JPH07179775A - Fluorenone derivative and laminated electrophotographic receptor using the derivative - Google Patents

Abstract

PURPOSE:To obtain a new fluorenone derivative useful for electrophotographic receptor having high charge potential and charge-retainability and exhibiting high sensitivity, low residual voltage and excellent repeated electrophotographic characteristics. CONSTITUTION:This compound is expressed by formula I [R is a (halogenated) alkyl or an alkoxy; R1 to R4 each is H, a (halogenated)alkyl or an alkoxy], e.g. N-(2,4,5,7-tetranitrofluorenylidene)-2,5-di-t-butylaniline. The compound of formula I can be produced by reacting 2,4,5,7-tetranitrofluorenone with a compound of formula II.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel fluorenone derivative and a laminated electrophotographic photosensitive member using the same as a charge transfer material.

[0002]

2. Description of the Related Art Conventionally, an inorganic photoconductive material mainly containing selenium, zinc oxide, cadmium sulfide or the like has been used as a photosensitive material used in an electrophotographic process or the like. However, these materials are not always satisfactory in terms of thermal stability and durability, and further have toxicity, which causes a problem in handling. On the other hand, a photoconductor using an organic photoconductive material has been attracting attention in recent years because it is relatively easy to manufacture, the cost is low, the handling is easy, and the heat stability is excellent. In particular, as the charge generating material contained in the charge generating layer, azo pigments, phthalocyanine compounds, anthraquinone compounds, perylene pigments,
Antantron pigments, cyanine dyes, thiopyrylium dyes, etc. are known as charge transfer materials contained in the charge transfer layer, such as amine derivatives, hydrazone compounds, oxazole derivatives, oxadiazole derivatives, triphenylmethane derivatives, and styryl compounds. ing.

However, since all of these charge transfer materials are of the hole transport type, the laminated type photoreceptors using these materials have to be negatively charged type organic photoreceptors. The negative charging type has a drawback in that a large amount of ozone is generated and the charge transfer material is deteriorated by the ozone generated, resulting in problems of repetitive characteristics and printing durability. On the other hand, in the electron transport type charge transfer material, the above problems caused by ozone are lessened, but the solubility is poor like trinitrofluorenone,
A sufficiently sensitive electrophotographic photoreceptor has not been obtained.

To solve these problems, Japanese Patent Laid-Open No. 5-27
General formula (II) in No. 9582

[0005]

[Chemical 2]

An electron-transporting charge composed of a fluorenone derivative represented by the formula (wherein R ₁ represents an alkyl group, an alkoxy group or a halogenated alkyl group, and R ₂ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogenated alkyl group). We propose moving materials. However, even though this derivative is sufficiently excellent in solubility and initial electrophotographic characteristics, repeated electrophotographic characteristics were not sufficiently satisfied, and further improvement was required.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-sensitivity electrophotographic photosensitive member which has improved repetitive characteristics, which is a problem of the above-mentioned electron transport type charge transfer material.

[0008]

The present invention is described in the above-mentioned Japanese Patent Laid-Open No.
In order to improve the repeating characteristics of the trinitrofluorenone derivative disclosed in JP-A-279582 and to improve the solubility at the same time, as a result of intensive studies, the present invention as described below has been completed. The present invention has the general formula (I)

[0009]

[Chemical 3]

(Wherein R represents an alkyl group, an alkoxy group or a halogenated alkyl group, and R _{1 to} R ₄ represent a hydrogen atom or the same or different alkyl group, an alkoxy group or a halogenated alkyl group). It is a fluorenone derivative. Substituents R and R of the compound of general formula (I)
Examples of the alkyl group for _{1 to} R ₄ include a methyl group, an ethyl group, a propyl group and a butyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group and a propoxy group, and examples of the halogenated alkyl group include a trifluoromethyl group.

The fluorenone derivative of the general formula (I) is
2,4,5,7-tetranitrofluorenone is represented by the general formula (III)

[0012]

[Chemical 4]

It can be obtained by reacting with a compound represented by the formula (R, R _{1 to} R ₄ in the formula have the above-mentioned meanings).

The reaction is carried out in the presence of an acidic catalyst such as zinc chloride, anhydrous aluminum chloride, acetic acid or phenol to obtain the product. The reaction temperature is from 100 ° C to the boiling temperature of the reaction mixture, preferably from 150 to 230 ° C. Then the product is dissolved in chloroform and suction filtered.
The fluorenone derivative of the present invention can be obtained by concentrating the filtrate and isolating and purifying by a method such as column chromatography. By such a method, fluorenone derivatives having the following structural formulas (1) to (5) were synthesized.

[0015]

[Chemical 5]

The fluorenone derivative represented by the general formula (I) of the present invention obtained as described above has excellent properties as an electron transport type charge transfer material in an electrophotographic photoreceptor.

Next, an electrophotographic photosensitive member using the fluorenone derivative of the present invention will be described. The electrophotographic photoreceptor of the present invention is one in which a photosensitive layer comprising a charge generation layer and a charge transfer layer containing the compound of the general formula (I) is formed on a conductive support. It is also possible to provide an undercoat layer between the photosensitive layer and the photosensitive layer. In this case, the order of stacking the photosensitive layers provided on the conductive support needs to be a stacking mode in which the charge generation layer and the charge transfer layer are sequentially stacked on the conductive support in order to reduce ozone deterioration of the charge transfer layer. . As the conductive support used in the present invention, for example, a metal sheet of aluminum, nickel, brass, copper, or a metal cylinder can be used. Further, for example, a film such as a polyester film or a paper in which a metal such as aluminum is vapor-deposited on the surface or a metal foil is adhered to the surface,
Sheet-like materials such as synthetic paper and non-woven fabric can also be used.

Casein, polyvinyl alcohol, polyvinyl butyral, polyamide resin, polyester resin, cellulose derivative and the like are used for the undercoat layer provided between the conductive support and the photosensitive layer as required. The thickness of the undercoat layer is preferably 0.1 to 5 μm.
As the charge generating material used in the charge generating layer, known organic or inorganic photoconductive substances can be used. Among these substances, disazo pigments, trisazo pigments, perylene pigments, quinacridone pigments or phthalocyanine pigments or zinc oxide have excellent characteristics as charge generating materials and are suitable.

The charge generation layer comprises a charge generation material and a suitable binder,
For example, polyvinyl butyral, polyester, polymethylmethacrylate, polystyrene, polycarbonate, etc. are dispersed and dissolved in an organic solvent to form a coating solution, which is then applied to a conductive support or a bottom layer by a method such as bar coating, spin coating or dip coating. It is formed by coating on the pulling layer. The thickness of the charge generation layer is preferably 0.1 to 5 μm. It is also possible to form the thin film charge generation layer by vacuum deposition of the charge generation material or by sputtering. In this case, the thickness of the charge generation layer is 0.01 to 0.5 μ.
About m is preferable. On the other hand, for the charge transfer layer, the charge transfer material comprising the fluorenone derivative of the general formula (I) of the present invention is dissolved in a suitable binder solution and applied.

Polycarbonate, polystyrene, polyvinyl chloride, polymethacrylate, polyvinyl acetate, silicone resin, vinyl chloride / vinyl acetate copolymer resin, epoxy resin and the like are suitable as the binder used together with the charge transfer material. . As the organic solvent for dissolving the binder, toluene, methyl ethyl ketone, ethylene chloride, chlorobenzene, ethyl acetate or the like can be used. The thickness of the charge transfer layer is 10 to 40 μm, preferably 1
It is 5 to 30 μm.

[0021]

