JP2010210777A - Electrophotographic photoreceptor and image-forming device equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which has high sensitivity characteristics at a wavelength of 405±20 nm and also has stable characteristics even when it is repeatedly used, and also to provide an image-forming device having the photoreceptor. <P>SOLUTION: The electrophotographic photoreceptor uses a light source of a wavelength of 405±20 nm as an exposing means. The photoreceptor includes; a conductive base material; and a photosensitive layer which is composed at least of an electric charge-generating layer and an electric charge-conveying layer which are sequentially stacked on the base material. The electric charge-conveying layer contains a phenylenediamine compound represented by a general formula (I) as an electric charge-conveying substance, and the electric charge-generating layer contains a specific crystal-type oxotitanyl phthalocyanine as an electric charge-generating substance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member used for electrophotographic image formation and an image forming apparatus including the same.

  2. Description of the Related Art An electrophotographic image forming apparatus (hereinafter also referred to as “electrophotographic apparatus”) that forms an image using electrophotographic technology is widely used in copying machines, printers, facsimile apparatuses, and the like.

  In an electrophotographic apparatus, an image is formed through the following electrophotographic process. First, a photosensitive layer of an electrophotographic photosensitive member (hereinafter also referred to as “photosensitive member”) provided in the apparatus is uniformly charged to a predetermined potential by a charger, and then laser light emitted from an exposure unit according to image information. An electrostatic latent image is formed by light exposure. Next, a developer is supplied from the developing means to the formed electrostatic latent image, and the electrostatic latent image is developed by attaching colored fine particles called toner, which is a component of the developer, to the surface of the photoreceptor. And visualized as a toner image. Next, the formed toner image is transferred from the surface of the photosensitive member to a transfer material such as a recording sheet by a transfer unit and fixed by a fixing unit to form a desired image on the transfer material.

In the transfer operation by the transfer unit, not all the toner on the surface of the photoconductor is transferred to the recording paper and transferred, but a part of the toner remains on the surface of the photoconductor. Further, the paper dust of the recording paper that comes into contact with the photoconductor during transfer may remain attached to the surface of the photoconductor.
Such foreign matters such as residual toner and adhering paper dust on the surface of the photosensitive member adversely affect the quality of the formed image and are removed by the cleaning device. In recent years, cleaner-less technology has advanced, and residual toner is collected (removed) by a cleaning function (development and cleaning system) added to the developing unit without having an independent cleaning unit. After the surface of the photoreceptor is cleaned in this manner, the surface of the photosensitive layer is neutralized by a static eliminator or the like, and the electrostatic latent image disappears.

  A photoreceptor used in such an electrophotographic process is configured by laminating a photosensitive layer containing a photoconductive material on a conductive support made of a conductive material.

  As a photoreceptor, an electrophotographic photoreceptor (hereinafter, also referred to as “inorganic photoreceptor”) having a photosensitive layer mainly composed of an inorganic photoconductive material has been widely used. As a typical inorganic photoreceptor, a selenium photoreceptor using a layer made of amorphous selenium (a-Se) or amorphous selenium arsenide (a-AsSe) as a photosensitive layer; zinc oxide (ZnO) or sulfide A zinc oxide photoreceptor or cadmium sulfide photoreceptor using a cadmium (CdS) dispersed in a resin together with a sensitizer such as a dye as a photosensitive layer; and a layer made of amorphous silicon (a-Si) as a photosensitive layer For example, an amorphous silicon photoconductor (a-Si photoconductor).

However, inorganic photoreceptors have the following drawbacks.
Selenium photoreceptors and cadmium sulfide photoreceptors have problems with heat resistance and storage stability, and selenium and cadmium are toxic to the human body and the environment. It must be discarded.
Zinc oxide photoreceptors have the disadvantage of low sensitivity and durability and are rarely used today.

  The a-Si photoreceptor is attracting attention as a non-polluting inorganic photoreceptor and has the advantage of high sensitivity and durability, but is manufactured using the plasma chemical vapor deposition method, so that the photosensitive layer can be uniformly formed. It is difficult to form a film, image defects are likely to occur, productivity is low, and manufacturing costs are high.

  As described above, since the inorganic photoconductor has many drawbacks, a photoconductor using an organic photoconductive material, that is, an organic photoconductor (abbreviation: OPC) (hereinafter referred to as “organic photoconductor”). R & D) is also progressing and has become the mainstream of photoconductors.

  Organic photoreceptors have some problems in sensitivity, durability, and environmental stability, but have many advantages over inorganic photoreceptors in terms of toxicity, manufacturing cost, and freedom of material design. Have. For example, an organic photoreceptor can form a photosensitive layer by an easy and inexpensive method typified by a dip coating method.

  Such an organic photoconductor has a structure in which both a charge generation substance and a charge transport substance (also referred to as “charge transfer substance”) are bound on a conductive support made of a conductive material (“binder resin”). , Also referred to as “binder resin”), a charge generation layer in which a charge generation material is dispersed in a binder resin on a conductive support, and a charge in which a charge transport material is dispersed in the binder resin Various configurations such as a laminated structure in which the transport layers are formed in this order or in the reverse order or an inverted two-layer laminated structure have been proposed. Among these, the functionally separated type photoconductor, in which a charge transport layer is laminated on the charge generation layer as the photosensitive layer, is excellent in electrophotographic characteristics and durability, and various characteristics of the photoconductor can be designed with a high degree of freedom in material selection. It is widely used because it can be done.

A typical example of an electrophotographic apparatus that uses laser light as an exposure light source is a laser printer. However, in recent years, copying machines have been increasingly digitized and lasers are generally used as exposure light sources. It was.
Lasers that are mainly used as light sources for exposure are low-cost, low-consumption, light-weight and small-sized semiconductor lasers that have been put into practical use. Near-infrared region around 800 nm in terms of oscillation wavelength, output stability, and lifetime. Those having an oscillation wavelength are generally used. This is because a laser that oscillates at a short wavelength has not been put into practical use due to technical problems.

  As a result, charge generating materials used in electrophotographic apparatus using a laser as an exposure light source are organic compounds that absorb light in the long wavelength region and have sensitivity, in particular, phthalocyanine pigments in the charge generating layer, and triphenylamine. Compound (Japanese Patent Publication No. 58-32372: Patent Document 1, Japanese Patent Application Laid-Open No. 2-190862: Patent Document 2), Stilbene Compound (Japanese Patent Application Laid-Open No. 54-151955: Patent Document 3, Japanese Patent Application Laid-Open No. 58-198043) Publication: Patent Document 4), hydrazone compound (Japanese Patent Laid-Open No. 54-150128: Patent Document 5, Japanese Patent Publication No. 55-42380: Patent Document 6, Japanese Patent Laid-Open Publication No. 55-52063: Patent Document 7), phenylene Diamine compounds (JP-A-4-291266: Patent Document 8) and enamine compounds (JP-A-7-134430: Patent Document 9) Multilayer photoconductor containing the transport layer have been developed.

  In 1990, a method for manufacturing a blue light emitting diode was invented (Japanese Patent No. 2628404: Patent Document 10). Since then, related technologies of blue semiconductor lasers have been actively developed, and the next generation disk called Blu-ray Disc has been rapidly developed. It is becoming popular.

  On the other hand, in recent years, in order to improve the image quality of the output image of the electrophotographic apparatus, higher resolution of the image quality has been studied. One means for achieving high resolution image quality with high recording density is to reduce the spot diameter of the laser beam and increase the writing density. Therefore, it is sufficient to shorten the focal length of the lens to be used. In addition to the difficulty in designing the optical system, in the case of a laser having an oscillation wavelength in the near infrared region near 800 nm, the beam diameter is reduced by operating the optical system. However, it is difficult to obtain a clear spot outline. The cause is the diffraction limit of laser light, which is an unavoidable phenomenon.

In general, when the spot diameter of the laser focused on the surface of the photosensitive member is D, the spot diameter D, the wavelength of the laser beam, and the lens numerical aperture NA have a relationship represented by the following formula.
D = 1.22λ / NA
(Where λ is the wavelength of the laser beam and NA is the numerical aperture of the lens)
From this equation, it is suggested that the spot diameter D is proportional to the oscillation wavelength of the laser beam, and in order to reduce the spot diameter D, a laser having a short oscillation wavelength may be used.

That is, it can be seen that higher resolution can be realized by using a blue semiconductor laser having a shorter wavelength instead of the currently mainstream near infrared semiconductor laser.
However, such blue lasers have achieved great results in the sense that they improve the recording density of optical discs, but have not been expected as light sources for exposure in electrophotographic apparatuses. This is because the conventional electrophotographic photosensitive member does not show sensitivity in this wavelength region.

Conventional multilayer electrophotographic photoreceptors in which a charge generation layer and a charge transport layer are laminated in order on a conductive support are generally put into practical use, but charge generation that absorbs light even at wavelengths of 425 nm or less. If a substance is used, it should also be sensitive to exposure to short wavelength lasers, typically 425 nm or less.
In practice, however, the charge transport layer laminated on the charge generation layer, particularly the charge transport material, absorbs light at a wavelength of 425 nm, so that the short wavelength laser light used as the exposure light source is absorbed by the surface of the photosensitive layer. Therefore, the multilayer electrophotographic photosensitive member does not show sensitivity in this wavelength region because it cannot reach the charge generation layer.

Further, since exposure is performed with high-intensity light having a uniform wavelength component, the charge transporting material and the charge generation material are likely to be altered, and the sensitivity of the photoconductor is reduced by long-term use, and high image quality cannot be maintained. It was.
Although an electrophotographic photosensitive member corresponding to these problems has been developed (Japanese Patent No. 3937602 gazette: Patent Document 11), there has been no one that can achieve both film transmittance and high sensitivity. In addition, a charge transport material that does not absorb light at a wavelength of 425 nm or less has a problem that a charge is not smoothly injected from a charge generation material, and a photoconductor is greatly deteriorated in sensitivity during repeated use.

Patent Document 1: Japanese Patent Publication No. 58-32372 Patent Document 2: Japanese Patent Application Laid-Open No. 2-190862 Patent Document 3: Japanese Patent Application Laid-Open No. 54-151955 Patent Document 4: Japanese Patent Application Laid-Open No. 58-198043 Patent Document 5: Japanese Patent Application Laid-Open No. 54-150128 Patent Document 6: Japanese Patent Publication No. 55-42380 Patent Document 7: Japanese Patent Application Laid-Open No. 55-52063 Patent Document 8: Japanese Patent Application Laid-Open No. 4-291266 Patent Document 9: Japanese Patent Application Laid-Open No. 7-2008 Patent Publication No. 134430 Patent Publication 10: Patent No. 2628404 Publication Patent No. 11: Patent No. 3937602 Publication

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity characteristics at a wavelength of 405 ± 20 nm, excellent durability without fatigue deterioration due to light, and stable characteristics even during repeated use.
Still another object is to provide an electrophotographic apparatus having high sensitivity and high resolution by using this photoconductor and a semiconductor laser having an oscillation wavelength in the range of 405 ± 20 nm.

However, according to the present invention, in an electrophotographic photosensitive member in which a light source having a wavelength of 405 ± 20 nm is used as an exposure unit, the photosensitive member includes at least an electric charge generated by sequentially laminating a conductive support and the support. A photosensitive layer composed of a layer and a charge transport layer,
The charge transport layer has the following general formula (I) as a charge transport material:

(In the formula, Ar represents an aryl group which may have a substituent, and R ₁ , R ₂ and R ₃ each independently represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group. K represents an integer of 1 to 5 and l and m represent an integer of 1 to 4)
Containing a phenylenediamine compound represented by
And the charge generation layer exhibits a maximum diffraction peak at a Bragg angle (2θ ± 0.2 °) of 9.4 ° or 9.7 ° in the X-ray diffraction spectrum as a charge generation material, and at least 7.3 °, There is provided an electrophotographic photoreceptor characterized by containing a crystalline oxotitanyl phthalocyanine having diffraction peaks at 9.4 °, 9.7 ° and 27.3 °.

  According to the present invention, the above-described electrophotographic photosensitive member, a charging unit for charging the electrophotographic photosensitive member, and a light source having a wavelength of 405 ± 20 nm with respect to the charged electrophotographic photosensitive member are used as the exposure unit. An image forming apparatus comprising: a developing unit that develops an electrostatic latent image formed by exposure.

In an electrophotographic photosensitive member using an exposure light source having a wavelength range of 405 ± 20 nm, the electrophotographic photosensitive member includes a conductive support, and at least a charge generation layer and a charge transport layer sequentially stacked on the support. The photosensitive layer is composed of the present phenylenediamine compound represented by the general formula (I) as a charge transport material, and as a charge generation material, a Bragg angle (2θ ± 0.2 °) in an X-ray diffraction spectrum. A crystalline form of oxotitanyl phthalocyanine having a maximum diffraction peak at 9.4 ° or 9.7 ° and at least at 7.3 °, 9.4 °, 9.7 ° and 27.3 °. By containing it as a charge generating substance, an electrophotographic photosensitive member and an electrophotographic apparatus having high sensitivity, high resolution, and high stability can be provided.

FIG. 2 is a schematic cross-sectional view showing a configuration of one laminated type photoreceptor of the present invention. 1 is an X-ray diffraction spectrum diagram of an oxotitanyl phthalocyanine crystal that can be used in the present invention. FIG. 5 is a schematic cross-sectional view showing another laminated photoconductor configuration of the present invention. It is a spectrum transmission absorption spectrum of the charge generation layer using the oxo titanyl phthalocyanine crystal of the present invention. 1 is a schematic side view illustrating a configuration of an image forming apparatus of the present invention.

In the present invention, the aryl group in the definition of Ar in the general formula (I) means a phenyl group, a naphthyl group, or a biphenyl group, and the substituent that the aryl group may have is a C _{1 to} C ₄ substituent. An alkyl group or an alkoxy group; a halogen atom in the definition of R ₁ , R ₂ and R ₃ means a fluorine, chlorine, sulfur or iodine atom, an alkyl group in the definition of R ₁ , R ₂ and R ₃ or alkoxy group means an alkyl group or an alkoxy group of C ₁ -C _4.

The above C ₁ -C ₄ alkyl group means a methyl group, an ethyl group, an n-propyl group, an isopropyloxy group, an n-butyl group or a t-butyl group.
Also, an alkoxy group of C ₁ -C ₄ means a methoxy group, an ethoxy group, n- propyl group, an isopropyl group, n- butoxy or t- butoxy.

Specifically, in the present invention, Ar in the general formula (I) is 3-methylphenyl group, 4-methylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 3-ethyl Phenyl group, 4-ethylphenyl group, 3,4-diethylphenyl group, 3,5-diethylphenyl group, 3-methoxyphenyl group, 4-methoxyphenyl group, 3,4-dimethoxyphenyl group, 3,5-dimethoxy Phenyl group, 3-ethoxyphenyl group, 4-ethoxyphenyl group, 3,4-diethoxyphenyl group, 3,5-diethoxyphenyl group, 1-naphthyl group, 2-naphthyl group, 2′-methyl-4- Biphenylyl group, 4′-methyl-4-biphenylyl group or 2 ′, 4′-dimethyl-4-biphenylyl group, 2′-methyl-4-biphenylyl group, 4′-ethyl-4-biphenylyl group, 2 ', it means a 4'-diethyl-4-biphenylyl group;
R ₁ represents a hydrogen atom, 2′-, 3′-, 4′-, 5′- or 6′-methyl or ethyl group, and R ₂ represents a hydrogen atom, 2-, 3-, 5- or 6-methyl or ethyl group means R ₃ means a hydrogen atom, 2-, 4-, 5- or 6-methyl or ethyl group.

More specifically, in the present invention, Ar in the general formula (I) represents a 3-methylphenyl group, a 4-methylphenyl group, a 3,4-dimethylphenyl group, a 3,5-dimethylphenyl group, 4- Ethylphenyl group, 4-methoxyphenyl group, 1-naphthyl group, 2-naphthyl group, 2′-methyl-4-biphenylyl group, 4′-methyl-4-biphenylyl group or 2 ′, 4′-dimethyl-4- R ₁ represents a hydrogen atom or a 2′- or 4′-methyl group, R ₂ represents a hydrogen atom or a 2-methyl group, and R ₃ represents a hydrogen atom or 5-methyl group. Means group.

で表されるフェニレンジアミン化合物である。 More specifically, in the present invention, the compound of the general formula (I) is represented by the following formula:

It is the phenylenediamine compound represented by these.

  A general charge transport material realizes high charge mobility by expanding the electron cloud as much as possible. However, as the electron cloud spreads, the absorption wavelength of the charge transport material tends to shift to the longer wavelength side.

The phenylenediamine compound of the present invention has a sufficient charge mobility in practical use, although the spread of the electron cloud is suppressed to be relatively small.
That is, compared with the conventional charge transfer substance, the phenylenediamine compound of the present invention has a structure in which the balance between the absorbance and the mobility with respect to the exposure light source in the range of 405 ± 20 nm is very excellent. Therefore, by including the phenylenediamine compound as a charge transport material in the charge transport layer, the charge transport layer exhibits good transparency with respect to an exposure light source in the range of 405 ± 20 nm and has good electrical characteristics. Can show.

Therefore, according to the present invention, the charge transport layer containing the phenylenediamine compound of the present invention and the maximum diffraction at the Bragg angle (2θ ± 0.2 °) of 9.4 ° or 9.7 ° in the X-ray diffraction spectrum. By incorporating a crystalline form of oxotitanyl phthalocyanine, which exhibits a peak and a diffraction peak at least at 7.3 °, 9.4 °, 9.7 °, and 27.3 °, into the charge generation layer as a charge generation material. Even when used repeatedly, an electrophotographic photosensitive member with little deterioration in sensitivity and an image forming apparatus including the photosensitive member are provided.
This is considered because the charge generation material of the present invention efficiently generates charges by using a light source having a wavelength of 405 ± 20 nm as an exposure means, and smoothly injects the generated charges into the phenylenediamine compound. It is done.

  According to the invention, there is provided an image forming apparatus characterized in that the light source is a blue-violet semiconductor laser.

  Next, materials for electrophotographic photoreceptors that are generally used will be described. The photoreceptor material according to the present invention is not limited to the contents described below.

FIG. 1 is a schematic cross-sectional view showing a simplified configuration of an electrophotographic photoreceptor 1 which is an example of an electrophotographic photoreceptor according to the present invention.
In the electrophotographic photosensitive member 1, an intermediate layer 18 is provided on a sheet-like conductive support 11 made of a conductive material, and a charge generation layer 15 containing a charge generation material 12 thereon, a charge transport material 13 and A laminated type photoreceptor having a photosensitive layer 14 having a laminated structure in which a charge transporting layer 16 containing a binder resin 17 for binding the charge transporting substance 13 is laminated on the conductive support 11 in this order. is there.

Conductive support As the conductive material constituting the conductive support 11, for example, a metal material such as aluminum, aluminum alloy, copper, zinc, stainless steel, and titanium, and a metal foil laminate, metal vapor deposition treatment, or Examples thereof include polymer materials such as polyethylene terephthalate, nylon, and polystyrene on which a layer of a conductive compound such as a conductive polymer, tin oxide, and indium oxide is deposited or coated, hard paper, or glass. It is particularly preferable to use aluminum alloys such as JIS3003, JIS5000, and JIS6000. Examples of the shape of the conductive support 11 include a sheet shape, a drum shape, and an endless belt shape.

  If necessary, the surface of the conductive support 11 may be anodized film treatment, surface treatment with chemicals or hot water, coloring treatment, or roughening the surface within a range not affecting the image quality. You may perform an irregular reflection process. In an electrophotographic process using a laser as an exposure light source, the laser light has the same wavelength, so that the incident laser light and the light reflected in the electrophotographic photosensitive member interfere with each other, and interference fringes due to this interference appear on the image. It may appear and image defects may occur. By performing the above-described treatment on the surface of the conductive support 11, image defects due to the interference of laser light having the same wavelength can be prevented.

Intermediate Layer The laminated photoreceptor of the present invention preferably has an intermediate layer 18 between the conductive support 11 and the photosensitive layer 14.
The intermediate layer has a function of preventing charge injection from the conductive support to the laminated photosensitive layer. That is, a decrease in chargeability of the photosensitive layer is suppressed, a decrease in surface charge other than that which should be erased by exposure is suppressed, and image defects such as fog are prevented from occurring. In particular, during image formation by the reversal development process, it is possible to prevent the occurrence of image fogging called black spots in which minute black dots made of toner are formed on a white background portion.

In addition, the intermediate layer covering the surface of the conductive support with the intermediate layer reduces the degree of unevenness, which is a defect on the surface of the conductive support, and makes the surface uniform, thereby improving the film formability of the multilayer photosensitive layer. The adhesion between the conductive support and the photosensitive layer can be improved.
The intermediate layer 18 is prepared by, for example, preparing a coating solution for forming an intermediate layer by dissolving a resin material in a suitable solvent, applying the coating solution to the surface of the conductive support, and removing the organic solvent by drying. Can be formed.

  Examples of the resin material include natural polymeric materials such as casein, gelatin, polyvinyl alcohol, and ethyl cellulose in addition to the same binder resin as that contained in the multilayer photosensitive layer. Can be used. Among these resins, polyamide resins are preferable, and alcohol-soluble nylon resins are particularly preferable. Examples of alcohol-soluble nylon resins include 6-nylon, 6,6-nylon, 6,10-nylon, 11-nylon, 2-nylon and 12-nylon, which are so-called copolymer nylon, and N- Examples thereof include resins obtained by chemically modifying nylon such as alkoxymethyl-modified nylon and N-alkoxyethyl-modified nylon.

  Examples of the solvent for dissolving or dispersing the resin material include alcohols such as water, methanol, ethanol and butanol, glymes such as methyl carbitol and butyl carbitol, chlorinated solvents such as dichloroethane, chloroform and trichloroethane, acetone, Examples include dioxolane and mixed solvents in which two or more of these solvents are mixed. Among these solvents, non-halogen organic solvents are preferably used in consideration of the global environment.

  Examples of the method for applying the intermediate layer 18 include a spray method, a bar coating method, a roll coating method, a blade method, a ring method, and a dip coating method. Among these application methods, an optimum method can be selected in consideration of the physical properties and productivity of the application. In particular, the dip coating method is a method in which a layer is formed on the conductive support 11 by immersing the conductive support 11 in a coating tank filled with a coating solution and then pulling it up at a constant speed or a sequentially changing speed. Since it is relatively simple and excellent in terms of productivity and cost, it is widely used in the production of electrophotographic photosensitive members.

Moreover, the coating liquid for intermediate | middle layer formation may contain the metal oxide particle.
The metal oxide particles can easily adjust the volume resistance value of the intermediate layer, can further suppress the injection of charges into the laminated photosensitive layer, and can maintain the electrical characteristics of the photoreceptor in various environments.

  Examples of the metal oxide particles include titanium oxide, aluminum oxide, aluminum hydroxide, and tin oxide.

  The ratio (C / D) of the total weight C of the binder resin and metal oxide particles in the coating solution for forming an intermediate layer and the weight D of the solvent is preferably 1/99 to 40/60, and 2/98 to 30 /. 70 is particularly preferred.

  The ratio E / F between the weight E of the binder resin and the weight F of the metal oxide particles is preferably 90/10 to 1/99, particularly preferably 70/30 to 5/95.

  The film thickness of the intermediate layer is not particularly limited, but is preferably 0.01 to 20 μm, and particularly preferably 0.05 to 10 μm.

  When the film thickness of the intermediate layer exceeds 20 μm, it is difficult to form a uniform intermediate layer, and it is difficult to form a uniform single-layer type photosensitive layer on the intermediate layer, which may reduce the sensitivity of the photoreceptor. On the other hand, when the film thickness of the intermediate layer is less than 0.01 μm, it does not substantially function as the intermediate layer, and there is a possibility that a uniform surface cannot be obtained by covering defects of the conductive support. That is, it becomes impossible to prevent the injection of charges from the conductive support to the laminated photosensitive layer, resulting in a decrease in chargeability.

  In addition, when the constituent material of an electroconductive support body is aluminum, the layer (alumite layer) containing an alumite can be formed and it can be set as an intermediate | middle layer.

Charge Generation Layer The charge generation layer 15 has a maximum diffraction peak at a Bragg angle (2θ ± 0.2 °) of 9.4 ° or 9.7 ° in the X-ray diffraction spectrum as the charge generation material 12, and at least 7 It contains oxotitanyl phthalocyanine crystals showing clear diffraction peaks at .3 °, 9.4 °, 9.7 ° and 27.3 ° (see FIG. 2—the vertical axis represents absorption intensity and the horizontal axis represents diffraction angle).

  The photoconductor containing the specific crystal type oxo titanyl phthalocyanine can provide high-sensitivity and high-quality images even with exposure light having an oscillation wavelength at a wavelength of 405 ± 20 nm. In addition, since it is excellent in matching with the phenylenediamine compound which is the charge transport material of the present invention, it is excellent in potential stability against repeated use.

FIG. 4 shows the spectral transmission absorption spectrum of the specific oxotitanyl phthalocyanine (the vertical axis indicates the absorption efficiency and the horizontal axis indicates the wavelength).
The sensitivity of the photoconductor is largely dependent on the absorption efficiency as a charge generating material found in this absorption spectrum. It can be seen that the absorption efficiency at a wavelength of 405 ± 20 nm is not necessarily large compared to that in the existing near-infrared region (about 780 nm), and the chromatic dispersion in the wavelength region is also large.
However, since the stability of the laser as the excitation light source has been improved, the thermal drift of the oscillation wavelength of the laser has become very small recently and does not become a problem.

  In addition, when the specific oxotitanyl phthalocyanine is used at a wavelength of 405 ± 20 nm, the reason for showing good matching with the phenylenediamine compound of the present invention is unclear, but a charge generating material, particularly a titanyl phthalocyanine charge In the generated substance, the diffusion length of the generated excitons depends greatly on the crystal structure, that is, the packing state of the constituent molecules.

  Therefore, even with the same molecular structure, the packing state, packing imperfection, ie, the existence probability of lattice defects, and the anisotropy of the particle shape as a crystallite influence the diffusion length of excitons. That is, even in the same titanyl phthalocyanine, since the difference in the characteristics is exhibited, it is considered that the matching specifically improved with the phenylenediamine of the present invention.

  The charge generation material 12 includes triphenylmethane dyes represented by methyl violet, crystal violet, knight blue and Victoria blue, erythrosine, rhodamine B, rhodamine 3R, acridine dyes represented by acridine orange and frapeosin, methylene blue and the like. Can be used in combination with sensitizing dyes such as thiazine dyes typified by methylene green, oxazine dyes typified by capri blue and meldra blue, cyanine dyes, styryl dyes, pyrylium salt dyes or thiopyrylium salt dyes Good.

  As a method for forming the charge generation layer 15, a method in which the charge generation material 12 is vacuum-deposited on the conductive support 11, or a charge generation layer coating solution obtained by dispersing the charge generation material 12 in a solvent is made conductive. There is a method of coating on the support 11. Among these, the charge generating material 12 is dispersed by a conventionally known method in a binder resin solution obtained by mixing a binder resin as a binder in a solvent, and the obtained coating solution is dispersed in the conductive support 11. The method of applying on top is preferred. Hereinafter, this method will be described.

  Examples of the binder resin include polyester resin, polystyrene resin, polyurethane resin, phenol resin, alkyd resin, melamine resin, epoxy resin, silicone resin, acrylic resin, methacrylic resin, polycarbonate resin, polyarylate resin, phenoxy resin, polyvinyl butyral resin and One type selected from the group consisting of resins such as polyvinyl formal resins and copolymer resins containing two or more of the repeating units constituting these resins is used alone or in combination of two or more types. The Specific examples of the copolymer resin include insulating resins such as vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, and acrylonitrile-styrene copolymer resin. be able to. The binder resin is not limited to these, and a commonly used resin can be used as the binder resin.

  Solvents include, for example, halogenated hydrocarbons such as dichloromethane and dichloroethane, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, ethers such as tetrahydrofuran (THF) and dioxane, 1,2- Alkyl ethers of ethylene glycol such as dimethoxyethane, aromatic hydrocarbons such as benzene, toluene and xylene, or aprotic polar solvents such as N, N-dimethylformamide and N, N-dimethylacetamide are used. Moreover, the mixed solvent which mixed 2 or more types of these solvents can also be used. In consideration of the global environment, it is preferable to use a non-halogen solvent.

  The blending ratio of the charge generation material 12 and the binder resin is preferably such that the ratio of the charge generation material 12 is in the range of 10 wt% to 99 wt%. When the ratio of the charge generation material 12 is less than 10% by weight, the sensitivity is lowered. When the ratio of the charge generation material 12 exceeds 99% by weight, not only the film strength of the charge generation layer 15 is decreased, but also the dispersibility of the charge generation material 12 is decreased to increase coarse particles, which are erased by exposure. The surface charge other than the power portion is reduced, and image defects, in particular, the fogging of the image called black spots where toner adheres to a white background and minute black spots are formed increases. Therefore, 10% by weight to 99% by weight is preferable.

  Prior to dispersing the charge generation material 12 in the binder resin solution, the charge generation material 12 may be pulverized by a pulverizer in advance. Examples of the pulverizer used for the pulverization treatment include a ball mill, a sand mill, an attritor, a vibration mill, and an ultrasonic disperser.

  Examples of the disperser used when dispersing the charge generation material 12 in the binder resin solution include a paint shaker, a ball mill, and a sand mill. As a dispersion condition at this time, an appropriate condition is selected so that impurities are not mixed due to wear of a container and a member constituting the disperser.

  Examples of the coating method for the coating solution for the charge generation layer obtained by dispersing the charge generation material 12 in the binder resin solution include a spray method, a bar coating method, a roll coating method, a blade method, a ring method, and a dip coating method. be able to. Among these application methods, an optimum method can be selected in consideration of the physical properties and productivity of the application. In particular, the dip coating method is a method in which a layer is formed on the conductive support 11 by immersing the conductive support 11 in a coating tank filled with a coating solution and then pulling it up at a constant speed or a sequentially changing speed. Since it is relatively simple and excellent in terms of productivity and cost, it is widely used in the production of electrophotographic photosensitive members. In addition, in order to stabilize the dispersibility of a coating liquid, the apparatus used for a dip coating method may be provided with the coating liquid dispersion apparatus represented by the ultrasonic generator.

  The film thickness of the charge generation layer 15 is preferably 0.05 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 1 μm or less. When the film thickness of the charge generation layer 15 is less than 0.05 μm, the efficiency of light absorption is lowered and the sensitivity is lowered. If the film thickness of the charge generation layer 15 exceeds 5 μm, the charge transfer inside the charge generation layer becomes a rate-limiting step in the process of erasing the charge on the surface of the photoreceptor, and the sensitivity is lowered.

Charge Transport Layer The charge transport layer 16 is obtained by including in the binder resin 17 a charge transport material 13 having the ability to accept and transport charges generated by the charge generation material 12.
As the charge transport material 13, the general formula (I) of the present invention:

(In the formula, Ar represents an aryl group which may have a substituent, and R ₁ , R ₂ and R ₃ each independently represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group. K represents an integer of 1 to 5 and l and m represent an integer of 1 to 4)
The phenylenediamine compound shown by these is used.

（式中、Ａｒ、Ｒ₃およびｍは前記一般式（Ｉ）において定義したとおりである）
で表されるフェニレンジアミン化合物を、一般式（ＩＩＩ）： The phenylenediamine compound represented by the above general formula (I) can be produced, for example, as follows.
That is, the general formula (II)

(In the formula, Ar, R ₃ and m are as defined in the general formula (I)).
A phenylenediamine compound represented by general formula (III):

（式中、Ｒ₁、Ｒ₂、ｋおよびｌは、前記一般式（Ｉ）において定義したとおりであり、
Ｘはヨウ素または臭素を意味する）
で表されるハロゲン化ビフェニル化合物と；銅粉末、酸化銅、ハロゲン化銅等からなる銅化合物から選択される銅系触媒；および炭酸カリウム、炭酸ナトリウム、水酸化カリウム、水酸化ナトリウム等のアルカリ金属の炭酸塩または水酸化物から選択される塩基性化合物の存在下；無溶媒か、またはニトロベンゼン、ジクロロベンゼン、キノリン、Ｎ,Ｎ−ジメチルホルムアミドおよびＮ−メチル−２−ピロリドン等からなる群から選択される有機溶媒中、１５０〜２６０℃で５〜５０時間加熱攪拌する。

Wherein R ₁ , R ₂ , k and l are as defined in the general formula (I),
X means iodine or bromine)
A copper-based catalyst selected from copper compounds comprising copper powder, copper oxide, copper halide, and the like; and alkali metals such as potassium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide In the presence of a basic compound selected from carbonates or hydroxides of: no solvent or selected from the group consisting of nitrobenzene, dichlorobenzene, quinoline, N, N-dimethylformamide, N-methyl-2-pyrrolidone and the like In an organic solvent heated at 150 to 260 ° C. for 5 to 50 hours.

  The reaction mixture is cooled, the product is dissolved in an organic solvent such as methylene chloride or toluene, insoluble matter is separated, the solvent is distilled off, and the residue is purified by an alumina column or silica gel column chromatography. A phenylenediamine compound can be produced by recrystallization from ethanol, ethyl acetate or the like.

  The amount of the phenylenediamine compound, halogenated biphenyl compound, copper-based catalyst and basic compound used may be usually a stoichiometric amount according to a conventional method, but preferably 1 mol of the phenylenediamine compound. The halogenated biphenyl compound may be used in the range of 2 to 10 mol, the copper catalyst 0.1 to 2 mol, and the basic compound 1 to 3 mol.

Examples of the phenylenediamine compound represented by the general formula (I) in the present invention include the following compounds.

In addition, the phenylenediamine compound of the present invention and other various known charge transport materials may be mixed and used together as long as the amount is 20% by weight or less in the total amount of the charge transport material in the charge transport layer.
Examples of such other charge transport materials include carbazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, and styryl compounds. , Hydrazone compounds, polycyclic aromatic compounds, indole derivatives, pyrazoline derivatives, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, triarylamine derivatives, triarylmethane derivatives, phenylene Examples thereof include diamine derivatives, stilbene derivatives, and benzidine derivatives.

  Also included are polymers having groups derived from these compounds in the main chain or side chain, such as poly-N-vinylcarbazole, poly-1-vinylpyrene and poly-9-vinylanthracene.

As the binder resin 17 used for the charge transport layer 16, a resin having excellent compatibility with the charge transport material 13 is selected.
Specific examples include vinyl polymer resins such as polymethyl methacrylate resin, polystyrene resin, polyvinyl chloride resin, and copolymer resins thereof, as well as polycarbonate resin, polyester resin, polyester carbonate resin, polysulfone resin, phenoxy resin, epoxy Examples thereof include resins such as resins, silicone resins, polyarylate resins, polyamide resins, polyether resins, polyurethane resins, polyacrylamide resins, and phenol resins. Moreover, you may use the thermosetting resin which bridge | crosslinked these resin partially.

These resins may be used alone or in combination of two or more. Among the above-mentioned resins, polystyrene resin, polycarbonate resin, polyarylate resin or polyphenylene oxide has a volume resistance of 10 ¹³ Ω or more and excellent electrical insulation, and also has excellent film properties and potential characteristics. Therefore, it is particularly preferable to use these for the binder resin 17.

The ratio A / B between the charge transport material 13 (A) and the binder resin 17 (B) is 10/12 to 10/30.
When the ratio A / B is less than 10/30 and the ratio of the binder resin 17 is high, when the charge transport layer 16 is formed by the dip coating method, the viscosity of the coating liquid increases. Is significantly worse. Further, if the amount of the solvent in the coating solution is increased in order to suppress an increase in the viscosity of the coating solution, a brushing phenomenon occurs and white turbidity is generated in the formed charge transport layer 16.
Further, when the ratio A / B exceeds 10/12 and the ratio of the binder resin 17 becomes low, the printing durability becomes lower than when the ratio of the binder resin 17 is high, and the wear amount of the photosensitive layer increases.

In order to improve the film formability, flexibility and surface smoothness, an additive such as a plasticizer or a leveling agent may be added to the charge transport layer 16 as necessary.
Examples of the plasticizer include dibasic acid esters, fatty acid esters, phosphate esters, phthalate esters, chlorinated paraffins, and epoxy type plasticizers.
Examples of the leveling agent include a silicone leveling agent.

  The charge transport layer 16 may be added with fine particles of an inorganic compound or an organic compound in order to enhance mechanical strength and improve electrical characteristics.

The charge transport layer 16 is formed by, for example, dissolving or dispersing the charge transport material 13 and the binder resin 17 and, if necessary, the additive in a suitable solvent, as in the case of forming the charge generation layer 15. The charge transport layer coating solution is prepared, and this coating solution is applied onto the charge generation layer 15 by spraying, bar coating, roll coating, blade method, ring method or dip coating method. The
Among these coating methods, the dip coating method is particularly excellent in various respects as described above, and is often used when the charge transport layer 16 is formed.

  Solvents used in the coating solution include aromatic hydrocarbons such as benzene, toluene, xylene and monochlorobenzene, halogenated hydrocarbons such as dichloromethane and dichloroethane, ethers such as THF, dioxane and dimethoxymethyl ether, and N, N -1 type chosen from the group which consists of aprotic polar solvents, such as a dimethylformamide, is used individually or in mixture of 2 or more types. Further, a solvent such as alcohols, acetonitrile or methyl ethyl ketone can be further added to the above-described solvent as necessary. In view of the global environment, it is preferable to use a non-halogen organic solvent.

  The film thickness of the charge transport layer 16 is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 40 μm or less. When the film thickness of the charge transport layer 16 is less than 5 μm, the charge holding ability on the surface of the photoreceptor is lowered. When the film thickness of the charge transport layer 16 exceeds 50 μm, the resolution of the photoreceptor decreases.

  The photosensitive layer 14 may further contain one or more electron-accepting substances and dyes in order to improve sensitivity and suppress an increase in residual potential and fatigue during repeated use.

  Examples of the electron acceptor include acid anhydrides such as succinic anhydride, maleic anhydride, phthalic anhydride and 4-chloronaphthalic anhydride, cyano compounds such as tetracyanoethylene and terephthalmalondinitrile, and 4-nitrobenzaldehyde. Aldehydes, anthraquinones such as anthraquinone and 1-nitroanthraquinone, polycyclic or heterocyclic nitro compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitrofluorenone, and diphenoquinone compounds An electron-withdrawing material or a material obtained by polymerizing these electron-withdrawing materials can be used.

  As the dye, for example, an organic photoconductive compound such as xanthene dye, thiazine dye, triphenylmethane dye, quinoline pigment or copper phthalocyanine can be used. These organic photoconductive compounds function as optical sensitizers.

FIG. 3 is a schematic cross-sectional view showing a simplified configuration of an electrophotographic photoreceptor 2 which is still another example of the electrophotographic photoreceptor according to the present invention.
The electrophotographic photosensitive member 2 is similar to the electrophotographic photosensitive member 1 shown in FIG. 1, and corresponding portions are denoted by the same reference numerals and description thereof is omitted.

It should be noted that the electrophotographic photoreceptor 2 is provided with a surface protective layer 150 on the charge transport layer 16 that is the outermost layer of the electrophotographic photoreceptor 1.
As the binder resin used for the surface protective layer 150, resins such as polystyrene, polyacetal, polyethylene, polycarbonate, polyarylate, polysulfone, polypropylene, and polyvinyl chloride are effectively used. In consideration of wear characteristics and electrical characteristics, polycarbonate and polyarylate are preferable. These binders can be used alone or as a mixture of two or more.

In addition, a filler material may be added to the surface protective layer 150 of the photoreceptor for the purpose of improving wear resistance.
Examples of the organic filler material include fluororesin powder such as polytetrafluoroethylene, silicone resin powder, a-carbon powder, etc., and inorganic filler material includes metal powder such as copper, tin, aluminum, indium, Examples thereof include inorganic materials such as silica, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, tin oxide doped with antimony, metal oxide such as indium oxide doped with tin, and potassium titanate.

  In particular, it is advantageous to use an inorganic material among them from the viewpoint of the hardness of the filler. The average primary particle size of the filler is preferably 0.01 to 0.5 μm from the viewpoint of light transmittance and wear resistance of the surface protective layer. These fillers may be surface-treated with an inorganic material or an organic material for reasons such as improving dispersibility. In general, those treated with a silane coupling agent as a water-repellent treatment, those treated with a fluorinated silane coupling agent, or treated with a higher fatty acid. As the inorganic treatment, a filler surface treated with alumina, zirconia, tin oxide, or silica is known.

  The higher the filler material concentration in the surface protective layer is, the better the wear resistance is. However, if it is too high, the residual potential increases, the write light transmittance of the protective layer decreases, and side effects may occur. . Therefore, it is about 50% by weight or less, preferably about 30% by weight or less based on the total solid content. Further, the charge transport material 13 may be contained in the surface protective layer.

The thickness of the surface protective layer 150 is suitably about 0.1 to 10 μm. Furthermore, it is preferable that it is the range of 1.0-8.0 micrometers. A photoreceptor that is used repeatedly over a long period of time is mechanically durable and is not easily worn. However, in the actual machine, ozone, NOx gas, and the like are generated from the charging member and adhere to the surface of the photoreceptor. If these deposits are present, image flow occurs. In order to prevent this image flow, it is necessary to wear the photosensitive layer at a certain speed or higher. For that purpose, it is preferable that the surface protective layer has a thickness of at least 1.0 μm or more in consideration of long-term repeated use. Further, when the surface protective layer thickness is larger than 8.0 μm, it is considered that the residual potential is increased and the fine dot reproducibility is decreased.

  The image forming apparatus of the present invention includes a multilayer photoreceptor of the present invention, a charging means for charging the multilayer photoreceptor, an exposure means for exposing the charged multilayer photoreceptor to a blue laser diode, and exposure. And a developing means for developing the electrostatic latent image formed by the above.

  The image forming apparatus of the present invention and the operation thereof will be described with reference to the drawings, but are not limited to the following description.

  An image forming apparatus (laser printer) 100 shown in FIG. 5 includes a laminated photosensitive member 1 (see FIG. 1) of the present invention, an exposure means (semiconductor laser) 31, a charging means (corona charger) 32, and a developing means ( A developing unit 33, a transfer unit (transfer charger) 34, a conveyance belt (not shown), a fixing unit (fixing unit) 35, and a cleaning unit (cleaner) 36 are configured. Reference numeral 51 denotes a transfer sheet.

