WO2005064416A1

WO2005064416A1 - Electrophotographic photoreceptor and electrophotograph

Info

Publication number: WO2005064416A1
Application number: PCT/JP2004/019065
Authority: WO
Inventors: Hajime Suzuki; Takumi Shinohara; Hideki Nakamura
Original assignee: Shindengen Electric Mfg. Co., Ltd.; Yamanashi Electronics Co., Ltd.
Priority date: 2003-12-26
Filing date: 2004-12-21
Publication date: 2005-07-14
Also published as: JPWO2005064416A1; CN1637852A

Abstract

An electrophotographic photoreceptor having an excellent repetition stability and an excellent environment characteristic and including a conductive substrate on which the defects are covered without marring its excellent electrophotographic characteristics. The electrophotographic photoreceptor has a conductive support and a photosensitive layer formed over the conductive support, with an under coat layer interposed therebetween. The electrophotographic photoreceptor is characterized in that the under coat layer contains a polyimide resin, and the photosensitive layer contains, as a charge generating agent, oxytitanium phthalocyanine the X-ray diffraction spectrum of which shows main diffraction peak intensities at the Bragg angle (2θ±0.2°) 7.5° and 28.6° when measured using CuKα as the radiation source.

Description

Specification

Electrophotographic photoreceptor and electrophotographic apparatus

Technical field

The present invention relates to an electrophotographic photoreceptor used for an electrophotographic apparatus such as a copying machine, an LED, and an LD printer, and more particularly, to an electrophotographic photoreceptor using an organic photoconductive material having an undercoat layer formed thereon, and The present invention relates to an electrophotographic apparatus equipped with such a photoconductor.

Background art

[0002] In general, an electrophotographic process using a photoconductor is performed as follows. That is, in a dark place, for example, charging is performed by a charging roller as a contact charging method, and then an LED or an LD is used as an image exposure means, and an electric charge of only an exposed portion is selectively eliminated to form an electrostatic latent image. And visualize with a developer to form an image.

The basic characteristics required for such an electrophotographic photoreceptor include being capable of being charged to an appropriate potential in a dark place and being provided with a function of eliminating surface charges by light irradiation.

The electrophotographic photoreceptor, which is currently in practical use! The basic structure of the electrophotographic photoreceptor is to form a photosensitive layer on a conductive support. When processing oil, cutting oil or cutting powder remains on the support and appears as a defect during image formation by applying a photosensitive layer on it, or when high voltage is applied to the surface of the photoconductor!] In addition, there is also a problem that current flows from a defective portion of the support such as cutting burrs, dirt, and adhesion of foreign matter, and a short circuit occurs partially. It also appears as image defects in Chile and Capri. Further, since the charge generation layer formed on the conductive substrate has a thickness of about 1 m, the charge generation layer is affected by the defect and adversely affects the function as a photoreceptor. In order not to be affected by such defects on the surface of the conductive substrate, anodizing treatment is usually performed on the conductive substrate to provide an alumite film, or a subbing layer using a resin material is provided. The method of covering the defect of the above is adopted.

[0003] However, in the manufacturing process, the alumite film is subjected to a process such as a sealing process for closing fine holes formed on the surface of the alumite film, a sealing process for closing the holes, and a cleaning process. There is a disadvantage that the coating surface is easily contaminated, and even if a defect on the surface of the conductive substrate is covered, contamination of the alumite coating itself has an adverse effect.

As the undercoat layer, for example, a resin material such as polyethylene, polypropylene, polystyrene, acrylate resin, chloride resin, acetate resin, polyurethane resin, epoxy resin, silicone resin, or polyamide resin is used. It has been known. Of these resins, polyamide resin is particularly preferred.

However, in the case of an electrophotographic photoreceptor using a polyamide resin or the like for the undercoat layer, the volume resistance of the undercoat layer is about 10 ^{12 to} 10 ¹⁵ Ω'cm. If the thickness is not reduced below, residual potential accumulates on the photoreceptor, causing dust and capri in the image. On the other hand, when the film is made thinner, not only is it impossible to cover defects on the conductive support, but also the injection of holes from the substrate during repeated use is accelerated, and the photosensitivity, which is markedly decreased by the charging potential, is reduced. In addition, there is a problem that capri and the like are generated and image quality is impaired.

[0004] An undercoating layer using a polyimide resin soluble in an organic solvent, specifically having a thickness of 0.5 m, has also been proposed (for example, see Patent Document 1).

Patent Document 1: Japanese Patent Application Laid-Open No. H8-30007

[0005] As described in Patent Document 1, the undercoat layer containing polyimide resin is formed of a thin film having a thickness of less than 1.0 m, and the conventional charge generation is performed. In combination with the agent, it was apparent that there was a problem that the residual potential after repeated use of the photoreceptor increased, causing dust and capri in the image.

In addition, in the case of an electrophotographic apparatus having a contact charging member in which the undercoat layer is brought into direct contact with the photoreceptor and a charging voltage is applied, a high voltage is applied directly to the electrophotographic photoreceptor. There is a problem that capri is easily generated.

Disclosure of the invention

Problems to be solved by the invention

[0006] An object of the present invention is to provide an electrophotographic photoreceptor that covers defects on a conductive substrate without impairing excellent electrophotographic characteristics, and has excellent repetition stability and environmental characteristics. Means for solving the problem

[0007] The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the conductive support An electrophotographic photoreceptor in which a photosensitive layer is formed via an undercoat layer on the electrophotographic photoreceptor, wherein the undercoat layer contains a specific polyimide resin and a specific charge generating agent, The inventors have found that there is no problem in the technology and that excellent electrostatic characteristics are maintained for a long period of time, and have completed the present invention.

[0008] That is, the present invention relates to an electrophotographic photoreceptor having a photosensitive layer formed on a conductive support via an undercoat layer, wherein the undercoat layer contains a polyimide resin, and the photosensitive layer contains Oxytitanium phthalocyanine showing main diffraction peak intensities at Bragg angles (2 ° ± 0.2 °) 7.5 ° and 28.6 ° in an X-ray diffraction spectrum using CuKo; The present invention relates to an electrophotographic photoreceptor characterized by containing guanine.

According to the invention as set forth in claim 1, which has a strong structure, the conductive support is covered with defects such as pinholes, the rise of the residual potential after repeated use is suppressed, and the dust and fog on the image are reduced. Occurrence can be eliminated.

[0009] The invention according to claim 2 relates to an electrophotographic photoreceptor, wherein the undercoat layer contains a polyimide resin represented by the general formula [I].

General formula (I)

[Chemical 1]

[In the formula, X is a divalent polycyclic aromatic group in which aromatic rings may be linked by different atoms, and n is an integer representing the degree of polymerization. ]

[0010] According to the second aspect of the invention, which has a powerful configuration, it is possible to suppress an increase in remaining power after repeated use.

[0011] The invention according to claim 3 relates to the electrophotographic photosensitive member according to claim 1, wherein the thickness of the undercoat layer is 1.0 m to 50 m. is there.

[0012] According to the invention according to claim 3, which has a strong structure, the conductive support has a relatively large size. Even defective portions can be covered, and image defects are eliminated.

[0013] The invention according to claim 4 is the electrophotographic photoreceptor according to claim 1, wherein the undercoat layer contains titanium oxide, whereby the dielectric constant of the undercoat layer can be increased and the dispersibility can be improved. improves. Further, the weight ratio between the polyimide resin and the titanium oxide is preferably in the range of 3: 1 to 1: 4.

[0014] The invention according to claim 5 is the electrophotographic photoreceptor according to claim 1, wherein the undercoat layer comprises a polyimide resin-containing layer represented by the general formula [I] and a thermosetting resin thereon. Alternatively, by providing a two-layer structure of a layer having a thermoplastic resin, the accumulation of residual potential is suppressed even if the undercoat layer is thick, and the chargeability is stabilized, so that the image quality is improved.

[0015] The invention according to claim 6 provides the electrophotographic photoreceptor according to any one of claims 116, wherein the conductive support uses a non-cutting tube so that the surface of the conductive support is reduced. Defects can be reliably coated.

[0016] The invention according to claim 7 is an electrophotographic apparatus according to any one of claims 116, wherein the electrophotographic photoreceptor has contact charging means as charging means. Thus, the object of the present invention can be achieved.

According to the invention described in claim 8, in the electrophotographic photoreceptor of claim 1, interference fringes of an image can be eliminated by applying an exposure unit using a semiconductor laser.

The invention's effect

The electrophotographic photoreceptor of the present invention has high electrostatic properties such as surface potential and post-exposure potential without any image defect that does not significantly deteriorate even after repetition, and has high repetition stability.

Therefore, according to the present invention, it is possible to provide an electrophotographic photoreceptor having excellent electrophotographic properties, cleaning properties, and oil resistance and capable of simplifying maintenance.

Hereinafter, preferred embodiments of the electrophotographic photosensitive member according to the present invention will be described in detail.

The present invention provides, for example, a function-separated electron in which a charge generation layer containing at least a charge generation agent is formed on a conductive support, and a charge transfer layer containing at least a charge transfer agent is formed thereon. It is applied to photographic photoreceptors. In this case, a photosensitive layer is formed by the charge generation layer and the charge transfer layer.

In addition, the present invention provides a single-layer type electrophotography in which a charge generating agent and a charge transfer agent are contained in the same layer. The present invention can also be applied to a true photoconductor, an inversely laminated electrophotographic photoconductor in which a charge transfer layer and a charge generation layer are laminated in this order.

Examples of the conductive support that can be used in the present invention include simple metals such as aluminum, brass, stainless steel, nickel, chromium, titanium, gold, silver, copper, tin, platinum, molybdenum, and indium, and alloys thereof. Processed metal, or a conductive plate such as a metal or carbon, and processed by a method such as vapor deposition or plating to give conductivity to plastic plates and films, as well as oxidized tin, indium oxide, and aluminum iodide. The conductive support can be formed using various materials having conductivity that are not limited to the type and shape, such as coated conductive glass. The conductive support may be in the form of a drum, a rod, a plate, a sheet, or a belt.

Among these, aluminum alloys such as JIS 3000 series, JIS 5000 series, and JIS 6000 series are used, and are formed by a general method such as EI method, ED method, DI method, and II method. A non-cutting tube that does not undergo any surface treatment such as cutting, polishing, or anodizing is preferable.

[0021] As the charge generating agent that can be used in the present invention, disazo pigments and oxytitanium phthalocyanine are preferable in terms of good compatibility with sensitivity. In particular, for oxytitanium phthalocyanine, several crystal types are introduced. Among them, oxytitanium phthalocyanine which shows the main diffraction peak intensities at Bragg angles (20 ± 0.2 °) 7.5 ° and 28.6 ° in the X-ray diffraction spectrum with CuKo; as the source Are particularly preferred for the electrophotographic photoreceptor of the present invention. The film thickness is preferably in the range of 0.01-5. O ^ m, preferably 0.1-1. 0111.

The above-mentioned charge generating agents may be used alone or in combination of two or more in order to obtain an appropriate photosensitivity wavelength ゃ sensitizing effect.

In the undercoat layer of the present invention, the mixing ratio of the polyimide precursor and the polyimide resin may include an intermediate before the polyimide resin. The content is preferably 20 to 70% of the total weight of the polyimide precursor and the polyimide precursor, and more preferably 30 to 50%. If it is less than 20%, the undercoat layer will be dissolved in the organic solvent, and if it exceeds 70%, it will be in a state close to imidation, and the residual potential after repeated use will be accumulated, resulting in image failure. [0024] The molecular weight of the positive imide is preferably in the range of 1,000 to 100,000, particularly preferably 10,000 to 30,000. Specific examples of X are as follows.

[X-1]

[Formula 2]

[0025] The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having a photosensitive layer formed via an undercoat layer, wherein the undercoat layer contains a polyimide resin represented by the general formula (I). Thus, the film forming property is improved, and even a thin film covers defects such as pinholes of the conductive support, and the barrier function and adhesive function of the light-sensitive layer are excellent. The film thickness is 1.0 to 50 m, preferably 20 to 40 m.

The drying temperature for forming the undercoat layer is suitably in the range of 110 ° C. to 170 ° C., and preferably 130 ° C. to 150 ° C. If the temperature is lower than 110 ° C, the undercoat layer is dissolved by the solvent, so that it cannot be applied to the photoreceptor. When dried at 110 ° C or more, it does not dissolve in organic solvents. If the temperature exceeds 170 ° C., the residual potential after repeated use rises, causing a slight problem that a change in image density occurs.

[0027] Further, by providing a two-layer structure of a subbing layer containing a polyimide resin represented by the general formula (I) and a layer composed of a thermosetting resin or a thermoplastic resin thereon, Thick undercoat layer Even if the film is formed, the accumulation of the residual potential can be suppressed, and the image quality can be improved.

[0028] In the electrophotographic photoreceptor of the present invention, the undercoat layer may contain titanium oxide. Various treatments may be applied to the surfaces of the titanium oxide particles used in the present invention as long as the volume resistivity is not reduced. For example, the surface of the particles can be coated with an oxidation film by using aluminum, silicon nickel or the like as a treating agent. In addition, if necessary, it is possible to impart water repellency to the coupling material or the like. The average particle diameter of the titanium oxide is preferably 1 μm or less, more preferably 0.01-0.5 / zm. The content of titanium oxide is preferably in the range of 0.5 to 4 times that of polyimide 1.

Further, as the undercoat layer, a two-layer structure of a layer made of polyimide resin and a layer made of thermosetting resin or thermoplastic resin may be provided thereon. Examples of the thermosetting resin include epoxy resin, polyurethane, phenol, melamine 'alkyd resin, and unsaturated polyester resin. Examples of the thermoplastic resin include a styrene-based elastomer, an olefin-based elastomer, a urethane-based elastomer, and a polychlorinated butyl-based elastomer. The thickness of the resin layer provided on the polyimide resin layer can be used in the range of 0.1 to 10. O / zm, preferably 0.8 to 5. O / zm.

[0030] Further, a white pigment may be contained in both or one of the above two layers for the purpose of suppressing light interference during semiconductor laser exposure. For example, titanium oxide, sodium oxide, silica and the like can be mentioned.

[0031] Examples of the binder resin that can be used to form the photosensitive layer include polycarbonate resin, styrene resin, acrylic resin, styrene acrylic resin, ethylene vinyl acetate resin, polypropylene resin, and vinyl chloride resin. Resins, chlorinated polyethers, Shii-Dani-Bull acetate resin, polyester resin, furan resin, nitrile resin, alkyd resin, polyacetate resin, polymethylpentene resin, polyamide resin , Polyurethane resin, epoxy resin, polyarylate resin, diarylate resin, polysulfone resin, polyether sulfone resin, polyallyl sulfone resin, silicone resin, ketone resin, polybutyral resin, polyether resin , Phenol resin, EVA (ethylene 'Butyl acetate' copolymer) resin, ACS (acrylonitrile 'chlorinated polyether There are light-cured resins such as styrene (styrene) resin, ABS (acrylonitrile) butadiene styrene) resin, and epoxy acrylate. These are one kind However, it is also possible to use a mixture of two or more. Further, it is more preferable to use a mixture of resins having different molecular weights, since the hardness and the abrasion resistance can be improved.

As the charge transfer material that can be used in the present invention, compounds represented by the general formulas [II] and Z or the general formula [III] are preferable.

[0033] General formula [II]

[Formula 5]

(Wherein, R and R each independently have a carbon number of 1

R represents a hydrogen atom or a dialkyl having at least one alkyl group having 2 or more carbon atoms.

Three

Represents any of a lumino group. )

[0034] General formula [III]

[Formula 6]

(Wherein, R may be the same or different, and each independently represents a hydrogen atom,

4 7

Represents a halogen atom, an alkyl or alkoxy group having 16 carbon atoms, or a substituted or unsubstituted aryl group, wherein R is a hydrogen atom, a halogen atom,

16 alkyl groups or alkoxy groups, aryl groups which may have a substituent, or aryl groups which may have a substituent, an alkyl group or an alkadiele group, or a compound represented by the general formula (IV): Without And n represents an integer of 0 or 1. )

[0035] The general formula [IV]

[Formula 7]

(Wherein, R and R may be the same or different and are each independently a hydrogen atom,

9 10

Represents any of a halogen atom, an alkyl group or an alkoxy group having 1 to 16 carbon atoms, or a substituted or unsubstituted aryl group, and n represents an integer of 0 or 1. )

The charge transfer material is compatible with oxytitanium phthalocyanine, and the electrophotographic photoreceptor of the present invention has high sensitivity, low residual potential and excellent electrical characteristics! /! General formula [II] In particular, the compounds represented by the formulas [V] and [VI] have good compatibility with oxytitanium phthalocyanine.

[0036] General formula [V]

[Formula 8]

[0037] The general formula [VI]

In addition, in the i-conjugated product represented by the general formula (m), particularly, the i-conjugated compound represented by the formula (νπ), the formula (vm), the formula (ιχ), and the formula (x) has compatibility with the oxytitanium phthalocyanine. Well preferred.

[0038] The general formula [VII]

[Formula 10]

[0039] The general formula [VIII]

[Formula 11]

[0040] General formula [IX]

[0041]

[0042] It is also preferable to simultaneously use a compound selected from the general formula [II] and a compound selected from the general formula [III] as the charge transfer material, since the characteristics can be obtained.

[0043] Other charge transfer materials than the above charge transfer materials can be used. Other charge transfer materials include polyvinyl carbazole, halogenated polyvinyl carbazole

Further, another charge transfer agent can be added to the photosensitive layer of the electrophotographic photosensitive member of the present invention. In that case, the sensitivity of the photosensitive layer can be increased or the residual potential can be reduced, so that the characteristics of the electrophotographic photosensitive member of the present invention can be improved.

[0044] Examples of the charge transfer agent that can be added to improve such properties include polyvinyl carbazole, halogenated polybutylcarbazole, polyvinylpyrene, polyvinylindoloquinoxaline, polyvinylbenzothiophene, and polyvinyl. Anthracene, polybulatalidine, polybulpyrazoline, polyacetylene, polythiophene, polypyrrole, polyphenylene, Use conductive polymer compounds such as polyphenylenevinylene, polyisothianaphthene, polyaniline, polydiacetylene, polyheptadiene, polypyridinediyl, polyquinoline, polyphenylenesulfide, polyphenyleneylene, polyperinaphthylene, and polyphthalocyanine. This comes out.

[0045] Examples of the low molecular weight compound include polycyclic aromatic compounds such as anthracene, pyrene and phenanthrene; indole; Nitrogen-containing heterocyclic compounds such as carbazole and imidazole, fluorenone, fluorene, oxadiazole, oxazole, pyrazoline, triphenylmethane, triphenylamine, enamin, stilbene, butadiene other than those described above, and hydrazone compounds other than the above. It can be added as a charge transfer agent.

As a charge transfer agent for the same purpose, a polymer solid obtained by doping a metal compound such as Li (lithium) ion into a polymer compound such as polyethylene oxide, polypropylene oxide, polyacrylonitrile, and polymethacrylic acid. An electrolyte or the like can be added.

Further, as a charge transfer agent for the same purpose, an organic charge transfer complex formed of an electron-donating substance represented by tetrathiafulvalene-tetracyanoquinodimethane and an electron-accepting substance is used. Can be.

[0048] The desired photoreceptor characteristics can be obtained by adding only one kind of the charge transfer agent or by mixing two or more kinds of compounds and adding the charge. The thickness of the charge transfer layer is 5.0 to 50 m, preferably 10 to 30 m.

In the case of the electrophotographic photoreceptor of the present invention, the thickness of the entire photosensitive layer is preferably in the range of 10 to 50 m, and more preferably 15 to 25 μm. For example, when the undercoat layer is provided as thick as about 25 μm, the charge transfer layer may be provided as thin as about 15 m. Conversely, when the undercoat layer is provided as thin as about L m, the charge transfer layer may be provided as thick as about 25 m.

For this reason, the pressure resistance of the photoreceptor is required in an electrophotographic process having a contact charging means as the charging means. In general, a photoreceptor having low pressure resistance has a defect on its surface from the photoreceptor due to a leak current, and this appears as an image defect. That is, since the pressure resistance of the photoconductor is determined by the total thickness of the photoconductor, the thickness of the undercoat layer should be increased. By doing so, the charge transfer layer can be made thin because the pressure resistance is improved.

The electrophotographic photoreceptor of the present invention contains an antioxidant or an ultraviolet ray in its photosensitive layer for the purpose of preventing the property change due to oxidative deterioration of a photoconductive material or a binder resin, preventing cracks, and improving mechanical strength. Preferably, it contains an absorbent.

[0050] Antioxidants that can be used in the present invention include 2,6-di-tert-butylphenol, 2,6-di-tert-methoxyphenol, 2tert-butyl-4-methoxyphenol, and 2,4-dimethyl-6 tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, butylated hydroxysol, stearyl propionate j8- (3,5-di-tert-butyl-4-hydroxyphenol), α-tocopherol, monophenols such as j8-tocopherol, η-octadedecyl 3- (3'-5'-zy tert-butyl-4'-hydroxyphenyl) propionate, 2,2'-methylenebis (6 tert-butyl-4 methylphenol), 4,4'butylidene-bis- (3-methyl-6-tert-butylphenol), 4,4'-thiobis (6-tert-butyl-3-methylphenol), 1 1,1,3-Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) ) Benzene, tetrakis [methylene 3 (3,5-di-tert-butyl 4-hydroxyphenyl) propionate] Phenols such as methane are preferred. One or more of these are simultaneously contained in the photosensitive layer. can do.

[0051] Examples of the ultraviolet absorber include 2- (5-methyl-2-hydroxyphenyl) benzotriazole and 2- [2-hydroxy-3,5bis (α, α-dimethylbenzyl) phenyl]. — 2Η benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-amylol 2-hydroxyphenyl) benzotriazole Benzotriazoles such as, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, salicylates, salicylates ρ-tert-butyl, salicylates such as otatylphenyl System is preferred instrument can one or more of these causes simultaneously contain sensitive optical layer 〖this.

[0052] Further, an antioxidant and an ultraviolet absorber can be added simultaneously. These calories are Any layer may be used as long as it is in the photosensitive layer, but it is preferably added to the outermost layer, particularly to the charge transfer layer.

It is preferable that the anti-oxidizing agent is used in an amount of 3 to 20% by weight based on the binder resin. It is preferable to set the weight%. further

When both the antioxidant and the ultraviolet absorber are added, the addition amount of both components is preferably 5 to 40% by weight based on the binder resin.

In addition to the antioxidant and the ultraviolet absorber, a light stabilizer such as a hinderdamine or a hindered phenol compound, an antioxidant such as a diphenylamine compound, a surfactant, or the like may be added to the light-sensitive layer. You can also.

As a method for forming the photosensitive layer, a method of dispersing or dissolving a predetermined photosensitive material and a binder resin in a solvent together with a solvent to prepare a coating solution, and applying the coating solution on a predetermined substrate is common. is there.

[0056] The coating method may be dip coating, curtain flow, bar coating, roll coating, ring coating, spin coating, spray coating, or the like, depending on the shape of the base and the state of the coating liquid. Monkey

Further, the charge generation layer can be formed by a vacuum evaporation method.

[0057] Solvents used in the coating solution include alcohols such as methanol, ethanol, n-propanol, i-propanol, butanol, methylcellosolve, and ethylcellosolve, pentane, hexane, heptane, octane, cyclohexane, Saturated aliphatic hydrocarbons such as cycloheptane, aromatic hydrocarbons such as toluene and xylene, chlorinated hydrocarbons such as dichloromethane, dichloroethane, chloroform and chlorobenzene, ethers such as dimethyl ether, getyl ether and tetrahydrofuran (THF) , Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and methyl propionate; N-dimethylformamide, di Sulfoxide, a amides such as N-methyl-2-pyrrolidone. These may be used alone or as a mixture of two or more solvents.

Further, as the undercoat layer of the present invention, an intermediate layer in which a metal compound, a metal oxide, carbon, silica, a resin powder or the like is dispersed in a resin may be used. Furthermore, to improve characteristics Various pigments, an electron accepting substance, an electron donating substance, and the like can be contained.

Further, on the surface of the photosensitive layer, an organic thin film such as polyvinyl formal resin, polycarbonate resin, fluorine resin, polyurethane resin, or silicone resin, or a hydrolyzate of a silane coupling agent is formed. In this case, a surface protective layer may be provided by forming a thin film comprising a siloxane structure, which is preferable because the durability of the photoconductor is improved. This surface protective layer may be provided to improve functions other than the enhancement of durability.

Next, the electrophotographic process and the electrophotographic apparatus of the present invention will be described. In the electrophotographic process of the present invention, known means such as charging means, exposure means, developing means, transfer means, fixing means, tally and Jung means can be used. As the charging means, a non-contact charging method such as a corona charging method and a contact charging method such as a charging roller and a charging brush can be used. As a light source of the image exposure means, a halogen light, a fluorescent lamp, a laser light, or the like can be used. The wavelength of the semiconductor laser is 780 nm or less, preferably 780-500 nm, and a method such as narrowing the laser beam diameter may be used. The development method may be any of dry development method, wet development method, two-component, one-component, magnetic Z and non-magnetic. The transfer method may be either a roller or a belt.

Example

Hereinafter, examples of the electrophotographic photosensitive member according to the present invention will be described in detail along with comparative examples.

Example 1

Alumina-coated titanium oxide particles and a polyimide resin with the general formula (ΠΙ) having the formula [X-1] are mixed at a weight ratio of 1: 1 on a cylindrical drum with a diameter of 30 mm and a non-cutting aluminum force. This was applied and dried at 140 ° C. for 30 minutes to form a first undercoat layer having a thickness of 18.0111. Next, on the undercoat layer, a melamine alkyd resin as a thermosetting resin and titanium oxide in a ratio of 1: 3 were dissolved in methyl ethyl ketone to form a coating solution. A second subbing layer was laminated on the layer to a thickness of 0.7 m.

Next, using polyvinyl butyral as a binder resin, dip coating with a dispersion of oxytitanium phthalocyanine (FIG. 1) having main peaks at X-ray diffraction intensities of 7.5 degrees and 28.6 degrees. Was applied to form a charge generation layer.

Next, a polycarbonate copolymer as a binder resin and a compound of the formula [VI] as a charge transfer agent A butadiene compound and 2,6-di-tert-butyl-4-methylphenol as an antioxidant are dissolved in chloroform at a weight ratio of polycarbonate copolymer = 1.0 / 0.8 / 0.18. A coating solution was prepared.

[0065] Then, after applying the coating liquid by dip coating, the coating liquid was dried at a temperature of 100 ° C for 1 hour.

A charge transfer layer having a thickness of 20 m was formed, and an electrophotographic photoreceptor was produced.

Example 2

An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the weight ratio between the polyimide resin and the titanium oxide of the first undercoat layer in Example 1 was changed to 2: 1.

Example 3

An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the weight ratio of the polyimide resin and the titanium oxide of the first undercoat layer in Example 1 was changed to 1: 4.

Example 4

An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the thickness of the first undercoat layer in Example 1 was changed to 1. O / zm.

Example 5

An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the thickness of the first undercoat layer in Example 1 was changed to 5. O / zm.

Example 6

An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the thickness of the first undercoat layer in Example 1 was changed to 30.0 m.

Example 7

An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the thickness of the first undercoat layer in Example 1 was changed to 50.0 m.

Example 8

An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the second undercoat layer in Example 1 was omitted.

Example 9

Example 1 was repeated except that the charge transfer agent of the formula (VI) in Example 1 was changed to the charge transfer agent of the formula (VII). An electrophotographic photosensitive member was produced in the same manner as in Example 1.

Example 10

An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the thickness of the first undercoat layer in Example 1 was changed to 0.5 / zm.

[0075] Comparative Example 1

An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the charge generating agent of Example 1 was changed to metal-free phthalocyanine.

Comparative Example 2

An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that an anodized alumite layer was formed instead of the undercoat layer in Example 1.

[0077] Comparative Example 3

An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the first undercoat layer in Example 1 was omitted.

[0078] Comparative Example 4

An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the first and second undercoat layers of Example 1 were omitted.

[0079] Comparative Example 5

An electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that the trisazoi conjugate was used in place of the charge generator of Example 1.

[0080] Evaluation method 1

[Measurement of electrostatic characteristics, repeated cycle test, image test]

In an environment of normal temperature and normal humidity (24 ° C., 40% RH), a cylindrical shape produced by Example 1-110 and Comparative Example 1-1-5 using a direct charging type Okidata Microline 14 printer. Charge the electrophotographic photoreceptor so that the surface potential of the photoreceptor after charging becomes -800 V, initialize the surface potential of the photoreceptor after LED exposure to 50 V, and then use A4 paper 20,000 The surface potential V0 (—V) and the residual potential VR (—V) after printing on the sheet were measured. The image test evaluated the image after continuous printing of 20,000 sheets. Table 1 shows the above results. In the judgment, “〇” was judged as good, and “X” was judged as having a problem in practical use due to image failure and the like. [Table 1]

[0082] As is clear from Table 1, the electrophotographic photoreceptors of Examples 110 were excellent in chargeability and light fatigue characteristics after 20,000 sheets were repeated, and image defects such as dust and capri were observed in the images. There was no power at all.

[0083] Further, good results were obtained even when the titanium oxide was mixed with the polyimide resin or when a thermosetting resin or a thermoplastic resin was laminated on the polyimide resin layer.

That is, in the case of Examples 110, the results were particularly good.

On the other hand, in Comparative Examples 3 and 4, when the polyimide resin layer was not displaced, black spots, dust, and capri due to the transfer memory occurred.

Brief Description of Drawings

FIG. 1 is an X-ray diffraction pattern of oxytitanium phthalocyanine having main peaks at X-ray diffraction intensities of 7.5 degrees and 28.6 degrees.

Claims

The scope of the claims

[1] In an electrophotographic photosensitive member having a photosensitive layer formed on a conductive support via an undercoat layer, the undercoat layer contains a polyimide resin, and CuK is used as a charge generating agent in the photosensitive layer. It is characterized by containing oxytitanium phthalocyanine which shows main diffraction peak intensities at the Bragg angles (20 ± 0.2 °) 7.5 ° and 28.6 ° in the X-ray diffraction spectrum with α as the source. Electrophotographic photoreceptor.

[2] The electrophotographic photoreceptor according to claim 1, wherein the undercoat layer contains a polyimide resin represented by the general formula [I].

General formula (I)

[Chemical 1]

(In the formula, X is a divalent polycyclic aromatic group in which aromatic rings may be linked by different atoms, and η is an integer representing the degree of polymerization.)

[3] The electrophotographic photoreceptor according to claim 1, wherein the thickness of the undercoat layer is 1.0 / ζm-m.

[4] The electrophotographic photoreceptor of claim 1, wherein the undercoat layer contains titanium oxide, and the weight ratio of the polyimide resin and titanium oxide is in the range of 3: 1 to 1: 4. An electrophotographic photosensitive member, comprising:

[5] The electrophotographic photoreceptor according to claim 1, wherein the undercoat layer has a two-layer structure of a layer containing a polyimide resin and a layer made of a thermosetting resin or a thermoplastic resin thereon. An electrophotographic photoreceptor characterized by the following.

6. The electrophotographic photosensitive member according to claim 1, wherein the conductive support is a non-cutting tube.

[7] Applying contact charging means to the electrophotographic photoreceptor according to any one of claims 1 to 6. An electrophotographic apparatus, comprising:

[8] An electrophotographic apparatus, characterized in that an exposure means using a semiconductor laser is applied to the electrophotographic photoreceptor according to any one of [1] to [6].