JPH01154067A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain superior carrier generating performance and superior durability by forming a photosensitive layer containing a specified bisazo compound on a conductive substrate. CONSTITUTION:The photosensitive layer 4 formed on the conductive substrate 1 contains at least one of the bisazo compounds represented by formula I in which each of R1 and R2 is halogen, alkyl, alkoxy, nitro, cyano, or hydroxy, optionally same or different from each other; each of R3-R7 is H, alkyl, alkoxy, halogen, cyano, or nitro; and each of m and n is an integer of 0-3, thus permitting the obtained electrophotographic sensitive body to be superior in carrier generating performance, high in sensitivity, small in residual potential, high in durability, and unchangeable in these characteristics even at the time of repeated uses.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a photosensitive layer containing a specific bisazo compound.

[Prior Art] Conventionally, as electrophotographic photoreceptors, B1-free photoreceptors having a photosensitive layer mainly composed of free photoconductive compounds such as selenium, zinc oxide, cadmium sulfide, and silicon have been widely used. However, these are not necessarily satisfactory in terms of sensitivity, thermal stability, moisture resistance, durability, etc. For example, when selenium crystallizes, its properties as a photoreceptor deteriorate, making it difficult to manufacture.Also, selenium crystallizes due to heat, fingerprints, etc., and its performance as a photoreceptor deteriorates.

Furthermore, cadmium sulfide has problems with moisture resistance and durability, and zinc oxide has problems with durability.

In order to overcome these drawbacks of inorganic photoreceptors, research and development of organic photoreceptors having photosensitive layers mainly composed of various organic photoconductive compounds has been actively conducted in recent years. For example, Japanese Patent Publication No. 50-10496@ describes an organic photoreceptor having a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-dolinitro-9-fluorenone. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability. In order to improve these shortcomings, the carrier generation function and the carrier transport function are assigned to different substances, respectively, resulting in higher performance! Attempts have been made to develop a photoreceptor. Many studies have been conducted on such so-called function-separated type photoreceptors because each material can be selected from a wide range and a photoreceptor having arbitrary performance can be produced relatively easily.

[Problems to be Solved by the Invention] Many compounds have been proposed as carrier-generating substances in the functionally separated type photoreceptor as described above.

An example of using an inorganic compound as a carrier-generating substance is amorphous selenium, which is described in Japanese Patent Publication No. 16198/1983, and is used in combination with an organic photoconductive compound. The disadvantage that the carrier generation layer consisting of the above crystallizes due to heat and deteriorates the characteristics as a photoreceptor has not been improved.

Furthermore, many electrophotographic photoreceptors using organic dyes or organic pigments as carrier generating substances have been proposed. For example, as electrophotographic photoreceptors containing a bisazo compound in the photosensitive layer, JP-A-54-22i34, JP-A-55-73057, JP-A-55-117151, and JP-A-56-46237 are already known. However, these azo compounds are not necessarily satisfactory in terms of sensitivity, residual potential, or stability during repeated use, and the selection range of carrier transport materials is also limited, making them difficult to use in a wide range of electrophotographic processes. It does not fully satisfy the requirements.

[Object of the Invention] An object of the present invention is to provide an electrophotographic photoreceptor containing a specific bisazo compound that is endowed with the ability to generate chyrelia.

Another object of the present invention is to provide high sensitivity and low residual potential.
Another object of the present invention is to provide an electrophotographic photoreceptor that is highly durable and whose properties do not change even after repeated use.

Still another object of the present invention is to provide an electrophotographic photoreceptor containing a bisazo compound that can effectively act as a carrier generating substance even in combination with a wide variety of carrier transporting substances.

[Means for Solving the Problems] As a result of extensive research to achieve the above objectives, the present inventors have discovered that a specific bisazo compound can act as an excellent active ingredient for electrophotographic photoreceptors. , has completed the present invention.

That is, the above object of the present invention can be achieved by using an electrophotographic photoreceptor having a photosensitive layer containing a bisazo compound represented by the following general formula [I] on a conductive support.

General Formula [I] [R+ and R2 each do not represent a halogen atom, an alkyl group, an alkoxy group, a nitro group, a cyan group, or a hydroxy group. However, R1 and R2 are each
They may be the same or different.

R3 and R7 each represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a cyan group or a nitro group. I and n represent integers from 0 to 3. ] [Specific details of the invention] In the general formula [I), R+ J5 and R2 are not represented respectively, and examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom, among which a chlorine atom Or a bromine atom is preferred.

The alkyl groups represented by R1 and R2 are preferably alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, isopropyl, t-butyl, trifluoromethyl and the like.

The alkoxy groups represented by R1 and R2 are preferably alkoxy groups having 1 to 4 carbon atoms, such as a methoxy group, an ethoxy group, an isoproboxy group, a [-butoxy group, a 2-aloethoxy group, etc. Can be done.

Among the substituents represented by R1 and R2, preferred are a halogen atom, an alkyl group, and an alkoxy group.

Specific examples of the alkyl group, alkoxy group, and halogen atom represented by R3 and R7 include those described for R1 and R2 above.

The bisazo compound of the present invention represented by the general formula [I] can be specifically represented by the following general formulas [A] to [1].

(A) CB) (C) CD) (E) CF) [G] (H) CI) Next, specific examples of the bisazo compound represented by the above-mentioned formula [I] of the present invention will be described. The bisazo compound is not limited.

