JPH02133470A - Bisazo compound and its production - Google Patents

Abstract

PURPOSE:To obtain a bisazo compound useful as an organic photoconductor used in a high-speed copier, a laser printer, especially, a laminated photoreceptor by coupling a specified tetrazonium salt with a specified coupler. CONSTITUTION:A bisazo compound of formula III (where Y is Cl, methyl or methoxy; R is H, an alkyl, an alkoxy, a halogen or a nitro, n is 1 or 2, and when n=2, R groups may be the same or different) is produced by coupling a tetrazonium salt of formula I (wherein X is an anionic functional group) with a coupler of formula II. This bisazo compound is very useful as an organic photoconductor used for an electrophotographic photoreceptor, especially, a laminated photoreceptor which can show a high sensitivity when used in a high-speed copier or a laser printer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel bisazo compound useful as an organic photoconductor and a method for producing the same.

Beans] 1 [Basket Traditionally, certain azo compounds are organic photoconductors used in laminated photoconductors, which is one form of electrophotographic photoconductor.
It is known to be particularly useful as a charge-generating pigment. As is well known, this laminated photoreceptor has a charge generation layer containing a charge generation pigment as a main component having the ability to generate charge carriers by light on a conductive support, and a charge carrier generated by the charge generation layer on top of the charge generation layer. This photoreceptor is provided with a charge transport layer mainly composed of a charge transport substance that can efficiently inject and further transport charge.

Conventionally, examples of azo compounds used in such photoreceptors include those disclosed in JP-A-47-37543 and JP-A-52-55.
Benzidine-based bisazo compounds described in JP-A No. 643, etc., stilbene-based bisazo compounds described in JP-A-52-8832, diphenylhexatriene-based bisazo compounds described in JP-A-58-222152, etc. Diphenylbutadiene-based bisazo compounds described in JP-A-58-222153 are known.

However, conventional laminated photoreceptors using azo compounds generally have low sensitivity and are unsatisfactory as photoreceptors for high-speed copying machines. On the other hand, in recent years, there has been a desire to develop high-sensitivity photoconductors that can cover the wavelength range of semiconductor lasers as photoconductors for laser printers. The reality is that you can't get it. Therefore, it is desired to produce an azo compound useful as an organic photoconductor that overcomes the conventional drawbacks.

The present inventors previously proposed a diphenylhexatriene-based bisazo compound in JP-A No. 58-222152, but as a result of further intensive study, they found that by introducing a substituent at the 8-position on the benzocarbazole ring, A compound with extremely high sensitivity was obtained, leading to the present invention. Furthermore, JP-A-62-147463 is known for introducing a substituent onto the benzocarbazole ring;
There is no description of using a diphenylhexatriene bisazo compound as the azo component.

the purpose The purpose of the present invention is, of course, for use in high-speed copying machines.

It is an object of the present invention to provide a bisazo compound useful as an organic photoconductor for use in a highly sensitive electrophotographic photoreceptor that is also practical for laser printers, particularly for use in a laminated photoreceptor, and a method for producing the same.

One aspect of the present invention is a tetrazonium salt represented by the formula (I) (wherein X represents an anionic functional group) and a tetrazonium salt represented by the formula III (wherein Y, R, and n are described later).
General formula I, characterized in that a coupling reaction is performed with a coupler represented by formula I (same as formula I) [wherein Y represents a chlorine atom, methyl group, or methoxy group, and R represents a hydrogen atom, an alkyl group, or an alkoxy group] , a halogen atom, or a nitro group, n is 1 or 2, and when n=2, R is a novel bisazo compound represented by , which may be the same or different.

Another aspect of the present invention is -Math x @ ・N, @-◎+CH=CH), -〇-N2・
・X'' ・(II) [In the formula, Y is a chlorine atom, a methyl group,
or represents a methoxy group, R is a hydrogen atom, an alkyl group,
represents an alkoxy group, a halogen atom, or a nitro group,
n is 1 or 2, and when n=2, R may be the same or different.] This is a method for producing a bisazo compound.

Here, representative examples of the anionic functional group X in general formula (II) are L1"CQ", B r8. Ie, B F,
ePF,. ,B(C,H,),. ,CQ○,',S
o4"H,C-◎-3Oa",AsF,',SbF,.

etc., and BF4' is preferred.

The bisazo compound represented by formula (I) of the present invention is produced as follows. First, the tetrazonium salt of formula (n) as a raw material is prepared by reducing 1,6-bis(4-nitrophenyl)-1,3,5-hexatriene (hereinafter referred to as dinitro compound). It is obtained by diazotizing bis(4-aminophenyl)-1,3,5-hexatriene (hereinafter referred to as a diamino compound).

Both dinitro compounds and diamino compounds used herein are new substances. Note that the dinitro compound is, for example, diethyl 4-nitrobenzylphosphonate and 5-(
4-nitrophenyl)-2,4-pentadienal-1
Modified Wittig reaction in which 1,4-bis(triphenylphosphonium chloride)-2-butene and 4-21-benzaldehyde are condensed in the presence of a basic catalyst, or 1,4-bis(triphenylphosphonium chloride)-2-butene and 4-21-benzaldehyde are condensed in the presence of a basic catalyst It can be produced by the Wittig reaction. The dinitro compound produced by the Wittisochi reaction contains a portion of the cis isomer, which is obtained by heating the reaction crude product as it is or after purification in an aromatic hydrocarbon solvent such as toluene or xylene with a catalytic amount of iodine. It can be converted to an all-trans form by treatment.

Reduction of the dinitro compound is usually carried out by heating to a temperature of 70 to 120''C using iron-hydrochloric acid, tin-chloride monohydrochloride, etc. as a reducing agent, and the reaction is completed in about 0.5 to 3 hours. In addition, when an iron-hydrochloric acid reducing agent is used, it is preferable to carry out the reaction in an organic solvent such as N,N-dimethylformamide.

Next, diazotization of the diamino compound thus obtained is carried out by dispersing the diamino compound in an inorganic acid such as hydrochloric acid or sulfuric acid, and adding sodium nitrite to this at a temperature of -10 to 20°C. The reaction is completed in about 0.5-3 hours.

This reaction yields the tetrazonium salt of the general formula (II), and by further adding an aqueous solution of, for example, borofluoric acid, sodium borofluoride, etc. to this diazotization reaction solution and converting it into a salt, the tetrazonium salt of the general formula (II) is obtained. The tetrazonium salt of can be obtained.

To prepare the bisazo compound of the present invention using the tetrazonium salt obtained in this way, first, the tetrazonium solution is isolated from the reaction solution, and then it is mixed with N,N-dimethylformamide, dimethyl sulfoxide, etc. together with the coupler of formula (2) above. What is necessary is to dissolve it in an organic solvent and dropwise add an alkaline aqueous solution such as an aqueous sodium acetate solution thereto at a temperature of about -10 to 40°C to cause a coupling reaction. This reaction is completed in about 5 minutes to 3 hours. After completion of the reaction, the precipitated crystals are collected in a furnace and purified by an appropriate method, such as washing with water and/or an organic solvent, recrystallization, etc., to obtain the desired bisazo compound. The bisazo compound can also be produced by directly reacting the diazotization reaction solution with a coupler.

(Margin below) The present invention will be explained below using examples and application examples.

Example 1 0.6 g of 2-hydroxy-3-phenylcarbamoyl-8-chloro-11H-benzo[α cocarbazole was dissolved in 70 m Q of dimethylformamide (DMF), and 1,6-diphenyl-1,3, After adding 0.345 g of 5-hexatriene-4',4''-bis(diazonium tetrafluoroborate) (obtained by the method described in JP-A-58-222152), 8.3% aqueous sodium acetate solution was added. 3.1 mQ was gradually added dropwise at room temperature.
Next, after stirring at the same temperature for 3 hours, the generated bisazo pigment was filtered and treated with dimethylformamide 100 mQ 6 times.
Subsequently, it was washed twice with water at 100+oR.

