JP2014210768A - Electron transport material and electronic material using the electron transport material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron transport material including an antipyrine derivative, which is excellent in solubility in an organic solvent, has an electron transport capability with excellent sensitivity, and further can be produced industrially with ease and safety and with high purity and with a high yield, and to provide an electronic material using the electron transport material.SOLUTION: An electron transport material containing an antipyrine derivative represented by formula (XV), and an electronic material using the electron transport material are disclosed. In formula (XV), it is preferable that A and D are identical to each other, B and E are identical to each other, and C and F are identical to each other.

Description

  The present invention relates to an electron transport material containing an antipyrine derivative that exhibits excellent electron transport ability and excellent solubility in an organic solvent, and an electronic material using the electron transport material.

  Naphthalene tetracarboxylic acid diimides represented by the following general formula (II) as described in Patent Document 1 (hereinafter sometimes referred to as “NTC”) are promising as electronic materials such as electron transport materials. Has been.

In general formula (II), R and R ′ are the same or different and each represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkoxy group.

The biggest drawback of the NTC (II) is that its solubility in an organic solvent is very poor. For example, when it is used as an electron transport material, the compatibility with the binder resin forming the photosensitive layer is low. Crystallization may occur in the layer.
In order to solve such a problem, by introducing asymmetric substituents into R and R ′ in the above formula (II), each substituent is 90% relative to the main skeleton (naphthalene tetracarboxylic acid diimide). Attempts have been made to increase the solubility by rotating the film by degrees to prevent molecular stacking (see, for example, Patent Document 2).
However, introduction of an asymmetric substituent is complicated in the synthesis process, tends to reduce the yield, and is industrially inferior.

In addition, as described in Patent Document 3, etc., NTC (II) of various substituents has been developed so far, but the market always has a simpler and more yield than those conventional products. There is a demand for the development of an electron transport material that can be synthesized at a high level and that has higher solubility and electron transport ability than the conventional products.
In particular, when used as an organic semiconductor material, the presence of impurities hinders electron transfer and causes deterioration. Therefore, the purity needs to be 100% as much as possible.

Japanese Patent Publication No. 1-339098 Japanese Patent No. 3292461 Japanese Patent No. 4339617

As a result of repeated studies to develop an electron transport material that is easier to dissolve and attract more electrons than conventional products, the present inventors have first made a medical drug (pharmaceutical) distributed as an analgesic. Then, we focused on whether it is involved in some kind of electronic exchange in nerve transmission in the body.
Then, under such knowledge, the pursuit of a substituent that can be easily chemically modified to obtain the NTC (II),
In order to introduce the antipyrine skeleton, which is also used as a pharmaceutical product, if it reacts with aminoantipyrine and its derivatives, it not only exhibits excellent electron transport ability, but also has high yield of highly transportable electron transport materials. It has been found that it can be synthesized with high efficiency and high purity (that is, the possibility of mass production of new highly practical electronic materials at the industrial level by the fusion of different fields of the medical field and the electronic field).
Furthermore, the present inventors paid attention to the fact that aminoantipyrine and its derivatives that can provide excellent electron transport ability as described above are easily introduced substituents,
As a result of studying alternatives to the central skeleton (naphthalenetetracarboxylic imide) on the side to be introduced, six new derivatives having high practicality as electronic materials were found, and the present invention was completed. .

  The present invention is an electron transport material comprising an antipyrine derivative that is excellent in solubility in an organic solvent, has a sensitive electron transport ability, and can easily produce a high-purity product in a high yield. It is another object of the present invention to provide an electronic material using the electron transport material.

  That is, the gist of the present invention is an electron transport material containing an antipyrine derivative represented by the formula (XV).

In formula (XV),
A to F are the same or different and each represents an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group. Of these groups, the alkyl group may further have an alkoxy group and / or a halogen atom as a substituent. Further, any of the cycloalkyl group, aryl group and aralkyl group may further have an alkyl group and / or a halogen atom as a substituent on the ring. Furthermore, the aralkyl group may further have an alkyl group and / or a halogen atom as a substituent on the alkylene chain.
X represents any one of the following seven structural formulas (X-1) to (X-7).

In formula (X-2), Y ₁ and Y ₂ are each a hydrogen atom, a halogen atom, an alkyl group, an allyl group, an alkoxy group, an aryl group, a dialkylamino group, and a diphenylamino group. One of the substituents selected from the group consisting of:

At this time, it is preferable that A and D, B and E, and C and F of the antipyrine derivative represented by the above formula (XV) are the same.
The antipyrine derivative represented by the above formula (XV) is selected from the group consisting of aminoantipyrine and derivatives thereof and carboxylic acid anhydrides of the following formulas (III-X-1) to (III-X-7). It can be synthesized by reaction with at least one species.

Y ₁ and Y ₂ in the formula (III-X-2) are the same as in the above formula (X-2).

  Furthermore, the gist of the present invention is also an electronic material using such an electron transport material.

The electron transport material of the present invention contains a novel antipyrine derivative and exhibits excellent electron transport ability. In addition, since it exhibits high solubility in an organic solvent, for example, it is excellent in compatibility with the binder resin that forms the photosensitive layer, so that the temporal stability of the photosensitive layer containing the electron transport material can be obtained. .
Such an electron transport material (ETM) of the present invention can be combined with, for example, a known charge generation material (CGM), a hole transport material (HTM), a binder resin, etc., to achieve a high sensitivity and high stability. Since a single layer photosensitive drum can be formed, its industrial utility value is extremely high.
The ETM of the present invention can also be used for a so-called laminated photosensitive drum.

Furthermore, in the present invention, such a novel compound useful as an electron transporting material is converted into 4-amino-1,2,3-substituted-5-pyrazolones such as aminoantipyrine (also known as a pharmaceutical precursor). In the specification, such a pyrazolone is also referred to as “aminoantipyrine and a derivative thereof” as a raw material) and can be easily produced in a high yield with a high purity by an original synthesis method. it can.
Moreover, since the pyrazolone ring, which is the main skeleton of the aminoantipyrine and its derivatives, is easily chemically modified, aminoantipyrine derivatives having various substituents can be easily obtained depending on the purpose. As a result, since the three substituents of the aminoantipyrine derivative as a raw material can be easily controlled, the properties of the synthesized new compound (antipyrine derivative (XV)) itself (for example, liquid crystallinity, film-forming property, etc.) can also be controlled. It is easy to realize and can be expected to be applied to organic semiconductors, etc., which have been researched recently.

2 is a diagram showing the NMR analysis result of the compound (XV-1) obtained in Example 1. FIG. 2 is a graph showing an IR analysis result of the compound (XV-1) obtained in Example 1. FIG. 4 is a diagram showing a result of NMR analysis of a compound (XV-2) obtained in Example 2. FIG. 2 is a graph showing an IR analysis result of the compound (XV-2) obtained in Example 2. FIG. FIG. 4 is a diagram showing an IR analysis result of the compound (XV-3) obtained in Example 3. FIG. 4 is a diagram showing the NMR analysis result of the compound (XV-4) obtained in Example 4. FIG. 6 is a diagram showing an IR analysis result of the compound (XV-4) obtained in Example 4. FIG. 4 is a diagram showing the NMR analysis result of the compound (XV-5) obtained in Example 5. FIG. 6 is a diagram showing an IR analysis result of the compound (XV-5) obtained in Example 5. FIG. 6 is a diagram showing the NMR analysis result of the compound (XV-6) obtained in Example 6. FIG. 6 is a diagram showing an IR analysis result of the compound (XV-6) obtained in Example 6. FIG. 4 is a diagram showing the NMR analysis result of the compound (XV-7) obtained in Example 7. FIG. 6 is a diagram showing an IR analysis result of the compound (XV-7) obtained in Example 7.

  The electron transport material of the present invention contains an antipyrine derivative represented by the above formula (XV).

When A to F in the formula (XV) is an alkyl group, the alkyl group preferably has 1 to 16 carbon atoms, more preferably 1 to 8 carbon atoms. This alkyl group may be linear or branched, and may further have an alkoxy group or a halogen atom.
Specific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl and isohexyl. , N-heptyl, n-octyl; 2-ethoxyethyl, 4-methoxypropyl; perchloromethyl, perfluoroethyl, trifluoromethyl and the like.

When A to F in the formula (XV) is a cycloalkyl group, the carbon number of the cycloalkyl group is preferably 12 or less, more preferably 8 or less. This cycloalkyl group may further have an alkyl group or a halogen atom on the ring.
Specific examples of the cycloalkyl group include cyclopentyl, cyclohexyl, cycloheptyl, 2,6-dimethylcyclohexane, 2-isopropyl-5-methylcyclohexyl, 1-5 substituted chlorocyclohexylphenyl groups and 1-5 substituted fluorocyclohexyl. Group and the like.

When A to F in Formula (XV) are an aryl group, the number of carbon atoms of the aryl group is preferably 12 or less, more preferably 10 or less. This aryl group may further have an alkyl group or a halogen atom on the ring.
Specific examples of the aryl group include phenyl, naphthyl, diphenyl; tolyl, xylyl, mesityl, cumenyl, 2-ethyl-6-methylphenyl, 1-3 substituted chlorophenyl groups and 1-3 substituted fluorophenyl groups. Can be mentioned.

When A to F in the formula (XV) is an aralkyl group, the aralkyl group preferably has 12 or less carbon atoms, more preferably 10 or less. This aralkyl group may further have an alkyl group or a halogen atom on the ring.
Specific examples of the aralkyl group include benzyl, phenethyl, 2,6-dimethylbenzyl and the like.

  In the present invention, in addition to the solubility in organic solvents, considering the ease of chemical modification to carboxylic acid, carboxylic acid monoanhydride, carboxylic acid dianhydride, etc., which are synthetic raw materials, industrial costs, etc. In the above formula (XV), it is preferable that A and D, B and E, and C and F are the same.

Furthermore, in the present invention, if both C and F are methyl groups, synthesis with high yield and purity can be reliably realized industrially easily and inexpensively.
Preferred examples of A and D include an alkyl group, a haloalkyl group, a phenyl group, and an aryl group.
Preferred examples of B and E include an alkyl group, a haloalkyl group, a phenyl group, and an aryl group.

  X in the formula (XV) is any one of the seven structural formulas (X-1) to (X-7). In terms of stability of the compound and electron transport performance, X is (X -1) antipyrine derivatives.

When X in Formula (XV) is Structural Formula (X-2), Y ₁ and Y ₂ in Formula (X-2) are a hydrogen atom, a halogen atom, an alkyl group, and an allyl group, respectively. And any one type of substituent selected from the group consisting of an alkoxy group, an aryl group, a dialkylamino group, and a diphenylamino group. In the present invention, Y ₁ and Y ₂ are preferably the same, and more preferably hydrogen atoms.

(Synthesis method)
The antipyrine derivative in which X is (X-1) is, for example, naphthalenetetracarboxylic dianhydride represented by the following formula (III-X-1) and the following formula (IV) and / or (IV ′): By reacting the aminoantipyrine and its derivative (4-amino-1,2,3-substituted-5-pyrazolones) represented by heating and stirring while dehydrating using a Dean Stark trap or the like, Moreover, a high-purity product can be synthesized with a high yield.
The naphthalenetetracarboxylic dianhydride (III-X-1) may be a monoanhydride or not an anhydride.

A to F in the formulas (IV) and (IV ′) are the same as those in the above formula (XV).

Similarly, for the antipyrine derivatives in which X is (X-2) to (X-7), the aminoantipyrine represented by the above formula (IV) and / or (IV ′) and its derivatives (4-amino-1 , 2,3-substituted-5-pyrazolones) and, for example,
Pyromellitic dianhydride represented by the following formula (III-X-2):
4,4′-biphthalic anhydride represented by the following formula (III-X-3):
4,4′-oxydiphthalic anhydride represented by the following formula (III-X-4):
4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride represented by the following formula (III-X-5):
3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride represented by the following formula (III-X-6):
Dehydrate one or more of 4,4 ′-[(isopropylidene) bis (p-phenyleneoxy)] diphthalic anhydride represented by the following formula (III-X-7) using a Dean-Stark trap The reaction can be carried out with stirring while heating, and a high-purity product can be easily synthesized in a high yield.
In addition, these carboxylic acid anhydrides (III-X-2) to (III-X-7) may also be monoanhydrides or not anhydrides.

Y ₁ and Y _{2 in} formula (III-X-2) both represent a hydrogen atom.

In the present invention, the carboxylic acid anhydride represented by any one of the above formulas (III-X-1) to (III-X-7) is compared with the compound represented by the above formula (IV) and the above formula (IV In the case where both of the compounds represented by ') are reacted, they may be supplied to the reaction system as a mixture of these two kinds of aminoantipyrines and derivatives thereof, or sequentially supplied to the reaction system, It is also possible to generate diimide via
Moreover, what is necessary is just to use organic solvents, such as a dimethylformamide, a dimethylacetamide, a dimethylsulfoxide, N-methylpyrrolidone, toluene, tetrahydrofuran, anisole, about the solvent at the time of making it heat and stir and react.
The antipyrine derivative (XV) thus obtained can be purified by an adsorbent such as activated carbon, clay, silica gel or the like.

The electronic material of the present invention uses an electron transport material (hereinafter referred to as “ETM”) containing the above novel antipyrine derivative.
The ETM of the present invention is combined with, for example, a known charge generation material (hereinafter also referred to as “CGM”), a hole transport material (hereinafter also referred to as “HTM”), a binder resin, and the like. As a result, an electrophotographic photosensitive member can be formed which is used as a photosensitive layer, and the photosensitive layer is provided on a conductive support.

As the CGM that can be combined with the ETM of the present invention, a conventionally known CGM as exemplified below may be used;
[Examples of CGM that can be combined]
Phthalocyanine compounds, disazo compounds, trisazo pigments, monoazo pigments, perylene compounds, dithioketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaraine pigments, trisazo pigments, indigo pigments, azurenium pigments, cyanine pigments, A pyrylium salt, an santhrone pigment, a triphenylmethane pigment, a selenium pigment, a toluidine pigment, a pyrazoline pigment, a quinacridone pigment, etc. may be used alone or in combination of two or more. Good.

Among them, metal-free phthalocyanine, aluminum phthalocyanine, vanadium phthalocyanine, cadmium phthalocyanine, antimony phthalocyanine, chromium phthalocyanine, copper 4-phthalocyanine, germanium phthalocyanine, iron phthalocyanine, dichlorotin phthalocyanine, chloroaluminum phthalocyanine, (oxy) titanyl having high photosensitivity Phthalocyanine compounds such as phthalocyanine, chloroindium phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, magnesium phthalocyanine, dialkyl phthalocyanine, tetramethyl phthalocyanine and tetraphenyl phthalocyanine are preferred.
As the crystal form of oxytitanyl phthalocyanine, any of α, β, γ, Y type, amorphous or mixed crystal thereof can be used. In the case of metal-free phthalocyanine, γ type can be used.
In addition, a mixture of chloroindium phthalocyanine and oxytitanyl phthalocyanine, a derivative obtained by reacting polyhydric alcohol and oxytitanyl phthalocyanine, in particular, a compound obtained by reacting butanediol and oxytitanyl phthalocyanine can be used.

As the HTM that can be combined with the ETM of the present invention, a conventionally known HTM as exemplified below may be used;
[Examples of HTMs that can be combined]
The compound represented by the following general formula (V), the compound represented by the general formula (VI), the compound represented by the general formula (VII), the compound represented by the general formula (VIII), etc. You may use, and 2 or more types may be mixed and used for it.

In the formula (V), R _{1 to} R ₃ are each a group consisting of a hydrogen atom, a halogen atom, an alkyl group, an allyl group, an alkoxy group, an aryl group, a dialkylamino group, and a diphenylamino group. Any one kind of substituent selected from the above, l, m, and n represent an integer of 0 or more and 2 or less.

In formula (VI), R _{4 to} R ₇ are each selected from the group consisting of a hydrogen atom, an alkyl group, an allyl group, an alkoxy group, an aryl group, a dialkylamino group, and a diphenylamino group. Any one type of substituent is shown.

In formula (VII), R _{8 to} R ₁₁ represent any one type of substituent selected from the group consisting of a hydrogen atom, an alkyl group, an allyl group, and an aryl group.

In Formula (VIII), R _{12 to} R ₁₄ represent any one type of substituent selected from the group consisting of a hydrogen atom, an alkyl group, an allyl group, and an aryl group.

  Among these HTMs, preferred compounds are those that do not depend on the molecular structure but have a large molecular weight and high mobility.

In the photosensitive layer, in addition to the ETM of the present invention, conventionally known ETMs as exemplified below can be used, including compounds generally used in photoreceptors;
[Examples of other ETMs that can be combined]
These compounds such as compounds represented by the following general formulas (IX) to (XIII) may be used alone or in combination of two or more.

In formulas (IX) to (XII), R _{15 to} R ₂₅ are each a hydrogen atom, a halogen atom, an alkyl group, an allyl group, an alkoxy group, an aryl group, a dialkylamino group, and a diphenylamino group. Any one type of substituent selected from the group consisting of:

In the formula (XIII), the substituents R _{26 to} R ₃₁ are a hydrogen atom, a cyano group, a nitro group, a halogen atom, a hydroxy group, an alkyl group, an aryl group, a heterocyclic group, and an ester group. And an alkoxy group, an aralkyl group, an allyl group, an amide group, an amino group, an acyl group, an alkenyl group, an alkynyl group, a carboxyl group, a carbonyl group, and a carboxylic acid group. Any one type of substituent selected. The substituent G ₁ is any one kind of substituent selected from the group consisting of oxygen, sulfur, and ═C (CN) ₂ , and the substituent G ₂ is derived from any one element of oxygen or sulfur. Become.

As the binder resin for forming the photosensitive layer containing ETM, CGM, HTM and the like as described above, conventionally known ones exemplified below may be used;
[Example of binder resin]
Polycarbonate resin, styrene resin, acrylic resin, styrene-acrylic resin, ethylene-vinyl acetate resin, polypropylene resin, vinyl chloride resin, chlorinated polyether resin, vinyl chloride-vinyl acetate resin, polyester resin, furan resin, nitrile resin, alkyd Resin, polyacetal resin, polymethylpentene resin, polyamide resin, polyurethane resin, epoxy resin, polyarylate resin, diarylate resin, polysulfone resin, polyethersulfone resin, polyallylsulfone resin, silicone resin, ketone resin, polyvinyl butyral resin, poly Ether resin, phenol resin, EVA (ethylene / vinyl acetate) resin, ACS (acrylonitrile / chlorinated polyethylene / styrene) resin, ABS (acrylonitrile / butadiene) Styrene), such as resins and epoxy arylate These may be used alone or may be used as a mixture of two or more.

[Other additives]
In addition to the above-described components, various additives such as a plasticizer, a surfactant, and a leveling agent can be added to the photosensitive layer.

For the conductive support on which the photosensitive layer as described above is formed, various materials having conductivity as exemplified below may be used;
[Example of conductive support]
Simple metals such as iron, aluminum, copper, tin, platinum, gold, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, brass; plastic materials on which the above metal is deposited or laminated, Examples thereof include glass coated with aluminum iodide, tin oxide, indium oxide, and the like; a resin substrate in which conductive fine particles such as carbon black are dispersed.
The shape of the conductive support may be any of a sheet shape and a drum shape according to the structure of the image forming apparatus to be used. The support itself has conductivity or the surface of the support is conductive. What is necessary is just to have sex. The conductive support preferably has sufficient mechanical strength when used.

Example 1
Antipyrine derivative according to the present invention: Compound (XV-1) in which X in formula (XV) is (X-1) was synthesized as follows.

In a reaction vessel, compound (III-X-1): 1,4,5,8-naphthalenetetracarboxylic dianhydride 1.35 g (5.0 mmol) and compound (IV ″): 4-amino- 2.34 g (11.5 mmol) of 2,3-dimethyl-1-phenyl-5-pyrazolone (aminoantipyrine) and 15 ml of toluene (hereinafter referred to as ml) were added and reacted under reflux for 3 hours. (See the following reaction formula [1]). During the reaction, by-product water was dehydrated using a Dean-Stark trap.
After completion of the reaction, the reaction mixture was cooled, 50 mL of methanol was added, and the precipitated crystals were filtered.
The obtained crystal was washed with methanol and purified with tetrahydrofuran and activated carbon, and compound (XV-1): N, N′-bis (2,3-dimethyl-1-phenyl-5-pyrazolon-4-yl) was obtained. ) -1,4,5,8-naphthalenetetracarboximide was obtained in an amount of 2.40 g (light pink crystals: yield 75.5%).

The obtained crystals were subjected to melting point measurement, elemental analysis, NMR analysis, IR analysis, and HPLC analysis. Results are shown below.
<Melting point measurement>
The melting point was measured using a melting point measuring apparatus (trade name “B545” manufactured by BUCHI, Germany). The results were as follows.
Melting point: 400 ° C or higher <Elemental analysis>
The product name “EA1108 type” manufactured by FISONS was used. The results were as follows.

Actual value (%) C: 67.52%, H: 4.01%, N: 13.01%
Calculated value (%) C: 67.71%, H: 4.10%, N: 13.16%

<NMR analysis>
R-1200 type fast sweep correlation nuclear magnetic resonance apparatus (manufactured by Hitachi) was used, and measurement was performed with CDCl ₃ . The result was as shown in FIG.
<IR analysis>
The measurement was performed by the KBr method using an infrared spectroscopic analyzer (trade name “NICOLET 380” manufactured by Thermo Corporation). The result was as shown in FIG.
<HPLC analysis>
When an analysis was performed using an HPLC apparatus (trade name “CR-7A” manufactured by Shimadzu Corporation), the purity was 99.85% (area percentage).

Examples 2-7
An antipyrine derivative according to the present invention using a carboxylic acid anhydride other than the above compound (III-X-1): a compound (XV-) wherein X in the formula (XV) is (X-2) to (X-7) 2) to (XV-7) were synthesized.

Instead of the compound (III-X-1) of Example 1, pyromellitic dianhydride (III-X-2 ′), 4,4′-biphthalic anhydride (III-X-3), 4, 4'-oxydiphthalic anhydride (III-X-4), 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride (III-X-5), 3,3', 4,4'-diphenylsulfone Except for using tetracarboxylic dianhydride (III-X-6), 4,4 '-[(isopropylidene) bis (p-phenyleneoxy)] diphthalic anhydride (III-X-7) It carried out similarly to the case of Example 1 (refer following Reaction formula [2]-[7]), and measured the weight (yield) of each obtained crystal | crystallization.
Table 1 shows the carboxylic acid anhydrides used and their amounts, the amount of solvent (toluene), the reaction time under reflux, the purification method and the results.

Melting point measurement, elemental analysis, NMR analysis, IR analysis, and HPLC analysis of the crystals obtained in Examples 2 to 7 were performed in the same manner as in Example 1.
The results of melting point measurement, elemental analysis, and HPLC analysis are shown in Table 2.
The results of NMR analysis and IR analysis are shown in FIGS. The compound of Example 3 (XV-3) was poorly soluble in chloroform and could not be analyzed by NMR.

Comparative Examples 1-5
Of the known NTC (II), in the general formula (II), R and R ′ are both substituted compounds represented by (A) to (O) as Comparative Examples 1 to 5, respectively.

<Solubility in organic solvents>
About the compound of Examples 1-7 and Comparative Examples 1-5, the solubility evaluation was performed as follows. The results are shown in Table 3.
0.1 g of each compound was placed in 1 mL of tetrahydrofuran, and stirred for 1 minute. “○” indicates that it was completely dissolved, “Δ” indicates that it was slightly dissolved, and “×” indicates that it was hardly dissolved.

<Photoconductor characteristics as ETM>
Regarding Examples 1 to 7 and Comparative Example 5 in which dissolution was confirmed in the above solubility test, the characteristics of the photoreceptor were evaluated as follows (Comparative Examples 1 to 4 having no solubility in tetrahydrofuran). ), The coating solution could not be prepared, the photosensitive layer could not be formed, and the photoreceptor characteristics could not be evaluated));
As CGM, 0.1 g of α-type oxytitanyl phthalocyanine was added to 100 mL of tetrahydrofuran together with 4.7 g of Z-type polycarbonate having a molecular weight of 40,000, and dispersed in an ultrasonic disperser for 24 hours.
Thereto, 1.7 g each of the compounds of Examples 1 to 7 and Comparative Example 5 as ETM, and m-TPD (N, N′-diphenyl-N, N′-di) represented by the above formula (V) as HTM (M-Tolyl) benzidine) (3.5 g) was added and mixed and dissolved to obtain a coating solution.

Each of the obtained coating liquids was applied to a drum-shaped conductive support made of aluminum with a single coating application device manufactured by Mitsubishi Materials Techno Corporation so that the film thickness was 30 μm. A layer type electrophotographic photosensitive member was produced.
In order to evaluate the sensitivity of the produced electrophotographic photosensitive member, a half exposure amount (μJ / cm ² ) was measured using an electrophotographic evaluation apparatus “CINDIE 743” manufactured by Gentec Corporation. The results are also shown in Table 3. The half-exposure amount is an exposure amount necessary to halve the surface potential when the surface of the charged photosensitive layer (photoconductive layer) is exposed. The smaller the half-exposure amount, the more sensitive the photoreceptor is. Indicates that it is large.

As for evaluation of half-exposure dose, in general, a positively charged single layer photoconductor using α-type oxytitanylphthalocyanine has a sensitivity of 0.28 μJ / cm ² or less, and has a sensitivity of about 0.35 μJ / cm ^2. Then, it is insufficient as a photosensitive drum and is regarded as defective.

The antipyrine derivative of the present invention is a novel compound that is extremely excellent in solubility in an organic solvent as well as electron transport ability.
Therefore, for example, it is extremely useful as an electron transport material (ETM) for an electrophotographic photosensitive member used in an image forming apparatus such as an electrostatic copying machine, a facsimile machine, a laser beam printer, etc., but also an organic semiconductor, an organic EL, It can be suitably used in a wide range of fields such as conductive polymers.

Claims (4)

An electron transporting material containing an antipyrine derivative represented by the formula (XV).
In formula (XV),
A to F are the same or different and each represents an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group. Of these groups, the alkyl group may further have an alkoxy group and / or a halogen atom as a substituent. Further, any of the cycloalkyl group, aryl group and aralkyl group may further have an alkyl group and / or a halogen atom as a substituent on the ring. Furthermore, the aralkyl group may further have an alkyl group and / or a halogen atom as a substituent on the alkylene chain.
X represents any one of the following seven structural formulas (X-1) to (X-7).

In formula (X-2), Y ₁ and Y ₂ are each a hydrogen atom, a halogen atom, an alkyl group, an allyl group, an alkoxy group, an aryl group, a dialkylamino group, and a diphenylamino group. One of the substituents selected from the group consisting of:
  The electron transport material according to claim 1, wherein A and D, B and E, and C and F of the antipyrine derivative represented by the above formula (XV) are the same. The antipyrine derivative represented by the above formula (XV) is
Aminoantipyrine and its derivatives;
It is synthesized by a reaction with at least one selected from the group consisting of carboxylic acid anhydrides of the following formulas (III-X-1) to (III-X-7). Electron transport material.

Y ₁ and Y ₂ in the formula (III-X-2) are the same as in the above formula (X-2).   The electronic material using the electron transport material as described in any one of Claims 1-3.