R1, R2=none Ry=H R+, R2=none Rs=l-1 Rt　-CHa R2=OCH3 R7=H R+ =CH5 R2=OCHa Margin below R+ = CHa R2=C1 R+ =CH3 R2=Cff1 s-H R+ -CH3 R2=3r R+ = CHa R2=Br R+ =CH3 R2=F R+ =CH3 R2=I R7=H R+ =CH3 R2=F Margin below R1=CH3 R2=CN R7=H R+ = CHa R2=NO2 R7=H R1=CH3 R2=CF3 R7=T1 R1, R2=OCH3 R7,=H R+ -0CHa R2=CHa 7-H R+ =OCH3 R2=CI! R7=H R+ =OCH3 R2=Br R7=H R+, R2=OCHa Rs=H Margin below ri, evening R+, R2=CH3 R7=H R+ -0CH3 R2-3r R+ -0CH3R7-1-I R+-0CI-13R7-1-1 R+ -0CHa 2-CN R1-0CH3 R2-NO2 R+=OCH3 R2=CF3 R+ -0CHa R2=CF3 R+, R2-C1l R1=Cl R2=CH3 7-H R1=Cl R2=OCH3 R7=H R+ = Cl R2=3r R+ -CI R2=F R+ -Cj! R2=I R7=H R+ -CR.

R2=CN R1-Cff1 R2-CF3 7-H 1-CI R2-NO2 s -H R1, R2=3r R+ =3r R2=CH3 R+ =Br R7=H R+ =13r R7=tIR1=Br
R? =H R+ =3r R7=H R+ =Br R7=H R2=ON R+ =3r R? =H R2=NO2 R+ -3r R? =H R2=CF3 R1,R2=F R7=H R+ =F R2=CH3 R7=H R+=F R2-0CH3 R+=F 2-CQ R+-F R2=13r R+-F R2=I R7=H R+ =F 2-CN R+-F R2-NO2 7-H R+=F R2-CF3 7-H R+, R2=I R+=I R2-CH5 R+=I R2=OCH3 R1=I R2=CQ 1-I 2 -Br R+=I R2=F R+=1 R2=NO2 R2=CN Below margin ゛R+, R2=CN R1=CN R2=CH3 R+ =CN R7'=H R+ -CN R7=H R1,R2-NO2 R+ =NO2R? -H R1=NO2R7-H R+ =NO2R7-H R+ -NO2 2-CN R1,R2=CFa R+ =CFa R2=CH3 R+ =CF3 R2=Br Ry =H R+ =CF3 R7=H R+ =CF3 R7=H R+ , R2-0H R+ =CHR7=H R+ =CHR7=H R+ =CHR7=H R+ =CHR7=H R2=3r R+ =CHRs =H R2=CN R+ =HR? =H R2=CH3 R+ =HR7=H R+ =HR7=H R+ =HR7=H R+ =H R2=CF3 R1=H R2=OH The bisazo compound of the present invention represented by the general formula [I] can also be represented by the following: It can also be specifically represented by general formula [J].

Examples of the compound represented by the general formula [J] include the following.

Hereinafter, Kanayama, 1 几j R,, R: = None Furthermore, the bisazo compound of the present invention represented by the general formula [I] can be specifically represented by the following general formulas [J] to [R]. .

(K) R1 (L) CM) R9 (N) [O] CP) R5 (Q) (R) Examples of the compounds represented by the general formulas [J] to [R] include the following. can.

R,,R,=CH.

R,=CH3R2=OCH3 R+=CH5R2=CI Rl=CH3R*=None R,=OCH,,R2=CN R,=OCH,R2=NO2 R,=OCH, R2=CF.

RI-R*=CI R,=(J!, R2=CH3 R+ = Br - Rx = OCHs R,=Br　,R-=None R1=Br　-Rz　=CN R+ =Br, R:=NO= The following meeting R+ = Br, R: = CF! R+ + R2=CN R,=CN, R,=CH.

R,=CN,R,=CI R+, Rt=NO! R,=NO□, R2=None R1=NO! ,R,=CH.

R,=NO,,R,=OH R+ -R1=CFs R,=CF,,R,=CH.

R+ = CFs −R2=CI R+ = CF3, R1=NO! R, = CF, , R, 1,000 M R, = OH, R1 = None R,, Rt = OH R, = OH, R1 = CI The following margin is ゛1゜゛, , - the above-mentioned formula of the present invention [ The bisazo compound represented by I] can be easily synthesized by a known method.

Synthesis Example 1 (-Synthesis of Exemplary Compound N016 represented by Formula [A]) 2.6-Diami2-9-fluorenone 2.10 (J(0
,01 mole) in 10 tons of hydrochloric acid! 2. Dispersed in 20tρ of water,
Sodium nitrite 1.40 (0,
A solution of 02 mol) dissolved in water 51Q was added dropwise. After continuing stirring for another hour at the same temperature, unnecessary materials were removed by filtration, and 4.6 g of ammonium hexafluorophosphate was added to the filtrate with 55 g of water.
The solution dissolved at 0t12 was added.

The precipitated tetrazonium salt was collected by filtration and dissolved in N,N-dimethylformamide (DMF) iood.

While keeping the temperature below 5°C, 2-hydroxy-3-naphthoyl-3'-ylanilide 5.94! A solution of II (0.02 mol) in DMF200i12 was added dropwise.

Subsequently, while keeping the temperature below 5°C, triethanolamine 6 (1 (0.04 mol)) dissolved in 30n12 DMF was added dropwise and stirred at below 5°C for 1 hour and at room temperature for 4 hours. After the reaction, the precipitated product was collected by filtration, washed with DMF, washed with water and dried to obtain the target product 5.89i).

Calculated value: C-68, 2%, H = 3.4%, N = 10
．． 2% actual value: C-68, 5%, H=3.7%, N=1
0.0% Synthesis Example 2 (-Synthesis of Exemplary Compound NO,160 represented by formula [8]) 2.6-cyamitsu-4methyl-7-chloro-9-fluorenone 2.59CI (0.01 mol) 101g of hydrochloric acid,
A solution of 1°4 (It (0.02 mol)) of sodium nitrite dissolved in 5 iN of water was added dropwise while maintaining the temperature below 5°C. Rough stirring was continued for 1 hour at the same temperature. After that, unnecessary materials were removed by filtration, and a solution of 4.6 g of ammonium hexafluorophosphate dissolved in 50 d of water was added to the filtrate. Dissolved in .6.5
A solution of 6.84 g (0.02 mol) of 2-hydroxy-3-naphthoic acid-2'-bromanilide dissolved in 200-degree DMF was added dropwise while maintaining the temperature below .degree.

While continuing to maintain the temperature below 5℃, add triethanolamine 6! A solution of J (0.04 mol) in DMF30d was added dropwise, and the mixture was stirred at 5° C. or lower for 1 hour and at room temperature for 4 hours. After the reaction, the precipitated crystals were collected by filtration, washed with DMF, washed with water, and dried to obtain 6.21 (l) of the desired product.

Calculation 1a: c-59.7%, H=3.1%, N=8.
7% actual measurement: C-59.2%, H-3.6%, N-8,
9% Synthesis Example 3 (-Synthesis of Exemplified Compound No. 719 Represented by Formula [E]) 3.68 (1 (0.01 mol)) of 2.6-diamitwo-3.7-dipromo-9-fluorenone was dissolved in hydrochloric acid 10 -Q.

It was dispersed in 201 g of water, and a solution of 1.40 (0.02 mol) of sodium nitrite dissolved in 5 ml of water was added dropwise while keeping the temperature below 5°C. After continuing to stir roughly for 1 hour at the same temperature, unnecessary materials were removed by filtration, and a solution of 4.6 g of ammonium hexafluorophosphate dissolved in 50% water was added to the filtrate. The precipitated tetrazonium salt was collected by filtration and dissolved in 100 iQ of N,N-dimethylformamide (DMF). 5
2-hydroxy-3-naphthoic acid-3'-bromoani IJ F 6.84Q (0,Q2
Mo/I/) ODM F 200tNGC11 dissolved solution was added dropwise.

Subsequently, while keeping the temperature below 5°C, a solution of triethanolamine 60 (0.04 mol) in DMF 30d was added dropwise, followed by stirring at below 5°C for 1 hour and at room temperature for 4 hours. After the reaction, the precipitated crystals were collected by filtration, washed with DMF, washed with water, and dried to obtain the desired product 6.340.

Calculated values: C=52.5%, H=2.5%, N=7.8%
Actual measurements: C=52.2%, H=2.8%, N=8.
2% Synthesis Example 4 (Synthesis of Exemplified Compound No.
01 mole)
A solution of 0.02 mol) dissolved in 5 mN of water was added dropwise. After continuing stirring for another hour at the same temperature, unnecessary materials were removed by filtration, and the filtrate contained 4.69% of ammonium hexafluoride phosphate.
A solution of was dissolved in 50 m+2 water was added.

The precipitated te(.lazonium salt) was collected by filtration and dissolved in 100 tR of N,N-dimethylformamide (DMF).

2-Hydroxy-3-(4-methoxy-2-methylphenylcarbamoyl)-benzo[
a]-Carbazole 7,80 (1 (0.02 mol)) dissolved in 0MF200.I2 was added dropwise.

Continuing to keep the temperature below 5°C, a solution of triethanolamine 6() (00.04 mol in DMF 30d) was added dropwise, and the mixture was stirred at below 5°C for 1 hour and at room temperature for 4 hours. After the reaction, the precipitated product was It was collected by filtration, washed with DMF, washed with water, and dried to obtain 6.51 g of the desired product.

Calculated values: C=73.8%, H=4.29%, N=10
．． 9% actual measurement 1st shift; C=73.5%, H=4.
36%, N=11.2% Synthesis Example 5 (-Synthesis of exemplary compound N 0.1048 represented by the formula [N]) 2.60 g (0,01 mole) salt fjlom12,
The mixture was dispersed in 201 g of water, and a solution of 1.4 iJ (0.02 mol) of nitrous acid and sodium dissolved in 5 d of water was added dropwise while keeping the temperature below 5°C. After continuing stirring at the same temperature for an additional hour, unnecessary substances were removed by filtration, and a solution of 4.60 ammonium hexafluorophosphate dissolved in 50 nQ of water was added to the filtrate. The precipitated tetrazonium salt was collected by filtration and N,N-
It was dissolved in 100 g of dimethylformamide (DMF).

While keeping the temperature below 5°C, add 7.32 (1 (0.02 mol)) of 2-hydroxy-3-(3-methylphenylcarbamoyl)-benzo[a]-rubazole to DMF2001.
A solution in N was added dropwise.

While keeping the temperature below 5°C, a solution of triethanolamine 6 (1 (0.04 mol) in DMF 30d) was added dropwise and stirred at below 5°C for 1 hour and at room temperature for 4 hours. After the reaction, the precipitated product was collected by filtration, washed with DMF, washed with water and dried to obtain the desired product 6.580.

Calculated value: C-69.5%, )l=3.60%, N=
13.3% actual value: C=69.1%, )-1=3.
67%, N=13.6% Synthesis Example 6 (-Synthesis of exemplary compound N 0.1006 represented by formula [R]) 2.6-Diami2-1-methoxy-7-trifluoromethyl-9-fluorenone3. 08 (1 (0.01 mol)
was dispersed in 10112 of hydrochloric acid and 2012 of water, and while keeping the temperature below 5°C, 1.4 (1 (0.02 mol)) of sodium nitrite was added.
A solution of 5112 dissolved in water was added dropwise. After stirring for another hour at the same temperature, unnecessary materials were removed by filtration, and 4.6 g of ammonium hexafluoride phosphate was added to the filtrate with 50 ti2 of water.
A solution dissolved in was added. The precipitated tetrazonium salt was collected by filtration and diluted with 10 N,N-dimethylformamide (DMF).
0. Dissolved in Q. While keeping the temperature below 5°C, a solution of 2-hydroxy-3-(2°4.6-drimethylphenylcarbamoylnzo[a]-carbazole 7 dissolved in 200 mQ of DMF) was added dropwise.

While continuing to maintain the temperature below 5°C, 5 g (0.04 mol) of triethanolamine was added to DMF 30
The solution dissolved in d was added dropwise, and the mixture was stirred at 5° C. or lower for 1 hour and at room temperature for 4 hours. After the reaction, the precipitated crystals were collected by filtration, washed with DMF, washed with water, and dried to obtain the desired product 8. I got 540.

Calculated values: C=73.8%, H-4.49%, N=7
．． 7% actual value: C = 72.9%, H- 4.73%,
N=7.9% For other compounds of the present invention, a tetrazo compound was prepared using 2,6-cyamitsu-substituted and unsubstituted-9-fluorenone in the same manner as in the above synthesis example, and then 2-hydroxy-
3-naphthoic acid-substituted anilide, 2-hydroxy-3-(
Substituted, unsubstituted phenylcarbamoyl)-benzo[a ]
-Substituted, unsubstituted carbazole or N-substituted. unsubstituted-
It can be produced by reacting 3- or 4-hydroxy-1,8-naphthalimide or the like.

The bisazo compound of the present invention has excellent photoconductivity,
The electrophotographic photoreceptor of the present invention can be manufactured by providing a photosensitive layer in which the photoreceptor is dispersed in a binder on a conductive support. The bisazo compound of the present invention takes advantage of its excellent carrier generation ability, and by using it as a carrier generation substance and using a carrier generation substance that can effectively act in combination with this, the bisazo compound can be used to create a so-called functionally separated photosensitive material. It can be a body. The functionally separated photoreceptor may be a mixed and dispersed type of both of the above substances, but it may be a carrier generation layer containing a carrier generation substance made of the bisazo compound of the present invention, and a carrier transport layer containing a carrier transport substance. It is more preferable to use a laminated type photoreceptor.

The electrophotographic photoreceptor of the present invention, for example, as shown in FIG. As shown in the second factor, the photosensitive layer 4 has a functionally separated laminated structure in which a carrier generation layer 2 containing a carrier transporting substance and a binder resin is a lower layer and a carrier transporting layer 3 containing a carrier transporting substance and a binder resin is an upper layer. A photosensitive layer 4 having a laminated structure including a carrier transport layer 3 as a lower layer and a carrier generation layer 2 as an upper layer is provided on a support 1, and a carrier generation substance and a carrier are provided on the support 1 as shown in FIG. Examples include those provided with a single-layer photosensitive layer 4 containing a transport substance and a binder resin.

In the case of a photosensitive layer with a laminated structure, most of the incident light is absorbed by the charge generation layer, generating many charge generation carriers, and the generated charge carriers are deactivated by recombination or trapping. It is preferable to make the layer as thin as possible within a range of thickness sufficient to generate photocarriers in order to inject them into the carrier transport layer without causing damage.

Further, the carrier transport layer is electrically connected to the carrier generation layer described above, and has the function of receiving and receiving charge carriers injected from the charge generation layer in the presence of an electric field and transporting these charge carriers to the surface. are doing.

In addition, in a functionally separated photoreceptor with a single layer structure, photocarriers are generated and transported in a single layer, and the carrier generation substance and the carrier transport substance are electrically bonded within the layer, and/or the carrier generation substance and the carrier transport substance are electrically bonded within the layer. Substances also contribute to carrier transport.

Further, the carrier generation layer may contain both the carrier generation substance and a part of the carrier transport substance.

In either layer structure, a protective layer may be provided on the photosensitive layer as shown in FIGS. 7 to 9, and a protective layer may be provided on the photosensitive layer as shown in FIGS. 4 to 6. A subbing layer (intermediate layer) having barrier function and adhesive properties may be provided between the two layers.

Photosensitive layer, protect! Examples of binder resins that can be used for the i-layer and subbing layer include polystyrene, polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin,
Polyester resin, alkyd resin, polycarbonate 1
-Addition polymer resins such as resins, silicone resins, and melamine resins, polyaddition resins, polycondensation resins, and copolymer resins containing two or more repeating units of these resins;
Examples include insulating resins such as vinyl chloride-vinyl acetate copolymer resin and vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, as well as polymeric organic semiconductors such as poly-N-vinylcarbazole.

Furthermore, organic amines can be added to the photosensitive layer of the present invention for the purpose of improving the carrier-generating function of the carrier-generating substance, and it is particularly preferable to add a secondary amine.

Such secondary amines include, for example, dimethylamine, diethylamine, di-n propylamine, di-isopropylamine, di-n butylamine, di-isobutylamine, di-n amylamine, di-isoamylamine, di-n
Hexylamine, di-isohexylamine, di-n-pentylamine, di-isopentylamine, di-n-octylamine, di-isooctylamine, di-n-nonylamine, di-isononylamine, di-n-decylamine, di- -isodecylamine, di-n-monodecylamine, di-isomonodecylamine, di-n-dodecylamine, di-isododecylamine, and the like.

The amount of organic amines to be added is preferably 1 times or less, preferably 0.2 times to 0,00 times the amount of the carrier generating substance, in moles.

Further, in the photosensitive layer of the present invention, an antioxidant can be added for the purpose of preventing ozone deterioration.

Typical examples of such antioxidants are shown below, but the invention is not limited thereto.

Group (I): Hindered phenols dibutylhydrogicitoluene, 2.2'-methylenebis(6-t-butyl-4-methylphenol), 4.4
'-Butylidenebis(6-(-butyl-3-methylphenol), 4,4'-Thiobis(6-1-butyl-3
-methylphenol), 2,2'-butylidenehis (6
-t-butyl-4-methylphenol), α-tocopherol, β-tocopherol, 2,2.4-t-dimethyl-6-hydroxy-7-t-butylphenol, pentaerythylte 1-rakis [3 -(3,5-di-monobutyl-4-hydroxyphenyl)propionate 1.2
．． 2'-thiodiethylenebis[3-(3゜5-di(
-butyl-4-hydroxyphenyl)propionate]
, 1,6-hexanediolbis[3-(3,5-di-
tert-butyl-4-hydroxyphenyl)propionate], butyl hydroxyanisole, dibutylhydroxyanisole, 1-[2-((3,5-di-tert-
Butyl-4-hydroxyphenyl)propionyloxy)ethylco4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]
-2,2,6,6-titramethylbiperidyl, etc.

<Group I [): Paraphenyl diamines N-phenyl-
N'-isopropyl-〇-phenylenediamine, N,N
'-5ec-butyl-p-phenylenediamine, N
-phenyl-N-3eC-butyl-p-phenylenediamine, N+N'-diisopropyl-p-phenylenediamine, N,N'-dimethyl-N, N'-di-t-butyl-p-phenylenediamine, etc.

(Group I
Octyl-5-methylhydroquinone, 2-(2-octadecenyl)-5-methylhydroquinone, etc.

(IV) Details: Organic sulfur compounds dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, ditetradecyl-3,3'-thiodipropionate, etc.

Group (V): Organophosphorus compounds such as triphenylphosphine, 1-heli(nonylphenyl)phosphine, tos(dinonylphenyl)phosphine, tricresylphosphine, tri(2,4-dibutylphenoxy)phosphine, and the like.

These compounds are known as antioxidants for rubber, Plusdec, oils and fats, and are easily available commercially.

These antioxidants may be added to any of the carrier generation layer, the carrier transport layer, or the carrier transport layer, but are preferably added to the carrier transport layer.

In that case, the layer to which the antioxidant is added is the carrier transport material 10
0.1 to 100 parts by weight, preferably 1 part by weight
~50 parts by weight, particularly preferably 5 to 2-5 parts by weight.

Next, the conductive support supporting the photosensitive layer may be a metal plate made of aluminum or nickel, a metal drum or cylinder, a plastic film deposited with aluminum, tin oxide, indium oxide, etc., or paper coated with a conductive substance. , a film or drum of plastic or the like can be used.

In the present invention, the carrier generation layer is typically formed by applying a dispersion of the bisazo compound of the present invention described above in a suitable dispersion medium or solvent alone or together with a suitable binder resin, for example, by dip coating, spray coating, blade coating, etc. It can be provided by a method of coating on a support or subbing layer or carrier transport layer by roll coating and drying.

The bisazo compound of the present invention is made into fine particles of an appropriate particle size using, for example, a ball mill or a sand mill.
It can be dispersed in a dispersion medium.

A ball mill, homomixer, sand mill, ultrasonic disperser, attritor, etc. are used for dispersing the bisazo compound of the present invention.

Examples of the dispersion medium for the bisazo compound of the present invention include hydrocarbons such as hexane, benzene, toluene, and xylene;
Methylene chloride, methylene bromide, 1,2-dichloroethane, 5yn-tetrachloroethane, cis-
1,2-dichloroethylene, 1.1.2-1~lichloroethane, 1,1.1-trichloroethane, 1.2-dichloropropane, chloroform, bromoform, halogenated hydrocarbons such as chlorobenzene, acetone, methyl ethyl ketone, cyclohexanone Ketones such as ethyl acetate, esters such as butyl acetate, methanol, ethanol, propatool, butanol, cyclohexanol, heptatool, ethylene glycol, methyl cellosolve,
Alcohols and their derivatives such as ethyl cellosolve and acetic acid cellosolve, ethers and acetals such as tetrahydrofuran, 1,4-dioxane, furan, and ralfural,
Amines such as pyridine, n-butylamine, diethylamine, ethylenediamine, isopropanolamine, N
In addition to nitrogen compounds such as amides such as , N-dimethylformamide, fatty acids and phenols, sulfur and phosphorus compounds such as carbon disulfide and triethyl phosphate, and the like.

When the photoreceptor of the present invention has a laminated structure, the weight ratio of binder:carrier generating substance:carrier transporting substance in the chitria generating layer is 0 to 100: i to 500:.

~500.

If the content of the carrier-generating substance is less than this, the photosensitivity will be low and the residual potential will increase, and if it is more than this, the dark decay and acceptance potential will decrease.

The thickness of the carrier generation layer formed as described above is
Preferably 0.01 to 10 μm1, particularly preferably 0.1
~5 μm.

Further, the carrier transport layer can be formed by coating and drying a carrier transport substance dissolved or dispersed in an appropriate solvent or dispersion medium alone or together with the above-mentioned binder resin. As the dispersion medium used, the dispersion medium used in dispersing the carrier-generating substance can be used.

Carrier transport substances that can be used in the present invention include:
Although not particularly limited, examples include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazoone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds,
Pyrazoline derivatives, amine derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran Ms derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives 23, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly -9-vinylanthracene and the like.

The carrier transporting substance used in the present invention is preferably one that has an excellent ability to transport holes generated during light irradiation to the support side, and is suitable for combination with the bisazo compound of the present invention. Preferred substances are the following formulas (A), (B) and (
Examples include those represented by C).

General formula (A) However, A r 1, A r 2, A r 41; t
'c Reso tL VRJ'A or an unsubstituted aryl group, Ar3 represents a substituted or unsubstituted arylene group, and R1 represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. represent.

Specific examples of such compounds are given on pages 3 to 4 of JP-A-58-65440 and pages 3-6 of JP-A-58-198043. -R1 However, R1 is a substituted or unsubstituted aryl group, or a substituted group.

It is an unsubstituted heterocyclic group, and R2 is a hydrogen atom and is substituted.

It represents an unsubstituted alkyl group, a substituted or unsubstituted aryl group, and in detail, it is described in JP-A-58-134642 and JP-A-58-134642.
It is described in the publication No. 166354.

- Formula (C) ■ R3 However, R1 is a substituted or unsubstituted 7-aryl group, and R2 is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group,
Substituted, unsubstituted alkoxy group, substituted.

unsubstituted amino group, hydroxy group, R3 is substituted,
Represents an unsubstituted aryl group, substituted or unsubstituted heterocyclic group. Synthesis methods and examples of these compounds are given in Japanese Patent Publication No. 57-
It is described in detail in Japanese Patent No. 148750, and can be incorporated into the present invention.

Other preferred carrier transport materials of the present invention include:
Examples include hydrazone compounds described in JP-A-57-67940, JP-A-59-15252, and JP-A-57-101844, respectively.

The carrier transport material in the carrier transport layer is preferably 20 to 200 parts by weight, particularly preferably 30 to 150 parts by weight, per 100 parts by weight of the binder resin.

The thickness of the key carrier transport layer to be formed is preferably 5 to 5.
50 μm, particularly preferably 5 to 30 μm.

Further, in the case of a monolayer functionally separated type electrophotographic photoreceptor using the bisazo compound of the present invention, the ratio of the binder to the bisazo compound of the present invention:carrier transport substance is 0 to 100:
1-500: O-500 is preferred, and the thickness of the photosensitive layer formed is preferably 5-50 μm, particularly preferably 5-50 μm.
It is 30 μm.

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

Examples of electron-accepting substances that can be used here include succinic anhydride, maleic anhydride, dibromaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride,
Tetrabromo phthalic anhydride, 3-nitro phthalic anhydride,
4-nitrophthalic anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, O-dini-1-lobenzene, -1-dinitrobenzene, 1.3.5-trinitrobenzene, to palani 1 lopenzonitrile, vicryl chloride, quinone chlorimide, chloranil, brumanil, dichlorodicyanobarabenzoquinone, anthraquinone, dinitroanthraquinone, 2.7-sinitrofluorenone, 2,4.7-trinitrofluorenone, 2゜4.5.7- Tetranitrofluorenone, 9-fluorenylidene [dicyanomethylene malonodinitrile], polynitro-9-fluorenylidene [dicyanomethylene malonodinitrile], picric acid, 0-nitrobenzoic acid, p-nitrobenzoic acid, 3.5-
Examples include dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3.5-dinitrosalicylic acid, phthalic acid, mellitic acid, and other compounds with high electron affinity.

Further, the addition ratio of the electron-accepting substance is the bisazo compound of the present invention:electron-accepting substance=100:0.01 to
200, preferably 100:0.1-100.

This electron-accepting substance may be added to the carrier transport layer. The ratio of addition of the electron-accepting substance to such a matrix is the ratio of total carrier transport substance:electron-accepting substance=100:0
．． 01-100, preferably 100:0.1-
It is 50.

In addition, the photoreceptor of the present invention may also contain, if necessary, an ultraviolet absorber, an antioxidant, etc. for the purpose of protecting the photosensitive layer, and may also contain a dye for color sensitivity correction.

The electrophotographic photoreceptor containing the bisazo compound of the present invention can be sensitive to visible light and near-infrared light, but preferably has an absorption maximum at a wavelength of about 400 to 700 μm.

Examples of light sources with such wavelengths include Hao Gunlamb,
Fluorescent lamps, tungsten lamps, etc. are commonly used.

The electrophotographic photoreceptor of the present invention has the above configuration,
As is clear from the Examples described below, it has excellent charging characteristics, sensitivity characteristics, and image forming characteristics, and especially shows little fatigue deterioration even when used repeatedly, and has excellent durability.

[Examples] Hereinafter, the present invention will be specifically explained with reference to Examples, which demonstrate the practical aspects of the present invention! ! There are no restrictions on who you are.

Example 1 Vinyl chloride-vinyl acetate-
An intermediate layer with a thickness of 0.05 μl made of maleic anhydride copolymer "S-LEC MF-104 (manufactured by Tsukiki Kagaku Co., Ltd.) was provided, and on top of that an exemplified compound N01 represented by the general formula [A]
6 and 2g of polycarbonate resin "Panlite L-12"
50J (manufactured by Yojin Kasei Co., Ltd.) 2 (J) was added to 1,2-dichloroethane 1101N and dispersed in a ball mill for 12 hours. This dispersion was applied to a dry film thickness of 0.5 μm, and carrier generation was performed. layer, and further on top of that, as a carrier transport layer, a film with the following structural formula (K-1>6o is a polycarbonate resin [Panlite L-1250J 10 (I dissolved in 1,2-dichloroethane 801R) after drying. A carrier transport layer was formed by coating to a thickness of 15 μm, and a photoreceptor of the present invention was prepared.

(K-1) The photoconductor obtained as described above was subjected to the following characteristic evaluation using an EPA-8100 electrostatic paper test machine manufactured by Yuyo Denki Seisakusho. After charging for 5 seconds at
Exposure amount required to attenuate the surface potential by half by irradiating halogen lamp light at 1ux-sec
Half-exposure ff1) E1/2 was determined. Also 3 Q lu
The surface potential (residual potential) VR after exposure with an exposure amount of x-sec was determined. Further, similar measurements were repeated 100 times. The results are shown in Table 1.

Comparative Example 1 The following bisazo compound (G-1) was used as a carrier generating substance.
A comparative photoreceptor was prepared in the same manner as in Example 1, except that .

(G-1) Regarding this comparative photoreceptor, measurements were performed in the same manner as in Example 1, and the results shown in Table 1 were obtained.

As is clear from the results in Table 1 and above, the photoreceptor of the present invention is extremely superior in sensitivity, residual potential, and repetition stability compared to the comparative photoreceptor.

