JPH0415466B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a photoreceptor, and more particularly to a novel photoreceptor having a photosensitive layer containing a specific azo compound.

[Conventional technology]

Conventionally, inorganic photoreceptors having a photosensitive layer containing an inorganic photoconductive compound such as selenium, zinc oxide, cadmium sulfide, silicon, etc. as a main component have been widely used as electrophotographic photoreceptors. 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. Cadmium sulfide also has moisture resistance, durability,
Even zinc oxide has problems with durability, etc. In order to overcome these drawbacks of inorganic photoreceptors, research and development have been actively conducted in recent years on organic photoreceptors having photosensitive layers containing various organic photoconductive compounds as main components. For example, in Japanese Patent Publication No. 50-10496, poly-N-vinylcarbazole and 2,4,7-
There is a description of an organic photoreceptor having a photosensitive layer containing trinitro-9-fluorenone. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability. In order to improve these drawbacks, attempts have been made to develop organic photoreceptors with higher performance by assigning the carrier generation function and the carrier transport function to different substances. 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]

A large number of compounds have been proposed as carrier generating substances for the functionally separated type photoreceptor as described above. As an example of using an inorganic compound as a carrier generating substance, for example,
There is amorphous selenium described in Publication No. 16198,
Although this is used in combination with an organic photoconductive compound, the drawback that the carrier generation layer made of amorphous selenium crystallizes due to heat and deteriorates the properties 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 an electrophotographic photoreceptor containing a bisazo compound in the photosensitive layer, JP-A-54-22834, JP-A-55-73057, JP-A-55-117151,
JP-A-56-46237 and the like are already known. However, these bisazo compounds have low sensitivity,
The characteristics of residual potential and stability during repeated use are not necessarily satisfactory.
Furthermore, the selection range of carrier transport substances is also limited, and the wide range of requirements of electrophotographic processes cannot be fully satisfied. Furthermore, in recent years, Ar laser has been used as a light source for photoreceptors.
Gas lasers such as He-Ne lasers and semiconductor lasers are beginning to be used. A characteristic of these lasers is that they can be turned on and off in chronological order, making them particularly promising light sources for copying machines with image processing functions, including intelligent copying machines, and printers for computer output. Among these, semiconductor lasers are attracting attention because their nature does not require electrical signal/optical signal conversion elements such as acoustic engineering elements, and they can be made smaller and lighter. However, this semiconductor laser has a low output compared to a gas laser,
Furthermore, since the oscillation wavelength is long (approximately 780 nm or more), the spectral sensitivity of conventional photoreceptors is higher on the short wavelength side, and as it is, it is impossible to use them as photoreceptors using semiconductor lasers as light sources. An object of the present invention is to provide a photoreceptor containing a specific azo compound that has excellent carrier generation performance. Another object of the present invention is to provide a photoreceptor with high sensitivity, low residual potential, and excellent durability whose characteristics do not change even after repeated use. Still another object of the present invention is to provide a photoreceptor containing an azo compound that can effectively act as a carrier generating substance even in combination with a wide range of carrier transport substances. Still another object of the present invention is to provide a photoreceptor having sufficient practical sensitivity even to long wavelength light sources such as semiconductor lasers. Still other objects of the present invention will become apparent from the description in the specification.

[Means to solve the problem]

As a result of intensive research to achieve the above object, the present inventors discovered that an azo compound represented by the following general formula [] can act as an excellent active ingredient of a photoreceptor, and completed the present invention. This is what I did. General formula [] In the formula, R ₁ and R ₂ are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms (C ₁
~ _C6 ) represents a halogen atom, a cyano group, an amide group, a carbamoyl group or a sulfamoyl group, and A
teeth