  The multilayer photoconductor 1 is rotatably supported by the main body of the image forming apparatus 100 (not shown) and is driven to rotate in the direction of the arrow 41 around the rotation axis 44 by a driving means (not shown). The driving means is configured to include, for example, an electric motor and a reduction gear, and transmits the driving force to the conductive support constituting the core of the multilayer photoconductor 1, thereby causing the multilayer photoconductor 1 to have a predetermined peripheral speed. To rotate.

The charger 32, the exposure means 31, the developing device 33, the transfer charger 34, and the cleaner 36 are rotated in this order along the outer peripheral surface of the multilayer photoconductor 1 by the arrow 41. It is provided from the direction upstream to the downstream.
The charger 32 is a charging unit that uniformly charges the outer peripheral surface of the multilayer photoreceptor 1 to a predetermined potential.

  The charging means in the image forming apparatus of the present invention is preferably positively charged from the viewpoint of reducing harmful ozone gas generation.

The exposure unit 31 includes a blue semiconductor laser as a light source, and is charged by irradiating the surface of the multilayer photoreceptor 1 between the charger 32 and the developer 33 with the light of the laser beam output from the light source. Further, exposure according to image information is performed on the outer peripheral surface of the single-layer type photoreceptor 1. Light is repeatedly scanned in the main scanning direction in the direction in which the rotation axis 44 of the multilayer photoconductor 1 extends, and these are imaged to sequentially form an electrostatic latent image on the surface of the multilayer photoconductor 1.
That is, the charge amount of the multilayer photoreceptor 1 uniformly charged by the charger 32 is different depending on whether the laser beam is irradiated or not, and an electrostatic latent image is formed.

  The developing device 33 is a developing unit that develops an electrostatic latent image formed on the surface of the multilayer photoreceptor 1 by exposure with a developer (toner), and is provided facing the multilayer photoreceptor 1. A developing roller 33a for supplying toner to the outer peripheral surface of the photoreceptor 1 and the developing roller 33a are rotatably supported around a rotation axis parallel to the rotation axis 44 of the single-layer type photoreceptor 1 and include toner in its internal space. A casing 33b for accommodating the developer.

  The transfer charger 34 transfers a toner image, which is a visible image formed on the outer peripheral surface of the multilayer photoreceptor 1 by development, from the direction of the arrow 42 by the conveying means (not shown), Transfer means for transferring the image onto transfer paper 51, which is a recording medium supplied during the period. The transfer charger 34 is, for example, a non-contact type transfer unit that includes a charging unit and transfers the toner image onto the transfer paper 51 by giving the transfer paper 51 a charge having a polarity opposite to that of the toner.

  The cleaner 36 is a cleaning unit that removes and collects toner remaining on the outer peripheral surface of the multilayer photoreceptor 1 after the transfer operation by the transfer charger 34, and is a cleaning unit that removes toner remaining on the outer peripheral surface of the multilayer photoreceptor 1. A blade 36a and a recovery casing 36b that stores toner separated by the cleaning blade 36a are provided. The cleaner 36 is provided together with a static elimination lamp (not shown).

  Further, the image forming apparatus 100 includes a fixing device 35 that is a fixing unit that fixes the transferred image to the downstream side where the transfer paper 51 that has passed between the multilayer photoreceptor 1 and the transfer charger 34 is conveyed. Is provided. The fixing device 35 includes a heating roller 35a having a heating unit (not shown), and a pressure roller 35b that is provided facing the heating roller 35a and is pressed by the heating roller 35a to form a contact portion.

Reference numeral 37 denotes a separating means for separating the transfer paper and the photosensitive member, and 38 denotes a housing (casing) that accommodates each means of the image forming method.
The image forming operation by the image forming apparatus 100 is performed as follows. First, when the multilayer photoconductor 1 is rotationally driven in the direction of the arrow 41 by the driving means, a charger 32 provided on the upstream side in the rotational direction of the multilayer photoconductor 1 with respect to the light imaging point by the exposure means 31. The surface of the single layer type photoreceptor 1 is uniformly charged to a predetermined positive potential.

  Next, light corresponding to image information is irradiated from the exposure unit 31 to the surface of the multilayer photoconductor 1. With this exposure, the surface charge of the portion irradiated with light is removed by this exposure, and a difference occurs between the surface potential of the portion irradiated with light and the surface potential of the portion not irradiated with light, An electrostatic latent image is formed.

  Toner is supplied to the surface of the multilayer photoconductor 1 on which the electrostatic latent image is formed from a developing device 33 provided on the downstream side in the rotation direction of the multilayer photoconductor 1 with respect to the light imaging point of the exposure means 31. The electrostatic latent image is developed to form a toner image.

  In synchronization with the exposure of the multilayer photoreceptor 1, the transfer paper 51 is supplied between the multilayer photoreceptor 1 and the transfer charger 34. The transfer charger 34 applies a charge having a polarity opposite to that of the toner to the supplied transfer paper 51, and the toner image formed on the surface of the multilayer photoreceptor 1 is transferred onto the transfer paper 51.

  The transfer paper 51 onto which the toner image has been transferred is conveyed to the fixing device 35 by the conveying means, and is heated and pressurized when passing through the contact portion between the heating roller 35a and the pressure roller 35b of the fixing device 35, and the toner The image is fixed on the transfer paper 51 and becomes a robust image. The transfer paper 51 on which the image is formed in this way is discharged to the outside of the image forming apparatus 100 by the conveying means.

  On the other hand, the toner remaining on the surface of the multilayer photoreceptor 1 after the transfer of the toner image by the transfer charger 34 is peeled off from the surface of the multilayer photoreceptor 1 by the cleaner 36 and collected. The charge on the surface of the multilayer photoreceptor 1 from which the toner has been removed in this manner is removed by the light from the static elimination lamp, and the electrostatic latent image on the surface of the multilayer photoreceptor 1 disappears. Thereafter, the multi-layer photosensitive member 1 is further rotated and a series of operations starting from charging is repeated to continuously form images.

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.
In addition, confirmation of the phenylenediamine compound prepared by the following manufacture examples measured the NMR spectrum with the following < ¹ > H-NMR measuring apparatus and measuring conditions.
Measuring instrument: MERCURY 300 type apparatus (manufactured by Varian, 300 MHz)
Measuring solvent: CDCl ₃
Sample concentration: about 4 mg sample / 0.4 m (CDCl ₃ )

で表される下記化合物（Ｂ）５.０ｇ（１.０当量）、以下の式：

で表される化合物（Ｃ）１１.７ｇ（２.１当量）、銅粉末２.２ｇ（２.０当量）、無水炭酸カリウム１９.１ｇ（８.０当量）を混合し、反応温度を１８０℃まで上げ、この温度を保つように加熱しながら１８時間撹拌および還流して反応させた。反応終了後、熱時セライト瀘過を行い、瀘液を濃縮し、残渣をシリカゲルカラムクロマトグラフィー（展開溶媒：トルエン／酢酸エチル＝１／１）で精製し、白色粉末化合物を得た。 Production Example 1
Production of Exemplary Compound 2 In 100 ml of o-dichlorobenzene, the following formula:

5.0 g (1.0 equivalent) of the following compound (B) represented by the following formula:

Compound (C) 11.7 g (2.1 equivalents), copper powder 2.2 g (2.0 equivalents), anhydrous potassium carbonate 19.1 g (8.0 equivalents) are mixed, and the reaction temperature is 180. The mixture was stirred and refluxed for 18 hours while heating to maintain this temperature. After completion of the reaction, hot Celite filtration was performed, the filtrate was concentrated, and the residue was purified by silica gel column chromatography (developing solvent: toluene / ethyl acetate = 1/1) to obtain a white powder compound.

で表されるフェニレンジアミン化合物であることを確認できた。 The obtained white powdery compound was subjected to ¹ H-NMR measurement and subjected to chemical structure analysis. As a result, the ¹ H-NMR spectrum has δ 2.31 (s, 6H), 6.68 (dd, J = 8.1 Hz, J = 2.4, 2H), 6.88 (t, J = 2). .1Hz, 1H), 7.00-7.13 (m, 13H), 7.27-7.32 (m, 2H), 7.34-7.44 (m, 8H), 7.47-7 .54 (m, 4H), and the structure of Exemplified Compound 2 has the following formula:

It has confirmed that it was a phenylenediamine compound represented by these.

