JP2001005203A - Laminated electrophotographic photoreceptor and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated electrophotographic photoreceptor exhibiting high sensitivity to semiconductor laser and excellent in stable repeatability by a crystal conversion treating method of oxyotitanium phthalocyanine vapor deposition film, which is suitable for a THF(tetrahydrofuran) based coating material, while good property is not attained when THF is used for a charge transfer coating material. SOLUTION: The laminated electrophotographic photoreceptor 10 is accomplished by forming the oxyotitanium phthalocyanine vapor deposition film on a conductive supporting body 11, forming a charge transfer layer 13 using a coating material consisting of tetrahydrofuran as a charge generating layer 12, allowing the vapor deposition film to come in contact with a vapor, which does not cause the lowering of the absorption of oxyotitanium phthalocyanine in >=800 nm even after the layer 13 is formed and contacts at least an organic solvent, to perform the crystal conversion treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated electrophotographic photoreceptor used in an electrophotographic apparatus and a method for manufacturing the same. The present invention relates to a laminated electrophotographic photoconductor using tetrahydrofuran as a coating for a charge transport layer and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, electrophotographic apparatuses have attracted attention for their advantages such as high speed, low noise, high image quality, and the ability to record on plain paper. Are rapidly spreading. Further, as a recent trend, in the field of printers and facsimile machines, the use form has shifted from office use to personal use, and there is a demand for smaller size, lower cost, and maintenance free. On the other hand, with the improvement of image processing techniques such as colorization of documents, higher resolution and higher quality image forming techniques are required.

As a photoreceptor used in the electrophotographic apparatus, an organic photoreceptor made of an organic photoconductive material having advantages such as being inexpensive and non-polluting has been actively developed.
It has been installed in many devices. Most of these practically used photoconductors are laminated photoconductors in which a charge generation layer containing a charge generation substance and a charge transport layer containing a charge transport substance are sequentially formed on a conductive support. By separating the functions in this manner, characteristics such as sensitivity and durability required for the electrophotographic apparatus have been satisfied. Among them, the development of photoreceptors having absorption in the oscillation wavelength region of a semiconductor laser, that is, in the near infrared wavelength region, has been actively performed.
Attention has been paid to a laminated electrophotographic photoreceptor using oxotitanium phthalocyanine as a charge generating substance.

[0004] There are a coating method and a vapor deposition method for forming a charge generation layer using the oxotitanium phthalocyanine as a charge generation material. The coating method includes a dip coating method, a spray coating method, and the like.However, the dip coating method involves immersing a conductive support in a dispersion coating composed of at least a specific crystal type of oxotitanium phthalocyanine, a binder resin and a solvent. This is a method of forming a charge generation layer on a conductive support by pulling up. The vapor deposition method is a method in which oxotitanium phthalocyanine heated and vaporized is deposited on a conductive support, and the deposited film is subjected to crystal transformation by exposure to an organic solvent solution or its vapor to form a predetermined charge generation layer. It is. This vapor deposition method can form a uniform film at the molecular level, and can be said to be a manufacturing method suitable for a high-resolution, high-quality electrophotographic apparatus. Regarding the vapor deposition method, for example, Japanese Patent Application Laid-Open No. S59-166959 describes a treatment method in which an oxotitanium phthalocyanine deposited film is left in a saturated vapor of an organic solvent such as tetrahydrofuran. In Japanese Patent Application Laid-Open No. 1-120564, by immersion in methanol, Japanese Patent Application Laid-Open No.
No. 0 reports that a long shift of the absorption wavelength, the appearance of a unique X-ray diffraction peak, and an increase in sensitivity as a photoreceptor are brought about by contact with a mixed vapor of an aromatic solvent and water.

[0005]

On the other hand, a chlorine-based organic solvent has been used for forming the characteristic charge transport layer on the charge generation layer described in these publications. The use of a non-chlorine organic solvent (organic solvent containing no chlorine group) is strongly desired. In the method described in JP-A-1-120564, chloroform is used in the method disclosed in
In the method described in JP-A-81860, chlorobenzene is used, and there is no specific description regarding a non-chlorine-based organic solvent. However, after the crystal conversion, in the case of using a chlorine-based organic solvent and in the case of using a non-chlorine-based organic solvent at the time of forming the charge transport layer, a change in the absorption band and a change in characteristics as a completed photosensitive member occur. That is, when a non-chlorine organic solvent, particularly, tetrahydrofuran is used, it is necessary to perform a crystal conversion treatment suitable for it.

Accordingly, these problems have been solved, and a method using a non-chlorine-based organic solvent, tetrahydrofuran, as a coating material for the charge transport layer exhibits high sensitivity to semiconductor laser light, as well as sensitivity and chargeability. There is a strong demand for a laminated electrophotographic photoreceptor excellent in the repetition stability of the photoreceptor characteristics and a method for producing the same.

[0007]

In order to solve this problem, a laminated electrophotographic photoreceptor according to claim 1 of the present invention comprises at least a charge generation layer and a charge transport layer on a conductive support. A stacked electrophotographic photoreceptor formed by laminating, wherein the charge generation layer is obtained by crystal-transforming an oxotitanium phthalocyanine vapor-deposited film, and further, on the charge generation layer, at least a charge transport material, a binder resin and The charge transport layer is formed by a paint composed of tetrahydrofuran, and the crystal conversion treatment is performed by contact with a vapor containing at least an organic solvent, wherein the absorption does not decrease in a wavelength region of 800 nm or more even after the charge transport layer is formed. Because of the processing, it is a laminated electrophotographic photoconductor.

[0008] The laminated electrophotographic photosensitive member according to claim 2 of the present invention is a laminated electrophotographic photosensitive member comprising at least a charge generation layer and a charge transport layer laminated on a conductive support. Wherein the charge generation layer is obtained by crystal-transforming an oxotitanium phthalocyanine vapor-deposited film, and further, on the charge generation layer, at least a charge transport material, a charge transport layer formed by a paint comprising a binder resin and tetrahydrofuran. The crystal conversion treatment is a treatment by contact with a vapor containing a water-insoluble organic solvent which forms an azeotrope with at least water, the absorption of which does not decrease in the wavelength region of 800 nm or more even after the formation of the charge transport layer. In this way, a laminated electrophotographic photosensitive member was obtained.

The laminated electrophotographic photoreceptor according to claim 3 of the present invention is a laminated electrophotographic photoreceptor comprising at least a charge generation layer and a charge transport layer laminated on a conductive support. Wherein the charge generation layer is obtained by crystal-transforming an oxotitanium phthalocyanine vapor-deposited film, and further, on the charge generation layer, at least a charge transport material, a charge transport layer formed by a paint comprising a binder resin and tetrahydrofuran. The multi-layer electrophotography is that the crystal conversion treatment is a treatment by contact with a vapor containing at least an aromatic hydrocarbon-based organic solvent in which the absorption does not decrease in a wavelength region of 800 nm or more even after the formation of the charge transport layer. It is a photoreceptor for use.

[0010] The laminated electrophotographic photosensitive member according to claim 4 of the present invention is a laminated electrophotographic photosensitive member comprising a conductive support and at least a charge generation layer and a charge transport layer laminated thereon. Wherein the charge generation layer is obtained by crystal-transforming an oxotitanium phthalocyanine vapor-deposited film, and further, on the charge generation layer, at least a charge transport material, a charge transport layer formed by a paint comprising a binder resin and tetrahydrofuran. Yes, the crystal conversion treatment is a treatment by contact with at least a vapor containing an ester organic solvent of an aliphatic carboxylic acid, the absorption of which does not decrease in the wavelength region of 800 nm or more even after the formation of the charge transport layer. This is a photoconductor for type electrophotography.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a multilayer electrophotographic photoreceptor, wherein at least a charge generation layer and a charge transport layer are laminated on a conductive support. A method for producing a body, comprising: a charge generation layer forming step of depositing and converting oxotitanium phthalocyanine into a crystal; and forming a charge transport layer on the charge generation layer using at least a charge transport material, a paint comprising a binder resin and tetrahydrofuran. A charge transport layer forming step, wherein the crystal conversion treatment of the charge generation layer forming step does not reduce absorption in a wavelength region of 800 nm or more even after the charge transport layer is formed.
The method is a method for producing a laminated electrophotographic photosensitive member because the treatment is performed by contact with at least a vapor containing an organic solvent.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a laminated electrophotographic photoreceptor, comprising laminating at least a charge generation layer and a charge transport layer on a conductive support. A method for producing a body, comprising: a charge generation layer forming step of depositing and converting oxotitanium phthalocyanine into a crystal; and forming a charge transport layer on the charge generation layer using at least a charge transport material, a paint comprising a binder resin and tetrahydrofuran. A charge transport layer forming step, wherein the crystal conversion treatment of the charge generation layer forming step does not reduce absorption in a wavelength region of 800 nm or more even after the charge transport layer is formed.
At least the process of contacting with steam containing a water-insoluble organic solvent that forms an azeotrope with water constitutes a method for producing a laminated electrophotographic photosensitive member.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a multilayer electrophotographic photoreceptor, comprising: laminating at least a charge generation layer and a charge transport layer on a conductive support. A method for producing a body, comprising: a charge generation layer forming step of depositing and converting oxotitanium phthalocyanine into a crystal; and forming a charge transport layer on the charge generation layer using at least a charge transport material, a paint comprising a binder resin and tetrahydrofuran. A charge transport layer forming step, wherein the crystal conversion treatment of the charge generation layer forming step does not reduce absorption in a wavelength region of 800 nm or more even after the charge transport layer is formed.
The method is a method for producing a laminated electrophotographic photoreceptor in that the treatment is performed by contact with at least a vapor containing an aromatic hydrocarbon-based organic solvent.

According to a second aspect of the present invention, there is provided a method for manufacturing a multilayer electrophotographic photoreceptor, wherein at least a charge generation layer and a charge transport layer are laminated on a conductive support. A method for producing a body, comprising: a charge generation layer forming step of depositing and converting oxotitanium phthalocyanine into a crystal; and forming a charge transport layer on the charge generation layer using at least a charge transport material, a paint comprising a binder resin and tetrahydrofuran. A charge transport layer forming step, wherein the crystal conversion treatment of the charge generation layer forming step does not reduce absorption in a wavelength region of 800 nm or more even after the charge transport layer is formed.
The method is a method for producing a laminated electrophotographic photoreceptor because the treatment is carried out by contacting at least a vapor containing an ester organic solvent of an aliphatic carboxylic acid.

The laminated electrophotographic photosensitive member according to the ninth aspect of the present invention is a laminated electrophotographic photosensitive member comprising a conductive support and at least a charge generation layer and a charge transport layer laminated on the conductive support. Wherein the charge generation layer is obtained by crystal-transforming an oxotitanium phthalocyanine vapor-deposited film, and further, on the charge generation layer, at least a charge transport material, a charge transport layer formed by a paint comprising a binder resin and tetrahydrofuran. Yes, after the formation of the charge transport layer, the ratio of the first absorbance at the absorption maximum wavelength near 800 nm of the visible absorption spectrum of the photosensitive layer to the second absorbance at 830 nm of the photosensitive layer is 0.5 or more. It is a photoreceptor.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing the structure of a laminated electrophotographic photosensitive member according to an embodiment of the present invention.
1, the laminated electrophotographic photoreceptor 10 is formed by laminating a charge generation layer 12 and a charge transport layer 13 on a conductive support 11.

The conductive support 11 may be any conductive material known in the art, such as a tube (cylindrical) made of a metal material such as aluminum, a plate, a sheet-like support, a plastic, or the like. Tubes, plates, sheet-like supports, etc., made by depositing a metal material on a tube, plate, sheet-like support made of paper or the like and imparting conductivity with a conductive paint, or by molding conductive plastics are used. .
In particular, a tube obtained by subjecting an aluminum alloy to processing such as cutting, a sheet obtained by depositing aluminum on a polyethylene terephthalate film, and the like are often used. In particular, when an aluminum tube is used for the conductive support 11, before forming the charge generation layer 12, cleaning of the support surface by cleaning using a surfactant or an organic solvent or glow discharge treatment in a vacuum is required. is necessary. Insufficient cleaning of the aluminum tube causes image defects and reduced adhesion resulting from electrical disturbances due to the adhering metal cuttings.

Next, the charge generation layer 12 formed on the conductive support 11 is made of oxotitanium phthalocyanine as a charge generation substance under a pressure of 6 × 10 ⁻³ Pa or less.
It is obtained by forming a thin film having a thickness in the range of 0.03 to 0.5 μm by an evaporation method using resistance heating, and then treating with a mixed solution vapor of the organic solvent and water according to the present invention.

As the oxotitanium phthalocyanine which is a charge generating substance, a pigment obtained by subjecting a crude pigment obtained by a known synthesis method to reflux washing in quinoline to obtain a highly crystalline pigment, and then purifying it by sublimation is used. FIG. 2 shows a sublimation purification apparatus used in the present invention, which is mainly composed of an electric furnace 21 and a glass test tube 22.
And a vacuum pump 29. Glass test tube 22
Inside, a quartz boat 23 containing oxotitanium phthalocyanine 20 and a glass collecting tube 24 are set,
The quartz boat 23 is arranged so as to be at the center of the electric furnace 21. Between the glass test tube 22 and the vacuum pump 29, a rubber stopper 25, a three-way cock 26, a pressure-resistant rubber tube 27, a trap 28
Piping. By reducing the pressure in the glass test tube and heating the electric furnace, the oxotitanium phthalocyanine in the quartz boat sublimates, and crystals adhere to the glass collection tube in the low temperature part. The purple glossy portion of the attached crystal is collected and used for vapor deposition. When vapor deposition is performed using an oxotitanium phthalocyanine pigment having low purity, the characteristics of the photoreceptor are deteriorated such as an increase in residual potential due to the influence of impurities or a thermal decomposition product during resistance heating due to the impurities. On the other hand, when oxotitanium phthalocyanine having high purity is used, a photoreceptor having less heat deterioration during vapor deposition and excellent characteristics can be obtained.

The vapor deposition apparatus for vapor-depositing oxotitanium phthalocyanine is only required to be capable of uniformly forming a film on the entirety of the conductive support 11, and if the conductive support 11 is an aluminum tube, it is shown in FIG. Such a device is used. FIG. 3 is a schematic diagram showing the inside of a chamber 31 of the vapor deposition apparatus. A mounted aluminum tube 32 revolves around the inside of the chamber, and a film is formed above a vapor deposition source 33. An oil diffusion pump or the like is attached to the exhaust port 34 to achieve a pressure of 6 × 10 ⁻³ or less. The vapor deposition source 33 may be any metal having a melting point equal to or higher than the sublimation point of oxotitanium phthalocyanine (about 500 ° C.), such as tungsten, molybdenum, tantalum,
Refractory metals such as niobium or their alloys are often used. Further, the deposition source 33 is heated by applying a current from a DC power source to sublime the oxotitanium phthalocyanine 30 filled in the deposition source 33, and is deposited on an aluminum tube 32 as a conductive support to obtain a predetermined film thickness. Things. If the thickness is less than the predetermined thickness, the sensitivity required for the photoreceptor cannot be obtained, and if it is more than the predetermined thickness, the charging property required for the photoreceptor cannot be obtained.

The oxotitanium phthalocyanine vapor-deposited film thus formed is in an amorphous state, and is exposed to an organic solvent vapor or immersed in an organic solvent.
Crystallization can be achieved by contact with an organic solvent. Actually, on the charge generation layer converted in this way, a charge transport material, a binder resin, a charge transport layer coating composed of an organic solvent is used, and the charge is applied by a known coating method such as a dip coating method. The transport layer 13 is formed, and the final crystal type is determined.

Therefore, it is desirable that the crystal state is optimal when the charge transport layer 13 is formed on the charge generation layer 12 which has been subjected to the crystal conversion treatment. That is, 800n before and after
It is desired that there is no change in the absorption band of m or more, in particular, that the absorption does not decrease. Until now, 1,
2- In a coating of a chlorine-based organic solvent such as dichloromethane, chloroform, etc., no significant change is observed in the absorption band regardless of the crystal conversion treatment, and the absorption with a chlorine-based organic solvent further increases the absorption wavelength. There was a tendency. However, when a non-chlorine organic solvent, particularly tetrahydrofuran, is used, the absorption at 800 nm or more may be reduced, and a crystal conversion treatment suitable for a tetrahydrofuran paint is required.

Tetrahydrofuran is a water-soluble organic solvent, and this property is a major difference from the chlorine-based organic solvents that have been frequently used, and has an influence on the crystal form of oxotitanium phthalocyanine in which water is involved. it seems to do. Therefore, as a crystal conversion treatment suitable for a paint for a charge transport layer using tetrahydrofuran, a method of treating with an organic solvent that forms an azeotropic mixture with water, particularly a vapor of a water-insoluble organic solvent is preferable. Specifically, an ester solvent of an aromatic hydrocarbon or an aliphatic carboxylic acid is suitable. In an aromatic hydrocarbon, m-
30% azeotropic mixture with water such as xylene and anisole
The above are suitable, and generally good results are obtained in the ester system of the aliphatic carboxylic acid. Also,
Depending on the environment of the steam treatment, especially the humidity, the addition of water to these solvents can further stabilize the properties.

Further, when looking at the correlation between the characteristics of the photoreceptor and the film properties, the crystal conversion treatment of the charge generation layer and the absorption spectrum of the film after the formation of the charge transport layer are effective crystal conversion treatments. Can be determined. Specifically, 800n
It is optimal to measure the ratio between the absorbance at the absorption maximum near m and the absorbance at 830 nm. By this evaluation, the change in the absorption spectrum after the formation of the charge transport layer can be measured even in the state of the finished photoreceptor. Although detailed measurement data is shown in the examples, if the ratio is 0.5 or more, the wavelength of absorption maximum becomes shorter, 800 n
It is considered that the absorption does not decrease by m or more, and it can be determined that the photoconductor has good characteristics.

The above-mentioned coating material for a charge transport layer can be mixed with an aromatic hydrocarbon organic solvent such as toluene or xylene using tetrahydrofuran as a main solvent, a charge transport material, a binder resin, and a nonvolatile component. Concentration 10
To 40% by weight. In general,
The charge transport layer 13 is formed by the dip coating device 41 as shown in FIG. 4 using the charge transport layer paint prepared as described above. Specifically, an aluminum tube 43, which is a conductive support having a charge generation layer formed thereon, is mounted on a movable portion 44 having a gripping device, and is dipped in a pot 42 containing a paint 40 for a charge transport layer. The charge transport layer is formed by pulling up at a predetermined speed. A circulation pump 45 and a filter unit 46 are piped to the pot 42. After the dip coating, the organic solvent is volatilized by a hot air drier or the like, and a charge transport layer having a thickness of about 5 to 40 μm is formed after drying.

As the charge transporting material used in the paint, electron-donating oxazole compounds, oxadiazole compounds, pyrazoline compounds, hydrazone compounds, stilbene compounds, tetraphenylbutadiene compounds, biphenyl compounds, and derivatives of these compounds Can be used. In particular, a compound having compatibility with oxotitanium phthalocyanine, which is a charge generating substance, is preferable, and has an ionization potential of 5.0 to 5.5 eV as measured by a surface analyzer AC-1 manufactured by Riken Keiki Co., Ltd.
Of these are often used. These compounds can be used as a mixture of two or more kinds.

As the binder resin, resins such as polyester, polycarbonate, polysulfone, polyarylate, and polymethyl methacrylate can be used. However, compatibility with the charge transport material, film strength, solubility in the solvent for coating, and Polycarbonate is preferred from the viewpoint of stability. The composition ratio of the binder resin and the charge transport material is 0.25 by weight to binder resin 1.
To 3 are used. Further, in addition to the charge transport material and the binder resin, an antioxidant, an ultraviolet absorber, and the like can be added to prevent deterioration of these materials.

[0029]

EXAMPLES Specific examples and comparative examples of the present invention will be described below.

(Example 1) Synthesis of oxotitanium phthalocyanine pigment In a four-necked flask equipped with a cooling tube, a dropping funnel, a stirrer, a thermometer and a nitrogen inlet tube, 1,3-chloronaphthalene (770 ml) was added to 1,3-chloronaphthalene (770 ml). Diiminoisoindoline (1
13 g) were suspended, and tetra-n-butyl titanate (75 g) was added thereto with stirring, and the mixture was added with a nitrogen atmosphere at 195 to 205 g.
Heat at 0 ° C for 4 hours. After cooling to 130 ° C, the mixture was filtered off.
Wash on a Buchner funnel with 100 ° C. 1-chloronaphthalene (100 ml). Further ethanol (100
0 ml), hot suspension washing with dimethylformamide and ethanol was repeated, and vacuum drying was performed at 50 ° C. for 24 hours to obtain 89 g of a pigment.

Next, 15 g of this pigment was added to 100 m of quinoline.
Heat under reflux for 1 hour with stirring in the flask. After cooling, filter off,
This is further refluxed by using 100 ml of fresh quinoline. Finally, after thoroughly washing with ethanol, the resultant was vacuum-dried at 50 ° C. for 10 hours and at 100 ° C. for 10 hours to obtain 14 g of red-purple crystal pigment. Further, 7.5 g of this pigment was purified by the above-described sublimation apparatus shown in FIG. 2 to obtain 6 g of an oxotitanium phthalocyanine pigment for vapor deposition.

Production of laminated electrophotographic photoreceptor Outer diameter 30 mm, inner diameter 28.5 mm, length 301.5 mm
The aluminum (aluminum-magnesium-silicon alloy) cutting tube is washed with a degreasing detergent (Clinthru LC870 manufactured by Kao Corporation) and ion-exchanged water,
It is installed in the vapor deposition device shown in FIG. Under reduced pressure of 5 × 10 ⁻³ Pa,
0.15 on the aluminum tube using the vapor deposition pigment described above.
A μm oxotitanium phthalocyanine vapor-deposited film was formed.

Next, the inside of the closed vessel is filled with m-xylene vapor, and the aluminum tube provided with the vapor-deposited film is left for 30 minutes to perform a crystal conversion treatment.

Subsequently, 18 parts by weight of 2-methyl-4-dibenzylaminobenzaldehyde-N, N-diphenylhydrazone and 1,1-bis (p-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene 2 4 parts by weight, using a paint consisting of 20 parts by weight of polycarbonate (Tafzet P-300 manufactured by Idemitsu Kosan Co., Ltd.) and 100 parts by weight of tetrahydrofuran, and transporting the charge so as to have a film thickness of 20 μm after drying with the dip coating apparatus of FIG. Layers were provided to complete the photoreceptor. Drying was performed at 100 ° C. for 60 minutes.

Evaluation of Characteristics of Laminated Electrophotographic Photoreceptor The electrostatic characteristics of the photoreceptor thus obtained were measured by using a photoreceptor drum measurement system (CYNT manufactured by Gentec Corporation).
HIA55).

The evaluation was performed by adjusting the corona current and the grid voltage so that the initial charging potential V0 (V) when the photoreceptor was negatively charged in a dark place became 500 V or more, and the surface potential after dark decay 2 seconds. Is measured as V2 (V), and the charge retention after 2 seconds of dark decay is measured as DDR2 (%).
A monochromatic light having an energy of 0.7 μJ / cm ² · s is irradiated for 5 seconds, and an exposure amount required for the surface potential to become 1 / 2V2 at this time is defined as a light sensitivity E1 / 2 (μJ / cm ² ). further,
The measurement was performed by measuring the surface potential 5 seconds after the exposure as a residual potential Vr (V). Table 1 shows the results.

A similar photoreceptor film was formed on a glass preparation, and the results of measuring the visible absorption spectrum before and after coating the charge transport layer are shown in FIG. In FIG. 5, the solid line shows the absorption spectrum before coating the charge transport layer, and the dotted line shows the absorption spectrum after coating the charge transport layer. Furthermore, the ratio of the first absorbance at an absorption maximum wavelength near 800 nm after coating of the charge transport layer to the second absorbance at 830 nm was 0.56.

(Embodiment 2) m of the crystal conversion process of Embodiment 1
-A photoreceptor was prepared in the same manner as in Example 1 except that anisole was used instead of xylene, and the same characteristics were evaluated. The results are shown in Table 1 and FIG. As in FIG.
Among them, the solid line shows the absorption spectrum before the charge transport layer coating, and the dotted line shows the absorption spectrum after the charge transport layer coating. Further, the ratio of the first absorbance at an absorption maximum wavelength around 800 nm after coating of the charge transport layer to the second absorbance at 830 nm was 0.57.

(Embodiment 3) m of the crystal conversion process of Embodiment 1
A photoconductor was prepared in the same manner as in Example 1, except that ethyl acetate was used instead of xylene, and the same evaluation of characteristics was performed. The results are shown in Table 1 and FIG. As in FIG.
Among them, the solid line shows the absorption spectrum before the charge transport layer coating, and the dotted line shows the absorption spectrum after the charge transport layer coating. Furthermore, the ratio of the first absorbance at an absorption maximum wavelength around 800 nm after coating of the charge transport layer to the second absorbance at 830 nm was 0.81.

(Embodiment 4) m of the crystal conversion process of Embodiment 1
A photoconductor was prepared in the same manner as in Example 1, except that n-propyl butyrate was used instead of -xylene, and the same characteristics were evaluated. The results are shown in Table 1 and FIG. As in FIG. 5, the solid line in FIG. 8 shows the absorption spectrum before coating the charge transport layer, and the dotted line shows the absorption spectrum after coating the charge transport layer. Further, the ratio of the first absorbance at the absorption maximum wavelength near 800 nm after the charge transport layer coating to the second absorbance at 830 nm is 0.8.
6 was indicated.

(Comparative Example 1) m of the crystal conversion treatment of Example 1
A photoconductor was prepared in the same manner as in Example 1, except that the immersion treatment in a methanol solution was performed for 1 minute instead of xylene, and the same characteristic evaluation was performed. The results are shown in Table 1 and FIG. Similar to FIG. 5, in FIG. 9, the solid line shows the absorption spectrum before coating the charge transport layer, and the dotted line shows the absorption spectrum after coating the charge transport layer.
Furthermore, the ratio of the first absorbance at an absorption maximum wavelength near 800 nm after coating of the charge transport layer to the second absorbance at 830 nm was 0.37.

(Comparative Example 2) m of the crystal conversion treatment of Example 1
A photoconductor was prepared in the same manner as in Example 1, except that the immersion treatment in a methanol solution was performed for 10 minutes instead of xylene, and the same characteristics were evaluated. The results are shown in Table 1 and FIG. As in FIG. 5, in FIG. 10, the solid line shows the absorption spectrum before coating the charge transport layer, and the dotted line shows the absorption spectrum after coating the charge transport layer. Furthermore, the ratio of the first absorbance at an absorption maximum wavelength near 800 nm after coating of the charge transport layer to the second absorbance at 830 nm was 0.37.

[0043]

[Table 1]

As is evident from the results shown in Table 1, the electrophotographic photoreceptor of the present invention exhibits good electrophotographic properties even when using a charge transport layer coating composed of tetrahydrofuran. Further, as is apparent from FIGS. 5 to 10, the laminated electrophotographic photoreceptor of the example of the present invention does not show a decrease in absorption of 800 nm or more as compared with the comparative example. This is clear from the ratio between the first absorbance and the second absorbance.

[0045]

As described above, according to the laminated electrophotographic photoreceptor of the present invention, a laminated electrophotographic photosensitive member comprising at least a charge generation layer and a charge transport layer laminated on a conductive support. In the body, the charge generation layer is obtained by subjecting an oxotitanium phthalocyanine vapor-deposited film to a crystal conversion, and further, on the charge generation layer, a charge transport layer is formed with a paint composed of at least a charge transport material, a binder resin and tetrahydrofuran. Wherein the crystal conversion treatment does not reduce absorption in a wavelength region of 800 nm or more even after the formation of the charge transport layer, at least an organic solvent, a water-insoluble organic solvent that forms an azeotrope with water, and an aromatic hydrocarbon. Organic solvents,
Or by the treatment by contact with steam containing an ester organic solvent of aliphatic carboxylic acid, with high sensitivity,
A photoreceptor having excellent repetition stability can be provided.

Further, according to the method for producing a laminated electrophotographic photosensitive member of the present invention, a laminated electrophotographic photosensitive member comprising at least a charge generation layer and a charge transport layer laminated on a conductive support is produced. A method for forming a charge generation layer for vapor-depositing and crystallizing oxotitanium phthalocyanine, and forming a charge transport layer on the charge generation layer with a coating material comprising at least a charge transport material, a binder resin and tetrahydrofuran. A layer forming step, wherein the crystal conversion process in the charge generating layer forming step is performed after the charge transport layer is formed.
Absorbance does not decrease in the wavelength region of at least nm, including at least an organic solvent, a water-insoluble organic solvent that forms an azeotrope with water, an aromatic hydrocarbon-based organic solvent, or an ester-based organic solvent of an aliphatic carboxylic acid. By performing the treatment by contact with steam, the above-described laminated electrophotographic photoconductor of the present invention can be reasonably and stably manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a configuration of a laminated electrophotographic photosensitive member according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a configuration of a sublimation purification apparatus used in an embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a vapor deposition apparatus used in an embodiment of the present invention.

FIG. 4 is a schematic diagram showing a configuration of a dip coating apparatus used in an embodiment of the present invention.

FIG. 5 is a diagram showing absorption spectra before and after formation of a charge transport layer of a laminated electrophotographic photosensitive member in Example 1 of the present invention, wherein a solid line is before coating of a charge transport layer, and a dotted line is after coating of a charge transport layer. Diagram showing absorption spectrum

FIG. 6 is a graph showing absorption spectra before and after formation of a charge transport layer of a laminated electrophotographic photosensitive member according to Example 2 of the present invention, wherein a solid line is before coating of a charge transport layer and a dotted line is after coating of a charge transport layer. Diagram showing absorption spectrum

FIG. 7 is a diagram showing absorption spectra before and after formation of a charge transport layer of a laminated electrophotographic photoreceptor in Example 3 of the present invention, wherein a solid line is before coating of a charge transport layer, and a dotted line is after coating of a charge transport layer. Diagram showing absorption spectrum

FIG. 8 is a graph showing absorption spectra before and after formation of a charge transport layer of a laminated electrophotographic photoreceptor in Example 4 of the present invention, wherein a solid line is before coating of a charge transport layer, and a dotted line is after coating of a charge transport layer. Diagram showing absorption spectrum

FIG. 9 is a diagram showing absorption spectra before and after formation of a charge transport layer of a laminated electrophotographic photoreceptor in Comparative Example 1 of the present invention, wherein a solid line is before coating of a charge transport layer and a dotted line is after coating of a charge transport layer. Diagram showing absorption spectrum

FIG. 10 is a diagram showing an absorption spectrum before and after formation of a charge transport layer of a laminated electrophotographic photosensitive member according to Comparative Example 2 of the present invention, wherein a solid line is before coating of a charge transport layer, and a dotted line is after coating of a charge transport layer. Diagram showing absorption spectrum

[Explanation of symbols]

REFERENCE SIGNS LIST 10 laminated electrophotographic photoreceptor 11 conductive support 12 charge generation layer 13 charge transport layer 20 charge generation material (oxo titanium phthalocyanine) 21 electric furnace 22 glass test tube 23 quartz boat 24 glass sampling tube 25 rubber stopper 26 three-way cock 27 Pressure-resistant rubber tube 28 Trap and dewar bottle 29 Vacuum pump 30 Charge generating substance (sublimated oxotitanium phthalocyanine) 31 Evaporator chamber 32 Aluminum tube (conductive support) 33 Evaporation source 34 Exhaust port 40 Paint for charge transport layer 41 Immersion Coating device 42 Pot portion 43 Aluminum tube (conductive support on which charge generation layer is formed) 44 Movable portion provided with support holding device 45 Circulation pump 46 Filter unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsumugi Oto 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F-term (reference) 2H068 AA19 AA37 BA02 BA39 EA14 EA22 EA43 FA14

Claims (9)

[Claims] 1. A laminated electrophotographic photoreceptor comprising at least a charge generation layer and a charge transport layer laminated on a conductive support, wherein the charge generation layer is obtained by crystallizing an oxotitanium phthalocyanine vapor-deposited film. Further, on the charge generation layer, at least a charge transport material, a charge transport layer is formed with a paint comprising a binder resin and tetrahydrofuran, and the crystal conversion treatment is performed at a wavelength of 800 nm or more even after the charge transport layer is formed. A multilayer electrophotographic photoconductor, wherein the absorption is not reduced in a region, and the treatment is performed by contact with a vapor containing at least an organic solvent. 2. A laminated electrophotographic photoreceptor comprising at least a charge generation layer and a charge transport layer laminated on a conductive support, wherein the charge generation layer is obtained by crystallizing an oxotitanium phthalocyanine vapor-deposited film. Further, on the charge generation layer, at least a charge transport material, a charge transport layer is formed with a paint comprising a binder resin and tetrahydrofuran, and the crystal conversion treatment is performed at a wavelength of 800 nm or more even after the charge transport layer is formed. A laminated electrophotographic photoreceptor, wherein the treatment is carried out by contact with a vapor containing a water-insoluble organic solvent which forms an azeotrope with water, the absorption of which does not decrease in the region. 3. A laminated electrophotographic photoreceptor comprising at least a charge generation layer and a charge transport layer laminated on a conductive support, wherein the charge generation layer is obtained by crystallizing an oxotitanium phthalocyanine vapor-deposited film. Further, on the charge generation layer, at least a charge transport material, a charge transport layer is formed with a paint comprising a binder resin and tetrahydrofuran, and the crystal conversion treatment is performed at a wavelength of 800 nm or more even after the charge transport layer is formed. A multilayer electrophotographic photoreceptor, wherein the treatment is performed by contact with a vapor containing at least an aromatic hydrocarbon-based organic solvent, the absorption of which does not decrease in the region. 4. A laminated electrophotographic photoreceptor comprising at least a charge generation layer and a charge transport layer laminated on a conductive support, wherein the charge generation layer is obtained by crystallizing an oxotitanium phthalocyanine vapor-deposited film. Further, on the charge generation layer, at least a charge transport material, a charge transport layer is formed with a paint comprising a binder resin and tetrahydrofuran, and the crystal conversion treatment is performed at a wavelength of 800 nm or more even after the charge transport layer is formed. A laminated electrophotographic photoreceptor, wherein the absorption is not reduced in a region, and the treatment is performed by contact with a vapor containing at least an ester organic solvent of an aliphatic carboxylic acid. 5. A method for producing a laminated electrophotographic photoreceptor comprising at least a charge generation layer and a charge transport layer laminated on a conductive support, wherein a oxotitanium phthalocyanine is deposited and crystal-converted. And, on the charge generation layer, at least a charge transport material, a charge transport layer forming step of forming a charge transport layer with a paint of a binder resin and tetrahydrofuran. A method for producing a laminated electrophotographic photoreceptor, wherein the absorption is not reduced in a wavelength region of 800 nm or more even after the formation of a transport layer, and the treatment is performed by contact with at least a vapor containing an organic solvent. 6. A method for producing a laminated electrophotographic photoreceptor comprising at least a charge generation layer and a charge transport layer laminated on a conductive support, wherein oxotitanium phthalocyanine is deposited and crystal-converted. And, on the charge generation layer, at least a charge transport material, a charge transport layer forming step of forming a charge transport layer with a paint of a binder resin and tetrahydrofuran. Multilayer electrophotography characterized in that the absorption is not reduced in the wavelength region of 800 nm or more even after the formation of the transport layer, and the treatment is at least contact with steam containing a water-insoluble organic solvent that forms an azeotrope with water. Manufacturing method of photoreceptor. 7. A method for producing a laminated electrophotographic photoreceptor comprising at least a charge generation layer and a charge transport layer laminated on a conductive support, wherein a oxotitanium phthalocyanine is deposited and crystal-converted. And, on the charge generation layer, at least a charge transport material, a charge transport layer forming step of forming a charge transport layer with a paint of a binder resin and tetrahydrofuran. A method for producing a laminated electrophotographic photoreceptor, wherein the treatment is performed by contact with a vapor containing at least an aromatic hydrocarbon-based organic solvent, the absorption of which does not decrease in the wavelength region of 800 nm or more even after the formation of the transport layer. . 8. A method for producing a laminated electrophotographic photoreceptor comprising a charge generating layer and a charge transporting layer laminated on a conductive support, wherein a charge generating layer is formed by vapor-depositing oxotitanium phthalocyanine and converting the charge. And, on the charge generation layer, at least a charge transport material, a charge transport layer forming step of forming a charge transport layer with a paint of a binder resin and tetrahydrofuran. A multilayer electrophotographic photoreceptor, wherein the absorption is not reduced in the wavelength region of 800 nm or more even after the formation of the transport layer, and the treatment is performed by contact with a vapor containing at least an ester organic solvent of an aliphatic carboxylic acid. Production method. 9. A laminated electrophotographic photoreceptor comprising at least a charge generation layer and a charge transport layer laminated on a conductive support, wherein the charge generation layer is obtained by crystallizing an oxotitanium phthalocyanine vapor-deposited film. Further, on the charge generation layer, a charge transport layer is formed by a paint comprising at least a charge transport substance, a binder resin and tetrahydrofuran. After the formation of the charge transport layer, the photosensitive layer has a visible absorption spectrum around 800 nm. Wherein the ratio of the first absorbance at the absorption maximum wavelength to the second absorbance at 830 nm is 0.5 or more.