JP6465694B2 - Electrophotographic photoreceptor and manufacturing method thereof, process cartridge and electrophotographic apparatus, and hydroxygallium phthalocyanine crystal and manufacturing method thereof - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, a method for producing an electrophotographic photosensitive member, a process cartridge having an electrophotographic photosensitive member, and an electrophotographic apparatus. Furthermore, the present invention relates to a hydroxygallium phthalocyanine crystal and a method for producing a hydroxygallium phthalocyanine crystal.

  Currently, the oscillation wavelength of a semiconductor laser, which is often used as an image exposure means in the electrophotographic field, is as long as 650 to 820 nm, and the development of an electrophotographic photosensitive member having high sensitivity to light of these long wavelengths has been advanced. It has been.

  The phthalocyanine pigment is effective as a charge generation material having high sensitivity to light up to such a long wavelength region. In particular, oxytitanium phthalocyanine and gallium phthalocyanine have excellent sensitivity characteristics, and various crystal forms have been reported so far.

  Patent Document 1 reports that a sensitizing effect can be obtained by adding a specific organic electron acceptor during the acid pasting process of the phthalocyanine pigment.

  Patent Document 2 describes a hydroxygallium phthalocyanine crystal containing a polar organic solvent. Specifically, Patent Document 2 uses a polar organic solvent such as N, N-dimethylformamide as a conversion solvent to obtain a crystal having high sensitivity characteristics in which the conversion solvent molecules are incorporated into the crystal. It is disclosed.

JP 2001-40237 A JP 7-331107 A

  According to the study by the present inventors, the production method according to Patent Document 1 may be difficult to chemically change the additive (organic electron acceptor) and may be difficult to convert to a desired crystal form. There was a problem. Moreover, it was confirmed that the crystal according to Patent Document 2 exhibits high sensitivity characteristics. However, with the recent increase in the speed of electrophotographic devices (higher process speed), the present inventors need a charge generating material having higher sensitivity, and the charge generating material is sensitive. Recognized the need for a further improved hydroxygallium phthalocyanine.

  Accordingly, an object of the present invention is to provide an electrophotographic photosensitive member containing a hydroxygallium phthalocyanine crystal having high sensitivity to light having a long wavelength, a method for producing the electrophotographic photosensitive member, and a process having the electrophotographic photosensitive member. The object is to provide a cartridge and an electrophotographic apparatus. Another object of the present invention is to provide a hydroxygallium phthalocyanine crystal having high sensitivity to light having a long wavelength and a method for producing the hydroxygallium phthalocyanine crystal.

The present invention is an electrophotographic photosensitive member having a support and a photosensitive layer formed on the support,
The photosensitive layer contains a hydroxygallium phthalocyanine crystal containing N-methylformamide in the crystal;
The content of the N-methylformamide contained in the hydroxygallium phthalocyanine crystal is 1.8% by mass or more and 2.0% by mass or less based on the content of hydroxygallium phthalocyanine in the hydroxygallium phthalocyanine crystal. An electrophotographic photosensitive member characterized by the above.

  The present invention also provides a process that integrally supports the electrophotographic photosensitive member and at least one means selected from the group consisting of a charging means, a developing means, and a cleaning means, and is detachable from the main body of the electrophotographic apparatus. It is a cartridge.

  The present invention also provides an electrophotographic apparatus having the electrophotographic photosensitive member, and a charging unit, an exposure unit, a developing unit, and a transfer unit.

  The present invention also relates to a hydroxygallium phthalocyanine crystal containing N-methylformamide in the crystal, wherein the content of the N-methylformamide contained in the hydroxygallium phthalocyanine crystal is within the hydroxygallium phthalocyanine crystal. A hydroxygallium phthalocyanine crystal characterized by being 1.8% by mass or more and 2.0% by mass or less based on the content of hydroxygallium phthalocyanine.

  The present invention also relates to a method for producing a hydroxygallium phthalocyanine crystal for producing the above-mentioned hydroxygallium phthalocyanine crystal, wherein N-methylformamide is added to hydroxygallium phthalocyanine and milled to obtain a crystal of hydroxygallium phthalocyanine. It is a manufacturing method of the hydroxygallium phthalocyanine crystal | crystallization characterized by having the process of converting.

Further, the present invention is a method for producing an electrophotographic photosensitive member for producing a support and an electrophotographic photosensitive member having a photosensitive layer formed on the support,
Forming the hydroxygallium phthalocyanine crystal by the method for producing the hydroxygallium phthalocyanine crystal,
Preparing a coating solution for a photosensitive layer containing the hydroxygallium phthalocyanine crystal; and
Forming a coating film of the coating solution for the photosensitive layer, and drying the coating film to form a photosensitive layer;
It is a manufacturing method of the electrophotographic photoreceptor characterized by having.

  According to the present invention, an electrophotographic photosensitive member containing a hydroxygallium phthalocyanine crystal having high sensitivity to light having a long wavelength, a method for producing the electrophotographic photosensitive member, a process cartridge having the electrophotographic photosensitive member, and An electrophotographic apparatus can be provided.

  Furthermore, according to the present invention, it is possible to provide a hydroxygallium phthalocyanine crystal having high sensitivity to long-wavelength light and a method for producing the hydroxygallium phthalocyanine crystal.

1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having the electrophotographic photosensitive member of the present invention. 2 is a powder X-ray diffraction pattern of a hydroxygallium phthalocyanine crystal obtained in Example 1-1. FIG. It is a figure which shows an example of the layer structure of an electrophotographic photoreceptor. ¹ is a diagram showing a ¹ H-NMR spectrum of a hydroxygallium phthalocyanine crystal obtained in Example 1-1. FIG. It is a diagram showing ¹ H-NMR spectrum of a hydroxygallium phthalocyanine crystal obtained in Comparative Example 1-1.

<Electrophotographic photoreceptor>
As described above, the electrophotographic photoreceptor of the present invention has a support and a photosensitive layer formed on the support.

  The photosensitive layer contains a hydroxygallium phthalocyanine crystal containing N-methylformamide in the crystal. Furthermore, the content of the N-methylformamide contained in the hydroxygallium phthalocyanine crystal is 1.8% by mass or more and 2.0% by mass or less with respect to the content of hydroxygallium phthalocyanine in the hydroxygallium phthalocyanine crystal. An electrophotographic photosensitive member is provided.

[Hydroxygallium phthalocyanine crystal]
The hydroxygallium phthalocyanine crystal of the present invention has a hydroxy group as an axial ligand on a gallium atom.

  Further, the hydroxygallium phthalocyanine crystal has peaks at 7.4 ° ± 0.3 ° and 28.3 ° ± 0.3 ° at a Bragg angle 2θ in X-ray diffraction of CuKα rays. On the other hand, it is preferable because higher sensitivity can be obtained.

  It is important that the content of the N-methylformamide contained in the hydroxygallium phthalocyanine crystal is 1.8% by mass or more and 2.0% by mass or less. When the content of N-methylformamide is within the above range, high sensitivity to long wavelength light can be obtained. Further, the content of N-methylformamide is more preferably 1.8% by mass or more and 1.9% by mass or less.

  A method for producing a hydroxygallium phthalocyanine crystal containing N-methylformamide in the crystal will be described.

  The hydroxygallium phthalocyanine crystal containing N-methylformamide in the crystal undergoes a step of crystal conversion of hydroxygallium phthalocyanine (crystal conversion step) by adding N-methylformamide to hydroxygallium phthalocyanine and milling. Can be obtained. In order to obtain a more sensitive hydroxygallium phthalocyanine crystal, the hydroxygallium phthalocyanine used for the milling treatment is preferably hydroxygallium phthalocyanine obtained by the acid pasting method.

  The milling process performed here is a process performed using a milling device such as a sand mill or a ball mill.

  If necessary, a dispersant such as glass beads, steel beads, or alumina balls may be added thereto. The amount of the dispersant used in the milling treatment is preferably 10 to 50 times that of hydroxygallium phthalocyanine on a mass basis. In addition to N-methylformamide, examples of the conversion solvent include amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylacetamide, N-methylpropioamide, and chloroform. A halogen-based solvent, an ether-based solvent such as tetrahydrofuran, or a sulfoxide-based solvent such as dimethyl sulfoxide may be used in combination. The amount of solvent used is preferably 5 to 30 times that of hydroxygallium phthalocyanine on a mass basis.

  The milling process is preferably performed for 120 hours or longer.

  The present inventors have newly discovered that the amount of N-methylformamide incorporated into the hydroxygallium phthalocyanine crystal decreases as the milling time is increased. As a result of the study by the present inventors, it was found that a hydroxygallium phthalocyanine crystal containing a specific amount of N-methylformamide in the crystal has excellent sensitivity.

  In the present invention, the content of N-methylformamide in the crystal was determined by NMR measurement of the obtained hydroxygallium phthalocyanine crystal and analyzing the data.

  The X-ray diffraction and NMR measurement of the hydroxygallium phthalocyanine crystal of the present invention were performed under the following conditions.

[Powder X-ray diffraction measurement]
Measuring instrument used: Rigaku Denki Co., Ltd., X-ray diffractometer RINT-TTRII
X-ray tube: Cu
Tube voltage: 50KV
Tube current: 300mA
Scanning method: 2θ / θ scan Scanning speed: 4.0 ° / min
Sampling interval: 0.02 °
Start angle (2θ): 5.0 °
Stop angle (2θ): 40.0 °
Attachment: Standard specimen holder Filter: Not used Incident monochrome: Used Counter monochromator: Not used Divergence slit: Open Divergence vertical limit slit: 10.00mm
Scattering slit: Open Photosensitive slit: Open Flat monochromator: Used Counter: Scintillation counter

[NMR measurement ( ¹ H-NMR measurement)]
Used measuring instrument: BRUKER, AVANCE III 500
Measurement nuclide: ¹ H
Solvent: Bisulfuric acid (D ₂ SO ₄ )
Integration count: 2000
The hydroxygallium phthalocyanine crystal of the present invention has an excellent function as a photoconductor, and can be applied to solar cells, sensors, switching elements and the like in addition to electrophotographic photoreceptors.

  Next, the case where the hydroxygallium phthalocyanine crystal of the present invention is applied as a charge generating material in an electrophotographic photoreceptor will be described.

  The electrophotographic photosensitive member of the present invention has a support and a photosensitive layer formed on the support.

  The photosensitive layer includes a single-layer photosensitive layer (single-layer type photosensitive layer) containing both a charge generation material and a charge transport material, and a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. Is a photosensitive layer (laminated type photosensitive layer). Among these, a multilayer photosensitive layer having a charge generation layer and a charge transport layer formed on the charge generation layer is preferable because the function of the charge generation layer can be efficiently exhibited.

  FIGS. 3A and 3B are diagrams showing an example of the layer structure of the electrophotographic photosensitive member of the present invention. In FIGS. 3A and 3B, 101 is a support, 102 is an undercoat layer, 103 is a photosensitive layer, 104 is a charge generation layer, and 105 is a charge transport layer.

[Support]
As the support used in the electrophotographic photosensitive member of the present invention, a conductive material (conductive support) is preferable. For example, a support made of metal or alloy such as aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, and platinum can be used. Another example is a plastic support having a layer in which aluminum, an aluminum alloy, indium oxide, tin oxide, and an indium oxide-tin oxide alloy are formed by vacuum deposition. In addition, there is a support in which conductive particles are coated on a plastic or the support together with a binder resin. Further, a support in which conductive particles are impregnated with plastic or paper, a plastic support having a conductive polymer, or the like can be used. Examples of the conductive particles include aluminum particles, titanium oxide particles, tin oxide particles, zinc oxide particles, carbon black, and silver particles.

[Conductive layer]
A conductive layer may be provided between the support and the undercoat layer described below for the purpose of suppressing interference fringes due to scattering of laser light, concealing (coating) scratches on the support, and the like. The conductive layer is formed by applying a conductive layer coating solution obtained by dispersing conductive particles such as carbon black, metal particles, metal oxide particles, a binder resin, and a solvent. It can form by drying the obtained coating film.

  Examples of the conductive particles include aluminum particles, titanium oxide particles, tin oxide particles, zinc oxide particles, carbon black, and silver particles. Examples of the binder resin include polyester, polycarbonate, polyvinyl butyral, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin. Examples of the solvent for the conductive layer coating solution include ether solvents, alcohol solvents, ketone solvents, and aromatic hydrocarbon solvents.

[Undercoat layer]
In the electrophotographic photoreceptor of the present invention, an undercoat layer (also referred to as a barrier layer or an intermediate layer) having a barrier function and an adhesive function can be provided between the support and the photosensitive layer. The undercoat layer can be formed by forming a coating film of the coating solution for the undercoat layer obtained by mixing the binder resin and the solvent, and drying the coating film.

  As the binder resin, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, methyl cellulose, casein, polyamide (nylon 6, nylon 66, nylon 610, copolymer nylon, N-alkoxymethylated nylon, etc.), polyurethane, or the like is used. The film thickness is 0.1 to 10 μm, preferably 0.5 to 5 μm.

(Photosensitive layer)
In the case of forming a single-layer type photosensitive layer, the hydroxygallium phthalocyanine crystal of the present invention is used as a charge generation material and mixed with a charge transport material in a binder resin solution to prepare a photosensitive layer coating solution. The photosensitive layer can be formed by coating the photosensitive layer coating solution on a support to form a coating film, and drying the resulting coating film.

  When forming a multilayer photosensitive layer, the charge generation layer is formed by applying a coating solution for the charge generation layer obtained by dispersing the hydroxygallium phthalocyanine crystal of the present invention in a binder resin solution. And it can form by drying the obtained coating film. Moreover, a charge generation layer can also be formed by vapor deposition.

  When forming a laminated photosensitive layer, the charge transport layer is formed by coating a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent on the charge generation layer. The obtained coating film can be dried to form.

  Examples of the charge transport material include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, triallylmethane compounds, and the like.

  Examples of the binder resin used for the single-layer type photosensitive layer, charge generation layer, and charge transport layer include the following. For example, resins such as polyester, acrylic resin, polyvinyl carbazole, phenoxy resin, polycarbonate, polyvinyl butyral, polystyrene, polyvinyl acetate, polysulfone, polyarylate, vinylidene chloride, acrylonitrile copolymer, and polyvinyl benzal are used.

  As a method for applying the photosensitive layer, application methods such as a dipping method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, and a beam coating method can be used.

  When the photosensitive layer is a single layer type, the film thickness is preferably 5 to 40 μm, and more preferably 10 to 30 μm.

  When the photosensitive layer is a laminated type, the thickness of the charge generation layer is preferably from 0.01 to 10 μm, and more preferably from 0.1 to 3 μm. The thickness of the charge transport layer is preferably 5 to 40 μm, and more preferably 10 to 30 μm.

  When the photosensitive layer is a laminate type, the content of the charge generation material in the charge generation layer is preferably 20 to 90% by mass, and preferably 50 to 80% by mass with respect to the total mass of the charge generation layer. Is more preferable. In addition, the content of the charge transport material in the charge transport layer is preferably 20 to 80% by mass, and more preferably 30 to 70% by mass with respect to the total mass of the charge transport layer.

  When the photosensitive layer is a single layer type, the content of the charge generating material is preferably 3 to 30% by mass with respect to the total mass of the photosensitive layer. Moreover, it is preferable that content of a charge transport material is 30-70 mass% with respect to the total mass of a photosensitive layer.

  When the hydroxygallium phthalocyanine crystal of the present invention is used as a charge generation material, it can be used by mixing with other charge generation materials. In this case, the content of the hydroxygallium phthalocyanine crystal of the present invention is preferably 50% by mass or more based on the total charge generating substance.

[Protective layer]
A protective layer may be provided on the photosensitive layer as necessary. The protective layer can be formed by applying a coating solution for a protective layer obtained by dissolving a binder resin in an organic solvent on the photosensitive layer and drying the obtained coating film. The binder resin used for the protective layer is polyvinyl butyral, polyester, polycarbonate (polycarbonate Z, modified polycarbonate, etc.), nylon, polyimide, polyarylate, polyurethane, styrene-butadiene copolymer, styrene-acrylic acid copolymer, styrene-acrylonitrile copolymer. Etc.

  The thickness of the protective layer is preferably 0.05 to 20 μm.

  The protective layer may contain conductive particles, an ultraviolet absorber, and the like. Examples of the conductive particles include metal oxide particles such as tin oxide particles.

<Process cartridge and electrophotographic apparatus>
FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention.

  In FIG. 1, a cylindrical (drum-shaped) electrophotographic photosensitive member 1 is rotationally driven around a shaft 2 at a predetermined peripheral speed (process speed) in the direction of an arrow.

  The surface of the electrophotographic photosensitive member 1 is charged to a predetermined positive or negative potential by the charging unit 3 during the rotation process. Next, the surface of the charged electrophotographic photosensitive member 1 is irradiated with image exposure light 4 from an image exposure unit (not shown), and an electrostatic latent image corresponding to target image information is formed. The image exposure light 4 is, for example, intensity-modulated light corresponding to a time-series electric digital image signal of target image information output from image exposure means such as slit exposure or laser beam scanning exposure.

  The electrostatic latent image formed on the surface of the electrophotographic photosensitive member 1 is developed (regular development or reversal development) with toner contained in the developing means 5, and a toner image is formed on the surface of the electrophotographic photosensitive member 1. Is done. The toner image formed on the surface of the electrophotographic photoreceptor 1 is transferred to the transfer material 7 by the transfer means 6. At this time, a bias voltage having a polarity opposite to the charge held in the toner is applied to the transfer unit 6 from a bias power source (not shown). When the transfer material 7 is paper, the transfer material 7 is taken out from a paper feed unit (not shown) and is synchronized with the rotation of the electrophotographic photosensitive member 1 between the electrophotographic photosensitive member 1 and the transfer means 6. Are sent.

  The transfer material 7 onto which the toner image has been transferred from the electrophotographic photosensitive member 1 is separated from the surface of the electrophotographic photosensitive member 1, conveyed to the image fixing means 8, and subjected to a toner image fixing process, thereby forming an image. Printed out as an object (print, copy) out of the electrophotographic apparatus.

  The surface of the electrophotographic photosensitive member 1 after the toner image has been transferred to the transfer material 7 is cleaned by the cleaning means 9 after removal of deposits such as toner (transfer residual toner). In recent years, a cleanerless system has also been developed, and the transfer residual toner can be directly removed by a developing device or the like. Further, the surface of the electrophotographic photosensitive member 1 is subjected to charge removal treatment with pre-exposure light 10 from a pre-exposure unit (not shown), and then repeatedly used for image formation. When the charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure unit is not always necessary.

  In the present invention, a plurality of the above-described electrophotographic photosensitive member 1, charging means 3, developing means 5, transfer means 6, cleaning means 9 and the like are selected, housed in a container, and integrally supported to process cartridges. You may form. The process cartridge can be configured to be detachable from the main body of the electrophotographic apparatus. For example, the charging unit 3, the developing unit 5, the transfer unit 6 and the cleaning unit 9 are integrally supported together with the electrophotographic photosensitive member 1 to form a cartridge. Then, the process cartridge 11 can be detachably attached to the main body of the electrophotographic apparatus using guide means 12 such as a rail of the main body of the electrophotographic apparatus.

  The image exposure light 4 may be reflected light or transmitted light from an original when the electrophotographic apparatus is a copying machine or a printer. Alternatively, it may be light emitted by reading a document with a sensor, converting it into a signal, scanning a laser beam performed according to this signal, driving an LED array, driving a liquid crystal shutter array, or the like.

  The electrophotographic photoreceptor 1 of the present invention can be widely applied to electrophotographic application fields such as laser beam printers, CRT printers, LED printers, FAX, liquid crystal printers, and laser plate making.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to these. In the following, “part” means “part by mass”, and “%” means “mass%”. In addition, the film thickness of each layer of the electrophotographic photoconductors of Examples and Comparative Examples is obtained with an eddy current film thickness meter (Fischerscope, manufactured by Fischer Instrument Co.), or obtained in terms of specific gravity from the mass per unit area. It was.

<Synthesis of hydroxygallium phthalocyanine pigment>
Hydroxygallium phthalocyanine was produced as follows.

  Under an atmosphere of nitrogen flow, 5.46 parts of phthalonitrile and 45 parts of α-chloronaphthalene were charged into the reaction kettle, heated and heated to a temperature of 30 ° C., and then maintained at this temperature. Next, 3.75 parts of gallium trichloride was added at this temperature (30 ° C.). The water content of the mixed solution at the time of charging was 150 ppm. Thereafter, the temperature was raised to 200 ° C. Next, after reacting at a temperature of 200 ° C. for 4.5 hours under an atmosphere of nitrogen flow, the product was cooled and filtered when the temperature reached 150 ° C. The obtained filtrate was dispersed and washed with N, N-dimethylformamide at a temperature of 140 ° C. for 2 hours and then filtered. The obtained filtrate was washed with methanol and dried to obtain 4.65 parts (yield 71%) of a chlorogallium phthalocyanine pigment.

  Next, 4.65 parts of the obtained chlorogallium phthalocyanine pigment was dissolved in 139.5 parts of concentrated sulfuric acid at a temperature of 10 ° C., and dropped and reprecipitated in 620 parts of ice water with stirring, using a filter press. And filtered. The obtained wet cake (filtered material) was dispersed and washed with 2% aqueous ammonia, and then filtered using a filter press. Next, the obtained wet cake (filtrate) was dispersed and washed with ion-exchanged water, and then filtration using a filter press was repeated three times. Thereafter, a hydrous hydroxygallium phthalocyanine having a solid content of 23% was obtained. 6.6 kg of the obtained hydrous hydroxygallium phthalocyanine was dried as follows using a hyper dry dryer (trade name: HD-06R, frequency (oscillation frequency): 2455 MHz ± 15 MHz, manufactured by Nippon Biocon Co., Ltd.). It was.

  Place the hydrous hydroxygallium phthalocyanine pigment on the special circular plastic tray in a lump state (hydrous cake thickness 4cm or less) as it is removed from the filter press, turn off far-infrared rays, and set the temperature of the inner wall of the dryer to 50 ° C. Set to. And at the time of microwave irradiation, the vacuum pump and the leak valve were adjusted, and the degree of vacuum was adjusted to 4.0-10.0 kPa.

  First, as a first step, a 4.8 kW microwave was irradiated to the hydroxygallium phthalocyanine pigment for 50 minutes, and then the microwave was turned off once and the leak valve was temporarily closed to a high vacuum of 2 kPa or less. At this time, the solid content of the hydroxygallium phthalocyanine pigment was 88%.

  As the second step, after adjusting the leak valve and adjusting the degree of vacuum (pressure in the dryer) to the set value (4.0 to 10.0 kPa), 1.2 kW microwave is applied to the hydroxygallium phthalocyanine pigment. Irradiation was performed for 5 minutes, and the microwave was turned off once to close the leak valve, and a high vacuum of 2 kPa or less was applied. This second step was repeated once more (total 2 times). At this time, the solid content of the hydroxygallium phthalocyanine pigment was 98%.

  Furthermore, as a third step, microwave irradiation was performed in the same manner as the second step except that the microwave in the second step was changed from 1.2 kW to 0.8 kW. This third step was repeated once more (total 2 times).

  Further, as a fourth step, the leak valve is adjusted, the vacuum degree (pressure in the dryer) is restored to the set value (4.0 to 10.0 kPa), and then a 0.4 kW microwave is applied to hydroxygallium phthalocyanine. The pigment was irradiated for 3 minutes, the microwave was turned off once, the leak valve was once closed, and a high vacuum of 2 kPa or less was applied. This fourth step was further repeated 7 times (8 times in total).

  As described above, 1.52 kg of a hydroxygallium phthalocyanine pigment having a water content of 1% or less was obtained in a total of 3 hours.

<Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-5>
[Example 1-1]
0.5 parts of hydroxygallium phthalocyanine pigment obtained in the above <Synthesis of hydroxygallium phthalocyanine pigment> and 9.5 parts of N-methylformamide (product code: F0059, manufactured by Tokyo Chemical Industry Co., Ltd.) Milling with a ball mill together with 15 parts of the glass beads was performed at room temperature (23 ° C.) for 120 hours. At this time, a standard bottle (product code: PS-6, manufactured by Yoyo Glass Co., Ltd.) was used, and the container was run under the condition that the container was rotated 60 times per minute. After adding 30 parts of tetrahydrofuran to the dispersion thus obtained, the mixture was filtered through a filter, and the filtered material remaining in the filter was thoroughly washed with tetrahydrofuran. The washed filtrate was vacuum dried to obtain 0.45 parts of hydroxygallium phthalocyanine crystal. The powder X-ray diffraction pattern of the obtained crystals is shown in FIG.

As is apparent from FIG. 2, the obtained hydroxygallium phthalocyanine crystal has peaks at 7.4 ° ± 0.3 ° and 28.3 ° ± 0.3 ° of the Bragg angle 2θ in the X-ray diffraction of CuKα ray. You can see that When this crystal was dissolved in bisulfuric acid and subjected to ¹ H-NMR measurement, a peak derived from N-methylformamide was observed in addition to a peak derived from a phthalocyanine molecule. Since N-methylformamide is a liquid and is compatible with tetrahydrofuran, it can be seen that N-methylformamide is contained in the hydroxygallium phthalocyanine crystal.

The content of N-methylformamide in the hydroxygallium phthalocyanine crystal was 2.0% by mass with respect to the content of hydroxygallium phthalocyanine in terms of the proton ratio. The ¹ H-NMR spectrum of the obtained hydroxygallium phthalocyanine crystal is shown in FIG.

[Example 1-2]
In Example 1-1, a hydroxygallium phthalocyanine crystal was obtained in the same manner as in Example 1-1 except that the milling time was changed to 140 hours. The powder X-ray diffraction spectrum of the obtained crystal is the same as in FIG. 2 and has peaks at Bragg angles 2θ of 7.4 ° ± 0.3 ° and 28.3 ° ± 0.3 ° in the X-ray diffraction of CuKα ray. Was. When ¹ H-NMR measurement was performed in the same manner as in Example 1-1, it was confirmed that 1.9% by mass of N-methylformamide was contained in the crystal with respect to the content of hydroxygallium phthalocyanine. It was.

[Example 1-3]
In Example 1-1, a hydroxygallium phthalocyanine crystal was obtained in the same manner as in Example 1-1 except that the milling time was changed to 180 hours. The powder X-ray diffraction spectrum of the obtained crystal is the same as in FIG. 2 and has peaks at Bragg angles 2θ of 7.4 ° ± 0.3 ° and 28.3 ° ± 0.3 ° in the X-ray diffraction of CuKα ray. Was. When ¹ H-NMR measurement was performed in the same manner as in Example 1-1, it was confirmed that 1.8% by mass of N-methylformamide was contained in the crystal with respect to the content of hydroxygallium phthalocyanine. It was.

[Comparative Example 1-1]
In Example 1-1, instead of 0.5 parts of hydroxygallium phthalocyanine pigment, 9.5 parts of N-methylformamide, and 15 parts of glass beads having a diameter of 0.8 mm, 1.25 parts of hydroxygallium phthalocyanine pigment, N, N -Dimethylformamide (product code: D0722, manufactured by Tokyo Chemical Industry Co., Ltd.) 9.5 parts, 25 parts of glass beads with a diameter of 5 mm were used, and the milling treatment time was 48 hours, as in Example 1-1. Thus, a hydroxygallium phthalocyanine crystal was obtained.

As described above, N-methylformamide is not used in the production process of the hydroxygallium phthalocyanine crystal. Therefore, N-methylformamide is not contained in the hydroxygallium phthalocyanine crystal obtained in this comparative example. When ¹ H-NMR measurement was performed in the same manner as in Example 1-1, it was confirmed that 2.1% by mass of N, N-dimethylformamide was contained in the crystal. FIG. 5 shows a ¹ H-NMR spectrum of the obtained hydroxygallium phthalocyanine crystal.

[Comparative Example 1-2]
In Example 1-1, N, N-dimethylformamide (product code: D0722, manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of N-methylformamide, and the milling treatment time was set to 100 hours. In the same manner as in -1, a hydroxygallium phthalocyanine crystal was obtained.

N-methylformamide is not used in the production process of the hydroxygallium phthalocyanine crystal obtained in this comparative example. Therefore, N-methylformamide is not contained in the hydroxygallium phthalocyanine crystal obtained in this comparative example. When ¹ H-NMR measurement was performed in the same manner as in Example 1-1, it was confirmed that 2.1% by mass of N, N-dimethylformamide was contained in the crystal.

[Comparative Example 1-3]
In Example 1-1, hydroxygallium phthalocyanine crystals were treated in the same manner as in Example 1-1 except that dimethyl sulfoxide (product code: D0798, manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of N-methylformamide. Got.

N-methylformamide is not used in the production process of the hydroxygallium phthalocyanine crystal obtained in this comparative example. Therefore, N-methylformamide is not contained in the hydroxygallium phthalocyanine crystal obtained in this comparative example. When ¹ H-NMR measurement was performed in the same manner as in Example 1-1, it was confirmed that 2.4% by mass of N, N-dimethylsulfoxide was contained in the crystal.

[Comparative Example 1-4]
7 parts of hydroxygallium phthalocyanine pigment obtained in the above <Synthesis of hydroxygallium phthalocyanine pigment> and 210 parts of N, N-dimethylformamide (product code: D0722, manufactured by Tokyo Chemical Industry Co., Ltd.) Milling with a sand mill together with 300 parts of beads was performed at room temperature (23 ° C.) for 5 hours. After 420 parts of tetrahydrofuran was added to the dispersion thus obtained, the mixture was filtered through a filter, and the filter residue remaining in the filter was thoroughly washed with tetrahydrofuran. The washed filtrate was vacuum dried to obtain 5.2 parts of hydroxygallium phthalocyanine crystals.

N-methylformamide is not used in the production process of the hydroxygallium phthalocyanine crystal obtained in this comparative example. Therefore, N-methylformamide is not contained in the hydroxygallium phthalocyanine crystal obtained in this comparative example. When ¹ H-NMR measurement was performed in the same manner as in Example 1-1, it was confirmed that 2.4% by mass of N, N-dimethylformamide was contained in the crystal.

[Comparative Example 1-5]
In Example 1-1, a hydroxygallium phthalocyanine crystal was obtained in the same manner as in Example 1-1 except that the milling time was 100 hours. When ¹ H-NMR measurement was performed in the same manner as in Example 1-1, it was confirmed that 2.1% by mass of N-methylformamide was contained in the crystal.

<Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-5>
[Example 2-1]
60 parts of barium sulfate particles coated with tin oxide (trade name: Pastoran PC1, manufactured by Mitsui Mining & Smelting Co., Ltd.), 15 parts of titanium oxide particles (trade name: TITANIX JR, manufactured by Teika Co., Ltd.), resol type phenol resin ( Product name: Phenolite J-325, DIC Corporation, solid content 70 mass% 43 parts, silicone oil (trade name: SH28PA, Toray Dow Corning Co., Ltd.) 0.015 parts, silicone resin (product) Name: Tospearl 120, manufactured by Momentive Performance Material Co., Ltd.) 3.6 parts, 50 parts of 2-methoxy-1-propanol, and 50 parts of methanol were subjected to a dispersion treatment with a ball mill for 20 hours. A coating solution was prepared.

  This conductive layer coating solution is dip coated on an aluminum cylinder (diameter 24 mm, conductive support) as a support, and the resulting coating film is dried at 140 ° C. for 30 minutes, whereby the film thickness is 15 μm. A conductive layer was formed.

  Next, 10 parts of copolymer nylon resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) and 30 parts of methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation) A coating solution for undercoat layer was prepared by dissolving in a mixed solvent of 400 parts of methanol / 200 parts of n-butanol.

  This undercoat layer coating solution was applied onto the conductive layer by dip coating, and the resulting coating film was dried to form an undercoat layer having a thickness of 0.5 μm.

  Next, 10 parts of a hydroxygallium phthalocyanine crystal (charge generation material) obtained in Example 1-1, 5 parts of polyvinyl butyral (trade name: S-LEC BX-1, manufactured by Sekisui Chemical Co., Ltd.), 200 parts of cyclohexanone, And 400 parts of glass beads having a diameter of 1 mm were placed in a sand mill and dispersed for 4 hours. A charge generating layer coating solution was prepared by adding 100 parts of cyclohexanone and 300 parts of ethyl acetate to the dispersion and diluting.

  This charge generation layer coating solution was dip-coated on the undercoat layer, and the resulting coating film was dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.20 μm.

  Next, 8 parts of a compound (charge transport material) represented by the following formula (4) and 10 parts of polycarbonate (trade name: Iupilon Z-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) are dissolved in 80 parts of monochlorobenzene. Thus, a charge transport layer coating solution was prepared.

  The charge transport layer coating solution was dip-coated on the charge generation layer, and the resulting coating film was dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 16 μm.

  Thus, a cylindrical (drum-shaped) electrophotographic photosensitive member of Example 2-1 was produced.

[Examples 2-2 to 2-3]
In Example 2-1, the hydroxygallium phthalocyanine crystal at the time of preparing the charge generation layer coating solution was changed to the hydroxygallium phthalocyanine crystal obtained in Examples 1-2 to 1-3. Other than that was carried out similarly to Example 2-1, and produced the electrophotographic photoreceptor of Examples 2-2 to 2-3, respectively.

[Comparative Examples 2-1 to 2-5]
In Example 2-1, the hydroxygallium phthalocyanine crystal at the time of preparing the charge generation layer coating solution was changed to the hydroxygallium phthalocyanine crystal obtained in Comparative Examples 1-1 to 1-5. Other than that was carried out similarly to Example 2-1, and produced the electrophotographic photoreceptor of Comparative Examples 2-1 to 2-5, respectively.

[Evaluation of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-5]
The sensitivity of the electrophotographic photoreceptors of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-5 was evaluated.

  As an electrophotographic apparatus for evaluation, a laser beam printer (trade name: Color Laser Jet M451dn) manufactured by Hewlett-Packard Japan Co., Ltd. was used with the following modifications. First, the charging condition and the image exposure amount were made variable and operated. The electrophotographic photosensitive member produced above was mounted on a cyan process cartridge and attached to a cyan process cartridge station. It was made to operate without mounting process cartridges for other colors (magenta, yellow, black) on the printer body. The wavelength of the image exposure light was 790 nm.

  First, when using a process cartridge equipped with the electrophotographic photosensitive member of Comparative Example 2-2 in a normal temperature and humidity environment of 23 ° C./humidity 55% RH, the dark portion potential is −600 V and the light portion potential is −150 V. The charging conditions and the image exposure amount were adjusted so that The measurement of the surface potential of the cylindrical electrophotographic photoreceptor when setting the potential was performed as follows. First, the process cartridge is modified, and a potential probe (trade name: model6000B-8, manufactured by Trek Japan Co., Ltd.) is attached to the development position. Thereafter, the potential of the central portion of the cylindrical electrophotographic photosensitive member was measured using a surface potentiometer (trade name: model 344, manufactured by Trek Japan Co., Ltd.).

  Under the above-described charging conditions and image exposure amount conditions, a process cartridge equipped with the electrophotographic photosensitive members of Examples 2-1 to 2-3 and Comparative Examples 2-1, 2-3 to 2-5 was used. The partial potential was measured. The closer the value of the bright part potential is to 0 V, the greater the difference between the dark part potential and the bright part potential, which means that the electrophotographic photosensitive member has higher sensitivity. When the value of the light portion potential is more positive than −115 V, that is, close to 0 V, it is determined that the effect of the present invention is obtained. The evaluation results are shown in Table 1.

  As apparent from Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-5 in Table 1, N-methylformamide was 1.8% by mass with respect to hydroxygallium phthalocyanine in the hydroxygallium phthalocyanine crystal. An electrophotographic photoreceptor containing a hydroxygallium phthalocyanine crystal containing 2.0% by mass or less in the photosensitive layer has high sensitivity to light having a long wavelength.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Axis 3 Charging means 4 Image exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Image fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Guide means 101 Support body 102 Undercoat layer 103 Photosensitive layer 104 charge generation layer 105 charge transport layer

Claims (11)

An electrophotographic photosensitive member having a support and a photosensitive layer formed on the support,
The photosensitive layer contains a hydroxygallium phthalocyanine crystal containing N-methylformamide in the crystal;
The content of the N-methylformamide contained in the hydroxygallium phthalocyanine crystal is 1.8% by mass or more and 2.0% by mass or less based on the content of hydroxygallium phthalocyanine in the hydroxygallium phthalocyanine crystal. An electrophotographic photosensitive member characterized by the above.   The hydroxygallium phthalocyanine crystal is a hydroxygallium phthalocyanine crystal having strong peaks at 7.4 ° ± 0.3 ° and 28.3 ° ± 0.3 ° at a Bragg angle 2θ in X-ray diffraction of CuKα rays. Item 2. The electrophotographic photosensitive member according to Item 1.   3. The electrophotographic photosensitive member according to claim 1, wherein a content of the N-methylformamide is 1.8% by mass to 1.9% by mass with respect to hydroxygallium phthalocyanine in the hydroxygallium phthalocyanine crystal.   An electrophotographic apparatus main body integrally supporting the electrophotographic photosensitive member according to any one of claims 1 to 3 and at least one means selected from the group consisting of a charging means, a developing means, and a cleaning means. A process cartridge that is detachable.   An electrophotographic apparatus comprising: the electrophotographic photosensitive member according to claim 1; and a charging unit, an exposing unit, a developing unit, and a transferring unit.   A hydroxygallium phthalocyanine crystal containing N-methylformamide in the crystal, wherein the content of N-methylformamide contained in the hydroxygallium phthalocyanine crystal is the content of hydroxygallium phthalocyanine in the hydroxygallium phthalocyanine crystal. A hydroxygallium phthalocyanine crystal characterized by being 1.8% by mass or more and 2.0% by mass or less based on the amount.   N-methylformamide is contained in the crystal, and the content of the N-methylformamide is 1.8% by mass or more and 1.9% by mass or less based on hydroxygallium phthalocyanine in the hydroxygallium phthalocyanine crystal. 6. The hydroxygallium phthalocyanine crystal according to 6.   The hydroxygallium phthalocyanine crystal has strong peaks at 7.4 ° ± 0.3 ° and 28.3 ° ± 0.3 ° at a Bragg angle 2θ in X-ray diffraction of CuKα rays. Of hydroxygallium phthalocyanine crystals. A method for producing a hydroxygallium phthalocyanine crystal for producing the hydroxygallium phthalocyanine crystal according to any one of claims 6 to 8,
A method for producing a hydroxygallium phthalocyanine crystal, comprising the step of adding N-methylformamide to hydroxygallium phthalocyanine and performing a milling treatment to convert the crystal of hydroxygallium phthalocyanine.   The method for producing a hydroxygallium phthalocyanine crystal according to claim 9, wherein the hydroxygallium phthalocyanine milled with the N-methylformamide is obtained by an acid pasting method. A method for producing an electrophotographic photosensitive member for producing a support and an electrophotographic photosensitive member having a photosensitive layer formed on the support,
A step of forming a hydroxygallium phthalocyanine crystal by the method for producing a hydroxygallium phthalocyanine crystal according to claim 9 or 10,
Preparing a coating solution for a photosensitive layer containing the hydroxygallium phthalocyanine crystal; and
Forming a coating film of the coating solution for the photosensitive layer, and drying the coating film to form the photosensitive layer;
A process for producing an electrophotographic photosensitive member, comprising: