JPH0471107B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel trisazo compound and a method for producing the same. BACKGROUND ART Inorganic photoreceptors using inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have been widely used in electrophotography. ``Electrophotography'' generally refers to a method in which a photoconductive photoreceptor is first charged in a dark place by corona discharge, etc., and then subjected to imagewise exposure to selectively discharge the charges in the exposed areas, leaving the unexposed areas free of electrostatic charge. This is one of the image forming methods in which an image is left behind and this latent image is visualized by a developing means using toner or the like to form an image. The basic characteristics required of the photoreceptor used in such electrophotography are (1) ability to be appropriately charged in the dark, (2) excellent charge retention in the dark, and ability to discharge the charge. (3) high photosensitivity and rapid discharge of charges upon irradiation with light; and excellent mechanical strength and flexibility. Although the conventional inorganic photoreceptors have several advantages, they also have various disadvantages. For example, the selenium photoreceptors currently widely used are (1) to
Although the condition (3) is satisfied to a considerable extent, the mechanical strength and flexibility are not satisfactory. In particular, as a variety of processes have been adopted in recent electrophotography methods, photoreceptors that are compatible with all of these processes have become required, and for example, flexible shapes are required. However, the selenium photoreceptor has low flexibility and is difficult to produce in such a shape. Similar drawbacks can also be cited for inorganic photoreceptors other than selenium photoreceptors. In recent years, in order to eliminate the drawbacks of these inorganic photoreceptors, organic electrophotographic photoreceptors using various organic photoconductive materials have been researched and developed, and have been put into practical use. For example, poly-N-vinylcarbazole and 2,4,7-trinitrofluorene-9 on a support.
Photoreceptor with a photosensitive layer containing poly-N-vinyl carbazole sensitized with a pyrylium salt dye (Japanese Patent Publication No. 48-25658) (see JP-A-47-37543), a photoreceptor provided with a photosensitive layer containing a disazo pigment as its main component (see JP-A-47-37543), and a photoreceptor provided with a photosensitive layer containing a eutectic complex consisting of a dye and a resin as its main component. Examples include photoreceptors (see Japanese Patent Application Laid-open No. 10735/1983). Among organic photoreceptors, a functionally separated photoreceptor is attracting attention, in which the generation of charge carriers and the movement of the generated charge carriers are performed by a charge generation substance and a charge transfer substance, respectively. Typical configuration examples of this type of photoreceptor include those provided with a photosensitive layer containing a charge generation substance and a charge transfer substance, and those provided with a photosensitive layer containing a charge generation substance (charge generation layer) and a charge transfer substance. A photosensitive layer of a laminated type in which a layer containing (charge transfer layer) is laminated is known. However, although these organic photoreceptors have improved the mechanical properties and flexibility of the inorganic photoreceptors to some extent, they generally have low photosensitivity and do not fully satisfy the requirements for electrophotographic photoreceptors. In general, the characteristics of an electrophotographic photoreceptor are greatly influenced by the materials used, the manufacturing method, etc., but they are particularly dependent on the photoconductive material. For this reason, research into photoconductive materials has been actively conducted, and the present invention also relates to this. An object of the present invention is to provide a trisazo compound that is effective as a photoconductive material, particularly as a charge-generating material, particularly for electrophotographic photoreceptors. Another object of the present invention is to provide a method for producing the above trisazo compound. That is, one of the present inventions is the general formula () or () (In the formula, Ar represents a naphthyl group, an anthryl group, a thienyl group, an N-lower alkylcarbazolyl group, a lower alkyl group, a lower alcohol group, a nitro group, or a phenyl group with or without a chlorine atom.) It is a trisazo compound. Furthermore, another aspect of the present invention is the general formula () [In the formula, X represents an anionic functional group. ] Hexazonium salt represented by and general formula ()
or() (In the formula, Ar represents a naphthyl group, an anthryl group, a thienyl group, an N-lower alkylcarbazolyl group, a lower alkyl group, a lower alcohol group, a nitro group, or a phenyl group with or without a chlorine atom.) General formula () or () characterized by reacting with a compound (In the formula, Ar is the same as above.) This is a method for producing a trisazo compound represented by the following formula. This trisazo compound has excellent properties as a photoconductive material for electrophotographic photoreceptors, especially as a charge generating substance. Ar in the general formula () or () is a naphthalene ring, an anthracene ring, a thiophene ring, an N-lower alkylcarbazole group having a substituent such as a methyl group or an ethyl group on N, a phenyl group, a methyl group, an ethyl group, Lower alkyl group of propyl group, lower alkoxy group such as methoxy group, ethoxy group, propioxy group, nitro group, 1 or 2 chlorine atoms
Substituted phenyl groups having ~3 substitutions can be mentioned. The trisazo compound of the present invention represented by the above general formula () or () is a novel compound that is a colored crystal at room temperature. Specific examples thereof are shown in Table 1 below along with melting points, elemental analysis values, and infrared absorption spectrum data. In addition, infrared absorption spectrum charts of typical compounds are shown in Figure 1~
It is shown in Figure 4. Figure 1: Compound No. 1, Figure 2: Compound No. 2, Figure 3: Compound No. 11, Figure 4: Compound No. 19. However, in the following, general formulas () and () are replaced by
Each It is abbreviated as .

【table】

【table】

[Table] In addition, in order to actually produce the trisazo compound of the general formula () or () according to the method of the present invention, the compound of the general formula () or () (sometimes referred to as a coupling component) and the general The hexazonium salt of formula () is dissolved in an organic solvent such as N,N-dimethylformamide or dimethyl sulfoxide, and an aqueous alkali solution such as an aqueous solution of sodium acetate is added dropwise to this at a temperature of about -10°C to 20°C. Bye. The reaction is completed in 5 to 30 minutes, and the desired trisazo compound of the present invention is obtained. The amount of the compound of general formula () or () to be used is 3 to 6 per mole of the compound of general formula ().
A mole level is appropriate. Specific examples of the anionic functional group of the hexazonium salt of general formula () are Cl , Br , I , BF ₄
, _PF6 ,

[Formula] ClO ₄ , SO ² ₄ ,

[Formula] A ₃ F ₆ and SbF ₆ are mentioned, and BF ₄ is particularly preferred. This hexazonium salt can be produced according to the method described in JP-A-53-132547. The trisazo compound of the present invention obtained as described above is particularly useful as a photoconductive material for electrophotographic photoreceptors. Thus, for example, (1) the trisazo compound is added to a suitable resin binder such as polyester, polyamide, polyurethane, polyketone, polycarbonate, polystyrene, polyvinyltoluene, etc. in fine particles (about 0.05 mm in diameter).
(2) In addition to the above system (1), an inorganic photoconductive material (e.g., known cadmium sulfide, cadmium sulfide-selenium, etc.) is added to the system (1) above. or a photoreceptor doped with an organic photoconductive material (e.g., known poly-N-vinylcarbazole, polyvinylpyrene, etc.); (3) a thin layer (charge generation layer) of a trisazo compound (approximately
0.05 to 10μ) on a conductive support using an appropriate method, and a layer (charge transfer layer) of another photoconductive substance is formed on top of the photoconductor. This can be cited as an example of the use of the compound. The photoreceptor produced in this manner is no inferior to conventional photoreceptors and can fully achieve the object of the present invention. Next, the effects of the novel trisazo compound of the present invention will be explained using an application example of a photoreceptor. 2 parts by weight of the trisazo compound of Compound No. 11 and 98 parts by weight of tetrahydrofuran were pulverized and mixed in a ball mill, and the resulting dispersion was applied onto an aluminum-deposited polyester film with a doctor blade and air-dried to generate a charge with a thickness of 1μ. formed a layer.
Separately, 2 parts by weight of 9-(4-diethylaminostyryl)anthracene and 2 parts by weight of polycarbonate resin [Panlite L, manufactured by Teijin Co., Ltd.] were dissolved in 16 parts by weight of tetrahydrofuran, and this was applied onto the charge generation layer with a doctor blade. Apply 10 at 120℃
A charge transfer layer having a thickness of 20 μm was formed by drying for a minute to obtain a laminated photoreceptor. Next, a -6KV corona discharge was applied to the photosensitive layer surface of this photoreceptor for 20 seconds using a commercially available electrostatic copying paper tester to negatively charge it, and then it was left in a dark place for 20 seconds.
Measure the surface potential Vp ₀ (volts) at that time, then irradiate the photosensitive layer with light from a tungsten lamp so that the surface has an illuminance of 20 lux, and measure the time until the surface potential becomes 1/2 of Vp ₀ . (seconds) was determined and the half-reduced exposure amount E1/2 lux·sec. The result was Vp ₀ 965 volts E1/2 1.1 lux-sec. Examples of the present invention are shown below. Example 1 Hexazonium salt represented by the general formula (however,
X is _BF4 ) 1.17g and 2.09g of the compound shown in Example No. 1 in Table 2 below as a coupling component.
was dissolved in 170 ml of N,N-dimethylformamide, and to this was added 1.0 g of sodium acetate and 10 ml of water.
A solution consisting of was added dropwise over a period of 5 minutes at a temperature of about 23°C, and then stirred for an additional 3 hours at room temperature. After that, the precipitate was collected and N,N dimethylformamide was added.
After washing 5 times with 300 ml of water and twice with 400 ml of water, the mixture was dried at 100° C. under reduced pressure of about 1 mmHg to obtain 1.50 g (yield: 63%) of Compound No. 1, a trisazo compound. The elemental analysis values and melting point are shown in Table 1, and the infrared absorption spectrum (KBr tablet method) is shown in Figure 1. Examples 2 to 20 Various trisazo compounds of the present invention were produced in the same manner as in Example 1, except that the compounds shown in Table 2 were used as coupling components. Among these trisazo compounds, the infrared absorption spectra of compounds No. 2, 11, and 19 are shown in Figures 2 to 4, respectively.

【table】

【table】

【table】

【table】 [Brief explanation of the drawing]

Figures 1 to 4 are infrared absorption spectra (KBr tablet method) of trisazo compounds. Figure 1...No.1 trisazo compound, Figure 2...No.2
Trisazo compound, Figure 3...No.11 trisazo compound, Figure 4...No.19 trisazo compound.

Claims (1)

[Claims] 1 General formula () or () (In the formula, Ar represents a naphthyl group, an anthryl group, a thienyl group, an N-lower alkylcarbazolyl group, a lower alkyl group, a lower alkoxy group, a nitro group, or a phenyl group with or without a chlorine atom.) trisazo compound. 2 General formula () [In the formula, X represents an anionic functional group. ] Hexazonium salt represented by and general formula ()
or () (In the formula, Ar represents a naphthyl group, an anthryl group, a thienyl group, an N-lower alkylcarbazolyl group, a lower alkyl group, a lower alkoxy group, a nitro group, or a phenyl group with or without a chlorine atom.) General formula () or () characterized by reacting with a compound (In the formula, Ar is the same as above.) A method for producing a trisazo compound represented by: