JP3977219B2 - Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member used in a specific electrophotographic apparatus, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus, and more particularly, to an electrophotographic apparatus having specific charging means and pre-exposure means. The present invention also relates to an electrophotographic photosensitive member having a surface layer containing fluorine atom-containing resin fine particles and specific polysiloxane, a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.
[0002]
[Prior art]
One typical example of the image holding member is an electrophotographic photosensitive member. In recent years, electrophotographic technology has been widely used and applied not only in the field of copying machines but also in the field of various printers because of its immediacy and high-quality images. As the core photoreceptor, there are inorganic materials such as selenium, cadmium sulfide and zinc oxide. In recent years, however, organic materials are used from the viewpoints of pollution-free, high productivity, ease of material design, and future prospects. System materials are being developed extensively.
[0003]
These electrophotographic photoreceptors are required to have electrical characteristics, mechanical characteristics, and optical characteristics according to the applied electrophotographic process. In particular, in electrophotographic photoreceptors that are used repeatedly, electrical and mechanical external forces such as charging, image exposure, toner development, transfer and cleaning are repeatedly applied directly or indirectly, so durability is required. Is done.
[0004]
Unlike an inorganic photoreceptor, an electrophotographic photoreceptor containing an organic photoconductive material composed of a relatively soft material is inferior in durability against mechanical deterioration, and various attempts have been made to satisfy durability characteristics. It was.
[0005]
Among them, as a method of effectively preventing mechanical deterioration and improving durability, the friction coefficient on the surface of the electrophotographic photosensitive member is reduced by making fluorine atom-containing resin fine particles present in the surface layer of the electrophotographic photosensitive member. The method of letting it be mentioned. With this configuration, the rubbing property with the cleaning member becomes smooth, and a strong shearing stress is not applied to the surface of the electrophotographic photosensitive member.
[0006]
However, generally, the fluorine atom-containing resin fine particles have a low surface tension, and it is difficult to uniformly disperse them in a resin having a relatively high surface tension. For this reason, attempts have been made to use various dispersion aids in combination, and a method for improving the dispersibility of fluorine atom-containing resin fine particles by using a specific polysiloxane has been proposed (for example, Patent Documents). 1).
[0007]
On the other hand, as charging means, contact charging means for charging an electrophotographic photosensitive member by applying a voltage obtained by superimposing an AC voltage on a DC voltage to a charging member arranged in contact with the electrophotographic photosensitive member is disclosed. (For example, refer to Patent Document 2).
[0008]
The contact charging means generates much less ozone than the corona charging means, and around 80% of the current that the corona charging means flows to the charger flows to the shield, but is wasted. It has the merit of being very economical without knowing.
[0009]
However, the charging frequency (f) of the alternating voltage applied to the charging member having the contact charging means described above is set to be larger than a certain value with respect to the process speed (Vp) (specifically, f / Vp ≧ 10). And an electrophotographic photosensitive member having a surface layer containing fluorine atom-containing resin fine particles is repeatedly applied to an electrophotographic apparatus (see, for example, Patent Document 3) having a pre-exposure means for neutralizing the electrophotographic photosensitive member. When used, the potential fluctuation may increase.
[0010]
[Patent Document 1]
JP 2000-81715 A
[Patent Document 2]
JP-A 63-149668
[Patent Document 3]
JP 2002-72632 A
[0011]
[Problems to be solved by the invention]
An object of the present invention is to provide an electrophotographic photosensitive member which is used in an electrophotographic apparatus having a specific charging means and pre-exposure means, has good potential stability even when used repeatedly, and has excellent durability, and the electrophotographic An object is to provide a process cartridge and an electrophotographic apparatus having a photoreceptor.
[0012]
[Means for Solving the Problems]
That is, the present invention relates to an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the electrophotographic photosensitive member disposed in contact with the electrophotographic photosensitive member, and a voltage obtained by superimposing an alternating voltage on a direct current voltage. A charging means having a charging member for charging the body, and a pre-exposure means for discharging the electrophotographic photosensitive member, and the relationship between the charging frequency f (Hz) and the process speed Vp (mm / sec) is expressed by the following equation: In the electrophotographic photoreceptor used in the electrophotographic apparatus satisfying the condition (1),
The surface layer of the electrophotographic photoreceptor contains at least fluorine atom-containing resin fine particles and a diorganopolysiloxane represented by the following formula (2), and the content of the diorganopolysiloxane is based on the fluorine atom-containing resin particles. And 7.5 The electrophotographic photosensitive member is characterized by being from 0.1% by mass to 10% by mass and from 0.1% by mass to 0.8% by mass with respect to the total solid content of the surface layer.
[0013]
10 ≦ f / Vp ≦ 15 (1)
[0014]
[Formula 4]
(Wherein R ₁₁ ~ R ₁₆ Represents a substituted or unsubstituted hydrocarbon group, B represents a substituted or unsubstituted organic group having a fluoroalkyl group, and at least one D is a substituted or unsubstituted hydrocarbon having a degree of polymerization of 3 or more whose end is blocked. Represents a group having a polystyrene chain, E ₁₁ And E ₁₂ Is R ₁₁ ~ R ₁₆ , B and D, x represents an integer of 0 to 1,000, and y and z represent an integer of 1 to 1,000. )
[0015]
The present invention also provides a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
In formula (2), R ₁₁ ~ R ₁₆ Examples of the substituted or unsubstituted hydrocarbon group include an alkyl group having 1 to 30 carbon atoms, an alkenyl group, an aryl group, and an arylalkenyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the alkenyl group include an ethenyl group and a propenyl group. Examples of the aryl group include a phenyl group, a tolyl group, and a xylyl group. And phenylethenyl group. Among these, a methyl group and a phenyl group are preferable. R ₁₁ ~ R ₁₆ May be the same or different.
[0017]
B is a substituted or unsubstituted organic group having a fluoroalkyl group, and is preferably represented by the following formula (3).
[0018]
[Chemical formula 5]
(Wherein R _{twenty one} Represents an alkylene group or an alkyleneoxyalkylene group, and m represents an integer of 3 or more. )
R _{twenty one} Examples of the alkylene group include an ethylene group and a propylene group, and examples of the alkyleneoxyalkylene group include an ethyleneoxyethylene group, an ethyleneoxypropylene group, and a propyleneoxypropylene group.
[0019]
The group having a substituted or unsubstituted polystyrene chain of D is preferably represented by the following formula (4).
[0020]
[Chemical 6]
(Wherein R ₃₁ And R ₃₂ Is a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and W ₃₁ Represents a hydrocarbon group, W ₃₂ Represents a substituted or unsubstituted polystyrene chain having a degree of polymerization of 3 or more whose end is blocked, and n represents 0 or 1. )
[0021]
R ₃₁ And R ₃₂ Examples of the alkyl group include a methyl group, an ethyl group, and a propyl group, and examples of the aryl group include a phenyl group. R ₃₁ And R ₃₂ May be the same or different.
[0022]
W ₃₁ Examples of the hydrocarbon group include alkylene groups such as a methylene group, an ethylene group, and a propylene group, and preferably have 1 to 10 carbon atoms.
[0023]
E ₁₁ And E ₁₂ Is R ₁₁ ~ R ₁₆ , B and D, which may be the same or different.
[0024]
Examples of the substituent that the above group may have include halogen atoms such as fluorine atom, chlorine atom and iodine atom, alkyl groups such as methyl group, ethyl group and propyl group, and aryl groups such as phenyl group. It is done.
[0025]
X is an integer of 0 to 1,000, but is preferably an integer of 5 to 200.
[0026]
Y is an integer of 1 to 1,000, but is preferably an integer of 5 to 200.
[0027]
Z is an integer of 1 to 1,000, but is preferably an integer of 5 to 200.
[0028]
X + Y + Z is preferably 2 to 2,000, particularly preferably 5 to 1,000, and more preferably 20 to 500.
[0029]
Y + Z is preferably 20 to 100.
[0030]
In the present invention, when X, Y and Z are 2 or more, R ₁₁ ~ R ₁₄ , B and D may each be two or more types. For example, when Y is 3, all three Bs may be the same, two Bs may be the same and one B may be different, or three Bs may be different.
[0031]
In the present invention, for convenience, R ₁₁ And R ₁₂ The number of siloxane units having X, R ₁₃ And the number of siloxane units having B and B is Y, R ₁₄ In the formula (2), the number of siloxane units having and D is shown as Z, but these units may be mixed. That is, R ₁₁ And R ₁₂ Siloxane units having R and R ₁₃ And siloxane units having B may be present alternately. For example, you may couple | bond as follows.
[0032]
[Chemical 7]
(F, g, h and i are integers.)
[0033]
Examples of the diorganopolysiloxane represented by the formula (2) are given below. These are merely examples and do not limit the present invention.
[0034]
[Table 1]
[0035]
[Table 2]
[0036]
[Table 3]
[0037]
Among these, (2-1), (2-2), (2-3) and (2-7) are preferable, and (2-1) and (2-7) are particularly preferable.
[0038]
The content of the diorganopolysiloxane is preferably 0.1% by mass or more and 0.8% by mass or less, particularly 0.25% by mass or more and 0.8% by mass with respect to the total solid content in the surface layer. % Or less is preferable. In the electrophotographic apparatus used in the present invention, even if the content of diorganopolysiloxane is less than 0.1% by mass or more than 0.8% by mass, potential fluctuations are likely to occur during repeated use.
[0039]
The weight average molecular weight of the diorganopolysiloxane used in the present invention is preferably 1,000 to 1,000,000, and more preferably 10,000 to 100,000.
[0040]
Examples of the fluorine atom-containing resin fine particles include tetrafluoroethylene resin, trifluoroethylene chloride resin, tetrafluoroethylene hexafluoroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluorodiethylene chloride resin, and Particles such as these copolymer resins are listed. Among these, tetrafluoroethylene resin (polytetrafluoroethylene) is particularly preferable.
[0041]
Further, the particle size is preferably 0.05 to 0.5 μm, particularly preferably 0.1 to 0.4 μm, in terms of volume average particle size.
[0042]
The content of the diorganopolysiloxane with respect to the fluorine atom-containing resin fine particles is preferably 3 to 20 parts by mass, particularly preferably 5 to 10 parts by mass with respect to 100 parts by mass of the fluorine atom-containing resin fine particles. If the content is too small, it is difficult to obtain an effect on the dispersibility of the fluorine atom-containing resin fine particles. On the other hand, if the amount is too large, carrier traps are caused, and sensitivity is deteriorated and potential fluctuations are likely to occur. In addition, when diorganopolysiloxane, fluorine atom-containing resin fine particles and binder resin are dispersed in advance, it is possible to disperse even if the amount of the binder resin is equal to or less than the mass part of the fluorine atom-containing resin fine particles. When the amount is preferably equal or more, more preferably 1.5 times or more, a better dispersion state can be obtained.
[0043]
The content of the fluorine atom-containing resin fine particles in the surface layer is preferably 0.5 to 30 parts by mass with respect to 100 parts by mass as a whole of the surface layer. If the amount is less than 0.5 parts by mass, the effect of abrasion resistance is small. If the amount exceeds 30 parts by mass, the light transmission is reduced, scattering, etc., and the electrophotographic characteristics are adversely affected.
[0044]
The surface layer described in the present invention is a charge transport layer in the case of a normal negatively chargeable laminated photoreceptor, and may be a protective layer formed thereon.
[0045]
Hereinafter, the configuration of the electrophotographic photosensitive member used in the present invention will be described. The electrophotographic photoreceptor in the present invention has a photosensitive layer on a support. The photosensitive layer may be a single layer type containing a charge transport material and a charge generation material in the same layer, or a stacked type having a charge transport layer containing a charge transport material and a charge generation layer containing a charge generation material. However, the laminate type is preferable from the electrophotographic characteristics.
[0046]
The support is only required to have conductivity, and examples thereof include metals such as aluminum and stainless steel, metals provided with a conductive layer, paper, plastics, and the like, and the shape includes a sheet shape and a cylindrical shape.
[0047]
In the present invention, a conductive layer may be provided between the support and the photosensitive layer for the purpose of preventing interference fringes and covering scratches on the support. This conductive layer can be formed by dispersing conductive particles such as carbon black and metal particles in a binder resin. It is also effective to add an appropriate amount of silica fine particles in order to suppress interference fringes. The thickness of the conductive layer is preferably 2 to 40 μm, more preferably 5 to 25 μm. In addition, the surface of the support can be cut, roughened, anodized or the like to suppress interference fringes.
[0048]
An intermediate layer having a layer adhesion function and a charge barrier function may be provided on the support or the conductive layer. Examples of the material for the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are dissolved in a suitable solvent and applied. The thickness of the intermediate layer is preferably 0.05 μm to 5 μm, more preferably 0.3 to 1.5 μm.
[0049]
The charge generation material used in the present invention is not particularly limited. And asymmetric quinocyanine pigments.
[0050]
In the case of the functional separation type, the charge generation layer is a dispersion in which the charge generation material is dispersed by a method such as an attritor, a roll mill, and a liquid collision type high-speed disperser together with a binder resin having a mass ratio of 0.3 to 4 times. It is formed by applying a liquid and drying. However, depending on the characteristics of the charge generation material, it is possible to add the binder resin after dispersing the solvent and the charge generation material, or not to use the binder resin. The film thickness of the charge generation layer is preferably 5 μm or less, more preferably 0.1 to 2 μm.
[0051]
The charge transport layer mainly comprises a charge transport material and a binder resin, and when the charge transport layer is a surface layer, further dissolves diorganopolysiloxane represented by the formula (2) in a solvent, and further contains fluorine atom-containing resin fine particles. It is formed by applying and drying the paint obtained by dispersing. Examples of the charge transport material used include triarylamine compounds, hydrazine compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, triallylmethane compounds, and thiazole compounds.
[0052]
Binder resins used for the charge transport layer and surface layer include phenoxy resin, polyacrylamide resin, polyvinyl butyral resin, polyarylate resin, polysulfone resin, polyamide resin, acrylic resin, acrylonitrile resin, methacrylic resin, vinyl chloride resin, vinyl acetate. Resins, phenolic resins, epoxy resins, polyester resins, alkyd resins, polycarbonate resins, polyurethane resins or copolymers containing two or more repeating units of these resins, such as styrene-butadiene copolymers, styrene-acrylonitrile copolymers and styrene- Mention may be made of maleic acid copolymers. Moreover, although it can also select from organic photoconductive polymers, such as poly-N-vinyl carbazole, polyvinyl anthracene, and polyvinyl birene, it is preferable from a durable point to use a polyarylate resin.
[0053]
The thickness of the charge transport layer is preferably 5 to 50 μm, more preferably 10 to 30 μm. The ratio (mass) of the charge transport material and the binder resin is about 5/1 to 1/5, preferably about 3/1 to 1/3. Examples of the application method include general methods such as dip coating, spray coating, blade coating and roll coating.
[0054]
Mixing devices such as homogenizers, line mixers, ultradispersers, homomixers, liquid collision type high-speed dispersers, ultrasonic dispersers, and other emulsifiers, dispersers, and mixers can be used to disperse fluorine atom-containing resin fine particles. .
[0055]
The electrophotographic apparatus of the present invention includes at least a contact charging unit that applies a voltage obtained by superimposing an AC voltage on a DC voltage, and a pre-exposure unit, and suppresses toner adhesion to the charging member, resulting in charging failure and image unevenness. Therefore, the relationship between the charging frequency f (Hz) and the process speed Vp (mm / sec) is set so as to satisfy the condition of the following formula (1).
10 ≦ f / Vp ≦ 15 (1)
[0056]
When the relationship between the charging frequency f (Hz) and the process speed Vp (mm / sec) is smaller than 10 or larger than 15, the toner easily adheres to the charging member, and thereby, charging failure and image unevenness easily occur. .
[0057]
Further, if there is no pre-exposure means, a phenomenon called a ghost in which the latent image formed on the drum appears on the image at the next rotation tends to occur.
[0058]
FIG. 1 shows a schematic configuration of an electrophotographic apparatus having the electrophotographic photosensitive member of the present invention.
[0059]
In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotated about a shaft 2 in the direction of an arrow at a predetermined peripheral speed. In the rotation process, the photosensitive member 1 is uniformly charged with a positive or negative predetermined potential on its peripheral surface by the primary charging unit 3, and then exposed from an exposure unit (not shown) such as slit exposure or laser beam scanning exposure. Receive light 4. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the photoreceptor 1.
[0060]
The formed electrostatic latent image is then developed with toner by the developing unit 5, and the developed toner image is rotated between the photosensitive member 1 and the transfer unit 6 from a sheet feeding unit (not shown). The image is sequentially transferred by the transfer means 6 to the transfer material 7 that is synchronously taken out and fed.
[0061]
The transfer material 7 that has received the image transfer is separated from the surface of the photosensitive member, introduced into the fixing means 8, and subjected to image fixing, thereby being printed out as a copy (copy).
[0062]
After the image transfer, the surface of the photoreceptor 1 is cleaned by removing the transfer residual toner by the cleaning unit 9, and is further subjected to charge removal processing by the pre-exposure light 10 from the pre-exposure unit (not shown). Used repeatedly for image formation.
[0063]
In the present invention, a plurality of components such as the electrophotographic photosensitive member 1, the primary charging unit 3, the developing unit 5, and the cleaning unit 9 described above are integrally coupled as a process cartridge. May be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photosensitive member 1 to form a cartridge, and is detachable from the apparatus main body using guide means such as a rail 12 of the apparatus main body. The process cartridge 11 can be obtained.
[0064]
Further, when the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 is a reflected light or transmitted light from the original, or the original is read by a sensor and converted into a signal, and a laser beam performed in accordance with this signal. The light is emitted by scanning, driving the LED array, driving the liquid crystal shutter array, and the like.
[0065]
The electrophotographic photosensitive member of the present invention can be used not only for electrophotographic copying machines but also widely for electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making.
[0066]
【Example】
Hereinafter, it demonstrates according to an Example. “Part” means part by mass.
[0067]
First, the diorganopolysiloxane used in the present invention can be synthesized as in the following example. A synthesis example is shown below.
[0068]
<Synthesis Example 1>
Synthesis of diorganopolysiloxane
3.23 g of polysiloxane represented by the following formula, 20 ppm of chloroplatinic acid (5% isopropyl alcohol solution),
[0069]
[Chemical 8]
As allyl functional polystyrene,
[0070]
[Chemical 9]
13.4 g and 80 g of m-xylene hexafluoride were mixed and gradually heated. Further, the reaction was continued at 80 ° C. for 6 hours. Next, the pressure was reduced to 20 Torr under the condition of 140 ° C. to remove the solvent and low-boiling components. The reaction product thus obtained is ²⁹ Si-NMR, ¹³ Analysis by C-NMR and FT-IR revealed a diorganopolysiloxane represented by the following formula (the exemplified compound (2-1)).
[0071]
[Chemical Formula 10]
[0072]
From the exemplified compound (2-2) to (2-10), other diorganopolysiloxanes can be synthesized by the same method.
[0073]
Example 1
An aluminum cylinder having a diameter of 30 mm and a length of 357 mm was ultrasonically cleaned with a water-based cleaning agent, then immersed in ion exchange water at 80 ° C., and then pulled up to obtain a dry and clean surface. On this support, a coating material composed of the following materials was applied by a dip coating method and thermally cured at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 15 μm.
[0074]
Conductive pigment: SnO ₂ Coated barium sulfate 10 parts
Resistance control pigment: Titanium oxide 2 parts
Binder resin: 6 parts of phenol resin
Leveling agent: 0.001 part of silicone oil
Solvent: methanol, methoxypropanol 0.2 / 0.8 20 parts
[0075]
Next, a solution obtained by dissolving 3 parts of N-methoxymethylated nylon and 3 parts of copolymer nylon in a mixed solvent of 65 parts of methanol and 30 parts of n-butanol is applied onto this conductive layer by a dip coating method and dried. Thus, an intermediate layer having a film thickness of 1.0 μm was formed.
[0076]
Next, 4 parts of a charge generation material (CGM-1) represented by the following structure and 70 parts of tetrahydrofuran were dispersed for 10 hours in a sand mill apparatus using glass beads having a diameter of 1 mm, and then a polyvinyl butyral resin (ESREC BLS, manufactured by Sekisui Chemical Co., Ltd.). ) A solution of 2 parts in 20 parts of tetrahydrofuran was added and dispersed for another 2 hours. Further, the glass beads were separated, and 100 parts of cyclohexanone was added to prepare a dispersion for the charge generation layer. This dispersion was applied onto the intermediate layer by a dip coating method and dried at 80 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.1 μm.
[0077]
Embedded image
[0078]
Next, a coating for the charge transport layer was prepared in order to form the charge transport layer. First, as binder resin, 10 parts of bisphenol-C type polyarylate resin (Mw = 110,000) was dissolved in 100 parts of chlorobenzene, and 10 parts of polytetrafluoroethylene resin particles (Lublon L-2: manufactured by Daikin Industries) and 1 part of diorganopolysiloxane represented by the formula (2-1) in Synthesis Example 1 was added. This mixture was dispersed three times using a liquid collision disperser (Nanomizer, dispersion pressure 600 bar) to prepare a fluorine atom-containing resin fine particle dispersion.
[0079]
Next, CTM-1 represented by the following formula,
[0080]
Embedded image
CTM-2 represented by the following formula
[0081]
Embedded image
[0082]
13 parts of the above polyarylate resin
2 parts of polytetrafluoroethylene resin fine particles
Diorganopolysiloxane 0.2 parts
[0083]
The paint was prepared so that the solvent was 100 parts. The diorganopolysiloxane contained in the paint is 0.8% by mass with respect to the total solid content.
[0084]
As the polytetrafluoroethylene resin fine particles, the fluorine atom-containing resin fine particle dispersion previously dispersed was used. The solvent was prepared so that the final ratio was monochlorobenzene: dichloromethane = 1: 1. This paint was applied by a dip coating method and dried at 140 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm.
[0085]
Next, evaluation will be described.
[0086]
As a device for evaluation, a modified copy machine GP-40 manufactured by Canon Inc. having pre-exposure means was used. In the modification, the process speed Vp was 100 mm / sec, the charging frequency f of the alternating voltage applied to the charging member was 1250 Hz, and the alternating current was 1100 μA. At this time, f / Vp is 12.5. The DC voltage was adjusted so that the dark portion potential Vd was −700V. The initial potential was measured after replacing the photoconductor for evaluation. The dark part potential Vd = −700V and the bright part potential Vl = −200V. The surface potential of the electrophotographic photosensitive member was measured by removing the developing cartridge from the evaluator and inserting a potential measuring device there. The potential measuring device is configured by arranging a potential measuring probe at the developing position of the developing cartridge. The position of the potential measuring probe with respect to the electrophotographic photosensitive member is approximately the center in the drum axis direction, and a gap from the drum surface is formed. It was 3 mm. Further, in a continuous mode in which A4 size plain paper is continuously copied, an image with a printing ratio of 6% is copied 50,000 sheets in an atmosphere environment of 30 ° C./85% RH, potential fluctuations, image defects and The amount of wear was evaluated.
[0087]
The potential fluctuation was evaluated by measuring the surface potential after the initial and 50,000 copies were repeatedly copied, and examining the difference in bright portion potential (ΔVl). In addition, (absolute value of bright part potential after 50,000 sheets
) − (The absolute value of the initial bright portion potential) is ΔVl.
Next, in a continuous mode in which A4 size plain paper is continuously copied, an image with a printing ratio of 6% is copied on 50,000 sheets in an atmosphere of 23 ° C./5% RH, and image defects and wear are detected. The amount was evaluated.
[0088]
The image evaluation was performed by outputting a copy image of a photographic document after copying 50,000 sheets and visually checking whether there are image defects such as image unevenness and fogging.
[0089]
Evaluation of the abrasion amount of the photoreceptor was performed by obtaining a difference in film thickness after durability from the film thickness before durability.
[0090]
(Example 2)
A photoconductor was prepared and evaluated in the same manner as in Example 1 except that 0.75 parts of the diorganopolysiloxane used in Example 1 was added to 10 parts of the polytetrafluoroethylene resin fine particles.
[0091]
(Example 3)
Example 1 except that the ratio of CTM-1 / CTM-2 / polycarbonate resin / polytetrafluoroethylene / diorganopolysiloxane used in Example 1 was 9/1/14/1 / 0.1 Similarly, a photoconductor was prepared and evaluated.
[0092]
Example 4
Example 1 except that the ratio of CTM-1 / CTM-2 / polycarbonate resin / polytetrafluoroethylene / diorganopolysiloxane used in Example 1 was changed to 6/1/12/1 / 0.05. Similarly, a photoconductor was prepared and evaluated.
[0093]
(Example 5)
Example except that the ratio of CTM-1 / CTM-2 / polycarbonate resin / polytetrafluoroethylene / diorganopolysiloxane used in Example 1 was 9/1/14 / 0.5 / 0.025 1 was prepared and evaluated.
[0094]
(Example 6)
A photoconductor was prepared and evaluated in the same manner as in Example 1 except that the charging frequency of the AC voltage applied to the charging member was 1000 Hz.
[0095]
(Example 7)
A photoconductor was prepared and evaluated in the same manner as in Example 1 except that the charging frequency of the AC voltage applied to the charging member was 1500 Hz.
[0096]
(Example 8)
A photoconductor was prepared and evaluated in the same manner as in Example 1 except that the diorganopolysiloxane represented by the formula (2-7) was used instead of the diorganopolysiloxane used in Example 1.
[0097]
(Comparative Example 1)
A photoconductor was prepared and evaluated in the same manner as in Example 1 except that 1.5 parts of the diorganopolysiloxane used in Example 1 was added to 10 parts of the polytetrafluoroethylene resin fine particles.
[0098]
(Comparative Example 2)
A photoconductor was prepared and evaluated in the same manner as in Example 1 except that 2 parts of the diorganopolysiloxane used in Example 1 was added to 10 parts of the polytetrafluoroethylene resin fine particles.
[0099]
(Comparative Example 3)
Example 1 except that the ratio of CTM-1 / CTM-2 / polycarbonate resin / polytetrafluoroethylene / diorganopolysiloxane used in Example 1 was 14/2/20/1 / 0.03 Similarly, a photoconductor was prepared and evaluated.
[0100]
(Comparative Example 4)
A photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the fluorine atom-containing resin fine particles were not used.
[0101]
(Comparative Example 5)
A photoconductor was prepared and evaluated in the same manner as in Comparative Example 2 except that the fluorine atom-containing resin fine particles were not used.
[0102]
(Comparative Example 6)
A photoconductor was prepared and evaluated in the same manner as in Comparative Example 3 except that the fluorine atom-containing resin fine particles were not used.
[0103]
(Comparative Example 7)
Photosensitive as in Example 1 except that 0.6 parts of acrylic resin having a fluorine alkyl side chain (GF300, manufactured by Toagosei Co., Ltd.) is added to 10 parts of polytetrafluoroethylene resin fine particles instead of diorganopolysiloxane. A body was made and evaluated.
[0104]
(Reference Example 1)
A photoconductor was prepared and evaluated in the same manner as in Example 1 except that the charging frequency of the AC voltage applied to the charging member was 1600 Hz.
