JP4251486B2 - Method for producing electrophotographic photosensitive member - Google Patents

Description

The present invention relates to a laser beam printer, a facsimile, producing how the electrophotographic photosensitive member used in the digital copy and the like.

  In recent years, there has been a remarkable development of information processing system machines using electrophotography. In particular, an optical printer that converts information into a digital signal and records information by light has a remarkable improvement in print quality and reliability. This digital recording technology is applied not only to printers but also to ordinary copying machines, and so-called digital copying machines have been developed. In addition, since a variety of information processing functions are added to a conventional copying machine equipped with this digital recording technology for analog copying, it is expected that its demand will increase further in the future. In addition, with the spread of personal computers and the improvement in performance, the progress of digital color printers for performing color output of images and documents is rapidly progressing.

  The electrophotographic photoreceptor used in these electrophotographic image forming apparatuses is an organic material having superiority in sensitivity, thermal stability, toxicity, etc., as a photoconductive material, compared to inorganic materials such as Se, CdS, and ZnO that are conventionally used. Electrophotographic photoreceptors using photoconductive materials have become mainstream. When forming a photosensitive layer of an electrophotographic photoreceptor using this organic photoconductive material, a function separation type in which a charge transport layer is laminated on a charge generation layer is generally used because of its excellent sensitivity and durability. .

  As the charge generation material contained in the charge generation layer, many charge generation materials such as various azo pigments, polycyclic quinone pigments, trigonal selenium, various phthalocyanine pigments have been developed. Among them, the phthalocyanine pigment exhibits high sensitivity to light having a long wavelength of 600 to 800 nm, and thus is extremely important and useful as a photosensitive material for electrophotographic printers and digital copying machines whose light sources are LEDs and LDs. .

  In general, an electrophotographic photoreceptor using the phthalocyanine pigment is prepared by dip-coating a dispersion containing a phthalocyanine pigment, a binder resin, a solvent, and the like onto a cylindrical drum. However, when a dispersion containing a phthalocyanine pigment is applied, the density of the coating film varies depending on the position of the drum surface, that is, density unevenness is likely to occur, and an image is produced using an electrophotographic photosensitive member in which such density unevenness has occurred. When forming, there is a problem that uneven density appears remarkably in a halftone image. Further, in the dip coating, if density unevenness occurs at the start of drum lifting, that is, the density at the upper end of the drum, and at the end of drum lifting, that is, the density at the lower end of the drum, the density is increased at both ends of the formed image. There was a problem that a malfunction such as a difference occurred.

  In order to solve such an abnormal image, a photoconductor is produced using a charge generation material, a binder resin, polydimethylsiloxane, and a coating solvent as a charge generation layer coating (see Patent Document 1), or There has been proposed a method of producing a photoconductor using vapor phase synthetic silica hydrophobized with a binder resin and polydimethylsiloxane and a coating solvent (see Patent Document 2 and Patent Document 3). However, these methods have problems such as causing deterioration of characteristics such as sensitivity deterioration and insufficient effects.

Further, as another method for reducing density unevenness, a method for forming a photosensitive layer is proposed in which the height dimension of the vapor layer of the solvent generated on the liquid surface of the immersion bath is set to a certain level or less (see Patent Document 4). . However, this method also has problems that it cannot be easily performed because it requires modification on the equipment and that the effect is not sufficient.
JP-A-6-208230 JP-A-6-194850 JP-A-6-230589 JP-A-5-337430

Considering circumstances described above, an object of the present invention is to provide a manufacturing how without an electrophotographic photosensitive member having such high sensitivity and uneven density.

  The present inventors have intensively studied the problem that abnormal images such as density unevenness occur when a charge generation layer coating solution containing at least a phthalocyanine pigment is used, and the above problems are solved by the following means. I found out.

(1) In the method for producing an electrophotographic photosensitive member in which at least a charge generation layer and a charge transport layer are sequentially provided on a conductive support, the charge generation layer is a phthalocyanine pigment having an average particle size of 0.3 μm or less, 30 to 40 mol Synthetic zeolite containing at least a dispersion chamber and a pore size of 0.4 nm or more at a liquid temperature of 10 ° C. or less, containing a polyvinyl acetal resin having a% hydroxyl group, an organic solvent, and water of 0.01 to 0.99 wt% It is formed from a coating solution for a charge generation layer that is dispersed by performing circulation of the dispersion several times between circulation tanks in which 1 to 20% by weight of the adsorbent is immersed in the dispersion. A method for producing an electrophotographic photoreceptor.

(2) In the above ( 1) , the phthalocyanine pigment is a titanyl phthalocyanine pigment having a maximum peak at 27.2 ± 0.2 ° of the Bragg angle 2θ with respect to the Cu—Kα ray (wavelength 1.542Å). A method for producing the electrophotographic photosensitive member according to claim.
(3 ) The titanyl phthalocyanine has a maximum peak at a Bragg angle 2θ of 27.2 ± 0.2 ° and a peak at a minimum angle of 7.3 ± 0.2 ° with respect to a Cu—Kα ray (wavelength 1.542 mm), The method for producing an electrophotographic photosensitive member according to ( 2) above, wherein no peak is present in the range of 7.4 to 9.4 °.

  In the present invention, the charge generation layer comprises a phthalocyanine pigment having an average particle size of 0.3 μm or less, a polyvinyl acetal resin having a hydroxyl group of 30 mol% or more, an organic solvent, and a charge containing 0.01 to 0.99% by weight of water. The reason why a photoconductor with high sensitivity and no density unevenness can be obtained by forming from the generation layer coating solution is not clear, but is estimated as follows.

  In other words, the phthalocyanine pigment, which is a charge generation material, achieves a smaller average particle size of 0.3 μm or less, so that most of the photocarriers generated inside the charge generation material particles move to the particle surface. Is less likely to be deactivated before reaching the carrier generation site on the particle surface (increased photocarrier generation efficiency). The other is that the surface area increases as the particle size decreases. And the photocarrier injection efficiency based on the increase in the amount of contact with the charge transporting material surrounding the pigment particle surface increases, thereby making it possible to increase the photosensitivity.

As a method for achieving this reduction in particle size, a dispersion method using a bead mill dispersion device that can obtain high dispersion efficiency by stirring a dispersion medium such as alumina or zirconia at high speed is desirable. Since the temperature rises due to the generated heat, it is necessary to disperse while cooling the dispersion chamber in order to prevent the temperature rise.
However, since the dispersion treatment is performed while cooling, the temperature of the dispersion liquid also decreases, and moisture easily enters the coating liquid due to condensation of the dispersion apparatus. Therefore, when the amount of moisture in the charge generation layer coating solution increases, the surface energy of the solution changes, and density unevenness is likely to occur during coating film formation. Therefore, it is considered that the charge generation layer coating solution free from density unevenness can be obtained by setting the water content in the charge generation layer coating solution to 0.01 to 0.99% by weight.
Further, as a resin used for the charge generation layer, a polyvinyl acetal resin having a hydroxyl group of 30 mol% or more is used, so that the adsorption of the pigment and the resin is increased and the dispersibility is improved. It is estimated that density unevenness is less likely to occur due to the improvement of the properties.

  Examples of the phthalocyanine pigment used in the present invention include metal-free phthalocyanine or metal phthalocyanine, and synthetic methods described in Moser and Thomas' "phthalocyanine compound" (Rheinhold, 1963), and other suitable methods. Use the one obtained by

  Examples of metal phthalocyanines include those having a central metal such as copper, silver, beryllium, magnesium, calcium, zinc, indium, sodium, lithium, titanium, tin, lead, vanadium, chromium, manganese, iron, and cobalt. . Further, a metal halide having a valence of 3 or more may be present in the central nucleus of phthalocyanine instead of the metal atom. Although various crystal forms of phthalocyanine are known, known forms such as crystal forms such as α-type, β-type, Y-type, ε-type, τ-type, and X-type, and amorphous forms can be used.

式中、Ｘ₁、Ｘ₂、Ｘ₃、Ｘ₄は各々独立に各種ハロゲン原子を表わし、ｎ、ｍ、ｌ、ｋは各々独立的に０〜４の数字を表わす。 Furthermore, according to the present invention, as shown below, titanyl phthalocyanine (hereinafter referred to as TiOPc) having titanium as a central metal is particularly desirable because of its particularly high sensitivity and excellent characteristics.

In the formula, X ₁ , X ₂ , X ₃ and X ₄ each independently represent various halogen atoms, and n, m, l and k each independently represent a number of 0 to 4.

References relating to the synthesis method and electrophotographic characteristics of TiOPc include, for example, JP-A-57-148745, JP-A-59-36254, JP-A-59-44054, JP-A-59-31965, JP-A 61-239248, JP-A 62-67094 and the like can be mentioned. Various crystal systems are known for TiOPc. JP 59-49544 A, JP 59-166959 A, JP 61-239248 A, and JP 62-67094 A. JP-A-63-366, JP-A-63-116158, JP-A-63-196067, JP-A-64-17066, JP-A-2001-19871, etc. Different TiOPc are described.
Of these crystal forms, TiOPc having a maximum diffraction peak at a Bragg angle 2θ of 27.2 ° exhibits particularly excellent sensitivity characteristics and is used favorably. In particular, it has a maximum diffraction peak at 27.2 ° described in JP-A-2001-19871, and has a peak at 7.3 ° as the lowest diffraction peak, and 7.4. By using TiOPc having no peak in the range of ˜9.4 °, it is possible to obtain a stable electrophotographic photosensitive member that does not lose chargeability even when it is repeatedly used without losing high sensitivity. Furthermore, the use of a crystal form having no peak at 26.3 ° among the above crystal forms can make the effects of the present invention more remarkable.

  As a method for obtaining the average particle diameter of the charge generating material, it can be obtained by observing with an electron microscope a coating film formed by applying a dispersion. The particle shape of the charge generation material has various forms such as a rice grain shape and a needle shape, and any shape can be adopted. Therefore, in the case of direct observation, the average particle diameter can be obtained by measuring the length in the major axis direction of a plurality of particles (at least 10 particles) and calculating the arithmetic average.

式中、Ｒは水素原子、又はアルキル基であり、Ｘ、Ｙ、Ｚは組成比を表わし、０．３≦Ｘ≦０．４、０≦Ｙ≦０．１、０．６≦Ｚ≦０．７である。 In the present invention, it is necessary that the charge generating layer coating solution contains a polyvinyl acetal resin having a hydroxyl group of 30 mol% or more, preferably 30 to 40 mol%. Polyvinyl acetal resin shows different properties depending on the degree of polymerization, the degree of acetalization, the ratio of hydroxyl groups, and acetyl groups, but because of the presence of hydroxyl groups at a specific ratio, it exhibits good characteristics regarding pigment dispersibility and adhesiveness. It is considered that density unevenness is reduced and electrostatic characteristics are also excellent.

In the formula, R is a hydrogen atom or an alkyl group, X, Y, and Z represent the composition ratio, 0.3 ≦ X ≦ 0.4, 0 ≦ Y ≦ 0.1, 0.6 ≦ Z ≦ 0. .7.

  In the present invention, it is necessary that the charge generation layer coating solution contains an organic solvent and 0.01 to 0.99% by weight of water. As the organic solvent, for example, non-halogen solvents such as methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, cyclohexane, toluene, xylene, ligroin and the like are desirable. Further, when the water content is less than 0.01%, problems such as poor sensitivity occur, and when the water content is more than 0.99%, the coating film has uneven density. Therefore, it is necessary to make the water content 0.01 to 0.99% by adding water to the charge generation layer coating liquid or removing the water by dehydration.

  In the present invention, these phthalocyanine pigment, polyvinyl acetal resin, and organic solvent are dispersed using a bead mill dispersing device capable of obtaining high dispersion efficiency as described above to produce a coating solution for a charge generation layer. By doing so, it is possible to obtain an electrophotographic photosensitive member with high sensitivity and no density unevenness. The structure of the bead mill dispersing apparatus is shown in FIG. The dispersion chamber (2) placed on the table (9), the circulation tank (4) charged with the adsorbent, the circulation pump (5) and the piping connecting them, that is, the dispersion chamber (2) and the circulation tank A pipe (3) connecting (4), a pipe (7) connecting the circulation tank (4) and the circulation pump (5), and a pipe (8) connecting the circulation pump (5) and the dispersion chamber (2). (2) contains a rotor that rotates at high speed, and this rotor is driven by the motor (1), and the dispersion liquid passes from the dispersion chamber (2) through the pipe (3) to the circulation tank (4). It flows out from the circulation tank (4) through the pipe (7) to the circulation pump (5) and is circulated from the circulation pump (5) to the dispersion chamber (2) through a valve (6) that can be shut off. The

At this time, by cooling the liquid temperature of the dispersion liquid to 10 ° C. or less, it is possible to prevent a temperature rise due to heat generation of the apparatus, and it is possible to keep the dispersion liquid stable. In addition, the dispersion liquid can be repeatedly circulated between the dispersion chamber and the circulation tank in which the adsorbent is immersed to disperse the dispersion liquid repeatedly at a low liquid temperature, and at the same time, the water content can be reduced. It can be controlled to 0.01 to 0.99% by weight, which is desirable. In the present invention, the plurality of dispersion treatments can be easily calculated from the ratio of the circulation flow rate to the amount of the dispersion charged in the dispersion apparatus.
In addition, when the particle size of the material to be dispersed is large in the bead mill dispersing device, it cannot be sufficiently dispersed and a dispersion failure may occur. In order to prevent this, a method of dispersing in advance by other means (Such processing is called pre-dispersion).

  The adsorbent used in the present invention can be repeatedly dispersed and adsorbed by being immersed in a circulation tank. The adsorbent can be used in any way as long as the adsorbent is held in the circulation tank and does not enter the dispersion chamber. Synthetic zeolite, silica gel, activated carbon, activated alumina, calcium sulfate, calcium hydride Adsorbents such as potassium carbonate can be used. Of these, synthetic zeolite has a pore size suitable for moisture adsorption and is more preferable because of its high adsorption capacity, and synthetic zeolite having a pore size of 0.4 nm or more is particularly desirable. The amount of adsorbent is 0.5 to 30% by weight, preferably 1 to 20% by weight, based on the dispersion.

  Moreover, the dispersion liquid in the present invention is subjected to a filtration step using a filter having an effective pore diameter of 3 μm or less, more preferably a filter having an effective pore diameter of 1 μm or less after the dispersion treatment is completed, so that the adsorbent enters the dispersion liquid. The coarse particles remaining in the dispersion can also be removed. Accordingly, it is possible to prevent foreign matters from being mixed into the photosensitive layer, and it is possible to prevent image defects such as black spots. Any material can be used for the filter as long as it is resistant to the solvent used in the dispersion to be filtered.

  According to the present invention, there are provided an electrophotographic photosensitive member having high sensitivity and no density unevenness, a manufacturing method thereof, an image forming apparatus using the electrophotographic photosensitive member, and a process cartridge for the image forming apparatus.

Next, the electrophotographic photosensitive member used in the present invention will be described in detail with reference to the drawings.
FIG. 2 is a cross-sectional view showing a configuration example of the electrophotographic photosensitive member used in the present invention. On the conductive support (31), a charge generation layer (35) mainly composed of a charge generation material, and a charge The charge transport layer (37) mainly composed of a transport material has a laminated structure.

FIG. 3 is another cross-sectional view showing a structural example of the electrophotographic photosensitive member used in the present invention. The conductive layer (31) has an intermediate layer (33) and a charge generation material as main components. The charge generation layer (35) and the charge transport layer (37) mainly composed of the charge transport material are stacked.
FIG. 4 is a sectional view showing still another structural example of the electrophotographic photosensitive member used in the present invention. On the conductive support (31), an intermediate layer (33), a charge generation layer (35) and A charge transport layer (37) is provided, and a protective layer (39) is laminated thereon.

Examples of the conductive support (31) include those having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, oxidation Metal oxide such as indium by vapor deposition or sputtering, film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel plates, etc. and methods such as extrusion and drawing And endless nickel belts, endless stainless steel belts and the like described in JP-A-52-36016, and a method for forming the surface of these belts into a continuous roughness with a cutting tool, liquid, Honing, superfinishing, wet or dry blasting, or anodic oxide film formation, etc. Is also preferably used more that surface-roughened.

In the electrophotographic photoreceptor of the present invention, an intermediate layer can be provided between the conductive support (31) and the photosensitive layer. In general, the intermediate layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, it is desirable that the resin be a resin having high solvent resistance with respect to a general organic solvent. .
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. Further, fine powder pigments of metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the intermediate layer in order to prevent moire and reduce residual potential.

Examples of the solvent used in these intermediate layers include methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, cyclohexane, toluene, xylene, ligroin, and other non-halogen-based solvents. A solvent is desirable. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the intermediate layer of the present invention. In addition, in the intermediate layer of the present invention, Al ₂ O ₃ is provided by anodic oxidation, organic matter such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO _2, etc. Those provided with an inorganic material by a vacuum thin film forming method can also be used satisfactorily. In addition, known ones can be used. The thickness of the intermediate layer is suitably from 0 to 5 μm.
As the coating method for the intermediate layer coating solution, methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, and ring coating can be used.

Next, the photosensitive layer will be described.
As described above, as the photosensitive layer, a laminated type composed of the charge generation layer (35) and the charge transport layer (37) exhibits excellent characteristics in sensitivity and durability, and is used favorably. The charge generation layer (35) is formed by dispersing the above-mentioned phthalocyanine pigment and polyvinyl acetal resin as a charge generation material in a solvent, coating this on a conductive support, and drying. Dispersion is performed using an apparatus, and the above-described method can be used as a coating method.
These charge generation layers can be added with additives and the like, and the film thickness is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.

  The charge transport layer (37) contains a charge transport material and a binder resin in a suitable solvent, preferably a cyclic ether such as tetrahydrofuran, dioxolane or dioxane, which is a non-halogen solvent, an aromatic hydrocarbon such as toluene or xylene, In addition, it can be formed by dissolving or dispersing in a derivative thereof and applying and drying this on the charge generation layer. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.

  Charge transport materials include hole transport materials and electron transport materials. Examples of the electron transport material include chloroanil, bromanyl, 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 the hole transport material 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, etc., bisstilbene derivatives, enamine derivatives, etc. Other known materials may be mentioned. These charge transport materials may be used alone or in combination of two or more.

  Binder resins include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, poly Vinylidene chloride, polyarate, 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, phenol resin And thermoplastic or thermosetting resins such as alkyd resins, and polycarbonates in particular exhibit excellent electrical properties and wear resistance.

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 about 5 to 100 μm.
In addition, a polymer charge transport material having a function as a charge transport material and a function of a binder resin is also preferably used for the charge transport layer. The charge transport layer composed of these polymer charge transport materials is excellent in wear resistance. Improving the wear resistance reduces the increase in the electric field strength applied to the photoreceptor in repeated use, and makes the effect of the present invention even more remarkable. A known material can be used as the polymer charge transport material, but a polycarbonate having a triarylamine structure as shown in the following structural formula in the main chain and / or side chain is preferably used.

式中、Ｒ₁、Ｒ₂、Ｒ₃はそれぞれ独立して置換もしくは無置換のアルキル基又はハロゲン原子、Ｒ₄は水素原子又は置換もしくは無置換のアルキル基、Ｒ₅、Ｒ₆は置換もしくは無置換のアリール基、ｏ、ｐ、ｑはそれぞれ独立して０〜４の整数、ｋ、ｊは組成を表わし、０．１≦ｋ≦１、０≦ｊ≦０．９、ｎは繰り返し単位数を表わし５〜５０００の整数である。Ｘは脂肪族の２価基、環状脂肪族の２価基、または下記一般式で表わされる２価基を表わす。

In the formula, R ₁ , R ₂ and R ₃ are each independently a substituted or unsubstituted alkyl group or a halogen atom, R ₄ is a hydrogen atom or a substituted or unsubstituted alkyl group, and R ₅ and R ₆ are substituted or unsubstituted. Substituted aryl group, o, p, q are each independently an integer of 0-4, k, j are compositions, 0.1 ≦ k ≦ 1, 0 ≦ j ≦ 0.9, n is the number of repeating units Represents an integer of 5 to 5000. X represents an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula.

式中、Ｒ₁₀₁、Ｒ₁₀₂は各々独立して置換もしくは無置換のアルキル基、アリール基またはハロゲン原子を表わす。ｌ、ｍは０〜４の整数、Ｙは単結合、炭素原子数１〜１２の直鎖状、分岐状もしくは環状のアルキレン基、−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−、−ＣＯ−、−ＣＯ−Ｏ−Ｚ−Ｏ−ＣＯ−（式中、Ｚは脂肪族の２価基を表わす。）または、

（式中、ａは１〜２０の整数、ｂは１〜２０００の整数、Ｒ₁₀₃、Ｒ₁₀₄は置換または無置換のアルキル基又はアリール基を表わす。）を表わす。ここで、Ｒ₁₀₁とＲ₁₀₂、Ｒ₁₀₃とＲ₁₀₄は、それぞれ同一でも異なってもよい。

In the formula, R ₁₀₁ and R ₁₀₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom. l and m are integers of 0 to 4, Y is a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —. , -CO-, -CO-O-Z-O-CO- (wherein Z represents an aliphatic divalent group), or

(Wherein, a represents an integer of 1 to 20, b represents an integer of 1 to 2000, and R ₁₀₃ and R ₁₀₄ represent a substituted or unsubstituted alkyl group or an aryl group). Here, R ₁₀₁ and R ₁₀₂ , and R ₁₀₃ and R ₁₀₄ may be the same or different.

式中、Ｒ₇、Ｒ₈は置換もしくは無置換のアリール基、Ａｒ₁、Ａｒ₂、Ａｒ₃は同一又は異なるアリレン基を表わす。Ｘ、ｋ、ｊおよびｎは、化３に示す場合と同じである。

In the formula, R ₇ and R ₈ represent a substituted or unsubstituted aryl group, and Ar ₁ , Ar ₂ , and Ar ₃ represent the same or different arylene groups. X, k, j, and n are the same as shown in Chemical Formula 3.

式中、Ｒ₉、Ｒ₁₀は置換もしくは無置換のアリール基、Ａｒ₄、Ａｒ₅、Ａｒ₆は同一又は異なるアリレン基を表わす。Ｘ、ｋ、ｊおよびｎは、化３に示す場合と同じである。

In the formula, R ₉ and R ₁₀ are substituted or unsubstituted aryl groups, and Ar ₄ , Ar ₅ and Ar ₆ represent the same or different arylene groups. X, k, j, and n are the same as shown in Chemical Formula 3.

式中、Ｒ₁₁、Ｒ₁₂は置換もしくは無置換のアリール基、Ａｒ₇、Ａｒ₈、Ａｒ₉は同一又は異なるアリレン基、ｐは１〜５の整数を表わす。Ｘ、ｋ、ｊおよびｎは、化３に示す場合と同じである。

In the formula, R ₁₁ and R ₁₂ are substituted or unsubstituted aryl groups, Ar ₇ , Ar ₈ and Ar ₉ are the same or different arylene groups, and p represents an integer of 1 to 5. X, k, j, and n are the same as shown in Chemical Formula 3.

式中、Ｒ₁₃、Ｒ₁₄は置換もしくは無置換のアリール基、Ａｒ₁₀、Ａｒ₁₁、Ａｒ₁₂は同一又は異なるアリレン基、Ｘ₁、Ｘ₂は置換もしくは無置換のエチレン基、又は置換もしくは無置換のビニレン基を表わす。Ｘ、ｋ、ｊおよびｎは、化３に示す場合と同じである。

In the formula, R ₁₃ and R ₁₄ are substituted or unsubstituted aryl groups, Ar ₁₀ , Ar ₁₁ and Ar ₁₂ are the same or different arylene groups, X ₁ and X ₂ are substituted or unsubstituted ethylene groups, or substituted or unsubstituted Represents a substituted vinylene group. X, k, j, and n are the same as shown in Chemical Formula 3.

式中、Ｒ₁₅、Ｒ₁₆、Ｒ₁₇、Ｒ₁₈は置換もしくは無置換のアリール基、Ａｒ₁₃、Ａｒ₁₄、Ａｒ₁₅、Ａｒ₁₆は同一又は異なるアリレン基、Ｙ₁、Ｙ₂、Ｙ₃は単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わし同一であっても異なってもよい。Ｘ、ｋ、ｊおよびｎは、化３に示す場合と同じである。

In the formula, R ₁₅ , R ₁₆ , R ₁₇ , R ₁₈ are substituted or unsubstituted aryl groups, Ar ₁₃ , Ar ₁₄ , Ar ₁₅ , Ar ₁₆ are the same or different arylene groups, Y ₁ , Y ₂ , Y ₃ are A single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group may be the same or different. X, k, j, and n are the same as shown in Chemical Formula 3.

式中、Ｒ₁₉、Ｒ₂₀は水素原子、置換もしくは無置換のアリール基を表わし、Ｒ₁₉とＲ₂₀は環を形成していてもよい。Ａｒ₁₇、Ａｒ₁₈、Ａｒ₁₉は同一又は異なるアリレン基を表わす。Ｘ、ｋ、ｊおよびｎは、化３に示す場合と同じである。

In the formula, R ₁₉ and R _{20 each} represent a hydrogen atom or a substituted or unsubstituted aryl group, and R ₁₉ and R ₂₀ may form a ring. Ar ₁₇ , Ar ₁₈ , Ar ₁₉ represent the same or different arylene groups. X, k, j, and n are the same as shown in Chemical Formula 3.

式中、Ｒ₂₁は置換もしくは無置換のアリール基、Ａｒ₂₀、Ａｒ₂₁、Ａｒ₂₂、Ａｒ₂₃は同一又は異なるアリレン基を表わす。Ｘ、ｋ、ｊおよびｎは、化３に示す場合と同じである。

In the formula, R ₂₁ represents a substituted or unsubstituted aryl group, and Ar ₂₀ , Ar ₂₁ , Ar ₂₂ , and Ar ₂₃ represent the same or different arylene groups. X, k, j, and n are the same as shown in Chemical Formula 3.

式中、Ｒ₂₂、Ｒ₂₃、Ｒ₂₄、Ｒ₂₅は置換もしくは無置換のアリール基、Ａｒ₂₄、Ａｒ₂₅、Ａｒ₂₆、Ａｒ₂₇、Ａｒ₂₈は同一又は異なるアリレン基を表わす。Ｘ、ｋ、ｊおよびｎは、化３に示す場合と同じである。

In the formula, R ₂₂ , R ₂₃ , R ₂₄ and R ₂₅ represent a substituted or unsubstituted aryl group, and Ar ₂₄ , Ar ₂₅ , Ar ₂₆ , Ar ₂₇ and Ar ₂₈ represent the same or different arylene groups. X, k, j, and n are the same as shown in Chemical Formula 3.

式中、Ｒ₂₆、Ｒ₂₇は置換もしくは無置換のアリール基、Ａｒ₂₉、Ａｒ₃₀、Ａｒ₃₁は同一又は異なるアリレン基を表わす。Ｘ、ｋ、ｊおよびｎは、化３に示す場合と同じである。

In the formula, R ₂₆ and R ₂₇ represent a substituted or unsubstituted aryl group, and Ar ₂₉ , Ar ₃₀ and Ar ₃₁ represent the same or different arylene groups. X, k, j, and n are the same as shown in Chemical Formula 3.

Further, as the polymer charge transport material used in the charge transport layer, in addition to the polymer charge transport material described above, in the state of the monomer or oligomer having an electron donating group at the time of film formation of the charge transport layer, A polymer having a two-dimensional or three-dimensional crosslinked structure is finally included by carrying out a curing reaction or a crosslinking reaction.
Examples of other polymers having an electron donating group include copolymers of known monomers, block polymers, graft polymers, star polymers, and, for example, JP-A-3-109406, JP-A-2000- It is also possible to use a crosslinked polymer having an electron donating group as described in JP-A-206723, JP-A No. 2001-34001, and the like.

  In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer (37). As the plasticizer, those used as general plasticizers such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is suitably about 0 to 30% by weight based on the binder resin. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain are used, and the amount used is 0 to 0 with respect to the binder resin. 1% by weight is suitable.

  In the present invention, it is also effective to provide a protective layer (39) on the photosensitive layer in order to prevent abnormal images such as black spots and fog. Materials used for the protective layer (39) include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone. , Polybutylene, polybutylene terephthalate, polycarbonate, polyarylate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane Resin such as polyvinyl chloride, polyvinylidene chloride, and epoxy resin, fluorine resin such as polytetrafluoroethylene, and silicone resin. That. Also, those obtained by dispersing inorganic materials such as titanium oxide, aluminum oxide, tin oxide, zinc oxide, zirconium oxide, magnesium oxide, potassium titanate, silica, and surface-treated products thereof in these resins can be used.

Among the filler materials used for the protective layer of the photoreceptor, examples of the organic filler material include fluorine resin powder such as polytetrafluoroethylene, silicone resin powder, a-carbon powder, and the like. Metals such as copper, tin, aluminum and indium, silica, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, tin oxide doped with antimony, tin doped indium oxide and other metals Examples thereof include inorganic materials such as oxides and potassium titanate. In particular, it is advantageous to use an inorganic material among them from the viewpoint of the hardness of the filler. In particular, silica, titanium oxide, and alumina can be used particularly effectively, and can be used effectively as a filler that has high electrical insulation (specific resistance is 10 ¹⁰ Ω · cm or more) and is less likely to cause image blur. Further, among these, α-alumina having a hexagonal close-packed structure can be most effectively used from the viewpoint of suppressing image blur and improving wear resistance.

The filler concentration in the protective layer varies depending on the type of filler used and also on the electrophotographic process conditions using the photoconductor, but the ratio of filler to the total solid content on the outermost layer side of the protective layer is preferably 5% by weight or more, preferably It is 10% by weight or more and 50% by weight or less, preferably about 30% by weight or less.
Further, the volume average particle size of the filler used is preferably in the range of 0.1 μm to 2 μm, and preferably in the range of 0.3 μm to 1 μm. In this case, if the average particle size is too small, the wear resistance is not sufficiently exhibited, and if it is too large, the surface property of the coating film is deteriorated or the coating film itself cannot be formed.

The specific resistance of the filler used in the present invention is defined as follows. Since the specific resistance value of a powder such as a filler varies depending on the filling rate, it is necessary to measure under certain conditions. In the present invention, the specific resistance value of the filler using the apparatus shown in FIG. 1 of JP-A-5-94049 and the apparatus having the same configuration as the measuring apparatus shown in FIG. 1 of JP-A-5-113688. Was measured and this value was used. In the measuring device, the electrode area is 4.0 cm ² . Prior to measurement, a load of 4 kg is applied to one electrode for 1 minute, and the sample amount is adjusted so that the distance between the electrodes is 4 mm.

At the time of measurement, the measurement is performed with the upper electrode weight (1 kg) loaded, and the applied voltage is measured at 100V. The area of 10 ⁶ Ω · cm or higher was measured with a HIGH RESISTANCE METER (manufactured by Yokogawa Hewlett Packard), and the area below it was measured with a digital multimeter (manufactured by Fluke). The specific resistance value thus obtained is defined as the specific resistance value of the present invention.
Further, these fillers can be surface-treated with at least one kind of surface treatment agent, and it is preferable from the viewpoint of filler dispersibility. Lowering the dispersibility of the filler not only increases the residual potential, but also lowers the transparency of the coating, causes defects in the coating, and lowers the wear resistance. It can develop into a big problem. As the surface treatment agent, a conventionally used surface treatment agent can be used, but a surface treatment agent capable of maintaining the insulating properties of the filler is preferable.

For example, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, etc., or a mixed 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 filler dispersibility 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 filler used, but is preferably 3 to 30 wt%, more preferably 5 to 20 wt%. If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if it is too much, the residual potential is significantly increased. These filler materials may be used alone or in combination of two or more. The surface treatment amount of the filler is defined by the weight ratio of the surface treatment agent used with respect to the filler amount as described above.
These filler materials can be dispersed by using an appropriate disperser. Further, from the viewpoint of the transmittance of the protective layer, it is preferable that the filler used is dispersed to the primary particle level and has less aggregates.

In addition, a charge transport material can be added to the protective layer for high-speed response and residual potential reduction, which is an effective means. As the charge transport material that can be used for the protective layer, the charge transport materials described in the description of the charge transport layer are used.
The use of a polymer charge transport material is very advantageous in terms of enhancing the durability of the photoreceptor. By constituting the components other than the filler of the protective layer only with the polymer, not only the mechanical wear resistance can be improved, but also the chemical stability can be enhanced. A polymer has poor chemical reactivity compared to a low molecule, and has a high resistance to an oxidizing gas generated from a charging member, or a high resistance to a sputtering effect caused by a discharge. When the surface has a highly wear-resistant film such as a protective layer, the problem of image blur due to repeated use becomes very significant. This is thought to be due to adsorption of oxidizing gas and adhesion (adsorption) of low-resistance substances on the surface of the photoconductor. However, as described above, a protective layer consisting only of filler and polymer components is used. In this case, the number of adsorption sites is reduced, which shows a high effect on image blur.
As a method for forming the protective layer, a normal coating method is employed. In addition, about 0.1-10 micrometers is suitable for the thickness of a protective layer.

In the present invention, in order to improve the reduction in surface energy of the protective layer, a method using a resin obtained by crosslinking reaction of a fluorosurfactant having a reactive hydroxyl group with the crosslinked resin is an effective means.
Examples of the crosslinked resin that can be used in the present invention include acrylic resins, urethane resins, melamine resins, alkyd resins, and the like, and melamine resins are particularly preferably used.
Moreover, a well-known material can be used for the fluorine-type surfactant in this invention. For example, as a copolymer containing (1) a (meth) acrylate having a fluoroalkyl group described in paragraph No. [0017] of JP-A-07-068398, for example, JP-A-60-212410 and JP-A No. A block copolymer comprising a fluorine-free vinyl monomer and a fluorine-containing vinyl monomer described in JP-A-60-228588, and (2) a fluorine-based graft polymer, for example, described in JP-A-60-187721 Examples thereof include a comb-type graft polymer obtained by copolymerizing a methacrylate macromonomer having polymethyl methacrylate in the side chain and a (meth) acrylate having a fluoroalkyl group. These fluororesins are commercially available as paint additives. For example, fluorine-containing random copolymers are commercially available from Asahi Glass Co., Ltd. as resin surface modifiers SC-101 and SC-105. As the fluorine-containing block copolymer, Modiper F series (for example, F100, F110, F200, commercially available from Nippon Oil & Fats Co., Ltd.) as a block copolymer comprising a fluoroalkyl group-containing polymer segment and an acrylic polymer segment. F210, F2020). Fluorine-based graft polymers are commercially available from Toa Gosei Co., Ltd. under the names Aron GF-150 and GF-300.

  In addition, when a crosslinkable resin is used, it is desirable to combine a charge transporting functional group in the crosslinkable resin to such an extent that photoinduced charge carriers can move in the protective layer, or to incorporate a polymer charge transport material. . If it is possible to mix the low molecular charge transport material and the cross-linked resin, the low molecular charge transport material may be mixed, but it cannot be fixed in the protective layer, and the low molecular component is on the surface. May precipitate. By using the above-described polymer charge transport material for such a case, precipitation can be prevented and sensitivity characteristics can be improved.

Next, an electrophotographic image forming apparatus equipped with the novel electrophotographic photosensitive member of the present invention will be described in detail.
FIG. 5 is a schematic view for explaining the electrophotographic process and the electrophotographic image forming apparatus of the present invention.
In FIG. 5, the photoreceptor (10) is formed by providing a photosensitive layer including at least a charge generation layer and a charge transport layer on a conductive support. The photoconductor (10) has a drum shape, but may be a sheet or endless belt. A charging roller (12), a pre-transfer charger (15), a transfer charger (18), a separation charger (19), and a pre-cleaning charger (23) include a corotron, a scorotron, a solid state charger, and charging. Known means such as a roller and a transfer roller are used.

Among these charging methods, the contact charging method or the non-contact proximity arrangement method is more desirable, and has advantages such as high charging efficiency, a small amount of ozone generation, and miniaturization of the apparatus.
Further, light sources such as an image exposure unit (13) and a charge removal lamp (11) include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LD), electroluminescence (EL). ) And other luminescent materials can be used.
In addition, various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

Among these light sources, light emitting diodes and semiconductor lasers have high irradiation energy and long wavelength light of 600 to 800 nm, so that the above-mentioned phthalocyanine pigment, which is a charge generation material, exhibits high sensitivity and is used well. The
Such a light source or the like irradiates the photosensitive member with light by providing a transfer process, a static elimination process, a cleaning process, or a pre-exposure process using light irradiation in addition to the process shown in FIG.

  The toner developed on the photoconductor (10) by the developing unit (14) is transferred to the transfer paper (17), but not all is transferred and remains on the photoconductor (10). Toner is also produced. Such toner is removed from the photoreceptor by the fur brush (22) and the blade (23). Cleaning may be performed only with a cleaning brush, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush.

When the electrophotographic photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with toner of negative (positive) polarity (electrodetection fine particles), a positive image can be obtained, and if developed with toner of positive (negative) polarity, a negative image can be obtained.
A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.

Next, an image forming element on which the novel electrophotographic photosensitive member of the present invention is mounted will be described.
In the case of a color electrophotographic image forming apparatus in which an image forming element is configured as a unit in which an electrophotographic photosensitive member and at least a charging member, a developing member, and a cleaning member are disposed around the electrophotographic photosensitive member, The number of image forming elements corresponding to the number of colors is mounted, and each image forming element can be fixed to the image forming apparatus or can be individually replaced.

FIG. 6 is a schematic diagram for explaining an electrophotographic image forming apparatus (generally called a tandem type full-color electrophotographic image forming apparatus) having a plurality of image forming elements. Modifications also belong to the category of the present invention.
In FIG. 6, reference numeral (1C, 1M, 1Y, 1K) denotes a drum-shaped photoconductor, and this photoconductor (1C, 1M, 1Y, 1K) rotates in the direction of the arrow in the figure and rotates at least around it. In order, a charging member (2C, 2M, 2Y, 2K), a developing member (4C, 4M, 4Y, 4K), and a cleaning member (5C, 5M, 5Y, 5K) are arranged. The charging members (2C, 2M, 2Y, 2K) are charging members that constitute a charging device for uniformly charging the surface of the photoreceptor.

  Laser light (3C, 3M, 3Y, 3K) from an exposure member (not shown) from the back side of the photoreceptor between the charging member (2C, 2M, 2Y, 2K) and the developing member (4C, 4M, 4Y, 4K) , And an electrostatic latent image is formed on the photoconductor (1C, 1M, 1Y, 1K). Then, four image forming elements (6C, 6M, 6Y, 6K) centering on such a photoreceptor (1C, 1M, 1Y, 1K) are along a transfer conveyance belt (10) which is a transfer material conveyance means. Are juxtaposed. The transfer / conveying belt (24) is provided between the developing member (4C, 4M, 4Y, 4K) and the cleaning member (5C, 5M, 5Y, 5K) of each image forming unit (6C, 6M, 6Y, 6K). 1C, 1M, 1Y, and 1K), and a transfer brush (11C, 11M, 11Y, and 11K) for applying a transfer bias to the back surface (back surface) of the transfer conveyance belt (24) that contacts the back side of the photoconductor. Is arranged. Each image forming element (6C, 6M, 6Y, 6K) is different in the color of the toner inside the developing device, and the others are the same in configuration.

  In the color electrophotographic image forming apparatus having the configuration shown in FIG. 6, the image forming operation is performed as follows. First, in each image forming element (6C, 6M, 6Y, 6K), the charging member (2C, 2M, 2Y) in which the photoconductor (1C, 1M, 1Y, 1K) rotates in the direction of the arrow (the direction along with the photoconductor). 2K), and then an electrostatic latent image corresponding to the image of each color to be created by laser light (3C, 3M, 3Y, 3K) by an exposure unit (not shown) disposed inside the photoconductor. It is formed.

Next, the latent image is developed by a developing member (4C, 4M, 4Y, 4K) to form a toner image. The developing members (4C, 4M, 4Y, 4K) are developing members that perform development with toners of C (cyan), M (magenta), Y (yellow), and K (black), respectively. 1M, 1Y, 1K) toner images of each color are superimposed on the transfer paper.
The transfer paper (25) is fed out of the tray by a paper feed roller (26), temporarily stopped by a pair of registration rollers (27), and transferred to the transfer conveyance belt (24) in synchronism with the image formation on the photosensitive member. Sent. The transfer paper (25) held on the transfer / conveying belt (24) is transported, and each color toner image is transferred at a contact position (transfer portion) with each photoconductor (1C, 1M, 1Y, 1K). It is.

  The toner image on the photosensitive member is transferred onto the transfer paper (by the electric field formed by the potential difference between the transfer bias applied to the transfer brush (11C, 11M, 11Y, 11K) and the photosensitive member (1C, 1M, 1Y, 1K). 25) Transferred onto. Then, the recording paper (25) on which the toner images of four colors are superimposed through the four transfer portions is conveyed to the fixing device (28), where the toner is fixed, and is discharged to a paper discharge portion (not shown). Further, residual toner that is not transferred by the transfer unit and remains on the photosensitive members (1C, 1M, 1Y, 1K) is collected by a cleaning device (5C, 5M, 5Y, 5K).

In the example of FIG. 6, the image forming elements are arranged in the order of C (cyan), M (magenta), Y (yellow), and K (black) from the upstream side to the downstream side in the transfer paper conveyance direction. However, it is not limited to this order, and the color order is arbitrarily set.
Further, when a black-only document is created, it is particularly effective to use the present invention to provide a mechanism that stops the image forming elements (6C, 6M, 6Y) other than black. Further, in FIG. 6, the charging member is in contact with the photoreceptor, but by providing an appropriate gap (about 10 to 200 μm) between them, the wear amount of both can be reduced and the toner film on the charging member can be reduced. It can be used satisfactorily with less ming.

The image forming element described above may be fixedly incorporated in an electrophotographic image forming apparatus such as a copying machine, a facsimile machine, or a printer. However, the image forming element is incorporated into the apparatus in the form of a process cartridge. May be.
In addition, the process cartridge does not mean the image forming element used in a full-color electrophotographic image forming apparatus, but is configured to be detachable from a monocolor image forming apparatus for image formation of only one color, A device incorporating the electrophotographic photosensitive member of the present invention and further comprising at least a charging means and a developing means will be described. There are many shapes and the like of the process cartridge, but a general example is shown in FIG. In FIG. 7, the same parts as those in FIG. 5 represent the same name portions.

Hereinafter, although an example is given and the present invention is explained, the present invention is not restricted by an example. All parts are parts by weight.
Example 1
First, the following intermediate layer coating solution prepared by ball mill dispersion for 72 hours was applied to an aluminum drum having a diameter of 30 mm and a length of 340 mm, and dried at 125 ° C. for 20 minutes to form an intermediate layer having a thickness of 3 μm.
[Coating liquid for intermediate layer]
Titanium oxide (CR-EL: manufactured by Ishihara Sangyo Co., Ltd.) 70 parts Alkyd resin 15 parts {Beckolite M6401-50-S (solid content 50%)
: Dainippon Ink and Chemicals}
Melamine resin 10 parts {Super Becamine L-121-60 (solid content 60%)
: Dainippon Ink and Chemicals}
100 parts of methyl ethyl ketone

Next, titanyl phthalocyanine was synthesized by the following procedure.
<Synthesis example>
29.2 g of 1,3-diiminoisoindoline and 200 ml of sulfolane are mixed, and 20.4 g of titanium tetrabutoxide is added dropwise under a nitrogen stream. After completion of the dropwise addition, the temperature was gradually raised to 180 ° C., and the reaction was carried out by stirring for 5 hours while maintaining the reaction temperature between 170 ° C. and 180 ° C. After completion of the reaction, the mixture was allowed to cool, and then the precipitate was filtered, washed with chloroform until the powder turned blue, then washed several times with methanol, further washed several times with hot water at 80 ° C., and dried. Crude titanyl phthalocyanine was obtained. Dissolve the crude titanyl phthalocyanine in 20 times the amount of concentrated sulfuric acid, add dropwise to 100 times the amount of ice water with stirring, filter the precipitated crystals, and then repeat washing with water until the washing solution becomes neutral. Got. 2 g of the obtained wet cake was put into 20 g of tetrahydrofuran and stirred for 4 hours.
100 g of methanol was added to this and stirred for 1 hour, followed by filtration and drying to obtain a titanyl phthalocyanine powder of the present invention. The obtained titanyl phthalocyanine powder was subjected to X-ray diffraction spectrum measurement under the following conditions. As a result, the Bragg angle 2θ with respect to Cu-Kα ray (wavelength 1.542Å) was 27.2 ± 0.2 °, and the maximum peak and minimum angle 7 A titanyl phthalocyanine powder having a peak at .3 ± 0.2 °, no peak in the range of 7.4 to 9.4 °, and no peak at 26.3 ° was obtained. The result is shown in FIG.

(X-ray diffraction spectrum measurement conditions)
X-ray tube: Cu
Voltage: 50kV
Current: 30mA
Scanning speed: 2 ° / min Scanning range: 3 ° -40 °
Time constant: 2 seconds Next, the obtained titanyl phthalocyanine powder and the following materials were dispersed using the bead mill dispersing device described above. As a dispersion condition, the dispersion temperature was set to 8 ° C., and 60 parts of molecular sieve 4A (manufactured by Kishida Chemical Co., Ltd.), which is a synthetic zeolite having a pore size of 0.4 nm, was put in a circulation tank and dispersed for 5 hours. . Subsequently, filtration was performed using a micro-wind type II (manufactured by Cuno Co., Ltd.), which is a cotton filter having a filtration accuracy of 3 μm, to prepare a charge generation layer coating solution.

[Coating liquid for charge generation layer]
Titanyl phthalocyanine pigment of Synthesis Example 1 15 parts Polyvinyl acetal resin (hydroxyl group 35 mol%) 10 parts Methyl ethyl ketone 600 parts The resulting coating liquid for charge generation layer has an average particle diameter of 0.2 μm, and the water content in the coating liquid Was 0.3%, and this was applied by dip coating on the intermediate layer. Then, it dried at 80 degreeC for 20 minute (s), and formed the charge generation layer with a film thickness of 0.2 micrometer.
Subsequently, a charge transport layer coating solution having the following composition was applied onto the charge generation layer and dried at 125 ° C. for 20 minutes to form a charge transport layer having a thickness of 25 μm, thereby preparing an electrophotographic photosensitive member.

[Charge transport layer coating solution]
Polycarbonate (Iupilon Z200: Mitsubishi Gas Chemical Co., Ltd. 10 parts Charge transport material of the following structural formula (1) 8 parts Tetrahydrofuran 80 parts

(Example 2)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the amount of the molecular sieve 4A charged into the circulation tank was changed to 15 parts. The charge generation layer coating solution obtained at this time had an average pigment particle size of 0.2 μm and a water content of 0.8% in the coating solution.

(Example 3)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the amount of the molecular sieve 4A charged into the circulation tank was changed to 120 parts. The charge generation layer coating solution obtained at this time had an average pigment particle size of 0.2 μm and a moisture content of 0.05% in the coating solution.

(Comparative Example 1)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the amount of the molecular sieve 4A charged into the circulation tank was changed to 5 parts. The charge generation layer coating solution obtained at this time had an average pigment particle size of 0.2 μm and a water content of 1.4% in the coating solution.

(Comparative Example 2)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the dispersion treatment was performed without introducing the molecular sieve into the circulation tank. The charge generation layer coating liquid obtained at this time had an average pigment particle size of 0.2 μm and a water content of 3.9% in the coating liquid.

(Comparative Example 3)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the amount of the molecular sieve 4A charged into the circulation tank was changed to 200 parts. The charge generation layer coating solution obtained at this time had an average pigment particle size of 0.2 μm and a water content of 0.007% in the coating solution.

(Example 4)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the polyvinyl acetal resin contained in the charge generation layer coating solution was changed to one having a hydroxyl group of 33 mol%.

(Example 5)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the polyvinyl acetal resin contained in the charge generation layer coating solution was changed to one having a hydroxyl group of 30 mol%.

(Comparative Example 4)
An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the polyvinyl acetal resin contained in the charge generation layer coating solution was changed to one having a hydroxyl group of 25 mol%.

(Comparative Example 5)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the polyvinyl acetal resin contained in the charge generation layer coating solution was changed to one having a hydroxyl group of 22 mol%.

The obtained electrophotographic photosensitive member was mounted on a process cartridge for an image forming apparatus as shown in FIG. The image was evaluated by mounting it on an electrophotographic image forming apparatus (image Rio MF-2200 manufactured by Ricoh Co., Ltd.) having a 780 nm semiconductor laser as the image exposure means and having a contact roller charger as the charging means. The results are shown in Table 1.

(Example 6)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that molecular sieve 5A (manufactured by Kishida Chemical Co.), which is a synthetic zeolite having a pore size of 0.5 nm, was used in the circulation tank. The charge generation layer coating solution obtained at this time had an average pigment particle size of 0.2 μm and a water content of 0.15% in the coating solution.

(Example 7)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that molecular sieve 13X (manufactured by Kishida Chemical Co.), which is a synthetic zeolite having a pore size of 1.0 nm, was used in the circulation tank. The charge generation layer coating solution obtained at this time had an average pigment particle size of 0.2 μm and a water content of 0.06% in the coating solution.

(Comparative Example 6)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that molecular sieve 3A (manufactured by Kishida Chemical Co.), which is a synthetic zeolite having a pore size of 0.3 nm, was used in the circulation tank. The charge generation layer coating solution obtained at this time had an average pigment particle size of 0.2 μm and a moisture content of 2.1% in the coating solution.

(Example 8)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that filtration was performed using a micro-wind type II (manufactured by Cuno), which is a cotton filter having a filtration accuracy of 1 μm. The charge generation layer coating solution obtained at this time had an average pigment particle size of 0.14 μm and a water content of 0.3% in the coating solution.

(Comparative Example 7)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that filtration was performed using a micro-wind type II (manufactured by Cuno), which is a cotton filter having a filtration accuracy of 5 μm. The charge generation layer coating solution obtained at this time had an average pigment particle size of 0.31 μm and a water content of 0.3% in the coating solution.

(Comparative Example 8)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that filtration was performed using a micro-wind type II (manufactured by Cuno), which is a cotton filter having a filtration accuracy of 10 μm. The charge generation layer coating solution obtained at this time had an average pigment particle size of 0.43 μm and a water content of 0.3% in the coating solution.

  The obtained electrophotographic photosensitive member was mounted on a process cartridge for an image forming apparatus as shown in FIG. Mounted in an electrophotographic image forming apparatus (Imagio MF-2200, manufactured by Ricoh Co., Ltd.) using a 780 nm semiconductor laser as the image exposure means and a contact roller charger as the charging means, the initial image and A4 size PPC paper are Image evaluation after passing 300,000 sheets by direction feeding was performed. The results are shown in Table 2.

It is the schematic of the bead mill dispersion | distribution apparatus used for this invention. It is sectional drawing which shows the structural example of the electrophotographic photoreceptor used for this invention. It is sectional drawing which shows another structural example of the electrophotographic photoreceptor used for this invention. It is sectional drawing which shows another structural example of the electrophotographic photoreceptor used for this invention. 1 is a schematic diagram for explaining an electrophotographic process and an electrophotographic image forming apparatus of the present invention. 1 is a schematic view of an electrophotographic image forming apparatus including a plurality of image forming elements of the present invention. It is a figure which shows the general example of the shape of a process cartridge. It is a figure which shows the result at the time of measuring an X-ray-diffraction spectrum about the titanyl phthalocyanine powder produced by the synthesis example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Dispersion chamber 3 Piping 4 Circulating tank 5 Circulating pump 6 Valve 7 Piping 8 Piping 9 Stand 31 Conductive support 33 Intermediate layer 35 Charge generation layer 37 Charge transport layer 39 Protective layer 10 Photoconductor 11 Static elimination lamp 12 Charging roller 13 Image exposure unit 14 Development unit 15 Pre-transfer charger 16 Registration roller 17 Transfer paper 18 Transfer charger and transfer roller 19 Separation charger 20 Separation claw 21 Pre-cleaning charger 22 Fur brush 23 Cleaning brush and cleaning blades 1C, 1M, 1Y, 1K Photoconductor 2C, 2M, 2Y, 2K Charging member 3C, 3M, 3Y, 3K Laser light 4C, 4M, 4Y, 4K Developing member 5C, 5M, 5Y, 5K Cleaning member 6C, 6M, 6Y, 6K Image forming elements 11C, 11M, 11Y, 11K transfer brush 24 roll Conveyor belt 25 transfer paper 26 paper feed roller 27 registration rollers 28 fixing device

Claims (3)

  In the method for producing an electrophotographic photosensitive member in which at least a charge generation layer and a charge transport layer are provided in this order on a conductive support, the charge generation layer comprises at least a phthalocyanine pigment having an average particle size of 0.3 μm or less, and a hydroxyl group of 30 to 40 mol%. A synthetic zeolite adsorbent containing at least a dispersion chamber and a pore diameter of 0.4 nm or more at a liquid temperature of 10 ° C. or less, containing a polyvinyl acetal resin having an organic solvent, an organic solvent, and moisture of 0.01 to 0.99 wt% An electrophotographic photosensitive film characterized in that it is formed from a coating solution for a charge generation layer that is subjected to dispersion treatment by circulating the dispersion liquid a plurality of times between circulation tanks immersed in the dispersion liquid in an amount of 1 to 20% by weight. Body manufacturing method.   2. The electrophotography according to claim 1, wherein the phthalocyanine pigment is a titanyl phthalocyanine pigment having a maximum peak at 27.2 ± 0.2 ° of a Bragg angle 2θ with respect to a Cu—Kα ray (wavelength 1.542 mm). A method for producing a photoreceptor.   The titanyl phthalocyanine has a maximum peak at a Bragg angle 2θ of 27.2 ± 0.2 ° and a peak at a minimum angle of 7.3 ± 0.2 ° with respect to a Cu—Kα ray (wavelength 1.542Å), 7.4 The method for producing an electrophotographic photosensitive member according to claim 2, wherein the method does not have a peak in the range of ˜9.4 °.

Images