Examples 2 to 4 Exemplary compound No. 1 represented by general formula [A] as a carrier generating substance, Exemplary compound No. 1 represented by general formula [B], Exemplary compound No. 0.78 represented by general formula [C], Exemplary compound N represented by general formula [C]
Photoreceptors of the present invention were prepared in the same manner as in Example 1, using O, 584, respectively, and the following compounds as carrier transport substances, and the same measurements were performed. Table 2 shows the results. The following results were obtained.

The following margins - (K-2) (K-3) C2Hq From the results shown in Table 2, the electrophotographic photoreceptor using the bisazo compound of the present invention as a carrier generating substance has high sensitivity as in Example 1. It can be seen that the residual potential is low and the repeatability is excellent.

Examples 5 to 9 Aluminum was vapor-deposited on a polyester film, the intermediate layer used in Example 1 was provided, and the general formula [A]
Exemplary compound No. 9° - Exemplary compound No. 0.169 represented by formula [B] - Exemplary compound No. 0.864 represented by formula [C].

- Exemplary compound No. 940 represented by formula [D].

- 2 g each of exemplified compounds No. 98 represented by formula [E] and polycarbonate-1/resin [Panlite L -
1250J 20 to 1,2-dichloroethane 1101g
In addition, the mixture was dispersed for 8 hours using a sand grinder.

Each of these dispersions was applied so that the dry film thickness was 0.5 μm to form a carrier generation layer.

Further, on each of these carrier generation layers, 6 g of the following structural formula (K-5) was applied as a main 11 rear transport layer to a polycarbonate resin [Panlite 11300J (Teijin Kasei Co., Ltd. 1
A solution prepared by dissolving 0 g of 1.2-dichloroethane in 801 g of 1,2-dichloroethane was applied to each layer so that the film thickness after drying was 15 μm to form a carrier transport layer, thereby producing photoreceptors 5 to 9 of the present invention. .

When the same measurements as in Example 1 were carried out on this photoreceptor, the results were not shown in Table 3.

Comparative Example 2 An electrophotographic photoreceptor was produced in the same manner as in Example 5, except that a bisazo pigment represented by the following structural formula (G-2) was used as a carrier-generating substance. The same measurements as in Example 1 were performed on this comparative photoreceptor, and the results are shown in Table 3.

(G-2) Table 3 Examples 10 to 12 Vinyl chloride-vinyl acetate-
Maleic anhydride copolymer “S-LEC MF-10J
(manufactured by Block Chemical Co., Ltd.) with a thickness of 0.05 μm is provided, and on top of that is an exemplified compound N represented by the general formula [A].
29 of 0.716 and polycarbonate resin "Panlite L-1250J 2 (l) and tetrahydrofuran 110
In addition to d, the mixture was dispersed in a ball mill for 12 hours. This dispersion liquid was applied to a dry film thickness of 0.5 μl to form a carrier generation layer, and furthermore, as a carrier transport layer, structural formulas (K-6), (K-7), (K- 6 g of each of the compounds shown in 8) and polycarbonate resin rZ-2
00J (manufactured by Mitsubishi Gas Chemical Co., Ltd.) dissolved in 1°2-dichloroethane 80112, the film thickness after drying was 15.
Coating to a thickness of μm to form a chyrelia transport layer,
A photoreceptor of the present invention was prepared.

Measurements were carried out in the same manner as in Example 1, except that a fluorescent lamp was used in place of the halogen lamp in Example 1, and the results were not shown in Table 4.

Table 4 Example 13 An intermediate layer with a thickness of 0.05 μI made of vinyl chloride-vinyl acetate-maleic anhydride copolymer [S-LEC MF-10J (manufactured by Hosui Kagaku Co., Ltd.) was provided on the surface of an aluminum drum with a diameter of 60III11. , and then an exemplary compound No.747 represented by the general formula [A].

Exemplary compound NO, 462 represented by the general formula CB].

Exemplary compound No.874 represented by general formula [C].

Exemplified compound represented by general formula [0] NO, 105° Exemplified compound represented by general formula [E] No. 0.176° Exemplified compound represented by general formula [F] No. 0.840 20 and polyester resin "Vylon 200" (Toyobo Co., Ltd. 1) 2(l) was mixed with 1001 g of 1,2-dichloroethane, and the dispersion was dispersed for 24 hours using a ball mill disperser. A generation layer was formed respectively.

Furthermore, on top of this, the following compound (K-9) 30! I+ and polycarbonate resin "Nipiron S-1000J (manufactured by Mitsubishi Gas Chemical Co., Ltd.) 50o and 1,2-dichloroethane 4
A carrier transport layer was formed by dissolving the solution in a solution of 00 nR and applying it to a film thickness of 18 μm after drying.

(K-9) The photoreceptor thus prepared is transferred to an electrophotographic copying machine r U
When the image was copied by installing it on a modified Bix1550M RJ (manufactured by Konica), it had a high contrast 1- and a clear copy image that was faithful to the original was obtained.

Moreover, this did not change even if it was repeated io and ooo times.

Comparative Example 3 The example compound of Example 131S Obanpuru was prepared by the following structural formula (G-
Example 9 except that the bisazo compound represented by 3) was used.
A drum-shaped comparative photoreceptor was prepared in the same manner as in Example 9, and the copied images were evaluated in the same manner as in Example 9. Only images with a lot of fog were obtained. Also, as copying is repeated, the contrast of the copied image decreases, and
When the process was repeated 0 times, almost no copy image was obtained.

(G-3) Example 14 Vinyl chloride-vinyl acetate-
An intermediate layer with a thickness of 1.05 μm made of maleic anhydride copolymer "S-LEC MF-104 (manufactured by Tsukisui Kagaku Co., Ltd.) was provided, and on top of this, as a carrier transport material, the following structural formula (K-1
0) and polycarbonate resin [Panlite L -
1250J 10Q and 1,2-dichloroethane 80i
A carrier transport layer was formed by applying a solution dissolved in & to a dry film thickness of 15 μm.

(K-10> Furthermore, an exemplary compound N represented by the general formula [F]
O, 402, exemplary compound NO represented by general formula [G]
,534, exemplified compound NO represented by the general formula [H],
630, exemplary compound represented by general formula [I] N0.7
29 of 2 (+, the above carrier transport substance 1.501 polycarbonate resin [Panlite L-1250J20] was added to 1.2-dichloroethane 301Q, the dispersed liquid was applied with a ball mill for 24 hours, and the film thickness after drying was 4 μm. A photoreceptor of the present invention was prepared by providing a carrier generation layer having the following properties.

When this photoreceptor was measured in the same manner as in Example 1, the results shown in Table 5 were obtained.

As is clear from the results of the Examples and Comparative Examples shown in Table 5 and above, the photoreceptor of the present invention is significantly superior to the comparative photoreceptor in terms of stability, sensitivity, durability, combination with a wide range of carrier transport substances, etc. It is excellent.

Example 18 Exemplary compound No. 0.943-2 represented by general formula [J]
g and polycarbonate resin “Panlite L-1250J
(Manufactured by Yojin Kasei Co., Ltd.>2a and 1,2-dichloroethane 1
10i12 and dispersed in a ball mill for 12 hours. This dispersion was applied onto a polyester film on which aluminum had been vapor-deposited so that the film thickness would be 1 μm when dried to form a gear generation layer, and on top of that a carrier transport layer was formed using the following structural formula (K-11) 6o. The polycarbonate resin "Panlite L-1250J 10 (L and 1.2-
A carrier transport layer was formed by applying a solution dissolved in dichloroethane 110 to a dry film thickness of 15 μm, thereby forming an electrophotographic photoreceptor of the present invention.

(K-11) This photoreceptor was measured in the same manner as in Example 1, and the results shown in Table 6 were obtained.

Comparative Example 4 The following bisazo compound (G-4) was used as a carrier generating substance.
A comparative photoreceptor was prepared in the same manner as in Example 11, except that .

(G-4) Regarding this comparative photoreceptor, measurements were performed in the same manner as in Example 1, and the results shown in Table 6 were obtained.

Table 6 Examples 19 to 21 Exemplary compounds No. 945 and 981. represented by the general formula [J] as carrier generating substances. A photoreceptor of the present invention was prepared in the same manner as in Example 1, using the exemplified compound N 0.1009 represented by the general formula [K] and each compound having the following structural formula as a carrier transport substance. When similar measurements were carried out, the results shown in Table 7 were obtained.

(K-12) (K-13> (K-14) Table 7 Example 22 Vinyl chloride-vinyl acetate-maleic anhydride copolymer [S-LEC MF-10J (soaked in water) (manufactured by Kagakusha) thickness 1
．． An intermediate layer of 05μ- was provided, and 4(+) of exemplified compound 1o33 represented by the general formula [L] was mixed with 400.(l) of 1,2-dichloroethane, and 2
A dispersion solution dispersed for 4 hours was applied so that the film thickness after drying was 0.6 μm to form a carrier generation layer.

Furthermore, 30 g of the structural formula (K-9) already described and polycarbonate resin "Nipiron S-10004 (Mitsubishi Gas Chemical) 509 were added to 400 ml of 1,2-dichloroethane.
A carrier transport layer was formed by applying the film to a dry film thickness of 13 μm to form a drum-shaped photoreceptor.

The photoreceptor created in this way can be printed on an electrophotographic printer.
When installed on a modified LP-30104 (manufactured by Konica), a copy image with high contrast, faithful to the original, and clear was obtained. Moreover, this did not change even after repeating it io and ooo times.

Comparative Example 5 Example 15 except that the carrier-generating substance was replaced with a gosuazo compound (G-5) represented by the following structural formula.
A drum-shaped comparative photoreceptor was prepared in the same manner as in Example 16, and the copied images were evaluated in the same manner as in Example 15. Only images with a large amount of fog were judged. Further, as copying was repeated, the contrast of the copied image decreased, and after 2000 repetitions, hardly any copied image could be obtained.

・1・−1,−=7 Less than blank □,! -・-Gosei (G-5) As is clear from the results of the above examples and comparative examples, the photoreceptor of the present invention has better stability, sensitivity, durability, and a wider range of carrier transport materials than the comparative photoreceptor. It is extremely excellent in combination with

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 9 are cross-sectional views showing the layer structure of the photoreceptor of the present invention, and 1 to 6 in the figures represent the following, respectively. 1... Conductive support 2... Carrier generation layer 3.
...Carrier transport layer 4...Photosensitive layer, 5...Intermediate layer 6...Protective layer Fig. 1 Fig. 4 Fig. 2 Fig. 5 Intermediate Fig. 3
6th interval 7th figure 8 Figure 9

Claims (3)

[Claims] (1) An electrophotographic photoreceptor comprising a photosensitive layer containing a bisazo compound represented by the following general formula [I] on a conductive support. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ [R_1 and R_2 each represent a halogen atom, an alkyl group, an alkoxy group, a nitro group, a cyano group, or a hydroxy group. However, R_1 and R_2 may be the same or different. R_3 to R_7 are each a hydrogen atom, an alkyl group,
Represents an alkoxy group, halogen atom, cyano group or nitro group. m and n each represent an integer of 0 to 3. ] (2) The photosensitive layer contains a carrier-generating substance and a carrier-transporting substance, and the carrier-generating substance has the general formula [
The electrophotographic photoreceptor according to claim (1), which is a bisazo compound represented by I]. (3) Claim No. 1, wherein the photosensitive layer is constituted by a laminate of a carrier generation layer containing a carrier generation substance and a carrier transport layer containing a carrier transport substance.
The electrophotographic photoreceptor according to item (2) or item (2).