で表される化合物（Ｅ）に変えた以外は、製造例１と同様の操作で目的物を得た。製造例１と同様にして化学構造分析も行った。
¹Ｈ−ＮＭＲスペクトルは、δ ２.２３ （ｓ, ６Ｈ), ２.３０ (ｓ, ６Ｈ), ６.６８ (ｄｄ, Ｊ＝８.１Ｈｚ、Ｊ＝２.１Ｈｚ、２Ｈ)、６.９２（ｔ、Ｊ＝２.４Ｈｚ、１Ｈ）、７.０３−７.３０（ｍ、２５Ｈ）を示し、例示化合物１３が、以下の式：

で表されるフェニレンジアミン化合物であることを確認できた。 Production Example 2
Production of Illustrative Compound 13 Compound (C) in Production Example 1 is represented by the following formula:

The target product was obtained in the same manner as in Production Example 1 except that the compound (E) was changed to Chemical structure analysis was also performed in the same manner as in Production Example 1.
^{The 1} H-NMR spectrum is δ 2.23 (s, 6H), 2.30 (s, 6H), 6.68 (dd, J = 8.1 Hz, J = 2.1 Hz, 2H), 6.92. (T, J = 2.4 Hz, 1H), 7.03-7.30 (m, 25H), and Exemplified Compound 13 has the following formula:

It has confirmed that it was a phenylenediamine compound represented by these.

で表される化合物（Ｆ）に変えた以外は、製造例２と同様の操作で生成物を得た。製造例１と同様の化学構造分析も行った。
¹Ｈ−ＮＭＲスペクトルは、δ ２.２７（ｓ、１２Ｈ）、６.８２(ｄｄ、Ｊ＝７.８Ｈｚ，Ｊ＝２.１Ｈｚ，２Ｈ)、７.０７（ｔ、Ｊ＝２.１Ｈｚ，１Ｈ）、７.１５−７.２６（ｍ、３３Ｈ）を示し、例示化合物２１が、以下の式：

で表されるフェニレンジアミン化合物であることを確認できた。 Production Example 3
Production of Illustrative Compound 21 Compound (B) in Production Example 1 is represented by the following formula:

A product was obtained in the same manner as in Production Example 2, except that the compound (F) was changed to The same chemical structure analysis as in Production Example 1 was also performed.
^{The 1} H-NMR spectrum has δ 2.27 (s, 12H), 6.82 (dd, J = 7.8 Hz, J = 2.1 Hz, 2H), 7.07 (t, J = 2.1 Hz, 1H), 7.15-7.26 (m, 33H), and Exemplified Compound 21 has the following formula:

It has confirmed that it was a phenylenediamine compound represented by these.

Example 1
3 parts by weight of titanium oxide (trade name: Taibake TTO-D-1, manufactured by Ishihara Sangyo Co., Ltd.) and 2 parts by weight of a commercially available polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) are added to 25 parts by weight of methyl alcohol. In addition, dispersion treatment was performed for 8 hours with a paint shaker to prepare 3 liters of an intermediate layer forming coating solution. The obtained intermediate layer coating solution was applied onto a PET film on which aluminum was deposited as a conductive support by an applicator coating method to form an intermediate layer having a thickness of 1 μm. Further, the intermediate layer coating solution obtained in the above is filled in a coating tank, and an aluminum drum-shaped support having a diameter of 30 mm and a length of 322 mm is immersed as a conductive support, and then lifted to form an intermediate layer having a thickness of 1 μm. Formed.

The charge generating material was then produced by the following method.
40 g of o-phthalodinitrile, 18 g of titanium tetrachloride, and 500 ml of α-chloronaphthalene were reacted by heating and stirring at 200 to 250 ° C. for 3 hours in a nitrogen atmosphere. Next, the mixture was allowed to cool to 100 to 130 ° C., filtered while hot, and washed with 200 ml of α-chloronaphthalene heated to 100 ° C. to obtain a crude dichlorotitanium phthalocyanine product (25 g).

  This crude product was washed with 200 ml of α-chloronaphthalene and then with 200 ml of methanol at room temperature, and then subjected to hot washing in 500 ml of methanol (suspension washing during heating) for 1 hour. After filtration, the obtained crude product was repeatedly subjected to hot washing in 500 ml of water until the pH reached 6-7. Then, it dried and the oxo titanyl phthalocyanine compound (24g) was obtained as an intermediate crystal. Further, this intermediate crystal was mixed with methyl ethyl ketone, milled with glass beads having a diameter of 2 mm by a paint conditioner device (manufactured by Red Level), washed with methanol, and dried to obtain crystals (20 g).

  The X-ray diffraction spectrum of the obtained crystal is shown in FIG. The obtained crystals have major diffraction peaks at Bragg angles (2θ ± 0.2 °) of 7.3 °, 9.4 °, 9.7 ° and 27.3 °, of which 9.4 ° and 9 ° It can be seen that it is a crystalline oxotitanyl phthalocyanine exhibiting a maximum diffraction peak in a peak bundle overlapped at 0.7 °.

  1.8 parts by weight of the oxotitanyl phthalocyanine crystal obtained here, 1.2 parts by weight of butyral resin (manufactured by Sekisui Chemical Co., Ltd .: ESREC BX-1), polydimethylsiloxane-silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd .: KF- 96) 0.06 parts by weight, 87.3 parts by weight of dimethoxyethane, and 9.7 parts by weight of cyclohexanone are mixed (mixing ratio = 90/10) and dispersed by a paint shaker to form a charge generation layer coating solution. 3 liters were adjusted. This coating solution was applied onto the aforementioned intermediate layer by the same applicator method and dip coating method as in the case of the intermediate layer, and then naturally dried to form a charge generation layer having a layer thickness of 0.3 μm.

  Next, 100 parts by weight of Exemplified Compound 2 in Table 1 as a charge transport material, 150 parts by weight of a polycarbonate resin (TS2050: manufactured by Teijin Chemicals), 0.02 part by weight of silicone oil SH200 (manufactured by Toray Dow Corning) are mixed, 3 liters of a coating solution for forming a charge transport layer having a solid content of 25% by weight was prepared using tetrahydrofuran as a solvent. This charge transport layer forming coating solution was applied to the surface of the charge generation layer previously provided by an applicator coating method and an immersion method, and dried at 120 ° C. for 1 hour to form a charge transport layer having a thickness of 25 μm. In this way, the multilayer photoreceptor shown in FIG. 1 was produced.

Example 2
A laminated photoreceptor was produced in the same manner as in Example 1 except that Example Compound 13 was used instead of Example Compound 2 in Example 1.

Example 3
A laminated photoreceptor was produced in the same manner as in Example 1 except that Example Compound 21 was used instead of Example Compound 2 in Example 1.

で表されるトリフェニルアミン系化合物（ＴＰＤ）（商品名：Ｄ２４４８、東京化成工業株式会社製）を用いたこと以外は実施例１と同様にして、図１の積層型感光体を作製した。 Comparative Example 1
In Example 1, instead of Exemplified Compound 2, the following formula:

1 was produced in the same manner as in Example 1 except that a triphenylamine compound (TPD) represented by the formula (trade name: D2448, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

で表されるエナミン系化合物（特許第３８８１６５１号公報記載の方法で合成した）を用いたこと以外は実施例１と同様にして、図１の積層型感光体を作製した。 Comparative Example 2
In Example 1, instead of Exemplified Compound 2, the following formula:

1 was produced in the same manner as in Example 1 except that an enamine compound represented by the formula (synthesized by the method described in Japanese Patent No. 3881651) was used.

で表されるトリフェニルアミン系化合物（商品名：Ｄ２５５８、東京化成工業株式会社製）を用いたこと以外は実施例１と同様にして、図１の積層型感光体を作製した。 Comparative Example 3
In Example 1, instead of Exemplified Compound 2, the following formula:

1 was produced in the same manner as in Example 1 except that the triphenylamine compound represented by the formula (trade name: D2558, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

Comparative Example 4
An oxo titanyl phthalocyanine having a strong peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° obtained from an X-ray diffraction spectrum of a crystal obtained according to the production example disclosed in JP-A-2000-105479 A photoconductor was prepared in the same manner as in Example 1 except that it was used as a charge generation material.

Comparative Example 5
The X-ray diffraction spectrum of the crystal obtained in accordance with the production example disclosed in JP-A No. 64-17066 has Bragg angles (2θ ± 0.2 °) of 9.5 °, 9.7 °, 11. A photoconductor was prepared in the same manner as in Example 1 except that oxotitanylphthalocyanine having strong peaks at 6 °, 14.9 °, 24.0 °, and 27.3 ° was used as the charge generating material.
Comparative Example 6
The X-ray diffraction spectrum of the crystal obtained according to the production example disclosed in JP-A-5-188614 has strong peaks at Bragg angles (2θ ± 0.2 °) of 9.6 ° and 27.3 °. A photoconductor was prepared in the same manner as in Example 1 except that the oxotitanyl phthalocyanine having was used as a charge generating material.

[Evaluation]
1. About each electrophotographic photosensitive member obtained by the applicator method of Examples 1 to 3 and Comparative Examples 1 to 6, using an electrostatic paper testing device (trade name: EPA-8200, manufactured by Kawaguchi Electric Co., Ltd.), the following: The electrical characteristics were evaluated as described above.

The photoreceptor was negatively charged so that the surface potential was 600 V, and 300 W of xenon lamp light was dispersed on the charged photoreceptor surface with an interference filter and adjusted to a wavelength of 400 nm and an intensity of 5 μW / cm ² with an ND filter. The exposure amount required to reduce the surface potential of the photoreceptor by light exposure was measured as a half exposure amount E1 / 2 [μJ / cm ² ]. In addition, the repetition characteristics were measured 5000 times after repeating the above charging and exposure operations for 1 cycle, and then measuring the half-exposure amount E1 / 2 [μJ / cm ² ] in the same manner as the initial characteristics.

2. The charge transport layer forming coating solution used in Examples and Comparative Examples was applied onto a polyethylene terephthalate (abbreviated as PET) film having a thickness of 100 μm by an applicator, dried with hot air at 120 ° C. for 60 minutes, and having a thickness of 20 μm. A charge transport layer was prepared. The light transmittance of this film at a wavelength of 405 nm was determined in units of% using a U-4000 type spectrophotometer (manufactured by Hitachi, Ltd.).

3. An exposure unit (LSU) of a digital copying machine (trade name: AR-266FP, manufactured by Sharp Corporation) with a resolution of 1200 dpi negative charging method is applied to the photoreceptors obtained by the immersion methods of Examples 1 to 3 and Comparative Examples 1 to 6. Was mounted on a test copying machine remodeled for a blue semiconductor laser (405 nm), and the resolution after initial and after passing 30,000 sheets of A4 plain paper was evaluated. Specifically, in the self-printing mode, a one-line image, a vertical and horizontal two-line image, a black solid one-line missing image, and a one-by-one dot (one dot is printed every other dot) image were evaluated.

The evaluation results are shown in Table 2.

  From Examples 1 to 3 and Comparative Examples 1 to 3, it can be seen that the electrophotographic photosensitive member using the phenylenediamine compound of the present invention as the charge transporting material has high transmittance of the charge transporting film and high sensitivity. Further, it has been found that by using the phenylenediamine compound of the present invention, an image forming apparatus can be realized that sufficiently utilizes the merit of the optical system due to the shortening of the wavelength of the exposure light source even in the case of higher resolution.

  It can be seen that the triphenylamine (TPD) compound and the enamine compound of Comparative Examples 1 and 2 have low transmittance, and sufficient light does not reach the charge generation layer, so that the sensitivity is poor. In addition, the triphenylamine (TPD) compound and enamine compound of Comparative Examples 1 and 2 absorbed light in the charge transport material and emitted light inside the charge transport layer, resulting in unclear images in image evaluation. Although the triphenylamine compound of Comparative Example 3 has excellent transmittance, it has a problem in the charge transport function, and therefore has very low sensitivity, and accordingly, the image density cannot be evaluated.

  Further, in Comparative Examples 4 to 6, when oxotitanyl phthalocyanine having a crystal type different from that of the present invention is used, the initial characteristics are good, but when the charge and exposure are repeated 5000 times, the sensitivity is greatly deteriorated and the image density is lowered. However, it shows that the level becomes a problem in actual use. This shows that the combination of phenylenediamine and oxotitanyl phthalocyanine of the present invention is useful for improving stability.

In an electrophotographic photoreceptor using an exposure light source having a wavelength range of 405 ± 20 nm, the electrophotographic photoreceptor is composed of a conductive support, and at least a charge generation layer and a charge transport layer sequentially stacked on the support. A photosensitive layer containing the phenylenediamine compound represented by the general formula (I) as a charge transport material, and a charge generation material having a Bragg angle (2θ ± 0.2 °) of 9 in the X-ray diffraction spectrum. Charge generation of crystalline oxotitanyl phthalocyanine showing maximum diffraction peak at .4 ° or 9.7 ° and diffraction peaks at least at 7.3 °, 9.4 °, 9.7 ° and 27.3 ° By containing as a substance, it is possible to provide an electrophotographic photosensitive member having high sensitivity, high resolution, and high stability, and an image forming apparatus including the photosensitive member.

1, 2 Electrophotographic photosensitive member 11 Conductive support 12 Charge generation material 13 Charge transport material (phenylenediamine compound)
14 Photosensitive layer 15 Charge generation layer 16 Charge transport layer 17 Binder resin 18 Intermediate layer 150 Surface protective layer 31 Exposure means (semiconductor laser)
32 Charging means (corona charger)
33 Developing means (developer)
33a Developing roller 33b Casing 34 Transfer means (transfer charger) 34
35 Fixing means (fixing device)
35a Heating roller 35b Pressure roller 36 Cleaning means (cleaner)
36a Cleaning blade 36b Recovery casing 37 Separating means 38 Housing (casing)
41, 42 Arrow 44 Rotation axis 51 Transfer paper 100 Image forming device (laser printer)

Claims (8)

In an electrophotographic photosensitive member in which a light source having a wavelength of 405 ± 20 nm is used as an exposure unit, the photosensitive member includes a conductive support, and at least a charge generation layer and a charge transport layer sequentially stacked on the support. Consisting of a photosensitive layer,
The charge transport layer has the following general formula (I) as a charge transport material:

(In the formula, Ar represents an aryl group which may have a substituent, and R ₁ , R ₂ and R ₃ each independently represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group. K represents an integer of 1 to 5 and l and m represent an integer of 1 to 4)
Containing a phenylenediamine compound represented by
And the charge generation layer exhibits a maximum diffraction peak at a Bragg angle (2θ ± 0.2 °) of 9.4 ° or 9.7 ° in the X-ray diffraction spectrum as a charge generation material, and at least 7.3 °, 1. An electrophotographic photoreceptor comprising a crystalline oxotitanyl phthalocyanine having diffraction peaks at 9.4 °, 9.7 ° and 27.3 °. In formula (I), the aryl group Ar is meant a phenyl group, a naphthyl group or a biphenyl group, a substituent the aryl group may have is, an alkyl group or an alkoxy group of C ₁ -C ₄ Yes; the halogen atom represented by R ₁ , R ₂ and R ₃ is a fluorine, chlorine, sulfur or iodine atom; the alkyl group or alkoxy group represented by R ₁ , R ₂ and R ₃ is C ₁ -C photoreceptor of claim 1 which is ₄ alkyl or alkoxy group. In the general formula (I), Ar is a 3-methylphenyl group, 4-methylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 3-ethylphenyl group, 4-ethylphenyl group. 3,4-diethylphenyl group, 3,5-diethylphenyl group, 3-methoxyphenyl group, 4-methoxyphenyl group, 3,4-dimethoxyphenyl group, 3,5-dimethoxyphenyl group, 3-ethoxyphenyl group 4-ethoxyphenyl group, 3,4-diethoxyphenyl group, 3,5-diethoxyphenyl group, 1-naphthyl group, 2-naphthyl group, 2′-methyl-4-biphenylyl group, 4′-methyl- 4-biphenylyl group or 2 ', 4'-dimethyl-4-biphenylyl group, 2'-methyl-4-biphenylyl group, 4'-ethyl-4-biphenylyl group or 2', 4'-diethyl- - be a biphenylyl group;
R ₁ is a hydrogen atom, 2′-, 3′-, 4′-, 5′- or 6′-methyl or ethyl group, and R ₂ is a hydrogen atom, 2-, 3-, 5- or 6-methyl. The photoconductor according to claim 1, wherein the photoconductor is an ethyl group and R ₃ is a hydrogen atom 2-, 4-, 5- or 6-methyl or an ethyl group. In the general formula (I), Ar is a 3-methylphenyl group, 4-methylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 4-ethylphenyl group, 4-methoxyphenyl group. 1-naphthyl group, 2-naphthyl group, 2′-methyl-4-biphenylyl group, 4′-methyl-4-biphenylyl group or 2 ′, 4′-dimethyl-4-biphenylyl group;
R ₁ is a hydrogen atom or a 2'- or 4'-methyl, R ₂ is a hydrogen atom or a methyl group, and any one of claims 1 to 3 R ₃ is 5-methyl group The photoreceptor described in 1. Said compound of general formula (I) is:

The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is a phenylenediamine represented by the formula:   6. The electrophotographic photosensitive member according to claim 1, further comprising an intermediate layer between the conductive support and the photosensitive layer.   An electrophotographic photosensitive member according to any one of claims 1 to 6, a charging means for charging the electrophotographic photosensitive member, and a light source having a wavelength of 405 ± 20 nm with respect to the charged electrophotographic photosensitive member. An image forming apparatus comprising: an exposure unit; and a developing unit that develops an electrostatic latent image formed by exposure.   The image forming apparatus according to claim 7, wherein the light source is a blue-violet semiconductor laser.

Images