This was heated and dried under reduced pressure to 1,6-bis[4-(2-
Hydroxy-3-phenylcarbamoyl-8-chloro-
0.59H of 11H-benzo[αcocarbazolyl-1-azo)phenyl]-1,3,5-hexatriene was obtained as a bluish black powder.

The infrared absorption spectrum (KBr tablet method) is shown in Figure 1. As can be seen from this figure, the NH stretching vibration of carbazole at 3450 cm-'', the stretching vibration of amide carbonyl at 1670 cm-'', and the stretching vibration of transolefin at 990 cm+-''. The decomposition point (exothermic peak temperature determined by thermal analysis) at which bending angle vibration was observed and the results of elemental analysis are shown in Table 1 below.

Examples 2 to 16 The bisazo compounds shown in Table 1 were produced in the same manner as in Example 1 except that the couplers shown in Table 1 below were used in place of the couplers used in Example 1. The decomposition points and elemental analysis results of these bisazo compounds are shown in Table 1 below.

(Margin below) table table (continued) Next, application examples of the bisazo compound of the present invention are shown below.

Application example 7.5 parts of the bisazo compound obtained in Example 1 as a charge generating substance and 500 parts of a 0.5% tetrahydrofuran solution of polyester resin [Vylon 200 manufactured by Toyobo Co., Ltd.]
The resulting dispersion was applied onto an aluminum-deposited polyester film using a doctor blade and air-dried to form a charge generating layer with a thickness of about 1 μm. Next, 2 parts of 9-ethylcarbazole-3-aldehyde-1-methyl-1-phenylhydrazone as a charge transport substance was dissolved in a 10% tetrahydrofuran solution of polycarbonate resin (Panlite-1300 manufactured by Ondai Co., Ltd.). This solution was applied onto the charge generation layer using a doctor blade and dried at 80° C. for 2 minutes and then at 120° C. for 5 minutes to form a charge transport layer with a thickness of about 20 μm.

Next, in order to examine the sensitivity of the laminated electrophotographic photoreceptor thus obtained in the visible range, this photoreceptor was tested in a dark place using an electrostatic copying paper tester (Model 5P428, manufactured by Kawaguchi Denki Seisakusho Co., Ltd.). After charging with 6KV corona discharge for 20 seconds, dark decay was performed for 20 seconds, and the surface potential Vo (volt) at this time was measured.
．． 5 Irradiate tungsten lamp light so that the surface potential becomes V.

The time (see) until it reached 172 was determined, and the half-reduction exposure amount E1/2 was determined as the sensitivity in the visible range.

As a result, V o = 513 volts, El/2 = 0.
38 flux, sec. Thus, it can be seen that the photoreceptor using the bisazo compound of the present invention has extremely high sensitivity in the visible range.

Effects As can be seen from the above explanation, the novel bisazo compound of the present invention can be used in electrophotographic photoreceptors that exhibit high sensitivity both for high-speed copying machines and laser printers, especially for organic photoconductors used in laminated photoreceptors. It is extremely useful for the body.

[Brief explanation of drawings]

Figures 1, 2, 3, 4 and 5 show bisazo compounds of the present invention obtained in Example 1, Example 2, Example 3, Example 10 and Example 16, respectively. The infrared absorption spectrum (Kbr Tablet Penal Code) is shown.

Claims (1)

[Claims] 1. General formula (I) ▲Mathematical formula, chemical formula, table, etc. are present on the conductive support▼...(I) [In the formula, Y represents a chlorine atom, a methyl group, or a methoxy group. , R represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a nitro group, n is 1 or 2, and when n = 2, R may be the same or different] Compound. 2. General formula (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ... (II) (However, X represents an anionic functional group.) Tetrazonium salt represented by and general formula III ▲ Numerical formulas, chemical formulas, tables, etc. There is ▼... (III) (However, Y, R, n are the same as general formula I below) General formula I characterized by coupling reaction with the coupler ▲ Numerical formula, chemical formula, table, etc. Yes▼...(I) [In the formula, Y represents a chlorine atom, methyl group, or methoxy group, R represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a nitro group, and n is 1 or 2 and when n=2, R may be the same or different.] A method for producing a bisazo compound.