JPH04267260A - Manufacture of photosensitive body - Google Patents

Abstract

PURPOSE:To obtain photosensitive body free from fatigue deterioration of electrophotographic characteristics and excellent in wear resistance by coating the outermost layer, at least, of a laminated sensitive layer by means of a circular stype hopper applicator. CONSTITUTION:At least an outermost layer of a laminated sensitive layer of a photoconductor which has a photosensitive layer with a charge conveying layer 3, laminated consisting of a charge generating layer 2 and plural constituent layers on a conductive cylindrical base 1, is coated by a circular slide hopper applicator, a circular extruding applicator or circular little dipping applicator. Therefore, application workability and productivity are improved and, what is more, the obtained photosensitive body does not cause uneven images strips, spots, etc., thus it has excellent electrophotographic performance and durability at the time of repeated use.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a photoreceptor which is free from fatigue deterioration of electrophotographic properties and has excellent abrasion resistance.

0002

[Prior Art] In an electrophotographic copying machine using the Carlson method, after the surface of a photoreceptor is charged, an electrostatic latent image is formed by exposure, and the electrostatic latent image is developed with toner, and then the visible Transfer and fix the image onto paper, etc. At the same time, the photoreceptor is subjected to removal of adhered toner, neutralization of static electricity, and surface cleaning, and is used repeatedly over a long period of time.

Therefore, as an electrophotographic photoreceptor, it is important not only to have electrophotographic properties such as good charging characteristics and sensitivity, and low dark decay, but also physical properties such as printing durability, abrasion resistance, and moisture resistance after repeated use. It is also required to have good properties and resistance to ozone generated during corona discharge, ultraviolet rays during exposure, etc. (environmental resistance).

Conventionally, electrophotographic photoreceptors include selenium,
Inorganic photoreceptors having a photosensitive layer mainly composed of an inorganic photoconductive substance such as zinc oxide or cadmium sulfide are widely used. On the other hand, the use of various organic photoconductive substances as materials for photosensitive layers of electrophotographic photoreceptors has been actively developed and researched in recent years.

For example, Japanese Patent Publication No. 50-10496 describes an organic photoreceptor having a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-trinitro-9-fluorenone. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability. In order to improve these drawbacks, organic photoreceptors with high sensitivity and durability have been developed by assigning the carrier generation function and carrier transport function to different substances in the photosensitive layer. There is. In such functionally separated electrophotographic photoreceptors, it is possible to independently select substances that exhibit each function, so it is relatively easy to produce electrophotographic photoreceptors with arbitrary characteristics. be.

According to such an organic electrophotographic photoreceptor,
Manufacturing costs are low because the photosensitive layer can be formed by coating.
It can also prevent pollution and environmental contamination, and can be easily processed into various shapes (sheet shapes, etc.).

However, organic electrophotographic photoreceptors have the following drawbacks, and there is a strong demand for solutions to these drawbacks.

(a) For example, since the layer is formed by binding a low-molecular organic compound with a high-molecular organic resin (binder), the mechanical strength is not necessarily sufficient, and when the photoreceptor is used repeatedly, The surface of the photoreceptor may be scratched or worn due to the rubbing of the cleaning blade.

(b) The photoreceptor is mainly used for negative charging, and as described in JP-A No. 60-247647, a thin carrier generation layer is provided on the support, and a relatively thick carrier is formed on the support. A configuration is adopted in which a transport layer is provided.

[0010] The reason for this is that in the case of using negative charging, the mobility of holes among carriers is high, so hole transporting materials can be used, which is advantageous in terms of photosensitivity, etc. This is because there are almost no transportable materials with excellent properties, or they are carcinogenic or teratogenic, so they cannot be used.

However, during negative corona discharge or negative charging by a charger, a large amount of ozone is generated in the atmosphere, resulting in deterioration of environmental conditions. This causes adsorption of ionic substances to the photoreceptor surface and deterioration of the material of the photoreceptor surface, resulting in a decrease in potential during repeated use, resulting in an increase in residual potential, a decrease in sensitivity, and a decrease in image quality. Decreases the life of the photoreceptor.

(c) Equipment such as electrophotographic copying machines are used for long periods of time under various conditions and are often placed under conditions of high temperature and high humidity. Therefore, it is desired to develop a photoreceptor that is resistant to fatigue deterioration due to repeated charging and exposure, has high mechanical abrasion resistance, and has high environmental resistance.

Therefore, for example, JP-A-2-160247 and JP-A-2-257142 disclose a photosensitive layer having a charge generation layer as a lower layer and a charge transport layer consisting of a plurality of constituent layers provided on the charge generation layer. A photoreceptor has been proposed in which the concentration of the charge transport substance in the charge transport layer is high in the constituent layers close to the underlying charge generation layer and small in the constituent layers far away. The disclosed technique describes that by configuring the photoreceptor as described above, a photoreceptor having excellent electrophotographic properties and particularly high durability can be obtained.

[0014]

Problems to be Solved by the Invention The photoelectric and mechanical durability and other environmental resistance of a photoreceptor are particularly closely related to the quality of the coating process of the surface layer of the photoreceptor. That is, if the lower layer is dissolved during coating of the surface layer, the coating film is destroyed, the functions of the surface layer and the lower layer are lost, and the performance of the photoreceptor is not achieved. Also, if unevenness, streaks, spots, unevenness, etc. occur during the application of the surface layer, the electrophotographic performance will differ partially or locally, resulting in image unevenness, deteriorating the image quality, and reducing the photoelectric and mechanical durability. also decreases.

Conventionally, various coating methods have been used to coat and form an organic photoconductive photosensitive layer, such as dip coating, blade coating, spin coating, beam coating, and spiral coating. The dip coating method, in which the object to be coated is immersed in a tank filled with a large amount of coating liquid, is the most popular method because it can easily produce a smooth coating film.

