JP2003149840A - Electrophotographic photoreceptor and image forming apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having high sensitivity characteristics in a short wavelength region and so excellent in durability that it is free of fatigue or deterioration due to light and to provide an image forming apparatus using the photoreceptor, having high sensitivity and high resolving power and giving stable image quality. SOLUTION: In the electrophotographic photoreceptor using a laser whose oscillation wavelength is in the range of 380-500 nm as a light source for exposure, an N,N-bisenamine compound of formula (1) is contained as a charge transfer material in a photosensitive layer on an electrically conductive support. The image forming apparatus using a laser having an oscillation wavelength at 380-500 nm as a light source for exposure is loaded with the electrophotographic photoreceptor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member using a laser oscillating at a short wavelength as a light source for exposure and an image forming apparatus using the same.

[0002]

2. Description of the Related Art In recent years, in electrophotographic photoreceptors, organic photoconductive materials have been generally and often used in comparison with conventionally used inorganic photoconductive materials due to the progress of their development. It started to come. The electrophotographic photoconductor using an organic photoconductive material has some problems in sensitivity, durability and environmental stability, but it has flexibility in material design, toxicity and cost. At
This is because it has many advantages over inorganic photoconductive materials. At present, as a constitution of an electrophotographic photosensitive member using an organic photoconductive material which has been generally put into practical use, a laminated structure in which a charge generating function and a charge transporting function in a photoconductive function are respectively shared by separate substances Type or dispersion type function-separated type photoreceptors. In such a function-separated type photoreceptor, since the selection range of each substance is widened, by combining the best substances in electrophotographic properties such as charging property, sensitivity, residual potential, repetitive property and printing durability, It is possible to provide a high-performance photoconductor. In addition, since an electrophotographic photoreceptor using an organic photoconductive material is produced by coating a photosensitive layer on a conductive support, it is possible to provide an inexpensive photoreceptor with extremely high productivity, and to charge The photosensitive wavelength region and photosensitivity can be freely controlled by appropriately selecting the generating substance. Further, there is an advantage that a photoreceptor having excellent abrasion resistance can be designed by appropriately selecting the binder resin contained in the charge transfer layer. As described above, by using the organic photoconductive material, the problem of the characteristics of the electrophotographic photosensitive member was overcome and the performance was improved, and as a result, the organic photoconductive material was changed to the inorganic photoconductive material. It is used more frequently than conductive materials.

On the other hand, a typical example of an image forming apparatus using an electrophotographic technique using a laser as an exposure light source is a laser printer. In recent years, however, digitalization has progressed even in copying machines, and the laser is used as the exposure light source. Is common. As a laser used as a light source for exposure, a semiconductor laser that is low in cost, consumes little energy, and is lightweight and compact has been put into practical use. A semiconductor laser generally has an oscillation wavelength in the near infrared region around 800 nm from the viewpoint of output stability and life.
Then, with the advancement of semiconductor laser technology, an image forming apparatus using electrophotographic technology using a laser as an exposure light source has appeared,
As the charge generating substance, a laminated type photoreceptor having an organic compound having a high sensitivity by absorbing light in a long wavelength region, particularly a phthalocyanine pigment, in a charge generating layer has been developed.

Further, in order to improve the image quality of the output image of the image forming apparatus by the electrophotographic technique, a high resolution image quality is being studied. There are several means for achieving high resolution with high recording density. As an optical means, there is a method of narrowing the spot diameter of the laser beam to increase the writing density. Therefore, it is conceivable to shorten the focal length of the lens used, but in addition to the difficulty in designing the optical system, with a laser having an oscillation wavelength in the near infrared region near 800 nm, the beam diameter can be adjusted by operating the optical system. Even if it is made thin, it is difficult to obtain the sharpness of the spot contour. The cause is the diffraction limit of laser light, which is an unavoidable phenomenon.

The spot diameter D of the laser focused on the surface of the photosensitive member is determined by the wavelength λ of the laser beam and the numerical aperture N of the lens.
It has the relationship shown by the following formula (I) with A. D = 1.22λ / NA (I) From the formula (I), the spot diameter D is proportional to the oscillation wavelength of the laser light. Therefore, in order to reduce the spot diameter D, a laser with a short oscillation wavelength should be used. I understand. Further, as described above, the development of a laser having a short oscillation wavelength was delayed compared with a laser having a long oscillation wavelength, but in the early 1990s, a red laser having an oscillation wavelength near 650 nm was put into practical use. In 1995, the successful development of a 410nm blue-violet laser was announced, and its practical application has become a reality.

Therefore, if the spot diameter D is reduced by using a laser having a short oscillation wavelength, a high resolution with a high recording density can be achieved. However, although such a blue laser has been greatly expected to improve the recording density in an optical disc, it has hardly been expected as an exposure light source for an image forming apparatus using an electrophotographic technique. This is because the conventional electrophotographic photoreceptor does not show sensitivity in this wavelength range. That is, the conventional laminated electrophotographic photoreceptor has a charge generation layer, a charge generation layer, and
A laminate of charge transfer layers is generally put into practical use. If a charge generating substance that also absorbs at a wavelength of 500 nm or less is used in the photoreceptor, it should generally show sensitivity even when exposed to a short wavelength laser of 500 nm or less. However, in practice, since the charge transfer layer laminated on the charge generation layer, particularly the charge transfer material, absorbs light at a wavelength of 500 nm or less, the short wavelength laser light used as the exposure light source is reflected on the surface of the photosensitive layer. Since it is absorbed and cannot reach the charge generation layer, the laminated electrophotographic photoreceptor does not show sensitivity in this wavelength range. In addition, since it is exposed to high-intensity light having a uniform wavelength component, the charge transfer material and the charge generation material are easily deteriorated, and the sensitivity of the photoconductor is lowered by long-term use, and high image quality cannot be maintained. is there.

[0007]

The object of the present invention is 38
An electrophotographic photosensitive member having high sensitivity characteristics in a wavelength range of 0 to 500 nm and excellent in durability that does not deteriorate due to light, and a high sensitivity using the photosensitive member as a light source of a laser in a wavelength range of 380 to 500 nm. And, it is to provide an image forming apparatus having high resolution and stable image quality.

[0008]

SUMMARY OF THE INVENTION The gist of the present invention is an electrophotographic photosensitive member using a laser having an oscillation wavelength in the range of 380 to 500 nm as an exposure light source, which is used as a photosensitive layer on a conductive support. An electrophotographic photoreceptor characterized by containing an N, N-bisenamine compound represented by the following general formula (1) as a charge transfer substance.

[Chemical 3] (In the formula, Ar ₁ represents an aryl group or a heterocyclic group which may have a substituent, and Ar _{2 to} Ar ₅ are the same or different, and an aryl group and a heterocyclic group which may have a substituent. , Represents an aralkyl group or an alkyl group.)

Further, the gist of the present invention resides in the above general formula (1)
The N, N-bisenamine compound represented by the formula (2) is an electrophotographic photoreceptor which is a compound represented by the following general formula (2).

[Chemical 4] (Wherein, Ar ₆ are the same or different, an optionally substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, Arirukokishi group having 6 to 15 carbon atoms, carbon atoms 1-10 thioalkoxy group, C6-C15 thioarylcoxy group, C1-C10 dialkylamino group or C6-C15 diarylamino group, or a hydrogen atom, and n is 1- Represents an integer of 5. Ar
_{2 to} Ar ₅ have the same meaning as in formula (1). Further, the gist of the present invention resides in an image forming apparatus for forming an image using the reversal development process equipped with the electrophotographic photosensitive member. Hereinafter, the present invention will be described in detail.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The electrophotographic photosensitive member of the present invention contains the N, N-bisenamine compound represented by the general formula (1) as a charge transfer substance in the photosensitive layer on the conductive support. It is characterized by. Specific examples of Ar _{1 in} the general formula (1) include phenyl, m-tolyl, 2,4-xylyl, 3,4-xylyl, p-methoxyphenyl, p-.
(Diphenylamino) phenyl, naphthyl, pyrenyl,
Aryl groups such as biphenyl, heterocyclic groups such as benzofuryl, benzothiazolyl, benzoxazolyl, N-ethylcarbazolyl, methyl benzyl, methoxy benzyl, 2
Examples thereof include aralkyl groups such as -thienylmethyl.

Specific examples of Ar _{2 to} Ar ₅ include:
Phenyl, m-tolyl, p-methoxyphenyl, p-
(Dimethyllamino) phenyl, aryl groups such as naphthyl, heterocyclic groups such as benzofuryl, benzothiazolyl, benzoxazolyl, methyl, ethyl, n-propyl, I
Examples thereof include alkyl groups such as so-propyl. Generally, electron donating substituents are preferred. The representative compounds of the N, N-bisenamine compounds represented by the general formula (1) are shown below. Needless to say, the N, N-bisenamine compound of the present invention is not limited to these compounds.

[0012]

[Chemical 5]

[0013]

[Chemical 6]

Next, regarding the electrophotographic photoreceptor of the present invention,
This will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view schematically showing an example of a function-separated electrophotographic photosensitive member in which a photosensitive layer 4 composed of a charge generation layer 5 and a charge transfer layer 6 is formed on a conductive support 1. The charge transfer layer 6 contains the N, N-bisenamine compound represented by the general formula (1) of the present invention as the charge transfer material 3. FIG. 2 is a cross-sectional view schematically showing an example of the function-separated electrophotographic photosensitive member of the electrophotographic photosensitive member of FIG. 1 in which an intermediate layer 8 is provided between the conductive support 1 and the photosensitive layer 4. is there.