EXAMPLES Next, examples of the present invention will be described. Example 1 Synthesis of N- (2,4,5,7-tetranitrofluorenylidene) -2,5-di-t-butylaniline [the structural formula (1)] 2,5-di-t-butyl Aniline 2.1g, 2,4
1.8 g of 5,7-tetranitrofluorenone and 0.1 g of zinc chloride were placed in a reaction vessel and the temperature was 210 to 215 ° C. for 3 hours.
Heated to. Then the product was dissolved in about 200 ml of chloroform and suction filtered. The filtrate was separated by silica gel chloroform column chromatography, concentrated, and then recrystallized from a hexane-chloroform solution to obtain 1.3 g of a target substance. (Yield 43%). The molecular weight is mass spectrometry (EI
-MS) confirmed (m / z = 547). Melting point 280
˜282 ° C., nuclear magnetic resonance spectrum (H-NMR
The measurement result of (270 MHz, CDCl ₃ )) was as follows. δ 1.27 (s, 9H), 1.36 (s, 9H), 6.70 (s, 1H), 7.42 (d, J = 8.4 Hz, 1H), 7.58 (d, J) = 8.4 Hz, 1H), 7.96 (d, J = 1.8 Hz, 1H), 8.87 (d, J = 1.8 Hz, 1H), 9.03 (d, J = 1.8 Hz, 1H), 9.15 (d, J = 1.8 Hz, 1H) Elemental analysis values by an elemental analyzer (EA-1108, Carlo Erba Co.) and theoretical values based on the structural formula were as follows. Elemental analysis value C H N measurement value (%) 58.74 4.38 12.42 theoretical value (%) 59.23 4.60 12.79

Example 2 Synthesis of N- (2,4,5,7-tetranitrofluorenylidene) -2-trifluoromethylaniline [the structural formula (3)] 1.6 g of 2-trifluoromethylaniline, 2, 4,
1.8 g of 5,7-tetranitrofluorenone and 0.1 g of zinc chloride were placed in a reaction vessel, and 175-180 for 3 hours.
Heated to ° C. The product was then dissolved in about 200 ml of chloroform and suction filtered. The filtrate is separated by silica gel / chloroform chromatography, concentrated, and then hexane-
Recrystallize with chloroform solution, 0.3 g of desired product
Got (Yield 10%). The molecular weight is determined by mass spectrometry (EI-M
It confirmed by S) (m / z = 503).

The melting point is 204 to 206 ° C., and the nuclear magnetic resonance spectrum (H-NMR (270 MHz, CDC
The measurement results of (l ₃ )) were as follows. δ 7.00 (d, J = 7.6 Hz, 1H), 7.56 (t, J = 7.6 Hz, 1H), 7.65 (s, 1H), 7.73 (t, J = 7. 6 Hz, 1 H), 7.93 (d, J = 7.6 Hz, 1 H), 8.88 (s, 1 H), 9.02 (s, 1 H), 9.16 (s, 1 H) Elemental analyzer ( The theoretical values based on the elemental analysis values and the structural formula by Carlo Erba EA-1108) are as follows. CHN measured value (%) 47.74 1.60 13.84 theoretical value (%) 47.73 1.60 13.92

Example 3 N- (2,4,5,7-tetranitrofluorenylidene) -2,6-diethylaniline [the above structural formula (5)]
Synthesis of 2,6-diethylaniline 3.0 g, 2,4,5,7-
Tetranitrofluorenone 3.6 g and zinc chloride 0.1
g was placed in a reaction vessel and heated to 150-155 ° C for 1.5 hours. The product was then dissolved in about 200 ml of chloroform and suction filtered. The filtrate was separated by silica gel chloroform column chromatography, concentrated and then recrystallized from a hexane-chloroform solution to obtain 0.5 g of the desired product. (Yield 10%). The molecular weight is determined by mass spectrometry (EI-M
It confirmed by S) (m / z = 491).

The melting point is 275 to 278 ° C., and the nuclear magnetic resonance spectrum (H-NMR (270 MHz, CDC
The results of measurement of l ₃ )) are as follows. δ 1.09 (t, J = 7.3 Hz, 6H), 2.35 (q, J = 7.3 Hz, 4H), 7.26-7.34 (m, 3H), 7.61 (d, J = 1.8Hz, 1H), 8.86 (d, J = 1.8Hz, 1H), 9.03 (d, J = 1.8Hz, 1H), 9.25 (d, J = 1.8Hz) , 1H) Elemental analysis values by an elemental analyzer (EA-1108, manufactured by Carlo Erba Co.) and theoretical values based on the structural formulas are as follows. CHN measured value (%) 55.02 3.36 13.74 theoretical value (%) 56.22 3.47 14.25

Example 4 Casein was coated on a 100 μm-thick polyester film on which aluminum was vapor-deposited so that the film thickness after drying was 2 μm, to form an undercoat layer. On the undercoat layer, the following composition was used, and 1 by a dispersing device using glass beads
Apply the coating solution prepared by time dispersion and dry at 60 ° C for 10 minutes, then vacuum dry at 50 ° C for 3 hours to give a thickness of 0.5.
A charge generation layer of μm was provided. X-type metal-free phthalocyanine pigment 2 parts by weight Polyvinyl butyral 1 part by weight (Denki Kagaku Kogyo KK # 4000-1) Dichloroethane 97 parts by weight Next, a coating solution for the charge transfer layer was prepared in the following manner. Compound of structural formula (I) 10 parts by weight Polycarbonate 10 parts by weight (Panlite L1250 manufactured by Teijin Chemicals Ltd.) Dichloroethane 80 parts by weight The above composition was mixed and dissolved to obtain a coating liquid for the charge transfer layer. This coating liquid was applied onto the charge generation layer and dried in the same manner to form a charge transfer layer having a thickness of 20 μm, and the electrophotographic photoreceptor of the present invention was obtained.

The electrophotographic characteristics of this electrophotographic photosensitive member were measured using an electrostatic paper analyzer EPA8100 type manufactured by Kawaguchi Electric Co., Ltd. The results are shown in Table 1. The measurement items and conditions are as follows. [Measurement Items] V ₀ : Initial surface potential of charging (V) DDR: Potential holding ratio (%) 2 seconds after the end of charging E _1/2 : Half exposure amount (lux · sec) V _R : From the start of exposure 1. Residual potential after 5 seconds (V) [Measurement conditions] Measurement mode: Static mode Corona discharge voltage: +6 kV Photoconductor charging speed: 167 mm / sec Exposure wavelength: White light Exposure light amount: 10 lux Pre-exposure: 300 lux (white light), 0 .2 seconds

Example 5 An electrophotographic photosensitive member was obtained and evaluated in the same manner as in Example 4, except that the compound of structural formula (3) was used instead of the compound of structural formula (1) of Example 4. The results are shown in Table 1.

Comparative Example 1 2,4 instead of the compound of structural formula (1) of Example 4
A charge transfer layer coating solution was prepared in the same manner as in Example 4 except that 5,7-tetranitrofluorenone was used.
5,7-Tetranitrofluorenone was hardly dissolved and remained, and a coating solution could not be prepared.

Comparative Example 2 Instead of the compound of the structural formula (1) of Example 4, N- (2,
An electrophotographic photosensitive member was obtained and evaluated in the same manner as in Example 4 except that 4,7-trinitrofluorenylidene) -2-ethylaniline was used. The results are shown in Table 1.

Comparative Example 3 Instead of the compound of the structural formula (1) of Example 4, N- (2,
An electrophotographic photosensitive member was obtained and evaluated in the same manner as in Example 4 except that 4,7-trinitrofluorenylidene) -2-trifluoromethylaniline was used. The results are shown in Table 1.

[0032]

[Table 1]

As shown in Table 1, the photoreceptor using the charge transfer material of the present invention shows that the charging potential and the residual potential change extremely stably after repeated use, and exhibits excellent characteristics in terms of sensitivity and dark decay. .

[0034]

The charge transfer material of the present invention has excellent solubility and has sufficiently excellent characteristics for electron transport. That is, the electrophotographic photoreceptor of the present invention has a high charging potential, a high charge retention rate, high sensitivity and a small residual potential, and these characteristics do not change even after repeated use, and the characteristics are stable and positively charged. It has the effect that it can be used as an electrophotographic photosensitive member.

Claims (2)

[Claims] 1. A compound represented by the general formula (I): (Wherein R represents an alkyl group, an alkoxy group or a halogenated alkyl group, and R _{1 to} R ₄ represent a hydrogen atom or the same or different alkyl groups, alkoxy groups or halogenated alkyl groups). 2. A multi-layer electrophotographic photosensitive member comprising a conductive support and a charge generation layer and a charge transfer layer containing the compound of formula (I), which are sequentially provided on the conductive support.