JPS6045664B2 - Novel disazo compound and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel disazo compound and a method for producing the same.

It has been known that disazo compounds are effective as charge-generating pigments used in charge-generating layers of laminated photoreceptors, which are one type of photoreceptor used in electrophotography.

The laminated photoreceptor referred to herein means that a charge-generating pigment having the ability to generate charge carriers by light is applied onto a conductive support by an appropriate method such as vacuum evaporation, application of a pigment solution, or application of a resin solution. , a charge generation layer is formed as a thin layer by coating a dispersion liquid containing fine particles of pigment, and charge carriers generated in the charge generation layer can be efficiently injected onto the charge generation layer, and the charge carriers can be transferred. Charge transfer layer (usually this charge transfer layer consists of a charge transfer substance and a binder resin).
) is formed on the photoreceptor. Conventionally, as a disazo compound used in this type of photoreceptor, for example, JP-A-47
-37543 publication or JP-A-52-55643
A benzidine-based disazo pigment disclosed in Japanese Patent Application Laid-Open No. 54-22834, and a fluorenone-based disazo pigment disclosed in JP-A-54-22834 are known.
However, conventional laminated photoreceptors using disazo pigments have lower sensitivity than inorganic photoreceptors using arsenic selenium (AS2Se3) alloys, and are not suitable as photoreceptors for high-speed copying machines. It has the following disadvantages. The purpose of the present invention is to provide a novel disazo compound that is effective in the above-mentioned laminated photoreceptor, and the laminated photoreceptor using the disazo compound of the present invention is superior to inorganic photoreceptors. It is also comparable in sensitivity.

Another object of the present invention is to provide a method for producing the above disazo compound. That is, one aspect of the present invention is a disazo compound represented by formula (1).

This novel disazo compound is a purple-black crystalline substance at room temperature. Figure 1 shows the ultraviolet absorption spectrum (KBr tablet method) of (1), and Figure 2 shows the thermal analysis diagram (TG-DS).
C) and an X-ray diffraction diagram is shown in FIG. The disazo compound of the present invention described above can be produced by the following method.

That is, another aspect of the present invention is 2 expressed by the formula (■)
,7-diamino-9-fluorenone is diazotized to form a tetrazonium salt represented by the general formula (■), where X represents an anionic functional group.

) This and 2-hydroxy-3-( represented by formula (■)
2-Chlorophenylcarbamoyl)naphthalene is reacted with the above novel disazo compound.

In this production method, 2,7-diamino-9-fluorenone is diazotized by adding an aqueous sodium nitrite solution in a dilute inorganic acid such as dilute hydrochloric acid or dilute sulfuric acid at -10°C to 10°C. This is done by

This diazotization reaction is completed in approximately 3 minutes to 3 hours. Furthermore, it is preferable to add, for example, hydroborofluoric acid or an aqueous solution of sodium borofluoride to the reaction mixture to precipitate the tetrazonium salt, and to use the crystals in the next reaction after offloading the crystals. Next, this tetrazonium salt is treated with 2-hydroxy-3-(2-chlorophenylcarbamoyl)naphthalene of formula (1) to cause a coupling reaction. In reality, this reaction is carried out by dissolving a tetrazonium salt and a coupler in an organic solvent such as N,N-dimethylformamide (DMF) or dimethyl sulfoxide, and then adding an aqueous sodium acetate solution to the mixture at about -10°C to 40°C. This is done by dropping an alkaline aqueous solution such as This reaction is complete in approximately 5 minutes to 3 hours. After the reaction is completed, the precipitated crystals are collected and purified by an appropriate method (for example, washing with water and/or an organic solvent, recrystallization method, etc.) to complete the production of the disazo compound. Examples of the production of the disazo compound of the present invention produced in this manner are as follows.

Production Example 2,7-diamino-9-fluorenone [Schmidt, Retzlaff, HaidAnn
．． 39O225 (1912)] 44.81y of sodium nitrite to a mixture of 63.07y and 1.2f of 6N hydrochloric acid.
A solution of r dissolved in 180 mt of water was added dropwise at 0° C. over about 1 hour.

