JPH05249707A - Production of photosensitive body - Google Patents

Abstract

PURPOSE:To improve the blocking characteristic of a hole and to reduce dark attenuation by standing or heating an aluminum substrate on which a charge generating layer is formed in an oxygen atmosphere to form an aluminum oxide film in between. CONSTITUTION:This photosensitive body is obtained by successively forming an aluminum oxide layer 2 having about 0.1mum thickness, a charge generating layer 3 and a charge-transfer layer 4 on an aluminum substrate 1 in this order. A three-electrode cell is used to form the charge generating layer 3, and the substrate 1 is used as a sample electrode, a platinum sheet as the counter electrode and a silver/silver chloride electrode as the reference electrode. A copper phthalocyanine film is formed on the substrate 1, then the substrate is taken out of a testing liq., washed with water and then with ethanol, and the charge generating layer 3 having about 0.2mum thickness is formed on the substrata 1. The sample is heated at 120 deg.C for 2hr in a drying furnace to form the aluminum oxide film 2 between the substrate 1 and the charge generating layer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a photoconductor used in electrophotography and the like.

[0002]

2. Description of the Related Art Conventionally, as a photosensitive member, a function-separated type photosensitive member has been put to practical use because it has a large material selectivity and is effective. Among them, a laminated type function-separated type photoreceptor in which a substrate, a charge generation layer, and a charge transport layer are sequentially laminated has attracted attention, and its development has been advanced in recent years. As a method for forming the charge generation layer and the charge transport layer in such a laminated type function-separated type photoreceptor, generally, a vapor deposition method, a polymer binding method, a slip casting method and the like are known. However, the vapor deposition method may decompose depending on the type of the light-sensitive material, and the polymer binding method makes it very difficult to peel off the charge generation layer during the production of the charge transport layer or to obtain a uniform film. There is a problem. further,
The slip casting method has a problem in that impurities such as a solvent enter and as a result, distortion occurs when the solvent is dried. Also, since a large amount of organic solvent is used, it is a serious environmental problem.

In recent years, a dispersion liquid obtained by dispersing or solubilizing a charge generating material or a charge transporting material with a surfactant in an aqueous solvent during preparation of the charge generating layer or the charge transporting layer of a photoreceptor, Alternatively, it has been reported that current is applied in a solution to form a charge generation layer or charge transport layer made of the above materials. Also, Japanese Patent Application No. 3-
No. 331296, a charge dispersion layer obtained by dispersing or solubilizing the charge generation material or the charge transport material with a surfactant in an aqueous solvent during preparation of the charge generation layer or the charge transport layer of the photoreceptor, Alternatively, a method of forming a charge generation layer or a charge transport layer made of the above material by heating a solution and immersing the substrate in the solution has been reported.

[0004]

However, when the charge generation layer is formed by applying electricity or heating with the aluminum substrate as the cathode, the blocking property of the holes between the aluminum substrate and the charge generation layer is poor, and the photoconductor having a large dark decay. There was a problem that

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to provide a photoconductor having a small dark decay.

[0006]

In order to achieve this object, the method for producing a photoconductor of the present invention is a method for producing a charge generation layer of a photoconductor, in which a charge generation material is mixed with a surfactant in an aqueous medium. Dispersion or solubilization, dispersion and solubilization steps, and the obtained dispersion or solution as an electrolytic solution for electrolysis using an aluminum substrate as a cathode to form a thin film of a charge generation material on the aluminum substrate. It includes a generation layer forming step and an oxidation step of leaving or heating the aluminum substrate on which the charge generation layer is formed in an oxygen atmosphere.

In order to achieve this object, another method for producing a photoreceptor of the present invention is to disperse the charge generating material in an aqueous medium with a surfactant during the production of the charge generating layer of the photoreceptor. Alternatively, solubilization, dispersion, solubilization step, and the resulting dispersion, or a solution, or a solution, a charge generation layer forming step of forming a thin film of the charge generation material on the aluminum substrate by heating and dipping the aluminum substrate, The aluminum substrate on which the charge generation layer is formed is left to stand in an oxygen atmosphere or is heated.

[0008]

According to the method of manufacturing a photoconductor of the present invention having the above structure, an aluminum oxide film is formed between an aluminum substrate and a charge generation layer, so that hole blocking characteristics are improved.

[0009]

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

[First Embodiment] FIG. 1 is a sectional view of a photosensitive member manufactured according to the first embodiment. In this photoconductor, an aluminum oxide layer 2 having a thickness of about 0.1 μm (micrometer) is present on an aluminum substrate 1, and a charge generation layer 3 and a charge transport layer 4 are further formed thereon.

Next, the manufacturing process of this embodiment will be described with reference to FIG.

First, in the solubilization and dispersion process, polyoxyethylene dodecyl ether (Brij35) and lithium bromide (LiBr), which are nonionic surfactants, were added to ion-exchanged water to a concentration of 2.0 mM (millimeter).・ Mole)
And 0.1 M (mol), and then β-type copper phthalocyanine, which is a charge generating material, is added to the above solution to 7 mM, and the mixture is stirred for several hours. This charge generating material dispersion liquid was irradiated with ultrasonic waves for 30 minutes, and then, the room temperature (about 2
Let stand at 5 ° C for 24 hours. After 24 hours, the supernatant was collected and used as a test solution 5.

Next, the charge generation layer forming step will be described. The three-electrode cell shown in FIG. 2 was used in the charge generation layer forming step. An aluminum substrate 1 was used as a sample electrode, a platinum plate 6 was used as a counter electrode, and an Ag / AgCl (silver / silver chloride) electrode 7 was used as a reference electrode. When preparing the charge generation layer,
The aluminum substrate 1 was ultrasonically degreased in acetone for 5 minutes. The test solution 5 is kept at 30 ° C. in a constant temperature bath 8, the aluminum substrate 1 is put therein, and a galvanostat (constant current power supply) 9 is used for 5 minutes, −0.8 mA / cm ²
A β-type copper phthalocyanine film was formed on the aluminum substrate 1 by carrying out cathode energization (millimeter-aperture per square centimeter). Then, the aluminum substrate 1 is used as a test liquid 5
Then, it was washed with water and ethanol to form a charge generation layer 3 having a thickness of about 0.2 μm on the aluminum substrate 1.

Next, the oxidation process will be described. As the oxidation step, the sample produced in the above-mentioned charge generation layer forming step is heated in a drying oven at 120 ° C. in air for 2 hours so that the aluminum oxide layer 2 is formed between the aluminum substrate 1 and the charge generation layer 3.
Formed.

Next, the step of forming the charge transport layer will be described.
The charge transport layer is formed by forming a chlorobenzene solution of polyvinylcarbazole (10 wt%) on the charge generation layer 3 previously formed.
(Weight percent) is applied by a bar coater, left at room temperature for 30 minutes, and then dried in a drying oven at 120 ° C. for 1 hour to prepare a charge transport layer 4 having a thickness of about 20 μm. completed.

Next, the evaluation of the dark attenuation was conducted by Kawaguchi Electric Co., Ltd.
Manufactured by SP-428 type tester. The photoreceptor was negatively charged on the surface of the photoreceptor by corona charging at a voltage of -6.0 kV (kilovolt) for 1 second.
The surface potential at this time was V ₁ , the surface potential after standing for 5 seconds in the dark was V _2, and the surface potential retention rate V ₂ / V ₁ after 5 seconds in the dark was used as an index of dark decay. Table 1 shows the results of comparison with a sample not heated at 120 ° C. for 2 hours, that is, a sample not subjected to the oxidation step.

[0017]

[Table 1]

As is clear from the above table, the photoreceptor subjected to the oxidation step by heating has a high surface potential retention rate in a dark place. This is because the photoconductor manufactured by the method for manufacturing a photoconductor of the present invention has an aluminum substrate 1 and a charge generation layer 3
It is considered that since the aluminum oxide layer 2 exists between and, the hole blocking property between the aluminum substrate 1 and the charge generation layer 3 is improved.

From the above, the method for producing a photoconductor of the present invention is effective for obtaining a photoconductor having a small dark decay.

[Second Embodiment] FIG. 3 is a sectional view of a photosensitive member manufactured according to the second embodiment. In this photoreceptor, an aluminum oxide layer 11 having a thickness of about 0.1 μm is present on an aluminum substrate 10, and a charge generation layer 1 is further formed on the aluminum oxide layer 11.
2. The charge transport layer 13 is formed.

Next, the manufacturing process of this embodiment will be described with reference to FIG.

First, in the solubilization and dispersion steps, polyoxyethylene dodecyl ether (Brij35) and lithium bromide (LiBr), which are nonionic surfactants, were added to ion-exchanged water at respective concentrations of 2.0 mM and 0. .1
Then, β-type copper phthalocyanine, which is a charge generating material, is added to the solution so that the concentration becomes 7 mM, and the mixture is stirred for several hours. The charge generation material dispersion liquid is irradiated with ultrasonic waves for 30 minutes and then left standing at room temperature (about 25 ° C.) for 24 hours. After the lapse of 24 hours, the supernatant was separated and used as a test solution 14.

Next, the charge generation layer forming step will be described. The heating cell shown in FIG. 4 was used in the charge generation layer forming step.
The aluminum substrate 10 was used as a sample electrode. In producing the charge generation layer, the aluminum substrate 10 was subjected to ultrasonic degreasing in acetone for 5 minutes. Test solution 14 in constant temperature bath 15
The temperature was maintained at 90 ° C. by the above, the aluminum substrate 10 was put therein, and left for 30 minutes to form a β-type copper phthalocyanine film on the aluminum substrate 10. afterwards,
The aluminum substrate 10 was taken out of the test solution 14 and washed with water and ethanol to form a charge generation layer 12 having a film thickness of about 0.2 μm on the aluminum substrate 10.

Next, the oxidation process will be described. As the oxidation step, the sample prepared in the charge generation layer forming step is heated in a drying oven at 120 ° C. for 2 hours to form the aluminum oxide layer 11 between the aluminum substrate 10 and the charge generation layer 12. Formed.

Next, the step of forming the charge transport layer will be described.
The charge transport layer was prepared by forming a chlorobenzene solution of polyvinylcarbazole (10 wt%) on the charge generation layer 12 formed previously.
%) Was applied by a bar coater, left at room temperature for 30 minutes, and then dried in a drying oven at 120 ° C. for 1 hour to prepare a charge transport layer 13 having a thickness of about 20 μm, thus completing the photoreceptor.

Next, the evaluation of dark attenuation was conducted by Kawaguchi Electric Co., Ltd.
Manufactured by SP-428 type tester. Corona charging was applied to the above-mentioned photoconductor at a voltage of -6.0 kV for 1 second to negatively charge the surface of the photoconductor. The surface potential at this time was V ₁ , the surface potential after standing for 5 seconds in the dark was V _2, and the surface potential retention rate V ₂ / V ₁ after 5 seconds in the dark was used as an index of dark decay. Table 2 shows the results of comparison with the sample that was not heated at 120 ° C. for 2 hours, that is, the sample that was not subjected to the oxidation step.

[0027]

[Table 2]

As is clear from the above table, the photoreceptor subjected to the oxidation process by heating has a high surface potential retention rate in a dark place. This is because the aluminum oxide layer 11 is present between the aluminum substrate 10 and the charge generation layer 12 in the photoreceptor manufactured by the method for manufacturing a photoreceptor of the present invention. It is considered that this is because the hole blocking property is improved.

From the above, the method for producing a photoconductor of the present invention is effective for obtaining a photoconductor having a small dark decay.

[0030]

As is apparent from the above description, in the method of manufacturing a photoreceptor of the present invention, an aluminum oxide film is formed between an aluminum substrate and a charge generation layer, so that hole blocking is improved in characteristics. However, it is possible to provide a photoreceptor having a small dark decay.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a photoconductor manufactured according to a first embodiment.

FIG. 2 is a graph of 3 used for manufacturing a photoconductor in the first embodiment.
It is a block diagram of an electrode cell.

FIG. 3 is a sectional view of a photoconductor manufactured according to a second embodiment.

FIG. 4 is a configuration diagram of a heating cell used for manufacturing a photoconductor in a second example.

[Explanation of symbols]

 1 Aluminum Substrate 2 Aluminum Oxide Layer 3 Charge Generation Layer (CGL) 4 Charge Transport Layer (CTL) 5 Test Solution 6 Platinum Plate 7 Ag / AgCl Electrode 8 Constant Temperature Water Bath 9 Galvanostat 10 Aluminum Substrate 11 Aluminum Oxide Layer 12 Charge Generation Layer (CGL) 13 Charge transport layer (CTL) 14 Test solution 15 Constant temperature water bath

Claims (2)

[Claims] 1. A charge generating material is dispersed in an aqueous medium with a surfactant during the preparation of the charge generating layer of a photoreceptor.
Alternatively, solubilization, dispersion, a solubilization step, and using the dispersion or solution obtained in the above step as an electrolytic solution, electrolysis is performed using an aluminum substrate as a cathode, and a thin film of the charge generating material is formed on the aluminum substrate. A method for producing a photoconductor, comprising: a charge generation layer forming step of forming the charge generation layer; and an oxidation step of leaving or heating the aluminum substrate on which the charge generation layer is formed in the above step in an oxygen atmosphere. 2. A charge generating material is dispersed in an aqueous medium with a surfactant during the preparation of the charge generating layer of a photoreceptor.
Alternatively, solubilization, solubilization, and a solubilization step, and the dispersion or the solution obtained in the above steps are heated to dip the aluminum substrate to form a thin film of the charge generation material on the aluminum substrate. A method for producing a photoconductor, comprising: a layer forming step; and an oxidation step of leaving or heating an aluminum substrate on which a charge generation layer is formed in the above step in an oxygen atmosphere.