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

[expression] or

[Formula] and Q ₁ , Q ₂ , Q ₃ , Q ₄ , Q ₅ and Q ₆ are

[Formula] or represents −SO ₂ NHY ₂ , Y ₁ , Y ₂ and Q ₇ represent a substituted or unsubstituted aryl group, R ₁₁ is a hydrogen atom,
It represents an alkyl group, a dialkylamino group, a diarylamino group, a dialkylamino group, a carbamoyl group, an alkoxycarbonyl group, or a cyano group, and R ₁₂ and R ₁₃ represent an alkyl group, an aralkyl group, or an aryl group. Examples of substituents for Y ₁ , Y ₂ and Q ₇ include a halogen atom, an alkyl group (C ₁ to _{C 4} ), an alkoxy group, a cyano group, a dialkyl group, and a carbamoyl group. Specific examples of the azo compound useful in the present invention represented by the general formula [] include those having the following structural formula, but the azo compound of the present invention is not limited thereto. . In the compound represented by the general formula [], the general formula [
Those having the structure of a] General formula [a]

【table】

【table】

[Table] Compound general formula [] represented by general formula []
Those having the structure of general formula [b]

【table】

【table】

〔Example〕

Example 1 2 g of Exemplified Compound B-1 and 2 g of polycarbonate resin "Panlite L-1250" (manufactured by Teijin Chemicals)
was added to 110 ml of 1,2-dichloroethane and dispersed in a ball mill for 12 hours. This dispersion was applied onto a polyester film on which aluminum was vapor-deposited so that the dry film layer had a thickness of 1 μm to form a carrier generation layer, and on top of this a 1-phenyl-(p-methyl Styril)-5-
6 g of (p-methoxyphenyl)pyrazoline (the following structural formula K-(1)) was mixed with 10 g of polycarbonate resin "Panlite L-1250" in 1,2-dichloroethane.
A carrier transport layer was formed by coating a solution dissolved in 110 ml so that the film thickness after drying was 15 μm, thereby producing a photoreceptor of the present invention. The photoreceptor obtained as described above was subjected to the following characteristic evaluation using an electrostatic paper tester model SP-428 manufactured by Kawaguchi Electric Seisakusho Co., Ltd. After charging with a charging voltage of -6KV for 5 seconds, leave in the dark for 5 seconds, then irradiate with halogen lamp light so that the illuminance on the photoreceptor surface is 35 lux, and calculate the amount of exposure required to attenuate the surface potential by half. (Half-reduced exposure amount) E1/2 was determined. Also
The surface potential (residual potential) V _R after exposure with an exposure amount of 30 lux·sec was determined. Furthermore, similar measurements were repeated 100 times. The results are shown in Table 1.

[Table] Comparative Example 1 The following bisazo compound G was used as a carrier generating substance.
A comparative photoreceptor was prepared in the same manner as in Example 1 except that -(1) was used. When this comparative photoreceptor was measured in the same manner as in Example 1, the results shown in Table 2 were obtained.

[Table] As is clear from the above results, the photoreceptor of the present invention is extremely superior in sensitivity, residual potential, and repetition stability compared to the comparative photoreceptor. Example 2-4 Exemplary compounds B-2 and B as carrier generating substances
-3 and B-4 as carrier transport substances, respectively.
4-carbazolyl)methylideneamine-1,2,
3,4-tetrahydroquinoline (compound K- below)
(2)), 1-(1-ethyl-4-carbazolyl)methylideneamino-1,2,3,4-tetrahydroquinoline (compound K-(3) below), and 4,4′-methyl-4″-( 4-Chlor)-styryltriphenylamine (compound K-(4) below) was used, and the others were as in Example 1.
A photoreceptor of the present invention was prepared in the same manner as above, and the same measurements were performed, and the results shown in Table 4 were obtained.

[Table] Example 5 A vinyl chloride-vinyl acetate-maleic anhydride copolymer "Eslec MF-10" (manufactured by Sekisui Chemical Co., Ltd.) was placed on a conductive support made of aluminum foil laminated on a polyester film. thickness
A 0.05 μm intermediate layer is provided, and exemplified compound B is placed on top of the intermediate layer.
-16.2 g was mixed with 110 ml of 1,2-dichloroethane and dispersed in a ball mill for 24 hours, and the dispersion was applied to a dry film thickness of 0.5 μm to form a carrier generation layer. On this carrier generation layer, 3,3',4-trimethyl-triphenylamine 6
g and 10 g of methacrylic resin "Acrypet" (manufactured by Mitsubishi Rayon Co., Ltd.) and 70 ml of 1,2-dichloroethane.
The photoreceptor of the present invention was prepared by applying a solution dissolved in the above to form a carrier transport layer so that the film thickness after drying was 10 μm. The same measurements as in Example 1 were carried out on this photoreceptor, and the first measurement was E1/2=2.9lux・
sec, V _R =0v was obtained. Example 6 On the conductive support provided with the intermediate layer used in Example 5, a 1% ethylenediamine solution of Exemplified Compound B-19 was applied to a dry film thickness of 1.3 μm, and a carrier generation layer was formed. It was created. Then, 4-methoxy-4'-styryltriphenylamine (compound K-(5) below) is added thereon. 6 g and 10 g of polyester resin "Vylon 200" (manufactured by Toyobo Co., Ltd.) were dissolved in 70 ml of 1,2 dichloroethane, and this solution was applied so that the film thickness after drying was 12 μm to form a carrier transport layer. A photoreceptor of the present invention was prepared. The same measurements as in Example 1 were performed on this photoreceptor, and the results shown in Table 4 were obtained. Comparative Example 2 A comparative photoreceptor was prepared in the same manner as in Example 6 except that exemplified compound B-19 was replaced with bisazo compound G-(2) represented by the following structural formula. The same measurements as in Example 1 were performed on this photoreceptor, and the results are shown in Table 4.

[Table] As seen from the results in the table, the sample of Example 6 has particularly excellent characteristics after repeated use compared to the comparative example. Example 7 A carrier generation layer was formed in the same manner as in Example 5 except that Exemplified Compound B-16 was replaced with Exemplified Compound B-6. On top of this, 6 g of 3-(p-methoxystyryl)9-(p-methoxyphenyl)carbazole and polycarbonate "Panlite L-
1250 (manufactured by Teijin Chemicals) in 70 ml of 1,2-dichloroethane, the film thickness after drying is 10 μm.
The photoreceptor of the present invention was prepared by coating the photoreceptor to form a carrier transport layer. Measurements were carried out on this photoreceptor in the same manner as in Example 1, and E1/2 = 2.1 lux・sec and V _R = 0v.
It was hot. Example 8 An intermediate layer with a thickness of 0.05 μm made of vinyl chloride-vinyl acetate-maleic anhydride copolymer “Eslec MF-10” (manufactured by Sekisui Chemical Co., Ltd.) was provided on the surface of an aluminum drum with a diameter of 100 mm, and then Add 4g of Exemplified Compound B-7 to 400ml of 1,2-dichloroethane.
The dispersion liquid was mixed with the following materials and dispersed for 24 hours using a ball mill dispersion machine, and the dispersion liquid was coated to a film thickness of 0.6 μm after drying to form a carrier product. Furthermore, on top of this, 3-(p-methoxystyryl)
-9-(p-methoxyphenyl)carbazole (compound K-(6) below) 30g and polycarbonate resin "Iupilon S-1000" (manufactured by Mitsubishi Gas Chemical Co., Ltd.)
50g and 1,2-dichloroethane A drum-shaped photoreceptor was prepared by dissolving the solution in 400 ml and applying it to a dry film thickness of 13 μm to form a carrier transport layer. The photoreceptor created in this way was attached to a modified electrophotographic copying machine "U-Bix1600MR" (manufactured by Konishiroku Photo Industry Co., Ltd.), and the image was copied with high contrast, faithful to the original image, and clear copy. Got the image. Moreover, this did not change even after repeating this 10,000 times. Comparative Example 3 A drum-shaped comparative photoreceptor was prepared in the same manner as in Example 8, except that Exemplary Compound B-7 was replaced with a trisazo compound (G-(3)) represented by the following structural formula. When the copied images were evaluated in the same manner as in Example 8, only images with a lot of fog were obtained. Furthermore, as copying was repeated, the contrast of the copied image decreased, and after 2000 repetitions, almost no copied image could be obtained. Example 9 A layer of vinyl chloride-vinyl acetate-maleic anhydride copolymer "Eslec MF-10" (manufactured by Sekisui Chemical Co., Ltd.) was placed on a conductive support made of aluminum foil laminated on a polyester film.
A 0.05 μm intermediate layer is provided, and exemplified compound B-
30 5g and polycarbonate resin “Panlite L”
A photoreceptor was prepared by adding 3.3 g of "-1250" (manufactured by Teijin Chemicals) to 100 ml of dichloromethane, dispersing it in a ball mill for 24 hours, and applying the dispersion to a dry film thickness of 10 μm. The photoconductor obtained in the above manner is charged with a +
E1/2 and E1/2 in the same manner as in Example 1 except that 6Kv was used.
_VR was measured. The first result is E1/2=2.8lux・
sec and V _R =+2v. Example 10 6 g of 4-methoxytriphenylamine and polyester resin "Vylon" were added as a carrier transport layer on a polyester film deposited with aluminum.
200" (manufactured by Toyobo Co., Ltd.) in 70 ml of 1,2-dichloroethane, and the film thickness after drying this solution.
It was applied to a thickness of 10 μm. Next, 1 g of exemplified compound B-23 and B-
A dispersion liquid was prepared by mixing 191 g with 110 ml of 1,2-dichloroethane and dispersing it in a ball mill for 24 hours so that the film thickness after drying was 0.5 μm to form a carrier generation layer, thereby forming the photoreceptor of the present invention. . The thus obtained photoreceptor was evaluated in the same manner as in Example 9, and found that E1/2=3.0lux・sec.
V _R = +7V. Example 11 A 2% ethylenediamine solution of Exemplified Compound B-8 was applied onto a polyester film laminated with aluminum to a dry film thickness of 0.5 μm to form a carrier generation layer. Furthermore, 1-methyl-3-(p
-diethylaminophenyl)-5-(p-diethylaminophenyl)pyrazoline (compound K-
(7)), 1-phenyl (p-methoxystyryl)-5
-(p-diethylaminophenyl)pyrazoline The following compound K-(8) or 1-phenyl-(p-methylstyryl)-5-(p-methylphenyl)pyrazoline (the following compound K-(9)), respectively. about
10g and polycarbonate Resin (manufactured by Teijin Chemicals, Panlite L-1250) 14g
A solution prepared by dissolving 1,2-dichloroethane in 140 ml of 1,2-dichloroethane was coated and dried to give a film thickness of 12 μm after drying, thereby obtaining photoreceptors containing three different carrier transport substances. These three types of photoreceptors are manufactured by Kawaguchi Electric Manufacturing Co., Ltd.
The following characteristics were evaluated using an electrostatic paper tester model SP-428 manufactured by Co., Ltd. Charged for 5 seconds at a charging voltage of -6Kv,
After leaving this for 5 seconds, halogen light is irradiated to the material surface at an illuminance of 35 lux, and the exposure amount required to attenuate the surface potential by half (half-reduced exposure amount, E1/
2) was measured. In addition, the surface potential (residual potential) V _R after exposure with an exposure amount of 30 lux·sec was measured.
As shown in Table 6, the results were good in combination with any carrier transport substance.

[Table] Comparative Example 4 Exemplary compound B-8 was mixed with the following bisazo compound (G
A comparison photoreceptor was prepared in the same manner as in Example 11 except that -(4)) was replaced, and the characteristics were evaluated. As shown in Table 6, the results varied depending on the carrier transport substance.

[Table] Example 12 On the conductive support provided with the intermediate layer used in Example 5, 2 g of Exemplified Compound B-9 and 100 ml of 1,2-dichloroethane were well dispersed and mixed, and the film thickness after drying was A carrier generation layer was created by coating to a thickness of 0.3 μm. 4- is then added thereon as a carrier transport material.
6 g of methyl-4'styryl-triphenylamine (compound K-(10) below) and polycarbonate "Panlite L-1250" (manufactured by Teijin Chemicals) A carrier transport layer was formed by coating a solution obtained by dissolving 10 g of 1,2-dichloroethane in 90 g of 1,2-dichloroethane so that the film thickness after drying was 10 μm, thereby producing a photoreceptor of the present invention. The electrophotographic properties of this photoreceptor at room temperatures of 25° C. and 60° C. were measured in the same manner as in Example 1. The results are shown in Table 7.

[Table] As is clear from the above results, the photoreceptor of the present invention has good sensitivity and residual potential characteristics even at high temperatures, and is stable against heat. Example 13 2 g of Exemplified Compound B-14 and 110 ml of 1,2-dichloroethane were well dispersed and mixed on the conductive support provided with the intermediate layer used in Example 5, and the film thickness after drying was
A carrier generation layer was created by coating the film to a thickness of 0.3 μm. In order to test the durability of this carrier generation layer against UV light, an ultra-high pressure mercury lamp (manufactured by Tokyo Shibaura Electric Co., Ltd.) was placed 30 cm away from the carrier for 10 minutes.
UV light of 1500 cd/cm ² was irradiated. Next, 4-methoxy-4'-(4-methylstyryl)-triphenylamine (compound K-
(11)) 7g and polycarbonate “Panlite L-
1250'' (manufactured by Teijin Chemicals) was dissolved in 90 g of 1,2-dichloroethane. A carrier transport layer was formed by applying the liquid to a film thickness of 12 μm after drying, thereby producing a photoreceptor of the present invention. The same measurements as in Example 5 were performed on this photoreceptor. The results are shown in Table 8. Example 14 A photoreceptor of the present invention was prepared in the same manner as in Example 13, except that UV light was not irradiated after the carrier generation layer was formed, and the same measurements as in Example 5 were performed. 8th result
Shown in the table.

[Table] As is clear from the above results, the photoreceptor of the present invention has excellent sensitivity and residual potential characteristics against UV light irradiation, has small fluctuations in acceptance potential, and is stable against light. can. Comparative Example 5 Compound B-14 was converted into the following bisazo compound (G-
Same as Example 13 and Example 14 except that (5)) was changed. A photoreceptor was prepared and the same measurements as in Example 5 were performed. The results are shown in Table 9.

〔Effect of the invention〕

According to the present invention, by using the azo compound represented by the above general formula [] as a photoconductive substance constituting the photosensitive layer of the photoreceptor, it is possible to achieve stability against heat and light, which is the object of the present invention. It is also an excellent photoreceptor that has excellent electrophotographic properties such as charge retention, sensitivity, and residual potential, and has little fatigue deterioration even after repeated use, and has sufficient sensitivity even in the long wavelength region of 780 nm or more. can be created.

[Brief explanation of drawings]

FIGS. 1 to 6 are cross-sectional views showing examples of the mechanical structure of the photoreceptor of the present invention.
~7 represent the following, respectively. 1... Conductive support, 2... Carrier generation layer,
3... Carrier transport layer, 4... Photosensitive layer, 5... Intermediate layer, 6... Layer containing a carrier transport substance, 7
...Carrier generating substance.

Claims (1)

[Scope of Claims] 1. A photoreceptor comprising a photosensitive layer containing an azo compound represented by the following general formula [] on a conductive support. General formula [] [In the formula, R ₁ and R ₂ are hydrogen atoms, carbon atoms 1 to 8
an alkyl group, an alkoxy group having 1 to 6 carbon atoms (C ₁ to C ₆ ), a halogen atom, a cyano group, an amide group,
represents a carbamoyl group or a sulfamoyl group,
A is [formula] [formula] [formula] [formula] [formula] [formula] [formula] [formula] or [formula] and Q ₁ , Q ₂ , Q ₃ , Q ₄ , Q ₅ and Q ₆ represents [Formula] or -SO ₂ NHY ₂ , Y ₁ , Y ₂ and Q ₇ represent a substituted or unsubstituted aryl group, and R ₁₁ represents a hydrogen atom, an alkyl group, a dialkylamino group, a diarylamino group, or a diarylamino group. represents an aralkylamino group, carbamoyl group, alkoxycarbonyl group or cyano group,
R ₁₂ and R ₁₃ represent an alkyl group, an aralkyl group or an aryl group. 2. The photoreceptor according to claim 1, wherein the photosensitive layer contains a carrier transporting substance and a carrier generating substance, and the carrier generating substance is an azo compound represented by the general formula []. 3. The photoreceptor according to claim 1 or 2, 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.