JPS58194035A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain a receptor excellent in photoconductivity, by using a specified bisazo compd. CONSTITUTION:The photosensitive layer of the receptor is incorporated with a bisazo compd. represented by a general formula (1), where Z: a set of atoms necessary to compose a substd. or unsubstd. arom. carbon ring or arom. heterocyclic ring; Y: hydrogen, hydroxyl, carboxylic or its ester, sulfo-substd. or unsubstd. carbamoyl or sulfamoyl, or carboxylic or its ester; R1: hydrogen, substd, or unsubstd. alkyl, amino or carbamoyl, carboxylic or its ester, or cyano group; Ar: substd. or unsubstd, aryl; and R: substd. or unsubstd. alkyl, aralkyl or aryl.

Description

[Detailed description of the invention] The present invention relates to an electrophotographic photoreceptor.

Conventionally, as an electrophotographic photoreceptor, a photoreceptor without a photoreceptor having a photosensitive layer whose main component is an inorganic light-guiding material such as selenium, zinc oxide, or cadmium sulfide has been widely used. However, these are not necessarily satisfactory in terms of the characteristics required for an electrophotographic photoreceptor, such as sensitivity, thermal stability, moisture resistance, and durability. For example, since selenium crystallizes due to heat, intoxication with dirt such as fingerprints, etc., its properties as an electrophotographic photoreceptor tend to deteriorate. Furthermore, when using cadmium sulfide, there are problems with moisture resistance and durability, and when using zinc oxide, there are problems with durability. The approx. is large.

In order to overcome the drawbacks of inorganic photoreceptors as described above, various types of light guides have been proposed. In recent years, research has been actively conducted on the development of the use of spherical substances as materials for the photosensitive layer of electrophotographic photoreceptors.

For example, see Japanese Patent Publication No. 50-10496 (Co, Poly-N
- vinyl carbazole and 2. Flea, 7-dorini) C7-9
- Organophotoreceptors with an n-photoreceptor comprising fluorenone are described. However, this photoreceptor
The sensitivity and durability are not necessarily satisfactory.In order to overcome these drawbacks, the carrier generation function and the carrier transport ability are assigned to different substances in the photosensitive layer. Attempts are being made to develop an f-sensitivity photoreceptor with high sensitivity and great durability.

In such electrophotographic photoreceptors of the functional type, it is possible to select substances that exhibit each function from a wide range of materials, so it is relatively easy to create an electrophotographic photoreceptor with arbitrary characteristics. (5) It is possible to make it.

A number of materials have been proposed as carrier-generating materials that are effective for electrophotographic photoreceptors of the adhesive type.

Examples of using S ■ things are, for example, Tokuko IH↓,,3
As described in Japanese Patent No. 16198, there is amorphous selenium. This is combined with an organic carrier transport material, but the carrier generating rflJ consisting of amorphous selenium is
As mentioned above, it has the disadvantage that it crystallizes due to heat etc. and its properties deteriorate.

In addition, many proposals have been made for electrophotographic photoreceptors using organic dyes or organic pigments as carrier-generating substances, such as photosensitive layers containing bisazo compounds. JP-A-47-37543, JP-A-55-22834, JP-A-54-79.6.32, JP-A-58
This is already known from Publication No. 116040 and the like. However, electrophotographic photoreceptors using these bisazo compounds are
It is not always satisfactory in terms of sensitivity, residual potential, or even stability during repeated use, and what is more, carrier transport? (III) The range of materials to be used as Iw is limited.
It does not fully satisfy the wide range of requirements in the child photographic process.

An object of the present invention is to provide an electrophotographic photoreceptor having a photosensitive layer containing a specific bisazo compound, being stable against heat and light, and having high carrier generation efficiency and excellent photoconductivity. be.

Another object of the present invention is to have high sensitivity and low residual potential.
Another object of the present invention is to provide an electrophotographic photoreceptor with excellent durability, which exhibits these good properties stably over a long period of time even when used with gravel.

Yet another object of the invention is to provide Kn in combination with any carrier transport material selected from a wide range of
It is an object of the present invention to provide an electrophotographic photoreceptor having unique characteristics and having a photosensitive layer containing a carrier-generating substance made of a specific bisazo compound, which exhibits carrier-generating ability.

