, an iodine atom, etc.).

[0143] Examples of the aryl group that replaces the hydrogen atom in the alkoxycarbonyl group include the following: 11 ~R 18 The same groups are used as the unsubstituted aryl groups represented.

[0144] In the general formula (1), R 11 ~R 18Examples of the aryloxycarbonyl group (—CO—OAr, Ar represents an aryl group) represented by the formula (hereinafter referred to as “aryloxycarbonyl”) include substituted or unsubstituted aryloxycarbonyl groups.

[0145] In the general formula (1), R 11 ~R 18 The carbon number of the aryl group in the unsubstituted aryloxycarbonyl group represented is preferably 6 or more and 30 or less, more preferably 6 or more and 14 or less, and even more preferably 6 or more and 10 or less.

[0146] Examples of the aryloxycarbonyl group having an aryl group having 6 to 30 carbon atoms include a phenoxycarbonyl group, a biphenyloxycarbonyl group, a 1-naphthyloxycarbonyl group, a 2-naphthyloxycarbonyl group, a 9-anthryloxycarbonyl group, a 9-phenanthrenyloxycarbonyl group, a 1-pyrenyloxycarbonyl group, a 5-naphthyloxycarbonyl group, a 1-indenyloxycarbonyl group, a 2-azulyloxycarbonyl group, a 9-fluorenyloxycarbonyl group, a biphenyleneoxycarbonyl group, a dicyclopentadienylphenyloxycarbonyl group, a fluoranthenyloxycarbonyl group, an acenaphthyloxycarbonyl group, a vinylanthryloxycarbonyl group, a propenylnaphthyloxycarbonyl group, a fluorenyloxycarbonyl group, an anthryloxycarbonyl group, a bianthryloxycarbonyl group, a trianthryloxycarbonyl group, a tetraanthryloxycarbonyl group, an anthraquinoneoxycarbonyl group, a phenanthryloxycarbonyl group, a triphenyleneoxycarbonyl group, a pyrenyloxycarbonyl group, 4-(4-phenyl)oxycarbonyl, ...

[0147] Examples of the substituent in the aryloxycarbonyl group include an alkyl group, a hydroxy group and a halogen atom (a fluorine atom, a bromine atom, an iodine atom, etc.).

[0148] Examples of the alkyl group which may substitute the hydrogen atom of the aryloxycarbonyl group include the following: 11 ~R 18 The same groups as the unsubstituted alkyl groups represented.

[0149] In the general formula (1), R 11 ~R 18 The alkoxycarbonylalkyl group represented by n H 2n )-CO-OR, R represents an alkyl group, and n represents an integer greater than or equal to 1), and examples thereof include substituted or unsubstituted alkoxycarbonylalkyl groups.

[0150] In the general formula (1), R 11 ~R 18 The alkoxycarbonyl group (-CO-OR) in the unsubstituted alkoxycarbonylalkyl group represented by the formula (1) may be exemplified by the following:11 ~R 18 The same groups as the alkoxycarbonyl groups represented.

[0151] In the general formula (1), R 11 ~R 18 The alkylene chain (-C n H 2n -), and examples thereof include a linear alkylene chain having 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), a branched alkylene chain having 3 to 20 carbon atoms (preferably 3 to 10 carbon atoms), and a cyclic alkylene chain having 3 to 20 carbon atoms (preferably 3 to 10 carbon atoms).

[0152] Examples of the linear alkylene chain having 1 to 20 carbon atoms include methylene, ethylene, n-propylene, n-butylene, n-pentylene, n-hexylene, n-heptylene, n-octylene, n-nonylene, n-decylene, n-undecylene, n-dodecylene, n-tridecylene, n-tetradecylene, n-pentadecylene, n-heptadecylene, n-octadecylene, n-nonadecylene, and n-eicosylene.

[0153] Examples of the branched alkylene chain having 3 to 20 carbon atoms include isopropylene, isobutylene, secondary butylene, tertiary butylene, isopentylene, neopentylene, tertiary pentylene, isohexylene, secondary hexylene, tertiary hexylene, isoheptylene, secondary heptylene, tertiary heptylene, isooctylene, secondary octylene, tertiary octylene, isononylene, secondary nonylene, tertiary nonylene, isodecylene, secondary decylene, tertiary decylene, isododecylene, secondary dodecylene, tertiary dodecylene, tertiary tetradecylene, and tertiary pentadecylene.

[0154] Examples of the cyclic alkylene chain having 3 to 20 carbon atoms include cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene, cyclononylene, and cyclodecylene.

[0155] Examples of the substituent in the alkoxycarbonylalkyl group include an aryl group, a hydroxyl group and a halogen atom (a fluorine atom, a bromine atom, an iodine atom, etc.).

[0156] Examples of the aryl group that replaces the hydrogen atom of the alkoxycarbonylalkyl group include the following: 11 ~R 18 The same groups are used as the unsubstituted aryl groups represented.

[0157] In the general formula (1), R 11 ~R 18 The aryloxycarbonylalkyl group (-(C n H2n )-CO-OAr, Ar represents an aryl group, and n represents an integer greater than or equal to 1), and examples thereof include substituted or unsubstituted aryloxycarbonylalkyl groups.

[0158] In the general formula (1), R 11 ~R 18 The aryloxycarbonyl group (-CO-OAr, Ar represents an aryl group) in the unsubstituted aryloxycarbonylalkyl group represented by the formula (1) may be exemplified by the following: 11 ~R 18 The same groups as the aryloxycarbonyl groups represented.

[0159] In the general formula (1), R 11 ~R 18 The alkylene chain (—C n H 2n -), which can be exemplified by R in the general formula (1) 11 ~R 18 The alkylene chain in the alkoxycarbonylalkyl represented by hereinafter is the same as that in the alkylene chain in the alkoxycarbonylalkyl represented by hereinafter.

[0160] Examples of the substituent in the aryloxycarbonylalkyl group include an alkyl group, a hydroxy group and a halogen atom (a fluorine atom, a bromine atom, an iodine atom, etc.).

[0161] Examples of the alkyl group which replaces the hydrogen atom of the aryloxycarbonylalkyl group include the following: 11 ~R 18 The same groups as the unsubstituted alkyl groups represented.

[0162] In the general formula (1), R 11 ~R 18 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0163] In the general formula (1), R 11 With R 12 , R 12 With R 13 , R 13 With R 14 , R 15 With R 16 , R 16 With R 17 or R 17 With R 18 Examples of the ring structure formed by connecting to each other include a benzene ring, a condensed ring having 10 to 18 carbon atoms (naphthalene ring, anthracene ring, phenanthrene ring, ring (benzo[α]phenanthrene ring), tetracene ring, benzanthracene ring (benzo[α]anthracene ring), triphenylene ring, etc. Among the above, the ring structure to be formed is preferably a benzene ring.

[0164] In the general formula (2), R 21 ~R 28 The alkyl group represented by can be exemplified by the same group as R in the general formula (1): 11 ~R 18 The same groups as those represented by the alkyl groups.

[0165] In the general formula (2), R 21 ~R 28 The alkoxy group represented by the formula (1) may be exemplified by R 11 ~R 18 The same groups as those represented by the alkoxy groups.

[0166] In the general formula (2), R 21 ~R 28 The aralkyl group represented by can be exemplified by the same group as R in the general formula (1): 11 ~R 18 The same groups as those represented by the aralkyl groups.

[0167] In the general formula (2), R 21 ~R 28 The aryl group represented by can be exemplified by the same as R in the general formula (1): 11 ~R 18 The same groups as those represented by the aryl groups.

[0168] In the general formula (2), R 21 ~R 28 The aryloxy group represented by can be exemplified by the same group as R in the general formula (1): 11 ~R 18 The same groups as those represented by the aryloxy groups.

[0169] In the general formula (2), R 21 ~R 28 The alkoxycarbonyl group represented by the formula (1) may be exemplified by the following: 11 ~R 18 The same groups as the alkoxycarbonyl groups represented.

[0170] In the general formula (2), R 21 ~R 28 The aryloxycarbonyl group represented by the formula (1) may be exemplified by the following: 11 ~R 18 The same groups as the aryloxycarbonyl groups represented.

[0171] In the general formula (2), R 21 ~R 28 The alkoxycarbonylalkyl represented by the present invention includes the following: 11 ~R 18 The same groups as the alkoxycarbonylalkyl groups represented.

[0172] In the general formula (2), R 21 ~R 28 The aryloxycarbonylalkyl represented by the present invention includes the following: 11 ~R 18 The same groups as those represented by the aryloxycarbonylalkyl groups.

[0173] In the general formula (2), R 21 ~R 28 The halogen atom represented by can be exemplified by the same as R in the general formula (1): 11 ~R 18 The halogen atoms represented are the same atoms.

[0174] In the general formula (2), R 21 With R 22 , R 22 With R 23 , R 23 With R 24 , R 25 With R 26 , R 26 With R 27 or R 27 With R 28 Examples of the ring structure formed by connecting to each other include a benzene ring, a condensed ring having 10 to 18 carbon atoms (naphthalene ring, anthracene ring, phenanthrene ring, ring (benzo[α]phenanthrene ring), tetracene ring, benzanthracene ring (benzo[α]anthracene ring), triphenylene ring, etc. Among the above, the ring structure to be formed is preferably a benzene ring.

[0175] From the viewpoint of further suppressing the decrease in photosensitivity and the increase in residual potential that occur when repeatedly forming images, R in the general formula (1) 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 and R 18 Preferably, each is independently a hydrogen atom, an alkyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group or an aryloxycarbonylalkyl group.

[0176] From the viewpoint of further suppressing the decrease in photosensitivity and the increase in residual potential that occur when repeatedly forming images, R in the general formula (2) 21 , R 22 , R 23 , R 24 , R 25 , R 26 , R 27 and R 28Preferably, each is independently a hydrogen atom, an alkyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group or an aryloxycarbonylalkyl group.

[0177] Specific examples of the perirone compound (1) and the perirone compound (2) are shown below, but the present embodiment is not limited thereto. In the following structural formula, Ph represents a phenyl group.

[0178] [Chemistry 3]

[0179]

[0180] [Chemistry 4]

[0181]

[0182] [Chemistry 5]

[0183]

[0184] [Chemistry 6]

[0185]

[0186] [Chemistry 7]

[0187]

[0188] [Chemistry 8]

[0189]

[0190] Violet ketone compound (1) and violet ketone compound (2) are in an isomer relationship (i.e., a cis-isomer and a trans-isomer relationship). As a general synthesis method, 2 moles of o-phenylenediamine compound and 1 mole of naphthalenetetracarboxylic acid compound are heated and condensed to obtain a mixture of cis-isomer and trans-isomer, and the mixing ratio is usually more cis-isomer than trans-isomer. Regarding the separation of cis-isomer and trans-isomer, for example, by heating and washing with an alcohol solution of potassium hydroxide, the soluble cis-isomer and the poorly soluble trans-isomer can be separated.

[0191] From the viewpoint of controlling the volume resistivity of the primer layer to be within an ideal range and from the viewpoint of film-forming properties, the total content of the perovskite compound (1) and the perovskite compound (2) is preferably 30% by mass or more, more preferably 30% by mass or more and 90% by mass or less, further preferably 40% by mass or more and 80% by mass or less, and further preferably 50% by mass or more and 70% by mass or less, relative to the total solid content of the primer layer.

[0192] -Bonding resin-

[0193] Examples of the binder resin used for the primer layer include known polymer compounds such as acetal resins (e.g., polyvinyl butyral), polyvinyl alcohol resins, polyvinyl acetal resins, casein resins, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, unsaturated polyester resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate-maleic anhydride resins, silicone resins, silicone-alkyd resins, urea resins, phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, alkyd resins, and epoxy resins; and known materials such as zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, and silane coupling agents.

[0194] Examples of the binder resin used for the primer layer include a charge transporting resin having a charge transporting group, and a conductive resin (for example, polyaniline).

[0195] Among these, the binder resin used for the primer layer is preferably a resin that is insoluble in the coating solvent of the upper layer, and is particularly preferably a thermosetting resin such as urea resin, phenol resin, phenol-formaldehyde resin, melamine resin, polyurethane resin, unsaturated polyester resin, alkyd resin, epoxy resin, or a resin obtained by reacting at least one resin selected from the group consisting of polyamide resin, polyester resin, polyether resin, methacrylic resin, acrylic resin, polyvinyl alcohol resin, and polyvinyl acetal resin with a hardener. When two or more of these binder resins are used in combination, the mixing ratio thereof is set as needed.

[0196] As the binder resin used in the primer layer, polyurethane is preferred from the viewpoint of good dispersion of the perinone compound and the metal titanate compound particles. Polyurethane is generally synthesized by a polyaddition reaction of a polyfunctional isocyanate and a polyol.

[0197] Examples of the polyfunctional isocyanate include diisocyanates such as methylene diisocyanate, ethylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethylbiphenyl diisocyanate, 4,4'-biphenyl diisocyanate, dicyclohexylmethane diisocyanate, and methylenebis(4-cyclohexyl isocyanate); isocyanurates obtained by trimerizing the diisocyanates; and blocked isocyanates obtained by blocking the isocyanate groups of the diisocyanates with a blocking agent. The polyfunctional isocyanate may be used alone or in combination of two or more.

[0198] Examples of the polyol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 2,2-dimethyl-1,3-propylene glycol, 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 3,3-dimethyl-1,2-butylene glycol, 2-ethyl-2-methyl-1,3-propylene glycol, 1,2-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,2-diethyl-1,3-propylene glycol, alcohol, 2,4-dimethyl-2,4-pentanediol, 1,7-heptanediol, 2-methyl-2-propyl-1,3-propanediol, 2,5-dimethyl-2,5-hexanediol, 2-ethyl-1,3-hexanediol, 1,2-octanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, hydroquinone, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol, poly(oxytetramethylene) glycol, 4,4'-dihydroxy-diphenyl-2,2-propane, 4,4'-dihydroxyphenyl sulfone and the like.

[0199] Examples of the polyol include polyester polyol, polycarbonate polyol, polycaprolactone polyol, polyether polyol, and polyvinyl butyral.

[0200] The polyol may be used alone or in combination of two or more.

[0201] As the polyurethane hardening catalyst (ie, a catalyst for the polyaddition reaction of polyfunctional isocyanate and polyol), a known organic acid metal salt or organic metal complex may be used.

[0202] The binder resin contained in the primer layer preferably accounts for 80% to 100% by mass of the total binder resin, more preferably 90% to 100% by mass, and even more preferably 95% to 100% by mass of the total binder resin.

[0203] In order to improve electrical characteristics, improve environmental stability, and improve image quality, various additives may also be included in the undercoat layer.

[0204] Examples of the additive include known materials such as polycyclic condensation-based and azo-based electron-transporting pigments, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, and silane coupling agents.

[0205] Examples of the silane coupling agent as an additive include vinyltrimethoxysilane, 3-methacryloxypropyl-tri(2-methoxyethoxy)silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N,N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, and 3-chloropropyltrimethoxysilane.

[0206] Examples of the zirconium chelate compound include zirconium butoxide, zirconium ethyl acetoacetate, zirconium triethanolamine, zirconium acetylacetonate butoxide, zirconium ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octanoate, zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, zirconium methacrylate butoxide, zirconium stearate butoxide, and zirconium isostearate butoxide.

[0207] Examples of the titanium chelate compound include tetraisopropyl titanate, tetra-n-butyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, titanium acetylacetonate, titanium polyacetylacetonate, titanium octyl glycolate, ammonium lactate titanium, titanium lactate, ethyl lactate titanium, triethanolamine titanium, and polyhydroxystearate titanium.

[0208] Examples of the aluminum chelate compound include aluminum isopropoxide, monobutoxyaluminum diisopropoxide, aluminum butoxide, diethyl acetoacetate aluminum diisopropoxide, and tris(ethyl acetoacetate)aluminum.

[0209] These additives may be used alone or as a mixture or polycondensate of a plurality of compounds.

[0210] From the viewpoint of leakage resistance, the thickness of the primer layer is preferably 3 μm or more, more preferably 5 μm or more, and further preferably 8 μm or more. From the viewpoint of suppressing the increase of residual potential during repeated use, the thickness of the primer layer is preferably 30 μm or less, more preferably 20 μm or less, and further preferably 10 μm or less.

[0211] The volume resistivity of the primer layer is preferably 1×10 10 Ω·cm or more, 1×10 12 Ω·cm or less.

[0212] The Vickers hardness of the primer layer is preferably 35 or higher.

[0213] In order to suppress moire images, the surface roughness (ten-point average roughness) of the undercoat layer is preferably adjusted to 1 / (4n) (n is the refractive index of the upper layer) to 1 / 2 of the wavelength λ of the exposure laser used.

[0214] In order to adjust the surface roughness, resin particles or the like may be added to the primer layer. Examples of the resin particles include silicone resin particles and cross-linked polymethyl methacrylate resin particles. In addition, in order to adjust the surface roughness, the surface of the primer layer may be ground. Examples of the grinding method include buff grinding, sandblasting, wet honing, grinding, and the like.

[0215] The formation of the undercoat layer is not particularly limited and can be performed by a known formation method, for example, by forming a coating film of an undercoat layer-forming coating liquid obtained by adding the above components to a solvent, drying the coating film, and optionally heating the coating film.

[0216] Examples of the solvent used for preparing the coating liquid 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, and ester solvents.

[0217] Specific examples of these solvents include common organic solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, dichloromethane, chloroform, chlorobenzene, and toluene.

[0218] Since the purple ketone compound (1) and the purple ketone compound (2) are difficult to dissolve in an organic solvent, it is desirable to disperse them in an organic solvent. As the dispersion method, for example, known methods such as a roller mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint stirrer can be cited. The titanate metal compound particles are also ideally dispersed in an organic solvent using the same dispersion method.

[0219] Examples of a method for applying the coating liquid for forming an undercoat layer onto the conductive substrate include common methods such as blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating.

[0220] [Conductive substrate]

[0221] As the conductive substrate, for example, metal plates, metal drums, and metal belts containing metals (aluminum, copper, zinc, chromium, nickel, molybdenum, vanadium, indium, gold, platinum, etc.) or alloys (stainless steel, etc.) can be cited. In addition, as the conductive substrate, for example, paper, resin films, and belts formed by coating, vapor deposition, or lamination of conductive compounds (such as conductive polymers, indium oxide, etc.), metals (such as aluminum, palladium, gold, etc.), or alloys can also be cited. Here, the term "conductive" means that the volume resistivity is less than 1×10 13 Ω·cm.

[0222] When the electrophotographic photoreceptor is used in a laser printer, it is preferred to roughen the surface of the conductive substrate so that the center line average roughness Ra is 0.04 μm or more and 0.5 μm or less in order to suppress interference fringes generated when irradiating laser light. When incoherent light is used as a light source, surface roughening for preventing interference fringes is not particularly necessary, but it suppresses the generation of defects caused by the surface unevenness of the conductive substrate, and is therefore suitable for a longer life.

[0223] Examples of the surface roughening method include wet honing in which an abrasive is suspended in water and sprayed onto the conductive substrate, centerless grinding in which the conductive substrate is pressed against a rotating grindstone and continuously ground, and anodizing.

[0224] As a method for roughening the surface, there is also a method in which, instead of roughening the surface of the conductive substrate, conductive or semiconductive powder is dispersed in a resin to form a layer on the surface of the conductive substrate, and the surface is roughened using particles dispersed in the layer.

[0225] The surface roughening treatment performed by anodic oxidation is to form an oxide film on the surface of the conductive substrate by using a conductive substrate made of metal (e.g., aluminum) as an anode and performing anodic oxidation in an electrolyte solution. As the electrolyte solution, for example, sulfuric acid solution, oxalic acid solution, etc. can be cited. However, the porous anodic oxide film formed by anodic oxidation is chemically active under the state of maintaining the original state, and is easily contaminated, and the resistance change caused by the environment is also large. Therefore, it is preferred to seal the porous anodic oxide film: in pressurized water vapor or boiling water (metal salts such as nickel can also be added), the volume expansion caused by the hydration reaction is used to block the micropores of the oxide film, thereby becoming a more stable hydrated oxide.

[0226] The film thickness of the anodic oxide film is preferably, for example, 0.3 μm or more and 15 μm or less. When the film thickness is within the above range, there is a tendency to exhibit barrier properties against injection, and there is a tendency to suppress an increase in residual potential due to repeated use.

[0227] The conductive substrate may be treated with an acidic treatment solution or subjected to a boehmite treatment.

[0228] The treatment using an acidic treatment solution is implemented, for example, in the following manner. First, an acidic treatment solution containing phosphoric acid, chromic acid and hydrofluoric acid is prepared. Regarding the mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment solution, for example, phosphoric acid is in the range of 10 mass % to 11 mass %, chromic acid is in the range of 3 mass % to 5 mass %, and hydrofluoric acid is in the range of 0.5 mass % to 2 mass %, and the overall concentration of these acids is preferably in the range of 13.5 mass % to 18 mass %. The treatment temperature is, for example, preferably 42° C. to 48° C. The film thickness of the film is preferably 0.3 μm to 15 μm.

[0229] Regarding the diaspore treatment, for example, the conductive substrate is immersed in pure water at 90° C. to 100° C. for 5 to 60 minutes, or is contacted with heated steam at 90° C. to 120° C. for 5 to 60 minutes. The film thickness of the film is preferably 0.1 μm to 5 μm. It can also 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.

[0230] [Middle layer]

[0231] Although not shown in the figure, an intermediate layer may be further provided between the undercoat layer and the photosensitive layer.

[0232] The intermediate layer is, for example, a layer containing a resin. Examples of the resin used for the intermediate layer include polymer compounds such as acetal resins (e.g., polyvinyl butyral), polyvinyl alcohol resins, polyvinyl acetal resins, casein resins, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate-maleic anhydride resins, silicone resins, silicone-alkyd resins, phenol-formaldehyde resins, and melamine resins.

[0233] The intermediate layer may be a layer containing an organic metal compound. Examples of the organic metal compound used for the intermediate layer include organic metal compounds containing metal atoms such as zirconium, titanium, aluminum, manganese, and silicon.

[0234] These compounds for the intermediate layer may be used alone or as a mixture or polycondensate of a plurality of compounds.

[0235] Among these, the intermediate layer is preferably a layer containing an organic metal compound containing a zirconium atom or a silicon atom.

[0236] The formation of the intermediate layer is not particularly limited and can be performed by a known formation method, for example, by forming a coating film of an intermediate layer-forming coating liquid obtained by adding the above components to a solvent, drying the coating film, and optionally heating it.

[0237] As a coating method for forming the intermediate layer, a common method 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, or a curtain coating method can be used.

[0238] The film thickness of the intermediate layer is preferably set within a range of, for example, 0.1 μm to 3 μm.

[0239] [Charge Generation Layer]

[0240] The charge generating layer is, for example, a layer comprising a charge generating material and a binder resin. In addition, the charge generating layer may also be a vapor-deposited layer of the charge generating material. The vapor-deposited layer of the charge generating material is suitable for the case where an incoherent light source such as a light emitting diode (LED) or an organic electroluminescence (EL) image array is used.

[0241] Examples of the charge generating material include azo pigments such as disazo and trisazo; condensed ring aromatic pigments such as dibromoanthraquinone; perylene pigments; pyrrolopyrrole pigments; phthalocyanine pigments; zinc oxide; and trigonal selenium.

[0242] Among these, in order to cope with laser exposure in the near-infrared region, it is preferable to use a metal phthalocyanine pigment or a metal-free phthalocyanine pigment as a charge generating material. Specifically, for example, hydroxygallium phthalocyanine disclosed in Japanese Patent Laid-Open No. 5-263007, Japanese Patent Laid-Open No. 5-279591, etc.; chlorogallium phthalocyanine disclosed in Japanese Patent Laid-Open No. 5-98181, etc.; dichlorotin phthalocyanine disclosed in Japanese Patent Laid-Open No. 5-140472, Japanese Patent Laid-Open No. 5-140473, etc.; oxytitanium phthalocyanine disclosed in Japanese Patent Laid-Open No. 4-189873, etc.

[0243] On the other hand, in order to cope with laser exposure in the near-ultraviolet region, preferred charge generating materials include: condensed-ring aromatic pigments such as dibromoanthraquinone; thioindigo pigments; porphyrazine compounds; zinc oxide; trigonal selenium; disazo pigments disclosed in Japanese Patent Laid-Open No. 2004-78147 and Japanese Patent Laid-Open No. 2005-181992, etc.

[0244] When using an incoherent light source such as an LED or an organic EL image array having a central wavelength of light emission between 450 nm and 780 nm, the charge generating material can also be used. However, from the viewpoint of resolution, when a photosensitive layer is used in a thin film of 20 μm or less, the electric field intensity in the photosensitive layer becomes high, and it is easy to generate image defects such as a decrease in charge caused by charge injection from the substrate, which is called a so-called black spot. This situation becomes significant when using a charge generating material that easily generates dark current in a p-type semiconductor, such as trigonal selenium and phthalocyanine pigments.

[0245] In contrast, when using an n-type semiconductor such as a condensed aromatic pigment, perylene pigment, or azo pigment as a charge generating material, dark current is less likely to be generated, and even when formed into a thin film, image defects known as black spots can be suppressed. Examples of n-type charge generating materials include, but are not limited to, compounds (CG-1) to (CG-27) described in paragraphs

[0288] to

[0291] of Japanese Patent Application Laid-Open No. 2012-155282.

[0246] The n-type can be determined by the polarity of the photocurrent flowing using the commonly used time of flight method, and the one that allows electrons to flow more easily as carriers than holes is defined as the n-type.

[0247] The binder resin used in the charge generating layer can be selected from a wide range of insulating resins. Alternatively, the binder resin can be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane.

[0248] Examples of the binder resin include polyvinyl butyral resin, polyarylate resin (condensation product of bisphenol and aromatic dicarboxylic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin, polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, etc. Here, the term "insulation" refers to a volume resistivity of 1×10 13 Ω·cm or more.

[0249] These binder resins may be used alone or in combination of two or more.

[0250] The mixing ratio of the charge generating material to the binder resin is preferably within a range of 10:1 to 1:10 in terms of mass ratio.

[0251] Furthermore, known additives may also be contained in the charge generating layer.

[0252] The formation of the charge generating layer is not particularly limited, and can be performed by a known formation method, for example, by forming a coating film of a coating liquid for forming a charge generating layer obtained by adding the above components to a solvent, drying the coating film, and heating as necessary. The formation of the charge generating layer can also be performed by vapor deposition of the charge generating material. The formation of the charge generating layer by vapor deposition is particularly suitable for the case where a condensed aromatic pigment or a perylene pigment is used as the charge generating material.

[0253] Examples of solvents for preparing the charge generating 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-butyl acetate, dioxane, tetrahydrofuran, dichloromethane, chloroform, chlorobenzene, toluene, etc. These solvents may be used alone or in combination of two or more.

[0254] As a method for dispersing particles (e.g., charge generating materials) in a coating liquid for forming a charge generating layer, for example, a medium disperser such as a ball mill, a vibrating ball mill, a grinder, a sand mill, a horizontal sand mill, or a medium-free disperser such as a stirrer, an ultrasonic disperser, a roll mill, a high-pressure homogenizer, etc. As a high-pressure homogenizer, for example, a collision method in which the dispersion liquid is subjected to liquid-liquid collision or liquid-wall collision and dispersed under high pressure, or a penetration method in which the dispersion liquid is caused to penetrate a fine flow path and dispersed under high pressure, etc. can be cited.

[0255] When performing the above dispersion, it is effective to set the average particle size of the charge generating material in the charge generating layer forming coating liquid to 0.5 μm or less, preferably 0.3 μm or less, and more preferably 0.15 μm or less.

[0256] Examples of a method for applying the charge generating layer-forming coating liquid onto the undercoat layer (or the intermediate layer) include common methods such as blade coating, wire bar coating, spray coating, dip coating, droplet coating, air knife coating, and curtain coating.

[0257] The film thickness of the charge generating layer is set, for example, preferably within the range of 0.1 μm or more and 5.0 μm or less, and more preferably within the range of 0.2 μm or more and 2.0 μm or less.

[0258] [Charge transport layer]

[0259] The charge transport layer is, for example, a layer containing a charge transport material and a binder resin. The charge transport layer may also be a layer containing a polymer charge transport material.

[0260] As charge transport materials, there are listed: quinone compounds such as p-benzoquinone, chloranil, bromoquinone, anthraquinone; tetracyanoquinodimethane compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone; xanthone compounds; benzophenone compounds; cyanovinyl compounds; vinyl compounds and other electron transport compounds. As charge transport materials, there are also listed: triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted vinyl compounds, distyrene compounds, anthracene compounds, hydrazone compounds and other hole transport compounds. These charge transport materials can be used alone or in combination of two or more, but are not limited to these.

[0261] 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 preferred.

[0262] [Chemistry 9]

[0263]

[0264] In the structural formula (a-1), Ar T1 ,Ar T2 and Ar T3 Each independently represents a substituted or unsubstituted aryl group, -C6H4-C(R T4 )=C(R T5 )(R T6 ), or -C6H4-CH=CH-CH=C(R T7 )(R T8 ). T4 , R T5 , R T6 , R T7 and R T8 Each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

[0265] Examples of substituents of the above groups include halogen atoms, alkyl groups having 1 to 5 carbon atoms, and alkoxy groups having 1 to 5 carbon atoms. Examples of substituents of the above groups include substituted amino groups substituted with alkyl groups having 1 to 3 carbon atoms.

[0266] [Chemistry 10]

[0267]

[0268] In the structural formula (a-2), R T91 and R T92 Each independently represents 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.T101 , R T102 , R T111 and R T112 Each independently represents a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, 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 represents 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.

[0269] Examples of substituents of the above groups include halogen atoms, alkyl groups having 1 to 5 carbon atoms, and alkoxy groups having 1 to 5 carbon atoms. Examples of substituents of the above groups include substituted amino groups substituted with alkyl groups having 1 to 3 carbon atoms.

[0270] Here, among the triarylamine derivatives represented by the structural formula (a-1) and the benzidine derivatives represented by the structural formula (a-2), the one having "-C6H4-CH=CH-CH=C(R T7 )(R T8 )" and triarylamine derivatives having "-CH=CH-CH=C(R T15 )(R T16 )" benzidine derivatives.

[0271] As the polymer charge transport material, known ones having charge transport properties such as poly-N-vinyl carbazole and polysilane can be used. In particular, polyester-based polymer charge transport materials disclosed in Japanese Patent Laid-Open No. 8-176293 and Japanese Patent Laid-Open No. 8-208820 are preferred. The polymer charge transport material can be used alone or in combination with a binder resin.

[0272] The binder resin for the charge transport layer can be listed as follows: 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-vinyl carbazole, polysilane, etc. Among these, as a binder resin, it is suitable to be a polycarbonate resin or a polyarylate resin. These binder resins are used alone or in combination of two or more.

[0273] The mixing ratio of the charge transport material to the binder resin is preferably 10:1 to 1:5 in terms of mass ratio.

[0274] Furthermore, known additives may also be contained in the charge transport layer.

[0275] The charge transport layer can be formed by any known method without particular limitation. For example, a coating film of a charge transport layer-forming coating solution prepared by adding the above components to a solvent is formed, and the coating film is dried and optionally heated.

[0276] Examples of the solvent used to prepare the charge transport layer-forming coating solution include aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; ketones such as acetone and 2-butanone; halogenated aliphatic hydrocarbons such as dichloromethane, chloroform, and dichloroethane; and common organic solvents such as cyclic or linear ethers such as tetrahydrofuran and diethyl ether. These solvents can be used alone or in combination of two or more.

[0277] Examples of the coating method for coating the charge transport layer-forming coating liquid on the charge generating layer include common methods such as blade coating, wire bar coating, spray coating, dip coating, droplet coating, air knife coating, and curtain coating.

[0278] The film thickness of the charge transport layer is set, for example, preferably within the range of 5 μm or more and 50 μm or less, and more preferably within the range of 10 μm or more and 30 μm or less.

[0279] [Protective layer]

[0280] The protective layer is provided on the photosensitive layer as needed. The protective layer is provided, for example, to prevent chemical changes of the photosensitive layer during charging or to further improve the mechanical strength of the photosensitive layer.

[0281] Therefore, the protective layer may be a layer including a cured film (crosslinked film). Examples of these layers include the layers described in the following 1) or 2).

[0282] 1) A layer comprising a cured film of a composition containing a reactive group-containing charge transport material having a reactive group and a charge transport skeleton in the same molecule (i.e., a layer comprising a polymer or a crosslinked body of the reactive group-containing charge transport material)

[0283] 2) A layer comprising a cured film of a composition containing a non-reactive charge transport material and a reactive group-containing non-charge transport material having no charge transport skeleton but having a reactive group (i.e., a layer comprising a non-reactive charge transport material and a polymer or crosslinked product of the reactive group-containing non-charge transport material)

[0284] Examples of the reactive group of the charge transport material containing a reactive group include a chain polymerizable group, an epoxy group, -OH, -OR [wherein R represents an alkyl group], -NH2, -SH, -COOH, -SiR Q1 3-Qn (OR Q2 ) Qn [Among them, R Q1 represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, R Q2 represents a hydrogen atom, an alkyl group, a trialkylsilyl group; Qn represents an integer of 1 to 3] or the like.

[0285] As a chain polymerizable group, there is no particular limitation as long as it is a functional group that can be subjected to free radical polymerization, and for example, it is a functional group having at least a group containing a carbon double bond. Specifically, there can be cited a group containing at least one selected from vinyl, vinyl ether, vinyl sulfide, styryl (vinyl phenyl), acryloyl, methacryloyl and their derivatives. Among them, in terms of its excellent reactivity, as a chain polymerizable group, it is preferably a group containing at least one selected from vinyl, styryl (vinyl phenyl), acryloyl, methacryloyl and their derivatives.

[0286] The charge transport skeleton of the charge transport material containing a reactive group is not particularly limited as long as it is a known structure in an electrophotographic photoreceptor, and examples thereof include skeletons derived from nitrogen-containing hole transport compounds such as triarylamine compounds, benzidine compounds, and hydrazone compounds, and having a structure conjugated with a nitrogen atom. Among these, a triarylamine skeleton is preferred.

[0287] The reactive group-containing charge transport material, the non-reactive charge transport material, and the reactive group-containing non-charge transport material having a reactive group and a charge transport skeleton can be selected from known materials.

[0288] Furthermore, known additives may also be contained in the protective layer.

[0289] The protective layer can be formed by any known method without particular limitation. For example, a coating film of a protective layer-forming coating liquid obtained by adding the above components to a solvent is formed, the coating film is dried, and if necessary, hardened by heating or the like.

[0290] Examples of solvents used to prepare the protective layer-forming coating solution include aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as tetrahydrofuran and dioxane; cellosolve solvents such as ethylene glycol monomethyl ether; alcohol solvents such as isopropyl alcohol and butanol, etc. These solvents may be used alone or in combination of two or more.

[0291] The protective layer-forming coating liquid may be a solvent-free coating liquid.

[0292] Examples of a method for applying the protective layer-forming coating liquid onto a photosensitive layer (eg, charge transport layer) include common methods such as dip coating, push-up coating, wire bar coating, spray coating, blade coating, knife coating, and curtain coating.

[0293] The film thickness of the protective layer is set, for example, preferably within the range of 1 μm or more and 20 μm or less, and more preferably within the range of 2 μm or more and 10 μm or less.

[0294] [Single-layer photosensitive layer]

[0295] The single-layer photosensitive layer (charge generation / charge transport layer) is, for example, a layer containing a charge generation material and a charge transport material, and optionally a binder resin and other known additives. These materials are the same as those described for the charge generation layer and the charge transport layer.

[0296] Moreover, in the monolayer type photosensitive layer, the content of the charge generating material is preferably 0.1 mass % or more and 10 mass % or less, preferably 0.8 mass % or more and 5 mass % or less, relative to the total solid content. In addition, in the monolayer type photosensitive layer, the content of the charge transporting material is preferably 5 mass % or more and 50 mass % or less, relative to the total solid content.

[0297] The method for forming the single-layer photosensitive layer is the same as the method for forming the charge generating layer or the charge transporting layer.

[0298] The film thickness of the single-layer photosensitive layer is preferably, for example, 5 μm or more and 50 μm or less, and preferably 10 μm or more and 40 μm or less.

[0299] [Image forming apparatus, process cartridge]

[0300] The image forming device of the present embodiment includes: an electrophotographic photoreceptor; a charging mechanism for charging the surface of the electrophotographic photoreceptor; an electrostatic latent image forming mechanism for forming an electrostatic latent image on the surface of the charged electrophotographic photoreceptor; a developing mechanism for developing the electrostatic latent image formed on the surface of the electrophotographic photoreceptor using a developer containing toner to form a toner image; and a transfer mechanism for transferring the toner image to the surface of a recording medium. Moreover, as the electrophotographic photoreceptor, the electrophotographic photoreceptor of the present embodiment described above can be applied.

[0301] The image forming device of this embodiment can apply the following known image forming devices: a device including a fixing mechanism, which fixes the toner image transferred to the surface of the recording medium; a device using a direct transfer method to directly transfer the toner image formed on the surface of the electronic photographic photosensitive body to the recording medium; a device using an intermediate transfer method to transfer the toner image formed on the surface of the electronic photographic photosensitive body to the surface of the intermediate transfer body for the first time, and to transfer the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium for the second time; a device including a cleaning mechanism, which cleans the surface of the electronic photographic photosensitive body before charging after the transfer of the toner image; a device including a de-staticizing mechanism, which irradiates the surface of the electronic photographic photosensitive body with de-staticizing light to de-staticize after the transfer of the toner image and before charging; a device including an electronic photographic photosensitive body heating component, which is used to increase the temperature of the electronic photographic photosensitive body and reduce the relative temperature.

[0302] In the case of an intermediate transfer device, the transfer mechanism may, for example, be applied with the following structure, which includes: an intermediate transfer body having a surface for transferring a toner image; a primary transfer mechanism for transferring the toner image formed on the surface of the electronic photographic photosensitive body to the surface of the intermediate transfer body; and a secondary transfer mechanism for secondary transferring the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium.

[0303] The image forming apparatus of the present embodiment may be any of a dry developing system image forming apparatus and a wet developing system (development system using a liquid developer) image forming apparatus.

[0304] In the image forming apparatus of the present embodiment, for example, the portion including the electrophotographic photoreceptor may be a cartridge structure (processing cartridge) detachably provided with respect to the image forming apparatus. As the processing cartridge, for example, a processing cartridge including the electrophotographic photoreceptor of the present embodiment may be suitably used. In addition to the electrophotographic photoreceptor, the processing cartridge may also include, for example, at least one selected from the group consisting of a charging mechanism, an electrostatic latent image forming mechanism, a developing mechanism, and a transfer mechanism.

[0305] An example of the image forming apparatus according to the present embodiment is shown below, but the present invention is not limited thereto. The main parts shown in the drawings will be described, and description of other parts will be omitted.

[0306] Figure 2 This is a schematic diagram showing the configuration of an example of the image forming apparatus according to the present embodiment.

[0307] like Figure 2 As shown, the image forming apparatus 100 of the present embodiment includes a process box 300 having an electrophotographic photoreceptor 7, an exposure device 9 (an example of an electrostatic latent image forming mechanism), a transfer device 40 (a primary transfer device), and an intermediate transfer body 50. In the image forming apparatus 100, the exposure device 9 is arranged at a position where the electrophotographic photoreceptor 7 can be exposed from the opening of the process box 300, and the transfer device 40 is arranged at a position opposite to the electrophotographic photoreceptor 7 via the intermediate transfer body 50, and the intermediate transfer body 50 is arranged in a manner that a part of it contacts the electrophotographic photoreceptor 7. Although not shown in the figure, there is also a secondary transfer device that transfers the toner image transferred to the intermediate transfer body 50 to a recording medium (such as paper). The intermediate transfer body 50, the transfer device 40 (a primary transfer device), and the secondary transfer device (not shown) are equivalent to an example of a transfer mechanism.

[0308] Figure 2 The process box 300 in the embodiment integrally supports the electrophotographic photoreceptor 7, the charging device 8 (an example of a charging mechanism), the developing device 11 (an example of a developing mechanism), and the cleaning device 13 (an example of a cleaning mechanism) in the housing. The cleaning device 13 has a cleaning blade (an example of a cleaning member) 131, and the cleaning blade 131 is arranged in a manner of contacting the surface of the electrophotographic photoreceptor 7. The cleaning member is not in the form of the cleaning blade 131, but may be a conductive or insulating fibrous member, and the fibrous member may be used alone or in combination with the cleaning blade 131.

[0309] Figure 2 In the example shown, as the image forming apparatus, there is provided a fibrous member 132 (roller-shaped) for supplying the lubricant 14 to the surface of the electrophotographic photoreceptor 7 and a fibrous member 133 (flat brush-shaped) for assisting cleaning, and these can be arranged as necessary.

[0310] Hereinafter, each structure of the image forming apparatus according to the present embodiment will be described.

[0311] -Electrified Devices-

[0312] As the charging device 8, for example, a contact type charging device using a conductive or semi-conductive charging roller, a charging brush, a charging film, a charging rubber blade, a charging tube, etc. can be used. In addition, a non-contact roller charging device, a scorotron charging device using corona discharge, a scorotron charging device or a corotron charging device, etc., which are known in themselves, can also be used.

[0313] -Exposure device-

[0314] As the exposure device 9, for example, there can be cited an optical system device that exposes the surface of the electrophotographic photoreceptor 7 with semiconductor laser light, light emitting diode (LED) light, liquid crystal shutter light, etc. as specified. The wavelength of the light source is set within the spectral sensitivity region of the electrophotographic photoreceptor. As the wavelength of the semiconductor laser, the mainstream is near-infrared with an oscillation wavelength around 780nm. However, it is not limited to the above wavelength, and an oscillation wavelength laser of about 600nm or a laser with an oscillation wavelength of more than 400nm and less than 450nm as a blue laser can also be used. In addition, in order to form a color image, a surface-emitting laser light source that can output multiple beams is also effective.

[0315] -Developing device-

[0316] As the developing device 11, for example, a common developing device that performs development by contacting or non-contacting the developer can be cited. As the developing device 11, there is no particular limitation as long as it has the above-mentioned function, and it can be selected according to the purpose. For example, a known developer having the following function can be cited: a single-component developer or a two-component developer is attached to the electrophotographic photoreceptor 7 using a brush, a roller, etc. Among them, it is preferable to use a developing roller that holds the developer on the surface.

[0317] The developer used in the developing device 11 may be a one-component developer containing only toner or a two-component developer containing toner and a carrier. In addition, the developer may be magnetic or non-magnetic. These developers may be known ones.

[0318] -Cleaning device-

[0319] The cleaning device 13 may be a cleaning blade type device including a cleaning blade 131 .

[0320] In addition to the cleaning blade method, a brush cleaning method and a simultaneous developing and cleaning method may also be used.

[0321] -Transfer device-

[0322] Examples of the transfer device 40 include known transfer chargers such as a contact transfer charger using a belt, a roller, a film, a rubber blade, and a grid electrode transfer charger or a gridless electrode transfer charger using corona discharge.

[0323] -Intermediate transfer body-

[0324] As the intermediate transfer body 50, a belt-shaped one (intermediate transfer belt) made of polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber, etc. imparted with semiconductivity can be used. In addition, as the form of the intermediate transfer body, a roll-shaped one can also be used.

[0325] Figure 3 This is a schematic diagram showing the configuration of another example of the image forming apparatus according to the present embodiment.

[0326] Figure 3 The image forming apparatus 120 shown is a tandem type multi-color image forming apparatus equipped with four process cartridges 300. The image forming apparatus 120 is configured such that the four process cartridges 300 are arranged in parallel on the intermediate transfer body 50, and one electrophotographic photoreceptor is used for each color. The image forming apparatus 120 has the same configuration as the image forming apparatus 100 except that it is a tandem type.

[0327] [Example]

[0328] The following examples are given to more specifically describe the electronic photographic photoreceptor of the present invention. The materials, usage amounts, ratios, processing procedures, etc. shown in the following examples may be appropriately changed without departing from the main purpose of the present invention. Therefore, the scope of the electronic photographic photoreceptor of the present invention should not be interpreted as limited by the specific examples shown below.

[0329] <Production of photoreceptor>

[0330] [Example 1]

[0331] (Formation of Primer Layer)

[0332] 20 parts by mass of blocked isocyanate (Sumidur BL3175, manufactured by Bayer Urethane, 75% by mass of solid content) and 7.5 parts by mass of butyral resin (S-LEC BL-1, manufactured by Sekisui Chemical Co., Ltd.) were dissolved in 150 parts by mass of methyl ethyl ketone. 0.005 parts by mass of bismuth carboxylate (K-KAT XK-640, manufactured by King Industries) as a polyurethane curing catalyst, 7.5 parts by mass of strontium titanate particles (average primary particle size of 100 nm), and 45 parts by mass of purple ketone compound (1-1) were mixed in the solution, and dispersed for 10 hours using glass beads with a diameter of 1 mm using a sand mill to obtain a coating solution for forming a primer layer. The coating solution was dip-coated on a cylindrical aluminum substrate, dried and cured at 160°C for 60 minutes to form a primer layer with a thickness of 20 μm.

[0333] (Formation of Charge Generation Layer)

[0334] As a charge generating material, a hydroxygallium phthalocyanine having diffraction peaks at positions of at least 7.3°, 16.0°, 24.9°, and 28.0° at the Bragg angle (2θ±0.2°) of the X-ray diffraction spectrum using CuKα characteristic X-rays is prepared. A mixture of 15 parts by mass of hydroxygallium phthalocyanine, 10 parts by mass of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Unicar Corporation of Japan) and 200 parts by mass of n-butyl acetate is dispersed for 4 hours using glass beads with a diameter of 1 mm and a sand mill. 175 parts by mass of n-butyl acetate and 180 parts by mass of methyl ethyl ketone are added to the obtained dispersion, and stirred to obtain a coating liquid for forming a charge generating layer. The coating liquid is dip-coated on the undercoat layer and dried at 150°C for 15 minutes to form a charge generating layer with a thickness of 0.2 μm.

[0335] (Formation of Charge Transport Layer)

[0336] 38 parts by mass of charge transport agent (HT-1), 10 parts by mass of charge transport agent (HT-2) and 52 parts by mass of polycarbonate resin (A) (viscosity average molecular weight 46,000) were added to 800 parts by mass of tetrahydrofuran for dissolution, and 8 parts by mass of tetrafluoroethylene resin (LUBRON L5, manufactured by Daikin Industries, with an average particle size of 300 nm) were added, and a homogenizer (ULTRA-TURRAX, manufactured by IKA) was used to disperse at 5500 rpm for 2 hours to obtain a coating liquid for forming a charge transport layer. The coating liquid was dip-coated on the charge generating layer and dried at 140°C for 40 minutes to form a charge transport layer with a thickness of 29 μm. Through the above treatment, the photoreceptor of Example 1 was obtained.

[0337] [Chemistry 11]

[0338]

[0339] [Chemistry 12]

[0340]

[0341] [Example 2 to Example 17]

[0342] In forming the undercoat layer, a photoreceptor was prepared in the same manner as in Example 1 except that the type and amount of the metal titanate compound particles or the type and amount of the perinone compound were changed as shown in Table 1.

[0343] [Example 18 to Example 20]

[0344] In forming the undercoat layer, a photoreceptor was prepared in the same manner as in Example 1 except that the perinone compound was replaced with an imide compound. The chemical structures of the imide compound (A), the imide compound (B), or the imide compound (C) used in Examples 18 to 20 are shown below.

[0345] [Chemistry 13]

[0346]

[0347] [Comparative Example 1]

[0348] A photoreceptor was prepared in the same manner as in Example 1 except that the metal titanate compound particles were not used in forming the undercoat layer.

[0349] [Comparative Example 2 to Comparative Example 4]

[0350] In forming the undercoat layer, a photoreceptor was prepared in the same manner as in Example 1 except that the metal titanate compound particles were not used and the perinone compound was replaced with an imide compound. The chemical structures of the imide compound (A), the imide compound (B) or the imide compound (C) used in Comparative Examples 2 to 4 are as described above.

[0351] <Photoreceptor performance evaluation>

[0352] [Electrical characteristics]

[0353] The photosensitive bodies of the examples or comparative examples were mounted on a laser printer-modified scanner (XP-15 modified machine) manufactured by Fuji Xerox. The photosensitive bodies were charged by a grid electrode type charger with a grid voltage of -700 V under an environment of a temperature of 20°C and a relative humidity of 40%, and irradiated with 10.0 erg (erg) / cm after 1 second using a 780nm semiconductor laser. 2 The light was discharged and irradiated with 50.0erg / cm3 after 3 seconds. 2 The red LED light was used for charge erasing. The potential of the photoreceptor was measured after discharge and after charge erasing.

[0354] The potential of the photoreceptor after discharge was used as an index of photosensitivity and was classified into the following A to D. Table 1 shows the evaluation results.

[0355] -Light Sensitivity-

[0356] A: -240V or above

[0357] B: -280V or more and less than -240V

[0358] C: -300V or more and less than -280V

[0359] D: - less than 300V

[0360] The difference between the potential of the photoreceptor after discharge and the potential of the photoreceptor after charge elimination was classified into the following A to D. Table 1 shows the evaluation results.

[0361] -Residual Potential-

[0362] A: -20V or above

[0363] B: -40V or more and less than -20V

[0364] C: -80V or more and less than -40V

[0365] D: - less than 80V

[0366] [Image quality (1)]

[0367] -Grayscale property-

[0368] The photosensitive body of each embodiment or each comparative example was mounted on an image forming apparatus manufactured by Fuji Xerox Corporation: a color multifunction machine Docu Centre Color 500, and 10 sheets of A4 size paper were outputted under an environment of a temperature of 20°C and a relative humidity of 40%. Then, an image chart including halftone images with image densities of 5%, 10%, 20%, 80%, 90%, and 100% and a solid image (all black) was outputted, and the images were visually observed and classified as follows. The evaluation results are shown in Table 1.

[0369] A: There is no difference from the set concentration.

[0370] B: There is a difference from the set concentration, but it is within the practically acceptable range.

[0371] C: There is a difference from the set concentration, which is a level that is not acceptable in practical use.

[0372] [Image quality (2)]

[0373] The photosensitive member of each embodiment or comparative example was mounted on an image forming apparatus manufactured by Fuji Xerox Corporation: a color multifunction machine Docu Centre Color 500, and 10 sheets of A4 paper were continuously outputted at a temperature of 20°C and a relative humidity of 40%. Figure 4 The images shown (including an area with five white characters "G" in a black image with an image density of 100% and an image of a black halftone image area with an image density of 40%). The first image and the tenth image were visually compared, and ghosting and density unevenness were classified into the following A to C. The evaluation results are shown in Table 1.

[0374] -Double Vision-

[0375] A: There is no density change on the letter "G".

[0376] B: There is some density variation on the letter "G", but it is tolerable in practical use.

[0377] C: The density of the letter "G" varies, which is unacceptable in practical use.

[0378] -Uneven concentration-

[0379] A: Halftone images have no density variation.

[0380] B: The halftone image has some density variation, but it is tolerable in practical use.

[0381] C: The halftone image has density variations, which is unacceptable in practical use.

[0382] [Table 1]

[0383]

Claims

1. An electrophotographic photoreceptor, comprising: Conductive substrate; A primer layer is disposed on the conductive substrate and contains metal titanate compound particles, an electron transporting compound and a binder resin; as well as A photosensitive layer is disposed on the base coating layer, The electron transporting compound contains at least one perirone compound selected from the group consisting of compounds represented by the following general formula (1) and compounds represented by the following general formula (2), In the general formula (1), R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 and R 18 R each independently represents a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group or a halogen atom; 11 With R 12 , R 12 With R 13 and R 13 With R 14 They can independently connect to each other to form a ring; R 15 With R 16 , R 16 With R 17 and R 17 With R 18 They can be independently connected to each other to form a ring; In the general formula (2), R 21 , R 22 , R 23 , R 24 , R 25 , R 26 , R 27 and R 28 R each independently represents a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group or a halogen atom; 21 With R 22 , R 22 With R 23 and R 23 With R 24 They can independently connect to each other to form a ring; R 25 With R 26 , R 26 With R 27 and R 27 With R 28 can be independently connected to each other to form a ring, The total content of the metal titanate compound particles contained in the undercoat layer is 5 mass % or more and 50 mass % or less relative to the total content of the electron transporting compound contained in the undercoat layer.

2. The electrophotographic photoreceptor according to claim 1, wherein The metal titanate compound particles include at least one selected from the group consisting of strontium titanate particles, barium titanate particles, calcium titanate particles, and magnesium titanate particles.

3. The electrophotographic photoreceptor according to claim 1, wherein The metal titanate compound particles have an average primary particle size of 30 nm or more and 1 μm or less.

4. The electrophotographic photoreceptor according to claim 1, wherein The total content of the metal titanate compound particles is 5 mass % or more and 40 mass % or less relative to the total solid content of the undercoat layer.

5. The electrophotographic photoreceptor according to claim 1, wherein The total content of the electron transport compound is 30% by mass or more relative to the total solid content of the undercoat layer.

6. The electrophotographic photoreceptor according to claim 1, wherein The binder resin contains polyurethane.

7. A process cartridge comprising the electrophotographic photoreceptor according to any one of claims 1 to 6, and The process cartridge is detachably disposed in the image forming apparatus.

8. An image forming device, comprising: The electrophotographic photoreceptor according to any one of claims 1 to 6; A charging mechanism for charging the surface of the electrophotographic photoreceptor; An electrostatic latent image forming mechanism for forming an electrostatic latent image on the charged surface of the electrophotographic photoreceptor; A developing mechanism for developing the electrostatic latent image formed on the surface of the electrophotographic photoreceptor using a developer containing toner to form a toner image; as well as The transfer mechanism transfers the toner image to the surface of the recording medium.

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