JP2005092064A - Method for manufacturing electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrophotographic photoreceptor with which the occurrence of an abnormal image is reduced in spite of repetitive long-term use, the image of stable and high image quality is obtained and durability is extremely high and more specifically, the method for manufacturing the electrophotographic photoreceptor which has sufficient durability even under severe electrostatic charge load conditions in an electrostatic charge process while maintaining good electrostatic characteristics and can prevent the occurrence of the abnormal image, such as the degradation of resolution, even if a means, such as a heater, is not used. <P>SOLUTION: The electrophotographic photoreceptor is constituted by successively forming at least a photosensitive layer and a protective layer containing inorganic fillers on a conductive support, wherein the inorganic fillers are subjected to surface treatment by being brought into contact with gaseous ozone. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing an extremely highly durable electrophotographic photoreceptor in which an inorganic filler surface-treated with ozone gas is contained in a photosensitive layer and a stable high-quality image can be obtained even after repeated use over a long period of time.

An electrophotographic method using an electrophotographic photosensitive member applied to a copying machine, a facsimile, a laser printer, a direct digital plate making machine, etc. means that at least an electrophotographic photosensitive member is subjected to charging, image exposure, and development processes, and then an image is obtained. This is a method comprising a process of transferring a toner image to a holding member (transfer paper), fixing, and cleaning the surface of the electrophotographic photosensitive member.
The basic characteristics required for the electrophotographic photosensitive member in this electrophotographic method are (1) that it can be charged to an appropriate potential in a dark place,
(2) Less charge dissipation in the dark,
(3) The ability to quickly dissipate charges by light irradiation,
Etc.
In recent years, in addition to these characteristics,
(4) low cost,
(5) Low pollution
(6) A stable image free from abnormal images can be obtained over a long period of time.
There is a very strong demand.

  Conventionally, as a photoconductor used in an electrophotographic system, a photoconductive layer mainly composed of selenium or a selenium alloy is provided on a conductive support, and an inorganic photoconductive material such as zinc oxide or cadmium sulfide is used as a binder. In general, those dispersed inside and those using amorphous silicon-based materials are known. However, in recent years, the cost is low, the degree of freedom in designing the photoconductor, and the low pollution. Rather, organic electrophotographic photoreceptors are widely used because of such demands.

  Organic electrophotographic photoreceptors include photoconductive resins typified by polyvinylcarbazole (PVK), charge transfer complex types typified by PVK-TNF (2,4,7-trinitrofluorenone), and phthalocyanines. -A pigment dispersion type represented by a binder, a function separation type photoreceptor using a combination of a charge generation material and a charge transport material, and the like are known. In particular, a function separation type photoreceptor is attracting attention.

The mechanism of electrostatic latent image formation in this function-separated type photoreceptor is that when the photoreceptor is charged and irradiated with light, the light passes through the transparent charge transport layer and is absorbed by the charge generation material in the charge generation layer, The charge-generating substance that has absorbed the light generates charge carriers, which are injected into the charge transport layer, move in the charge transport layer according to the electric field generated by the charge, and neutralize the charge on the surface of the photoreceptor. Thus, an electrostatic latent image is formed.
In the function-separated type photoreceptor, it is known and useful to use a combination of a charge transport material having absorption mainly in the ultraviolet region and a charge generation material having absorption mainly in the visible region. However, such an organic electrophotographic photoreceptor is not always satisfactory particularly in terms of durability.

In recent years, an electrophotographic apparatus is excellent in high-speed recording performance among image forming apparatuses, and thus is widely used not only for office use but also for personal use. Along with this, there is a strong demand from the market for the implementation of miniaturization of devices and suppression of machine troubles.
In addition, with the remarkable development of information technology, electrophotographic devices are required to evolve accordingly. Specifically, there is a demand for reduction in running cost, further increase in printing speed, and colorization of an apparatus that enables color printing from monochrome printing.
In colorization, there is a strong expectation for high image quality that enables printing of landscapes and human images with a natural texture.

In response to such a demand, for example, a charger often uses a charging roller from a scorotron charger. As a result, low power consumption and a reduction in the amount of ozone generated during charging can be obtained. Furthermore, in order to ensure the stability of image quality, a method of superimposing an AC component on the charger is often used.
For the purpose of improving the image quality, both the monochrome device and the color device have been developed to reduce the particle size of the developer.
Looking at the particle size of printing ink dyes and pigments as submicron, the current developers used in electrophotographic equipment are very large particles, and there are issues with further particle size reduction going forward. Is left.
In addition, the photosensitive member is used at a high linear velocity in order to cope with the miniaturization and high speed of the process.
The response of the apparatus that meets such market demand is a major hazard for the electrophotographic photosensitive member. In order to be able to cope with such an apparatus and meet the demands of the market, high durability of the electrophotographic photosensitive member is the most important issue.

In order to obtain a stable output image even when mass printing is performed on an organic electrophotographic photosensitive member, there is no image defect due to mass printing, and there is a technology for preventing a decrease in image density and a decrease in resolution. Required.
It is a well-known fact that the occurrence of such an abnormal image is mainly caused by a wound on the surface of the photosensitive member or film removal of the photosensitive layer. Therefore, in order to prevent the output of abnormal images even after mass printing, it is necessary to impart excellent mechanical strength and abrasion resistance to the organic electrophotographic photosensitive member. At the same time, it is necessary to ensure electrostatic performance.

Various proposals have been made so far in order to improve the wear resistance of the surface layer of the photoreceptor. (1) Means by providing a surface protective layer: For example, by providing a protective layer containing a metal or metal oxide such as tin oxide or antimony oxide having a specific range of particle sizes and particle size distributions, Means for improving the mechanical strength have been proposed (see Patent Documents 1 to 4).
Such a method can be said to be a useful means for improving the durability of the photoreceptor because the mechanical strength of the photoreceptor surface can be improved relatively easily.
However, when a surface protective layer is provided, resolution is often lowered. When the ionic substance generated from the charger is used while being attached to the surface of the photosensitive member, it is considered that charge leakage in the lateral direction with respect to the surface of the photosensitive member is caused, resulting in a decrease in resolution. .
In a photoconductor that does not wear at all, contamination of the photoconductor surface caused by repeated or long-term use of the photoconductor cannot be removed due to the property of zero wear, and a reduction in surface resistance cannot be avoided. Such an abnormal situation is a phenomenon often seen in a photoreceptor provided with a surface protective layer. For this reason, it is preferable that the photoconductor has high wear resistance, but it is considered impractical to have extremely high wear resistance.
It is not easy to control the wear rate of a photoreceptor on which a surface protective layer is formed. In addition, if a surface protective layer is provided, the residual potential is increased, so that the film thickness is limited to use with a very thin film thickness.
In addition, when an attempt is made to provide a protective layer on the photoconductor for a small-diameter photoconductor drum corresponding to the miniaturization of the apparatus, the drum-shaped curvature may be high and only the protective layer may be peeled off. As described above, the means for providing the surface protective layer is not an appropriate means because of many restrictions in design.

(2) Means by modification of the charge transport layer: For example, by incorporating a lubricious filler on the surface of the photoreceptor, the lubricity of the surface of the photoreceptor can be improved, and as a result, the life of the photoreceptor can be extended. It has been proposed (see Patent Documents 5 and 6).
Further, means for improving the mechanical strength of the photosensitive member by including a filler in the insulating layer or photoconductive layer of the image holding member has been proposed (see Patent Documents 7 and 8).
In addition, it has been proposed to add a filler to the surface of the photoreceptor or the charge transport layer in the multilayer electrophotographic photoreceptor to enhance the hardness of the photoreceptor surface or to provide lubricity (Patent Document 9). 10).
Furthermore, a means for improving the mechanical strength of the photoreceptor by containing 1 to 30 parts by weight of hydrophobic titanium oxide fine powder with respect to 100 parts by weight of the charge transport medium has been proposed (see Patent Document 11). ).
However, when a filler is simply added to the photosensitive layer or the charge transport layer in accordance with these means, there are many cases in which the function as the photosensitive member is lost due to severe deterioration of sensitivity and accumulation of residual potential.
Many of the photoreceptors in which the filler is dispersed in the photosensitive layer cause a rapid increase in the residual potential as the thickness of the photosensitive layer in which the filler is dispersed increases. For this reason, in addition to the above technique, it is necessary to take some measures to reduce the residual potential.
When the amount of abrasion of the surface layer is reduced due to improvement in mechanical durability and electrostatic characteristics, the occurrence of abnormal images is highlighted as a serious problem. Occurrence of abnormal images, for example, when using paper that has absorbed moisture under high temperature and high humidity, the oxidized and deteriorated resin and surface deposits cannot be sufficiently removed from the surface of the photoconductor, causing a decrease in photoconductor surface resistance The output image will flow.

As described above, the conventionally proposed technology for enhancing the durability of the photoreceptor is intended to improve either the wear resistance or the characteristics relating to the prevention of contamination of the photoreceptor surface. It is difficult to say that these two characteristics of the technology are improved at the same time, and improving the durability characteristics of one reduces the durability characteristics of the other. There are many cases that are related.
Although it can be said that the conventionally proposed technology is useful for improving the specific performance of the photoconductor, it cannot be said to be a technology that directly extends the life (high durability) of the photoconductor.
Actually, the electrophotographic photosensitive member has a strong personality as a disposable consumable among electrophotographic apparatuses, and it has not yet been obtained what can be said to be a long-life component.

Japanese Unexamined Patent Publication No. 57-30846 JP 58-121044 A JP 59-223443 A JP 59-223445 A JP-A-46-782 Japanese Patent Laid-Open No. 52-2531 Japanese Patent Laid-Open No. 54-44526 JP 60-57346 A JP-A-1-205171 JP-A-7-261417 JP 61-251860 A

An object of the present invention is to provide a method for producing an extremely high durability electrophotographic photosensitive member in which abnormal images are not generated even after repeated use over a long period of time and a stable high-quality image can be obtained.
More specifically, while maintaining good electrostatic characteristics, it has sufficient durability even under harsh charging load conditions in the charging process, and abnormal images such as reduced resolution can be generated without using a means such as a heater. An object of the present invention is to provide a method for producing an electrophotographic photosensitive member that can be prevented.

  As a result of intensive studies, the inventors of the present invention have made it possible to include an inorganic filler surface-treated with ozone gas in the protective layer so that the electrophotographic photoreceptor having an excellent wear-resistant filler-dispersed protective layer can be used for a long time. A method for producing an electrophotographic photoreceptor that has good cleaning properties even during repeated use, does not cause abnormal images due to filming or poor cleaning, and suppresses the occurrence of abnormal images due to a decrease in charging potential or an increase in residual potential I found that I can provide.

That is, the above-mentioned problem is (1) of the present invention. In the electrophotographic photosensitive member in which a protective layer containing at least a photosensitive layer and an inorganic filler is sequentially formed on a conductive support, the inorganic filler contacts ozone gas. Electrophotographic photosensitive member characterized in that it is surface-treated ”, (2)“ Item (1) above, wherein the ozone gas is generated using pure oxygen as a raw material ” (3) “The electrophotographic photosensitive member according to (1) above, wherein the ozone gas is generated using air as a raw material”, (4) “The electrophotographic photosensitive member according to any one of (1) to (3) above, wherein the inorganic filler contained in the protective layer is at least one metal oxide”, ( 5) “At least 1 in the protective layer The electrophotographic photosensitive member according to any one of (1) to (4) above, wherein the protective layer contains at least a polycarbonate resin. Or an electrophotographic photosensitive member according to any one of items (1) to (5), characterized in that any one of polyarylate resins or a mixture thereof is contained. The electrophotographic photosensitive member according to any one of (1) to (6) above, wherein the thickness of the layer is 0.5 to 10 μm, (8) “Thickness of the protective layer” Is solved by the electrophotographic photosensitive member according to item (7), characterized in that it is 2 to 10 μm.
Further, the above problem is (9) of the present invention, in the electrophotographic photosensitive member in which at least a photosensitive layer and a protective layer containing a filler are sequentially formed on a conductive support, the inorganic filler is in contact with ozone gas, Electrophotographic photosensitive member manufacturing method characterized in that surface treatment is performed ”, (10)“ Electrophotography according to (9) above, which is ozone gas generated using pure oxygen as a raw material ” Photoconductor manufacturing method ”, (11)“ Electrophotographic photoconductor manufacturing method according to item (9) above, which is ozone gas generated using air as a raw material ”, (12)“ Protection ” The method for producing an electrophotographic photosensitive member according to any one of (9) to (11), wherein the inorganic filler contained in the layer is at least one metal oxide. 13) “At least the protective layer The method for producing an electrophotographic photosensitive member according to any one of (9) to (12) above, wherein the protective layer contains a kind of charge transporting substance, At least one of a polycarbonate resin and a polyarylate resin, or a mixture thereof, and the method for producing an electrophotographic photoreceptor according to any one of (9) to (13) above (15) “The method for producing an electrophotographic photosensitive member according to any one of (9) to (14) above, wherein the thickness of the protective layer is 0.5 to 10 μm”. (16) “The method for producing an electrophotographic photosensitive member according to any one of (9) to (15) above, wherein the protective layer has a thickness of 2 to 10 μm”. The
The above-described problem is solved by (17) “the electrophotographic photosensitive member according to any one of (1) to (8)”, at least a charging unit, an image exposing unit, a developing unit, a transferring unit, and the like. An electrophotographic image forming apparatus comprising at least a fixing unit ”, (18), wherein the electrophotographic photosensitive member according to any one of (1) to (8) is used. An electrophotographic image comprising the electrophotographic photosensitive member according to any one of items (1) to (8) and a developing unit. A process cartridge that is detachably attached to the forming apparatus ”, (20), and used in the protective layer of the electrophotographic photosensitive member according to any one of (1) to (8). Inorganic filler surface-treated with ozone gas It is solved by.

The present invention has been made based on the knowledge that the wear resistance of an electrophotographic photosensitive member can be improved by including an inorganic filler surface-treated with ozone gas in a protective layer.
Since the film thickness reduction due to wear is less likely to occur in this way, the electrophotographic photosensitive member of the present invention causes a discharge breakdown due to the film thickness reduction as in the prior art, and abnormal images such as scumming caused by pinholes associated therewith. Therefore, stable image output is possible over a long period of time.
In addition, when an inorganic filler composed of at least one metal oxide is used, the amount of wear is extremely small, abnormal images such as dirt due to wear can be prevented, and high-quality and long-life electrophotography over a long period of time. It can be a photoconductor.
In addition, when an inorganic filler treated with ozone gas with strong oxidation characteristics is used, the surface charge density is lowered, and when it is included in the protective layer, charge traps are less likely to occur near the interface between the inorganic filler and the binder resin, Accumulation of residual potential due to repeated use is unlikely to occur, so that an electrophotographic photosensitive member with high image quality, excellent mechanical strength, and high wear resistance is obtained.
In addition, when a charge transport material is contained in the protective layer, the charge transfer is performed well, the sensitivity is good, the residual potential is small, and the difference between the bright part potential and the dark part potential can be sufficiently taken. Therefore, it is possible to provide an electrophotographic photosensitive member that can perform stable image output and can perform high-speed image output, high-quality image output, and high-stable image output.
In addition, by using a polycarbonate resin and / or polyarylate resin as a binder resin in the protective layer, the inorganic filler has high retention, excellent mechanical strength, and as a result, wear resistance excellent in mechanical strength. The electrophotographic photosensitive member can be made strong.

As described above, when an inorganic filler is included in the photosensitive layer of the electrophotographic photosensitive member, although there is a great improvement in abrasion resistance, the residual potential is increased and abnormal images are likely to occur. .
In the electrophotographic photosensitive member of the present invention, by including an inorganic filler surface-treated with ozone gas in the photosensitive layer, it is possible to realize a highly durable photosensitive member that does not easily increase the residual potential while maintaining high wear resistance.
Inorganic fillers (for example, alumina, silica, etc.) that are generally used as a reinforcing agent in the photosensitive layer of an electrophotographic photoreceptor are either acidic or basic, so the surface charge density of the inorganic filler is higher than that of the binder. , Is at a high level.
Therefore, when an electrophotographic photoreceptor having a photosensitive layer containing a filler is repeatedly used, a charge trap that causes a residual potential increase is likely to occur near the interface between the inorganic filler and the binder.
On the other hand, it is known that when the inorganic filler is surface-treated with ozone gas, the surface charge density can be lowered.
For example, JP-A-11-116236, “Journal of Fermentation and Bioengineering, Vol. 84, No. 5, 407-413 (1997)” describes that the surface charge density of alumina is lowered by ozone gas treatment. The mechanism is presumed to be due to the fact that ozone having strong oxidation characteristics reacts with active sites on the filler surface such as alumina.
There are two types of ozone gas generation sources, pure oxygen and dry air. The latter generates NOx simultaneously with ozone when ozone is generated. In the case of surface treatment of an inorganic filler using a reinforcing agent for the photosensitive layer of the photoreceptor, both can be used.
Although the contact conditions to the inorganic filler are not particularly limited, the ozone concentration is usually 50 to 2,000 ppm, preferably 100 to 1,000 ppm, the contact time is 10 minutes to 4 hours, preferably 30 minutes to 1 hour, The contact temperature is 10 to 40 ° C, preferably 20 to 30 ° C.

An embodiment of the electrophotographic photoreceptor of the present invention will be described below.
1 to 3 are cross-sectional views showing examples of the electrophotographic photoreceptor of the present invention.
The electrophotographic photoreceptor of the present invention is one in which an inorganic filler surface-treated with ozone gas is contained in the photosensitive layer (2), (2 ′), (2 ″). It can be used as shown in FIG.

In the electrophotographic photoreceptor of FIG. 1, a photosensitive layer (8) mainly composed of a charge generating substance (5) and a charge transporting substance is provided on a conductive support (1), and further the surface of the photosensitive layer is protected. A layer (6) is provided.
In this case, the inorganic filler (3) surface-treated with ozone gas is contained in the protective layer (6).
The electrophotographic photoreceptor of FIG. 2 has a charge generation layer (7) mainly composed of a charge generation material (5) and a charge transport layer mainly composed of a charge transport material (1) on a conductive support (1). 4) and a protective layer (6) provided on the charge transport layer.
In this case, the protective layer (6) may contain an inorganic filler (3) surface-treated with ozone gas.
The electrophotographic photoreceptor shown in FIG. 3 has a charge transport layer (4) mainly composed of a charge transport material and a charge generation layer composed mainly of a charge generation material (5) on a conductive support (1). 7) and a protective layer (6) provided on the charge generation layer.
In this case, the inorganic filler (3) surface-treated with ozone gas is contained in the protective layer (6).

As the conductive support (1) used in the electrophotographic photoreceptor of the present invention, a conductive material having a volume resistance of 10 ¹⁰ Ω · cm or less, such as aluminum, nickel, chromium, nichrome, copper, gold, Metals such as silver and platinum, metal oxides such as tin oxide and indium oxide, and film or cylindrical plastics coated with paper by vapor deposition or sputtering, or aluminum, aluminum alloys, nickel, stainless steel, etc. Plates and pipes that have been surface-treated by cutting, super-finishing, polishing, etc. can be used after making them into raw pipes by methods such as extrusion and drawing. Further, an endless nickel belt and an endless stainless steel belt disclosed in JP-A-52-36016 can be used as the conductive support (1).

In addition, the conductive support dispersed in a suitable binder resin and coated on the support can also be used as the conductive support (1) of the present invention.
Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, or metal oxide powder such as conductive tin oxide and ITO. It is done. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.

  Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support (1) of the present invention.

Next, the photosensitive layer will be described.
The photosensitive layer of the photoreceptor used in the present invention may have a single layer structure or a stacked structure. For convenience of explanation, the photosensitive layer is first described from the case of a stacked structure including a charge generation layer (7) and a charge transport layer (4). .
The charge generation layer (7) is a layer mainly composed of the charge generation material (5).
A known charge generation material can be used for the charge generation layer (7), and representative examples thereof include inorganic materials such as selenium, selenium-tellurium, cadmium sulfide, cadmium sulfide-selenium, and α-silicon, organic Examples of the material include C.I. Pigment Blue 25 (Color Index CI21180), C.I. Pigment Red 41 (CI21200), C.I. Acid Red 52 (CI45100), C.I. Basic Red 3 (CI45210), and an azo pigment having a carbazole skeleton. 95033), azo pigments having a distyrylbenzene skeleton (Japanese Patent Laid-Open No. 53-133445), azo pigments having a triphenylamine skeleton (described in Japanese Patent Laid-Open No. 53-132347), dibenzothiophene skeleton A Pigments (described in JP-A No. 54-21728), azo pigments having an oxadiazole skeleton (described in JP-A No. 54-12742), azo pigments having a fluorenone skeleton (JP-A No. 54-22834) ), An azo pigment having a bisstylbene skeleton (described in JP-A-54-17733), an azo pigment having a distyryloxadiazole skeleton (described in JP-A-54-2129), a distyrylcarbazole Azo pigments such as azo pigments having a skeleton (described in JP-A No. 54-14967), indigo pigments such as C-Ibut Brown 5 (CI73410), C-Ibutte Die (CI73030), Argo Scarlet B (manufactured by Bayer) ), Perylene pigments such as Indence Ren Scarlet R (manufactured by Bayer) It is done.
In addition, phthalocyanine pigments represented by the following general formula (N) are also useful as charge generating substances. In the formula, M (central metal) represents a metal and a metal-free (hydrogen) element.

ここで挙げられるＭ（中心金属）は、Ｈ、Ｌｉ、Ｂｅ、Ｎａ、Ｍｇ、Ａｌ、Ｓｉ、Ｋ、Ｃａ、Ｓｃ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎ、Ｇａ、Ｇｅ、Ｙ、Ｚｒ、Ｎｂ、Ｍｏ、Ｔｃ、Ｒｕ、Ｒｈ、Ｐｄ、Ａｇ、Ｃｄ、Ｉｎ、Ｓｎ、Ｓｂ、Ｂａ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｏｓ、Ｉｒ、Ｐｔ、Ａｕ、Ｈｇ、ＴＩ、Ｌａ、Ｃｅ、Ｐｒ、Ｎｄ、Ｐｍ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｅｒ、Ｔｍ、Ｙｂ、Ｌｕ、Ｔｈ、Ｐａ、Ｕ、Ｎｐ、Ａｍ等の単体、もしく酸化物、塩化物、フッ化物、水酸化物、臭化物などの２種以上の元素からなる。中心金属は、これらの元素に限定されるものではない。
本発明におけるフタロシアニン骨格を有する電荷発生物質とは、少なくとも一般式（Ｎ）の基本骨格を有していればよく、２量体、３量体など多量体構造を持つもの、さらに高次の高分子構造を持つものでも良い。また基本骨格に様々な置換基があるものでも良い

M (central metal) mentioned here is H, Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga , Ge, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, TI , La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, Pa, U, Np, Am, etc., or oxide, chloride It consists of two or more elements such as fluoride, fluoride, hydroxide and bromide. The central metal is not limited to these elements.
The charge generation material having a phthalocyanine skeleton in the present invention may have at least a basic skeleton of the general formula (N), a substance having a multimeric structure such as a dimer or trimer, and a higher order high-order substance. It may have a molecular structure. In addition, the basic skeleton may have various substituents.

Of these various phthalocyanines, oxotitanium phthalocyanine having TiO as the central metal and metal-free phthalocyanine having H are particularly preferable from the viewpoint of the characteristics of the electrophotographic photoreceptor.
These phthalocyanines are also known to have various crystal systems. For example, in the case of oxotitanium phthalocyanine, α, β, γ, m, y type, etc., in the case of copper phthalocyanine, α, β, γ, etc. It has a polycrystal system of Even in a phthalocyanine having the same central metal, various properties change as the crystal system changes. Among them, it has been reported that the characteristics of the photoconductor also change with such a change in crystal system (see Journal of Electrophotographic Society, Vol. 29, No. 4, (1990)).
For this reason, each phthalocyanine has an optimum crystal system in terms of the characteristics of the photoreceptor, and in particular for oxotitanium phthalocyanine, a y-type crystal system is desirable.
Further, two or more kinds of the charge generating materials described above may be mixed.

The charge generation layer (7) is obtained by dispersing the charge generation material (5) in a suitable solvent together with a binder resin, if necessary, using a ball mill, attritor, sand mill, ultrasonic wave, etc. It is formed by coating on top and drying.
As the binder resin used for the charge generation layer (7) as necessary, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly -N-vinyl carbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulosic resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone Etc. The amount of the binder resin is suitably 0 to 500 parts by weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generating material. The binder resin may be added before or after dispersion.
Examples of the solvent used here include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, and ligroin. In particular, ketone solvents, ester solvents, and ether solvents are preferably used. These may be used alone or in combination of two or more.

The charge generation layer (7) is mainly composed of the charge generation material (5), a solvent and a binder resin, and includes a sensitizer, a dispersant, a surfactant, silicone oil, and the like. May be.
As a coating method for the coating solution, a dip coating method, spray coating, beat coating, nozzle coating, spinner coating, ring coating, or the like can be used.
The film thickness of the charge generation layer (7) is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.

The charge transport layer (4) can be formed by dissolving or dispersing a charge transport material and a binder resin in a suitable solvent, and applying and drying the solution on the charge generation layer. Further, if necessary, two or more kinds of plasticizers, leveling agents, antioxidants and the like can be added.
Charge transport materials include hole transport materials and electron transport materials.

  Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.

  Examples of hole transport materials include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, etc. Other known materials may be used. These charge transport materials may be used alone or in combination of two or more.

  As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin And thermoplastic or thermosetting resins such as phenol resins and alkyd resins.

The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin. The thickness of the charge transport layer is preferably 25 μm or less from the viewpoint of resolution and responsiveness. The lower limit varies depending on the system to be used (particularly charging potential), but is preferably 5 μm or more.
As the solvent used here, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used. These may be used alone or in combination of two or more.

Next, the case where the photosensitive layer has a single layer structure will be described. For the single photosensitive layer, the above-described charge generating material, charge transporting material, binder resin and the like can be used.
The photosensitive layer can be formed by dissolving or dispersing a charge generating substance and a charge transporting substance, the above-described sulfur-based compound, and a binder resin in a suitable solvent, and applying and drying them. Moreover, a plasticizer, a leveling agent, etc. can also be added as needed. The amount of the charge generating material with respect to 100 parts by weight of the binder resin is preferably 5 to 40 parts by weight, and the amount of the charge transporting material is preferably 0 to 190 parts by weight, and more preferably 50 to 150 parts by weight. The photosensitive layer is formed by dip coating, spray coating, bead coating, a coating solution in which a charge generating material and a binder resin are dispersed together with a charge transporting material using a solvent such as tetrahydrofuran, dioxane, dichloroethane, and cyclohexane. It can be formed by coating with a ring coat or the like. The film thickness of the photosensitive layer is suitably about 5 to 25 μm.

Next, the protective layer (6) provided on the electrophotographic photosensitive member of the present invention will be described.
The protective layer (6) contains an inorganic filler surface-treated with ozone gas, which is a feature of the present invention.
The protective layer (6) is prepared by dispersing the inorganic filler in a suitable solvent together with a binder resin, and further adding and dissolving a leveling agent, a charge transporting material, an antioxidant, or the like, and the dispersion thus obtained is used as a photosensitive layer. It is formed by applying and drying on.
Examples of the inorganic filler material used in the present invention include silica, tin oxide, zinc oxide, titanium oxide, alumina, zirconium oxide, indium oxide, antimony oxide, bismuth oxide, calcium oxide, antimony-doped tin oxide and tin. -Metal oxides such as indium oxide, metal fluorides such as tin fluoride, calcium fluoride and aluminum fluoride, potassium titanate, boron nitride and the like.
Among these fillers, the use of an inorganic pigment that is an inorganic filler is particularly effective for improving the abrasion resistance in view of the hardness of the filler.

Moreover, in order to improve the dispersibility of an inorganic filler, it is preferable to add a suitable surface treating agent. As the surface treatment agent, a conventionally used surface treatment agent can be used, but it is particularly preferable to use a surface treatment agent capable of maintaining the insulating properties of the inorganic filler.
For example, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, etc., or a mixing treatment of these with a silane coupling agent, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Silicone, aluminum stearate, or the like, or a mixture thereof is more preferable from the viewpoint of dispersibility of the inorganic filler and image blur.
The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent.
The surface treatment amount varies depending on the average primary particle size of the inorganic filler used, but 3 to 30 wt% is suitable, and 5 to 20 wt% is more preferable. If the surface treatment amount is less than this, the inorganic filler dispersion effect cannot be obtained, and if the surface treatment amount is too much, the residual potential is significantly increased.

  The binder resin material used for the protective layer (6) includes ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, aryl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate. , Polyallylsulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, polyarylate, AS resin, butadiene-styrene Resins such as polymers, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resins can be used. From the viewpoint of filler dispersibility, residual potential, and coating film defects, polycarbonate or polyarylate is particularly effective and useful.

As a solvent to be used, a solvent used in the charge transport layer (7) such as tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like can be used. However, a solvent having a high viscosity is preferable at the time of dispersion, but a solvent having high volatility is preferable at the time of coating.
When there is no solvent satisfying these conditions, it is possible to use a mixture of two or more solvents having respective physical properties, which may have a great effect on filler dispersibility and residual potential. .

In addition, the addition of the charge transport material mentioned in the charge transport layer (7) to the protective layer is effective and useful for reducing the residual potential and improving the image quality.
When the ion transport potential contained in the protective layer is equal to or smaller than the ionization potential (Ip) of the charge transport material contained in the photosensitive layer, the protective layer is added. As a result, the electric charge injecting property is improved and the residual potential can be further reduced. The ionization potential Ip can be measured using various methods such as a method for obtaining spectroscopically and a method for obtaining electrochemically.

The inorganic filler material can be dispersed using a conventional method such as ball milling, high-pressure liquid collision, attritor, sand mill, or ultrasonic wave. Among these, it is more preferable from the viewpoint of dispersibility to use a ball mill that is less contaminated with impurities from the outside. As for the material of the media used, known media such as zirconia, alumina, and agate used conventionally can be used.
Moreover, as an average primary particle diameter of an inorganic filler, it is preferable from the point of the light transmittance of a protective layer, and abrasion resistance as it is 0.01-0.6 micrometer.
When the average primary particle size of the inorganic filler is less than 0.01 μm, it tends to cause a decrease in abrasion resistance, a decrease in dispersibility, etc., and when it exceeds 0.6 μm, the sedimentation property of the inorganic filler is promoted. Or toner filming may occur.

As a method for forming the protective layer, conventional methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, and ring coating can be used, but spray coating is particularly preferable from the viewpoint of the uniformity of the coating film. .
In addition, it is possible to form the protective layer by coating the required film thickness of the protective layer at one time, but it is more uniform for the filler in the film to be applied two or more times and the protective layer to be multilayered It is more preferable from the viewpoint of sex. By doing so, a further effect can be obtained with respect to reduction of residual potential, improvement of resolution, and improvement of wear resistance.
In addition, about 0.1-10 micrometers is suitable for the thickness of a protective layer.

Furthermore, an organic filler other than the inorganic filler surface-treated with the above and ozone gas can be added to the protective layer. Examples of the organic filler material include fluororesin powder such as polytetrafluoroethylene, silicone resin powder, a-carbon powder, and the like.
In addition, a leveling agent such as silicone oil, an antioxidant and a filler dispersion material as shown below can be added to the protective layer.
A conventionally well-known thing can be used as antioxidant, The compound which has both a hindered amine structure and a hindered phenol structure can be used.
As the filler dispersant used, known dispersants can be used, and organic compounds having a structure containing at least one carboxyl group in the polymer or copolymer are particularly preferable. Is more preferably a polycarboxylic acid derivative.
The carboxylic acid portion of the dispersant plays an important role of giving an acid value and increasing dispersibility. A hydrophilic inorganic filler has low affinity with an organic solvent or a binder resin, and as such, it cannot be dispersed well by any dispersing means.
However, the dispersant used in the present invention has high affinity with the inorganic filler at the carboxylic acid site, and high affinity with the binder resin and organic solvent at the other polymer sites, so that the inorganic dispersant is added via the dispersant. It becomes possible to increase the affinity between the filler and the organic solvent, the binder resin, or the like.
Moreover, as an acid value of these dispersing agents, 10-400 mgKOH / g is preferable, More preferably, 30-200 mgKOH / g is suitable.
If the acid value is higher than necessary, there may be an effect on the image such as a decrease in resolution. If the acid value is too low, it is necessary to increase the amount of addition, which tends to cause a decrease in electrical characteristics.
The thickness of the protective layer is preferably 0.5 μm or more, more preferably 2 μm or more. If the film thickness of the filler-reinforced charge transport layer is less than 0.5 μm, the durability improving effect is small and the utility is lacking. On the other hand, when the thickness of this layer is thicker than 2 μm, durability comparable to the life of the apparatus is often obtained, which is an extremely useful means.
Such thickening often caused severe sensitivity deterioration and residual potential increase in the prior art, but the functional separation of the charge transport layer according to the present invention makes it possible to easily avoid defects in electrostatic characteristics. It becomes. However, increasing the film thickness more than necessary only increases the manufacturing cost and also contributes to the improvement in durability. Therefore, it is determined that the maximum value of this layer is approximately 10 μm.

In the electrophotographic photosensitive member of the present invention, an undercoat layer can be provided between the conductive support (1) and the photosensitive layer.
In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, it may be a resin having a high solvent resistance with respect to a general organic solvent. desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. In addition, a fine powder pigment of a metal oxide which can be exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moire and reduce residual potential.

These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer of the present invention. In addition, in the undercoat layer of the present invention, Al ₂ O ₃ is provided by anodization, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO ₂ A material provided with an inorganic material such as a vacuum thin film can also be used favorably. In addition, known ones can be used. The thickness of the undercoat layer is suitably from 0 to 5 μm.

The electrophotographic photosensitive member of the present invention is used by being provided in an electrophotographic image forming apparatus together with at least a charging unit, an image exposing unit, a developing unit, a transferring unit and a fixing unit, and is based on a general electrophotographic process. After the photosensitive member is charged and exposed, development is performed, and the developed toner image is transferred to a recording medium such as paper and fixed to form a copy image.
Further, the electrophotographic photosensitive member of the present invention is used in a full color image forming apparatus including a tandem type, and is also used in a process cartridge including at least an electrophotographic photosensitive member and a developing unit.
Since the electrophotographic photosensitive member of the present invention contains an inorganic filler surface-treated with ozone gas in the surface protective layer, it has a high sensitivity and extremely excellent durability regardless of the mode. It can be demonstrated.

Next, the image forming apparatus of the present invention will be described with reference to the drawings.
FIG. 4 is a schematic view showing an example of an electrophotographic image forming apparatus using the electrophotographic photosensitive member of the present invention.
The electrophotographic image forming apparatus shown in FIG. 4 is provided with various means around the electrophotographic photosensitive member (11) of the present invention. The main components are a charging charger (13) and an image exposure unit (15). A developing unit (16) and a transfer charger (20), after the electrophotographic photosensitive member (11) is charged by the charging charger (13), a latent image is formed by image exposure of the image exposure unit (15), and the developing unit The toner image is developed by toner according to (16), and then the toner image is transferred to the transfer paper (19) by the transfer charger (20) after using the pre-transfer charger (17), and finally the copied image is fixed. It is formed.
In many cases, the toner is not completely transferred during the transfer, and the toner remaining on the electrophotographic photosensitive member (11) is cleaned by using the fur brush (24), the cleaning blade (25), or a combination thereof. In addition, a pre-cleaning charger (23) can be used for more efficient cleaning.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not restrict | limited by an Example. All parts are parts by weight.
Example 1 (ozone treatment of alumina)
6 g of alumina (average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical Co., Ltd.) is placed in an ozone treatment column (6 mmφ × 300 mmL), and ozone gas (1, 1, 000 ppm) was aerated at room temperature at a rate of 5 liters / minute for 1 hour to modify the surface of the alumina powder.
The zero charge point of alumina after surface modification moved to the alkaline side, and the negative surface charge density decreased.
Potentiometric titration method (pH meter) confirms that the zero-charge point of alumina after surface modification moved to the alkaline side and increased from pH = 4.2 to pH = 4.8, and the negative surface charge density decreased. did.

Example 2 (ozone treatment of alumina)
6 g of alumina (average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical Co., Ltd.) is placed in an ozone treatment column (6 mmφ × 300 mmL), and ozone gas (1, 1, 000 ppm) was aerated at room temperature for 2 hours at a rate of 5 liters / minute to modify the surface of the alumina powder.
The zero charge point of alumina after surface modification moved to the alkaline side, and the negative surface charge density decreased.
Potentiometric titration method (pH meter) confirms that the zero-charge point of alumina after surface modification moved to the alkaline side and rose from pH = 4.2 to pH = 5.2, and the negative surface charge density decreased. did.

Example 3 (Production of electrophotographic photoreceptor)
An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition are sequentially applied onto an aluminum cylinder by dip coating and dried to obtain a 3.5 μm undercoat layer, 0. A 2 μm charge generation layer and a 20 μm charge transport layer were formed.
<Undercoat layer coating solution>
Titanium dioxide powder: 400 parts Melamine resin: 40 parts Alkyd resin: 60 parts 2-butanone: 500 parts <Charge generating layer coating solution>
Bisazo pigment with the following structure: 12 parts

ポリビニルブチラール：５部
２−ブタノン：２００部
シクロヘキサノン：４００部
＜電荷輸送層塗工液＞
ポリカーボネート（Ｚポリカ、帝人化成製）：１０部
下記構造式の電荷輸送物質：１０部

Polyvinyl butyral: 5 parts 2-butanone: 200 parts Cyclohexanone: 400 parts <Charge transport layer coating solution>
Polycarbonate (Z Polyca, manufactured by Teijin Chemicals): 10 parts Charge transport material having the following structural formula: 10 parts

テトラヒドロフラン：１００部
１％シリコーンオイル（ＫＦ５０−１００ＣＳ、信越化学工業製）
テトラヒドロフラン溶液：１部

Tetrahydrofuran: 100 parts 1% silicone oil (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)
Tetrahydrofuran solution: 1 part

Further, a protective layer coating solution having the following composition obtained by ball milling was formed on the charge transporting layer by a ring coating method to form a protective layer having a thickness of about 5 μm. Thus, an electrophotographic photoreceptor of Example 3 was produced.
Alumina obtained in Example 1: 1.1 parts Charge transport material having the following structural formula (Ip: 5.4 eV): 4 parts

ポリカーボネート（Ｚポリカ、帝人化成製）：５．５部
分散剤 ＢＹＫ−Ｐ１０４（ビックケミー社製）：０．１部
テトラヒドロフラン：２２０部
シクロヘキサノン：８０部
振動ミル分散：６０分

Polycarbonate (Z Polyca, manufactured by Teijin Chemicals): 5.5 parts Dispersant BYK-P104 (manufactured by Big Chemie): 0.1 part Tetrahydrofuran: 220 parts Cyclohexanone: 80 parts Vibration mill dispersion: 60 minutes

Example 4 (Production of electrophotographic photosensitive member)
An electrophotographic photosensitive member was produced in the same manner as in Example 3, except that the alumina obtained in Example 2 was used for the protective layer.

Comparative Example 1
In Example 3, an electrophotographic photosensitive member was produced in the same manner as in Example 3 except that the protective layer was not provided.

Comparative Example 2
An electrophotographic photoreceptor was prepared in the same manner except that untreated alumina was used for the protective layer in Example 3.

The electrophotographic photoreceptors of Examples 3 and 4 and Comparative Examples 3 and 4 produced as described above were mounted on an electrophotographic process cartridge (however, no exposure before cleaning), and an image exposure light source First, 50,000 sheets were printed continuously with a modified Ricoh laser printer using a 655 nm semiconductor laser, then imaged in an environment with a temperature of 25 ° C. and a humidity of 90%. The bright part potential and the image quality were evaluated.
The dark part potential, the bright part potential, and the image quality were evaluated as follows.
Dark portion potential: photoreceptor surface potential when moved to development position after primary charging Bright portion potential: photoreceptor surface potential when moved to development portion position after primary charging and subjected to image exposure (full exposure) Image quality: Comprehensive evaluation of output image density, fine line reproducibility, text blurring, resolution, background stains, etc. In addition, the film thickness is measured after printing 50,000 sheets. Evaluation was performed. The results are shown in Table 1.

1 is a cross-sectional view showing a layer structure of an electrophotographic photoreceptor according to the present invention. It is sectional drawing which shows the other layer structure of the electrophotographic photoreceptor concerning this invention. It is sectional drawing which shows the other layer structure of the electrophotographic photoreceptor concerning this invention. 1 is a schematic view showing an example of an electrophotographic image forming apparatus using the electrophotographic photosensitive member of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive support body 2,2 ', 2 "Photosensitive layer 3 Inorganic filler 4 Charge transport layer or charge transport medium 5 Charge generation material 6 Protective layer 7 Charge generation layer 8 Photosensitive layer 11 Photoconductor 12 Static elimination lamp 13 Charge charger 14 Eraser 15 Image exposure unit 16 Development unit 17 Pre-transfer charger 18 Registration roller 19 Transfer paper 20 Transfer charger 21 Separation charger 22 Separation claw 23 Charger 24 before cleaning Fur brush 25 Cleaning blade (cleaning brush)

Claims (20)

An electrophotographic photosensitive member in which at least a photosensitive layer and a protective layer containing an inorganic filler are sequentially formed on a conductive support, wherein the inorganic filler is surface-treated by contacting with ozone gas. An electrophotographic photoreceptor. The electrophotographic photosensitive member according to claim 1, wherein the ozone gas is generated using pure oxygen as a raw material. The electrophotographic photosensitive member according to claim 1, wherein the ozone gas is generated using air as a raw material. The electrophotographic photoreceptor according to claim 1, wherein the inorganic filler contained in the protective layer is at least one metal oxide. The electrophotographic photosensitive member according to claim 1, wherein the protective layer contains at least one charge transport material. 6. The electrophotographic photosensitive member according to claim 1, wherein the protective layer contains at least one of a polycarbonate resin and a polyarylate resin, or a mixture thereof. The electrophotographic photosensitive member according to claim 1, wherein the protective layer has a thickness of 0.5 to 10 μm. The electrophotographic photosensitive member according to claim 7, wherein the protective layer has a thickness of 2 to 10 μm. An electrophotographic photosensitive member comprising a conductive support and at least a photosensitive layer and a protective layer containing a filler sequentially formed thereon, wherein the inorganic filler comes into contact with ozone gas and is subjected to a surface treatment. Body manufacturing method. The method for producing an electrophotographic photosensitive member according to claim 9, wherein the gas is ozone gas generated using pure oxygen as a raw material. The method for producing an electrophotographic photosensitive member according to claim 9, wherein the gas is ozone gas generated using air as a raw material. The method for producing an electrophotographic photosensitive member according to claim 9, wherein the inorganic filler contained in the protective layer is at least one metal oxide. 13. The method for producing an electrophotographic photosensitive member according to claim 9, wherein the protective layer contains at least one kind of charge transport material. 14. The method for producing an electrophotographic photosensitive member according to claim 9, wherein the protective layer contains at least one of a polycarbonate resin and a polyarylate resin, or a mixture thereof. The method for producing an electrophotographic photosensitive member according to claim 9, wherein the protective layer has a thickness of 0.5 to 10 μm. 16. The method for producing an electrophotographic photosensitive member according to claim 9, wherein the protective layer has a thickness of 2 to 10 [mu] m. 9. An electrophotographic image forming apparatus comprising at least the electrophotographic photosensitive member according to claim 1, at least a charging unit, an image exposing unit, a developing unit, a transfer unit, and a fixing unit. A full-color electrophotographic image forming apparatus using the electrophotographic photosensitive member according to claim 1. 9. A process cartridge detachably attached to an electrophotographic image forming apparatus, comprising the electrophotographic photosensitive member according to claim 1 and a developing unit. An inorganic filler surface-treated with ozone gas, wherein the inorganic filler is used by being contained in a protective layer of the electrophotographic photosensitive member according to any one of claims 1 to 8.

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