JPS5966460A - Novel disazo compound and its production method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 certain disazo compounds are effective as charge-generating pigments used in charge-generating layers of laminated photoreceptors, which are one form of electrophotographic photoreceptors. 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, coating with a pigment solution, or adding a pigment to a resin solution. A charge generation layer is formed as a thin layer by coating a dispersion liquid containing fine particles dispersed therein, 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. It is a photoreceptor on which a charge transport layer (usually this charge transport layer consists of a charge transport substance and a binder resin) is formed.

Conventionally, as disazo compounds used in this type of photoreceptor, for example, benzidine-based disazo compounds described in JP-A-47-37543 and JP-A-52-55643, or JP-A-52-55643, etc. Showa 52-883
Stilbene-based disazo compounds described in Publication No. 2 are known. However, conventional laminated photoreceptors using disazo compounds generally have low sensitivity, and their photosensitive wavelength range in the visible range extends from approximately 450 to 700 nm. Image reproducibility of the original was poor. Therefore, when this photoreceptor is mounted, there is a disadvantage in the design of the copying machine because it is necessary to use a filter that cuts red light.

An object of the present invention is to provide a new disazo compound that is effective in electrophotographic photoreceptors, particularly the above-mentioned laminated type photoreceptor, The body has higher sensitivity than conventional photoreceptors using disazo compounds, and its sensitivity wavelength range is on the short wavelength side of the visible range (approximately 450 to 600 nm).
Therefore, the reproducibility of copied images of red originals is also excellent.

Another object of the present invention is to provide a method for producing the above-mentioned disazo compound.

That is, one aspect of the present invention is a novel disazo compound represented by general formula (1).

(In the formula, Ar represents a substituted or unsubstituted aromatic ring or heterocycle.) Specific examples of the aromatic ring and heterocycle in this general formula include a benzene ring, a naphthalene ring, an anthracene ring, a pyrene ring, a thiophene ring, Examples include carbazole rings,
Examples of substituents in these terms include lower alkyl groups, lower alkoxy groups, halogens, and nitro groups.

Another aspect of the present invention is to diazotize 2,6-diamithanthraquinone represented by formula (It) 5- to obtain a compound represented by general formula (III) (wherein, Y represents an anionic functional group). and then reacting this tetrazonium salt with a coupler represented by the general formula (IV) H (wherein Ar represents a substituted or unsubstituted aromatic ring or heterocycle). This is a method for producing a disazo compound represented by the general formula (1) (wherein Ar represents a substituted or unsubstituted aromatic ring or heterocycle).

In this production method, 2,6-diamithanthraquinone is diazotized by diazotizing it with nitrous acid in an inorganic acid such as hydrochloric acid or sulfuric acid.
This is done by adding at 0°C. This diazotization reaction is completed in approximately 30 minutes to 3 hours. Furthermore, it is desirable to add, for example, hydroborofluoric acid or an aqueous solution of sodium borofluoride to the reaction mixture to precipitate a tetrazonium salt, and use the crystals in the next reaction after collecting them in a furnace. Next, this tetrazonium salt is reacted with a coupler represented by the general formula (IV) to cause a coupling reaction. In fact, the reaction with N,N-dimethylformamide (DMF
), a tetrazonium salt and a coupler are mixed and dissolved in an organic solvent such as dimethyl sulfoxide, and an alkaline aqueous solution such as a sodium acetate aqueous solution is added dropwise to the mixture at about -10°C to 40°C. This reaction is completed in approximately 5 minutes to 3 hours. After the reaction is complete, the precipitated crystals are collected and purified using an appropriate method (e.g., washing with water and/or an organic solvent,
Recrystallization method, etc.) completes the production of the disazo compound.

An example of the production of the disazo compound of the present invention produced in this manner is as follows.

Production Example 2.6-Diamithanthraquinone [Aldrich Chemical
Co, , Ml 1wakee)) 14.3F (
0.06 mol) and 155 m7 of 36% hydrochloric acid! Sodium nitrite is added to the mixture with 9. A solution of O2 dissolved in 30 Tnt of water was added dropwise at a temperature of -5°C to 0°C over about 20 minutes. After the dropwise addition was completed, the mixture was stirred for another 2 hours at the same temperature, then poured into 3 tons of cold water, filtered to remove a small amount of insoluble matter, and 40 grams of 42-thioboric acid was added to the filtrate. The precipitated crystals were collected in a furnace, washed with about 50 methanol, and dried to produce anthraquinone-2, anthraquinone-2, and anthraquinone-2 as light brown crystals.
6-Pisdiazonium bistetrafluoro7+? A rate of 22.6 t (86.3%) was obtained.

Infrared absorption spectrum (KBr tablet method) νN2
2310 ryn-' νC01695 sub-1 Then, the tetrazonium salt thus obtained 2.18
F (0.05 mol) and 0.01 mol of Cassilla represented by general formula (IV) are dissolved in DMF300d,
A solution prepared by dissolving 1.64 f of sodium acetate in 14 g of water was added dropwise to this at room temperature over about 15 minutes. After the dripping is finished,
After further stirring at the same temperature for 2 hours, the precipitated crystals were collected. The obtained crude crystal cake was dispersed in 300 d of DMF, stirred at 9-80°C for 2 hours, and then the crystals were collected again in the furnace, and this operation was repeated twice. Thereafter, the crystals were washed with water and dried to obtain the disazo compound of the present invention. Tables 1 and 2 show examples of the disazo compounds of the present invention synthesized according to the above production examples.