As a result of extensive research aimed at achieving the above objectives, Fubenban et al. discovered that the bisazo compound represented by the following general formula [E] has excellent photoconductivity, and in particular, has the worrying ability to generate carbon (7). The present invention has been completed based on this discovery.

・General formula CI) In the formula, A lj Hz:ii! Atom group Y necessary for constituting a substituted/unsubstituted aromatic carbocycle or a substituted/unsubstituted aromatic heterocycle: a hydrogen atom, a hydroxy group, a carboxy group, or an ester group, a sulfo group, Substituted/unsubstituted carbamoyl group or i substituted/unsubstituted sulfamoyl group R□: hydrogen atom, substituted/unsubstituted alkyl group, i &
Unsubstituted amino group, 1-substituted carbamoyl group, carboxy group or its ester group, or cyano group 1r: fii! R2 represents a substituted or unsubstituted aryl group, R2 represents a substituted or unsubstituted alkyl group, an unsubstituted aralkyl group, or an unsubstituted aryl group. ) That is, in the present invention, the above general formula [
An electrophotographic photoreceptor is constructed by providing a photosensitive layer containing a bisazo compound represented by the following formula.

According to the present invention, it is stable against heat and light, and has charge retention ability,
It is possible to provide an electrophotographic i-optical material that has electrophotographic properties such as Ie degree and residual level (31B) and has high durability with little fatigue change even when used repeatedly (9).In particular, the present invention Utilizing the fact that the bisazo compound t represented by the above general formula [C] has an excellent carrier generation ability, it is combined with an n'r carrier transport substance to separate the photosensitive layer. By forming the structure into a mold, it is possible to obtain an electrophotographic photoreceptor with characteristics that are one step higher.As a specific example of the biszo compound represented by the general formula [E] which is effective in the present invention, for example, the following structure may be used. Shown with bamboo 2
However, this does not limit the bisazo compounds to be used in the present invention.

knee 1) (10) (I-2) (11) (I-3) (I-4) fI-s) (I-83 (13) (I-7) (I-8) (14) (I -9) (knee 10) <1!1) fI-11) (I-12) (I-14) (17) (I-18) (18) +I-17) (I-18) (19) ( I-19) (I-40) (I-1) (I-22) fI-23) (Nee 241) (21) CI-25) (I-26) (22) f 23) OH8 H8 (I- 34) ON ON (25) I-35) 1-aa ) (26) (Nee 37) (Nee 38) (I-39) □HLjN UN (JH (27) The above envy bisazo compound can be synthesized, for example, by the following synthesis method. It can be synthesized by the method shown in the example.

Synthesis Example (Synthesis of Exemplified Compound (Nee 1)) 2.7-dinitro-9-fluorenone and malonic acid nitrile were synthesized by a known method (for example, J. Org.

Compound 2.7 obtained by dehydration condensation according to Ohem 6, Vol. 30, p. 644 (see 19 [published in i5])
-Sinitro 9-dicyanomethylidenefluorene is reduced by tin and hydrochloric acid G to give 2,7-diamitu-9-dicyanomethylidenefluorene diacid salt. 31910.01 mol of IJum) was dispersed in 100 mol of hydrochloric acid, the dispersion was cooled to a temperature of 5°C with stirring, and 1.4 mol of IJum was dissolved in 20 fnt of water. The diluted aqueous solution was added dropwise. After the dropwise addition was completed, stirring was continued under cooling for an additional hour, and the filter was filtered through a port.
was processed, and the raw crystals were collected by filtration to obtain tetrazonium nonhexafluorophosphate. This crystal was dissolved in 200% of N,N-dimethylformamide to obtain a dropwise solution for the next coupling reaction.

2-Hydroxy-3-naphthoanilide (su7)-
(AS) 5.27% (0.02%) was dissolved in 200yri of NIJ-dimethylformamide, to which 5.59% of triethanolamine was added, the solution was cooled to a temperature of 5'C and stirred vigorously. Meanwhile, the above-mentioned dropping liquid was added dropwise to this. After the dropwise addition was completed, the mixture was stirred for 1 hour under cooling and further stirred for 2 hours at room temperature, and the resulting crystals were collected by filtration. This crystal? i:11) J, Wheat washed twice with N-dimethylformamide and twice with 1 a7thone was dried to obtain 6.70 of a blue compound (yield: 83.0%).

