JP3823344B2 - Electrophotographic photosensitive member, electrophotographic apparatus and apparatus unit - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an electrophotographic photosensitive member having excellent durability and sensitivity, and to an electrophotographic apparatus and an apparatus unit having the photosensitive member.
[0002]
[Prior art]
In general, when an image is formed by electrophotography, the surface of a photoconductor is charged, image exposed and developed to form a toner image, and the toner image is transferred and fixed on a transfer material to obtain an image. The subsequent photoreceptor is repeatedly used for a long time after the residual toner is cleaned and discharged.
[0003]
Therefore, the photoconductor is not only electrophotographic performance such as charging potential, sensitivity, dark decay and residual potential characteristics, but also physical properties such as printing durability, abrasion resistance and moisture resistance during repeated use, and occurs during corona discharge. Good resistance to ozone and image exposure is also required.
[0004]
On the other hand, as conventional electrophotographic photoreceptors, inorganic photoconductive photoreceptors using amorphous silicon, selenium, cadmium sulfide and the like have been used in many cases. However, in recent years, they are low-cost, non-toxic and excellent in processability. Organic photoconductive photoconductors (hereinafter simply referred to as organic photoconductors or OPCs) that have a high degree of freedom of selection depending on the purpose have become mainstream.
[0005]
Fatigue deterioration due to repeated use of these electrophotographic photoreceptors is caused by charging, exposure, development, transfer of toner images formed on the photoreceptor onto transfer materials, separation, and cleaning of residual toner on the photoreceptor after transfer. According to each process. The causes are presumed to be friction and damage on the surface of the photosensitive layer due to rubbing, decomposition of the photosensitive layer in each step such as charging to the surface of the photosensitive member, image exposure, static elimination, and alteration.
[0006]
Therefore, improvement of the surface of the photosensitive layer is an important issue in preventing fatigue deterioration of the photoreceptor. In particular, the photosensitive layer of the organic photoreceptor is softer than the inorganic photoreceptor, and the photoconductive substance is an organic substance, so the fatigue deterioration during repeated use of the photoreceptor is great, and the surface of the photosensitive layer is improved. Becomes more important.
[0007]
In JP-A-56-117245, JP-A-63-91666 and JP-A-1-205171, silica particles are contained in the protective layer of the photosensitive member to increase the mechanical strength of the surface of the photosensitive member, and durability. It is described that can be improved. JP-A-57-176057, JP-A-61-117558, or JP-A-3-155558 discloses hydrophobic silica particles obtained by treating the silica particles with a silane coupling agent or the like. It is described that it can be contained in the outermost surface protective layer to increase the mechanical strength of the photoreceptor and to provide lubricity, thereby obtaining a more durable photoreceptor.
[0008]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a photoreceptor having improved wear resistance and scratch resistance without impairing electrophotographic characteristics such as sensitivity.
[0009]
In addition, even if a cleaning blade used as a cleaning means is used in combination with the photosensitive member, the photosensitive member is not worn or damaged in the process of repeated image formation and is highly durable, and a high density and clear image is stable from start to finish. It is an object of the present invention to provide an electrophotographic photoreceptor obtained in this manner and an electrophotographic apparatus using the same.
[0010]
Furthermore, another object of the present invention is that the incorporated photoconductor is highly durable, so that it is possible to repeatedly and stably form an image without replacing the photoconductor. An object of the present invention is to provide an apparatus unit that can be replaced quickly and easily even if a defect occurs in an image forming means, and can stably obtain a high-quality image over a long period of time.
[0011]
[Means for Solving the Problems]
The above-mentioned objects of the present invention are achieved by the following configurations.
[0012]
[1] conductive substrate in at least a charge generating layer having laminated a charge transport layer in this order, the charge transport layer is formed by a plurality layers, electrons on the surface layer containing silica mosquitoes fine particles In the photographic photoreceptor, the surface layer contains at least one of the polycarbonate-containing polycarbonate copolymer having the structure of the general formula [ 3], and includes an electrification, image exposure, development, transfer, and blade cleaning steps. An electrophotographic photosensitive member, wherein the dynamic friction coefficient of the surface of the photosensitive member with respect to the cleaning blade after 5,000 times has the following relationship with the dynamic friction coefficient before the image forming process.
1.1 ≦ μ ₅₀₀₀ / μ _S ≦ 4.2
μ ₅₀₀₀ : Dynamic friction coefficient after 5000 times of image forming process
μ _S : Dynamic friction coefficient before going through image forming process
However, μ _S = 0.01 to 1.0
[C]
(In the formula, A and B are a carbon atom, oxygen or sulfur atom having a substituent, and the substituents of the carbon atom may be bonded to each other to form a ring. X is alkylene or arylene.
R _{1 to} R ₃ represent hydrogen or a halogen atom, an alkyl group or a phenyl group. M and n are positive integers. )
[0013]
[2] An electrophotographic apparatus comprising the electrophotographic photosensitive member according to [1], an electrostatic latent image forming unit, a developing hand, a transfer unit, and a blade cleaning unit.
[0014]
[3] In the apparatus unit having the electrophotographic photosensitive member and the image forming unit according to [1], at least one of the electrophotographic photosensitive member and the charging unit, the developing unit, the transfer unit, and the blade cleaning unit as the image forming unit is integrated. A device unit characterized in that it is supported and is detachably attached to the device body.
[0019]
As a preferred embodiment of the apparatus unit, an elastic cleaning blade is used as the cleaning means, and at least the cleaning blade and the photoconductor are integrally supported and are detachable from the apparatus main body.
[0020]
As described above, by adding high-hardness inorganic fine particles to the outermost surface layer of the photoconductor, the mechanical strength of the surface of the photoconductor is improved, and as a result, film thickness wear and scratch defects after repeated use can be reduced.
[0021]
However, although the mechanical strength of the photoreceptor surface is improved by the addition of high-hardness particles, the problem is that the roughness of the photoreceptor surface increases, so that the cleaning property is deteriorated and the durability of the cleaning blade is deteriorated. did.
[0022]
As a result of intensive studies by the inventors, when the relationship of the dynamic friction coefficient between the surface of the photosensitive layer and the cleaning blade satisfies the above relationship, the friction can be reduced, and as a result, the cleaning property can be improved, and the durability of the cleaning blade is also improved. I was able to improve.
[0023]
Here, the dynamic friction coefficient (μ) of the surface of the photoreceptor with respect to the cleaning blade is measured by a surface test apparatus (model HEIDON-14) manufactured by HEIDON manufactured by preparing the photoreceptor in a sheet shape. This measures the force (g) applied when the blade is pressed against the photosensitive member with a constant load (g) and moved parallel to the surface of the photosensitive member. The dynamic friction coefficient is obtained by [force applied to the photosensitive member (g)] / [load applied to the blade (g)] when the blade is moving. The blade used is incorporated in the electrophotographic apparatus. For example, it is a urethane blade (rubber hardness 67) manufactured by Hokushin Kogyo Co., Ltd., cut to 5 mm × 30 mm × 2 mm, applied with a load of 10 g, at a trail direction at an angle of 30 °. It was measured. A schematic cross-sectional view of the cleaning blade fixing device is shown in FIG.
[0024]
In the present invention, the photosensitive member was removed from the apparatus before being mounted on the electrophotographic apparatus and after image formation 5000 times, and the coefficient of dynamic friction was measured to determine whether or not the above relationship was satisfied.
[0025]
As the uppermost binder resin for maintaining the dynamic friction coefficient in the above relationship, a copolymer made of polycarbonate containing silicon is preferable, and may be a block polymer or a graft polymer.
[0026]
Preferable compounds are represented by the general formula [1], [2] or [3]. Specific examples of the compounds represented by the general formulas [1] to [3] are shown below.
[0027]
[Chemical 3]
[0028]
[Formula 4]
[0029]
[Chemical formula 5]
[0030]
The binder resin preferably has a weight average molecular weight of 10,000 to 150,000, more preferably 20,000 to 150,000.
[0031]
The Mohs hardness of 5 or more inorganic particles in the present invention, Ru preferably is an inorganic particles having a volume average particle diameter of 0.05~2.0μm the surface layer of the photosensitive member. Examples of inorganic particles include amina, silica, titanium oxide, zirconium oxide, and the like, and silica is particularly preferable. The addition amount is 0.1 to 100% by weight, more preferably 1 to 50% by weight, based on the resin.
[0032]
The electrophotographic photoreceptor of the present invention is preferably an organic photoreceptor containing an organic charge generating material (CGM) and a charge transport material (CTM). The layer structure of the organic photoreceptor is shown in FIG.
[0033]
FIG. 2 (a) shows a photoreceptor having a single-layered photosensitive layer 6 containing both a charge generating substance (CGM) and a charge transporting substance (CTM) on an electroconductive support 1 via an intermediate layer 2. FIG. 2 (b) shows the charge transport layer (CTL) 3 containing the charge transport material (CTM) as the main component and the charge generation material (CGM) as the main components on the conductive support 1 through the intermediate layer 2. 2 is a photosensitive member having a photosensitive layer 6 formed by laminating a charge generating layer (CGL) 4 in this order, and FIG. 2C shows the charge generating layer (CGL) on the conductive support 1 through an intermediate layer. 4 and a photosensitive layer 6 having a charge transport layer (CTL) 3 laminated in this order.
[0034]
2 (D), (E), and (F) show a structure in which the outermost photosensitive layer 5 is further laminated on the photosensitive layers shown in FIGS. 1 (A), (B), and (C), respectively. The above drawings (a), (b), (c), (d), (e), and (f) show typical configurations of organic photoreceptors, and the present invention includes these layer configurations. It is not limited to. For example, the intermediate layer 2 shown in these drawings may be omitted if not necessary.
[0035]
Among the above layer configurations, it is more preferable to use a so-called CTL two-layer structure in which the outermost photosensitive layer contains a charge transport material (CTM). Inclusion of a charge transport material (CTM) in these outermost surface layers can prevent an increase in residual potential and a decrease in sensitivity due to repeated use of the electrophotographic photosensitive member.
[0036]
Examples of the charge generation material (CGM) contained in the photosensitive layer 6 of each of the photoreceptors shown in FIGS. 2A to 2F include, for example, phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, indigo pigments, and quinacridone. Pigments, azulenium pigments, squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, xanthene dyes, triphenylmethane dyes, styryl dyes, and the like. Formation takes place.
[0037]
Examples of the charge transport material (CTM) contained in the photosensitive layer 6 include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazoline derivatives, bisimidazolidine derivatives, and styryl. Compound, hydrazone compound, benzidine compound, pyrazoline derivative, stilbene compound, amine derivative, oxazolone derivative, benzothiazole derivative, benzimidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, poly-N-vinylcarbazole , Poly-1-vinylpyrene, poly-9-vinylanthracene, etc., and these charge transport materials (CTM) Layer formation is performed with the binder resin.
[0038]
Among these, particularly preferred charge transport materials (CTM) include compounds represented by the following general formula.
[0039]
[Chemical 6]
[0040]
(In the formula, Ar ₁ , Ar ₂ and Ar ₄ represent a substituted or unsubstituted aromatic hydrocarbon group or heterocyclic group, and Ar ₃ represents a substituted or unsubstituted divalent aromatic hydrocarbon group or heterocyclic group. R ₂ represents a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group or a heterocyclic group, n is 1 or 2. Ar ₄ and R ₂ may be bonded to each other to form a ring. Good.)
