JP2009288289A - Electrophotographic photoreceptor and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor capable of effectively suppressing changes in a bright potential even when the environment varies, by incorporating not only conductive inorganic particles but crystals of a phthalocyanine compound crystal into an intermediate layer, and to provide an image forming apparatus using the photoreceptor. <P>SOLUTION: The electrophotographic photoreceptor has an intermediate layer and a photosensitive layer on a substrate, and the image forming apparatus mounted with the photoreceptor. The intermediate layer contains a binder resin, conductive inorganic particles and crystals of a phthalocyanine compound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrophotographic photoreceptor and an image forming apparatus. In particular, the present invention relates to an electrophotographic photosensitive member capable of effectively suppressing a change in bright potential even when the environment changes, and an image forming apparatus using the same.

In general, organic photoreceptors are widely used in recent years for electrophotographic photoreceptors used in electrophotographic machines such as copiers and laser printers due to demands for low cost and low environmental pollution.
In such an organic photoreceptor, as a method for forming a photosensitive layer on a substrate, a method in which a photosensitive layer coating solution is applied to the substrate and then dried is employed.
However, when such a coating solution for photosensitive layer is applied, it tends to be difficult to form a photosensitive layer uniformly because it is easily affected by the surface of the substrate. As a result, various image defects and There was a problem that uneven density tends to occur.

In order to solve such problems, a method of providing an intermediate layer made of an alcohol-soluble polyamide resin between a substrate and a photosensitive layer is disclosed (for example, Patent Documents 1 and 2).
However, in the intermediate layer disclosed in Patent Documents 1 and 2, the resistance of the alcohol-soluble polyamide resin that is a constituent material of the intermediate layer changes greatly with changes in the environment such as temperature and humidity. There was a problem that the electrical characteristics were likely to change and become unstable as the environment changed.

Therefore, a method of incorporating titanium oxide as conductive inorganic particles into the intermediate layer has been disclosed in order to improve the environment dependency of the intermediate layer (for example, Patent Document 3).
JP 52-25638 (Claims) Japanese Patent Publication No. 63-018185 (Claims) JP-A-56-52757 (Claims)

  However, even when the method disclosed in Patent Document 3 is used, it is still difficult to sufficiently suppress the change in electrical characteristics accompanying the change in environment.

Therefore, as a result of intensive studies, the present inventors have determined that the light potential can be obtained even when the environment is changed by adding a crystal of a phthalocyanine compound in addition to the conductive inorganic particles to the intermediate layer. The present invention has been completed by finding that it is possible to effectively suppress these changes.
That is, an object of the present invention is to provide an electrophotographic photosensitive member and an image forming apparatus using the same that can effectively suppress a change in bright potential even when the environment changes.

According to the present invention, an electrophotographic photosensitive member having an intermediate layer and a photosensitive layer on a substrate, the intermediate layer comprising a binder resin, conductive inorganic particles, and crystals of a phthalocyanine compound. An electrophotographic photoreceptor characterized in that it is provided can solve the above-mentioned problems.
That is, since the crystal of the phthalocyanine compound itself has predetermined conductivity, the resistance of the intermediate layer can be finely adjusted efficiently.
Further, since the crystal of the phthalocyanine compound exhibits the action as a dispersion aid for the conductive inorganic particles, it effectively suppresses aggregation of the conductive inorganic particles and the crystal of the phthalocyanine compound in the intermediate layer, An intermediate layer having a uniform resistance can be obtained.
Therefore, these actions of the crystal of the phthalocyanine compound can effectively suppress the change in the bright potential even when the environment changes as shown in FIG.

In constituting the electrophotographic photosensitive member of the present invention, the content of the phthalocyanine compound crystal is preferably set to a value in the range of 1 to 100 parts by weight with respect to 100 parts by weight of the binder resin.
By comprising in this way, the balance of the effect | action which finely adjusts the resistance of an intermediate | middle layer and the effect | action as a dispersion | distribution adjuvant of electroconductive inorganic particle can be improved more.

In constituting the electrophotographic photoreceptor of the present invention, the number average particle diameter of the phthalocyanine compound crystal is preferably set to a value in the range of 5 to 500 nm.
By comprising in this way, the balance of the effect | action which finely adjusts the resistance of an intermediate | middle layer, and the effect | action as a dispersion | distribution adjuvant of electroconductive inorganic particle can be improved further.

In constituting the electrophotographic photosensitive member of the present invention, the phthalocyanine compound crystal is a titanyl phthalocyanine crystal having a main peak at a Bragg angle 2θ ± 0.2 ° = 27.2 ° in a Cukα characteristic X-ray diffraction spectrum. Preferably there is.
By comprising in this way, the electroconductivity and dispersibility in the crystal | crystallization of a phthalocyanine compound can be stabilized more.

In constituting the electrophotographic photosensitive member of the present invention, the titanyl phthalocyanine crystal may not have a peak in the range of 50 to 400 ° C. other than the peak due to vaporization of adsorbed water in the differential scanning calorimetry. preferable.
By comprising in this way, the electroconductivity and dispersibility in the crystal | crystallization of a phthalocyanine compound can be stabilized further.

In constituting the electrophotographic photosensitive member of the present invention, the specific resistance of the conductive inorganic particles is preferably a value within the range of 1 × 10 ⁵ to 1 × 10 ¹⁵ Ω · cm.
By comprising in this way, the intermediate | middle layer which has predetermined resistance more uniformly can be obtained with the effect | action as a dispersion | distribution adjuvant which the crystal | crystallization of a phthalocyanine compound has.
Therefore, even if the environment changes, the change in the bright potential can be more effectively suppressed.

In constituting the electrophotographic photosensitive member of the present invention, the content of the conductive inorganic particles is preferably set to a value within the range of 50 to 500 parts by weight with respect to 100 parts by weight of the binder resin.
With this configuration, even when the environment changes, the change in the bright potential can be more effectively suppressed.

In constituting the electrophotographic photosensitive member of the present invention, the number average particle diameter of the conductive inorganic particles is preferably set to a value within the range of 0.5 to 100 nm.
With this configuration, even when the environment changes, the change in the bright potential can be more effectively suppressed.

In constituting the electrophotographic photosensitive member of the present invention, the conductive inorganic particles are preferably titanium oxide particles.
With this configuration, even when the environment changes, the change in the bright potential can be more effectively suppressed.

In constituting the electrophotographic photosensitive member of the present invention, the conductive inorganic particles are preferably surface-treated with at least one compound selected from the group consisting of alumina, silica and organosilicon compounds.
By comprising in this way, the dispersibility and electroconductivity of electroconductive inorganic particle can be adjusted easily.

According to another aspect of the present invention, there is provided an image forming apparatus including any one of the above-described electrophotographic photosensitive members.
That is, since the electrophotographic photosensitive member having the predetermined intermediate layer is mounted, the change in the bright potential can be effectively suppressed even when the environment changes.
Therefore, even when the environment changes, a high quality image can be stably formed.

[First Embodiment]
The first embodiment of the present invention is an electrophotographic photoreceptor having an intermediate layer and a photosensitive layer on a substrate, the intermediate layer comprising a binder resin, conductive inorganic particles, and a phthalocyanine compound. An electrophotographic photosensitive member comprising: a crystal;
The electrophotographic photoreceptor as the first embodiment of the present invention will be specifically described below.

1. 2. Basic Configuration As shown in FIG. 2, the basic configuration of the electrophotographic photosensitive member according to the present invention is a single layer type in which an intermediate layer 16 is provided on a substrate 12, and a single layer type photosensitive layer 14 is provided thereon. As shown in FIG. 3, an electrophotographic photosensitive member or a laminated electrophotographic photosensitive member in which an intermediate layer 16 is provided on a substrate 12 and a laminated photosensitive layer 15 comprising a charge generation layer 24 and a charge transport layer 22 is provided thereon. It can be a body.
Further, as will be described later, the intermediate layer 16 is characterized by containing a binder resin, conductive inorganic particles, and crystals of a phthalocyanine compound.

2. Substrate As the substrate 12 illustrated in FIGS. 2 and 3, various materials having conductivity can be used. For example, metals such as iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, brass, and plastic materials on which the above-mentioned metals are deposited or laminated And glass coated with aluminum iodide, alumite, tin oxide, indium oxide, and the like.
Further, the shape of the substrate may be any of a sheet shape, a drum shape, or the like according to the structure of the image forming apparatus to be used. The substrate itself has conductivity, or the surface of the substrate has conductivity. If you do. Further, the substrate preferably has a sufficient mechanical strength when used.

3. Intermediate Layer In the present invention, as illustrated in FIGS. 2 and 3, an intermediate layer 16 including a binder resin, conductive inorganic particles, and a phthalocyanine compound is provided on a substrate 12. .

(1) Conductive inorganic particles The intermediate layer contains conductive inorganic particles.
This reason is because predetermined | prescribed electroconductivity can be provided to an intermediate | middle layer because an intermediate | middle layer contains an electroconductive inorganic particle.
As a result, accumulation of residual charges in the photosensitive layer can be suppressed, which can contribute to stabilization of the electrical characteristics of the electrophotographic photosensitive member when the environment changes.

In addition, as specific electroconductivity which electroconductive inorganic particle has, it is preferable that the specific resistance is a value within the range of 1 * 10 < ⁵ > -1 * 10 < ¹⁵ > (omega | ohm) * cm.
The reason for this is that by setting the specific resistance of the conductive inorganic particles in such a range, the intermediate layer having a predetermined resistance can be more uniformly combined with the action as a dispersion aid of the crystal of the phthalocyanine compound described later. This is because it can be obtained.
That is, when the specific resistance of the conductive inorganic particles is less than 1 × 10 ⁵ Ω · cm, it is difficult to obtain a predetermined resistance as the intermediate layer regardless of the interaction with the crystal of the phthalocyanine compound. Because there is. On the other hand, when the specific resistance of the conductive inorganic particles exceeds 1 × 10 ¹⁵ Ω · cm, it is possible to impart predetermined conductivity to the intermediate layer regardless of the interaction with the crystal of the phthalocyanine compound. This is because it may be difficult.
Therefore, the specific resistance of the conductive inorganic particles is more preferably in the range of 1 × 10 ⁷ to 1 × 10 ¹³ Ω · cm, and is preferably in the range of 1 × 10 ⁸ to 1 × 10 ¹¹ Ω · cm. More preferably, it is a value.
Such a specific resistance measurement method will be described in Examples.

(1) -1 Type In addition, the type of conductive inorganic particles is not particularly limited as long as it can be dispersed in the intermediate layer and can impart predetermined conductivity. For example, titanium oxide Particles, tin oxide, indium oxide, antimony oxide, and the like can be used.
Particularly preferable conductive inorganic particles include titanium oxide particles.
The reason for this is that if the particles are titanium oxide particles, the action of the phthalocyanine compound crystal, which will be described later, combined with the action as a dispersion aid, effectively suppresses the change in the light potential even when the environment changes. This is because it can be done.
That is, if it is a titanium oxide particle, since it is easy to adjust a specific resistance and a particle size to a predetermined range, a desired intermediate | middle layer can be obtained easily by using the crystal | crystallization of a phthalocyanine compound together. It is.

(1) -2 Surface treatment Moreover, it is preferable that the electroconductive inorganic particle is surface-treated with at least 1 type of compound selected from the group which consists of an alumina, a silica, and an organosilicon compound.
This is because the dispersibility and conductivity of the conductive inorganic particles can be easily adjusted when the conductive inorganic particles are surface-treated with these compounds.
That is, the basic dispersibility of the conductive inorganic particles in the intermediate layer can be improved by performing a surface treatment with alumina (Al ₂ O ₃ ) or silica (SiO ₂ ).
In addition, by performing surface treatment with an organosilicon compound, the water absorption of the conductive inorganic particles can be controlled and the dispersibility can be further improved, so that the dispersibility of the conductive inorganic particles and the electrical insulation can be improved. This is because it is possible to effectively adjust the balance between sex.
Examples of such organosilicon compounds include alkylsilane compounds, alkoxysilane compounds, vinyl group-containing silane compounds, mercapto group-containing silane compounds, amino group-containing silane compounds, or polysiloxane compounds that are condensation polymers thereof. More specifically, siloxane compounds such as methyl hydrogen polysiloxane and dimethyl polysiloxane are preferable, and methyl hydrogen polysiloxane is particularly preferable.
In addition, it is preferable to set it as the value within the range of 0.1-50 weight part in total as a processing amount of an alumina and a silica with respect to 100 weight part of electroconductive inorganic particles, The value is preferably in the range of 1 to 15 parts by weight with respect to 100 parts by weight of the conductive inorganic particles.

(1) -3 Number average particle diameter The number average particle diameter of the conductive inorganic particles (number average primary particle diameter, the same shall apply hereinafter) is preferably set to a value in the range of 0.5 to 100 nm.
The reason for this is that even if the environment changes in combination with the action as a dispersion aid possessed by the crystals of the phthalocyanine compound described later, by setting the number average particle diameter of the conductive inorganic particles in such a range. This is because the change in the bright potential can be more effectively suppressed.
That is, when the number average particle diameter of the conductive inorganic particles is less than 0.5 nm, the conductive inorganic particles are likely to be excessively aggregated, and it may be difficult to uniformly disperse. On the other hand, when the number average particle diameter of the conductive inorganic particles is a value exceeding 100 nm, even when the conductive inorganic particles are uniformly dispersed, the conductivity of the intermediate layer is likely to be uneven.
Therefore, the number average particle diameter of the conductive inorganic particles is more preferably set to a value within the range of 1 to 50 nm, and further preferably set to a value within the range of 5 to 30 nm.
The number average particle diameter of the conductive inorganic particles can be measured using, for example, a transmission electron microscope (TEM).

