JPH1172931A - Apparatus for production of photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a coating application defect by prohibiting the intrusion of air bubbles into the coating liquid supplied to a coating application tank at the time of applying a photosensitive layer on a conductive substrate. SOLUTION: The conductive substrate 4 is immersed into the coating application tank 1 filled with the coating liquid 2 which is a photosensitive material prepd. by mixing a binder resin and a photosensitive material by a solvent. At this time, the coating liquid 2 flows over from the upper part of the coating application tank 1 and is received in an overflow receiving tank 3 and is returned to an stirring tank 5 to which the solvent or the coating liquid is additionally replenished. The coating liquid is circulated and supplied from the stirring tank 5 to the coating application tank 1. At this time, the coating liquid or solvent additionally replenished to the stirring tank 5 is additionally replenished via a metallic mesh 18 which is disposed in correspondence to the feeding port 14a of a replenishing section 14 of a cylindrical shape disposed to be segmented from the stirring tank 5. At the time of the replenishment, the intrusion of the air bubbles is suppressed and simultaneously the insoluble matter and are removed together, by which the coating application defect by the air bubbles, etc., is prohibited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing an electrophotographic photosensitive member by applying a pigment dispersion-based coating solution to a support surface, and more particularly to a photoconductive material used for an electrophotographic photosensitive member. The present invention relates to an apparatus for producing a photoconductor for electrophotography by forming a coating film on a support with a coating solution.

[0002]

2. Description of the Related Art In an image forming apparatus, for example, an image forming apparatus using an electrophotographic system, a toner image is formed on a photoreceptor for electrophotography which is a recording medium, and the toner image is transferred onto a sheet such as plain paper. In order to hold the toner image on the sheet as a permanent image on the sheet, the toner is heated and fixed by, for example, passing through a heat fixing device, and then discharged outside the apparatus main body.

[0003] The electrophotographic photosensitive member used in such an image forming apparatus has a photoconductive layer formed on the surface of a cylindrical body, an endless belt, or the like made of a metal such as aluminum as a conductive base. As a material for the photoconductive layer, an organic semiconductor (OPC) has recently become mainstream. Therefore, an electrophotographic photosensitive member is manufactured by applying a photosensitive material of an organic semiconductor to a conductive substrate.

[0004] When manufacturing a photoconductor for electrophotography, a dip coating method is generally used to form a photosensitive layer. An apparatus for manufacturing a photoreceptor by the dip coating method includes a circulating system for circulating a coating solution for forming a photosensitive layer and a device for elevating and lowering the substrate of the photoreceptor.

[0005] The coating liquid circulation system includes a coating tank filled with the coating liquid, a stirring tank storing a predetermined amount of the coating liquid to supply the coating liquid to the coating tank, and a coating liquid from the stirring tank. And a circulating pump for supplying the coating solution to the coating tank. In addition, the coating liquid having a capacity equal to or larger than the capacity of the coating tank overflows from the coating tank, and the overflowing coating liquid is returned to the stirring tank. After the mixture is sufficiently stirred, the mixture is circulated so as to be sent to the coating tank.

As described above, the coating tank is filled with a predetermined amount of coating liquid, and a conductive support (substrate) for electrophotography is immersed in the coating liquid in this coating tank by using an elevating device. The substrate is pulled up with. As a result, the coating liquid is applied to the surface of the substrate, and a photosensitive layer having a predetermined thickness is formed. In such a photoreceptor manufacturing apparatus using the dip coating method, the coating liquid is circulated in order to make the coating liquid uniform and prevent defects from occurring in the coating film.

On the other hand, as a coating solution used for an electrophotographic photoreceptor, for example, a charge generating layer is prepared by mixing and dispersing a charge generating material with a binder resin and a volatile organic solvent such as tetrahydrofuran. Used. When these dispersions are used as a coating liquid, in a manufacturing apparatus in the above-mentioned conventional dip coating method, when the coating liquid is circulated, particles such as pigments aggregate or the uniformity of the coating liquid decreases, and the resin component is reduced. Phenomenon such as separation of pigment components from the pigment occurs.

For the charge transport layer, a material in which a charge transport material and a binder resin are dissolved or dispersed in a volatile organic solvent such as dichloromethane is used. When used in an apparatus of the system, the viscosity and solid content of the coating liquid change due to the evaporation of the solvent when the coating liquid is circulated and applied. Therefore, by continuously performing coating for a long time, the number of coating layers on the substrate increases. That is, even if the film is pulled up at a constant speed, uniform coating cannot be performed.

Therefore, conventionally, in order to adjust the viscosity in a stirring tank, for example, as disclosed in Japanese Patent Application Laid-Open No. 2-131241, the viscosity of a coating solution is measured as needed, and the measured viscosity of the coating solution is measured. A solvent or the like is additionally supplied in accordance with a deviation value between the control value and a set value (reference value), and the viscosity of the coating liquid is controlled to a constant state so that the coating layer, that is, the coating film is uniform.

Further, by continuously manufacturing the electrophotographic photosensitive member, the amount of the coating solution is reduced. By replenishing the reduced coating liquid, the coating liquid is stabilized. Thus, the coating with the coating liquid is always performed under the same conditions to form a uniform coating film.

[0011]

However, according to the conventional dip coating apparatus, when the coating liquid is circulated,
It is very difficult to maintain the above-mentioned uniform dispersion state, and black spots and white spots are generated due to agglomerates and the like, so that a uniform image cannot be obtained.

In addition, when adding a coating liquid or adding a solvent for adjusting viscosity, there is a problem that air bubbles are mixed in the additional replenishment, and the air bubbles are sent to the coating tank. When these bubbles adhere to the substrate, the coating liquid is not applied to the bubble portions, or the coating layer becomes thin. In addition, if the mixing of the solvent and the coating liquid becomes non-uniform, coating defects due to density unevenness such as streaks occur, and there is a problem that it is impossible to manufacture a good photoconductor.

In view of the above-mentioned problems, the present invention eliminates the incorporation of bubbles when the amount of a coating solution is insufficient or when a solvent or a coating solution is added according to a change in the viscosity of the coating solution. It is an object of the present invention to provide a photoreceptor manufacturing apparatus capable of obtaining dispersibility and performing stable application.

[0014]

According to the present invention, there is provided an apparatus for manufacturing a photoreceptor for achieving the above-mentioned object, comprising a coating liquid obtained by mixing a binder resin and a photosensitive material with a solvent,
In a photoconductor manufacturing apparatus for manufacturing a photoconductor for electrophotography by applying the stored coating solution to a conductive support surface to form a photoconductive layer having a predetermined thickness, the coating solution is applied to the coating tank. A stirrer for accommodating the coating solution for supply and stirring the coating solution is provided, and a mesh is provided at a portion where the coating solution or a solvent for adjusting the viscosity of the coating solution is charged into the stirring tank. It is characterized by.

According to this configuration, when the coating liquid or the solvent is additionally supplied to the stirring tank, the coating liquid or the solvent is additionally supplied through the mesh. At this time, while the insoluble matter and dust are captured by the mesh, the incorporation of air bubbles is suppressed and replenished. Thereby, even if the coating liquid is supplied to the coating tank from the stirring tank, coating defects due to bubbles are eliminated, and good coating can be performed without disturbing dispersibility.

Here, when the photosensitive layer comprises at least a charge generation layer and a charge transport layer, the viscosity of the coating solution for forming the charge transport layer is usually higher than the viscosity of the charge generation layer. In addition, when additional replenishment of a high-viscosity coating solution is performed, bubbles are easily taken in. Therefore, by providing the mesh at the portion where the additional replenishment is performed as described above, the incorporation of air bubbles can be prevented, and thus, when applying with a high-viscosity coating solution, the coating defects due to air bubbles can be eliminated together. In addition, at the time of additional replenishment of the solvent, air is taken in particularly by collision with the coating liquid in the stirring tank, and air bubbles are mixed in.Also, by providing a mesh, air bubbles are suppressed from being mixed in the coating liquid, and thereby, Coating defects due to the inclusion of bubbles can be eliminated.

In the apparatus for manufacturing a photoreceptor having the above-described configuration, the mesh provided at the charging portion may be 1 mesh.
By setting the mesh size to be equal to or larger than 00 mesh and equal to or smaller than 500 mesh, the effect of suppressing air bubble mixing can be promoted. In particular, 1
By setting the mesh size to 00 mesh or more, the incorporation of air bubbles can be reliably prevented. By setting the mesh size to 500 mesh or less, insoluble matter and dust can be removed, and good replenishment can be performed without causing poor replenishment due to clogging of the mesh. . In particular, by providing the mesh, when the solvent is additionally supplied, the compatibility with the coating liquid can be improved.

In the photoreceptor manufacturing apparatus having the above-described configuration, the liquid to be additionally replenished to the stirring tank is a solvent, and if the additional replenishing speed of the solvent is set to 1 cc / sec or less, compatibility with the coating liquid can be achieved. Is further improved, the generation of agglomerates and the like is suppressed, good application can be performed, and productivity can be improved.

Further, in the photoreceptor manufacturing apparatus having the above-described configuration, a replenishing section which is separated from the stirring tank is provided in the charging section, and a stirring member for stirring the coating liquid or the solvent supplied to the replenishing section is provided. If it is provided, when the coating liquid or the solvent is added, the stirring with the coating liquid is performed in advance, and the stirring tank is additionally supplied via the mesh. Therefore, it is possible to eliminate coating defects such as streak-like sagging caused by non-uniform coating liquid. In addition, when the solvent is added, the compatibility with the coating liquid becomes good, and the solvent is supplied to the stirring tank.

Further, in the photoconductor manufacturing apparatus having the above-described configuration, if a stirring member provided in the stirring tank for stirring the coating liquid is provided with a floating mechanism for floating according to the amount of the coating liquid, The position of the stirring member is moved up and down according to the amount of the coating liquid in the stirring tank. Therefore, stirring according to the amount of the coating liquid can be performed. For example, when the stirring member is exposed from the surface of the coating liquid and is driven to be stirred, it is possible to prevent air bubbles from being mixed due to the rebound of the coating liquid. Therefore, controlling the stirring speed of the stirring member in accordance with the amount of the coating liquid not only promotes the effect of preventing bubbles from being mixed as described above, but also achieves good stirring in accordance with the amount of the coating liquid. Will be possible.

On the other hand, another apparatus for manufacturing a photoreceptor for achieving the object of the present invention accommodates a coating liquid obtained by mixing a binder resin and a photosensitive material with a solvent, and converts the accommodated coating liquid. In a photoconductor manufacturing apparatus for manufacturing a photoconductor for electrophotography by forming a photoconductive layer having a predetermined thickness by coating on the surface of a conductive support, the coating is performed to supply a coating liquid to the coating tank. Containing a liquid, comprising a stirring tank for stirring the coating liquid,
When a solvent for adjusting the viscosity of the coating liquid is supplied to the stirring tank, a spraying means for supplying the solvent in a mist form is provided.

With such a configuration, it is possible to improve the reconciliation with the coating liquid in the stirring tank and to reliably prevent air bubbles from being mixed. In other words, since additional replenishment is carried out in the form of a mist via the spraying means, the factor of air bubble mixing, that is, the mixing of air bubbles caused by collision with the coating liquid at the time of addition is eliminated.
In particular, since the compatibility between the coating liquid and the solvent is not good, many bubbles are generated by collision at the time of additional replenishment, which can be solved.

[0023]

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

FIG. 2 shows an example of the overall structure of a photoconductor manufacturing apparatus according to the present invention. FIG.
FIG. 3 is a configuration diagram showing details of a stirring tank for describing a first embodiment of the present invention using the manufacturing apparatus shown in FIG. 2.

First, the structure of the photoconductor manufacturing apparatus of the present invention will be described with reference to FIG. In the figure, 1 is a coating tank,
Reference numeral 2 denotes a coating solution for forming a photosensitive layer stored in a coating tank, 3 denotes an overflow receiving tank for receiving a coating solution overflowing from the coating tank 1, 4 denotes a conductive cylindrical support (substrate), and 5 denotes an overflow. A stirring tank according to the present invention for collecting a coating liquid and sending it to the coating tank again, wherein a new coating liquid or solvent is supplied as needed.

In order to feed the coating solution 2 in the stirring tank 5 to the coating tank 1, a supply pipe 6 is connected between the stirring tank 5 and the coating tank 1, and is provided in the middle. The coating liquid 2 is supplied to the coating tank 1 via the circulation pump 7 which is provided. A collecting pipe 8 is connected between the receiving tank 3 and the stirring tank 5 to collect the coating liquid from the receiving tank 3 that receives the overflowed coating liquid into the stirring tank 5.

An elevating device 10 for elevating and lowering the base 4 constituting the electrophotographic photosensitive member is provided so as to correspond to the coating tank 1. The elevating device 10 holds a conductive support 4 which is the above-mentioned cylindrical substrate, immerses the support 4 in a coating solution 1 in a coating tank 1, and lifts the support after immersion. And a ball screw 12 for driving the ball screw, and a motor 13 for driving the ball screw.

In the apparatus for manufacturing a photoreceptor shown in FIG. 2, the ball screw 12 for elevating and lowering is rotated via a ball screw driving motor 13 whose speed is controlled (rotational speed control) by a speed controller or the like. The support 4 attached to the body holding unit 11 is immersed in the coating liquid 2 by descending into the coating tank 1. Therefore, when the support 4 is immersed in the coating liquid 2, a part (upper part) of the coating liquid 2 in the coating tank 1 is formed.
Overflows, collects in the overflow receiving tank 3, and is collected in the stirring tank 5 via the collecting pipe 8.

As described above, the coating liquid 2 is supplied from the stirring tank 5 through the supply pipe 6 to the coating tank 1 by the action of the circulation pump 7, and overflows from the coating tank 1 in the dip coating, and overflows. The coating liquid is circulated to the stirring tank 5 via the recovery pipe 8.

Here, the coating solution 2 and the support 4 for forming a photosensitive layer on the support 4 will be described. The manufacturing apparatus for forming the photosensitive layer according to the present invention, that is, the manufacturing apparatus shown in FIG. 2 can be applied to either a single-layer type or a laminated type electrophotographic photoreceptor.

Here, the single-layer type is one in which a photosensitive layer is formed by one layer. The layered type is a layer in which layers having different functions are stacked, and a charge generating layer and a charge transport layer are stacked to form a photosensitive layer.

First, as the material of the conductive support 4 used in the present invention, a material having a conductive base itself, for example, aluminum, aluminum alloy, copper, zinc, stainless steel, nickel, titanium, etc. may be used. it can. In addition, a plastic or paper on which aluminum, gold, silver, copper, zinc, nickel, titanium, indium oxide, tin oxide, or the like is deposited, a plastic or paper containing conductive particles, a plastic containing a conductive polymer, or the like is used. be able to.

Between the conductive support 4 and the photosensitive layer, a well-known barrier layer (undercoat layer) which is usually used may be provided. As the barrier layer, for example, an anodized aluminum film, aluminum oxide, an inorganic layer such as aluminum hydroxide, an organic layer such as polyvinyl alcohol, ezein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, etc. Can be used.

Examples of the charge generating material used in the laminated charge generating layer constituting the photosensitive layer include bisazo compounds such as chlordian blue, polycyclic quinone compounds such as dibromoanthanthrone, perylene compounds, and the like. Quinacridone compounds, phthalocyanine compounds, azulenium salt compounds, and the like are known, and one or two or more of them can be used in combination.

In this charge generation layer, an electron-accepting material such as tetracyanoethylene, 7,7,
A cyan compound such as 8,8-tetracyanoquinodimenta,
Quinones such as anthraquinone and p-benzoquinone;
Nitro compounds such as 4,7-trinitrofluorenone and 2,4,5,7-tetranitrofluorenone, or dyes such as xanthene dyes, thiazine dyes and triphenylmeta dyes as optical sensitizers are added. Is also good.

The charge generation layer has a thickness of 0.0
It is 5-5 μm, preferably 0.1-1 μm.

As the resin for the binder resin solution of the charge generating material, well-known resins such as polyvinyl butyral, polycarbonate, polyester, polyarylate, phenoxy, epoxy, polystyrene, polymethyl methacrylate, polyvinyl chloride, silicone resin, etc. Is used. As a solvent for dissolving these resins, acetone, methyl ethyl ketone, ketones such as cyclohexanone, ethyl acetate, esters such as butyl acetate, ethers such as tetrahydrofuran, dioxane,
Aromatic hydrocarbons such as benzene, toluene and xylene,
An aprotic polar solvent such as N, N-dimethylformamide, dimethylsulfoxide and the like can be used.

Finally, the other charge transport layer constituting the laminated photosensitive layer is basically composed of a charge transport material and a binder resin.

As the charge transporting material in the charge transporting layer, conventionally known materials can be used.
Examples thereof include high molecular compounds such as polyvinyl carbazole and polysilane, and low molecular compounds such as hydrazone compounds, pyrazoline compounds, oxadiazole compounds, stilbene compounds, triphenylmethane compounds, and triphenylamine compounds.

As the binder resin used for the charge transporting layer, polycarbonate, polyester, phenoxy, epoxy, polystyrene, polymethyl methacrylate, polyvinyl chloride, silicone resin and the like are used.
Specific examples of the solvent include dichloromethane, halogen-based solvents such as 1,2 dichloroethane, esters such as acetone, ethers such as tetrahydrofuran and dioxane,
Aromatic hydrocarbons such as benzene, toluene and xylene,
An aprotic polar solvent such as N, N-dimethylformamide, dimethylsulfoxide and the like can be used.

The thickness of the charge transport layer is 5 to 50.
μm, and preferably about 10 to 40 μm.

As an additive to be added to the charge generation layer and the charge transport layer, an antioxidant may be added. Examples of the antioxidant include vitamin E, hydroquinone, hindered amine, hindered phenol, paraphenylenediamine, arylalkane and derivatives thereof,
Organic sulfur compounds and the like can be used.

In order to form an electrophotographic photosensitive member as described above, a coating solution for forming a barrier layer, a charge generation layer, a charge transport layer, etc. on the support 4 as described above in order to form a photosensitive layer. 2 is circulated and supplied in a state of being stored in each of the tanks 1 and 5 of the manufacturing apparatus shown in FIG. 1 to contribute to coating.

As the coating liquid 2, a solvent, a binder resin, and a photosensitive material, which are appropriately selected from the above-described materials and the like, are used after being mixed and dispersed.

In the present invention, the occurrence of coating unevenness and the like is prevented by preventing bubbles and the like at the time of replenishing the coating liquid 2 and supplying the solvent in order to make the viscosity of the coating liquid 2 constant. I am trying to do it.

Various embodiments for preventing the above and various examples for verifying the effects of the various embodiments will be described below.

(First Embodiment) In the manufacturing apparatus for manufacturing a photoconductor for electrophotography shown in FIG. 2, the stirring tank 5 will be described with reference to the detailed structure of the stirring tank in FIG. Is a method of stirring the coating liquid overflowed and collected from the coating tank 1 and the coating liquid or the solvent supplied from a replenishing device (supply pipe) 15 via a coating liquid replenishing section or a solvent replenishing section 14 as appropriate. A member 16 and a driving device 17 for driving the stirring member 16 are provided.

As described above, a part of the replenishing section 14 having a hollow cylindrical structure for partitioning is immersed in the coating liquid 2 in the stirring tank 5 in order to additionally supply the solvent or the coating liquid. It is provided as follows. A metal mesh 18 having a mesh shape is provided at an input port 14 a which is an opening of a cylindrical structure of the supply unit 14. Further, a detecting device for detecting shortage of the coating liquid 2 in the stirring tank 5 and performing additional replenishment of the coating liquid, or a detecting device 19 for detecting a viscosity state of the coating liquid 2 is provided.

The above-mentioned detecting device 19 is used for the coating liquid 2 in the stirring tank 5.
Is to detect the level of the coating liquid 2 stored in the stirring tank 5, and to detect the characteristics of the coating liquid 2, for example, the viscosity state. This is to detect viscosity.

The detecting device 19 compares the detected value with a reference value, outputs a signal when the detected value deviates greatly from the reference value, and replenishes the solvent or the coating liquid to the stirring tank 5 in order to replenish the solvent or the coating liquid. 45 is operated to control the supply via the supply unit 14. Thereby, in response to the detection result by the detection device 19, the amount of the coating liquid 2 in the stirring tank 5 or the viscosity of the coating liquid 2 can be controlled so as to be constantly maintained at a constant state.

As described above, when a solvent or a new coating liquid is supplied to the stirring tank 5, the coating liquid in the mixing tank 5 is supplied from the charging port 14 a through the cylinder partitioned from the stirring tank 5, that is, the supply section 14. 2 will be replenished. At this time,
The metal mesh 18 removes insolubles, dust, and the like contained in the liquid together, and suppresses the incorporation of bubbles generated when the liquid is poured into the coating liquid 2 in the stirring tank 5.

Thus, even if the coating liquid 2 in the stirring tank 5 is fed into the coating tank 1 by the action of the circulation pump 7, the influence of bubbles is eliminated, and coating defects are prevented.

Examples of manufacturing a photoreceptor by the photoreceptor manufacturing apparatus according to the first embodiment of the present invention and comparative examples for comparison with the examples will be described below. These examples and comparative examples will further clarify the functions and effects described in the first embodiment of the present invention described above.

Example 1 First, a conductive support (4)
The thickness is 1 mm, the diameter is 65 mm, and the axial length is 3.
A 48 mm aluminum cylindrical conductive support was used.

In order to form a charge generating layer constituting a photosensitive layer on the support (4), a charge generating material, a bisazo pigment (chlorodiane blue) represented by the following structural formula (Chemical Formula 1) 1.5 wt. Parts, phenoxy resin as binder resin (manufactured by Union Carbide: PKHH) 1.5 parts by weight,
A coating solution (2) for charge generation was prepared by dispersing a mixture of 97 parts by weight of 1,2-dimethoxyethane as a solvent with a paint shaker for 8 hours, and prepared a coating tank (2) of the manufacturing apparatus shown in FIG. 1) was satisfied.

[0056]

Embedded image

A cylindrical conductive support (4) made of aluminum is moved up and down by an elevating device (1) by a manufacturing apparatus as shown in FIG.
In 0), the charge generating layer was immersed in the coating solution (2) in the coating tank (1), pulled up at a predetermined speed, and coated so that the thickness of the support surface after drying was about 0.8 μm to form a charge generation layer. . In this case, as shown in FIG. 1, an application port (14a) of a replenishing section (14) is provided to replenish the application liquid (2) to a stirring tank (5) for circulating and supplying the application liquid (2). The metal mesh (17) used was a 500 mesh.
The 500 mesh is a state in which 500 wires (lines) are knitted vertically and horizontally in one inch.

After the formation of the charge generation layer as described above, a charge transport layer constituting another photosensitive layer is formed from above the charge generation layer. To this end, 1 part by weight of a hydrazone-based compound represented by the following structural formula (Chemical Formula 2) as a charge transport material, 1 part by weight of a polycarbonate resin (Iupilon, manufactured by Mitsubishi Gas Chemical Company, Ltd.) as a binder resin, and dichloromethane 8 as a solvent A charge transport layer coating solution (2) was prepared by stirring and dissolving a mixture of the mixture and a weight part, and the solution was filled in a coating tank (1) of a photoconductor manufacturing apparatus as shown in FIG. The support (4) having the charge generation layer formed thereon as described above is immersed in the coating tank (1) in the same manner as the formation of the charge generation layer.
The charge transport layer was formed such that the film thickness after lifting and drying was about 20 μm.

[0059]

Embedded image

In this way, 20 drum-shaped photoconductors for electrophotography were continuously manufactured. The prepared photoreceptor was visually inspected for defects. As a result, good photoconductors could be obtained in all cases without occurrence of coating defects due to mixing of insolubles, dust and bubbles.

Example 2 In Example 2, only when forming a charge generation layer, the stirring tank (5) shown in FIG. 1 was used.
The metal mesh (18) provided in the first embodiment is different from the metal mesh of the first embodiment in 500 mesh. Except for this point, 100 drum-shaped photoconductors were continuously manufactured in the same manner as in Example 1.

As a result of visually examining the photoreceptors produced as described above for defects, 95 out of 100 photoreceptors were found to be good photoreceptors.

Example 3 When preparing the charge generation layer and the charge transport layer, a metal mesh (18) was similarly provided for replenishment of the coating solution (2) as shown in FIG. A photoconductor was prepared in the same manner as in Example 2 except that the mesh was changed to a mesh.

As a result, 100 photoconductors were manufactured continuously in the same manner as in Example 2, and the defects were visually inspected.
93 out of 100 were good.

(Example 4) In Example 3, the solvent to be added to the coating liquid (2) in the stirring tank (5) was the same as that described above except that the solvent was additionally replenished and the rate of the additional replenishment was set to 1 cc / sec. In the same manner as in Example 3, 100 photoconductors were continuously produced.

Good results were obtained by replenishing the solvent as described above in order to adjust the viscosity of the coating solution (2) and replenishing it through the mesh (18) when controlling the viscosity to a constant. In particular, the compatibility with the coating solution was improved, and the incorporation of air bubbles was suppressed, and 97 good products out of 100 were obtained.

For this reason, when the additional supply control of the solvent is performed to control the viscosity, the effect is promoted by performing the additional supply at a speed of about 1 cc / sec, and at this time through the mesh.

(Example 5) In Example 2, when the coating liquid for forming the charge transport layer is replenished to the stirring tank (5), the liquid is supplied into the cylindrical replenishing portion (14) for replenishment. As shown in FIG. 3, a stirring member (20) is provided. The stirring member (20) is connected to the driving device (21) and is driven to rotate. In this way, replenishment is performed while simultaneously stirring the replenishment of the coating liquid (2). Further, 100 photoconductors were produced continuously in the same manner as in Example 2 except that 250 mesh was used as the metal mesh (18) at the time of replenishment.

As a result, 99 excellent photosensitive members could be obtained. In other words, in the additional replenishment of the coating liquid and the solvent, it is preferable that the replenishment is carried out while stirring at the same time before the replenishment into the stirring tank (5). Provided the best result.

On the other hand, various comparative examples will be described below in order to make a comparison with each of the above-mentioned Examples 1 to 5.

(Comparative Examples 1 and 2)
To replenish the coating liquid (2) etc., use a metal mesh (1
Without providing 7), 100 photoconductors were continuously manufactured in the same manner as in Examples 2 and 3.

As a result of visually examining the photoreceptor thus manufactured for the presence or absence of defects, nonuniform defects in the coating film due to the incorporation of bubbles, and streak-like spot irregularities, etc., occurred frequently.

Accordingly, by providing the mesh (18) at the portion corresponding to the inlet (14a) of the replenishing section (14) when the coating liquid (2) is additionally replenished, it is possible to suppress the incorporation of air bubbles and thereby to prevent coating defects. That is, the effect of preventing the above was confirmed.

(Comparative Example 3) In Example 4, the replenishing rate at the time of additionally replenishing the solvent for performing the viscosity adjustment control to the coating liquid (2) by the charge transport layer was 5 cc / sec.
100 photoconductors were produced continuously in the same manner as in Example 4 except that c was used.

As a result of visually inspecting the produced photoreceptor for defects, it was observed that many coating defects were generated as in Comparative Examples 1 and 2.

Comparative Example 4 The procedure of Example 2 was repeated, except that the mesh (18) provided at the inlet (14a) of the replenishing section (14) of the stirring tank (5) was a 50 mesh mesh. In the same manner as in Example 2, 100 photoconductors were produced continuously.

As a result of visually inspecting the produced photoreceptor for the presence or absence of a defect, a non-uniform defect of the coating film due to the inclusion of bubbles was generated.

Comparative Example 5 A photoconductor was prepared by the same method as that of Example 3 except that the mesh (18) provided in the stirring tank (5) was changed to 600 mesh.

At this time, when the coating liquid (2) is additionally supplied,
The coating liquid (2) to be additionally supplied enters the stirring tank (5) after a considerable time. As a result, the time required for the coating operation is increased and the manufacturing cost is increased.

That is, in the additional replenishment of the coating liquid (2) to the stirring tank (5), the replenishment is completed, and the coating liquid (2) in the stirring tank (5) is sufficiently mixed and stirred. (1)
To be circulated. Therefore, the production of the photoconductor is not performed during the additional replenishment.

Examples 1 to 5 and Comparative Examples 1 to 4
Table 1 shows the results.

[0082]

[Table 1]

As can be understood from Table 1 above, coating liquid 2
The additional supply of the solvent and the additional supply of the coating liquid for adjusting the viscosity of
By providing the metal mesh 18 at the charging port 14a, the incorporation of air bubbles is suppressed, insoluble matter and dust are prevented, and coating defects and the like can be significantly reduced.

In this case, the mesh 18 is 100
In order to smoothly supply the coating liquid 2 more than the mesh, it is optimal to set the mesh to 500 mesh or less, so that the object of the present invention can be achieved.

In the case where the metal mesh 18 is provided, when the coating liquid 2 has a high viscosity, particularly when a charge transport layer is formed, the effect is increased by providing the metal mesh 18 in the stirring tank 5. In other words, since the viscosity of the coating liquid 2 is high, bubbles are likely to be mixed during replenishment. However, if the metal mesh 18 is provided to perform additional replenishment of the coating liquid 2, coating defects can be reduced.

Further, when the coating liquid 2 is additionally replenished, a stirring member 20 is also provided in a cylindrical replenishing section 14 provided separately from the stirring tank 5, so that the coating liquid and the solvent to be additionally replenished can be reduced. And the unevenness of application can be further reduced. In particular, it is possible to prevent line-shaped sagging in the coating film.

When the solvent is additionally replenished due to a change in the viscosity of the coating liquid 2 in the stirring tank 5, the replenishment speed of the additional replenishment is set to about 1 cc / sec, thereby reducing the incorporation of bubbles. In particular, it can be understood from Comparative Example 4 that the coating defect frequently occurs at 5 cc / sec.

The replenishment unit 14 for performing additional replenishment
Means that a cylindrical member having a lower portion or an opening is provided so as to be immersed in the coating liquid 2, and the supply pipe 15 is immersed in the coating liquid in the supply section 14 when the coating liquid 2 and the solvent are supplied. Thus, the incorporation of bubbles taken in when the replenishing liquid collides with the coating liquid 2 can be prevented.

(Second Embodiment) In the additional replenishment of the coating liquid 2 in the first embodiment described above, the stirring tank 5
The replenishing unit 14 is immersed in the application liquid 2 of
4a, a metal mesh is provided at the input port 14a, and the mixture is stirred and mixed by the stirring member 16 with the additionally supplied coating liquid 2 and the like. In particular, the stirring member 16 is fixedly disposed at the bottom of the stirring tank 5 and is fixed at a constant stirring speed, particularly at a rotation speed.

In the second embodiment, the stirring tank 5
The stirrer 22 as a stirrer is configured to move up and down according to the amount of the coating liquid 2. The stirring blades 22
The coating solution 2 is connected to a driving device 23 and is rotationally driven by the driving device 23 to stir and mix the coating liquid 2 in the stirring tank 5.
The driving device 23 controls the rotation speed of the stirring blade 22 according to, for example, the amount of the coating liquid 2 and moves the stirring blade 22 up and down. Other structures are the same as those shown in FIG.

In such a configuration, the stirring blade 2
2 is adjusted and controlled in position according to the amount of the coating liquid 2 in the stirring tank 5. For example, when the amount of the coating liquid 2 in the stirring tank 5 decreases, the coating liquid 2 descends to the lower position, and when the amount of the coating liquid 2 increases, moves to the upper position. And the coating liquid 2
The rotation speed for stirring is controlled in accordance with the amount of. That is, when the amount of the coating liquid 2 is small, the stirring speed, that is, the rotation speed, is decreased, and when the amount of the coating liquid 2 is large, the rotation speed of the stirring blade 22 is controlled to be increased.

With this configuration, it is possible to suppress the reduction of the coating liquid 2 and the rebound of the coating liquid 2 generated by the stirring blades 22, thereby preventing the generation and mixing of bubbles, thereby achieving stable and efficient stirring. Can be performed.

The above-described stirring is positively performed by replenishing the coating liquid 2, and the aggregating port 14a as shown in FIG. A metal mesh 18 is provided. This metal mesh 18 is the same as that described in the first embodiment, and it is possible to prevent air bubbles from being mixed at the time of replenishment and prevent coating defects due to this.

Further, in the apparatus as shown in FIG. 5, a floating mechanism 24 is separately connected to a vertically movable stirring blade 22. That is, the stirring blade 22 is mechanically connected to the driving device 23 and can move up and down. The stirring blade 22 is connected to the floating mechanism 24 and the floating mechanism 2
4 in conjunction with the floating state.

That is, the floating mechanism 24 is configured to float in the coating liquid 2 and move up and down according to the level of the liquid.

Therefore, the stirring blade 22 is moved up and down in accordance with the level of the liquid surface of the coating liquid 2, and there is no need to detect the liquid surface and move it up and down. The control by the driving device 23 for vertically moving the stirring blade 22 is not required, and the mechanism for vertically moving the stirring blade 22 becomes very simple.

Therefore, in FIG.
This is the case where the amount of the coating liquid 2 is large, and the levitation mechanism 24 rises in accordance with the amount, and the stirring blades, that is, the stirring members 22 are also raised to the upper position in conjunction with this.

Then, the coating liquid 2 gradually decreases as the photoreceptor is manufactured, and the coating liquid 2 in the stirring tank 5 also decreases. Therefore, the liquid level of the coating liquid 2 in the stirring tank 5 drops. At this time, as shown in FIG. 5B, the floating mechanism 24 simultaneously lowers due to the lowering of the liquid level, so that the stirring blade 22 also lowers to the lower position.

With such a configuration, as described with reference to FIG. 4, when the coating liquid 2 is stirred, bubbles are prevented from being mixed in by the repulsion of the stirring blades 22, and coating defects due to this can be prevented.

Further, the stirring tank 5 is provided with a detecting device for adjusting the viscosity of the coating liquid 2, and a solvent is additionally supplied as needed for adjusting the viscosity. In this case, in the embodiment of the present invention, the replenishing unit 1 for replenishing
Although the metal mesh 18 is provided in the input port 14a of No. 4,
In addition, by providing a spraying means and supplying in a mist state, it is possible to prevent air bubbles from entering.

FIG. 6 shows an example. In FIG. 6, the mechanism for replenishing the solvent is different from the mechanism for providing the metal mesh described above, and the other mechanisms are completely the same.

In FIG. 6, as a configuration for supplying the solvent, a spray nozzle 25 constituting a replenishing spray means for replenishing the solvent by spraying is provided. From the spray nozzle 25, replenishment control is performed via the replenishment device 15 in accordance with the viscosity detection signal from the detection device 19.

According to the spray replenishment by the spray nozzle 25, the compatibility with the coating liquid 2 in the stirring tank 5 can be further improved, and the mixing with the coating liquid 2 can be uniformly performed by the stirring member 16, while the mixing of bubbles is completely prevented. Can be held down.

In order to confirm the effect of the second embodiment, an example in which the above-described stirring tank 5 shown in FIGS. 4 to 6 is used will be described below.

Example 6 First, a conductive support (4)
A cylindrical conductive support made of aluminum having a thickness of 1 mm, a diameter of 30 mm, and a length of 245 mm in the rotation axis direction was used.

In order to form a charge generation layer constituting a photosensitive layer on the support (4), 2 parts by weight of an X-type inorganic metal phthalocyanine pigment represented by the following structural formula (Chemical Formula 3), which is a charge generation material, was used. A charge generating coating liquid (2) prepared by dispersing a mixture of 1 part by weight of a polybitilal resin (Eslek BMS manufactured by Sekisui Chemical Co., Ltd.) and 100 parts by weight of tetrahydrofuran as a solvent in a ball mill for 8 hours was used. It was adjusted. The coating liquid (2) was filled in the coating tank (1) of the manufacturing apparatus shown in FIG. Then, the coating liquid 2 was circulated and supplied from a stirring tank 5 having a structure as shown in FIG. In particular, stirring was performed by moving the stirring blade (22) up and down according to the amount of the coating liquid (2).

[0107]

Embedded image

A cylindrical conductive support (4) made of aluminum is immersed in a coating solution (2) of a coating tank (1) by an elevating device (10) using a photoconductor manufacturing apparatus as shown in FIG. ,
After drying, the resultant was coated so as to have a thickness of about 0.4 μm to form a charge generation layer on the surface.

After forming the charge generation layer as described above, a charge transport layer constituting another photosensitive layer is formed from above the charge generation layer. For this purpose, 1 part by weight of a still-based compound represented by the following structural formula (Formula 4) as a charge transport material, 1 part by weight of a polycarbonate resin (Iupilon, manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a binder resin, and dichloromethane 8 as a solvent The mixture was stirred and dissolved with a magnetic stirrer to prepare a coating liquid (2) for the charge transport layer. The coating liquid (2) is filled in a coating tank (1) of a manufacturing apparatus as shown in FIG. 2, and a charge is applied to a support (4) having a charge generation layer formed thereon as described above. Similarly to the formation of the generating layer, the charge transport layer was formed so that the film thickness after dipping, lifting and drying was about 25 μm. In this case, the coating liquid (2) was supplied to the coating tank (1) by using a stirring tank (5) having a structure as shown in FIG.

[0110]

Embedded image

In this way, 100 drum-shaped photoconductors for electrophotography were continuously manufactured. The prepared photoreceptor was visually inspected for defects. As a result, 97 good photoconductors could be obtained without causing coating defects due to the inclusion of air bubbles.

(Example 7) In particular, only when a charge transport layer is prepared, the coating liquid (2) is supplied to the coating tank (1) by using the stirring tank 5 having the structure shown in FIG. Except for the above, 100 photoconductors were continuously produced in the same manner as in Example 6.

Further, as shown in FIG. 5, the height of the stirring blade (22), which is a stirring member, is adjusted according to the amount of the coating liquid (2) by the floating mechanism (24) according to the coating liquid level. Accordingly, the stirring speed, that is, the rotation speed of the stirring blade (22) was increased when the liquid amount was large, and was decreased when the liquid amount was small.

As a result of visually examining the defects of the 100 photoconductors thus manufactured, 96 good products out of 100 were obtained. As described above, the position of the stirring member (22) and the stirring ability (rotation speed) of the stirring member (22) are adjusted by the flotation mechanism (24) in accordance with the decrease of the coating liquid (2), so that the coating liquid decreases. Thus, a stable supply of the coating liquid can be performed, and at this time, the incorporation of air bubbles can be suppressed, and the coating defects caused thereby can be prevented.

Example 8 When forming the charge generation layer and the charge transport layer, a solvent was used to control the viscosity of the coating solution (2) in the stirring tank (5) to be constant as shown in FIG. Replenish as needed. Refill the spray nozzle (2
Example 6 except that the fuel was supplied by spraying via 5).
As described above, 100 photoconductors were continuously manufactured.

As a result, the produced photoreceptor was visually inspected for defects. As a result, 99 non-defective products could be obtained. In other words, it has been found that by supplying the solvent by spraying and controlling the viscosity adjustment, it is possible to prevent air bubbles from being mixed in, thereby suppressing coating defects as much as possible.

Table 2 shows the results of Examples 7 to 9 described above.

[0118]

[Table 2]

As shown in Table 2 above, non-defective photoreceptors could be manufactured at a considerably high rate in any of them. In particular, it is possible to prevent air bubbles from entering and obtain a photoconductor free from coating defects. In addition, in the case of additionally replenishing the solvent, by replenishing the coating liquid 2 in the stirring tank 5 in the form of a mist, the compatibility with the coating liquid 2 can be improved, and the incorporation of bubbles can be minimized. .

[0120]

According to the dip coating apparatus of the present invention, in the replenishment of the solvent and the replenishment of the coating liquid, the incorporation of air bubbles can be suppressed, and the coating defects caused thereby can be suppressed. A simple photoreceptor can be easily obtained.

In particular, when a solvent or the like is additionally replenished, the effect is further promoted by providing a mesh and limiting the mesh to a specific mesh. In this case, when the solvent is additionally replenished, the replenishment rate is further limited, so that the reconstitution with the coating liquid can be performed well, the incorporation of air bubbles is eliminated, and the effect is further promoted.

In order to additionally replenish the solvent or the coating liquid, a replenishing section is provided in the stirring tank and a stirring member for stirring the replenishing liquid and the like supplied to the replenishing section is provided, so that compatibility with the coating liquid can be improved. Further, a photosensitive member having a high non-defective rate and a high non-defective rate can be easily obtained.

Further, by moving the stirring member in the stirring tank up and down according to the state of the coating liquid surface, the stirring effect is enhanced and at the same time, the mixing of air bubbles due to the rebound of the coating liquid at the time of stirring can be prevented. .

On the other hand, when the additional replenishment of the solvent is performed, by performing the replenishment in the form of a mist, the compatibility with the coating liquid is further improved, and the effect of preventing bubbles from being mixed is further increased.

[Brief description of the drawings]

FIG. 1 is a view for explaining a first embodiment of the present invention, and is a configuration diagram showing a structure of a stirring tank constituting a part of a photoconductor manufacturing apparatus.

FIG. 2 is a configuration diagram showing a structure of a photoconductor manufacturing apparatus according to the present invention.

FIG. 3 is a configuration diagram of a stirring tank showing another embodiment in the first embodiment of the present invention.

FIG. 4 is a view for explaining a second embodiment of the present invention, and is a configuration diagram showing a structure of a stirring tank constituting a part of a photoconductor manufacturing apparatus.

FIG. 5 is a configuration diagram showing another structure of a stirring tank for explaining a second embodiment of the present invention.

FIG. 6 is a configuration diagram showing another structure of a stirring tank for explaining a second embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 coating tank 2 coating liquid 3 overflow receiving tank 4 conductive support (substrate) 5 stirring tank 6 supply pipe 7 circulation pump 8 recovery pipe 10 elevating device 14 replenishing unit 14a input port 15 replenishing device 16 stirring member 18 metal Mesh 19 Detector 20 Stirring member 22 Stirring blade (stirring member) 23 Drive unit 24 Floating mechanism 25 Spray nozzle (spraying means)

Continued on the front page (72) Inventor Jun Yamaguchi 22-22, Nagaikecho, Abeno-ku, Osaka City, Osaka Inside Sharp Corporation (72) Inventor ▲ Taka ▼ Tanihiko 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp Inside the corporation

Claims (6)

[Claims] 1. A coating solution obtained by mixing a binder resin and a photosensitive material with a solvent is accommodated, and the accommodated coating solution is applied to the surface of a conductive support to form a photosensitive layer having a predetermined thickness. A photoreceptor manufacturing apparatus for manufacturing a photoreceptor for electrophotography, comprising: a stirrer for containing the coating solution for supplying the coating solution to the coating tank, and stirring the coating solution. An apparatus for manufacturing a photoreceptor, wherein a mesh is provided at a portion where a coating liquid or a solvent for adjusting the viscosity of the coating liquid is charged into a tank. 2. The apparatus according to claim 1, wherein the mesh provided in the charging portion is set to 100 mesh or more and 500 mesh or less. 3. The apparatus according to claim 1, wherein the liquid to be additionally replenished to the stirring tank is a solvent, and the replenishing speed of the solvent is set to 1 cc / sec or less. 4. A replenishing section, which is separated from the stirring tank, is provided in the charging section, and a stirring member for stirring a coating liquid or a solvent supplied to the replenishing section is provided.
An apparatus for manufacturing the photosensitive member according to the above. 5. The apparatus according to claim 1, wherein the agitating member provided in the agitating tank for agitating the coating liquid is provided with a flotation mechanism for floating according to the amount of the coating liquid. 6. A coating solution obtained by mixing a binder resin and a photosensitive material with a solvent is accommodated, and the accommodated coating solution is applied to the surface of a conductive support to form a photosensitive layer having a predetermined thickness. A photoreceptor manufacturing apparatus for manufacturing a photoreceptor for electrophotography, comprising: a stirrer for containing the coating solution for supplying the coating solution to the coating tank, and stirring the coating solution. An apparatus for manufacturing a photoreceptor, comprising: spraying means for supplying a solvent for adjusting the viscosity of a coating solution into a tank when the solvent is supplied in the form of a mist.