[0041]
[Chemical 7]
[0042]
(Wherein R ₄ and R ₅ represent a substituted, unsubstituted aromatic hydrocarbon group, heterocyclic group or alkyl group, and may be linked to each other to form a ring. R ₃ represents a hydrogen atom or a substituted group; An unsubstituted aromatic hydrocarbon group, a heterocyclic group or an alkyl group is represented, Ar ₅ represents a substituted, unsubstituted aromatic hydrocarbon group or a heterocyclic group, and m is 0 or 1.)
[0043]
[Chemical 8]
[0044]
(In the formula, Y represents a substituted, unsubstituted phenyl group, naphthyl group, pyrenyl group, fluorenyl group, carbazolyl group, diphenyl group, or 4,4'-alkylidene diphenyl group, and Ar ₆ and Ar ₇ are substituted and unsubstituted. An aromatic hydrocarbon group or a heterocyclic group in which 1 represents an integer of 1 to 3)
[0045]
[Chemical 9]
[0046]
(In the formula, Ar ₈ , Ar ₉ , Ar ₁₀ , Ar ₁₁ represent a substituted or unsubstituted aromatic hydrocarbon group or heterocyclic group.)
Of these, specific examples of compounds preferably used in the photoreceptor of the present invention are illustrated below.
[0047]
[Chemical Formula 10]
[0048]
Embedded image
[0049]
Embedded image
[0050]
Embedded image
[0051]
Embedded image
[0052]
Embedded image
[0053]
As the binder resin contained in the charge generation layer (CGL) and the charge transport layer (CTL) other than the outermost surface layer in the case of the laminated structure, polyester resin, polystyrene resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, Polyvinylidene chloride resin, polycarbonate resin, polyvinyl butyral resin, polyvinyl acetate resin, styrene-butadiene resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-maleic anhydride copolymer resin, urethane resin, silicone resin, epoxy resin, Silicone-alkyd resin, phenol resin, polysilane resin, polyvinyl carbazole and the like can be mentioned.
[0054]
Solvents or dispersion media used in forming each layer include n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone. , Benzene, toluene, xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, tetrahydrofuran, dioxane, methanol , Ethanol, isopropylina, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve and the like. Although this invention is not limited to these, When a ketone solvent is used, a sensitivity, the electric potential change at the time of repeated use, etc. become still better. These solvents can be used alone or as a mixed solvent of two or more.
[0055]
In the present invention, the ratio of the charge generation material to the binder resin in the charge generation layer is preferably 1: 5 to 5: 1, particularly 1: 2 to 3: 1 in terms of weight ratio. The thickness of the charge generation layer is preferably 5 μm or less, particularly preferably 0.05 to 2 μm.
[0056]
Alternatively, the charge transport material and binder resin of the charge transport layer are dissolved in an appropriate solvent, and the solution is applied and dried. The mixing ratio between the charge transport material and the binder resin is preferably 3: 1 to 1: 3, and particularly preferably 2: 1 to 1: 2.
[0057]
The thickness of the charge transport layer is preferably 5 to 50 μm, particularly 10 to 40 μm.
[0058]
When the photoreceptor is of a single layer type, it can be obtained by applying and drying a solution in which the charge generating material and the charge transporting material as described above are dispersed and dissolved in a binder resin.
[0059]
When the outermost photosensitive layer of the present invention is formed, the photosensitive layer is formed by dissolving and dispersing the thermosetting resin and inorganic particles of the present invention together with a solvent and applying the solution onto the above-described photosensitive layer. In this case, the ratio of resin to CTM in the layer is preferably 3: 1 to 1: 3. In particular, it is 2: 1 to 1: 2, and the film thickness of the outermost photosensitive layer is preferably 0.2 to 10 μm. If it is less than 0.2 μm, it is difficult to obtain the effects of the present invention. On the other hand, if it exceeds 10 μm, the resolution of the image deteriorates due to light scattering by the inorganic particles in the photosensitive layer. In addition, the sensitivity may decrease and the residual potential may increase. A particularly preferable range is 0.4 to 5 μm.
[0060]
Next, as the conductive support of the electrophotographic photosensitive member of the present invention,
1) Metal plate such as aluminum plate and stainless steel plate,
2) A thin metal layer such as aluminum, palladium or gold provided on a support such as paper or plastic film by lamination or vapor deposition,
3) What provided the layer of conductive compounds, such as a conductive polymer, an indium oxide, a tin oxide, by application | coating or vapor deposition on support | carriers, such as paper or a plastic film, etc. are mentioned.
[0061]
Next, as a coating processing method for producing the electrophotographic photosensitive member of the present invention, a coating processing method such as dip coating, spray coating, circular amount regulation type coating or the like is used, but coating processing on the surface layer side of the photosensitive layer is used. In order to prevent the lower layer film from being dissolved as much as possible, and in order to achieve uniform coating processing, it is preferable to use a coating processing method such as spray coating or circular amount regulation type coating. The spray coating is described in detail in, for example, JP-A-3-90250 and JP-A-3-269238, and the circular amount-regulating coating is described in detail in, for example, JP-A-58-189061. Yes.
[0062]
In addition, according to the spray coating and the circular amount regulation type coating, there is no wasteful consumption of the coating solution compared to the dip coating, the lower layer is not dissolved and damaged, and uniform coating is achieved. Have advantages.
[0063]
In the present invention, as described above, an intermediate layer having both a barrier function and an adhesive resin can be provided between the conductive support and the photosensitive layer.
[0064]
Examples of the material for the intermediate layer include casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin polyamides (nylon 6, nylon 66, nylon 610, copolymer nylon, alkoxymethylated nylon, etc. ), Polyurethane, gelatin, aluminum oxide and the like. The film thickness of the intermediate layer is preferably from 0.1 to 10 μm, particularly preferably from 0.1 to 5 μm.
[0065]
In the present invention, a coating for compensating for surface defects of the support is further provided between the support and the intermediate layer, and interference fringes that are problematic when the image input is laser light are prevented. A conductive layer for the purpose of, for example, can be provided. This conductive layer can be formed by applying and drying a solution in which conductive powder such as carbon black, metal particles, or metal oxide particles is dispersed in an appropriate binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, particularly preferably 10 to 30 μm.
[0066]
The support may be in the form of a drum, a sheet or a belt, and is preferably a shape suitable for the electrophotographic apparatus to be applied.
[0067]
The electrophotographic photosensitive member of the present invention can be applied to general electrophotographic apparatuses such as copying machines, laser printers, LED printers, and liquid crystal shutter printers, and further displays, recordings, and light printings using electrophotographic technology. It can also be widely applied to apparatuses such as plate making and facsimile.
[0068]
FIG. 3 is a schematic sectional view of an electrophotographic apparatus having the electrophotographic photosensitive member of the present invention.
[0069]
In FIG. 3, reference numeral 10 denotes a photosensitive drum as an image carrier, which is coated with an organic photosensitive layer on the drum, grounded, and rotated clockwise. Reference numeral 12 denotes a scorotron charger, which gives a uniform charge to the circumferential surface of the photosensitive drum 10 by corona discharge. Prior to the charging by the charger 12, in order to eliminate the history of the photosensitive member in the previous image formation, the peripheral surface of the photosensitive member may be discharged by performing the exposure using a light emitting diode or the like.
[0070]
After the photoreceptor is uniformly charged, the image exposure unit 13 performs image exposure based on the image signal. The image exposure means 13 in this figure is scanned on the photosensitive drum by bending the optical path by a reflecting mirror 132 through a polygon mirror 131 rotating with a laser diode (not shown) as a light source, an fθ lens, etc., and an electrostatic latent image is formed. Is done.
[0071]
The electrostatic latent image is then developed by the developing device 14. On the periphery of the photosensitive drum 10, there are provided developing devices 14 each containing a developer composed of toner such as yellow (Y), magenta (M), cyan (C), and black (K) and a carrier. The development of the first color is performed by a developing sleeve 141 that contains a magnet and rotates while holding the developer. The developer consists of a carrier with a ferrite core and an insulating resin coating around it, and a toner containing polyester as a main material and a pigment according to the color and a charge control agent, silica, titanium oxide, etc. The agent is regulated to a layer thickness of 100 to 600 μm on the developing sleeve 141 by the layer forming means and conveyed to the developing zone for development. At this time, development is usually performed by applying a direct current or alternating current bias potential between the photosensitive drum 10 and the developing sleeve 141.
[0072]
In the color image formation, after the first color visualization is completed, the second color image formation process is started, and uniform charging is performed again by the scorotron charger 12, and the second color latent image is converted into the image exposure means 13. Formed by. For the third and fourth colors, the same image forming process as that for the second color is performed, and a four-color visible image is formed on the circumferential surface of the photosensitive drum 10.
[0073]
On the other hand, in the monochrome electrophotographic apparatus, the developing device 14 is composed of one type of black toner, and an image can be formed by one development.
[0074]
The recording paper P is fed to the transfer area by the rotation operation of the paper feed roller 17 at the time when the transfer timing is ready after image formation.
[0075]
In the transfer area, the transfer roller 18 is pressed against the peripheral surface of the photosensitive drum 10 in synchronism with the transfer timing, and the fed recording paper P is sandwiched to transfer the multicolor images all at once.
[0076]
Next, the recording paper P is neutralized by the separation brush 19 brought into a pressure contact state almost simultaneously, separated by the peripheral surface of the photosensitive drum 10 and conveyed to the fixing device 20, and the toner is heated and pressed by the heat roller 201 and the pressure roller 202. Are then discharged to the outside of the apparatus via the paper discharge roller 21. The transfer roller 18 and the separation brush 19 are retracted away from the peripheral surface of the photosensitive drum 10 after the recording paper P has passed to prepare for the next toner image formation.
[0077]
On the other hand, the photosensitive drum 10 from which the recording paper P has been separated removes and cleans residual toner by the pressure contact of the blade 221 of the cleaning device 22, and is again subjected to charge removal by 11 and charging by the charger 12 to form the next image. Enter the process. When superposing a color image on the photoconductor, the blade 221 moves immediately after cleaning the photoconductor surface and retracts from the peripheral surface of the photoconductor drum 10.
[0078]
Reference numeral 30 denotes a mounting unit in which the electrophotographic photosensitive member, the charging unit, and the cleaning unit are integrated and detachable.
[0079]
As an electrophotographic apparatus, a plurality of constituent elements such as the above-described photosensitive member, developing means, and cleaning means are integrally coupled as an apparatus unit, and this unit is configured to be detachable from the apparatus main body. It is preferable. For example, a unit is formed by integrally supporting at least one of a charging unit, a developing unit, and a cleaning unit together with a photosensitive member to form a single unit that can be attached to and detached from the apparatus main body, and is attached or detached using a guide means such as a rail of the apparatus main body. It is a free configuration. At this time, the apparatus unit may be configured with a charging unit and / or a developing unit.
[0080]
When the electrophotographic apparatus is used as a copying machine or a printer, the image exposure means irradiates the photosensitive member with reflected light or transmitted light from the original, or reads the original with a sensor and converts it into a laser beam. Is a means for irradiating light to the photosensitive member by scanning the light source, driving the LED array or driving the liquid crystal shutter array.
[0081]
When used as a facsimile printer, the image exposure means 13 becomes an exposure means for printing received data.
[0082]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this.
