JPH0711703B2 - Electrophotographic photoreceptor and method for manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrophotographic photosensitive member having a surface-treated image forming layer and a method for producing the same, and in particular, to a surface-treated photosensitive member having a charge generating layer and a charge transporting layer. The present invention relates to an electrophotographic photoreceptor and a method for manufacturing the same.

2. Description of the Related Art Generally, in an electrophotographic photosensitive member, for example, a laminated electrophotographic photosensitive member having an upper layer as a charge transporting layer and a lower layer as a charge generating layer, when charging and exposure are performed in an electrophotographic process, light is transferred to the charge transporting layer. After passing through and reaching the charge generation layer, both positive and negative charges are generated, and charges of opposite polarity to the charged charges on the surface of the photoreceptor move in the charge transport layer and reach the surface, where the surface charge is neutralized. . On the contrary, when there is a charge generation layer on the upper layer, one of the positive and negative charges generated on the surface neutralizes the charge, and the other one,
It moves in the charge transport layer and neutralizes the charge having the opposite polarity to the charge of the conductive layer. Photoconductivity like this is the most important property of the photoreceptor, but in electrophotographic processes,
There are various processes such as development, transfer, and cleaning that are affected by the photoconductor, and unless the adverse effects in these processes are minimized and stable photoconductivity is exhibited, the photoconductor is not a practical photoconductor.

By the way, in the processes other than charging and exposure, the major problems are adhesion of toner and paper powder or water to the surface of the photoconductor, generation of scratches due to contact with the developer, paper, and cleaning blade, water adhering to the surface and toner components, Adhesion of a conductive or insulating product due to corona discharge often deteriorates the image quality and shortens the life of the photoconductor. As a solution to these problems, it is known to add a fluorine-containing resin to the binder resin at the time of producing the photoconductor to increase the surface releasability of the photoconductor.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, the fluorine-containing resin has poor compatibility with other resins due to its low surface energy, and therefore it is difficult to mix the other resins to form a uniform layer, It also has a poor affinity for photoconductive materials and other low-molecular compounds,
It was not possible to obtain their uniform dispersion. Therefore, an electrophotographic photosensitive member having good characteristics could not be obtained. Further, since the fluorine-containing resin layer is extremely inferior in adhesiveness to other layers, it was not possible to adhere it to obtain an electrophotographic photoreceptor having sufficient mechanical strength.

The present invention aims to remedy the above-mentioned drawbacks of the prior art, and to provide an electrophotographic photosensitive member that is not susceptible to adverse effects that are susceptible to electrophotographic processes other than charging and exposure. Is.

That is, a first object of the present invention is to manufacture a photoconductor that hardly causes toner filming. A second object of the present invention is to produce a photoconductor to which moisture hardly adheres. A third object of the present invention is to manufacture a photoconductor in which paper dust is unlikely to adhere. A fourth object of the present invention is to produce a photoconductor in which scratches due to a developer, paper, and a cleaning blade do not easily occur. A fifth object of the present invention is to manufacture a photoconductor that is less likely to cause generation or adhesion of a conductive or insulating substance on the photoconductor surface.

Means and Actions for Solving Problems The above object of the present invention is to provide an electrophotographic photosensitive member having an image forming layer containing a binder resin on a support, the surface of the image forming layer having a compound containing a fluorine atom. Was achieved by fluorinating the binder resin present on the surface of the imaging layer by treatment with.

Explaining the constitution of the present invention in detail, the electrophotographic photoreceptor of the first invention has an image forming layer containing a binder resin on a support, and the image forming layer is coated with the binder resin containing layer. It is characterized by being formed by fluorinating the binder resin only on the surface of the binder resin-containing layer after the formation.
The method for producing an electrophotographic photosensitive member according to the second aspect of the present invention is the glow discharge of a gas containing a compound containing a fluorine atom as a main component on the surface of an electrophotographic photosensitive member having an image forming layer containing a binder resin on a support. It is characterized in that the binder resin existing on the surface of the image forming layer is fluorinated by irradiating with plasma.

In the present invention, in the electrophotographic photoreceptor to be surface-treated with a gas containing a molecule containing a fluorine atom as a main component, the image forming layer containing the binder resin provided on the support is composed of only the photosensitive layer. However, it may be composed of a photosensitive layer and a surface layer. The photosensitive layer may be composed of a single layer, but preferably has a laminated layer structure in which a charge transport layer and a charge generation layer are separated.

In the present invention, in the case where the image forming layer has the above-mentioned laminated layer structure, either the charge transport layer or the charge generating layer may be the upper layer. However, it is desirable that the charge transport layer is provided on the charge generation layer from the viewpoint of the change in the photoconductive property due to the fluorination.

In the case where the image forming layer in the electrophotographic photoreceptor of the present invention has the above-mentioned laminated layer structure, the charge transporting agent which is the main component of the charge transporting layer includes an electron transporting substance and a hole transporting substance.

As the electron transporting substance, chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-2-fluorenone, 2,4,
5,7-Tetranitro-9-fluorenone, 2,4,7-trinitro-9-dicyanomethylenefluorenone, 2,4,5,7-
Examples thereof include electron-withdrawing substances such as tetranitroxanthone and 2,4,8-trinitrothioxanthone, and polymers obtained by polymerizing these electron-withdrawing substances.

Further, as the hole-transporting substance, N-ethylcarbazole, N-isopropylcarbazole, N-methyl-N-
Phenylhydrazino-3-methylidene-9-ethylcarbazole, N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N, N-diphenylhydrazino-3-methylden-10-ethylphenothiazine, N,
N-diphenylhydrazino-3-methylden-10-ethylphenoxazine, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehyde-N-α-naphthyl-N-phenylhydrazone, p-pyrrolidinobenzaldehyde- N, N-diphenylhydrazone, 1,3,3-trimethylindolenine-ω-aldehyde-N, N-diphenylhydrazone, p-
Hydrazones such as diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1-phenyl-3-(-p Diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [quinolyl (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)] -3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [6-methoxypyridyl (2)]
-3- (p-diethylaminostyryl) -5- (P-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (p-diethylaminostyryl) -5-
(P-Diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (p-diethylaminostyryl)
-5- (p-diethylaminophenyl) pyrazoline, 1
-[Pyridyl (2)]-3- (p-diethylaminostyryl) -4-methyl-5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (α-
Methyl-p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1-phenyl-3
-(P-Diethylaminostyryl) -4-methyl-5-
Pyrazolines such as (p-diethylaminophenyl) pyrazoline, 1-phenyl-3- (α-benzyl-p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline and spiropyrazolin, 2- (p-
Diethylaminostyryl) -6-diethylaminobenzoxazole, 2- (p-diethylaminophenyl)-
Oxazole compounds such as 4- (p-chlorophenyl) oxazole, 2- (p-diethylaminostyryl)
Thiazole compounds such as -6-diethylaminobenzothiazole, triazole methane compounds such as bis (4-diethylamino-2-methylphenyl) -phenylmethane, 1,1-bis (4-N, N-diethylamino-2-methyl) Phenyl) heptane, 1,1,2,2-tetrakis (4-
Polyarylalkanes such as N, N-dimethylamino-2-methylphenyl) ethane, triphenylamine, poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, poly-9-
Examples thereof include vinylphenylanthracene, pyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin and the like.

These charge transport agents can be used alone or in combination of two or more. When the charge transport material does not have a good film-forming property, it is blended with the same binder resin as that used in the charge generation layer to be described later and provided for coating.

On the other hand, as the charge generating agent which is the main component of the charge generating layer,
In addition to inorganic pigments such as selenium, selenium tellurium, and cadmium sulfide, as organic pigments, an azo pigment having a carbazole bone nucleus, a styrylstilbene nucleus, a triphenylamine bone nucleus, a fluorenone bone nucleus, or the like, or a phthalocyanine pigment. Indigo pigments, perylene pigments and the like are used. They are used in combination with a binder resin and a sensitizer, if necessary.

As the binder resin, a condensation resin such as polyamide, polyurethane, polyester, epoxy, polyketone, or polycarbonate, or a vinyl polymer such as polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, or polyacrylamide is used. However, since the aromatic hydrocarbon moieties are more easily fluorinated than the aliphatic hydrocarbon moieties of the molecular main chain in the resin, those having an aromatic ring rather than those having no aromatic ring in these binder resins, for example, Polycarbonate resin and polyester resin are more preferable.

As the sensitizer, xanthene dyes, thiazine dyes,
Cyanine dyes, pyrylium dyes, etc. are used.

In the present invention, when the image forming layer is composed of a photosensitive layer and a surface layer, the surface layer may be an insulating layer composed of the above-mentioned binder resin, and a metal or a metal oxide may be contained in the above-mentioned binder resin. It may be a conductive layer in which is dispersed.

In the present invention, the support is electrically conductive, and specifically, a metal plate such as aluminum or a plastic film on which a metal such as aluminum is deposited is used. Further, if necessary, a blocking layer may be provided between the conductive support and the photosensitive layer. As the blocking layer, a thin film of 1 μm or less made of polyamide, aluminum oxide, nitrocellulose or the like is used.

Next, a method for manufacturing the electrophotographic photosensitive member of the present invention will be described.

In order to manufacture the electrophotographic photosensitive member of the present invention, the surface of the electrophotographic photosensitive member to be fluorinated is irradiated with glow discharge plasma of a gas whose main component is a molecule containing a fluorine atom.

As such an apparatus for performing the plasma fluorination treatment on the surface of the photoconductor, the capacitively coupled plasma polymerization apparatus as shown in FIG. 1 has the simplest structure, but the plasma generator is not necessarily the capacitively coupled type. The present invention is not limited to the one having the induction type structure as shown in FIG. 2, and the one having the plasma generation mechanism by the microwave discharge, even if the direct current is used as the power source. Even so, the object of the present invention is achieved. In the plasma generator as described above, the gas pressure during discharge is usually 65
A range of pa to 130 pa, for example 100 pa is used. The temperature of the substrate on which the photoconductor is placed can be appropriately selected, but is preferably low, usually about 20 ° C. If the temperature is too high, the binder resin is adversely affected, and the opposite side of the substrate is exposed to high temperature plasma, so that it is desirable to cool the substrate. Further, the electrode shape may be a flat plate as shown in FIG. 1, but various electrode shapes can be used in order to uniformly process and process the drum type photoreceptor.

As an example of using the plasma generator shown in FIG. 1, the photoreceptor to be fluorinated is placed on the lower electrode, that is, on the substrate 12 on the substrate support 13 having the heater 14 for heating the substrate, and the vacuum is applied. By the pump (exhaust system 16),
Pull the bell jar to less than 2 pa, and then introduce high-purity CF ₄ gas, for example, from the gas injection port 15 via the introduction system 17 equipped with the needle valve 18, and keep it at a gas pressure of about 100 pa, and use a high-frequency power source. An RF discharge is generated between the upper electrode 11 and the lower electrode by 10.

A high frequency coil 21 as shown in FIG. 2 may be used instead of the upper electrode. As a result, especially the binder resin on the surface of the image forming layer of the photoconductor is fluorinated, and the surface energy is reduced mainly in the vicinity of the surface. In this case, within a practical time (5
(Minutes to 1 hour), the fluorination is limited to the reaction in the vicinity of the surface, so that the bulk property is less affected, and in particular, the photoconductive property of the photoconductor in which the charge transport layer is on the charge generation layer is
The surface properties are improved with little change. This fluorination reaction is presumed to be based on, for example, active fluorine atoms in the plasma accompanying the dissociation of CF ₄ and the etching mechanism, but the detailed reaction route has not been clarified. However, for example, in the case of a polyester binder, it has been found that the following positions are easily fluorinated,
During long-term treatment, hydrogen in the main chain methylene group may be replaced with fluorine.

In the present invention, as the molecule containing a fluorine atom which causes the above-mentioned plasma fluorination reaction, tetrafluoromethane (CF ₄ ) described above is preferable because it is inexpensive. However, trifluoromethane (CHF ₃ ), hexafluoroethane (C ₂
F ₆ ), perfluoropropane (C ₃ F ₈ ), sulfur tetrafluoride (SF
It is also possible to use various other fluorine-containing gases such as ₄ ) and sulfur hexafluoride (SF ₆ ). In some cases, these may be mixed with a carrier gas such as hydrogen, argon, helium, or the like.

Example 700 [Å] on a 75 μm thick polyester film
A coating solution having the following composition was applied on a conductive support having aluminum vapor-deposited on it by the Meyer bar method and dried at 70 ° C. for 30 minutes to form a charge generation layer having a thickness of 2 μm.

Coating liquid for charge generation layer: Next, a solution having the following composition was applied onto this charge generation layer by a doctor blade method, and the same was dried at 70 ° C. for 30 minutes to form a charge transport layer having a thickness of 20 μm, to obtain a laminated photoreceptor.

Coating liquid for charge transport layer: Half of the obtained photoconductor was fixed on the lower substrate in the plasma polymerization apparatus of FIG. 1 with the charge transport layer facing upward. First, the inside of the venger was pulled up to 2 pa by a vacuum pump, and then tetrafluorinated methane ( CF ₄ ) was introduced, kept at 100 pa, RF power was turned on, impedance matching was performed and the input power was 100 W, and plasma irradiation was performed for 30 minutes. During this time, the substrate temperature was kept at 20 ° C. with cold water.

After the plasma irradiation, the photoconductor after the treatment was taken out, and the contact angle to pure water was measured. As a result, an increase of 30 degrees or more was observed as compared with that before the treatment.

The photoreceptor after this treatment was used in a modified machine of FX3500 manufactured by Fuji Xerox Co., Ltd., and when it was developed to obtain a copy, the image quality was clear, and there was no change from the image quality before the plasma fluorination treatment. Further, even after the copying operation of 20,000 sheets, the toner filming was small and the scratches were smaller than that of the untreated one. In addition, there were almost no missing images or black dots. 30
There was almost no change under the environment of ℃ and 80%.

Similarly, when an operation was performed with an unprocessed photoconductor, fog occurred from about 5.000 copies, and after 10,000 copies, it was almost impossible to read the character image. When the surface of the drum after the operation was observed, the toner filming was remarkable, and the presence of paper dust was found from the analysis result. Also, 30 ℃, 80
In the operation under high temperature and high humidity of 100%, missing images of unknown cause occurred.

〔The invention's effect〕

As described above, according to the present invention, in electrophotographic processes other than charging and exposure, (1) toner filming is unlikely to occur, (2) moisture is unlikely to adhere, (3) paper dust is unlikely to occur, (4) It is possible to easily obtain an electrophotographic photosensitive member having a remarkable effect that scratches due to a developer, paper, and a cleaning blade hardly occur. Further, the electrophotographic photoreceptor of the present invention has an effect that a high quality image can be obtained with almost no omission or black spots in the image even after repeated operation for a long time, as compared with the conventional one.

[Brief description of drawings]

1 and 2 are schematic views of a plasma generator for producing the electrophotographic photosensitive member of the present invention. 10, 20 ... High frequency power supply, 11 ... Upper electrode, 21 ... High frequency coil, 12, 22 ... Substrate, 13, 23 ... Substrate support, 14, 24 ... Substrate heating heater, 15, 25 ... Gas inlet, 16, 26 ... Exhaust system, 1
7,27… Introduction system, 18,28… Needle valve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toyofumi Inoue, 2274 Hongo, Ebina, Ebina, Kanagawa Prefecture Fuji Zero Tsux Co., Ltd.Ebina Business Office (72) Inventor, Kazuaki Aoki 2274, Hongo, Ebina, Kanagawa Fuji Zero Tux Co., Ltd.Ebina Co., Ltd. On-site (56) References JP-A-59-188655 (JP, A) JP-A-57-14845 (JP, A)

Claims (6)

[Claims] 1. An electrophotographic photosensitive member having an image forming layer containing a binder resin on a support, wherein the image forming layer is formed by coating to form a binder resin containing layer, and then the binder resin containing layer is formed. An electrophotographic photosensitive member, which is formed by fluorinating a binder resin only on the surface. 2. The electrophotographic photosensitive member according to claim 1, wherein the image forming layer is a photosensitive layer. 3. The electrophotographic photoreceptor according to claim 1, wherein the image forming layer comprises a photoreceptor and a surface layer. 4. The electrophotographic photoreceptor according to claim 2 or 3, wherein the photosensitive layer comprises a charge generation layer and a charge transport layer. 5. The electrophotographic photosensitive member according to claim 4, wherein the charge transport layer is provided on the charge generating layer. 6. The image forming layer is formed by irradiating the surface of an electrophotographic photosensitive member having an image forming layer containing a binder resin on a support with glow discharge plasma of a gas containing a molecule containing a fluorine atom as a main component. A method for producing an electrophotographic photosensitive member, which comprises fluorinating a binder resin present on the surface of the.