However, in the dip coating method, the lower layer is dissolved when the photosensitive layer is coated in layers. In particular, when the photosensitive layer is composed of a plurality of substantially identical constituent layers and an upper constituent layer is coated, the lower constituent layers are significantly damaged by dissolution and the electrophotographic performance is impaired. In addition, in the dip coating method, the objects to be coated are immersed one by one in a tank containing a large amount of coating solution, so there is a lot of wasted coating solution, and the coating efficiency is low. Problems also arise, such as variations in electrophotographic performance due to changes in the coating liquid within.

[0017]

[Means for Solving the Problems] An object of the present invention is to provide a method for manufacturing a photoreceptor that can provide a photoreceptor with high image quality and high durability.

The object of the present invention is to manufacture a photoreceptor in which a photoreceptor is provided with a photosensitive layer in which a charge generation layer and a charge transport layer consisting of a plurality of constituent layers are laminated on a conductive cylindrical support. Both are achieved by a method for manufacturing a photoreceptor, characterized in that the outermost layer is coated using a circular slide hopper coater, a circular extrusion coater, or a circular small-volume dipping coater.

In an embodiment of the present invention, the photosensitive layer comprises:
It is preferable to adopt a layer structure in which a plurality of charge transport layers are provided on the charge generation layer, and the concentration of the charge transport substance to the binder in each layer of the charge transport stack is made smaller as the layer is further away from the charge generation layer.

That is, in the present invention, the charge transport layer is constructed by laminating a plurality of layers, and preferably the concentration of the charge transport substance in the constituent layers closer to the lower charge generation layer is higher, and the higher the charge is in the upper constituent layers closer to the surface side of the photosensitive layer. By reducing the concentration of transport substances, the photoreceptor is resistant to environmental changes and has high durability.

Further, in the present invention, at least in a photosensitive layer having a laminated structure, the overlying constituent layer can be coated at high speed without giving time for dissolving in the lower constituent layer, and the circular shape allows for uniform coating. A slide hopper coater, circular extrusion coater, or circular small volume dip coater is selected to provide a photoreceptor with high image quality and high durability.

[0022] Examples of the charge transport substance contained in the charge transport layer according to the present invention include oxazole derivatives,
Oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazoline derivatives, styryl compounds, hydrazone compounds, pyrazoline derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives , benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-
Vinyl carbazole, poly-1-vinylpyrene, poly-
Examples include 9-vinylanthracene.

Among the charge transport substances, particularly preferred are carbazole derivatives of general formula (1), hydrazone compounds of general formulas (2) to (5), pyrazoline derivatives of general formula (6), and general formula (7). ) and amine derivatives of general formula (8).

[0024]

[Chemical formula 1]

However, in this general formula, R1 is a substituted or unsubstituted aryl group, R2 is a hydrogen atom, a halogen atom,
Substituted or unsubstituted alkyl group, alkoxy group, amino group, hydroxyl group, substituted amino group, R3 represents a substituted or unsubstituted aryl group, substituted or unsubstituted heterocyclic group.

[0026]

[Case 2]

In the general formula (2), R4 and R5 each represent a hydrogen atom or a halogen atom, R6 and R7 each represent a substituted or unsubstituted aryl group, and Ar1 represents a substituted or unsubstituted arylene group.

In the general formula (3), R8 is a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, and R9 is a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. The group Q represents a hydrogen atom, a halogen atom, an alkyl group, a substituted amino group, an alkoxy group or a cyano group, and p represents an integer of 0 or 1.

In the general formula (4), R10 is a substituted or unsubstituted aryl or a substituted or unsubstituted heterocyclic group, R11 is a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, X represents a hydrogen atom, a halogen atom, an alkyl group, a substituted amino group, an alkoxy group, or a cyano group, and q represents an integer of 0 or 1.

In the general formula (5), R12 and R13 represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.

Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, etc.; examples of the aralkyl group include benzyl group, phenethyl group; and examples of the aryl group include phenyl group, α-naphthyl group, Examples include β-naphthyl group. As a substituent, a halogen atom,
Examples include an alkyl group, an alkoxy group, a substituted amino group (dimethylamino group, diethylamino group, dipropylamino group, dibenzylamino group), and the like. Further, D represents a substituted or unsubstituted phenyl group or a substituted or unsubstituted carbazolyl group. Specifically, the above-mentioned groups are mentioned, and R
14, R15, and R21 represent the same as R12 and R13. R16, R17, R18, R19, R20, and R22 represent an alkyl group, an alkoxy group, a halogen atom, or the like.

[0032]

[Chemical formula 3]

In the general formula (6), l is an integer of 0 or 1, R23, R24, and R25 are substituted or unsubstituted aryl groups, R26 and R27 are hydrogen atoms, and have 1 to 4 carbon atoms.
or a substituted or unsubstituted aryl group or aralkyl group (however, R26 and R27 are not both hydrogen atoms, and when l is 0, R26 is not a hydrogen atom).

In the general formula (7), R28 and R29 represent a substituted or unsubstituted alkyl group or phenyl group, and an alkyl group, an alkoxy group, or a phenyl group is used as the substituent. R30 represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group, fluorenyl group, or heterocyclic group, and the substituents include an alkyl group, an alkoxy group,
A halogen atom, hydroxyl group, or phenyl group is used. R31 represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a phenyl group. R32, R33, R34, and R35 represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an alkylamino group.

In the general formula (8), Ar2 and Ar3 represent a substituted or unsubstituted phenyl group, and a halogen atom, an alkyl group, a nitro group, or an alkoxy group is used as a substituent. Ar4 represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group, fluorenyl group, or heterocyclic group, and substituents include an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, an aryloxy group, an aryl group, an amino group, Nitro groups, piperidino groups, morpholino groups, naphthyl groups, anthryl groups and substituted amino groups are used. However, as a substituent for a substituted amino group, an acyl group, an alkyl group,
An aryl group or an aralkyl group is used.

Specific examples of compounds included in the general formulas (1) to (8) are listed in JP-A-60-172044, page 6, bottom right column, line 2 to page 21, top right column, line 20. It is described in.

Next, the charge generating substances contained in the charge generating layer of the present invention include: (1) Azo pigments such as monoazo pigments, polyazo pigments, metal complex azo pigments, pyrazolone azo pigments, stilbene azo pigments, and thiazole azo pigments. (2) Perylene pigments such as perylene anhydride and perylene imide (3) Anthraquinone derivatives, anthorone derivatives, dibenzpyrenequinone derivatives, pyrantrone derivatives,
Anthraquinone or polycyclic quinone pigments such as violanthrone derivatives and isoviolanthrone derivatives (4) Indigoid pigments such as indigo derivatives and thioindigo derivatives (5) Phthalocyanine pigments such as metal phthalocyanines and metal-free phthalocyanines (6) Diphenylmethane pigments Pigments, carbonium pigments such as triphenylmethane pigments, xanthene pigments and acridine pigments (7) quinone imine pigments such as azine pigments, oxazine pigments and thiazine pigments (8) methine pigments such as cyanine pigments and azomethine pigments (9) quinoline Pigments (10) Nitro pigments (11) Nitroso pigments (12) Benzoquinone and naphthoquinone pigments (13)
Naphthalimide pigments (14) Perinone pigments such as bisbenzimidazole derivatives are included. Among the various pigments mentioned above, particularly preferred charge generating substances include polycyclic quinone pigments represented by the following general formulas (9) to (11).

[0038]

[C4]

In each of the above general formulas, X represents a halogen atom, a nitro group, a cyano group, an acyl group or a carboxyl group,
n represents an integer of 0 to 4, and m represents an integer of 0 to 6.

[0040] Furthermore, bisazo compounds of the following general formulas (12) to (14) can be used as charge generating substances.

[0041]

[C5]

In this general formula (12), Ar5 and Ar6 are each substituted or unsubstituted carbocyclic aromatic ring group, or substituted or unsubstituted heterocyclic aromatic ring group, R36
, R37 are each an electron-withdrawing group or a hydrogen atom (however,
At least one of R36 and R37 is -CN, a halogen such as -Cl, an electron-withdrawing group such as -NO2), and X of A is -OH group, -N(R39)-R40 or -NHSO2
R41 (R39 and R40 are each a hydrogen atom, a substituted or unsubstituted alkyl group, R41 is a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group), Y is a hydrogen atom, a halogen atom, a substituted or an unsubstituted alkyl group, an alkoxy group, a carboxyl group, a sulfo group, a substituted or unsubstituted carbamoyl group, or a substituted or unsubstituted sulfamoyl group (however, when m is 2 or more, different groups may be used) ), Z is an atomic group necessary to constitute a substituted or unsubstituted carbocyclic aromatic ring group or a substituted or unsubstituted heterocyclic aromatic ring group, R38 is a hydrogen atom, substituted or unsubstituted amino group, substituted or unsubstituted carbamoyl group, carboxyl group or ester group thereof, B is a substituted or unsubstituted aryl group, n is an integer of 1 or 2, m is 0 to 4
is an integer.

Among the general formulas (12), particularly preferred charge generating substances are shown in the following general formula (12a).

[0044]

[C6]

(However, Ar7, Ar8 and A have the general formula (
12). ) More preferred are Ar7 in general formula (12a),
Ar8 represents a substituted or unsubstituted phenyl group, and examples of substituents include alkyl groups such as methyl group and ethyl group, alkoxy groups such as methoxy group and ethoxy group, halogen atoms such as chlorine atom and bromine atom, hydroxyl group, and cyano group. A compound selected from the group

Further, a preferable charge generating substance in the charge generating layer according to the present invention is represented by the following general formula (13).

[0047]

[C7]

In the above A, Z is an atomic group necessary to constitute a substituted or unsubstituted aromatic carbocycle or a substituted or unsubstituted aromatic heterocycle, and Y is a hydrogen atom, a hydroxyl group, a carboxyl group, or an ester thereof. group, a sulfo group, a substituted or unsubstituted carbamoyl group, or a substituted or unsubstituted sulfamoyl group, R42 is a hydrogen atom,
Substituted or unsubstituted alkyl group, substituted or unsubstituted amino group, substituted or unsubstituted carbamoyl group, carboxyl group or its ester group, or cyano group, Ar9 is substituted or unsubstituted aryl group, R43 is substituted or unsubstituted It represents a substituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.

Of the general formula (13), the following general formula (1)
Particularly preferred are bisazo compounds having a carbazole group in 3a).

[0050]

[Chemical formula 8]

In the general formula (13a), R44, R45
is an alkyl group, an alkoxy group or an aryl group, R46,
R47, R48, R49, R50, R51 are hydrogen atoms,
halogen atom, alkyl group, alkoxy group, amino group,
They are hydroxyl group and aryl group.

Further, a preferable charge generating substance in the charge generating layer according to the present invention is represented by the following general formula (14).

[0053]

[Chemical formula 9]

In the general formula (14), X1 and X2 are
respectively, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group,
It represents a cyano group, a hydroxy group, or a substituted or unsubstituted amino group, and at least one of X1 and X2 is a halogen atom.

p and q each represent an integer of 0, 1 or 2, p and q are never 0 at the same time, and p
When q is 2, X1 may be the same or different groups, and when q is 2, X2 may be the same or different groups.

Furthermore, Ar10 of A represents an aromatic carbocyclic group or an aromatic heterocyclic group having at least a fluorinated hydrocarbon group. Z represents a group of nonmetallic atoms necessary to form a substituted or unsubstituted aromatic carbocycle or a substituted or unsubstituted aromatic heterocycle.

m and n each represent an integer of 0, 1 or 2. However, m and n never become 0 at the same time.

The halogen atoms represented by X1 and X2 in general formula (14) include chlorine atom, bromine atom, fluorine atom, and iodine atom. At least one of X1 and X2 has a halogen atom.

The alkyl group represented by X1 and X2 is preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. Examples of such alkyl groups include methyl group, ethyl group, β -cyanoethyl group, i
Examples include so-propyl group, trifluoromethyl group, t-butyl group, and the like.

The alkoxy group represented by X1 and X2 is preferably a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms, and examples of such alkoxy groups include methoxy group, ethoxy group, Examples include β-chloroethoxy group and sec-butoxy group.

Furthermore, substituted or unsubstituted amino groups represented by X1 and X2 include, for example, alkyl groups,
those substituted with an aryl group (preferably a phenyl group), such as an N-methylamino group, an N-ethylamino group,
N,N-dimethylamino group, N,N-diethylamino group, N-phenylamino group, N,N-diphenylamino group, and further acetylamino group substituted with acyl group, p
-chlorobenzoylamino group and the like. In the general formula (14), p and q each represent 0, 1 or 2, but p and q are never 0 at the same time, preferably p = 1, q = 0 or p = 1, q This is the case when =1.

Furthermore, when p or q is 2, X1 or X2 can be the same or different groups, respectively.

The bisazo compound represented by the general formula (14) is preferably represented by the following general formulas (14a) and (14b).
, (14c), (14d).

[0064]

[Chemical formula 10]

[0065]

[Chemical formula 11]

In the above formula, X1a, X1b, X2a and X2b each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxy group, or a substituted or unsubstituted alkyl group. Represents an unsubstituted amino group, X1a, X1b, X2
At least one of a and X2b is a halogen atom. X1a and X1b, and X2a and X2
b may be the same or different groups.

Ar1 is Ar in the general formula (14)
It is synonymous with 10.

Y has the same meaning as the substituent for Z in the general formula (14).

The bisazo compound represented by the general formula (14) can be easily synthesized by a known method.

[0070] Furthermore, the above general formulas (9) to (14)
Specific compound examples include, for example, JP-A-60-172044.
No. 23, bottom right column, line 1 to page 46, top right column, line 8.

Among the phthalocyanine pigments, pigments preferably used in the present invention include, for example, metal phthalocyanines containing copper, cobalt, lead, zinc, etc. as central atoms, and metal-free phthalocyanines that do not contain these. Preferably, α-type, β-type, γ-type, X-type, τ-type, τ'-type, η-type, η'-type, etc. are used. Further detailed descriptions of such phthalocyanine pigments are given in JP-A-62-79470 and JP-A-62-47054.

A particularly preferred phthalocyanine pigment is a black angle of 2 in the CuKα characteristic X-ray diffraction spectrum.
θ is at least 9.6±0.2° and 27.2±0.2°
There are titanyl phthalocyanine pigments in a crystalline state that exhibit peaks in X-ray intensity at .

1 to 4 show the layer structure of the photoreceptor according to the manufacturing method of the present invention, in which 1 is a conductive support, 2 is a conductive support, and 2 is a conductive support.
3 is a charge generation layer, and 3 is a charge transport layer consisting of a plurality of constituent layers, and the plurality of constituent layers are a lower constituent layer 3A and an upper constituent layer 3.
B (3C), and 6 is an intermediate layer.

To manufacture a cylindrical photoreceptor having the above-described layer structure, first, a conductive layer is formed by steaming or laminating a metal on a metal cylinder such as aluminum, steel, stainless steel, copper, brass, zinc, or a plastic cylinder. An intermediate layer 6 having a thickness of 0.01 to 2 μm is provided on the cylindrical support 1 as required.

[0075] The intermediate layer 6 is made of, for example, polyamide resin,
Acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride -Vinyl acetate-maleic anhydride copolymer resin, cellulose resin, polyvinyl alcohol resin, casein and other resins such as butylamine, diethylamine, ethylenediamine, isopropanolamine, monoethanolamine, triethanolamine, triethylenediamine, N,N-dimethyl Dissolved in organic solvents such as formamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, etc. The resulting resin solution is applied by a coating method such as blade coating, roll coating, spin coating, dip coating, circular slide hopper coating, circular extrusion coating, and small circular dip coating.

The intermediate layer 6 shields surface defects of the object 1 to be coated, adheres to the photosensitive layer, prevents charge injection from the object 1 to be coated,
It is provided for the purpose of adjusting the image quality of the photosensitive layer, etc., and the film thickness is 0.
．． If the thickness is less than 0.01 μm, the above objective will not be achieved, and if it is more than 2 μm, the residual charge on the photosensitive layer during image exposure will increase, fog will increase, and the electrophotographic performance will deteriorate in the process of repeated image formation. become.

Next, the charge generation layer 2 is provided on the intermediate layer 6. To form the charge generation layer 2, for example, polyester, methacrylic resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, melamine resin, polyurethane, styrene-acrylic copolymer, styrene-butadiene copolymer, etc. polymer,
Vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, styrene-alkyd resin, polyvinyl carbazole, polyvinyl butyral, etc. No. 172044, 60
-172045, 63-65444, 63-1
No. 48263, JP 1-269942, JP 1-26
The polycarbonate resin described in No. 9942 is mixed and dissolved in 1 to 100 parts by weight with respect to 1000 parts by weight of a solvent selected for the charge generation layer from the group of solvents described for the intermediate layer. The charge generating substance is mixed and dispersed in the obtained solution in an amount of 10 to 1000 parts by weight, preferably 20 to 500 parts by weight, per 100 parts by weight of the binder resin, and the obtained dispersion is placed on the intermediate layer 6. The film is coated using any of the coating methods used during formation of No. 6 to give a film thickness of 0.05 to 3 μm after drying.