(1) -4 Content The content of the conductive inorganic particles is preferably set to a value in the range of 50 to 500 parts by weight with respect to 100 parts by weight of the binder resin of the intermediate layer.
This is because even if the environment changes due to the action of the phthalocyanine compound crystal, which will be described later, in combination with the action as a dispersion aid by setting the content of the conductive inorganic particles in such a range. This is because the potential change can be more effectively suppressed.
That is, when the content of the conductive inorganic particles is less than 50 parts by weight, the electrical insulation of the intermediate layer becomes excessively large, and it may be difficult to release residual charges in the photosensitive layer to the substrate side. Because. On the other hand, when the content of the conductive inorganic particles exceeds 500 parts by weight, the conductivity in the photosensitive layer becomes excessively large, and it may be difficult to stably obtain a bright potential.
Therefore, it is more preferable to set the content of the conductive inorganic particles to a value within the range of 100 to 400 parts by weight with respect to 100 parts by weight of the binder resin of the intermediate layer, and within the range of 200 to 300 parts by weight. More preferably, it is a value.

(2) Crystals of phthalocyanine compound The intermediate layer contains crystals of a phthalocyanine compound.
This is because the crystal of the phthalocyanine compound itself has a predetermined conductivity, so that the resistance of the intermediate layer can be finely adjusted efficiently.
In addition, since the crystals of the phthalocyanine compound have a function as a dispersion aid for the conductive inorganic particles, it is possible to effectively suppress the aggregation of the conductive inorganic particles and the crystals of the phthalocyanine compound in the intermediate layer. This is because an intermediate layer having excellent resistance can be obtained.
Therefore, these actions of the crystal of the phthalocyanine compound can effectively suppress the change in the light potential even when the environment changes.

(2) -1 Kind Moreover, it does not specifically limit as a crystal | crystallization of a phthalocyanine compound, For example, a titanyl phthalocyanine crystal, a metal-free phthalocyanine crystal, a hydroxygallium phthalocyanine crystal, a vanadyl phthalocyanine crystal, etc. can be used.
Particularly preferred phthalocyanine compound crystals include titanyl phthalocyanine crystals, and particularly titanyl phthalocyanine crystals having a main peak at a Bragg angle of 2θ ± 0.2 ° = 27.2 ° in the Cukα characteristic X-ray diffraction spectrum. It is done.
This is because the conductivity and dispersibility of the titanyl phthalocyanine crystal having such optical characteristics can be further stabilized.
That is, since the titanyl phthalocyanine crystal having such optical characteristics has a specific crystal type, the conductivity and dispersibility of the titanyl phthalocyanine crystal can be stabilized due to the specific crystal type. Because.
As further optical characteristics, it is more preferable that there are no peaks at Bragg angles 2θ ± 0.2 ° = 7.4 ° and 26.2 °.
That is, these peaks are characteristically possessed by crystals that are not of a specific crystal type. More specifically, the peak at 7.4 ° is a characteristic peak of the α-type crystal, and the peak at 26.2 ° is a peak characteristic of the β-type crystal.

Moreover, it is preferable that a titanyl phthalocyanine crystal does not have a peak in the range of 50-400 degreeC except the peak accompanying vaporization of adsorbed water in a differential scanning calorimetry.
The reason for this is that the above-described titanyl phthalocyanine crystal has such thermal characteristics, so that its conductivity and dispersibility can be further stabilized.
By having such thermal characteristics, it is possible to specify characteristics of the crystal structure that cannot be specified from the optical characteristics described above (for example, the degree of mixed crystals is estimated), and titanyl having such thermal characteristics. This is because it has been found that phthalocyanine crystals have further excellent conductivity and dispersibility.

Further, as a thermal characteristic different from the thermal characteristic described above, the titanyl phthalocyanine crystal may have one peak in the range of 270 to 400 ° C. in the differential scanning calorimetry, in addition to the peak due to the vaporization of the adsorbed water. preferable.
This is because the titanyl phthalocyanine crystal can further improve dispersibility by having such thermal characteristics.
In addition, it is more preferable that one peak appearing in the range of 270 to 400 ° C. other than the peak accompanying vaporization of adsorbed water appears in the range of 290 to 400 ° C., and the range of 300 to 400 ° C. More preferably, it appears within.

(2) -2 Number average particle diameter Moreover, it is preferable to make the number average particle diameter of the crystal | crystallization of a phthalocyanine compound into the value within the range of 5-500 nm.
The reason for this is that the balance between the effect of finely adjusting the resistance of the intermediate layer and the effect as a dispersion aid for the conductive inorganic particles by further adjusting the number average particle diameter of the crystals of the phthalocyanine compound to such a range, This is because it can be improved.
That is, when the number average particle diameter of the phthalocyanine compound crystal is less than 5 to 500 nm, it becomes difficult to maintain dispersibility and crystal stability, and the stability of the bright potential with respect to environmental fluctuations tends to decrease. This is because there are cases.
Therefore, the number average particle diameter of the phthalocyanine compound crystal is more preferably set to a value within the range of 7 to 100 nm, and further preferably set to a value within the range of 10 to 50 nm.
In addition, the number average particle diameter of a phthalocyanine compound can be measured using a transmission electron microscope (TEM), for example.

(2) -3 Content In addition, the content of crystals of the phthalocyanine compound is preferably set to a value in the range of 1 to 100 parts by weight with respect to 100 parts by weight of the binder resin of the intermediate layer.
The reason for this is that the balance between the effect of finely adjusting the resistance of the intermediate layer and the effect as a dispersion aid for the conductive inorganic particles is further improved by setting the crystal content of the phthalocyanine compound in such a range. Because it can.
That is, when the content of crystals of the phthalocyanine compound is less than 1 part by weight, the absolute amount is excessively small, so that it is difficult to finely adjust the resistance of the intermediate layer, and the dispersion aid for the conductive inorganic particles This is because it may be difficult to sufficiently exhibit the above-described effects. On the other hand, when the content of the phthalocyanine compound crystal exceeds 100 parts by weight, the phthalocyanine compound crystal itself may inhibit the dispersibility of the conductive inorganic particles.
Therefore, it is more preferable to set the content of the phthalocyanine compound crystal to a value within the range of 3 to 50 parts by weight with respect to 100 parts by weight of the binder resin of the intermediate layer, and within a range of 5 to 30 parts by weight. More preferably, it is a value.
The phthalocyanine crystal content is set to a value within the range of 3 to 50 parts by weight with respect to 100 parts by weight of the conductive inorganic particles in order to more effectively exert the action as a dispersion aid for the conductive inorganic particles. It is preferable to set the value within a range of 5 to 30 parts by weight.

Next, the relationship between the content of crystals of the phthalocyanine compound and the like and the change range of the bright potential when the environment changes will be described with reference to FIG.
That is, in FIG. 1, the horizontal axis represents the content of phthalocyanine compound crystals (parts by weight) with respect to 100 parts by weight of the binder resin of the intermediate layer, and the vertical axis represents a low temperature and low humidity environment (temperature 10 ° C., humidity 20% RH). ) And in a high temperature and high humidity environment (temperature 35 ° C., humidity 85% RH), a characteristic curve taking a change width (V) of the bright potential is shown.
In addition, 200 parts by weight of titanium oxide particles as conductive inorganic particles was contained with respect to 100 parts by weight of the binder resin of the intermediate layer. In addition, specific configurations of other electrophotographic photosensitive members, methods for measuring a bright potential, and the like will be described in Examples.

As can be understood from the characteristic curve, as the content of the titanyl phthalocyanine crystal increases, the value of the change range of the bright potential decreases.
More specifically, when the content of the titanyl phthalocyanine crystal is 0 part by weight, the value of the change range of the light potential, which is a value of less than 50 V, is 40 V when the content of the phthalocyanine crystal is 1 part by weight. It can be seen that the value rapidly decreases to a value less than. And if content of a titanyl phthalocyanine crystal | crystallization is the range of 10 weight part or more, it turns out that the value of the change width of a bright potential can be stably suppressed to the value of less than 30V. In this respect, it has been confirmed that even if the content of the titanyl phthalocyanine crystal is increased to 100 parts by weight, the variation range of the bright potential can be stably suppressed.
Therefore, from FIG. 1, even when the titanyl phthalocyanine crystal is contained within a very wide range of 1 to 100 parts by weight with respect to 100 parts by weight of the binder resin of the intermediate layer, the light potential is stably obtained. It can be understood that the change width of can be suppressed.

(3) Binder resin (3) -1 type As the binder resin, for example, from the group consisting of polyamide resin, polyvinyl alcohol resin, polyvinyl butyral resin, polyvinyl formal resin, vinyl acetate resin, phenoxy resin, polyester resin, acrylic resin. It is preferable to use at least one selected resin.

Here, in the case of using a polyamide resin, it has excellent solubility in a solvent, can disperse crystals of phthalocyanine compounds and conductive inorganic particles more effectively, and adheres to a substrate and a photosensitive layer. Therefore, it is preferable to use an alcohol-soluble polyamide resin.
Specific examples include what is called a copolymer nylon obtained by copolymerizing nylon 6, nylon 66, nylon 610, nylon 11, nylon 12, and the like, N-alkoxymethyl-modified nylon, N-alkoxyethyl nylon, and the like. It is preferable to use what is called modified nylon obtained by chemically modifying nylon.
Moreover, when using polyvinyl butyral resin and polyvinyl formal resin, what contains 50-75 mol% of vinyl acetal, 10-50 mol% of polyvinyl alcohol, and polyvinyl acetate 0-15 mol% in the structure is used. It is preferable.
The polyvinyl butyral resin is obtained by reacting butyraldehyde with a polyvinyl alcohol resin, and the polyvinyl formal resin can be obtained by reacting formaldehyde with a polyvinyl alcohol resin. It is a preferable resin because it is excellent in compatibility with a resin and has excellent reactivity and adhesion with a phenol resin.

(3) -2 Average molecular weight Moreover, it is preferable to make the average molecular weight (number average molecular weight, the same applies hereinafter) of the binder resin to a value in the range of 1,000 to 50,000.
The reason for this is that when the average molecular weight of the binder resin is less than 1,000, the viscosity of the coating liquid when forming the intermediate layer is remarkably lowered, making it difficult to obtain a uniform film thickness or mechanical strength. This is because the film formability or the adhesiveness may be significantly lowered. On the other hand, if the average molecular weight of the binder resin exceeds 50,000, the viscosity of the coating liquid when forming the intermediate layer is remarkably increased, making it difficult to control the thickness of the intermediate layer, and charge mobility. This is because there is a case in which the remarkably decreases.
Therefore, the average molecular weight of the binder resin is more preferably set to a value within the range of 2,000 to 30,000, and further preferably set to a value within the range of 5,000 to 15,000.
The average molecular weight of the binder resin can also be measured as a molecular weight in terms of polystyrene using gel permeation chromatography (GPC), or when the binder resin is a condensation resin, its degree of condensation. It can also be calculated by calculation.

(3) -3 Solution Viscosity In addition, it is preferable to set the solution viscosity of the binder resin (ethanol / toluene = 1/1 solvent in 5 wt% concentration) to a value in the range of 10 to 200 mPa · sec.
The reason for this is that when the solution viscosity of the binder resin is less than 10 mPa · sec, the film formability of the intermediate layer decreases and the film thickness difference increases, or the mechanical strength and adhesiveness of the intermediate layer significantly decrease. Further, this is because the dispersibility of the conductive inorganic particles may be lowered. On the other hand, if the solution viscosity of the binder resin exceeds 200 mPa · sec, it may be difficult to form an intermediate layer having a uniform thickness.
Therefore, it is more preferable that the solution viscosity of the binder resin (ethanol / toluene = 1/1 solvent in 5 wt% concentration) be a value within the range of 30 to 180 mPa · sec, and within the range of 50 to 150 mPa · sec. More preferably, the value of

(3) -4 Amount of hydroxyl group When the binder resin is a film-forming resin having a hydroxyl group, the amount of the hydroxyl group is preferably set to a value in the range of 10 to 40 mol%.
The reason for this is that when the amount of hydroxyl groups in the film-forming resin having hydroxyl groups is less than 10 mol%, the mechanical strength, film formability, or adhesiveness of the intermediate layer is significantly reduced, or the dispersibility of the conductive inorganic particles, etc. This is because there is a case where it also decreases. On the other hand, if the amount of hydroxyl groups in the film-forming resin having hydroxyl groups exceeds 40 mol%, gelation tends to occur or it may be difficult to form an intermediate layer having a uniform thickness.
Therefore, when a film-forming resin having a hydroxyl group is used as the binder resin, the amount of the hydroxyl group is more preferably set to a value in the range of 20 to 38 mol%, and a value in the range of 25 to 35 mol%. Is more preferable.

(4) Film thickness Moreover, since the concealability of the unevenness | corrugation in a support base material increases by making a film thickness thick, it is preferable in the direction which reduces a spot-like image quality defect, On the contrary, Electrical characteristics such as an increase in residual potential tend to decrease.
Accordingly, the thickness of the intermediate layer is preferably set to a value within the range of 0.1 to 50 μm, and more preferably set to a value within the range of 1 to 30 μm.

4). Photosensitive layer (1) Single layer type photosensitive layer The photosensitive layer in the present invention is preferably a single layer type photosensitive layer 14 as shown in FIG.
This is because the single layer type electrophotographic photoreceptor is advantageous in that it can be easily manufactured and film defects can be effectively suppressed.