[0105]
(Reference Example 2)
A photoconductor was prepared and evaluated in the same manner as in Example 1 except that the charging frequency of the AC voltage applied to the charging member was 900 Hz.
[0106]
(Reference Example 3)
A photoconductor was prepared and evaluated in the same manner as in Comparative Example 1 except that the charging frequency of the AC voltage applied to the charging member was set to 900 Hz.
[0107]
(Reference Example 4)
A photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the pre-exposure means was not used.
[0108]
The evaluation results are shown in Table 1.
[0109]
[Table 4]
[0110]
【The invention's effect】
As described above, according to the present invention, even in an electrophotographic apparatus having a specific charge setting and pre-exposure means, fluorine atom-containing resin fine particles and a specific diorganopolysiloxane are added to the surface layer of the photoconductor. When it is contained, an electrophotographic photosensitive member, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus that can obtain favorable electric potential characteristics and further excellent durability characteristics can be realized.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having an electrophotographic photosensitive member of the present invention.
[Explanation of symbols]
1 Electrophotographic photoreceptor of the present invention
2 axis
3 Primary charging means
4 exposure light
5 Development means
6 Transfer means
7 Transfer material
8 Fixing means
9 Cleaning means
10 Pre-exposure light
11 Process cartridge
12 rails

Claims (6)

An electrophotographic photosensitive member having a photosensitive layer on a conductive support, and a charging member that is placed in contact with the electrophotographic photosensitive member and charges the electrophotographic photosensitive member by applying a voltage in which an alternating voltage is superimposed on a direct current voltage At least a pre-exposure means for neutralizing the electrophotographic photosensitive member, and the relationship between the charging frequency f (Hz) and the process speed Vp (mm / sec) satisfies the condition of the following formula (1): In the electrophotographic photosensitive member used in the electrophotographic apparatus to satisfy,
The surface layer of the electrophotographic photoreceptor contains at least fluorine atom-containing resin fine particles and a diorganopolysiloxane represented by the following formula (2), and the content of the diorganopolysiloxane is based on the fluorine atom-containing resin particles. An electrophotographic photosensitive member characterized by being 7.5 % by mass or more and 10% by mass or less and 0.1% by mass or more and 0.8% by mass or less based on the total solid content of the surface layer. .
10 ≦ f / Vp ≦ 15 (1)
(Wherein, R ₁₁ to R ₁₆ represents a substituted or unsubstituted hydrocarbon group, B represents a substituted or unsubstituted organic group having a fluoroalkyl group, at least one of D degree of polymerization terminals blocked 3 or more, a group having a substituted or unsubstituted polystyrene chain, E ₁₁ and E ₁₂ are groups selected from R _{11 to} R ₁₆ , B and D, and x is an integer of 0 to 1,000. Y and z represent an integer of 1 to 1,000.) The electrophotographic photosensitive member according to claim 1, wherein at least one of R _{11 to} R ₁₆ of the diorganopolysiloxane is a methyl group or a phenyl group. The electrophotographic photosensitive member according to claim 1, wherein the substituted or unsubstituted organic group having a fluoroalkyl group of B of the diorganopolysiloxane is represented by the following formula (3).
(Wherein, R ₂₁ represents an alkylene group or alkylene oxyalkylene group, m represents an integer of 3 or more.) The electrophotographic photoreceptor according to any one of claims 1 to 3, wherein the group having a substituted or unsubstituted polystyrene chain of D of the diorganopolysiloxane is represented by the following formula (4).
(Wherein R ₃₁ and R ₃₂ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, W ₃₁ represents a hydrocarbon group, and W ₃₂ has a degree of polymerization of 3 or more whose end is blocked. Represents a substituted or unsubstituted polystyrene chain, and n represents 0 or 1.)   5. The electrophotographic photosensitive member according to claim 1 and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means are integrally supported and detachably attached to the main body of the electrophotographic apparatus. Process cartridge characterized by being.   An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit.