JP2010032715A - Method for producing application liquid for electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an application liquid having excellent dispersion stability and coating properties for organic pigment. <P>SOLUTION: The method for producing an application liquid for electrophotographic photoreceptor which is obtained by dispersing N-alkoxy alkylated nylon and an organic pigment to a solvent includes steps of: preparing an N-alkoxy alkylated nylon solution by dissolving the N-alkoxy alkylated nylon to an alcohol; gelling the N-alkoxy alkylated nylon solution while setting its liquid temperature to -80°C or higher and 15°C or lower and the storage time to at least 1 hour; dispersing the gelled N-alkoxy alkylated nylon and the organic pigment, or dispersing the gelled N-alkoxy alkylated nylon and the organic pigment to a diluting solvent. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a coating solution for an electrophotographic photoreceptor obtained by dispersing an N-alkoxyalkylated nylon gelled by containing an alcohol and an organic pigment.

  Organic pigments such as azo pigments represented by monoazo pigments and disazo pigments, and polycyclic pigments represented by phthalocyanine pigments generally have a lower specific gravity compared to inorganic pigments such as titanium oxide, so in the liquid. It is difficult to settle and high liquid stability can be maintained. In addition, it has various advantages such as various absorption wavelengths by modifying to a specific molecular structure and maintaining high quality with high purity because it can be synthesized by chemical reaction industrially. Therefore, various printing inks and photosensitive characteristics are applied as pigments and used in optical disks, solar cells, electrophotographic materials and the like.

  Polyamide resins have good mechanical properties and chemical resistance, and are used in a wide range of fields as electronic parts, automobile parts, fibers, and films as engineering plastics. Among them, there are alcohol-soluble polyamide resins such as N-alkoxyalkylated nylon and copolymer nylon, which are polyamide resins modified so as to increase solubility in alcohol. Alcohol-soluble polyamide resins have characteristics such as transparency, flexibility, and adhesiveness, and are used for surface treatment of clothing, adhesives for electronic materials, water-based inks, electrophotographic materials, and the like.

  The coating surface of the dispersion liquid in which the organic pigments such as azo pigments and polycyclic pigments described above are dispersed in a small particle size in the alcohol-based liquid of the alcohol-soluble polyamide resin has no unevenness of application and gives a glossy feeling. It is done. However, it is possible to obtain organic pigments such as azo pigments and polycyclic pigments as described above as a stable dispersion with a small particle size for a long time in the alcohol-based liquid of alcohol-soluble polyamide resin. May occur and is very difficult.

  In addition, the electrophotographic photosensitive member using the organic electrophotographic material as described herein is pollution-free and easy to manufacture as compared with conventional electrophotographic photosensitive members using inorganic electrophotographic materials such as Se and CdS. There is an advantage that the degree of freedom in functional design is high due to the variety of selection of materials. An electrophotographic photosensitive member using such an organic electrophotographic material has been widely used in the market due to the rapid spread of laser beam printers and copying machines in recent years. In recent years, as the image quality and color of printers and copiers have been improved, the requirements for the quality of electrophotographic photoreceptors have increased, and electrophotographic photoreceptors free from image defects are desired.

  An electrophotographic photoreceptor basically comprises a photosensitive layer that forms a latent image by exposure using charging and light, and a support as a support member for providing the photosensitive layer. To date, an undercoat layer has been provided between the support and the photosensitive layer in order to ensure adhesion to the support, protect the photosensitive layer from electrical breakdown, improve the carrier injection property of the photosensitive layer, and the like. I came. In order to further improve the properties of the undercoat layer, various methods for dispersing the organic pigment in the undercoat layer have been proposed.

  For example, Patent Document 1 discloses a technique for reducing the residual potential of the photoreceptor by using an undercoat layer.

  Patent Document 2 suppresses the increase in residual potential during repeated use, Patent Document 3 suppresses charging stability from the first print rotation process, and Patent Documents 4 to 6 suppress potential fluctuations and ghosts during continuous printing. Technology to do is presented.

Patent Document 7 describes an oxytitanium phthalocyanine pigment as an example of a phthalocyanine pigment.
Japanese Patent No. 3384231 Japanese Patent Publication No.7-111586 Japanese Patent No. 3417145 Japanese Patent No. 3774673 JP 2003-316049 A International Publication No. 2005/116777 Pamphlet Japanese Patent No. 2502404

  However, these proposals use a pigment dispersion as a coating solution for an electrophotographic photoreceptor. For this reason, the film thickness of the electrophotographic photosensitive member becomes non-uniform due to local solid content fluctuation of the dispersion due to sedimentation of the dispersed pigment particles and increase in particle size due to aggregation of the dispersed pigment particles. There is a potential problem that density unevenness and defects (pots) due to foreign matter increase on the coated surface. Such density unevenness and defects (pots) due to foreign matters can be fatal defects of the electrophotographic photosensitive member in the above-described improvement in image quality of the printer and the copying machine.

  In addition, in the electrophotographic photosensitive member production, the conductive support in a state heated by the heat drying step in the previous step is in direct contact with the coating solution for the electrophotographic photosensitive member, thereby causing aggregation and sedimentation of the dispersed pigment particles. There is also a problem that the coating life of the coating solution for an electrophotographic photosensitive member is shortened. In order to solve these problems, further improvement in the stability of the pigment particles contained in the coating solution for electrophotographic photoreceptors is required.

  The present invention has been made in view of the problems of the background art described above, has few defects in the coating film using the electrophotographic photosensitive member coating solution, has a long coating life of the coating solution for the electrophotographic photosensitive member, and has high stability. It is an object of the present invention to provide a method for producing a coating solution for a photographic photoreceptor.

  As a result of intensive studies to solve the above problems, the present inventors have developed an N-alkoxyalkylated nylon for use in the production of a coating solution for an electrophotographic photoreceptor obtained by dispersing an organic pigment and N-alkoxyalkylated nylon. Pay attention.

In the production of the electrophotographic photoreceptor coating solution, an N-alkoxyalkylated nylon solution obtained by dissolving N-alkoxyalkylated nylon in alcohol was obtained, and the N-alkoxyalkylated nylon solution was stored at a constant storage temperature and storage. The gelled N-alkoxyalkylated nylon is obtained by storing with time. Next, the gelled N-alkoxyalkylated nylon and the organic pigment are dispersed in a solvent to prepare an electrophotographic photoreceptor coating solution. As a result, a highly stable electron in which the volume average particle diameter (D ₅₀ ) of the organic pigment contained in the coating solution for an electrophotographic photoreceptor is small as measured by the dynamic light scattering method and the stability in heating is improved. The inventors have found that a coating solution for a photographic photoreceptor can be produced, and completed the present invention.

  That is, the present invention is as follows.

  In a method for producing a coating solution for an electrophotographic photoreceptor obtained by dispersing N-alkoxyalkylated nylon and an organic pigment in a solvent, the N-alkoxyalkylated nylon solution is obtained by dissolving the N-alkoxyalkylated nylon in alcohol. A step of obtaining a gelled N-alkoxyalkylated nylon having a liquid temperature of the N-alkoxyalkylated nylon solution of −80 ° C. to 15 ° C. and a storage time of at least 1 hour, and the gelation A step of dispersing the N-alkoxyalkylated nylon and the organic pigment, or a step of dispersing the gelled N-alkoxyalkylated nylon and the organic pigment in a diluting solvent. A method for producing a coating solution for an electrophotographic photoreceptor.

  According to the method for producing a coating solution for an electrophotographic photosensitive member of the present invention, there is a remarkable effect that a coating solution for an electrophotographic photosensitive member having few coating film defects, a long paint life, and high stability can be obtained. .

  Hereinafter, embodiments of the present invention will be described in detail.

  The method for producing a coating solution for an electrophotographic photoreceptor of the present invention is characterized by the following points. First, N-alkoxyalkylated nylon is dissolved in alcohol to obtain an N-alkoxyalkylated nylon liquid. Next, this N-alkoxyalkylated nylon solution is gelated by storing at a constant storage temperature and storage time. Further, an organic pigment is dispersed in gelled N-alkoxyalkylated nylon, or an N-alkoxyalkylated nylon gelled in a solvent and an organic pigment are dispersed to prepare a coating solution for an electrophotographic photoreceptor. It is characterized by preparing.

  The method for producing a coating solution for an electrophotographic photosensitive member of the present invention includes the following steps.

  First, a step of obtaining N-alkoxyalkylated nylon solution by dissolving N-alkoxyalkylated nylon in alcohol is included. Next, a step of obtaining a gelled N-alkoxyalkylated nylon by setting the liquid temperature of the N-alkoxyalkylated nylon solution to −80 ° C. to 15 ° C. and a storage time of at least 1 hour is included. Further, the third step includes a step of dispersing the gelled N-alkoxyalkylated nylon and the organic pigment in a solvent.

  The gelled N-alkoxyalkylated nylon can be prepared by combining the following conditions after dissolving N-alkoxyalkylated nylon in alcohol with heating.

  Here, the type of N-alkoxyalkylated nylon is not particularly limited as long as a desired gelled N-alkoxyalkylated nylon can be prepared. For example, as the type of alkoxyalkyl of N-alkoxyalkylated nylon, conventionally known ones such as methoxymethyl, ethoxymethyl, ethoxyethyl and butoxymethyl can be used. In addition, as a kind of N-alkoxyalkylated nylon, conventionally known ones such as nylon 6, nylon 11, nylon 12, nylon 66, nylon 610 and the like can be used in combination.

  The type of N-alkoxyalkylated nylon is determined in consideration of the solubility in the alcohol that gels the polyamide resin and the ease of gelation of the N-alkoxyalkylated nylon. One type or two or more types of N-alkoxyalkylated nylons may be used in combination.

  The polyamide resin to be used preferably contains at least N-alkoxyalkylated nylon having an N-alkoxyalkylation rate of 20% to 45%. Alternatively, it is more preferable that N-methoxymethylated 6 nylon having an N-alkoxyalkylation rate of 20% or more and 45% or less is included. In addition, N-alkoxyalkylation rate was measured by the method shown below by NMR.

  N-alkoxyalkylated nylon is superior in crystallinity because the repeating unit of the nylon main chain is constant, compared to copolymer nylon in which a plurality of types of nylon are chemically bonded to the main chain. Gelled N-alkoxyalkylated nylon is easy to prepare. Further, when the N-alkoxyalkylated nylon has an N-alkoxyalkylation rate lower than 20%, the solubility in a solvent is lowered, and it may be difficult to prepare a gelled polyamide resin. If the N-alkoxyalkylation rate is higher than 45%, the solubility in alcohol increases, and the stability of the electrophotographic photosensitive member coating solution may deteriorate.

  The method for measuring the N-methoxymethylation rate is described below.

<Measurement method of N-alkoxyalkylation rate>
apparatus:
Measuring apparatus: FT NMR apparatus JNM-EX400 (manufactured by JEOL Ltd.)
Measurement frequency: 400MHz
Pulse condition: 5.0 μS
Data points: 32768
Frequency range: 10500Hz
Integration count: 32 times Measurement temperature: 25 ° C
sample:
N-alkoxyalkylated nylon 25mg
Methanol-D4 (99.8 atom% D) 0.75 ml made by Aldrich
Tetramethylsilane (internal standard) 0.05% by weight based on methanol-D4
Method of calculation:
A: Integral value of methylene proton (ca.2.4 ppm) next to the carbonyl moiety of the amide group which is N-alkoxyalkylated B: Methylene proton (ca) next to the carbonyl moiety of the amide group which is not N-alkoxyalkylated 2.2 ppm) N-alkoxyalkylation rate (%) = A / (A + B) × 100

  In order to obtain a desired gelled polyamide resin, the temperature at which the polyamide resin is gelled is such that an N-alkoxyalkylated nylon solution obtained by dissolving N-alkoxyalkylated nylon in alcohol is cooled to -80 ° C or higher and 15 ° C or lower. It is preferable to do. More preferably, it is a case where it cools to -80 degreeC or more and less than 5 degreeC, It is still more preferable to cool to -80 degreeC or more and 0 degrees C or less, It is especially preferable to cool to -80 degreeC or more and -10 degrees C or less.

  In order to obtain a desired gelled polyamide resin, the storage time of the N-alkoxyalkylated nylon solution obtained by dissolving N-alkoxyalkylated nylon in alcohol is preferably at least 1 hour. More preferably, the storage time is at least 6 hours, more preferably at least 24 hours, and particularly preferably at least 72 hours.

  The alcohol for gelling the polyamide resin is not particularly limited as long as the desired gelled N-alkoxyalkylated nylon can be prepared. However, it is preferable to contain at least one of ethanol, isopropanol, n-propanol, and n-butanol, and it is more preferable to contain ethanol. Further, the alcohol may be combined with one or more alcohols in consideration of the solubility of N-alkoxyalkylated nylon and the ease of preparation of gelled N-alkoxyalkylated nylon.

  The N-alkoxyalkylated nylon solid content in the gelled N-alkoxyalkylated nylon is not particularly limited as long as the desired gelled N-alkoxyalkylated nylon can be prepared. Considering the stability of the gelled N-alkoxyalkylated nylon, the solid content of the N-alkoxyalkylated nylon is preferably 2.0% or more by mass%, more preferably 5.0% or more. The most preferable range is 5.0% or more and 30.0% or less. If the solid content of N-alkoxyalkylated nylon is too low, gelled N-alkoxyalkylated nylon may not be prepared.

  The shape of the gelled N-alkoxyalkylated nylon is not particularly limited as long as a desired coating solution for an electrophotographic photoreceptor can be prepared. Considering the workability in the dispersion operation, it is preferable to crush the gelled N-alkoxyalkylated nylon to a size of 0.5 mm to 10 mm before dispersion. If the gelled N-alkoxyalkylated nylon is smaller than 0.5 mm, the crushed gelled N-alkoxyalkylated nylon tends to adhere to each other, and workability may deteriorate. If the gelled N-alkoxyalkylated nylon is larger than 10 mm, an undispersed portion of the gelled N-alkoxyalkylated nylon may remain after the dispersion is completed. Use a paint shaker, ball mill, sand mill, ultrasonic disperser, high-pressure homogenizer, stirrer, mixer, stirrer, roll mill, emulsifying disperser, mesh, sieve or mincer for crushing the gelled N-alkoxyalkylated nylon. .

  When the gelled N-alkoxyalkylated nylon and the organic pigment are dispersed, a diluent solvent may or may not be added. However, considering the dispersibility of the electrophotographic photoreceptor coating liquid, it is preferable to add a diluting solvent to increase the fluidity of the electrophotographic photoreceptor coating liquid during dispersion.

  As a dispersion method, a known method, for example, a method using a dispersion device such as a paint shaker, a ball mill, a sand mill, an ultrasonic disperser, a high-pressure homogenizer, a stirrer, a mixer, a stirrer, a roll mill, or an emulsifying disperser is used. Can do. The above-mentioned solvent for dilution preferably contains at least one of methanol, ethanol, isopropanol, n-propanol, n-butanol, sec-butanol, isobutanol and propylene glycol monomethyl ether.

  The mass ratio of the organic pigment and the N-alkoxyalkylated nylon contained in the coating solution for electrophotographic photoreceptor is the liquid stability of the coating solution for electrophotographic photoreceptor and the electrophotographic photoreceptor using the coating solution for electrophotographic photoreceptor. Is determined in consideration of density unevenness of the output image. Preferably, the mass ratio of the organic pigment and the N-alkoxyalkylated nylon contained in the coating solution for an electrophotographic photoreceptor is 1: 100 or more and 2: 1 or less. When the mass ratio of the organic pigment and N-alkoxyalkylated nylon contained in the coating solution for electrophotographic photoreceptors is higher than 2: 1, the dispersibility of the pigment deteriorates and the liquid stability of the coating solution for electrophotographic photoreceptors May be inferior. In addition, when the mass ratio of the organic pigment and the N-alkoxyalkylated nylon contained in the coating solution for an electrophotographic photoreceptor is lower than 1: 100, the electrophotographic photoreceptor using the coating solution for an electrophotographic photoreceptor during continuous printing. The density unevenness of the output image may be worsened.

  The N-alkoxyalkylated nylon solution and the electrophotographic photoreceptor coating solution are preferably filtered using a filter in order to remove dust and the like that cause coating film defects in the electrophotographic photoreceptor coating solution. This filter has a pore size that does not affect the amount of N-alkoxyalkylated nylon contained in the N-alkoxyalkylated nylon solution and the mass ratio of the organic pigment and N-alkoxyalkylated nylon contained in the coating solution for electrophotographic photoreceptors. It is preferable to have.

  The solid content of the coating solution for an electrophotographic photosensitive member is determined in consideration of the stability and coating properties of the coating solution for an electrophotographic photosensitive member, and is preferably 0.5% or more and 15% or less by mass%, and more preferably. Is 1% or more and 10% or less. If the solid content of the electrophotographic photosensitive member coating liquid is higher than 15%, the fluidity of the electrophotographic photosensitive member coating liquid may be lost, or the dispersibility may deteriorate and the liquid stability of the dispersion liquid may decrease. . Also, if the solid content of the electrophotographic photosensitive member coating solution is lower than 0.5%, image density unevenness and image defects due to coating unevenness, film sag, etc. of the electrophotographic photosensitive member using the electrophotographic photosensitive member coating solution occur. Sometimes.

  Here, the gelled N-alkoxyalkylated nylon is an N-alkoxyalkylated nylon comprising an N-alkoxyalkylated nylon and an alcohol which can be determined as a solid state by performing a solid-liquid determination test according to ASTM D 4359-90. Means sample. Non-gelled N-alkoxyalkylated nylon is an N-alkoxyalkylated nylon comprising an N-alkoxyalkylated nylon and an alcohol which can be determined to be in a liquid state by performing a solid-liquid determination test according to ASTM D 4359-90. Means sample. In addition, whether the stability is high or not is determined by putting the coating solution for an electrophotographic photosensitive member into a closed graduated cylinder (capacity 10 ml) so that the liquid level becomes 50 mm, and the environment at 23 ° C. and the environment at 42 ° C. Each is judged to be left for one month. If there is no separation of the organic pigment in the supernatant of the coating solution for electrophotographic photoreceptors after standing for 1 month, or the separation of the organic pigment is 1 mm or less, the coating solution for electrophotographic photoreceptors has high stability. It can be judged.

  As the organic pigment, conventionally known pigments such as azo pigments such as monoazo, bisazo, trisazo, and tetrakisazo, phthalocyanine pigments such as gallium phthalocyanine and titanyl phthalocyanine, and perylene pigments can be used. Of these, phthalocyanine pigments and azo pigments are preferred. Moreover, these organic pigments can be used alone or in combination of two or more.

  As the above-mentioned phthalocyanine pigment, conventionally known ones such as a metal-free phthalocyanine pigment, a titanyl phthalocyanine pigment, and a gallium phthalocyanine pigment can be used, and are not particularly limited.

The azo pigment is preferably a bisazo pigment represented by the following general formula (1).

The volume average particle diameter (D ₅₀ ) of the organic pigment in the coating solution for an electrophotographic photosensitive member is measured using “MICROTRAC PATICLE-SIZE ANALYZER 9340 UPA” (Leeds & Northrup) based on the dynamic light scattering method. . Specific measurement conditions are as follows.

<Microtrack UPA measurement conditions>
Calculation and control program version: 4.53E
Mode: FullRange
Transparent Particles: No
Physical Particles: No
Particle Refractive Index: 1.51
Particle Density: 1.20 g / cc bisazo pigment, 1.50 g / cc phthalocyanine pigment
Fluid: Ethanol
Fluid Refractive Index: 1.33
Fluid High Temp: 30.0 ° C. Viscosity 1.003 mPa · s
Fluid Low Temp: 20.0 ° C. Viscosity 1.200 mPa · s
Run Time: 180sec

  Further, an electrophotographic photosensitive member formed using the electrophotographic photosensitive member coating solution obtained by the production method of the present invention is formed by laminating at least an undercoat layer and a photosensitive layer on a conductive support. . Even if this photosensitive layer is a single-layer type photosensitive layer (FIG. 1A) containing the charge transport material and the charge generation material in the same layer, the charge generation layer containing the charge generation material and the charge transport material are separated. It may be a laminated type (functionally separated type) photosensitive layer (FIG. 1B) separated into a charge transport layer contained therein. However, from the viewpoint of electrophotographic characteristics, a laminated photosensitive layer is preferable. 1A and 1B, reference numeral 101 denotes a support, 102 denotes an undercoat layer, 103 denotes a photosensitive layer, 104 denotes a charge generation layer, and 105 denotes a charge transport layer. In the following, an electrophotographic photoreceptor containing a laminated (functionally separated type) photosensitive layer will be described in detail.

  The conductive support only needs to have conductivity, and examples thereof include metals such as aluminum, stainless steel, and nickel, or metals provided with a conductive layer, plastics, paper, and the like. Can be mentioned. In particular, cylindrical aluminum is excellent in terms of mechanical strength, electrophotographic characteristics, and cost. These conductive supports may be used as they are, but those subjected to physical treatment such as cutting and honing, anodizing treatment, or chemical treatment using acid or the like may be used. Among them, by performing physical processing such as cutting or honing, the surface roughness is processed to be 0.1 μm or more and 3.0 μm or less in terms of Rz value, thereby providing an interference fringe prevention function.

  An interference fringe preventing layer (not shown in FIG. 1) may be provided between the conductive support and the undercoat layer. The interference fringe prevention layer is not necessary when the support itself has an interference fringe prevention function, but by using the conductive support as it is and forming an interference fringe prevention layer by coating on it, An interference fringe preventing function can be imparted to the conductive support by a simple method. For this reason, it is very useful in terms of productivity and cost. As a preferable method for forming the interference fringe prevention layer, inorganic particles such as tin oxide, indium oxide, titanium oxide, and barium sulfate are dispersed in a suitable solvent together with a curable resin such as a phenol resin to prepare a coating liquid, and conductive Examples of the method include coating to a conductive support and drying. The thickness of the interference fringe prevention layer is preferably 1 μm or more and 40 μm or less.

  On the support or the interference fringe prevention layer, an undercoat layer is necessary for ensuring adhesion to the support, protecting the photosensitive layer from electrical breakdown, improving the carrier injection property of the photosensitive layer, and the like.

  The undercoat layer is formed by applying the above-mentioned dispersion composed of an organic pigment and a polyamide resin on the conductive support or the interference fringe prevention layer. The film thickness is preferably 0.01 μm or more and 30 μm or less, and more preferably 0.1 μm or more and 20 μm or less. By including the organic pigment in the undercoat layer, it is possible to suppress density unevenness in the output image of the electrophotographic photosensitive member using the coating solution for the electrophotographic photosensitive member during continuous printing.

  As the charge generation material, azo pigments such as monoazo, bisazo, trisazo, and tetrakisazo, phthalocyanine pigments such as gallium phthalocyanine and titanyl phthalocyanine, and perylene pigments can be used. A gallium phthalocyanine pigment is preferable from the viewpoint of characteristic stability due to environmental fluctuations. More preferably, from the viewpoints of high sensitivity and optical memory characteristics, strong peaks at Bragg angles 2θ = 7.4 ° ± 0.3 ° and 2θ = 28.2 ° ± 0.3 ° in CuKα characteristic X-ray diffraction A hydroxygallium phthalocyanine crystal having

  The coating solution for the charge generation layer is prepared by the above-described known dispersion method using the above-described charge generation material as a suitable solvent. Suitable solvents include, for example, tetrahydrofuran, cyclohexanone, methyl ethyl ketone, ethyl acetate, methanol, methyl cellosolve, acetone, dioxane and N, N-dimethylformamide. At this time, a polymer substance may be added together as a binder, or the binder may be added after being dispersed in advance only with a pigment and a solvent.

  The binder can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinyl anthracene, and polyvinyl porene. Preferred examples include insulating resins such as polyvinyl butyral, polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, and polyacrylamide resin. In addition, insulating resins such as polyamide, polyvinyl pyridine, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol, and polyvinyl pyrrolidone can be given.

  The charge generation layer is formed by applying a dispersion containing the above substances on the undercoat layer, and the film thickness is preferably 5 μm or less, and particularly preferably 0.05 μm or more and 1 μm or less.

  The charge transport layer is formed by applying and drying a paint in which a charge transport material and a binder are mainly dissolved in a solvent.

  Examples of the charge transport material used include various triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triallylmethane compounds. A binder may be added after preliminarily dispersing and dissolving only with the charge transport material and the solvent. Moreover, what was mentioned above can be used as a binder.

  The thickness of the charge transport layer is preferably 5 μm or more and 40 μm or less, and more preferably 10 μm or more and 30 μm or less.

  When the charge transport layer is a single layer, it can be formed similarly using the above-described substances, and the film thickness is preferably 5 μm or more and 40 μm or less, and particularly preferably 10 μm or more and 30 μm or less.

  In the present invention, a protective layer may be provided on the charge transport layer for the purpose of improving durability, transferability and cleaning properties.

  The protective layer can be formed by applying and drying a protective layer coating solution obtained by dissolving a resin in an organic solvent. Examples of the resin include polyvinyl butyral, polyester, polycarbonate, polyamide, polyimide, polyarylate, polyurethane, styrene-butadiene copolymer, styrene-acrylic acid copolymer, and styrene-acrylonitrile copolymer.

  Further, in order to provide the protective layer with the charge transport ability, the protective layer may be formed by curing a monomer material having a charge transport ability or a polymer type charge transport material using various crosslinking reactions. . Examples of the curing reaction include radical polymerization, ionic polymerization, thermal polymerization, photopolymerization, radiation polymerization (electron beam polymerization), plasma CVD method, and photo CVD method.

  Furthermore, you may include electroconductive particle, a ultraviolet absorber, an abrasion resistance improving agent, etc. in a protective layer. As the conductive particles, for example, metal oxides such as tin oxide particles are preferable. As the wear resistance improver, fluorine resin fine powder, alumina, silica and the like are preferable.

  The thickness of the protective layer is preferably 0.5 μm or more and 20 μm or less, and particularly preferably 1 μm or more and 10 μm or less.

  As a coating method for these various layers, a dipping method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, and the like can be used.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, embodiments of the present invention are not limited to these. In the examples, “parts” means “parts by mass”.

  In this embodiment, ethanol and isopropanol are manufactured by Kishida Chemical Co., Ltd. and special grades are used, and n-propanol, n-butanol and propylene glycol monomethyl ether are manufactured by Kishida Chemical Co., Ltd. In addition, the phthalocyanine pigment of the formula (2) has strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° with a Bragg angle 2θ ± 0.2 ° in the X-ray diffraction of CuKα. Oxytitanium phthalocyanine pigment was used.

  First, a method for preparing an N-alkoxyalkylated nylon sample used in the method for producing a coating solution for an electrophotographic photoreceptor of the present invention will be described.

<Examples 1 to 40, Comparative Examples 3, 4, 7, and 8>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, methoxymethylation rate 36.1%) 15 parts Alcohol corresponding to Table 1 85 parts

  In the above configuration, N-methoxymethylated 6 nylon resin is heated and dissolved at 70 ° C., and filtered through a polyflon filter (PF020, pore size 2 μm, manufactured by Advantech Toyo Co., Ltd.) at a liquid temperature of 30 ° C. or higher and 40 ° C. or lower. -An alkoxyalkylated nylon solution was prepared. This N-alkoxyalkylated nylon solution was stored in a sealed container at the storage temperature shown in Table 1 for the storage time shown in Table 1. Thereafter, a liquid-solid determination test was performed based on ASTM D 4359-90 to prepare gelled N-methoxymethylated 6 nylon which is a solid.

  Subsequently, the gelled N-methoxymethylated 6 nylon having the following constitution was passed through a sieve (a sieve opening of 1.0 mm).

Gelled N-methoxymethylated 6 nylon 10 parts Alcohol corresponding to Table 1 18 parts φ1.0 glass beads 22 parts Formula (1) bisazo pigment 0.5 parts

  The material passed through the sieve is dispersed for 24 hours using a paint shaker, and 25 parts of alcohol corresponding to Table 1 and 13 parts of propylene glycol monomethyl ether are added and mixed as a solvent for dilution. A liquid was obtained.

After preparing the electrophotographic photosensitive member coating solution as described above, the liquid level height is 50 mm in a stoppered graduated cylinder (capacity 10 ml), and the coating solution is 30 ° C and 42 ° C, respectively. I left it for a day. Thereafter, using a Microtrac UPA particle size distribution measuring device, the UPA particle size was measured as the volume average particle size (D ₅₀ ) of the organic pigment in the electrophotographic photosensitive member coating solution.

  Moreover, the liquid stability of the coating solution for an electrophotographic photosensitive member after standing as described above was visually evaluated. As a result of visual evaluation, “no sedimentation” was observed when no separation of the bisazo pigment was observed, “slight sedimentation” was observed when the separation of the bisazo pigment was observed at a position about 1 mm from the liquid level, and 10 mm from the liquid level. The one where separation of the bisazo pigment was observed at a lower position was defined as “precipitation”.

  The electrophotographic photosensitive member coating solution after standing as described above was applied to an aluminum sheet (side 9 cm square) with a film thickness of 0.5 μm and dried at 100 ° C. for 10 minutes, A coated aluminum sheet coated with a coating solution for an electrophotographic photoreceptor was obtained. The evaluation result was “Pochi Level 5” where no foreign matter was observed on the coated surface. Also, “Pochi Level 4” was observed when 1 to 3 foreign substances were observed on the coated surface, and “Pochi Level 3” was observed where 4 to 6 foreign objects were observed on the coated surface. Furthermore, “Pochi Level 2” was observed when 7 or more and 9 or less foreign matters were observed on the coated surface, and “Pochi Level 1” when 10 or more foreign materials were observed on the coated surface. The results are shown in Table 1.

<Examples 41 to 80, Comparative Examples 11, 12, 15, and 16>
N-methoxymethylated 6 nylon (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, methoxymethylation rate 36.1%) 10 parts 90 parts alcohol corresponding to Table 1

  In the above configuration, N-methoxymethylated 6 nylon resin is heated and dissolved at 70 ° C., and filtered through a polyflon filter (PF020, pore size 2 μm, manufactured by Advantech Toyo Co., Ltd.) at a liquid temperature of 30 ° C. or higher and 40 ° C. or lower. -An alkoxyalkylated nylon solution was prepared. This N-alkoxyalkylated nylon solution was stored in a sealed container at the storage temperature shown in Table 1 for the storage time shown in Table 1. Thereafter, a liquid-solid determination test was performed based on ASTM D 4359-90 to prepare gelled N-methoxymethylated 6 nylon which is a solid.

  Subsequently, the gelled N-methoxymethylated 6 nylon having the following constitution was passed through a sieve (a sieve opening of 1.0 mm).

The gelled N-methoxymethylated 6 nylon 9 parts Alcohol corresponding to Table 1 8 parts φ1.0 glass beads 22 parts The formula (1) bisazo pigment 0.3 parts

  The material passed through the sieve is dispersed for 24 hours using a paint shaker, and 15 parts of alcohol corresponding to Table 1 and 8 parts of propylene glycol monomethyl ether are added and mixed as a solvent for dilution. A liquid was obtained.

After preparing the electrophotographic photosensitive member coating solution as described above, the liquid level height is 50 mm in a stoppered graduated cylinder (capacity 10 ml), and the coating solution is 30 ° C and 42 ° C, respectively. I left it for a day. Thereafter, using a Microtrac UPA particle size distribution measuring device, the UPA particle size was measured as the volume average particle size (D ₅₀ ) of the organic pigment in the electrophotographic photosensitive member coating solution.

  Moreover, the liquid stability of the coating solution for an electrophotographic photosensitive member after standing as described above was visually evaluated. As a result of visual evaluation, “no sedimentation” was observed when no separation of the bisazo pigment was observed, “slight sedimentation” was observed when the separation of the bisazo pigment was observed at a position about 1 mm from the liquid level, and 10 mm from the liquid level. The one where separation of the bisazo pigment was observed at a lower position was defined as “precipitation”.

  The electrophotographic photosensitive member coating solution after standing as described above was applied to an aluminum sheet (side 9 cm square) with a film thickness of 0.5 μm and dried at 100 ° C. for 10 minutes, A coated aluminum sheet coated with a coating solution for an electrophotographic photoreceptor was obtained. The evaluation result was “Pochi Level 5” where no foreign matter was observed on the coated surface. Also, “Pochi Level 4” was observed when 1 to 3 foreign substances were observed on the coated surface, and “Pochi Level 3” was observed where 4 to 6 foreign objects were observed on the coated surface. Furthermore, “Pochi Level 2” was observed when 7 or more and 9 or less foreign matters were observed on the coated surface, and “Pochi Level 1” when 10 or more foreign materials were observed on the coated surface. The results are shown in Table 1.

<Comparative Examples 1, 2, 5, 6>
N-methoxymethylated 6 nylon (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, methoxymethylation rate 36.1%) 15 parts Alcohol corresponding to Table 1 85 parts

  In the above configuration, N-methoxymethylated 6 nylon resin is heated and dissolved at 70 ° C., and filtered through a polyflon filter (PF020, pore size 2 μm, manufactured by Advantech Toyo Co., Ltd.) at a liquid temperature of 30 ° C. or higher and 40 ° C. or lower. -An alkoxyalkylated nylon solution was prepared. This N-alkoxyalkylated nylon solution was stored in a sealed container at the storage temperature shown in Table 1 for the storage time shown in Table 1. Thereafter, a liquid-solid determination test was performed based on ASTM D 4359-90, and non-gelled N-methoxymethylated 6 nylon which was a liquid was prepared.

  Subsequently, the non-gelled N-methoxymethylated 6 nylon described above was configured as follows.

Non-gelled N-methoxymethylated 6 nylon 10 parts Alcohol corresponding to Table 1 18 parts φ1.0 glass beads 22 parts Formula (1) bisazo pigment 0.5 parts

  The composition described above was dispersed for 24 hours using a paint shaker, and 25 parts of alcohol corresponding to Table 1 and 13 parts of propylene glycol monomethyl ether were added and mixed as a solvent for dilution, and applied to an electrophotographic photoreceptor. A liquid was obtained.

After preparing the electrophotographic photosensitive member coating solution as described above, the liquid level height is 50 mm in a stoppered graduated cylinder (capacity 10 ml), and the coating solution is 30 ° C and 42 ° C, respectively. I left it for a day. Thereafter, using a Microtrac UPA particle size distribution measuring device, the UPA particle size was measured as the volume average particle size (D ₅₀ ) of the organic pigment in the electrophotographic photosensitive member coating solution.

  Moreover, the liquid stability of the coating solution for an electrophotographic photosensitive member after standing as described above was visually evaluated. As a result of visual evaluation, “no sedimentation” was observed when no separation of the bisazo pigment was observed, “slight sedimentation” was observed when the separation of the bisazo pigment was observed at a position about 1 mm from the liquid level, and 10 mm from the liquid level. The one where separation of the bisazo pigment was observed at a lower position was defined as “precipitation”.

  The electrophotographic photosensitive member coating solution after standing as described above was applied to an aluminum sheet (side 9 cm square) with a film thickness of 0.5 μm and dried at 100 ° C. for 10 minutes, A coated aluminum sheet coated with a coating solution for an electrophotographic photoreceptor was obtained. The evaluation result was “Pochi Level 5” where no foreign matter was observed on the coated surface. Also, “Pochi Level 4” was observed when 1 to 3 foreign substances were observed on the coated surface, and “Pochi Level 3” was observed where 4 to 6 foreign objects were observed on the coated surface. Furthermore, “Pochi Level 2” was observed when 7 or more and 9 or less foreign matters were observed on the coated surface, and “Pochi Level 1” when 10 or more foreign materials were observed on the coated surface. The results are shown in Table 1.

<Comparative Examples 9, 10, 13, 14>
N-methoxymethylated 6 nylon (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, methoxymethylation rate 36.1%) 10 parts 90 parts alcohol corresponding to Table 1

  In the above configuration, N-methoxymethylated 6 nylon resin is heated and dissolved at 70 ° C., and filtered through a polyflon filter (PF020, pore size 2 μm, manufactured by Advantech Toyo Co., Ltd.) at a liquid temperature of 30 ° C. or higher and 40 ° C. or lower. -An alkoxyalkylated nylon solution was prepared. This N-alkoxyalkylated nylon solution was stored in a sealed container at the storage temperature shown in Table 1 for the storage time shown in Table 1. Thereafter, a liquid-solid determination test was performed based on ASTM D 4359-90, and non-gelled N-methoxymethylated 6 nylon which was a liquid was prepared.

  Subsequently, the non-gelled N-methoxymethylated 6 nylon described above was configured as follows.

Non-gelled N-methoxymethylated 6 nylon 9 parts Alcohol corresponding to Table 1 8 parts φ1.0 glass beads 22 parts Formula (1) bisazo pigment 0.3 parts

  The above composition is dispersed for 24 hours using a paint shaker, and 15 parts of alcohol corresponding to Table 1 and 8 parts of propylene glycol monomethyl ether are added and mixed as a solvent for dilution, and applied to an electrophotographic photoreceptor. A liquid was obtained.

After preparing the electrophotographic photosensitive member coating solution as described above, the liquid level height is 50 mm in a stoppered graduated cylinder (capacity 10 ml), and the coating solution is 30 ° C and 42 ° C, respectively. I left it for a day. Thereafter, the UPA particle size was measured as the volume average particle size (D ₅₀ ) of the organic pigment in the electrophotographic photosensitive member coating solution using a Microtrac UPA particle size distribution analyzer.

  Moreover, the liquid stability of the coating solution for an electrophotographic photosensitive member after standing as described above was visually evaluated. As a result of visual evaluation, “no sedimentation” was observed when no separation of the bisazo pigment was observed, “slight sedimentation” was observed when the separation of the bisazo pigment was observed at a position about 1 mm from the liquid level, and 10 mm from the liquid level. The one where separation of the bisazo pigment was observed at a lower position was defined as “precipitation”.

  The electrophotographic photosensitive member coating solution after standing as described above was applied to an aluminum sheet (side 9 cm square) with a film thickness of 0.5 μm and dried at 100 ° C. for 10 minutes, A coated aluminum sheet coated with a coating solution for an electrophotographic photoreceptor was obtained. The evaluation result was “Pochi Level 5” where no foreign matter was observed on the coated surface. Also, “Pochi Level 4” was observed when 1 to 3 foreign substances were observed on the coated surface, and “Pochi Level 3” was observed where 4 to 6 foreign objects were observed on the coated surface. Furthermore, “Pochi Level 2” was observed when 7 or more and 9 or less foreign matters were observed on the coated surface, and “Pochi Level 1” when 10 or more foreign materials were observed on the coated surface. The results are shown in Table 1.

<Examples 81 to 100, Comparative Examples 19 and 20>
N-methoxymethylated 6 nylon (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, methoxymethylation rate 36.1%) 15 parts ethanol 85 parts

  In the above configuration, N-methoxymethylated 6 nylon resin is heated and dissolved at 70 ° C., and filtered through a polyflon filter (PF020, pore size 2 μm, manufactured by Advantech Toyo Co., Ltd.) at a liquid temperature of 30 ° C. or higher and 40 ° C. or lower. -An alkoxyalkylated nylon solution was prepared. This N-alkoxyalkylated nylon solution was stored in a sealed container at the storage temperature shown in Table 2 for the storage time shown in Table 2. Thereafter, a liquid-solid determination test was performed based on ASTM D 4359-90 to prepare gelled N-methoxymethylated 6 nylon which is a solid.

  Subsequently, the gelled N-methoxymethylated 6 nylon having the following constitution was passed through a sieve (a sieve opening of 1.0 mm).

Gelled N-methoxymethylated 6 nylon 10 parts Ethanol 18 parts φ1.0 glass beads 22 parts The following formula (2) phthalocyanine pigment 0.5 parts

After preparing the electrophotographic photosensitive member coating solution as described above, the liquid level height is 50 mm in a stoppered graduated cylinder (capacity 10 ml), and the coating solution is 30 ° C and 42 ° C, respectively. I left it for a day. Thereafter, using a Microtrac UPA particle size distribution measuring device, the UPA particle size was measured as the volume average particle size (D ₅₀ ) of the organic pigment in the electrophotographic photosensitive member coating solution.

  Moreover, the liquid stability of the coating solution for an electrophotographic photosensitive member after standing as described above was visually evaluated. As a result of the visual evaluation, the case where no separation of the phthalocyanine pigment was recognized as “no sedimentation”. The case where separation of the phthalocyanine pigment was observed at a position of about 1 mm from the liquid level was designated “slightly settled”, and the case where separation of the phthalocyanine pigment was observed at a position lower than 10 mm from the liquid level was designated as “precipitation”.

  The electrophotographic photosensitive member coating solution after standing as described above was applied to an aluminum sheet (side 9 cm square) with a film thickness of 0.5 μm and dried at 100 ° C. for 10 minutes, A coated aluminum sheet coated with a coating solution for an electrophotographic photoreceptor was obtained. The evaluation result was “Pochi Level 5” where no foreign matter was observed on the coated surface. Also, “Pochi Level 4” was observed when 1 to 3 foreign substances were observed on the coated surface, and “Pochi Level 3” was observed where 4 to 6 foreign objects were observed on the coated surface. Furthermore, “Pochi Level 2” was observed when 7 or more and 9 or less foreign matters were observed on the coated surface, and “Pochi Level 1” when 10 or more foreign materials were observed on the coated surface. The results are shown in Table 2.

<Comparative Examples 17 and 18>
N-methoxymethylated 6 nylon (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, methoxymethylation rate 36.1%) 15 parts ethanol 85 parts

  In the above configuration, N-methoxymethylated 6 nylon resin is heated and dissolved at 70 ° C., and filtered through a polyflon filter (PF020, pore size 2 μm, manufactured by Advantech Toyo Co., Ltd.) at a liquid temperature of 30 ° C. or higher and 40 ° C. or lower. -An alkoxyalkylated nylon solution was prepared. The N-alkoxyalkylated nylon solution was stored in a sealed container at the storage temperature shown in Table 2 for the storage time shown in Table 2. A liquid-solid determination test was performed based on ASTM D 4359-90 to prepare non-gelled N-methoxymethylated 6 nylon which is a liquid.

  Subsequently, the non-gelled N-methoxymethylated 6 nylon described above was configured as follows.

Non-gelled N-methoxymethylated 6 nylon 10 parts Ethanol 18 parts φ1.0 glass beads 22 parts The formula (2) phthalocyanine pigment 0.5 parts

  The above composition was dispersed for 24 hours using a paint shaker, and 25 parts of ethanol and 13 parts of propylene glycol monomethyl ether were added and mixed as a solvent for dilution to obtain a coating solution for an electrophotographic photoreceptor.

After preparing the electrophotographic photosensitive member coating solution as described above, the liquid level height is 50 mm in a stoppered graduated cylinder (capacity 10 ml), and the coating solution is 30 ° C and 42 ° C, respectively. I left it for a day. Thereafter, using a Microtrac UPA particle size distribution measuring device, the UPA particle size was measured as the volume average particle size (D ₅₀ ) of the organic pigment in the electrophotographic photosensitive member coating solution.

  Moreover, the liquid stability of the coating solution for an electrophotographic photosensitive member after standing as described above was visually evaluated. As a result of the visual evaluation, the case where no separation of the phthalocyanine pigment was recognized as “no sedimentation”. The case where separation of the phthalocyanine pigment was observed at a position of about 1 mm from the liquid level was designated “slightly settled”, and the case where separation of the phthalocyanine pigment was observed at a position lower than 10 mm from the liquid level was designated as “precipitation”.

  The electrophotographic photosensitive member coating solution after standing as described above was applied to an aluminum sheet (side 9 cm square) with a film thickness of 0.5 μm and dried at 100 ° C. for 10 minutes, A coated aluminum sheet coated with a coating solution for an electrophotographic photoreceptor was obtained. The evaluation result was “Pochi Level 5” where no foreign matter was observed on the coated surface. Also, “Pochi Level 4” was observed when 1 to 3 foreign substances were observed on the coated surface, and “Pochi Level 3” was observed where 4 to 6 foreign objects were observed on the coated surface. Furthermore, “Pochi Level 2” was observed when 7 or more and 9 or less foreign matters were observed on the coated surface, and “Pochi Level 1” when 10 or more foreign materials were observed on the coated surface. The results are shown in Table 2.

  Table 1 shows the following. In Examples 1 to 80 in which the storage temperature is 15 ° C. or lower, the pigment is not settled as a result of standing at 23 ° C. for 30 days, and the rank is 4 or higher. Even in the result of standing at 42 ° C. for 30 days, only a slight sedimentation of the pigment is observed, and the result of visual inspection of the coating remains only about 1-2 rank worse than the standing at 23 ° C. for 30 days. On the other hand, in Comparative Examples 1 to 16 in which the storage temperature is 23 ° C., 23 ° C. in Comparative Examples 1, 2, 5, 6, 9, 10, 13, and 14 determined as liquids in the liquid-solid determination test Sedimentation of the pigment was observed both at 30 days and at 42 ° C. for 30 days. As a result, it is Pochi rank 1.

  Further, in Comparative Examples 3, 4, 7, 8, 11, 12, 15, and 16 that were determined to be solid in the liquid-solid determination test, only a slight precipitation of the pigment was observed in the result of standing at 23 ° C. for 30 days. It was 3 or more. However, as a result of standing at 42 ° C. for 30 days, sedimentation of the pigment is observed under all conditions, which is Pochirank 1, and the result of visual inspection of the coating is deteriorated by 3 to 4 ranks. From this, the coating liquid for electrophotographic photoreceptors of Examples 1 to 80 manufactured at a storage temperature of 15 ° C. or less was the same as the coating liquid for electrophotographic photoreceptors of Comparative Examples 1 to 16 manufactured at a storage temperature of 23 ° C. It can be said that the stability is high.

  The lower the storage temperature, the more the stability of the electrophotographic photosensitive member coating solution tends to increase. For example, when Examples 1 and 17 having the same storage time and different storage temperatures are compared, the UPA particle size at 23 ° C. for 30 days is 0.38 μm when the storage temperature is 15 ° C., whereas the storage temperature − It is 0.23 μm at 72 ° C. Further, the UPA particle size after standing at 42 ° C. for 30 days is 0.63 μm when the storage temperature is 15 ° C., and 0.26 μm when the storage temperature is −72 ° C. The lower the storage temperature, the smaller the increase in particle size.

  The longer the storage time, the more the stability of the electrophotographic photosensitive member coating solution tends to increase. For example, when Examples 1 and 4 having the same storage temperature but different storage times are compared, the UPA particle size at 23 ° C. for 30 days is 0.38 μm at 1 hour, whereas it is 0 at 72 hours. .26 μm. Further, the UPA particle size after standing at 42 ° C. for 30 days is 0.63 μm at 1 hour, whereas 0.41 μm at 72 hours, and the longer the storage time, the smaller the increase in particle size.

  When ethanol is used as the type of alcohol, the stability of the electrophotographic photosensitive member coating liquid tends to increase. For example, when Examples 4, 24, 44, and 64 having the same storage temperature and storage time and different alcohol types are compared, the UPA particle size after standing at 23 ° C. for 30 days is 0.26 μm in the case of ethanol. In the case of other alcohols, the thickness is 0.30 to 32 μm. Also, the UPA particle size after standing at 42 ° C. for 30 days is 0.41 μm in the case of ethanol, whereas 0.48 to 0.49 μm in the case of other alcohols, ethanol increases the particle size. The amount is also small.

  Tables 1 and 2 show the following. Examples of the different types of organic pigments include, for example, alcohol species, storage temperature and storage time under the same conditions, bisazo pigment examples 4, 8, 12, 16, and 20 and phthalocyanine pigment examples 84, 88, 92, and 96. , 100. As a result, the phthalocyanine pigment tends to have a slightly larger UPA particle size of the organic pigment contained in the electrophotographic photoreceptor coating solution than the bisazo pigment, but the stability of the electrophotographic photoreceptor coating solution is It turns out that it is equivalent to a bisazo pigment.

  Next, an electrophotographic photosensitive member was prepared using the dispersion liquid obtained above, and image evaluation was performed using a digital copying machine.

<Examples 101 to 124, Comparative Examples 21 to 24>
Titanium oxide powder coated with tin oxide (trade name Kronos ECT-62, manufactured by Titanium Industry Co., Ltd.) 50 parts resol type phenol resin 25 parts methyl cellosolve 20 parts spherical silicone resin powder (trade name Tospearl 120, manufactured by Toshiba Silicone) 3 .8 parts methanol 5 parts silicone oil (polydimethylsiloxane / polyoxyalkylene copolymer, average molecular weight 3000) 0.002 parts

  With the above configuration, the coating solution for interference fringe prevention layer was prepared by dispersing for 2 hours in a sand mill using glass beads having a diameter of 0.8 mm. This coating solution was dip-coated on an aluminum cylinder (diameter 30 mm, drawn tube) as a conductive support and dried at 140 ° C. for 30 minutes to form an interference fringe preventing layer having a thickness of 15 μm.

  On the obtained interference fringe prevention layer, an electrophotographic photosensitive member coating solution corresponding to the examples and comparative examples in Table 3 is dip coated and dried at 100 ° C. for 10 minutes. A pulling layer was formed.

  Next, the Bragg angles (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction are 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 °. 10 parts of a crystalline form of hydroxygallium phthalocyanine having a strong peak at the position was used. To this, 0.1 part of a compound represented by the following formula (3) and 5 parts of a polyvinyl butyral resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) are added to 250 parts of cyclohexanone, and the diameter is 0.8 mm. For 3 hours in a sand mill using glass beads. To this, 100 parts of cyclohexanone and 450 parts of ethyl acetate were further added and diluted to obtain a charge generation layer coating solution. The obtained coating solution was dip-coated on the undercoat layer and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.16 μm.

  Next, 10 parts of a charge transport material represented by the following formula (4) and 10 parts of a polycarbonate resin (trade name: Iupilon Z-200, manufactured by Mitsubishi Engineering Plastics) were dissolved in 70 parts of monochlorobenzene. The obtained solution was dip-coated on the charge generation layer and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 25 μm. Electrophotographic photoreceptors corresponding to the examples and comparative examples in Table 3 Was made.

  As an image forming apparatus, a digital copying machine using a laser beam (manufactured by Canon Inc .: GP405) was used. The apparatus includes a charging roller as a charging unit for an electrophotographic photosensitive member, a one-component developing unit employing a non-contact one-component jumping developing method between a developer and an electrophotographic photosensitive member as a developing unit, and a charging roller as a transfer unit. Blade cleaning means and pre-charging exposure means.

  In addition, the electrophotographic photosensitive member, the charger, and the cleaning means are an integrated unit. The process speed is 210 mm / s. An electrophotographic photosensitive member corresponding to the examples and comparative examples shown in Table 3 is attached to the digital copying machine, and an A4 size solid white image and an A4 size solid white and solid black intermediate in an environment of a temperature of 33 ° C. and a humidity of 80%. A halftone solid image having a density of 1 was output and image evaluation was performed.

  The solid white image was evaluated as “black pot level 5” when no black spot was observed on the solid white image. “Black spot level 4” means that black spots with a width of 0.1 mm or less are observed in part of the image, “Black spot level 3” means that black spots with a width of 0.2 mm or less are observed in part of the image, A black spot having a width of 0.3 mm or less observed in a part of the image was designated as “black spot level 2”. Further, a black spot having a width of 0.5 mm or less observed in the entire image was designated as “black spot level 1”. In the evaluation of the halftone solid image, the case where no density unevenness is visually observed in the image is “no density unevenness”, and the case where the density unevenness is visually observed in the image is “density unevenness”. The results are shown in Table 3.

  Table 3 shows the following. In the electrophotographic photoreceptors 1 to 24, the black spot level is in the range of 2 to 5 in the evaluation of the solid white image, and even if black spots occur in these evaluations, the maximum size is 0.3 mm width or less. Moreover, it occurs only in a part of the output image. Further, in the evaluation of the solid white image of the electrophotographic photosensitive members 25 to 28, the black spot level is 1, and the black spot in this case occurs over the entire image output with a size of 0.5 mm width or less. Further, in the evaluation of the halftone solid image, density unevenness is not observed in the electrophotographic photoreceptors 1 to 24, whereas density unevenness is observed in the electrophotographic photoreceptors 25 to 28.

  From this, N-alkoxyalkylated nylon is dissolved in alcohol to obtain an N-alkoxyalkylated nylon liquid. Next, gelled N-alkoxyalkylated nylon is obtained by setting the temperature of the N-alkoxyalkylated nylon liquid to −80 ° C. or higher and 15 ° C. or lower and the storage time of 1 hour or longer. Further, for an electrophotographic photoreceptor produced under conditions including a step of dispersing an organic pigment in the gelled N-alkoxyalkylated nylon or a step of dispersing an N-alkoxyalkylated nylon and an organic pigment gelled in a solvent. A coating solution is obtained. It can be said that the electrophotographic photoreceptors 1 to 24 prepared using the coating solution for the electrophotographic photoreceptor have clearly fewer output image defects than the other electrophotographic photoreceptors 25 to 28.

It is a figure which shows the structure of a photosensitive layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Support body 102 Undercoat layer 103 Photosensitive layer 104 Charge generation layer 105 Charge transport layer

Claims (13)

In the method for producing a coating solution for an electrophotographic photoreceptor obtained by dispersing N-alkoxyalkylated nylon and an organic pigment in a solvent,
Dissolving the N-alkoxyalkylated nylon in alcohol to obtain an N-alkoxyalkylated nylon solution;
Obtaining a gelled N-alkoxyalkylated nylon having a liquid temperature of the N-alkoxyalkylated nylon liquid of -80 ° C to 15 ° C and a storage time of at least 1 hour;
The step of dispersing the gelled N-alkoxyalkylated nylon and the organic pigment, or the step of dispersing the gelled N-alkoxyalkylated nylon and the organic pigment in a diluent solvent. A method for producing a coating solution for an electrophotographic photosensitive member.   2. The electron according to claim 1, wherein in the step of obtaining the gelled N-alkoxyalkylated nylon, the liquid temperature is set to −80 ° C. or higher and lower than 5 ° C., and the storage time is set to at least 1 hour. A method for producing a coating solution for a photographic photoreceptor.   2. The electron according to claim 1, wherein in the step of obtaining the gelled N-alkoxyalkylated nylon, the liquid temperature is set to −80 ° C. to 0 ° C., and the storage time is set to at least 1 hour. A method for producing a coating solution for a photographic photoreceptor.   The step of obtaining the gelled N-alkoxyalkylated nylon is characterized in that the liquid temperature is -80 ° C or higher and -10 ° C or lower and the storage time is at least 1 hour. A method for producing a coating solution for an electrophotographic photoreceptor.   The process for obtaining the gelled N-alkoxyalkylated nylon is characterized in that the storage time is at least 6 hours, and the electrophotographic photoreceptor coating solution according to any one of claims 1 to 4 is produced. Method.   The process for obtaining the gelled N-alkoxyalkylated nylon is characterized in that the storage time is at least 24 hours, and the electrophotographic photoreceptor coating liquid according to any one of claims 1 to 4 is produced. Method.   The process for obtaining the gelled N-alkoxyalkylated nylon is characterized in that the storage time is at least 72 hours, and the electrophotographic photosensitive member coating solution according to any one of claims 1 to 4 is produced. Method.   The N-alkoxyalkylated nylon solution is filtered using a filter at a solution temperature of 30 ° C or higher and 40 ° C or lower, and the electrophotographic photosensitive member coating solution according to any one of claims 1 to 7 is produced. Method.   9. The electrophotographic photosensitive member coating solution according to claim 1, wherein the alcohol is at least one selected from the group consisting of ethanol, isopropanol, n-propanol, and n-butanol. Manufacturing method.   The said solvent for dilution is at least 1 selected from the group which consists of ethanol, isopropanol, n-propanol, and n-butanol, and propylene glycol monomethyl ether in any one of Claim 1 thru | or 9 characterized by the above-mentioned. The manufacturing method of the coating liquid for electrophotographic photoreceptors of description.   The method for producing a coating solution for an electrophotographic photosensitive member according to any one of claims 1 to 10, wherein the organic pigment is a phthalocyanine pigment or an azo pigment. The method for producing a coating solution for an electrophotographic photosensitive member according to claim 11, wherein the azo pigment is represented by the following general formula (1).

The method for producing a coating solution for an electrophotographic photosensitive member according to claim 11, wherein the phthalocyanine pigment is represented by the following general formula (2).

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