JP2007334097A - Electrophotographic photoreceptor and method for manufacturing electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having high sensitivity upon exposure by uniformly dispersing a charge generating agent having excellent charge generating ability in a photosensitive layer, and to provide a method for easily manufacturing the electrophotographic photoreceptor. <P>SOLUTION: The electrophotographic photoreceptor and the method for manufacturing the photoreceptor have a photosensitive layer of a single layer structure containing at least a charge generating agent, a hole transporting agent, an electron transporting agent and a binder resin on a substrate, wherein the photosensitive layer contains a perionone pigment as well as an oxotitanyl phthalocyanine crystal as a charge generating agent. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member and a method for producing the electrophotographic photosensitive member, and particularly relates to an electrophotographic photosensitive member having excellent sensitivity and a method for producing such an electrophotographic photosensitive member.

In general, organic photoconductors are often used as electrophotographic photoconductors used in electrophotographic machines such as copying machines and laser printers due to demands for low cost and low environmental pollution.
In addition, the surface of such an organic photoreceptor is charged (main charging step) and an electrostatic latent image is formed (exposure step), and then the electrostatic latent image is applied with a developing bias voltage. An image forming process is performed in which toner development (development process) is performed, and the formed toner image is transferred to transfer paper by a reversal development method (transfer process), which is heated and fixed to form a predetermined image. ing.
The residual toner on the organic photoconductor is removed using a cleaning blade (cleaning step), and the residual charge on the organic photoconductor is erased by an LED or the like (static elimination step). .
In order to increase the speed of such image formation, the organophotoreceptor is rotated and used at a high speed, so that the sensitivity to exposure needs to be higher than in the past.

  However, a metal-free phthalocyanine crystal generally used as a charge generating agent used in a single layer type electrophotographic photosensitive member has insufficient charge generating ability and cannot achieve high sensitivity. The problem was seen.

Therefore, in place of the metal-free phthalocyanine crystal, an oxotitanyl phthalocyanine crystal, particularly, a quantum yield of 90%, and a Y-type oxo titanyl phthalocyanine crystal having more excellent charge generation ability is used as a charge generator. Attempts have been made to achieve high sensitivity (for example, Patent Documents 1 and 2).
Patent No. 3463032 (Claims) JP 2004-145284 (Claims)

However, as in Patent Documents 1 and 2, simply using a Y-type oxotitanyl phthalocyanine crystal excellent in charge generation ability as a charge generation agent has been insufficient in increasing sensitivity. This is because the Y-type oxotitanyl phthalocyanine crystal is inferior in dispersibility in an organic solvent, so that it cannot be uniformly dispersed in the photosensitive layer and cannot fully exhibit its excellent charge generation ability. Because.
In addition, since the Y-type oxotitanyl phthalocyanine crystal is inferior in dispersibility in an organic solvent, the Y-type oxotitanyl phthalocyanine crystal aggregates and precipitates when the photosensitive layer coating solution is stored for a long period of time. Also, there has been a problem that it is difficult to efficiently manufacture the electrophotographic photosensitive member.

Accordingly, the inventors of the present invention have made extensive studies, and as a result, in the single-layer electrophotographic photosensitive member, a perinone pigment is contained, and an oxotitanyl phthalocyanine crystal is used as a charge generating agent, whereby a highly sensitive electrophotographic photosensitive member is obtained. It has been found that the body can be easily manufactured.
That is, an object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity to exposure and an easy method for producing such an electrophotographic photoreceptor.

  According to the present invention, there is provided an electrophotographic photosensitive member having a photosensitive layer having a single layer structure including at least a charge generating agent, a hole transporting agent, an electron transporting agent, and a binder resin on a substrate, wherein the photosensitive layer comprises In addition, an electrophotographic photoreceptor characterized in that it contains a perinone pigment and an oxo titanyl phthalocyanine crystal as a charge generating agent can solve the above-described problems.

That is, the sensitivity of the electrophotographic photosensitive member to exposure can be improved by using an oxotitanyl phthalocyanine crystal having a charge generation ability superior to that of a metal-free phthalocyanine crystal generally used as a charge generator.
In addition, due to the effect of perinone pigment, oxo titanyl phthalocyanine crystal, which is inferior in dispersibility than metal-free phthalocyanine crystal, can be effectively dispersed in the photosensitive layer, so that its excellent charge generation ability is sufficiently exhibited. be able to. Therefore, an electrophotographic photosensitive member having high sensitivity to exposure can be obtained.

Further, in constituting the electrophotographic photosensitive member of the present invention, the mobility of the hole transfer agent is 5.0 × 10 ⁻⁶ to 5.0 × 10 ⁻⁴ cm ² / V / sec (concentration 30% by weight, electric field). It is preferable to set the value within the range of the condition of an intensity of 3.0 × 10 ⁵ V / cm.
By comprising in this way, since the electric charge generated from the charge generating agent can be transported more efficiently, the sensitivity to exposure can be further improved.

Further, in constituting the electrophotographic photoreceptor of the present invention, the amount of perinone pigment added may be set to a value within the range of 50 to 200 parts by weight with respect to 100 parts by weight of the oxotitanyl phthalocyanine crystal as the charge generator. preferable.
By comprising in this way, it becomes easier to adjust the balance of the compatibility of the perinone pigment, the oxotitanyl phthalocyanine crystal and other components in the photosensitive layer coating solution in the photosensitive layer coating solution.

In constituting the electrophotographic photoreceptor of the present invention, the perinone pigment is preferably in the form of particles, and the average particle size of the perinone pigment is preferably set to a value in the range of 30 to 150 nm.
By using a perinone pigment having such an average particle size, the dispersibility of the oxotitanyl phthalocyanine crystal can be further improved. Also, the dispersibility of the perinone pigment itself can be improved. Therefore, as a result of the improved dispersibility, it is possible to obtain an electrophotographic photosensitive member that is highly sensitive to exposure.

In constituting the electrophotographic photoreceptor of the present invention, it is preferable that the perinone pigment is insoluble in an organic solvent.
By comprising in this way, in the coating liquid for photosensitive layers used when manufacturing a photosensitive layer, the particle diameter of the particle | grains which consist of a perinone pigment can be hold | maintained in the value within a preferable range. As a result, the balance between the interaction between the perinone pigment and the oxotitanyl phthalocyanine crystal and the compatibility with the other components in the coating solution for the photosensitive layer becomes suitable, and the dispersibility of the oxo titanyl phthalocyanine crystal as a charge generating agent Can be improved.

Further, in constituting the electrophotographic photosensitive member of the present invention, it is preferable that an oxo titanyl phthalocyanine crystal having the following characteristics (a) and (b) or any one of the characteristics is contained as a charge generator.
(A) In the differential scanning calorimetry, there is no peak in the range of 50 to 400 ° C. other than the peak due to vaporization of the adsorbed water. (B) In the differential scanning calorimetry, except for the peak due to vaporization of the adsorbed water. , Having no peak in the range of 50 to 200 ° C., and having one peak in the range of 200 to 400 ° C. By constituting in this way, in the coating solution for the photosensitive layer during the production of the photosensitive layer The aging stability and dispersibility of the oxo titanyl phthalocyanine crystal can be further improved.

In constituting the electrophotographic photosensitive member of the present invention, it is preferable to contain an oxotitanyl phthalocyanine crystal having the following characteristics (c) as a charge generator.
(C) After immersing in an organic solvent for 24 hours, the CuKα characteristic X-ray diffraction spectrum has a maximum peak at least at Bragg angle 2θ ± 0.2 ° = 27.2 ° and a peak at 26.2 °. Preferably not.
By comprising in this way, the temporal stability and dispersibility of the oxo titanyl phthalocyanine crystal | crystallization in the coating liquid for photosensitive layers can be made further excellent.

Another aspect of the present invention is a method for producing an electrophotographic photosensitive member comprising a single layer type photosensitive layer containing at least a charge generating agent, a hole transporting agent, an electron transporting agent, and a binder resin on a substrate. In the binder resin solution containing the binder resin and the organic solvent, the photosensitive layer is formed by dispersing the oxotitanyl phthalocyanine crystal, the hole transport agent, the electron transport agent, and the perinone pigment as the charge generating agent. An electrophotographic photoreceptor comprising: a step of producing a photosensitive layer coating solution for coating; and a step of coating the photosensitive layer coating solution on a substrate and then drying to form a photosensitive layer. It is a manufacturing method.
That is, even when the photosensitive layer coating solution is stored for a long period of time, it suppresses aggregation and precipitation of oxotitanyl phthalocyanine crystals as charge generating agents in the photosensitive layer coating solution, thereby improving the dispersibility. Can be effectively maintained.
Therefore, an electrophotographic photoreceptor having high sensitivity to exposure can be easily produced.

[First Embodiment]
The first embodiment of the present invention is an electrophotographic photosensitive member provided with a photosensitive layer having a single layer structure including at least a charge generating agent, a hole transporting agent, an electron transporting agent, and a binder resin on a substrate, An electrophotographic photoreceptor, wherein the photosensitive layer contains a perinone pigment and an oxo titanyl phthalocyanine crystal as a charge generating agent.
Hereinafter, the electrophotographic photosensitive member of the first embodiment will be described separately for each component.

1. Basic Configuration As shown in FIG. 1A, a single-layer electrophotographic photosensitive member 10 is obtained by providing a single photosensitive layer 14 on a substrate (conductive substrate) 12. The photosensitive layer 14 is characterized in that it contains a perinone pigment, an oxo titanyl phthalocyanine crystal as a charge generating agent, a hole transport agent, an electron transport agent, and a binder resin in the same layer.
The reason is that the dispersibility of the oxo titanyl phthalocyanine crystal is improved as described later by including oxo titanyl phthalocyanine crystal as a charge generating agent and perinone pigment as a dispersion aid in the same photosensitive layer. This is because the sensitivity of the electrophotographic photosensitive member can be improved. In addition, by including both a hole transport agent and an electron transport agent in the same photosensitive layer, it is possible to efficiently transport charges generated from the oxotitanyl phthalocyanine crystal as a charge generating agent at the time of exposure. This is because it can.
In addition, as shown in FIG. 1B, an electrophotographic photosensitive member 10 ′ in which a barrier layer 16 is formed between the substrate 12 and the photosensitive layer 14 in a range that does not inhibit the characteristics of the electrophotographic photosensitive member may be used. . In addition, as shown in FIG. 1C, an electrophotographic photoreceptor 10 ″ having a protective layer 18 formed on the surface of the photosensitive layer 14 may be used.

2. Charge Generating Agent (1) Type As the charge generating agent used in the electrophotographic photosensitive member according to the present invention, a crystal of an oxotitanyl phthalocyanine compound represented by the following general formula (1) is used.
This is because the metal-free phthalocyanine crystal generally used as a charge generator cannot sufficiently achieve high sensitivity in an electrophotographic photoreceptor, whereas the oxo represented by the general formula (1). This is because if the crystal is a titanyl phthalocyanine compound, the quantum yield can be remarkably improved depending on the crystal type.
In addition, the compound represented by following formula (2) can be mentioned as a specific example of the oxo titanyl phthalocyanine compound represented by General formula (1).

(In the general formula (1), X ¹ , X ² , X ³ and X ⁴ are the same or different substituents, and each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a cyano group, or a nitro group. And the repeating numbers a, b, c and d each represent an integer of 1 to 4, and may be the same or different.

Moreover, it is preferable that the crystal type in the oxo titanyl phthalocyanine crystal is a Y type.
This is because such a Y-type oxo titanyl phthalocyanine crystal improves the quantum yield in the charge generating agent, and can improve the sensitivity during exposure. That is, if the quantum yield is said to be about 90%, it is possible to efficiently generate charges according to the light irradiated by exposure, thereby sufficiently improving the sensitivity during exposure. This is because it can.

(2) Optical characteristics and thermal characteristics In addition, it is preferable to contain an oxotitanyl phthalocyanine crystal having the following characteristics (a) and (b) or one of the characteristics as a charge generator.
(A) In the differential scanning calorimetry, there is no peak in the range of 50 to 400 ° C. other than the peak due to vaporization of the adsorbed water. (B) In the differential scanning calorimetry, except for the peak due to vaporization of the adsorbed water. , Having no peak in the range of 50 to 200 ° C., and having one peak in the range of 200 to 400 ° C. This is because the oxotitanyl in the coating solution for the photosensitive layer is constituted in this way. This is because the aging stability and dispersibility of the phthalocyanine crystal can be further improved.

More specifically, when the oxo titanyl phthalocyanine crystal has the characteristic (a), the oxo titanyl phthalocyanine crystal is a stable crystal that hardly undergoes crystal transition.
That is, even when a photosensitive layer coating solution is manufactured and used after being stored for a certain period of time, oxotitanyl phthalocyanine crystals are produced by the action of an organic solvent such as tetrahydrofuran contained in the photosensitive layer coating solution. Little crystal transition from type to α or β type occurs. Therefore, the oxo titanyl phthalocyanine crystal can maintain the Y type which is a crystal type excellent in charge generation.

Further, when the oxo titanyl phthalocyanine crystal has the characteristic (b), the aging stability and dispersibility of the oxo titanyl phthalocyanine crystal in the photosensitive layer coating solution can be further improved.
More specifically, in the case of having the characteristics (b), the oxotitanyl phthalocyanine crystal can suppress crystal transition in an organic solvent and exhibits particularly excellent dispersibility in a coating solution for a photosensitive layer. can do.
That is, when producing a photosensitive layer coating solution for producing a photosensitive layer, the crystal type does not transition to α or β type, and the Y type can be maintained, and the dispersibility in the photosensitive layer coating solution is particularly high. Since it is excellent, charge generation at the time of exposure in the formed photosensitive layer can be performed very efficiently. Furthermore, the excellent dispersibility enables efficient charge transport between the oxotitanyl phthalocyanine crystal and the charge transport agent, thereby improving the sensitivity of the electrophotographic photoreceptor and increasing the sensitivity in the photosensitive layer. Generation of residual potential can be prevented and exposure memory can be effectively suppressed.
In addition, it is more preferable that one peak appearing in the range of 200 to 400 ° C. other than the peak accompanying vaporization of the adsorbed water appears in the range of 270 to 400 ° C., and the range of 300 to 400 ° C. More preferably, it appears within.

In addition, the oxo titanyl phthalocyanine crystal | crystallization which has the characteristic of (a) and (b) may be used individually, respectively, and may be used in combination.
Therefore, when the oxo titanyl phthalocyanine crystal having the characteristics of (a) and (b) is used in combination, the oxo titanyl phthalocyanine crystal having the characteristics of (a) by weight ratio: the oxo titanyl having the characteristics of (b) The phthalocyanine crystal is preferably in the range of 10/90 to 90/10, and more preferably in the range of 20/80 to 80/20.

Moreover, it is preferable to further contain another oxo titanyl phthalocyanine crystal other than the oxo titanyl phthalocyanine crystal having the characteristics (a) or (b) as the charge generating agent.
The reason for this is that the oxotitanyl phthalocyanine crystal having no characteristics of (a) or (b) may have poor stability over time and dispersibility in the coating solution for the photosensitive layer by itself. This is because the problem is remarkably improved by combining with an oxo titanyl phthalocyanine crystal having the characteristic (b).
That is, as long as a predetermined amount of the oxotitanyl phthalocyanine crystal having the characteristics (a) or (b) is used, even the conventional oxotitanyl phthalocyanine crystal not having the characteristics (a) or (b) can be suitably combined. Can be used. Therefore, by using an oxotitanyl phthalocyanine crystal having a plurality of properties as a charge generating agent in this way, it is easy to adjust the charge generating ability for exposure, and an inexpensive electrophotographic photosensitive member is provided. Can do.

Moreover, it is preferable to contain the oxo titanyl phthalocyanine crystal | crystallization which has the characteristic of the following (c) as a charge generator.
(C) After immersing in an organic solvent for 24 hours, the CuKα characteristic X-ray diffraction spectrum has a maximum peak at least at a Bragg angle 2θ ± 0.2 ° = 27.2 ° and a peak at 26.2 °. This is because, when the oxotitanyl phthalocyanine crystal has the characteristic (c), the oxo titanyl phthalocyanine crystal can control the crystal transition in the organic solvent more reliably.
That is, even when the oxo titanyl phthalocyanine crystal was actually immersed in an organic solvent such as tetrahydrofuran for 24 hours, it was confirmed that the crystal form did not transition to the α or β form and retained the Y form. This is because the crystal transition in the organic solvent can be reliably controlled.

Moreover, the thermal characteristic in an oxo titanyl phthalocyanine crystal can be measured as follows as an example.
That is, it can be measured under the following conditions using a differential scanning calorimeter (TAS-200 type, DSC8230D manufactured by Rigaku Corporation).
Sample pan: Aluminum heating rate: 20 ° C / min

Moreover, the optical characteristic in an oxo titanyl phthalocyanine crystal can be measured as follows as an example.
Specifically, 0.3 g of Y-type oxotitanyl phthalocyanine was dispersed in 5 g of tetrahydrofuran and stored in a closed system for 24 hours under conditions of a temperature of 23 ± 1 ° C. and a relative humidity of 50-60% RH. A sample holder of RINT1100 (manufactured by Rigaku Denki Co., Ltd.) is filled, and measurement can be performed under the following conditions.
X-ray tube: Cu
Tube voltage: 40 kV
Tube current: 30 mA
Start angle: 3.0 °
Stop angle: 40.0 °
Scanning speed: 10 ° / min

(3) Addition amount The addition amount of the oxotitanyl phthalocyanine crystal as the charge generating agent is preferably set to a value in the range of 0.6 to 3.0% by weight with respect to the total amount of the photosensitive layer. .
The reason for this is that by making the addition amount of oxotitanyl phthalocyanine crystal within such a range, the dispersibility in the photosensitive layer becomes good, and when the electrophotographic photoreceptor is exposed, the oxo titanyl phthalocyanine is This is because the crystals can efficiently generate charges and also efficiently transport charges between the crystals and the charge transport agent.
That is, when the amount of oxotitanyl phthalocyanine added is less than 0.6% by weight, the amount of charge generation becomes insufficient, and it becomes difficult to form a predetermined electrostatic latent image on the electrophotographic photosensitive member. This is because there are cases. On the other hand, when the added amount of the charge generating agent exceeds 3% by weight, it may be difficult to uniformly disperse in the photosensitive layer coating solution.
Therefore, it is more preferable that the addition amount of the charge generating agent is set to a value within the range of 0.8 to 2.8% by weight with respect to the total amount of the photosensitive layer.

3. Dispersion aid (1) type Moreover, it contains a perinone pigment as a dispersion aid.
This is because the use of such a perinone pigment as a dispersion aid can improve the dispersibility of the oxotitanyl phthalocyanine crystal as a charge generating agent in the photosensitive layer.
That is, due to the effect of the perinone pigment, dispersibility in an electrophotographic photosensitive member can be improved even with an oxotitanyl phthalocyanine crystal having relatively poor dispersibility, and its excellent charge generation ability is sufficiently exhibited. Because it can. Therefore, an electrophotographic photosensitive member having high sensitivity to exposure can be obtained.

The perinone pigment is preferably insoluble in an organic solvent.
The reason for this is that, as will be described later, when a particulate perinone pigment is used, the particle diameter of the particles composed of the perinone pigment can be kept within a preferred range in the photosensitive layer coating solution. is there. As a result, the balance between the interaction between the perinone pigment and the oxotitanyl phthalocyanine crystal and the compatibility with the other components in the coating solution for the photosensitive layer becomes suitable, and the dispersibility of the oxo titanyl phthalocyanine crystal as a charge generating agent It is because it can improve.
Specific examples of such organic solvents include, for example, alcohols such as methanol, ethanol, isopropanol and butanol; aliphatic hydrocarbons such as n-hexane, octane and cyclohexane; aromatic systems such as benzene, toluene and xylene. Halogenated hydrocarbons such as hydrocarbon, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dioxane, dioxolane; acetone, methyl ethyl ketone, cyclohexanone, etc. Ketones; esters such as ethyl acetate and methyl acetate; dimethylformaldehyde, dimethylformamide, dimethylsulfoxide, etc. It is.
Further, among the organic solvents described above, it is more preferable that the organic solvent is insoluble in ethers, and it is more preferable that the ethers are particularly insoluble in tetrahydrofuran.
The reason for this is that the oxo titanyl phthalocyanine crystal can retain its crystal structure without being dissolved by tetrahydrofuran, so that it is a good solvent for the polycarbonate, which is a binder resin usually used for forming an electrophotographic photoreceptor. This is because tetrahydrofuran that is can be used.

  Further, specific examples of perinone pigments that are insoluble in an organic solvent that is preferably used in the electrophotographic photoreceptor of the present invention include compounds represented by the following formulas (3) to (4) (perinone pigments). -A, perinone pigment -B).

(2) Average particle diameter In addition, it is preferable that the perinone pigment is particulate, and the average particle diameter of the perinone pigment is set to a value in the range of 30 to 150 nm.
This is because the dispersibility of the oxotitanyl phthalocyanine crystal can be further improved by setting the average particle size of the particles made of perinone pigment to a value in the range of 30 to 150 nm. Moreover, it is because the dispersibility of perinone pigment itself can also be improved. Therefore, as a result of improving the dispersibility of each, the sensitivity of the electrophotographic photosensitive member can be improved.
That is, if the average particle size of particles made of perinone pigment is less than 30 nm, it may be difficult to handle the perinone pigment or the production thereof may be inefficient. On the other hand, when the average particle diameter of the particles composed of perinone pigment exceeds 150 nm, it may be difficult to sufficiently exert the effect as a dispersion aid in the dispersion of oxotitanyl phthalocyanine crystals. .
Therefore, the average particle diameter of the particles made of perinone pigment is more preferably set to a value within the range of 35 to 120 nm, and further preferably set to a value within the range of 40 to 100 nm.

Here, the relationship between the average particle diameter of the particles made of perinone pigment and the dispersibility of the oxotitanyl phthalocyanine crystal will be described with reference to FIG.
In FIG. 2, the horizontal axis represents the average particle diameter (nm) of the particles made of perinone pigment, and the vertical axis represents the sedimentation time (relative value) of the oxotitanyl phthalocyanine crystal.
In addition, this sedimentation test was performed using the dispersion liquid obtained by adding and dispersing Y type | mold oxo titanyl phthalocyanine crystal | crystallization, perinone pigment, and tetrahydrofuran with respect to a container.
As understood from the characteristic diagram, the sedimentation time (relative value) is shortened as the average particle diameter (nm) of the particles made of perinone pigment increases.
More specifically, in the range where the average particle diameter (nm) of the particles made of perinone pigment is 150 nm or less, the settling time (relative value) is stable and above a certain value (relative value) regardless of the change in the value. Value). On the other hand, when the average particle diameter (nm) of the particles made of perinone pigment exceeds 150 nm, it is understood that the sedimentation time (relative value) is rapidly shortened as the value increases.

Further, the relationship between the average particle diameter of the particles made of perinone pigment and the sensitivity of the electrophotographic photosensitive member will be described with reference to FIG.
In FIG. 3, the horizontal axis shows the characteristic particle diameter (nm) of the particles made of perinone pigment, and the vertical axis shows the sensitivity (relative value) of the electrophotographic photosensitive member.
As understood from the characteristic diagram, the sensitivity (relative value) in the electrophotographic photosensitive member increases as the average particle diameter (nm) in the perinone pigment particles increases. In addition, it means that the sensitivity with respect to exposure is excellent, so that the value of a sensitivity (relative value) is small.
More specifically, when the average particle diameter (nm) of the particles made of perinone pigment is in the range of 150 nm or less, the sensitivity (V) value of the electrophotographic photosensitive member increases gently as the value increases. I keep doing it. And when the average particle diameter (nm) in the particle | grains which consist of a perinone pigment exceeds 150 nm, it turns out that the value of the sensitivity (V) in an electrophotographic photoreceptor is increasing greatly with the increase in this value.
Therefore, from FIG. 2 and FIG. 3, the dispersibility of the oxotitanyl phthalocyanine crystal and the sensitivity of the electrophotographic photosensitive member are improved by setting the average particle diameter (nm) of the particles made of perinone pigment to a value of 150 nm or less. I understand.

(3) Addition amount The addition amount of the perinone pigment is preferably set to a value in the range of 50 to 200 parts by weight with respect to 100 parts by weight of the oxotitanyl phthalocyanine crystal as the charge generating agent.
The reason for this is that the amount of perinone pigment added is set to a value within the range of 50 to 200 parts by weight with respect to 100 parts by weight of oxotitanyl phthalocyanine crystals as a charge generator, so that the perinone pigment in the coating solution for the photosensitive layer is used. This is because the interaction between oxotitanyl phthalocyanine crystals can be easily controlled. In addition, it is easy to adjust the compatibility with components in the coating solution for the photosensitive layer other than the oxotitanyl phthalocyanine crystal. As a result, the dispersibility of the oxotitanyl phthalocyanine crystal can be further improved by adjusting the balance between the two.
That is, when the amount of the perinone pigment added is less than 50 parts by weight with respect to 100 parts by weight of the oxo titanyl phthalocyanine crystal as the charge generating agent, the dispersibility improvement effect by the perinone pigment may not be exhibited. On the other hand, when this value exceeds 200 parts by weight, the perinone pigment itself may physically inhibit dispersion of the oxotitanyl phthalocyanine crystal.
Therefore, the amount of perinone pigment added is more preferably 60 to 180 parts by weight with respect to 100 parts by weight of oxotitanyl phthalocyanine crystals as a charge generator, and 70 to 150 parts by weight. More preferably, it is a value.

4). Type of hole transport agent (1) The hole transport agent used in the present invention is not particularly limited, and any of various conventionally known hole transport compounds can be used. In particular, benzidine compounds, phenylenediamine compounds, naphthylenediamine compounds, phenanthrylenediamine compounds, oxadiazole compounds [for example, 2,5-di (4-methylaminophenyl) -1,3,4-oxa Diazole etc.], styryl compounds [eg 9- (4-diethylaminostyryl) anthracene etc.], carbazole compounds [eg poly-N-vinylcarbazole etc.], organic polysilane compounds, pyrazoline compounds [eg 1-phenyl-3 -(P-dimethylaminophenyl) pyrazoline etc.], hydrazone compounds, triphenylamine compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazols Compounds, triazole compounds, butadiene compounds, pyrene-hydrazone compounds, acrolein compounds, carbazole-hydrazone compounds, quinoline-hydrazone compounds, stilbene compounds, stilbene-hydrazone compounds, diphenylenediamine compounds, etc. Are preferably used. These may be used alone or in combination of two or more.
In particular, the hole transport agents (HTM-A to I) represented by the following formulas (5) to (13) are all compatible with the above-described oxotitanyl phthalocyanine crystal and have a positive hole. It is preferably used as a hole transport agent having excellent transport ability.

(2) Mobility Further, the mobility of the hole transport agent is set to 5.0 × 10 ⁻⁶ to 5.0 × 10 ⁻⁴ cm ² / V / sec (concentration 30% by weight, electric field strength 3.0 × 10 ^5. It is preferable to set the value within the range (under the condition of V / cm).
This is because charge is generated by using a hole transporting agent having a mobility within the range of 5.0 × 10 ⁻⁶ to 5.0 × 10 ⁻⁴ cm ² / V / sec under such conditions. This is because the charge generated from the agent can be transported more efficiently, and the sensitivity to exposure can be further improved.
That is, if the mobility under such conditions is less than 5.0 × 10 ⁻⁶ cm ² / V / sec, the charge generated from the charge generating agent may not be fully transported. . On the other hand, when the mobility under such conditions is a value exceeding 5.0 × 10 ⁻⁴ cm ² / V / sec, it is preferable to improve the sensitivity, but it is possible to obtain such a high-performance hole transport agent. This is because it may be technically and costly difficult. Further, the balance with the electron transporting ability of the electron transporting agent is lost, so that charges may remain in the photosensitive layer.
Therefore, the mobility under such conditions is more preferably set to a value within the range of 8.0 × 10 ^{−6 to} 5.0 × 10 ⁻⁵ cm ² / V / sec, and 1.0 × 10 ⁻⁵ to More preferably, the value is within a range of 3.0 × 10 ⁻⁵ cm ² / V / sec.
In addition, the mobility is in the range of 5.0 × 10 ⁻⁶ to 5.0 × 10 ⁻⁴ cm ² / V / sec (concentration of 30% by weight, electric field strength of 3.0 × 10 ⁵ V / cm). As specific examples of the hole transport agent having a value within the range, among the specific examples of the hole transport agent described above, the hole transport agents (HTM-A to E) represented by the formulas (5) to (9) Is mentioned. Further, the mobility in these HTM-A to E is 1 × 10 ⁻⁵ , 3.61 × 10 ⁻⁵ , 5.74 × 10 ⁻⁵ , 5.33 × 10 ⁻⁵ and 3.09 × 10 ^{−, respectively. 5} cm ² / V / sec.

Here, the relationship between the mobility of the hole transport agent and the sensitivity of the electrophotographic photosensitive member will be described with reference to FIG.
In FIG. 4, the mobility of the hole transport agent (cm ² / V / sec) measured under the conditions of a concentration of 30% by weight and an electric field strength of 3.0 × 10 ⁵ V / cm on the horizontal axis, The characteristic diagram which each took the sensitivity (V) in an electrophotographic photoreceptor is shown.
As understood from the characteristic diagram, as the mobility (cm ² / V / sec) of the hole transport agent increases, the value of sensitivity (V) in the electrophotographic photosensitive member decreases. In addition, it means that the sensitivity with respect to exposure is excellent, so that the value of sensitivity (V) is small.
More specifically, when the mobility (cm ² / V / sec) of the hole transport agent is less than 5.0 × 10 ⁻⁶ cm ² / V / sec, as the value increases. Although the value of the sensitivity (V) in the electrophotographic photosensitive member is rapidly decreased, a high value exceeding 250 V is adopted. On the other hand, when the mobility (cm ² / V / sec) of the hole transport agent is 5.0 × 10 ⁻⁶ cm ² / V / sec or more, the sensitivity (V) value in the electrophotographic photoreceptor is 250 V. It can be seen that the following values are taken.
Therefore, by setting the mobility (cm ² / V / sec) of the hole transporting agent to a value of 5.0 × 10 ⁻⁶ cm ² / V / sec or more, the sensitivity in the electrophotographic photosensitive member is improved. I understand.

(3) Addition amount The addition amount of the hole transport agent is preferably set to a value within the range of 20 to 500 parts by weight with respect to 100 parts by weight of the binder resin.
This is because when the amount of the hole transporting agent added is less than 20 parts by weight, the hole transporting function in the photosensitive layer is lowered, which may adversely affect image characteristics. On the other hand, when the added amount of the hole transport agent exceeds 500 parts by weight, the dispersibility is lowered and crystallization is likely to occur.
Therefore, the amount of the hole transport agent added is more preferably set to a value within a range of 30 to 200 parts by weight, and a value within a range of 40 to 100 parts by weight with respect to 100 parts by weight of the binder resin. Is more preferable.

5). Electron Transfer Agent (1) Type As the electron transfer agent, any of various conventionally known electron transfer compounds can be used. In particular, fluorenone compounds such as benzoquinone compounds, diphenoquinone compounds, naphthoquinone compounds, malononitrile, thiopyran compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, such as 2,4,7-trinitro-9-fluorenone , Dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, succinic anhydride, maleic anhydride, dibromomaleic anhydride, 2,4,7-trinitrofluorenone imine compound, ethylated nitrofluorenone imine compound, tryptoanthrin Compounds, tryptoanthrinimine compounds, azafluorenone compounds, dinitropyridoquinazoline compounds, thioxanthene compounds, 2-phenyl-1,4-benzoquinone compounds, Electron-withdrawing compounds such as nyl-1,4-naphthoquinone compounds, 5,12-naphthacenequinone compounds, α-cyanostilbene compounds, nitrostilbene compounds, and salts of anion radicals and cations of benzoquinone compounds Preferably used. These may be used alone or in combination of two or more.

  Specific examples of the electron transport agent described above include electron transport agents (ETM-A to G) represented by the following formulas (14) to (20).

(2) Addition amount The addition amount of the electron transfer agent is preferably set to a value within the range of 20 to 500 parts by weight with respect to 100 parts by weight of the binder resin.
This is because, when the amount of the electron transfer agent added is less than 20 parts by weight, the sensitivity is lowered and a practical problem may occur. On the other hand, when the added amount of the electron transport agent exceeds 500 parts by weight, the electron transport agent is easily crystallized, and it may be difficult to form an appropriate film as the photosensitive layer. Therefore, it is more preferable that the addition amount of the electron transport agent is a value within a range of 30 to 200 parts by weight, and a value within a range of 40 to 100 parts by weight with respect to 100 parts by weight of the binder resin. Is more preferable.

6). Binder resin As the binder resin, for example, styrene polymer, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic polymer, styrene-acrylic copolymer, Polyethylene, ethylene-vinyl acetate copolymer, chlorinated polyethylene, polyvinyl chloride, polypropylene, vinyl chloride-vinyl acetate copolymer, polyester, alkyd resin, polyamide, polyurethane, polycarbonate, polyarylate, polysulfone, diallyl phthalate resin, ketone Thermoplastic resins such as resins, polyvinyl butyral resins, and polyether resins, silicone resins, epoxy resins, phenol resins, urea resins, melamine resins, and other crosslinkable thermosetting resins, and epoxy-acrylates, and Examples thereof include a photocurable resin such as urethane-acrylate. These binder resins can be used alone or in combination of two or more.
In constituting the electrophotographic photosensitive member of the present invention, a preferred binder resin is a Z-type polycarbonate resin (Resin-A) containing a structural unit represented by the following formula (21).

7). Additives In addition to the above-described components, various additives such as sensitizers, fluorene compounds, ultraviolet absorbers, plasticizers, surfactants, and leveling agents are added to the photosensitive layer. You can also. In order to improve the sensitivity of the electrophotographic photoreceptor, a sensitizer such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generator.

8). Thickness The thickness of the photosensitive layer is preferably set to a value in the range of 5.0 to 100 μm.
This is because, when the thickness of the photosensitive layer is less than 5.0 μm, the mechanical strength as an electrophotographic photosensitive member may be insufficient. On the other hand, when the thickness of the photosensitive layer exceeds 100 μm, it may be easily peeled off from the substrate or may be difficult to form uniformly. Accordingly, the thickness of the photosensitive layer is more preferably set to a value within the range of 10 to 80 μm, and further preferably set to a value within the range of 20 to 40 μm.

9. Substrate As the substrate on which the above-described photosensitive layer is formed, various conductive materials can be used. For example, a conductive substrate formed of a metal such as iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass; Examples include a substrate made of a plastic material on which a metal is deposited or laminated, or a glass substrate coated with aluminum iodide, tin oxide, indium oxide, or the like.
That is, it is only necessary that the substrate itself has conductivity or the surface of the substrate has conductivity. Further, it is preferable that the substrate has sufficient mechanical strength when used.
The shape of the substrate may be any of a sheet shape and a drum shape according to the structure of the image forming apparatus to be used.

10. Image Forming Apparatus Further, as an image forming apparatus equipped with the electrophotographic photosensitive member of the present invention, a structure such as an image forming apparatus 100 shown in FIG. 5 is preferably used.
Here, FIG. 5 is a schematic diagram showing the overall configuration of the image forming apparatus. Hereinafter, the operation will be described in order.
First, the electrophotographic photosensitive member 111 of the image forming apparatus 100 is rotated at a predetermined process speed (peripheral speed) in the direction indicated by the arrow A, and then the surface is charged to a predetermined potential by the charging unit 112.
Next, the exposure unit 113 exposes the surface of the electrophotographic photosensitive member 111 through a reflection mirror or the like while being light-modulated according to image information. By this exposure, an electrostatic latent image is formed on the surface of the electrophotographic photosensitive member 111.
Next, based on the electrostatic latent image, latent image development is performed by the developing unit 114. The developing means 114 stores toner, and the toner adheres corresponding to the electrostatic latent image on the surface of the electrophotographic photosensitive member 111 to form a toner image.
The recording paper 120 is conveyed to the lower part of the electrophotographic photosensitive member along a predetermined transfer conveyance path. At this time, the toner image can be transferred onto the recording material 120 by applying a predetermined transfer bias between the electrophotographic photoreceptor 111 and the transfer means 115.

Next, the recording paper 120 to which the toner image has been transferred is separated from the surface of the electrophotographic photosensitive member 111 by a separating means (not shown) and conveyed to a fixing device by a conveying belt. Next, the toner image is fixed on the surface by being heated and pressed by the fixing device, and then discharged to the outside of the image forming apparatus 100 by a discharge roller.
On the other hand, the electrophotographic photosensitive member 111 after the transfer of the toner image continues to rotate, and residual toner (adhered matter) that has not been transferred to the recording paper 120 at the time of transfer is transferred from the surface of the electrophotographic photosensitive member 111 to the cleaning device 117 of the present invention. Removed by.

In the present invention, the above-described electrophotographic photosensitive member 111 includes an electron including a photosensitive layer having a single layer structure including at least a charge generating agent, a hole transporting agent, an electron transporting agent, and a binder resin on a substrate. In the photographic photoreceptor, the photosensitive layer includes a perinone pigment represented by the above-described formulas (3) to (4) and the like, and includes an oxo titanyl phthalocyanine crystal as a charge generating agent.
Therefore, as described above, the electrophotographic photoreceptor 111 can exhibit excellent sensitivity to exposure.
Therefore, the image forming apparatus 100 according to the present invention can form a sufficient electrostatic latent image on the surface of the electrophotographic photosensitive member even when the electrophotographic photosensitive member 111 is rotated at a high speed. Formation is possible.

[Second Embodiment]
Further, in the second embodiment of the present invention, an electrophotographic photoreceptor having a single layer type photosensitive layer containing at least a charge generator, a hole transport agent, an electron transport agent, and a binder resin on a substrate is provided. A method comprising dispersing an oxo titanyl phthalocyanine crystal as a charge generator, a hole transport agent, an electron transport agent, and a perinone pigment in a binder resin solution containing a binder resin and an organic solvent. And a step of producing a photosensitive layer coating solution for forming a photosensitive layer, and a step of coating the photosensitive layer coating solution on a substrate and then drying to form a photosensitive layer. And an electrophotographic photosensitive member manufacturing method.
Hereinafter, the contents already described in the first embodiment will be omitted, and the second embodiment will be described focusing on differences from the first embodiment.

1. Coating liquid preparation process Binder resin, oxo titanyl phthalocyanine crystal as a charge generator, electron transport agent, hole transport agent, and perinone pigment are added to a solvent, for example, a roll mill, a ball mill, an attritor, It is preferable to disperse and mix using a paint shaker, an ultrasonic disperser or the like to obtain a coating solution.
More specifically, it is preferable to prepare a coating solution having a solid content concentration of 1 to 7% by weight. This is because when the solid content concentration of the coating liquid is less than 1% by weight, film defects may occur. On the other hand, when the solid content concentration of the coating liquid exceeds 7% by weight, layer unevenness occurs. This is because it tends to occur and it may be difficult to form a thin film having a uniform thickness as an electrophotographic photosensitive member.

Moreover, various organic solvents can be used as the solvent for preparing the coating liquid. For example, alcohols such as methanol, ethanol, isopropanol and butanol; aliphatic hydrocarbons such as n-hexane, octane and cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene, dichloromethane, dichloroethane, chloroform and tetrachloride Halogenated hydrocarbons such as carbon and chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dioxane and dioxolane; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and methyl acetate Class, dimethylformaldehyde, dimethylformamide, dimethylsulfoxide, etc., alone or in combination of two or more. That.
Furthermore, in order to improve the dispersibility of the electron transporting agent, the charge generating agent and the like and the smoothness on the surface of the photosensitive layer, it is also preferable to add a surfactant, a leveling agent or the like when preparing the coating solution.

2. Application Step In carrying out the application step, it is also preferable to apply the application liquid directly on the conductive substrate, or to apply it indirectly via a barrier layer.
As a coating method, it is preferable to use, for example, a spin coater, an applicator, a spray coater, a bar coater, a dip coater, a doctor blade or the like in order to form a photosensitive layer having a uniform thickness.

3. Drying process Moreover, it is preferable to dry at a drying temperature of, for example, 60 ° C. to 150 ° C. using a high-temperature dryer or a vacuum dryer in the drying step after the coating step. This is because when the drying temperature is less than 60 ° C., the drying time becomes excessively long, and it may be difficult to efficiently form a photosensitive layer having a uniform thickness. . On the other hand, if the drying temperature exceeds 150 ° C., the photosensitive layer may be thermally decomposed.

In the method for producing an electrophotographic photoreceptor described above, even when the photosensitive layer coating solution is stored for a long period of time, aggregation and precipitation of oxotitanyl phthalocyanine crystals as a charge generating agent in the photosensitive layer coating solution Etc. can be suppressed, and the dispersibility can be effectively maintained.
Therefore, since it becomes possible to manufacture the coating liquid for photosensitive layers in large quantities at once, simplification of a manufacturing process, reduction of manufacturing cost, etc. are realizable.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these description content.

[Example 1]
1. Production of Electrophotographic Photoreceptor 5 parts by weight of a Y-type oxotitanyl phthalocyanine crystal composed of an oxo titanyl phthalocyanine compound represented by formula (2), and a perinone pigment (perinone) insoluble in an organic solvent represented by formula (3) 3 parts by weight of particles having an average particle diameter of 109 nm composed of pigment-A), 45 parts by weight of a hole transporting agent (HTM-A) represented by formula (5), and an electron transporting agent represented by formula (14) (ETM-A) 30 parts by weight and Z-type polycarbonate (Resin-A) represented by formula (21) having a viscosity average molecular weight of 20,000 as a binder resin (TS2020 made by Teijin Chemicals Ltd.) 100 weight Were mixed and dispersed with 800 parts by weight of tetrahydrofuran using a ball mill for 50 hours to prepare a coating solution for a photosensitive layer.
Next, this photosensitive layer coating solution was applied by dip coating to an aluminum drum-shaped support substrate having a diameter of 30 mm and a total length of 254 mm as a substrate. Subsequently, it was dried with hot air at 100 ° C. for 40 minutes to prepare an electrophotographic photosensitive member having a single-layer type photosensitive layer having a film thickness of 25 μm.

2. Evaluation of Electrophotographic Photoreceptor (1) Precipitation Test Further, when preparing the above-described photosensitive layer coating solution, a sedimentation test of oxotitanyl phthalocyanine crystals as a charge generating agent was performed.
That is, 0.25 g of Y-type oxotitanyl phthalocyanine crystal, 0.15 g of perinone pigment, and 30 g of tetrahydrofuran were weighed into a sample bottle (manufactured by Nidec Rika Glass Co., Ltd., SV50A), and a tabletop ultrasonic cleaner (Branson Co., Ltd., A dispersion was obtained by dispersing for 1 hour using Bransonic 1200). Subsequently, in this dispersion liquid, the time (days) until both Y-type oxo titanyl phthalocyanine crystal and perinone pigment settle completely was measured. The obtained results are shown in Table 1.

(2) Sensitivity measurement Moreover, the sensitivity measurement of the obtained electrophotographic photoreceptor was measured under the following conditions.
That is, using a drum sensitivity tester (produced by GENTEC Co., Ltd.), the surface potential of the electrophotographic photosensitive member is charged to +850 V, and the wavelength of 660 nm is extracted from the white light of the halogen lamp using a bandpass filter. Monochromatic light (half-width 20 nm, light intensity 0.6 μJ / cm ² ) was irradiated to the electrophotographic photoreceptor surface for 50 msec. Next, the surface potential at the time when 0.35 seconds passed from the start of exposure was measured as sensitivity. Further, the measurement results were evaluated according to the following criteria. The obtained results are shown in Table 1.
○: The value of sensitivity is less than 250 (V).
(Triangle | delta): The value of a sensitivity is a value less than 250-300 (V).
X: The value of sensitivity is 300 (V) or more.

[Examples 2 to 5]
In Examples 2 to 5, as shown in Table 1, the types of hole transporting agents used in producing the electrophotographic photosensitive member are compounds represented by formulas (6) to (9) (HTM-B to An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except for changing to E). The obtained results are shown in Table 1.

[Example 6]
In Example 6, the type of particles made of perinone pigment used in the production of the electrophotographic photoreceptor was changed to the compound represented by formula (4) (perinone pigment-B), and the average particle size was also changed. The electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the thickness was 88 nm. The obtained results are shown in Table 1.

[Examples 7 to 8]
In Examples 7 to 8, as shown in Table 1, the types of hole transport agents used in producing the electrophotographic photosensitive member are compounds represented by formulas (6) to (7) (HTM-B to An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 6 except for changing to C). The obtained results are shown in Table 1.

[Examples 9 to 12]
In Examples 9 to 12, as shown in Table 1, the types of hole transporting agents used in producing the electrophotographic photosensitive member are compounds represented by formulas (10) to (13) (HTM-F to An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that it was changed to I). The obtained results are shown in Table 1.

[Comparative Example 1]
In Comparative Example 1, an electrophotographic photoreceptor was produced and evaluated in the same manner as in Example 1 except that no perinone pigment was added when producing the electrophotographic photoreceptor. The obtained results are shown in Table 1.

[Comparative Example 2]
Comparative Example 2 was the same as Comparative Example 1 except that the type of hole transporting agent used when producing the electrophotographic photosensitive member was changed to the compound (HTM-B) represented by formula (6). An electrophotographic photoreceptor was manufactured and evaluated. The obtained results are shown in Table 1.

According to the electrophotographic photosensitive member and the method for producing the same according to the present invention, in the single-layer type electrophotographic photosensitive member, a perinone pigment is contained, and an oxotitanyl phthalocyanine crystal is used as a charge generating agent, whereby high-sensitivity electrophotography is achieved. The photoreceptor can be easily manufactured.
Therefore, the electrophotographic photosensitive member of the present invention and the image forming apparatus using the same are expected to contribute to higher speed, higher image quality, and reduced manufacturing cost in the image forming apparatus.

(A)-(c) is a figure provided in order to demonstrate the structure of a single layer type electrophotographic photoreceptor. It is a figure provided in order to demonstrate the relationship between the average particle diameter of the particle | grains which consist of a perinone pigment, and the dispersibility of an oxo titanyl phthalocyanine crystal. It is a figure provided in order to demonstrate the relationship between the average particle diameter of the particle | grains which consist of a perinone pigment, and the sensitivity in an electrophotographic photoreceptor. It is a figure provided in order to demonstrate the relationship between the mobility of a hole transport agent, and the sensitivity in an electrophotographic photoreceptor. 1 is a diagram for explaining a schematic configuration of an image forming apparatus including an electrophotographic photosensitive member according to the present invention.

Explanation of symbols

10: Single layer type electrophotographic photosensitive member 10 ': Single layer type electrophotographic photosensitive member 10 ": Single layer type electrophotographic photosensitive member 12: Base 14: Photosensitive layer 16: Barrier layer 18: Protective layer 100: Image forming apparatus 111: Electrophotographic photosensitive member 112: Charging means 113: Exposure means 114: Development means 115: Transfer means 117: Cleaning device 120: Recording paper

Claims (8)

An electrophotographic photosensitive member provided with a photosensitive layer having a single layer structure including at least a charge generating agent, a hole transporting agent, an electron transporting agent, and a binder resin on a substrate,
The electrophotographic photoreceptor, wherein the photosensitive layer contains a perinone pigment and an oxo titanyl phthalocyanine crystal as the charge generating agent. The mobility of the hole transport agent is 5.0 × 10 ⁻⁶ to 5.0 × 10 ⁻⁴ cm ² / V / sec (concentration of 30% by weight, electric field strength of 3.0 × 10 ⁵ V / cm. 2. The electrophotographic photosensitive member according to claim 1, wherein the value is within the range of (1).   The amount of the perinone pigment added is set to a value in the range of 50 to 200 parts by weight with respect to 100 parts by weight of the oxotitanyl phthalocyanine crystal as the charge generating agent. Electrophotographic photoreceptor.   The electrophotographic photosensitive member according to any one of claims 1 to 3, wherein the perinone pigment is particulate, and the average particle diameter of the perinone pigment is set to a value in the range of 30 to 150 nm. .   The electrophotographic photosensitive member according to claim 1, wherein the perinone pigment is insoluble in an organic solvent. The oxo titanyl phthalocyanine crystal having the following characteristics (a) and (b) or any one of the characteristics is contained as the charge generating agent. Electrophotographic photoreceptor.
(A) In the differential scanning calorimetry, there is no peak in the range of 50 to 400 ° C. other than the peak due to vaporization of the adsorbed water. (B) In the differential scanning calorimetry, except for the peak due to vaporization of the adsorbed water. , Have no peak in the range of 50-200 ° C, but have one peak in the range of 200-400 ° C The electrophotographic photosensitive member according to any one of claims 1 to 6, wherein the charge generating agent contains an oxo titanyl phthalocyanine crystal having the following property (c).
(C) After immersing in an organic solvent for 24 hours, the CuKα characteristic X-ray diffraction spectrum has a maximum peak at least at Bragg angle 2θ ± 0.2 ° = 27.2 ° and a peak at 26.2 °. Not to do A method for producing an electrophotographic photosensitive member comprising a photosensitive layer having a single layer structure including at least a charge generating agent, a hole transporting agent, an electron transporting agent, and a binder resin on a substrate,
In the binder resin solution containing the binder resin and the organic solvent, oxo titanyl phthalocyanine crystal as the charge generating agent, the hole transport agent, the electron transport agent, and a perinone pigment are dispersed to form the photosensitive layer. A step of producing a photosensitive layer coating solution for forming;
Applying the photosensitive layer coating solution on the substrate and then drying to form the photosensitive layer; and
A process for producing an electrophotographic photosensitive member, comprising:

Images