JP2002091022A - Electrophotographic photoreceptor, process cartridge and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having high sensitivity to light of a light source for writing having an oscillation wavelength in the range of 400-450 nm and excellent in stability even with repeated use. SOLUTION: In the laminate type electrophotographic photoreceptor obtained by disposing a photosensitive layer including an electric charge generating layer and an electric charge transferring layer on an electrically conductive substrate, the electric charge transferring layer transmits monochromatic radiated light in the wavelength range of 390-460 nm and fluorescing efficiency by the monochromatic radiated light is <=0.8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photoreceptor,
More specifically, the present invention relates to a process cartridge and an electrophotographic apparatus using the same, and more particularly, to an electrophotographic photoreceptor having high sensitivity characteristics and excellent repetition stability even when a writing light source in a wavelength region of 400 to 450 nm is used. The present invention relates to a process cartridge and an electrophotographic apparatus.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductors and organic photoconductors are generally classified as photoconductors of photoconductors used in electrophotography. The "electrophotographic method" as used herein generally means that a photoconductive photoreceptor is first charged in a dark place, for example, by corona discharge, and then subjected to image exposure to selectively dissipate the charge of only the exposed portion and statically. A so-called Carlson process, in which an electrostatic latent image is obtained, and this latent image portion is developed with a toner composed of a colorant such as a dye or a pigment and a polymer material to visualize and form an image. This is an image forming process. Photoreceptors using organic photoconductors have advantages over inorganic photoconductors in the degree of freedom of the photosensitive wavelength range, film formability, flexibility, film transparency, mass productivity, toxicity and cost. At present, most photoconductors use an organic photoconductor. In addition, the photoreceptor that is used repeatedly in this electrophotographic method and similar processes must have excellent electrostatic characteristics such as sensitivity, receiving potential, potential holding property, potential stability, residual potential, and spectral sensitivity characteristics. Required. In recent years, the development of information processing system machines using this electrophotographic system has been remarkable. In particular, a printer using a digital recording method of converting information into a digital signal and recording information by light has remarkably improved in print quality and reliability. Also,
This digital recording method is applied not only to printers but also to ordinary copying machines, and so-called digital copying machines have been developed. Further, since the digital copier is added with various information processing functions, it is expected that the demand thereof will further increase in the future.

At present, electrophotographic photoreceptors used in these systems generally have a charge generation layer formed on a conductive support and a so-called function-separated type laminated photoreceptor provided with a charge transport layer thereon. Is the mainstream. Further, a surface protective layer is formed on the outermost surface of the photoreceptor for improving mechanical or chemical durability. In this function-separated type photoconductor, when the photoconductor whose surface is charged is exposed, light passes through the charge transport layer and is absorbed by the charge generation material in the charge generation layer. The charge generating material absorbs this light to generate charge carriers. The generated charge carriers are injected into the charge transport layer and move in the charge transport layer along the electric field generated by the charging to neutralize the surface charge of the photoreceptor. As a result, an electrostatic latent image is formed on the surface of the photoconductor. Accordingly, the charge-separation type photoreceptor mainly has a charge generation material that absorbs from the near-infrared part to the visible part and a visible part (yellow light region) that does not hinder the transmission of the absorbed light of the charge generation material.
In many cases, a combination with a charge transporting material having absorption in the ultraviolet region to ultraviolet region is used. Light sources compatible with such digital recording methods include, for example, small, inexpensive and highly reliable semiconductor lasers (LDs) and light emitting diodes (LEs).
D) is frequently used. At present, the most frequently used oscillation wavelength range of the LD is in the near-infrared light region around 780 to 800 nm. The emission wavelength of a typical LED is 74
At 0 nm.

On the other hand, recently, violet to blue short-wavelength LDs and LEDs having an oscillation wavelength of 400 to 450 nm have been developed and listed as writing light sources compatible with the digital recording method. For example, when a short-wavelength LD whose oscillation wavelength is about half that of a conventional near-infrared region LD is used as a writing light source, as shown in the following equation (1),
The spot diameter of the laser beam on the photoreceptor can theoretically be considerably reduced. Therefore, they are extremely advantageous for improving the writing density (resolution) of the latent image.

D∝ (π / 4) (λf / D) (1) (where d is the spot diameter on the photoconductor, λ is the wavelength of the laser beam, f is the focal length of the fθ lens, and D is the lens diameter. Is shown). In addition, the short wavelength LD and LED have advantages such as downsizing of an electrophotographic apparatus including an optical system and speeding up of an electrophotographic method.
There is a demand for a high-sensitivity, high-stable electrophotographic photosensitive member corresponding to a 0 nm LD or LED oscillation light source.

As described above, the mainstream of the electrophotographic photosensitive member is a function-separated type laminated photosensitive member. In the case of this layer configuration, since the charge transport layer is located above the charge generation layer, it is necessary to efficiently send short-wavelength LD and LED irradiation light, which are writing light, to the charge generation layer through the charge transport layer in order to achieve high sensitivity. There is. That is, it is important that the charge transport layer does not absorb such light.

[0006] A general charge transport layer is formed by dispersing a low molecular charge transport material in a binder resin in a molecular weight of about 10 to 30 µm.
m of a solid solution film. As the binder resin, a bisphenol-based polycarbonate resin or a copolymer thereof with another resin is used in most electrophotographic photoreceptors. Since this bisphenol-based polycarbonate resin has no spectral absorption in the wavelength range of 390 to 460 nm, it does not significantly hinder writing light transmission.

[0007] Further, as a charge transporting material which has been commercialized conventionally, there is known 1,1-bis (p-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene (Japanese Patent Application Laid-Open No. Sho 62-30255). ), 5- [4- (N, N-
Di-p-tolylamino) benzylidene] -5H-dibenzo [a, d] cycloheptene (JP-A-63-22566)
No. 0) and pyrene-1-aldehyde 1,1-diphenylhydrazone (JP-A-58-159536).
m, the short wavelength LD, LE
The D writing light is absorbed in the vicinity of the surface of the charge transport layer, cannot reach the charge generation layer, and does not exhibit sensitivity in principle.

Further, Japanese Patent Application Laid-Open No. 55-67778 discloses
Japanese Patent Application Laid-Open No. 9-190054 describes that when light in a wavelength range absorbed by the charge transport layer is used, in the case of repeated use, a decrease in chargeability and an increase in residual potential are described.
The light absorption of the charge transport material not only lowers the sensitivity but also has an adverse effect on repeated fatigue.

On the other hand, some charge transporting layers exhibit high sensitivity as a laminated photoreceptor although they hardly transmit short-wavelength writing light. This mechanism is disclosed in JP-A-5-61216, Japan Hardcop.
y'91, p165. That is, when the charge transporting material absorbs the writing irradiation light, the charge transporting material is raised to a photo-excited state, and emits fluorescence of longer wavelength light than the writing irradiation light to deactivate. The emitted fluorescence passes through the charge transport layer and excites the charge generation material to generate charges. However, in general, some of the fluorescence emitted by the charge transport material is dissipated from the surface to the outside, but most of it is confined in the photoconductor, and multiple reflections are repeated in the photosensitive layer until it is absorbed by the charge generation material. It is reported in the above-mentioned publicly known materials. The fluorescence is generated near the surface of the charge transport layer, and the light travels in all directions. As a result, the resolution of the latent image is reduced (bleeding of the image).

