JPH056015A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the photosensitive body which exhibits good performance at the time of initial and repetitive use in electrophotographic characteristics and physical properties by incorporating a specific perylene deriv. as a carrier generating material and polycarbonate as a binder into the photosensitive body. CONSTITUTION:A photosensitive layer(PCL) of laminated constitution consisting of a carrier transfer layer(CTL) 5 as a lower layer and a carrier generating layer(CGL) 6 as an upper layer on a base 1. This photosensitive layer contains the perylene deriv. expressed by formula I or formula II as the carrier generating material and the polycarbonate as the binder. In the formulas I, II, Z denotes the atom group necessary for forming a substd. or unsubstd. arom. ring. The photosensitive body obtd. in this way has the high spectral sensitivity up to a long wavelength region and high image quality, obviates the generation of a degradation in charge potential and an increase in white paper potential in iterative use, is chemically durable to O3 and NOx or UV rays and is less chemically worn in film thickness and flawed in the iterative use.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor.

[0002]

BACKGROUND OF THE INVENTION Since the development of electrophotography, the scope of photoconductive materials used in photoconductors has been expanded from inorganic to organic photoconductors (OPC) using organic photoconductive materials (PCM). Further, the photoconductive functions of carrier generation and carrier transport are separated into carrier generating substance (CGM) and carrier transporting substance (CTM), respectively, and the photoconductive layer (photosensitive layer; P
The layer structure of (CL) has also been improved by analysis of carrier behavior, and the binder resin used for layer formation is also being actively improved or pioneered.

With the improvement of these technologies, since the pre-paper can be used as a transfer material machine, the electrophotographic copying method has been generalized, suitable for mass use, improved performance, improved durability, and improved running cost. In particular, consideration for environmental hygiene during use has been required.

Under these circumstances, various organic substances have been developed as the CGM used in the PCM, and one of them is a perylene compound, in particular, a perylene derivative (BIP) into which imidazolopyridone is introduced. ) (JP-B-63-8423, JP-A-59-59686, JP-A-59-59686)
3-180956, 61-291061).

On the other hand, in OPCs which have been put into practical use up to now, the mainstream is for negative charging, but negative charging due to corona discharge produces 5 to 10 times more ozone than positive charging, and deterioration due to high-concentration ozone occurs. It becomes remarkable and there is a problem in terms of durability.

Further, due to the increase in the frequency of use, the amount of ozone emitted from the copying machine has become a problem in terms of work environment hygiene. It doesn't fit.

Therefore, the positive charging method is attracting attention, but the conventional P
CM (CGM) is still unsatisfactory in terms of sensitivity, chargeability, ozone resistance, etc., and the above-mentioned BIP is the same.

The layer structure of the PCL applied to the positive charging system may be a single layer type, a CTL / CGL / base type in which a carrier transport layer (CTL) is laminated on a carrier generation layer (CGL), or the reverse structure. Although any CGL / CTL / substrate type laminated type can be constructed, a single layer type and CGL / CTL / substrate type are convenient because it is difficult to obtain a high-performance n-type CTM.

However, in this case, since the surface of PCL has PCM having poor chemical and mechanical stability, chemical and mechanical obstacles such as ozone adsorption, film thickness loss, and scratches are likely to occur, and the performance is adjusted. The durability of CGL, which is a thin layer, is extremely weak, and if a protective layer is provided to compensate for this drawback, sensitivity,
The residual potential characteristics are deteriorated, and the binder needs to be improved.

Of course, many studies have been disclosed so far on the binder, and the excellent characteristics of polycarbonate (P-BPC) are shown therein.

However, demands for functional improvement in accordance with recent needs are more severe, and the above-mentioned perylene derivative (BIP) and polycarbonate (P-BPC) each exhibiting good performance.
A new technical study is required for the combination of.

[0012]

The object of the present invention is: (1) Spectral sensitivity in the long wavelength region, high image quality, (2) No decrease in charging potential or increase in blank sheet potential due to repeated use, (3) To provide an electrophotographic photosensitive member that is chemically resistant to O ₃ , NO _x or ultraviolet rays, and (4) has little mechanical film thickness wear and scratches caused by repeated use.

[0013]

The above-mentioned object of the present invention is as follows: as a carrier generating substance for an electrophotographic photoreceptor, the following general formula (BIP-1)
Alternatively, it is achieved by an electrophotographic photoreceptor containing a perylene derivative represented by (BIP-2) and a polycarbonate as a binder.

[0014]

[Chemical 3]

However, in the formula, Z represents an atomic group necessary for forming a substituted or unsubstituted aromatic ring.

Preferred as Z are benzene ring,
Examples thereof include naphthalene ring, anthracene ring, phenanthrene ring, pyridine ring, pyrimidine ring, pyrazole ring, and anthraquinone ring, and particularly preferable are benzene ring and naphthalene ring.

The substituent of Z is alkyl, alkoxy, aryl, aryloxy, acyl, acyloxy,
Amino, carbamoyl, halogen, nitro, cyano and the like can be mentioned.

These derivatives were found to have a Bragg angle of 2θ of 6.3 ° ± 0.
Those having peaks at 2 °, 12.5 ° ± 0.2 °, 25.4 ° ± 0.2 ° and 27.0 ° ± 0.2 ° are preferred.

Specific compound A-1 of the above-mentioned perylene derivative
Denotes a Z of -21.

[0020]

[Chemical 4]

[0021]

[Chemical 5]

General formula (BIP-1) or (BIP-
The compound represented by 2) is represented by the reaction formula (1):
It can be easily synthesized.

[0023]

[Chemical 6]

Further, in the embodiment of the present invention, the binder resin used is 2,2'-bis (4-
The carbonic acid ester unit derived from oxyphenyl) propane is represented by the following general formula (BPA-1), (BPA-2) or (BPZ).
-1), a polymer which is (BPZ-2), a copolymer thereof, or a mixture of the polymer copolymers is preferably contained.

[0025]

[Chemical 7]

The above-mentioned perylene derivative of the present invention has excellent photoconductivity, and by providing PCL in which the perylene derivative is dispersed in the binder containing the polycarbonate of the present invention on a conductive support, the electrophotographic photosensitive material of the present invention. Can form a body. The perylene derivative of the present invention, by utilizing its excellent carrier generation ability, is used as CGM, and by using CTM which can effectively act in combination with it,
A so-called function-separated type photoreceptor can be used. The function-separated type photoconductor may be a mixed dispersion type of the above substances, or may be a CGM comprising the perylene derivative of the present invention.
It is also possible to use a multi-layer type photoconductor in which CGL containing the above and CTL are laminated.

The electrophotographic photoreceptor of the present invention includes, for example,
As shown in FIG. 4, a support 1 (a conductive support or a sheet on which a conductive layer is provided) is provided with a single-layer PCL2 containing CGM, CTM and a binder resin. As shown in FIG. 8, there may be mentioned one in which a PCL having a laminated structure in which CTL 5 is a lower layer and CGL 6 is an upper layer is provided on a support 1.

In the single-layer function-separated type photoreceptor, photocarriers are generated and transported in a single layer, and whether CGM and CTM are electrically connected in the layer, and /
CGM also contributes to carrier transportation.

In the case of a laminated PCL, the CGL is that most of the incident light amount is absorbed by the CGL to generate many charge generation carriers, and the generated charge carriers are deactivated by recombination and trapping. However, it is preferable to make the layer as thin as possible within the range of a film thickness sufficient to generate photocarriers for injection into the CTL.

The CTL is electrically connected to the above-mentioned CGL and has a function of transporting charge carriers injected from the CGL to the surface in the presence of an electric field.

In any of the layer structures, a protective layer may be provided on the PCL, and an undercoat layer (intermediate layer) having a barrier function and adhesiveness may be provided between the support and the PCL. CTM is preferably added to the single-layer type PCL and the function-separated type CGL, if necessary.

The thickness of the single-layer type PCL is preferably 10 to 60 μm. The functionally separated CGL has a film thickness of 0.5 to 15 μm.
Is preferred. The thickness of the CTL is preferably 10-60 μm.

The thickness of the surface protective layer is preferably 0.1 to 7 μm. The thickness of the intermediate layer is preferably 0.05 to 10 μm.

Examples of the layer structure of the photoreceptor of the present invention are shown in FIGS. In the figure, 1 is a support, and 2 is a PCL containing CGM and CTM or PCM containing PCM having both carrier generation and carrier transport functions. 3 is a protective layer, and 4 is an intermediate layer for improving the barrier function and adhesiveness.

Further, 5 is a CTL and 6 is a CGL.

The binder resin usable for the protective layer and the intermediate layer is, for example, polystyrene, polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin. , Polyester resins, alkyd resins, polycarbonate resins, silicone resins, melamine resins, and other addition-polymerization resins, polyaddition-type resins, polycondensation-type other resins, and copolymers containing two or more of the repeating units of these resins. Coalescing resin,
Examples thereof include insulating resins such as vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, and polymer organic semiconductors such as poly-N-vinylcarbazole.

An antioxidant may be added to the PCL of the present invention for the purpose of preventing ozone deterioration.

Typical specific examples of such an antioxidant are shown below, but the antioxidant is not limited thereto.

Group (1): hindered phenols dibutylhydroxytoluene, 2,2'-methylenebis (6-
t-butyl-4-methylphenol), 4,4'-butylidene bis (6-t-butyl-3-methylphenol), 4,4'-thiobis (6-t-butyl-3-methylphenol), 2, 2'-butylidene bis (6-t-butyl-4-methylphenol), α-tocophenol, β-tocophenol, 2,2,4-trimethyl-6-
Hydroxy-7-t-butylchroman, pentaerythryltetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3-
(3,5-di-t-butyl-4-hydroxyphenyl) propionate], butylhydroxyanisole, dibutylhydroxyanisole, 1- [2-{(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl Oxy} ethyl] -4-
[3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidyl and the like.

Group (2): para-phenylenediamines N-phenyl-N'-isopropyl-p-phenylenediamine,
N, N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N′-dimethyl-N, N, ′-di-t-butyl- such as p-phenylenediamine.

Group (3): Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl
-5-Chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) -5-methylhydroquinone, etc.

Group (4): Organophosphorus compounds dilauryl-3,3'-thiodipropionate, distearyl-3-3'-thiodipropionate, ditetradecyl-3,
3'-thiodipropionate etc.

These compounds are known as antioxidants for rubbers, plastics, fats and oils, etc., and commercially available products can be easily obtained.

These antioxidants may be added to either CGL, CTL or the protective layer. In that case, the amount of the antioxidant added is 0.1-100 parts by weight, preferably 1-50 parts by weight, particularly preferably 5-25 parts by weight, based on 100 parts by weight of CTM.
Parts by weight.

Next, as a conductive support for supporting the PCL, a metal plate such as aluminum or nickel, a metal drum or a metal foil laminated, or aluminum,
A plastic film deposited with tin oxide, indium oxide, or the like, a paper coated with a conductive substance, a film such as plastic, or a drum can be used.

In the present invention, PCL is typically a dispersion prepared by dispersing the above-mentioned perylene derivative of the present invention in a suitable dispersion medium or solvent alone or together with a suitable binder resin containing at least the P-BPC of the present invention. It can be provided by a method of applying the liquid on the support or the undercoat layer or CTL by dip coating, spray coating, blade coating, roll coating, etc. and drying.

The perylene derivative of the present invention can be dispersed in a dispersion medium after being crushed into fine particles having an appropriate particle diameter by using, for example, a ball mill or a sand mill. A ball mill, a homomixer, a sand mill, an ultrasonic disperser, an attritor, or the like is used for the dispersion treatment.

Examples of the dispersion medium used in the present invention include hydrocarbons such as hexane, benzene, toluene, xylene; methylene chloride, methylene bromide, 1,2-
Halogenated hydrocarbons such as dichloroethane, sym-tetrachloroethane, cis-1,2-dichloroethane, 1,1,2-trichloroethane, 1,2-dichloropropane, chloroform, bromoform, chlorobenzene; acetone, methyl ethyl ketone, cyclohexanone Such as ketones; esters such as ethyl acetate and butyl acetate: alcohols such as methanol, ethanol, propanol, butanol, cyclohexanol, heptanol, ethylene glycol, methyl cellosolve, ethyl cellosolve and cellosolve acetate, and derivatives thereof; tetrahydrofuran Ethers such as 1,4-dioxane, furan and furfural, acetals; amines such as pyridine, butylamine, diethylamine, ethylenediamine, isopropanolamine; amides such as N, N-dimethylformamide Containing compound, other fatty acids and phenols, sulfur, such as carbon disulfide and triethyl phosphate may be used alone or in combination of two or more of such phosphorus compounds.

When the photoreceptor of the present invention has a laminated structure, CG
The weight ratio of binder: CGM: CTM in L is 0 to 100:
1 to 500: 0 to 500.

If the content ratio of CGM is less than this range, the sensitivity is low and the residual potential increases, and if it is more than this range, dark decay and receptive potential decrease.

The CTM can be formed by coating a suitable solvent or dispersion medium alone or dissolved and dispersed with the above-mentioned binder resin and drying it. As the dispersion medium used, the dispersion medium used in the dispersion of the CGM can be used. The CTM that can be used in the present invention is not particularly limited, and examples thereof include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl. Compound,
Hydrazine compounds, pyrazoline compounds, amine derivatives,
Oxazolone derivative, benzothiazole derivative, benzimidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, poly-N-vinylcarbazole, poly-
Examples are 1-vinylpyrene and poly-9-vinylanthracene. The CTM used in the present invention is excellent in the ability to transport holes generated at the time of light irradiation to the support side, and is preferably used in combination with the perylene derivative of the present invention.

In the present invention, CGL may contain one or more electron-accepting substances for the purpose of improving sensitivity, reducing residual potential or reducing fatigue during repeated use.

Examples of the electron-accepting substance that can be used here include succinic anhydride, maleic anhydride, dibrom anhydride, maleic acid, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride and 3-nitroanhydride. Phthalic acid, 4-nitrophthalic anhydride, pyromellitic dianhydride, mellitic dianhydride, tetracyanourylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, para Nitrobenzene, picrylclyde, quinone chlorimide, chloralyl, bulmannyl, dichlorodicyanoparabenzonone, anthraquinone, dinitroanotraquinone, 2,7-dinitrofluorenone, 2,4,7-trinitrofluorenone, 9-fluorenylidene [dicyano Methylene malonodinitrile],
Polynitro-9-fluorenidene- [dicyanomethylene malonodinitrile], picric acid, 0-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5 -Dinitrosalicylic acid, phthalic acid, mellitic acid, and other compounds having a high electron affinity can be mentioned. The addition ratio of the electron-accepting substance is a weight ratio of the perylene derivative of the present invention: the electron-accepting substance = 100: 0.01-200, preferably 100: 0.1-10.
It is 0.

This electron-accepting substance may be added to CTL. The addition ratio of the electron accepting substance to such a layer is, by weight ratio, total CTM: electron accepting substance = 100: 0.01-100, preferably
100: 0.1 to 50.

The photoconductor of the present invention may further contain an ultraviolet absorber and a dye for color sensitivity correction for the purpose of protecting PCL, if necessary.

The electrophotographic photoreceptor containing the perylene derivative of the present invention can be well sensitive to visible rays and near infrared rays, but preferably has an absorption maximum at a wavelength of about 400 to 700 μm. There is.

As a light source having such a wavelength, a halogen lamp, a fluorescent lamp, a tungsten lamp or the like is generally used.

[0058]

【Example】

Example 1 An Al drum was used as the substrate.

15 parts by weight of a styryl compound having the following structural formula C-1 as CTM, 20 parts by weight of a BPZ-1 type polycarbonate resin Iupilon Z-200 (manufactured by Mitsubishi Gas Chemical Co., Inc.) as a binder, and an antioxidant Irganox 1010 (Ciba Geigy) 0.4 parts by weight) was dissolved in 100 parts by weight of 1,2-dichloroethane to obtain a CTL coating liquid.

