JPH1138653A - Coating composition for electrophotographic photoreceptor, electro photoreceptor and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition for the electrophotographic photoreceptor using a coating solvent containing no halogen and small in toxicity and causing no environmental problem, especially, ozone hole and carcinogenic problems, and superior in potential characteristics and image forming characteristics for a long period from an initial time of image formation and superior in coatability and laminating property and the like, and to provide this photoreceptor and its manufacturing method. SOLUTION: This coating composition can dissolve a binder and a silicone oil and contains a dioxolane derivative having a boiling point of <=150 deg.C and it is represented by the formula, in which R1 -R6 are each an H atom or an optionally substituted 1-3C alkyl group and each is not an H atom at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coating composition for an electrophotographic photosensitive member, a method for producing an electrophotographic photosensitive member, and an electrophotographic photosensitive member.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic photosensitive member, an inorganic photosensitive member having a photosensitive layer mainly composed of an inorganic photoconductive compound such as selenium, zinc oxide, cadmium sulfide, and silicon has been widely used. However, these are not always satisfactory in sensitivity, thermal stability, moisture resistance, durability, and the like. In addition, some inorganic photoreceptors contain substances that are harmful to the human body in the photoreceptor, and thus pose a problem in disposal. There is.

In order to overcome the disadvantages of these inorganic photoconductors, research and development of organic photoconductors having a photosensitive layer containing various organic photoconductive compounds as main components have been actively conducted in recent years. In particular, a function-separated type photoreceptor in which the charge generation function and the charge transport function are respectively assigned to different substances allows each material to be selected from a wide range, and a photoreceptor having any performance can be relatively easily formed. A lot of research has been done because they can be produced, and many of them are practically used.

[0004] To prepare these organic photoreceptors, a compound having a charge generation function and a charge transport function is applied in a layer form on a conductive support. Therefore, the coating composition usually has a multilayer structure, and each layer is formed by applying a coating composition obtained by dissolving a solid compound with a solvent using various coating methods.

However, organic solvents, particularly solvents having a high solubility and a suitable boiling point suitable for industrial production, are often harmful, and those having excellent properties, such as halogen-based solvents, tend to be strong.

Needless to say, as long as it is a solvent used for the production of a photoreceptor, it cannot be used unless it has solubility and an appropriate boiling point and does not adversely affect the characteristics as an electrophotographic photoreceptor. The need for a solvent that satisfies all of the above was extremely high.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to use a solvent containing no halogen as a coating solvent and to have low toxicity, no environmental problems, especially no ozone hole problem or carcinogenicity problem. To provide a coating composition for an electrophotographic photoreceptor, an electrophotographic photoreceptor, and a method for producing the same, which have excellent potential characteristics and image characteristics over a long period of time from the initial stage of image formation, and have excellent coating properties and layering properties. is there.

[0008]

The above object of the present invention is attained by employing the following constitution.

(1) A coating composition for an electrophotographic photoreceptor, comprising a dioxolane derivative represented by the following general formula (1) and having a boiling point of 150 ° C. or lower and dissolving a binder and silicone oil.

[0010]

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[Wherein R _{1 to} R ₆ are a hydrogen atom or a carbon atom
Represents a substituted or unsubstituted alkyl group of ₁ to 3, and R _{1 to} R ₆ are not simultaneously a hydrogen atom. (2) The coating composition for an electrophotographic photosensitive member according to (1), wherein the binder is a polycarbonate.

(3) The coating composition for an electrophotographic photosensitive member according to (1) or (2), further comprising a charge transport material dissolved therein.

(4) The coating composition for an electrophotographic photosensitive member according to any one of (1) to (3), further comprising an antioxidant dissolved therein.

(5) An electrophotographic method comprising applying a coating composition containing a dioxolane derivative having a boiling point of 150 ° C. or lower, represented by the general formula (1), a binder and silicone oil onto a conductive support. Manufacturing method of photoreceptor.

(6) The coating composition is (2) to (4).
The method for producing an electrophotographic photosensitive member according to (5), which is the coating composition according to any one of (1) to (3).

(7) An electrophotographic photoreceptor containing a dioxolane derivative represented by the general formula (1) and having a boiling point of 150 ° C. or lower and dissolving a binder and silicone oil.

(8) The electrophotographic photosensitive member according to (7), wherein the binder is polycarbonate.

(9) The electrophotographic photosensitive member according to (7) or (8), further comprising a charge transporting material dissolved therein.

(10) The electrophotographic photosensitive member according to any one of (7) to (9), further comprising an antioxidant dissolved therein.

(11) The electrophotographic photoreceptor according to any one of (7) to (10), wherein the residual amount of the dioxolane derivative in the photoreceptor is 20 to 50,000 ppm of the entire photosensitive layer.

Hereinafter, the present invention will be described in detail.

In the case of an electrophotographic photoreceptor, particularly, in the case of an organic photoreceptor, in order to form the photosensitive layer and the photosensitive auxiliary layer, the best method is to dissolve the compounds constituting them in a solvent and apply them.

