JPS5999442A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To raise sensitivity, and stability during repeated uses and to form an always good visible image by combining a carrier generating phase contg. a specified bisazo compd. with a carrier transfer phase contg. a specified hydrazone compd. CONSTITUTION:A photosensitive layer 4 formed on a conductive substrate 1 is composed of a combination of a carrier generating phase contg. a carrier generating material (CGM) of a bisazo compd. represented by formula I , and a carrier transfer phase contg. a carrier transfer material (CTM) of a hydrazone compd. represented by formula I . Said layer 4 may be formed by laminating a carrier generating layer 2 contg. CGM first on the substrate 1, and a carrier transfer layer 3 contg. CTM on the layer 2, or laminated in the reverse order. The substrate 1 may be flexible by laminating a conductive layer 1B on an insulating substrate 1A, such as a resin sheet. Further, an intermediate layer 5 having various functions may be formed between the substrate 1 and the layer 4. A good photosensitive layer 4 is obtained with such a combination of CGM and CTM, and an always superior visible image can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor in which a photosensitive layer comprising a combination of a carrier generation phase and a carrier transport layer is provided on a conductive support.

To date, carrier-generating substances (hereinafter simply referred to as "carriers") that absorb visible light and generate charge carriers (hereinafter simply referred to as "carriers") have been developed.
A carrier generation layer (hereinafter referred to as 1'-CGLJ) containing a carrier generation layer (hereinafter referred to as "cGMJ") and a carrier transport material (hereinafter referred to as " It has been proposed to form a photosensitive layer of an electrophotographic photoreceptor by combining a carrier transport layer (hereinafter referred to as cTLJ) containing a carrier transport layer (referred to as cTMJ). By assigning the two basic functions necessary for the photosensitive layer, generation and transport, to separate layers, the selection range of materials that can be used in the composition of the photosensitive layer is widened, and each function can be optimized. By doing so, it is possible to independently select the material or material system that is effective for the electrophotographic process. is large,
It becomes possible to construct an electrophotographic photoreceptor having excellent characteristics such as high photosensitivity (and high stability over repeated use).

Conventionally, as such a photosensitive layer, the following ones are known, for example.

(1) CGL composed of amorphous superolefin or cadmium sulfide
and CTL made of poly-N-vinylcarbazole are laminated.

(2) CGL composed of amorphous cadmium or cadmium sulfide
and CTL containing 2,4.7-dolinitro-9-fluorenone are laminated.

(3) A structure in which a CGL composed of a beryl/derivative and a CTL containing an oxadiazole derivative are laminated (see US Pat. No. 3,871,882).

(4) CT containing CGL consisting of chlordiane blue or methylscalyllium and pyrazoline derivative
A structure in which L-tons are laminated (see Japanese Patent Laid-Open No. 51-90827).

(5) CGL made of amorphous carbon or its alloy and C containing polyaryl alkali/aromatic amine compound
TL groove laminated structure (Patent application 147251/1989)
No. Specification).

(6) A structure in which CGL containing a perylene derivative and CTL containing a polyarylalkane aromatic amine compound are laminated (Japanese Patent Application No. 19907/1983)
.

As described above, there are many photosensitive layers of this type on the market, but in conventional electrophotographic photoreceptors having such a photosensitive layer, the photoreceptor is The disadvantage is that the electrical fatigue of the layer is severe and the service life is very short.

For example, when subjected to an electrophotographic process repeatedly,
The potential history state of the electrophotographic photoreceptor is not maintained stably, making it impossible to obtain stable image forming characteristics.

In addition, specific bisazo compounds can be used as CGM, for example, in JP-A-55-117151 and JP-A-54.
Although it is disclosed in Publication No.-145142, etc.
Even if there are eight combinations with CTM that can be combined with M, the above-mentioned drawbacks are considerable.

As can be understood from this, a carrier transporting substance that is effective against a certain carrier-generating substance is not always effective against other carrier-generating substances (and is not always effective against other carrier-generating substances). An effective carrier-generating substance is
Nor can it be said that it is always effective for other carrier transport substances.

If the combination of both substances is inappropriate, the electrophotographic sensitivity will be low (
Not only that, but the discharge efficiency is poor especially in low electric fields, so the so-called residual potential becomes large, and in the worst case, the potential accumulates with each repeated use, making it difficult for practical electrophotographic applications. You won't get any more.

In this way, there is no lawful way to select a suitable combination of the constituent substances of the carrier generation phase and the constituent substances of the carrier transport phase. Need to decide.

The present invention has a photosensitive layer consisting of a combination of a carrier generation phase and a carrier transport phase, and has a high sensitivity, and furthermore, the potential history state is maintained stably even when repeatedly subjected to an electrophotographic process. The object of the present invention is to provide an electrophotographic photoreceptor that can consistently form good visible images.

The purpose of the above is to provide an electrophotographic photoreceptor comprising a photosensitive layer comprising a combination of a carrier generation phase and a carrier transport phase and provided on a conductive support. An electrophotographic photoreceptor characterized in that the carrier generation phase contains a bisazo compound represented by the following general formula [I], and the carrier transport phase contains a hydrazino compound represented by the following general formula [■]. achieved by.

General formula CI) [In the formula, Ar1, Ar2g and Ar3: each substituted or unsubstituted carbocyclic aromatic ring group, R1s and R2: each electron-withdrawing group, (9) -NH8O, R6, Y: hydrogen Atom, halogen atom, substituted or unsubstituted alkyl group, alkoxy group, carboxyl group, sulfo group, substituted or unsubstituted carbamoyl group, or i is t-substituted or unsubstituted sulfamoyl group (however, when m is 2 or more may be mutually different groups.) Z: Atom group necessary to constitute a substituted or unsubstituted carbocyclic aromatic ring or a substituted or unsubstituted heterocyclic aromatic ring, R3: Hydrogen Atom, substituted or unsubstituted 1-mino group, substituted or unsubstituted carbamoyl group, carboxyl group or ester group thereof, A': substituted or unsubstituted aryl group n: integer of 1 or 2, m of 20 to 4 Represents an integer. ] General formula (n) [in the formula.

R7 and R8, each represents a hydrogen atom or a halogen atom, R93 and R11]' each represents a substituted or unsubstituted aryl group, Ar4: represents a substituted or unsubstituted arylene group. ] Among the bisazo compounds represented by the general formula CI), preferred are those represented by the following general formula (, Ia).

General formula (Ia) CN CN A-N=N-Ar1-C=CH-Ar2-CH=C-A
r3-N-N-A [wherein Ar1, Ar2, Ar3 M and A general formula CI)?
It is the same as defined by ] More preferred are those represented by the following general formula CIb.

General formula (Ib) CN CN [wherein A is the same as defined in 8 in general formula [■], Ar 5 , Ar 6 M and Ar 7 represent substituted or unsubstituted phenyl groups, and the substituents are: Those selected from alkyl groups such as methyl group and ethyl group, alkoxy groups such as methoxy group and ethoxy group, halogen atoms such as chlorine atom and bromine atom, hydroxyl group and cyan group are preferable. ] That is, according to the present invention, the bisazo compound represented by the general formula CI) is used as iCGM, and the hydrazone compound represented by the general formula (II) is used as CTM, and by combining these, carrier generation is achieved. The photosensitive layer of a so-called function-separated type photoreceptor is composed of separate materials for transportation, transportation, and transportation.

As a result, it is possible to provide an electrophotographic photoreceptor which has high sensitivity, maintains a stable potential history state even when subjected to repeated electrophotographic processes, and can therefore always form a good visible image.

In addition, in the electrophotographic photoreceptor of the present invention, the wavelength is particularly 600.
Large spectral sensitivity can be obtained even in the long wavelength region of ~700 nm,
Therefore, for example, it can be used as a source for forming a helium-neon laser latent image with a wavelength of 6328X, and even in a low electric field. The so-called edge of the potential is good, and the potential of the non-image area is zero or close to it during development, so it is necessary to have a large effective bias. Good development can be achieved even with a one-component developer consisting of toner that cannot be obtained.

Specific examples of the bisazo compound represented by the general formula CI) include those having the following structural formula, but are not limited thereto.

Exemplary compound 1 1 1 ()
()
()1 1
1-N- 1-N- - - Specific examples of the hydrazone compound represented by the above general formula [■] include, but are not limited to, those having the following structural formula: isn't it.