[0083]
Example 1
<Preparation of photoconductor 1 for reference example>
Coating obtained by dissolving 1.5 parts by weight of a copolymer type polyamide resin “Amilan CM-8000” (manufactured by Toray Industries, Inc.) in a mixed solvent of 90 parts by volume of methanol and 10 parts by volume of butanol on an aluminum drum having a diameter of 80 mm. The liquid was dip-coated to form an intermediate layer having a thickness of 0.3 μm. Next, 0.8 parts by weight of polyvinyl butyral resin “S-LEC BL-S” (manufactured by Sekisui Chemical Co., Ltd.) was dissolved in a mixed solvent of 80 parts by weight of methyl ethyl ketone and 20 parts by weight of cyclohexanone. A coating solution obtained by mixing and dispersing 4 parts by weight of the charge generation material (CGM-1) represented by the structural formula (CGM / binder amount ratio is 5.0) is dip-coated on the intermediate layer and dried. A charge generation layer having a thickness of 0.2 μm was formed.
[0084]
Embedded image
[0085]
Next, 15 parts by weight of polycarbonate resin “Iupilon Z300” (Mitsubishi Gas Chemical Co., Ltd.) as a binder, 10 parts by weight of exemplary compound (T-2) as a charge transport material, hindered phenolic antioxidant “Irganox 1010” ( Ciba Geigy Co., Ltd.) A coating solution prepared by dissolving 0.25 parts by weight in 100 parts by volume of methylene chloride was dip coated on the charge generation layer to form a first charge transport layer having a thickness of 25 μm after drying. .
[0086]
Next, 1.5 parts by weight of a siloxane-polycarbonate copolymer (1-1) as a binder, 0.6 parts by weight of inorganic particles in Table 1, and 1 part by weight of an exemplary compound (T-2) as a charge transfer material, hindered A coating solution prepared by dissolving and dispersing 0.025 parts by weight of a phenolic antioxidant “Irganox 1010” in 100 parts by volume of 1,2-dichloroethane is applied to the circular charge control type coating machine on the first charge transfer layer. Was applied to form a second charge transport layer having a dried film thickness of 1 μm, and a photoreceptor 1 for reference example shown in Table 1 was obtained. The coefficient of dynamic friction of this photoconductor was 0.7.
[0087]
< Preparation of Reference Photoconductors 2 to 8, Example Photoconductors 9 to 12 and Comparative Photoconductors 1 and 2>
Second charge transport layer binder resin of the type and kinetic friction other is varied in the same manner as the photosensitive member 1 for Reference Example Reference Example photoconductor 2-8 as the coefficient table 1 of Reference Example photoconductor 1 Example photoconductors 9 to 12 and comparative photoconductors 1 and 2 were obtained.
[0088]
[Table 1]
[0089]
< Photoconductors for Reference Examples 2 to 8, Photoconductors for Examples 9 to 12 and Photoconductors 1 and 2 for Comparative Examples>
The photocopier obtained as described above is an analog copying machine "Konica U having a charging unit, an image exposing unit, a developing unit, a transferring unit, a static eliminating unit, and a cleaning unit, in which the photoconductor unit and the cleaning unit are integrally formed. -BIX4145 "(manufactured by Konica) was subjected to an image formation test for each photoconductor under normal temperature and normal humidity (20 ° C., 60% RH), and the dynamic friction coefficient after 5000 copies was measured.
[0090]
1) Image evaluation The photoconductor was sequentially mounted on the copying machine, and actual copying was performed 100,000 times using a halftone original. A scorotron charger was used as the charger, and image formation was performed on the photoconductor under a constant charging condition of -750 V by grid control.
[0091]
The image formation test was conducted 100,000 times, and the presence or absence of background fogging due to poor cleaning, the presence or absence of streak failure due to turning over of the cleaning blade and the sharpness of the image were visually observed, and the results are shown in Table 2. .