In the infrared absorption spectrum of this blue compound, absorption due to the a=o bond of the amide was observed at ν=188Qcm-12! The target exemplary compound (I-
1) was confirmed.

Elemental analysis results (chemical formula is C6°H8oN80.

) (29) Element OHN Actual value 1%) 74.81 3.70 1L
67 theoretical value c%)? 4.411 3.74
1L89 In order to construct the photosensitive layer of the electrophotographic photoreceptor of the present invention using the bisazo compound represented by the above general formula [E], a layer in which the bisazo compound is dispersed in a binder is provided on a conductive support. n is good. Alternatively, the bisazo compound may be used as a carrier generating substance and combined with a xa-rea transport substance having carrier transport ability to provide a so-called functionally separated photosensitive layer of a layer type or a dispersion type.

In the composition of the photosensitive layer, not only one type of bisazo compound represented by the above general formula [E] but also a combination of two or more types can be used, and it can also be used in combination with other bisazo compounds and other carrier-generating substances.

In the case where the electrophotographic photoreceptor of the present invention is of a functionally separated type, the phenomechanical configuration may be any of the conventionally known configurations. Normally, the configuration shown in FIGS. 1 to 6 is used. 1st
The one shown in FIGS. 3 and 3 is a layer consisting of a carrier generation layer 2 containing the above-mentioned bisazo compound as a main component and a carrier transport layer 3 containing a carrier transport substance as a generated component on a conductive (30) support 1. The structure provided with a photosensitive layer 4 consisting of a body, the one shown in FIG. 2 and the one shown in FIG.
In the structure shown in FIGS. and 3, the conductive support 1 and the photosensitive layer 4
It has a configuration in which an intermediate layer 5 is inserted between the two. As described above, the best electrophotographic properties can be obtained when the photosensitive layer t has a two-layer structure. In Fig. 5, a photosensitive layer 4 is provided directly on a conductive support 1, in which a carrier generation product W7 made of the above-mentioned bisazo compound is dispersed in a layer 6 containing a carrier transport substance component. ## The structure shown in FIG. 6 is the same as that shown in FIG. 5, in which four photosensitive layers are provided on a conductive support 1 via an interlayer r*5.

Examples of the carrier transporting substance include electron-transporting electron-accepting substances such as trinitrofluorenone and tetranitrofluorenone, or heterocyclic compounds such as H&IJ-N-vinylcarbazole in the side chain. Polymers with tri(31) zole derivatives, oxadiazole derivatives, imidazole derivatives, pyrazoline derivatives, polyaryl γ/l/can derivatives, 71-dienediamine derivatives, hydrazone derivatives, amine-substituted chalcone derivatives, triarylamine derivatives, carbazole Examples include hole-transporting electron-donating substances such as derivatives and stilbene derivatives. 1 as a preferred carrier transport material, JP-A-4TL-10
Pyrazoline compounds described in Japanese Patent Publication No. 55117, Japanese Patent Publication No. 55-Nai 2380, Japanese Patent Application Laid-open No. 150128-1982
Examples include hydrazone compounds described in Japanese Patent Application Laid-Open No. 55-52084, but the carrier transporting substance used in the present invention is not limited to these.

Carrier generation Jl 2 when forming a two-layered photosensitive layer! 1. It can be provided by the following method.

b) A method of applying a solution prepared by dissolving the above-mentioned bisazo compound in a suitable solvent, or a solution obtained by adding a binder to the solution and mixing and dissolving it.

(b) A method in which the above-mentioned bisazo compound is made into fine particles in a dispersion medium using a ball mill, a homomixer, etc., and a binder is added as necessary, and a dispersion obtained by mixing is applied.

Examples of the solvent or dispersion medium used for forming the carrier generation layer include n-butylamine, diethylamine, ethylenediamine, impropaturamine, triethanolamine, triethylenediamine, N,N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, Examples include benzene, toluene, xylene, cycloform, 2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, and dimethyl sulfoxide.

When a binder is used to form a carrier generation layer or a carrier transport layer, any binder can be used, but particularly an electrically insulating film-forming agent that is hydrophobic and has a high dielectric constant. High molecular weight polymers are preferred. Examples of such polymers include (a3), but are not limited to these, for example.

a) Polycarbonate b) Polyester C) Methacrylic resin d) Acrylic resin e) Polyvinyl chloride f) Polyvinylidene chloride g) Polystyrene h) Polyvinyl acetate 1) Styrene-butadiene copolymer j) Vinylidene chloride-acrylonitrile copolymer k) Vinyl chloride-vinyl acetate copolymer 1) Vinyl chloride-vinyl acetate-maleic anhydride copolymer m) Silicone resin n) Silicone-alcohol resin o) Phenol-formaldehyde resin p) Styrene-
Alkyd Resin Q) t'1J-N-Vinylcarbazole These binders can be used alone or as a mixture of two or more (34).

Thickness ij of carrier generation layer 2 formed in this way
It is preferably 0.01 to 20 pm, more preferably 0.05 to 5 pm. Further, when the above-mentioned bisazo compound is dispersed to form a photosensitive layer or a carrier generation layer, it is preferable that the bisazo compound is in the form of powder having a particle size of 5 μm or less, preferably 1 μm or less.

The conductive support in the present invention may be a metal plate, a metal drum, or a conductive thin layer made of a conductive polymer, a conductive compound such as indium oxide, or a metal such as aluminum, palladium, or gold, by coating, vapor deposition, lamination, etc. A material that can be mounted on a substrate such as paper or a plastic film by means of this method is used. The intermediate layer that functions as an adhesive layer or barrier layer may be made of a high molecular weight polymer as described above as a binder, a superior polymer such as polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, or aluminum oxide. is used.

(35) A configuration including one or more quantum photographic photoreceptors of the present invention,
It has excellent charging characteristics, sensitivity characteristics, and image forming characteristics, is stable against heat and light, shows little fatigue deterioration even after repeated use, and has excellent durability.

Examples of the present invention will be described below, but the implementation RFP of the present invention is not limited thereto.Example 1 Vinyl chloride-vinegar Vinyl-maleic anhydride copolymer
(manufactured by Suikagaku Co., Ltd.) with a thickness of 0.05 μm was formed, and the exemplified compound (I-1) 29 and the polycarbonate resin “Panlite L-1250J (manufactured by Ryotai Kasei Co., Ltd.) 2 were formed.
A dispersion obtained by adding 1,2-dichloroethane to 1,2-dichloroethane and allowing it to stand for 12 hours in a ball mill was coated and dried on the intermediate layer so that the film thickness after drying was 0.5 μm. A carrier generation layer was formed, and a carrier transport substance 3-(p-methoxystyryl)-9-+p-methoxyphenyl)carbazole 6 was dissolved in 100 ml of 1,2-dichloroethane along with polycarbonate resin "Panlite L-1250J10". The film thickness after drying the solution is 12
The carrier transport layer 2 is formed by coating and drying to give a thickness of μm.
An electrophotographic photoreceptor of the present invention was produced.

The electrophotographic photoreceptor thus obtained was tested using a static paper tester "5P".
-428 type” (newly manufactured by Kawaguchi Electric), the following %
A sex test was conducted. That is, a voltage of -[3 kV was applied to the charger for 5 seconds to charge the photosensitive layer by corona discharge, and then the device was kept for 5 seconds, and then a halogen lamp was applied with an illumination intensity of 35/ux on the surface of the photosensitive layer. The necessary exposure amount to attenuate the surface potential of the photosensitive layer to 1/2 by irradiating the photosensitive layer with light, that is, the half-reduction exposure 5iE1/2 was determined. Also a
The surface potential, ie, the residual potential VR, was determined after exposure with an exposure amount of o tux·sec. Further, similar measurements were repeated 100 times. The results are shown in Table 1.

(37) Table 1 Comparative Example ■ A comparative electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that a bisazo compound represented by the ##shield formula below was used as a carrier generating substance, and it had the same characteristics. I conducted a test. The results are shown in Table 2.

(38) Examples 2 to 4 Exemplary compounds (nee 2),
A total of three types of electrophotographic photoreceptors of the present invention were prepared in the same manner as in Example 1 and (2) except that (I-3) and (I-7) were used, and the same characteristic tests were conducted on each of them. Ta. The results are shown in Table 3. Table 3 (39') Example 5 Vinyl chloride-vinyl acetate-
Maleic anhydride copolymer [Eslec MF-104 [1]
An intermediate layer with a thickness of 0.05 μm is formed, and 2 g of the exemplified compound (Nie 25) is added to 1,2-dichloroethane 110- and dispersed in a ball mill for 24 hours. The dispersion was coated and dried on the intermediate layer to a film thickness of 0.5 μm after drying to form a carrier generation layer, and the carrier transport substance tree p-)lylamine 6 was added to the methacrylic resin “Acrypet”. (Mitsubishi Rayon Co., Ltd. IA) 10 g of a solution dissolved in 1,2-dichloroethane 70- was coated and dried so that the film thickness after drying was 10 μm to form a carrier transport layer. The body was created.

When a characteristic test similar to that in Example 1 was conducted on this electrophotographic photoreceptor, in the first test, 8073M3.
02 uX·sec, VR'=-5-Vt' atta.

Example 6 A 1% ethylenediamine m solution of exemplified compound fI-4) was applied onto the intermediate layer of a conductive support provided with an intermediate layer similar to that used in Example 2 so that the thickness after drying was 0. 3μm
A carrier generation layer was formed by coating and drying so as to obtain the following. Furthermore, 1-phenyl-3-(p-diethylaminophenyl)
-s-ip-diethylaminophenyl)pyrazoline 6g
was dissolved in 1,2-diquaroethane 70- together with a polydiester resin [Vylon 200-+ (Toyobo Co., Ltd. #) lo9, and this solution was coated and dried to give a film thickness of 12 μm after drying to form a carrier. A transport layer was formed to produce an electrophotographic photoreceptor of the present invention. .

Characteristic tests similar to those in Example 1 were conducted on this electrophotographic photoreceptor. The results are shown in Table 4.

Comparative Example 2 A comparative electrophotographic photoreceptor was prepared in the same manner as in Example 6, except that a bisazo compound represented by the following ma formula was used as a carrier generating substance, and a collar opening characteristic test was conducted.

The results are shown in Table 4 (41) be.

Table Φ Example 7 For injuries using Exemplified Compound (I-89) instead of Exemplified Compound (I-25) as a carrier generating substance, (t2) A carrier generating layer was formed in the same manner as in Example 5. , history,
■, l-bis(p-N,N-dibenzylaminophenyl)butane 69 in polycarbonate resin [Panlite L-
1250J 10 and 1,2-cycloethane 70
An electrophotographic photoreceptor of the present invention was prepared by drying a solution dissolved in - to form a carrier transport layer so that the film thickness after drying was 10 μm.

When this electrophotographic photoreceptor was subjected to characteristic tests in Example 1 and open collar, it was found that 'E1/2-3.01Hz・sec, V
It was R Snow ov.

Example 8 An intermediate layer with a thickness of 0.05 μm made of vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC IF-10J (manufactured by Tanezu Kagaku Co., Ltd.) was placed on the surface of a drum made of aluminum and having a diameter of 10,011 times. ?Form and exemplified compound (
Add 49 of I-5) to 400 bottles of 1,2-dichloroethane and leave it for 24 hours...1 minute in a ball mill, and apply a fractional solution on the intermediate layer so that the film thickness after drying is 0.6 μm. It was dried (43) to form a carrier generation layer.

On this carrier generation layer, a carrier transport product iN, N-diethylaminobenzaldehyde-1,1-diphenylhydrazone 80
9 is made of polycarbonate resin [2-pyro, 'N S-to
OOJ (Mitsubishi Gas Chemical Co., Ltd.) 50g with 1,2-
A solution dissolved in dichloroethane 400d? A carrier transport layer was formed by coating and drying so that the film thickness after drying was 13 μm, thereby producing a drum-type photoreceptor according to the present invention.

This photoconductor is a copy of the photoconductor U-Bxxv
2" (manufactured by Konishiroku Photo Industry Co., Ltd.) to form a copy image, a copy image with high contrast, faithful to the original, and clear was obtained. Also make 20 copies
I repeated it 00 times, but Ml! A copy image equivalent to the first one was obtained.

Comparative Example 3 A comparative drum-type electrophotographic photoreceptor was prepared in the same manner as in Example 8, except that a bisazo compound represented by the following structural formula was used as a carrier-generating substance. When the same copying test as in Example 8 was carried out, the obtained copied image had low image density and a lot of fog.Also, since copying was repeated 2000 times, the copied image Il!II was The contrast gradually decreased, and in the end, almost no image was formed.

(45) Example 9 A conductive support made of a polyester film laminated with aluminum foil was coated with a layer of vinyl chloride-vinyl acetate-maleic anhydride copolymer [Eslek Bin F-10J (manufactured by Tanezu Kagaku Co., Ltd.)]. An intermediate layer of 0.05 μm was formed, and five of the exemplified compounds (I-11) and polycarbonate [Panlite L-1250 (manufactured by Yondai Kasei Co., Ltd.)]
A dispersion obtained by adding 3.39 to 1,2-dichloroethane lOOtne and dispersing it in a ball mill for 24 hours was coated and dried on the intermediate layer so that the film thickness after drying was 10 μm. A photographic photoreceptor was planned and manufactured.

For this electrophotographic photoreceptor, the voltage applied to the charger is +
When the same characteristic test as in Example 1 was conducted except that the voltage was set to 6 kV, E1/z −4, Otux·sec, Vu =
+t5V.

Example 10 Carrier transport material '&1-phenyl-
3-(p-diethylaminostyryl)(46) -5-(p-di; thylaminophenyl)pyrazoline 6
jil wo polyester resin [bya > 200
A carrier transport layer was formed by coating and drying a bath solution in which J109 and 1,2-dichloroethane were dissolved in 70 m/m of 1,2-dichloroethane so that the film thickness after drying was 1oPm. -3) Same as 17 (I-7)
17 and 1,2-dichloroethane 110-,
A dispersion solution that had been left in a ball mill for 24 hours was coated and dried so that the film thickness after drying was 0.5 pm to form a carrier generation layer, thereby producing an electrophotographic photoreceptor of the present invention.・
.

Characteristic tests were conducted on this electrophotographic photoreceptor in the same manner as in Example 9, and the results were as follows: K, /2-3.6 ux-sec, VR=+5Vr, F+e.

As is clear from the above results, the electrophotographic photoreceptor of the present invention is superior in characteristics such as sensitivity and residual potential, as well as in durability and stability in repeated use.

[Brief explanation of drawings]

1 to 6 are sectional views showing examples of the mechanical structure of the electrophotographic photoreceptor (47) of the present invention, respectively. ... Conductive support 2. ...Carrier generation layer 1
...Carrier transport layer Committee...Photosensitive layer...Middle 1
15 layers 6...Carrier transport substance color rIv
7...Carrier generating substance Figure 1 Figure 2 Figure 5 Male Figure 4 239-

Claims (1)

[Scope of 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 [Engine] (In the formula, A is (2) h 2: Atomic group necessary to form substituted/unsubstituted aromatic carbocycle or substituted/unsubstituted aromatic double S ring fI# Y: Hydrogen Atom, hydroxy group, carboxy group or its ester group, sulfo group, substituted or unsubstituted carbamoyl group or substituted or unsubstituted sulfamoyl group, carboxy group or its ester group, or cyano group Ar:lIt substituted or unsubstituted Substituted aryl group R2: substituted or unsubstituted alkyl group, substituted or unsubstituted aralkyl group (8) or (represents a substituted or unsubstituted aryl group) 2) The photosensitive layer is a carrier transporting compound. 2. The electrophotographic photoreceptor according to claim 1, wherein the electrophotographic photoreceptor contains a carrier-generating material and a carrier-generating material, and the carrier-generating material contains the bisazo compound.