JPH01258659A - 2-hydroxy-3-carbamoylbenzo(a)carbazole derivative - Google Patents

Abstract

NEW MATERIAL:2-Hydroxy-3-(2-methyl-4-chlorophenyl)carbamoylbenzo>>a] carbazole. USE:Useful as a coupler to obtain an azo compound usable as an electric charger generating substance in an electrophotographic sensitized material. PREPARATION:Benzadilic acid(R) (2-hydroxy-3-carboxybenzo>>a]carbazole) is reacted with 2-methyl-4-chloroaniline in a solvent in the presence of a conden sation agent such as phosphorous trichloride under heating to give a compound shown by formula. In the operation, since the solvent is suitable for condensation reaction through dehydration and required to dissolved benzadilic acid in a certain degree, a solvent having >=100 deg.C boiling point, immisicible with water and having >=1.20 Debye dipole moment, such as anisole, chlorobenzene or benzonitrile is preferable as the solvent. When azo pigment is produced by using a compound shown by the formula as a coupler and used as an electrophotographic sensitized material, a sensitized material having high sensitiv ity and high stability is obtained.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a 2-hydroxy-3-carbamoylbenzo[al carbazole derivative as a coupler for azo dyes, and more specifically to the synthesis of an azo compound useful as an organic photoconductor. A novel 2-hydroxy-3-
This invention relates to carbamoylbenzoCal carbazole derivatives.

[Conventional technology]

It has been known that certain azo compounds are useful as charge-generating pigments used in charge-generating layers of laminated photoreceptors, which are one form of electrophotographic photoreceptors.

The laminated photoreceptor referred to here is a charge-generating layer formed by applying a charge-generating pigment that has the ability to generate charges by light onto a conductive support in a thin layer by an appropriate method such as vapor deposition or coating with a pigment dispersion. (hereinafter referred to as CGL),
This is a photoreceptor on which a charge transport layer (hereinafter abbreviated as CTL) is formed to efficiently transfer charges generated by CGL.

One of the advantages of choosing azo pigments as a charge-generating material is that you can choose from a variety of pigments depending on the wavelength of the exposing light.

In recent years, the demand for photoreceptors for laser printers has increased, and in particular, it has been desired to develop a photoreceptor having sensitivity in the semiconductor laser wavelength range (71SOn+a). Examples of the azo pigments used in this paper include, for example, JP-A No. 58-19403
No. 5, No. 62-147463, No. 62-298574
Compounds described in this number are known, but they are not satisfactory as photoreceptors for high sensitivity.

[Purpose of the invention]

An object of the present invention is to provide a coupler for obtaining an azo compound useful as a CGM in a highly sensitive electrophotographic photoreceptor, particularly a photoreceptor applied to a semiconductor laser.

[Structure of the invention]

As a result of research, the present inventors found that the above object of the present invention can be achieved by a compound represented by the following structural formula (hereinafter referred to as the compound of the present invention).

Structural formula: When an azo pigment is prepared using this compound as a coupler and incorporated into an electrophotographic photoreceptor, a highly sensitive and highly stable photoreceptor can be obtained. The details will be described in the application examples.

The synthesis of the compounds of the present invention involves combining benzazilic acid (2-hydroxy-3-carboxybenzo[a]carbazole) with
-Methyl-4-chloroaniline in a solvent, added with a condensing agent such as phosphorus trichloride, and heated.

At this time, the solvent needs to be suitable for the dehydration condensation reaction and dissolve benzazilic acid to some extent, so the boiling point is 10.
Dipole moment immiscible in water above 0°C l-1,20
Debye or higher is preferred.

For example, anisole (dipole moment 1.35D).

Chlorobenzene (1,78D), σ-dichlorobenzene (2,53D), benzonitrile (4,18D)
etc.

In a solvent with a dipole moment of 1.20D or less, such as toluene (0.37D), benzazilic acid does not dissolve, so even if the reaction is refluxed for 100 hours, a large amount of raw material remains, making it difficult to separate and purify the desired anilide. Ta.

When dimethylacetamide, which is a water-miscible solvent, is used, the reaction proceeds quickly, but stops after a certain point, and a small amount of raw material remains forever.

In this regard, if the reaction is carried out in the above-mentioned water-immiscible solvent with a certain degree of polarity, the reaction will proceed quickly and the purification will be easy since no raw materials will be used.

Synthesis Example 2-Hydroxy-3-(2-methyl-4-chlorophenyl)carbamoylbenzo[alcarbazolebenzadic acid (manufactured by Rohner) 55.49 (0.2 mo(+) dispersed in orthodichlorobenzene 250IIQ , and 2-amino-5-chlorotoluene (Tokyo Kasei) 42.
Add 3g (0.3+so(2)) and heat until the internal temperature is 80°.
When the temperature reached C, 139 phosphorus trichloride was dissolved in 20 m<1 of dichlorobenzene and added dropwise over about 5 minutes. Increase the internal temperature by 1 more
The temperature was raised to 50° C. to 160° C. (reacted for months).

After cooling, methanol 500+IQ was added, the precipitated crystals were collected by filtration, and washed with methanol 500ml (2) to give a crude product of 33
, 0g was obtained. Yield 41.2%.

Dissolve this in 75ml of diethylformamide,
After the activated carbon treatment, methanol 75Ilff was added to precipitate crystals. It was filtered to obtain 25.5 g of purified product. Yield 32%, melting point 322°0-324°C.

The infrared absorption spectrum is shown in Figure 1.

Elemental analysis (%) Calculated value C 71.91; H 4.28; N 6.9
9 CQ 8.84 Actual value C 71.78; H 4
．． 34i N 6.90 CQ 8.80 [Example] Next, in order to show how useful the coupler of the present invention is, an example will be shown in which it was incorporated into an electrophotographic photoreceptor in the form of an azo dye. Of course, this does not limit the application of the present invention.

Application Example 1 Synthesis of Azo Pigment According to JP-A-58-194035, 2,7-diami2-9-dicyanomethylidenefluorene is tetrazotized with sodium nitrite, and then tetrazolium hexafluorophosphate is obtained with ammonium phosphorus hexatsodide. The coupler of the present invention and the azo pigment 1 using the compound of the present invention were mixed in an N,N-dimethylformamide solution with 1 part by weight of the azo pigment 1 using the compound of the present invention in a polycarbonate resin "Panlite L-1250" ( 0.5 parts by weight (manufactured by Taikasei Co., Ltd.) and 120 parts of 1,2-dichloroethane
The solution was dispersed for 10 hours using a sand mill in a solution consisting of parts by weight, and then applied with a wire bar to a conductive support made of a polyester film on which aluminum was vapor-deposited to form CG L (0.2 μmO). child .

Next, 12 parts by weight of the following compound (A), polycarbonate resin "Panlite K-13004 (Ondai Kasei Co., Ltd. 1)"
1%) 1511I parts and 1,2-dichloroethane 1 part
A solution containing 20 parts by weight was coated using a blade coater to form a CTL with a thickness of 23 μl to obtain a photoreceptor.

Compound (A) Comparative Examples 1 to 4 The couplers used in the synthesis of azo pigment 1 were as shown in Comparative Examples 1 to 4 in Table 1.
A comparative azo pigment was synthesized in the same manner as in Application Example 1, except that the coupler shown in column 4 was replaced, and a comparative photosensitive compound was synthesized in the same manner as in Application Example 2, except that Azo Pigment 1 was replaced with the above comparative azo pigment. I got a body.

Comparative Example 5 A photoreceptor was produced in the same manner as Comparative Example 5, except that the charge transport material (A) was replaced with the following compound (B).

Compound (B) Evaluation■ The photoreceptors of Application Example 2 and Comparative Examples 1 to 5 were as follows! Strain and evaluate.

Electrostatic test TLT (newly manufactured by Kawaguchi Electric Co., Ltd., sp-4) on the photoreceptor
28m'). Next, the surface potential Va (V
), and then the surface potential vi (V) when left for 5 seconds was obtained, and the dark decay rate D D =v, (%) was determined.

Next, white light exposure is performed, and the exposure amount Esgg (ff
ux-sea) and the exposure amount E% (<2ux-sec) required to reduce the surface potential to 1/2 of Vi.

The results are shown in Table 1.

Table 1 Looking at Azo Pigment (1) using the coupler of the present invention and Comparative Examples 1 to 5, it can be seen that the coupler of the present invention imparts excellent properties to the pigment in terms of electrophotographic performance.

The difference in sensitivity is particularly large at E78°, that is, in the low electric field region.

The azo pigment used in Comparative Example 4 was commercially available Su7tor ASSR.
(manufactured by Hoechst) as a coupler, JP-A-58-
No. 194035 as an exemplary compound. The difference between this and the product of the present invention is too large.

However, as is clear from Comparative Example 6, naphthol ASS
Even in the case where compound (B) is selected as a charge transport material (CTM) in which R(7: lido moiety substituent 2-CH5-4-OCH3) is used as a doubler, the sensitivity is almost the same as that of the product of the present invention. However, like general amine compounds, compound (B) also has the problem that those having an electron-donating group are more unstable to oxidation than those having an attracting group.

This is indicated by an evaluation ■.

Evaluation ■ Ozone gas generated by an ozone generator (Japan Ozone Co., Ltd. model 0-1-2) was tested using an electrostatic tester (Kawaguchi Electric 5P).
-428), and the internal ozone concentration was set at 80 ppm. The sample of Application Example 1 and the sample of Comparative Example 6 were placed on this device and charged and exposed in the same manner as in Evaluation I. This operation was further repeated 100 times, and the initial potential V after 100 times was
i... Measure the initial potential retention rate. /V
i was found. The results are shown in Table 2.

Table 2 That is, the azo pigment using the coupler of the present invention can use a more stable CTM than the comparative example, and can provide a highly sensitive and stable photoreceptor.

〔Effect of the invention〕

By using the compound of the present invention as a coupler to obtain an azo compound used as a charge generating substance in an electrophotographic photoreceptor, it is possible to obtain a photoreceptor with higher sensitivity and stability than an azo compound using a known coupler. , is useful as a coupler for obtaining an azo compound useful as a charge generating substance in a highly sensitive electrophotographic photoreceptor, particularly a photoreceptor applied to a semiconductor laser.

[Brief explanation of the drawing]

FIG. 1 is an infrared absorption spectrum of the compound of the present invention.

Claims (1)

[Scope of Claims] A 2-hydroxy-3-carbamoylbenzo[a]carbazole derivative represented by the following structural formula. Structural formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