JPH0675387A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the electrophotographic sensitive body which maintains toner-filming resistance for continuous picture copy. CONSTITUTION:In the electrophotographic sensitive body having at least an electric charge generating layer and an electric charge transferring layer on a conductive substrate, the stable electrophotographic sensitive body is obtained by using the mixture of at least one kind of resin select from the group (a) consisting of polysulfon or polyarylate and at last one selected from group (b) consisting of polystyrene, acrylonitrile-styrene copolymer, styrene-butadiene copolymer as the component of a binder to prevent toner filming on the surface of the photosensitive body, and by adjusting the wt. ratio of (a) group resin and (b) group resin in 100:(0.5-20) to prevent the deterioration of the initial sensitivity of the photosensitive body and the degradation of sensitivity even if used repeatingly.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to improvements in electrophotographic photoreceptors.

[0002]

2. Description of the Related Art In recent years, as a photosensitive member used in an electrophotographic copying machine, a photosensitive member using an organic photosensitive material having advantages such as low cost, productivity and no pollution has begun to spread.
Polyvinylcarbazole is used for organic electrophotographic photoreceptors.
Photoconductive resin typified by (PVK), charge transfer complex type typified by PVK-TNF (2,4,7-trinitrofluorenone), pigment dispersion type typified by phthalocyanine-binder, and charge generation material A function-separated type photoconductor that uses a charge-transporting substance in combination is known, and a function-separated type photoconductor is particularly drawing attention.

In the case of this function-separated type photoreceptor, when charging and exposure are carried out according to the Carlson process, light passes through the charge transfer layer and reaches the charge generation layer, where both positive and negative charges are formed. Occur. Of these charges, the charges having the opposite polarity to the charged charges on the surface of the photoconductor are attracted by the charged charges and move in the charge transfer layer to reach the surface, where they are discharged and neutralized. . On the other hand, the charge remaining in the charge generation layer is neutralized by discharging in the conductive layer below the charge generation layer, the charge having a polarity opposite to that of the charged charge. Therefore, the most necessary characteristic of the function-separated type photoconductor in these steps is, of course, photoconductivity, but in the electrophotographic process, various properties of the photoconductor are affected by the development step and transfer step. The function-separated type photoreceptor must exhibit sufficiently satisfactory characteristics even in these steps.

By the way, in electrophotographic processes other than charging and exposure, one of the biggest problems is adhesion of toner to the surface of the photoconductor, and abrasion and scratches when the surface of the photoconductor is contacted with the developer or transfer paper. Is. In particular, when such a function-separated high-sensitivity photoconductor is applied to the Carlson process and incorporated in a copying machine or the like to repeatedly produce images, a film may be formed on the surface of the photoconductor. To be inspected. This phenomenon, which should be called toner filming, is considered to be caused by the adhesion of the toner material used for forming an electrostatic charge to a visible image on the surface of the photoconductor. In this way, the toner film attached to the surface of the photoconductor is not easily removed, and streaks are formed on the photoconductor during image copying. Such toner films also cause a substantial loss in sensitivity of the photoreceptor and a sharp decrease in the electrical properties of the photoreceptor, resulting in a significant increase in the useful number of copies obtained from such photoreceptor. make low.

In order to prevent this drawback, polycarbonate, polyester, polyvinylidene chloride, polystyrene or the like is useful in JP-A-49-105537 as a resin for the binder component of the transfer agent in the transfer layer. However, the surface of these single photoreceptors is extremely soft, easily damaged, and quickly loses the smoothness required to achieve good quality photocopying. Further, the surface of the charge transfer layer is easily worn even if a relatively small number of copies are made. To solve the above problem,
JP-A-52-72231 proposes to use a polycarbonate and an acrylic resin together, but the toner filming resistance is still insufficient, and the sensitivity of the photoreceptor itself is lowered during continuous image copying. Further, JP-A-59-1684451 proposes a polyarylate and an acrylic (methacrylic acid) ester-styrene copolymer resin as a binder resin for the transfer layer. Inadequate,
In addition, the sensitivity of the photoconductor itself is significantly reduced during continuous image copying.

Further, the problem of film formation becomes more serious as the temperature to which the photoreceptor surface is exposed becomes higher. Therefore, it is desirable not only to be able to overcome the problem of toner filming, but also to sufficiently overcome the problem of such toner filming formation even at high temperatures.

[0007]

DISCLOSURE OF THE INVENTION The present invention shows stable electrical characteristics even when the environment such as temperature and humidity changes, and
It is an object of the present invention to provide an electrophotographic photoconductor that sufficiently maintains the toner filming resistance against continuous image copying and does not cause a decrease in the sensitivity of the photoconductor itself.

[0008]

According to the present invention, a binder for forming a charge transfer layer in a function-separated electrophotographic photoreceptor having at least a charge generation layer and a charge transfer layer on a conductive substrate. At least one resin of group (a) consisting of polysulfone and polyarylate as components, polystyrene, acrylonitrile-styrene copolymer resin, styrene-butadiene copolymer resin, hydrogenated styrene-butadiene copolymer resin and hydrogenated From styrene-isoprene copolymer resin resin, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer resin, polyvinylcarbazole, styrene-maleic acid copolymer resin, polyvinylidene chloride, phenoxy resin, and polyvinyl acetal A mixed system with at least one resin selected from the group (b) This prevents toner filming in which toner adheres to the surface of the electrophotographic photosensitive member, and the mixing ratio of the resin of group (a) and the resin of group (b) is set to 100: 0.5 to 20 by weight. This suppresses the decrease in the initial sensitivity of the photoconductor, the decrease in the charging potential and the increase in the residual potential are small even after repeated use, and the sensitivity does not deteriorate even if the environment of temperature or humidity changes. The inventors have found that an electrophotographic photoreceptor having electric characteristics can be obtained, and completed the present invention.

Next, each constituent material used in the present invention will be described. The conductive substrate is intended to supply a charge having a polarity opposite to that of the charged charge to the substrate side, has a specific electric resistance of 10 ⁸ Ωcm or less, and is of an intermediate layer, a charge generation layer and a charge transfer layer. A material that can withstand film forming conditions can be used. Examples of these are electrically conductive metals and alloys such as Al, Ni, Cr, Zn and stainless, and glass,
The surfaces of inorganic insulating materials such as ceramics and organic insulating materials such as polyester, polyimide, phenol resin, nylon resin, and paper are coated with Al, Ni, Cr, Zn, stainless steel by vacuum deposition, sputtering, spray coating, or the like.
Examples thereof include those coated with an electrically conductive substance such as carbon, tin oxide, indium oxide, etc. and subjected to a conductive treatment.

The charge generation layer is composed of a charge generation material alone or a resin in which the charge generation material is dispersed or compatible. As the charge generating material, for example, CI Pigment Bull-25
(CI <Color Index> 21180), Sea Eye Pigment Red 41 (CI 21100), Sea Eye Acid Red 52 (CI
45100), CI Basic Red 3 (CI 45210), a phthalocyanine pigment having a porphyrin skeleton, an azurenium salt pigment, a squalic salt pigment, an anthane santhuron pigment, an azo pigment having a carbazole skeleton (JP-A-53-95033). JP-A-53-1325), azo pigments having a stilbene skeleton (described in JP-A-53-138229), and azo pigments having a triphenylamine skeleton (JP-A-53-1325).
47), azo pigments having a dibenzothiophene skeleton (described in JP-A-54-21728), azo pigments having an oxadiazole skeleton (described in JP-A-54-12742), fluorenone skeleton Azo pigment having
54-22834), azo pigments having a bisstilbene skeleton (described in JP-A-54-17733), azo pigments having a distyryloxadiazole skeleton (JP-A-54-
No. 2129), a trisazo pigment having a distyrylcarbazole skeleton (described in JP-A-54-17734), a trisazo pigment having a carbazole skeleton (described in JP-A-57-195767), and CI AVA Organic pigments such as indigo pigments such as brown 5 (CI 73410) and sea bud dye (CI 73030), and perylene pigments such as Argol Scarlet B and Indus Scarlet R (manufactured by Bayer) can be used.

Among these charge generating materials, azo pigments are particularly preferable, and among the azo pigments, disazo pigments or trisazo pigments are most preferable. Specific examples of the disazo pigment or the trisazo pigment are shown in Tables 1 to 15
Shown in. However, Table 2 to Table 4, Table 6 to Table 10, and Table 12
-The general formula which shows the position of the substituent A of Table 15 is based on the general formula shown in Table 1, Table 5, and Table 11, respectively.

[0012]

[Table 1] Table 1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 2] Table 2 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 3] Table 3 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 4] Table 4 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 5] Table 5 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 6] Table 6 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 7] Table 7 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 8] Table 8 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 9] Table 9 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 10] Table 10 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 11] Table 11 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 12] Table 12 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 13] Table 13 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 14] Table 14 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 15] Table 15 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

The thickness of the charge generation layer is suitably about 0.05 to 2 μm, preferably 0.1 to 1 μm. The charge generation layer is formed by dispersing or compatibilizing the charge generation material together with the resin in a suitable solvent, and coating and drying the charge generation material on the substrate or the undercoat layer.

Examples of such resins include polystyrene,
Styrene-butadiene copolymer resin, styrene-acrylonitrile copolymer resin, styrene-maleic anhydride copolymer resin, polyester, polyarylate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, polyvinyl acetate, Polyvinylidene chloride, polyacrylate, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl acetal,
Thermoplastic or thermosetting resin such as polyvinyl formal, phenoxy resin, polyvinyl pyridine, polyvinyl carbazole, acrylic resin, silicone resin, nitrile rubber, chloroprene rubber, butadiene rubber, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin Is mentioned. These binder materials may be used alone or as a mixture. The weight ratio of the charge generating material to the binder material is preferably 100: 0 to 100: 50.

As the solvent, benzene, toluene, xylene, methylene chloride, dichloroethane, monochlorobenzene, dichlorobenzene, ethyl alcohol, methyl alcohol, butyl alcohol, isopropyl alcohol, ethyl acetate, butyl acetate, methyl ethyl ketone, dioxane, tetrahydrofuran, cyclohexane. , Methyl cellosolve, ethyl cellosolve and the like, and these solvents can be used alone or in combination.

The charge transfer layer of the present invention is composed mainly of a charge transfer agent and a binder, and by using a mixed system of the resin of group (a) and the resin of group (b) as a binder. By preventing toner filming and controlling the mixing ratio of each resin, it is possible to suppress the decrease in sensitivity. The mixing ratio of the resin of group (a) and the resin of group (b) is 100: 0.5 to 100: 20 by weight, preferably 100: 1.
~ 100: 10. If the usage ratio exceeds 100: 20, the initial sensitivity is lowered, and in some cases, the sensitivity deteriorates repetitively, and if it is less than 100: 0.5, the effect of preventing toner filming is small.

As the polysulfone used in the present invention, those represented by the following formula (I) are suitable. Specific examples thereof include cordel polysulfone, Radel polysulfone having improved heat resistance and chemical resistance, Furthermore, there are Mindelpolisulfones A, B, C, etc. that are easy to handle (all manufactured by Amoco Japan).

[0018]

[Chemical 1] However, n is a positive integer of 50 to 60. Further, as the polyarylate used in the present invention, those represented by the following formula (II) are suitable.

[0019]

[Chemical 2] However, R ₁ and R _{2 are} hydrogen, an alkyl group having 1 to 7 carbon atoms, an aryl group, or R ₁ and R _{2 which} are cyclically bonded. R ₃ , R ₄ , R ₅ , R ₆ : H, an alkyl group having 1 to 7 carbon atoms,
Phenyl group, cycloalkyl group, halogen. n is an integer of 20 or more. Specific examples of polyarylate are listed in Tables 16-17.

[0020]

[Table 16] Table 16 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 17] Table 17 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Next, specific examples of the binder component resin for the moving layer included in the group (b) of the present invention will be described below.

The polystyrene used in the present invention is a polymer having a constitutional unit represented by the following general formula, which is obtained by dehydrogenating ethylbenzene obtained by the reaction of benzene and ethylene to obtain a styrene monomer, and polymerizing the styrene monomer. is there.

[0023] Further, the copolymerization ratio of the acrylonitrile-styrene copolymer used in the present invention is preferably acrylonitrile: styrene = 1: 100 to 500: 100 by weight ratio, and more preferably 10: 100 to 100: 100. .

The copolymerization ratio of the styrene-butadiene copolymer used in the present invention is a weight ratio of styrene:
Butadiene = 10: 100 to 100: 100 is preferable, and 20: 100 to 80: 100 is more preferable.

In the present invention, the hydrogenated styrene-butadiene copolymer and hydrogenated styrene-isoprene copolymer resin contained in the charge transfer layer mainly contain -CH = CH- double bond portion based on butadiene or isoprene. By hydrogenation-
CH ₂ --CH _2-
It has a (SP value) of around 7.5 to 9.0 and has excellent compatibility with additive substances such as charge transfer substances added to the photosensitive layer. Therefore, the charge transfer layer film formed from such a copolymer is excellent in durability, weather resistance, ozone resistance, and transparency. The hydrogenated styrene-butadiene copolymer or hydrogenated styrene-isoprene copolymer used in the present invention is, for example, a copolymer such as a styrene-butadiene or styrene-isoprene block copolymer, a random polymer or a graft polymer. Can be easily obtained by hydrogenating the compound in the presence of a hydrogenation catalyst such as a supported heterogeneous catalyst or a Ziegler type homogeneous catalyst. In this case, the supported heterogeneous catalyst may be, for example, Ni, Pt, Pd, Ru, Rh.
A catalyst in which a metal such as carbon is supported on a carrier such as carbon, silica, alumina, silica-alumina, diatomaceous earth, etc., and as a Ziegler type homogeneous catalyst, for example, organic acid Ni
Examples thereof include salts, Co salts, Fe salts, Cr salts, or catalysts obtained by reacting a metal chelate compound of acetylacetone with a metal such as Ni, Co, Fe, or Cr and a reducing agent such as an organic Al compound in a solvent. To be The hydrogenation rate of the copolymer used in the present invention is suitably 40% or more, preferably 80% or more. If the hydrogenation rate is less than 40%, the residual potential will increase with repeated use and it will cause scumming, which is not desirable.

The polyvinyl chloride used in the present invention is obtained by polymerizing a vinyl chloride monomer and has the general formula:-(CH ₂ -C
It is represented by HCl-) n-.

The polyvinyl acetate used in the present invention is represented by the following general formula.

The vinyl chloride-vinyl acetate copolymer resin used in the present invention is a copolymer of vinyl chloride and vinyl acetate, which are monomers, and may also contain other monomers if necessary. It may be polymerized. Examples of monomers to be copolymerized are methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n- Hexyl methacrylate, lauryl methacrylate, acrylic acid, methacrylic acid, maleic acid, maleic anhydride,
Examples thereof include itaconic acid, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, acrylamide, N-methylol acrylamide, diacetone acrylamide, glycidyl methacrylate, vinyltoluene, acrylonitrile and vinyl alcohol. The copolymerization ratio of vinyl chloride and vinyl acetate is a weight ratio, and vinyl chloride: vinyl acetate is preferably 50:50 to 90:10. The copolymerization ratio of monomers other than vinyl chloride and vinyl acetate is a weight ratio, and the monomers other than vinyl chloride-vinyl acetate: vinyl chloride-vinyl acetate are preferably 100: 0 to 80:20.

The polyvinyl carbazole used in the present invention refers to poly-N-vinyl carbazole or carbazole ring having a hydrogen atom substituted. As the substituent, an alkyl group, an aryl group, an amino group, a nitro group,
Examples thereof include a halogen atom, an alkylaryl group and an alkylamino group.

The styrene-maleic acid type copolymer resin used in the present invention is a styrene monomer and a maleic acid monomer having various ratios represented by the following general formula.
Further, maleic anhydride or an esterified product of maleic anhydride may be used instead of maleic acid. The maleic acid monomer is preferably 0.01 to 1 mol, more preferably 0.1 to 0.5 mol, based on 1 mol of the styrene monomer.

The vinylidene chloride resin used in the present invention is a vinylidene chloride homopolymer or copolymer.
Examples of monomers copolymerized with vinylidene chloride include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate. , N-hexyl methacrylate, lauryl methacrylate, acrylic acid,
Methacrylic acid, maleic acid, maleic anhydride, itaconic acid, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, acrylamide, N-methylol acrylamide, diacetone acrylamide, glycidyl methacrylate, vinyl toluene,
Examples thereof include vinyl acetate, acrylonitrile, styrene and the like. Further, the copolymerization ratio of vinylidene chloride and these monomers is from vinylidene chloride: the above-mentioned monomer = 100: 0.5.
100: 100 is preferable, and more preferably 100: 1 to 10
It is 0:50.

The phenoxy resin used in the present invention is a high molecular weight polyhydroxy ether based on bisphenol A and epichlorohydrin, and is composed of a monomer represented by the following structural formula.

The polyvinyl acetal resin used in the present invention is made by adding an aldehyde to polyvinyl alcohol under an acid catalyst, and is represented by the following general formula. Here, R ₁ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. The copolymerization ratio is preferably 60 mol% or more for the l-mer containing an acetal group, 6 mol% or less for the n-mer containing an acetyl group, and the remaining mol% for the m-mer containing a hydroxyl group.

In the charge transfer layer of the present invention, the charge transfer substance and at least one resin of group (a) and at least one resin of group (b) are dissolved or dispersed in a suitable solvent, and the resulting solution is dispersed. It can be formed by coating and drying. The weight ratio of the charge transfer material to the binder resin is preferably 2: 8 to 8: 2. The thickness of the charge transfer layer is preferably 5 to 100 μm.

As the charge transfer agent to be combined with the resin of the binder component of the present invention as described above, all known electron donating substances or electron accepting substances can be used. First, among the charge transfer agents, electron-donating substances include poly-N-carbazole and its derivatives, poly-γ-carbazolyethylglutamate and its derivatives, pyrene-formaldehyde dehydrate condensates and their derivatives, polyvinylpyrene, polyvinylphenanthrene, There are oxazole derivatives, imidazole derivatives, triphenylamine derivatives, and the compounds shown below.

(1) (JP-A-55-154955, JP-A-55-15)
(Described in the 6954 publication) [In the formula, R ₁ represents a methyl group, an ethyl group, a 2-hydroxyethyl group, or a 2-chloroethyl group, and R ₂ represents a methyl group, an ethyl group, a benzyl group, or a phenyl group,
R ₃ is hydrogen, chlorine, bromine, an alkyl group having 1 to 4 carbon atoms,
An alkoxyl group having 1 to 4 carbon atoms, a dialkylamino group,
Or represents a nitro group] (2) (described in JP-A-55-52063) [In the formula, Ar represents a naphthalene ring, anthracene ring, a styryl group and a substituted product thereof, or a pyridine ring, a furan ring and a thiophene ring, and R represents an alkyl group or a benzyl group] (3) (JP-A-56- (Described in JP 81850) [In the formula, R ₁ represents an alkyl group, a benzyl group or a phenyl group, R ₂ represents hydrogen, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group, a diaralkylamino group or Represents a diarylamino group, n is 1
Represents an integer of 4 and n is 2 or more, and R ₂ may be the same or different. R ₃ represents hydrogen or a methoxy group] (4) (described in JP-A-51-10983) [In the formula, R ₁ represents an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group or a heterocyclic group, and R ₂ ,
R ₃ may be the same or different and each represents hydrogen, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a chloroalkyl group or a substituted or unsubstituted aralkyl group, and R ₂ and R ₃ are mutually different. It may combine with each other to form a heterocycle containing nitrogen. R _{4 s} may be the same or different and represent hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group or halogen] (5) (described in JP-A-51-94829). [In the formula, R represents hydrogen or a halogen atom, and Ar represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group or carbazolyl group] (6) (described in JP-A-52-128373) [In the formula, R ₁ is hydrogen, halogen, a cyano group, or a carbon number of 1 to 1.
4 represents an alkoxy group of 4 or an alkyl group having 1 to 4 carbon atoms, and Ar is R ₂ represents an alkyl group having 1 to 4 carbon atoms, R ₃ represents hydrogen, halogen, an alkyl group having 1 to 4 carbon atoms, and 1 carbon atom.
To 4 alkoxy groups or dialkylamino groups, n is 1 or 2, and when n is 2, R ₃ may be the same or different, R ₄ and R ₅ are hydrogen, and the number of carbon atoms is 1 To 4 substituted or unsubstituted alkyl groups or substituted or unsubstituted benzyl groups] (7) (described in JP-A-56-29245) [In the formula, R represents a carbazolyl group, a pyridyl group, a thienyl group, an indolyl group, a furyl group, or a substituted or unsubstituted phenyl group, a styryl group, a naphthyl group, or an anthryl group, and these substituents are dialkylamino groups. Group, alkyl group, alkoxy group, carboxy group or ester thereof, halogen atom, cyano group, aralkylamino group, N-alkyl-N-aralkylamino group, amino group, nitro group, and acetylamino group. Group (8) (described in JP-A-58-58552) [Wherein R ₁ represents a lower alkyl group or a benzyl group, and R ₂ is substituted with a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, an amino group, or a lower alkyl group or a benzyl group. Represents an amino group, and n represents an integer of 1 or 2] (9) (described in JP-A-57-73075). [Wherein, R ₁ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, R ₂ and R ₃ represent a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and R ₄ represents A hydrogen atom, a lower alkyl group, or a substituted or unsubstituted phenyl group, and Ar represents a phenyl group or a naphthyl group] (10) (described in JP-A-58-198043) [In the formula, n is an integer of 0 or 1, R ₁ represents a hydrogen atom, an alkyl group containing a substituted alkyl group, or a substituted or unsubstituted phenyl group, Ar ₁ represents a substituted or unsubstituted aryl group, R ₅ is an alkyl group including a substituted alkyl group,
Or a substituted or unsubstituted aryl group, A is represented by the following formula, Alternatively, it represents a 9-anthryl group or a substituted or unsubstituted carbazolyl group, wherein R ₂ is a hydrogen atom, an alkyl group, an alkoxyl group, a halogen atom, or a group represented by the following formula. However, R ₃ and R ₄ represent an alkyl group containing a substituted alkyl group or a substituted or unsubstituted aryl group, R ₃ and R ₄ may be the same or different, and R ₄ forms a ring. Good. In addition, m is an integer of 0, 1, 2 or 3, and m is 2
In the above cases, R ₂ may be the same or different. When n is 0, A and R ₁ may jointly form a ring] (11) (described in JP-A-49-105537) [Wherein R ₁ , R ₂ and R ₃ represent hydrogen, a lower alkyl group, a lower alkoxy group, a dialkylamino group, or a halogen atom, and n represents 0 or 1] (12) (JP-A-52) (Described in JP-139066) [Wherein R ₁ and R ₂ represent an alkyl group containing a substituted alkyl group or a substituted or unsubstituted aryl group, and A represents a substituted amino group, or a substituted or unsubstituted aryl group or allyl group] 13) (described in JP-A-52-139065) [In the formula, X represents a hydrogen atom, a lower alkyl group, or a halogen atom, and R is an alkyl group containing a substituted alkyl group,
Or a substituted or unsubstituted aryl group, A represents a substituted amino group, a substituted or unsubstituted aryl group, or an allyl group]