Exemplary compound (II-1) (II-2) (II-3) ([-4) (n-5) Sushi n3 (H-6) CI (II-7) ('1 (n-s) l ( n-9) CI (I[-10) (n-11) (n-12) (ff-13) (II-14) Next, explain BA about the mechanical structure of the uninvented electrophotographic photoreceptor.
I will.

In an example of the present invention, as shown in FIG. CTL3 containing a hydrazone compound as a component
The CGL 2 and CTL 3 constitute a photosensitive layer 4.

Here, as the material of the conductive support 1, metal sheets such as aluminum, zinc, copper, zinc, palladium, silver, indium, tin, platinum, gold, stainless steel, and brass may be used. I can do it. However, the invention is not limited thereto, and for example, as shown in FIG. 2, a conductive layer IB may be provided on an insulating substrate IA and a conductive support 1 may be constructed. The substrate IA should be one that is flexible, such as paper or a glass sheet, and that has sufficient strength against stress such as bending and tensile stress. The conductive layer IB can also be provided by laminating metal sheets, vacuum depositing metals, or by other methods.

Is CGL2 the above-mentioned bisazo compound alone, or a binder resin suitable for it? It can be formed by adding CTMi, or a substance having high mobility for carriers of specific or non-specific polarity, that is, CTMi.

As a specific method, it is convenient to place the above-mentioned nohisazo compound on the support by dissolving or dispersing it in a suitable solvent or with a suitable binder resin and drying it with a cloth. used for.

In this method, examples of the solvent or dispersion medium include n-bunalamine, diethylamine, ethenenediamine, isoglobanolamine, monoethanolamine, triethanolamine, triethylenediamine, N,N-
Dimethylpolamide, acetone, methyl ethyl ketone, cyclohegisanone, benzene, toluene, xylene,
Chloromethane, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, ingropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, and others may be used.

Further, as the binder resin, for example, polyethylene fV
7. Voriglopyrene, acrylic 4fi resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin,
Addition polymerization resins such as polyurethane resins, phenolic resins, polyester resins, alkyd resins, polycarbonate resins, silicone resins, melamine resins, polyaddition resins,
Polycondensation resins and copolymer resins containing two or more repeating units of these resins, such as vinyl chloride-
In addition to insulating resins such as vinyl acetate copolymer resin and vinyl chloride-vinyl acetate-mannic anhydride copolymer resin, poly-
Examples include polymeric organic conductors such as N-vinylcarbazole. The ratio of this binder resin to the bisazo compound is 0 to 100% by weight, particularly 0 to 1% by weight.
It is in the range of 0% by weight.

Appropriate CTMi may be added to the CGL2 as necessary.

The thickness of the CGL 2 formed as described above is preferably 0.005 to 20 microns, particularly preferably 0.005 to 20 microns, particularly preferably 0.
, 05-5 microns. If it is less than 0.005 microns, sufficient photosensitivity cannot be obtained, and if it is more than 20 microns, sufficient charge retention cannot be obtained.

In addition, the CTL3 can be obtained by the above-mentioned hydrazo/compound.
It can be formed in the same manner as CGL2 described above, ie alone or together with a binder resin.

Further, other CTMi may be contained. This CTL
3 has a thickness of 2 to 100 microns, preferably 5 to 30 microns.

The electrophotographic photoreceptor of the present invention may have other mechanical configurations. For example, as shown in FIG. 3, a suitable intermediate layer 5 may be provided on the conductive support 1, a CGL2 layer may be formed through the intermediate layer 5, and a CTL3 layer may be formed on the CGL2. When the photosensitive layer 4 is charged, this intermediate layer 5 contains ? The photosensitive layer 4 may have a function of preventing free carriers from being injected into the photosensitive layer 4 from the conductive support 1, or a function as an adhesive layer that integrally adheres the photosensitive layer 4 to the conductive support. can. The material of the intermediate layer 5 includes metal oxides such as aluminum oxide and indium oxide;
Acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride A polymeric material such as -vinyl acetate-mannic anhydride copolymer resin can be used.

Further, as shown in FIG. 4, CTLa is formed on the conductive support 1 with or without intervening the intermediate layer 5, and this C
CGL2'Y may be formed on TL3 to constitute four photosensitive layers.

Furthermore, it is also possible to form a single-layer photosensitive layer by dispersing the bisazo compound or the hydrazone compound described above in a carrier transporting phase to form a carrier generation phase.

What? Various additives can be added to the layers constituting the third photosensitive layer of the present invention, if necessary.

Examples of the present invention will be described below, but the present invention is not limited thereto.

Example 1 A vinyl chloride-vinyl acetate-maleic anhydride copolymer "Eslenc MP-10J" (Built Chemical Co., Ltd. An intermediate layer of about 0,000 s microns thick consisting of exemplified compound (I-
The bisazo compound L5f-'vl shown in 9) was dispersed with 100 ml of 2-dichloroethane in a ball mill for 8 hours, and the resulting dispersion was coated on the intermediate layer using a Dr. Breton, and dried sufficiently to form a thick layer. A CGL with a diameter of about 0.5 microns was formed.

Hydrazone compound IL25P shown as exemplified compound (n-2) and polycarbonate resin
t-i 125) qJ C Yondaikasei Co., Ltd.) 15F and 1
, dissolved in 100 ml of 2-dichloroethane, and applied the resulting solution onto the CGL using a doctor Breton,
It was sufficiently dried to form a CTLi layer with a thickness of 12 microns, thereby producing an electrophotographic photoreceptor of the present invention. This is "Sample 1"
shall be.

Examples 2 to 5 Exemplary compounds (I-5), (I-45), (I-76) and (I-76) were used as bisazo compounds in the formation of CGL.
Four types of electrophotographic photoreceptors of the present invention were manufactured in the same manner as in Example 1, except that each of those shown in Example 1 was used. These are respectively referred to as "Sample 2" to "Sample 5."

Examples 6 to 9 Exemplary compounds (I[-1), (II-5), (II-7) as hydrazone compounds in the formation of CTLs
Four types of electrophotographic photoreceptors of the present invention were prepared in the same manner as in Example 1, including those shown in Example 1 and (II-13'). These will be referred to as "Sample 6" to "Sample 9", respectively.

Example 10 Example 1? An intermediate layer was formed on the conductive support in the same manner as above, and the bisazo compound L5i shown as exemplified compound (I-9) and the polycarbonate resin "Panlite L-12" were added.
50J of 15y-ton 1,2-dichloroetha 7100m
In addition to e, dispersion was carried out using a ball mill for 12 hours, and the resulting dispersion was applied onto the intermediate layer using a doctor blade, and thoroughly dried to give a CGL% thickness of approximately 1 micron.
Formed.

On this CGL, apply CTL in the same manner as in Example 1-2.
Thus, an electrophotographic photoreceptor according to the present invention was manufactured.

This will be referred to as "Sample 10."

Comparative Example 1 For the formation of C'I' L in Example 1? A comparative electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that a pyrazoline derivative having the following structural formula was used in place of the hydrazone compound. This will be referred to as "Comparative Sample 1."

2H5 Comparative Example 2 Formation of CTL in Example 1? A comparative electrophotographic photoreceptor was produced in the same manner as in Example 1, except that an oxadiazole derivative having the following structural formula was used in place of the hydrazone compound. This will be referred to as "comparative sample 2."

For each of the electrophotographic photoreceptors obtained as described above, Samples 1 to 10, Comparative Sample 1 and Comparative Sample 2, an electrometer 5P-428 model (manufactured by Kawaguchi Electric) 7 was used to measure I looked into the characteristics of the photo. That is, the acceptance potential VA (V) when the photoreceptor surface is charged at a charging voltage of -6 KV for 5 seconds, and the exposure required to attenuate the potential VI (initial potential) after dark decay for 5 seconds to η. quantity E'/2 (zu'X・sec), and the dark decay rate (VA-
VI )/VA X 100 (%) G/<f.

The results are shown in Table 1.

From the results shown in Table 1, it is clear that the FjA electrophotographic light source of the present invention has high sensitivity.

In addition, each of Samples 1 to 10, Comparative Sample 1, and Comparative Sample 2 was equipped with a dry type electronic copying machine 1" U-Bix 2000RJ (
Konishi Roku Photo Industry Co., Ltd.) was installed to make 7 consecutive copies, and the black paper potential vb (v) and the white paper potential Vw (V) Yr enctrostatus voltmeter 144D- LD type (manufactured by Monroe Electronics Co., Ltd.) (manufactured by Monroe Electronics Co., Ltd.) (The measurement was carried out immediately before development. The results are shown in Table 2.

The black paper potential here refers to the surface potential of the photoreceptor when the above-mentioned copying cycle is performed using two black paper documents with reflection density L3, and the white paper potential represents the surface potential of the photoreceptor when two black paper documents with reflection density L3 are used. Represents surface potential.

Table 2 (However, Δvb (v) and ΔVw (V) in the table are the black paper potential vb (v) and white paper potential Vw (V
) indicates the amount of variation in the amount of variation, + indicates an increase and - indicates a decrease. ) As is clear from the results in the second section, the electrophotographic photoreceptor of the present invention maintains a stable potential history state even when subjected to repeated electrophotographic processes, and produces stable visible images with good image quality. can be formed into

[Brief explanation of the drawing]

FIG. 1 is an explanatory sectional view showing an example of the structure of the electrophotographic photoreceptor of the present invention, FIG. 2 is an explanatory sectional view showing another example of the structure of the electrophotographic photoreceptor of the invention, and FIGS. 3 and 4 2A and 2B are explanatory cross-sectional views showing still other structural examples of the electrophotographic photoreceptor of the present invention. 1... Conductive support 2... Carrier generation layer (CGL) 3... Carrier transport layer (CTL) 4...-Photosensitive layer 5... Intermediate layer IA...Insulating base IB--・Conductive layer] f7 + mount of juj
'(j″ji′;.: No renewals 941 Figure 2 Figure 3 Proceedings Sleeve Book (Method) April 23, 1985 Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Indication of the case 1988 Patent Application Nos. 208512 and 2 Title of the invention Electrophotographic photoreceptor 3 Person making the amendment Relationship in the case Patent applicant: 1-26 Nishi-Shinjuku, Shinjuku-ku, Tokyo
@ No. 2 Trap” - 4S (Awa (127) Konishi Roku Photo Industry Co., Ltd. 4, Agent 5 Daily publication of amendment order March 29, 1981 2) Complete drawing ゛ ゛ ゛ ゛ ゛ ゛ ゛ ゛ ゛ ゛ ゛No change) Procedural amendment (voluntary) February 29, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1, Description of the case 1983 Patent Application No. 208512 2, Title of the invention Electrophotographic photoreceptor 3, Amendment Patent applicant address 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Name (127) Roku Konishi Photo Industry Co., Ltd. 4, Agent 5, Detailed description of the invention in the specification subject to amendment Explanation Column 6, Contents of Amendment, No. 1) The structural formula in Comparative Example 1 on page 53 of the specification is corrected as follows.

Claims (1)

[Scope of Claims] 1) An electrophotographic photoreceptor comprising a photosensitive layer formed of a combination of a carrier generation phase and a carrier transport phase on a conductive electrode support, wherein the carrier generation phase has the following general formula CI: An electrophotographic photoreceptor comprising a bisazo compound represented by the following formula (n), wherein the carrier transport phase contains a hydrazone compound represented by the following general formula (n). General formula CI) 1R2 A N=N ArI C=CHAr2 CH=CARr
-, -N=NA [wherein, Ar1, Ar2s and Ar3: each substituted or unsubstituted carbocyclic aromatic ring group, R2H and R2: each electron-withdrawing group, 367- -NH302-R6, Y : Hydrogen atom, halogen atom, substituted or unsubstituted alkyl group, alkoxy group, carboxyl group, sulfo group. Substituted or unsubstituted carbamoyl group or substituted or unsubstituted sulfamoyl group (However, when m is 2 or more, mutually different groups may be used.) Z: Substituted or unsubstituted carbocyclic aromatic group Atom group necessary to constitute a ring or substituted or unsubstituted polycyclic aromatic ring, R3: hydrogen atom, substituted or unsubstituted amine group, substituted or unsubstituted carbamoyl group, carboxyl group or ester group thereof , A': substituted or unsubstituted aryl group, n: 5 integer of 1 or 2, m: 7 integer of 0 to 4. ] General Formula (n) [In the formula, R7g and R8 are each a hydrogen atom or a halogen atom, R9 and Rlo are each a substituted or unsubstituted aryl group, and Ar4 is a substituted or unsubstituted arylene group. ]