However, the coating solvents for the electrophotographic photoreceptor layer which have been widely used in the past are organic solvents of halogen-containing elements such as methylene chloride, ethylene chloride, chloroform, monochlorobenzene and the like, and these are environmental problems, carcinogenicity and the like. From the viewpoint of the ban on use.

As the organic solvent containing no halogen, toluene, tetrahydrofuran (THF), dioxane, methyl ethyl ketone (MEK), cyclohexanone and the like have been used. In addition, problems such as insufficient coating film thickness due to the inability to increase the concentration of the coating solution cannot be solved. In particular, in the case of a charge transport layer, a film thickness of 12 μm or more is required, but when the film thickness is large, the coatability becomes difficult, and the surface state causes a coating defect such as a bell shape or a stripe shape. For example, it is preferable that a high-concentration coating liquid of at least 5% by weight or more, preferably 8% by weight or more has a viscosity of 300 cp (22 ° C.) or less. However, such properties cannot be obtained with the halogen-free organic solvent, and
In some cases, it is necessary to adopt a method such as application in up to three times.

As will be described later, polycarbonate is often used as an excellent binder in the photosensitive layer of an electrophotographic photosensitive member. As a good solvent that does not contain halogen of polycarbonate, there is dioxane, a cyclic ether containing two oxygen atoms in the molecule, but dioxane is highly toxic,
It has carcinogenic properties and cannot be put into the manufacturing process.

As a result of diligent studies, the present inventors have found that the above-mentioned objects of the present invention can be achieved by using dioxolane and its derivatives, and have reached the present invention.

The dioxolane derivative having a substituted or unsubstituted dioxolane nucleus of the present invention (hereinafter also referred to as the dioxolane derivative of the present invention) is a substituted or unsubstituted cyclic 5-membered ether compound which is adjacent to each other in the molecule. A dioxolane derivative having a dioxolane nucleus containing no oxygen atoms. Among them, the dioxolane derivative according to the present invention has a dioxolane nucleus in its molecular structure, dissolves a binder or other additives used for a photoreceptor, and when producing a photoreceptor, it may be any as long as it can be dried. Usually 20
Those having a temperature of 0 ° C. or less are used.

As the dioxolane derivative of the present invention, specifically, those represented by the following general formula (1) are preferably used.

[0029]

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[Wherein R _{1 to} R ₆ represent a hydrogen atom or a carbon atom
Represents a substituted or unsubstituted alkyl group of ₁ to 3, and R _{1 to} R ₆ are not simultaneously a hydrogen atom. As the substituent of this alkyl group, any may be used,
Preferably, an alkoxy group, an acyl group, an acyloxy group, a hydroxyl group, etc. each having 1 to 2 carbon atoms are exemplified.

The dioxolane derivative of the present invention preferably has a boiling point of 150 ° C. or less at normal pressure.
A temperature of 0 ° C is more preferable, and a temperature of 80 to 100 ° C is particularly preferable.

The reason for this is that if the boiling point is high, the drying step is lengthened, which is disadvantageous in terms of cost. If the boiling point is lower than 80 ° C., coating unevenness occurs, which is practically disadvantageous.

Dioxolan has a strong dissolving power for polycarbonate, but has a low boiling point, so that when dried at a higher temperature, the surface of the dried coating film dries rapidly, preventing evaporation of the internal solvent. As a result, the difference between the amount of the residual solvent on the surface and the amount of the residual solvent on the inside becomes large, and there is a problem in drying unevenness on the surface, repetition characteristics of electrophotographic characteristics and durability. The dioxolane derivative of the present invention has an appropriate affinity for a binder by introducing an alkyl group into the substituent, balances internal evaporation with evaporation on the surface, and further has a synergistic effect with silicone oil. Was improved. This silicone oil was found to be effective for smoothing the coated surface and also for image blurring when a large number of sheets were used. This is because the adsorption ability of nitrogen oxides generated during charging is relatively large and image blur is easy to occur,
It has been found that the addition can be prevented by adding silicone oil. The addition of silicone oil also has the effect of turning over the blade against image deterioration when a large number of sheets are used.

Specific exemplary compounds which can be preferably used for the dioxolane derivative of the present invention are shown below.

[0035]

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[0036]

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The dioxolane derivative of the present invention remains in the produced electrophotographic photoreceptor, and the amount of the residual dioxolane derivative (dioxolane solvent) contained in the photoreceptor is preferably 20 ppm to 50,000 ppm based on the total solid content of the photosensitive layer. , 30 to 10,000 ppm are more preferred. 50
When the amount is more than 000 ppm, the storage stability of the potential with the lapse of time is poor.

Since the residual content slightly varies depending on the thickness of the photosensitive layer, the affinity for the binder, the coating speed, the diameter of the drum, the process, and the like, it is actually preferable to produce the toner after confirming the content in the drum. The content is controlled by a preferable combination of a drying temperature, a drying time, a drying air speed, an air volume, and the like.

The content can be detected by a method well known to those skilled in the art, for example, gas chromatography.

As the silicone oil, Japanese Patent Application Laid-Open No.
No. 143643, JP-A-57-5050, JP-A-57-50
Silicone oils described in JP-A-212453, JP-A-59-208556, JP-A-63-80262, JP-A-1-234854, JP-A-4-199154 and JP-A-5-27456 are preferred. Particularly, methyl phenyl silicone oil and dimethyl silicone oil are preferable, and the content of the contained layer in the solid content is 10%.
~ 1000 ppm is preferred.

The binder preferably used in the present invention includes polycarbonate, polyester polycarbonate, polyester, polyurethane, polystyrene, polystyrene-based copolymer, polysiloxane, polyacrylate, polyacrylate-based copolymer, phenoxy resin,
ABS resin, polyvinyl chloride, polyvinyl chloride-based copolymer, polyvinyl acetate-based copolymer, polyvinyl formal, polyvinyl butyral, and the like.

Among them, polycarbonate-based ones are more preferable, and for example, bisphenol A-type polycarbonate (BPA), bisphenol Z-type polycarbonate, or the following polycarbonates are preferable. That is, p5 to p7 of JP-A-3-171506 and JP-A-5-113.
No. 670, p26-p2 of Japanese Patent Application No. 6-225081
9, p36 to p41, p52 to p57, p61 to p63
Polycarbonate containing Si element described in JP-A-3-4-4
No. 5958, p. 3, F-atom-containing polycarbonates described in JP-A-5-188628, JP-A-4-179962.
Polycarbonate described in JP-A No. 7-13361, polycarbonate described in pages 6 to 13 of JP-A No. 7-13361,
And polycarbonates described on pages 9 to 14 of No. 272125.

The coating is preferably CSH coating. The coater is described in JP-A-58-189061, Japanese Patent Application No. 7-12 / 1990.
No. 8023 and Japanese Patent Application No. 7-162021.

It is known that a dioxolane solvent forms a peroxide during storage and storage, and is used as an antioxidant (AO agent).
Has been added. However, when used as an electrophotographic photoreceptor, an antioxidant which does not adversely affect the electrophotographic properties and has excellent solution stability has not yet been found.

The antioxidants used in the present invention include:
There is no particular limitation on the chemical structure or the like as long as it meets the above conditions. Examples of preferably used compounds include, for example, those having a hindered amine structural unit or a hindered phenol structural unit, or those having both, an organic phosphorus compound, an organic sulfur compound, a hydroquinone compound, a phenylamine compound and the like. There is
It is not limited to these.

(1) Examples of compounds having a hindered phenol structural unit

[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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[0056]

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[0057]

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[0058]

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(2) Examples of compounds having a hindered amine structural unit and a hindered phenol structural unit

[0060]

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[0061]

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[0062]

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(3) Examples of compounds having hindered amine structural units

[0064]

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[0065]

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[0066]

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(4) Examples of Organic Phosphorus Compounds For example, compounds represented by the general formula RO-P (OR) -OR, and typical examples include the following. Here, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

[0068]

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[0069]

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(5) Organic Sulfur Compounds For example, compounds represented by the general formula RSR are listed below as typical ones. Here, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

[0071]

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(6) Hydroquinone Compound Examples of the hydroquinone compound include compounds represented by the following general formula.

[0073]

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In the formula, R _{1 to} R ₄ represent a hydrogen atom, an alkyl group,
Represents a substituent such as a benzyl group or an aralkyl group. Each represents a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

Representative examples include the following.

[0076]

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[0077]

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(7) Phenylamine Compound Examples of the phenylamine compound include compounds represented by the following general formula.

[0079]

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In the formula, Ar represents an aryl group, and R ₆ represents a substituent such as an alkyl group, an aryl group, and a benzyl group.

Representative examples include the following.

[0082]

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Preferred antioxidants having a hindered phenol group in the molecule are advantageous in terms of the stability of the coating solution composition, the repetition characteristics of the formed photoreceptor and the stability of the potential. Different mixtures of antioxidants may be used.

The addition amount of the antioxidant is preferably 20 ppm to 5%, more preferably 50 ppm to 3%, based on the coating composition. 0.00 for the total solids of the dried coating
1% to 10% is preferable, and 0.01% to 5% is more preferable. If the addition amount is small, the storage stability of the solvent and the repetition characteristics of electrophotography are poor. If the addition amount is too large, the rise in residual potential becomes severe and image fogging occurs.

Next, as the conductive support for supporting the photosensitive layer, a metal plate or metal drum of aluminum, nickel, or the like, a plastic film on which aluminum, tin oxide, indium oxide, or the like is deposited, or a conductive material is applied. Paper, plastic film and drums can be used.

When an intermediate layer is provided, a resin-based intermediate layer using a polyamide-based compound such as nylon or a so-called ceramic-based intermediate layer (also referred to as a curable intermediate layer) using an organometallic compound and a silane coupling agent. Is preferably used.

The formation of the photosensitive layer is performed by an organic photoconductive layer, particularly a function-separated type containing both a charge transporting substance and a charge generating substance.
In particular, it is preferable that each is formed as a separate layer and formed by multi-layer coating.

The charge generation layer is formed by dispersing a charge generation material (CGM) in a binder resin as required. As CGM, azo compounds such as metal or metal-free phthalocyanine compounds, bisazo compounds, trisazo compounds, squarium compounds, azurenium compounds, perylene compounds, indico compounds, quinacridone compounds, polycyclic quinone compounds, cyanine dyes, xanthene dyes, poly Examples include, but are not limited to, a charge transfer complex comprising -N-vinylcarbazole and trinitrofluorenone. These may be used as a mixture of two or more as necessary.

However, in order to achieve the object of the present invention at the highest level, one of perylene compounds, imidazole perylene compound or metal phthalocyanine compound such as titanyl phthalocyanine (TiOPc) gallium phthalocyanine (GaPc) or hydroxygallium phthalocyanine (GaOHPc) Are preferred.

The binder resin usable for the charge generation layer includes, for example, polystyrene resin, polyethylene resin, polypropylene resin, polyacryl resin, polymethacryl resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinyl butyral resin, Polyepoxy resin, polyurethane resin, polyphenol resin, polyester resin, polyalkyd resin, polycarbonate resin, polysilicone resin, polymelamine resin, and copolymer resins containing two or more of these resin repeating units, for example, vinyl chloride- Examples include, but are not limited to, vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, and high molecular organic semiconductors such as poly-N-vinyl carbazole.

Among the above, polyvinyl butyral resin is preferable as a binder when an imidazole perylene compound is used as CGM, and polysilicone resin and polyvinyl butyral resin, or a mixture of both are preferable as a binder when TiOPc is used. And the like.

The charge transport layer is composed of a charge transport material (CTM) alone or together with a binder resin. C
As TM, for example, carbazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds,
Hydrazone compounds, pyrazoline derivatives, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives,
Benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, triarylamine derivatives, phenylenediamine derivatives, stilbene derivatives,
Examples include, but are not limited to, benzidine derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, and the like.
These may be used alone or in combination of two or more.

Examples of the binder resin usable for the charge transport layer include polycarbonate resin, polyacrylate resin, polyester resin, polystyrene resin, styrene-acrylonitrile copolymer resin, polymethacrylate resin, and styrene-methacrylic acid. Examples include, but are not limited to, ester copolymer resins. In addition, in order to reduce fatigue deterioration upon repeated use or to improve durability, any known antioxidant, electron-accepting substance, surface modifier, plasticizer, etc. may be used in each layer of the photoreceptor. , Environment-dependent reducing agents, etc.
If necessary, an appropriate amount can be added and used.

In order to improve the durability, a non-photosensitive layer such as a protective layer may be provided, if necessary, in addition to the photosensitive layer. It may be a photoreceptor having a charge transport layer of the type.

Further, a dye for correcting color sensitivity may be added to the photoreceptor of the present invention. Further, an additive such as an antioxidant may be used in combination.

There are various methods for applying these photoreceptor layers. In particular, it is preferable to apply a circular amount-regulated coating method (apparatus), especially a slide hopper type coating apparatus. For these technologies,
JP-A-58-189061, Japanese Patent Application No. 7-128023
Or Japanese Patent Application No. Hei 7-162021.

Hereinafter, this method will be described.

FIG. 1 is a schematic sectional view of a coating apparatus which can be used in the present invention. In FIG. 1, a cylindrical base material 1A, 1B vertically overlapped along a center line Y, and a slide hopper type in which a coating solution 2 for a photosensitive layer is sequentially applied to the cylindrical base materials 1A, 1B. 1 shows a coating device 3.

An application liquid slide surface 4 of the application liquid 2 is formed so as to surround the cylindrical substrate 1A, and the application liquid 2 supplied to the application liquid slide surface 4 is sequentially applied to the cylindrical substrate 1A. It is configured to do so. As the coating method, the annular coating device 3 is fixed, and the cylindrical substrate 1A is coated from the upper end while being moved upward in the direction of the arrow along the center line Y. In order to supply the coating liquid 2 to the coating liquid slide surface 4 of the coating apparatus 3, a coating liquid supply pump 6-1, a liquid feeding pipe 6-1 ′, and a coating liquid supply unit 6 A are provided from a coating liquid tank 5 provided outside. The coating liquid 2 is supplied by being connected to the annular circular amount-regulating coating device 3.

Next, the supplied coating liquid 2 is supplied to an annular coating liquid distribution chamber 7 formed in the annular coating apparatus 3 and sent from the coating liquid distribution slit 8 to an endless coating liquid outlet. The coating liquid 2 is continuously supplied from 9 to the coating liquid slide surface 4, and the coating liquid 2 is applied to the entire peripheral surface of the cylindrical substrate 1A. Reference numeral 12 denotes a liquid storage section for storing the coating liquid 2 dropped from the coating liquid slide surface 4.

FIG. 2 is a perspective view of the slide hopper type coating apparatus 3 shown in FIG.

FIG. 3 is a schematic cross-sectional view of a coating apparatus showing a simultaneous multi-layer coating method for simultaneously coating the cylindrical substrates 1A and 1B with a coating liquid to be a photoreceptor using the slide hopper type coating apparatus 3. .

In FIG. 3, cylindrical substrates 1A and 1B which are vertically overlapped along the center line Y, and the cylindrical substrates 1A and 1B
Reference numerals A and 1B denote an annular coating device 3 for sequentially applying the coating liquid 2 for photosensitivity. As shown in the figure, a coating liquid slide surface 4 of the coating liquids 2 and 2A is formed so as to surround the cylindrical substrate 1A, and the coating liquids 2 and 2A supplied to the coating liquid slide surface 4 are formed.
Are sequentially applied to the cylindrical substrate 1A. As the coating method, the annular coating device 3 is fixed, and the coating is performed from the upper end while the cylindrical substrate 1A is moved upward in the direction of the arrow along the center line Y. The coating device 3
In order to supply the coating liquids 2 and 2A to the coating liquid slide surface 4 of FIG.
The coating liquid is sent from the liquid supply pipe 6-1 'and the coating liquid supply section 6A to the coating liquid distribution chamber 7.

The feeding of the liquid from the coating liquid tank 51 to the coating liquid distribution chamber 71 is performed in the same manner.

Next, the supplied coating liquids 2 and 2 A are supplied to the annular coating liquid distribution chamber 7 formed in the coating apparatus 3 and the coating liquid 2 is supplied to the annular coating liquid distribution chamber 7 formed in the coating apparatus 3. The coating liquid 2A is supplied to the liquid distribution chamber 71. First, the applied coating liquid 2 is continuously supplied to the coating liquid slide surface 4 from an endless coating liquid outlet 9 through a coating liquid distribution slit 8, and is first applied to the entire peripheral surface of the cylindrical substrate 1A. The application liquid 2 is applied.

Further, the coating liquid 2A is supplied to the coating liquid distribution chamber 71. The supplied coating liquid 2A is continuously supplied onto the surface of the coating liquid 2 from an endless coating liquid outlet 91 through a coating liquid distribution slit 81, and the cylindrical substrate 1
A coating liquid 2 is first applied over the entire peripheral surface of A, and a coating liquid 2A is applied thereon by multi-layer coating.

Reference numeral 12 denotes a liquid reservoir for storing the coating liquid 2 dropped from the coating liquid slide surface 4.

FIG. 4 is a schematic cross-sectional view of a coating apparatus used in a sequential multi-layer coating method in which the coating apparatuses 3 used in FIG. 1 are vertically arranged. This is also an example in which the coating liquid is applied to the cylindrical substrates 1A and 1B formed endlessly as shown in FIG.

First, in the same manner as in FIG.
Is applied to the cylindrical substrate 1A. As the coating method, the coating device 3 is fixed, and the coating is performed from the upper end while the cylindrical substrate 1A is moved upward in the direction of the arrow along the center line Y. In order to supply the coating liquid 2 to the coating liquid slide surface 4 of the coating device 3, a liquid supply pump 6-1, a liquid supply pipe 6-1 ′, and a coating liquid supply unit 6A are provided from a coating liquid tank 5 provided outside. The coating liquid is sent to the coating liquid distribution chamber 7 (the liquid is also sent from the coating liquid tank 52 to the coating liquid distribution chamber 72).

Thus, the coating liquid 2 is supplied to the annular coating liquid distribution chamber 7 formed in the coating apparatus 3, and the coating liquid 2 is continuously applied to the coating liquid slide surface 4 through the coating liquid distribution slit 8 through an endless coating liquid outlet 9. Is applied to the entire surface of the cylindrical substrate 1A.

Further, a coating device 32 is provided above the coating device 3.

The cylindrical substrate 1A on which the first coating liquid 2 has been applied rises in the direction of the arrow and enters the coating liquid slide surface 42 of the coating device 32. Coating liquid slide surface 42
The coating liquid 2A supplied to the cylindrical base material 1A is sequentially coated on the surface of the coating liquid 2 applied to the cylindrical substrate 1A. As the coating method, the coating device 32 is fixed in the same manner as described above, and the multilayer coating is performed from the upper end while the cylindrical substrate 1A is moved upward in the direction of the arrow along the center line Y.

In order to supply the coating liquid 2A to the coating liquid slide surface 42 of the annular coating apparatus 32, a coating liquid supply section of a liquid feed pump is connected to the coating apparatus 32 from a coating liquid tank 52 provided outside (connection). The method is the same as that for the coating apparatus 3), and the coating liquid 2A is supplied. Next, the supplied coating liquid 2A is supplied to an annular coating liquid distribution chamber 72 formed in the coating device 32, and is applied to the coating liquid slide surface 42 from an endless coating liquid outlet 92 through a coating liquid distribution slit 82. The liquid 2A is continuously supplied, and the coating liquid 2A is applied to the entire peripheral surface of the coating liquid 2 applied to the cylindrical substrate 1A.

[0114]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto.

Example 1 << Photosensitive Drum No. Preparation of 1-1 >> A mirror-finished aluminum drum support having a diameter of 80 mm and a height of 355 mm was used as the conductive support.

The coating solution composition U was formed on the support as described below.
CL-3 was prepared and dip-coated to a dry film thickness of 1.0 μ to obtain a coating drum.

[0117] 1. UCL-3 coating solution composition ・ Ethylene-vinyl acetate copolymer (L-vacs 4260, manufactured by Mitsui DuPont Chemical Co., Ltd.) 50 g ・ Toluene / n-butanol = 5/1 (vol ratio) 2000 ml The coating liquid composition CGL-3 was dispersed and prepared as described above, and dip-coated to 1.5 μ to obtain a coating drum.

[0118] 2. CGL-3 coating solution composition ・ Y-type titanyl phthalocyanine (CGM-3) 100 g ・ Silicone resin (KR-5240 manufactured by Shin-Etsu Chemical Co., Ltd.) 100 g ・ t-butyl acetate 1000 ml The above coating solution composition is dispersed using a sand mill for 17 hours. A coating solution composition CTL-3 was prepared on the CGL layer as described below, and was dipped and applied to a dry film thickness of 23 μm.
After drying at 0 ° C. for 1 hour, the coating drum No. 1-1 was obtained.

[0119] 3. CTL-3 coating solution composition ・ CTM-3 500 g ・ Polycarbonate (Z-200 manufactured by Mitsubishi Gas Chemical Company) 560 g ・ Dioxolane derivative (compound example 1, bp 80-83 ° C.) 2800 ml ・ Silicone oil (KF-54 manufactured by Shin-Etsu Chemical Co., Ltd.) ) 100 ppm based on total solids ・ AO agent (butylhydroxytoluene) 20 g

[0120]

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<< Photosensitive drum No. Preparation of 1-2 to 1-6> The photoconductor drum No. 1-1 except that the dioxolane or the dioxolane derivative of Table 1 was used in place of the compound 1 of the dioxolane derivative of CTL-1 of Example 1-1. 1-1, the photosensitive drum No. 1-2
1-6 were produced. Table 1 summarizes the applicability.

[0122]

[Table 1]

As is evident from Table 1, when dioxolane having a low boiling point is used, there is a problem in coatability, and a cited-like coating unevenness occurs.

Example 2 << Photosensitive Drum No. Preparation of 2-1 >> A mirror-finished aluminum drum support having a diameter of 80 mm and a height of 355 mm was used as the conductive support.

The coating solution composition U was formed on the support as described below.
CL-1 was prepared and dip-coated to a dry film thickness of 1.0 μ to obtain a coating drum.

1. UCL-1 coating solution composition-Copolymer nylon resin (CM-8000, manufactured by Toray Industries, Ltd.) 2 g-Methanol / n-butanol = 10/1 (vol ratio) 1000 ml The following coating composition CGL-4 is dispersed on this UCL It was prepared and dip-coated to a dry film thickness of 1.5 μm.

[0127] 2. CGL-4a coating solution composition-Perylene pigment (CGM-2) 50 g-Butyral resin (Eslec BX-L, Sekisui Chemical Co., Ltd.) 50 g-Methyl ethyl ketone 2,800 ml-Methyl phenyl silicone oil (KF-54, Shin-Etsu Chemical Co., Ltd.) All solids 100 ppm per minute

[0128]

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The above coating solution composition was prepared using a sand mill.
Dispersed for 0 hour On this CGL layer, a coating solution composition CTL-4-
a2 was prepared, dip-coated so as to have a dry film thickness of 19 μm, and further coated thereon with a coating liquid composition CTL-4-
After preparing CSH and applying CSH to a dry film thickness of 5 μm, drying was performed at 120 ° C. for 1 hour to obtain a coating drum No. 2
-1 was obtained.

[0130] 3. CTL-4-a2 coating solution composition ・ CTM-3 500 g ・ Polycarbonate (Z-200 manufactured by Mitsubishi Gas Chemical Company) 560 g ・ Dioxolane derivative (Compound Example 3, bp 98-100 ° C.) 2800 ml ・ Methylphenyl silicone oil (KF-54) 20 ppm based on the total solid content. CTL-4-b coating liquid composition ・ CTM-3 400 g ・ Polycarbonate (Z-800 manufactured by Mitsubishi Gas Chemical Company) 560 g ・ Dioxolane derivative (compound example 1, bp 80-83 ° C.) 2600 ml ・ Dioxolane derivative (compound example 9, bp 92) -93 ° C) 100 ml ・ Methylphenyl silicone oil (KF-54 Shin-Etsu Chemical Co., Ltd.) 100 ppm based on the total solid content ・ AO agent (pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-) Hydroxyphenyl) propionate]) 10 g The above-mentioned coating solution composition was dispersed using a sand mill for 20 hours. 2-1
Had good coatability. ± 2 variation in film thickness in image area
It was within μm.