[0060]

[Chemical 8]

This coating solution was applied on an Al drum and the temperature was 100 ° C.
After drying for 20 minutes, a CTL having a thickness of 20 μm was formed.

Exemplified compound A-1 as CGM; 20 parts by weight of BPZ-1 type polycarbonate resin Iupilon Z-200 (manufactured by Mitsubishi Gas Chemical Co., Inc.) as a binder in 10 parts by weight of the above CT
15 parts by weight of M, C-1; 1.5 parts by weight of the antioxidant Irganox 1010 (manufactured by Ciba Geigy) are added to 100 parts by weight of 1,2-dichloroethane, and dispersed by a sand grinder for 20 hours to prepare a CGL coating solution. Got

Next, this coating solution was applied onto the CTL to obtain 100
Drying was carried out at 20 ° C. for 20 minutes to form CGL having a thickness of 5 μm to obtain an electrophotographic photosensitive member.

Examples 2 to 7 An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the CTM and binder were changed as shown in Table-1.

Examples 8 and 9 An Al drum was used as the substrate. CG used in Example 1
The L coating liquid was applied onto the Al drum to obtain a single-layer type electrophotographic photosensitive member 8 having a thickness of 20 μm. Further, the combination of CGM and the binder is shown in Table 1 to obtain a single-layer type electrophotographic photosensitive member 9.

Comparative Examples (1) to (7) A combination of CGM and a binder is shown in Table 1 to obtain a photoconductor of Comparative Example.

[0067]

[Chemical 9]

However, in Comparative Example (5), an acrylic resin dialnal BR-80 (manufactured by Mitsubishi Rayon) was used as a binder for CGL. Further, in Comparative Example (6), as the binder of the PCL of the single-layer type photoconductor, the above-mentioned Dialnal BR-80 was used.
Was used.

The photoconductor thus obtained was mounted on a remodeling machine of the Konica copier U-Bix2025, which was positively charged, and an actual copying test of 100,000 copies was conducted. Table 2 shows the changes in the characteristics of the photoconductor and the changes in the image quality. In the image quality evaluation, when there is no problem in practical use, it is indicated as ○, when there is some problem, it is indicated as Δ, and when it is not practical, as ×.

[0070]

[Table 1]

[0071]

[Table 2]

As is clear from Table 2, the samples of the examples of the present invention have good practicability in the chargeability, sensitivity, image quality and film thickness loss in the initial and repeated use, but in the comparative examples, Most of the evaluation performances have problems in practicality.

[0073]

EFFECT OF THE INVENTION By using the perylene derivative of the present invention and the polycarbonate selected in the present invention as a binder, it is possible to obtain a photoreceptor having excellent electrophotographic properties and physical properties at initial and repeated use.

[Brief description of drawings]

1 is a cross-sectional view of an example of a photoconductor having an aspect of the present invention.

[Explanation of symbols]

1 ... Support 2 ... Photoconductive layer (PCL) 3 ... Protective layer 4 ... Middle layer 5 ... Carrier Transport Layer (CTL) 6 ... Carrier generation layer (CGL)

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 16, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

1 (1) to (8) are cross-sectional views of an example of a photoconductor having an embodiment of the present invention.

[Explanation of symbols] 1 Support 2 Photoconductive layer (PCL) 3 Protective layer 4 Middle layer 5 Carrier Transport Layer (CTL) 6 Carrier generation layer (CGL)

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshiaki Takei             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company

Claims (2)

[Claims] 1. A perylene derivative represented by the following general formula (BIP-1) or (BIP-2) as a carrier generating substance for an electrophotographic photosensitive member; [In the formula, Z represents an atomic group necessary for forming a substituted or unsubstituted aromatic ring. ] And an electrophotographic photoreceptor containing polycarbonate as a binder. 2. The polycarbonate of the binder 2,
Carbonic acid ester units derived from 2'-bis (4-oxyphenyl) propane are represented by the following general formulas (BPA-1) and (BPA-2).
The electrophotographic photosensitive member according to claim 1, which is a polymer of (BPZ-1) or (BPZ-2), a copolymer thereof, or a mixture of the polymers and copolymers. [Chemical 2]