JP2014056197A - Method for manufacturing electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrophotographic photoreceptor, for solving problems such as non-uniformity of electrophotographic characteristics due to non-uniformity of drying by hot blast drying and non-uniformity of electrophotographic characteristics due to non-uniformity of drying by an induction heating method using a high-frequency induction coil, and for obtaining an electrophotographic photoreceptor having uniform electrophotographic characteristics.SOLUTION: The method for manufacturing an electrophotographic photoreceptor comprises forming a coating layer on a conductive support body 1. Induction heat generating members 3, 4, which can be heated by eddy currents induced by a high-frequency induction coil 2, are disposed at both ends in an axial direction of the conductive support body 1; the length of the high-frequency induction coil 2 is controlled to generate eddy currents by high frequencies in the induction heat generating members 3, 4; and the coating layer is dried and cured by induction heating in the conductive support body 1 and the induction heat generating members 3, 4.

Description

  The present invention relates to a method for producing an electrophotographic photosensitive member.

Organic photoreceptors are widely used as photoreceptors used in electrophotography.
The organic photoreceptor includes a photoreceptor having at least an intermediate layer in which an inorganic pigment is dispersed, a charge generation layer, and a charge transport layer in this order on a conductive support, and a photosensitive layer containing a charge generation material and a charge transport material. There is a single-layer photoconductor provided as a single layer.

  Regarding the method for producing this photoreceptor, there are various coating methods such as dipping, spraying, blade coater, etc., and a cylindrical conductive support that is easy to obtain a uniform coating film is immersed in the coating solution. Many methods are used.

  In addition, the coating layer is dried and / or cured by hot air drying using a heat drying apparatus. Thereafter, the cylindrical conductive support is formed with a necessary coating layer by repeating the coating and heat-drying steps as necessary.

Heat drying with hot air is often used, but the temperature in the drying device tends to be non-uniform, and in particular, a temperature gradient often occurs from the upstream to the downstream of the hot air, resulting in non-uniform drying and curing of the coating film. Easily and adversely affects electrophotographic characteristics.
In order to improve the problem caused by such hot air drying, Patent Document 1 discloses an induction heating method using a high-frequency induction coil spirally wound around the outside of a cylindrical conductive support. Discloses an induction heating method using a loop-shaped high-frequency induction coil.

However, it cannot be said that these all have sufficient uniformity of the temperature in the axial direction of the cylindrical conductive support. In general, in order to dry a coating film applied to a cylindrical conductive support, the upper, lower, or both upper and lower sides of the cylindrical conductive support are held by a holding jig.
At this time, heat transfer from the cylindrical conductive support to the holding jig occurs in the cylindrical conductive support during induction heating. At the location where the heat has moved to the gripping jig, the temperature becomes low, thereby causing a phenomenon that the temperature distribution changes. This phenomenon appears remarkably at the stage where the temperature is controlled to be constant. As a result, the uniformity of the temperature of the cylindrical conductive support during heating becomes poor, and the electrophotographic characteristics become non-uniform.

Moreover, in order to dry the coating film apply | coated to the cylindrical electroconductive support body, it is necessary to control temperature. If a non-contact type radiation thermometer is used, the temperature of the coating film during drying can be directly measured, and this method is often used.
However, according to this method, depending on the material of the coating film, the temperature measured by the thickness of the coating film may be different from the actual temperature. In addition, it may be affected by the shape of the base of the coating film, so that accurate measurement may not be possible. If the temperature cannot be measured accurately, the appropriate coating film is not dried, which affects the electrophotographic characteristics.

  The object of the present invention is to provide non-uniformity of electrophotographic characteristics due to non-uniform drying by hot air drying, and non-uniformity of electrophotographic characteristics due to non-uniform drying by an induction heating method using a high frequency induction coil. And to provide a method for producing an electrophotographic photosensitive member having uniform electrophotographic characteristics.

The inventors of the present invention provide a method for producing an electrophotographic photosensitive member having a step of drying and / or curing a layer formed by coating on a conductive support and / or a layer laminated thereon by high-frequency induction heating. A member (induction heating member) capable of generating and heating an eddy current by a high-frequency induction coil is disposed at both ends in the axial direction of the body, and the length of the high-frequency induction coil is set to the induction heating member by a high frequency. It has been found that the above problem can be solved by setting the length to be generated.
That is, the present invention relates to a method for producing an electrophotographic photoreceptor as described below.

  The above-mentioned problem is a method for producing an electrophotographic photosensitive member by forming a coating layer on a conductive support according to the present invention, wherein eddy currents are generated by high-frequency induction coils at both ends in the axial direction of the conductive support. An induction heating member that can be heated and disposed is disposed, and the length of the high-frequency induction coil is set such that an eddy current is generated by high frequency in the induction heating member, and the conductive support and the induction heating member are induction-heated. This can be solved by “a method for producing an electrophotographic photosensitive member, wherein the coating layer is dried and cured.”

  According to the present invention, a non-uniformity of electrophotographic characteristics due to nonuniform drying temperature is solved, and a method for producing an electrophotographic photoreceptor having uniform electrophotographic characteristics is provided.

It is a figure which shows the manufacturing method of the conventional electrophotographic photoreceptor using a high frequency induction coil. It is a figure which shows an example of a structure of the apparatus which enforces the manufacturing method of the electrophotographic photoreceptor of this invention. It is a figure which shows an example of the heating apparatus used in the Example of this invention. It is a figure which shows an example of the heating apparatus used by the comparative example of this invention. It is a figure which shows the measurement position of the temperature about the electrophotographic photoreceptor in an Example and a comparative example.

Hereinafter, the present invention will be described in more detail.
In the method for producing an electrophotographic photosensitive member using the cylindrical conductive support of the present invention, a high frequency induction coil is used for heating and drying and / or curing of the coated film without using hot air. By heating the conductive support itself, the coating film is heat-dried and cured.
In other words, in the present invention, the line of magnetic force generated by the high-frequency induction coil is applied to the conductive support, and the conductive support is directly heated by the eddy current generated as a result, so that the temperature is raised to the set temperature for drying in a short time. The heating principle with a high frequency induction coil that can be used is used.

Next, a method for uniformly drying the coating film coated on the conductive support in the axial direction will be specifically described.
The induction heating member disposed on both sides of the drum-like conductive support of the present invention will be described.
FIG. 1 shows a conventional heating device using a high-frequency induction coil 2 having a spiral shape.
In the present invention, as shown in FIG. 2, induction heat generating members 3 and 4 that can be heated by generating an eddy current by the high frequency induction coil 2 are disposed on both sides of the axial end of the cylindrical conductive support 1. Further, the high frequency induction coil 2 has a length applied to the induction heating member as shown in FIG. 2, and the high frequency induction coil 2 generates an eddy current in the induction heating member. The material of the induction heating member is a metal such as aluminum, copper, stainless steel or nickel, a plastic in which a conductive pigment such as carbon is dispersed; a metal is deposited on an insulating support (such as a plastic or plastic film) or The thing which applied the conductive paint can be illustrated. In addition, the induction heating members on both sides need not be the same, and the shape, such as the material, length, and thickness of the induction heating member can be set in accordance with the distribution of the drying temperature.

  According to the present invention, the induction heating members arranged above and below the cylindrical conductive support are also induction-heated by the high frequency induction coil in the same manner as the conductive support, and the conductive support has a uniform drying temperature in the axial direction. Thus, an electrophotographic photoreceptor having good electrophotographic characteristics can be obtained.

Next, the temperature measuring method in the present invention will be described.
Although it is necessary to measure the temperature in order to control the drying temperature, the temperature is measured on the induction heating member arranged at the end of the cylindrical conductive support (see FIG. 2). As a measuring method, a method in which a tape-type thermocouple thermometer is brought into contact or a method in which a non-contact type radiation thermometer 5 is used is possible.
When the non-contact type radiation thermometer 5 is used, a paint or the like may be applied to the surface of the induction heating member in order to increase the measurement accuracy of the non-contact type radiation thermometer 5. This is because the degree of detection of the non-contact type radiation thermometer varies depending on the material and reflectance of the coating film, and can be determined by checking in advance.
Further, temperature control is possible by controlling the temperature data measured by the non-contact type radiation thermometer with the program unit and changing the current flowing through the high frequency induction coil.

The shape of the high frequency induction coil used for electromagnetic induction heating can be a spiral shape, a loop shape, a spiral shape, or the like.
In addition, the shorter the distance between the high frequency induction coil and the coating film applied to the conductive support, the more eddy current is generated in the cylindrical conductive support due to the lines of magnetic force due to electromagnetic induction, and the longer the distance is. In this case, the eddy current generated by the lines of magnetic force due to electromagnetic induction is reduced.
It is preferable to arrange a material such as ferrite or copper on the side of the coil opposite to the conductive support, since the heating efficiency is improved.

Further, the temperature of the cylindrical conductive support during electromagnetic induction heating is highest at the portion directly below the coil. Therefore, it is preferable to rotate the cylindrical conductive support at an appropriate speed in the circumferential direction during heating since the temperature becomes uniform and the drying uniformity of the coating film is improved.
Furthermore, it is preferable to cool so that cooling water can be passed through the high-frequency induction coil, because overheating can be prevented.

An electrophotographic photoreceptor for which the method for producing an electrophotographic photoreceptor of the present invention is used will be described.
The electrophotographic photosensitive member in which the method for producing an electrophotographic photosensitive member of the present invention is used is a cylindrical electrophotographic photosensitive member in which a photosensitive layer containing an organic photoconductive substance is formed on a cylindrical conductive support. .
This photosensitive layer is formed by drying and / or curing after applying the photosensitive layer coating solution.
When the electrophotographic photosensitive member is a laminated type, the process of applying the coating liquid for each layer for each function, drying and / or curing is repeated a plurality of times. At this time, the method for producing an electrophotographic photosensitive member of the present invention can be used in the step of drying and / or curing an arbitrary coating layer.

  Examples of the conductive support used in the present invention include metals such as aluminum, nickel, and stainless steel; plastic in which conductive pigments such as carbon are dispersed; metal is deposited on an insulating support (such as plastic or plastic film). Or those coated with a conductive paint.

Next, the intermediate layer provided on the conductive support will be described. The inorganic pigment used in the intermediate layer may be a commonly used pigment, but white or a pigment with almost no absorption in visible light and near infrared light is desirable when considering higher sensitivity of the photoreceptor.
Examples thereof include white pigments such as titanium oxide, zinc white, zinc sulfate, lead white, and lithopone, and extender pigments such as aluminum oxide, silica, calcium carbonate, and barium sulfate.
Of these, titanium oxide is preferable because it has a higher refractive index than other white pigments, is chemically and physically stable, has a large hiding power, and has a high degree of whiteness.

Further, as the intermediate layer binder resin used in the present invention, an appropriate one can be used.
For example, water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, curable resins that form a three-dimensional network structure such as polyurethane, melamine resin, and epoxy resin Etc.

The intermediate layer coating solution can be prepared by dissolving the binder resin in a solvent and dispersing it together with an inorganic pigment using a ball mill, roll mill, sand mill, attritor or the like.
This dispersion is coated on the conductive support using a coating method such as blade coating, knife coating, spray coating, or dip coating.

The mass ratio range of the binder resin / inorganic pigment in the intermediate layer is preferably in the range of 1/15 to 2/1.
The thickness of the intermediate layer is preferably 0.5 μm or more and 20.0 μm or less. However, in order to obtain a highly durable photoreceptor that is less likely to be stained due to repeated use, the thicker the intermediate layer, the more advantageous. An intermediate layer of 3.0 μm or more is desirable.
Further, when the charging means is a contact charging means, it is more desirable to use an intermediate layer of 3.0 μm or more in order to prevent discharge breakdown.

The photosensitive layer provided on the intermediate layer may be a single layer type or a laminated type.
However, in either case, the solvent used in the photosensitive layer coating solution is at least one solvent selected from cyclic ether compounds, ketone compounds, and aromatic hydrocarbon compounds.
The film thickness of the photosensitive layer is desirably 20 μm or more, and preferably 25 to 50 μm, in order not to generate an abnormal image even when used repeatedly.

The photoreceptor is worn by the contact member due to repeated use, and the film thickness decreases.
As a result, the electric field strength applied to the photosensitive member increases, and abnormal images such as background stains are generated by charge injection from the conductive support.
Therefore, by increasing the thickness of the photosensitive layer, it is possible to continue to provide high-quality images even after repeated use.
The film thickness of the photosensitive layer here is the total film thickness of the charge generation layer and the charge transport layer when the photosensitive layer is composed of a stack of a charge generation layer and a charge transport layer. In the case of a single layer, it is the film thickness of the photosensitive layer itself.

First, the case where the photosensitive layer is composed of a charge generation layer and a charge transport layer will be described.
The charge generation layer is a layer mainly composed of a charge generation material.
As the charge generation material, inorganic and organic materials are used, and representative examples include monoazo pigments, disazo pigments, trisazo pigments, perylene pigments, perinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, squalic acid dyes, Examples include phthalocyanine pigments, naphthalocyanine pigments, azurenium salt dyes, selenium, selenium-tellurium, selenium-arsenic alloys, and amorphous silicon.
The charge generation material may be used alone or in combination of two or more.

For the charge generation layer, the charge generation material is dispersed with a binder resin and a cyclic ether compound, ketone compound, and / or aromatic hydrocarbon compound using a ball mill, attritor, sand mill, etc., and a dispersion is applied. To form.
The coating can be performed using a dip coating method, a spray coating method, a bead coating method, or the like.

  Examples of the binder resin that is appropriately used include polyurethane, polyester, epoxy resin, polycarbonate, acrylic resin, polyvinyl butyral, polyvinyl formal, polystyrene, and polyacrylamide that are soluble in the organic solvent.

The thickness of the charge generation layer is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.
The amount of the charge generating material is suitably 10 to 10000 parts by mass, preferably 20 to 5000 parts by mass with respect to 100 parts by mass of the binder resin.
The charge transport layer is obtained by dissolving or dispersing a charge transport material and a binder resin in a cyclic ether compound, a ketone compound, and / or an aromatic hydrocarbon compound, and applying and drying the solution on the charge generation layer. Can be formed.
Moreover, a plasticizer, a leveling agent, etc. can also be added as needed.

Charge transport materials include hole transport materials and electron transport materials.
Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.

  Examples of hole transport materials include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutarate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, and oxal derivatives. Oxadiar derivative, imidazole derivative, monoaramine derivative, diaramine derivative, triaramine derivative, stilbene derivative, α-phenylstilbene derivative, benzidine derivative, diarylmethane derivative, triarylmethane derivative, 9-styrylanthracene derivative, pyrazoline derivative, divinyl Benzene derivatives, hydrazine derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, other polymers And known materials such as hole transport materials.

  Examples of the binder resin used for the charge transport layer include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. Coalescence, polyvinyl acetate, polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, There are thermoplastic or thermosetting resins such as melamine resin, urethane resin, phenol resin, alkyd resin, and various polycarbonate copolymers described in JP-A-5-158250 and JP-A-6-51544. It is.

The amount of the charge transport material is appropriately 20 to 300 parts by mass, preferably 40 to 150 parts by mass with respect to 100 parts by mass of the binder resin.
The amount of the hole transport material is appropriately 20 to 300 parts by mass, preferably 40 to 150 parts by mass with respect to 100 parts by mass of the binder resin.

In the present invention, a leveling agent and an antioxidant may be added to the charge transport layer.
As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain can be used, and the amount used is 100 parts by mass of the binder resin. 0 to 1 part by mass is appropriate.

  Antioxidants such as hindered phenol compounds, sulfur compounds, phosphorus compounds, hindered amine compounds, pyridine derivatives, piperidine derivatives, morpholine derivatives can be used as the antioxidant, and the amount used is binder resin 100. About 0-5 mass parts is suitable with respect to mass parts.

Next, the case where the photosensitive layer has a single layer structure will be described.
In this case, at least the charge generating material and the charge transporting material are used as a binder resin, a phenol compound, and an organic sulfur compound as one or more solvents selected from cyclic ether compounds, ketone compounds, and aromatic hydrocarbon compounds. It can be formed by dissolving or dispersing, coating and drying.
Moreover, a plasticizer etc. can also be added as needed.

As the binder resin, the binder resin mentioned above in the charge transport layer can be used as it is, and the binder resin mentioned in the charge generation layer may be mixed.
In the photoreceptor of the present invention, a protective layer may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer.

  Materials used for the protective layer include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenolic resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene. , Polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, Examples of the resin include polyvinylidene chloride and epoxy resin.

In addition to the protective layer, fluorine resins such as polytetrafluoroethylene, silicone resins, and inorganic materials such as titanium oxide, alumina, silica, tin oxide, and potassium titanate are used for the purpose of improving wear resistance. A dispersed product or the like can be added.
Among inorganic materials, metal oxides are effectively used.
In particular, titanium oxide, alumina, and silica are effectively used.

In addition, it is an effective means to use a charge transport material in combination with the protective layer.
As the charge transport material, a low molecular charge transport material and a polymer charge transport material can be used, and the materials described in the description of the charge transport layer can be used effectively.

As a method for forming the protective layer, a normal coating method (spray coating, beat coating, nozzle coating, spinner coating, ring coating, etc.) is employed.
The thickness of the protective layer is suitably about 0.1 to 10 [μm].
In addition to the above, a known material such as a-C or a-SiC formed by a vacuum thin film forming method can be used as the protective layer.

  EXAMPLES Hereinafter, although an Example and a comparative example further demonstrate this invention, this invention is not restrict | limited to the following example.

  In Example 1 and Comparative Example 1, the temperature distribution of the conductive support (without the coating film) with and without the induction heating member was measured with a non-contact type radiation thermometer (digital radiation temperature sensor FT series manufactured by KEYENCE).

[Example 1]
An electromagnetic induction heating device for heating the drum-like conductive support was configured as follows (see FIG. 3).
(High frequency induction coil)
Shape: Spiral pipe shape Coil winding outer diameter: 130mm
Coil winding pitch: 30 mm (13 windings)
Coil length: 410mm
Coil diameter: 12mm

(Heating conditions)
After heating at a current of 367 A and a frequency of 190 KHz, the cylindrical conductive support was heated at a speed of 10 revolutions per minute in the circumferential direction while PID control was performed to maintain 150 ° C. The coil was used through cooling water.
At this time, temperature control was performed by measuring the temperature in the axial center of the cylindrical conductive support using a non-contact type radiation thermometer (a digital radiation temperature sensor made by KEYENCE) and a PLC unit made by KEYENCE. .

(Conductive support)
Material: Aluminum Outer diameter: 100mm
Length: 270mm
Thickness: 1.2mm
(Induction heating member)
Material: Aluminum Outer diameter: 100mm
Length: 60mm
Thickness: 2.0mm, some 0.8mm

[Comparative Example 1]
The electromagnetic induction heating device for heating the drum-shaped conductive support was configured as follows (see FIG. 4).
(High frequency induction coil)
Shape: Spiral pipe shape Coil winding outer diameter: 130mm
Coil winding pitch: 30 mm (9 windings)
Coil length: 290mm
Coil diameter: 12mm

(Heating conditions)
After heating at a current of 367 A and a frequency of 190 KHz, the cylindrical conductive support was heated at a speed of 10 revolutions per minute in the circumferential direction while PID control was performed to maintain 150 ° C. The coil was used through cooling water.
At this time, temperature control was performed by measuring the temperature in the axial center of the cylindrical conductive support using a non-contact type radiation thermometer (a digital radiation temperature sensor made by KEYENCE) and a PLC unit made by KEYENCE. .

(Conductive support)
Material: Aluminum Diameter: 100mm
Length: 270mm
Thickness: 1.2mm
The results of Example 1 and Comparative Example 1 are shown in Table 1. The temperature measurement position is shown in FIG.

As can be seen from Table 1, conductive support is provided by arranging induction heating members on both sides of a cylindrical conductive support and making the high-frequency induction coil have a length that causes eddy currents due to the high-frequency induction coil on the induction heating member. Good body temperature uniformity is obtained.

In Example 2 and Comparative Example 2 described below, a liquid was applied to the conductive support and dried with or without an induction heating member to evaluate image unevenness.

[Example 2]
Alkyd resin Beccosol 1307-60EL (solid content 60% by mass) (manufactured by Dainippon Ink Chemical) 80 parts by mass, Butylated benzoguanamine resin Super Becamine TD-126 (solid content 60% by mass) (manufactured by Dainippon Ink Chemical) 55 mass A part was dissolved in 350 parts by mass of methyl ethyl ketone, and 350 parts by mass of titanium oxide powder CR-EL (manufactured by Ishihara Sangyo) was ball-milled for 48 hours using alumina balls to prepare an intermediate layer coating solution.
The intermediate layer coating solution thus obtained is dip-coated on the conductive support of Example 1, and the applied cylindrical conductive material is applied at the set temperature of 150 ° C. by the same electromagnetic induction heating as in Example 1. The support was dried while rotating in the circumferential direction at a speed of 10 revolutions per minute to obtain an intermediate layer having a thickness of 3.5 μm.
At this time, the temperature is controlled by using a non-contact type radiation thermometer (a digital radiation temperature sensor made by KEYENCE) and a PLC unit made by KEYENCE, and the temperature on the coating film at the center in the axial direction of the cylindrical conductive support. Performed by measurement.

Next, 20 parts by mass of titanyl phthalocyanine pigment was placed in a glass pot together with zirconia beads having a diameter of 2 mm, and 350 parts by mass of tetrahydrofuran was further added, followed by ball milling at room temperature of 25 ° C. for 20 hours.
Thereafter, a resin solution prepared by dissolving 10 parts by mass of polyvinyl butyral resin ESREC BX-1 (manufactured by Sekisui Chemical Co., Ltd.) in 600 parts by mass of methyl ethyl ketone is added, and ball milling is further performed for 2 hours to thereby apply a coating solution for charge generation layer. It was created.

The charge generation layer coating solution thus obtained is dip-coated on the intermediate layer, dip-coated on the conductive support of Example 1, and set temperature 65 ° C. by the same electromagnetic induction heating as in Example 1. Then, the coated cylindrical conductive support was dried while rotating in the circumferential direction at a speed of 10 revolutions per minute to obtain a charge generation layer having a thickness of 0.5 μm.
At this time, the temperature is controlled by using a non-contact type radiation thermometer (a digital radiation temperature sensor made by KEYENCE) and a PLC unit made by KEYENCE, and the temperature on the coating film at the center in the axial direction of the cylindrical conductive support. Performed by measurement.

  Next, 770 parts by weight of a charge transport material of the following structural formula (1), 100 parts by weight of polycarbonate resin Iupilon Z-200 (Mitsubishi Gas Chemical), 0.002 parts by weight of silicone oil KF-50 (Shin-Etsu Chemical Co., Ltd.) Dissolved in parts by mass of tetrahydrofuran.

The charge transport layer coating solution thus obtained is dip-coated on the charge generation layer, dip-coated on the conductive support of Example 1, and set temperature 135 by the same electromagnetic induction heating as in Example 1. The coated cylindrical conductive support was dried at 10 ° C. while rotating at a speed of 10 revolutions per minute in the circumferential direction to form a charge transport layer having a film thickness of 25 μm, thereby producing an electrophotographic photosensitive member. .
At this time, the temperature is controlled by using a non-contact type radiation thermometer (a digital radiation temperature sensor made by KEYENCE) and a PLC unit made by KEYENCE, and the temperature on the coating film at the center in the axial direction of the cylindrical conductive support. Performed by measurement.

[Comparative Example 2]
Using the same cylindrical conductive support as in Example 2 and the same high-frequency induction coil as in Comparative Example 1, drying was performed in the same manner as in Example 2 to obtain an electrophotographic photosensitive member.
Next, the obtained electrophotographic photosensitive members of Example 2 and Comparative Example 2 were mounted on a remodeled machine of IMAGIO MF-7070 (manufactured by Ricoh), and halftone images were evaluated.
The halftone image evaluation was visually observed and performed as follows.
○: Good image with no image unevenness Δ: Image with some image unevenness ×: Image results with many image unevenness and practical problems are shown in Table 2.

  As can be seen from Table 2, in high-frequency induction heating, induction heating members are arranged on both sides of a cylindrical conductive support, and the high-frequency induction coil is made long enough to generate eddy currents on the induction heating member. Thus, a good image can be obtained without unevenness of the image.

[Example 3]
Alkyd resin Beccosol 1307-60EL (solid content 60% by mass) (manufactured by Dainippon Ink and Chemicals) 80 parts by mass, Butylated benzoguanamine resin Superbecamine TD-126 (solid content 60% by mass) (manufactured by Dainippon Ink and Chemicals) 55 mass A part was dissolved in 350 parts by mass of methyl ethyl ketone, and 350 parts by mass of titanium oxide powder CR-EL (manufactured by Ishihara Sangyo) was ball-milled for 48 hours using alumina balls to prepare an intermediate layer coating solution.
The intermediate layer coating solution thus obtained was dip-coated on the conductive support of Example 1 to a film thickness of 3.5 μm, and by the same electromagnetic induction heating as in Example 1, at a set temperature of 150 ° C. The coated cylindrical conductive support was dried and cured while rotating in the circumferential direction at a speed of 10 revolutions per minute to obtain an intermediate layer.
At this time, temperature measurement for temperature control was performed on the surface of the induction heating member in which an intermediate layer having a film thickness of 3.5 μm was formed in advance on the surface of the induction heating member arranged on both sides of the cylindrical conductive support.

[Example 4]
In the same manner as in Example 3, an intermediate layer having a thickness of 4.5 μm was obtained.
At this time, the temperature measurement for temperature control is performed by the induction heating member in which an intermediate layer having a film thickness of 3.5 μm is formed in advance on the surface of the induction heating member arranged on both sides of the same cylindrical conductive support as in Example 3. Done on the surface.

[Comparative Example 3]
An intermediate layer having a thickness of 3.5 μm was obtained in the same manner as in Example 3 except that the temperature measurement for temperature control was performed at the central portion in the axial direction of the coating film on the cylindrical conductive support.

[Comparative Example 4]
An intermediate layer having a thickness of 4.5 μm was obtained in the same manner as in Example 4 except that the temperature measurement for temperature control similar to that in Comparative Example 3 was performed.

In Examples 3 and 4 and Comparative Examples 3 and 4, as a measurement of the temperature during high-frequency induction heating of the cylindrical conductive support, the surface of the central portion in the axial direction of the coating film on the cylindrical conductive support was measured. The temperature was measured with a non-contact type radiation thermometer, and the coating film of the cylindrical support at the same position and the opposite side (inside the cylindrical support) were measured with a contact-type thermocouple thermometer.
The results are shown in Table 3.

  As can be seen from Table 3, when the temperature measurement for temperature control is performed at the temperature on the coating film in the intermediate layer, the measured value of the non-contact type radiation thermometer differs from the actual temperature due to the film thickness of the coating film. However, the temperature can be controlled at the same temperature regardless of the thickness of the coating film by measuring the temperature for controlling the temperature on the surface of the coated induction heating member surface.

  In the method of manufacturing an electrophotographic photosensitive member in which a coating film formed by coating is dried and cured by high-frequency induction heating, the high-frequency induction coil is formed at both ends in the axial direction of the conductive support. By arranging a member (induction heating member) capable of generating and heating an eddy current due to the high frequency induction coil, the induction heating member has a length that generates an eddy current due to a high frequency. It can be seen that the temperature is obtained. Further, it can be seen that drying and curing can be performed at a target temperature by measuring the temperature on the surface of the induction heating member with temperature control.

DESCRIPTION OF SYMBOLS 1 Conductive support body 2 High frequency induction coil 3 Induction heating member 4 Induction heating member 5 Non-contact type radiation thermometer 6 Temperature measurement position 7 High frequency power supply

JP-A-9-114111 JP 2005-43807 A

Claims (4)

  A method for producing an electrophotographic photosensitive member by forming a coating layer on a conductive support, wherein induction is possible in which eddy currents are generated by high-frequency induction coils at both ends in the axial direction of the conductive support. A heating member is arranged, and the length of the high-frequency induction coil is set to a length at which eddy current is generated by high frequency in the induction heating member, and the coating layer is dried by induction heating the conductive support and the induction heating member. A method for producing an electrophotographic photoreceptor, comprising curing.   2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the coating layer is for forming an intermediate layer and a photosensitive layer.   3. The method for producing an electrophotographic photoreceptor according to claim 2, wherein the photosensitive layer comprises a charge generation layer and a charge transport layer. The method of manufacturing an electrophotographic photosensitive member according to claim 1, wherein a surface temperature of the induction heating member is measured and temperature control is performed based on the measurement signal.

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