JP2003186223A - Electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable the output of a high quality image which is free of an image defect, by preventing a photoreceptor from being worn or damaged to extend its life, and achieving stable electrification, in an electrophotographic device having a means for electrifying by the application of only a DC voltage and a developer carrier disposed in contact with the surface of the photoreceptor. <P>SOLUTION: In the electrophotographic device having a electrophotographic photoreceptor, a means for electrifying the photoreceptor by applying a voltage to an electrifying member that is in contact with the surface of the photoreceptor, and a developer carrier which is disposed in contact with the surface of the photoreceptor, the photoreceptor has a protective layer on its surface. The protective layer contains conductive particles, and/or one or more kinds of charge transfer substances having at least one hydroxyl group in a molecule, and a three-dimensionally crosslinked resin. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus, and more particularly, to an electrophotographic apparatus which directly charges an electrophotographic photosensitive member and which has a developer carrier in contact with the photosensitive member.

[0002]

2. Description of the Related Art In the electrophotographic method, as a charging process, conventionally, charging by corona discharge generated by applying a high voltage (DC 5 to 8 kV) to a metal wire has been widely used.

However, in this method, when corona occurs, corona products such as ozone and NOx deteriorate the surface of the photosensitive member to cause image blurring and deterioration, and wire stains affect image quality, resulting in white spots and black images. There was a problem such as streaking.

In the case of corona charging, the electric current flowing to the photoconductor is only 5 to 30% in terms of electric power, and most of the current flows to the shield plate, which is inefficient as a charging means.

In order to eliminate such a problem, without using a corona discharger, JP-A-57-178267, JP-A-56-104351, and JP-A-58-4.
As proposed in Japanese Patent Application No. 0566, Japanese Patent Application Laid-Open No. 58-139156, Japanese Patent Application Laid-Open No. 58-150975, etc., contact charging methods have been studied and put to practical use.

Specifically, the surface of the photoconductor is charged to a predetermined potential by contacting the surface of the photoconductor with a charging member such as a conductive elastic roller to which a voltage is applied from the outside.

However, in this charging method, when the applied voltage is only DC, the uniformity of charging is not sufficient, and spot-like or streak-like uneven charging is likely to occur.

On the other hand, by superposing the AC voltage on the DC voltage, the uniformity of charging is improved, but the increase of the current flowing into the photoconductor tends to accelerate the deterioration and wear of the photoconductor surface. . Along with this, deep scratches are likely to be formed on the surface of the photoconductor, but there is a problem in that such scratched parts are not sufficiently charged and streak-shaped image defects are generated.

Also in such a contact charging device, since the essential charging mechanism uses the discharging phenomenon from the charging member to the photosensitive member, a slight amount of ozone is generated.

On the other hand, as means for alleviating the non-uniformity of charging in such direct charging, the thickness of the photosensitive member is reduced to increase the surface charge amount, and in the reversal developing system, the developing bias and the dark portion potential of the photosensitive member are increased. There is a case where uneven charging is made difficult to see as an image by increasing the difference between and.

Incidentally, the developing system can be roughly classified into a two-component developing system and a one-component developing system. Most electrophotographic devices, such as a laser printer as an output device of a personal computer, a small copying machine, and a plain paper facsimile, use a one-component developing system. Among them, there is a contact developing system in which a developing roller carrying toner is brought into contact with a photoconductor to develop. In this method, since the toner on the developing roller is uniformly charged with a relatively thin layer thickness, reversal fog is unlikely to occur. Therefore,
When the developing bias is set so as to increase the difference between the developing bias and the photoconductor dark area potential as described above, the contact developing method is suitable.

As described above, in the electrophotographic apparatus using the direct charging method, it is preferable to use the contact developing method in order to make uneven charging hardly appear as an image.

However, when this developing method is used, the developing roller comes into contact with the photosensitive member and rotates while rubbing, so that the photosensitive member is apt to be worn or damaged. Further, in order to sufficiently supply the toner carried on the surface of the developing roller onto the photoconductor, the peripheral speed thereof is often set to be higher than the peripheral speed of the photoconductor. In such a case, the photoconductor is more easily worn.

In particular, in a direct charging system in which only a DC voltage is applied, if the thickness of the photosensitive member is thinned as another means for alleviating nonuniformity of charging, the latitude for abrasion and scratches is small, and as a result, the photosensitive member is reduced. There is a problem that the service life of will be very short.

Further, even if the film thickness of the photoconductor is increased, if the photoconductor is greatly scraped, the change in the capacitance of the photoconductor causes a large change in the charging potential in the direct charging system in which only the DC voltage is applied. Therefore, a stable image cannot be obtained.

On the other hand, in the electrophotographic apparatus using the direct charging method and the contact developing method, it is relatively easy to design a so-called cleanerless process in which the toner remaining on the photoconductor after the transfer step is recovered by the developing step. Yes, some have been put to practical use.

However, in this case, the scraped substances due to the abrasion of the photoconductor are not directly recovered but mixed in the charging device and the developing device. Therefore, image defects such as uneven charging due to contamination of the charging member and deterioration of developability due to contamination of the toner and the developing roller are likely to occur.

Therefore, when the wear of the photoreceptor is large, these phenomena become more remarkable.

[0019]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a means for applying a voltage to a charging member in contact with an electrophotographic photosensitive member to charge it, and a developer carrying member arranged in contact with the surface of the photosensitive member. In an electrophotographic apparatus having a body, it is to solve the above problems. That is, the photosensitive member is less likely to be worn or damaged, the life of the photosensitive member can be extended, and stable charging can be performed, thereby enabling high-quality image output without image defects.

[0020]

As a result of repeated studies on the above problems, the present inventor has found that an electrophotographic photosensitive member and a means for applying a voltage to a charging member in contact with the surface of the photosensitive member to charge it. In an electrophotographic apparatus having a developer carrying member arranged in contact with the surface of the photoconductor, the photoconductor has at least one conductive particle on its surface and / or at least one hydroxyl group in the molecule.
It has been found that the above-mentioned problems can be solved by providing an electrophotographic apparatus characterized by having a protective layer containing one or more charge-transporting substances having three and three-dimensionally crosslinked resin.

It was also found that the above-mentioned problems can be satisfactorily solved by containing a curable phenol resin in the protective layer of the electrophotographic photosensitive member.

It has also been found that the above-mentioned problems can be satisfactorily solved by the fact that the protective layer of the electrophotographic photosensitive member contains the fluorine atom-containing resin fine particles.

In the case of contact development, an elastic sponge roller is often used as the developing roller which is a toner carrier.
Since this roller rotates in contact with the photoconductor and its peripheral speed is generally set to 20 to 100% faster than the peripheral speed of the photoconductor, the surface of the photoconductor is strongly rubbed. .
Therefore, the surface of the photoconductor is mainly composed of a three-dimensionally crosslinked resin, so that abrasion of the photoconductor can be reduced.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The constitution of the photoreceptor of the present invention will be briefly described. It is preferable to use an organic photoconductor as the photoconductor of the present invention. The photosensitive layer made of an organic photoconductor generally has a function separation type structure in which a charge transport layer is laminated on a charge generation layer. Therefore, the protective layer of the present invention is provided on these photosensitive layers.

Since the surface of the photosensitive member can be provided with the strength of the photosensitive member, it is possible to reduce the thickness of the photosensitive layer, and in particular, the nonuniform charging caused by the direct charging method in which only the DC voltage is applied. Can be reduced.

In the electrophotographic photosensitive member used in the present invention,
Examples of the three-dimensionally crosslinked resin include monomers or oligomers having a reactive functional group that crosslinks by heat or light, such as acrylic, urethane, epoxy and silicone.

Among them, it is particularly preferable to use a curable resol type phenol resin. Usually, the resol type phenol resin is produced by subjecting a phenol compound and an aldehyde compound to an alkali catalyst. The main phenols used for this purpose include, but are not limited to, phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, resorcin, bisphenol and the like. As aldehydes, formaldehyde, paraformaldehyde, furfural, acetaldehyde, etc.
It is not limited to these. Monomers of these phenols and aldehydes are reacted under an alkaline catalyst, monomers of dimethylolphenols, dimethylolphenols, trimethylolphenols, and mixtures thereof, or those obtained by oligomerizing them, and monomers and oligomers. To create a mixture of. Of these, relatively large molecules having repeating structural units of about 2 to 20 are oligomers, and those having a smaller number are monomers.
As the alkaline catalyst used at this time, NaOH, KOH, Ca (O
Although hydroxides of alkali metals and alkaline earth metals such as H) 2 and amine catalysts are used, it is more preferable to use amine catalysts in consideration of fluctuations in resistance under high humidity. Amine catalysts include ammonia, hexamethylenetetramine, trimethylamine, triethylamine, triethanolamine, etc., but are not limited thereto. In the present invention, it is more preferable to use an amine-based catalyst excluding ammonia in terms of solution stability.

Further, the conductive particles contained in the photoconductor protective layer in the present invention are for adjusting the resistance of the protective layer, whereby the charging potential can be further stabilized. Examples of the conductive particles include metals, metal oxides and carbon black. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver, stainless steel, and the like, or those obtained by vapor-depositing these metals on the surface of resin particles. As the metal oxide, ultrafine particles such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, tin-doped indium oxide, antimony-doped tin oxide and zirconium oxide can be used. These may be used alone or in combination of two or more.

The average particle size of the conductive particles used in the present invention is preferably 0.3 μm or less, and particularly preferably 0.1 μm or less, from the viewpoint of the transparency of the protective layer.

Further, in the present invention, among the above-mentioned conductive particles, it is particularly preferable to use a metal oxide in terms of transparency.

The ratio of the resin to the conductive particles is a value that directly determines the resistance of the protective layer, and the resistance of the protective layer is 10 ¹⁰ to.
It is set to be in the range of 10 ¹⁵ (Ω · cm). Since the mechanical strength of the film decreases as the ratio of the conductive particles increases, it is preferable to reduce the amount of the conductive particles within a range in which the resistance and residual potential of the protective layer are acceptable.

The conductive particles may be subjected to surface treatment by known materials and means, if necessary.

By having such a resistance-adjusted protective layer on the surface of the photoconductor, as a secondary effect, direct charge injection from the charging member is performed and the uniformity of charging is improved. .

As another aspect of the present invention, it is preferable that the photoreceptor protective layer contains a phenol resin and at least one charge transport material having at least one hydroxyl group in the molecule.

As the charge transport substance, a charge transport substance having at least one selected from the group consisting of a hydroxyalkyl group, a hydroxyalkoxy group and a hydroxyphenyl group which may have a substituent in the molecule is particularly preferable.

The charge transporting material used in the present invention has good compatibility with the phenol resin and can easily form a coating film which is uniformly dissolved, but in order to further improve the compatibility, the general formula ( In 1) to (3), R _{11 to} R
_The divalent hydrocarbon group represented by ₁₃ , R _{21 to} R ₂₃ and R _{31 to} R ₃₄ preferably has 4 or less carbon atoms, and the number of hydroxyalkyl groups and hydroxyalkoxy groups is 2 or more. It is preferable.

In the general formulas (4) to (6), the phenol group contained in the charge transport material reacts with the phenol resin to incorporate the charge transport material into the protective layer matrix,
The strength as a surface layer may be improved.

As a result, a protective layer having a high hardness can be obtained without impairing the electrophotographic characteristics. By using a photoconductor having such a protective layer, the electrophotographic apparatus of the present invention has the above-mentioned problems. It can be solved in dimensions.

General formulas (1) to (6) used in the present invention
The charge-transporting substance having the specific structure of is uniformly dissolved or dispersed in the coating material for forming the surface layer, and is applied to form the coating. The mixing ratio of the charge transport material of the general formulas (1) to (6) and the curable phenol resin binder is, by weight ratio, charge transport material / phenol resin binder = 0.1.
/ 10 to 20/10, preferably 0.5 / 10 to 10 /
It is 10. If the charge transport material is too small for the phenol resin binder, the effect of lowering the residual potential becomes small,
If it is too large, the strength of the protective layer may be weakened.

Examples of compounds of the charge transport material are shown below.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

[0044]

[Table 4]

[0045]

[Table 5]

[0046]

[Table 6]

[0047]

[Table 7]

Further, in the present invention, the protective layer further comprises
It is preferable to contain fine resin particles containing a fluorine atom. As a result, it is possible to reduce the frictional resistance caused by the sliding friction between the cleaning member and the photoconductor in the cleaning process, and it is possible to further reduce the abrasion.

On the other hand, when the apparatus of the present invention is applied to the cleanerless process, since the photoconductor is less worn, the contamination of the charging member, the developing roller, the developer and the like can be reduced. Therefore, the output image can be stabilized.

By the way, when such a photoconductor having a surface which is hard to be worn is used, there is a problem that image flow or bleeding phenomenon easily occurs at high temperature and high humidity. this is,
It has been known that this occurs because the surface of the transfer material, which is a component of paper, adheres to the photoconductor and the surface of the photoconductor is charged with a low resistance. It tended to be difficult.

Therefore, by incorporating the fluorine atom-containing resin fine particles into the photoconductor, the components of the transfer paper are less likely to adhere to the surface, and the photoconductor is not worn by rubbing the surface of the photoconductor by contact development. The deposit can be removed.
Therefore, it is possible to reduce the image deletion due to the low resistance of the surface.

Further, the protective layer composed of phenol resin and conductive particles has a high resistance stability, and it is difficult to reduce the resistance under high temperature and high humidity, so that it is also effective in preventing image deletion. It was.

In the present invention, as the fluorine atom-containing resin fine particles, powders of polytetrafluoroethylene, polyvinylidene fluoride and the like are used, which are dispersed in the monomers and oligomers. The powder content is 1 based on the total solid content.
-10 mass% is preferred, and more preferably 5-50 mass%.

Next, the photosensitive layer will be described.

The electrophotographic photosensitive member of the present invention is constituted by further providing the protective layer of the present invention on a general photosensitive layer, for example, a laminate of a charge generating layer and a charge transporting layer.

The charge generating layer is an inorganic charge generating material such as selenium, selenium-tellurium, and amorphous silicon, a cationic dye such as pyrylium dye, thiapyrylium dye, azurenium dye, thiacyanine dye, and quinocyanine dye; squarylium. Salt-based pigments; Phthalocyanine-based pigments; Polycyclic quinone pigments such as anthanthrone-based pigments, dibenzpyrenequinone-based pigments and pyrantrone-based pigments, indigo-based pigments, quinacridone-based pigments and azo-based pigments These materials can be used alone or in combination, and can be formed as a vapor deposition layer by a vacuum vapor deposition device, or can be formed as a coating layer by applying a coating liquid obtained by dispersing in a binder resin and drying. can do.

The binder resin can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole and polyvinylpyrene. Preferred are polyvinyl butyral, polyalates (polycondensates of bisphenol A and phthalic acid, etc.), polycarbonates, polyesters, polyvinyl acetates, acrylic resins, polyacrylamides, polyamides, cellulosic resins, urethane resins, epoxy resins and polyvinyl alcohols. Resin can be mentioned. The resin contained in the charge generation layer is preferably 80% by mass or less, and particularly preferably 40% by mass or less.

The thickness of the charge generation layer is preferably 5 μm or less, and particularly preferably 0.01 to 1 μm.

The charge transport layer is formed by dissolving a charge transporting material such as a hydrazone compound, a pyrazoline compound, a styryl compound, a triphenylmethane compound, an oxazole compound and a thiazole compound in a solvent together with a binder resin and coating the solution. To form.

Examples of the binder resin include resins such as polyalate, polycarbonate, polyester, acrylic resin, polysulfone, polyphenylene oxide, urethane resin and epoxy resin. The mixing ratio of the charge transport material and the binder resin in the charge transport layer is 2: based on mass.
It is about 1 to 1: 2.

The thickness of the charge transport layer is preferably 5 to 40 μm.
m, more preferably 10 to 30 μm.

Further, the charge generation layer and the charge transport layer may contain various additives such as an antioxidant, an ultraviolet absorber, a lubricant and a plasticizer.

In the present invention, a layer having a barrier function and an adhesive function, a so-called subbing layer, may be provided between the conductive support and the photosensitive layer. Examples of the material for the undercoat layer include polyvinyl alcohol, polyethylene oxide, nitrocellulose, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, alcohol-soluble polyamide, polyamide, polyurethane, casein, glue and gelatin.

These are dissolved in a suitable solvent and coated on a conductive support. The film thickness is preferably 5 μm or less,
Particularly, 0.2 to 3.0 μm is preferable.

As the conductive support, for example, aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold and platinum are used. In addition, a plastic (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, etc.) or conductive particles (for example, carbon black, silver particles, etc.) formed by coating such a metal or alloy by a vacuum deposition method is appropriately bound. It is possible to use the above-mentioned plastic, a support coated on the support of metal or alloy, or a support obtained by impregnating plastic or paper with conductive particles together with the resin.

Examples of the shape of the support include a drum shape, a sheet shape, a belt shape and the like, but it is preferable to make the shape most suitable for the applied electrophotographic apparatus.

[0067]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the electrophotographic apparatus of the present invention is applied to a laser printer will be described with reference to FIGS.

In FIGS. 1 and 2, 11 and 21 are charging members, which are in contact with the surface of the photoconductor. 11 shows an example in which a material having rubber elasticity and a conductive agent such as carbon are kneaded and formed into a roller shape around a metal core and used. In No. 21, as the brush-shaped charging member, a member in which fibers in which carbon is dispersed is transplanted into rayon and which is wound around a metal core is used. A DC voltage is applied to these charging members from a power source (not shown).

Reference numerals 12 and 22 denote a wavelength 780 having image information.
nm laser light source.

Numerals 13 and 23 are developing units, which are arranged in contact with the surface of the photoconductor, in which toners 14 and 24 are stored. Reference numerals 15 and 25 denote developing rollers that carry toner and develop the photoconductor. The developing roller is made of a material having rubber elasticity because it contacts the photoconductor with a nip. As this material, urethane rubber, hydrin rubber, silicone rubber, etc. are used. A DC voltage is applied to these developing rollers from a power source (not shown).

In this example of the apparatus, the reversal development method is used for developing the exposed portion of the photoconductor.

Reference numerals 16 and 26 designate photoconductors which rotate in the directions of the arrows.

Numerals 17 and 27 are transfer chargers. Here, a configuration is shown in which the conductive sponge roller is brought into contact with the photoconductor.

Reference numerals 18 and 28 denote papers on which the toner is transferred.

A cleaning unit 19 removes the transfer residual toner from the photosensitive member. Here, a configuration is shown in which a rubber blade is pressed against the photoconductor to scrape off the toner. On the other hand, the apparatus of FIG. 2 shows an example in which the positive toner cleaning mechanism as in FIG. 1 is not provided.
Reference numeral 29 denotes a conductive brush to which a voltage is applied, which has a function of physically dispersing the transfer residual toner on the surface of the photoconductor and aligning the polarities of the toner.

Example 1 A photoconductor was prepared as follows.

An aluminum cylinder of φ30 mm × 260.5 mm was used as a support, on which 5 polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) was used.
A mass% methanol solution is applied by a dipping method to obtain a film thickness of 0.
An undercoat layer of 5 μm was provided. Next, CuK of the following structural formula
It has strong peaks at 9.0, 14.2, 23.9, and 27.1 ° at the Bragg angle 2θ ± 0.2 ° in α characteristic X-ray diffraction.

[0078]

[Chemical 7] Oxytitanium phthalocyanine pigment 4 parts (parts by mass; hereinafter the same), polyvinyl butyral resin (trade name: BX-
1, Sekisui Chemical Co., Ltd.) 2 parts and cyclohexanone 80
Part is a sand mill using φ1mm glass beads,
Dispersed for about 4 hours.

This dispersion was applied on the undercoat layer in the previous period,
A 0.2 μm charge generation layer was formed.

Next, the following structural formula

[0081]

[Chemical 8] 10 parts of the compound and 10 parts of bisphenol Z-type polycarbonate (trade name: Z-200, manufactured by Mitsubishi Gas Chemical Co., Inc.) were dissolved in 100 parts of monochlorobenzene. This solution was applied on the charge generation layer and dried in hot air at 105 ° C. for 1 hour to form a charge transport layer having a thickness of 14 μm.

Then, as a protective layer, 50 parts of antimony-doped tin oxide ultrafine particles surface-treated with the following structural formula (treatment amount 7%)

[0083]

[Chemical 9] And 150 parts of ethanol were dispersed in a sand mill for 66 hours, and further 20 parts of polytetrafluoroethylene fine particles (average particle size 0.18 μm) were added and dispersed. After that, resol type phenol resin (trade name: PL
-4804: Using an amine-based catalyst other than ammonia and using Gunei Chemical Industry Co., Ltd. as a resin component, 22 parts was dissolved to prepare a preparation liquid.

Using this formulation, a film was formed on the above charge transport layer by a dip coating method, and dried with hot air at 145 ° C. for 1 hour to obtain a protective layer (surface layer). At this time, the film thickness of the obtained protective layer was 3 μm. Further, the dispersibility of the protective layer preparation liquid was good, and the film surface was a uniform and even surface.

This photosensitive member was mounted on the printer illustrated in FIG. The toner used was a one-component magnetic toner.
The developing roller is made of urethane rubber with a diameter of 20 mm, the Asker C hardness is 50 °, and the contact nip with the photoconductor is 0.5 mm.
Set to.

The peripheral speed of the photoconductor is 94 mm / sec. The peripheral speed of the developing roller is 1.5 times, 141 mm / sec. And

The charging potential is set so that the dark potential of the photoconductor is-.
The laser exposure amount was adjusted so that the bright portion potential was set to −80 V by setting it to 700 V.

The bias voltage applied to the developing sleeve was set to -300V.

When a printing durability test was performed on 10,000 sheets of this apparatus in an environment of 23 ° C. and 50% RH, a good image was obtained from the initial stage to the end of the durability, and image unevenness and
Fog and streaks did not occur.

The amount of abrasion of the photosensitive member after printing 10,000 sheets was 0.6 μm, which was extremely small.

(Embodiment 2) Using the printer illustrated in FIG. 2 as an electrophotographic apparatus, the peripheral speed of the photoconductor is 94 mm /
sec. The structure of the developing unit and the structure of the photoconductor were the same as in Example 1.

The charging potential setting and the developing bias setting were adjusted to the following values. Dark potential: -650 V, Bright potential: -7
0V, development bias: -300V
When a printing durability test was performed on 0 sheets, a good image was obtained from the initial stage to the end of the durability, and image unevenness, fog, and streaks did not occur.

The amount of abrasion of the photoconductor after printing 10,000 sheets was 0.4 μm, which was extremely small.

Example 3 A charge transporting layer was prepared in the same manner as the photoconductor of Example 1. Next, a protective layer having the following constitution was provided on this.

As a photocurable acrylic monomer, a mixture of 2 parts and 2 parts of the following (1) and (2) respectively was added, and tin oxide ultrafine particles 8 doped with antimony having an average particle diameter before dispersion of 400 Å were used. And 3 parts of polytetrafluoroethylene fine particles were dispersed by a sand mill. To this, 0.32 parts of diethylthioxanthone as a photopolymerization initiator was added and dissolved, and the solution was applied onto the above photoconductive layer and irradiated with UV by a high pressure mercury lamp to form a surface layer of 3 μm.

This photoreceptor was mounted on the electrophotographic apparatus used in Example 1 and the same printing durability test was conducted.

[0097]

[Chemical 10] The charging potential setting and the developing bias setting were adjusted to the following values. Dark part potential: -800 V, light part potential: -100 V, developing bias: -350 V (Comparative Example 1) With respect to the photoreceptor of Example 1, the charge transport layer had a film thickness of 17 μm and no surface layer was provided. Except for the above, a photoconductor was prepared in the same manner.

This photoreceptor was mounted on the electrophotographic apparatus used in Example 1 and the same printing durability test was conducted. The latent image conditions and development conditions were adjusted to be the same as in Example 1.

In addition to the above examples, the results are summarized in Table 1.

[0100]

[Table 8] As shown in Table 1, in Examples 1 to 3, the amount of wear of the surface layer of the photoconductor was small, no scratch was generated, and a good image was maintained throughout the durability test. Further, in the cleanerless process, no image defect due to contamination of the charging portion or the developing portion appeared.

On the other hand, in the comparative example, the amount of abrasion of the surface layer of the photoconductor was large, streaks due to scratches and uneven charging occurred, and fogging occurred due to the thinning of the film due to durability.

Next, a high temperature and high humidity environment (30 ° C., 80% R
The printing durability test in H) was performed. The results are also shown in the table.

In Examples 1 to 3, in a high-temperature and high-humidity environment, and although the surface of the photoconductor was less worn, the so-called image blur phenomenon such as image bleeding or blurring did not occur, and the temperature was kept at room temperature. A good image similar to a normal humidity environment was obtained.

On the other hand, in the comparative example, image deletion did not occur due to a large amount of wear, but as in the case of normal temperature and normal humidity, scratches and uneven charging occurred, and vertical stripes appeared in the image.

Example 4 A charge transporting layer was prepared in the same manner as the photoconductor of Example 1. Next, a protective layer having the following constitution was provided on this.

100 parts of antimony-doped tin oxide fine particles were mixed with a fluorine atom-containing compound having the following structural formula (trade name: LS-1).
090, manufactured by Shin-Etsu Silicone Co., Ltd.) and surface treated with 7 parts (hereinafter, treated amount: 7%), and treated tin oxide fine particles 35 parts.

[0107]

[Chemical 11] Disperse 150 parts of ethanol in a sand mill for 66 hours, further add 18 parts of polytetrafluoroethylene fine particles (average particle size 0.18 μm), and further add 12 parts.
Dispersion was performed with a sand mill for an hour.

After that, as a resin component, a resol type curable phenol resin (trade name: P manufactured by Sumitomo Durez Co., Ltd.)
R-53123) 54 parts (nonvolatile content: 45%),
As a charge-transporting substance having a hydroxyalkyl group, 15 parts of the compound No. (8) was dissolved and diluted with 35 parts of ethanol to obtain a protective layer coating material.

Using this coating composition, a film was formed on the above charge transport layer by a dip coating method and then dried with hot air at 145 ° C. for 1 hour to form a protective layer having a thickness of 3 μm.

This electrophotographic photosensitive member was mounted on the electrophotographic apparatus used in Example 1, and the photosensitive member was similarly exposed under the environment of 23 ° C. and 50% RH.
When a printing durability test was performed on 0000 sheets, a good image was obtained from the initial stage to the end of the durability, and image unevenness, fog, and streaks did not occur.

The amount of abrasion of the photoconductor after printing 10,000 sheets was 0.4 μm, which was extremely small.

The charging potential setting and the developing bias setting were adjusted to the following values.

Dark part potential: -750 V, light part potential: -70
V, development bias: -350 V (Example 5) The charge transport layer was formed in the same manner as in Example 1.

Next, 42 parts (nonvolatile content: 58%) of a resol type curable phenol resin (trade name: PL-2211) manufactured by Gunei Chemical Industry Co., Ltd. was used as a resin component of the protective layer. 15 parts of the above compound No. (31) was dissolved as a charge transporting substance having a hydroxyalkyl group to obtain a protective layer coating material.

Using this coating composition, a film was formed on the above charge transport layer by a dip coating method, and then dried with hot air for 1 hour at 145 ° C. to form a protective layer having a thickness of 3 μm.

This electrophotographic photosensitive member was mounted on the electrophotographic apparatus used in Example 1, and the photosensitive member was similarly exposed under the environment of 23 ° C. and 50% RH.
When a printing durability test was performed on 0000 sheets, a good image was obtained from the initial stage to the end of the durability, and image unevenness, fog, and streaks did not occur.

The amount of abrasion of the photosensitive member after printing 10,000 sheets was 0.3 μm, which was extremely small.

The charging potential setting and the developing bias setting were adjusted to the following values.

Dark part potential: -700 V, light part potential: -60
V, developing bias: -300 V (Example 6) The electrophotographic apparatus prepared in Example 5 was mounted on the electrophotographic apparatus used in Example 1. Furthermore, in this embodiment,
The charging roller was modified so that AC voltage was superimposed and applied in addition to DC voltage. Similarly, under these conditions, 23 ° C and 50
When a printing durability test was performed on 10,000 sheets in an environment of% RH, a good image was obtained from the initial stage to the end of the durability, and image unevenness, fog, and streaks did not occur.

The amount of abrasion of the photosensitive member after printing 10,000 sheets was 0.8 μm, which was extremely small.

The charging potential setting and the developing bias setting were adjusted to the following values.

Dark part potential: -650 V, light part potential: -60
V, development bias: -350V These results are shown in Table 2.

[0123]

[Table 9] As shown in Table 2, in Examples 4 to 6, the amount of wear of the surface layer of the photoconductor was small, no scratch was generated, and good images were maintained throughout the durability test.

In addition, the high temperature and high humidity environment (30
The results of the printing durability test at 80 ° C. and 80% RH are also shown in the table.

In Examples 4 to 6, in a high temperature and high humidity environment, and although the surface of the photoconductor was less worn, the so-called image blur phenomenon such as image blurring or blurring did not occur, and the temperature was kept at room temperature. A good image similar to a normal humidity environment was obtained.

[0126]

According to the present invention, an electron having means for applying a voltage to a charging member in contact with an electrophotographic photosensitive member to be charged and a developer carrier arranged in contact with the surface of the photosensitive member. In a photographic device, abrasion and scratches on the photoconductor are less likely to occur, the life of the photoconductor is extended, and there are no image defects, and high-quality image output is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an electrophotographic apparatus according to the present invention.

FIG. 2 is a diagram showing another configuration of the electrophotographic apparatus according to the present invention.

[Explanation of symbols]

11, 21 Charging member 12, 22 Laser light source 13, 23 Developer 14, 24 toner 15, 25 Development roller 16, 26 photoconductor 17, 27 Transfer charger 18, 28 Transfer paper 19 Cleaning unit 29 Conductive brush

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor ▲ Yoshi ▼ Kimihiro Mura             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Koichi Nakata             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F term (reference) 2H068 AA03 AA04 AA05 BB31 BB35                       BB57 BB58 CA37 EA04 FC01                       FC08

Claims (11)

