JP3521038B2 - Electrophotographic photoreceptor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to a photoreceptor using an aluminum substrate having an anodized film.

[0002]

2. Description of the Related Art Conventionally, electrophotographic photoreceptors have low chargeability,
In addition to poor charge retention, it has the disadvantage that these properties are greatly deteriorated by repeated use, and in order to improve the electrostatic properties of such an electrophotographic photoreceptor, especially the charging property,
Various attempts have been made. As one of them, it has been proposed to provide an anodized film as a blocking layer in order to prevent injection of a charge having a polarity opposite to that of the charge from the conductive substrate side during charging into the highly sensitive charge generation layer. (Japanese Patent Laid-Open No. 63-116162) However, since the porous anodic oxide coating of aluminum has numerous fine pores in the coating itself, it is poor in moisture resistance and environmental stability and is inferior in electrification and durability. It has the drawback. Therefore, sealing treatment is applied to the anodized film, and the anodized film (Al
Part of 2O3) is converted to boehmite (Al2O3 ・ 3H2
O) is common. Conventionally, as a sealing treatment method, a hydration sealing method of forming boehmite on the anodized film by boiling water for sealing (Japanese Patent Laid-Open No. 1-312554) and boehmite on the anodized film by hot water containing a metal salt. There is a metal salt sealing method for generating and sealing. Regarding the metal salt sealing method, a method of sealing at a low temperature with a sealing agent containing nickel fluoride as a main component (Japanese Patent Publication No. 6-75208) is also known.

However, among the conventional techniques, the hydration-sealing method and the metal-sealing method, in which the boehmite layer is formed on the porous anodic oxide film, are processed at a high temperature, so that the stability of the sealing bath is poor and the anodized surface is not formed. Defects are likely to occur due to dust wiping. Further, the sealing treatment method using a low-temperature sealing agent containing nickel fluoride as a main component has poor corrosion resistance immediately after the treatment, so that the anodic oxide surface is apt to deteriorate and a durability problem occurs. It takes several hours to several days or more to stabilize. Furthermore, when the repetitive characteristics of the residual potential were evaluated, it was found that the residual potential increased.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, that is, to provide an electrophotographic photosensitive member in which the residual potential does not rise during repeated charging and exposure. We have found that the above problem can be solved by providing a bayerite layer on a porous anodized film, and completed the present invention.

[0005]

Therefore, an object of the present invention is to (1) "an electrophotographic photosensitive member comprising a photoconductive layer on a conductive support (provided that a silicon atom is a base material, hydrogen original
Amorphous containing at least either child or halogen atom
(Excluding a photoconductive layer made of a material) , aluminum or an aluminum alloy having an anodized film and a bayerite layer sequentially formed on the surface is used as the conductive support, and the thickness of the bayerite layer is 0. 0.02 μm or more
An electrophotographic photoreceptor having a thickness of 5 μm or less ”,
(2) “After the conductive support forms an anodized film by anodizing the surface of aluminum or an aluminum alloy, the anodized film is formed at a liquid temperature of 20 ° C. or higher and a temperature of 80 ° C. or higher.
The electrophotographic photoreceptor according to (1) above, wherein the bayerite layer is formed by immersion treatment in a sealing bath at a temperature of not more than 0 ° C., and (3) “pH 2.0 or more and 5.0 or less”. An electrophotographic photosensitive member according to (2) above, characterized in that a sealing bath is used, and (4) " a photoconductive layer is provided on a conductive support.
Larger electrophotographic photoreceptor (however, silicon atom
With at least either hydrogen or halogen atoms
(Excluding photoconductive layer composed of amorphous material)
A conductive support made of aluminum or an aluminum alloy having an anodized film and a bayerite layer sequentially formed on the surface thereof , and the thickness of the bayerite layer is 0.02 μm or more and 1.5 μm or less. And a conductive support for an electrophotographic photoconductor.

In the present invention, the bayerite layer having good characteristics can be obtained by immersing it in pure water. In this case, a small amount of nickel acetate, cobalt acetate, sodium silicate, potassium dichromate, ammonia, triethanolamine and the like may be contained. At this time, the liquid temperature is 20 ° C. or higher and lower than 80 ° C., the pH is 2.0 or higher and 5.0 or lower, and the immersion time is 5 minutes or longer and 60.
Within minutes is preferable. In this case, the thickness of the bayerite layer is preferably 0.02 μm or more and 1.5 μm or less. The presence of the bayerite layer can be confirmed by X-ray microanalysis (EPMA).

As an aluminum material for obtaining the bayerite layer, in addition to pure Al-based materials, Al--Mg, Al
-Mg-Si, Al-Mg-Mn, Al-Mn, Al-
Cu-Ni, Al-Cu, Al-Si, Al-Cu-Z
It is possible to select and use from among aluminum alloy materials such as n, Al-Cu-Si and Al-Mg-Si.

Further, the bayerite layer is formed by forming an object to be treated having aluminum on an anodized film. Before applying the anodizing treatment, an acid alkali, an organic solvent, a surfactant, an emulsion, electrolysis, etc. Degreasing treatment by various degreasing cleaning methods is preferable.

The anodic oxide film is usually formed by anodizing treatment in an acidic bath of chromic acid, sulfuric acid, oxalic acid, tartaric acid, phosphoric acid, sulfamic acid, benzenesulfonic acid or the like. In this case, either DC or AC may be used,
Voltage is 2-160V, current density is 0.1-5A / d
It is preferable that m ² and liquid temperature be 10 to 40 ° C.

Next, the charge generating layer is a layer containing a charge generating substance as a main material, and a binder resin may be used if necessary.

As the binder resin, polyamide, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, polyacrylamide and the like are used. To be These binder resins may be used alone or in combination of two or more.

As the charge generating substance, for example, CI Pigment Blue 25 [Color Index (ICI) 2
1180], CI Pigment Red 41 [CI21
200], CI Acid Red 52 [CI4510
0], CI Basic Red [CI45210],
Furthermore, a phthalocyanine-based pigment having a polyfin skeleton,
Azurenium salt pigment, squaric salt pigment, azo pigment having a carbazole skeleton (described in JP-A-53-95033), azo pigment having a stilbene skeleton (described in JP-A-53-138229), triphenylamine skeleton Azo pigments (described in JP-A-53-132547), azo pigments having a dibenzothiophene skeleton (described in JP-A-54-21728), azo pigments having an oxadiazole skeleton (JP-A-54). -1274
2), azo pigments having a fluorenone skeleton (described in JP-A-54-22834), azo pigments having a bisstilbene skeleton (described in JP-A-54-17733), and distyryl oxadiene. Azo pigments having an azole skeleton (described in JP-A-54-2129), azo pigments having a distyrylcarbazole skeleton (JP-A-5-205)
4-17734), triazo pigments having a carbazole skeleton (JP-A-54-195767,
JP-A-57-195768), and phthalocyanine-based pigments such as CI Pigment Blue 16 (CI74100), CI BAT Brown 5 (CI).
73410), CI Bad Die (CI73030)
And organic pigments such as perylene-based pigments such as Indigo Scarlet B (manufactured by Violet) and Indanth Scarlet R (manufactured by Bayer).

These charge generating substances may be used alone or in combination of two or more. The binder resin is suitably used in a weight ratio of 0/1 to 10/1, preferably 0/1 to 1/1 with respect to the charge generating substance.

In the charge generating layer, the charge generating substance is dispersed with a binder resin if necessary using a solvent such as tetrahydrofuran, cyclohexanone, methyl ethyl ketone, dioxane, dichloroethane, etc. by a ball mill, an attritor, a sand mill, etc., and the dispersion liquid is appropriately diluted. Then, it can be formed by coating. The coating can be performed by using a dip coating method, a spray coating method, a roll coating method, or the like. A suitable film thickness of the charge generation layer is about 0.01 to 5 μm, preferably 0.1 to 2 μm.

Next, the charge transport layer is composed of a charge transport material and a binder resin which is optionally used. The charge transport layer can be formed by dissolving or dispersing these substances in a suitable solvent and coating and drying the substances. The charge transport material includes a hole transport material and an electron transport material.

As the hole-transporting substance, poly-N-vinylcarbazole and its derivative, poly-γ-carbazolylethylglutamate and its derivative, pyrene-formaldehyde condensate and its derivative, polyvinylpyrene, polyvinylphenanthrene, and oxazole derivative. , Oxadiazole derivative, imidazole derivative, triphenylamine derivative, 9- (p-diethylaminostyryl) anthracene, 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones , An electron-donating substance such as α-phenylstilbene derivative. Among these, triphenylamine derivatives, phenylhydrazones, and α-phenylstilbene derivatives are particularly desirable.

Examples of the electron transporting substance include chloranil, bromanyl, tetracyanoethylene, tetracyanoquinone dimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone,
2,4,8-trinitrothioxanthone, 2,6,8-
Examples of electron accepting substances include trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, diphenoquinone derivatives, and thiopyran derivatives. . These charge transport materials may be used alone or in combination of two or more.

Further, as the binder resin used in the present invention as necessary, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene-copolymer, styrene-maleic anhydride-copolymer, polyester, polyvinyl chloride, Vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyacrylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene,
Thermoplastic or thermosetting resins such as poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin may be mentioned. These binder resins may be used alone or in combination of two or more.

Tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride and the like are used as the solvent. The binder resin has a weight ratio of 10/1 to 1/100 to the charge transport material,
It is preferably 3/1 to 1/10.

A suitable thickness of the charge transport layer is about 5 to 100 μm. Further, in the present invention, a plasticizer or a leveling agent may be added to the charge transport layer. As the plasticizer, those used as a plasticizer for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount thereof is preferably about 0 to 30% by weight based on the charge transport layer. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil are used, and the amount thereof is preferably about 0 to 1% by weight based on the charge transport layer.

[0021]

The present invention will be described in more detail with reference to the following examples. Example 1 An aluminum plate was ultrasonically cleaned with distilled water. Subsequently, using a 15% sulfuric acid solution as an electrolyte solution, anodization was performed at a liquid temperature of 20 ° C. at a current density of 1 A / dm ² to form an anodized film of 5 μm, which was washed with water and dried. Next, the anodic oxide film prepared above is immersed in pure water adjusted to pH 4 at 50 ° C. for 30 minutes to make the surface of the anodic oxide film into a bayerite, forming a bayerite film of 0.5 μm and performing a sealing treatment, It was washed with water and dried.

(Coating liquid for charge generation layer) 400 g of cyclohexanone, 25 g of azo pigment 1 of the following chemical formula 1 and 40 g of polyvinyl butyral resin (Sekisui Chemical Slex BM)
-3) was added and ball milled for 48 hours to mix. Further, 400 g of cyclohexanone was added and mixed for 24 hours, and then 800 g of the dispersion liquid taken out was stirred to add 800 g of methyl ethyl ketone to obtain a coating liquid for the charge generation layer.

[0023]

[Chemical 1]

[0024] (Coating liquid for charge transfer layer)       10 parts of α-phenylstilbene-based charge transfer substance of Chemical formula 2

[0025]

[Chemical 2]

Polycarbonate resin (K1300, Teijin Ltd.) 10 parts Silicon oil (KF50, manufactured by Shin-Etsu Silicone) 0.0002 parts Tetrahydrafuran 80 parts The above charge generation layer on the anodized film subjected to sealing treatment. Blade coating solution, dried at 120 ° C. for 10 minutes to form a charge generation layer having a film thickness of 0.1 μm, and further coated with a charge transfer layer coating solution by blade coating at 120 ° C., 20 ° C. After being dried for a minute, a charge transfer layer having a film thickness of 20 μm was formed to prepare an electrophotographic photoreceptor.

Example 2 50 ° C. in pure water adjusted to pH 4 in Example 1 for 10
A photoconductor was prepared in the same manner as in Example 1 except that the bayerite layer having a film thickness of 0.01 μm was formed by immersion for a minute and sealing treatment was performed.

Example 3 In Example 1 in pure water adjusted to pH 4 at 50 ° C., 60
A photoreceptor was prepared in the same manner as in Example 1 except that the bayerite layer having a film thickness of 2 μm was formed by immersion for a minute, and the sealing treatment was performed.

Example 4 In pure water adjusted to pH 4 in Example 1, 80 ° C., 30
A photoconductor was prepared in the same manner as in Example 1, except that the bayerite layer having a film thickness of 1 μm was formed by immersion for a minute, and the sealing treatment was performed.

Example 5 In pure water adjusted to pH 4 in Example 1, 10 ° C., 30
A photoconductor was prepared in the same manner as in Example 1, except that the bayerite layer having a film thickness of 0.3 μm was formed by immersion for a minute, and the sealing treatment was performed.

Example 6 50 in pure water adjusted to pH 7 in Example 1
A photoreceptor was prepared in the same manner as in Example 1 except that the bayerite layer having a film thickness of 0.2 μm was formed by immersion at 30 ° C. for 30 minutes, and then the sealing treatment was performed.

Example 7 50 in pure water adjusted to pH 1 in Example 1
A photoreceptor was prepared in the same manner as in Example 1 except that the bayerite layer having a film thickness of 0.1 μm was formed by immersing at 30 ° C. for 30 minutes and then sealing treatment was performed.

Comparative Example 1 A photoconductor was prepared in the same manner as in Example 1 except that it was immersed in pure water at 90 ° C. for 30 minutes for sealing treatment to form a boehmite.

Comparative Example 2 A photosensitive member was prepared in the same manner as in Example 1 except that the nickel acetate solution was immersed in the nickel acetate solution at 90 ° C. for 10 minutes for sealing treatment.

Comparative Example 3 A photosensitive member was prepared in the same manner as in Example 1 except that the sealing treatment was not performed after the anodization in Example 1.

Comparative Example 4 A photoconductor was prepared in the same manner as in Example 1 except that anodic oxidation and sealing treatment were not performed.

The electrostatic characteristics of the electrophotographic photosensitive member produced as described above were evaluated as follows using an electrostatic characteristics measuring device (Kawaguchi Electric EPA-8100). -6KV corona charging for 20 seconds, then dark decay for 10 seconds 5
It was irradiated with tungsten light of lux. At this time, the surface potential 1 second after the start of charging is V1 (V) and the tungsten light is 1
The surface potential Vr (V) when irradiated for 0 seconds was measured. Next, it was charged to −800 V and irradiated with 5 lux of tungsten light, and the exposure amount E (lux · sec) required to bring the surface potential to −400 V was measured. After that, a series of operations of the above charging and exposure was repeated 5000 times, and V1, Vr, and E were measured.

[0038]

[Table 1]

[0039]

As described above in detail and concretely,
The electrophotographic photoreceptor provided with a photosensitive layer on an aluminum substrate having an anodized film of the present invention has a bayerite layer on the anodized film, so that the charging does not deteriorate during repeated charging and exposure, and remains It can be seen that this is extremely excellent in that the potential does not rise.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-281467 (JP, A) JP-A-5-232733 (JP, A) JP-A-57-104938 (JP, A) JP-A-7- 295241 (JP, A) JP-A 1-312554 (JP, A) JP-A 64-79754 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 5/00-5 / 16

Claims (4)

(57) [Claims] 1. An electrophotographic photosensitive member comprising a photoconductive layer on a conductive support (provided that a silicon atom serves as a base material and hydrogen is used as a base material).
Amorphous containing at least either atom or halogen atom
A photoconductive layer composed of a high-quality material) , aluminum or an aluminum alloy having an anodized film and a bayerite layer sequentially formed on the surface is used as the conductive support, and the thickness of the bayerite layer is An electrophotographic photoreceptor having a thickness of 0.02 μm or more and 1.5 μm or less. 2. The conductive support forms an anodized film by anodizing the surface of aluminum or an aluminum alloy, and then the anodized film is subjected to a sealing bath at a liquid temperature of 20 ° C. or higher and 80 ° C. or lower. The electrophotographic photoreceptor according to claim 1, wherein the bayerite layer is formed by immersion treatment. 3. The electrophotographic photosensitive member according to claim 2, wherein a sealing bath having a pH of 2.0 or more and 5.0 or less is used. 4. A photoconductive layer provided on a conductive support.
Electrophotographic photoreceptor (however, with silicon atoms as the base material, water
Non-containing at least either elementary atom or halogen atom
Conductors used for photoconductive layers composed of crystalline materials)
A conductive substrate, an anodized film and bayerite layer is made of aluminum or aluminum alloy formed by sequentially formed on the surface, the film thickness of the bayerite layer 0.02μ
A conductive support for an electrophotographic photosensitive member, characterized in that it is at least m and at most 1.5 μm.