JPH07252181A - 2-methylidene-1,3-indanedione derivative, and aromatic or aromatic heterocyclic aldehyde derivative, and production of these derivatives - Google Patents

Abstract

PURPOSE:To obtain a new compound useful as an electron transport material for photoreceptors to be used in electrophotographic system. CONSTITUTION:The objective compound is expressed by (A is a divalent aromatic group or a divalent aromatic heterocyclic group; R1 and R2 each an alkyl, an aromatic group or an aromatic heterocyclic group), e.g. a compound of formula II. The compound of formula I can be obtained by reaction between a compound of formula III and a compound of formula IV.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel compound useful for producing a novel compound effective as an electron transporting material for a photoconductor used in an electrophotographic system, and an electron transporting material for a photoconductor used in an electrophotographic system. The present invention relates to a novel compound effective as a compound and a method for producing them.

[0002]

2. Description of the Related Art In recent years, electrophotographic copying machines, printers, facsimiles and the like have been remarkably developed, and are being widely used not only in offices of companies but also in general households.

Behind this development, selenium and its alloys, which have been conventionally used as photoreceptors used in electrophotography,
Or, it is largely due to the advent of organic photoconductors using organic substances instead of inorganic photoconductors such as cadmium sulfide.

This organic photoconductor is generally harmless and advantageous in cost as compared with the inorganic photoconductor, and essentially, by selecting an appropriate material, This is because it has a characteristic that the spectral sensitivity can be controlled arbitrarily.

For this reason, for example, it has become possible to develop a photoconductor having good sensitivity matching with a semiconductor laser widely used as a writing light source in current laser printers. It can be said that it has greatly supported the development of photocopiers, printers, facsimiles and the like.

By the way, the most widely used organic photoconductor is a laminated photoconductor in which a charge transport layer is laminated on a charge generation layer.

This laminated photoreceptor has been widely put to practical use because it has high sensitivity and high durability among the organic photoreceptors studied so far.

Most of the current laminated photoconductors have a charge transporting layer having a hole transporting property laminated on a charge generating layer, and the operation characteristics thereof are negatively charged.

[0009]

However, the negative charging process using a corona discharger or the like is accompanied by the generation of more ozone than the positive charging process, and it is not suitable for use in the copying machine, printer, facsimile, etc. On the other hand, it is not always preferable because it has a bad influence or accelerates the deterioration of the photoreceptor itself.

Despite this background, however, current laminated photoconductors are limited to negative chargeability. One of the reasons is that a charge transfer material having an excellent electron transport property has been found so far. Since it has not been obtained, it is because the charge transporting phase having the electron transporting property cannot be realized, and in principle, the positively charged laminated photoreceptor cannot be realized.

Therefore, under such circumstances, development of an excellent electron transporting material is desired.

An object of the present invention is to solve the problems of the present organic photoconductors, and to produce a novel compound effective as an electron transport material in order to finally realize a photoconductor such as a laminate which operates by positive charging. Another object of the present invention is to provide a useful novel compound, a novel compound effective as an electron transporting material thereof, and a method for producing them.

[0013]

In order to achieve the above object, the present invention is represented by the following chemical formula (Formula 7).
A methylidene-1,3-indandione derivative.

[0014]

[Chemical 7]

[Wherein A represents a divalent aromatic group or a divalent aromatic heterocyclic group, R ₁ and R ₂ represent an alkyl group, an aromatic group or an aromatic heterocyclic group, Also R ₁ and R ₂
May be the same or different. Or an aromatic or aromatic heterocyclic aldehyde derivative represented by the following chemical formula (Formula 8).

[0016]

[Chemical 8]

[Wherein A represents a divalent aromatic group or a divalent aromatic heterocyclic group, R ₁ and R ₂ represent an alkyl group, an aromatic group or an aromatic heterocyclic group, Also R ₁ and R ₂
May be the same or different. ] Further, the aromatic compound represented by the chemical formula (Chemical formula 8) having a step of reacting the compound represented by the chemical formula (Chemical formula 9) below with the compound represented by the chemical formula (Chemical formula 10) below. Alternatively, it is a method for producing an aromatic heterocyclic aldehyde derivative.

[0018]

[Chemical 9]

[In the above formula, A represents a divalent aromatic group or a divalent aromatic heterocyclic group. ]

[0020]

[Chemical 10]

[Wherein A represents a divalent aromatic group or a divalent aromatic heterocyclic group, R ₁ and R ₂ represent an alkyl group, an aromatic group or an aromatic heterocyclic group, Also R ₁ and R ₂
May be the same or different. R ₅ and R ₆ represent an alkyl group and may be the same or different. Or a step of reacting a compound represented by the chemical formula (Formula 10) with a compound represented by the following chemical formula (Formula 11) to obtain a product, and a step of saponifying the product. A method for producing an aromatic or aromatic heterocyclic aldehyde derivative represented by the chemical formula (Chemical Formula 8).

[0022]

[Chemical 11]

[Wherein A represents a divalent aromatic group or a divalent aromatic heterocyclic group, and R ₃ and R ₄ represent alkyl groups, which may be the same or different. Furthermore, 2-methylidene-1,3-indandioneone represented by the chemical formula (Chemical formula 7) for reacting the compound represented by the chemical formula (Chemical formula 8) with the compound represented by the following chemical formula (Chemical formula 12) It is a method for producing a derivative.

[0024]

[Chemical 12]

The compounds according to the present invention and the method for producing them will be described in more detail below.

The compound of the present invention (Chemical Formula 8) is a dialdehyde derivative of an aromatic or aromatic heterocyclic compound represented by (Chemical Formula 9) or a monodialkyl acetal of the same compound represented by (Chemical Formula 11), It can be obtained by reacting with a methylphosphonic acid dialkyl ester derivative represented by Chemical formula 10.

In this reaction, as the reaction solvent, water or alcohols such as methanol, ethanol, butanol, amyl alcohol, etc., aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, chlorobenzene, nitrobenzene, etc., diethyl ether, Ethers such as tetrahydrofuran and dioxane, halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane and the like, heterocyclic aromatic hydrocarbons such as pyridine and quinoline,
Other examples include N, N-dimethylformamide, dimethylsulfoxide, and the like, and generally any ordinary organic solvent can be used.

In this reaction, the action of a catalytic amount or a chemical equivalent or excess of a base is preferable, and the base used here is an inorganic base such as potassium carbonate, sodium carbonate, potassium hydroxide or sodium hydroxide, Organic bases such as triethylamine, triethanolamine, pyridine or hexamethylenetetramine,
Examples thereof include alkali metal salts of alcohols such as sodium methoxide, sodium ethoxide, potassium butoxide, and sodium amide.

Further, the reaction temperature is about -10 ° C.
To about 150 ° C, but usually about 0 °
More preferably, it is carried out within the range of C to about 80 ° C.

Further, as described above, when the monodialkyl acetal represented by (Chemical formula 11) is used, the diamine of the aromatic or aromatic heterocyclic compound represented by (Chemical formula 9) obtained by the reaction is used. The compound (Formula 8) can be obtained by saponifying the dialkyl acetal of the aldehyde derivative.

The crude product obtained by the reaction can be purified by a commonly used method such as column chromatography or recrystallization.

Next, the compound represented by the chemical formula 7 which is the electron transporting substance of the present invention will be described.

This compound (Chemical formula 7) is a compound of the chemical formula (Chemical formula 1) with the aldehyde derivative represented by the above compound (Chemical formula 8).
It can be produced by reacting with 1,3-indandione represented by 2).

In this reaction, as a reaction solvent, water or alcohols such as methanol, ethanol, butanol and amyl alcohol, aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, chlorobenzene and nitrobenzene, diethyl ether, Ethers such as tetrahydrofuran and dioxane, halogenated hydrocarbons such as chloroform, dichloromethane and dichloroethane, organic acids such as acetic acid and formic acid, heterocyclic aromatic hydrocarbons such as pyridine and quinoline, and other N, N-dimethylformamide and dimethyl. Examples thereof include sulfoxide and the like, and generally, all common organic solvents can be used.

In this reaction, if necessary, a catalytic amount or a stoichiometric amount of a base or an acid can be added, which makes it possible to accelerate the progress of the reaction.

The reaction is usually carried out in the temperature range of 0 to 200 ° C., but it is desirable that the reaction is carried out at the lowest temperature at which the reaction can be initiated under each reaction condition of the selected solvent, base, acid or the like. .

The reaction time depends largely on the reaction conditions selected, but it is usually about 1 hour to 10 days.

The crude product obtained by the reaction can be purified by a recrystallization method, a column chromatography method or the like.

Now, specific examples of the compounds represented by the chemical formulas (Formula 7) and (Formula 8) of the present invention are shown below. It goes without saying that the scope of the present invention is not limited to these specific examples.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

[0043]

[Table 4]

[0044]

[Table 5]

[0045]

[Table 6]

[0046]

[Table 7]

[0047]

[Table 8] The electron-transporting substance of the present invention can be applied to a photoconductor as follows.

For example, when applied to a laminated photoreceptor,
It is prepared by forming a charge generation phase composed of an inorganic or organic charge generation material on a conductive substrate, and forming a charge transport phase composed of the electron transport material of the present invention and optionally a binder resin on the charge generation phase. be able to.

As described above, the photoconductor using the electron transport material of the present invention operates with positive charge and has high sensitivity.

[0050]

The compound represented by the chemical formula (Chemical formula 7) according to the present invention is similarly produced through the compound represented by the chemical formula (Chemical formula 8) according to the present invention.

The compound represented by the chemical formula (Formula 7) according to the present invention functions as an electron transporting substance having a high electron transporting property.

Further, when it is applied to a photoreceptor, it contributes to the formation of an excellent charge transport phase, which makes it a photoreceptor which operates with positive charging with high durability and high sensitivity.

[0053]

EXAMPLES The present invention will now be described in more detail by way of examples.

Example 1 Hereinafter, Example 1 of the present invention will be described.

First, 11.24 g of terephthalaldehyde monodiethyl acetal and 16.43 g of diethyl diphenylmethylphosphonate are dissolved in 95 g of N, N-dimethylformamide, and potassium ter is added at 5 to 10 ° C.
7.07 g of t-butoxide was added portionwise over 30 minutes.

Then, after reacting at room temperature for 17 hours with stirring, 60.5 g of concentrated hydrochloric acid was added and the mixture was stirred at 80 to 85 ° C for 1 hour.
After stirring for an hour, the mixture was poured into about 800 ml of cold water, and the precipitated crystals were filtered, washed with water, and dried to obtain 13.32 g of crude 4′-formyl-α-phenylstilbene (Compound No. 9) as pale yellow crystals. It was This melting point is 93.5-97.
It was 0 ° C.

Further, recrystallized from ethanol to obtain a purified product. This melting point is 97.0 to 98.5 ° C, and according to the elemental analysis value, carbon 88.53% (calculated value 88.7).
0%) and hydrogen 5.43% (calculated value 5.67%).

Next, to a mixture of 5.69 g (20 mmol) of 4'-formyl-α-phenylstilbene, 2.92 g (20 mmol) of 1,3-indandione, and 50 ml of methanol obtained as described above. , NaO
3.86 g of a 28% methanol solution of CH3 was added, and the mixture was stirred at room temperature for 7 days, then 5 ml of acetic acid was added, and the precipitated crystals were filtered, washed with water and dried to give 7.16 g of a crude compound No. 36 of the present invention as orange. Obtained as a powder. This melting point is
It was 161.5 to 162.5 ° C.

Then, the crude product was recrystallized from ethyl acetate to obtain a purified product as orange crystals. Melting point is 16
At 4.0 to 165.0 ° C, the elemental analysis value is carbon 87.
It was 11% (calculated value 87.35%) and hydrogen 4.55% (calculated value 4.89%).

Finally, an infrared absorption spectrum (KBr tablet method) is shown in FIG. 1, and a proton nuclear magnetic resonance spectrum (solvent CDCl3, internal standard TMS) is shown in FIG.

Example 2 Compound No. 3 of the present invention will be described below.
Example 2 for obtaining 6 will be described.

5.69 g (20 mmol) of 4'-formyl-α-phenylstilbene, 2.92 g (20 mmol) of 1,3-indandione and 100 ml of ethanol.
1 drop of piperidine was added to the mixture consisting of and the mixture was refluxed for 4 hours with stirring.

The precipitated crystals were filtered, washed with water and dried to obtain a crude product of the compound of Compound No. 36 of the present invention, which was recrystallized from ethyl acetate in the same manner as in Example 1 to obtain a purified product. .

Example 3 Compound No. 3 of the present invention will be described below.
Example 3 in which No. 6 is applied to a photoconductor will be described.

First, 75 parts by weight of oxotitanium phthalocyanine was prepared by depositing about 800 liters of aluminum on a conductive film on a polyester film having a thickness of about 75 μm.
A dispersion obtained by pulverizing and mixing a mixture of 25 parts by weight of polyester resin and 4900 parts by weight of tetrahydrofuran with a ball mill was applied using a doctor blade and dried at room temperature for 5 minutes to obtain a charge having a thickness of about 0.5 μm. A generator layer was formed.

Next, on this charge generation layer, 1 part by weight of the compound of Compound No. 36 of the present invention obtained by the method of Example 1 or Example 2, 1 part by weight of a polycarbonate resin and 8 parts by weight of tetrahydrofuran were formed. The solution was applied using a doctor blade and dried at 120 ° C. for 10 minutes to form a charge transport phase having a thickness of about 20 μm, and a laminated photoreceptor was prepared.

The photoreceptor characteristics of the thus prepared photoreceptor were evaluated. To evaluate the characteristics of the photoconductor, an electrostatic copying paper tester model 8100 manufactured by Kawaguchi Denki Seisakusho was used.
Charge the photoreceptor by corona discharge of plus 6KV
The surface potential after dark decay for 2 seconds is Vo, and the exposure amount required for Vo to become 1/2 (half exposure amount) from the light attenuation curve when the white light of 10 lux is irradiated at the exposure surface illuminance. Was calculated as the sensitivity.

The Vo and the sensitivity of this photoconductor are 92
It was achieved to realize an organic photoreceptor which operates at a positive charge and has an excellent characteristic of 5 volts and 1.0 lux · second, which is extremely high sensitivity and can be sufficiently put into practical use.

[0069]

INDUSTRIAL APPLICABILITY As described above, the compound represented by the chemical formula (Formula 7) according to the present invention is a realistic electron-transporting substance and can realize high electron-transporting properties.

Furthermore, the electron transporting substance represented by the chemical formula (Formula 7) according to the present invention can be efficiently prepared by the compound represented by the chemical formula (Formula 8) according to the present invention.

The photoconductor to which the electron transporting material according to the present invention is applied can be positively charged and have high sensitivity.

[Brief description of drawings]

FIG. 1 is a diagram showing an infrared absorption spectrum of an electron-transporting substance of the present invention.

FIG. 2 is a diagram showing a proton nuclear magnetic resonance spectrum of the electron transporting substance of the present invention.

Claims (5)

[Claims] 1. A compound represented by the following chemical formula (Formula 1)
Methylidene-1,3-indandione derivative. [Chemical 1] [Wherein A represents a divalent aromatic group or a divalent aromatic heterocyclic group, R ₁ and R ₂ represent an alkyl group, an aromatic group or an aromatic heterocyclic group, and R ₁ And R ₂ may be the same or different. ] 2. An aromatic or aromatic heterocyclic aldehyde derivative represented by the following chemical formula (Formula 2). [Chemical 2] [Wherein A represents a divalent aromatic group or a divalent aromatic heterocyclic group, R ₁ and R ₂ represent an alkyl group, an aromatic group or an aromatic heterocyclic group, and R ₁ And R ₂ may be the same or different. ] 3. The method for producing a compound according to claim 2, comprising a step of reacting a compound represented by the following chemical formula (Formula 3) with a compound represented by the following chemical formula (Formula 4). [Chemical 3] [In the above formula, A represents a divalent aromatic group or a divalent aromatic heterocyclic group. ] [Chemical 4] [Wherein A represents a divalent aromatic group or a divalent aromatic heterocyclic group, R ₁ and R ₂ represent an alkyl group, an aromatic group or an aromatic heterocyclic group, and R ₁ And R ₂ may be the same or different. R ₅ and R ₆ represent an alkyl group and may be the same or different. ] 4. A step of reacting a compound represented by the chemical formula (formula 4) according to claim 3 with a compound represented by the following chemical formula (formula 5) to obtain a product, and the product. And a step of saponifying the compound. [Chemical 5] [Wherein A represents a divalent aromatic group or a divalent aromatic heterocyclic group, and R ₃ and R ₄ represent alkyl groups, which may be the same or different. ] 5. The method for producing a compound according to claim 1, comprising a step of reacting the compound represented by the chemical formula (formula 2) according to claim 2 with a compound represented by the following chemical formula (formula 6). . [Chemical 6]