(The following is a blank space) 10- These novel disazo compounds are red to reddish-purple powders at room temperature. 1 to 13 show infrared green absorption spectra (KBr tablet method) of typical disazo compounds of the present invention.

Figure 1...Compound N0.1 Figure 2...Compound N
[L22 3rd... Compound Yin 3 Figure 4... Compound I
VkL4 Figure 5...Compound N115 Figure 6...
Compound ■66 No. 7... Compound NrL7 Figure 8...
・Compound N [18 Figure 9... Compound N [lL9 Figure 10... Compound N010 Figure 11... Compound Nn
11 Figure 12... Compound N [112 Figure 13.
...Compound N [113 As mentioned above, the disazo compound of the present invention is effective as a photosensitive material for electrophotographic photoreceptors, especially as a charge-generating material for laminated photoreceptors, and in order to clarify this point, Specific usage examples are shown below. Furthermore, in order to clarify the inventive step of the present invention, a comparison with conventional disazo compounds is also shown.

Application example 76 parts by weight of the disazo compound 1J1112 of the present invention, 1
6-15- Tetrahydrofuran solution (solid content humidity 2%) of polyester resin (Paishin 2001 manufactured by Toyobo Co., Ltd.) 12
60 parts by weight, and 3,700 parts by weight of tetrahydrofuran, 3? - Pulverize and mix in Lumir, apply the resulting dispersion onto the aluminum surface of aluminum-deposited polyester paste (conductive support) using a doctor blade, and air dry to generate a charge with a thickness of approximately 1 μm. Form a layer. On the other hand, 2 parts by weight of 9-ethylcarbasol-3-aldehyde-1-methyl-1-phenylhydrazone and polycarbonate resin (Nosonrai) K1300. After mixing and dissolving 2 parts by weight (manufactured by Teijin Kasei Ltd.) and 16 parts by weight of tetrahydrofuran to form a solution, this was applied onto the charge generation layer using a doctor blade and heated at 80°C for 2 minutes, then for 10 minutes.
A charge transport layer having a thickness of about 20 μm was formed by drying at 0° C. for 5 minutes, and a laminated photoreceptor (A) shown in FIG. 14 was prepared.

For comparison, the disazo compound of the present invention was prepared according to the procedure for producing the photoreceptor described above. 4゜4'-bis(2-hydroxy-3-7enylcarpamoyl-1-naphthyla7'), which is a benzidine-based disazo compound
-3,3'-dichlorodiphenyl and -4゜4'-bis(2-hydroxy-3-phenylcarnomoyl-1- A photoreceptor (B) and a photoreceptor (C) were prepared in exactly the same manner except that naphthylaso)stilbene was used.

The electrostatic properties of the photoreceptors (A), (B), and (C) thus prepared were measured using a commercially available electrostatic copying paper testing device (Kawaguchi Electric Co., Ltd., 5P-428 model). did. That is, the photoreceptor was subjected to corona discharge of 16 KV for 20 seconds to become negatively charged, the surface potential at that time was measured, and Vdo (yg silt) was determined. The surface potential at that time was measured and determined as Vpo (71?/reto).Next, the photosensitive layer was irradiated with light from a tungsten lamp so that the surface had an illuminance of 4.5 lux, and the surface potential was determined to be Vp.
The time (seconds) until it becomes oOi was determined and defined as exposure iE% (looks/seconds). Similarly, Vp.

h and first name. Find the time (seconds) until the exposure amount E1
5 (lux φ seconds) and E/10 (lux φ seconds) were determined. The results are shown in Table 3.

(Space below) 20- As is clear from the results in Table 3, the photoreceptor (A) using the disazo compound of the present invention has a higher performance than the photoreceptors (B) and (C) using the conventional disazo compound. It can be seen that the sensitivity is high.

From what has been described above, it will be understood that the disazo compound of the present invention is an extremely effective material.

Further, the disazo compound of the present invention can be used as a charge generating substance in an electrophotographic photoreceptor having a single-layer type photosensitive layer in which a charge generating substance and a charge transporting substance are dispersed in the resin, and also as a photoconductive substance in the resin. It is also useful as a photoconductive material in an electrophotographic photoreceptor having a photosensitive layer in which a substance is dispersed.

[Brief explanation of drawings]

Figures 1 to 13 are infrared absorption spectra (KBr tablet method) of typical disazo compounds of the present invention. FIG. 14 is an enlarged sectional view of an electrophotographic photoreceptor according to the present invention, in which 11 represents a polyester base, 22 represents an aluminum vapor deposited film, 33 represents a charge generation layer, and 21-44 represent a charge transport layer. -22-

Claims (1)

[Claims] 1. A disazo compound represented by the general formula (I) (wherein Ar represents a substituted or unsubstituted aromatic ring or heterocycle). 2. 2,6-diamithanthraquinone represented by formula (II) is diazotized to form a tetrazonium salt represented by general formula (III) (wherein, Y represents an anionic functional group), and then this tetrazonium salt and General formula (I) characterized by reacting with a coupler represented by general formula (IV) (wherein Ar represents a substituted or unsubstituted aromatic ring or heterocycle) (wherein Ar represents a substituted or unsubstituted aromatic ring or heterocycle). A method for producing a disazo compound represented by (representing a substituted or unsubstituted aromatic ring or heterocycle).