[0092]
2) Measurement of potential fluctuation amount The black paper potential (Vb) and the white paper potential (Vw) before and after the 100,000 image formation tests are measured, and the potential fluctuation of each photoconductor before and after image output from the difference ΔVb and ΔVw. The amount was determined and the results are shown in Table 2. A document having a solid black area having a reflection density of 1.3 and a solid white area having a reflection density of 0.050 is used as a measurement document. After charging at −750 V by the scorotron charger, image exposure from the document is performed. The formed electrostatic latent image was measured by an electrometer arranged at the position of the developing device, and the black paper potential (Vb) and the white paper potential (Vw) were measured.
[0093]
[Table 2]
[0094]
From Table 2, in the examples using the respective photoreceptors for the examples, a clear image without potential fluctuations such as black paper potential and blank paper potential and ground fogging, streak failure, etc. is obtained in the process of repeated image formation. In each of the comparative examples using the photoconductors for the examples, it can be seen that fog and streak failures occur in the process of repeated image formation, and a good image cannot be obtained.
[0106]
【The invention's effect】
According to the present invention, a clear image free from potential fluctuations such as black paper potential and white paper potential, ground fogging, and streak failure can be obtained in the process of repeated image formation.
FIG. 1 is a cross-sectional view of a blade fixing device for measuring a dynamic friction coefficient.
FIG. 2 is a cross-sectional view showing the layer structure of the photoreceptor of the present invention.
FIG. 3 is a schematic sectional view of the electrophotographic apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Conductive support body 2 Intermediate | middle layer 3 Charge transport layer 4 Charge generation layer 5 Resurface photosensitive layer 6 Photosensitive layer 10 Photosensitive drum (image carrier)
DESCRIPTION OF SYMBOLS 11 Exposure static eliminator 12 Scorotron charger 13 Image exposure means 131 Polygon mirror 132 Reflection mirror 14 Developer 141 Development sleeve 17 Paper feed roller 18 Transfer roller 19 Separation brush 20 Fixing device 201 Heat roller 202 Pressure roller 21 Paper discharge roller 22 Cleaning device 221 Blade 30 Image holding member (cartridge)
40 Urethane rubber blade 41 Strut 42 Holder strut arm 43 Upper holder 44 Lower holder 45 Fixing screw 46 Sample P Recording paper

Claims (3)

At least a charge generation layer on a conductive support, a by laminating a charge transporting layer in this order, the charge transport layer is formed by a plurality layers, the electrophotographic photosensitive member on the surface layer containing silica mosquitoes fine particles The surface layer contains at least one of the polycarbonate-containing polycarbonate copolymers having the structure represented by the following general formula [ 3], and the image forming process including charging, image exposure, development, transfer and blade cleaning steps is performed 5000 times. An electrophotographic photosensitive member characterized in that the dynamic friction coefficient of the surface of the photosensitive member with respect to the cleaning blade after passing has the following relationship with the dynamic friction coefficient before passing through the image forming process.
1.1 ≦ μ ₅₀₀₀ / μ _S ≦ 4.2
μ ₅₀₀₀ : Coefficient of dynamic friction after 5000 times of image forming process μ _S : Coefficient of dynamic friction before passing through image forming process where μ _S = 0.01 to 1.0
(In the formula, A and B are a carbon atom, oxygen or sulfur atom having a substituent, and the substituents of the carbon atom may be bonded to each other to form a ring. X is alkylene or arylene.
R ₁ to R ₃ represent hydrogen or a halogen atom, an alkyl group or a phenyl group. M and n are positive integers. )   An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, an electrostatic latent image forming unit, a developing hand, a transfer unit, and a blade cleaning unit.   2. The apparatus unit having an electrophotographic photosensitive member and image forming means according to claim 1, wherein at least one of the electrophotographic photosensitive member and the charging means, developing means, transfer means and blade cleaning means as the image forming means is integrally supported. The apparatus unit is detachably attached to the apparatus body.