When the thickness of the charge generation layer is less than 0.05 μm, it is difficult to obtain a uniform coating layer, and sufficient charge cannot be generated by imagewise exposure, resulting in insufficient sensitivity. Also 3μm
If this value is exceeded, the area where the image exposure light does not reach increases, and the charges generated on the surface are trapped and the residual charges become large, causing fatigue deterioration when image formation is repeated. If the content of the charge generating substance in the binder resin is less than 10 parts by weight, sensitivity will be insufficient and residual charge will increase, and if it exceeds 1000 parts by weight, the accepted potential will decrease and charging will be poor.

Next, a charge transport layer 3 is formed on the charge generation layer 2.
A lower constituent layer 3A is provided. That is, a binder resin and a solvent for the charge transport layer are selected from the resin group and solvent group described for the charge generation layer and the intermediate layer, and the solvent 100 is
50 to 300 parts by weight of binder resin is dissolved in 0 parts by weight,
The charge transport material was added to the resulting solution as a binder resin (100%).
30 parts by weight or more, preferably 30 to 300 parts by weight, are mixed and dissolved to prepare a coating solution for the lower constituent layer, and this is coated on the charge generation layer using any of the coating methods for forming a charge generation layer. The lower constituent layer 3A is coated with a thickness of 5 to 50 μm, preferably 10 to 40 μm.

If the layer thickness of the lower constituent layer 3A is less than 5 μm, the potential will drop and the charge transport function will be insufficient, leading to a decrease in sensitivity. If it exceeds 50 μm, the charge transport path will become too large and This results in insufficient sensitivity.

Next, when the amount of the charge transport substance relative to the binder resin is less than 30 parts by weight, the charge transport function is insufficient, resulting in insufficient sensitivity, and when it exceeds 300 parts by weight, the dark resistance of the photosensitive layer decreases. Causes potential shortage.

[0082] Next, an upper constituent layer 3B is formed on the lower constituent layer 3A. That is, a binder resin and a solvent for the charge transport layer are selected from the resin group and solvent group described above, 50 to 300 parts by weight of the binder resin is dissolved in 1000 parts by weight of the solvent, and the charge transport material is added to the resulting solution as a binder. 70 parts by weight or less, preferably 5 to 70 parts by weight per 100 parts by weight of resin
A coating solution for the upper constituent layer is prepared by mixing and dissolving parts by weight, and this is coated on the lower constituent layer 3A to form a coating solution of 0.1 to 30 μm.
m thickness, preferably 0.5 to 10 μm membrane upper constituent layer 3B
The photoreceptor of the present invention is obtained by forming the following.

The upper constituent layer usually forms the surface layer of the photoreceptor, and has excellent electrophotographic performance, abrasion resistance, environmental resistance, etc., and is particularly required to be coated uniformly. For this reason, as mentioned above, the concentration of the charge transport substance in the layer is reduced and the layer is made thin, and as a coating means, the lower constituent layer 3A is not dissolved too much and uniform coating can be performed with high efficiency. The coating is carried out using a circular slide hopper coater as shown in the figure, a circular extrusion coater as shown in Figure 6, or a circular small quantity dip coater as shown in Figure 7.

Note that as shown in FIG. 3, the lower constituent layer 3A
An intermediate constituent layer 3C may be provided between the lower constituent layer 3B and the lower constituent layer 3B.
It is preferable that it is smaller than A and larger than the upper constituent layer 3B.

In FIG. 5, 10 is a cylindrical support conveyed in direction A, 11 is a circular slide hopper coating machine, 12 is a coating liquid distribution chamber of the coating machine 11, 13 is a coating liquid distribution slit, 14 is a coating liquid supply pipe, 15 is a liquid receiver,
16 is a hopper edge, 17 is a coating liquid slide surface, and 18 is a coating layer. FIG. 5(a) is a cross-sectional view of the coating machine 11 including the cylindrical support 10, and FIG. 5(b) is a partially broken view thereof. FIG.

During coating, the required amount of the coating liquid S is supplied to the coating liquid supply pipe 14 by a pump or the like, and the coating liquid S is supplied to the coating liquid distribution chamber 12.
distributed uniformly in the circumferential direction by the distribution slit 1
3, and flows uniformly down the slide surface 17 in the circumferential direction. Thereafter, a bead of the coating liquid S is formed between the hopper edge 16 and the outer peripheral surface of the cylindrical support 10, and the support 10 is conveyed in the direction of arrow A with this bead in contact with the outer peripheral surface of the support 10. A coating layer 18 is formed on the surface. According to such a coating machine, since the solvent evaporates quickly from the coating layer 18, a dry coating film can be easily obtained by providing a simple drying device. Further, since only the necessary amount of the coating liquid S is sent, there is no waste of the coating liquid, and the cost of materials can be reduced. In addition, since it is a circular coating method, seamless uniform coating is possible, and the coating film is determined by the liquid supply amount, viscosity, and moving speed of the object to be coated, making it easy to control the coating thickness. Since there is little variation in coating thickness, high quality and high productivity coating is possible. In the circular slide hopper coating machine,
The gap between the diameter of the end of the slide surface and the outer diameter of the cylindrical support is preferably 0.05 to 1 mm, more preferably 0.1 to 0.6 mm. The inclination angle of the sliding surface is 10° with respect to the horizontal
~70° is preferred, and 20° ~ 45° is more preferred.

The viscosity of the coating liquid is preferably within the range of 0.5 to 700 Cp, and even more preferably 1 to 500 Cp.

[0088] In order for the coating liquid to flow uniformly in the circumferential direction from the coating liquid distribution slit, in the slide hopper device, the distribution chamber resistance (Pc) and the flow rate through the coating liquid distribution slit must be The slit resistance (Ps) is P
s/Pc≧80, more preferably 100 to 100,0
The range is 00.

Next, FIG. 6 is a sectional view of the circular extrusion coating machine 11', and the same parts as in FIG. 5 are given the same reference numerals. In the circular extrusion coating device 11', the amount of coating liquid S necessary for coating is supplied to the coating liquid supply pipe 14 by a pump or the like.
The coating liquid is distributed uniformly in the circumferential direction by the coating liquid distribution chamber 12, pushed out through the distribution slit 13, uniformly and continuously flows out from the hopper edge 16, and the coating liquid is distributed between it and the outer peripheral surface of the support. A bead is formed by which the coating layer 18 is applied.

[0090] The length of the hopper edge 16 is 0.1 to 10 m.
m, preferably 0.5 to 4 mm. The angle of inclination of the hopper edge is preferably within the range of 30° from the vertically downward direction, and more preferably within the range of 20° from the vertically downward direction. If the angle of inclination of the hopper edge exceeds 30°, the crosslinking of the coating solution will be shortened, making it difficult to obtain a good coating film.

[0091] Furthermore, in the extrusion coating machine 11',
By maintaining the relationship between the distribution chamber resistance (Pc) and the slit resistance (Ps) when the coating liquid flows through the coating liquid distribution slit in the range of Ps/Pc≧40, more preferably within the range of 40 to 100,000, It is possible to apply the liquid stably and uniformly.

These distribution chamber resistance (Pc) and slit resistance (Ps) may be determined depending on the coating liquid supply rate, viscosity, and supply pressure. Furthermore, in the extrusion coating machine 11', the hopper edge is 0.05 to 1 mm larger than the outer diameter of the object to be coated.
mm, more preferably a coating film thickness in the range of 2ho mm to 4ho mm, and a length in the coating direction of 0.1 to 10 mm, more preferably 0.0 mm.
It is desirable that it has a diameter of 5 to 4 mm.

FIG. 7 is a sectional view of the circular small quantity dip coating machine 11'', in which the bottom plate 21 is fixed to the loading plate 20,
The liquid stopping blade 23 is connected to the upper surface of the bottom plate 21 and the pressing plate 2.
2 and are held tightly together. The coating liquid S is stored in a liquid tank 24, and a liquid replenishment plate 25 for replenishing the coating liquid S to the liquid tank 24 is provided on the upper surface of the liquid tank 24.
A pair of liquid supply ports 26 are provided in the .

The entire coating machine 11'' is formed into a cylindrical shape. The liquid stopping blade 23 is made of flexible rubber, synthetic resin, etc., and is configured to hold the support 10 in a narrow manner. .

Holes 27a, 27a', 27a'' are provided through the bottom plate 21, press plate 22, and liquid tank 24, and holes 27a, 27a', and 27a'' are provided in the liquid replenishment plate 25, each having a smaller diameter than the holes 27a, 27a', and 27a''. A hole 27b is provided through the blade 23, and a hole 27c having a smaller diameter than the hole 27b is provided through the blade 23.

Further, the periphery of the hole 27c of the blade 23 is in close contact with the outer peripheral surface of the object to be coated 10, and the periphery of the hole 27b of the liquid supply plate 25 faces the outer periphery of the object to be coated with a very small gap formed therebetween. As a result, evaporation of the coating liquid during coating is suppressed, and rapid drying immediately after coating is prevented. Liquid tank 24
A liquid storage chamber 28 is provided in the lower half, and a liquid reservoir 29 is provided in the upper half. A plurality of communication holes 30 are arranged in the circumferential direction to replenish the coating liquid S in the liquid reservoir 29 to the liquid storage chamber 28 in the lower half, and a reflux hole for overflow is provided in the outer peripheral wall of the storage section 28. 31, which is designed to keep the liquid level constant at all times. Also, storage section 2
A plurality of air holes 33 are provided in the inner peripheral wall of 8 in the circumferential direction,
It is communicated with the outside air via the hole 27b. In this circular small amount dip coating machine, a small amount of liquid at a constant level is stably held in the storage portion 28, and the circular liquid end surface contacts the outer periphery of the support to apply the liquid. Typical examples of the circular slide hopper coater 11, the circular extrusion coater 11', and the circular small-volume dip coater 11''' used in the photoreceptor manufacturing method of the present invention have been described above. is suitable for applying a coating liquid to a cylindrical support, and especially when forming the surface layer of a photoreceptor, there is little dissolution or erosion of the underlying layer, and uniform coating is possible at high speed. can achieve high quality and high productivity.

For coating the cylindrical support, a conveying coating device 45 as shown in FIG. 8, for example, is used. In the figure,
40a, 40b, 40c are cylindrical supports 10a, 10b
It is a spacer that alternately fits and connects (10c) etc.,
Continuous coating is made possible by a circular coater 41 that is conveyed in the vertical direction integrally with the support and performs the circular slide hopper coating, circular extrusion coating, or small circular dip coating. The support body is transported by gripping the spacers 40b and 40c fitted on the top and bottom of the support body 10b.
A pair of upper and lower gripping parts 42a and 42b that transport 0b upward
and a gripping tool 43B having a pair of upper and lower gripping parts 42c and 42d that grip spacers 40a and 40b fitted on the upper and lower sides of the support 10a and transport the support 10a upward. . The gripping tools 43A and 43B are supported by a device main body 45, and are moved through lifting members 46A and 46B screwed to ball screws 44A and 44B which are rotationally driven by a drive source (not shown) and coil springs 47A and 47B which are buffer members. They are connected to each other and are moved up and down as the elevating members 46A and 46B move up and down in conjunction with the rotation of the ball screws 44A and 44B. The lifting members 46A and 46B are moved up and down based on a predetermined program signal, so that while one lifting member is gripping the spacer and transporting the support upward, the other lifting member is gripping the spacer without colliding with each other. It is lowered with the support released, and the spacer below is grasped in order to convey the next support.

Reference numeral 49 denotes a support supplying hand, and if the cylindrical supports are successively set on this by a robot or the like in accordance with the timing, the lifting movement of the hand to a predetermined position and the above-mentioned gripping tool are performed. In cooperation with the upward transport movement 43A or 43B, the support is continuously fed to a circular coater 41, coated, and dried by an air jet dryer 47 directly above the coater 41. A drum-shaped photoreceptor is formed. This photoreceptor is suction-carried and carried out of the apparatus by the carry-out hand 48.

In addition to the conveying coating device 45, the cylindrical support is continuously conveyed vertically upward by a pair of left and right chain belts provided with a large number of elastic grippers, for example, as described in JP-A-56-101149. It may also be applied by

[0100]

[Examples] The present invention will be specifically explained below with reference to Examples, but the embodiments of the present invention are not limited thereto. Note that the following charge generation materials, charge transport materials, charge generation layers, and charge transport layers are CGM, CTM, CGL, and C
It is abbreviated as TL.

(Preparation of cylindrical support) Length 355.5 m
Prepare 11 aluminum tubes with an outer diameter of 80 mm and fill each tube with vinyl chloride-vinyl acetate-maleic anhydride copolymer (Sekisui Chemical Co., Ltd., S-LEC MF-10).
) Dissolve 10 parts by weight in 1000 parts by weight of methyl ethyl ketone, apply the resulting solution by a normal dip coating method,
This was dried to form an intermediate layer with a dry film thickness of 0.1 μm, and 11 cylindrical supports for testing were prepared.

(Preparation of photoreceptor for testing of the present invention) (1) Test No. 1~No. 3. Preparation of photoreceptor: CGL coating liquid (1) of the following formulation was applied to three of the 11 supports by dip coating and dried to form a 1 μm thick CGL.
GL was formed.

Coating liquid for CGL (1): Polycarbonate (manufactured by Mitsubishi Gas Chemical Co., Ltd., PCZ-2
00) 10 parts by weight CG of the following structure
M(1)
50 parts by weight Tetrahydrofuran
1,000 parts by weight of CTM (1) in the basic formulation (1) of the coating liquid for the lower constituent layer shown below was added to the CGL as shown in Table 1-1: 75%, 100%,
125% (75 parts by weight, 100 parts by weight, 125 parts by weight)
Three types of coating liquids for the lower constituent layer were prepared, and using the coating device 45 shown in FIG. 1
The lower constituent layers were formed by coating to a film thickness of 8 μm and 18 μm.

Basic formulation of coating liquid for lower constituent layer (1): Polycarbonate (PCZ-200)
100 parts by weight CTM (1) with the following structure
x parts by weight Silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., KF-54)
0.005 parts by weight 1,2-dichloromethane

1000 parts by weight

[0105]

[Chemical formula 12]

Next, the content (content x) of CTM (1) in the basic formulation (1) of the coating liquid for the lower constituent layer is shown in Table 1-
1, 20%, 40%, and 70% (20 parts by weight, 40 parts by weight, 70 parts by weight) were used to prepare three types of coating liquids for the upper constituent layer, and these were applied to the lower constituent layer. Using the same coating device 45 as in the case of the lower component layer, coating was performed on the three coated bodies formed so that the film thickness was 3 μm, 5 μm, and 4 μm as shown in Table 1-1, and the upper layer was formed. A layer was formed on the photoreceptor No. 1 for the test of the present invention. 1~No. I got 3. Note that the film thickness was changed by adjusting the conveyance speed of the object to be coated.

(2) Test No. 4~No. 6 Preparation of photoreceptor: CGM (2) having the following structure was used in place of CGM (1) in the CGL coating liquid (1) for three of the remaining eight objects to be coated. A CGL coating liquid (2) was prepared in the same manner as above, and the coating liquid was coated and dried using an ordinary dip coater to form a CGL having a thickness of 0.5 μm.

Next, the basic formulation of the coating liquid for the lower constituent layer (1)
A coating liquid (2) for the lower constituent layer was used, which was the same as the basic formulation (1) above, except that CTM (2) having the following structure was used in place of CTM (1), and the coating liquid (2) was The content rate (content x) of CTM (2) is 100% and 150% as shown in Table 1-1.
, 200% (100 parts by weight, 150 parts by weight, 200 parts by weight) to prepare three types of coating liquids for the lower constituent layer. Using these three types of coating liquids, coat the three objects coated with the CGL using a normal dip coater, as in the case of CGL, so that the coating thickness is 20 μm as shown in Table 1-1. A lower constituent layer was formed by coating.

[0109]

[Chemical formula 13]

Next, the coating liquid formulation for the lower constituent layer (2)
The content of CTM (2) (content x) was adjusted to 50% (50 parts by weight) as shown in Table 1-1 to prepare three types of coating liquids for the upper constituent layer. These are applied to the coating device 4 of FIG. 8, which is equipped with the circular extrusion coating machine 11' of FIG. 6.
No. 5 was used to form the upper constituent layer by coating so that the total dry film thickness was 3 μm.
4~No. 6 was formed.

(3) Test No. 7~No. 9 Preparation of photoreceptor: Three of the remaining five supports were coated with the CG
C with the following structure in place of CGM (1) in L coating liquid (1)
Coating liquid for CGL (3) was prepared in the same manner except that GM (3) was used.
) and apply the coating solution using a normal dip coater.
It was dried to form a 0.5 μm thick CGL.

[0112] First, CTM (3) having the following structure was used instead of CTM (1) in the basic formulation (1) of the coating liquid for the lower constituent layer.
The CTM (3) content percentage (content , 250%, 300
% (200 parts by weight, 250 parts by weight, 300 parts by weight) to prepare three types of coating liquids for the lower constituent layer. This was coated with a normal dip coater to give a dry film thickness of 20μm and 19μm.
A lower constituent layer was formed by coating to a thickness of 20 μm.

[0113] Next, the basic formulation of the coating liquid for the lower constituent layer (3). Next, the content percentage (content x) of the basic formulation of the coating liquid for the lower constituent layer was determined by 70% as shown in Table 1-1. %, 5
0%, 50% (70 parts by weight, 50 parts by weight, 50 parts by weight)
Three types of coating liquids for the upper constituent layer were created. These are coated with a coating device 45 equipped with a small circular dip coater 11'' to achieve a dry film thickness of 4 μm and 3 μm as shown in Table 1-1.
The upper constituent layer was formed by coating to a thickness of 3 μm and 3 μm. 7~No. 9 was formed.

[0114]

[Chemical formula 14]

(Preparation of photoreceptor for comparison test) (4) Test No. 10 Preparation of photoreceptor: Test No. 1 was used, except that the lower constituent layer was coated using a normal dip coater, and the upper constituent layer was also coated using a dip coater. Comparative test No. 2 was carried out in the same manner as 2. Ten photoreceptors were obtained.

(5) Test No. 11 Preparation of photoreceptor: Test No. 1 except for the upper constituent layer. Comparison test No. 2 was conducted in the same manner as 2. Twelve photoreceptors were obtained.

(Test method) The above-mentioned photoreceptor No. 1 for testing of the present invention. 1~No. 9 and photoconductor No. 9 for comparison test. 1
0 and no. 11 was attached to Konica's U-Bix-3035, and each test was repeated 10,000 times in an atmosphere with a relative humidity of 60% and a temperature of 20°C.
00th image density and degree of fogging as "○", "△",
Evaluation was made in three stages of "x", and the results are shown in Table 1-2.

In addition, the black paper potential (VB) and white paper potential (VW) of the photoreceptor were measured before and after the 10,000th repeated photographing test, and the results are shown in Table 1-2.

[0119] In Table 1-2, the black paper potential (VB) is the surface potential of the photoconductor for an original with a reflection density of 1.3, and the white paper potential (VW) is the surface potential of the photoconductor for an original with a reflection density of "0". In each case, measurements were taken by placing an electrometer probe at the developing device before and after photographing.

[0120] In evaluating the image quality of the live-action test, we focused on the image density and the degree of fog, and evaluated the image density 1.1 or higher as "○";
0.9 to 1.09 is "△", less than 0.9 is "x",
A fog of 0.10 or more is marked "x", and a fog of 0.02 to 0.09 is marked "
△", less than 0.02 was rated as "○".

[0121]

[Table 1]

[0122]

[Table 2]

From Tables 1-1 and 1-2, the photoreceptor obtained by the manufacturing method of the present invention has better coating processing than the comparative photoreceptor, and therefore has fewer image defects such as streaks, unevenness, and spots. It has excellent electrophotographic performance, has high durability with little wear of the photosensitive layer in the process of repeated image formation, and has other advantages such as excellent coating processing efficiency. .

[0124]

Effects of the Invention As is clear from the above description, the method for manufacturing a photoreceptor of the present invention has excellent coating processability and productivity, and the resulting photoreceptor has
Effects such as no image unevenness, streaks, spots, etc. are produced, and the electrophotographic performance and durability during repeated use are excellent.

[Brief explanation of the drawing]

FIG. 1 to FIG. 4 are cross-sectional views showing the layer structure of the photoreceptor of the present invention.

2] FIG. 5(a) and FIG. 5(b) are a sectional view and a perspective view of a coating machine used in the present invention.

FIGS. 6 and 7 are cross-sectional views of other coating machines used in the present invention.

FIG. 4 is a sectional view of a coating device used in the present invention.

[Explanation of symbols]

1...Electroconductive support 2...Charge generation layer 3...Charge transport layer 10...Cylindrical object to be coated 11...Coating machine 12...Coating liquid distribution chamber 13...Distribution slit 16…Hopper edge 23… Liquid stopper blade 24…Liquid tank 28...Liquid storage section 40a, b, c...spacer 41...Coating machine 42a, b, c, d...Gripping part 45...Coating device

Claims (4)

[Claims] 1. In the production of a photoreceptor, in which a photoreceptor layer is provided, in which a photoreceptor layer is formed by laminating a charge generation layer and a charge transport layer consisting of a plurality of constituent layers on a conductive cylindrical support, at least the outermost layer of the laminated photoreceptor layer is provided. A method for manufacturing a photoreceptor, characterized in that coating is performed using a circular slide hopper coating machine. 2. In the production of a photoreceptor in which a photoreceptor layer is provided with a photoreceptor layer having a charge generation layer and a charge transport layer consisting of a plurality of constituent layers laminated on a conductive cylindrical support, at least the outermost layer of the laminated photoreceptor layer, A method for producing a photoreceptor, characterized in that coating is performed using a circular extrusion coater. 3. In the production of a photoreceptor, in which a photoreceptor layer is provided, in which a photoreceptor layer is formed by laminating a charge generation layer and a charge transport layer consisting of a plurality of constituent layers on a conductive cylindrical support, at least the outermost layer of the laminated photoreceptor layer, A method for manufacturing a photoreceptor, characterized in that coating is performed using a circular small-volume dipping coating machine. 4. The photosensitive layer has a layered structure in which a plurality of charge transport layers are provided on the charge generation layer, and the concentration of the charge transport substance in each layer of the charge transport stack relative to the binder is separated from the charge generation layer. 4. The method for manufacturing a photoreceptor according to claim 1, wherein the layer size is made smaller.