After the dropwise addition, the powder was stirred for three more times at the same temperature, a small amount of unreacted material was removed, and 42% 400% borofluoric acid was added to the bottom liquid.
m1 was added. The precipitated crystals were collected, washed with cold water, and dried to give 9-fluorenone-2 as yellow-orange crystals.
,7-bisdiazonium bistetrafluoroborate 1
08.2. yr (88.4%) was obtained. Decomposition point approx. 1
55°C infrared absorption spectrum (KBr tablet method) Next, the tetrazonium salt 61.2q obtained as above
89.3yr of r and 2-hydroxy-3-(2-chlorophenylcarbamoyl)naphthalene were dissolved in DMF9e, and 42.9yr of sodium acetate was added to 420ml of water.
1 was added dropwise at room temperature.

After the addition was completed, the mixture was stirred at the same temperature for another 2 hours, and then the precipitated crystals were collected. The obtained coarse crystal cake was mixed with DMF.
After stirring at 80'C for 2 hours, the crystals were recovered again and this operation was repeated twice. Thereafter, the crystals were washed with water and dried to obtain 97.8 Da (78.7%) of the disazo compound of the present invention. Purple-black crystal decomposition point 300°C or higher Elemental analysis Infrared absorption spectrum (KBr tablet method) νCO (Fluorenone) 1725 cm-1 νCO(
(Second amide) 1675 cm-1 As mentioned above, the disazo compound of the present invention is effective as a charge-generating pigment for a laminated photoreceptor, and in order to clarify this point, specific examples of use will be shown below.

Further, in order to clarify the inventive step of the present invention, a comparison with conventional disazo compounds or an inorganic photoreceptor is also shown. Application examples (1) 7 parts of the disazo compound of the present invention, polyester resin (
126 parts of a tetrahydrofuran solution (solid content concentration 2%) of Byron 2-Ko (manufactured by Toyobo Co., Ltd.) and 370 parts of tetrahydrofuran were pulverized and mixed in a ball mill, and the resulting dispersion was mixed with an aluminum-deposited polyester base ( It was coated onto the aluminum surface of a conductive support (conductive support) using a doctor verade and air-dried to form a charge generation layer with a thickness of about 1 μm.

On the other hand, 1,1-bis(4-dibenzylaminophenyl)
2 parts by weight of propane, 2 parts by weight of polycarbonate resin (manufactured by Teijin Panlite Kl3OOl Co., Ltd.) and 1 part by weight of tetrahydrofuran were mixed and dissolved to form a solution, which was then applied onto the charge generation layer with a doctor blade and heated at 80°C. 2 minutes at 1000C, then dried at 1000C for 5 minutes to a thickness of approx.
A charge transfer layer having a thickness of 0 μm was formed, and a laminated photoreceptor A shown in FIG. 4 was prepared. For comparison, in place of the disazo compound of the present invention, a benzine-based disazo pigment disclosed in JP-A No. 47-37543 or JP-A No. 52-55643 was used for comparison. A certain 4,4″-bis(2-hydroxy-3-
Phenylcarbamoyl-1-naphthylazo)-3,3″
-Dichlorophenyl [Comparative Pigment 1], JP-A-54-22
2,7-bis[2-hydroxy. Sea 3-(4
-chlorphenylcarbamoyl)-1-naphthacylazo]-9-fluorenone [Comparative face test 2] and 2,7-
Bis[2-hydroxy-3-(2-methyl-5-chlorophenylcarbamoyl)-1-naphthylazo]-9-
Photoreceptors were prepared in exactly the same manner except that fluorenone (comparative pigment 3) was used, and photoreceptors B, C, and D were obtained as comparative photoreceptors.

Next, four types of photoreceptors were created as described above, namely:
(1) Laminated photoreceptor using the disazo compound of the present invention
... Photoreceptor A (2) Laminated photoreceptor using comparative pigment 1
... Photoreceptor B (3) Laminated photoreceptor using comparative pigment 2 ...
・Photoreceptor C (4) Laminated photoreceptor using comparative pigment 3
...For photoreceptor D, a commercially available electrostatic copying paper tester (SP- manufactured by Kawaguchi Electric Seisakusho) was used.
42? ) was used to measure its electrostatic properties.

That is, first, a single corona discharge is applied to the photoreceptor for 2 minutes to negatively charge it, and the surface potential at that time is measured to determine Vd.
After determining the O (volt) circle, it was allowed to decay in the dark for two [phases] in the dark, and the surface potential at that time was measured and determined as VpO (volt).

Next, the photosensitive layer is irradiated with light from a tungsten lamp so that the surface has an illuminance of 20 lux, and the time (seconds) until the surface potential reaches VpO of 112 is determined and the exposure amount Ell2 (lux seconds) is determined. did. Similarly, find the time (seconds) until VpO reaches 115 and 1110, and calculate the exposure amount Ell5 (lux/second) and EllO (lux/sec).
seconds) was calculated. Table 1 shows the measurement results for photoreceptors A to D.

As is clear from the results in Table 1, photoconductor A according to the present invention has extremely high sensitivity compared to other photoconductors, and it is also understood that dark decay is small. It will be understood that the disazo compound of the present invention is an extremely excellent compound. Application Example (2) In the photoreceptor A in Application Example (1), 1,1-bis(4-dibenzyl aminophenyl)
A photoreceptor was prepared in exactly the same manner except that 9-ethyl-3-carbazolecarboxaldehydemethyl-1-phenylhydrazone was used instead of propane to obtain photoreceptor E of the present invention.

Furthermore, an As2se3 photoreceptor was used as an inorganic comparison photoreceptor, and a Se-As (40 wt%) alloy was used as a vapor deposition raw material on an aluminum substrate at a substrate temperature of 200°C and an evaporation source temperature of 4.
A photoreceptor having a photosensitive layer of about 60 pm was prepared by vapor deposition under a vacuum of 10 -6 T0rr at 10 to 415 C. The As2se3 photoreceptor thus produced was designated as Photoreceptor F as a comparative photoreceptor. Next, the photoconductors E and F were measured in the same manner as in Application Example (1) (however, photoconductor F
was charged by +6KV corona discharge.

), the measurement results shown in Table 2 were obtained. As is clear from the results in Table 2, photoreceptor E according to the present invention is comparable in sensitivity to inorganic photoreceptor F, and the disazo compound of the present invention is superior in sensitivity. It turns out that it is a compound.

In order to further clarify this point, the spectral sensitivities of photoreceptors E and F were measured. Spectral sensitivity was measured using the following procedure. First, charge the photoconductor in a dark place by corona discharge so that its surface potential becomes 800 volts or more (photoconductor E is negatively charged, photoconductor F is positively charged) until the surface potential reaches 800 volts. After dark decay and when the surface potential reached 800 V, the photoreceptor was irradiated with monochromatic light of 1 μW/Cd separated using a monochromator. Then, the time (seconds) for the surface potential to attenuate to 400μ was calculated (the attenuation of the surface potential due to this time decay was corrected), and the exposure amount (μW-Sec) was determined.
cTl) and the optical attenuation rate (VOItIcd●μ~V
-1◆Sec-1) was calculated, and the results are shown in FIG. From FIG. 5, photoreceptor E according to the present invention has a sensitivity peak at approximately 640r1m, which is equal to helium.
Comparative photoreceptor F for neon laser light (6328A)
It can be seen that the sensitivity is approximately 1.6 times that of the previous one.

As described above, the disazo compound of the present invention is an extremely useful material for electrophotographic photoreceptors, and because it is an organic material, it has many advantages such as being lightweight and low cost. It can be clearly understood that the disazo compound of the present invention is an extremely excellent material.

[Brief explanation of the drawing]

FIG. 1 shows an infrared absorption spectrum of the disazo compound of the present invention, FIG. 2 shows a thermal analysis diagram, and FIG. 3 shows an X-ray diffraction diagram. FIG. 4 shows an example of a photoreceptor in which the disazo compound of the present invention is used, and FIG. 5 shows a spectral sensitivity curve. 1...
Conductive support, 2... polyester base, 3...
Aluminum vapor deposited film, 4... Charge generation layer, 5... Charge transfer layer.

Claims (1)

[Claims] 1. A disazo compound represented by formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I)2 Formula (II
2,7-diamino-fluorenone represented by ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) is diazotized and made into a tetozonium salt represented by general formula (III) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ( III) (However, X represents an anionic functional group.) This and 2-hydroxy-3-(
2-chlorophenylcarbamoyl) naphthalene ▲ formula,
There are chemical formulas, tables, etc.▼It is characterized by reacting with (IV). A method for producing a disazo compound represented by formula (I). ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼ (I)