JP2005226013A - Chlorogalium phthalocyanine pigment and method for producing the same, electrophotographic photoreceptor, process cartridge, and electrophotographic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chlorogalium phthalocyanine pigment which gives an electrophotographic photoreceptor sufficient in sensitivity, chargeability, and dark decay and capable of giving stable image quality over a long period of time without causing image quality defects such as photographic fog, to provide a method for efficiently and surely producing the same, and to provide an electrophotographic photoreceptor, a process cartridge, and an electrophotographic apparatus using the same. <P>SOLUTION: The chlorogalium phthalocyanine pigment has a longest wavelength absorption maximum in the range of 740 to 770 nm in a spectral absorption spectrum in the wavelength region of 700 to 900 nm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a chlorogallium phthalocyanine pigment and a method for producing the same, an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus.

  Various inorganic and organic photoconductive materials are known as photoconductive materials used in electrophotographic photoreceptors as charge generation materials. Among these, organic photoconductive materials have transparency, good film formability, flexibility when used in electrophotographic photoreceptors, are non-polluting and relatively low cost, etc. Therefore, various researches and developments have been made in the past.

  In recent years, there has been an increasing demand for electrophotographic photoreceptors that have a photosensitive wavelength region in the wavelength region of near-infrared semiconductor lasers and can be used for digital recording such as laser printers, full-color digital copiers, and fax machines. Several photoconductive materials for use in electrophotographic photoreceptors have been proposed. In particular, for phthalocyanine compounds, many reports have been made on the relationship between the crystal form and electrophotographic characteristics.

  In general, pigments made of phthalocyanine compounds exhibit several crystal types due to differences in their production methods or processing methods, and it is known that the difference in crystal types greatly affects the photoelectric conversion characteristics of phthalocyanine pigments. . As for the crystal form of the phthalocyanine pigment, for example, in the case of a metal-free phthalocyanine pigment, crystal forms such as α-type, β-type, π-type, γ-type and X-type are known. In addition, regarding gallium phthalocyanine pigments, many reports have been made on their crystal types and electrophotographic characteristics. In an X-ray diffraction pattern using CuKα characteristic X-rays, at least a Bragg angle (2θ ± 0.2 °) has been reported. Chlorogallium phthalocyanine pigment having diffraction peaks at 7.4 °, 16.6 °, 25.5 ° and 28.3 ° (hereinafter sometimes referred to as “type II chlorogallium phthalocyanine pigment”) and an electron using the same Photoconductors are known (for example, Patent Document 1 and Non-Patent Document 1).

Furthermore, the present inventors have a type II chlorogallium phthalocyanine pigment that, when used as a charge generating material, can be adjusted in sensitivity over a wide range, has excellent dispersibility in a resin dispersion, and has good electrophotographic characteristics. In addition, an electrophotographic photosensitive member and an electrophotographic apparatus using the same were reported (Patent Document 2).
Japanese Patent Laid-Open No. 5-98181 JP-A-11-174142 Proceedings of the 67th Annual Meeting of the Chemical Society of Japan, IB404, 1994

  However, when the conventional chlorogallium phthalocyanine pigment is used for an electrophotographic photosensitive member, it has achieved a level with almost no problem with respect to the resolution and black spot density of the image, but image defects such as fog in the background of the image have been achieved. In terms of prevention, it is not always sufficient, and further improvement has been desired.

  The present invention has been made in view of the above-described problems of the prior art, and when used in an electrophotographic photoreceptor, achieves sufficient sensitivity, chargeability, dark decay characteristics, and causes image quality defects such as fogging. Chlorogallium phthalocyanine pigment capable of obtaining stable image quality over a long period of time, a method for producing a chlorogallium phthalocyanine pigment capable of efficiently and reliably producing such a pigment, and electrophotographic photosensitive film using the same It is an object to provide a body, a process cartridge, and an electrophotographic apparatus.

  The chlorogallium phthalocyanine pigment of the present invention has a maximum absorption maximum wavelength in the range of 740 to 770 nm in the spectral absorption spectrum in the wavelength range of 700 to 900 nm.

  By having the maximum absorption maximum wavelength in the specific range as described above, the phthalocyanine pigment of the present invention has an unprecedented finely divided state and particle uniformity, and is sufficient when used in an electrophotographic photoreceptor. It achieves sensitivity, chargeability, and dark decay characteristics, and provides stable image quality over a long period of time without causing image quality defects such as fogging.

  For example, as described in Patent Document 2, a type II chlorogallium phthalocyanine pigment having a maximum absorption maximum wavelength in a range exceeding 770 nm is conventionally known. In contrast, in the chlorogallium phthalocyanine pigment of the present invention, the maximum absorption maximum wavelength is shifted to the shorter wavelength side. Thus, the fact that the maximum absorption maximum wavelength has shifted to the short wavelength side corresponds to the weakening of the interaction between chlorogallium phthalocyanine molecules in the pigment, and the weakening of the interaction between molecules. It is presumed that the electric charge is less likely to flow through the pigment, and the effect of reducing dark current and thus preventing fogging is obtained.

The chlorogallium phthalocyanine pigment of the present invention preferably has an average particle size of 0.1 μm or less and a BET specific surface area of 45 m ² / g or more. By using a chlorogallium phthalocyanine pigment having such an average particle size and BET specific surface area for an electrophotographic photoreceptor, the dispersibility of the pigment in the binder resin can be improved, and variations in sensitivity, chargeability and dark attenuation characteristics can be achieved. Can be reduced, and stable image quality can be obtained over a longer period of time.

  The chlorogallium phthalocyanine pigment of the present invention has diffraction peaks at Bragg angles (2θ ± 0.2 °) of 7.4 °, 16.6 °, 25.5 ° and 28.3 ° with respect to CuKα characteristic X-rays. It is preferable. Since the chlorogallium phthalocyanine pigment has the above-described diffraction peak, when such a pigment is used for an electrophotographic photoreceptor, excellent photosensitivity, repeatability and environmental stability are obtained, and sufficient charging is achieved. Characteristics and dark decay characteristics can be obtained, image quality defects can be sufficiently prevented, and stable image quality can be obtained over a longer period of time.

  The method for producing chlorogallium phthalocyanine according to the present invention is to obtain a refined chlorogallium phthalocyanine pigment by dry milling an I-type chlorogallium phthalocyanine pigment, and wet milling the refined chlorogallium phthalocyanine pigment for a predetermined time. To obtain a crystal-converted chlorogallium phthalocyanine pigment, wherein the wet pulverization is carried out by a pulverizer using a spherical media having an outer diameter of 0.1 to 3.0 mm. Chlorogallium is used for a predetermined time for wet pulverization (hereinafter sometimes referred to as “wet pulverization time”) in an amount of 50 parts by weight or more based on 1 part by weight of the I-type chlorogallium phthalocyanine pigment. The average particle size of the phthalocyanine pigment is 0.1μm It is characterized in that in the range of a time.

  The wet pulverization time is when the time of the minimum point of the curve obtained by plotting the maximum absorption maximum wavelength in the spectral absorption spectrum of the chlorogallium phthalocyanine pigment in the wavelength range of 700 to 900 nm for each wet pulverization time is Ta. Or a time selected from the range of 0.7 Ta to 1.3 Ta, or when the time of the maximum point of the curve in which the BET specific surface area of the chlorogallium phthalocyanine pigment is plotted for each wet grinding time is Tb The time is preferably selected from the range of 0.7 Tb to 1.3 Tb.

  According to the production method of the present invention as described above, while maintaining the high sensitivity characteristic of the conventional chlorogallium phthalocyanine pigment, it has an unprecedented excellent atomization state and particle uniformity, and has a wavelength of 700 to 900 nm. In the spectral absorption spectrum in the region, a chlorogallium phthalocyanine pigment having a maximum absorption maximum wavelength in the range of 740 to 770 nm can be obtained efficiently and reliably.

  When the obtained chlorogallium phthalocyanine pigment is used as a material for an electrophotographic photosensitive member, excellent dispersibility, sufficient sensitivity, chargeability, and dark decay characteristics can be obtained, and long without causing image quality defects. It is possible to obtain stable image quality over a period.

  The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor comprising a conductive support and a photosensitive layer disposed on the support, wherein the photosensitive layer contains the chlorogallium phthalocyanine pigment of the present invention. To do.

  The process cartridge of the present invention includes the electrophotographic photosensitive member, a charging unit for charging the electrophotographic photosensitive member, an exposure unit for forming an electrostatic latent image on the electrophotographic photosensitive member, and the electrophotographic photosensitive member. Selected from the group consisting of developing means for developing the electrostatic latent image formed on the body with toner to form a toner image and cleaning means for removing the toner remaining on the electrophotographic photosensitive member. And at least one kind.

  The electrophotographic apparatus of the present invention includes the electrophotographic photosensitive member, a charging unit for charging the electrophotographic photosensitive member, an exposure unit for forming an electrostatic latent image on the electrophotographic photosensitive member, A developing unit for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image; and a transfer unit for transferring the toner image to a transfer target. is there.

  These electrophotographic photoreceptors, process cartridges, and electrophotographic apparatuses all use the chlorogallium phthalocyanine pigment of the present invention, and have excellent pigment dispersibility, sufficient sensitivity, chargeability, and dark decay characteristics. As a result, it is possible to obtain stable image quality over a long period of time without causing image quality defects such as fogging, black spots, and white spots.

  According to the present invention, when used as a material for an electrophotographic photosensitive member, excellent dispersibility, sufficient sensitivity, chargeability, and dark decay characteristics can be obtained, and long-term without causing image quality defects such as fogging. It is possible to provide a chlorogallium phthalocyanine pigment capable of obtaining a stable image quality over a wide range, and a method for producing a chlorogallium phthalocyanine pigment capable of efficiently and reliably producing such a pigment. In addition, by using the chlorogallium phthalocyanine pigment of the present invention, the dispersibility of the pigment is excellent, and sufficient sensitivity, chargeability and dark decay characteristics can be obtained, and thereby stable over a long period of time without causing image quality defects. It is possible to provide an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus that can obtain the obtained image quality.

  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.

(Chlorogallium phthalocyanine pigment)
The chlorogallium phthalocyanine pigment of the present invention has a maximum absorption maximum wavelength at 740 to 770 nm in the spectral absorption spectrum in the wavelength range of 700 to 900 nm. When the maximum absorption maximum wavelength is in the above range, a sufficient fog prevention effect can be obtained. When the maximum absorption maximum wavelength is less than 740 nm, the crystal conversion is insufficient, or the mixture of crystal forms other than the type II chlorogallium phthalocyanine pigment increases, resulting in a decrease in sensitivity or an increase in dark attenuation. When it exceeds 770 nm, fog tends to occur. In order to further improve dispersibility, the above range is more preferably 745 to 770 nm.

The chlorogallium phthalocyanine pigment of the present invention preferably has an average particle diameter in a specific range and a BET specific surface area in a specific range. Specifically, the average particle size is preferably 0.10 μm or less, more preferably 0.01 to 0.08 μm, while the BET specific surface area is preferably 45 m ² / g or more, more preferably 50 m ² / g or more, and even more preferably 55~120m ² / g.

When the average particle diameter of the chlorogallium phthalocyanine pigment is larger than 0.10 μm, or when the BET specific surface area is less than 45 m ² / g, the pigment particles are coarsened or aggregates of the pigment particles are formed. When used as a material for an electrophotographic photosensitive member, defects such as dispersibility, sensitivity, chargeability, and dark decay characteristics tend to easily occur, which may easily cause image quality defects.

  Further, the chlorogallium phthalocyanine pigment of the present invention has a Bragg angle (2θ ± 0.2 °) of 7.4 °, 16.6 °, 25.5 °, and X-ray diffraction spectrum using CuKα characteristic X-ray. It preferably has a diffraction peak at 28.3 °. In addition, although the chlorogallium phthalocyanine pigment having such a Bragg angle has been conventionally known, as described above, the chlorogallium phthalocyanine pigment of the present invention has a specific maximum absorption maximum wavelength, as described above. It ’s clearly different.

  The chlorogallium phthalocyanine pigment of the present invention described above can be used in various applications such as dyes, electrophotographic photoreceptors, optical disks, solar cells, sensors, deodorants, antibacterial agents, and nonlinear optical materials. In particular, when the chlorogallium phthalocyanine pigment of the present invention is used as a charge generation material for an electrophotographic photosensitive member, it is possible to obtain the optimum sensitivity and excellent photoelectric characteristics of the photosensitive member, and the results included in the photosensitive layer. Since it is excellent in dispersibility in the resin, it is particularly effective in that it has excellent image quality characteristics.

(Method for producing chlorogallium phthalocyanine pigment)
The method for producing chlorogallium phthalocyanine according to the present invention is to obtain a refined chlorogallium phthalocyanine pigment by dry milling an I-type chlorogallium phthalocyanine pigment, and wet milling the refined chlorogallium phthalocyanine pigment for a predetermined time. To obtain a crystal-converted chlorogallium phthalocyanine pigment, wherein the wet pulverization is carried out by a pulverizer using a spherical media having an outer diameter of 0.1 to 3.0 mm. Chlorogallium is used for a predetermined time for wet pulverization (hereinafter sometimes referred to as “wet pulverization time”) in an amount of 50 parts by weight or more based on 1 part by weight of the I-type chlorogallium phthalocyanine pigment. When the average particle size of the phthalocyanine pigment is 0.1 μm It is characterized in that in the range of.

  The type I chlorogallium phthalocyanine pigment used as a raw material for this production method can be obtained by a conventionally known method. The I-type chlorogallium phthalocyanine means a substance having a diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.1 ° with respect to the CuKα characteristic X-ray.

  Examples of methods for obtaining type I chlorogallium phthalocyanine pigments include the diiminoisoindoline method in which 1,3-diiminoisoindoline is heated and condensed in gallium trichloride and an organic solvent, and phthalonitrile and gallium trichloride are heated and melted. Or a phthalonitrile method of heating in the presence of an organic solvent, a Weiler method of heating and melting phthalic anhydride and urea and gallium trichloride or heating in the presence of an organic solvent, and the like can be suitably employed. it can.

  As the organic solvent used when obtaining the type I chlorogallium phthalocyanine pigment by the above method, α-chloronaphthalene, β-chloronaphthalene, methoxynaphthalene, diphenylethane, ethylene glycol, dialkyl ether, quinoline, sulfolane, dimethyl sulfoxide, High boiling solvents that are inert to the synthesis reaction, such as dichlorobenzene, dichlorotoluene, and dimethylsulfoamide, are preferred.

  In addition, when employ | adopting the said diiminoindoline method, heat condensation temperature is 130-220 degreeC, Preferably it is good to set it as 140-180 degreeC.

  The type I chlorogallium phthalocyanine pigment synthesized by the above method has a strong diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.1 ° with respect to the CuKα characteristic X-ray, as shown in the following examples. Yes.

  In the present invention, first, a fine chlorogallium phthalocyanine pigment is obtained by dry pulverizing the I-type chlorogallium phthalocyanine pigment. Examples of the apparatus that can be used for this dry pulverization include a vibration mill, an automatic mortar, a sand mill, a dyno mill, a Sco mill, a coball mill, an attritor, a planetary ball mill, and a ball mill.

  The primary particle size of the refined chlorogallium phthalocyanine pigment after dry pulverization is preferably 0.001 to 0.1 μm. The primary particle diameter in such a range can be obtained by controlling grinding conditions such as grinding time, rotation speed, media size, and pigment / media ratio. The refined chlorogallium phthalocyanine pigment obtained by dry pulverization has a Bragg angle (2θ ± 0.2 °) of 27.1 ° with respect to the CuKα characteristic X-ray characteristic of the type I chlorogallium phthalocyanine pigment, as shown in the following examples. Diffraction peak disappeared and newly converted to crystal form close to amorphous type with broad and weak diffraction peaks at 7.4 °, 16.6 °, 25.5 °, and 28.3 ° .

  Next, the chlorogallium phthalocyanine pigment obtained as described above and refined is further crystallized by wet pulverization with a solvent to obtain the desired chlorogallium phthalocyanine pigment.

  The wet pulverization is performed using a pulverizer using a spherical media having an outer diameter of 0.1 to 3.0 mm, preferably an outer diameter of 0.2 to 2.5 mm. When the outer shape of the media is larger than 3.0 mm, the pulverization efficiency is lowered, so that the particle diameter does not become small and aggregates tend to be easily generated. Further, when the outer diameter of the medium is smaller than 0.1 mm, it tends to be difficult to separate the medium and the chlorogallium phthalocyanine pigment. In addition, when the media is not spherical, but in other shapes such as a columnar shape or an indefinite shape, the crushing efficiency is reduced, and the media wears during the crushing to generate wear powder. There exists a tendency for the characteristic of a gallium phthalocyanine pigment to deteriorate easily.

  The material of the media is not particularly limited, but is preferably a material that does not easily cause image quality defects even when mixed in a pigment, and glass, zirconia, alumina, menor, and the like are preferable.

  Further, the material of the container for performing the wet pulverization is not particularly limited, but those that are less likely to cause image quality defects even when mixed in the pigment are preferable, glass, zirconia, alumina, menor, polypropylene, Teflon (registered trademark), Polyphenylene sulfide and the like are preferable. Alternatively, glass, polypropylene, Teflon (registered trademark), polyphenylene sulfide, or the like may be lined on the inner surface of a metal container such as iron or stainless steel.

  The amount of the media used is in the range of 50 parts by weight or more, preferably 55 to 100 parts by weight with respect to 1 part by weight of the I-type chlorogallium phthalocyanine pigment, and is optimized according to the apparatus to be used. If the amount of media used is less than 50 parts by weight, the pulverization efficiency may not be sufficient, so that miniaturization may be difficult.

  In addition, as the outer diameter of the media decreases, the density of the media occupying the device increases even with the same weight (use amount), and the viscosity of the mixed solution increases and the pulverization efficiency changes. It is preferable to perform wet pulverization at an optimum mixing ratio by appropriately controlling the amount of media used and the amount of solvent used.

  The temperature at which the wet pulverization is performed is preferably 0 to 100 ° C, more preferably 5 to 80 ° C, and still more preferably 10 to 50 ° C. If the temperature at which the wet pulverization is performed is less than 0 ° C, the rate of crystal transition is slow, and if the temperature exceeds 100 ° C, the solubility of the chlorogallium phthalocyanine pigment becomes high and crystal growth is likely to be difficult. Tend to be.

  Examples of the solvent used for wet grinding include amides such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone, esters such as ethyl acetate, n-butyl acetate and iso-amyl acetate, In addition to ketones such as acetone, methyl ethyl ketone, and methyl iso-butyl ketone, dimethyl sulfoxide and the like can be mentioned. The amount of these solvents used is usually 1 to 200 parts by weight, preferably 1 to 100 parts by weight, per 1 part by weight of the chlorogallium phthalocyanine pigment.

  For the wet pulverization, a pulverizer using a medium as a dispersion medium, such as a vibration mill, an automatic mortar, a sand mill, a dyno mill, a coball mill, an attritor, a planetary ball mill, or a ball mill, can be used.

  The speed of atomization and crystal conversion of chlorogallium phthalocyanine pigment in the wet grinding process is greatly affected by the scale of the wet grinding, stirring speed, media material, etc., but the wet grinding time is the chlorogallium phthalocyanine pigment in the wet grinding process. The average particle size is within the range of time when it is 0.1 μm or less.

  The wet pulverization time is determined in advance by measuring the average particle size of the chlorogallium phthalocyanine pigment in the wet pulverization process for each predetermined pulverization time and obtaining the pulverization time when the average particle size is 0.1 μm or less. It is preferable.

  By the way, as a result of examining in detail the relationship between the absorption maximum wavelength of the chlorogallium phthalocyanine pigment and the pulverization time in the wet pulverization process, the present inventors have determined that the spectral absorption spectrum of the chlorogallium phthalocyanine pigment in the wavelength region of 700 to 900 nm. It has been found that the maximum absorption maximum wavelength at 1 is shifted to the short wavelength side in the wet pulverization process after the wet pulverization is started, and then returns to the long wavelength side after reaching a minimum at a certain point.

  Therefore, when the minimum point of the curve obtained by plotting the maximum absorption maximum wavelength in the spectral absorption spectrum of the chlorogallium phthalocyanine pigment in the wavelength range of 700 to 900 nm for each time of wet grinding is Ta, The target chlorogallium phthalocyanine is set to a time selected from the range of 7Ta to 1.3Ta, preferably within the range of 0.8Ta to 1.2Ta, and more preferably within the range of 0.9Ta to 1.1Ta. In order to obtain a pigment efficiently and reliably, it is preferable.

In addition, the above Ta measures λ _MAX in the spectral absorption spectrum in the 700 to 900 nm wavelength region of the phthalocyanine pigment in the wet pulverization process at every predetermined pulverization time, and uses the measured λ _MAX value as the pulverization time. On the other hand, a set of plotted points is regarded as a curve, and the time corresponding to the minimum point of the curve can be determined as Ta. At this time, the measurement of λ _MAX is preferably performed every 1 to 50 hours, more preferably every 2 to 40 hours.

The λ _{MAX of the} chlorogallium phthalocyanine pigment in the wet pulverization process is obtained by, for example, sampling a small amount of the pigment solution from a wet pulverizer and diluting it with a solvent such as acetone or ethyl acetate, and then using a spectrophotometer. It can be measured by the cell method.

  Furthermore, according to the results of experiments by the present inventors, the BET specific surface area of the chlorogallium phthalocyanine pigment in the wet grinding process gradually increases at the beginning of the wet grinding, but reaches a maximum at a certain point. It became clear that it turned to decrease after becoming.

  This started wet grinding in the balance between the action of increasing the specific surface area due to the effect of grinding / atomization in wet grinding and the action of crystal growth of chlorogallium phthalocyanine pigment in the solvent to reduce the specific surface area. Immediately after that, the BET specific surface area increases because the former action is large, and it is assumed that the latter action increases thereafter.

  Therefore, as another method for determining the wet pulverization time, when the time of the maximum point of the curve obtained by plotting the BET specific surface area of the chlorogallium phthalocyanine pigment for each wet pulverization time is Tb, 0.7 Tb to 1 A method in which the time selected from the range of 3 Tb is used as the wet grinding time can also be suitably employed.

  The Tb is a set of points obtained by measuring the BET specific surface area of the phthalocyanine pigment in the wet pulverization process for each predetermined pulverization time and plotting the measured BET specific surface area value against the pulverization time as a curve. The time corresponding to the maximal point of this curve can be determined as Tb. At this time, the measurement of the BET specific surface area is preferably performed every 1 to 50 hours, more preferably every 2 to 40 hours.

  As a method for measuring the BET specific surface area value of the chlorogallium phthalocyanine pigment in the wet pulverization process, a sample partially sampled from the slurry in which the chlorogallium phthalocyanine pigment in the wet pulverization process is dispersed is filtered and washed, and further dried. Thus, it is possible to suitably employ a method of measuring the powder using a laser diffraction / scattering particle size distribution measuring apparatus.

Wet milling time may be determined based on both λ _MAX and BET specific surface area. For example, using the above Ta and Tb, a time within a range satisfying the following formula (1), more preferably the following formula (2) can be set as the wet grinding time.

  0.7 (Ta + Tb) /2≦T≦1.3 (Ta + Tb) / 2 (1)

  0.8 (Ta + Tb) /2≦T≦1.2 (Ta + Tb) / 2 (2)

As described above, when the wet pulverization treatment time is determined based on the change with time of λ _MAX or the BET specific surface area, the pulverization time and the maximum absorption maximum wavelength or BET under the same wet pulverization conditions as the wet pulverization to be performed. It is preferable to measure in advance the relationship with the specific surface area and to predetermine the wet grinding time based on this. It may take a little longer to measure the maximum absorption maximum wavelength and BET specific surface area after sampling the sample liquid, and the chlorogallium phthalocyanine pigment in the wet pulverization process is further increased until the measurement value is obtained. Although there is a possibility that it may change with time, if the wet pulverization time is determined in advance, it is easy to perform wet pulverization in an optimum time.

  The wet pulverization time thus determined is usually in the range of 5 to 500 hours, preferably in the range of 7 to 300 hours. When the wet pulverization time is less than 5 hours, the crystal conversion is not completed, and there is a tendency that the electrophotographic characteristics are deteriorated, in particular, the problem of insufficient sensitivity is likely to occur. On the other hand, when the wet pulverization time exceeds 500 hours, problems such as a decrease in sensitivity, a decrease in productivity, and mixing of media abrasion powder tend to occur due to the influence of pulverization stress. By determining the wet pulverization time in this way, it becomes possible to complete the wet pulverization process in a state where the particles of the chlorogallium phthalocyanine pigment are uniformly finely divided, and furthermore, when the wet pulverization is repeated for a plurality of lots. It becomes possible to suppress the quality variation between lots.

  After the wet pulverization, it is preferable to filter out the chlorogallium phthalocyanine pigment dispersed in the solvent, and further perform washing with a solvent and / or heat drying. By removing or reducing residual solvents and impurities contained in the crystals of chlorogallium phthalocyanine pigments by washing with such solvents and heating and drying, sensitivity, chargeability, dark decay characteristics, and repeated use due to these are eliminated. It is possible to suppress the potential stability at the time and the influence on the image quality.

  Examples of the solvent used for washing include water, ethanol, methanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, Organic solvents such as methylene chloride, chloroform, benzene, toluene, xylene, chlorobenzene, dimethylformaldehyde, dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, and mixed solvents thereof, and supercritical fluids such as carbon dioxide and nitrogen Etc. As a cleaning method, a known method can be used without any particular limitation. From the viewpoint of cleaning efficiency, a ceramic filter, an ultrasonic cleaner, a Soxhlet extractor, a micromixer having a channel diameter of 10 to 1000 μm, or the like A cleaning method using is effective and preferable.

  Moreover, when heat-drying, the temperature of heat-drying becomes like this. Preferably it is 50-200 degreeC, More preferably, it is 100-180 degreeC. When the heating temperature is less than 50 ° C., it tends to be difficult to completely remove impurities affecting various properties of the chlorogallium phthalocyanine pigment. When the heating temperature exceeds 200 ° C., the sensitivity of the chlorogallium phthalocyanine pigment is remarkably increased. It tends to decrease. Moreover, it is preferable that the heat drying treatment time is appropriately adjusted according to the weight of the chlorogallium phthalocyanine pigment to be treated.

  In order to efficiently remove impurities and the like contained in the chlorogallium phthalocyanine pigment crystals by heat drying, it is preferable to heat and dry the chlorogallium phthalocyanine pigment under reduced pressure. When performing heat drying under reduced pressure, there is an advantage that the temperature of heat drying can be made lower than when performing under normal pressure. The heat drying temperature at this time is preferably in the range of 50 to 200 ° C., although it depends on the degree of reduced pressure.

  Moreover, it is preferable to perform heat drying in presence of an inert gas. Examples of the inert gas include helium, neon, argon, and the like of group 0 of the periodic table, and these can be used alone or in admixture of two or more. By performing heat drying in the presence of these inert gases, there is an advantage that the chlorogallium phthalocyanine pigment is prevented from being oxidized by oxygen in the air, and heat drying at high temperatures becomes possible. Moreover, it is also preferable to perform heat drying in the state which interrupted light. Thereby, it is possible to prevent the chlorogallium phthalocyanine pigment from being light fatigued during the heat drying.

  The chlorogallium phthalocyanine pigment of the present invention obtained by the production method of the present invention is used for various applications such as dyes, electrophotographic photoreceptors, optical disks, solar cells, sensors, deodorants, antibacterial agents, and nonlinear optical materials. Can do. In particular, when the chlorogallium phthalocyanine pigment of the present invention is used as a charge generation material for an electrophotographic photosensitive member, it is possible to obtain the optimum sensitivity and excellent photoelectric characteristics of the photosensitive member, and the results included in the photosensitive film. Since it is excellent in dispersibility in the resin, it is particularly effective in that it has excellent image quality characteristics.

(Electrophotographic photoreceptor)
FIG. 1A is a schematic cross-sectional view showing a first embodiment of the electrophotographic photosensitive member of the present invention. An electrophotographic photoreceptor 100 shown in FIG. 1A is a laminated type in which functions are separated into a layer containing a charge generation material (charge generation layer 1) and a layer containing a charge transport material (charge transport layer 2). It has a photosensitive layer 6 and has a structure in which a charge generation layer 1 and a charge transport layer 2 are sequentially laminated on a conductive support 3. The chlorogallium phthalocyanine pigment of the present invention is contained in the charge generation layer 1 as a charge generation material.

  As the conductive support 3, for example, a metal such as aluminum, copper, iron, zinc, nickel, a polymer sheet, paper, plastic, glass, etc. on a base such as aluminum, copper, gold, silver, platinum, Conductive treatment by depositing a metal such as palladium, titanium, nickel-chromium, stainless steel, copper-indium, etc., or conducting a conductive treatment by depositing a conductive metal compound such as indium oxide or tin oxide on the substrate. In addition, a conductive material obtained by laminating a metal foil on the substrate, carbon black, indium oxide, tin oxide-antimony oxide powder, metal powder, copper iodide, etc. are dispersed in a binder resin, The thing etc. which carried out the electroconductive process by apply | coating are mentioned. The shape of the conductive support 3 may be any of a drum shape, a sheet shape, and a plate shape.

  Here, when using a metal pipe base material as the conductive support 3, even if the surface remains as a raw tube, mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing, It is preferable to perform a treatment such as a coloring treatment. By roughening the surface of the substrate by performing the surface treatment, it is possible to prevent wood-like density spots due to the interference light in the photoconductor that may occur when a coherent light source such as a laser beam is used.

  When a metal pipe substrate is used as the conductive support 3, the surface thereof may remain as it is, but in advance, mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing, coloring treatment It is preferable to roughen the substrate surface by a surface treatment such as In this way, by roughening the surface of the substrate, it is possible to prevent grain-like density spots due to interference light in the photoconductor that may occur when a coherent light source such as a laser beam is used.

  The charge generation layer 1 contains the chlorogallium phthalocyanine pigment of the present invention as a charge generation material and a binder resin.

  Examples of the binder resin include polycarbonate, polystyrene, polysulfone, polyester, polyimide, polyester carbonate, polyvinyl butyral, methacrylic acid ester polymer, vinyl acetate homopolymer or copolymer, cellulose ester, cellulose ether, polybutadiene, polyurethane, phenoxy. Examples thereof include resins, epoxy resins, silicone resins, fluororesins, and partially crosslinked cured products thereof. One of these can be used alone, or two or more can be used in combination.

  The compounding ratio (weight ratio) of the chlorogallium phthalocyanine pigment of the present invention and the binder resin in the charge generation layer 1 is preferably 40: 1 to 1: 4, more preferably 20: 1 to 1: 2. . If the blending amount of the chlorogallium phthalocyanine of the present invention exceeds 40 times the blending amount of the binder resin, the dispersibility of the pigment in the dispersion used in the electrophotographic photoreceptor manufacturing process tends to be insufficient. On the other hand, if the blending amount of the binder resin is less than ¼, the sensitivity of the electrophotographic photosensitive member tends to be insufficient.

  The charge generation layer 1 may contain other charge generation materials other than the chlorogallium phthalocyanine pigment of the present invention. Here, as other charge generation materials used for the charge generation layer 1, azo pigments, perylene pigments, condensed aromatic pigments and the like can be used, but it is preferable to use metal-containing or metal-free phthalocyanines. Among them, it is particularly preferable to use a chlorogallium phthalocyanine pigment, a hydroxygallium phthalocyanine pigment, a dichlorotin phthalocyanine pigment or an oxytitanyl phthalocyanine pigment which is different from the chlorogallium phthalocyanine pigment of the present invention. The amount of these other charge generation materials is preferably 50% by weight or less based on the total amount of substances contained in the charge generation layer.

  When another layer such as the charge transport layer 2 is further formed on the charge generation layer 1, the charge generation layer 1 is not dissolved or swollen by the solvent used in the coating solution. The combination of the binder resin of the charge generation layer 1 and the solvent of the coating solution applied onto the charge generation layer 1 is preferably selected as appropriate. The binder resin of the charge generation layer 1 and the binder resin of the charge transport layer 2, which will be described later, are preferably used in combination with ones whose refractive indices are close to each other. The difference is preferably 1 or less. When a binder resin having a similar refractive index is used in combination, light reflection at the interface between the charge generation layer 1 and the charge transport layer 2 is suppressed, and the interference fringe prevention effect tends to be improved.

  The charge generation layer 1 is prepared by adding the chlorogallium phthalocyanine pigment of the present invention and a binder resin to a predetermined solvent, a sand mill, a colloid mill, an attritor, a dyno mill, a jet mill, a coball mill, a roll mill, an ultrasonic disperser, a gorin homogenizer, a micro Coating liquid obtained by mixing and dispersing using fluidizer, optimizer, milder, etc., blade coating method, Meyer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, It can be obtained by applying and drying by a curtain coating method or the like.

  Here, as a solvent used for the coating liquid of the charge generation layer 1, specifically, methanol, ethanol, n-butanol, benzyl alcohol, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran , Methylene chloride, chloroform, toluene, xylene, chlorobenzene, dimethylformamide, dimethylacetamide, water, and the like. One of these may be used alone, or a mixture of two or more may be used.

  The film thickness of the charge generation layer 1 thus obtained is preferably 0.05 to 5 μm, more preferably 0.1 to 1 μm, in order to obtain good electrical characteristics and image quality. When the film thickness of the charge generation layer 1 is less than 0.05 μm, the sensitivity tends to decrease, and when the film thickness exceeds 5 μm, there is a tendency that adverse effects such as poor chargeability tend to occur.

  The charge transport layer 2 contains a charge transport material and a binder resin. The charge transport material used for the charge transport layer 2 can be used without particular limitation as long as it has a function of transporting charges. For example, oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)] Pyrazoline derivatives such as -3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenylamine, tri (P-methyl) phenylamine, N, N′-bis (3,4-dimethylphenyl) ) Aromatic tertiary amino compounds such as biphenyl-4-amine, dibenzylaniline, 9,9-dimethyl-N, N′-di (p-tolyl) fluorenon-2-amine, N, N′-diphenyl- Aromatic tertiary diamino compounds such as N, N′-bis (3-methylphenyl)-[1,1-biphenyl] -4,4′-diamine, 3- (4′dimethyla Nophenyl) -5,6-di- (4′-methoxyphenyl) -1,2,4-triazine, 1,2,4-triazine derivatives, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-diphenyl Hydrazone derivatives such as aminobenzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1-naphthyl) phenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6-hydroxy-2, Benzofuran derivatives such as 3-di (p-methoxyphenyl) -benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N′-diphenylaniline, enamine derivatives, N-ethylcarbazole, etc. Carbazole derivatives, poly-N-vinylcarbazole and Hole transport materials such as derivatives thereof, quinone compounds such as chloranil, bromoanil and anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9- Fluorenone compounds such as fluorenone, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3 Oxadiazole compounds such as 4-oxadiazole, 2,5-bis (4-diethylaminophenyl) 1,3,4 oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′tetra And electron transport materials such as diphenoquinone compounds such as -t-butyldiphenoquinone. Further, as the charge transport material, a polymer having the basic structure of the compound exemplified above in the main chain or side chain can be used. These charge transport materials can be used singly or in combination of two or more.

  As the binder resin used for the charge transport layer 2, a known resin can be used without any particular limitation, but a resin capable of forming an electrically insulating film is preferably used. For example, polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-acetic acid Vinyl copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-carbazole, polyvinyl butyral, polyvinyl formal, polysulfone , Casein, gelatin, polyvinyl alcohol, ethyl cellulose, phenol resin, polyamide, carboxy-methyl cellulose, vinylidene chloride polymer wax, polyurea Emissions, and the like. These binder resins can be used alone or in combination of two or more. In particular, a polycarbonate resin, a polyester resin, a methacrylic resin, and an acrylic resin are preferably used because they are excellent in compatibility with a charge transporting material, solubility in a solvent, and strength.

  Further, the blending ratio (mass ratio) of the binder resin and the charge transport material can be arbitrarily set in consideration of a decrease in electrical characteristics and a decrease in film strength.

  Furthermore, the thickness of the charge transport layer 2 is preferably 5 to 50 μm, and more preferably 10 to 35 μm.

  As a solvent used for the coating liquid for forming the charge transport layer 2, a common organic solvent such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene and the like can be used alone or in combination. As a coating method of the charge transport layer 2, methods such as 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, and a curtain coating method can be used.

  FIG. 1B is a schematic cross-sectional view showing a second embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor 110 shown in FIG. 1B is similar to the electrophotographic photoreceptor 100 shown in FIG. 1A except that the undercoat layer 4 is provided between the conductive support 3 and the photosensitive layer 6. It has the same structure.

  The undercoat layer 4 has a function of preventing charge injection from the conductive support 3 to the photosensitive layer 6 when the photosensitive layer 6 is charged. The undercoat layer 4 also functions as an adhesive layer that integrally holds the photosensitive layer 6 to the conductive support 3. Further, the undercoat layer 4 has a function of preventing light reflection of the conductive support 3.

  The undercoat layer 4 is made of a material arbitrarily selected from a binder resin, an organic or inorganic powder, an electron transporting substance, and the like. Here, as the binder resin, acetal resin such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin , Vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, polymer resin compound such as melamine resin, zirconium chelate compound, titanium chelate compound, aluminum chelate compound, titanium alkoxide compound Known materials such as organic titanium compounds and silane coupling agents can be used. These compounds can be used alone, as a mixture of a plurality of compounds, or as a polycondensate. Among these, a zirconium chelate compound and a silane coupling agent are preferable because they have excellent performance such as low residual potential, little potential change due to environment, and little potential change due to repeated use.

  Examples of the silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycid. Xylpropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (amino And ethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane. Among these, silicon compounds particularly preferably used include vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, Examples include silane coupling agents such as N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane.

  Titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium Examples include lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate).

  In the undercoat layer 4, various organic compound fine powders or inorganic compound fine powders can be added for the purpose of improving electrical characteristics and light scattering properties. In particular, white pigments such as titanium oxide, zinc oxide, zinc white, zinc sulfide, lead white and lithopone, inorganic pigments as extender pigments such as alumina, calcium carbonate and barium sulfate, Teflon resin particles, and benzoguanamine resin particles In addition, styrene resin particles are effective. The added fine powder has a particle size of 0.01 to 2 μm. The fine powder is added as necessary, but the addition amount is preferably 10 to 90% by weight, preferably 30 to 80% by weight, based on the total weight of the solid content of the undercoat layer 4. More preferably.

  In addition, it is also effective in the undercoat layer 4 to contain the electron transporting substance, the electron transporting pigment and the like described above from the viewpoint of lowering the residual potential and environmental stability. Furthermore, the thickness of the undercoat layer 4 is preferably 0.01 to 30 μm, and more preferably 0.05 to 25 μm.

  In addition, when preparing a coating liquid for forming the undercoat layer 4, when adding a fine powder substance, it is added to a solution in which the resin component is dissolved and dispersed. As the dispersion treatment method, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used.

  The undercoat layer 4 can be formed by applying a coating solution for forming the undercoat layer 4 on the conductive support 3 and drying it. As a coating method at this time, usual methods such as 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, and the like can be used.

  FIG. 1C is a schematic cross-sectional view showing a third embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member 120 shown in FIG. 1C has the same configuration as the electrophotographic photosensitive member 100 shown in FIG. 1A except that the protective layer 5 is provided on the photosensitive layer 6.

  The protective layer 5 is used to prevent chemical change of the charge transport layer 2 when the electrophotographic photosensitive member 120 is charged or to further improve the mechanical strength of the photosensitive layer 6. The protective layer 5 is formed by applying a coating solution containing a conductive material in an appropriate binder resin on the photosensitive layer 6.

  The conductive material used for the protective layer 5 is not particularly limited, and examples thereof include metallocene compounds such as N, N′-dimethylferrocene, N, N′-diphenyl-N, N′-bis (3-methylphenyl). -Aromatic amine compounds such as [1,1′-biphenyl] -4,4′-diamine, molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, indium oxide, tin oxide and antimony, barium sulfate and oxidation Carrier of solid solution with antimony, mixture of the above metal oxide, titanium oxide, tin oxide, zinc oxide or barium sulfate mixed with the above metal oxide, or titanium oxide, tin oxide, oxidation Examples include zinc or barium sulfate single particles coated with the above metal oxide.

  The binder resin used for the protective layer 5 is polyamide resin, polyvinyl acetal resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, polyimide resin, polyamideimide resin. Known resins such as these are used. These can also be used by cross-linking each other as necessary.

  The thickness of the protective layer 5 is preferably 1 to 20 μm, and more preferably 2 to 10 μm.

  As a coating method of the coating liquid for forming the protective layer 5, conventional methods such as 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, and a curtain coating method are used. Can be used. Moreover, as a solvent used for the coating liquid for forming the protective layer 5, normal organic solvents, such as a dioxane, tetrahydrofuran, a methylene chloride, chloroform, chlorobenzene, toluene, can be used individually or in mixture of 2 or more types. However, it is preferable to use a solvent that hardly dissolves the photosensitive layer 6 to which the coating solution is applied.

  The preferred embodiment of the electrophotographic photoreceptor of the present invention has been described in detail above, but the electrophotographic photoreceptor of the present invention is not limited to the above embodiment. For example, as in the electrophotographic photoreceptor 130 shown in FIG. 2A, the undercoat layer 4 is provided between the conductive support 3 and the photosensitive layer 6, and the protective layer 5 is further provided on the photosensitive layer 6. It may be.

  In the electrophotographic photoreceptors 100, 110, and 120 of the above-described embodiment, the case where the photosensitive layer 6 has a laminated structure has been described. For example, the electrophotographic photoreceptor shown in FIG. As in 140, the photosensitive layer 6 may have a single layer structure. In this case, the undercoat layer 4 may be provided between the conductive support 3 and the photosensitive layer 6, and the protective layer 5 may be provided on the photosensitive layer 6. And the protective layer 5 may be provided together.

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)
3 and 4 are cross-sectional views schematically showing a basic configuration of a preferred embodiment of the electrophotographic apparatus of the present invention.

  An electrophotographic apparatus 200 shown in FIG. 3 includes an electrophotographic photosensitive member 7 of the present invention, a charging unit 8 for charging the electrophotographic photosensitive member 7 by a corona discharge method, a power source 9 connected to the charging unit 8, and a charging unit. Exposure means 10 that exposes the electrophotographic photosensitive member 7 charged by 8 to form an electrostatic latent image, and developing means that develops the electrostatic latent image formed by the exposure means 10 with toner to form a toner image. 11, a transfer unit 12 that transfers the toner image formed by the developing unit 11 to the transfer target 20, a cleaning unit 13, a static eliminator 14, and a fixing device 15.

  The electrophotographic apparatus 210 shown in FIG. 4 has the same configuration as that of the electrophotographic apparatus 200 shown in FIG. 3 except that it includes a charging unit 8 that charges the electrophotographic photoreceptor 7 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 14 may not be provided.

  Here, as the charging means 8, 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 a corona discharge, or a corotron A non-contact type charger such as a charger is used.

  As the exposure means 10, an optical system device that can expose a light source such as a semiconductor laser, an LED (light emitting diode), and a liquid crystal shutter in a desired image-like manner on the surface of the electrophotographic photosensitive member is used.

  As the developing means 11, 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 12, 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. 3 and 4, 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. 5 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the process cartridge of the present invention. In the process cartridge 300, together with the electrophotographic photosensitive member 7 of the present invention, a charging unit 8, a developing unit 11, a cleaning unit 13, an opening 18 for exposure, and a static eliminator 14 are combined using a mounting rail 16 and integrated. It has become. The process cartridge 300 is detachable from the main body of the electrophotographic apparatus comprising the transfer means 12, the fixing device 15, and other components not shown, and the electrophotographic apparatus together with the main body of the electrophotographic apparatus. It constitutes.

  Since the electrophotographic apparatus and the process cartridge of the present invention described above include the electrophotographic photosensitive member using the chlorogallium phthalocyanine pigment of the present invention, stable image quality can be obtained over a long period without causing image quality defects. I can.

  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.

(Synthesis of type I chlorogallium phthalocyanine pigment)
30 parts by weight of 1,3-diiminoisoindoline and 9.1 parts by weight of gallium trichloride were added to 230 parts by weight of dimethyl sulfoxide and reacted at 160 ° C. with stirring for 6 hours to obtain reddish purple crystals. The obtained crystals were washed with dimethyl sulfoxide, then washed with ion-exchanged water, and dried to obtain 28 parts by weight of type I chlorogallium phthalocyanine pigment.

  The X-ray diffraction spectrum of the I-type chlorogallium phthalocyanine pigment 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 used: X-ray diffractometer RAD-B system manufactured by Rigaku Corporation
X-ray tube: Cu
Tube current: 30 mA
Scan speed: 2.0 deg. / Min
Sampling interval: 0.01 deg.
Start angle (2θ): 5 deg.
Stop angle (2θ): 35 deg.
Step angle (2θ): 0.01 deg.

(Example 1)
<Preparation of chlorogallium phthalocyanine pigment E1>
[Dry milling of type I chlorogallium phthalocyanine pigment]
20 parts by weight of the I-type chlorogallium phthalocyanine pigment obtained as described above was put in an alumina pot together with 400 parts by weight of an alumina spherical media having a diameter of 5 mm. This was mounted on a vibration mill (MB-1 type, manufactured by Chuo Kako Co., Ltd.) and dry-pulverized for 180 hours to obtain 18 parts by weight of a refined chlorogallium phthalocyanine pigment having a primary particle size of 0.02 μm. An X-ray diffraction pattern of the obtained fine chlorogallium phthalocyanine pigment is shown in FIG.

[Wet grinding of fine chlorogallium phthalocyanine pigment]
Next, 6 parts by weight of the resulting fine chlorogallium phthalocyanine pigment was used for 72 hours at 25 ° C. using a glass ball mill together with 120 parts by weight of dimethyl sulfoxide and 350 parts by weight of glass spherical media having an outer diameter of 1.0 mm. Wet pulverization by ball milling was performed. In the wet pulverization, the progress of crystal conversion of the chlorogallium phthalocyanine pigment in the wet pulverization process is monitored by measuring λ _MAX in the spectral absorption spectrum in the 700 to 900 nm wavelength region of the wet pulverization treatment liquid. _This was performed until _MAX reached 758 nm. The wet pulverized chlorogallium phthalocyanine pigment is filtered off, washed with acetone, heated and dried at 80 ° C. under vacuum for 24 hours, and Bragg angle with respect to CuKα characteristic X-ray (2θ ± 0.2 °). 5.5 parts by weight of chlorogallium phthalocyanine pigment (E1) having diffraction peaks at 7.4 °, 16.6 °, 25.5 ° and 28.3 ° were obtained. The X-ray diffraction pattern of the obtained chlorogallium phthalocyanine pigment E1 is shown in FIG. 8, the spectral absorption spectrum is shown in FIG. 10, and the transmission electron micrograph (magnification: 30,000 times) is shown in FIG. Further, Table 1 shows the values of λ _MAX , BET specific surface area and average particle diameter of the obtained chlorogallium phthalocyanine pigment E1.

  In addition, the measurement of the spectral absorption spectrum in a present Example was performed using the Hitachi U-4000 type spectrophotometer. The measurement liquid was prepared by sonicating a small amount of chlorogallium phthalocyanine pigment together with acetone at room temperature using an ultrasonic cleaner (DTH-8210, manufactured by Yamato Scientific Co., Ltd.).

  Further, the BET specific surface area was measured using a BET specific surface area measuring instrument (Flow Soap II 2300, manufactured by Shimadzu Corporation), and the average particle diameter was measured using a laser diffraction scattering type particle size distribution measuring apparatus (LA-700, manufactured by Horiba, Ltd.). Was observed using a transmission electron microscope (H-9000, manufactured by Hitachi, Ltd.).

(Example 2)
<Preparation of chlorogallium phthalocyanine pigment E2>
Except for using 350 parts by weight of glass spherical media having an outer diameter of 1.5 mm instead of 350 parts by weight of glass spherical media having an outer diameter of 1.0 mm, wet pulverization was performed in the same manner as in Example 1, The chlorogallium phthalocyanine pigment was sampled every 24 hours and its BET specific surface area was measured up to the point of 192 hours of grinding time. A curve in which the measured values are plotted against the grinding time is shown in FIG. Further, FIG. 16 shows a curve obtained by plotting the value of λ _MAX of the chlorogallium phthalocyanine pigment in the wet grinding process, which was measured by sampling in the same manner, with respect to the grinding time.

As shown in FIG. 15, the value of the specific surface area becomes maximum (72 m ² / g) when the wet grinding time is 96 hours, and as shown in FIG. 16, λ _MAX is reached when the wet grinding time is 96 hours. Became extremely small (760 nm).

  Therefore, the wet pulverization time was changed to 96 hours, and wet pulverization was performed again. After filtration, the powder was washed with acetone and dried to obtain 5.5 parts by weight of chlorogallium phthalocyanine pigment (E2). The spectral absorption spectrum of the resulting chlorogallium phthalocyanine pigment E2 is shown in FIG.

Table 1 shows the values of λ _MAX , BET specific surface area, and average particle size of the chlorogallium phthalocyanine pigment E2.

(Example 3)
<Preparation of chlorogallium phthalocyanine pigment E3>
A chlorogallium phthalocyanine pigment E3 was obtained in the same manner as in Example 2 except that the wet grinding time was changed to 120 hours. Table 1 shows the values of λ _MAX , BET specific surface area and average particle diameter of the resulting chlorogallium phthalocyanine pigment E3.

Example 4
<Preparation of chlorogallium phthalocyanine pigment E4>
Instead of 350 parts by weight of glass spherical media with an outer diameter of 1.0 mm, 450 parts by weight of glass spherical media with an outer diameter of 0.3 mm was used, and the amount of dimethyl sulfoxide used was changed from 120 parts by weight to 160 parts by weight. Then, a chlorogallium phthalocyanine pigment E4 was obtained in the same manner as in Example 1 except that a stainless steel (SUS304) ball mill was used instead of the glass ball mill. Table 1 shows the values of λ _MAX , BET specific surface area and average particle size of the resulting chlorogallium phthalocyanine pigment E4.

(Comparative Example 1)
<Preparation of chlorogallium phthalocyanine pigment C1>
5 parts by weight of refined chlorogallium phthalocyanine obtained in the same manner as in Example 1 was placed in a stirring vessel equipped with a thermostatic device provided with an inclined paddle type stirring blade and a baffle plate together with 500 parts by weight of dimethyl sulfoxide. The mixture was stirred at 250 ° C. for 24 hours at a stirring speed of 250 ° C., filtered using a filter dryer (manufactured by Tanabe Wiltech), washed with ion-exchanged water, and further stirred at 80 ° C. as the first drying treatment. And dried in a vacuum for 24 hours. Next, by vacuum drying at 150 ° C. for 5 hours as a second drying treatment, at least 7.4 °, 16.6 °, 25.5 of the Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-rays. 4.7 parts by weight of a chlorogallium phthalocyanine pigment (C1) composed of type II chlorogallium phthalocyanine crystals having diffraction peaks at ° and 28.3 ° were obtained.

FIG. 9 shows an X-ray diffraction spectrum of the obtained chlorogallium phthalocyanine pigment C1, FIG. 12 shows a spectral absorption spectrum, and FIG. 14 shows a transmission electron micrograph (magnification: 30,000 times). Further, Table 1 shows the values of λ _MAX , BET specific surface area and average particle diameter of the obtained chlorogallium phthalocyanine pigment C1.

(Comparative Example 2)
<Preparation of chlorogallium phthalocyanine pigment C2>
After ball milling for 24 hours at room temperature in 20 parts of chlorobenzene using 0.5 parts by weight of the refined chlorogallium phthalocyanine pigment obtained in the same manner as in Example 1, using 60 parts by weight of 1 mmφ glass spherical media. Filtered off and washed with 10 parts of methanol to obtain chlorogallium phthalocyanine pigment C2. Table 1 shows the values of λ _MAX , BET specific surface area and average particle size of the resulting chlorogallium phthalocyanine pigment C2.

(Example 5)
<Preparation of electrophotographic photoreceptor sheet>
6 parts by weight of BM-1 (trade name, manufactured by Sekisui Chemical Co., Ltd.) which is a polyvinyl butyral resin, 12 parts by weight of Sumijoule 3175 (trade name, manufactured by Sumitomo Bayern Urethane Co., Ltd.) which is a blocked isocyanate as a curing agent, and zinc oxide. Nano Tech ZnO (trade name, manufactured by CI Kasei Co., Ltd., primary particle size 30 nm) 41 parts by weight, Tospearl 120 (trade name, manufactured by Toshiba Silicone) as a silicone ball, silicone oil SH29PA (trade name, Toray) as a leveling agent 100 ppm and 52 parts by weight of methyl ethyl ketone were mixed, and this was kneaded in a batch mill for 10 hours to prepare a coating solution for an undercoat layer.

  This coating solution was dip-coated on an aluminum sheet (thickness: 50 μm) as a conductive support and dried by heating at 150 ° C. for 30 minutes to produce an undercoat layer having a thickness of 20.0 μm.

  Next, a solution prepared by dissolving 1 part by weight of VMCH (trade name, manufactured by Nihon Unicar), which is a vinyl chloride / vinyl acetate copolymer resin, in 100 parts by weight of n-butyl acetate and the chlorogallium phthalocyanine pigment obtained in Example 1 (E1) 1 part by weight was mixed and kneaded in a sand mill for 5 hours together with 150 parts by weight of glass beads having an outer diameter of 1 mm to prepare a coating solution for forming a charge generation layer. The obtained coating solution was dip coated on the 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 by weight 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 Is a coating solution for forming a charge transport layer by mixing 6 parts by weight of 30,000 bisphenol Z polycarbonate resin, 80 parts by weight of tetrahydrofuran, and 0.2 parts by weight of 2,6-di-t-butyl-4-methylphenol. Was prepared. This coating solution was applied onto the above charge generation layer by a dip coating apparatus, and heated and dried at 120 ° C. for 40 minutes to produce a charge transport layer having a thickness of 25 μm, thereby producing a desired electrophotographic photosensitive sheet. .

<Production of electrophotographic photosensitive drum>
An aluminum pipe with a diameter of 84 mmφ × 347 mm and a wall thickness of 1 mm is roughened by subjecting it to a liquid honing process using an alumina bead CB-A30S (trade name, manufactured by Showa Titanium Co., Ltd., average particle diameter D50 = 30 μm). A subbing layer, a charge generation layer, a charge are formed by the same procedure as that for the electrophotographic photoreceptor sheet except that a surface roughened to a roughness Ra of 0.18 μm is used as a conductive support. A transport layer was sequentially produced, and an intended electrophotographic photosensitive drum was produced.

(Examples 6 to 8)
An electrophotographic photoreceptor sheet was prepared in the same manner as in Example 5 except that the chlorogallium phthalocyanine pigments E2 to E4 obtained in Examples 2 to 4 were used in place of the chlorogallium phthalocyanine pigment E1 as the charge generation material. And an electrophotographic photosensitive drum was produced.

(Comparative Examples 3-4)
An electrophotographic photoreceptor sheet and a charge generating material were prepared in the same manner as in Example 5 except that the chlorogallium phthalocyanine pigments C1 and C2 obtained in Comparative Examples 1 and 2 were used in place of the chlorogallium phthalocyanine pigment E1. An electrophotographic photosensitive drum was produced.

[Electrophotographic characteristic evaluation test of electrophotographic photosensitive member]
(1) Characteristic evaluation at the initial stage of use In order to evaluate the electrophotographic characteristics of the electrophotographic photoreceptor sheets of Examples 5 to 8 and Comparative Examples 3 to 4 obtained as described above, the electrophotographic characteristics were as follows. Was measured.

First, using a small area mask of 20 mmφ, electrophotographic photosensitivity by -5.0 kV corona discharge using an electrostatic copying paper test apparatus (EPA8200: manufactured by Kawaguchi Electric Co., Ltd.) in an environment of 20 ° C. and 50% RH. The body sheet was negatively charged. Subsequently, the halogen lamp light dispersed at 780 nm using an interference filter was irradiated while adjusting the illuminance on the surface of the electrophotographic photoreceptor sheet to 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 results are shown in Table 2.

(2) Evaluation of repetitive characteristics With respect to the electrophotographic photoreceptor sheet after 10,000 times of the above charging, exposure and static elimination operations, the surface potential V ₀ [V], until the surface potential becomes 1/2 of V _0. The half-exposure dose E _1/2 [μJ / cm ² ] and dark decay rate (DDR) [%] from the start of exposure were measured. The results are shown in Table 2.

(3) Image Quality Evaluation Test Each of the electrophotographic photosensitive drums of Examples 5 to 8 and Comparative Examples 3 to 4 is mounted on a laser printer (DocuPrint 260, manufactured by Fuji Xerox Co.) having the configuration shown in FIG. The image quality was evaluated.

  In an environment of 32.5 ° C / 90% RH, a halftone image of 1 dot and 1 space and an entire white image (background image) are output and observed visually and with a magnifying glass. The degree of toner scattering was evaluated. The dark potential Vd of the electrophotographic photosensitive member was also measured.

  Subsequently, after outputting 20,000 images in which lines having a width of about 2 mm are printed 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 loupe. The degree of black line collapse and toner scattering was evaluated.

  In the above laser printer, a roller charger (BCR) as a charging device, ROS using a 780 nm semiconductor laser as an exposure device, a two-component reversal development method as a development method, and a roller charger (BTR) as a transfer device The belt intermediate transfer system was adopted as the transfer device. These results are shown in Table 3.

(4) Dispersibility evaluation of charge generation material In order to evaluate the dispersibility of chlorogallium phthalocyanine pigments E1 to E4 and C1 to C3, a charge generation layer is formed on a glass plate, and the dispersion state is measured using a microscope. Observed. 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. .

  As shown in Tables 1 to 3, the electrophotography of Examples 5 to 8 using a chlorogallium phthalocyanine pigment having a maximum absorption maximum wavelength in the range of 740 to 770 nm in the spectral absorption spectrum in the wavelength range of 700 to 900 nm. The photoconductor has excellent electrophotographic characteristics as compared with the electrophotographic photoconductors of Comparative Examples 3 to 4, has good dispersibility, and repeats without causing phenomena such as thickening and thinning of thin lines and fogging. It was confirmed that good image quality can be obtained even during use.

(A)-(c) is a schematic cross section which shows 1st-3rd embodiment of the electrophotographic photoreceptor of this invention, respectively. (A)-(b) is a schematic cross section which shows other embodiment of this invention, respectively. 1 is a cross-sectional view schematically illustrating a basic configuration of a preferred embodiment of an electrophotographic apparatus of the present invention. It is sectional drawing which shows schematically the basic composition of other suitable one Embodiment of the electrophotographic apparatus of this invention. 1 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of a process cartridge of the present invention. FIG. 2 is a powder X-ray diffraction pattern of an I-type chlorogallium phthalocyanine pigment synthesized in Examples. It is a powder X-ray diffraction pattern of the refined | miniaturized chlorogallium phthalocyanine pigment prepared in the Example. 2 is a powder X-ray diffraction pattern of a chlorogallium phthalocyanine pigment E1 produced in Example 1. FIG. 2 is a powder X-ray diffraction pattern of a chlorogallium phthalocyanine pigment C1 produced in Comparative Example 1. FIG. 2 is a spectral absorption spectrum of a chlorogallium phthalocyanine pigment E1 produced in Example 1. 2 is a spectral absorption spectrum of a chlorogallium phthalocyanine pigment E2 produced in Example 2. 2 is a spectral absorption spectrum of a chlorogallium phthalocyanine pigment C1 produced in Comparative Example 1. 2 is a transmission electron micrograph of a chlorogallium phthalocyanine pigment E1 produced in Example 1. 2 is a transmission electron micrograph of a chlorogallium phthalocyanine pigment C1 produced in Comparative Example 1. In Example 2, it is the figure which showed the time-dependent change of the BET specific surface area in the wet grinding process of the chlorogallium phthalocyanine pigment. In Example 2, it is the figure which showed the time-dependent change of the maximum absorption maximum wavelength (lambda) _MAX in the wet grinding process of chlorogallium phthalocyanine.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Charge generating layer, 2 ... Charge transport layer, 3 ... Conductive support body, 4 ... Undercoat layer, 5 ... Protective layer, 6 ... Photosensitive layer, 7 ... Electrophotographic photoreceptor, 8 ... Charging means, 9 ... Power supply DESCRIPTION OF SYMBOLS 10 ... Exposure means, 11 ... Developing means, 12 ... Transfer means, 13 ... Cleaning means, 14 ... Static eliminator, 15 ... Fixing device, 16 ... Mounting rail, 18 ... Opening for exposure, 20 ... Transfer object , 100, 110, 120, 130, 140 ... electrophotographic photosensitive member, 200, 210 ... electrophotographic apparatus, 300 ... process cartridge.

Claims (9)

  A chlorogallium phthalocyanine pigment having a maximum absorption maximum wavelength in a range of 740 to 770 nm in a spectral absorption spectrum in a wavelength region of 700 to 900 nm. The chlorogallium phthalocyanine pigment according to claim 1, having an average particle size of 0.1 µm or less and a BET specific surface area of 45 m ² / g or more.   In the X-ray diffraction spectrum using CuKα characteristic X-rays, diffraction peaks are present at Bragg angles (2θ ± 0.2 °) of 7.4 °, 16.6 °, 25.5 ° and 28.3 °. Item 3. The chlorogallium phthalocyanine pigment according to Item 1 or 2. A finely divided chlorogallium phthalocyanine pigment is obtained by dry pulverizing type I chlorogallium phthalocyanine pigment, and the finely divided chlorogallium phthalocyanine pigment is wet pulverized for a predetermined time to obtain a crystal-converted chlorogallium phthalocyanine pigment. A method for producing a chlorogallium phthalocyanine pigment, comprising:
The wet pulverization is performed using a pulverizer using spherical media having an outer diameter of 0.1 to 3.0 mm, and the amount of the media used is 50 parts by weight or more with respect to 1 part by weight of the I-type chlorogallium phthalocyanine pigment. I,
A method for producing a chlorogallium phthalocyanine pigment, wherein the predetermined time is within a time range in which an average particle size of the obtained chlorogallium phthalocyanine pigment is 0.1 μm.   The predetermined time in the previous period is within the time range in which the average particle diameter of the obtained chlorogallium phthalocyanine pigment is 0.1 μm or less, and the maximum in the spectral absorption spectrum of the chlorogallium phthalocyanine pigment in the wavelength region of 700 to 900 nm The chlorogallium according to claim 4, wherein a time selected from the range of 0.7 Ta to 1.3 Ta is set, where Ta is the time of the minimum point of the curve in which the absorption maximum wavelength is plotted for each wet grinding time. Method for producing phthalocyanine pigment.   A curve obtained by plotting the predetermined time within the time range in which the average particle diameter of the obtained chlorogallium phthalocyanine pigment becomes 0.1 μm and the BET specific surface area of the chlorogallium phthalocyanine pigment for each time of wet grinding. The method for producing a chlorogallium phthalocyanine pigment according to claim 4, wherein a time selected from the range of 0.7 Tb to 1.3 Tb is set, where Tb is the time of the maximum point. An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer disposed on the support,
An electrophotographic photoreceptor in which the photosensitive layer contains the chlorogallium phthalocyanine pigment according to any one of claims 1 to 3. An electrophotographic photoreceptor according to claim 7;
A charging unit for charging the electrophotographic photosensitive member, an exposure unit for forming an electrostatic latent image on the electrophotographic photosensitive member, and developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner And at least one selected from the group consisting of a developing means for forming a toner image and a cleaning means for removing the toner remaining on the electrophotographic photosensitive member,
A process cartridge comprising: An electrophotographic photoreceptor according to claim 7;
Charging means for charging the electrophotographic photosensitive member;
Exposure means for forming an electrostatic latent image on the electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image;
Transfer means for transferring the toner image to a transfer object;
An electrophotographic apparatus comprising:

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