As described above, it is known that the light absorption of the charge transporting material adversely affects not only the sensitivity but also the repetitive fatigue and the resolution of the latent image. JP-A-12-1054
No. 71 discloses an electrophotographic photoreceptor for short-wavelength writing light using a charge transport layer having a transmittance of 30% or more. Although this is effective in increasing the sensitivity, in the case of an electron transport layer having a high fluorescence generation efficiency, the resolution of the latent image is reduced as described above. In addition, these charge transport materials have a problem in terms of repetition stability because of their large absorption of writing light. Japanese Patent Application Laid-Open No. 12-89492 discloses that a charge transport material having a quantum yield of luminescence of 0.1 or more is used, but this is also disadvantageous in terms of resolution.

An electrophotographic apparatus using an LD having an oscillation wavelength of 400 to 500 nm as a light source is disclosed in Japanese Patent Laid-Open No. 9-240051.
No. 6,086,045. However, the layer configuration of the electrophotographic photosensitive member used in this electrophotographic apparatus has a layer configuration opposite to that of the present invention in which a charge transport layer and a charge generation layer are sequentially laminated on a conductive support for the purpose of high resolution. ing. In the case of this photoreceptor layer configuration, a fragile and thin charge generation layer is formed on the outermost surface, which is susceptible to mechanical and chemical hazards due to charging, development, transfer, and cleaning means. It is not practical because the body deteriorates significantly. At the same time, an electrophotographic photoreceptor having a single-layer structure is also disclosed, but this has a problem that it is difficult to design a constituent material of the photoreceptor and realize a sensitivity as high as that of the function-separated type laminated photoreceptor.

Further, as described above, the speed, size, and image quality of electrophotographic printers, electrophotographic copiers, and the like using the electrophotographic system are currently being improved. And the use conditions in the electrophotographic process are becoming more and more severe. In particular, the abrasion of the photoconductor is promoted by the installation of a charging roller around the photoconductor and cleaning with a rubber blade, etc., causing potential fluctuations and sensitivity fluctuations. Inconveniences such as a problem occur. In addition, oxidative deterioration of the binder resin and charge transport material due to ozone generated during charging due to long-term use,
Deterioration of image quality due to accumulation of ionic compounds generated during charging, for example, nitrate ions, sulfate ions, ammonium ions, organic acid compounds, etc. on the surface of the photoreceptor causes a problem. For this reason, it is more important to further increase the durability of the photoreceptor and to improve the physical properties of its surface layer.

[0013]

SUMMARY OF THE INVENTION
An electrophotographic photosensitive member having high sensitivity to an LD or LED writing light source having an oscillation wavelength in a range of 50 nm and having excellent stability even when used repeatedly, and a process cartridge using the electrophotographic photosensitive member And an electrophotographic apparatus.

[0014]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, the following electrophotographic photosensitive member, process cartridge and electrophotographic apparatus are provided. (1) In a laminated electrophotographic photoreceptor in which a photosensitive layer including a charge generation layer and a charge transport layer is provided on a conductive support, the charge transport layer transmits monochromatic irradiation light having a wavelength range of 390 to 460 nm, And the fluorescence generation efficiency by the monochromatic irradiation light is 0.8
An electrophotographic photoreceptor characterized by the following. (2) The electrophotography according to (1), wherein the charge transport layer shows a transmittance of 50% or more to the monochromatic irradiation light, and the fluorescence generation efficiency is 0.5 or less. Photoconductor. (3) The electrophotographic photosensitive member according to (1), wherein the charge transport layer exhibits a transmittance of 90% or more to the monochromatic irradiation light and has a fluorescence generation efficiency of 0.3 or less. body. (4) The above (1) to (1), wherein the outermost surface of the photosensitive layer is formed by dispersing at least a filler.
The electrophotographic photosensitive member according to any one of (3). (5) The electrophotographic photoreceptor according to any one of (1) to (4), wherein the charge transport layer comprises at least a charge transport material and a filler. (6) The electrophotograph according to any one of (1) to (4), wherein the charge transport layer comprises at least a layer made of a charge transport material and at least a layer made of a filler and a binder resin. Photoconductor. (7) The electron according to any one of (1) to (4), wherein the charge transport layer comprises at least a layer made of a charge transport material and at least a layer made of a filler and a charge transport material. Photoreceptor. (8) The filler is titanium oxide, tin oxide, zinc oxide, zirconium oxide, indium oxide, silicon nitride,
Calcium oxide, barium sulfate, indium oxide, silica, colloidal silica, alumina, carbon black,
(4) to (7), which are one kind of substance selected from a fluorine resin fine powder, a polysiloxane resin fine powder, and a polymer charge transporting material fine powder, or a mixture of two or more substances.
The electrophotographic photosensitive member according to any one of the above. (9) The charge transport material used in the charge transport layer is a low-molecular charge transport material or a mixture thereof.
The electrophotographic photosensitive member according to any one of (8) and (8). (10) The charge transport material used in the charge transport layer is a polymer type charge transport material or a mixture thereof.
The electrophotographic photosensitive member according to any one of (8) and (8). (11) The charge transport material used in the charge transport layer is a mixture of a low molecular charge transport material and a high molecular charge transport material. Electrophotographic photoreceptor. (12) an electrophotographic photosensitive member, a charging unit, an image exposing unit,
In a process cartridge which integrally supports at least one unit selected from the group consisting of a developing unit, a transfer unit and a cleaning unit and is detachably attached to the main body of the electrophotographic apparatus, the electrophotographic photoreceptor includes 1)
A process cartridge using the electrophotographic photosensitive member according to any one of (1) to (11). (13) The writing light source in the image exposure means is 400
The process cartridge according to (12), wherein the process cartridge is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range of from 450 to 450 nm. (14) In an electrophotographic apparatus equipped with an electrophotographic photosensitive member, a charging unit, an image exposing unit, a developing unit, and a transfer unit,
An electrophotographic apparatus, wherein the electrophotographic photoconductor according to any one of the above (1) to (11) is used as the electrophotographic photoconductor. (15) The wavelength of the writing light source in the image exposure means is
The electrophotographic apparatus according to the above (14), which is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range of 400 to 450 nm.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The electrophotographic photoreceptor of the present invention (hereinafter referred to as "photoreceptor")
40) as a writing light source in a process cartridge and an electrophotographic apparatus using the same.
A semiconductor laser (LD) or a light emitting diode (LED) having an oscillation wavelength in the range of 0 to 450 nm is used. Although these light sources have a very narrow light intensity wavelength distribution, the charge transport layer is 390 to 460 nm because the oscillation peak wavelength fluctuates to a longer or shorter wavelength side by several nm depending on the temperature environment, production lot, and the like. It is preferable to transmit light in the range described above sufficiently. Also,
Since these LDs and LEDs have an extremely narrow light intensity wavelength distribution, the charge transport layer does not need to transmit light in the entire wavelength range of 390 to 460 nm, and it is sufficient that at least one desired monochromatic light can be transmitted in this region. In this case, the transmittance of the irradiation light is preferably 50% or more, and more preferably 90% or more.

The charge transport layer has a substantially flat shape due to the shape of the photosensitive member such as a drum or a sheet or a problem in manufacturing.
Since it does not have smoothness, a decrease in the amount of light due to scattering or reflection of writing light is not small. The transmittance referred to in the present invention is simply the ratio of the light obtained by subtracting the scattered or reflected light inside the charge transport layer, that is, the ratio of the light incident on the charge transport layer surface and the light emerging from the opposite surface. Means For example, FIG. 1 shows a schematic diagram of a transmission spectrum of the charge transport layer film. From FIG. 1, the transmittance for light having a wavelength of λ2 (nm) within the wavelength range of 390 to 460 nm can be obtained from the following equation (2).

## EQU2 ## Transmittance (%) = T2 / T1 × 100 (2)

2 to 4 show schematic cross sections of the electrophotographic photosensitive member of the present invention. The photoreceptor shown in FIG. 2 has a charge generation layer 2 having a charge generation material as a main component on a conductive support 1,
It has a configuration in which a charge transporting material or a charge transporting material and a charge transporting layer 3 containing a filler as an essential component are laminated. 3 has a configuration in which a charge transport layer 5 containing a filler and a binder resin as essential components is laminated on a charge transport layer 4 containing a charge transport material as a main component. The structure shown in FIG. 4 has a configuration in which a charge transport layer 6 containing a filler and a charge transport material as essential components is laminated on a charge transport layer 4 mainly containing a charge transport material. The charge generation layer 2 and the charge transport layers 3 to 6 may contain a binder resin for the purpose of improving the dispersibility of the coating solution for forming a photoreceptor and the strength of the photosensitive layer. Further, an intermediate layer may be formed between the conductive support 1 and the charge generation layer 2 for the purpose of improving the chargeability, improving the adhesiveness, or preventing a moire image due to interference light of laser writing light.

The charge transport layers 3 to 6 according to the present invention are composed of 390 to 4
It transmits monochromatic light in a wavelength range of 60 nm. Therefore, it is necessary that the binder resin to be used for this is one that transmits light in this wavelength range. For example, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, Polyalate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal,
Polyvinyl toluene, poly-N-vinyl carbazole,
Thermoplastic or thermosetting resins such as acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin can be used. Among them, a binder resin represented by the following general formula (1) and / or general formula (2) is preferable.

[0019]

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Embedded image In the above formula, R ₄ , R ₅ , R ₆ , and R ₇ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12, preferably 1 to 6 carbon atoms, or a halogen atom, or Alternatively, it represents an unsubstituted aryl group having 6 to 12 carbon atoms or an arylalkyl group having 7 to 12 carbon atoms. X and Y are a single bond, an aliphatic divalent group, a cycloaliphatic divalent group,-
O -, - S -, - SO -, - SO 2 -, - CO -, - C
O—O—Z—O—CO— (wherein, Z represents an aliphatic divalent group) or the following general formula (3)

Embedded image (In the formula, a is an integer of 1 to 20, b is an integer of 1 to 2,000, R ₈ and R ₉ are a substituted or unsubstituted alkyl group having 1 to 12, preferably 1 to 6, carbon atoms or a substituted or unsubstituted alkyl group. Represents an aryl group or an arylalkyl group having 6 to 12 carbon atoms). Here, R ₆ and R ₇ , and R ₈ and R ₉ may be the same or different. p and q represent compositions.
1 ≦ p ≦ 1, 0 ≦ q ≦ 0.9, n represents the number of repeating units and is an integer of 5 to 5000.

The aliphatic divalent group has 1 to 12 carbon atoms.
And oxyalkylene groups of the formula (1).
The cycloaliphatic divalent group includes a cycloalkylene group having 5 to 12 carbon atoms and a cycloalkylenedialkylene group. The substituent includes an alkoxy group having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms, an acyl group or an acyloxy group, a halogen atom (chlorine, bromine, iodine, fluorine) and the like.

Specific examples include those having a structure having the following polymerization component or copolymerization component, but are not limited thereto.

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The charge transporting material used in the charge transporting layer of the present invention is roughly classified into a low molecular weight charge transporting material and a high molecular weight charge transporting material. For example, poly-N-carbazole and its derivatives, poly-γ-carbazolylethylglutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, imidazole derivatives, triphenylamine derivatives and Compounds represented by the following general formulas (24) to (29) and (33) to (35) can be exemplified.

(Low molecular charge transport material)

Embedded image (Wherein, R ¹ represents a methyl group, an ethyl group, 2-hydroxyethyl group or a 2-chloroethyl group, R ² represents a methyl group, an ethyl group, a benzyl group or a phenyl group, R ³
Represents a hydrogen atom, a chlorine atom, a bromine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a dialkylamino group or a nitro group.

Embedded image (In the formula, Ar represents a naphthalene ring, an anthracene ring, a pyrene ring or a substituted product thereof, or a pyridine ring, a furan ring, or a thiophene ring, and R represents an alkyl group, a phenyl group, or a benzyl group.)

Embedded image (Wherein, R ¹ represents an alkyl group, a benzyl group, a phenyl group or a naphthyl group; R ² represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group, Represents an aralkylamino group or a diarylamino group, n represents an integer of 1 to 4, and when n is 2 or more, R ² may be the same or different, and R ³ represents a hydrogen atom or a methoxy group. Represent)

Embedded image (In the formula, R ¹ represents an alkyl group, a substituted or unsubstituted phenyl group or a heterocyclic group 1 to 11 carbon atoms, R ^2,
R ³ may be each the same or different, represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a chloroalkyl group, or a substituted or unsubstituted aralkyl group, also, R ² and R ³ It may combine with each other to form a nitrogen-containing heterocyclic ring. R ⁴ may be the same or different and represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group or a halogen atom.

Embedded image (Wherein, R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, R ² and R ³ represents an alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R ⁴ Represents a hydrogen atom, a lower alkyl group or a substituted or unsubstituted phenyl group;
r represents a substituted or unsubstituted phenyl group or a naphthyl group)

Embedded image [In the formula, n is an integer of 0 or 1, R ¹ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted phenyl group;
¹ represents a substituted or unsubstituted aryl group; R ⁵ represents an alkyl group containing a substituted alkyl group or a substituted or unsubstituted aryl group; A represents the following general formula (30) or (3)
Represents a group represented by 1), a 9-anthryl group or a substituted or unsubstituted carbazolyl group.

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Embedded image In the general formulas (30) and (31), R ² represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a group represented by the following general formula (32).

Embedded image (However, R ³ and R ⁴ represent an alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R ³ and R ⁴ may be the same or different, and R ⁴ is In the above formulas (30) and (31), when m is 2 or more, R ² may be the same or different. When n is 0, A and R ¹ may form a ring together. ]

Embedded image (In the formula, R ¹ represents a lower alkyl group, a lower alkoxy group or a halogen atom, and R ² and R ³ may be the same or different and are a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom. Represents l, m, and n represent an integer of 0 to 4)

Embedded image (Wherein R ¹ , R ³ and R ⁴ are a hydrogen atom, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom or a substituted or unsubstituted Is an aryl group of R
² represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group or a halogen atom. Where R ¹ , R ² ,
R ³ and R ⁴ are excluded unless they are all hydrogen atoms. Further, k, l, m and n are integers of 1, 2, 3 or 4, and when each is an integer of 2, 3 or 4, the above R ¹ ,
R ² , R ³ and R ⁴ may be the same or different)

Embedded image (Wherein, Ar represents a condensed polycyclic hydrocarbon group having 18 or less carbon atoms which may have a substituent, and R ¹ and R ² represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl Represents an alkoxy group, a substituted or unsubstituted phenyl group, and may be the same or different.
Represents an integer of 1 or 2. )

The compound represented by the general formula (24) includes, for example, 9-ethylcarbazole-3-aldehyde-1-aldehyde.
Methyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde-1-benzyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde-
1,1-diphenylhydrazone and the like. The compound represented by the general formula (25) includes, for example, 4-diethylaminostyryl-β-aldehyde-1-methyl-1-methyl
Examples include phenylhydrazone, 4-methoxynaphthalene-1-aldehyde-1-benzyl-1-phenylhydrazone. The compound represented by the general formula (26) includes, for example, 4-methoxybenzaldehyde-1-methyl-1-
Phenylhydrazone, 2,4-dimethoxybenzaldehyde-1-benzyl-1-phenylhydrazone, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-methoxybenzaldehyde-1- (4-
Methoxy) phenylhydrazone, 4-diphenylaminobenzaldehyde-1-benzyl-1-phenylhydrazone, 4-dibenzylaminobenzaldehyde-1,1
-Diphenylhydrazone and the like. The general formula (2)
Compounds represented by 7) include, for example, 1,1-bis (4
-Dibenzylaminophenyl) propane, tris (4-
Diethylaminophenyl) methane, 1,1-bis (4-
Dibenzylaminophenyl) propane and 2,2′-dimethyl-4,4′-bis (diethylamino) -triphenylmethane. Examples of the compound represented by the general formula (28) include 4-diphenylaminostilbene,
Examples include dibenzylaminostilbene, 4-ditolylaminostilbene, 1- (4-diphenylaminostyryl) naphthalene, and 1- (4-diethylaminostyryl) naphthalene. Examples of the compound represented by the general formula (29) include 4′-diphenylamino-α-phenylstilbene, 4′-bis (4-methylphenyl) amino-α-phenylstilbene, and the like. Examples of the benzidine compound represented by the general formula (33) include N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,
1'-biphenyl] -4,4'-diamine, 3,3'-
Dimethyl-N, N, N ', N'-tetrakis (3,4-
Dimethylphenyl)-[1,1′-biphenyl] -4,
4'-diamine and the like. The biphenylylamine compound represented by the general formula (34) includes, for example, 4′-
Methoxy-N, N-diphenyl- [1,1′-biphenyl] -4-amine, 4′-methyl-N, N-bis (4-
Methylphenyl)-[1,1'-biphenyl] -4-amine, 4'-methoxy-N, N-bis (4-methylphenyl)-[1,1'-biphenyl] -4-amine, N,
N-bis (3,4-dimethylphenyl)-[1,1′-
Biphenyl] -4-amine and the like. The triarylamine compound represented by the general formula (35) includes, for example, N-di (p-tolyl) -1-naphthylamine,
N, N-di (p-tolyl) -1-phenanthrylamine, 9,9-dimethyl-2- (di-p-tolylamino)
Fluorene, N, N, N ', N'-tetrakis (4-methylphenyl) -phenanthrene-9,10-diamine, N, N, N', N'-tetrakis (3-methylphenyl) -m-phenylenediamine and so on.

Further, examples of the polymer type charge transporting material include polymer type charge transporting materials represented by the following general formulas (36) to (46) or a mixture thereof.

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Embedded image[Wherein, R₁₁, R₁₂, R₁₃Is a hydrogen atom or independent
Substituted or unsubstituted alkyl group or halogen source
Child, R_TenIs a hydrogen atom or a substituted or unsubstituted alkyl
Group, R₁₄, R_FifteenIs a substituted or unsubstituted aryl group, R
₁₆Is a hydrogen atom, a substituted or unsubstituted alkyl group,
Or an unsubstituted aryl group, Ar₁₁, Ar ₁₂, A
r₁₃, Ar₁₈, Ar₁₉, Ar₂₀, Ar_{twenty one}, Ar_{twenty two}, Ar
_{twenty three}, Ar_{twenty four}, Ar _{twenty five}, Ar₂₆, Ar₂₇, Ar₂₈, Ar₂₉
Are the same or different arylene groups, p and q represent the composition,
0.1 ≦ p ≦ 1, 0 ≦ q ≦ 0.9, n is the number of repeating units
And an integer of 5 to 5000. W is aliphatic divalent
Group, cyclic aliphatic divalent group, or the following general formula (47)
Represents a divalent group represented by

Embedded image [Wherein, R ₁₀₁ and R ₁₀₂ each independently represent a substituted or unsubstituted alkyl group, aryl group, or halogen atom.
Y is a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-,
-SO _2- , -CO-, -CO-O-Z-O-CO-
(In the formula, Z represents an aliphatic divalent group)

Specific examples include the following.

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Embedded image These polymer transport materials may be any of a homopolymer, a random copolymer, an alternating copolymer, and a block copolymer. Further, a mixture of these low-molecular-weight charge transport materials and high-molecular-weight charge transport materials may be used as the charge transport material.

Specific examples of the filler include titanium oxide,
Tin oxide, zinc oxide, zirconium oxide, indium oxide, silicon nitride, calcium oxide, barium sulfate, IT
Any one or a mixture of O (indium oxide), silica, colloidal silica, alumina, carbon black, fine powder of fluororesin, fine powder of polysiloxane resin, and fine powder of polymer charge transport material can be given. These fillers may be surface-treated with an inorganic substance or an organic substance for reasons such as improvement in dispersibility and surface property modification. In general, those treated with a silane coupling agent as a water-repellent treatment, those treated with a fluorine-based silane coupling agent, those treated with a higher fatty acid or copolymerized with a polymer material, and the like, and those treated with an inorganic substance include filler surfaces. The alumina,
Examples thereof include zirconia, tin oxide, and silica-treated ones. The filler is pulverized or dispersed together with a low-molecular charge transport material, a high-molecular charge transport material, a binder resin, and a dispersion solvent, and coated as a photosensitive layer. The filler content in the formed charge transport layer is 5 to 50% by weight.
If it is less than 10%, the abrasion resistance is not sufficient, and if it exceeds 40%, the transparency of the charge transport layer is impaired, resulting in a decrease in sensitivity. The average particle size is 0.05 to 1.0 μm, preferably 0.05
Pulverized to 0.8 μm and dispersed. If the particle size is large, the cleaving cleaning blade is damaged on the surface, cleaning failure occurs, and the image quality deteriorates.

As the dispersion solvent, methyl ethyl ketone,
Uses ketones such as acetone, methyl isobutyl ketone and cyclohexanone, ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve, aromatics such as toluene and xylene, halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate. Is done. When a pulverizing step is added, a ball mill, a sand mill, a vibration mill or the like is used.

The amount of the charge transporting material is 0.2 to 3 parts, preferably 0.4 to 3 parts by weight based on 1 part of the binder resin.
1.5 parts. When a high molecular charge transport material is used as the charge transport material, a charge transport layer can be formed without the presence of a binder resin. When a low-molecular charge transport material is used, a high-molecular charge transport material can be used instead of the binder resin. Coating methods include dipping, spray coating, ring coating,
A roll coater method, a gravure coating method, a nozzle coating method, a screen printing method and the like are employed. The thickness of the charge transport layer 3 or 4 is preferably about 5 to 30 μm. The thickness of the charge transport layers 5 and 6 is 0.5 to 10 μm.
And preferably 0.5 to 5 μm.

In the present invention, a plasticizer or a leveling agent may be added to the photosensitive layer. As the plasticizer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount of the plasticizer is 0 to 30 based on the weight of the binder resin.
% Is appropriate. As the leveling agent, silicone oils such as dimethyl silicone oil and methyl phenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in a side chain are used. ~ 1%
Is appropriate. Examples of the conductive support 1 include a metal plate such as aluminum, nickel, copper, titanium, gold, and stainless steel, a metal drum or metal foil, and a plastic film on which aluminum, nickel, copper, titanium, gold tin oxide, indium oxide, or the like is deposited. Alternatively, a film or a drum of paper, plastic, or the like coated with a conductive substance may be used.

Further, the intermediate layer 7 formed on the conductive substrate
As a general rule, resins are the main component, but considering that these resins are coated with a photosensitive layer with a solvent,
It is desirable that the resin has high solvent resistance to general organic solvents. Examples of such a resin include water-soluble resins such as polyvinyl alcohol, casein and sodium polyacrylate, alcohol-soluble resins such as copolymerized nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy resin. Curable resins that form a three-dimensional network structure, such as resins, are exemplified. A fine powder pigment of a metal oxide such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, or indium oxide may be added to prevent moiré and optimize the resistance value. These intermediate layers can be formed using a suitable solvent and a coating method. Further, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used. In addition, the intermediate layer according to the present invention is provided with Al2O3 by anodic oxidation, an organic substance such as polyparaxylylene (parylene), SiO2,
Those provided with an inorganic substance such as SnO2, TiO2, ITO, CeO2 by a vacuum thin film forming method can also be used favorably. In addition, known materials can be used. The thickness of the intermediate layer is suitably from 0 to 5 μm.

The charge generating layer 2 can be provided by adding or dissolving or dispersing a binder resin to a charge generating material and an appropriate solvent, if necessary, coating and drying. As a dispersion method of the dispersion liquid for the charge generation layer, for example,
Examples thereof include a ball mill, an ultrasonic wave, and a homomixer. Examples of the application means include a dipping coating method, a blade coating method, and a spray coating method. When the charge generating material is dispersed to form a photosensitive layer, the charge generating material has an average particle size of 2 μm or less, preferably 1 μm or less, in order to improve dispersibility in the layer. However, if the above particle size is too small, it tends to agglomerate rather, increasing the resistance of the layer, reducing the sensitivity and repetition characteristics due to an increase in crystal defects, and also has a limit in miniaturization. It is preferable that the lower limit of the particle size be 0.01 μm. The thickness of the charge generation layer is suitably about 0.01 to 5 μm, and preferably 0.1 to 2 μm.

Examples of the charge generating material include the following pigments. As the organic pigment, for example, CI Pigment Blue 25 (Color Index CI
21180), C.I. Pigment Red 41 (CI
21200), CI Acid Red 52 (CI 4
5100), CI Basic Red 3 (CI 45
210), an azo pigment having a carbazole skeleton (described in JP-A-53-95033), an azo pigment having a distyrylbenzene skeleton (JP-A-53-133445), and an azo pigment having a triphenylamine skeleton ( JP-A-53-132347), azo pigments having a dibenzothiophene skeleton (described in JP-A-54-21728), and azo pigments having an oxadiazole skeleton (described in JP-A-54-12742). Described), an azo pigment having a fluorenone skeleton (described in JP-A-54-22834), an azo pigment having a bisstilbene skeleton (described in JP-A-54-17733), and having a distyryloxadiazole skeleton Azo pigments (JP-A-54-21)
Azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-14967) and azo pigments having a benzanthrone skeleton. For example, CI Pigment Blue 16 (CI
74100), phthalocyanine pigments such as oxotitanium phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, indigo pigments such as C-Ivat Brown 5 (CI 73410) and C-Iabut Die (CI 73030), Argoscarlet B (manufactured by Bayer AG) And perylene pigments such as Insence Scarlet R (manufactured by Bayer AG). These charge generating materials may be used alone or
More than one type may be used in combination. As the solvent used when preparing the dispersion or solution of the charge generation layer, for example,
N, N-dimethylformamide, toluene, xylene,
Monochlorobenzene, 1,2-dichloroethane, 1,
1,1-trichloroethane, dichloromethane, 1,1,
Examples thereof include 2-trichloroethane, trichloroethylene, tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, and dioxane.

As the binder resin, any conventionally known binder resin having good insulating properties can be used, and there is no particular limitation. For example, polyethylene, polyvinyl butyral, polyvinyl formal, polystyrene resin, phenoxy resin, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, Polyamide resin, silicone resin, addition polymerization type resin such as melamine resin, polyaddition type resin, polycondensation type resin,
And copolymer resins containing two or more of the repeating units of these resins, for example, vinyl chloride-vinyl acetate copolymer, styrene-acrylic copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer In addition to an insulating resin such as a resin, a polymer organic semiconductor such as poly-N-vinylcarbazole may be used. These binders can be used alone or as a mixture of two or more. The amount of the binder resin is 0 to 5 with respect to 1 part of the charge generating material on a weight basis.
Parts, preferably 0.1 to 3 parts, are suitable. Further, in the photosensitive layer, a phenol compound, a hydroquinone compound, a hindered phenol compound, a hindered amine compound, a compound in which hindered amine and hindered phenol are present in the same molecule and the like are added for the purpose of improving the chargeability and the like. be able to.

Next, an electrophotographic method and an electrophotographic apparatus according to the present invention will be described with reference to the drawings. FIG. 5 is a schematic view for explaining the electrophotographic process cartridge and the electrophotographic apparatus of the present invention, and the following modified examples also belong to the category of the present invention. In FIG. 5, a photoreceptor 1 is provided with a photosensitive layer of the present invention in which a charge generation layer and a charge transport layer are laminated in this order on a conductive support. The photoconductor 1 has a drum shape, but may have a sheet shape or an endless belt shape. As the charging charger 3, the pre-transfer charger 7, the transfer charger 10, the separation charger 11, and the pre-cleaning charger 13, known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used. Can be As the transfer means, generally, the above-mentioned charger can be used, but as shown in the figure, a combination of a transfer charger and a separation charger is effective.
An LD or LED having an oscillation wavelength in the range of 400 to 450 nm is used for the image exposure unit 5. In addition, as the light source such as the static elimination lamp 2, a general light emitting material such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, an LED, an LD, and an electroluminescent element (EL) can be used. To irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used. Such a light source or the like irradiates the photoreceptor with light by providing a transfer step, a charge removal step, a cleaning step, or a pre-exposure step using light irradiation in addition to the step shown in FIG. The toner developed on the photoconductor 1 by the developing unit 6 is transferred to the transfer paper 9, but not all of the toner is transferred, and some toner remains on the photoconductor 1. Such toner is supplied to the fur brush 14 and the blade 15
As a result, it is removed from the photoconductor. The cleaning may be performed only by the cleaning brush, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush. When a positive (negative) charge is applied to the electrophotographic photosensitive member and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. This is negative (positive)
A positive image can be obtained by developing with a polar toner (electric detection fine particles), and a negative image can be obtained by developing with a positive (negative) toner. A known method is applied to the developing means, and a known method is also used for the charge removing means.

FIG. 6 shows another example of the electrophotographic process according to the present invention. The photoreceptor 21 has a photosensitive layer, is driven by drive rollers 22a and 22b, is charged by a charger 23, is exposed by a light source 24, is exposed, and is developed (not shown).
Transfer using the charger 25, exposure before cleaning by the light source 26, cleaning by the brush 27, and static elimination by the light source 28 are repeatedly performed. In FIG. 6, the photosensitive member 2
1 (of course, in this case, the support is translucent), light irradiation for pre-cleaning exposure is performed from the support side.

Such an illustrated electrophotographic process comprises:
This is an example of an embodiment of the present invention, and other embodiments are possible. For example, in FIG. 6, the pre-cleaning exposure is performed from the support side. However, this may be performed from the photosensitive layer side, or the image exposure and the erasing light irradiation may be performed from the support side. On the other hand, the light irradiating step includes image exposure, pre-cleaning exposure, and static elimination exposure. However, in addition to this, a pre-transfer exposure, a pre-exposure of image exposure, and other known light irradiating steps are provided to irradiate the photosensitive member with light. Can also be performed. Such an image forming means may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, or may be incorporated in the apparatus in the form of a process cartridge. The process cartridge is one device (part) that includes a photoconductor and further includes a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge removing unit. There are many shapes and the like of the process cartridge. As a general example, there is a process cartridge shown in FIG. The photoreceptor 16 is provided with a photosensitive layer in which a charge generation layer and a charge transport layer are laminated on a conductive support in that order.

[0038]

The present invention will be described below with reference to examples.
The present invention is not limited by the embodiments. All parts are parts by weight. The irradiation light wavelength in the fluorescence generation efficiency measurement was all 405 nm.

(Preparation of Electrophotographic Photoreceptors Nos. 1 to 7) 1.5 parts of oil-free alkyd resin (manufactured by Dainippon Ink and Chemicals, Beccolite M6401) and melamine resin (manufactured by Dainippon Ink and Chemicals: Super Beckamine G-) 821) 1 part,
Titanium dioxide [Ishihara Sangyo Co., Ltd .: Taipe CR-E
L] A mixture of 5 parts and 22.5 parts of 2-butanone was placed in a ball mill pot, and ball milling was performed for 48 hours using alumina balls having a diameter of 10 mm to prepare a coating solution for the intermediate layer. The coating solution was dipped on an aluminum cylinder and dried at 130 ° C. for 20 minutes to form an intermediate layer having a thickness of about 3.5 μm. Next, 0.5% of 7.5 parts of a bisazo compound represented by the following structural formula (72) and 2.5 parts of a vinyl butyral resin [XYHL manufactured by Union Carbide]
500 parts of the cyclohexanone solution was pulverized and mixed in a ball mill, and the resulting dispersion was applied onto the intermediate layer by dip coating, followed by natural drying to form a charge generating layer having a thickness of about 0.5 μm.

Embedded image Next, 7 parts of an aminobiphenyl compound (light generation efficiency: 0.28) represented by the following structural formula (73) as a charge transporting material and a polycarbonate resin [Panelite TS manufactured by Teijin Limited]
-2050] was dissolved in tetrahydrofuran, and the coating solution for the charge transport layer was applied on the charge generation layer.
C. for 2 minutes and then at 130.degree. C. for 20 minutes to form a charge transport layer having a thickness of about 20 .mu.m.
1) was created.

Embedded image Further, only the charge transport layer film was formed on the polyester film by the same operation using the charge transport layer coating solution.
The charge transport layer film was peeled off from the polyester film, the transmission spectrum of the obtained charge transport layer film was measured with a spectrophotometer, and the transmittance at each wavelength was obtained from the above equation (2).
Table 1 shows the results. FIG. 8 shows the obtained transmission spectrum diagram.

The charge transport material (73) is represented by the following structural formula (7)
Photoreceptors were prepared in the same manner as above (photoreceptors Nos. 2 to 7), and the transmittance was measured, except that the compounds represented by 4) to (79) were used. FIG. 9 shows the obtained transmission spectrum diagram.
To 14 are shown.

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(Measurement of Electrophotographic Characteristics) The spectral sensitivity of the obtained electrophotographic photosensitive member at a short wavelength LD oscillation wavelength was measured.
A xenon lamp was used as a light source, and spectroscopy was performed with a monochromator (manufactured by Nikon Corporation). First, after charging the photoreceptor to −800 (V) or more by corona discharge, the charging is stopped, and exposure is performed with each monochromatic light, and the time required for the surface potential to change from −800 (V) to −100 (V). And the exposure amount (μJ / cm ² ) was calculated from the irradiation light intensity (μW / cm ² ) of each wavelength. The light attenuation potential difference at this time, 700 (V), was divided by the exposure amount, and the obtained value was defined as a spectral sensitivity value (V · cm ² / μJ). However, since the potential drop due to dark decay is included during light decay, the dark decay amount of each photoreceptor was measured before measuring the light sensitivity, and each spectral sensitivity value was corrected using this value. Table 1 shows the results.

[0042]

[Table 1]

(Preparation of Electrophotographic Photoreceptor No. 8) Polycarbonate resin [Panelite TS-205 manufactured by Teijin Limited]
0] 5 parts, 2 parts of titanium oxide fine particles (CR97, manufactured by Ishihara Sangyo Co., Ltd.) as filler, 3 parts of aminobiphenyl compound represented by the structural formula (73), 40 parts of THF, and 140 parts of cyclohexanone To photoconductor N
o. 1 was applied by a spray method, and dried at 80 ° C. for 2 minutes and then at 130 ° C. for 20 minutes to form a second charge transport layer having a thickness of about 5 μm. 8 was created.

(Preparation of Electrophotographic Photoreceptor No. 9) Photoconductor No. 8 except that the charge transport material of No. 8 was replaced with the compound represented by the structural formula (75). 8 in the same manner as in photoconductor No. 9 was produced.

(Preparation of Electrophotographic Photoreceptor No. 10) 8 of the coating solution for the second charge transport layer, 7 parts of a polycarbonate resin [Panlite C-1400 manufactured by Teijin Limited], and silica fine particles (KMPX10 manufactured by Shin-Etsu Chemical Co., Ltd.) as a filler.
0) except that 2 parts and 200 parts of dichloromethane were used. 8 in the same manner as in photoconductor No. 10 was produced.

(Preparation of Electrophotographic Photoreceptor No. 11) 1.5 parts of oil-free alkyd resin (manufactured by Dainippon Ink and Chemicals: Beckolite M6401), melamine resin (manufactured by Dainippon Ink and Chemicals: Super Beckamine G-821) 1 part, titanium dioxide [manufactured by Ishihara Sangyo Co., Ltd .: Taipe CR-E
L] A mixture of 5 parts and 22.5 parts of 2-butanone was placed in a ball mill pot, and ball milling was performed for 48 hours using alumina balls having a diameter of 10 mm to prepare a coating solution for the intermediate layer. The coating solution was dipped on an aluminum cylinder and dried at 130 ° C. for 20 minutes to form an intermediate layer having a thickness of about 3.5 μm. Next, 1.5 parts of Y-type oxotitanium phthalocyanine and 500 parts of a 0.5% dichloromethane solution of 1 part of a polyester resin [Vylon 200 manufactured by Toyobo Co., Ltd.] were pulverized and mixed in a ball mill, and the obtained dispersion was subjected to the above-mentioned treatment. Dipping coating was performed on the intermediate layer, followed by air drying to form a charge generation layer. Next, as a charge transporting material, 7 parts of an aminobiphenyl compound represented by the following structural formula (80) and a polycarbonate resin [Panlite C-1 manufactured by Teijin Limited]
400] 10 parts in tetrahydrofuran, dip-coating the first charge transport layer coating solution on the charge generation layer, drying at 80 ° C. for 2 minutes and then at 130 ° C. for 20 minutes to obtain a layer having a thickness of about 20 μm. A first charge transport layer was formed. next,
7 parts of a polymer type charge transport material of a random copolymer represented by the following structural formula (81), 3 parts of alumina fine particles (Alumina-C manufactured by Nippon Aloesil Co., Ltd.) as a filler, THF40
Part of the second charge transport layer and 140 parts of cyclohexanone are spray-coated on the first charge transport layer and dried at 80 ° C. for 2 minutes and then at 160 ° C. for 20 minutes to form a second charge transport layer having a thickness of about 3 μm. Layer to form a photosensitive member No. 11 was created.

Embedded image

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(Preparation of Electrophotographic Photoreceptor No. 12) No. 8 except that the butadiene compound represented by the structural formula (77) was used instead of the charge transport material of No. 8 8 in the same manner as in photoconductor No. No. 12 was produced. Further, the photosensitive member No. By operating in the same manner as in Nos. 1 to 7, the transmittance and the spectral sensitivity value at each wavelength of the charge transport layer film were measured. The results are shown in the table below.

[0048]

[Table 2]

As can be seen from Table 1, 90% of the total wavelength light is 90%.
The photoreceptor No. having the above transmittance was obtained. Nos. 1 and 3 show high sensitivity in all wavelength regions. The photosensitive member No. which does not transmit the irradiation light of all wavelengths at all and has low fluorescence generation efficiency. 5 shows no sensitivity in the wavelength region of Table 1. The photoconductor No. whose generation efficiency is as high as 0.83 6 hardly transmits light in the entire wavelength region, but exhibited high sensitivity because the charge transporting material was raised to a photoexcited state by light absorption as described above, and the charge generating material absorbed the fluorescence emitted upon deactivation. (Fluorescence sensitization). Photoconductor No. 2, 4, and 7 also exhibited relatively high sensitivity values even at low transmittance due to similar fluorescence sensitization on the short wavelength side. Also, the photosensitive member No. having a low fluorescence generation efficiency (low sensitizing effect by fluorescence). Sample No. 4 exhibited a remarkable decrease in sensitivity when the transmittance was 50% or less. Further, as can be seen from Table 2, the photoconductor No. 8 to 10 are photosensitive member Nos. Although the transmittance is slightly inferior to that of No. 1, it shows good light transmission characteristics, indicating that the electrophotographic photosensitive member has high sensitivity. Electrophotographic photosensitive member No. No. 12 is a photosensitive member No. As in the case of No. 5, since there is no light transmission in this region, it is understood that no sensitivity is exhibited. As described above, it is important that the transmittance of the charge transport layer for writing light is high for achieving high sensitivity in the laminated electrophotographic photosensitive member. On the other hand, even at a transmittance of 0%, high sensitivity can be exhibited by sensitization of fluorescence generation. However, as described above, a high fluorescence generation efficiency is inferior in resolution and repetition stability. Therefore, in order to function as a high-sensitivity and high-resolution electrophotographic photoreceptor in the oscillation wavelength region of a blue to violet semiconductor laser or light emitting diode,
It is important that the charge transport layer has high transmittance and low fluorescence generation efficiency with respect to the writing light wavelength.

An example of producing an electrophotograph (copy) by an electrophotographic apparatus using the photosensitive member will be described below.

Examples 1 to 6 and Comparative Examples 1 to 3 The above-mentioned electrophotographic photosensitive drum was manufactured by Ricoh's Imagio MF22.
00 (equivalent to 600 dpi, process cartridge). However, the image exposure light source is 405 nm, 435 n.
The LD was changed to an LD having an oscillation wavelength of m or 450 nm, and a modification was made so that the amount of light could be set by an external LD driving device. The initial dark surface potential was set to about -700 (V) and the bright part surface potential was set to about -100 (V), and 10,000 sheets were continuously printed, and the surface potential at that time was measured. In the image evaluation, it was evaluated in three steps whether or not one dot / one space isolated dot was well resolved (reproduced) on the copy. The results are shown in the following table.

[0052]

[Table 3] ○ Clear △ Slightly clear × No reproduction

Examples 7 to 10 Regarding 8 to 11, the electrophotographic photosensitive member was evaluated in the same manner as described above. The following table shows the results.

[0054]

[Table 4] ○ Clear △ Slightly clear × No reproduction

From the above results, Examples 1 to 10 having high transmittance at the writing light wavelength and low fluorescence emission generation efficiency have excellent potential stability upon repeated use, and have excellent dot reproducibility and stability. You can see that there is. Comparative Examples 1 to 3 having low transmittance to writing light and high fluorescence generation efficiency
Indicates that the potential fluctuation during repeated use is large, the dot reproducibility is not clear from the beginning, and the stability is further poor. Further, for the writing LD in this wavelength range, the photosensitive member No. Nos. 5 and 12 were not evaluated because they had no sensitivity and no image was obtained.

Examples 11 to 14 and Comparative Example 4 The photosensitive member No. was formed on an aluminum substrate. Each of the second charge transport layer liquids used in 8 to 11 was applied by a doctor blade,
After drying at 130 ° C. for 2 minutes and then at 130 ° C. for 20 minutes, a second charge transport layer having a thickness of about 5 μm was formed to prepare a wear measurement sample. The sample thus prepared was subjected to a Taber abrasion tester (manufactured by Toyo Seiki Co., Ltd.) using a worn wheel CS-5 under a load of 1 kg for 60 r. p. m. At 3000 rotations and a wear test was performed for each (Examples 11 to 14). The weight difference between the photoreceptor sample before and after the abrasion test was defined as the abrasion amount (mg). The results are shown in the table below. Further, the coating solution for the second charge transport layer was added to 5 parts of a polycarbonate resin [Panlite TS-2050 manufactured by Teijin Limited], 3 parts of the aminobiphenyl compound represented by the structural formula (73), 40 parts of THF, and 140 parts of cyclohexanone. The wear characteristics were evaluated by operating in the same manner as in Examples 11 to 14, except that a film having a thickness of about 5 μm containing no change filler was formed.

[0057]

[Table 5]

From Table 5, it can be seen that the electrophotographic photosensitive members of the present invention containing fillers (Examples 11 to 14) have significantly less wear than the electrophotographic photosensitive members of Comparative Example 4 containing no filler. That is, it is understood that the electrophotographic photoreceptor of the present invention is very excellent in mechanical durability.

(Preparation of Photoreceptor No. 13) An intermediate layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following compositions were sequentially applied and dried on an electroformed nickel belt. A laminated photoreceptor (photoreceptor No. 13) having a thickness of about 4 μm for the intermediate layer, about 0.3 μm for the charge generation layer, 27.0 μm for the charge transport layer, and 3.0 μm for the protective layer was prepared. Intermediate layer coating liquid Titanium dioxide (TA-300) 5 parts Copolymer polyamide resin (Toray CM-8000) 4 parts Methanol 50 parts Isopropanol 20 parts Charge generation layer coating liquid Y-type oxotitanium phthalocyanine pigment powder 4 parts Polyvinyl butyral 2 parts Cyclohexanone 50 parts Tetrahydrofuran 100 parts Charge transport layer coating liquid Polycarbonate resin (Panlite TS-2050) 10 parts Charge transport material of the structural formula represented by the above formula (72) 9 parts Tetrahydrofuran 80 parts Protective layer Polycarbonate resin (Pan Light TS-2050) 5 parts Charge transporting material of the structural formula represented by the above formula (72) 3 parts Alumina fine particles (Alumina-C manufactured by Nippon Aloesil Co.) 2 parts Tetrahydrofuran 80 parts

Example 15 The electrophotographic photosensitive member belt No. 1
5 was mounted on the electrophotographic process shown in FIG. 5, and the image exposure light source was a semiconductor laser of 405 nm (image writing by a polygon mirror), and a probe of a surface electrometer was inserted so that the surface potential of the photoconductor immediately before development could be measured. did.
100,000 sheets were printed continuously. The results are shown in Table 6. From Table 6, it can be seen that the potential stability during repeated use is excellent, and the dot reproducibility and stability are excellent, as in the previous example. When the change in the film thickness due to repeated use was measured, no decrease in the film thickness was observed even after printing 100,000 sheets.

[0061]

[Table 6]

[0062]

According to the present invention, there is provided an electrophotographic photosensitive member having high sensitivity and excellent mechanical durability even in the oscillation wavelength region of a blue semiconductor laser or a light emitting diode.
Further, a stable electrophotographic apparatus and a process cartridge for the electrophotographic apparatus which do not cause a decrease in chargeability and a rise in residual potential even when repeatedly used without losing high sensitivity are provided, and greatly contribute to the electrophotographic field. It is.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a transmission spectrum of a charge transport layer film.

FIG. 2 is a schematic view of a cross section of the electrophotographic photosensitive member of the present invention.

FIG. 3 is a schematic view of a cross section of another electrophotographic photosensitive member of the present invention.

FIG. 4 is a schematic view of a cross section of another electrophotographic photosensitive member of the present invention.

FIG. 5 is a schematic view of an electrophotographic process cartridge and an electrophotographic apparatus of the present invention.

FIG. 6 is a schematic view showing another example of the electrophotographic process according to the present invention.

FIG. 7 is a schematic view showing an example of the process cartridge of the present invention.

FIG. 8 is a transmission spectrum diagram of a charge transport layer film of photoconductor No. 1.

FIG. 9 is a transmission spectrum diagram of a charge transport layer film of photoconductor No. 2.

FIG. 10 is a transmission spectrum diagram of a charge transport layer film of photoconductor No. 3;

FIG. 11 is a transmission spectrum diagram of a charge transport layer film of photoconductor No. 4;

FIG. 12 is a transmission spectrum diagram of a charge transport layer film of photoconductor No. 5;

FIG. 13 is a transmission spectrum diagram of a charge transport layer film of photoconductor No. 6.

FIG. 14 is a transmission spectrum diagram of a charge transport layer film of photoconductor No. 7;

[Explanation of symbols]

 (FIGS. 2, 3, and 4) 1 conductive support 2 charge generation layer 3 to 6 charge transport layer (FIG. 5) 1 photoreceptor 2 static elimination lamp 3 charging charger 4 eraser 5 image exposure unit 6 developing unit 7 before transfer Charger 8 Registration roller 9 Transfer paper 10 Transfer charger 11 Separation charger 12 Separation claw 13 Charger before cleaning 14 Fur brush 15 Cleaning brush (FIG. 6) 21 Photoconductors 22a, 22b Driving roller 23 Charging charger 24 Image exposure source 25 Transfer charger 26 Cleaning Pre-exposure 27 Cleaning brush 28 Static elimination light source (FIG. 7) 16 Photoconductor 17 Charging charger 18 Cleaning brush 19 Image exposure section 20 Developing roller

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme Court II (Reference) G03G 15/04 (72) Inventor Michihiko Nanba 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72 ) Inventor Shinichi Kawamura 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Chiaki 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2H068 AA14 AA20 AA28 BA12 BA13 BA21 BB31 BB33 BB49 CA02 CA05 CA06 CA22 CA29 CA33 CA37 CA40 CA54 CA60 FA01 FA13 FA27 FB08 2H076 AB05 AB16 AB42 DA37

Claims (15)

[Claims] In a laminated electrophotographic photosensitive member having a photosensitive layer including a charge generation layer and a charge transport layer on a conductive support, the charge transport layer transmits monochromatic irradiation light in a wavelength region of 390 to 460 nm. An electrophotographic photoreceptor, wherein the monochromatic irradiation light has a fluorescence generation efficiency of the charge transport layer of 0.8 or less. 2. The method according to claim 1, wherein the charge transporting layer is not exposed to the monochromatic irradiation light.
0% or more, and the fluorescence generation efficiency is 0.5
2. The electrophotographic photoreceptor according to claim 1, wherein: 3. The charge transport layer according to claim 1, wherein
0% or more, and the fluorescence generation efficiency is 0.3% or more.
The electrophotographic photosensitive member according to claim 1, wherein: 4. The electrophotographic photosensitive member according to claim 1, wherein the outermost surface of the photosensitive layer is formed by dispersing at least a filler. 5. The charge transport layer according to claim 1, wherein the charge transport layer comprises at least a charge transport material and a filler.
The electrophotographic photosensitive member according to any one of the above. 6. The charge transport layer according to claim 1, wherein the charge transport layer comprises at least a layer comprising a charge transport material and at least a layer comprising a filler and a binder resin.
The electrophotographic photosensitive member according to any one of the above. 7. The electrophotograph according to claim 1, wherein the charge transporting layer comprises at least a layer comprising a charge transporting material and at least a layer comprising a filler and a charge transporting material. Photoconductor. 8. The method according to claim 1, wherein the filler is titanium oxide, tin oxide,
Zinc oxide, zirconium oxide, indium oxide, silicon nitride, calcium oxide, barium sulfate, indium oxide, silica, colloidal silica, alumina, carbon black, fluorine resin fine powder, polysiloxane resin fine powder, and polymer charge transport material fine 4. A material selected from powders or a mixture of two or more materials.
8. The electrophotographic photosensitive member according to any one of 7. 9. The charge transport material used for the charge transport layer,
The electrophotographic photoreceptor according to any one of claims 1 to 8, which is a low-molecular-weight charge transport material or a mixture thereof. 10. The electrophotographic photoreceptor according to claim 1, wherein the charge transporting material used for the charge transporting layer is a polymer type charge transporting material or a mixture thereof. 11. The charge transport material according to claim 1, wherein the charge transport material used in the charge transport layer is a mixture of a low molecular charge transport material and a high molecular charge transport material. Electrophotographic photoreceptor. 12. An electrophotographic photosensitive member and at least one unit selected from the group consisting of a charging unit, an image exposing unit, a developing unit, a transfer unit and a cleaning unit are integrally supported, and are detachably attached to an electrophotographic apparatus main body. 12. A process cartridge according to claim 1, wherein the electrophotographic photosensitive member according to claim 1 is used as the electrophotographic photosensitive member. 13. The process cartridge according to claim 12, wherein a writing light source in said image exposure means is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range of 400 to 450 nm. 14. An electrophotographic apparatus according to claim 1, wherein said electrophotographic photoreceptor, charging means, image exposing means, developing means and transfer means are mounted thereon. An electrophotographic apparatus characterized by using a body. 15. The electrophotographic apparatus according to claim 14, wherein a wavelength of a writing light source in said image exposure means is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range of 400 to 450 nm.