JPH061922A - Bisazo compound - Google Patents

Abstract

(57) [Summary] [Object] To provide a bisazo compound useful as a charge generating substance or a photoconductive substance in a photosensitive layer of an electrophotographic photoreceptor. [Structure] An asymmetric bisazo compound represented by the following general formula [I] (Formula 1). [Chemical 1]

Description

Detailed Description of the Invention

[0001]

The present invention relates to a bisazo compound,
More specifically, it relates to an asymmetric bisazo compound useful as an organic photoconductor.

[0002]

2. Description of the Related Art It has been conventionally known that a certain azo compound is effective as a charge generating pigment used in a charge generating layer of a laminated type photoreceptor which is one form of the electrophotographic photoreceptor. There is. The laminated-type photoreceptor as used herein means that a charge-generating pigment having the ability to generate charge carriers by light is formed on a conductive support by an appropriate method such as vacuum deposition, coating of a pigment solution or a resin solution. The charge generation layer is formed as a thin layer by applying a dispersion liquid in which the fine particles are dispersed, and the charge carriers generated in the charge generation layer can be efficiently injected onto the charge generation layer, and the charge transfer is performed where it moves. It is a photoreceptor on which a layer (generally, the charge carrier layer is composed of a charge carrier substance and a binder resin) is formed. Conventionally, as an azo compound used for this type of photoreceptor, for example, JP-A-47-37543 and JP-A-5-37543 are known.
The benzidine bisazo compounds described in JP-A-2-55643 and the stilbene bisazo compounds described in JP-A-52-8832 are known. However, the conventional laminated type photoreceptor using an azo compound generally has low sensitivity and is not sufficient as a photoreceptor for a high speed copying machine.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a bisazo compound which is effective in an electrophotographic photoreceptor, particularly useful in the above-mentioned laminated type photoreceptor.

[0004]

According to the present invention, there is provided a bisazo compound represented by the following general formula [I] (Formula 1).

[Chemical 1]

The bisazo compound represented by the general formula [I] (Formula 1) of the present invention is asymmetrical, and as described above,
The charge generating substance is useful as a charge generating substance for a laminated type electrophotographic photoreceptor, and further has a single layer type photosensitive layer in which a charge generating substance and a charge carrier substance are dispersed in a resin. Also, it is useful as a photoconductive substance in an electrophotographic photoreceptor having a photosensitive layer in which a photoconductive substance is dispersed in a resin.

The bisazo compound represented by the above general formula [I] (Chemical formula 1) of the present invention has the following general formula [II] (Chemical formula 2).
And a diazonium salt compound represented by the following general formula [II
I] (Chemical Formula 3) or a coupler represented by the following general formula [IV] (Chemical Formula 4) is sequentially reacted in two steps, or the general formula [V] obtained by the first coupling reaction
It can be obtained by isolating the diazonium salt compound of the chemical formula (5) or the general formula [VI] (chemical formula 6), and further reacting a coupler corresponding to each. still,
The coupler represented by the general formula [III] (Formula 3) is 1:
It is a mixture of isomers in a ratio of 1. (Mitsubushi
i Chemical R & D Review, 1
(1), P57, 1987) Therefore, the bisazo compound represented by the above general formula [I] of the present invention is also represented by the following formula: It is a mixture of isomers.

[0007]

[Chemical 2]

[Chemical 3]

[Chemical 4]

[Chemical 5]

[Chemical 6] X in the formulas [II], [V] and [VI] represents an anionic functional group, for example, tetrafluoroborate, perchlorate, iodode, chloride, bromide,
Sulfate, hexafluorophosphate, hexafluoroantimonate, periodate, p-toluenesulfonate and the like are preferable.

Actually, the above reaction is carried out by using N, N-dimethylformamide (DMF) or dimethylsulfoxide (DM).
The coupler represented by the general formula [III] (Chemical formula 3) or the general formula [IV] (Chemical formula 4) used for the coupling reaction in the first step is dissolved in an organic solvent such as SO) and the like.
The diazonium salt compound represented by the general formula [II] (Formula 2) is added, and if necessary, a basic substance such as an aqueous solution of sodium acetate or an organic amine is added to complete the coupling reaction in the first step. . The reaction temperature at this time is preferably about -20 ° C to about 40 ° C.

The second-step coupling reaction is carried out by adding a general formula [III] (Chemical Formula 3) to the reaction mixture obtained above, which is different from the coupler used in the first-step coupling reaction.
Alternatively, it may be completed by further adding a coupler represented by the general formula [IV] (Chemical Formula 4) and adding a basic substance such as an aqueous solution of sodium acetate or an organic amine, if necessary, as in the coupling reaction in the first step. Alternatively, water or an acidic aqueous solution such as dilute hydrochloric acid is added to the coupling reaction mixture in the first step (in this case,
It is necessary to perform sufficient cooling so that the diazonium salt compound of the general formula [V] (formula 5) or the general formula [VI] (formula 6) produced by the reaction is not decomposed. It is desirable to treat at 10 ° C. or lower. ), The diazonium salt compound of the general formula [V] (Chemical formula 5) or the general formula [VI] (Chemical formula 6) is isolated by filtration, and the diazonium salt compound and the coupler used in the coupling reaction of the first step are isolated. It is completed by reacting with a coupler of the general formula [III] (Chemical formula 3) different from that of the general formula [IV] (Chemical formula 4) in the same manner as in the coupling reaction of the first step.

In any reaction mixture prepared by any method, after the completion of the reaction, the precipitated crystals are collected by filtration,
The production of the bisazo compound represented by the general formula [I] (Formula 1) is completed by purification by a suitable method (for example, washing with water and / or organic solvent, recrystallization method, etc.).

[0011]

EXAMPLES In order to clarify that the bisazo compound of the present invention can be easily produced as described above and is an effective material for an electrophotographic photoreceptor, the following examples and application examples are given. However, the present invention is not limited to this.

Example 1 2-Hydroxy and 5-hydroxy-7H-benzimidazo [2,1-a] benz [de] isoquinoline-7
0.43 g (1.5 mmol) of a mixture of -one (Chemical Formula 3) was dissolved in 200 ml of DMF, and 9-fluorenone-2,7-bis (diazonium tetrafluoroborate) (Chemical Formula 2, X: BF ₄ ) was dissolved at room temperature. 0.67 g (1.5 mmol) was added. After stirring at room temperature for 10 minutes, 0.45 g (1.5 mmol) of 2-hydroxy-3- (2-chlorophenyl) carbamoylnaphthalene was added, and then 4.7 g of a 10.5% sodium acetate aqueous solution was added for 2 hours. Stir at room temperature. The precipitate formed is filtered off and
Wash 3 times with 150 ml of DMF heated to ℃, then water 1
It was washed twice with 50 ml. After drying at 120 ° C. under reduced pressure, 0.49 g of bisazo compound shown below (yield 40
%)Obtained. The melting point was 280 ° C. or higher. The elemental analysis values (%) were as follows for C ₄₈ H ₂₆ N ₇ O ₅ Cl. An infrared absorption spectrum diagram (KBr tablet method) of this product is shown in FIG.

Examples 2 and 3 Under the same conditions as in Example 1, the bisazo compounds shown below were obtained. Table 1 shows yields and elemental analysis values. Further, infrared absorption spectrum diagrams (KBr tablet method) of the bisazo compounds obtained in Examples 2 and 3 are shown in FIGS. 2 and 3, respectively.

[Table 1]

Application Example 1 76 parts by weight of the bisazo compound obtained in Example 1, 1260 parts by weight of a polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) in tetrahydrofuran (solid content concentration 2%), and 3700 parts by weight of tetrahydrofuran were ball milled. And the obtained dispersion liquid was applied onto the aluminum surface of an aluminum-deposited polyester base (conductive support) using a doctor blade and air-dried to form a charge generation layer having a thickness of 1 μm. . On this charge generation layer,
As a charge carrier substance, 2 parts by weight of 4'-diphenylamino-α-phenylstilbene, 2 parts by weight of a polycarbonate resin (Panlite K-1300 manufactured by Teijin Ltd.) and 16 parts by weight of tetrahydrofuran were mixed and dissolved, and the solution was applied using a doctor blade. At 80 ° C for 2 minutes, then 12
It was dried at 0 ° C. for 5 minutes to form a charge carrying layer having a thickness of about 20 μm to prepare a laminated type photoreceptor.

The laminated type photoreceptor prepared as described above was subjected to a negative corona discharge of -6 KV for 20 seconds using an electrostatic copying paper tester (SP428 type, manufactured by Kawaguchi Electric Co., Ltd.). After being charged to, the sample was left in a dark place for 20 seconds, the surface potential Vpo (V) at that time was measured, and then a tungsten lamp was used to irradiate the surface so that the illuminance was 4.5 lux. Vpo is 1
The time (sec) until it becomes / 2 was obtained, and the half-exposure amount E1 / 2 (lux.sec) was calculated as the sensitivity of the photoconductor. The photoconductor according to the present invention has Vpo of -1001 V and E1 / 2 of 0.91 lux · sec, which shows that the photoconductor has high sensitivity.

[0016]

As can be seen from the above description and examples,
The bisazo compound of the present invention can be easily produced and is used as a charge generating pigment in a high-sensitivity electrophotographic photoreceptor practically used for high-speed copying machines, especially in a laminate type photoreceptor, as is apparent from application examples. Very useful as a bisazo compound.

[Brief description of drawings]

FIG. 1 is a diagram showing an infrared absorption spectrum of the bisazo compound of the present invention obtained in Example 1.

FIG. 2 is a diagram showing an infrared absorption spectrum of the bisazo compound of the present invention obtained in Example 2.

FIG. 3 is a graph showing an infrared absorption spectrum of the bisazo compound of the present invention obtained in Example 3.

Claims (1)

[Claims] 1. A bisazo compound represented by the following general formula [I] (Formula 1). [Chemical 1]