JP2017076126A - Xerographic photoreceptor, process cartridge and electrophotographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a xerographic photoreceptor superior in suppression of fog capable of outputting high quality images.SOLUTION: The xerographic photoreceptor includes: a support; a charge generation layer containing charge generation substance; and a charge transport layer containing a charge transport material and polycarbonate in this order. The polycarbonate has a structure unit represented by a formula (3). The charge generation substance is a gallium phthalocyanine crystal which has a peak Bragg angles of 7.4° ±0.3° and 28.3°±0.3° in CuKα characteristics X-ray diffraction.SELECTED DRAWING: None

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus.

As an electrophotographic photosensitive member mounted on an electrophotographic apparatus or a process cartridge, a functionally separated type laminated photosensitive member having a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance is common. .
The charge transport layer is often a surface layer of an electrophotographic photoreceptor, and is required to have mechanical strength and resistance to discharge deterioration. Accordingly, development of a high mobility charge transport material and development of a resin having mechanical strength and discharge resistance are in progress.
In particular, there is a problem that the charge transport layer becomes thin due to wear of the charge transport layer due to repeated use of the electrophotographic photosensitive member, thereby increasing the electric field strength and causing fogging. The fog is a phenomenon in which the toner is thinly developed in a portion where the toner should not be developed.

Patent Document 1 describes an electrophotographic photosensitive member containing a polycarbonate copolymer having excellent wear resistance.
Patent Document 2 describes an electrophotographic photosensitive member that is a combination of a specific charge generating substance and a polycarbonate copolymer and has little potential fluctuation.

JP 2011-26574 A Japanese Patent Laid-Open No. 9-43882

  However, further improvement in fog is desired from the viewpoint of recent demand for higher image quality and the suppression of toner consumption. As a result of the study by the present inventors, it was found that the electrophotographic photosensitive member containing the polycarbonate copolymer of Patent Document 1 has room for further improvement of fog suppression. Further, it has been found that there is room for further improvement of fog suppression even in the electrophotographic photosensitive member using a good combination of the charge generation material and the polycarbonate copolymer of Patent Document 2.

An object of the present invention is to provide an electrophotographic photoreceptor excellent in suppression of fog and capable of outputting a high-quality image.
Another object of the present invention is to provide an electrophotographic apparatus and a process cartridge having the electrophotographic photosensitive member.

The present invention provides an electrophotographic photosensitive member having a support, a charge generation layer containing a charge generation material, and a charge transport layer containing a charge transport material and a polycarbonate in this order. A gallium phthalocyanine crystal having a peak at 7.4 ° ± 0.3 ° and 28.3 ° ± 0.3 ° of the Bragg angle in CuKα characteristic X-ray diffraction An electrophotographic photosensitive member characterized by the above.

Further, the present invention integrally supports the electrophotographic photosensitive member and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means, and is detachable from the main body of the electrophotographic apparatus. It is a process cartridge characterized by being.
Furthermore, the present invention is an electrophotographic apparatus comprising the electrophotographic photosensitive member, and a charging unit, an exposing unit, a developing unit, and a transfer unit.

  According to the present invention, it is possible to provide an electrophotographic photosensitive member that is excellent in suppression of fog and that can output a high-quality image, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having an electrophotographic photosensitive member. 2 is a powder X-ray diffraction pattern of a hydroxygallium phthalocyanine crystal obtained in Preparation Example 1 of a gallium phthalocyanine crystal. FIG. FIG. 4 is a powder X-ray diffraction pattern of a hydroxygallium phthalocyanine crystal obtained in Preparation Example 2 of gallium phthalocyanine crystal.

As described above, the electrophotographic photosensitive member of the present invention has a support, a charge generation layer containing a charge generation material, and a charge transport layer containing a charge transport material and a polycarbonate in this order. The polycarbonate contained in the charge transport layer has a structural unit represented by the formula (3), and the charge generation material in the charge generation layer has a Bragg angle of 7.4 ° ± 0.00 mm in CuKα characteristic X-ray diffraction. It is characterized by being a gallium phthalocyanine crystal having peaks at 3 ° and 28.3 ° ± 0.3 °.

  The electrophotographic photoreceptor of the present invention uses a resin containing a polycarbonate having a structural unit represented by the formula (3) as a resin for a charge transport layer, and uses a gallium phthalocyanine crystal having a peak at a specific Bragg angle as a charge generation material. By using it, it is possible to continue to output a high-quality image without fogging, maintaining the uniformity of the charging property very well through durability, rather than using each of them individually. The mechanism is not clear, but the combination of a low-memory, charge-generating substance with suppressed dark decay and a resin that is resistant to discharge degradation has worked well, is resistant to wear, has excellent wear resistance, and even wear. For this reason, the inventors of the present invention consider that a remarkable fog suppression effect can be realized.

[Polycarbonate]
The polycarbonate according to the present invention is a copolymer having the structural unit represented by the formula (3) and other structural units. The proportion of the structural unit represented by the formula (3) in the polycarbonate is preferably 20 mol% or more and 50 mol% or less.

Other structural units included in the polycarbonate together with the structure represented by the formula (3) include a structural unit represented by the formula (2), a structural unit represented by the formula (7), a structural unit represented by the formula (8), The structural unit represented by formula (9), the structural unit represented by formula (10), the structural unit represented by formula (11) and the structural unit represented by formula (12) are preferred.

Examples of the method for obtaining the polycarbonate having the structural unit represented by the formula (3) include the following two methods. The first method is a method of directly reacting a compound represented by the formula (1-OH) with phosgene (phosgene method) to obtain a polycarbonate having a structural unit represented by the formula (3). The second method is a method of obtaining a polycarbonate having a structural unit represented by the formula (3) by transesterifying the compound represented by the formula (1-OH) with a bisaryl carbonate (a transesterification method). .

  Examples of the carbonic acid ester forming compound used to obtain the polycarbonate having the structural unit represented by the formula (3) include phosgene or triphosgene used in the phosgene method, diphenyl carbonate used in the transesterification method, di-p- Examples include bisaryl carbonates such as tolyl carbonate, phenyl-p-tolyl carbonate, di-p-chlorophenyl carbonate, and dinaphthyl carbonate. Two or more of these compounds can be used in combination.

  In the phosgene method, the bisphenol compound represented by the formula (1-OH) and phosgene are usually reacted in the presence of a base and a solvent. Examples of the base include pyridine, alkali metal hydroxides such as potassium hydroxide and sodium hydroxide. Examples of the solvent include methylene chloride and chloroform. Furthermore, a catalyst or a molecular weight regulator may be added to promote the condensation polymerization reaction. Examples of the catalyst include tertiary amines such as triethylamine or quaternary ammonium salts. Examples of the molecular weight regulator include monofunctional compounds such as phenol, p-cumylphenol, t-butylphenol, and long-chain alkyl-substituted phenol.

  Moreover, when manufacturing the polycarbonate used for this invention, you may add branching agents, such as antioxidants, such as sodium sulfite and hydrosulfite, phloroglucin, and 1, 3-bisphenol as needed. The reaction temperature for producing the polycarbonate is 0 to 150 ° C, preferably 5 to 40 ° C. While the reaction time depends on the reaction temperature, it is generally 0.5 min-10 hr, preferably 1 min-2 hr. During the reaction, it is desirable to maintain the pH of the reaction system at 10 or more.

  The weight average molecular weight of the polycarbonate used in the present invention is preferably 20,000 or more and 80,000 or less. The weight average molecular weight of the polycarbonate is a polystyrene-reduced weight average molecular weight measured according to a conventional method, specifically, a method described in JP-A-2007-79555.

When the polycarbonate is a copolymer of the structural unit represented by the formula (3) and the structural unit represented by the formula (2) and the formula (7) to the formula (12), for example, in the formula (1-OH) According to the method of obtaining the polycarbonate having the structural unit represented by the formula (3) by mixing the compound represented by the formula (2-OH) to the compound represented by the formula (12-OH) at an arbitrary ratio, Polycarbonate can be obtained.

[Support]
The support used in the present invention is preferably one having conductivity (conductive support). Examples thereof include metals and alloys such as aluminum and stainless steel, metals provided with a conductive layer, alloys, plastics, and paper. Examples of the shape of the support include a cylindrical shape and a film shape.

In the present invention, an undercoat layer (also referred to as an intermediate layer) having a barrier function and an adhesive function may be provided between the support and the charge generation layer. The undercoat layer contains a binder resin.
Examples of the binder resin include polyvinyl alcohol, polyethylene oxide, ethyl cellulose, methyl cellulose, casein, polyamide, polyurethane, and alkyd-melamine resin. The undercoat layer can be formed by mixing a binder resin and a solvent to prepare a coating solution for the undercoat layer, forming a coating film of the coating solution for the undercoat layer on the support, and drying the coating film. . Metal oxide particles may be contained for the purpose of controlling the resistance of the undercoat layer.
The thickness of the undercoat layer is preferably 0.3 to 5.0 μm.

Further, a conductive layer may be provided between the support and the undercoat layer for the purpose of covering unevenness and defects on the support and preventing interference fringes.
The conductive layer can be formed by dispersing conductive particles such as carbon black, metal particles, and metal oxide particles in a binder resin. As the binder resin, a binder resin similar to the binder resin used for the undercoat layer can be used.
The thickness of the conductive layer is preferably 5 to 40 μm, and particularly preferably 10 to 30 μm.

(Charge generation layer)
The charge generation layer is formed by applying a charge generation layer coating solution prepared by dispersing a charge generation material in a solvent together with a binder resin to form a coating film, and then drying the obtained coating film. be able to.
The content of the charge generation material in the charge generation layer is preferably 40% by mass to 85% by mass, and more preferably 60% by mass to 80% by mass with respect to the total mass of the charge generation layer.
The thickness of the charge generation layer is preferably 0.05 to 1.0 μm, and more preferably 0.1 to 0.3 μm.

The charge generation material contained in the charge generation layer is made of gallium phthalocyanine crystals having peaks at Bragg angles of 7.4 ° ± 0.3 ° and 28.3 ° ± 0.3 ° in CuKα characteristic X-ray diffraction.
The gallium phthalocyanine crystal used in the present application includes crystal forms having peaks at 7.4 °, 16.6 °, 25.5 ° and 28.3 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction. Chlorogallium phthalocyanine, having peaks at 7.3 °, 24.9 ° and 28.1 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction, and the peak at 28.1 ° is the maximum peak A crystalline form of hydroxygallium phthalocyanine having a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction of 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 ° and 28 And a crystalline form of hydroxygallium phthalocyanine having a peak at 3 °. In the present specification, these are also referred to as “gallium phthalocyanine crystals having a peak at a specific Bragg angle”.

  The gallium phthalocyanine crystal is preferably a gallium phthalocyanine crystal containing an amide compound in the crystal. Among the amide compounds, N, N-dimethylformamide and N-methylformamide are more preferable. Further, the content of the amide compound in the gallium phthalocyanine crystal is preferably 0.1% by mass or more and 2.0% by mass or less, and 0.3% by mass or more and 1.7% by mass with respect to the mass of the gallium phthalocyanine crystal. It is particularly preferable that the content is not more than mass%.

Gallium phthalocyanine crystal containing an amide compound in the crystal is preferably obtained by wet milling treatment of gallium phthalocyanine treated by the acid pasting method or dry milling and a solvent containing the amide compound and crystal conversion. .
The wet milling process is a process performed using a milling apparatus such as a sand mill or a ball mill together with a dispersing agent such as glass beads, steel beads, or alumina balls.
The content of the amide compound in the gallium phthalocyanine crystal can be measured using ¹ H-NMR. ^The measuring method by ¹ H-NMR will be described later.

  Further, in the charge generation layer of the electrophotographic photosensitive member of the present invention, the charge generation material is combined with other charge generation materials such as phthalocyanine crystals or azo pigments in addition to the gallium phthalocyanine crystal having a peak at a specific Bragg angle. It may be used. In that case, it is preferable that the gallium phthalocyanine crystal having a peak at a specific Bragg angle is 70% by mass or more with respect to the total mass of all the charge generation materials in the charge generation layer.

  Examples of the binder resin used for the charge generation layer include resins such as polyester, acrylic resin, polycarbonate, polyvinyl butyral, polystyrene, polyvinyl acetate, polysulfone, acrylonitrile copolymer, and polyvinyl benzal. Among these, polyvinyl butyral and polyvinyl benzal are preferable as the resin for dispersing the gallium phthalocyanine crystal.

(Charge transport layer)
The charge transport layer is prepared by mixing a charge transport material, a polycarbonate having the structural unit represented by formula (3), and a solvent to prepare a charge transport layer coating solution, and forming a coating film of the charge transport layer coating solution. The coating film can be formed by drying. In addition, the charge transport layer is provided with a release agent for the purpose of increasing toner transfer efficiency, an anti-fingerprint agent for the purpose of suppressing dirt, a filler for the purpose of suppressing abrasion, and a lubricant for the purpose of improving lubricity. It may be added.

  Solvents used in the charge transport layer coating solution include ketone solvents such as acetone and methyl ethyl ketone; ester solvents such as methyl acetate and ethyl acetate; aromatic hydrocarbon solvents such as toluene, xylene and chlorobenzene; 1,4-dioxane And ether solvents such as tetrahydrofuran; hydrocarbon solvents such as chloroform substituted with halogen atoms; and the like. These solvents may be used alone or in combination of two or more. Among these solvents, a solvent having a dipole moment of 1.0 D or less is preferable. Examples of the solvent having a dipole moment of 1.0 D or less include o-xylene (dipole moment = 0.64D) and methylal (dimethoxymethane) (dipole moment = 0.91 D). By using these solvents in combination with a polycarbonate having a structural unit represented by the formula (3) and a charge transporting material in the production of the charge transporting layer, electrons that have excellent coating properties and are less likely to cause fogging during use. A photographic photoreceptor is obtained.

The thickness of the charge transport layer is preferably 5 to 40 μm, and particularly preferably 7 to 25 μm.
The content of the charge transport material is preferably 20 to 70% by mass, and particularly preferably 30 to 60% by mass with respect to the total mass of the charge transport layer.

式（１３）中、Ａｒ^１〜Ａｒ^４はそれぞれ独立に、置換もしくは無置換のフェニル基、置換もしくは無置換のベンジル基、９，９−ジメチル−９Ｈ−フルオレン−２−イル基である。また、式（１３）中、Ｘはフェニレン基を示す。 Examples of the charge transport material include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triallylmethane compounds. Among these, as the charge transport material, a triarylamine compound is preferable, and further, the compound represented by the formula (13) has good compatibility with the polycarbonate having the structural unit represented by the formula (3). Particularly preferred.

In formula (13), Ar ^{1 to} Ar ⁴ are each independently a substituted or unsubstituted phenyl group, a substituted or unsubstituted benzyl group, or a 9,9-dimethyl-9H-fluoren-2-yl group. In formula (13), X represents a phenylene group.

In Ar ^{1 to} Ar ⁴ , examples of the substituent of the substituted phenyl group include an alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, a dimethylamino group, a diethylamino group, or a phenyl group. Further, in the ^Ar 1 to Ar ^4, substituent of the substituted benzyl group, a methyl group or an ethyl group,.

  The content of the polycarbonate having the structural unit represented by the formula (3) is preferably 30 to 80% by mass, and particularly preferably 50 to 70% by mass with respect to the total mass of the charge transport layer. Further, it may be used in combination with other resins such as polycarbonate or polyarylate. In that case, the polycarbonate having the structural unit represented by the formula (3) is 50% by mass with respect to the total resin mass in the charge transport layer. % Or more is preferable.

  As a coating method of each layer, coating methods such as a dip coating method (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.

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.
The cylindrical (drum-shaped) electrophotographic photosensitive member 1 is rotationally driven with a predetermined peripheral speed (process speed) in the direction of the arrow about the shaft 2. 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 exposure light 4 from an exposure means (not shown), and an electrostatic latent image corresponding to target image information is formed. The exposure light 4 is light that has been intensity-modulated in response to a time-series electrical digital image signal of target image information that is 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 fixing unit 8, and subjected to a fixing process of the toner image, whereby an image formed product Printed out of the electrophotographic apparatus as (print, copy).

  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 it is possible to remove the transfer residual toner directly with 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, among the components such as the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, the transfer unit 6 and the cleaning unit 9 described above, a plurality of components are housed in a container and integrally supported. The cartridge 11 may be formed. The process cartridge 11 can be configured to be detachable from the main body of the electrophotographic apparatus. For example, at least one selected from the charging unit 3, the developing unit 5, and the cleaning unit 9 is 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 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. “Part” described below means “part by mass”. However, the present invention is not limited to these. 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.

The content of the amide compound in the gallium phthalocyanine crystal was measured using ¹ H-NMR under the following conditions.
^[1 H-NMR measurement]
Used measuring instrument: BRUKER, AVANCE III 500
Solvent: Bisulfuric acid (D ₂ SO ₄ )

[Polycarbonate Synthesis Example 1]
In 1100 ml of 5% by weight aqueous sodium hydroxide solution, 10.54 g (0.04 mol) of the compound represented by the formula (12-OH) and 94.4 g (0.36 mol) of the compound represented by the formula (1-OH) And 0.1 g of hydrosulfite were dissolved. To this, 500 ml of methylene chloride was added and stirred, while maintaining at 15 ° C., 80 g of triphosgene was then slowly added.
After adding triphosgene, 1.3 g of pt-butylphenol (hereinafter abbreviated as “PTBP”: manufactured by Tokyo Chemical Industry Co., Ltd., product code B0383) was added as a molecular weight regulator and stirred to emulsify the reaction solution. After emulsification, 0.4 ml of triethylamine was added, and the mixture was stirred at 23 ° C. for 1 hour for polymerization.
After completion of the polymerization, the reaction solution was separated into an aqueous phase and an organic phase, the organic phase was neutralized with phosphoric acid, and washing with water was repeated until the conductivity of the washing solution (aqueous phase) became 10 μS / cm or less. The obtained polymer solution was dropped into warm water maintained at 45 ° C., and the solvent was removed by evaporation to obtain a white powdery precipitate. The obtained precipitate was filtered, dried at 110 ° C. for 24 hours, and a polycarbonate having a structural unit represented by formula (2) and a structural unit represented by formula (3) at 1: 9 (hereinafter referred to as PC-1). (Abbreviation).

[Polycarbonate Synthesis Example 2]
In Synthesis Example 1 of polycarbonate, 10.54 g (0.04 mol) of the compound represented by the formula (12-OH) and 94.4 g (0.36 mol) of the compound represented by the formula (1-OH) Synthesis Example 1 of polycarbonate except that 31.62 g (0.12 mol) of the compound represented by (12-OH) and 73.4 g (0.28 mol) of the compound represented by the formula (1-OH) were changed. It carried out similarly and obtained the polycarbonate (PC-2) which has the structural unit shown by Formula (2), and the structural unit shown by Formula (3) by 3: 7.

[Polycarbonate Synthesis Example 3]
In Synthesis Example 1 of polycarbonate, 10.54 g (0.04 mol) of the compound represented by the formula (12-OH) and 94.4 g (0.36 mol) of the compound represented by the formula (1-OH) Synthesis Example 1 of polycarbonate except that 52.5 g (0.2 mol) of the compound represented by (12-OH) and 52.5 g (0.2 mol) of the compound represented by the formula (1-OH) were changed. It carried out similarly and obtained the polycarbonate (PC-3) which has the structural unit shown by Formula (2), and the structural unit shown by Formula (3) by 5: 5.

[Polycarbonate Synthesis Example 4]
In Synthesis Example 1 of polycarbonate, 10.54 g (0.04 mol) of the compound represented by the formula (12-OH) and 94.4 g (0.36 mol) of the compound represented by the formula (1-OH) Except that the compound was changed to 73.4 g (0.28 mol) represented by (12-OH) and 31.6 g (0.12 mol) compound represented by the formula (1-OH), Synthesis Example 1 of polycarbonate and In the same manner, a polycarbonate (PC-4) having a structural unit represented by the formula (2) and a structural unit represented by the formula (3) at 7: 3 was obtained.

[Polycarbonate Synthesis Example 5]
In Synthesis Example 1 of polycarbonate, 10.54 g (0.04 mol) of the compound represented by the formula (12-OH) and 94.4 g (0.36 mol) of the compound represented by the formula (1-OH) Except for changing to 94.4 g (0.36 mol) of the compound represented by (12-OH) and 10.5 g (0.04 mol) of the compound represented by the formula (1-OH), Synthesis Example 1 of polycarbonate and It carried out similarly and obtained the polycarbonate (PC-5) which has the structural unit shown by Formula (2), and the structural unit shown by Formula (3) by 9: 1.

[Polycarbonate Synthesis Example 6]
In Synthesis Example 1 of polycarbonate, 10.54 g (0.04 mol) of the compound represented by the formula (12-OH) and 94.4 g (0.36 mol) of the compound represented by the formula (1-OH) Except having changed to 104.9 g (0.4 mol) of the compound represented by (1-OH), it was carried out in the same manner as in Synthesis Example 1 of polycarbonate, and polycarbonate (PC-6) having a structural unit represented by formula (3) Got.

[Polycarbonate Synthesis Example 7]
In Synthesis Example 1 of polycarbonate, 10.54 g (0.04 mol) of the compound represented by the formula (12-OH) and 94.4 g (0.36 mol) of the compound represented by the formula (1-OH) Synthesis Example 1 of polycarbonate except that 52.5 g (0.2 mol) of the compound represented by (1-OH) and 54.1 g (0.2 mol) of the compound represented by the formula (5-OH) were changed. In the same manner, a polycarbonate (PC-7) having a structural unit represented by the formula (3) and a structural unit represented by the formula (7) at 5: 5 was obtained.

[Polycarbonate Synthesis Example 8]
In Synthesis Example 1 of polycarbonate, 10.54 g (0.04 mol) of the compound represented by the formula (12-OH) and 94.4 g (0.36 mol) of the compound represented by the formula (1-OH) Synthesis Example 1 of polycarbonate except that 52.5 g (0.2 mol) of the compound represented by (1-OH) and 37.2 g (0.2 mol) of the compound represented by the formula (9-OH) were changed. It carried out similarly and obtained the polycarbonate (PC-8) which has the structural unit shown by Formula (3), and the structural unit shown by Formula (11) by 5: 5.

[Preparation example of phthalocyanine crystal]
[Synthesis example 1 of gallium phthalocyanine]
Under an atmosphere of nitrogen flow, 5.46 parts of phthalonitrile and 45 parts of α-chloronaphthalene were charged into a reaction kettle, heated and heated to a temperature of 60 ° C., and then maintained at this temperature. Next, 3.75 parts of gallium trichloride was added at this temperature (60 ° C.). The water content of the mixed solution at the time of charging was 60 ppm. Thereafter, the temperature was raised to 200 ° C. Next, after reacting at a temperature of 200 ° C. for 5 hours under an atmosphere of nitrogen flow, cooling was performed, and when the temperature reached 150 ° C., the product was filtered. The obtained filtrate was dispersed and washed with N, N-dimethylformamide at a temperature of 130 ° C. for 2 hours and then filtered. The obtained filtrate was washed with methanol and dried to obtain 4.47 parts (yield 68%) of a chlorogallium phthalocyanine pigment.

[Synthesis Example 2 of Gallium Phthalocyanine]
4.65 parts of chlorogallium phthalocyanine pigment obtained by the method described in Synthesis Example 1 of gallium phthalocyanine is dissolved in 139.5 parts of concentrated sulfuric acid at a temperature of 10 ° C., and added dropwise to 620 parts of ice water under stirring. Precipitated and filtered using a filter press. 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 (filtered material) was dispersed and washed with ion-exchanged water, and then filtration using a filter press was repeated three times to obtain a hydroxygallium phthalocyanine pigment (hydrous hydroxygallium phthalocyanine pigment) having a solid content of 23%. It was.

  Next, 6.6 kg of the obtained hydroxygallium phthalocyanine pigment (hydrous hydroxygallium phthalocyanine pigment) was used as a hyper dry dryer (trade name: HD-06R, frequency (oscillation frequency): 2455 MHz ± 15 MHz, manufactured by Nippon Biocon Co., Ltd. ) And dried as follows.

  The obtained hydroxygallium phthalocyanine pigment is placed on a special circular plastic tray in a lump state (water cake thickness 4 cm or less) as it is taken out from the filter press, the far infrared ray is turned off, and the temperature of the inner wall of the dryer is 50 ° C. Was set as follows. 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, the leak valve was adjusted, and the degree of vacuum (pressure in the dryer) was adjusted within the set value (4.0 to 10.0 kPa). Thereafter, 1.2 kW microwave was irradiated on the hydroxygallium phthalocyanine pigment for 5 minutes, and then the microwave was turned off once to close the leak valve and to make a high vacuum of 2 kPa or less. 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 was adjusted, and the degree of vacuum (pressure in the dryer) was restored to the set value (4.0 to 10.0 kPa). Thereafter, 0.4 kW microwave was irradiated to the hydroxygallium phthalocyanine pigment for 3 minutes, and the microwave was turned off once and the leak valve was temporarily closed to make a high vacuum of 2 kPa or less. 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.

[Preparation Example 1 of Gallium Phthalocyanine Crystal]
Milling treatment of 0.5 parts of the hydroxygallium phthalocyanine pigment obtained in Synthesis Example 2 of gallium phthalocyanine and 10 parts of N, N-dimethylformamide together with 20 parts of glass beads having a diameter of 0.8 mm at room temperature (23 ° C. ) And under the condition of 60 rpm for 48 hours. Gallium phthalocyanine crystals were filtered from the dispersion thus obtained, and the filter was thoroughly washed with tetrahydrofuran. The filtered product was vacuum-dried to obtain 0.45 part of a hydroxygallium phthalocyanine crystal. The powder X-ray diffraction pattern of the obtained crystals is shown in FIG.

In addition, by ¹ H-NMR measurement, the hydroxygallium phthalocyanine crystal obtained in Preparation Example 1 contains 2.1% by mass of N, N-dimethylformamide based on the mass of the crystal in terms of proton ratio. It was confirmed that Since N, N-dimethylformamide is compatible with tetrahydrofuran, it is understood that N, N-dimethylformamide is contained in the crystal.

[Preparation Example 2 of Gallium Phthalocyanine Crystal]
Milling treatment of 0.5 parts of the hydroxygallium phthalocyanine pigment obtained in Synthesis Example 2 of gallium phthalocyanine and 10 parts of N-methylformamide together with 20 parts of glass beads having a diameter of 0.8 mm at room temperature (23 ° C.) For 200 hours at 60 rpm. Hydroxygallium phthalocyanine crystals were filtered from the dispersion thus obtained, and the filter was thoroughly washed with tetrahydrofuran. The filtered product was vacuum-dried to obtain 0.46 parts of hydroxygallium phthalocyanine crystals. A powder X-ray diffraction pattern of the obtained crystals is shown in FIG.

Further, by ¹ H-NMR measurement, the hydroxygallium phthalocyanine crystal obtained in Preparation Example 2 contains 1.7% by mass of N-methylformamide with respect to the mass of the crystal, calculated from the proton ratio. It was confirmed. Since N-methylformamide is compatible with tetrahydrofuran, it can be seen that N-methylformamide is contained in the crystal.

[Preparation Example 3 of Gallium Phthalocyanine Crystal]
Milling treatment of 0.5 parts of the hydroxygallium phthalocyanine pigment obtained in Synthesis Example 2 of gallium phthalocyanine and 10 parts of N-methylformamide together with 20 parts of glass beads having a diameter of 0.8 mm at room temperature (23 ° C.) For 600 hours under the condition of 60 rpm. Hydroxygallium phthalocyanine crystals were filtered from the dispersion thus obtained, and the filter was thoroughly washed with tetrahydrofuran. The filtered product was vacuum-dried to obtain 0.45 part of a hydroxygallium phthalocyanine crystal. The powder X-ray diffraction of the obtained hydroxygallium phthalocyanine crystal was the same as in FIG.

Further, by ¹ H-NMR measurement, the hydroxygallium phthalocyanine crystal obtained in Preparation Example 3 contains 0.9% by mass of N-methylformamide based on the mass of the crystal in terms of proton ratio. It was confirmed. Since N-methylformamide is compatible with tetrahydrofuran, it can be seen that N-methylformamide is contained in the crystal.

[Example 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 Materials Japan GK) 3.6 parts, 50 parts of 2-methoxy-1-propanol, 50 parts of methanol for 20 hours by a ball mill for a conductive layer A coating solution was prepared.
The conductive layer coating solution was dip-coated on an aluminum cylinder as a support, and the resulting coating film was dried at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 15 μm.

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 Teikoku Chemical Co., Ltd.) were added to methanol. An undercoat layer coating solution was prepared by dissolving in a mixed solvent of 400 parts / 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 0.7 μm.

Next, 10 parts of a hydroxygallium phthalocyanine crystal (charge generation material) obtained in Preparation Example 1 of gallium phthalocyanine crystal, 5 parts of polyvinyl butyral (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.), and 250 parts of cyclohexanone was placed in a sand mill using glass beads having a diameter of 1 mm, dispersed for 6 hours, and 250 parts of ethyl acetate was added thereto and diluted to prepare a charge generation layer coating solution.
The 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 0.22 μm.

この電荷輸送層用塗布液を電荷発生層上に浸漬塗布し、得られた塗膜を１時間１２５℃で乾燥させることによって、膜厚が１５．５μｍの電荷輸送層を形成した。
このようにして、円筒状（ドラム状）の本実施例の電子写真感光体１を作製した。 Next, 6 parts of the compound represented by the formula (CTM-1) (charge transporting substance), 3 parts of the compound represented by the formula (CTM-2) (charge transporting substance), and the polycarbonate obtained in Synthesis Example 1 of the polycarbonate (PC -1) A coating solution for charge transport layer was prepared by dissolving 10 parts in 70 parts of tetrahydrofuran and 20 parts of toluene.

This charge transport layer coating solution was dip coated on the charge generation layer, and the resulting coating film was dried at 125 ° C. for 1 hour to form a charge transport layer having a thickness of 15.5 μm.
Thus, a cylindrical (drum-shaped) electrophotographic photosensitive member 1 of this example was produced.

[Example 2]
In Example 1, except that the polycarbonate (PC-1) obtained in Synthesis Example 1 of polycarbonate in preparing the coating solution for charge transport layer was changed to the polycarbonate (PC-2) obtained in Synthesis Example 2 of polycarbonate. In the same manner as in Example 1, an electrophotographic photoreceptor 2 of this example was produced.

Example 3
In Example 1, except that the polycarbonate (PC-1) obtained in Synthesis Example 1 of polycarbonate in preparing the coating solution for charge transport layer was changed to the polycarbonate (PC-3) obtained in Synthesis Example 3 of polycarbonate. In the same manner as in Example 1, an electrophotographic photoreceptor 3 of this example was produced.

Example 4
In Example 1, except that the polycarbonate (PC-1) obtained in Synthesis Example 1 of polycarbonate in preparing the coating solution for charge transport layer was changed to the polycarbonate (PC-4) obtained in Synthesis Example 4 of polycarbonate. Produced an electrophotographic photosensitive member 4 of this example in the same manner as in Example 1.

Example 5
In Example 1, except that the polycarbonate (PC-1) obtained in Synthesis Example 1 of polycarbonate in preparing the coating liquid for charge transport layer was changed to the polycarbonate (PC-5) obtained in Synthesis Example 5 of polycarbonate. In the same manner as in Example 1, an electrophotographic photoreceptor 5 of this example was produced.

Example 6
In Example 1, except that the polycarbonate (PC-1) obtained in Synthesis Example 1 of polycarbonate in preparing the coating solution for charge transport layer was changed to the polycarbonate (PC-6) obtained in Synthesis Example 6 of polycarbonate. In the same manner as in Example 1, an electrophotographic photoreceptor 6 of this example was produced.

Example 7
In Example 1, except that the polycarbonate (PC-1) obtained in Synthesis Example 1 of polycarbonate when preparing the coating solution for charge transport layer was changed to the polycarbonate (PC-7) obtained in Synthesis Example 7 of polycarbonate. In the same manner as in Example 1, an electrophotographic photoreceptor 7 of this example was produced.

Example 8
In Example 1, except that the polycarbonate (PC-1) obtained in Synthesis Example 1 of polycarbonate in preparing the coating solution for charge transport layer was changed to the polycarbonate (PC-8) obtained in Synthesis Example 8 of polycarbonate. Produced an electrophotographic photosensitive member 8 of this example in the same manner as in Example 1.

Example 9
In Example 2, the hydroxygallium phthalocyanine crystal obtained in Preparation Example 1 of the gallium phthalocyanine crystal when preparing the coating solution for the charge generation layer was changed to the hydroxygallium crystal obtained in Preparation Example 2 of the gallium phthalocyanine crystal. Except for this, the electrophotographic photosensitive member 9 of this example was produced in the same manner as in Example 2.

Example 10
In Example 3, the hydroxygallium phthalocyanine crystal obtained in Preparation Example 1 of the gallium phthalocyanine crystal when preparing the coating solution for the charge generation layer was changed to the hydroxygallium crystal obtained in Preparation Example 2 of the gallium phthalocyanine crystal. Except for this, the electrophotographic photosensitive member 10 of this example was produced in the same manner as in Example 3.

Example 11
In Example 4, the hydroxygallium phthalocyanine crystal obtained in Preparation Example 1 of the gallium phthalocyanine crystal when preparing the coating solution for the charge generation layer was changed to the hydroxygallium crystal obtained in Preparation Example 3 of the gallium phthalocyanine crystal. Except for this, the electrophotographic photosensitive member 11 of this example was produced in the same manner as in Example 4.

Example 12
In Example 6, the hydroxygallium phthalocyanine crystal obtained in Preparation Example 1 of the gallium phthalocyanine crystal when preparing the coating solution for the charge generation layer was changed to the hydroxygallium crystal obtained in Preparation Example 3 of the gallium phthalocyanine crystal. Except for this, the electrophotographic photosensitive member 12 of this example was produced in the same manner as in Example 6.

(式中、構造単位の右下の数字は、共重合比を示す。) [Comparative Example 1]
Example 1 is the same as Example 1 except that the polycarbonate (PC-1) obtained in Synthesis Example 1 of polycarbonate in preparing the coating solution for the charge transport layer is changed to the polycarbonate shown in (Comparative Compound 1). Similarly, a comparative electrophotographic photoreceptor 1 of this comparative example was produced.

(In the formula, the number on the lower right of the structural unit indicates the copolymerization ratio.)

(式中、構造単位の右下の数字は、共重合比を示す。) [Comparative Example 2]
Example 1 is the same as Example 1 except that the polycarbonate (PC-1) obtained in Synthesis Example 1 of polycarbonate in preparing the coating solution for the charge transport layer was changed to the polycarbonate shown in (Comparative Compound 2). Similarly, a comparative electrophotographic photosensitive member 2 of this comparative example was produced.

(In the formula, the number on the lower right of the structural unit indicates the copolymerization ratio.)

[Comparative Example 3]
In Example 7, the hydroxygallium phthalocyanine crystal obtained in Preparation Example 1 of the gallium phthalocyanine crystal when preparing the coating solution for the charge generation layer was subjected to the Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction of 9. A comparative electrophotographic photosensitive member 3 of this comparative example was produced in the same manner as in Example 7 except that the oxytitanium phthalocyanine crystal having peaks at 0 °, 14.2 °, 23.9 ° and 27.1 ° was used. did.

[Evaluation of Examples 1-12 and Comparative Examples 1-3]
For the electrophotographic photoreceptors 1 to 12 and comparative electrophotographic photoreceptors 1 to 3 prepared in Examples 1 to 12 and Comparative Examples 1 to 3, fog evaluation was performed on output images after repeated use of 10,000 sheets.
As an evaluation apparatus, a laser beam printer CP-4525 manufactured by Hured Packard was remodeled so that the charging potential (dark part potential) of the electrophotographic photosensitive member could be adjusted, and the dark part potential was set to -450V. Evaluation was performed in an environment of a temperature of 23 ° C. and a relative humidity of 50%.

<Cover evaluation>
Using A4 size plain paper, 10,000 sheets of image were output using a test chart with a printing ratio of 4%, and then a solid white image was output to evaluate the fog image rank.
The image rank evaluation of the fog was performed by sensual observation according to the following criteria.
A: No minute black spots are visually observed at all B: Very small amounts of black spots are visually observed (one place) C: A minute amount of black spots are visually observed (2 to 3 places) D: Several minute black spots are visually observed (4 to 5 places) E: Some minute black spots are visually observed (six or more places) F: Black spots are recognized on the entire surface A indicates the best. A to D were levels at which the effects of the present invention were obtained. The evaluation results of Examples and Comparative Examples are shown in Table 1.

  As shown in Examples 1 to 12 and Comparative Examples 1 to 3, the electrophotographic photosensitive member containing the polycarbonate containing the structural unit represented by the formula (3) in the charge transport layer is suppressed from fogging after repeated use. Images can be provided.

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

Claims (8)

In an electrophotographic photosensitive member having a support, a charge generation layer containing a charge generation material, and a charge transport layer containing a charge transport material and a polycarbonate in this order,
The polycarbonate has a structural unit represented by the formula (3),
An electrophotography wherein the charge generation material is a gallium phthalocyanine crystal having peaks at Bragg angles of 7.4 ° ± 0.3 ° and 28.3 ° ± 0.3 ° in CuKα characteristic X-ray diffraction Photoconductor.

The polycarbonate further includes a structural unit represented by formula (2), a structural unit represented by formula (7), a structural unit represented by formula (8), a structural unit represented by formula (9), and a formula (10). The electrophotographic photosensitive member according to claim 1, comprising at least one structural unit selected from a structural unit represented by formula (11), a structural unit represented by formula (11), and a structural unit represented by formula (12):

  The electrophotographic photosensitive member according to claim 1, wherein a proportion of the structural unit represented by the formula (3) in the polycarbonate is 20 mol% or more and 50 mol% or less.   The electrophotographic photosensitive member according to claim 1, wherein the gallium phthalocyanine crystal contains N, N-dimethylformamide and / or N-methylformamide in the gallium phthalocyanine crystal.   The total content of the N, N-dimethylformamide and the N-methylformamide in the gallium phthalocyanine crystal is 0.3% by mass to 1.7% by mass with respect to the mass of the gallium phthalocyanine crystal. The electrophotographic photosensitive member according to claim 4. The electrophotographic photosensitive member according to claim 1, wherein the charge transport material is a compound represented by the formula (13).

(In the formula, Ar ^{1 to} Ar ⁴ each independently represent a substituted or unsubstituted phenyl group, a substituted or unsubstituted benzyl group, or a 9,9-dimethyl-9H-fluoren-2-yl group, and X represents phenylene. Group,
The substituent of the substituted phenyl group is an alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, a dimethylamino group, a diethylamino group, or a phenyl group, and the substituent of the substituted benzyl group is a methyl group, or An ethyl group. )   An electrophotographic photosensitive member according to any one of claims 1 to 6 and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means, are integrally supported, and electrophotographic A process cartridge which is detachable from the apparatus main body.   An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an exposure unit, a developing unit, and a transfer unit.

Images