RU2566607C2 - Electrophotographic light-sensitive cell, cartridge and electrophotographic device - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: this invention is referred to electrophotographic light-sensitive cell, cartridge and electrophotographic device having the above electrophotographic light-sensitive cell. The claimed group of inventions include cartridge comprised of electrophotographic light-sensitive cell and at least one unit selected from the group consisting of a charging unit, developing unit, transferring unit and cleaning unit entirely supported in it, at that cartridge can be attached to a case of the electrophotographic device and detached from it. At that electrophotographic light-sensitive cell comprises a laminated body and hole transfer layer formed at the laminated body, moreover the laminated body includes substrate, electron transfer layer with thickness of d1 [mcm] formed at the substrate and charge generating layer with thickness of d2 [mcm] formed at electron transfer layer, at that the laminated body meets the following expressions (2) and (4): |Vl2(B)-Vl1(B)|≤0.35 (2) and 0.10≤|(Vd2(B)-Vl3(B))/Vd2(B)|≤0.20 (4), where in the expressions (2) and (4) Vl1(B) represents potential for surface of the charge generating layer at charge of the layer surface so that surface has potential Vd1 [V] represented by the following expression (1): Vd1(V)=-50 (V per thickness unit (mcm))×(d1(mcm)+d2(mcm)) (1), and at radiation with light of surface of the charge generating layer having potential Vd1 with interval of 0.18s upon radiation, at that light intensity is regulated so that potential of the surface drops per 20% in regard to Vd1 [V] at radiation of the charge generating layer with interval of 0.20s upon radiation; Vl2(B) represents potential for surface of the charge generating layer at surface charging so that potential of this surface is Vd1 [V] and at radiation with light of surface of the charge generating layer having potential Vd1 with interval of 0.22s upon radiation, and Vl3(B) represents potential for surface of the charge generating layer at charging of surface of the charge generating layer so that surface has potential Vd2 [V] represented by the following expression (3): Vd2(V)=-30 (per thickness unit (mcm))×(d1(mcm)+d2(mcm)) (3), and at radiation with light of surface of the charge generating layer having potential Vd2 with interval of 0.20s upon radiation.

EFFECT: provision of electrophotographic light-sensitive cell with suppression of positive ghost and suppression of reduced charging capability upon multiple usage, and in provision of cartridge and electrophotographic device having such electrophotographic light-sensitive cell.

11 cl, 8 dwg, 14 tbl

Description

BACKGROUND OF THE INVENTION

Field of Invention

[0001] The present invention relates to an electrophotographic photosensitive member, as well as a working cartridge and an electrophotographic device having an electrophotographic photosensitive member.

Description of the Related Art

[0002] As electrophotographic photosensitive elements used for working cartridges and electrophotographic devices, currently mainly electrophotographic photosensitive elements containing organic photoconductive material predominate. The electrophotographic photosensitive member typically has a substrate and a photosensitive layer formed on the substrate. Then, a coating sublayer is provided between the substrate and the photosensitive layer in order to suppress the injection of charge from the side of the substrate towards the photosensitive layer (charge generation layer) and to suppress the generation of image defects such as tarnishing.

[0003] Recently, charge-generating substances having a higher sensitivity have been used. However, such a problem arises that the charge tends to be held in the photosensitive layer due to the fact that the amount of charge generated becomes larger as the sensitivity of the charge-generating substance increases, and a tendency for a repeated image (“shadow”) to appear. Specifically, in a printed image, a phenomenon of the so-called positive repeated image tends to occur, in which only the parts irradiated with light in the previous rotation time become high.

[0004] A technique is described for suppressing (reducing) such a re-image phenomenon in which a coating sublayer is made into a layer (hereinafter also referred to as an electron transfer layer) having an electron transfer ability by introducing an electron-transporting substance into the coating sublayer. National Publication of International Patent Application No. 2009-505156 describes a condensed polymer (electron transferring substance) having an aromatic tetracarbonylbisimide skeleton and an active crosslinking center, and an electron transfer layer containing a polymer with a crosslinking agent. Japanese Patent Application Laid-Open No. 2003-330209 describes that a polymer of an electron-transporting substance having a non-hydrolyzable polymerizable functional group is introduced into the sublayer of the coating. Japanese Patent Application Laid-Open No. 2005-189764 describes a technology for imparting an electron mobility of 10 ^-7 cm ² / V · sec or more to a sublayer to improve electron transfer ability.

[0005] The quality requirements for electrophotographic images have been steadily increasing in recent years, and margins for positive repeat images have become noticeably stricter. The result of the studies of the authors of the present invention shows that the technologies for suppressing (reducing) positive repeated image described in the national publication of International patent application No. 2009-505156 and Japanese patent applications laid out No. 2003-330209 and 2005-189764, provide an insufficient reduction in positive repeated images in some cases where there is still room for improvement. At the same time, if the sublayer of the coating is made an electron transfer layer, and in the case where the electron transfer layer has insufficient uniformity, since the ability to charge after repeated use tends to decrease, the decrease in the ability to charge should be suppressed.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to provide an electrophotographic photosensitive member with suppressing positive re-image and suppressing a decrease in chargeability after repeated use, as well as a working cartridge and an electrophotographic device having such an electrophotographic photosensitive member.

[0007] The present invention relates to an electrophotographic photosensitive member comprising a laminated body and a hole transport layer formed on the laminated body, the laminated body comprising a substrate, an electron transfer layer having a thickness d1 [μm] formed on the substrate, and a charge generation layer having the thickness d2 [μm] formed on the electron transfer layer, and the laminated body satisfies the following expressions (2) and (4).

Vl2-Vl1 | ≤0.35 ... (2)

0.10≤ | (Vd2-Vl3) / Vd2 | ≤0.20 ... (4)

[0008] In the expressions (2) and (4),

Vl1 represents the surface potential of the charge generation layer when charging the surface of the charge generation layer so that the surface has the potential Vd1 [B] represented by the following expression (1):

(1), и Vd1 = -50 × (d1 + d2)

(1), and

irradiating the surface of the charge generation layer having the potential Vd1 with light at an interval of 0.18 seconds after irradiation, the light intensity being regulated so that the surface potential drops by 20% with respect to Vd1 [B] when the surface of the charge generation layer is irradiated , at an interval of 0.20 seconds after exposure.

Vl2 is the surface potential of the charge generation layer when charging the surface of the charge generation layer in such a way that the surface potential is Vd1 [B], and the surface of the charge generation layer having the potential Vd1 is irradiated with light, at an interval of 0.22 seconds after irradiation.

Vl3 is the surface potential of the charge generation layer when charging the surface of the charge generation layer so that the surface has a potential Vd2 [B] represented by the following expression (3):

(3), и Vd2 = -30 × (d1 + d2)

(3), and

irradiating the surface of the charge generation layer having the potential Vd2 with light at an interval of 0.20 seconds after irradiation.

[0009] The present invention also relates to a working cartridge comprising the aforementioned electrophotographic photosensitive member and at least one assembly selected from the group consisting of a charging unit, a developing unit, a transfer unit, and a cleaning unit, all supported therein, the cartridge is attached to and removable from the body of the electrophotographic device.

[0010] The present invention also relates to an electrophotographic device comprising the above electrophotographic photosensitive member, a charging unit, a light irradiation unit, a developing unit, and a transfer unit.

[0011] The present invention can provide an electrophotographic photosensitive member with suppressing positive re-image and suppressing a decrease in chargeability after repeated use, as well as a working cartridge and an electrophotographic device having such an electrophotographic photosensitive member.

[0012] Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings.

Brief Description of the Drawings

[0013] FIG. 1 is a diagram illustrating one example of a principle structure of a determination device for implementing the determination method in accordance with the present invention.

[0014] FIG. 2 is a diagram illustrating another example of the basic structure of a determination device for implementing the determination method in accordance with the present invention.

[0015] FIG. 3A is a graph for describing Vd1, Vl1, and Vl2.

[0016] FIG. 3B is a graph for describing Vd2 and Vl3.

[0017] Fig. 4A and Fig. 4B are graphs illustrating Comparative examples in which charging cannot be established by the determination method in accordance with the present invention.

[0018] FIG. 5 is a graph for describing a conventional measurement method.

[0019] FIG. 6 is a diagram illustrating a schematic structure of an electrophotographic device having a working cartridge with an electrophotographic photosensitive member.

[0020] FIG. 7A is a diagram for describing an image for evaluating a repeated image used in evaluating a repeated image.

[0021] FIG. 7B is a diagram for describing an image of a one-point Keima structure (similar to a knight's move).

[0022] FIG. 8 is a diagram illustrating one example of a layer structure of an electrophotographic photosensitive member in accordance with the present invention.

Description of Embodiments

[0023] Preferred embodiments of the present invention will now be described in detail in accordance with the accompanying drawings.

[0024] First, a determination method (hereinafter, referred to as a "determination method in accordance with the present invention") will be described to determine whether an electrophotographic photosensitive member satisfies the above expressions (1) to (4) in accordance with the present invention.

[0025] The temperature and humidity conditions in the implementation of the determination method in accordance with the present invention can correspond to an environment in which an electrophotographic device having an electrophotographic photosensitive element is used, and can correspond to a normal temperature and normal humidity of the environment (23 ± 3 ° C, 50 ± 2% relative humidity (RH)).

[0026] The measurement method includes measurement using a laminated body (also referred to below as an “electrophotographic photosensitive member for detecting”) having a substrate, an electron transfer layer formed on the substrate, and a charge generation layer formed on the electron transfer layer.

[0027] In this case, the hole transport layer is peeled off from the electrophotographic photosensitive member having a laminated body and a hole transport layer formed on the laminated body, and the laminated body can be used as an object of determination. A method for exfoliating a hole transfer layer includes a method in which an electrophotographic photosensitive member is immersed in a solvent that dissolves the hole transfer layer well and poorly dissolves the electron transfer layer and the charge generation layer, and a method in which the hole transfer layer is ground.

[0028] As a solvent that dissolves the hole transport layer well and poorly dissolves the electron transfer layer and the charge generation layer, a solvent used as a liquid for applying the hole transport layer can be used. The types of solvent will be described later. The electrophotographic photosensitive member is immersed in a solvent so that the hole transport layer dissolves in the solvent, and then dried, thereby obtaining an electrophotographic photosensitive member for determination. The fact that the hole transfer layer is peeling off can be confirmed, for example, by the fact that no resin components of the hole transfer layer can be detected using the ATR method (total internal reflection method) in the FTIR measurement method (Fourier transform infrared spectrometry).

[0029] A method for grinding a hole transfer layer includes, for example, using a drum grinding device manufactured by Canon Inc. and using a lapping belt (C2000 manufactured by Fujifilm Corp.). In this case, it is possible to measure while the entire hole transport layer disappears, although the thickness of the hole transport layer is subsequently measured so that there is no grinding to the charge generation layer due to excessive grinding of the hole transfer layer, and the surface of the electrophotographic photosensitive member is observed. The case when the thickness of the charge generation layer remains 0.10 μm or more after grinding to the charge generation layer turned out to give approximately the same value with the above determination method, as in the case when grinding is not carried out before the charge generation layer. Therefore, the above determination method can be used even if not only the hole transport layer is polished, but also the charge generation layer, in the case where the thickness of the charge generation layer is 0.10 μm or more.

[0030] FIG. 1 illustrates one example of the basic structure of a determination device for implementing the determination method in accordance with the present invention.

[0031] In FIG. 1, reference numeral 101 denotes an electrophotographic photosensitive member (cylindrical laminated body) for detection, and reference numeral 102 denotes a corona discharge device of the charging device. Reference numeral 103 denotes a device for emitting pulsed laser light (a light emitting device for irradiating an image); reference numeral 103L denotes pulsed light (light for irradiating an image); reference number 104P denotes a transparent probe for transmitting pulsed light 103L, and reference number 104 denotes an electrometer for measuring the surface potential of the laminated body charge generation layer from the transparent probe. The electrophotographic photosensitive member 101 to be determined is rotationally moved in the direction of the arrow and stopped in the position of the transparent probe 104P. The surface potential of the electrophotographic photosensitive member 101 to be determined is measured with an electrometer 104 and a transparent probe 104P from the stop time. Thereafter, the electrophotographic photosensitive member 101 for detection is irradiated with pulsed light 103L emitted from the pulsed laser light emitting device 103 and transmitted through the transparent probe 104P, and then the change in surface potential over time is measured.

[0032] Figure 2 illustrates another example of the basic structure of a determination device for implementing the determination method in accordance with the present invention. Reference number 201 denotes an electrophotographic photosensitive member (sheet-shaped laminated body) for detection; reference numeral 202 denotes a corona arrester of a charging device; reference numeral 203 denotes a device for emitting pulsed laser light (a light emitting device for irradiating an image); reference numeral 203L denotes pulsed light (light for irradiating an image); reference numeral 204P denotes a transparent probe for transmitting pulsed light 203L, and reference numeral 204 denotes an electrometer for measuring the surface potential of a laminated body charge generation layer from a transparent probe. The electrophotographic photosensitive member 201 to be determined is driven in the direction of the arrow and stopped in the position of the transparent probe 204P. The surface potential of the electrophotographic photosensitive member 201 to be determined is measured with an electrometer 204 and a transparent probe 204P from the stop time. The electrophotographic photosensitive member 201 to be detected is then irradiated with pulsed light 203L emitted from the pulsed laser light emitting device 203 and transmitted through the transparent probe 204P, and then the change in surface potential over time is measured.

[0033] The position of the corona arrester 102 (202), the position of the light irradiation and the speed of movement of the electrophotographic photosensitive member to be determined are controlled so that the time between charging the corona arrester and the irradiation (also referred to as exposure) for pulsed light 103L (203L) becomes equal to 1.00 sec. As a corona arrester 102 (202), a speedron arrester can be used, which has the ability to give a constant potential at the output. As the pulsed light 103L (203L), laser pulsed light with a wavelength of 780 nm and a pulse width of 10 microseconds can be used, and the light intensity can be controlled using an ND filter.

[0034] The above expressions (1) to (4) will be described later.

[0035] Fig. 3A is a graph for describing Vd1, Vl1 and Vl2 in the above expressions (1) and (2), and Fig. 3B is a graph for describing Vd2 and Vl3 in the above expressions (3) and (4).

[0036] The charging conditions C1 and C2 described below and the light intensity E are determined before determining whether the electrophotographic photosensitive member satisfies the above expressions (1) to (4).

[0037] <Charging conditions C1>

[0038] The magnitude of the network voltage applied to the corona spark gap and the magnitude of the current of the discharge wire are controlled so that the surface potential of the charge generation layer after 1.00 sec after charging with the corona gap becomes Vd1 (V) represented by the following expression (1 ), as a result of charging the surface intended for determining the electrophotographic photosensitive element (layer of the charge generation of the laminated body). The voltage value of the grid and the current value of the discharge wire are taken so that they meet the charging condition C1.

Vd1 = -50 × (d1 + d2) ... (1)

[0039] <Charging conditions C2>

[0040] The magnitude of the network voltage applied to the corona spark gap and the magnitude of the current of the discharge wire are adjusted so that the surface potential of the charge generation layer after 1.00 sec after charging with the corona gap becomes Vd2 (V), represented by the following expression (3 ), as a result of charging the surface intended for determining the electrophotographic photosensitive element.

Vd2 = -30 × (d1 + d2) ... (3)

[0041] <Light intensity E>

[0042] The surface of the electrophotographic photosensitive member to be detected is charged under charging conditions C1 so that its surface potential becomes Vd1 (B) represented by the above expression (1), and the light intensity is regulated by the ND filter so that the surface potential in the interval of 0.20 sec after irradiation with light or exposure of the surface of the charge generation layer, it decreases by 20% with respect to Vd1 (B). The light intensity is taken so that it is equal to the light intensity E.

[0043] FIG. 3A is a graph illustrating a change in time of the surface potential of the electrophotographic photosensitive member 101 for detecting when the electrophotographic photosensitive member for detecting is charged under the above charging conditions C1 and is irradiated with light with the above light intensity E through 1, 00 sec after charging. Vl1 represents the surface potential in the range of 0.18 seconds after exposure to light with light intensity E, and Vl2 represents the surface potential in the interval of 0.22 seconds after exposure to light with light intensity E.

[0044] FIG. 3B is a graph illustrating a change in time of the surface potential of the electrophotographic photosensitive member 101 for detecting when the electrophotographic photosensitive member for detecting is charged under the above charging conditions C2 and irradiated with light with the above light intensity E through 1, 00 sec after charging. Vl3 represents the surface potential in the interval of 0.20 seconds after exposure to light with light intensity E.

[0045] Thus, Vl1, Vl2 and Vl3 are measured.

[0046] In the case where the charging conditions C1 and the light intensity E cannot be set, it is not possible to satisfy the conditions of the determination method in accordance with the present invention. 4A is a graph illustrating an example in which charging conditions C1 cannot be set, and this example in which charging conditions C1 cannot be set is a solid line, illustrated as a Comparative example. An example is an example in which, since the charging ability is insufficient, charging cannot be carried out in such a way that the surface potential after 1.00 seconds after charging becomes equal to Vd1 (B) represented by the above expression (1).

[0047] FIG. 4B is a graph illustrating an example in which the light intensity E cannot be set, and this example in which the light intensity E cannot be set, is a solid line, illustrated as a Comparative example. This example is an example in which, since the ability of electrons to move is insufficient, even if the light intensity becomes high, the surface potential in the interval of 0.20 seconds after irradiation with light cannot fall by 20% with respect to Vd1 (B).

[0048] Vd1 (B) represented by the above expression (1) means adjusting the surface potential so that the potential becomes −50 V per unit thickness (μm), relative to the total thickness (μm) of the electron transport layer with a thickness d1 and a charge generation layer of thickness d2.

[0049] | Vl2-Vl1 | in the following expression (2) means a change in the surface potential not due to electrons in the region where the electron mobility is calculated, linearly incident immediately after exposure to light, but due to electrons in the slow region after that, not contributing to the calculation of electron mobility, from electrons generated in the charge generation layer injected into the electron transfer layer and moving in the electron transfer layer. The linear incidence region immediately after exposure to light is the area of overlap of the straight line, illustrated as a broken line in FIG. 5, and the electron mobility is typically calculated from the linear incidence region immediately after exposure to light.

| Vl2-Vl1 | ≤0.35 ... (2)

[0050] The fact that the surface potential in the interval of 0.20 sec after irradiation with light with light intensity E is regulated to fall by 20% with respect to Vd1 (B), means that the amount of charge generated in the charge generation layer becomes a constant amount ; and a value of 20% means that the light intensity is such that the generated charge itself does not disturb the electric field, and is a satisfactory value, like the magnitude of the drop at which a change in potential can be observed against the background of noise. The interval of 0.20 seconds after exposure to light, which is set as the time for which the surface potential drops by 20%, corresponds to the time from exposure to light until subsequent charging under the assumption of an electrophotographic device having a high process speed, and represents the time at which it is observed electron decay in a slow region. The expression | Vl2-Vl1 | how the magnitude of the change in the surface potential within 0.02 sec from 0.20 sec (after 0.18 sec, after 0.22 sec) is a description of how the magnitude of the drop that can be observed is not in the linear drop region immediately after irradiation by light, but in order to distinguish a change in potential in a slow region from noise. If | Vl2-Vl1 | equal to 0.35 or less, as can be seen from the above expression (2), the motion of electrons in the slow region decreases, thus meaning that the change in the surface potential becomes small. During subsequent charging after exposure to light, the movement of electrons is expectedly reduced.

[0051] Vd2 (B) represented by the above expression (3) means adjusting the surface potential so that the potential becomes −30 V per unit thickness (μm), with respect to the total thickness (μm) of an electron transfer layer of thickness d1 and a charge generation layer of thickness d2.

[0052] | (Vd2-Vl3) / Vd2 | in the following expression (4), it shows the fraction of the fall from Vd2, where Vl3 is the surface potential in the interval of 0.20 sec after exposure to light at the same light intensity as the light intensity at which the surface potential in the range of 0.20 sec after light irradiation drops by 20% with respect to Vd1 (B). A change in the proportion of electrons injected into the charge generation layer injected into the electron transfer layer is observed when the surface potential at the beginning of light irradiation decreases from Vd1 to Vd2. The fact that the surface potential is regulated in such a way that Vd2 (V) becomes equal to -30 V per unit thickness (μm) is due to the fact that the difference in the efficiency of the electrons injected into the charge generation layer injected into the electron transfer layer is easily observed by adjusting surface potential at the beginning of light irradiation from Vd1 to a lower value of Vd2. This value is also associated with the possibility of observing a drop in the surface potential against a background of noise. If | (Vd2 - Vl3) / Vd2 | equal to 0.10 or more, it can be assumed that the electrons generated in the charge generation layer are sufficiently injected into the electron transfer layer, and the electron retention inside the electron transfer layer and at the interface between the charge generation layer and the hole transfer layer is suppressed. Since irradiation with light is carried out at the same light intensity as the light intensity at which the surface potential in the interval of 0.20 seconds after irradiation with light drops by 20% with respect to Vd1 (B), the upper limit is | (Vd2-Vl3) / Vd2 | is 0.20.

0.10≤ | (Vd2-Vl3) / Vd2 | ≤0.20 ... (4)

[0053] The authors of the present invention suggest that the reason for suppressing a positive repeated image and suppressing a decrease in chargeability while satisfying both the above expression (2) and the above expression (4) is as follows.

[0054] Namely, in the case of an electrophotographic photosensitive member provided with a substrate and an electron transfer layer (a coating sublayer), a charge generation layer and a hole transfer layer on the substrate in this order, it is considered that in the parts onto which the irradiating light (light for irradiation of the image), from the charges (holes, electrons) generated in the charge generation layer, the holes are injected into the hole transfer layer, and the electrons are injected into the electron transfer layer and transferred to the substrate. However, if the electrons generated in the charge generation layer cannot completely transfer to the electron transfer layer before the subsequent charge, the motion of the electrons still occurs during the subsequent charge. In this case, the electrons are held inside the electron transfer layer and at the interface between the charge generation layer and the electron transfer layer, and holes tend to be injected from the substrate into the electron transfer layer and into the charge generation layer during subsequent charging. This is expected to produce a positive reimage.

[0055] With respect to these reasons, an electrophotographic photosensitive member in which the electrons generated in the charge generation layer cannot sufficiently move in the electron transport layer before subsequent charging cannot satisfy the above expression (2). In addition, the electrophotographic photosensitive element in which the confinement of electrons occurs inside the electron transfer layer and at the interface between the charge generation layer and the electron transfer layer cannot satisfy the above expression (4). It is assumed that in the electrophotographic photosensitive element, which satisfies both the above expression (2) and the above expression (4), since the above electrons can sufficiently move in the electron transport layer before subsequent charging and electron holding is suppressed, suppressed and positive repeat image.

[0056] The technology of Japanese Patent Application Laid-Open No. 2005-189764, in which the electron mobility in the coating sublayer (electron transfer layer) is made equal to 10 ^-7 cm ² / V · sec or more, is an object for improving the linear incidence region immediately after exposure to light. However, this technology does not eliminate the reason for generating a positive repeated image that the electrons generated in the charge generation layer cannot move sufficiently in the electron transfer layer before subsequent charging. That is, the technology does not control the movement of electrons in the slow region. Japanese Patent Application Laid-Open No. 2010-145506 describes that the charge mobility in the hole transfer layer and the electron transfer layer (coating sublayer) is made to be in specific ranges, but it does not eliminate the reason for generating a positive repeated image, as in the laid out Japanese Patent Application No. 2005-189764. In addition, in this patent literature, electron mobility in the electron transfer layer is measured using a structure in which an electron transfer layer is formed on the charge generation layer, and this structure is inverse to the layer structure used in the electrophotographic photosensitive member. However, it cannot be said that such a measurement would make it possible to sufficiently evaluate the motion of electrons in the electron transfer layer of an electrophotographic photosensitive element.

[0057] For example, in the case where the electron transfer layer is made by introducing the electron-transporting substance into the sublayer of the coating, when liquids for applying the charge generation layer and the hole transfer layer as the upper layers are applied to form the charge generation layer and the hole transfer layer, transferring The electrons substance in some cases elutes. In this case, it can be assumed that even if the electron mobility is measured by performing the electron transfer layer and the charge generation layer as layers in the reverse order, as described above, since the electron-transporting substance is eluted in the electrophotographic photosensitive element, the movement of electrons in the electron transfer layer of the electrophotographic photosensitive item cannot be appreciated sufficiently. Therefore, the determination should be made using an electron transfer layer, from which the hole transfer layer and the charge generation layer are peeled off after the charge generation layer and the hole transfer layer are formed on the electron transfer layer.

[0058] In the case of an electrophotographic photosensitive member provided with an electron transport layer, a charge generation layer and a hole transport layer in this order on the substrate, an electrophotographic photosensitive member having a low early charging ability is expected to be obtained mainly by injecting holes from substrate towards the electron transfer layer and towards the charge generation layer. The decrease in rechargeability with repeated use is expected to occur due to a more facilitated injection of holes due to the retention of charges inside the coating sublayer and at the interface between the charge generation layer and the electron transfer layer. An electron transfer layer having low uniformity, such as an electron transfer layer containing an electron-transporting substance such as a pigment, or an electron transfer layer containing dispersed metal oxide particles and an electron-transporting substance has a low ability to charge at an early stage and in many cases causes a decrease rechargeable ability. Such an electron transfer layer having a low charge capacity, in some cases, cannot be charged to Vd1 in the determination method in accordance with the present invention. This can be assumed from the fact that if the electrophotographic photosensitive element after peeling the hole transfer layer can be charged to Vd1, the early charging ability is sufficient, and a decrease in rechargeability with repeated use can be suppressed.

[0059] The thickness d1 of the electron transfer layer may be 0.2 μm or more and 0.7 μm or less.

[0060] In the above expression (2), from the point of view of further reducing the positive repeated image, the following expression (9) can be satisfied.

| Vl2-Vl1 | ≤0.28 ... (9)

[0061] In the above expression (4), more preferably, the following expression (10) is satisfied.

0.10≤ | (Vd2-Vl3) / Vd2 | ≤0.16 ... (10)

[0062] The electrophotographic photosensitive member according to the present invention has a laminated body and a hole transport layer formed on the laminated body. The laminated body has a substrate, an electron transfer layer formed on the substrate, and a charge generation layer formed on the electron transfer layer.

[0063] FIG. 8B is a diagram illustrating one example of a layer structure of an electrophotographic photosensitive member in accordance with the present invention. 8B, reference numeral 21 denotes a substrate; reference numeral 22 denotes an electron transfer layer; reference number 24 denotes a charge generation layer, and reference number 25 denotes a hole transport layer.

[0064] As a conventional electrophotographic photosensitive member, a cylindrical electrophotographic photosensitive member is widely used in which the photosensitive layer (charge generation layer, hole transfer layer) is formed on the cylindrical substrate, but an element of a different shape, for example, in the form of a tape or in the form, can be used sheet.

[0065] the layer of electron transfer

[0066] The structure of the electron transfer layer will be described.

[0067] The electron transfer layer may comprise an electron-transporting substance or a polymer of an electron-transporting substance. The electron transfer layer may further comprise a polymer obtained by polymerizing the composition of an electron-transporting substance having polymerizable functional groups, a thermoplastic resin having polymerizable functional groups, and a crosslinking agent.

[0068] Electron Carrier

[0069] Examples of electron-transporting substances include quinone compounds, imide compounds, benzimidazole compounds, and cyclopentadienylidene compounds.

[0070] The electron transporting substance may be an electron transporting substance having polymerizable functional groups. The polymerizable functional group includes a hydroxyl group, a thiol group, an amino group, a carboxyl group, and a methoxy group.

[0071] Specific examples of electron-transporting matter are shown below. The electron transporting substance includes compounds represented by one of the following formulas (A1) to (A9).

[0072]

[0073] In the formulas (A1) to (A9), R ¹⁰¹ -R ¹⁰⁶ , R ²⁰¹ -R ²¹⁰ , R ³⁰¹ -R ³⁰⁸ , R ⁴⁰¹ -R ⁴⁰⁸ , R ⁵⁰¹ -R ⁵¹⁰ , R ⁶⁰¹ -R ⁶⁰⁶ , R ^701- R ⁷⁰⁸ , R ⁸⁰¹ -R ⁸¹⁰ and R ⁹⁰¹ -R ⁹⁰⁸ each independently represent a monovalent group represented by the following formula (A), hydrogen atom, cyano group, nitro group, halogen atom, alkoxycarbonyl group, substituted or unsubstituted alkyl a group which may be interrupted by O, S, NH or NR ¹⁰⁰¹ (R ¹⁰⁰¹ represents an alkyl group), a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. A substituent of a substituted alkyl group includes an alkyl group, an aryl group, an alkoxycarbonyl group and a halogen atom. The substituent of the substituted aryl group and the substituent of the substituted heterocyclic group include a halogen atom, a nitro group, a cyano group, an alkyl group and an alkyl halide group. Z ²⁰¹ , Z ³⁰¹ , Z ⁴⁰¹ and Z ⁵⁰¹ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. In the case when Z ²⁰¹ represents an oxygen atom, R ²⁰⁹ and R ^{210 are} not present, and in the case when Z ²⁰¹ represents a nitrogen atom, R ^{210 is} not present. In the case when Z ³⁰¹ represents an oxygen atom, R ³⁰⁷ and R ^{308 are} not present, and in the case when Z ³⁰¹ represents a nitrogen atom, R ^{308 is} not present. In the case when Z ⁴⁰¹ represents an oxygen atom, R ⁴⁰⁷ and R ^{408 are} not present, and in the case when Z ⁴⁰¹ represents a nitrogen atom, R ^{408 is} not present. In the case when Z ⁵⁰¹ represents an oxygen atom, R ⁵⁰⁹ and R ^{510 are} not present, and in the case when Z ⁵⁰¹ represents a nitrogen atom, R ^{510 is} not present.

[0074]

[0075] In formula (A), at least one of α, β and γ is a group having a substituent, and this substituent is at least one group selected from the group consisting of a hydroxyl group, a thiol group, an amino group, carboxyl group and methoxy group. l and m, each independently, are 0 or 1, and the sum of l and m is from 0 to 2.

[0076] α represents an alkylene group having 1-6 atoms in the main chain, an alkylene group having 1-6 atoms in the main chain and substituted by an alkyl group having 1-6 carbon atoms, an alkylene group having 1-6 atoms in the main chain and substituted by a benzyl group, an alkylene group having 1-6 atoms in the main chain and substituted by an alkoxycarbonyl group, or an alkylene group having 1-6 atoms in the main chain and substituted by a phenyl group, and these groups may have at least one substituent selected from the group, consisting s from a hydroxyl group, a thiol group, an amino group and a carboxyl group. One of the carbon atoms in the backbone of the alkylene group can be replaced by O, S, NH or NR ¹⁰⁰² (R ¹⁰⁰² represents an alkyl group).

[0077] β represents a phenylene group, a phenylene group substituted by an alkyl group having 1-6 carbon atoms, a nitro group substituted by a nitro group, a halogen substituted phenylene group or an alkoxy group phenylene group, and these groups may have at least one substituent, selected from the group consisting of a hydroxyl group, a thiol group, an amino group and a carboxyl group.

[0078] γ represents a hydrogen atom, an alkyl group having 1-6 atoms in the main chain, or an alkyl group having 1-6 atoms in the main chain and substituted by an alkyl group having 1-6 carbon atoms, and these groups may have at least one substituent selected from the group consisting of a hydroxyl group, a thiol group, an amino group and a carboxyl group. One of the carbon atoms in the main chain of the alkyl group can be replaced by O, S, NH or NR ¹⁰⁰³ (R ¹⁰⁰³ represents an alkyl group).

[0079] Among the electron transporting substances represented by one of the above formulas (A-1) to (A-9), more preferred are electron-transporting substances that have a polymerizable functional group representing a monovalent group represented by the above formula (A ), at least one of R ¹⁰¹ -R ¹⁰⁶ , at least one of R ²⁰¹ -R ²¹⁰ , at least one of R ³⁰¹ -R ³⁰⁸ , at least one of R ⁴⁰¹ -R ⁴⁰⁸ , at least one of R ⁵⁰¹ -R ⁵¹⁰ , at least one of R ⁶⁰¹ -R ⁶⁰⁶ , at least one of R ⁷⁰¹ -R ⁷⁰⁸ , at least about dyne of R ⁸⁰¹ -R ⁸¹⁰ and at least one of R ⁹⁰¹ -R ⁹⁰⁸ .

[0080] An electron transferring material having polymerizable functional groups can form a polymer obtained by polymerizing a composition of a thermoplastic resin having polymerizable functional groups and a crosslinking agent. A method of forming an electron transfer layer includes forming a coating film from a liquid for applying an electron transfer layer containing a thermoplastic resin composition having polymerizable functional groups and a crosslinking agent, and drying the coating film by heating to polymerize the composition to thereby form an electron transfer layer. After the formation of the coating film, the crosslinking agent and the polymerizable functional groups of the thermoplastic resin and the electron-transporting substance are polymerized by a chemical reaction, and the chemical reaction is accelerated by heating at this time with acceleration of the polymerization.

[0081] Specific examples of electron-transporting substances having polymerizable functional groups will be described below.

[0082] The heating temperature, when the coating film of the liquid for applying the electron transfer layer is dried by heating, can be from 100 to 200 ° C.

[0083] In the Tables, the symbol A 'is represented by the same structure as the symbol A, specific examples of the monovalent group are shown in columns A and A'.

[0084] Specific examples of the compounds represented by the above formula (A1) are shown in Table 1-1, Table 1-2, Table 1-3, Table 1-4, Table 1-5, and Table 1-6. In these Tables, the case where γ is indicated as “-” indicates a hydrogen atom, and this hydrogen atom as γ is introduced into the structure shown in the column α or β.

[0085] Table 1-1 (see the end of the description)

[0086] Table 1-2 (see end of description)

[0087] Table 1-3 (see end of description)

[0088] Table 1-4 (see the end of the description)

[0089] Table 1-5 (see the end of the description)

[0090] Table 1-6 (see the end of the description)

[0091] Specific examples of the compounds represented by the above formula (A2) are shown in Table 2-1, Table 2-2, and Table 2-3. In these Tables, the case where γ is indicated as “-” indicates a hydrogen atom, and this hydrogen atom as γ is introduced into the structure shown in the column α or β.

[0092] Table 2-1 (see the end of the description)

[0093] Table 2-2 (see end of description)

[0094] Table 2-3 (see the end of the description)

[0095] Specific examples of the compounds represented by the above formula (A3) are shown in Table 3-1, Table 3-2, and Table 3-3. In these Tables, the case where γ is indicated as “-” indicates a hydrogen atom, and this hydrogen atom as γ is introduced into the structure shown in the column α or β.

[0096] Table 3-1 (see end of description)

[0097] Table 3-2 (see end of description)

[0098] Table 3-3 (see end of description)

[0099] Specific examples of the compounds represented by the above formula (A4) are shown in Table 4-1 and Table 4-2. In these Tables, the case where γ is indicated as “-” indicates a hydrogen atom, and this hydrogen atom as γ is introduced into the structure shown in the column α or β.

[00100] Table 4-1 (see the end of the description)

[00101] Table 4-2 (see the end of the description)

[00102] Specific examples of the compounds represented by the above formula (A5) are shown in Table 5-1 and Table 5-2. In these Tables, the case where γ is indicated as “-” indicates a hydrogen atom, and this hydrogen atom as γ is introduced into the structure shown in the column α or β.

[00103] Table 5-1 (see the end of the description)

[00104] Table 5-2 (see the end of the description)

[00105] Specific examples of the compounds represented by the above formula (A6) are shown in Table 6. In this Table, the case when γ is indicated as “-” indicates a hydrogen atom, and this hydrogen atom as γ is introduced into the structure shown in column α or β.

[00106] Table 6 (see end of description)

[00107] Specific examples of the compounds represented by the above formula (A7) are shown in Table 7-1, Table 7-2, and Table 7-3. In these Tables, the case where γ is indicated as “-” indicates a hydrogen atom, and this hydrogen atom as γ is introduced into the structure shown in the column α or β.

[00108] Table 7-1 (see the end of the description)

[00109] Table 7-2 (see the end of the description)

[00110] Table 7-3 (see the end of the description)

[00111] Specific examples of the compounds represented by the above formula (A8) are shown in Table 8-1, Table 8-2, and Table 8-3. In these Tables, the case where γ is indicated as “-” indicates a hydrogen atom, and this hydrogen atom as γ is introduced into the structure shown in the column α or β.

[00112] Table 8-1 (see the end of the description)

[00113] Table 8-2 (see the end of the description)

[00114] Table 8-3 (see the end of the description)

[00115] Specific examples of the compounds represented by the above formula (A9) are shown in Table 9-1 and Table 9-2. In these Tables, the case where γ is indicated as “-” indicates a hydrogen atom, and this hydrogen atom as γ is introduced into the structure shown in the column α or β.

[00116] Table 9-1 (see the end of the description)

[00117] Table 9-2 (see the end of the description)

[00118] A derivative (derivative of an electron-transporting substance) having structure (A1) can be synthesized using a well-known synthesis method described, for example, in US Pat. Nos. 4,442,193, 4,992,349 and 5,468,583 and Chemistry of Materials, Vol.19, No.11, 2703-2705 (2007). The derivative can also be synthesized by the reaction of naphthalene tetracarboxylic dianhydride and monoamine derivative, which are commercially available from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. and Johnson Matthey Japan Inc.

[00119] The compound represented by (A1) has polymerizable functional groups (hydroxyl group, thiol group, amino group, carboxyl group, and methoxy group) polymerizable by a crosslinking agent. A method for introducing these polymerizable functional groups into a derivative having structure (A1) includes a method for directly introducing polymerizable functional groups and a method for introducing structures having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups. Examples of the latter method include, based on the naphthylimide derivative halide, a method for introducing a functional group-containing aryl group, for example, using a cross-coupling reaction using a palladium catalyst and a base, a method for introducing a functional group-containing alkyl group using a cross-coupling reaction using a catalyst FeCl ₃ and the base and the method of administration hydroxyalkyl group and a carboxyl group and causing the epoxy compound and CO ₂ to act after lithiation. There is a method of using a naphthalene tetracarboxylic dianhydride derivative or a monoamine derivative having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups as starting materials for the synthesis of a naphthylimide derivative.

[00120] Derivatives having structure (A2) are commercially available, for example, from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. and Johnson Matthey Japan Inc. Derivatives can also be synthesized based on the phenanthrene derivative or phenanthroline derivative using the synthesis methods described in Chem. Educator No.6, 227-234 (2001), Journal of Synthetic Organic Chemistry, Japan, vol. 15, 29-32 (1957) and Journal of Synthetic Organic Chemistry, Japan, vol. 15, 32-34 (1957). The dicyanomethylene group may also be introduced by reaction with malononitrile.

[00121] The compound represented by (A2) has polymerizable functional groups (hydroxyl group, thiol group, amino group, carboxyl group, and methoxyl group) polymerizable by a crosslinking agent. A method for introducing these polymerizable functional groups into a derivative having structure (A2) includes a method for directly introducing polymerizable functional groups and a method for introducing structures having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups. Examples of the latter method include, based on phenatrenquinone halide, a method for introducing a functional group-containing aryl group using a cross-coupling reaction using a palladium catalyst and a base, a method for introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base and route of administration hydroxyalkyl group and a carboxyl group, forcing epoxy compound or CO ₂ to act after itiirovaniya.

[00122] Derivatives having structure (A3) are commercially available from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. and Johnson Matthey Japan Inc. Derivatives can also be synthesized based on the phenanthrene derivative or phenanthroline derivative using the synthesis method described in Bull. Chem. Soc., Jpn., Vol. 65, 1006-1011 (1992). The dicyanomethylene group may also be introduced by reaction with malononitrile.

[00123] The compound represented by (A3) has polymerizable functional groups (hydroxyl group, thiol group, amino group, carboxyl group, and methoxy group) polymerizable by a crosslinking agent. A method for introducing these polymerizable functional groups into a derivative having the structure of the above formula (A3) includes a method for directly introducing polymerizable functional groups and a method for introducing structures having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups. There are methods, including, for example, phenatrolinquinone halide based, a method for introducing a functional group-containing aryl group using a cross-coupling reaction using a palladium catalyst and a base, a method for introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base and method for introducing a hydroxyalkyl group and a carboxyl group, causing the epoxy compound or CO _{2 to} act on after lithiation.

[00124] Derivatives having structure (A4) are commercially available, for example, from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. and Johnson Matthey Japan Inc. Derivatives can also be synthesized based on the acenaphtenequinone derivative using the synthesis methods described in Tetrahedron Letters, 43 (16), 2991-2994 (2002) and Tetrahedron Letters, 44 (10), 2087-2091 (2003). The dicyanomethylene group may also be introduced by reaction with malononitrile.

[00125] The compound represented by formula (A4) has polymerizable functional groups (hydroxyl group, thiol group, amino group, carboxyl group, and methoxy group) polymerizable by a crosslinking agent. A method for introducing these polymerizable functional groups into a derivative having a structure (A4) includes a method for directly introducing polymerizable functional groups and a method for introducing structures having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups. Examples of the latter method include, based on acenaphthenquinone halide, a method for introducing a functional group containing an aryl group, for example, using a cross-coupling reaction using a palladium catalyst and a base, a method for introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl catalyst ₃ and the base and method of introducing a hydroxyalkyl group and a carboxyl group, causing the epoxy compound or CO ₂ action after lithiation.

[00126] Derivatives having structure (A5) are commercially available, for example, from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. and Johnson Matthey Japan Inc. Derivatives can also be synthesized using the fluorenone derivative and malononitrile using the synthesis method described in US Pat. No. 4,562,132. Derivatives can also be synthesized using the fluorenone derivative and aniline derivative using the synthesis methods described in Japanese Patent Application Laid-Open No. H5 -279582 and H7-70038.

[00127] The compound represented by formula (A5) has polymerizable functional groups (hydroxyl group, thiol group, amino group, carboxyl group, and methoxy group) polymerizable by a crosslinking agent. A method for introducing these polymerizable functional groups into a derivative having a structure (A5) includes a method for directly introducing polymerizable functional groups and a method for introducing structures having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups. Examples of the latter method include, based on fluorenone halide, a method for introducing a functional group-containing aryl group, for example, using a cross-coupling reaction using a palladium catalyst and a base, a method for introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl catalyst ₃ and a base and the method of administration hydroxyalkyl group and a carboxyl group, forcing epoxy compound or CO ₂ to act After lithiation.

[00128] Derivatives having structure (A6) can be synthesized using synthesis methods described, for example, in Chemistry Letters, 37 (3), 360-361 (2008) and Japanese Patent Application Laid-Open No. H9-151157. Derivatives are commercially available from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. and Johnson Matthey Japan Inc.

[00129] The compound represented by formula (A6) has polymerizable functional groups (hydroxyl group, thiol group, amino group, carboxyl group, and methoxy group) polymerizable by a crosslinking agent. A method for introducing these polymerizable functional groups into a derivative having a structure (A6) includes a method for directly introducing polymerizable functional groups into a naphthoquinone derivative and a method for introducing a structure having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups into a naphthoquinone derivative. Examples of the latter method include, based on the naphthoquinone halide, a method for introducing a functional group-containing aryl group, for example, using a cross-coupling reaction using a palladium catalyst and a base, a method for introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl catalyst ₃ and the base and method of introducing a hydroxyalkyl group and a carboxyl group, causing the epoxy compound or CO _{2 to} act after lithiation.

[00130] Derivatives having structure (A7) can be synthesized using the synthesis methods described in Japanese Patent Application Laid-Open No. H1-206349 and Proceedings of PPCI / Japan Hard Copy '98, Proceedings, p.207 (1998). Derivatives can be synthesized, for example, using phenolic derivatives commercially available from Tokyo Chemical Industry Co., Ltd., or Sigma-Aldrich Japan Co., Ltd., as starting materials.

[00131] The compound represented by (A7) has polymerizable functional groups (hydroxyl group, thiol group, amino group, carboxyl group, and methoxy group) polymerizable by a crosslinking agent. A method for introducing these polymerizable functional groups into a derivative having a structure (A7) includes a method for introducing a structure having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups. Examples of the method include, based on the diphenoquinone halide, a method for introducing a functional group containing an aryl group, for example, using a cross-coupling reaction using a palladium catalyst and a base, a method for introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base and the method of administration hydroxyalkyl group and a carboxyl group, forcing epoxy compound or CO ₂ to act after lit. ation.

[00132] Derivatives having structure (A8) can be synthesized using a well-known synthetic method described, for example, in Journal of American Chemical Society, Vol.129, No.49, 15259-78 (2007). Derivatives can also be synthesized by the reaction of perylene tetracarbonate dianhydride and a monoamine derivative commercially available from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. and Johnson Matthey Japan Inc.

[00133] The compound represented by formula (A8) has polymerizable functional groups (hydroxyl group, thiol group, amino group, carboxyl group, and methoxy group) polymerizable by a crosslinking agent. A method for introducing these polymerizable functional groups into a derivative having a structure (A8) includes a method for directly introducing polymerizable functional groups and a method for introducing structures having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups. Examples of the latter method include, based on the peryleneimide derivative halide, a method for using a cross coupling reaction using a palladium catalyst and a base, and a method for using a cross coupling reaction using a FeCl ₃ catalyst and a base. There is a method of using a perylenetetracarboxylic dianhydride derivative or monoamine derivative having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups as starting materials for synthesizing the perylene imide derivative.

[00134] Derivatives having structure (A9) are commercially available, for example, from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. and Johnson Matthey Japan Inc.

[00135] The compound represented by formula (A9) has polymerizable functional groups (hydroxyl group, thiol group, amino group, carboxyl group and methoxyl group) polymerizable by a crosslinking agent. A method for introducing these polymerizable functional groups into a derivative having a structure (A9) includes a method for introducing a structure having polymerizable functional groups or functional groups that can become precursors of polymerizable functional groups into a commercially available anthraquinone derivative. Examples of the method include, based on the anthraquinone halide, a method for introducing a functional group-containing aryl group, for example, using a cross-coupling reaction using a palladium catalyst and a base, a method for introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base and the method of administration hydroxyalkyl group and a carboxyl group, forcing epoxy compound or CO ₂ to act after lithium tion.

[00136] Crosslinking agent

[00137] A crosslinking agent will then be described.

[00138] As a crosslinking agent, a compound that polymerizes or crosslinks with an electron-transporting substance having polymerizable functional groups and a thermoplastic resin having polymerizable functional groups can be used. Specifically, the connections described in the Crosslinking Agent Handbook, ed. Shinzo Yamashita, Tosuke Kaneko, published by Taiseisha Ltd. (1981) (in Japanese), and the like.

[00139] The crosslinking agents used for the electron transfer layer can be isocyanate compounds and amine compounds. Crosslinking agents are more preferably crosslinking agents (isocyanate compounds, amine compounds) having 3-6 groups of an isocyanate group, a blocked isocyanate group or a monovalent group represented by —CH ₂ —OR ¹ from the point of view of obtaining a uniform polymer layer.

[00140] An isocyanate compound having a molecular weight in the range of 200-1300 can be used as the isocyanate compound. You can also use an isocyanate compound having 3-6 isocyanate groups or blocked isocyanate groups. Examples of isocyanate compounds include isocyanurate modified, biuret modified, allophanate modified and modifications trimethylolpropane or pentaerythritol adducts triisocyanatobenzene, triizotsianatometilbenzola, triphenylmethane triisocyanate, lizintriizotsianata and, further, diisocyanates such as tolylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, 2,2 , 4-trimethylhexamethylene diisocyanate, me yl-2,6-diizotsianatgeksanoat and norbornane. First of all, modified isocyanurate and modified adducts are more preferred.

[00141] A blocked isocyanate group is a group having the structure —NHCOX ¹ (X ¹ is a blocking group). X ¹ may be any blocking group, provided that X ¹ can be introduced into the isocyanate group, but a group represented by one of the following formulas (H1) to (H7) is more preferred.

[00142]

[00143] Specific examples of isocyanate compounds will be described below.

[00144]

[00145]

[00146] The amine compound may be at least one compound selected from the group consisting of compounds represented by the following formula (C1), oligomers of the compounds represented by the following formula (C1), compounds represented by the following formula (C2) , oligomers of compounds represented by the following formula (C2), compounds represented by the following formula (C3), oligomers of compounds represented by the following formula (C3), compounds represented by the following formula (C4), oligomers of the compounds represented by the following formula (C4), compounds represented by the following formula (C5), and oligomers of the compounds represented by the following formula (C5).

[00147]

[00148] In the formulas (C1) to (C5) R ¹¹ -R ¹⁶ , R ²² -R ²⁵ , R ³¹ -R ³⁴ , R ⁴¹ -R ⁴⁴ and R ⁵¹ -R ⁵⁴ each independently represent a hydrogen atom, a hydroxyl group, an acyl group or a monovalent group represented by —CH ₂ —OR ¹ ; at least one of R ¹¹ -R ¹⁶ , at least one of R ²² -R ²⁵ , at least one of R ³¹ -R ³⁴ , at least one of R ⁴¹ -R ^44, and at least one of R ⁵¹ —R ⁵⁴ are a monovalent group represented by —CH ₂ —OR ¹ ; R ¹ represents a hydrogen atom or an alkyl group having 1-10 carbon atoms; the alkyl group may be a methyl group, an ethyl group, a propyl group (n-propyl group, iso-propyl group) or a butyl group (n-butyl group, iso-butyl group, tert-butyl group), from the point of view of polymerizability; R ²¹ represents an aryl group, an alkyl group substituted by an aryl group, a cycloalkyl group or a cycloalkyl group substituted by an alkyl group.

[00149] Specific examples of the compounds represented by one of formulas (C1) to (C5) will be described below. Oligomers (multimers) of the compounds represented by one of the formulas (C1) to (C5) may be contained. Compounds (monomers) represented by one of formulas (C1) to (C5) may be contained in an amount of 10% by mass or more in the total mass of amine compounds from the point of view of obtaining a uniform polymer layer.

[00150] The degree of polymerization of the above multimer may be 2 or more and 100 or less. The above multimer and monomer can be used as a mixture of two or more.

[00151] Examples of the compounds represented by the above formula (C1), which are usually commercially available, include Supermelami No. 90 (manufactured by NOF Corp.), Superbekamine (R) TD-139-60, L-105-60, L127-60, L110-60, J-820-60 and G-821-60 (manufactured by DIC Corporation), Yuban 2020 (manufactured by Mitsui Chemicals Inc.), Sumitex Resin M-3 (manufactured by Sumitomo Chemical Co., Ltd.) and Nikalac MW-30, MW-390 and MX-750LM (Nihon Carbide Industries, Co., Inc.). Examples of compounds represented by the above formula (C2), which are usually commercially available, include Superbekamine (R) L-148-55, 13-535, L-145-60, and TD-126 (manufactured by Dainippon Ink and Chemicals, Inc. ) and Nikalac BL-60 and BX-4000 (Nihon Carbide Industries, Co., Inc.). Examples of compounds represented by the above formula (C3), which are usually commercially available, include Nikalac MX-280 (Nihon Carbide Industries, Co., Inc.). Examples of compounds represented by the above formula (C4), which are usually commercially available, include Nikalac MX-270 (Nihon Carbide Industries, Co., Inc.). Examples of compounds represented by the above formula (C5), which are usually commercially available, include Nikalac MX-290 (Nihon Carbide Industries, Co., Inc.).

[00152] Specific examples of compounds of formula (C1) will be described below.

[00153]

[00154]

[00155] Specific examples of compounds of formula (C2) will be described below.

[00156]

[00157] Specific examples of compounds of formula (C3) will be described below.

[00158]

[00159] Specific examples of compounds of formula (C4) will be described below.

[00160]

[00161] Specific examples of compounds of formula (C5) will be described below.

[00162]

[00163] Resin

[00164] A thermoplastic resin having polymerizable functional groups will be described. A thermoplastic resin having polymerizable functional groups can be a thermoplastic resin having a structural unit represented by the following formula (D).

[00165]

[00166] In the formula (D), R ⁶¹ represents a hydrogen atom or an alkyl group; Y ¹ represents a single bond, an alkylene group or a phenylene group; and W ¹ represents a hydroxyl group, a thiol group, an amino group, a carboxyl group, or a methoxy group.

[00167] A resin (also referred to as resin D below) having a structural unit represented by formula (D) can be prepared by polymerizing, for example, a monomer commercially available from Sigma-Aldrich Japan Co., Ltd. and Tokyo Chemical Industry Co., Ltd. and having a polymerizable functional group (hydroxyl group, thiol group, amino group, carboxyl group and methoxy group).

[00168] Resins are usually commercially available. Examples of resins that are commercially available include polyol ether resins such as AQD-457 and AQD-473, Nippon Polyurethane Industry Co., Ltd. products, and Sunnix GP-400, GP-700 and the like, products Sanyo Chemical Industries, Ltd., polyester polyol resins such as Phthalkid W2343, Hitachi Chemical Co., Ltd., Watersol S-118 and CD-520 and Beckolite M-6402-50 and M-6201-40IM, DIC Corporation products, Haridip WH-1188, manufactured by Harima Chemicals Group, Inc. and ES3604, ES6538, and the like, Japan UPICA Co., Ltd. products, polyacrylic polyol resins such as Burnock WE-300 and WE-304, DIC Corporation products, polyvinyl alcohol resins such as Kuraray Poval PVA- 203, manufactured by Kuraray Co., Ltd., polyvinyl acetal-based resins such as BX-1, BM-1, KS-1 and KS-5, Sekisui Chemical Co., Ltd. products, polyamide-based resins such as Toresin FS-350, manufactured by Nagase ChemteX Corp., carboxy group-containing resins such as Aqualic, manufactured by Nippon Shokubai Co., Ltd., and Finelex SG2000, manufactured by Namariichi Co., Ltd., polyamine resins such as Rackamide, manufactured by DIC Corporation and Poly thiol resins such as QE-340M manufactured by Toray Industries, Inc. First of all, resins based on polyvinyl acetal, resins based on polyester polyols and the like are more preferable from the point of view of polymerizability and uniformity of the electron transfer layer.

[00169] The weight average molecular weight (Mw) of resin D may be in the range of 5000-400000, and more preferably in the range of 5000-300000.

[00170] Examples of a method for quantifying the polymerizable functional groups in a resin include titration of carboxyl groups using potassium hydroxide, titration of amino groups using sodium nitrite, titration of hydroxyl groups using acetic anhydride and potassium hydroxide, titration of thiol groups using 5.5'-dithiobis (2-nitrobenzoic acid) and a calibration curve method using IR spectra of samples in which the ratio of the introduction of polymerizable functional groups changes Nos.

[00171] In Table 10 below, specific examples of resin D will be described.

[00172] Table 10 (see the end of the description)

[00173] The electron-transporting substance having polymerizable functional groups can be 30% by mass or more and 70% by mass or less with respect to the total mass of the composition of the electron-transporting substance having polymerizable functional groups, a crosslinking agent and a resin having polymerizable functional groups.

[00174] the Substrate

[00175] The substrate may be a substrate having electrical conductivity (conductive substrate), and for example, substrates made of a metal or an alloy of aluminum, nickel, copper, gold, iron or the like can be used. The substrate includes substrates in which a thin film of metallic aluminum, silver, gold or the like is formed on an insulating substrate of polyester resin, polycarbonate resin, polyimide resin, glass or the like, and substrates in which a thin film of conductive material is formed from indium oxide, tin oxide or the like.

[00176] The surface of the substrate may be subjected to a treatment, such as an electrochemical treatment, such as anodic oxidation, wet honing, blasting and cutting, to improve electrical properties and suppress harmful inhomogeneities.

[00177] A conductive layer may be provided between the substrate and the coating sublayer described below. A conductive layer is obtained by forming a coating film on a substrate from a liquid for applying a conductive layer in which the conductive particles are dispersed in the resin, and drying the coating film. Examples of conductive particles include carbon black, acetylene black, metal powders such as aluminum, nickel, iron, nichrome, copper, zinc and silver, and metal oxide powders such as conductive tin oxide and ITO (indium tin oxide).

[00178] Examples of the resin include polyester resins, polycarbonate resins, polyvinyl butyral resins, acrylic resins, silicone resins, epoxies, melamine resins, urethane resins, phenolic resins and alkyd resins.

[00179] Examples of a solvent for applying a conductive layer include ether solvents, alcohol solvents, ketone solvents, and aromatic hydrocarbon solvents. The thickness of the conductive layer may be 0.2 μm or more and 40 μm or less, more preferably 1 μm or more and 35 μm or less, and even more preferably 5 μm or more and 30 μm or less.

[00180] a charge generation layer

[00181] A charge generation layer is provided on the coating sublayer (electron transfer layer).

[00182] The charge generating substance includes azo pigments, perylene pigments, anthraquinone derivatives, anthanthron derivatives, dibenzopyrenquinone derivatives, virantantrone derivatives, isoviolantrone derivatives, indigo derivatives, thioindigo derivatives, phthalo cyano, phthalo cyano, . First of all, at least one of the azo pigments and phthalocyanine pigments can be used. Among the phthalocyanine pigments, oxytitanium phthalocyanine, chlorogallium phthalocyanine and hydroxygallium phthalocyanine can be used.

[00183] Examples of the binder resin used for the charge generation layer include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic ester, methacrylic ester, vinylidene fluoride and trifluoroethylene, polyvinyl alcohol based resins, polyvinyl acetal resins, polycarbonate resins, polyester resins, polysulfone resins, polyphenylene oxide resins, polyurethane resins, cellulose resins, phenolic resins, melamine resins, silicone resins and epoxies. First of all, polyester resins, polycarbonate resins and polyvinyl acetal resins can be used, and polyvinyl acetal is more preferred.

[00184] In the charge generation layer, the ratio of the charge generating substance to the binder resin (charge generating substance / binder resin) may be in the range of 10/1 to 1/10, and more preferably it is in the range of 5/1 to 1 / 5. The solvent used as the liquid for applying the charge generation layer includes alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

[00185] The thickness of the charge generation layer may be 0.05 μm or more and 5 μm or less.

[00186] The hole transport layer

[00187] A hole transport layer is provided on the charge generation layer.

[00188] Examples of a hole transporting substance include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, benzidine compounds and triarylamine compounds, triphenylamine and polymers having a group derived from these compounds in the main chain or side chain. First of all, triarylamine compounds, benzidine compounds and styryl compounds can be used.

[00189] Examples of a binder resin used for the hole transfer layer include polyester resins, polycarbonate resins, polymethacrylate ester resins, polyarylate resins, polysulfone resins and polystyrene resins. First of all, polycarbonate resins and polyarylate resins can be used. Regarding their molecular weight, the weight average molecular weight (Mw) may be in the range of 10,000-300,000.

[00190] In the hole transport layer, the ratio of the hole transporting substance to the binder resin (hole transporting substance / binder resin) can be from 10/5 to 5/10, and more preferably it is from 10/8 to 6/10.

[00191] The thickness of the hole transport layer may be 3 μm or more and 40 μm or less. More preferably, the thickness is 5 μm or more and 16 μm or less in terms of the thickness of the electron transfer layer. The solvent used for the liquid for applying the hole transfer layer includes alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

[00192] Another layer, such as a second coating sublayer that does not contain a polymer in accordance with the present invention, may be provided between the substrate and the electron transfer layer and between the electron transfer layer and the charge generation layer.

[00193] A surface protecting layer may be provided on the hole transfer layer. The surface protecting layer contains conductive particles or a charge transfer agent and a binder resin. The surface protecting layer may further comprise additives, such as a lubricant. The binder resin of the protective layer itself may have electrical conductivity and charge transfer ability; in this case, the protective layer should not contain conductive particles and a charge transfer substance other than a binder resin. The binder resin of the protective layer may be a thermoplastic resin, or it may be a curable resin, which may polymerize under the influence of heat, light, radiation (electron beams) or the like.

[00194] A method for forming each layer, such as an electron transfer layer, a charge generation layer and a hole transfer layer constituting the electrophotographic photosensitive member, may be a method in which a coating liquid is obtained by dissolving and / or dispersing a material constituting each layer, in a solvent, and the resulting coating film are dried and / or cured. Examples of a method for applying a coating liquid include a dip coating method, a spray coating method, a bulk coating method, and a centrifugal coating method. First of all, you can use the method of coating by immersion in terms of efficiency and productivity.

[00195] Work cartridge and electrophotographic device

[00196] FIG. 6 illustrates the basic structure of an electrophotographic device having a working cartridge with an electrophotographic photosensitive member.

[00197] In FIG. 6, reference numeral 1 denotes a cylindrical electrophotographic photosensitive member that is rotationally driven at a predetermined peripheral speed in the direction of the arrow around shaft 2 as a center. The surface (peripheral surface) of the rotationally moving electrophotographic photosensitive member 1 is uniformly charged at a given positive or negative potential using the charging unit 3 (primary charging unit: charging roller or the like). Then, the surface is exposed to irradiating light (light for exposing the image) 4 from the light irradiation unit (not illustrated), such as irradiating light through a slit or irradiating light with a scanning laser beam. Thus, electrostatic latent images corresponding to the target images are successively formed on the surface of the electrophotographic photosensitive member 1.

[00198] Electrostatic latent images formed on the surface of the electrophotographic photosensitive member 1 are developed using toner contained in the developer of the developing unit 5, thereby obtaining toner images. Then, the toner images formed and located on the surface of the electrophotographic photosensitive member 1 are sequentially transferred to the material to be transferred (paper or the like) P by a transfer bias voltage from the transfer unit 6 (transfer roller or the like). The material P intended for transfer is supplied from the supply unit of the material intended for transfer (not illustrated) and is supplied between the electrophotographic photosensitive member 1 and the transfer unit 6 (into the contacting part) in synchronization with the rotation of the electrophotographic photosensitive member 1.

[00199] The transfer material P with the transferred toner images is separated from the surface of the electrophotographic photosensitive member 1, inserted into the fixing unit 8 to undergo the fixing of the image, and printed as material with the generated image (print, copy) outside the device.

[00200] The surface of the electrophotographic photosensitive member 1, after transferring the toner image, is subjected to removal of the un transferred developer (toner) by the cleaning unit 7 (a cleaning blade or the like) for cleaning in this manner. Then, the surface is subjected to a charge neutralizing treatment using irradiating light (not illustrated) from the light irradiation unit (not illustrated), and then it is used repeatedly for imaging. As illustrated in FIG. 6, in the case where the charging unit 3 is a contact charging unit using a charging roller or the like, light irradiation is not necessary.

[00201] Many of the constituent elements of the constituent elements, including the above-described electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, the transfer unit 6, and the cleaning unit 7, can be selected and suitably disposed in the container and generally comprise a working cartridge; and the working cartridge can be made detachable from the body of the electrophotographic device of a copy machine, laser printer, or the like. 6, the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5 and the cleaning unit 7 are supported in their entirety and are designed as a cartridge, thereby obtaining a working cartridge 9 connected to and disconnected from the body of the electrophotographic device using the guide unit 10, such as guide rails of the body of an electrophotographic device.

[00202] Examples

[00203] Next, the manufacture and evaluation of electrophotographic photosensitive elements will be described.

[00204] (Example 1)

[00205] An aluminum cylinder (JIS-A3003, aluminum alloy) with a length of 260.5 mm and a diameter of 30 mm was made as a substrate (conductive substrate).

[00206] Then, 50 parts of oxygen deficient tin oxide particles coated with powder (specific resistivity of powder: 120 Ohm · cm, tin oxide coating ratio: 40%), 40 parts of phenolic resin (Plyophen J-325 manufactured by DIC Corporation, content solid resin components: 60%) and 50 parts of methoxypropanol as a solvent (dispersion solvent) were placed in a sand mill using glass beads with a diameter of 1 mm and subjected to dispersion treatment for 3 hours, thereby obtaining a liquid (liquid dispersion) for application conductive layer. The liquid for applying the conductive layer was applied by immersion on a substrate, and the resulting coating film was dried and thermally polymerized for 30 min at 150 ° C, thereby forming a conductive layer having a thickness of 16 μm.

[00207] The average particle diameter of oxygen deficient tin oxide coated titanium oxide particles in a conductive layer deposition liquid was measured using a centrifugal precipitation method using tetrahydrofuran as a dispersion medium at a speed of 5000 rpm using a particle size distribution analyzer (trade name: CAPA700) manufactured by HORIBA Ltd. As a result, the average particle diameter was 0.31 μm.

[00208] Then, 4 parts of an electron transporting substance (A101), 7.3 parts of a crosslinking agent (B1: blocking group (H1) = 5.1: 2.2 (mass ratio)), 0.9 parts of a resin (D1) and 0.05 parts of dioctyltin laurate as a catalyst was dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby preparing a liquid for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 40 minutes at 160 ° C for polymerization, thereby forming an electron transfer layer (coating sublayer) having a thickness of 0.53 μm.

[00209] The content of the electron transferring substance with respect to the total mass of the electron transferring substance, a crosslinking agent and a resin was 33% by weight.

[00210] Then, 10 parts of crystalline hydroxylgallium phthalocyanine (a charge generating substance) having a crystalline form showing strong peaks at Bragg angles (2θ ± 0.2 °) 7.5 °, 9.9 °, 12.5 °, 16, 3 °, 18.6 °, 25.1 ° and 28.3 ° for CuKα characteristic radiation X-ray diffraction, 5 parts of polyvinyl butyral resin (trade name: Eslec BX-1 manufactured by Sekisui Chemical Co., Ltd.) and 250 parts cyclohexanone was placed in a sand mill using glass beads with a diameter of 1 mm and subjected to dispersion treatment for 1.5 hours owls Then, 250 parts of ethyl acetate were added thereto, thereby obtaining a liquid for applying a charge generation layer. The liquid for applying the charge generation layer was applied by immersion on the electron transfer layer, and the resulting coating film was dried for 10 minutes at 100 ° C., thereby forming a charge generation layer having a thickness of 0.15 μm. Thus, a laminated body was formed having a substrate, a conductive layer, an electron transfer layer and a charge generation layer.

[00211] Then, 8 parts of a triarylamine compound (hole transporting substance) represented by the following structural formula (15) and 10 parts of a polyarylate having a repeating structural unit represented by the following formula (16-1) and a repeating structural unit represented by the following further by formula (16-2), in a 5/5 ratio, and having a weight average molecular weight (Mw) of 100,000, it was dissolved in a mixed solvent of 40 parts of dimethoxymethane and 60 parts of chlorobenzene, thereby obtaining a liquid for applying a layer of per nose holes. The liquid for applying the hole transport layer was applied by immersion on the charge generation layer, and the resulting coating film was dried for 40 minutes at 120 ° C., thereby forming a hole transfer layer having a thickness of 15 μm.

[00212]

[00213]

[00214] Thus, an electrophotographic photosensitive member having a laminated body and a hole transfer layer was manufactured to evaluate positive re-image and potential change. In addition, as above, another electrophotographic photosensitive member was made and made for determination by an electrophotographic photosensitive member.

[00215] (Study to determine)

[00216] The electrophotographic photosensitive member to be determined was immersed for 5 minutes in a mixed solvent of 40 parts of dimethoxymethane and 60 parts of chlorobenzene; and the hole transfer layer was peeled off, and then the resulting product was dried for 10 min at 100 ° C, thereby obtaining a laminated body having a substrate, an electron transfer layer and a charge generation layer in this order, and made it intended to be detected by a photosensitive element. Using the FTIR-ATR method, it was confirmed that the surface did not have a hole transport layer.

[00217] Then, the electrophotographic photosensitive member to be determined was allowed to stand in an environment with a temperature of 25 ° C and a humidity of 50% RH for 24 hours; thereafter, using the above determination method, and as described above, Vd1 (expression 1) and Vd2 (expression 2) were calculated and Vl1, Vl2 and Vl3 were measured, and | Vl2-Vl1 | and | (Vd2-Vl3) / Vd2 |. The measurement results are shown in Table 11.

[00218] (Assessment of positive re-image and potential change)

[00219] An electrophotographic photosensitive member for evaluating a positive repeat image and potential change was installed on an upgraded laser printer device (trade name: LBP-2510) manufactured by Canon Corp. and the following process conditions were set and surface potential (potential changes) evaluated and evaluated printed image (repeat image). Modernization included changing the process speed by 200 mm / s, setting the potential of the dark region at -700 V and setting a variable intensity of the irradiating light (light to irradiate the image). Details are as follows.

[00220] 1. Evaluation of the positive repeated image

[00221] A working cyan cartridge for a laser printer was upgraded, and a potential sensor (model: 6000B-8, manufactured by Trek Japan KK) was installed in the developing position; and an electrophotographic photosensitive member was installed to evaluate positive re-image and potential changes, and the potential of the central portion of the electrophotographic photosensitive member was measured in an environment with a temperature of 23 ° C. and a humidity of 50% RH using a surface electrometer (model: 344, manufactured by Trek Japan KK). The intensity of the irradiating light was controlled so that the potential of the dark region (Vd) of the surface potential of the electrophotographic photosensitive element became -700 V, and the potential of its bright region (Vl) became -200 V.

[00222] Then, the electrophotographic photosensitive member was mounted on a blue print cartridge for a laser printer, and the print cartridge was installed on a blue print cartridge station and images were printed. The images were printed continuously in this order: one sheet of a solid white image, 5 sheets of an image for evaluating a repeated image, one sheet of a solid black image and 5 sheets of an image for evaluating a repeated image.

[00223] The image for evaluating the repeated image, as illustrated in FIG. 7A, had a “white image” printed in its main part, in which square “solid images” were printed, and had a “halftone image of a one-point Keima structure” illustrated in FIG. .7B received after the main part. In FIG. 7A, the parts with “repeated image” were those parts where repeated images (“shadows”) caused by “solid images” could appear.

[00224] Evaluation of the positive repeat image was carried out by measuring the density difference between the image density of the halftone image of the Keima single-point structure and the image density of the portion with the repeated image. 10 density difference points were measured on a single image sheet to evaluate duplicate images using a spectrodensitometer (trade name: X-Rite 504/508, manufactured by X-Rite Inc.). This operation was carried out for all 10 sheets of image to evaluate repeated images, and the average value was calculated for 100 points in total. The results are shown in Table 11. It was found that a higher density of the repeated image part caused a stronger positive repeated image. This means that the smaller the density difference on the Macbeth scale, the stronger the positive repeat image is suppressed. The image density difference for the repeated image (the density difference on the Macbeth scale) of 0.05 or more gave its level having a visually obvious difference, and the image density difference for the repeated image less than 0.05 gave its level that did not have a visually obvious difference.

[00225] 2. Changes in potential

[00226] The cyan working cartridge for the laser printer was upgraded and the potential sensor (model: 6000B-8, manufactured by Trek Japan KK) was set to the developing position; and the potential of the central part of the electrophotographic photosensitive element was measured in a medium with a temperature of 23 ° C and a humidity of 5% RH using a surface electrometer (model: 344, manufactured by Trek Japan KK). The intensity of the irradiating light was controlled so that the potential of the dark region (Vd) became equal to -700 V, and the potential of the bright region (Vl) became equal to -200 V. An electrophotographic photosensitive element was repeatedly used at the above intensity of the irradiating light in this state (state, at which the potential sensor is in the position where the development unit should be) for 1000 sheets continuously. Vd and Vl after continuous 1000-sheet reuse are shown in Table 11.

[00227] (Examples 2-5)

[00228] Electrophotographic photosensitive elements were made and evaluated as in Example 1, except for changing the thickness of the electron transfer layer from 0.53 μm to 0.38 μm (Example 2), 0.25 μm (Example 3), 0.20 μm ( Example 4) and 0.15 μm (Example 5). The results are shown in Table 11.

[00229] (Example 6)

[00230] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 11.

[00231] 4 parts of an electron-transporting substance (A101), 5.5 parts of an isocyanate compound (B1: blocking group (H1) = 5.1: 2.2 (mass ratio)), 0.3 parts of resin (D1) and 0 , 05 parts of dioctyltin laurate as a catalyst was dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. Liquid for applying an electron transfer layer was applied by immersion on a conductive layer, and the resulting coating film was heated for 40 minutes at 160 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 0.61 μm.

[00232] (Examples 7-9)

[00233] Electrophotographic photosensitive elements were manufactured and evaluated as in Example 6, except for changing the thickness of the electron transfer layer from 0.61 μm to 0.52 μm (Example 7), 0.40 μm (Example 8) and 0.26 μm ( Example 9). The results are shown in Table 11.

[00234] (Example 10)

[00235] An electrophotographic photosensitive member was made and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 11.

[00236] 5 parts of an electron-transporting substance (A-101), 2.3 parts of an amine compound (C1-3), 3.3 parts of a resin (D1) and 0.1 parts of dodecylbenzenesulfonic acid were dissolved as a catalyst in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. Liquid for applying an electron transfer layer was applied by immersion on a conductive layer, and the resulting coating film was heated for 40 minutes at 160 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 0.51 μm.

[00237] (Examples 11 and 12)

[00238] Electrophotographic photosensitive elements were manufactured and evaluated as in Example 10, except for changing the thickness of the electron transfer layer from 0.51 μm to 0.45 μm (Example 11) and 0.34 μm (Example 12). The results are shown in Table 11.

[00239] (Example 13)

[00240] An electrophotographic photosensitive member was fabricated and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 11.

[00241] 5 parts of an electron-transporting substance (A-101), 1.75 parts of an amine compound (C1-3), 2.0 parts of a resin (D1) and 0.1 parts of dodecylbenzenesulfonic acid were dissolved as a catalyst in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 40 minutes at 160 ° C for polymerization, thereby forming an electron transfer layer having a thickness of 0.70 μm.

[00242] (Examples 14-16)

[00243] Electrophotographic photosensitive elements were manufactured and evaluated as in Example 13, except for changing the thickness of the electron transfer layer from 0.70 μm to 0.58 μm (Example 14), 0.50 μm (Example 15) and 0.35 μm ( Example 16). The results are shown in Table 11.

[00244] (Examples 17-32)

[00245] Electrophotographic photosensitive elements were manufactured and evaluated as in Example 9, except for replacing the electron-transporting substance from Example 9 s (A-101) with the electron-transporting substances shown in Table 11. The results are shown in Table 11.

[00246] (Examples 33-47)

[00247] Electrophotographic photosensitive elements were manufactured and evaluated as in Example 16, except for replacing the electron-transporting substance from Example 16 s (A-101) with the electron-transporting substances shown in Tables 11 and 12. The results are shown in Tables 11 and 12.

[00248] (Examples 48-53)

[00249] Electrophotographic photosensitive elements were made and evaluated as in Example 9, except for the replacement of a crosslinking agent (B1: blocking group (H1) = 5.1: 2.2 (mass ratio)) from Example 9 with crosslinking agents shown in Table 12. The results are shown in Table 12.

[00250] (Examples 54 and 55)

[00251] Electrophotographic photosensitive elements were made and evaluated as in Example 16, with the exception of replacing the crosslinking agent (C1-3) from Example 16 with crosslinking agents shown in Table 12. The results are shown in Table 12.

[00252] (Example 56)

[00253] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 12.

[00254] 4 parts of an electron-transporting substance (A-101), 4 parts of an amine compound (C1-9), 1.5 parts of a resin (D1) and 0.2 parts of dodecylbenzenesulfonic acid as a catalyst were dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. Liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 40 minutes at 160 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 0.35 μm.

[00255] (Examples 57 and 58)

[00256] Electrophotographic photosensitive elements were made and evaluated as in Example 56, with the exception of replacing the crosslinking agent (C1-9) from Example 56 with crosslinking agents shown in Table 12. The results are shown in Table 12.

[00257] (Examples 59-62)

[00258] Electrophotographic photosensitive elements were made and evaluated as in Example 9, except for replacing the resin (D1) from Example 9 with the resins shown in Table 12. The results are shown in Table 12.

[00259] (Example 63)

[00260] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 12.

[00261] 6 parts of the electron-transporting substance (A-124), 2.1 parts of the amine compound (C1-3), 1.2 parts of the resin (D1) and 0.1 part of dodecylbenzenesulfonic acid as a catalyst were dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 40 minutes at 160 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 0.45 μm.

[00262] (Examples 64 and 65)

[00263] Electrophotographic photosensitive elements were manufactured and evaluated as in Example 63, except for replacing the electron-transporting substance from Example 63 s (A-124) with the electron-transporting substances shown in Table 12. The results are shown in Table 12.

[00264] (Example 66)

[00265] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 12.

[00266] 6 parts of the electron-transporting substance (A-125), 2.1 parts of the amine compound (C1-3), 0.5 parts of the resin (D1) and 0.1 parts of dodecylbenzenesulfonic acid were dissolved as a catalyst in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 160 minutes at 160 ° C for polymerization, thereby forming an electron transfer layer having a thickness of 0.49 μm.

[00267] (Example 67)

[00268] An electrophotographic photosensitive member was made and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 12.

[00269] 6.5 parts of the electron-transporting substance (A-125), 2.1 parts of the amine compound (C1-3), 0.4 parts of the resin (D1) and 0.1 parts of dodecylbenzenesulfonic acid were dissolved as a catalyst in a mixed solvent from 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 160 minutes at 160 ° C for polymerization, thereby forming an electron transfer layer having a thickness of 0.49 μm.

[00270] (Example 68)

[00271] An electrophotographic photosensitive member was manufactured and evaluated as in Example 66, except for changing the thickness of the electron transfer layer from 0.49 μm to 0.72 μm. The results are shown in Table 12.

[00272] (Example 69)

[00273] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 12.

[00274] 3.6 parts of an electron-transporting substance (A101), 7 parts of an isocyanate compound (B1: blocking group (H1) = 5.1: 2.2 (mass ratio)), 1.3 parts of a resin (D1) and 0 , 05 parts of dioctyltin laurate as a catalyst was dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. Liquid for applying an electron transfer layer was applied by immersion on a conductive layer, and the resulting coating film was heated for 40 minutes at 160 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 0.32 μm.

[00275] (Example 70)

[00276] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for changing the thickness of the charge generation layer from 0.15 μm to 0.12 μm. The results are shown in Table 12.

[00277] (Example 71)

[00278] An electrophotographic photosensitive member was fabricated and evaluated as in Example 1, except for the formation of a charge generation layer by the method described below. The results are shown in Table 12.

[00279] Used 10 parts of phthalocyanine oxytitanium, showing strong peaks at Bragg angles (2θ ± 0.2 °) of 9.0 °, 14.2 °, 23.9 ° and 27.1 ° when x-ray diffractometry using CuKα radiation, and 166 parts of a solution were prepared in which the polyvinyl butyral resin (trade name: Eslec BX-1, manufactured by Sekisui Chemical Co., Ltd.) was dissolved in a mixed solvent of cyclohexanone: water = 97: 3 to obtain a 5% by weight solution. The solution and 150 parts of a mixed solvent of cyclohexanone: water = 97: 3 were dispersed together for 4 hours in a sand mill using 400 parts of glass beads with a diameter of 1 mm, and then 210 parts of a mixed solvent of cyclohexanone: water = 97: 3 were added to them. and 260 parts of cyclohexanone, thereby obtaining a liquid for applying a charge generation layer. The liquid for applying the charge generation layer was applied by immersion on an electron transfer layer, and the resulting coating film was dried for 10 minutes at 80 ° C., thereby forming a charge generation layer having a thickness of 0.20 μm.

[00280] (Example 72)

[00281] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of a charge generation layer by the method described below. The results are shown in Table 12.

[00282] 20 parts of a bisazopigment represented by the following structural formula (17) and 10 parts of a polyvinyl butyral resin (trade name: Eslec BX-1 manufactured by Sekisui Chemical Co., Ltd.) were mixed and dispersed in 150 parts of tetrahydrofuran, thereby liquids for applying a charge generation layer. This application liquid was applied to a bare aluminum tube as a conductive substrate using a dipping coating method and dried by heating at 110 ° C. for 30 minutes, thereby forming a charge generation layer having a thickness of 0.30 μm.

[00283]

[00284] (Example 73)

[00285] An electrophotographic photosensitive member was fabricated and evaluated as in Example 1, except for replacing the triarylamine compound (hole transporting substance) from Example 1 with a benzidine compound (hole transporting substance) represented by the following structural formula (18) to form a hole transport layer . The results are shown in Table 12.

[00286]

[00287] (Example 74)

[00288] An electrophotographic photosensitive member was made and evaluated as in Example 1, except for replacing the triarylamine compound (hole transporting substance) from Example 1 with a styryl compound (hole transporting substance) represented by the following structural formula (19) to form a hole transport layer . The results are shown in Table 12.

[00289]

[00290] (Examples 75 and 76)

[00291] Electrophotographic photosensitive elements were manufactured and evaluated as in Example 1, except for changing the thickness of the hole transfer layer from 15 μm to 10 μm (Example 75) and 25 μm (Example 76). The results are shown in Table 12.

[00292] (Example 77)

[00293] An aluminum cylinder (JIS-A3003, aluminum alloy) with a length of 260.5 mm and a diameter of 30 mm was made as a substrate (conductive substrate).

[00294] Then, 214 parts of oxygen-deficient tin oxide particles (TiO ₂ ) coated as metal oxide particles, 132 parts of phenolic resin (trade name: Plyophen J-325) as a binder resin and 98 parts of 1-methoxy- 2-propanol as a solvent was placed in a sand mill using 450 parts of glass beads with a diameter of 0.8 mm and subjected to dispersion treatment under conditions of a rotation speed of 2000 rpm, a dispersion treatment time of 4.5 hours and a predetermined cooling water temperature of 18 ° C s getting those liquid dispersion. Glass beads were removed from the liquid dispersion with a sieve (sieve mesh opening: 150 μm). Particles of silicone resin (trade name: Tospearl 120 manufactured by Momentive Performance Materials Inc., average particle diameter: 2 μm) as a surface imparting roughness of the material was added to the liquid dispersion after removing the glass balls so that they were 10% by weight relative to the total mass of particles of metal oxide and a binder resin in a liquid dispersion; and silicone oil (trade name: SH28PA manufactured by Dow Corning Toray Co., Ltd.) was added to the liquid dispersion as a leveling agent so that it was 0.01% by weight with respect to the total particle weight of the metal oxide and the binder resin in liquid dispersion; and the resulting mixture was mixed, thereby obtaining a liquid for applying a conductive layer. A liquid for applying a conductive layer was applied by immersion on a substrate, and the resulting coating film was dried and thermally cured for 30 minutes at 150 ° C., thereby forming a conductive layer having a thickness of 30 μm.

[00295] Then, 6.2 parts of an electron-transporting substance (A157), 8.0 parts of a crosslinking agent (B1: blocking group (H5) = 5.1: 2.9 (mass ratio)), 1.1 parts of a resin (D25 ) and 0.05 parts of dioctyltin laurate as a catalyst were dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 160 minutes at 160 ° C for polymerization, thereby forming an electron transfer layer (coating sublayer) having a thickness of 0.53 μm. The content of the electron-transporting substance with respect to the total mass of the electron-transporting substance, crosslinking agent and resin was 34% by weight.

[00296] Then formed a charge generation layer having a thickness of 0.15 μm, as in Example 1.

[00297] 9 parts of a triarylamine compound represented by the above structural formula (15), 1 part of a benzidine compound (hole transporting substance) represented by the following structural formula (18), 3 parts of a polyester resin E (weight average molecular weight: 90,000), having a repeating structural unit represented by the following formula (24), and a repeating structural unit represented by the following formula (26), and a repeating structural unit represented by the following formula (25), when a ratio of 7: 3 and 7 parts of a polyester resin F (weight average molecular weight: 120,000) having a repeating structure represented by the following formula (27) and a repeating structure represented by the following formula (28), with a ratio of 5: 5, was dissolved in a mixed solvent of 30 parts of dimethoxymethane and 50 parts of orthoxylene, thereby obtaining a liquid for applying a hole transport layer. The content of the repeating structural unit represented by the following formula (24) in the polyester resin E was 10% by mass, and the content of the repeating structural units represented by the following formulas (25) and (26) was 90% by mass .

[00298]

[00299]

[00300] The liquid for applying the hole transport layer was immersed on the charge generation layer and dried for 1 hour at 120 ° C., thereby forming a hole transfer layer having a thickness of 16 μm. It was confirmed that the formed hole transfer layer had a domain structure in which the matrix containing the hole transporting substance and the polyester resin F contained the polyester resin E.

[00301] The evaluation was carried out as in Example 1. The results are shown in Table 13.

[00302] (Example 78)

[00303] An electrophotographic photosensitive member was manufactured as in Example 1, except for forming a hole transport layer by the method described below. The results are shown in Table 13.

[00304] 9 parts of a triarylamine compound represented by the above structural formula (15), 1 part of a benzidine compound represented by the above structural formula (18), 10 parts of a polycarbonate resin G (weight average molecular weight: 70,000), having a repeating structure represented by the following further by formula (29), and 0.3 parts of a polycarbonate resin H (weight average molecular weight: 40,000) having a repeating structure represented by the following formula (29), a repeating structure represented by the following further by formula (30), and the structure of at least one final group represented by the following formula (31) was dissolved in a mixed solvent of 30 parts of dimethoxymethane and 50 parts of orthoxylene, thereby obtaining a liquid for applying a hole transport layer. Moreover, the total mass of the repeating structural units represented by the following formulas (30) and (31) in the polycarbonate resin H was 30% by weight. The liquid for applying the hole transport layer was applied by immersion on the charge generation layer and dried for 1 hour at 120 ° C, thereby forming a hole transport layer having a thickness of 16 μm.

[00305]

[00306] (Example 79)

[00307] An electrophotographic photosensitive member was fabricated and evaluated as in Example 78, with the exception of replacing 10 parts of polycarbonate resin G (weight average molecular weight: 70,000) in a liquid for applying a hole transfer layer from Example 78 to 10 parts of polyester resin F (weight average molecular weight: 120,000). The results are shown in Table 13.

[00308] (Example 80)

[00309] An electrophotographic photosensitive member was manufactured and evaluated as in Example 77, except for the formation of a conductive layer as follows. The results are shown in Table 13.

[00310] 207 parts of particles of titanium oxide (TiO ₂ ) coated with tin oxide (SnO ₂ ) doped with phosphorus (P) as metal oxide particles, 144 parts of phenolic resin (trade name: Plyophen J-325) as a binder resin and 98 parts of 1-methoxy-2-propanol as a solvent were placed in a sand mill using 450 parts of glass beads with a diameter of 0.8 mm and subjected to dispersion treatment under conditions of a rotation speed of 2000 rpm, a dispersion treatment time of 4.5 hours and a predetermined cooling water temperature 18 ° C to obtain liquid dispersion. Glass beads were removed from the liquid dispersion with a sieve (sieve mesh opening: 150 μm).

[00311] Particles of silicone resin (trade name: Tospearl 120) as a surface roughness material was added to the liquid dispersion after removing the glass balls so that they were 15% by weight relative to the total mass of particles of metal oxide and a binder resin in the liquid dispersion ; and silicone oil (trade name: SH28PA) was added to the liquid dispersion as a leveling agent so that it was 0.01% by weight relative to the total mass of the metal oxide particles and the binder resin in the liquid dispersion; and the resulting mixture was mixed, thereby obtaining a liquid for applying a conductive layer. A liquid for applying a conductive layer was applied by immersion on a substrate, and the resulting coating film was dried and thermally cured for 30 minutes at 150 ° C., thereby forming a conductive layer having a thickness of 30 μm.

[00312] (Examples 81-99)

[00313] Electrophotographic photosensitive elements were fabricated and evaluated as in Example 77, except for replacing the electron-transporting substance from Example 77 s (A157) with the electron-transporting substances shown in Table 13. The results are shown in Table 13.

[00314] (Comparative example 1)

[00315] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. As a result of the method for determining, as illustrated in FIG. 4B, the surface potential could not fall by up to 20% with respect to Vd1 after exposure to light. The results are shown in Table 12.

[00316] 2.4 parts of an electron-transporting substance (A101), 4.2 parts of an isocyanate compound (B1: blocking group (H1) = 5.1: 2.2 (mass ratio)), 5.4 parts of a resin (D1) and 0.05 parts of dioctyltin laurate as a catalyst was dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. Liquid for applying an electron transfer layer was applied by immersion on a conductive layer, and the resulting coating film was heated for 40 minutes at 160 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 0.53 μm.

[00317] (Comparative example 2)

[00318] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 12.

[00319] 3.2 parts of an electron-transporting substance (A101), 5.0 parts of an isocyanate compound (B1: blocking group (H1) = 5.1: 2.2 (mass ratio)), 4.2 parts of a resin (D1) and 0.05 parts of dioctyltin laurate as a catalyst was dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. Liquid for applying an electron transfer layer was applied by immersion on a conductive layer, and the resulting coating film was heated for 40 minutes at 160 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 0.53 μm.

[00320] (Comparative Examples 3 and 4)

[00321] Electrophotographic photosensitive elements were manufactured and evaluated as in Comparative Example 2, except for changing the thickness of the electron transfer layer from 0.53 μm to 0.40 μm (Comparative Example 3) and 0.32 μm (Comparative Example 4). The results are shown in Table 12.

[00322] (Comparative Examples 5-8)

[00323] Electrophotographic photosensitive elements were made and evaluated as in Example 1, except for changing the thickness of the electron transfer layer from 0.53 μm to 0.78 μm (Comparative Example 5), 1.03 μm (Comparative Example 6), 1.25 μm (Comparative Example 7) and 1.48 μm (Comparative Example 8). The results are shown in Table 12.

[00324] (Comparative example 9)

[00325] An electrophotographic photosensitive member was fabricated and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 12.

[00326] 4 parts of the electron transporting substance (A225), 3 parts of hexamethylene diisocyanate and 4.0 parts of resin (D1) were dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. Liquid for applying an electron transfer layer was applied by immersion on a conductive layer, and the resulting coating film was heated for 160 minutes at 160 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 1.00 μm.

[00327] (Comparative example 10)

[00328] An electrophotographic photosensitive member was made and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 12.

[00329] 5 parts of an electron-transporting substance (A124), 2.5 parts of 2,4-toluene diisocyanate and 2.5 parts by weight of poly (p-hydroxystyrene) (trade name: Malkalinker, manufactured by Maruzen Petrochemical Co., Ltd.) were dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 160 minutes at 160 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 0.40 μm.

[00330] (Comparative Example 11)

[00331] An electrophotographic photosensitive member was made and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 12.

[00332] 7.0 parts of an electron-transporting substance (A124), 2.0 parts of 2,4-toluene diisocyanate and 1.0 parts of poly (p-hydroxystyrene) (trade name: Malkalinker, manufactured by Maruzen Petrochemical Co., Ltd.) were dissolved in a mixed solvent of 100 parts of dimethylacetoamide and 100 parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 160 minutes at 160 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 0.40 μm.

[00333] Table 11 (see the end of the description)

[00334] Table 12 (see the end of the description)

[00335] Table 13 (see the end of the description)

[00336] (Comparative example 12)

[00337] An electrophotographic photosensitive member was fabricated and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. As a result of the method for determining, as illustrated in FIG. 4B, the surface potential could not fall by up to 20% with respect to Vd1 after exposure to light. The results are shown in Table 14.

[00338] 5 parts of an electron-transporting substance (A922), 13.5 parts of an isocyanate compound (Sumidule 3173 manufactured by Sumitomo Bayer Urethane Co., Ltd.), 10 parts of a butyral resin (BM-1 manufactured by Sekisui Chemical Co., Ltd. ) and 0.005 mass parts of dioctyltin laurate as a catalyst were dissolved in a solvent of 120 mass parts of methyl ethyl ketone, thereby obtaining a liquid for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 40 minutes at 170 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 1.00 μm.

[00339] (Comparative example 13)

[00340] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 14.

[00341] 5 parts of an electron-transporting substance (A101) and 2.4 parts of a melamine resin (Yuban 20HS manufactured by Mitsui Chemicals Inc.) were dissolved in a mixed solvent of 50 parts of THF (tetrahydrofuran) and 50 parts of methoxypropanol, thereby obtaining a coating liquid electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 60 minutes at 150 ° C. for polymerization, thereby forming an electron transfer layer having a thickness of 1.00 μm.

[00342] (Comparative example 14)

[00343] An electrophotographic photosensitive member was manufactured and evaluated as in Comparative Example 12, except for changing the thickness of the electron transfer layer from 1.00 μm to 0.50 μm. The results are shown in Table 14.

[00344] (Comparative example 15)

[00345] An electrophotographic photosensitive member was made and evaluated as in Comparative Example 12, except for replacing the melamine resin (Yuban 20HS manufactured by Mitsui Chemicals Inc.) with an electron transfer layer to a phenolic resin (Plyophen J-325 manufactured by DIC Corporation). The results are shown in Table 14.

[00346] (Comparative example 16)

[00347] An electrophotographic photosensitive member was made and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 14.

[00348] 10 parts of a mixture of two compounds having the structures represented by the following formulas (20-1) and (20-2) were dissolved in a mixed solvent of 30 parts of N-methyl-2-pyrrolidone and 60 parts of cyclohexanone, thereby fluids for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the obtained coating film was heated for 30 minutes at 150 ° C for polymerization, thereby forming an electron transfer layer having a structural unit represented by the following formula (20-3), and having a thickness of 0.20 μm.

[00349]

[00350] (Comparative Examples 17 and 18)

[00351] Electrophotographic photosensitive elements were manufactured and evaluated as in Comparative Example 16, except for changing the thickness of the electron transfer layer from 0.20 μm to 0.30 μm (Comparative Example 17) and 0.60 μm (Comparative Example 18). The results are shown in Table 14.

[00352] (Comparative example 19)

[00353] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 14.

[00354] 10 parts of an electron-transporting substance represented by the following formula (21) were dissolved in a mixed solvent of 60 parts of toluene, thereby obtaining a liquid for applying an electron transfer layer. A liquid for applying an electron transfer layer was applied by immersion on a conductive layer, and the resulting coating film was irradiated with electron beams under conditions of an accelerating voltage of 150 kV and an irradiation dose of 10 Mrad for polymerization, thereby forming an electron transfer layer having a thickness of 1.00 μm.

[00355]

[00356] (Comparative example 20)

[00357] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 14.

[00358] 5 parts of the electron-transporting substance represented by the above formula (19), 5 parts of trimethylol propane triacrylate (Kayarad TMPTA, Nippon Kayaku Co., Ltd.) and 0.1 parts of AIBN (2,2-azobisisobutyronitrile) were dissolved in 190 parts of tetrahydrofuran (THF), thereby obtaining a liquid for applying an electron transfer layer. Liquid for applying an electron transfer layer was applied by immersion on a conductive layer, and the resulting coating film was heated for 30 minutes at 150 ° C for polymerization, thereby forming an electron transfer layer having a thickness of 0.80 μm.

[00359] (Comparative example 21)

[00360] An electrophotographic photosensitive member was made and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 14.

[00361] 5 parts of an electron-transporting substance represented by the above formula (19) and 5 parts of a compound represented by the following formula (22) were dissolved in a mixed solvent of 60 parts of toluene, thereby obtaining a liquid for applying an electron transfer layer. A liquid for applying an electron transfer layer was applied by immersion on a conductive layer, and the resulting coating film was irradiated with electron beams under conditions of an accelerating voltage of 150 kV and an irradiation dose of 10 Mrad for polymerization, thereby forming an electron transfer layer having a thickness of 1.00 μm.

[00362]

[00363] (Comparative example 22)

[00364] An electrophotographic photosensitive member was made and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 14.

[00365] An electron transfer layer (coating sublayer) (structure from Example 1 of the national publication of International Patent Application No. 2009-505156) was formed using a block copolymer represented by the following structure, a blocked isocyanate compound and a vinyl chloride-vinyl acetate copolymer to form the most electron transfer layer 0.32 μm thick.

[00366]

[00367] (Comparative example 23)

[00368] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 14.

[00369] 5 parts of an electron-transporting substance (A101) and 5 parts of a polycarbonate resin (Z200 manufactured by Mitsubishi Gas Chemical Co., Inc.) were dissolved in a mixed solvent of 50 parts by weight of dimethylacetoamide and 50 parts by weight of chlorobenzene, thereby obtaining a coating liquid electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 30 minutes at 120 ° C., thereby forming an electron transfer layer having a thickness of 1.00 μm.

[00370] (Comparative example 24)

[00371] An electrophotographic photosensitive member was fabricated and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. As a result of the method for determining, as illustrated in FIG. 4A, the electrophotographic photosensitive member could not be charged to Vd1. The results are shown in Table 14.

[00372] 5 parts of an electron-transporting substance (pigment) having the following structural formula (23) was added to a liquid in which 5 parts of a resin (D1) were dissolved in a mixed solvent of 200 parts of methyl ethyl ketone and subjected to a dispersion treatment for 3 hours using a sand mill, thereby obtaining a liquid for applying an electron transfer layer. The liquid for applying the electron transfer layer was applied by immersion on the conductive layer, and the resulting coating film was heated for 10 minutes at 100 ° C., thereby forming an electron transfer layer having a thickness of 1.50 μm.

[00373]

[00374] (Comparative example 25)

[00375] An electrophotographic photosensitive member was made and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 14.

[00376] An electron transfer layer (coating sublayer) was formed using a liquid to apply an electron transfer layer, in which the polymer of the electron-transporting substance described in Example 1 of Japanese Patent Application Laid-Open No. 2004-093801 was dissolved in a solvent, thereby forming a transfer layer electrons having a thickness of 2.00 μm.

[00377] (Comparative example 26)

[00378] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. The results are shown in Table 14.

[00379] An electron transfer layer (coating sublayer) was formed using particles of a copolymer containing an electron transferring substance described in Example 1 of Japanese Patent No. 4,594,444, thereby forming an electron transfer layer having a thickness of 1.00 μm.

[00380] (Comparative example 27)

[00381] An electrophotographic photosensitive member was manufactured and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. As a result of the method for determining, as illustrated in FIG. 4A, the electrophotographic photosensitive member could not be charged to Vd1. The results are shown in Table 14.

[00382] (Electron Transfer Layer)

[00383] The electron transfer layer (coating sublayer) (structure described in Example 1 of Japanese Patent Application Laid-Open No. 2006-030698) was formed using a zinc oxide pigment subjected to a surface treatment with a silane coupling agent, alizarin (A922) blocked by an isocyanate compound, and butyral resin, thereby forming an electron transfer layer 25 microns thick.

[00384] (Comparative example 28)

[00385] An electrophotographic photosensitive member was fabricated and evaluated as in Example 1, except for the formation of an electron transfer layer by the method described below. As a result of the method for determining, as illustrated in FIG. 4A, the electrophotographic photosensitive member could not be charged to Vd1. The results are shown in Table 14.

[00386] An electron transfer layer was formed (a coating sublayer using an electron transferring pigment, a polyvinyl butyral resin and a curable electron transfer substance having an alkoxysilyl group) described in Example 25 of Japanese Patent Application Laid-Open No. H11-119458.

[00387] Table 14 (see the end of the description)

[00388] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the described exemplary embodiments. The scope of the following claims should be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims (11)

1. Electrophotographic photosensitive element containing:
laminated body and
hole transport layer formed on the laminated body,
moreover
laminated body contains:
substrate
an electron transfer layer having a thickness d1 [μm] formed on the substrate, and
a charge generation layer having a thickness d2 [μm] formed on the electron transfer layer, and
wherein
a laminated body satisfies the following expressions (2) and (4):
| Vl2 (B) -Vl1 (B) | ≤0.35 (2) and
0.10≤ | (Vd2 (B) -Vl3 (B)) / Vd2 (B) | ≤0.20 (4),
where in the expressions (2) and (4)
Vl1 (B) represents the surface potential of the charge generation layer at
charging the surface of the charge generation layer so that the surface has a potential Vd1 [B] represented by the following expression (1):
Vd1 (V) = - 50 (V per unit of thickness (μm)) × (d1 (μm) + d2 (μm)) (1), and
irradiating the surface of the charge generation layer having the potential Vd1 with light at an interval of 0.18 seconds after irradiation,
wherein the light intensity is controlled so that the surface potential drops by 20% with respect to Vd1 [V] when the charge generation layer is irradiated, after an interval of 0.20 seconds after irradiation,
Vl2 (B) represents the surface potential of the charge generation layer at
charging the surface of the charge generation layer so that the surface potential is Vd1 [V], and
irradiating the surface of the charge generation layer having the potential Vd1 with light at an interval of 0.22 seconds after irradiation, and
Vl3 (B) represents the surface potential of the charge generation layer at
charging the surface of the charge generation layer so that the surface has a potential Vd2 [B] represented by the following expression (3):
Vd2 (V) = - 30 (V per unit of thickness (μm)) × (d1 (μm) + d2 (μm)) (3), and
irradiating the surface of the charge generation layer having the potential Vd2 with light at an interval of 0.20 seconds after irradiation. 2. An electrophotographic photosensitive member according to claim 1, wherein the electron transfer layer has a thickness d1 of 0.2 μm or more and 0.7 μm or less. 3. Electrophotographic photosensitive element according to claim 1 or 2, while in the expression (2) | Vl2 (B) -Vl1 (B) | satisfies the following expression (9):
| Vl2 (B) -Vl1 (B) | ≤0.28 ... (9). 4. Electrophotographic photosensitive element according to claim 1 or 2, while in the expression (4) | (Vd2 (B) -Vl3 (B)) / Vd2 (B) | satisfies the following expression (10):
0.10≤ | (Vd2 (B) -Vl3 (B)) / Vd2 (B) | ≤0.16 ... (10). 5. An electrophotographic photosensitive member according to claim 1 or 2, wherein the electron transfer layer contains a polymer obtained by polymerizing a composition containing an electron-transporting substance having a polymerizable functional group, a thermoplastic resin having a polymerizable functional group, and a crosslinking agent. 6. The electrophotographic photosensitive member according to claim 5, wherein the crosslinking agent has 3-6 groups of an isocyanate group, a blocked isocyanate group or a monovalent group represented by —CH ₂ —OR ¹ (R ¹ represents an alkyl group). 7. An electrophotographic photosensitive member according to claim 5, wherein the electron-transporting substance having a polymerizable functional group has a content of 30% by mass or more and 70% by mass or less with respect to the total weight of the composition. 8. An electrophotographic photosensitive member according to claim 1 or 2, wherein the charge generating layer comprises at least one charge generating substance selected from the group consisting of phthalocyanine pigments and azo pigments. 9. An electrophotographic photosensitive member according to claim 1 or 2, wherein the hole transfer layer contains at least one charge transfer agent selected from the group consisting of triarylamino compounds, benzidine compounds, and styryl compounds. 10. A working cartridge comprising an electrophotographic photosensitive member according to claim 1 or 2 and at least one assembly selected from the group consisting of a charging unit, a developing unit, a transfer unit, and a cleaning unit, all supported therein, the working cartridge being attachable to the body of the electrophotographic device and disconnected from it. 11. An electrophotographic device comprising an electrophotographic photosensitive member according to claim 1 or 2, a charging unit, a light irradiation unit, a developing unit and a transfer unit.

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