JP2006276271A - Method for manufacturing phthalocyanine pigment, electrophotographic photoreceptor, process cartridge, and electrophotographic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a phthalocyanine pigment by which the crystal type and the particle size of a phthalocyanine pigment can accurately and efficiently be controlled and sufficient characteristics as a charge generating material can be stably imparted to the phthalocyanine pigment. <P>SOLUTION: In the method for manufacturing the phthalocyanine pigment to be used as a charge generating material in an electrophotographic photoreceptor, a first fluid containing a phthalocyanine compound and a first solvent, and a second fluid containing a second solvent capable of converting the crystalline types of a phthalocyanine compound are respectively charged into a processing device selected from a microreactor 5 and a micromixer 12, and the first fluid and the second fluid are joined in the processing device to produce a laminar flow, thereby converting the crystalline types of the phthalocyanine compound by diffusing the phthalocyanine compound from the first fluid to the second fluid. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a phthalocyanine pigment used as a charge generation material for an electrophotographic photoreceptor, an electrophotographic photoreceptor comprising a charge generation layer containing a phthalocyanine pigment obtained by the production method, and the electrophotographic photoreceptor. The present invention relates to a process cartridge and an electrophotographic apparatus.

  The mainstream of electrophotographic photoreceptors used in electrophotographic apparatuses such as copying machines, printers, and digital multifunction machines (hereinafter simply referred to as “photoreceptors” in some cases) uses organic pigments as charge generation materials. It has become. A photoreceptor using an organic pigment is effective in terms of measures against environmental pollution, and has advantages such as high productivity and low cost.

The organic pigment as the charge generation material can be obtained by subjecting the crude crystals of the pigment synthesized according to various synthesis methods to treatments such as pulverization, acid pasting, solvent treatment, and heat treatment. Among the above treatments, the solvent treatment is for the purpose of making the pigment finer, changing the crystal form, purifying the pigment, and the like, and is used for various pigments (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 03-269061

  However, even with the above conventional solvent treatment method, it is not always easy to stably impart sufficient characteristics as a charge generation material to an organic pigment. When a phthalocyanine pigment and a solvent are mixed with a dispersion medium using a container having a certain amount of volume such as a mill, it is difficult to control the temperature and fluid behavior in the container with high precision, and the phthalocyanine pigment to be produced The crystal type becomes non-uniform and the particle size tends to vary.

  The present invention has been made in view of the above-described problems of the prior art, and controls the crystal form and particle size of the phthalocyanine pigment with high accuracy and efficiency so that the phthalocyanine pigment has sufficient characteristics as a charge generation material. It aims at providing the manufacturing method of the phthalocyanine pigment which can be provided stably. Another object of the present invention is to provide an electrophotographic photosensitive member on which a functional layer containing a phthalocyanine pigment obtained by the production method is formed, and a process cartridge and an electrophotographic apparatus including the electrophotographic photosensitive member. To do.

  In order to solve the above problems, the present invention provides a method for producing a phthalocyanine pigment used as a charge generation material for an electrophotographic photosensitive member, the first fluid containing a phthalocyanine compound and a first solvent, and crystals of the phthalocyanine compound. And a second fluid containing a second solvent capable of converting the mold, respectively, and the first fluid and the second fluid are combined to form a laminar flow, and the second phthalocyanine compound The crystal form of the phthalocyanine compound is converted by diffusion from one fluid side to the second fluid side.

  In this way, each of the first fluid and the second fluid is transported, and these fluids are merged to generate a laminar flow, so that the first fluid and the second fluid contact each other at the interface. These fluids mix with each other, and the components contained in each fluid diffuse to each other. Diffusion conditions when the phthalocyanine compound diffuses from the first fluid side to the second fluid side to convert the crystal form in the channel in which the first fluid and the second fluid are in a laminar flow state Variations in pigment concentration, temperature, specific interfacial area, etc. are sufficiently suppressed. Therefore, the crystal form and particle size of the phthalocyanine pigment can be controlled accurately and efficiently, and sufficient characteristics as a charge generating material can be stably imparted to the phthalocyanine pigment.

  In the method for producing a phthalocyanine pigment of the present invention, the first and second fluids are fed so that the feeding speeds of the first fluid and the second fluid satisfy the condition represented by the following formula (1). It is preferable to do. Thereby, the crystal type and particle diameter of the pigment can be controlled more accurately and efficiently.

1 <(V ₂ / V ₁ ) ≦ 100 (1)
Wherein (1), _{V 1} and _{V 2} denotes the feeding speed of the first and second fluids, respectively. ]

  Moreover, in the manufacturing method of the phthalocyanine pigment of this invention, it is preferable that solid content concentration of a 1st fluid is 0.01-10 mass%.

  The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member comprising a conductive substrate and a photosensitive layer formed on the substrate, and the photosensitive layer is obtained by the method for producing a phthalocyanine pigment of the present invention. It is characterized by including the functional layer containing the phthalocyanine pigment obtained. Here, the functional layer refers to, for example, a single layer type photosensitive layer when the photosensitive layer is a single layer type, and a charge generation layer when the photosensitive layer is a function separation type.

  According to the electrophotographic photosensitive member of the present invention, by providing a charge generation layer containing the phthalocyanine pigment manufactured by the manufacturing method of the present invention, electrons such as photosensitivity, chargeability, dark decay, environmental characteristics, cycle characteristics, etc. Since the photographic characteristics are sufficiently enhanced, it is possible to stably obtain good image quality.

  The process cartridge of the present invention includes the electrophotographic photosensitive member of the present invention, a charging device that charges the electrophotographic photosensitive member, a developing device that develops an electrostatic latent image formed by exposure to form a toner image, and a transfer And at least one selected from a cleaning device that removes toner remaining on the electrophotographic photosensitive member later.

  According to the process cartridge of the present invention, since the electrophotographic photosensitive member of the present invention is provided, electrophotographic characteristics such as photosensitivity, chargeability, dark decay, environmental stability, and cycle characteristics are sufficiently enhanced. Image quality can be obtained stably.

  The electrophotographic apparatus of the present invention includes the electrophotographic photosensitive member of the present invention, a charging device that charges the electrophotographic photosensitive member, an exposure device that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image, The image forming apparatus includes: a developing device that develops the electrostatic latent image to form a toner image; and a transfer device that transfers the toner image from the electrophotographic photosensitive member to a transfer medium.

  According to the electrophotographic apparatus of the present invention, by including the electrophotographic photosensitive member of the present invention, the electrophotographic characteristics such as photosensitivity, chargeability, dark decay, environmental stability, and cycle characteristics are sufficiently enhanced. It is possible to obtain a stable image quality.

  According to the present invention, a method for producing a phthalocyanine pigment capable of accurately and efficiently controlling the crystal form and particle size of a phthalocyanine pigment and stably imparting sufficient characteristics as a charge generation material to the phthalocyanine pigment. Is provided. In addition, according to the present invention, there are provided an electrophotographic photosensitive member on which a charge generation layer containing a phthalocyanine pigment obtained by the production method is formed, and a process cartridge and an electrophotographic apparatus including the electrophotographic photosensitive member. .

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

(Solvent processing method)
FIG. 1 is a schematic configuration diagram showing an example of a processing apparatus suitably used in the solvent processing method according to the method for producing a phthalocyanine pigment of the present invention. As an apparatus used in the method for producing a phthalocyanine pigment of the present invention, for example, a microreactor or a micromixer is used.

  FIG. 1 relates to a processing apparatus using a microreactor. The processing apparatus 10 includes a first flow path L1 that passes a fluid 1a (first fluid) containing a phthalocyanine compound and a first solvent, and a crystal form of the phthalocyanine compound. It is connected to a flow path L2 through which the fluid 2a containing the second solvent that can be converted (second fluid) passes, and the terminal ends of the flow paths L1 and L2, and the fluid 1a and the fluid 2a merge. And a flow path L3 that generates a laminar flow.

  The microsyringe 1 in which the fluid 1a is accommodated is connected to the upstream end of the flow path L1, and the microsyringe 2 in which the fluid 2a is accommodated is connected to the upstream end of the flow path L2.

  The fluid 1a is a solution containing a phthalocyanine compound as described above. Phthalocyanine pigments have already been put into practical use as charge generation materials for digital recording photoreceptors such as laser printers and full-color copiers, where the photosensitive wavelength region has been extended to the near infrared region of semiconductor lasers. By the method for producing the phthalocyanine pigment of the present invention described later, the quality stability is further improved.

  The phthalocyanine pigment is not particularly limited, and examples thereof include a metal-free phthalocyanine pigment, a titanyl phthalocyanine pigment, a copper phthalocyanine pigment, a chlorogallium phthalocyanine pigment, a hydroxygallium phthalocyanine pigment, a vanadyl phthalocyanine pigment, a chloroindium phthalocyanine pigment, and a dichlorotin phthalocyanine pigment. It is done.

Among the phthalocyanine pigments, a hydroxygallium phthalocyanine pigment (crude crystal) is, for example, a method of reacting o-phthalodinitrile or 1,3-diiminoisoindoline with gallium trichloride in a predetermined solvent (type I). Chlorogallium phthalocyanine method); manufactured by a method (phthalocyanine dimer method) in which o-phthalodinitrile, alkoxygallium and ethylene glycol are heated and reacted in a predetermined solvent to synthesize a phthalocyanine dimer (phthalocyanine dimer) be able to.

  As the solvent in the above reaction, α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, dimethylaminoethanol, diphenylethane, ethylene glycol, dialkyl ether, quinoline, sulfolane, dichlorobenzene, dimethylformamide, dimethyl It is preferable to use an inert and high boiling point solvent such as sulfoxide or dimethylsulfamide.

  The phthalocyanine compound contained in the fluid 1a is preferably dispersed in a solvent, and the first solvent used in the fluid 1a is preferably one that does not convert the crystal form of the phthalocyanine compound. As such a solvent, a nonpolar solvent such as n-hexane, cyclohexane, benzene, acetone, diethyl ether, n-heptane can be used.

  The mixing ratio of the phthalocyanine compound and the solvent contained in the fluid 1a is preferably 10 to 1000 parts by mass, more preferably 15 to 100 parts by mass with respect to 1 part by mass of the phthalocyanine compound. When the mixing ratio of the phthalocyanine compound and the solvent is less than 10 parts by mass with respect to 1 part by mass of the phthalocyanine compound, the dispersion of the phthalocyanine compound tends to be insufficient. The conversion tends to be less likely to occur.

  Moreover, it is preferable that the liquid viscosity of the 1st fluid 1a is 250 mPa * S or less.

  On the other hand, the 2nd fluid 2a contains the 2nd solvent which can convert the crystal form of a phthalocyanine compound. Examples of the second solvent include amides (N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc.), esters (ethyl acetate, n-butyl acetate, i-amyl acetate, etc.), ketones (Acetone, methyl ethyl ketone, cyclohexanone, etc.), dimethyl sulfoxide and the like. The liquid viscosity of the second fluid 2a is preferably 250 mPa · S or less. The fluid 2a may contain a phthalocyanine compound at a lower concentration than the fluid 1a.

  The fluid 1a in the microsyringe 1 and the fluid 2a in the microsyringe 2 are pushed out to the flow paths L1 and L2 by the liquid feeding pumps P1 and P2, respectively, sent to the microreactor 5 through the filters F1 and F2, and flow Merge on the path L3.

  The flow paths (channels) L1, L2, and L3 of the microreactor 5 are microscale. That is, the widths of the flow paths L1, L2, and L3 are 5000 μm or less, preferably 10 to 1000 μm, and more preferably 30 to 500 μm. Therefore, in the microreactor, both the flow rate and the flow rate of the fluid are small, and the Reynolds number is 200 or less.

  The flow paths L1, L2, and L3 of the microreactor 5 are produced on a solid substrate by a fine processing technique. Materials used for the substrate are glass, ceramics, silicon and the like. Moreover, a plastic resin can also be used if it is acid resistance and alkali resistance.

  Examples of microfabrication methods for forming the flow paths L1, L2, and L3 include, for example, a method using LIGA technology using X-rays, a method using a resist portion as a structure by a photolithography method, and etching a resist opening There are processing methods, micro electrical discharge machining methods, laser machining methods, and mechanical micro cutting methods using micro tools made of hard materials such as diamond. These techniques may be used alone or in combination.

  Further, when the microreactor 5 is assembled, a joining technique is used. Bonding techniques can be broadly divided into solid phase bonding and liquid phase bonding. Solid phase bonding includes anodic bonding, direct bonding, diffusion bonding, and the like. Liquid phase bonding includes fusion welding and adhesive.

  The microreactor 5 is provided with a heater 7 and its temperature is adjusted by a temperature control device 9. Further, a metal resistor, polysilicon or the like is used as the heater, and the heater 7 may be built in the apparatus. For temperature control, the entire apparatus may be placed in a temperature-controlled container.

  The microreactor 5 enables a reaction not by turbulent flow but by laminar flow as in a conventional processing apparatus. In the reaction by laminar flow, for example, when two liquids are mixed, they can be mixed by diffusion through the interface between the two liquids. Moreover, since the specific interface area is large in a microscale space, it is advantageous when performing diffusive mixing at such an interface.

  FIG. 2 is an explanatory view conceptually showing a state when the fluid 1a and the fluid 2a merge in the microreactor 5. FIG. As illustrated, when the fluid 1a and the fluid 2a are merged in the flow path L3, the region C mainly composed of the fluid 1a, the region A mainly composed of the fluid 2a, and the region B that is a mixed region thereof are used. Produces a laminar flow. As a result, the phthalocyanine compound in the fluid 1a gradually diffuses from the region C to the region A through the mixed region B, and the crystal form is converted. The phthalocyanine pigment converted in crystal form is accommodated in the container 3 through the flow path L3 together with the mixed fluid 3a.

Among the channels of the microreactor 5, the channel diameter D2 of the _second channel L2 through which the fluid 2a passes is, as shown in FIG. 2, the channel diameter D1 of the _first channel L1 through which the fluid 1a passes. Larger is preferred. When the Nagarero径D ₂ larger than the channel diameter D _1, at the time of solvent treatment, the phthalocyanine compound is well dispersed in the fluid 2a, more accurately and efficiently control the crystal form and particle size of the phthalocyanine pigment Can do. It is more preferable that the ratio D ₂ / D ₁ between the channel diameter D ₂ and the channel diameter D ₁ satisfies the condition represented by the following formula (2). When D ₂ / D ₁ is 1 or less, the dispersion of the phthalocyanine compound tends to be insufficient. On the other hand, when D ₂ / D ₁ exceeds 500, conversion of the crystal form tends to be difficult.

1 <(D ₂ / D ₁ ) ≦ 500 (2)

  The flow paths L1, L2, and L3 only have to have the above configuration in the microreactor 5, and the configuration of the portion exposed from the microreactor 5 is not particularly limited.

Further, feed rate V ₂ of the first feed rate V ₁ and the second fluid 2a of the fluid 1a so as to satisfy the condition represented by the following formula (1), each of the first and second fluid Is preferably fed to the microreactor 5.

1 <(V ₂ / V ₁ ) ≦ 100 (1)

When V ₂ / V ₁ is 1 or less, the dispersion of the phthalocyanine compound tends to be insufficient. On the other hand, when V ₂ / V ₁ exceeds 100, conversion of the crystal form tends to be difficult.

  The temperature of the first fluid 1a supplied to the microreactor 5 is preferably 50 ° C. or lower, more preferably 20 ° C. or lower, and further preferably 10 ° C. or lower. The temperature of the second fluid 2a is preferably the same as that of the first fluid 1a. The temperature is adjusted to a temperature at which the solution does not solidify. The temperature control of the solution is performed by a temperature control device (not shown) provided in the container 1.

In the microreactor 5, the time required for mixing depends on the cross-sectional area of the interface and the thickness of the liquid layer. According to the diffusion theory, the mixing time t is t = W ² / D (W: channel width, D: diffusion coefficient), and the diffusion time becomes faster as the channel width is reduced. That is, if the flow path width becomes 1/10, the mixing time becomes 1/100. Further, since the surface area per unit volume is large, the efficiency of heat exchange is extremely high, and temperature control can be easily performed. Therefore, by using the microreactor 5 for the solvent treatment method, the crystal form and particle size of the phthalocyanine pigment can be controlled accurately and efficiently, and the phthalocyanine pigment can stably have sufficient characteristics as a charge generation material. Can be granted.

  The flow path length of the third flow path L3 is particularly long as long as the mixed fluid 3a passes through the third flow path L3 and the time for ensuring the diffusion mixing of the phthalocyanine pigment and the conversion of the crystal form thereof is ensured. It is not limited. Further, the third flow path L3 may have a wave shape, a saw blade shape, or the like in the subsequent stage (downstream side) as long as a region for generating a laminar flow can be secured.

  The phthalocyanine pigment produced by solvent treatment in this way is accommodated in the container 3 disposed at the downstream end of the flow path L3 together with the mixed fluid 3a. As the container 3, a beaker or a flask can be used.

  A solvent-treated phthalocyanine pigment is dispersed in the mixed fluid 3 a accommodated in the container 3. Thereafter, the mixture 3a is filtered and dried to obtain a phthalocyanine pigment (charge generation material) having a converted crystal form.

  Next, a processing apparatus including a micromixer will be described with reference to FIG. The processing apparatus 15 illustrated in FIG. 3 has the same configuration as the processing apparatus 10 illustrated in FIG. 1 except that the micromixer 12 is provided instead of the microreactor 5. The micromixer includes a mixing space for diffusing and mixing a plurality of liquids, and a plurality of fine supply paths called microchannels for feeding a plurality of types of fluids to the mixing space. The fluid in the microchannel is usually set to a very small Reynolds number of about 10 to several hundreds, and the fluid flow is a laminar flow like the microreactor. Since multiple fluids are sent from the multiple microchannels to the mixing space in an extremely thin laminar laminar state, the fluids sent from the respective microchannels are diffusely mixed in the mixing space. Can do. The flow path of the microchannel preferably has an equivalent diameter of 1000 μm or less, more preferably 10 to 700 μm, when its cross section is converted to a circle.

  Examples of the micromixer include those disclosed in JP-T-9-512742 and PCT International Publication WO400 / 76648. Specific examples of the micromixer used in the present invention include those known in the art such as the Mainz Institute for Microtechnology (IMM) in Germany (Institut fuer Mikrotechnik Mainz GmbH) and the Research Center for Karlsruhe (Forschungszentrum Karlsruhe). It is not limited at all.

  Diffusion mixing of the fluid 1a and the fluid 2a in the mixing space of the micromixer occurs at the interface where these fluids come into contact. Therefore, when diffusion mixing is performed in a minute space, the area of the interface becomes relatively large and the diffusion efficiency is increased. Remarkably improved. In addition, the diffusion time of the molecule itself is proportional to the square of the distance. This means that even if a plurality of fluids are not actively mixed as the scale is reduced, mixing proceeds due to diffusion of molecules, and dispersion is likely to occur sufficiently. Also, in the micro space, since the scale is small, it becomes a laminar flow dominant flow, and the fluids are in a laminar flow state and are diffused and mixed with each other. When a micromixer is used for mixing a plurality of liquids, the specific interface area can be made larger than when a microreactor as described above is used.

  As a microfabrication technique for forming the flow path of the micromixer, as with the microreactor, for example, a method using the LIGA technique using X-rays, a method using the resist portion as a structure by a photolithography method, a resist There are a method of etching an opening, a micro electric discharge machining method, a laser machining method, and a mechanical micro cutting method using a micro tool made of a hard material such as diamond. These techniques may be used alone or in combination.

  Further, when assembling the micromixer, a joining technique is used. Bonding techniques can be broadly divided into solid phase bonding and liquid phase bonding. Solid phase bonding includes anodic bonding, direct bonding, diffusion bonding, and the like. Liquid phase bonding includes fusion welding and adhesive.

  As a flow rate control method for feeding a fluid to a microchannel of a micromixer, there are generally a method of sending a solution by a pressure generated by a pump or the like prepared outside the micromixer and a method of using an electroosmotic flow. The method used as the flow rate control method is appropriately selected depending on the purpose, but a continuous flow type pressure driving method is preferably employed. The micromixer may be provided with a heater, and the temperature may be adjusted by a temperature control device. Further, a metal resistor, polysilicon, or the like is used as the heater, and the heater may be built in the apparatus. For temperature control, the entire apparatus may be placed in a temperature-controlled container.

  If a phthalocyanine pigment is produced using a microreactor or a micromixer as described above, for example, compared with a conventional batch method using a container having a certain volume as a place for converting the crystal form of the phthalocyanine compound, the flow rate It is possible to control the conditions for converting the crystal form, such as the concentration distribution and temperature of the phthalocyanine compound, with high accuracy. For this reason, according to the solvent treatment using a micromixer, a plurality of fluids circulate continuously with almost no stagnation in the mixing space, so that the phthalocyanine pigment can be sufficiently prevented from staying. The crystal form and particle size can be controlled accurately and efficiently.

  In addition, if a phthalocyanine pigment is produced using a microreactor or a micromixer, when a small amount of chemical substances produced by an experimental production facility is produced in large quantities (scale-up) by a large-scale production facility, it is conventional. In contrast to experimental production equipment, it took a lot of labor and time to obtain reproducibility in a large-scale production equipment using a batch method. However, depending on the amount of production required, a microreactor or micromixer It is possible that the labor and time required to obtain such reproducibility can be greatly reduced by parallelizing (numbering up) production lines using the.

  Depending on the type of the solvent-treated phthalocyanine pigment, it may be used as it is as a charge generation material for an electrophotographic photosensitive member, or may be further subjected to another treatment such as a solvent treatment or a pulverization treatment if necessary. .

  The processing apparatus may be configured to circulate a solution containing a phthalocyanine pigment that has undergone a crystal form conversion as shown in FIGS. 4 and 5 to a microreactor (or a micromixer). Specifically, the mixed fluid 3a accommodated in the container 3 is circulated through the return flow path in which the valve and the pump P3 are arranged, and returned to the container 11 accommodating the fluid 1a, and again from the flow path L1. The structure which can be sent to the microreactor 5 or the micromixer 12 may be sufficient. When the mixed fluid 3a containing the phthalocyanine pigment whose crystal form has been converted in this way can be returned to the microreactor (or micromixer), it is easy to control the conversion state of the crystal form depending on the number of times of return. Thus, a phthalocyanine pigment having a desired crystal conversion state can be finally obtained.

  In this way, the first fluid 1a and the second fluid 2a are combined in a microreactor or micromixer to generate a laminar flow, whereby the phthalocyanine pigment is transferred from the first fluid 1a side to the second fluid 2a side. Variations in diffusion conditions (pigment concentration, temperature, specific interfacial area, etc.) at the time of diffusion into the crystal form are sufficiently suppressed. Therefore, the crystal type and particle size of the phthalocyanine pigment can be controlled accurately and efficiently, and sufficient characteristics as a charge generation material can be stably imparted to the pigment. Such a solvent treatment method is particularly suitable when the phthalocyanine compound is a hydroxygallium phthalocyanine compound and a titanyl phthalocyanine compound.

  For example, the crystal form can be converted to V-type hydroxygallium phthalocyanine by treating the hydroxygallium phthalocyanine compound with the above solvent treatment method. V-type hydroxygallium phthalocyanine is a Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-ray of 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °. , 25.1 ° and 28.3 °.

  When the above-mentioned hydroxygallium phthalocyanine pigment having a diffraction peak is used as an electrophotographic photoreceptor as a charge generation material, excellent photosensitivity, repeat stability and environmental stability are obtained, and sufficient chargeability and dark decay characteristics are obtained. Therefore, image quality defects can be sufficiently prevented, and stable image quality can be obtained over a longer period of time.

  Among the above-mentioned hydroxygallium phthalocyanine pigments, hydroxygallium phthalocyanine pigments having a maximum wavelength peak of a spectral absorption spectrum particularly in the wavelength region of 600 to 900 nm in the wavelength region of 810 to 839 nm are particularly highly dispersible, and the aggregation of the pigment particles Is unlikely to occur. Such a hydroxygallium phthalocyanine pigment can be obtained by converting the crystal form of type I hydroxygallium phthalocyanine obtained by acid pasting treatment. Conversion of the crystal form from type I hydroxygallium phthalocyanine to hydroxygallium phthalocyanine can be performed by the method of the present invention.

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor of the present invention includes a functional layer whose photosensitive layer contains the phthalocyanine pigment of the present invention.

  6 to 10 are schematic sectional views showing a preferred embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member 20 shown in FIGS. 6 to 8 includes a layer containing a charge generating material (charge generation). The electrophotographic photoreceptor 20 shown in FIGS. 9 to 10 is provided with a photosensitive layer 23 whose functions are separated into a layer 25) and a layer containing a charge transport material (charge transport layer 26). The transport material is contained in the same layer (single-layer type photosensitive layer 28).

  The electrophotographic photoreceptor 20 shown in FIG. 6 has a structure in which an undercoat layer 24, a charge generation layer 25, and a charge transport layer 26 are sequentially laminated on a conductive substrate 21; the electrophotographic photoreceptor 20 shown in FIG. A structure in which an undercoat layer 24, a charge generation layer 25, a charge transport layer 26, and a protective layer 27 are sequentially laminated on the conductive substrate 21; the electrophotographic photoreceptor 20 shown in FIG. 8 has an undercoat layer on the conductive substrate 21. 24, a charge transport layer 26, a charge generation layer 25, and a protective layer 27 are sequentially stacked.

  Further, the electrophotographic photoreceptor 20 shown in FIG. 9 has a structure in which an undercoat layer 24 and a single layer type photosensitive layer 28 are sequentially laminated on a conductive substrate 21; the electrophotographic photoreceptor 20 shown in FIG. The substrate 21 has a structure in which an undercoat layer 24, a single-layer type photosensitive layer 28, and a protective layer 27 are sequentially laminated.

  Hereinafter, each element of the electrophotographic photoreceptor 20 will be described in detail.

  The conductive substrate 21 is made of a metal such as aluminum, nickel, chromium, and stainless steel; paper, plastic, or glass; aluminum, copper, gold, silver, platinum, palladium, titanium, nickel-chromium, stainless steel, copper-indium A thin film is formed by depositing or laminating a metal such as indium oxide / tin oxide, etc .; carbon black, indium oxide, tin oxide-antimony oxide powder, metal on paper, plastic or glass Examples thereof include those obtained by conducting a conductive treatment by dispersing powder and copper iodide in a binder resin.

  In addition, the shape of the conductive substrate 21 according to the present invention is not particularly limited, but those having a drum shape, a sheet shape, a plate shape, or the like are preferably used. Furthermore, in the present invention, the surface of the conductive substrate 21 may be subjected to surface treatment such as mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing as necessary. By roughening the surface of the conductive substrate 21 by these surface treatments, it is possible to prevent grain-like density spots due to interference light in the electrophotographic photosensitive member that may occur when a coherent light source such as a laser beam is used. Can do.

  The electrophotographic photoreceptor of the present invention preferably comprises an undercoat layer 24 on a conductive substrate 21 as shown in FIGS.

  Examples of the material of the undercoat layer 24 include an organometallic compound and a silane coupling agent, and may include a binder resin.

As organometallic compounds, zirconium chelate compounds, zirconium alkoxide compounds, organozirconium compounds such as zirconium coupling agents, titanium chelate compounds, titanium alkoxide compounds, organotitanium compounds such as titanate coupling agents, aluminum chelate compounds, aluminum coupling agents Organic aluminum compounds such as, antimony alkoxide compounds, germanium alkoxide compounds, indium alkoxide compounds, indium chelate compounds, manganese alkoxide compounds, manganese chelate compounds, tin alkoxide compounds, tin chelate compounds, aluminum silicon alkoxide compounds, aluminum titanium alkoxide compounds, aluminum zirconium Examples include alkoxide compounds, Among these, organic zirconium compound, an organic titanyl compound, the organoaluminum compound residual potential is used preferably for exhibiting good electrophotographic properties lower.

  As silane coupling agents, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxy Silane, γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercapropropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, β-3 , 4-epoxycyclohexyltrimethoxysilane and the like.

  As the binder resin, polyvinyl alcohol, polyvinyl methyl ether, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, polyimide, casein, conventionally used for the undercoat layer, Gelatin, polyethylene, polyester, phenol resin, vinyl chloride-vinyl acetate copolymer, epoxy resin, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, polyacrylic acid, and the like can also be used. The above materials may be used alone or in combination of two or more.

  Further, the undercoat layer 24 may be a material obtained by mixing and dispersing an electron transporting pigment in the above material. Examples of electron transporting pigments include organic pigments such as perylene pigments, bisbenzimidazole perylene pigments, polycyclic quinone pigments, indigo pigments, and quinacridone pigments; electron-withdrawing substituents such as cyano groups, nitro groups, nitroso groups, and halogen atoms Bisazo pigments having an organic color; organic pigments such as phthalocyanine pigments; inorganic pigments such as zinc oxide and titanium oxide. Among these charge transporting pigments, perylene pigments, bisbenzimidazole perylene pigments and polycyclic quinone pigments are preferably used because they have high electron mobility. The content of these electron transport pigments is preferably 95% by mass or less, more preferably 90% by mass or less, based on the total solid content in the undercoat layer 24. When the content of the electron transporting pigment in the undercoat layer 24 exceeds the upper limit, the strength of the undercoat layer 24 tends to decrease, and coating film defects tend to occur.

  The undercoat layer 24 is formed by preparing a coating solution for forming an undercoat layer using the above materials and using the coating solution.

  The charge transporting pigment may be mixed and dispersed in the undercoat layer 24 by dispersing the electron transporting pigment in the undercoat layer forming coating solution containing the material of the undercoat layer 24; A method of adding and mixing the material of the undercoat layer 24 to the solution in which the pigment is dispersed; a method of adding and mixing the material of the undercoat layer 24 to a solution in which the electron transporting pigment is dispersed in the resin; A method of dispersing the electron transporting pigment after adding and mixing the material of the undercoat layer 24; a method of adding and mixing the material of the undercoat layer 24 to the electron transporting pigment and then dispersing the material in the resin solution, and the like. However, it is important to suppress the occurrence of gelation or aggregation in the mixed / dispersed liquid.

In addition, when mixing and dispersing the electron transporting pigment, a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like can be used. This mixing / dispersing step is performed in an organic solvent. The organic solvent is not particularly limited as long as it dissolves a fixed metal compound or resin and does not cause gelation or aggregation when an electron transporting pigment is mixed and dispersed. Specifically, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform , Chlorobenzene, toluene, or a mixture of two or more thereof.

  The undercoat layer 24 can be formed by applying the coating solution for forming the undercoat layer thus prepared on the conductive substrate 21, evaporating the solvent, and then drying. Examples of the application method of the coating solution for forming the undercoat layer include a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method. Moreover, the temperature in a drying process becomes like this. Preferably it is 80-170 degreeC.

  The thickness of the undercoat layer 24 thus obtained is preferably 0.1 to 20 μm, more preferably 0.2 to 10 μm.

Further, when the undercoat layer 24 is provided on such a conductive substrate 21, the following effects (i) to (vi) can be obtained.
(I) Unnecessary carrier injection from the conductive substrate to the photosensitive layer is prevented and image quality is improved; (ii) the environmental dependence (temperature, humidity, etc.) of the light attenuation curve of the electrophotographic photosensitive member is reduced. Stable image quality;
(Iii) Due to the moderate charge transport ability, no charge is accumulated even when used repeatedly over a long period of time, and the occurrence of sensitivity fluctuations is suppressed;
(Iv) generation of image defects due to dielectric breakdown is prevented due to moderate pressure resistance against charging voltage;
(V) The photosensitive layer can be integrally held on the substrate as an adhesive layer;
(Vi) Light reflection of the substrate is prevented.

  The charge generation layer 25 is formed by applying and drying a charge generation layer forming liquid containing a phthalocyanine pigment obtained by the method for producing a phthalocyanine pigment of the present invention.

  The charge generation material may include a phthalocyanine pigment obtained by the above-described method for producing a phthalocyanine pigment of the present invention, and may include a charge generation material that is not produced by the production method of the present invention.

  Examples of the charge generation material not produced by the production method of the present invention include known organic pigments such as polycyclic quinone pigments, perylene pigments, azo pigments, indigo pigments, quinacridone pigments, and phthalocyanine pigments. . Among them, phthalocyanine pigments are preferable, and examples of phthalocyanine pigments include metal-free phthalocyanine pigments, titanyl phthalocyanine pigments, copper phthalocyanine pigments, chlorogallium phthalocyanine pigments, hydroxygallium phthalocyanine pigments, vanadyl phthalocyanine pigments, chloroindium phthalocyanine pigments, and dichlorotin phthalocyanine pigments. Can be mentioned.

  Specific examples of the binder resin include polyvinyl butyral resin, polyvinyl acetal resin, polyarylate resin, polycarbonate resin, polyester resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polystyrene resin, Acrylic resin, methacrylic resin, polyacrylamide resin, polyamide resin, polyvinyl pyridine resin, cellulose resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, casein, vinyl chloride-vinyl acetate copolymer, modified vinyl chloride-acetic acid Vinyl copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, styrene-alkyd resin, phenol-form Aldehyde resins.

  In addition, an organic photoconductive polymer such as poly-N-vinylcarbazole, polyvinyl anthracene, or polyvinyl pyrene can be used as the binder resin. In the case where another layer (charge transport layer 26 or the like) is further laminated after the film formation of the charge generation layer 25, a resin that dissolves in the solvent of the coating solution for the layer laminated on the charge generation layer 25 is not preferable.

  The mixing ratio of the charge generation material and the binder resin in the charge generation layer 25 is appropriately selected according to the type of the charge generation layer 25, and is preferably 40: 1 to 1: 4 in terms of mass ratio. : It is more preferable that it is 1-1: 2. When the blending amount of the charge generation material exceeds 40 times (mass conversion value) of the binding resin, the stability of the coating solution for forming the charge generation layer used for forming the charge generation layer 25 tends to be insufficient. It is in. On the other hand, when the blending amount of the charge generating material is less than 1/4 (mass conversion value) of the blending amount of the binder resin, the sensitivity of the electrophotographic photosensitive member tends to be insufficient.

  The charge generation layer 25 is formed by applying a charge generation layer forming coating liquid obtained by dispersing a charge generation material and a binder resin in a predetermined solvent (conductive substrate 21, charge transport layer 26, undercoat layer 24). Etc.) and can be suitably obtained by drying.

  Here, specific examples of the organic solvent used for forming the charge generation layer 25 include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, Examples include methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the method for dispersing the charge generating material and the binder resin in these organic solvents include a sand mill, a colloid mill, an attritor, a ball mill, a dyno mill, a high-pressure homogenizer, an ultrasonic disperser, a coball mill, and a roll mill. In this case, it is preferable to carry out the process under conditions where the crystal form of the charge generating material does not change due to dispersion.

  In addition, as a method of applying the coating solution for forming the charge generation layer, a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, etc. This method can be used.

  The film thickness of the charge generation layer 25 thus obtained is preferably 0.01 to 5 μm, more preferably 0.03 to 2 μm. If the film thickness of the charge generation layer 25 is less than the lower limit value, the film formability tends to deteriorate and it becomes difficult to obtain sufficient mechanical strength. On the other hand, when the film thickness of the charge generation layer 25 exceeds the upper limit, sufficient light attenuation tends to be difficult to obtain in terms of electrical characteristics.

  The charge transport layer 26 includes a charge transport material and a binder resin.

The charge transport material is not particularly limited as long as it has a function of transporting charges. Specifically, quinone compounds such as p-benzoquinone, chloranil, bromanyl, anthraquinone, tetracyanoquinodi Methane compounds, electron transport compounds such as fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds, cyanovinyl compounds, ethylene compounds; triarylamine compounds, benzidine compounds, Examples include arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, and hydrazone compounds. These charge transport materials may be used alone or in combination of two or more. Among these charge transport materials, triphenylamine compounds and benzidine compounds are particularly preferable because they have high charge (hole) transport ability and excellent stability.

  As the charge transporting material, a polymer charge transporting material having charge transporting properties such as poly-N-vinylcarbazole and polysilane can be used. In particular, polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 have a high charge transport property and are particularly preferable. When a polymer charge transport material is used as the charge transport material, the charge transport layer 26 can be formed without using a binder resin, but a mixture of the polymer charge transport material and a binder resin described later is used. You may form into a film using.

  Specific examples of the binder resin include polycarbonate resin, polyarylate resin, polystyrene resin, polyester resin, styrene-acrylonitrile copolymer, polysulfone, polymethacrylic acid ester, styrene-methacrylic acid ester copolymer, and polyolefin. Can be mentioned. These binder resins may be used alone or in combination of two or more.

  The charge transport layer 26 is obtained by applying a charge transport layer forming coating liquid obtained by dispersing a charge transport material and a binder resin in a predetermined solvent to a predetermined layer (the conductive substrate 21, the undercoat layer 24, the charge generation layer 25. Etc.) and can be obtained by drying. Here, the blending ratio (mass ratio) of the charge transport material and the binder resin in the charge transport layer forming coating solution is preferably 5: 1 to 1: 5, and 3: 1 to 1: 3. More preferably. When the blending amount of the charge transport material exceeds 5 times (mass conversion value) of the blending amount of the binder resin, the mechanical strength of the charge transport layer 26 tends to decrease. On the other hand, when the blending amount of the charge transport material is less than 1/5 times (mass conversion value) of the blending amount of the binder resin, the photosensitivity tends to decrease.

  Moreover, as a solvent used for the coating liquid for charge transport layer formation, aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene; ketones such as acetone and 2-butanone; methylene chloride, chloroform, ethylene chloride and the like Halogenated aliphatic hydrocarbons: Cyclic or linear ethers such as tetrahydrofuran and ethyl ether, and one organic solvent such as a mixture of two or more organic solvents can be used.

  Furthermore, examples of the method for applying the coating solution for forming the charge transport layer include a blade coating method, a Mayer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method.

  The thickness of the charge transport layer 26 thus obtained is preferably 5 to 50 μm, more preferably 10 to 40 μm.

  The single-layer type photosensitive layer 28 of the electrophotographic photosensitive member shown in FIGS. 9 to 10 includes the above-described charge generation material, charge transport material, and binder resin. Examples of the charge generation material, the charge transport material, and the binder resin include the charge generation material, the charge transport material, and the binder resin exemplified in the description of the charge generation layer 25 and the charge transport layer 26.

  The mixing ratio of the charge generation material and the charge transport material in the single-layer type photosensitive layer 28 is preferably 1:10 to 10: 1 by mass ratio, and more preferably 5: 1 to 1:20. Further, the mixing ratio of the charge generation material and the binder resin is preferably 5: 1 to 1:20 by mass ratio.

In the film formation process of the single-layer type photosensitive layer 28, a coating solution for forming a photosensitive layer is prepared in the same manner as the charge generation layer 25 and the charge transport layer 26, and the coating solution is applied and dried to form a single-layer type. A photosensitive layer 28 can be formed.

  The film thickness of the single-layer type photosensitive layer 28 thus obtained is preferably 5 to 50 μm, and more preferably 10 to 40 μm.

  In the electrophotographic photosensitive member according to the present invention, it is preferable to provide a protective layer 27 as shown in FIGS. In the case where the electrophotographic photosensitive member is provided with the protective layer 27, both stability against heat, electricity, chemical substances, etc. and mechanical strength are further improved, and contamination by water, discharge products, toner, etc. is prevented. The effect tends to be further improved. Further, the protective layer 27 has a function as the charge transport layer 26 in addition to the function of imparting stability and mechanical strength to the electrophotographic photosensitive member and preventing adhesion of contaminants to the surface. This protective layer 27 can be used as it is as the charge transport layer 26 of the multilayer photoconductor.

  Examples of the material of the protective layer 27 include organic metal compounds, silane coupling agents, binder resins, and the like exemplified in the description of the undercoat layer 24, and charge transport materials exemplified in the description of the charge transport layer 26. It is done.

  The protective layer 27 is obtained by applying a coating liquid for forming a protective layer obtained by dispersing the above-described material in a predetermined solvent on a predetermined layer (the charge generation layer 25, the charge transport layer 26, etc.) and drying it. Obtainable.

  Here, examples of the solvent and the coating method used in the coating liquid for forming the protective layer include the solvents and the coating methods exemplified in the description of the charge transport layer 26.

  The film thickness of the protective layer 27 thus obtained is not particularly limited as long as the photosensitive properties of the electrophotographic photosensitive member are not impaired. For example, when the protective layer 27 is provided on the charge transport layer 26, the film thickness is 0.5 to It is preferably 20 μm, and more preferably 1 to 10 μm.

The electrophotographic photosensitive member of the present invention described above is provided in an electrophotographic apparatus such as a laser beam printer, a digital copying machine, an LED printer, or a laser facsimile that emits near-infrared light or visible light, and such an electrophotographic apparatus. Can be mounted on a process cartridge. The electrophotographic photoreceptor of the present invention can be used in combination with a one-component or two-component regular developer or reversal developer. The electrophotographic photosensitive member of the present invention is mounted on a contact charging type electrophotographic apparatus using a charging roller or a charging brush, and good characteristics with little occurrence of current leakage can be obtained.

  (Electrophotographic Apparatus and Process Cartridge) FIGS. 11 and 12 are cross-sectional views schematically showing the basic configuration of a preferred embodiment of the electrophotographic apparatus of the present invention.

  An electrophotographic apparatus 200 shown in FIG. 11 includes an electrophotographic photoreceptor 20 of the present invention, a charging unit 32 that charges the electrophotographic photoreceptor 20 by a corona discharge method, a power source 33 connected to the charging unit 32, and a charging unit. An exposure unit 34 that exposes the electrophotographic photosensitive member 20 charged by 32 to form an electrostatic latent image, and a developing unit that develops the electrostatic latent image formed by the exposure unit 34 with toner to form a toner image. 35, a transfer unit 36 that transfers the toner image formed by the developing unit 35 to the transfer target 40, a cleaning unit 37, a static eliminator 38, and a fixing device 39.

  Further, the electrophotographic apparatus 210 shown in FIG. 12 has the same configuration as the electrophotographic apparatus 200 shown in FIG. 11 except that it includes a charging means 32 for charging the electrophotographic photoreceptor 20 of the present invention by a contact method. Have In particular, an electrophotographic apparatus that employs contact-type charging means in which an AC voltage is superimposed on a DC voltage can be preferably used because it has excellent wear resistance. In this case, the static eliminator 38 may not be provided.

  Here, as the charging means 32, for example, a contact-type charger using a roller-like, brush-like, film-like or pin-electrode-like conductive or semiconductive charging member, a scorotron charger using corona discharge or a corotron A non-contact type charger such as a charger is used.

  As the exposure means 34, an optical system device or the like capable of exposing a light source such as a semiconductor laser, an LED (light emitting diode), a liquid crystal shutter or the like to the surface of the electrophotographic photosensitive member in a desired image-like manner is used.

  As the developing means 35, a conventionally known developing means using a regular or reversal developer such as a one-component system or a two-component system is used.

  As the transfer means 36, a contact transfer charger using a belt, a roller, a film, a rubber blade or the like, a scorotron transfer charger using a corona discharge, a corotron transfer charger, or the like is used.

  Although not shown in FIGS. 11 and 12, the electrophotographic apparatus of the present invention may include an intermediate transfer unit. As the intermediate transfer means according to the present invention, one having a structure in which an elastic layer containing rubber, elastomer, resin, etc. and at least one coat layer is laminated on a conductive support can be used. The materials used are polyurethane resin, polyester resin, polystyrene resin, polyolefin resin, polybutadiene resin, polyamide resin, polyvinyl chloride resin, polyethylene resin, fluorine resin, etc. Examples thereof include those obtained by dispersing and mixing conductive carbon particles, metal powder, and the like. Examples of the shape of the intermediate transfer unit include a roller shape and a belt shape.

  FIG. 13 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the process cartridge of the present invention. The process cartridge 300 is combined with the electrophotographic photosensitive member 20 of the present invention by combining a charging unit 32, a developing unit 35, a cleaning unit 37, an opening 42 for exposure, and a static eliminator 38 by using a mounting rail 44. It has become. The process cartridge 300 is detachably attached to an electrophotographic apparatus main body comprising transfer means 36, a fixing device 39, and other components not shown, and the electrophotographic apparatus together with the electrophotographic apparatus main body. It constitutes.

  The electrophotographic apparatus and the process cartridge of the present invention described above include the electrophotographic photosensitive member on which the functional layer containing the phthalocyanine pigment obtained by the present invention is formed. Stable image quality can be obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all. In the following examples, “part” means part by mass.

Example 1
[Synthesis of type I hydroxygallium phthalocyanine]
30 parts of 1,3-diiminoisoindoline and 9.1 parts of gallium trichloride were reacted in 230 parts of dimethyl sulfoxide with stirring at 160 ° C. for 6 hours to obtain reddish purple crystals. Next, after washing with dimethyl sulfoxide, it was washed with ion-exchanged water and dried to obtain 28 parts of crude crystals of type I chlorogallium phthalocyanine pigment.

[Acid pasting process]
Next, 2 parts of the obtained crude crystals of type I chlorogallium phthalocyanine were sufficiently dissolved in 80 parts of sulfuric acid (concentration 97%) at 65 ° C. and cooled to 25 ° C. This was dropped into a mixed solution of 150 parts of 25% aqueous ammonia and 100 parts of ion-exchanged water. The precipitated crystals were collected by filtration, further washed with ion exchange water and dried to obtain 1.8 parts of a type I hydroxygallium phthalocyanine pigment.

The X-ray diffraction spectrum of the I-type hydroxygallium phthalocyanine thus obtained was measured. The result is shown in FIG. In addition, the measurement of the X-ray diffraction spectrum in a present Example was performed on condition of the following using the CuK (alpha) characteristic X ray by the powder method.
Measuring instrument: X-ray diffractometer Miniflex manufactured by Rigaku Corporation
X-ray tube: Cu
Tube current: 15 mA
Scan speed: 5.0 deg. / Min
Sampling interval: 0.02 deg.
Start angle (2θ): 5 deg.
Stop angle (2θ): 35 deg.
Step angle (2θ): 0.02 deg.

[Preparation of the first fluid]
1 part of the type I hydroxygallium phthalocyanine pigment obtained by the acid pasting treatment was placed in a homomixer (ACE homogenizer, manufactured by Nippon Seiki Co., Ltd.) together with 20 parts of acetone and stirred for 2 minutes at 15000 rpm. Thus, the 1st fluid whose solid content concentration is 4.76 mass% was prepared.

  Further, N, N-dimethylformamide was used as a second solvent capable of converting the crystal form of the hydroxygallium phthalocyanine pigment, and this was used as the second fluid.

[Conversion of crystal form of hydroxygallium phthalocyanine]
Next, the crystal form of hydroxygallium phthalocyanine was converted using a processing apparatus having the same configuration as the processing apparatus shown in FIG.

  The first fluid as described above is set in the container 11 and the second fluid is set in the microsyringe 2 equipped with a pump, and the microreactor (IMT: ICC-SY15) is supplied at a constant flow rate to the inlet portion. Liquid was sent. In a microreactor set at 20 ° C. with a temperature controller, the crystalline form of hydroxygallium phthalocyanine was converted, and the hydroxygallium phthalocyanine pigment was recovered in the container 3. In the microreactor, the first, second, and third flow paths have a width of 300 μm, a depth of 50 μm, and a length of the third flow path of 10 cm. The first fluid flow rate (liquid feeding speed) was set to 0.20 ml / hr and the second fluid flow rate (liquid feeding speed) was set to 10.0 ml / hr for liquid feeding. At this time, there was no leakage of the first fluid or the second fluid or loss of the pigment.

  The average particle size of the V-type hydroxygallium phthalocyanine pigment in the treatment liquid thus obtained was measured using a laser diffraction / scattering particle size distribution analyzer (LA700, manufactured by Horiba, Ltd.). The particle size distribution is a general index GSD (with respect to the particle size range (channel) obtained by dividing the particle size distribution to be measured). The particle diameter at which the volume accumulation is 84% is defined as volume D84, and the value obtained from D84 / D16 is defined as volume average particle size distribution GSD). The average particle diameter and GSD value of the obtained V-type hydroxygallium phthalocyanine pigment are shown in Table 1, and a graph showing the particle size distribution is shown in FIG.

  Moreover, after filtering the said process liquid, it wash | cleans using acetone, and vacuum-drys it at 80 degreeC for 24 hours using a vacuum dryer, 0.9 parts V-type hydroxygallium phthalocyanine pigment is collect | recovered, This powder X-ray | X_line The diffraction spectrum was measured. The result is shown in FIG.

(Creation of electrophotographic photoreceptor sheet)
Using the obtained V-type hydroxygallium phthalocyanine pigment, an electrophotographic photosensitive member was produced as follows. First, an aluminum pipe of 40 mmφ × 319 mm was prepared as a conductive substrate.

  Next, 6 parts by weight of polyvinyl butyral (trade name: ESREC BM-1, manufactured by Sekisui Chemical Co., Ltd.), 12 parts of blocked isocyanate (trade name: Sumidur 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as a curing agent, primary particle size Zinc oxide (trade name: Nano Tech ZnO, manufactured by CI Kasei Co., Ltd.) 41 parts, silicone ball (trade name: Tospearl 120, manufactured by Toshiba Silicone) 1 part, leveling agent (trade name: silicone oil SH29PA, Toray Industries, Inc.) 100 ppm of Dow Corning Silicone) and 52 parts of methyl ethyl ketone were kneaded in a batch mill for 10 hours to prepare a coating solution for forming an undercoat layer.

  This coating solution for preparing the undercoat layer was dip-coated on a 50 μm thick aluminum sheet and dried by heating at 150 ° C. for 30 minutes to form an undercoat layer having a thickness of 20.0 μm.

  Next, a solution obtained by dissolving 1 part of vinyl chloride / vinyl acetate copolymer resin (trade name: VMCH, manufactured by Nihon Unicar) in 100 parts of n-butyl acetate and 1 part of the V-type hydroxygallium phthalocyanine pigment were mixed. Then, together with 150 parts of glass beads having an outer diameter of 1.0 mm, the mixture was dispersed for 5 hours by a sand mill to prepare a coating solution for forming a charge generation layer. The obtained coating solution for forming a charge generation layer was dip-coated on the above undercoat layer and dried by heating at 100 ° C. for 10 minutes to produce a charge generation layer having a thickness of 0.20 μm.

  Furthermore, 4 parts of N, N′-diphenyl-N, N′-bis (3-methyl)-[1,1′biphenyl] -4,4′-diamine as a charge transport material and a viscosity average molecular weight as a binder resin 6 parts of 30,000 bisphenol Z-type polycarbonate resin, 80 parts of tetrahydrofuran and 0.2 part of 2,6-di-t-butyl-4-methylphenol were mixed to prepare a coating solution for forming a charge transport layer.

  The obtained coating solution for forming a charge transport layer is dip-coated on the surface of the charge generation layer and dried by heating at 120 ° C. for 40 minutes to form a charge transport layer having a thickness of 20 μm. A sheet was obtained.

<Electrophotographic characteristic evaluation test of electrophotographic photoreceptor sheet>
In order to evaluate the electrophotographic characteristics of the electrophotographic photoreceptor sheet thus obtained, the electrophotographic characteristics were measured according to the following procedure.

  First, using a small-area mask of 20 mmφ, and using an electrostatic copying paper test apparatus (trade name: EPA8200, manufactured by Kawaguchi Denki Co., Ltd.) in an environment of 20 ° C. and 50% RH, by corona discharge of −5.0 kV. The electrophotographic photoreceptor sheet was negatively charged.

Next, the electrophotographic photosensitive sheet was irradiated with a halogen lamp light split at 780 nm using an interference filter so that the illuminance on the surface of the electrophotographic photosensitive sheet was 5.0 μW / cm ² . After measuring the initial surface potential V ₀ [V], the half-exposure amount E _1/2 [μJ / cm ² ] until the surface potential becomes ½ of V ₀ , and the surface potential V ₀ at this time. The dark decay rate (DDR) [%] obtained by {(V ₀ −V ₁ ) / V ₀ } × 100 was measured with the surface potential after 1 second as V ₁ . The electrophotographic photosensitive sheet is mounted on an electrophotographic apparatus, and after 10,000 sheets of images having lines of about 2 mm width printed at intervals of 7 mm are output, the initial surface potential V ₀ and the half exposure amount are the same as described above. E1 _{/ 2} and dark decay rate (DDR) were measured. These results are shown in Table 2.

<Evaluation of dispersibility of charge generation material>
In order to evaluate the dispersibility of the obtained V-type hydroxygallium phthalocyanine pigment, a charge generation layer forming coating solution was applied and dried on a glass plate to form a charge generation layer, and the dispersion state of the pigment was observed using a microscope did. The results are shown in Table 2. In Table 2, “good” means that no agglomerates were found in the charge generation layer, and “bad” means that agglomerates were observed or the coating film surface was rough. .

(Production of electrophotographic photosensitive drum)
An undercoating layer, a charge generation layer, and a charge transport layer are sequentially formed in the same procedure as the production of the electrophotographic photosensitive sheet except that an aluminum pipe having a diameter of 30 mmφ is prepared and used as a conductive support. The intended electrophotographic photosensitive drum was obtained.

(Electrophotographic equipment)
The obtained electrophotographic photosensitive drum was mounted on an electrophotographic apparatus (trade name: PR1000, manufactured by NEC Corporation) having the configuration shown in FIG. 11, and the following evaluation tests were performed. The charging device is a roller charger (BCR), the exposure device is a ROS using a 780 nm semiconductor laser, the developing device is a one-component reversal developing device, and the transfer device is a roller charger (BTR). .

<10,000 sheet print test>
In an environment of 32.5 ° C. and 90% RH, a halftone image of one dot and one space and an entire white image (background image) are output and observed visually and with a magnifying glass. The presence or absence was evaluated. The dark potential Vd of the electrophotographic photosensitive member was also measured. Note that fogging refers to dullness of an image due to countless minute black spots.

  Subsequently, after outputting 10,000 images printed with lines of about 2 mm width every 7 mm in length and width, a halftone image and a background image are output in the same manner as described above, and the images are observed visually and with a magnifying glass. The presence of fog and latent image ghost was evaluated. These results are shown in Table 3.

(Example 2)
Using the processing apparatus having the same configuration as the processing apparatus shown in FIG. 4, the solid content concentration of the first fluid is 8.33% by mass, and the flow rate (liquid feeding speed) of the first fluid is 0.10 ml. / Hr and the flow rate of the second fluid (liquid feeding speed) are set to 7.0 ml / hr, and the liquid is fed in the microreactor set at 20 ° C. by the temperature controller in the same manner as in Example 1. The crystal form of phthalocyanine was converted, and the hydroxygallium phthalocyanine pigment was recovered in the container 3. Note that the widths of the first, second, and third flow paths in the microreactor were the same as in Example 1, 300 μm, 50 μm in depth, and 10 cm in length of the third flow path. Further, the operation of returning the mixed fluid collected in the container 3 to the container 11 via the return flow path L4 and the pump P3 and feeding the mixed fluid to the inlet portion of the microreactor 5 at a constant flow rate is repeated. The crystal form was converted 10 times. Table 1 shows the average particle diameter and GSD value of the obtained V-type hydroxygallium phthalocyanine pigment. Note that the powder X-ray diffraction spectrum was the same as that shown in FIG.

(Comparative Example 1)
The type I hydroxygallium phthalocyanine pigment obtained by the acid pasting treatment was pulverized in an automatic mortar for 5.5 hours to obtain an amorphous pigment, and 5.0 parts of this amorphous pigment, 150 parts of dimethylformamide, A glass bead having a diameter of 1 mm was milled to convert the crystal form for 24 hours to obtain 4.5 parts of a V-type hydroxygallium phthalocyanine pigment, and various tests and evaluations were performed. The average particle diameter and GSD value of the obtained V-type hydroxygallium phthalocyanine pigment are shown in Table 1, and a graph showing the particle size distribution is shown in FIG. Note that the powder X-ray diffraction spectrum was the same as that shown in FIG.

(Example 3)
An amorphous titanyl phthalocyanine pigment was produced in place of the hydroxygallium phthalocyanine pigment, and the first fluid was prepared using this pigment, and the titanyl phthalocyanine was used in the same manner as in Example 1 except that the microreactor was passed 5 times. A pigment was produced and subjected to various tests and evaluations. A titanyl phthalocyanine pigment and a first fluid containing the pigment were prepared as follows.

(Preparation of amorphous titanyl phthalocyanine)
3 parts of 1,3-diiminoisoindoline and 1.7 parts of titanium tetrabutoxide were placed in 20 parts of 1-chloronaphthalene and reacted at 190 ° C. for 5 hours. Then, the product was filtered, ammonia water, water And washed with acetone to obtain 4.0 parts of crude crystals of titanyl phthalocyanine pigment. The powder X-ray diffraction spectrum of this crystal is shown in FIG. Next, 2.0 parts of the obtained crude titanyl phthalocyanine crystal was dissolved in 100 parts of 97% sulfuric acid at 5 ° C. and then poured into 1300 parts of ice water to precipitate crystals. The precipitated crystals were separated by filtration, washed successively with dilute aqueous ammonia and water, and dried to obtain 1.6 parts of amorphous titanyl phthalocyanine. FIG. 17 shows a powder X-ray diffraction spectrum of the obtained amorphous titanyl phthalocyanine.

[Preparation of the first fluid]
1 part of the obtained amorphous titanyl phthalocyanine was placed in a homomixer (Ace homogenizer, manufactured by Nippon Seiki Co., Ltd.) together with 100 parts of distilled water, and stirred for 2 minutes at 15000 rpm. Thus, the 1st fluid whose solid content concentration is 0.99 mass% was prepared.

  In addition, monochlorobenzene was used as a second solvent capable of converting the crystal form of the titanyl phthalocyanine pigment, and this was used as the second fluid.

  Table 1 shows the average particle size and GSD value of the titanyl phthalocyanine pigment obtained by solvent treatment using a microreactor. Further, FIG. 18 shows a powder X-ray diffraction spectrum of the titanyl phthalocyanine pigment.

(Comparative Example 2)
A titanyl phthalocyanine pigment was produced in the same manner as in Example 3 except that the crystalline form of amorphous titanyl phthalocyanine was converted by stirring instead of the microreactor, and various tests and evaluations were performed. The crystal form was converted by stirring for 1 hour at 50 ° C. in a mixed solvent of 10 parts of amorphous titanyl phthalocyanine and 10 parts of water and 1 part of monochlorobenzene. After the conversion of the crystal form, the pigment was filtered. And washed with methanol and water to obtain 0.9 parts of a titanyl phthalocyanine pigment. The average particle diameter and GSD value of the obtained titanyl phthalocyanine pigment are shown in Table 1. The powder X-ray diffraction spectrum was the same as that shown in FIG.

Example 4
Example 1 except that an α-type metal-free phthalocyanine pigment is produced in place of the hydroxygallium phthalocyanine pigment, the first fluid is prepared using this, and the number of passes of the micromixer as shown in FIG. As in Example 1, an X-type metal-free phthalocyanine pigment was produced and subjected to various tests and evaluations. Table 1 shows the average particle size and GSD value of the X-type metal-free phthalocyanine pigment thus obtained. Further, FIG. 19 shows a powder X-ray diffraction spectrum of the X-type metal-free phthalocyanine pigment. The α-type metal-free phthalocyanine pigment was prepared as follows.

(Preparation of α-type metal-free phthalocyanine pigment)
100 parts of o-phthalodinitrile and 10 parts of piperidine were added to 300 parts of chlorotoluene and reacted with stirring at 200 ° C. for 10 hours to obtain reddish purple crystals. Next, reddish purple crystals were separated by filtration, washed with methanol, N, N-dimethylformamide, and N-methylpyrrolidone in this order, and dried to obtain crude metal-free phthalocyanine crystals. 12 parts of the obtained crude metal-free phthalocyanine crystal was uniformly dissolved in 200 parts of 97% sulfuric acid cooled to 0 to 5 ° C., and this was dropped into 2000 parts of pure water to precipitate crystals. The precipitated crystals were separated by filtration, washed with methanol, N, N-dimethylformamide, and N-methylpyrrolidone in this order, and then dried to obtain 10 parts of α-type metal-free phthalocyanine.

(Comparative Example 3)
An X-type metal-free phthalocyanine pigment was produced in the same manner as in Example 4 except that the α-type metal-free phthalocyanine crystal was converted by stirring instead of the micromixer, and various tests and evaluations were performed. In addition, the conversion of the crystal form was carried out by dry-grinding 1 part of α-type metal-free phthalocyanine crystal together with 0.05 part of X-type metal-free phthalocyanine pigment and 60 parts of alumina beads having a diameter of 5 mm for 4 days using an alumina ball mill. Went by. The obtained pigment was ultrasonically dispersed with acetone for 5 minutes, and the average particle diameter was measured using a centrifugal sedimentation type particle size distribution measuring device to calculate GSD. The average particle size and GSD values are shown in Table 1. The powder X-ray diffraction spectrum was the same as that shown in FIG.

  The hydroxygallium phthalocyanine pigment, the titanyl phthalocyanine pigment, and the X-type metal-free phthalocyanine pigment prepared in Examples 1 to 4 have an average particle size that is not much different from those of Comparative Examples 1 to 3, but a GSD showing a dispersion state of the particle size distribution. Is very small and well sized. For this reason, the characteristics of the electrophotographic photoreceptor using them are excellent in durability and image quality. On the other hand, the hydroxygallium phthalocyanine pigment, the titanyl phthalocyanine pigment, and the X-type metal-free phthalocyanine pigment prepared in Comparative Examples 1 to 3 had a nonuniform particle size and a large GSD value. For this reason, the characteristics and image quality of the electrophotographic photosensitive member using them are also inferior.

It is a schematic block diagram which shows an example of the processing apparatus used suitably for the manufacturing method of this invention. It is explanatory drawing which shows notionally the state when the 1st fluid and the 2nd fluid merge in the microreactor 5 in FIG. It is a schematic block diagram which shows another example of the processing apparatus used suitably for the manufacturing method of this invention. It is a schematic block diagram which shows another example of the processing apparatus used suitably for the manufacturing method of this invention. It is a schematic block diagram which shows another example of the processing apparatus used suitably for the manufacturing method of this invention. 1 is a schematic cross-sectional view showing an embodiment of an electrophotographic photoreceptor according to the present invention. It is a schematic cross section which shows other embodiment of the electrophotographic photoreceptor concerning this invention. It is a schematic cross section which shows other embodiment of the electrophotographic photoreceptor concerning this invention. It is a schematic cross section which shows other embodiment of the electrophotographic photoreceptor concerning this invention. It is a schematic cross section which shows other embodiment of the electrophotographic photoreceptor concerning this invention. 1 is a schematic configuration diagram showing an embodiment of an electrophotographic apparatus according to the present invention. It is a schematic block diagram which shows other embodiment of the electrophotographic apparatus concerning this invention. 1 is a cross-sectional view schematically showing a basic configuration of an embodiment of a process cartridge according to the present invention. 2 is a powder X-ray diffraction pattern of an I-type hydroxygallium phthalocyanine pigment prepared in Example 1. FIG. 2 is a powder X-ray diffraction pattern of a V-type hydroxygallium phthalocyanine pigment prepared in Example 1. FIG. FIG. 4 is a powder X-ray diffraction pattern of a crude crystal of a titanyl phthalocyanine pigment prepared in Example 3. 4 is a powder X-ray diffraction pattern of amorphous titanyl phthalocyanine produced in Example 3. FIG. 4 is a powder X-ray diffraction pattern of a titanyl phthalocyanine pigment prepared in Example 3. FIG. 6 is a powder X-ray diffraction pattern of an X-type metal-free phthalocyanine pigment prepared in Example 4. FIG. It is a graph which shows the particle size distribution of the pigment produced in Example 1 and Comparative Example 1, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 ... Micro syringe, 1a ... 1st fluid, 2a ... 2nd fluid, 3 ... Container, 5 ... Micro reactor, 12 ... Micro mixer, L1, L2, L3 ... Channel, 20 ... Electrophotographic photoreceptor 21 ... conductive support, 23 ... photosensitive layer, 24 ... undercoat layer, 25 ... charge generation layer, 26 ... charge transport layer, 27 ... protective layer, 32 ... charging means, 33 ... power source, 34 ... exposure means, 35 ... developing means, 37 ... cleaning means, 38 ... static discharger, 39 ... fixing device, 40 ... transfer means, 42 ... opening for exposure, 44 ... mounting rail, 200,210 ... electrophotographic apparatus, 300 ... process cartridge.

Claims (6)

A method for producing a phthalocyanine pigment used as a charge generation material for an electrophotographic photoreceptor,
A first fluid containing a phthalocyanine compound and a first solvent, and a second fluid containing a second solvent capable of converting the crystal form of the phthalocyanine compound, respectively. A fluid and the second fluid are joined to form a laminar flow, and the crystal form of the phthalocyanine compound is converted by diffusion of the phthalocyanine compound from the first fluid side to the second fluid side. A method for producing a characteristic phthalocyanine pigment. The first fluid and the second fluid are fed so that the feeding speeds of the first fluid and the second fluid satisfy a condition represented by the following formula (1): The manufacturing method of the phthalocyanine pigment of Claim 1.
1 <(V ₂ / V ₁ ) ≦ 100 (1)
Wherein (1), _{V 1} and _{V 2} denotes the feeding speed of the first and second fluids, respectively. ] The method for producing a phthalocyanine pigment according to claim 1 or 2, wherein the solid content concentration of the first fluid is 0.01 to 10% by mass. In an electrophotographic photosensitive member comprising a conductive substrate and a photosensitive layer formed on the substrate,
An electrophotographic photoreceptor, wherein the photosensitive layer includes a functional layer containing a phthalocyanine pigment obtained by the method for producing a phthalocyanine pigment according to any one of claims 1 to 3. The electrophotographic photosensitive member according to claim 4,
A charging device that charges the electrophotographic photosensitive member, a developing device that develops an electrostatic latent image formed by exposure to form a toner image, and a cleaning device that removes toner remaining on the electrophotographic photosensitive member after transfer A process cartridge comprising at least one selected from the group consisting of: The electrophotographic photosensitive member according to claim 4,
A charging device for charging the electrophotographic photoreceptor;
An exposure apparatus that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image; and
A developing device for developing the electrostatic latent image to form a toner image;
An electrophotographic apparatus comprising: a transfer device that transfers the toner image from the electrophotographic photosensitive member to a transfer medium.

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