Embodiment 3 << Photosensitive Drum No. Production of 3-1 >> Coating drum No. of Example 1 1-1, the following OCL-1 coating composition was prepared, and after applying CSH to a dry film thickness of 3 μm,
C. for 1 hour. 3-1 was obtained.

OCL-1 coating solution composition ・ Polycarbonate (Z-800, manufactured by Ryogas Kagaku) 150 g ・ CTM-3 100 g ・ Silicone-based fine particles (Tospearl 103 manufactured by Toshiba Silicone Co., Ltd.) 60 g ・ Dioxolane derivative (Compound Example 1, bp80) -83 ° C) 1000 ml ・ Methylphenyl silicone oil (KF-54 Shin-Etsu Chemical Co., Ltd.) 200 ppm based on the total solid content ・ AO agent (butylhydroxytoluene) 20 g The above coating solution composition was dispersed for 3 hours using a sand mill The photosensitive drum No. 3-1
Had good coatability. ± 2 variation in film thickness in image area
It was within μm.

Embodiment 4 << Photosensitive Drum No. Preparation of 4-1 >> A mirror-finished aluminum drum support having a diameter of 80 mm and a height of 355 mm was used as the conductive support.

The coating solution composition U was formed on the support as described below.
CL-6 was prepared and dip-coated to a dry film thickness of 1.0 μ to obtain a coating drum.

[0135] 1. UCL-6 coating solution composition ・ Titanium chelate compound (TC-750 manufactured by Matsumoto Pharmaceutical) 30 g ・ Silane coupling agent (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) 17 g ・ 2-propanol 150 ml Coating solution on this UCL layer as follows The composition CGL-3 was dispersed and prepared, and dip-coated so as to have a thickness of 0.5 μm to obtain a coating drum.

[0136] 2. CGL-3 coating solution composition ・ Y-type titanyl phthalocyanine (CGM-3) 10 g ・ Silicone resin (KR-5240 manufactured by Shin-Etsu Chemical Co., Ltd.) 10 g ・ t-vinyl acetate 1000 ml The above coating solution composition is dispersed using a sand mill for 20 hours. A coating solution composition CTL-6 was prepared on the CGL layer as described below, and CSH was applied to a dry film thickness of 23 μm.
After drying at 120 ° C. for 1 hour, the coating drum No. 4-1
I got

[0137] 3. CTL-6 coating liquid composition ・ CTM-3 500 g ・ Polycarbonate (Z-200 manufactured by Mitsubishi Gas Chemical Company) 560 g ・ Dioxolane derivative (Compound example 1, bp 80-83 ° C.) 2600 ml ・ Dioxolane derivative (Compound example 6, bp 113-115) ° C) 200 ml ・ Silicone oil (KF-54 Shin-Etsu Chemical Co., Ltd.) 100 ppm based on the total solid content ・ AO agent ([4- (4-hydroxy-3,5-di-t-butylphenyl) propionyl] -N- (4-hydroxy-3,5-di-t-butylphenyl) methyl-2,2,6,6-tetramethylpiperidine) 20 g. 4-1
Had good coatability. ± 2 variation in film thickness in image area
It was within μm.

The electrophotographic photosensitive drum no. 1-1 to 4-1 are Konica Copier U-BIX
The following photoreceptor characteristics were evaluated using the No. 4045.

[0139] 1. Electrophotographic characteristics The above copier was modified and equipped with a surface potentiometer, and when the process of charging → exposure → static elimination was repeated 10,000 times, 2
Absolute values (ΔVb, ΔVw, ΔVr, respectively) of the difference between the black paper potential, the white paper potential, and the residual potential at the first and the 10,000th time
Was measured and evaluated. The black paper potential referred to here is the surface potential of the photoconductor when copying a black paper original having a reflection density of 1.3. Similarly, the blank potential refers to the surface potential of the photoconductor when copying a blank document having a reflection density of 0.0.

2. Image Evaluation The image samples after 10,000 copies were examined for ground fog, image streaks such as white streaks and black streaks in halftone images, image defects due to photoreceptor deterioration such as shading unevenness, and the presence of blade turning.

3. Resolution 2.0 equally spaced vertical lines per 1mm, 3.0,
4.0 lines, 5.0 lines, 6.0 lines, 7.0 lines, and 8.0 lines are provided, and a grade in which vertical lines can be distinguished is defined as a resolution. It indicates the degree of blurring, and the smaller the number, the worse it is.

[0142] 4. Abrasion loss The photoreceptor film thickness was measured after 10,000 copies and compared with the initial value.

Table 2 shows the results.

[0144]

[Table 2]

As is clear from Table 2, the photoreceptor of the present invention has good electrophotographic characteristics, image characteristics,
Since a solvent having excellent resolution and abrasion resistance and containing no halogen is used as a coating solvent, environmental problems, particularly ozone hole problems and carcinogenicity problems, do not occur. Further, it can be seen that a large number of coatings have good coating stability from the beginning and have excellent properties such as layering properties in the production method.

As a good solvent not containing halogen of polycarbonate, cyclic 6 containing two oxygen atoms in the molecule is used.
There is dioxane, a membered ring ether, but dioxane is highly toxic and carcinogenic and cannot be put into the process.

The electrophotographic photosensitive member No. 1-1 and No. 1 4-1 was modified to a digital image exposure system using a semiconductor laser light source (780 nm),
-Mounted on a modified BIX4145 machine and performed an image forming test 10,000 times, and observed the amount of potential fluctuation, image evaluation, resolution, and abrasion loss.

1. Measurement of the potential fluctuation amount The potential of the unexposed portion (VH) before and after the 10,000 times of the image forming test and the potential (VL) of the exposed portion when the exposure light is fully turned on are measured, and the image is extracted from the absolute differences ΔVH and ΔVL. The potential fluctuation amount of each of the photoconductors before and after was obtained.

Table 3 shows the results.

[0150]

[Table 3]

As is clear from Table 3, the photoreceptor of the present invention exhibited electrophotographic characteristics, image characteristics,
It is excellent in resolution and abrasion resistance, and uses a solvent that does not contain halogen as a coating solvent, so it does not cause environmental problems, especially ozone hole problems and carcinogenicity problems. It turns out that it has excellent characteristics.

As a good solvent containing no halogen in polycarbonate, there is dioxane which is a cyclic ether containing two oxygen atoms in the molecule. However, dioxane is highly toxic and carcinogenic and cannot be put into the process.

[0153]

According to the present invention, a solvent containing no halogen is used as a coating solvent, and it has low toxicity, environmental problems,
In particular, there is no ozone hole problem or carcinogenic problem, etc., and it has excellent potential characteristics, image characteristics, and resolution over the long term from the initial stage of image formation, and has excellent coating properties and layering properties. A composition, an electrophotographic photoreceptor, and a method for producing the same were provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a coating apparatus.

FIG. 2 is a perspective view of a slide hopper type coating apparatus.

FIG. 3 is a schematic cross-sectional view of a coating apparatus of a simultaneous multilayer coating method.

FIG. 4 is a schematic cross-sectional view of a coating apparatus of a sequential multilayer coating method.

[Explanation of symbols]

 1A, 1B Cylindrical substrate 2, 2A Coating liquid 3, 32 Coating device 4, 42 Coating liquid slide surface 5, 51, 52 Coating liquid tank 6-1 Liquid supply pump 6-1 'Liquid supply pipe 6A Coating liquid supply unit 7, 71, 72 Coating liquid distribution chamber 8, 82 Coating liquid distribution slit

Claims (11)

[Claims] 1. A boiling point of 150 represented by the following general formula (1)
A coating composition for an electrophotographic photoreceptor, comprising a dioxolane derivative having a temperature of not higher than 0.degree. C. and dissolving a binder and silicone oil. Embedded image [Wherein, R _{1 to} R ₆ are a hydrogen atom or C 1-3 substituted;
Represents an unsubstituted alkyl group, and R _{1 to} R ₆ are not simultaneously a hydrogen atom. ] 2. The coating composition according to claim 1, wherein the binder is a polycarbonate. 3. The coating composition for an electrophotographic photosensitive member according to claim 1, further comprising a charge transport material dissolved therein. 4. The coating composition for an electrophotographic photoreceptor according to claim 1, further comprising an antioxidant dissolved therein. 5. The boiling point represented by the general formula (1): 150
A method for producing an electrophotographic photoreceptor, comprising applying a coating composition containing a dioxolane derivative, a binder and silicone oil at a temperature of not more than ° C on a conductive support. 6. The method according to claim 5, wherein the coating composition is the coating composition according to any one of claims 2 to 4. 7. A boiling point of 150 represented by the general formula (1)
An electrophotographic photoreceptor containing a dioxolane derivative at a temperature of not more than ℃ and dissolving a binder and silicone oil. 8. The electrophotographic photosensitive member according to claim 7, wherein said binder is polycarbonate. 9. The electrophotographic photosensitive member according to claim 7, wherein a charge transport material is further dissolved. 10. The electrophotographic photosensitive member according to claim 7, wherein an antioxidant is further dissolved. 11. The electrophotographic photoreceptor according to claim 7, wherein the residual amount of the dioxolane derivative in the photoreceptor is 20 to 50,000 ppm of the entire photosensitive layer.