JPH0683097A - Electrophotographic photoreceptor and electrophotographic apparatus - Google Patents

Abstract

(57) [Summary] [Object] It is an object of the present invention to provide an electrophotographic photosensitive member which has a high transfer efficiency and which does not cause uneven transfer by reducing the surface energy remarkably. According to the present invention, in an electrophotographic photoreceptor having a surface layer containing at least carbon atoms and fluorine atoms, the mole fraction ratio F / C of carbon atoms to fluorine atoms measured by XPS on the surface of the photoreceptor is: An electrophotographic photosensitive member having F / C = 0.01 to 1.0, and an electrophotographic apparatus using the same,
Also, the above-mentioned electrophotographic photoreceptor used for a transfer material for electrophotography having a surface shape having a ten-point average surface roughness Rz defined by JIS B061 of Rz = 7.0 to 30.0 μm, and electrophotography using the same. It is a device. [Effects] The present invention enables an electrophotographic photosensitive member that provides a high quality image with high transfer efficiency and no image defects such as transfer unevenness by significantly reducing the surface energy.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
In particular, the present invention relates to an electrophotographic photosensitive member that realizes a high-quality image with few transfer defects.

[0002]

2. Description of the Related Art Conventionally, inorganic materials such as zinc oxide, selenium and cadmium sulfide have been known as photoconductive materials used in electrophotographic photoreceptors. Organic polyvinylcarbazole, phthalocyanine, azo pigments and the like have come to be widely used although their advantages such as high productivity and pollution-free have been noted, and they are inferior in photoconductive characteristics and durability. . Recently, new materials are being devised in which these drawbacks have been improved, and in particular, their photoconductive properties are surpassing those of inorganic materials.

These electrophotographic photoconductors are repeatedly subjected to various actions such as charging, exposure, development, transfer, cleaning and charge removal in the electrophotographic process of copying machines, laser beam printers and the like, so that they are subjected to various chemical and physical processes. Durability is required. In particular, the surface properties such as the surface energy of the photoconductor are involved in the developer transferability on the photoconductor, stains on the photoconductor, etc., and are important factors for obtaining a high quality image.
On the other hand, the above-mentioned organic photoconductive material generally does not have film-forming properties, so that it is generally formed together with a binder resin. Therefore, it is no exaggeration to say that the surface properties such as surface energy are almost limited by the selection of the binder resin. However, the binder resins that satisfy the photoconductive properties are quite limited, and in reality, the desired surface properties have not been obtained. The binder resin used in the photoreceptor using the organic photoconductor, polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamide imide, polysulfone, polyallyl ether, polyacetal, Nylon, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, butyral resin and the like can be mentioned, but none of them gives a sufficiently low energy surface.

[0004]

The electrophotographic process is
Image formation is performed through processes such as charging, exposure, development, transfer, and fixing. The transfer step corresponds to a process of transferring the developed developer from the photosensitive member to a transfer material such as transfer paper to obtain a final image. Therefore, faithful transfer of the developed image of the photoreceptor is required to obtain a high quality image. The method of transferring the developer is mainly based on an electrostatic force having a polarity opposite to that of the developer, but the transfer is not complete by itself. The reason is that the force acting between the developer and the photoconductor includes not only electrostatic force but also intermolecular force and the like. In particular, in the area where a large amount of developer is developed, sufficient electrostatic transfer force does not reach the developer on the photoconductor side, so it is affected by intermolecular forces such as electrostatic attraction and van der Waals force due to polar groups. Untransferred developer remains on the photoconductor. As a result, problems such as deterioration of image quality due to transfer failure and increase of waste developer occur. In particular, when the above-mentioned conventional organic photoconductor is used, image defects such as uneven transfer of solid image portions and voids in transfer of character portions occur, and a large amount of waste developer must be discarded.

The surface shape of the transfer material also affects the transfer. Conventionally, as a transfer material, a thin material such as pulp is used, but there is a problem such as high cost for processing a completely flat surface, and the surface has unevenness to some extent. Then, during transfer, a portion including an air layer as shown in FIG. 5 is inevitably formed between the photoconductor and the transfer material. The air layer has a low dielectric constant, weakens the electrostatic force toward the photosensitive layer, and promotes the transfer failure. Especially the photosensitive layer is 5
When the thickness is less than 0 μm, the influence is great, and the conventional combination of the transfer material and the photosensitive member cannot completely solve the transfer failure.

An object of the present invention is to obtain an electrophotographic photoconductor which has improved surface properties of the photoconductor without deteriorating the electrophotographic properties, particularly low surface energy and improved transfer property of the developer. .

[0007]

That is, the present invention relates to an electrophotographic photosensitive member having a surface layer containing at least carbon atoms and fluorine atoms, and the mol of carbon atoms and fluorine atoms measured by XPS on the surface of the photosensitive member. Fraction ratio F / C
Is an F / C = 0.01 to 1.0, which is an electrophotographic photosensitive member.

Further, the present invention is used for an electrophotographic transfer material having a surface shape having a ten-point average surface roughness Rz defined by JIS B061 of Rz = 7.0 to 30.0 μm, and at least carbon. In an electrophotographic photoreceptor having a surface layer containing atoms and fluorine atoms, the mole fraction ratio F / C of carbon atoms to fluorine atoms measured by XPS on the surface of the photoreceptor is F / C = 0.01 to 1 It is an electrophotographic photosensitive member characterized by being 0.0.

Specifically, the surface layer is formed by containing a binder resin and a fluorine-substituted compound. Further, the fluorine-substituted compound is preferably contained in at least two kinds, one kind is incompatible with the binder and the other kind is compatible or emulsifiable with the binder. The two kinds of fluorine-substituted compounds are uniformly contained on the surface of the photoconductor when they coexist. As a result, the electrophotographic photosensitive member of the present invention has a surface energy lower than that of the conventional photosensitive member, thereby making it possible to solve the above problems.

If the F / C mol fraction ratio is less than 0.01, the effect of lowering the surface energy is small, and if it exceeds 1.0, the film strength is lowered and the adhesion to the lower layer is lowered.

The constitution is an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, and the surface layer of the photoreceptor contains at least a binder resin and a fluorine-substituted compound to form the surface layer. Is characterized by. Specific examples of the fluorine-substituted compound include carbon fluoride, polymers such as tetrafluoroethylene, hexafluoropropylene, trifluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride, perfluoroalkyl vinyl ether, and the like. Polymers and graft polymers, block polymers, surfactants, etc. containing them in the molecule are used. In the case of an incompatible and powdery fluorine-substituted compound, the particle size is 0.01 to 5
It can be used in the range of μm, and its molecular weight is 3000 to
It can be used in the range of 5,000,000. In the case of powder, it is dispersed as a surface layer composition together with a binder resin. As a dispersing method, a sand mill, a ball mill, a roll mill, a homogenizer, a nanomizer, a paint shaker, an ultrasonic wave or the like is used. The content of the fluorine-substituted compound in the surface layer of the photoreceptor is preferably 4 to 70% by weight, more preferably 10 to 55% by weight. If the amount is less than 4% by weight, the decrease in surface energy is insufficient, and 7
When it is 0% by weight or more, the film strength of the surface layer is lowered. As the binder resin for dispersing the fluorine-substituted compound, polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallyl ether, polyacetal, nylon, phenol resin, acrylic resin , Silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, butyral resin and the like. Furthermore, reactive epoxy and (meth) acrylic monomers and oligomers can be mixed and used after curing.

The photosensitive layer of the present invention has a single layer or a laminated structure. In the case of a single layer structure, generation and transfer of photocarriers are carried out in the same layer, and the fluorine-substituted compound of the present invention is contained in this layer which is a surface layer. In the case of a laminated structure, a charge generation layer that generates photocarriers and a charge transport layer that moves carriers are laminated. The surface layer may be formed by either the charge generation layer or the charge transport layer. In any case, the fluorine-substituted compound of the present invention is contained in the layer forming the surface layer. The single-layer photosensitive layer can have a thickness of 5 to 100 μm, more preferably 10 to 60 μm. The charge generation material and the charge transport material are contained in 20 to 80% by weight, and more preferably 30 to 70% by weight. In the laminated photoreceptor, the thickness of the charge generation layer is 0.001 to 6 μm, more preferably 0.01 to 2 μm. The amount of the charge generating material is 10 to 100% by weight, more preferably 40 to 100% by weight. The thickness of the charge transport layer is 5 to 100 μm, more preferably 10 to 60 μm. The amount of charge transport material is 2
It is 0 to 80% by weight, more preferably 30 to 70% by weight.

The charge generating material used in the present invention includes phthalocyanine pigments, polycyclic quinone pigments, azo pigments,
Perylene pigment, indigo pigment, quinacridone pigment, azurenium salt dye, squarylium dye, cyanine dye,
Pyrylium dyes, thiopyrylium dyes, xanthene dyes, quinoneimine dyes, triphenylmethane dyes, styryl dyes, selenium, selenium-tellurium, amorphous silicon, cadmium sulfide and the like can be mentioned. Examples of the charge transport material used in the present invention include pyrene compounds, carbazole compounds, hydrazone compounds, N, N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl compounds and stilbene compounds. Is mentioned.

In the electrophotographic photoreceptor of the present invention, a protective layer may be laminated on the photosensitive layer. The thickness of the protective layer is 0.01 to 2
0 μm is possible, more preferably 0.1 to 10 μm
Is. The protective layer may contain the above-mentioned charge generating material or charge transporting material, metal and its oxide, nitride, salt, alloy, and conductive material such as carbon. At this time, the fluorine-substituted compound of the present invention is also contained in the protective layer which is the outermost surface layer. As the binder resin used for the protective layer, polyester, polyurethane, polyarylate,
Polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallyl ether, polyacetal, nylon, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, butyral resin Etc. Furthermore, reactive epoxy and (meth) acrylic monomers and oligomers can be mixed and used after curing.

The conductive support used in the electrophotographic photoreceptor of the present invention is a metal or alloy of iron, copper, nickel, aluminum, titanium, tin, antimony, indium, lead, zinc, gold, silver, or the like. Oxides and carbon,
A conductive resin or the like can be used. The shape may be cylindrical, belt-like or sheet-like. In addition, the conductive material,
Sometimes it is molded, but it can be applied as paint,
You may vapor-deposit.

An undercoat layer may be provided between the conductive support and the photosensitive layer. The undercoat layer is mainly composed of a binder resin, but may contain the above-mentioned conductive material or acceptor.
As the binder resin forming the undercoat layer, polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallyl ether, polyacetal, nylon, phenol resin, acrylic resin , Silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, butyral resin and the like.

As the method for producing the electrophotographic photosensitive member of the present invention, methods such as vapor deposition and coating are used. For coating, bar coater, knife coater, roll coater, attritor,
Spraying, dipping coating, electrostatic coating, powder coating and the like are used.

An electrophotographic apparatus according to the present invention is shown in FIG. It can be used as an output device for this electrophotographic device, copier, printer, facsimile, and the like.

The image forming process is basically performed in the order of charging, exposure, development, transfer, cleaning, and charge removal. First, after charging the surface of the photoconductor with a charger 2 such as a corotron or a scorotron, a light image is irradiated on the photoconductor from the light source 4. The optical image generates charge carriers during exposure to erase surface charges on the photoconductor to form an electrostatic latent image. The electrostatic latent image formed on the photoconductor 1 is
It is developed by the developing machine 5.

The image developed by the developer is transferred to a transfer material such as transfer paper in a transfer process. Transfer is mainly performed by an electrostatic force having a polarity opposite to that of the developer, and a corotron, a scorotron, a conductive brush, a conductive roller 7 or the like is used.
At the same time, a pressure member may be used together to impart a transfer effect by pressure.

The residual developer after transfer is removed by cleaning. As a cleaning method, it is desirable to adopt blade cleaning in order to realize a simpler device configuration in association with space saving of the device. The blade cleaning has a simple configuration in which an elastic member such as a plate-shaped polyurethane is merely abutted on the photoconductor in the generatrix direction. The abutting direction of the blade cleaning is a forward direction in which the blade tip is oriented in the rotation direction of the photoconductor, a counter direction in which the blade tip is oriented in the direction opposite to the rotation direction of the photoconductor, and a case where the photoconductor and the blade are vertical, etc. There is. Further, the blade is not limited to a single blade, but a plurality of blades can be used together. Further, a cleaning brush, a web, a magnetic brush or the like may be used in combination as an auxiliary.

[0022]

EXAMPLES Next, specific examples of the present invention will be shown below.

Example 1 10 parts by weight of conductive titanium oxide (tin oxide coating, average primary particle size 0.4 μm), 10 parts by weight of phenol resin precursor (resole type), 10 parts by weight of methanol, and 10 parts by weight of butanol. Was dispersed in a sand mill, dip-coated in an aluminum cylinder having an outer diameter of 80 mm and a length of 360 mm and cured at 140 ° C., and then a conductive layer having a volume resistance of 5 × 10 ⁹ Ω · cm and a thickness of 20 μm was provided.

Next, 10 parts by weight of the following methoxymethylated nylon (degree of methoxymethylation is about 30%):

[0025]

[Chemical 1] And 150 parts by weight of isopropanol were mixed and dissolved, and then dip-coated on the conductive layer to form an undercoat layer of 1 μm.

Next, 10 parts by weight of the following azo pigment,

[0027]

[Chemical 2] Polycarbonate resin (bisphenol A, molecular weight 30
000) 5 parts by weight and 700 parts by weight of cyclohexanone were dispersed in a sand mill, and this dispersion was dip-coated on the undercoat layer to obtain a charge generation layer of 0.05 μm.

Next, 10 parts by weight of the following triphenylamine,

[0029]

[Chemical 3] Polycarbonate resin (bisphenol Z, molecular weight 20
000) 10 parts by weight, 50 parts by weight of monochlorobenzene,
And 15 parts by weight of dichloromethane were mixed by stirring, and then dip-coated on the charge generation layer. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 1 part by weight of carbon fluoride fine powder (average particle size 0.23 μm, manufactured by Central Glass Co., Ltd.), polycarbonate resin (bisphenol Z, molecular weight 8000).
0) 6 parts by weight, the following perfluoroalkyl acrylate-methyl methacrylate block copolymer (molecular weight 30
000) 0.1 part by weight,

[0031]

[Chemical 4] 120 parts by weight of monochlorobenzene and 80 parts by weight of dichloromethane were dispersed and mixed in a sand mill. To this, 3 parts by weight of the triphenylamine (1) was added, mixed and dissolved, and then applied on the charge transport layer by spray coating.
A photoconductor drum was provided with a protective layer of μm.

[Comparative Example 1] In the photosensitive member of Example 1,
The photoconductor coated with the charge transport layer without the protective layer was used as the photoconductor drum of Comparative Example 1.

[F / C Ratio XPS Measurement] After peeling off the surface of the photoconductor, ESCALAB200-X type X manufactured by VG
Surface elements were quantified with a line photoelectron spectrometer. Using MgCa (300 W) as an X-ray source, measurement was carried out at a depth of several Å in a region of 2 × 3 mm. The surface of the photoconductor of Example 1 had F atoms of 5.2 mol% and C atoms of 81.3 mol%, and the F / C mol fraction ratio was 0.064. On the surface of the photoreceptor of Comparative Example 1, no F atom was detected and the F / C ratio was 0. The XPS spectrum is shown in FIG.

[Contact Angle] The contact angle of pure water on the surface of the photosensitive drum was compared by a dropping type contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.). As a result, the contact angle of the photoconductor of Example 1 showed a large value of 108 degrees and realized a low energy surface, whereas Comparative Example 1 had a contact angle of 82 degrees and a low energy surface was not obtained. It was

[Transfer Efficiency] Each photoconductor was set in the apparatus shown in FIG. 1 and the initial transfer efficiency was measured. A negative polarity scorotron was used for charging, and a halogen lamp was used as a light source for exposure. The developer was a negative polarity corotron using a two-component positive polarity developer. The transfer efficiency is measured when the halftone solid pattern is output in a single color.
The density of the developer transferred to the transfer material and the density of the developer remaining on the photoconductor were measured by a reflection type Macbeth densitometer and then calculated. The image density of the halftone solid pattern was set to 0.80 by the reflection type Macbeth density measurement on the transfer material. Example 1
The transfer efficiency was as high as 93% in Comparative Example 1, whereas the transfer efficiency was as low as 86% in Comparative Example 1. It was also found that the measured value of the contact angle had a correlation with the actual transfer efficiency, and the transfer efficiency was found to increase as the surface energy decreased.

[Transfer unevenness] The photosensitive drum was put into the apparatus shown in FIG. 1 and a halftone solid pattern image was output. The photoconductor of Example 1 obtained a uniform image, but the photoconductor of Comparative Example 1 had transfer unevenness in which various portions of the image were missing due to poor transfer. As shown by the above results, the reduction of the surface energy was effective for the transfer unevenness as well as the transfer efficiency.

[Breakage in Transfer] The photoconductor drum was put into the apparatus shown in FIG. 1 and a character pattern image was output. With the photoreceptor of Example 1, a uniform character pattern was obtained,
With respect to the photoconductor of Comparative Example 1, a portion other than the outline of the character pattern was missing due to improper transfer. An enlarged photograph of the character pattern in which transfer omission occurred is shown in FIG. As shown by the above results, the reduction of the surface energy was effective not only in the transfer efficiency but also in the voids in the transfer.

Example 2 Aluminum cylinder, conductive layer,
The same layers as in Example 1 were prepared up to the undercoat layer and the charge generation layer.

Next, 10 parts by weight of the following triphenylamine,

[0040]

[Chemical 5] Polycarbonate resin (bisphenol Z, molecular weight 20
000) 10 parts by weight, 50 parts by weight of monochlorobenzene,
And 15 parts by weight of dichloromethane were mixed by stirring, and then dip-coated on the charge generation layer. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 3 parts by weight of carbon fluoride fine powder (average particle size 0.23 μm, manufactured by Central Glass Co., Ltd.), polycarbonate resin (bisphenol Z, molecular weight 8000).
0) 5 parts by weight, 0.3 parts by weight of perfluoroalkyl acrylate-methyl methacrylate block copolymer (AB type copolymer, molecular weight 30000) used in Example 1, 110 parts by weight of monochlorobenzene, and dichloromethane 80 Parts by weight were dispersed and mixed in a sand mill. To this, 2.5 parts by weight of the triphenylamine (2) was added, mixed and dissolved, and coated on the charge transport layer by spray coating to provide a protective layer of 6 μm to obtain a photosensitive drum of Example 2.

This photoreceptor has 10.2 mol% of F atom and C
Atoms 76.7 mol%, F / C mol fraction ratio is 0.1
It was 33. The contact angle with pure water was 113 °, which was a sufficiently low surface energy. Further, when this photoreceptor was put into the apparatus shown in FIG. 1 and the transfer efficiency was measured, it showed a good value of 96%. With regard to the image, good results were obtained for both transfer unevenness and voids in transfer.

[Example 3] Aluminum cylinder, conductive layer,
The same layers as in Example 1 were prepared up to the undercoat layer and the charge generation layer.

Next, 3 parts by weight of the triphenylamine (1), 7 parts by weight of the triphenylamine (2), a polycarbonate resin (bisphenol Z, molecular weight 2000)
0) 10 parts by weight, 50 parts by weight of monochlorobenzene, and 15 parts by weight of dichloromethane were mixed by stirring, and then dip-coated on the charge generation layer. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 3 parts by weight of carbon fluoride fine powder (average particle size 0.27 μm, made of central glass), polycarbonate resin (bisphenol Z, molecular weight 8000)
0) 55.5 parts by weight, the following fluorine-substituted graft polymer (F content 27% by weight, molecular weight 25000) 0.3 parts by weight,

[0046]

[Chemical 6] 120 parts by weight of monochlorobenzene and 80 parts by weight of dichloromethane were dispersed and mixed in a sand mill. To this, 2.5 parts by weight of the triphenylamine (2) was added, mixed and dissolved, and coated on the charge transport layer by spray coating,
A photosensitive layer of Example 3 was prepared by providing a 4 μm protective layer.

This photoreceptor has 11.3 mol% of F atom and C
Atoms 75.5 mol%, F / C mol fraction ratio is 0.1
It was 50. The contact angle with pure water was 114 °, which was a sufficiently low surface energy. Further, when this photoreceptor was put into the apparatus shown in FIG. 1 and the transfer efficiency was measured, it showed a good value of 96%. With regard to the image, good results were obtained for both transfer unevenness and voids in transfer.

[Example 4] Aluminum cylinder, conductive layer,
The same layers as in Example 1 were prepared up to the undercoat layer and the charge generation layer.

Next, 3 parts by weight of the triphenylamine (1), 7 parts by weight of the triphenylamine (2), a polycarbonate resin (bisphenol Z, molecular weight 2000)
0) 10 parts by weight, 50 parts by weight of monochlorobenzene, and 15 parts by weight of dichloromethane were mixed by stirring, and then dip-coated on the charge generation layer. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 4 parts by weight of carbon fluoride fine powder (average particle size 0.27 μm, made of central glass), polycarbonate resin (bisphenol Z, molecular weight 8000).
0) 4 parts by weight, 0.3 parts by weight of perfluoroalkyl acrylate-methyl methacrylate block copolymer (molecular weight 30000) used in Example 1, 120 parts by weight of monochlorobenzene, and 80 parts by weight of dichloromethane were dispersed and mixed in a sand mill. did. To this, 2 parts by weight of the triphenylamine (2) was added, mixed and dissolved, and spray-coated on the charge-transporting layer to provide a protective layer of 4 μm to obtain a photosensitive drum of Example 4.

This photoconductor has 12.5 mol% of F atoms and C
Atoms 72.9 mol%, F / C mol fraction ratio is 0.1
It was 71. The contact angle with pure water was 114 °, which was a sufficiently low surface energy. Further, when this photosensitive member was put into the apparatus shown in FIG. 1 and the transfer efficiency was measured, it showed a good value of 95%. With regard to the image, good results were obtained for both transfer unevenness and voids in transfer.

[Embodiment 5] Aluminum cylinder, conductive layer,
The same layers as in Example 1 were prepared up to the undercoat layer and the charge generation layer.

Next, 3 parts by weight of the triphenylamine (1), 7 parts by weight of the triphenylamine (2), a polycarbonate resin (bisphenol A, molecular weight 2500)
0) 10 parts by weight, 50 parts by weight of monochlorobenzene, and 15 parts by weight of dichloromethane were mixed by stirring, and then dip-coated on the charge generation layer. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, a tetrafluoroethylene-hexafluoropropylene copolymer fine powder (monomer ratio tetrafluoroethylene / hexafluoropropylene = 3 /
7, emulsion polymerization fine powder, average particle size 0.32μ
m, molecular weight about 600000) 3 parts by weight, polycarbonate resin (bisphenol A, molecular weight 100000) 5.
5 parts by weight, perfluoroalkyl acrylate-methyl methacrylate block copolymer used in Example 1 (A
-B type copolymer, molecular weight 30000) 0.3 parts by weight, monochlorobenzene 100 parts by weight, and dichloromethane 7
0 part by weight was dispersed and mixed in a sand mill. To this, 2.5 parts by weight of the triphenylamine (2) was added, mixed and dissolved, and then applied on the charge transport layer by spray coating.
A photoconductor drum of Example 5 was prepared by providing a protective layer of μm.

This photoconductor has 9.5 mol% of F atoms and 80.5 mol% of C atoms, and the F / C mol fraction ratio is 0.11.
It was 8. Further, the contact angle with respect to pure water was 112 ° and the surface energy was sufficiently low. Further, when this photoreceptor was put into the apparatus shown in FIG. 1 and the transfer efficiency was measured, it showed a good value of 96%. With regard to the image, good results were obtained for both transfer unevenness and voids in transfer.

[Comparative Example 2] Aluminum cylinder, conductive layer,
The same layers as in Example 1 were prepared up to the undercoat layer and the charge generation layer.

Next, the triphenylamine (2) 10
Parts by weight, polycarbonate resin (bisphenol Z, molecular weight 25000) 10 parts by weight, monochlorobenzene 50
After stirring and mixing 15 parts by weight of dichloromethane and 15 parts by weight of dichloromethane, the charge generation layer was dip-coated. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 0.3 part by weight of carbon fluoride fine powder (average particle size 0.27 μm, made of central glass), polycarbonate resin (bisphenol Z, molecular weight 800)
00) 6.4 parts by weight, 0.03 parts by weight of the perfluoroalkyl acrylate-methyl methacrylate block copolymer (molecular weight 30000) used in Example 1, 120 parts by weight of monochlorobenzene, and 80 parts by weight of dichloromethane in a sand mill. Dispersed and mixed. To this, 3.2 parts by weight of the triphenylamine (2) was added, mixed and dissolved, and spray-coated on the charge transport layer to provide a protective layer of 4 μm to obtain a photosensitive drum of Comparative Example 2.

This photoconductor has 0.83 mol% of F atom and C
Atoms 85.5mol%, F / Cmol fraction ratio is 0.0
It was 097. Further, the contact angle with pure water was 83 °, and the surface energy was not low. Further, when this photoreceptor was put into the apparatus shown in FIG. 1 and the transfer efficiency was measured, it was not good at 87%. Regarding the image, both transfer unevenness and voids in transfer occurred.

[0060]

[Table 1] Example 6 10 parts by weight of conductive titanium oxide (tin oxide coating, average primary particle size 0.4 μm), 10 parts by weight of phenol resin precursor (resole type), 10 parts by weight of methanol,
And 10 parts by weight of butanol are dispersed in a sand mill,
The aluminum cylinder with an outer diameter of 80 mm and a length of 360 mm was applied by dipping and cured at 140 ° C, and then the volume resistance was 5 x 1
A conductive layer having a thickness of ⁰⁹ Ω · cm and a thickness of 20 μm was provided.

Then, 10 parts by weight of methoxymethylated nylon (having a methoxymethylation degree of about 30%) used in Example 1 and 150 parts by weight of isopropanol were mixed and dissolved.
The conductive layer was applied by dip coating to provide a 1 μm undercoat layer.

Next, 10 parts by weight of the azo pigment used in Example 1, 5 parts by weight of a polycarbonate resin (bisphenol A, a molecular weight of 30,000), and 700 parts by weight of cyclohexanone were dispersed in a sand mill, and this dispersion was subjected to the above-mentioned undercoating. After dip coating on the layer, a 0.05 μm charge generating layer was obtained.

Next, the triphenylamine (2) 10
Parts by weight, polycarbonate resin (bisphenol Z, molecular weight 20000) 10 parts by weight, monochlorobenzene 50
After stirring and mixing 15 parts by weight of dichloromethane and 15 parts by weight of dichloromethane, the charge generation layer was dip-coated. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, polytetrafluoroethylene fine powder (emulsion polymerization, average particle size 0.23 μm, molecular weight 35,000)
0) 2.5 parts by weight, 5 parts by weight of polycarbonate resin (bisphenol Z, molecular weight 70,000), 120 parts by weight of monochlorobenzene, and 80 parts by weight of dichloromethane were dispersed and mixed in a sand mill. To this, 3 parts by weight of the triphenylamine (2) was added, mixed and dissolved, and spray-coated on the charge transport layer to provide a protective layer of 5 μm to obtain a photosensitive drum.

[Comparative Example 3] In the photosensitive member of Example 6,
The photoconductor coated with the charge transport layer without the protective layer was used as the photoconductor drum of Comparative Example 3. [F / C ratio XPS measurement] After peeling the surface of the photoreceptor,
The surface elements were quantified with an ESCALAB200-X type X-ray photoelectron spectrometer manufactured by VG. MgC as X-ray source
Using a (300W), a few Å for 2 × 3mm area
The depth was measured. The surface of the photoconductor of Example 6 has 4.2 mol% of F atoms and 82.3 mol% of C atoms, and is F / C.
The mol fraction ratio was 0.051. No F atom was detected on the surface of the photoconductor of Comparative Example 3, and the F / C ratio was 0. The XPS spectrum is shown in FIG.

[Contact Angle] The contact angle of pure water on the surface of the photosensitive drum was compared by a dropping type contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.). As a result, the contact angle of the photoconductor of Example 6 showed a large value of 109 degrees and realized a low energy surface, whereas Comparative Example 3 had a small contact angle of 82 degrees and a low energy surface could not be obtained. It was

[Transfer Efficiency] Each photoconductor was set in the apparatus shown in FIG. 1 and the initial transfer efficiency was measured. A negative polarity scorotron was used for charging, and a laser having a wavelength of 778 nm was used as a light source for exposure. A two-component negative polarity developer was used as the developer, and transfer was performed with a positive polarity corotron. The transfer efficiency is measured by measuring the density of the developer transferred to the transfer material when the halftone solid pattern is output in a single color,
The developer concentration remaining on the photoconductor was calculated by measuring with a reflection type Macbeth densitometer. The image density of the halftone solid pattern is 0.8 by the reflection type Macbeth density measurement on the transfer material.
It was set to 0. In Example 6, the transfer efficiency was as high as 94%, whereas in Comparative Example 3, the transfer efficiency was as low as 86%. It was also found that the measured value of the contact angle had a correlation with the transfer efficiency, and the transfer efficiency was found to increase as the surface energy decreased.

[Transfer unevenness] The photosensitive drum was put into the apparatus shown in FIG. 1 and a halftone solid pattern image was output. As the transfer material, a polyethylene terephthalate film (PET) of Rz 0.56 μm, a transfer paper 1 of Rz 10.2 μm, and a transfer paper 2 of Rz 15.3 μm were used. With the photoconductor of Example 6, a uniform image was obtained with any of the transfer materials, but with the photoconductor of Comparative Example 3, a uniform image was obtained with PET, but with transfer papers 1 and 2, transfer failure was observed at various parts of the image. As a result, the transfer unevenness was generated. As shown by the above results, the reduction of the surface energy was effective for the transfer unevenness as well as the transfer efficiency.

Example 7 Aluminum cylinder, conductive layer,
The same layers as in Example 6 were prepared up to the undercoat layer and the charge generation layer.

Next, the triphenylamine (1) 10
Parts by weight, polycarbonate resin (bisphenol Z, molecular weight 20000) 10 parts by weight, monochlorobenzene 50
After stirring and mixing 15 parts by weight of dichloromethane and 15 parts by weight of dichloromethane, the charge generation layer was dip-coated. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 3 parts by weight of carbon fluoride fine powder (average particle size 0.23 μm, made of central glass), polycarbonate resin (bisphenol Z, molecular weight 8000)
0) 5.5 parts by weight, 0.3 parts by weight of the perfluoroalkyl acrylate-methyl methacrylate block copolymer (molecular weight 30,000) used in Example 1, 120 parts by weight of monochlorobenzene, and 80 parts by weight of dichloromethane were placed in a sand mill. Dispersed and mixed. To this, 2.5 parts by weight of the triphenylamine (1) was added, mixed and dissolved, and spray-coated on the charge-transporting layer to form a protective layer of 6 μm, and the photosensitive drum of Example 7 was obtained.

This photoconductor has 10.0 mol% of F atom and C
The atomic ratio is 77.5 mol% and the F / C mol fraction ratio is 0.1.
It was 29. The contact angle with pure water was 113 °, which was a sufficiently low surface energy. Further, when this photoreceptor was put into the apparatus shown in FIG. 1 and the transfer efficiency was measured, it showed a good value of 96%. Regarding the image, good results were obtained with no transfer unevenness on any of the transfer materials.

[Embodiment 8] Aluminum cylinder, conductive layer,
The same layers as in Example 6 were prepared up to the undercoat layer and the charge generation layer.

Next, 3 parts by weight of the triphenylamine (1), 7 parts by weight of the triphenylamine (2), a polycarbonate resin (bisphenol Z, molecular weight 2000)
0) 10 parts by weight, 50 parts by weight of monochlorobenzene, and 15 parts by weight of dichloromethane were mixed by stirring, and then dip-coated on the charge generation layer. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 3 parts by weight of carbon fluoride fine powder (average particle size 0.27 μm, made of central glass), polycarbonate resin (bisphenol Z, molecular weight 8000)
0) 5.5 parts by weight, the fluorine-substituted graft polymer used in Example 3 (F content 27% by weight, molecular weight 25000)
0.3 parts by weight, 120 parts by weight of monochlorobenzene, and 80 parts by weight of dichloromethane were dispersed and mixed in a sand mill. To this, 2.5 parts by weight of the triphenylamine (2) was added, mixed and dissolved, and applied onto the charge transport layer by spray coating to provide a protective layer of 3 μm to obtain a photosensitive drum of Example 8.

This photoconductor has 9.7 mol% of F atoms and 79.6 mol% of C atoms, and the F / C mol fraction ratio is 0.12.
It was 2. The contact angle with pure water was 114 °, which was a sufficiently low surface energy. Further, when this photosensitive member was put into the apparatus shown in FIG. 1 and the transfer efficiency was measured, it showed a good value of 95%. Regarding the image, good results were obtained with no transfer unevenness on any of the transfer materials.

[Example 9] Aluminum cylinder, conductive layer,
The same layers as in Example 6 were prepared up to the undercoat layer and the charge generation layer.

Next, 3 parts by weight of the triphenylamine (1), 7 parts by weight of the triphenylamine (2), a polycarbonate resin (bisphenol Z, molecular weight 2000)
0) 10 parts by weight, 50 parts by weight of monochlorobenzene, and 15 parts by weight of dichloromethane were mixed by stirring, and then dip-coated on the charge generation layer. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 4 parts by weight of carbon fluoride fine powder (average particle size 0.27 μm, made of central glass), polycarbonate resin (bisphenol Z, molecular weight 8000)
0) 4 parts by weight, 0.3 parts by weight of the perfluoroalkyl acrylate-methyl methacrylate block copolymer (molecular weight 30000) used in Example 1, 120 parts by weight of monochlorobenzene, and 80 parts by weight of dichloromethane were dispersed and mixed in a sand mill. did. To this, 2 parts by weight of the triphenylamine (2) was added, mixed and dissolved, and applied onto the charge transport layer by spray coating to provide a protective layer of 3 μm to obtain a photosensitive drum of Example 9.

This photoreceptor has 11.3 mol% of F atom and C
Atoms 75.5 mol%, F / C mol fraction ratio is 0.1
It was 50. The contact angle with pure water was 114 °, which was a sufficiently low surface energy. Further, when this photoreceptor was put into the apparatus shown in FIG. 1 and the transfer efficiency was measured, it showed a good value of 96%. Regarding the image, good results were obtained with no transfer unevenness on any of the transfer materials.

[Example 10] The same materials as in Example 6 were prepared up to the aluminum cylinder, the conductive layer, the undercoat layer, and the charge generation layer.

Next, the triphenylamine (2) 10
Parts by weight, polycarbonate resin (bisphenol A, molecular weight 25000) 10 parts by weight, monochlorobenzene 50
After stirring and mixing 15 parts by weight of dichloromethane and 15 parts by weight of dichloromethane, the charge generation layer was dip-coated. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, tetrafluoroethylene-hexafluoropropylene copolymer fine powder (monomer ratio tetrafluoroethylene / hexafluoropropylene = 3 /
7, emulsion polymerization fine powder, average particle size 0.32μ
m, molecular weight about 600000) 3 parts by weight, polycarbonate resin (bisphenol A, molecular weight 100000) 5.
5 parts by weight, 0.3 parts by weight of the perfluoroalkyl acrylate-methyl methacrylate block copolymer (molecular weight 30000) used in Example 1, monochlorobenzene 1
20 parts by weight and 80 parts by weight of dichloromethane were dispersed and mixed in a sand mill. To this, 2.5 parts by weight of triphenylamine (2) was added, mixed and dissolved, and spray-coated on the charge-transporting layer to form a protective layer of 4.5 μm, and the photosensitive drum of Example 10 was obtained. .

This photoconductor has 9.5 mol% of F atoms and 80.5 mol% of C atoms, and the F / C mol fraction ratio is 0.11.
It was 8. Further, the contact angle with respect to pure water was 112 ° and the surface energy was sufficiently low. Further, when this photoreceptor was put into the apparatus shown in FIG. 1 and the transfer efficiency was measured, it showed a good value of 96%. Regarding the image, good results were obtained with no transfer unevenness on any of the transfer materials.

[Comparative Example 4] Aluminum cylinder, conductive layer,
The same layers as in Example 6 were prepared up to the undercoat layer and the charge generation layer.

Next, the triphenylamine (2) 10
Parts by weight, polycarbonate resin (bisphenol Z, molecular weight 25000) 10 parts by weight, monochlorobenzene 50
After stirring and mixing 15 parts by weight of dichloromethane and 15 parts by weight of dichloromethane, the charge generation layer was dip-coated. The coated cylinder was dried with hot air to form a 20 μm charge transport layer.

Next, 0.3 parts by weight of carbon fluoride fine powder (average particle size 0.27 μm, made of central glass), polycarbonate resin (bisphenol Z, molecular weight 800)
00) 6.4 parts by weight, 0.03 parts by weight of the perfluoroalkyl acrylate-methyl methacrylate block copolymer (molecular weight 30000) used in Example 1, 120 parts by weight of monochlorobenzene, and 80 parts by weight of dichloromethane in a sand mill. Dispersed and mixed. To this, 3.2 parts by weight of the triphenylamine (2) was added, mixed and dissolved, and spray-coated on the charge transport layer to provide a protective layer of 4 μm to obtain a photosensitive drum of Comparative Example 4.

This photoconductor has 0.83 mol% of F atoms and C
Atoms 85.5mol%, F / Cmol fraction ratio is 0.0
It was 097. Further, the contact angle with pure water was 83 °, and the surface energy was not low. Further, when this photoreceptor was put into the apparatus shown in FIG. 1 and the transfer efficiency was measured, it was not good at 87%. Regarding images, transfer unevenness did not occur in PET, but transfer unevenness occurred in transfer materials 1 and 2.

[0089]

[Table 2]

[0090]

EFFECT OF THE INVENTION The electrophotographic photosensitive member of the present invention realizes an electrophotographic photosensitive member having high transfer efficiency by significantly lowering the surface energy as compared with the conventional one. This makes it possible to provide a high-quality image with no transfer unevenness.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an electrophotographic apparatus used in a multiple transfer process.

FIG. 2 is an XPS spectrum diagram of a surface layer.

FIG. 3 is a transfer void image.

FIG. 4 is a schematic diagram showing a configuration of a photoconductor.

FIG. 5 is a schematic view showing surface irregularities of a transfer material.

[Explanation of symbols]

1 Photoreceptor Drum 2 Charging Device 3 Reading Device, Information Processing Device, Storage Device, Communication Device, etc. 4 Light Source 5 Developer 6 Original 7 Transfer Charging 8 Cleaning Device 9 Eliminating 10 Fixing 11 Paper Feeding 21 Conductive Support 22 Conductive Layer 23 Undercoat layer 24 Charge generation layer 25 Charge transport layer 26 Protective layer 27 Single-layer photosensitive layer 28 Fluorine-substituted resin powder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Yamagami 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Issei Nakamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Kya Non-Incorporated (72) Inventor Kasuya Precious 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tatsuya Ikezue 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (15)

[Claims] 1. An electrophotographic photoreceptor having a surface layer containing at least carbon atoms and fluorine atoms, wherein mo of carbon atoms and fluorine atoms measured by XPS on the surface of the photoreceptor is measured.
An electrophotographic photosensitive member characterized in that the 1-fraction ratio F / C is F / C = 0.01 to 1.0. 2. The electrophotographic photosensitive member according to claim 1, wherein the surface layer is a layer containing at least two kinds of fluorine-substituted compounds. 3. The electrophotographic photoreceptor according to claim 1, wherein the fluorine content of the fluorine-substituted compound is 15% by weight or more and 80% by weight or less. 4. The two fluorine-substituted compounds are compounds which are incompatible with the binder resin contained in the surface layer, and compounds which are compatible or emulsifiable.
The electrophotographic photosensitive member described. 5. The electrophotographic photosensitive member according to claim 1, wherein the binder resin contained in the surface layer is an aromatic binder. 6. The electrophotographic photosensitive member according to claim 1, wherein the binder resin contained in the surface layer is one kind or a mixture of two or more kinds selected from polycarbonate, polyarylate and polyallyl ether. 7. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1. 8. A ten-point average surface roughness Rz defined by JIS B061 is used for an electrophotographic transfer material having a surface shape of Rz = 7.0 to 30.0 μm, and at least carbon atoms and fluorine atoms are used. In an electrophotographic photosensitive member having a surface layer containing, the molar fraction ratio F / C of carbon atoms and fluorine atoms measured by XPS on the surface of the photosensitive member is F / C = 0.01 to 1.0. An electrophotographic photoreceptor characterized by the above. 9. The electrophotographic photosensitive member according to claim 8, wherein the thickness of the photosensitive layer is 50 μm or less. 10. The electrophotographic photosensitive member according to claim 8, wherein the surface layer is a layer containing at least two kinds of fluorine-substituted compounds. 11. The electrophotographic photosensitive member according to claim 8, wherein the fluorine content of the fluorine-substituted compound is 15% by weight or more and 80% by weight or less. 12. The electrophotographic photosensitive material according to claim 8, wherein the two kinds of fluorine-substituted compounds are a compound which is incompatible with a binder resin contained in the surface layer and a compound which is compatible or emulsifiable. body. 13. The electrophotographic photoreceptor according to claim 8, wherein the binder resin contained in the surface layer is an aromatic binder. 14. The electrophotographic photosensitive member according to claim 8, wherein the binder resin contained in the surface layer is one kind or a mixture of two or more kinds selected from polycarbonate, polyarylate and polyallyl ether. 15. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 8.