As the conductive support 1 constituting the electrophotographic photosensitive member, aluminum, aluminum alloy,
Metallic drums and sheets made of copper, zinc, stainless steel, titanium, etc., polymeric materials such as polyethylene terephthalate, nylon and polystyrene, hard paper and glass surface, metal foil lamination and metal deposition treatment, conductive polymer , A drum, a sheet, and a seamless belt having a layer of a conductive compound such as tin oxide and indium oxide vapor-deposited or applied thereon. If necessary, the surface of the conductive support 1 may be anodized, treated with chemicals or hot water, colored, or roughened the surface of the conductive support to the extent that the image quality is not affected. An image defect due to the interference of lasers having a regulated wavelength may be prevented by performing a diffuse reflection process such as. In the electrophotographic process using a laser as an exposure light source, this process prevents the incident laser and the light reflected in the electrophotographic photosensitive member from interfering with each other, and this interference fringe appears on the image to cause an image defect. It is for.

The intermediate layer 8 of the photoreceptor shown in FIG. 2 prevents image defects in the reversal development process, covers defects on the surface of the conductive support, improves chargeability, improves adhesion of the photosensitive layer, and It is provided between the conductive support 1 and the photosensitive layer 4 in order to improve the coating property of the photosensitive layer. In particular, when an image is formed using the reversal development process, a toner image is formed on the portion of the exposed portion where the surface charge has decreased, so if the surface charge decreases due to factors other than exposure, the toner will adhere to the white background. Image fogging such as black spots occurs, and the image quality is significantly deteriorated. In other words, due to the lack of the conductive support 1 and the photosensitive layer 4, the chargeability is lowered in a minute area, and an image called a black spot (black spot) where toner adheres to a white background is formed. Since the image defect such as fog is remarkable, it is prevented by the intermediate layer 8.

As the material of the intermediate layer 8, various resin materials,
Those containing metal particles and metal oxide particles are used. Specifically, examples of the metal oxide particles include titanium oxide, aluminum oxide, aluminum hydroxide and tin oxide. As the resin material used for the intermediate layer, polyethylene resin, polypropylene resin, polystyrene resin, acrylic resin, vinyl chloride resin, vinyl acetate resin, polyurethane resin, epoxy resin, polyester resin, melamine resin, silicone resin,
Examples thereof include resin materials such as polyvinyl butyral resin and polyamide resin, copolymer resins containing two or more of monomers constituting these resins, casein, gelatin, polyvinyl alcohol, ethyl cellulose and the like. Of these, polyamide resins are particularly preferable, and more preferable polyamide resins include alcohol-soluble nylon resins such as 6-nylon and 66-nylon.
610-nylon, 11-nylon, 12-nylon and the like, so-called copolymerized nylon and N
Resins of the type that are chemically modified nylon are suitable, such as -alkoxymethyl modified nylon and N-alkoxyethyl modified nylon.

In the intermediate layer 8, a metal such as titanium oxide is used to adjust the volume resistance value, prevent the injection of charges from the conductive support 1, and maintain the electrical characteristics of the photoconductor in various environments. You may contain an oxide. In this case, the above-mentioned resin is used as a single solvent of water and various organic solvents, particularly water, methanol, ethanol or butanol, water and alcohols, two or more kinds of alcohols, acetone or dioxolane and the like, or dichloroethane, A metal oxide such as titanium oxide is dispersed in a solution prepared by dissolving a chlorine-based solvent such as chloroform or trichloroethane in a mixed solvent of alcohols to prepare a coating liquid for the intermediate layer, and the coating liquid is used as the conductive support 1 The intermediate layer 8 is formed by applying it on the upper surface.

As a method for dispersing the metal oxide in the coating liquid for the intermediate layer, a general method such as a ball mill, a sand mill, an attritor, a vibration mill and an ultrasonic disperser can be applied. The total content A of the resin and the metal oxide in the coating solution for the intermediate layer is 3/97 to 20/80 with respect to the content B of the organic solvent used in the coating solution for the intermediate layer. Is preferable. The weight ratio of resin / metal oxide is preferably 90/10 to 1/99, and 7
0/30 to 5/95 is more preferable.

Examples of the coating method include spraying method, bar coating method, roll coating method, blade method, ring method and dipping method. From these coating methods, the most suitable method is selected in consideration of the physical properties and productivity of the coating liquid. Particularly, the dip coating method is a method of forming an intermediate layer by immersing the conductive support 1 in a coating tank filled with a coating solution and then pulling the conductive support 1 at a constant speed or a speed that sequentially changes. The dip coating method is relatively simple and excellent in productivity and cost. Therefore, the dip coating method is often used for manufacturing an electrophotographic photoreceptor. The apparatus used for the dip coating method may be provided with a coating liquid dispersion device typified by an ultrasonic wave generation device in order to stabilize the dispersibility of the metal particles.

The thickness of the intermediate layer 8 is usually 0.01 μm or more and 20 μm or less, preferably 0.05 μm or more and 10 μm or more.
It is in the range of μm or less. The thickness of the intermediate layer 8 is 0.01 μm
When the thickness is thinner, the defects of the conductive support 1 cannot be covered to obtain a uniform surface property, and the charge injection from the conductive support 1 cannot be prevented, so that the chargeability is deteriorated. Occurs, and substantially does not function as the intermediate layer 8. On the other hand, it is not preferable to make the thickness thicker than 20 μm, because when the intermediate layer is applied by dip coating, it becomes difficult to manufacture the photoconductor and the sensitivity of the photoconductor decreases.

Substances effective as the charge generating substance 2 include azo pigments such as monoazo, bisazo and trisazo pigments, indigo pigments such as indigo and thioindigo, helylene pigments such as berylenimide and bernic anhydride, and anthraquinone. Examples thereof include polycyclic quinone pigments such as pyrene quinone, phthalocyanine pigments such as metal phthalocyanine and non-metal phthalocyanine, squarylium dyes, pyrylium salts and thiopyrylium salts, triphenylmethane dyes, selenium, and inorganic materials such as amorphous silicon. These charge generating substances may be used alone or in combination of two or more kinds. Furthermore, triphenylmethane dyes represented by methyl violet, crystal violet, night blue and Victoria blue, acridine dyes represented by erythrosine, rhodamine B, rhodamine 3R, acridine orange and flaveocin, methylene blue and methylene green, etc. It may be combined with a sensitizing dye such as a thiazine dye typified, an oxazine dye typified by capri blue or meldra blue, a cyanine dye, a styryl dye, a pyrylium salt dye or a thiopyrylium salt dye.

The charge generation layer 5 may be formed by vacuum-depositing the charge generation material 2, or by applying a dispersion liquid in which the charge generation material 2 is mixed and dispersed in an organic solvent mixed with a binder resin. A film forming method or the like is used. Generally, a method in which the charge generating substance 2 is dispersed in a binder resin mixed solution by a known method and then applied is preferable.

As the binder resin, polyester resin, polystyrene resin, polyurethane resin, phenol resin, alkyd resin, melamine resin, epoxy resin,
Resins such as silicone resin, acrylic resin, methacrylic resin, polycarbonate resin, polyarylate resin, phenoxy resin, polyvinyl utilal resin and polyvinyl formal resin, or copolymer resin containing two or more of repeating units of these resins. Is used.
Examples of the copolymer resin include vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, acrylonitrile-styrene copolymer resin, and other insulating resins. .

Solvents for dissolving these binder resins include halogenated hydrocarbons such as methylene chloride and ethane dichloride, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran (THF). )
And ethers such as dioxane, cellosolves such as dimethoxyethane, aromatic hydrocarbons such as benzene, toluene and xylene, aprotic polar solvents such as N, N-dimethylformamide and N, N-dimethylacetamide, or the like. It is possible to use a mixed solvent of the above.

The compounding ratio of the charge generating substance 2 and the binder resin is preferably such that the ratio of the charge generating substance 2 is 10% by weight to 99% by weight. When the amount is less than this range, the sensitivity is lowered, and when the amount is more than the range, not only the film strength of the charge generation layer is lowered but also the dispersibility is lowered and coarse particles are increased, so that image defects, especially black spots are increased. Before the mixing and dispersing treatment, the binder resin may be pulverized by a pulverizer in advance. Examples of the pulverizer used for the pulverization include a ball mill, a sand mill, an attritor, a vibration mill and an ultrasonic disperser. Appropriate conditions are selected as the dispersion conditions so that impurities are not mixed due to abrasion of the container and the dispersion medium used.

Examples of the coating method include spray method, bar coating method, roll coating method, blade method, ring method and dipping method. In particular, the dip coating method is relatively simple as described above, and is excellent in productivity and cost. Therefore, it is often used for forming the charge generation layer 5. The thickness of the charge generation layer 5 is preferably 0.05 μm
Or more and 5 μm or less, more preferably 0.1 μm or more and 1 μm
The range is as follows.

The charge transfer layer 6 is formed by containing, as the charge transfer material 3, one or more kinds of N, N-bisenamine compounds represented by the general formula (1) of the present invention in a binder resin. This N, N-bisenamine compound does not absorb light in the wavelength range even when a semiconductor laser or the like having an oscillation wavelength in the range of 380 to 500 nm is used, and has high intensity light with uniform wavelength components. It has an extremely excellent property that it is hard to deteriorate even when exposed to light. That is, when the N, N-bisenamine compound is used as a charge transfer material, the charge transfer material does not absorb light in the emission wavelength range, and the charge generation material absorbs the light to exhibit high sensitivity and high sensitivity. Since the quality of the electrophotographic photosensitive member does not easily change even with intense light, it is possible to provide an electrophotographic photosensitive member that does not lose its sensitivity and maintain high image quality due to long-term use.

In the charge transfer layer 6, not only the N, N-bisenamine compound represented by the general formula (1) but also other charge transfer substances may be mixed and used. As the charge transfer substance, a carbazole derivative, an oxazole derivative, an oxadiazole derivative, a thiazole derivative, a thiadiazole derivative, a triazole derivative, an imidazole derivative, an imidazolone derivative, an imidazolidine derivative, a bisimidazolidine derivative, a styryl compound,
Hydrazone compounds, polycyclic aromatic compounds, indole derivatives, pyrarizone derivatives, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, triarylamine derivatives, triarylmethane derivatives, phenylenediamine Examples thereof include derivatives, stilbene derivatives and benzidine derivatives. Further, a polymer having a group composed of these compounds in its main chain or side chain, for example, poly-N-vinylcarbazole,
Examples thereof include poly-1-vinylpyrene and poly-9-vinylanthracene, and polysilane.

However, in the case of the function-separated type photosensitive layer 4 illustrated in FIGS. 1 and 2, the upper charge transfer layer 6 is transparent to the oscillation wavelength of the semiconductor laser used as described above. is important. The electrophotographic photoreceptor of the present invention has an exposure light source of 380 to 500 nm, particularly 400 to 500 nm.
Since a semiconductor laser with an oscillation wavelength of nm is used,
As the charge transfer substance 3, an N, N-bisenamine compound represented by the general formula (1), which has no absorption in the short wavelength region of 400 to 500 nm and has high mobility, is used. It should be noted that the charge transfer layer 6 may be further used in combination with an arylamine, penzidine or stilpen type compound.

The binder resin of the charge transfer layer 6 is selected to be compatible with the charge transfer material 3. For example, vinyl polymers such as polymethylmethacrylate, polystyrene, polyvinyl chloride and copolymers thereof, as well as polycarbonate, polyester, polyester carbonate, polysulfone, phenoxy, epoxy, silicone, polyarylate, polyamide, polyester, polyurethane, polyacrylamide. , And resins such as phenol. These may be used alone or in combination of two or more, or may be a partially crosslinked thermosetting resin. In particular, resins such as polystyrene, polycarbonate, polyarylate, and polyphenylene oxide have a volume resistance value of 10 ¹³ Ω or more and are excellent in film forming property and potential property.

A known plasticizer or a silicone-based leveling agent may be added to the charge transfer layer 6 as needed to impart processability and flexibility to the photosensitive layer and improve surface smoothness. it can. Examples of the plasticizer include dibasic acid ester, fatty acid ester, phosphoric acid ester, phthalic acid ester, chlorinated paraffin, and epoxy type plasticizer. Further, fine particles of an inorganic or organic compound can be added to the charge transfer layer 6 to increase mechanical strength and electric characteristics. The addition amount of the binder resin and the N, N-bisenamine compound is generally 10:12 by weight. Since the N, N-bisenamine compound has high mobility, the weight ratio of the N, N-bisenamine compound / binder resin is 10/12 to 10/25 while maintaining high sensitivity, and the content of the binder resin is The rate can be increased. By increasing the content of the binder resin in this way, the printing durability of the charge transfer layer 6 can be improved and the durability of the electrophotographic photosensitive member can be improved. The ratio of the binder resin is 10 /
When it exceeds 25, the viscosity of the coating solution increases, so that when the photosensitive drum is prepared by the dip coating method, the coating speed is lowered and the productivity is remarkably deteriorated. Further, when it is 10/12 or less, abrasion resistance is lowered and the viscosity of the coating solution is further lowered. Therefore, when a photosensitive drum is prepared by a dip coating method, it is difficult to secure an appropriate film thickness even by adjusting the coating speed. The problem occurs.

The charge transfer layer 6 is formed by using an appropriate organic solvent as in the intermediate layer 8 and the charge generation layer 5 described above.
It can be carried out by a spray method, a bar coating method, a roll coating method, a blade coating method, a ring method, a dipping method or the like. In particular, the dip coating method is excellent in various points as described above and is therefore widely used. As the coating solvent, aromatic hydrocarbons such as benzene, toluene, xylene and monochlorobenzene, halogenated hydrocarbons such as dichloromethane and dichloroethane, solvents such as THF, dioxane, dimethoxymethyl ether and dimethylformamide, or a mixture of two or more thereof. Mixed solvent is used,
If necessary, solvents such as alcohols, acetonitrile and methyl ethyl ketone can be further added and used. The thickness of the charge transfer layer 6 is usually 5 to 50 μm, preferably 10 to 40 μm.

The photosensitive layer 4 may further contain one or more kinds of electron accepting substances and dyes 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 tonitroanthraquinone, polycyclic or heterocyclic nitro compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitrofluorenone, diphenoquinone compounds or electron withdrawing thereof For example, the material is a polymerized material. By providing a protective layer on the surface of the photosensitive layer 4, it is possible to improve the abrasion resistance of the photosensitive layer 4 and prevent chemical adverse effects due to ozone and nitrogen oxides.

Each layer of the photoreceptor may contain various additives such as an antioxidant and a sensitizer, if necessary. Especially as an antioxidant, a hindered phenolic compound,
An appropriate amount of antioxidants such as hydroquinone compounds, tocophenol compounds and hindered amine compounds, and ultraviolet absorbers may be added as necessary. These antioxidants are used in an amount of 0.1 wt% or more and 5 wt% or less (0.1 wt% or more and 50 wt% or less of the charge transfer substance in the case of a hindered amine compound) with respect to the charge transfer substance. Is preferred. This is expected to improve characteristics in terms of potential characteristics, stability as a coating solution, reduction of fatigue deterioration when the photoreceptor is repeatedly used, durability and the like.

Next, an image forming apparatus using the above electrophotographic photosensitive member will be described. The image forming apparatus of the present invention is not limited to the contents described below. FIG. 3 is a schematic diagram showing an image forming apparatus incorporating the electrophotographic photosensitive member of the present invention. Around the electrophotographic photosensitive member 11, a charger 32, a semiconductor laser 31, a developing device 33, a transfer charger 34, a fixing device 35, and a cleaner 36 are sequentially arranged.

The drum-shaped electrophotographic photosensitive member 11 is rotationally driven in the direction of arrow 41 at a predetermined peripheral speed by a driving means (not shown). During the rotation process, the photoconductor 11 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the contact type or non-contact type charger 32. Next, the laser beam from the semiconductor laser 31 is repeatedly scanned on the surface of the photoconductor 11 in its longitudinal direction (main scanning direction),
An electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 11. The formed electrostatic latent image is developed as a toner image by the developing device 33 provided downstream of the image formation point in the rotational direction.

In synchronism with the exposure of the photoconductor 11, the transfer paper is supplied to the transfer charger 34 provided further downstream in the rotational direction of the developing device 33, and the toner image is transferred onto the transfer paper. The transfer sheet is conveyed to the fixing device 35 by the conveyance belt, and the toner image is fixed on the transfer sheet. The transfer paper on which the image is formed in this manner is ejected. The cleaner 36 is
On the downstream side in the rotating direction and on the upstream side in the rotating direction of the charger 32,
The transfer charger 34 is further provided with a charge eliminating lamp (not shown) to clean the toner remaining on the surface of the photoconductor 11. Further, by rotating the photoconductor 11, the above-described rotation process is repeated to form an image. When the peripheral surface of the photoconductor 11 is negatively charged by the charger 32, a reversal development process is employed in which negatively charged toner is attached to the exposed area where the surface charge is reduced by exposure to develop.

A semiconductor laser 31 having an oscillation wavelength of 380 to 500 nm is used as an exposure light source, and an electrophotographic photosensitive member containing the above-mentioned N, N-bisenamine compound as a charge transfer substance is mounted to provide high sensitivity and high resolution. It is possible to provide an image forming apparatus that can stably obtain an image quality. Especially in the reversal development process, by using the electrophotographic photoreceptor, there is no fatigue deterioration of the photoreceptor,
It is possible to provide an image forming apparatus that has high durability and high sensitivity, is extremely excellent in dot reproducibility and character reproducibility, and can obtain an output image of high resolution. In addition, the charger 32
Is a contact charging means using a charging roller or the like,
The contact charger 32 may be provided with a function of cleaning the residual toner on the photoconductor 11 and the cleaning means 36 may be omitted. Furthermore, the photo-static elimination process can be omitted.

Further, the photoconductor 11 may be integrated with at least one of the charger 32, the developing unit 33 and the cleaner 36 to form a process cartridge. For example, a process cartridge including all of the photoconductor 11, the charger 32, the developing unit 33 and the cleaner 36, a process cartridge including the photoconductor 11, the charger 32 and the developing unit 33, the photoconductor 11 and the cleaner 36, It is possible to configure a process cartridge having the built-in type and a process cartridge having the photoconductor 11 and the developing unit 33 incorporated. Using such a process cartridge facilitates replacement in a printer or the like.

(Examples) Next, the electrophotographic photosensitive member of the present invention and the image forming apparatus using the same will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. is not.

Example 1 Dendritic titanium oxide surface-treated with Al ₂ O ₃ and ZrO ₂ (T manufactured by Ishihara Sangyo Co., Ltd.)
TO-D-1) 9 parts by weight and copolymer nylon resin (CM8000 manufactured by Toray Industries Inc.) 9 parts by weight were added to 41 parts by weight of 1,3-dioxolane and 41 parts by weight of methyl alcohol,
It was dispersed for 12 hours using a paint shaker to prepare an intermediate layer coating solution. The prepared coating solution for intermediate layer was applied onto an aluminum substrate with a baker applicator so that the film thickness after drying would be 1 μm to form an intermediate layer. Then, 2 parts by weight of an azo compound represented by the following structural formula (3) was added to a resin solution prepared by dissolving 1 part by weight of butyral resin (BX-1 manufactured by Sekisui Chemical Co., Ltd.) in 97 parts by weight of THF,
It was dispersed for 10 hours with a paint shaker to prepare a charge generation layer coating liquid. This charge generation layer coating solution was applied onto the intermediate layer previously formed so that the film thickness after drying was 0.3 μm using a baker applicator to form a charge generation layer.

[0043]

[Chemical 7]

Next, the above-mentioned No. 1, 10 parts by weight of N, N-bisenamine compound, 14 parts by weight of polycarbonate resin (Z200 manufactured by Mitsubishi Gas Chemical Co., Inc.), 2,6-
Di-t-butyl-4-methylphenol (0.2 parts by weight) was dissolved in 80 parts by weight of THF to prepare a charge transfer layer coating solution. On the charge generation layer previously formed with this charge transfer layer coating liquid, the film thickness after drying with a baker applicator is 1
The charge transfer layer was formed by coating so as to have a thickness of 8 μm. In this way, a laminated electrophotographic photosensitive member having the layer structure illustrated in FIG. 2 was produced.

[Examples 2, 3, 4 and 5] Nos. Used in Example 1 In place of the N, N-bisenamine compound of No. 1, the exemplified No. 6, 9, 15 and 19 N, N
Four types of electrophotographic photoconductors were produced in the same manner as in Example 1 except that the -bisenamine compound was used.

[Comparative Example 1] No. 1 used in Example 1 An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the comparative compound (1) represented by the following structural formula (4) was used in place of the N, N-bisenamine compound of 1.

[0047]

[Chemical 8]

Example 6 Polycarbonate resin was added to 20
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the parts by weight were used.

Example 7 Polycarbonate resin was added to 25
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the parts by weight were used.

[Comparative Example 2] Polycarbonate resin 11
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the parts by weight were used.

[Comparative Example 3] 26 polycarbonate resin
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the parts by weight were used.

[Evaluation 1] Each electrophotographic photosensitive member produced as described above was evaluated using an electrostatic copying paper test apparatus (EPA-8200 manufactured by Kawaguchi Electric Co., Ltd.). -5k on photoconductor
Vo [V] is the charging potential when V is applied, wavelength 450 and 680 nm dispersed by a monochromator 1 μW / c
The exposure amount required to expose the light of m ² to halve the potential was the sensitivity (E1 / 2) [μJ / cm ² ], and the potential after 10 seconds of exposure was the residual potential (Vr) [V]. . Furthermore, the sensitivity (El / 2), the charging potential (Vo), and the residual potential (Vr) after the charging and the exposure were repeated 5000 times were obtained. Further, with respect to the photoconductors of Examples 1, 6, 7 and Comparative Examples 2 and 3, the degree of decrease in the photoconductor film thickness was evaluated using a wear tester manufactured by Suga Test Instruments Co., Ltd. The measurement conditions were as follows: abrasive = aluminum oxide # 2000, load = 1.96 N, and number of times of friction = 10,000. The weight of the photoconductor was measured at the initial stage and after 10,000 times of rubbing, and the difference in wear amount was determined. In addition, the electrophotographic photoreceptors of Example 1 and Comparative Example 1 were attached to a conductive support, and a solid-state blue SHG laser (exposure light source) was used as an exposure light source in a copying machine (AR-N200 manufactured by Sharp Corporation) that employs a reversal development method. Hitachi Metals ICD-
430: 430nm) with a modified machine equipped with 1200
1 dot equivalent to dpi (dot per inch)
A space image and a 5-point character image were output and the image was evaluated. The results of these evaluations are shown in Table 1.

[0053]

[Table 1]

[0054] Example 8 _A1 2 _{0 3} and dendritic titanium oxide subjected to surface treatment with ZrO ₂ (manufactured by Ishihara Sangyo Kaisha, Ltd. T
TO-D-1) 9 parts by weight and copolymer nylon resin (CM8000 manufactured by Toray Industries Inc.) 9 parts by weight were added to 41 parts by weight of 1,3-dioxolane and 41 parts by weight of methyl alcohol,
It was dispersed for 12 hours using a paint shaker to prepare an intermediate layer coating solution. 30 mm of prepared intermediate layer coating solution
It was applied to a cylindrical aluminum tube of Φ × 340 mm by dip coating so that the film thickness after drying would be 1 μm, to form an intermediate layer. Then, 2 parts by weight of the azo compound represented by the structural formula (3) was added to a resin solution prepared by dissolving 1 part by weight of butyral resin (BX-1 manufactured by Sekisui Chemical Co., Ltd.) in 97 parts by weight of THF, and then using a paint shaker. Dispersion was carried out for 10 hours to prepare a coating liquid for charge generation layer. This charge generation layer coating liquid was applied onto the previously formed intermediate layer by dip coating so that the film thickness after drying was 1 μm to form a charge generation layer. Next, the No. THF80 of 10 parts by weight of N, N-bisenamine compound 1 of 1, 12 parts by weight of a polycarbonate resin (Z200 manufactured by Mitsubishi Gas Chemical Co., Inc.), and 0.2 parts by weight of 2,6-di-t-butyl-4-methylphenol.
A coating liquid for a charge transfer layer was prepared by dissolving it in parts by weight. This charge transfer layer coating liquid is formed on the charge generation layer previously formed,
A charge transfer layer was formed by coating so that the dry film thickness after dip coating was 18 μm. In this way, the laminated electrophotographic photosensitive drum shown in FIG. 3 was produced.

Example 9 Polycarbonate resin was added to 25
An electrophotographic photosensitive drum was produced in the same manner as in Example 8 except that the parts by weight were used.

Comparative Example 4 Polycarbonate resin was added to 30
An attempt was made to manufacture an electrophotographic photosensitive drum in the same manner as in Example 8 except that the weight part was used. However, the resin was not completely dissolved, an amount of THF was added, and coating was performed with the completely dissolved coating solution for the charge transfer layer. Since the amount of the coating solvent is large, a brushing phenomenon (whitening at the lower end portion) occurred at the lower end portion of the producing drum, and the electrophotographic photosensitive drum for evaluation could not be completely produced.

Comparative Example 5 An electrophotographic photosensitive drum was produced in the same manner as in Example 8 except that the polycarbonate resin was changed to 7 parts by weight. However, the viscosity of the coating liquid for the charge transfer layer did not reach an appropriate value, so that a predetermined CT film thickness could not be secured, and the evaluation electrophotographic photosensitive drum could not be produced.

[Evaluation 2] The electrophotographic photosensitive drums of Examples 8 and 9 were evaluated for initial and / or accelerated fatigue fatigue electrophotographic characteristics with a drum simulator. As the evaluation method, the sensitivity E1 / 2, which is the exposure amount required to halve the potential by exposure, the dragon potential Vo when -5 kV was applied to the photoconductor, and the residual potential Vr after 3 seconds of exposure were measured. It depends on how you do it. The results of these evaluations are shown in Table 2.

[0059]

[Table 2]

From the results shown in Tables 1 and 2, the following was confirmed. The electrophotographic photoreceptors of Examples are superior in sensitivity in the short wavelength region, particularly in the vicinity of 500 nm, as compared with Comparative Examples, and
Stable in repeatability. The image forming apparatus of the embodiment is extremely excellent in dot reproducibility and character reproducibility, and can obtain a high-resolution output image. The image forming apparatus of the embodiment has excellent durability and can obtain a high-resolution output image.

[0061]

As is apparent from the above description in detail, according to the present invention, a specific N, N- is formed in the charge transfer layer.
By including a charge transfer substance composed of a bis enamine compound, the oscillation wavelength of the exposure light source is 380 to 5
It is possible to provide an electrophotographic photosensitive member which has high sensitivity characteristics to a laser in the range of 00 nm and which is excellent in durability and is not fatigue-degraded by light. Further, according to the present invention, by using a laser having an oscillation wavelength in the range of 380 to 500 nm as a light source and mounting the electrophotographic photosensitive member, it is possible to obtain stable image quality with high sensitivity and high resolution. The image forming apparatus can be provided.

[Brief description of drawings]

FIG. 1 shows a charge generation layer 5 and a charge transfer layer 6 on a conductive support.
FIG. 3 is a cross-sectional view schematically showing an example of a function-separated type electrophotographic photosensitive member having a structure.

2 is a cross-sectional view schematically showing an example of a function-separated type electrophotographic photosensitive member having an intermediate layer 8 between a conductive support and a photosensitive layer 4 in the electrophotographic photosensitive member of FIG.

FIG. 3 is a schematic view showing an example of an image forming apparatus incorporating the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

1 Conductive support 2 Charge generation material 3 Charge transfer material 4 Photosensitive layer 5 Charge generation layer 6 Charge transfer layer 8 Middle class 11 Electrophotographic photoreceptor 31 Semiconductor laser 32 charger 33 Developer 34 Transfer charger 35 Fixing device 36 cleaner

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 5/14 101 G03G 5/14 101

Claims (6)

[Claims] 1. An electrophotographic photosensitive member using a laser having an oscillation wavelength in the range of 380 to 500 nm as an exposure light source, wherein a photosensitive layer on a conductive support has the following general formula (1) as a charge transfer substance. An electrophotographic photoconductor containing the N, N-bisenamine compound represented by: [Chemical 1] (In the formula, Ar ₁ represents an aryl group or a heterocyclic group which may have a substituent, and Ar _{2 to} Ar ₅ are the same or different, and an aryl group and a heterocyclic group which may have a substituent. , Represents an aralkyl group or an alkyl group.) 2. The electrophotographic photosensitive member according to claim 1, wherein the N, N-bisenamine compound represented by the general formula (1) is a compound represented by the following general formula (2). [Chemical 2] (Wherein, Ar ₆ are the same or different, an optionally substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, Arirukokishi group having 6 to 15 carbon atoms, carbon atoms 1 to 10 thioalkoxy group, 6 to 15 carbon thioarylcoxy group, 1 to 10 carbon dialkylamino group or 6 to 15 carbon diarylamino group, or a hydrogen atom, and n is 1 to 1 Represents an integer of 5. Ar ₂ ~
Ar ₅ has the same meaning as in formula (1). ) 3. The electrophotography according to claim 1, wherein the photosensitive layer has a laminated structure having a charge generation layer containing a charge generation substance and a charge transfer layer containing a charge transfer substance. Photoconductor. 4. The electrophotographic photosensitive member according to claim 3, wherein the charge transfer layer contains a charge transfer substance / binder resin in a weight ratio of 10/12 to 10/25. 5. The electrophotographic photoreceptor according to claim 1, wherein an intermediate layer is provided between the conductive support and the photosensitive layer. 6. An image forming apparatus equipped with the electrophotographic photosensitive member according to claim 1, wherein an image is formed by using a reversal development process.