[Claims] 1. An electrophotographic apparatus comprising an electrophotographic photosensitive member, a means for charging a charging member in contact with the surface of the photosensitive member by applying a voltage, and a developer carrying member arranged in contact with the surface of the photosensitive member. In the apparatus, the photoreceptor may have conductive particles on the surface thereof, and / or one or more kinds of charge transport substances having at least one hydroxyl group in the molecule, and a protective layer containing a three-dimensionally crosslinked resin. Characteristic electrophotographic device. 2. The electrophotographic apparatus according to claim 1, wherein the three-dimensionally crosslinked resin of the protective layer contains a curable phenol resin. 3. The electrophotographic apparatus according to claim 2, wherein the curable phenol resin is a resol type phenol resin. 4. The electrophotographic apparatus according to claim 3, wherein the resol type phenol resin is a resin produced by using an amine compound. 5. The electrophotographic apparatus according to claim 4, wherein the amine compound is a secondary or tertiary alkylamine compound. 6. The electrophotographic apparatus according to claim 2, wherein the curable phenol resin is a thermosetting phenol resin. 7. The charge transport material contained in the protective layer has a charge having at least one selected from the group consisting of a hydroxyalkyl group, a hydroxyalkoxy group and a hydroxyphenyl group which may have a substituent in the molecule. The electrophotographic apparatus according to claim 1, which is a transport material. 8. The charge transport material contained in the protective layer is
Formulas selected from the group consisting of general formulas (1) to (6)
8. The battery according to claim 7, wherein the structure is at least one type of
Child photography device. [Chemical 1] (In the formula, R₁₁, R₁₂And R₁₃Each has 1 to 8 carbon atoms
Represents a divalent hydrocarbon group which may be branched, α, β
And γ are a halogen atom and a substituent, respectively.
An alkyl group which may have an alkyl group which may have a substituent
Coxy group, an aryl group which may have a substituent, a substituent
Benzene which may have one or more heterocyclic groups which may have
Represents a ring, a1, b1 and c1 are 0 or 1;
m1 and n1 are 0 or 1. ) [Chemical 2] (In the formula, R_{twenty one}, R_{twenty two}And R_{twenty three}Each has 1 to 8 carbon atoms
Represents a divalent hydrocarbon group which may be branched,
And ε each have a halogen atom or a substituent as a substituent.
Alkyl which may be substituted, Alkoxy which may have a substituent
Si group, an aryl group which may have a substituent, a substituent
A benzene ring which may have one or more heterocyclic groups
Where a2, b2 and c2 are 0 or 1. m
2, n2 and p2 are 0 or 1 and all are simultaneously
It never becomes zero. τ and υ are substituents
Halogen atom, optionally substituted alkyl group,
Alkoxy group which may have a substituent, which may have a substituent
1 aryl group or 1 or more heterocyclic group which may have a substituent
Represents a benzene ring which may be present above. Note that τ and υ are replaced
They may form a ring jointly via a group. ) [Chemical 3] (In the formula, R₃₁, R₃₂, R₃₃And R₃₄Is the number of carbon
1 to 8 divalent hydrocarbon groups which may be branched,
ζ, η, θ and ι are halogen atoms as substituents.
Child, an alkyl group which may have a substituent, and a substituent
Optionally alkoxy group, optionally substituted aryl
Group, optionally having one or more heterocyclic groups which may have a substituent
Represents a good benzene ring, and a3, b3, c3 and d3 are
0 or 1 and m3, n3 and p3 are 0 or 1
Is. φ and χ are halogen atoms as substituents
Child, an alkyl group which may have a substituent, and a substituent
Optionally alkoxy group, optionally substituted aryl
Group, optionally having one or more heterocyclic groups which may have a substituent
Represents a good benzene ring. In addition, φ and χ are
You may form a circle jointly. ) [Chemical 4] (In the formula, R₄₁Is divalent with 1 to 8 carbon atoms and may be branched
Represents a hydrocarbon group of R, ₄₂Has a hydrogen atom and a substituent
Aralkyl, optionally substituted aralkyl
Represents a group and a phenyl group which may have a substituent. Ar₄₁Oh
And Ar₄₂Is an alkyl group which may have a substituent, a substituent
An aralkyl group which may have a substituent or an aralkyl group which may have a substituent.
It represents a reel group or a heterocyclic group which may have a substituent. Ar
₄₃Is an arylene group which may have a substituent, a divalent substituent
Represents a heterocyclic group which may have. m4 and n4 are
It is 0 or 1, respectively. However, when n4 = 0, m4
= 0. κ and λ are halogens as substituents, respectively.
Group atom, an alkyl group which may have a substituent, a substituent
Optionally an alkoxy group, an aryl which may have a substituent
Having one or more heterocyclic groups that may have substituents
Represents a good benzene ring. ) [Chemical 5] (In the formula, R₅₁Is divalent with 1 to 8 carbon atoms and may be branched
Represents a hydrocarbon group of. Ar₅₁And Ar₅₂Has a substituent
Optionally alkyl group, optionally substituted aralkyl
Group, an aryl group which may have a substituent, and a substituent
Represents a heterocyclic group which may be present. μ and ν are substituents
As a halogen atom, optionally substituted alkyl
Group, an alkoxy group which may have a substituent, a substituent
Optionally an aryl group, a heterocyclic group which may have a substituent
Represents one or more benzene rings. Note that μ and ν
May jointly form a ring via a substituent. m5 is 0
Or 1. ) [Chemical 6] (In the formula, R₆₁And R₆₂Are branches each having 1 to 8 carbon atoms
Represents a divalent hydrocarbon group which may be substituted. Ar₆₁Is replaced
An alkyl group which may have a group and an alkyl group which may have a substituent
Ralalkyl group, aryl group which may have a substituent, substituent
Represents a heterocyclic group which may have. ξ, π, ρ and σ are
Even if each has a halogen atom as a substituent or a substituent
A good alkyl group, an alkoxy group which may have a substituent,
An aryl group which may have a substituent, or an aryl group which may have a substituent
Represents a benzene ring which may have one or more heterocyclic groups.
Note that ξ and π, and ρ and σ are jointly via a substituent.
It may form a ring. m6 and n6 are each 0 or
It is 1. ) 9. The electrophotographic apparatus according to claim 1, wherein the voltage applied to the charging member is only direct current. 10. The electrophotographic apparatus according to claim 1, wherein the voltage applied to the charging member is a direct current superimposed with an alternating current. 11. The electrophotographic apparatus according to claim 1, wherein the protective layer of the electrophotographic photosensitive member contains fluorine atom-containing resin fine particles.