Examples of the compound represented by the general formula (1) include 9-ethylcarbazole-3-aldehyde-1-methyl-1.
-Phenylhydrazone, 9-ethylcarbazole-3-aldevid-1-benzyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde-1,1-diphenylhydrazone and the like. Examples of the compound represented by the general formula (2) include:
4-diethylaminostyryl-β-aldehyde-1-methyl-1-
Examples include phenylhydrazone and 4-methoxynaphthalene-1-aldehyde-1-benzyl-1-phenylhydrazone. Examples of the compound represented by the general formula (3) include 4-methoxybenzaldehyde-1-methyl-1-phenylhydrazone, 2,
4-dimethoxybenzaldehyde-1-benzyl-1-phenylhydrazone, 4-diethylaminobenzaldehyde-1,1-
Diphenylhydrazone, 4-methoxybenzaldehyde-1
-Benzyl-1- (4-methoxy) phenylhydrazone, 4-diphenylaminobenzaldehyde-1-benzyl-1-phenylhydrazone, 4-dibenzylaminobenzaldehyde-1,1
-There is diphenylhydrazone etc. Examples of the compound represented by the general formula (4) include 1,1-bis (4-dibenzylaminophenyl) propane, tris (4-diethylaminophenyl) methane, 1,1-bis (4-dibenzylaminiphenyl) ) Propane, 2-2'-dimethyl-4,4'-bis (diethylamino) -triphenylmethane and the like. Examples of the compound represented by the general formula (5) include 9- (4-diethylaminostyryl) anthracene and 9-bromo-10- (4-diethylaminostyryl) anthracene. Examples of the compound represented by the general formula (6) include 9- (4-dimethylaminobenzylidene) fluorene and 3- (9-fluorenylidene)-
9-ethylcarbazole and the like. Examples of the compound represented by the general formula (7) include 1,2-bis (4-diethylaminostyryl) benzene and 1,2-bis (2,4-dimethoxystyryl) benzene. Examples of the compound represented by the general formula (8) include 3-styryl-9-ethylcarbazole and 3-
(4-methoxystyryl) -9-ethylcarbazole and the like. Examples of the compound represented by the general formula (9) include 4-
Examples include diphenylaminostilbene, 4-dibenzylaminostilbene, 4-ditolylaminostilbene, 1- (4-diphenylaminostyryl) naphthalene, and 1- (4-diethylaminostyryl) naphthalene. Examples of the compound represented by the general formula (10) include 4′-diphenylamino-α-phenylstilbene and 4′-N, Nbis (4-methylphenyl) amino-α-phenylstilbene. Examples of the compound represented by the general formula (11) include 1-phenyl-3- (4-diethylaminostyryl) -5- (4-diethylaminophenyl) pyrazoline and 1-phenyl-3- (4-dimethylaminostyryl). -
Examples include 5- (4-dimethylaminophenyl) pyrazoline.
Examples of the compound represented by the general formula (12) include 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, 2-N, N-diphenylamino-5- (4- Examples include diethylaminophenyl) -1,3,4-oxadiazole and 2- (4-dimethylaminophenyl) -5- (4-diethylaminophenyl) -1,3,4-oxadiazole. Examples of the compound represented by the general formula (13) include 2-N, N-diphenylamino-5 (N-ethylcarbazol-3-yl) -1,3,4-oxadiazole and 2- (4-
Diethylaminophenyl) -5- (N-ethylcarbazole-3-
Yl) -1,3,4-oxadiazole and the like.

Still other examples of charge transfer materials are listed below. (14) (described in JP-A-58-32372) [In the formula, R ₁ represents a lower alkyl group, a lower alkoxy group, or a halogen atom, n represents an integer of 0 to 4, and R 1
₂ , R ₃ may be the same or different and represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, or a halogen atom] (15) (described in JP-B-63-7890) [Wherein R ₁ , R ₃ and R ₄ are a hydrogen atom, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom, or a substituted or unsubstituted The substituted aryl group is represented by R
₂ represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group, or halogen. However, R ₁ , R ₂ , R ₃
And R ₄ is excluded when all are hydrogen atoms. Also,
k, l, m and n are integers of 1, 2, 3 or 4, and when each is an integer of 2, 3 or 4, R ₁ , R ₂ , R ₃ and R ₄ are the same or different. (16) (described in Japanese Patent Application No. 1-77839) [In the formula, Ar represents a condensed polycyclic hydrocarbon group having 18 or less carbon atoms, and R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted group. Represents a phenyl group, which may be the same or different] (17) (described in Japanese Patent Application No. 62-98394) [In the formula, Ar represents a substituted or unsubstituted aromatic hydrocarbon group, and A is represented by the following formula. However, Ar ′ represents a substituted or unsubstituted aromatic hydrocarbon group, and R ₁ and R ₂ represent a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group] (18) (Described in 2-94812) [In the formula, Ar represents an aromatic hydrocarbon group, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, or an aryl group.
n is 0 or 1, m is 1 or 2, and n = 0, m
= 1, Ar and R may jointly form a ring]

Examples of the benzine compound represented by the general formula (14) include N, N'-diphenyl-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine, 3 , 3'-dimethyl
There are -N, N, N ', N'-tetrakis (4-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine and the like. Examples of the biphenylamine compound represented by the general formula (15) include 4'-methoxy-N, N-diphenyl- [1,1'-biphenyl] -4-amine and 4 '.
-Methyl-N, N'-bis (4-methylphenyl) -4-amine, 4'-
Methoxy-N, N-bis (4-methylphenyl)-[1,1'-biphenyl] -4-amine and the like. Examples of the triarylamine compound represented by the general formula (16) include 1-N, N-diphenylaminopyrene and 1-N, N-bis (p-toluamino) pyrene. Examples of the diolefin aromatic compound represented by the general formula (17) include 1,4-bis (4-N, Ndiphenylamino) styrylbenzene and 1,4-bis [4-N, N-bis (p -Truly) amino] styrylbenzene etc. Examples of the styrupyrene compound represented by the general formula (18) include 1- (4-N, N
-Diphenylamino) styrylpyrene, 1- [4-N, N-bis (p-
Trilyl) amino] stilpyrene and the like.

In particular, a substance that transports a negative charge, that is, an electron may be used for the electrophotographic photoreceptor. Examples of the electron transport material include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,
7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-
9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,
4,8-Trinitrothioxanthone, 2,6,8-Trinitro-indy 4H-indeno [1,2,6] thiophen-4-one, 1,3,7-
Examples include trinitrodibenzothiophene-5,5-dioxide.

As a solvent for coating the charge transfer layer, tetrahydrofuran, dioxane, cyclohexane, toluene, monochlorobenzene, dichloroethane, methylene chloride or the like can be used. The solvent may also be used alone or in combination of two or more. Moreover, you may add a plasticizer and a leveling agent as needed. Examples of the plasticizer include halogenated pyrafine, dimethylnaphthalene, dibutyl phthalate, dioctyl phthalate, tricresyl phosphate and the like, and polymers and copolymers of polyester and the like. Examples of the leveling agent include silicone oil and perfluoro group-containing oligomer or polymer.

Further, in the present name, an intermediate layer of polyamide, polyvinyl alcohol, polyvinyl acetal, polyacrylic acid, polyhydroxymethacrylate, epoxy resin or the like, or the resin and a white pigment such as an oxide is provided between the support and the photosensitive layer. A white pigment layer made of titanium, zinc oxide, magnesium oxide, barium sulfate or lithopone can be provided. The thickness of the intermediate layer or white material layer is
The thickness is preferably 0.05 to 10 μm, and more preferably 0.2 to 5 μm. Hereinafter, the present name will be described in more detail with reference to examples.

[0043]

【Example】

Example 1 An outer surface of an aluminum cylinder having a diameter of 80 mm was coated with the following coating solution for an intermediate layer by a dipping method and dried by heating at 120 ° C. for 10 minutes to form an intermediate layer having a thickness of 0.5 μm.

<Intermediate Layer Coating Liquid> 8 parts of an alcohol-soluble polyamide resin (Amilan CM-8000, manufactured by Toray Industries, Inc.), 60 parts of methanol and 32 parts of butanol were mixed to prepare an intermediate layer coating liquid. . Next, the following charge generation layer coating liquid was applied on the intermediate layer by a dipping method, and dried by heating at 120 ° C. for 10 minutes to obtain a film thickness.
A 0.2 μm charge generation layer was provided.

<Coating Liquid for Charge Generation Layer> 20 g of the bisazo pigment having the following structural formula and 400 parts of cyclohexanone were kneaded and dispersed in a ball mill for 48 hours, and then cyclohexanone was further added.
600 parts was added and kneaded and dispersed for 2 hours. 1000 parts of cyclohexanone was added dropwise and diluted to this dispersion liquid to prepare a charge generation layer coating liquid.

[0046]

[Chemical 3]

Further, the following charge transfer layer coating liquid was applied onto the charge generation layer by a dipping method and dried by heating at 130 ° C. for 20 minutes to form a charge transfer layer having a thickness of 20 μm. did. <Coating liquid for charge transfer layer> 10 parts of charge transfer agent with the following structural formula

[0048]

[Chemical 4] Polysulfone 10 parts [Udel P-1700, manufactured by Amoco Japan] Phenoxy resin [PKHH, manufactured by United Carbon (USA)] 0.5 parts Silicone oil [KF-50, manufactured by Shin-Etsu Silicone] 0.002 parts It was dissolved in 90 parts of methylene to obtain a charge transfer layer coating liquid. The electrophotographic photosensitive drum thus obtained was mounted on a commercially available copying machine (Recopy FT 4820, manufactured by Ricoh Co., Ltd.), and a large number of images were printed at a standard exposure amount.

Example 2 A photoconductor drum was prepared in the same manner as in Example 1 except that the mixing ratio of the binder component resin used in the charge transfer layer coating liquid was changed from 10: 0.5 to 10: 1. , A commercially available copier (Recopy F
T4820) and printed a large number of images with standard exposure.

Example 3 A photosensitive drum was prepared in the same manner as in Example 1 except that the mixing ratio of the binder component resin used in the charge transfer layer coating liquid was changed from 10: 0.5 to 10: 2. , A commercially available copier (Recopy F
T4820) and printed a large number of images with standard exposure.

Example 4 A photoconductor drum was prepared in the same manner as in Example 1 except that the mixing ratio of the binder component resin used in the charge transfer layer coating solution was changed from 10: 1 to 10: 3. , A commercially available copier (Recopy FT48
20), and printed a large number of images with standard exposure.

Comparative Example 1 A photosensitive drum was prepared in the same manner as in Example 1 except that the binder component resin used in the coating liquid for the charge transfer layer was only polysulfone, and the same evaluation was performed. As described above, Examples 1 to 1
Table 18 shows the results of No. 4 and Comparative Example 1.

[0053]

[Table 18]

Examples 5 to 7 and Comparative Examples 2 and 3 Examples 5 to 7 were carried out in the same manner as Examples 1 to 3 except that an aluminum plate was used instead of the aluminum cylinder, and Example 4 and Comparative Example 1 were used. The electrophotographic photoreceptors of Comparative Examples 2 and 3 were prepared in the same manner as in.

The electrophotographic photosensitive member produced as described above was subjected to an electrostatic copying paper test apparatus (SP428 type manufactured by Kawaguchi Denki Seisakusho).
Was used to evaluate electrophotographic characteristics as follows. First, -6KV corona charging is performed for 20 seconds (charge potential at this time is V ₀ [V]), and then left in the dark to reduce surface potential to −
When 800 [V] was reached, a half-exposure amount E1 / 2 [lux · sec] required for irradiating with 4.5 lux tungsten light to bring the surface potential to −400 [V] was determined. The results are shown in Table 19.

[0056]

[Table 19]

Example 8 A phenoxy resin [PKHH (manufactured by United Carbon Co., USA)] of the resin of group (b) of the coating liquids for charge transfer layer of Examples 1 to 4 was added to the other (b) group. Resin, namely polystyrene (HRM700; manufactured by Denki Kagaku Kogyo Co., Ltd.), acrylonitrile-styrene copolymer resin (Sunlex SAN-A;
Mitsubishi Monsanto), styrene-butadiene copolymer resin (Clarene; manufactured by Denki Kagaku Kogyo), hydrogenated styrene-butadiene copolymer resin [hydrogenated styrene-butadiene
(Tuftec H1051, manufactured by Asahi Kasei) 10 g of toluene 400 ml
Dissolved in water, filtered through Celite to adsorb impurities to Celite, poured the filtrate into a large amount of methanol, separated, filtered, and dried at 80 ° C for 5 hours (hydrogenation rate 92%)] or Hydrogenated styrene-isoprene copolymer resin [hydrogenated styrene
-Isoprene (Sekton 2002, Kureha) treated in the same manner as hydrogenated styrene-butadiene copolymer resin (hydrogenation rate 95%), polyvinyl chloride (SH-250; manufactured by Denki Kagaku Kogyo), poly Vinyl acetate (Dencarac No.500H: manufactured by Denki Kagaku Kogyo Co., Ltd.), vinyl chloride-vinyl acetate copolymer resin (Hexaflex CM131: Hoechst Co., Ltd.), polyvinylcarbazole (Tokyo Kasei Kogyo Co., Ltd.), styrene-maleic acid co-polymer Polymer resin [Suprapal AP-80: manufactured by Badishaniline (BASF)], phenoxy resin [PKHH: United Carbon Co. (UCC)], polyvinyl-acetal (polyvinyl butyral, S-REC BL-1: Sekisui Chemical Co., Ltd.) Electrophotographic photosensitive drums were prepared in the same manner as in Examples 1 to 4 except that each of them was mounted on a copying machine (Recopy FT4820), and polysulfone / (b ) In the case of group resin = 100/5 to 100/20, the standard exposure of FT4820
In the case of 100/30, a large number of images were repeatedly printed with the maximum exposure amount of FT4820.
No filming was observed. In addition, polysulfone /
(b) When the group resin = 100/0, toner filming was observed on 3,000 to 10,000 sheets.

Example 9 In place of the phenoxy resin belonging to the group (b) of Examples 5 to 7 and Comparative Examples 2 to 3, each of the other resins of the group (b) other than the phenoxy resin was used to form an aluminum plate. An electrophotographic photoconductor was prepared using the above. When electrophotographic characteristics were evaluated in the same manner as above using an electrostatic copying paper tester (SP428 type manufactured by Kawaguchi Electric Co., Ltd.), polysulfone / (b) group resin = 100 / 0-
The half-exposure amount at 100/20 is almost the same as that at high sensitivity (however, as mentioned above, toner filming occurred on 3,000 to 10,000 sheets when the image was repeatedly printed on the drum photoreceptor of 100/0). , Polysulfone / (b) group resin = 100/30, it increased to about 1.5 to 2 times the half-dose exposure amount.

Examples 10 to 13 and Comparative Example 4 Polysulfone (Udel-1700, manufactured by Amoco Japan Limited) in the charge transfer layer coating solutions of Examples 1 to 4 and Comparative Example 1 was converted into polyarylate (U-100, Example 10 was carried out in the same manner as in Examples 1 to 4 and Comparative Example 1 except that it was changed to Unitika Ltd.).
13 to 13, the electrophotographic photosensitive drums of Comparative Example 4 were prepared.
The electrophotographic photosensitive drum thus obtained was mounted on a commercially available copying machine (Recopy FT4820), and a large number of sheets were repeatedly imaged. The results are shown in Table 20.

[0060]

[Table 20]

Examples 14 to 16 and Comparative Examples 5 and 6 Examples 14 to 16 are the same as Examples 10 to 12 except that an aluminum plate is used instead of the aluminum cylinder, and Example 13 and Comparative Example 4 are used. The electrophotographic photoreceptors of Comparative Examples 5 and 6 were prepared in the same manner as in. The electrophotographic characteristics were evaluated using the above photoreceptors and in the same manner as described above. The results are shown in Table 21.

[0062]

[Table 21]

Example 17 Phenoxy resin (PKHH: United Carbon Co. (UCC)) of the resin of group (b) of the coating solutions for charge transfer layer of Examples 10 to 13
Manufactured by the same company) was changed for each of the other resins of the group (b), electrophotographic photosensitive drums were prepared in the same manner as in Examples 10 to 13, and mounted on a copying machine (Recopy FT4820).
Standard exposure of FT4820 when polyarylate / (b) group resin = 100/5 to 100/20, FT4820 when 100/50
When a large number of images were repeatedly printed with the maximum exposure amount of 1, the toner filming was not observed up to a total of 30,000 or more. When polyarylate / (b) group resin = 100/0, toner filming occurred on 3,000 to 10,000 sheets.

Example 18 Instead of the phenoxy resin [PKHH: manufactured by United Carbon Co. (UCC)] belonging to the group (b) of Examples 14 to 16 and Comparative Examples 5 to 6, the other (b) was used. An aluminum plate electrophotographic photoreceptor was prepared using each of the resins in the group. When the electrophotographic characteristics were evaluated in the same manner as before using an electrostatic copying paper tester (SP428 type manufactured by Kawaguchi Electric Co., Ltd.), polyarylate / (b) group resin = 100/0 to 100/20 The half-exposure is about the same as the high sensitivity (however, as mentioned above, 100/0
Toner image was generated on 3,000 to 10,000 sheets when the image was repeatedly printed on the drum photoconductor of
(b) When the group resin is 100/50, the half-exposure amount is about 1.5.
Doubled to doubled.

[0065]

The binder component resin forming the charge transfer layer comprises at least one resin (a) consisting of polysulfone or polyarylate, polystyrene, acrylonitrile-styrene copolymer resin, styrene-butadiene copolymer resin. Combined resin, hydrogenated styrene-butadiene or styrene-isoprene copolymer resin, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinylcarbazole, styrene-maleic acid copolymer resin,
The electrophotographic photoreceptor using at least one resin selected from the group (b) consisting of polyvinylidene chloride, phenoxy resin, and polyvinyl acetal does not cause toner filming even after repeated use, and has a good image quality. It is possible to provide a photoconductor for electrophotography which produces Further, by setting the weight ratio of the resin of group (a) and the resin of group (b) which form the charge transfer layer to the resin of group (a) / group resin of group (b) = 100 / 0.5 to 100/20, It is possible to provide an electrophotographic photoreceptor having excellent toner filming resistance and excellent sensitivity in initial use or repeated use.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Tamura 1-3-6 Nakamagome, Nakamagome, Ota-ku, Higashizuka Kyoto

Claims (2)

[Claims] 1. In a function-separated electrophotographic photoreceptor having at least a charge generation layer and a charge transfer layer on a conductive substrate, the binder component of the charge transfer layer comprises polysulfone and polyarylate (a) group. At least one resin selected from the above resins, polystyrene, acrylonitrile-
Styrene copolymer resin, styrene-butadiene copolymer resin, hydrogenated styrene-butadiene copolymer resin and hydrogenated styrene-isoprene copolymer resin resin, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer Coalescing resin, polyvinylcarbazole, styrene-maleic acid copolymer resin, polyvinylidene chloride, phenoxy resin,
And a function-separated type electrophotographic photoreceptor, which is a mixed resin with at least one selected from the resins of group (b) consisting of polyvinyl acetal. 2. In the binder component of the charge transfer layer,
2. The function-separated type electrophotographic photoreceptor according to claim 1, wherein the mixing ratio of the resin of the group (a) and the resin of the group (b) is 100: 0.5 to 100: 20 by weight.