(1) -1 Charge Generator In addition, examples of the charge generator in the present invention include phthalocyanine pigments such as metal-free phthalocyanine and oxotitanyl phthalocyanine, perylene pigments, bisazo pigments, diketopyrrolopyrrole pigments, and metal-free naphthalene. Phthalocyanine pigments, metal naphthalocyanine pigments, squaraine pigments, trisazo pigments, indigo pigments, azurenium pigments, cyanine pigments, pyrylium pigments, ansanthrone pigments, triphenylmethane pigments, selenium pigments, toluidine pigments, pyrazoline pigments, quinacridone pigments Conventionally known charge generators such as organic photoconductors such as pigments and inorganic photoconductive materials such as selenium, selenium-tellurium, selenium-arsenic, cadmium sulfide, and amorphous silicon can be used.
More specifically, it is more preferable to use phthalocyanine pigments (CGM-A to CGM-D) represented by the following formulas (1) to (4).
This is because a photoreceptor having sensitivity in a wavelength region of 600 to 800 nm or more is required when used in a digital optical image forming apparatus such as a laser beam printer or a facsimile provided with a semiconductor laser as a light source. It is.
On the other hand, when used in an analog optical image forming apparatus such as an electrostatic copying machine having a white light source such as a halogen lamp, a photosensitive member having sensitivity in the visible region is required. Perylene pigments and bisazo pigments can be preferably used.

Further, the amount of the charge generating agent added is preferably a value within the range of 0.1 to 50 parts by weight with respect to 100 parts by weight of the binder resin.
This is because the charge generating agent can efficiently generate charges when the photosensitive member is exposed by setting the amount of the charge generating agent within the above range. That is, when the amount of the charge generating agent added is less than 0.1 parts by weight with respect to 100 parts by weight of the binder resin, the amount of charge generated is insufficient to form an electrostatic latent image on the photoreceptor. This is because there is a case of becoming. On the other hand, when the added amount of the charge generating agent exceeds 50 parts by weight with respect to 100 parts by weight of the binder resin, it may be difficult to uniformly disperse in the coating solution for the photosensitive layer. It is.
Therefore, it is more preferable that the amount of the charge generator added relative to 100 parts by weight of the binder resin is a value within the range of 0.5 to 30 parts by weight.

(1) -2 Charge transfer agent In addition, as the charge transfer agent (hole transfer agent and electron transfer agent), an oxalate such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole is used. Pyrazoline derivatives such as diazole derivatives, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenyl Aromatic tertiary amino compounds such as amine, tri (p-methyl) phenylamine, N, N-bis (3,4-dimethylphenyl) biphenyl-4-amine, dibenzylaniline, N, N′-diphenyl- Aromatic tertiary diamino compounds such as N, N′-bis (3-methylphenyl)-[1,1-biphenyl] -4,4′-diamine, 3- (4′-dimethylamino) 1,2,4-triazine derivatives such as phenyl) -5,6-di- (4′-methoxyphenyl) -1,2,4-triazine, and hydrazone derivatives such as 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone Quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, benzofuran derivatives such as 6-hydroxy-2,3-di (p-methoxyphenyl) -benzofuran, p- (2,2-diphenylvinyl) -N, Hole transport materials such as α-stilbene derivatives such as N-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly-N-vinylcarbazole and derivatives thereof; quinone compounds such as chloranil, bromoanil and anthraquinone; Tetracyanoquinodimethane compounds, 2,4,7-trinitro Fluorenone compounds such as luolenone, 2,4,5,7-tetranitro-9-fluorenone, electron transport materials such as xanthone compounds, thiophene compounds, diphenoquinone compounds; and groups composed of the above compounds in the main chain or side chain A single polymer or a combination of two or more polymers can be used.

Moreover, it is preferable to make the addition amount of a charge transport agent into the value within the range of 1-120 weight part with respect to 100 weight part of binder resin.
The reason for this is that when the amount of the charge transport agent added is less than 1 part by weight, the charge transport ability of the photosensitive layer is extremely lowered, which may adversely affect image characteristics.
Further, when the added amount exceeds 120 parts by weight, there is a problem that dispersibility is lowered and crystallization is easily caused.
Therefore, the amount of the charge transport agent added is preferably set to a value in the range of 5 to 100 parts by weight, and a value in the range of 10 to 90 parts by weight with respect to 100 parts by weight of the binder resin. More preferred.

(1) -3 Additive In addition, for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, light, or heat generated in the electrophotographic apparatus, an antioxidant, a light stabilizer, It is preferable to add a heat stabilizer or the like.
For example, as the antioxidant, hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, organic phosphorus compounds, and the like are used. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine.

(1) -4 Binder Resin The type of binder resin used in the electrophotographic photosensitive member of the present invention is not particularly limited, and examples thereof include polycarbonate resins, polyester resins, polyarylate resins, and styrene-butadiene. Copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene, ethylene-vinyl acetate copolymer, chlorinated polyethylene, polyvinyl chloride, Polypropylene, ionomer, vinyl chloride-vinyl acetate copolymer, alkyd resin, polyamide, polyurethane, polysulfone, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin, etc., silicone resin, epoxy resin, phenol resin Urea resin, Ramin resin, other crosslinking thermosetting resins, epoxy acrylate, urethane - resin such as photocurable resin such as acrylate can be used.

(1) -5 Film thickness The film 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 of the photosensitive member may be insufficient. On the other hand, when the thickness of the photosensitive layer exceeds 100 μm, it may be easy to peel off from the intermediate layer or it may be difficult to form it 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.

(2) Multilayer Photosensitive Layer In constituting the electrophotographic photosensitive member of the present invention, it is also preferable that the photosensitive layer is a multilayer photosensitive layer 15 as shown in FIG.
In addition, when such a laminated type photosensitive layer is employed, there are advantages that options for photosensitive materials such as a charge generating agent and a charge transport agent are widened, and the degree of freedom in structural design can be improved.

In the laminated photosensitive layer 15, the thickness of the photosensitive layer (charge generation layer and charge transport layer) is not particularly limited, but the charge generation layer is preferably set to a value in the range of 0.01 to 5 μm. More preferably, the value is in the range of 0.1 to 3 μm. On the other hand, the charge transport layer is preferably set to a value in the range of 2 to 100 μm, and more preferably set to a value in the range of 5 to 50 μm.
In addition, the content of the charge generating agent is preferably a value within the range of 5 to 1000 parts by weight, and a value within the range of 30 to 500 parts by weight with respect to 100 parts by weight of the binder resin of the charge generation layer. More preferably.
The content of the charge transport agent is preferably a value in the range of 10 to 100 parts by weight with respect to 100 parts by weight of the binder resin of the charge transport layer, and a value in the range of 20 to 80 parts by weight. More preferably.

5. Production Method (1) Method for Producing Photoreceptor The method for producing an electrophotographic photoreceptor is not particularly limited, but an example of a method for producing a single-layer electrophotographic photoreceptor is described below.
First, an intermediate layer is formed on the substrate.
In forming this intermediate layer, a binder resin, conductive inorganic particles and phthalocyanine compound crystals are used together with an appropriate dispersion medium, and a known method such as a roll mill, a ball mill, an attritor, a paint shaker, an ultrasonic disperser or the like is used. The mixture is dispersed and mixed to prepare a coating solution, which is applied by a known means such as a blade method, a dipping method or a spray method, and subjected to heat treatment to form an intermediate layer.
In addition, various organic solvents can be used as a dispersion medium for preparing the dispersion, for example, alcohols such as methanol, ethanol, isopropanol, and butanol; aliphatic carbonization such as n-hexane, octane, and cyclohexane. Hydrogen: aromatic hydrocarbons such as benzene, toluene, xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride, chlorobenzene; dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, 1, 3 -Ethers such as dioxolane and 1,4-dioxane; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and methyl acetate; dimethylformaldehyde, Examples thereof include dimethylformamide and dimethyl sulfoxide. These solvents may be used alone or in admixture of two or more.

Next, a photosensitive layer is formed on the intermediate layer.
The photosensitive layer can be formed in the same manner as the intermediate layer except that a charge generating agent, a charge transporting agent, a binder resin, an additive, and the like are used as a solvent.

(2) Method for producing crystal of phthalocyanine compound The method for producing the crystal of phthalocyanine compound is not particularly limited, and a conventionally known method can be used.
Below, the manufacturing method of the titanyl phthalocyanine crystal | crystallization as a crystal | crystallization of a phthalocyanine compound is schematically described as an example.

(2) -1 Production of titanyl phthalocyanine compound The production method of titanyl phthalocyanine compound includes o-phthalonitrile or a derivative thereof, or 1,3-diiminoisoindoline or a derivative thereof, and a titanium alkoxide as a production material of such a molecule. Alternatively, it is preferable to produce a titanyl phthalocyanine compound by reacting with titanium tetrachloride.
At this time, it is also preferable to react these production materials in the presence of a urea compound.
Such urea compounds include urea, thiourea, O-methylisourea sulfate, O-methylisourea carbonate, and O-methylisourea hydrochloride.

Further, the addition amount of titanium alkoxide such as titanium tetrabutoxide or titanium tetrachloride is 0.40 to 0.000 per mol of o-phthalonitrile or a derivative thereof, or 1,3-diiminoisoindoline or a derivative thereof. A value within the range of 53 mol is preferred.
By setting such an addition amount, the final peak in the Cukα characteristic X-ray diffraction spectrum has a main peak at a Bragg angle 2θ ± 0.2 ° = 27.2 °, and in the differential scanning calorimetry, This is because a titanyl phthalocyanine crystal having no peak in the range of 50 to 400 ° C. can be efficiently obtained except for the peak accompanying vaporization.

When these production materials are reacted in the presence of a urea compound, the amount of the urea compound added is based on 1 mol of o-phthalonitrile or a derivative thereof, or 1,3-diiminoisoindoline or a derivative thereof. The value is preferably in the range of 0.1 to 0.95 mol.
By setting such an addition amount, the final peak in the Cukα characteristic X-ray diffraction spectrum has a main peak at a Bragg angle 2θ ± 0.2 ° = 27.2 °, and in the differential scanning calorimetry, This is because a titanyl phthalocyanine crystal having one peak in the range of 270 to 400 ° C. in addition to the peak accompanying vaporization can be efficiently obtained.

Examples of usable solvents include hydrocarbon solvents such as xylene, naphthalene, methylnaphthalene, tetralin, and nitrobenzene, halogenated hydrocarbon solvents such as dichlorobenzene, trichlorobenzene, dibromobenzene, and chloronaphthalene, Alcohol solvents such as hexanol, octanol, decanol, benzyl alcohol, ethylene glycol, and diethylene glycol; ketone solvents such as cyclohexanone, acetophenone, 1-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone; Examples thereof include one or two or more arbitrary combinations of the group consisting of amide solvents such as formamide and acetamide, and nitrogen-containing solvents such as picoline, quinoline, and isoquinoline.
The reaction temperature is preferably a value within the range of 180 to 250 ° C., and the reaction time is preferably within the range of 0.5 to 10 hours.

(2) -2 Production method of titanyl phthalocyanine crystal The obtained titanyl phthalocyanine compound is added to a water-soluble organic solvent, and is stirred for a certain time under heating, and then for a certain time under temperature conditions lower than the stirring treatment. It is preferable to carry out a pre-acid treatment step in which the solution is allowed to stand and be stabilized.
Examples of the water-soluble organic solvent used in the pre-acid treatment step include alcohols such as methanol, ethanol, and isopropanol, N, N-dimethylformamide, N, N-dimethylacetamide, propionic acid, acetic acid, N- 1 type, or 2 or more types, such as methyl pyrrolidone and ethylene glycol, are mentioned. Note that a water-insoluble organic solvent may be added to the water-soluble organic solvent in a small amount.

Moreover, although the conditions of a stirring process are not specifically limited among the processes before an acid treatment, It is preferable to perform the stirring process for about 1 to 3 hours on the fixed temperature conditions of about 70-200 degreeC temperature range.
Furthermore, the conditions for the stabilization treatment after the stirring treatment are not particularly limited, but are about 10 to 50 ° C., particularly preferably about 5 to 15 hours under a constant temperature condition of about 23 ± 1 ° C. It is preferable to stabilize by standing. Thus, a crude titanyl phthalocyanine crystal can be obtained by performing the pre-acid treatment step.

Subsequently, it is preferable to implement an acid treatment process as follows.
That is, after dissolving the titanyl phthalocyanine crystal obtained in the acid treatment pre-process described above in an acid, the solution is dropped into water and recrystallized, and then the obtained titanyl phthalocyanine crystal is washed with water. preferable. Specifically, the obtained crude crystals are dissolved in an acid, this solution is dropped into water under ice cooling, stirred for a certain period of time, and allowed to stand again at a temperature within the range of 10 to 30 ° C. Crystallization is preferred.
Next, in order to convert the crystal form into a predetermined crystal form, the obtained crystal is not dried and stirred in a non-aqueous solvent at 30 to 70 ° C. for 2 to 15 hours in the presence of water. It is preferable to obtain a final titanyl phthalocyanine crystal.

In addition, as an acid used for acid treatment, it is preferable to use concentrated sulfuric acid, trifluoroacetic acid, sulfonic acid, etc., for example.
Examples of the non-aqueous solvent for the stirring treatment include halogen solvents such as chlorobenzene and dichloromethane.

[Second Embodiment]
The second embodiment is an image forming apparatus including the electrophotographic photosensitive member as the first embodiment.
Hereinafter, the image forming apparatus as the second embodiment will be described focusing on the points different from the contents described in the first embodiment.

The basic configuration and operation of the image forming apparatus according to the present invention will be described with reference to FIG.
First, the photosensitive member 111 of the image forming apparatus 100 is rotated at a predetermined process speed (circumferential speed) in the direction indicated by the arrow A, and then the surface is charged to a predetermined potential (plus polarity) by the charging unit 112. In FIG. 4, a charging roll is used as the charging unit 112.
Next, the exposure unit 113 exposes the surface of the photoconductor 111 through a reflection mirror or the like while being optically modulated according to image information. By this exposure, an electrostatic latent image is formed on the surface of the photoreceptor 111.
Next, based on the electrostatic latent image, latent image development is performed by the developing unit 114. The developing means 114 contains toner, and the toner adheres corresponding to the electrostatic latent image on the surface of the photoconductor 111 to form a toner image.
Further, the recording paper 120 is conveyed to the lower part of the photoconductor along a predetermined transfer conveyance path. At this time, a toner image can be transferred onto the recording material 120 by applying a predetermined transfer bias between the photosensitive member 111 and the transfer unit 115.

Next, the recording paper 120 on which the toner image has been transferred is separated from the surface of the photoreceptor 111 by a separating unit (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 photoconductor 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 removed from the surface of the photoconductor 111 by the cleaning device 117. Further, the electric charge remaining on the surface of the photoconductor 111 is erased by the charge eliminating means 102 and used for the next image formation.

In the image forming apparatus according to the present invention, as described in the first embodiment, an electrophotographic photoreceptor containing conductive inorganic particles and crystals of a phthalocyanine compound is used in the intermediate layer.
Therefore, even if the environment changes, the change in the bright potential can be effectively suppressed.
Therefore, even when the environment changes, a high quality image can be stably formed.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these description content.
[Example 1]
1. Production of titanyl phthalocyanine crystal (1) Production of titanyl phthalocyanine compound In an argon-substituted flask, 25 g of o-phthalonitrile, 28 g of titanium tetrabutoxide, and 300 g of quinoline were added, and the temperature was raised to 150 ° C while stirring.
Next, after evaporating the vapor generated from the reaction system, the temperature was raised to 215 ° C. while distilling out of the system, and the mixture was further stirred for 2 hours while maintaining this temperature.
Then, after the reaction is completed, when the reaction mixture is cooled to 150 ° C., the reaction mixture is taken out from the flask, filtered through a glass filter, and the resulting solid is washed successively with N, N-dimethylformamide and methanol and then vacuum-dried. 24 g of a blue-violet solid was obtained.

(2) Pre-pigmentation treatment 10 g of the blue-violet solid obtained in the production of the above-mentioned titanyl phthalocyanine compound is added to 100 ml of N, N-dimethylformamide, heated to 130 ° C. with stirring, and stirred for 2 hours. Processed.
Next, the heating was stopped when 2 hours passed, and further the stirring was stopped when the temperature was cooled to 23 ± 1 ° C. In this state, the liquid was allowed to stand for 12 hours for stabilization treatment. The stabilized supernatant was filtered off with a glass filter, and the resulting solid was washed with methanol and then vacuum dried to obtain 9.83 g of a crude crystal of a titanyl phthalocyanine compound.

(3) Pigmentation treatment 5 g of crude crystals of the titanyl phthalocyanine compound obtained by the above-mentioned pigmentation pretreatment were added to 100 ml of 97% concentrated sulfuric acid and dissolved. This acid treatment was performed at 5 ° C. for 1 hour.
Next, this solution was dropped into 5 liters of pure water under ice cooling at 10 ml / min, stirred at room temperature for 15 minutes, and then allowed to stand at 23 ± 1 ° C. for 30 minutes. The solution was then filtered through a glass filter to obtain a wet cake.
Next, the obtained wet cake was washed with water until the washing liquid became neutral, and then dispersed in 200 ml of chlorobenzene in a state where water was present without being dried, followed by heating and stirring at 50 ° C. for 10 hours. .
The crystal obtained by filtering the supernatant with a glass filter is vacuum-dried at 50 ° C. for 5 hours to obtain 4.1 g of a titanyl phthalocyanine compound (CGM-B) crystal (blue powder) represented by the formula (2). Obtained.
Moreover, it was 35 nm when the number average particle diameter of this titanyl phthalocyanine crystal | crystallization was measured using the transmission electron microscope (TEM).

2. Evaluation of titanyl phthalocyanine crystal (1) Cukα characteristic X-ray diffraction spectrum The obtained titanyl phthalocyanine crystal was filled in a sample holder of an X-ray diffractometer (RINT1100 manufactured by Rigaku Corporation) and measured. The obtained spectrum chart is shown in FIG. Moreover, from such a spectrum chart, it can be confirmed that it has a main peak at a Bragg angle 2θ ± 0.2 ° = 27.2 ° and no peaks at 7.4 ° and 26.2 °. did it.
The same spectrum chart was obtained even when the obtained titanyl phthalocyanine crystal was immersed in 1,3-dioxolane or tetrahydrofuran for 7 days.
The measurement conditions were as follows.
X-ray tube: Cu
Tube voltage: 40 kV
Tube current: 30 mA
Start angle: 3.0 °
Stop angle: 40.0 °
Scanning speed: 10 ° / min

(2) Differential scanning calorimetry Further, differential scanning calorimetry of the obtained titanyl phthalocyanine crystal was performed using a differential scanning calorimeter (TAS-200 type, DSC8230D manufactured by Rigaku Corporation). The obtained differential scanning analysis chart is shown in FIG. Moreover, in this chart, it was confirmed that there was no peak in the range of 50 to 400 ° C. other than the peak near 90 ° C. accompanying vaporization of adsorbed water.
Moreover, even when the obtained titanyl phthalocyanine crystal was immersed in 1,3-dioxolane or tetrahydrofuran for 7 days, a similar differential scanning analysis chart was obtained.
The measurement conditions were as follows.
Sample pan: Aluminum heating rate: 20 ° C / min

3. Formation of an intermediate layer Using a paint shaker, titanium oxide particles (titanium oxide particles having a number average primary particle diameter of 10 nm and a specific resistance of 1.2 × 10 ⁸ Ω · cm, surface-treated with alumina, silica and methylhydrogenpolysiloxane) 200 parts by weight (manufactured by Teika Co., Ltd., MT-02)), 100 parts by weight of a quaternary copolymerized polyamide resin (manufactured by Toray Industries, Inc., CM8000), and 30 parts by weight of titanyl phthalocyanine crystals obtained as described above Then, 1000 parts by weight of methanol and 250 parts by weight of n-butanol were mixed and dispersed for 10 hours, and further filtered through a 5 micron filter to obtain an intermediate layer coating solution.
Next, an intermediate layer coating solution is applied by dipping the aluminum substrate (supporting substrate) having a diameter of 30 mm and a length of 238.5 mm at one end at a rate of 5 mm / sec with the one end of the aluminum substrate (supporting substrate) facing up. did. Then, the hardening process was performed on 130 degreeC and the conditions for 30 minutes, and the intermediate | middle layer with a film thickness of 2 micrometers was formed.
The specific resistance of the titanium oxide particles was measured as follows.
That is, using an ultra high resistance meter (ULTRA HIGH RESISTANCE METER) (manufactured by Advantest Co., Ltd., R8340A), 10 g of titanium oxide particles were compressed at a pressure of 58.8 MPa to form a cylindrical shape having a diameter of 25 mm. While applying a 1 kg load in the axial direction, a voltage of 10 V was applied between both ends of the cylinder, and the measurement was performed. The obtained results are shown in Table 1.

4). Formation of Photosensitive Layer Next, using a ball mill, 5 parts by weight of a metal-free phthalocyanine (CGM-A) crystal represented by the formula (1) and a compound (HTM-1) 60 represented by the following formula (5) Parts by weight, 30 parts by weight of a compound (ETM-1) represented by the following formula (6), 100 parts by weight of a polycarbonate resin (Resin-1) having a viscosity average molecular weight of 30000 represented by the formula (7), and tetrahydrofuran 800 parts by weight were mixed and dispersed for 50 hours to obtain a photosensitive layer coating solution.
Subsequently, the obtained photosensitive layer coating solution was applied on the above-described intermediate layer by a dip coating method. Next, the film was dried with hot air at 100 ° C. for 40 minutes to form a photosensitive layer having a thickness of 25 μm to obtain a single-layer electrophotographic photosensitive member.

5. Evaluation (1) Measurement of light potential The light potential of the obtained electrophotographic photosensitive member was measured.
That is, the obtained electrophotographic photosensitive member is mounted on a printer (FS-1050 modified machine manufactured by Kyocera Mita Co., Ltd.), and is printed on a black printing portion in a high temperature and high humidity environment (temperature 35 ° C., humidity 85% RH). The surface potential of the corresponding electrophotographic photosensitive member was measured to obtain a bright potential (V). The surface potential at the blank paper portion was set to 400 ± 10V.
Similarly, the light potential (V) was measured in a low-temperature and low-humidity environment (temperature 10 ° C., humidity 20%). The obtained results are shown in Table 1.

Also, by subtracting the value of the bright potential under the high temperature and high humidity environment from the value of the bright potential under the low temperature and low humidity environment, the value of the change width (V) of the bright potential due to the environmental change is calculated and evaluated according to the following criteria: did. The obtained results are shown in Table 1.
A: The change range of the bright potential is less than 25 V. O: The change range of the bright potential is less than 25-30 V. Δ: The change range of the bright potential is less than 30-45 V. X: The bright potential Is a value of 45V or more.

[Example 2]
In Example 2, the titanium oxide particles contained in the intermediate layer were surface-treated with siloxane, the number average primary particle diameter was 10 nm, and the specific resistance was 7.6 × 10 ⁸ Ω · cm (manufactured by Teika Co., Ltd.). The electrophotographic photosensitive member was manufactured and evaluated in the same manner as in Example 1 except that SMT-02) was changed. The obtained results are shown in Table 1.

[Example 3]
In Example 3, an electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the content of the titanyl phthalocyanine crystal in the intermediate layer was 10 parts by weight with respect to 100 parts by weight of the binder resin in the intermediate layer. ,evaluated. The obtained results are shown in Table 1.

[Example 4]
In Example 4, an electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the content of the titanyl phthalocyanine crystal in the intermediate layer was 50 parts by weight with respect to 100 parts by weight of the binder resin in the intermediate layer. ,evaluated. The obtained results are shown in Table 1.

[Example 5]
In Example 5, an electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the electron transport agent contained in the photosensitive layer was a compound (ETM-2) represented by the following formula (8). evaluated. The obtained results are shown in Table 1.

[Example 6]
In Example 6, while producing an electrophotographic photosensitive member in the same manner as in Example 2 except that the electron transport agent contained in the photosensitive layer was a compound (ETM-3) represented by the following formula (9), evaluated. The obtained results are shown in Table 1.

[Example 7]
In Example 7, an electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the electron transport agent contained in the photosensitive layer was a compound (ETM-4) represented by the following formula (10). evaluated. The obtained results are shown in Table 1.

[Comparative Example 1]
In Comparative Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 2 except that the phthalocyanine compound crystal was not included in the intermediate layer. The obtained results are shown in Table 1.

According to the electrophotographic photosensitive member of the present invention and the image forming apparatus using the same, when the environment is changed by adding phthalocyanine compound crystals to the intermediate layer in addition to the conductive inorganic particles. Even if it exists, it became possible to suppress the hostility of the effect of the bright potential.
Therefore, the electrophotographic photosensitive member of the present invention and the image forming apparatus using the same are expected to significantly contribute to improvement of electrical characteristics and stabilization of quality in various image forming apparatuses such as copying machines and printers.

FIG. 1 is a diagram provided to explain the relationship between the crystal content of a phthalocyanine compound and the variation range of the bright potential. FIG. 2 is a diagram for explaining the configuration of the single-layer electrophotographic photosensitive member of the present invention. FIG. 3 is a diagram for explaining the configuration of the multilayer electrophotographic photosensitive member of the present invention. FIG. 4 is a diagram for explaining the configuration of the image forming apparatus of the present invention. FIG. 5 is a Cukα characteristic X-ray spectrum of the titanyl phthalocyanine crystal in Example 1 and the like. FIG. 6 is a differential scanning calorimetry chart of titanyl phthalocyanine crystal in Example 1 and the like.

Explanation of symbols

10: Single layer type electrophotographic photosensitive member 12: Substrate 14: Single layer type photosensitive layer 16: Intermediate layer 20: Multilayer type electrophotographic photosensitive member 15: Multilayer type photosensitive layer 22: Charge transport layer 24: Charge generation layer 100: Image Forming apparatus 102: Static elimination means 111: Electrophotographic photosensitive member 112: Charging means 113: Exposure means 114: Developing means 115: Transfer means 117: Cleaning device 120: Recording paper

Claims (11)

An electrophotographic photosensitive member having an intermediate layer and a photosensitive layer on a substrate,
The electrophotographic photoreceptor, wherein the intermediate layer includes a binder resin, conductive inorganic particles, and crystals of a phthalocyanine compound. 2. The electrophotographic photosensitive member according to claim 1, wherein a content of the crystal of the phthalocyanine compound is set to a value within a range of 1 to 100 parts by weight with respect to 100 parts by weight of the binder resin.   3. The electrophotographic photosensitive member according to claim 1, wherein the number average particle diameter of the phthalocyanine compound crystal is set to a value within a range of 5 to 500 nm.   The crystal of the phthalocyanine compound is a titanyl phthalocyanine crystal having a main peak at a Bragg angle 2θ ± 0.2 ° = 27.2 ° in a Cukα characteristic X-ray diffraction spectrum. The electrophotographic photosensitive member according to claim 1.   5. The electrophotographic photosensitive member according to claim 4, wherein the titanyl phthalocyanine crystal does not have a peak in a range of 50 to 400 [deg.] C. other than a peak due to vaporization of adsorbed water in differential scanning calorimetry. . The electrophotographic photosensitive member according to claim 1, wherein a specific resistance of the conductive inorganic particles is a value within a range of 1 × 10 ⁵ to 1 × 10 ¹⁵ Ω · cm. .   7. The content of the conductive inorganic particles is set to a value within a range of 50 to 500 parts by weight with respect to 100 parts by weight of the binder resin. Electrophotographic photoreceptor.   The electrophotographic photosensitive member according to claim 1, wherein the number average particle diameter of the conductive inorganic particles is set to a value within a range of 0.5 to 100 nm.   The electrophotographic photosensitive member according to claim 1, wherein the conductive inorganic particles are titanium oxide particles.   The conductive inorganic particles are subjected to a surface treatment with at least one compound selected from the group consisting of alumina, silica, and an organic silicon compound. Electrophotographic photoreceptor.   An image forming apparatus comprising the electrophotographic photosensitive member according to claim 1.