JPS6037561A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide stability to irradiated ultraviolet rays and superior electophotographic characteristics by incorporating a specified oxazole deriv. CONSTITUTION:A layer contg. a charge generating substance and a charge transferring substance is formed on an electrically conductive support to obtain a sensitive body. At this time, an oxazole deriv. represented by the formula (where each of R1-R4 is alkyl) is used as the charge transferring substance. A layer contg. the charge generating substance and a layer contg. the charge transferring substance may be formed. The oxazole deriv. has stability to irradiated ultraviolet rays and does not deteriorate the superior electrophotographic characteristics of the sensitive body during manufacture. Thus, the oxazole deriv. is used in the formation of a single layer contg. the deriv. mixed with an inorg. or org. charge generating substance or a separated function type photosensitive layer. In case of a two-layered structure, it is preferable that a charge generating layer and a charge transferring layer contg. the oxazole deriv. are successively formed on a support.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor containing a novel chemically stable oxazole derivative.

Conventionally, oxazole derivatives include 2-(4-dipropylaminophenyl)-4-(4-dimethylaminophenyl)-5-(2-chlorophenyl)-i,a-oxazole [Compound (II):], 2 -(4-diethylaminophenyl)-4-(4-dimethylaminophenyl)-5-(2-chlorophenyl)-1,3-oxazole [Compound (I[[l], 2-(4-dimethylaminophenyl)- 4-(4-dimethylaminophenyl)-5
-(2-chlorophenyl)-1,3-oxazole [compound (■)] is known and is used as an electrophotographic material for copying machines and laser beam printers (% Opening and Closing No. 56-123544). Public bulletin). However, this oxazole derivative is particularly easily decomposed by ultraviolet irradiation in a solution state, and mainly produces 2-(4-dig p-pylaminophenyl)-6 as a decomposition product.
- Dimethylaminophenanthro[9゜1O-d)oxazole is generated and its properties are destroyed, so care must be taken when handling it, especially during the production of electrophotographic photoreceptors. It has the disadvantage that it is easy to

The present invention is intended to solve these problems, and is an electrophotographic photosensitive material containing an oxazole derivative, which is a novel compound and has properties that are stable against ultraviolet irradiation, and has excellent electrophotographic properties. The object of the present invention is to provide an electrophotographic photoreceptor that does not lose its properties even during its manufacture.

That is, 1. The present invention provides an electrophotographic method containing an oxazole derivative represented by the general formula +11 (in formula 1, R+, Rx, Rs, and R4 represent an alkyl group, and may be the same or different). Regarding photoreceptors.

The compound represented by the above general formula fil is the above compound f
ill, flllrl and (ll/l to Okel CI!
Although it contains F atoms, it is very stable against ultraviolet rays, and does not decompose even when exposed to ultraviolet rays, giving electrophotographic photoreceptors stable and excellent properties. It is something to give.

The oxazole derivative represented by the general formula (11) is:

Mainly functions as a charge transport material. This compound is different from other charge transporting substances 9 such as polymer compounds! j-N
-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene.

Polyvinylindoquinoxaline, polyvinylbenzothiophene, polyvinylanthracene, polyvinylacridine, polyvinylpyrazoline, etc.

Among low-molecular compounds, fluorene, fluorenone, 2
．． 7-sinitro 9-fluorenone, 2,4.7-dolinitro 9-fluorenone, 4H-indeno(1,2,
6) Thiophen-4-one, 3,7-sinitrodibenzothiophene-5-oxide, 1-bromopyrene, 2
-Phenylpyrene, carbazole, 3-phenylcarbazole, 2-phenylindole, 2-phenylnaphthalene, oxadiazole, tri'rzole, 1-phenyl-3-(4-diethylaminostyryl)-5-(4-
diethylaminophenyl) hyazoline, 2-phenyl-
It can be used in combination with 4-(4-diethylaminophenyl)-5-phenyloxazole, triphenylamine, imidazole, chrysene, tetraphen, acridine, derivatives thereof, and the like.

The blending ratio of other charge transporting substances is preferably 1 part by weight or less per 1 part by weight of the oxazole derivative represented by the general formula (1) so as not to impair the improvement in electrophotographic properties. Particularly preferred is 0.25 parts by weight or less.

The electrophotographic photoreceptor according to the present invention can be constructed by forming a single layer containing a mixture of a charge transport material and a charge generation material as a photoconductor layer on a conductive support.

It is also possible to form the charge-generating material and the charge-transporting material as separate layers 5-- so that a so-called two-layer structure is constructed as a photoconductor layer on one of the conductive supports.

The above charge generating substances include Sin Se, As*S
s.

Sb*Ss, Sb*Ses, ccts, CdSe
, CdTe, ZnO.

Metal phthalocyanine pigments such as α-type, β-type, etc. thermometal phthalocyanine a materials, m-phthalocyanine, aluminum phthalocyanine, zinc phthalocyanine, cobalt phthalocyanine, etc., and azo pigments.

Examples include anthraquinone pigments, indigoid pigments, quinacridone pigments, perylene pigments, polycyclic quinone pigments, and methine squaric acid pigments. Examples of pigments include 9,
Japanese Patent Publication No. 47-37453 Publication N, % Publication No. 47-3754
4 Publication, 'Pii Publication No. 18543, Japanese Patent Publication No. 47-18544, Japanese Patent Publication No. 48-43942
Publication No. 1987-70538 1% Publication No. 1987-
1231, JP 49-105536, JP 50-75214, JP 50-92738
There are some that are disclosed in the No. 1 gazette, etc.

Known additives such as binders, plasticizers, flow agents, pinhole inhibitors, etc. can be used in the photoconductor layer. As a binder, linear saturated polyester resin, polycarbonate resin, acrylic resin, butyral resin, polyketone resin, polyurethane resin, poly-N-
, vinylcarbazole.

v-<p-vinylphenyl)anthracene, silicone resin, polyamide resin, epoxy resin.

Selected from polystyrene resin, etc.

Furthermore, thermosetting and photocuring resins that are crosslinked by heat and/or light can also be used. In any case, there are no particular limitations as long as the resin is insulative and has film-forming ability in a normal state, and/or resin that can be cured by light to form a film. Examples of the plasticizer include halogenated paraffin, dimethylnaphthalene, and dibutyl phthalate. Examples of the fluidity imparting agent include Modaflow (manufactured by Monsanto Chemical Company) and Acronal 4F (manufactured by Basf Company), and examples of the pinhole suppressing agent include benzoin and dimethyl tereclate. These may be selected and used as appropriate, and the amount thereof may be determined as appropriate.

When a single layer structure is adopted, the amount of the charge transporting material to be mixed with respect to the charge generating material is 1 part by weight of the former.

The latter amount is generally 1 to 10 parts by weight. Preferably the former 1
The latter is 1 to 5 parts per part by weight. The amount of binder used is 91 to 3 parts by weight per 1 part by weight of the charge generating material, and if it exceeds 3 parts by weight, the electrophotographic properties deteriorate. In addition, the above-mentioned plasticizers and additives are appropriately used in amounts of several weights or less relative to the charge generating substance. Further, the total thickness of the photoconductor layer is generally 5 to 100 μm. However, in the end, it is desirable to make a decision so as not to impair photosensitivity, that is, charging characteristics.

On the other hand, when adopting a two-layer structure, the charge generation layer includes the above-mentioned Si,
In the case of Se, when using it as a conductive charge-generating substance in a vacuum evaporation method, etc., it is necessary to use the above-mentioned binder to form a film, and the amount used is 1 part by weight of the charge-generating substance. The amount is 1 to 3 parts by weight, and if it exceeds 3 parts by weight, the electrophotographic properties will deteriorate. In addition, the above plasticizers and additives are:
It is suitably used in an amount of several f't% or less relative to the charge generating substance. In addition, when the charge transport layer uses an oxazole derivative represented by the general formula (summer) alone as a charge transport substance, the above-mentioned binder may be added in an amount of 1 to 1 part by weight per part by weight of the charge transport substance.
It is common to use 3 parts by weight. Also.

When using other charge transport substances in combination, if the charge transport substance is a polymer compound, it is not necessary to use a binder, but
The binder may be used in an amount of 3 parts or less per 1 part by weight of the polymer compound ¥/J. If it exceeds 3 parts by weight, electrophotographic properties will deteriorate. When a low molecular compound is used as the charge transporting substance, the binder is used in an amount of 0.3 to 3 parts by weight per 1 part by weight of the oxazole derivative of general formula +11 and the low molecular compound. If it is less than 0.3 parts by weight, it will be difficult to form a charge transport layer, and if it exceeds 3 parts by weight, the electrophotographic properties will deteriorate. The above-mentioned plasticizers and additives are appropriately used in an amount of 0.05 parts by weight or less per 1 part by weight of the above-mentioned charge transporting substance. The thickness of the charge generation layer is 0.01 to 1
0 μm, preferably 0.2 to 5 μm. If it is less than 0.01 μm, it will be difficult to uniformly form a charge generation layer, and if it exceeds 10 μm, the electrophotographic properties will deteriorate. In addition, the thickness of the charge transport layer is 5 to 50μ
m, preferably 8 to 25 μm.

If it is less than 5 μm, the initial potential will decrease, and if it exceeds 50 μm, the sensitivity will decrease.

However, in any case, it is desirable that the final determination be made with consideration given to not impairing the photosensitivity, that is, the charging characteristics. If the thickness of the photoconductive layer is too thick, there is a risk that the flexibility of the layer itself will decrease, so care must be taken.

When the electrophotographic photoreceptor of the present invention has a two-layer structure having a charge generation layer and a charge transport layer, the charge generation layer is formed on a conductive support, and the charge transport layer is formed thereon. , although it is suitable for electrophotographic characteristics.

The charge generation layer and charge transport layer may be reversed.

Aluminum, brass, copper for conductive supports.

Gold is used.

To form two layers consisting of 10-, the components of each layer are acetone,
After dispersing it in a chthonic solvent such as methyl ethyl ketone, it can be applied and dried on a conductive support. Of these, after the charge generation layer or the charge transport layer is formed, the charge transport layer or the charge generation layer can be similarly applied thereon and dried to form a two-layer structure.

For coating and drying, the coating is applied to a predetermined thickness using, for example, a doctor blade, and then air-dried for 15 minutes.

This can be done by drying at 80 to 110°C for 40 minutes.

The electrophotographic photoreceptor according to the present invention may further have a thin adhesive layer or barrier layer immediately above the conductive support. Further, a protective layer such as silicon can be provided on one surface.

The copying method using the electrophotographic photoreceptor according to the present invention is similar to the conventional method, in which the 9 surface is charged and exposed, and then developed.
All that is required is to transfer the image onto the paper and fix it.

The electrophotographic photoreceptor of the present invention has excellent advantages such as high sensitivity, low dark decay, and little optical fatigue.

As the oxazole derivative represented by general formula (I), 2-<4-diglopylaminophenyl)-4-(4-
dimethylaminophenyl)-5-(2-fluorophenyl)-i,a-oxazole, 2-(4-diethylaminophenyl)-4-(4-dimethylaminophenyl)-
5-(2-fluorophenyl)-1,3-oxazole, 2-(4-dimethylaminophenyl)-4-(4-
dimethylaminophenyl)-5-(2-fluorophenyl)-1,3-oxazole, 2-(4-diglopylaminophenyl)-4-(4-diethylaminophenyl)
-5-(2-fluorophenyl) -1,3-oxazole, 2-(4-diethylaminophenyl) -4-(
4-ethylaminophenyl-5-(2-fluorophenyl)-t,a-oxazole.

2-(4-dimethylaminophenyl)-4-(4-diethylaminophenyl)-5-(2-fluorophenyl)-1,3-oxazole, 2-(4-dimethylaminophenyl)-4-(4- diglopylaminophenyl)-
Examples include 5-(2-fluorophenyl)-1,3-oxazole.

The oxazole derivative represented by general formula (1) is.

H (wherein R1 and R: represent an alkyl group such as a methyl group, ethyl group, or propyl group, and these may be the same or different), and a compound represented by the general formula (
Bl (However, in formula 1, Rs and R4 represent an alkyl group such as a methyl group, an ethyl group, a propyl group, and these may be the same or different). =13-ru.

Compounds represented by the formula (Al) include 1 mole each of 4-dimethylaminebenzaldehyde, 2-fluorobenzaldehyde and KCN.

It can be produced by adding it to a 50% aqueous ethanol solution in a ratio of 1 mol and 0.1 to 1.5 mol and heating under reflux for 1.5 to 4 hours.

The compound represented by the general formula (Bl) can be synthesized, for example, by the reaction route represented by the following formula. That is, 1 mole of aniline and the general formula (C) (RO)s PO(C) (wherein R represents an alkyl group such as a methyl group, an ethyl group, or a propyl group, and the three R's may be the same or different. Dialkylaniline (
ζ Here, the alkyl group includes methyl, ethyl group, propyl group, etc. (same below) is obtained. Subsequently, 0.3 dialkylaniline was added to 1 mol of N,N-dimethylformamide.
~0.4 mol was added dropwise at 19~22°C, @90°C after the bottom was finished.
The mixture was reacted at ~9514°C for 2 hours and distilled under reduced pressure to obtain dialkylaminobenzaldehyde. Hydroxyamine hydrochloride 1.0 to 1.3 per mole of dialkylaminobenzaldehyde
The moles were allowed to react for 20 minutes at room temperature.

The reaction solution is left in the refrigerator to precipitate dialkylaminobenzaldehyde oxime. Finally, 2 to 3 moles of acetic anhydride are heated under reflux for 20 minutes per mole of dialkylaminobenzaldehyde oxime to cause a dehydration reaction, thereby producing a compound represented by the general formula (Bl).

In the above, in order to produce dialkylaminobenzonitrile from dialkylaminobenzaldehyde, it can also be carried out by a route between the following formulas.

That is, 1.15 mol of NHsOH-HCl, HCOO for 1 mol of dialkylaminobenzaldehyde.
A large excess of Na and 1500 cc of formic acid are mixed and reacted under reflux for 1 hour, and then the reaction solution is immediately added to water to precipitate dialkylaminobenzonitrile. This precipitate may be recrystallized with water.

(G) The compound represented by the general formula +11 can be obtained by dissolving the compound represented by the general formula (2) and the general formula (Bl) in concentrated sulfuric acid.

It can be obtained by reacting in the dark. The reaction temperature is 20
~70°C is preferred. When the reaction temperature is set to 50 to 70°C, the reaction is completed in 0.5 to 2 hours.

The reaction product is purified by recrystallization with methanol, and when the metal is added alone to concentrated sulfuric acid, the general formula (B) is obtained.
It undergoes a dehydration reaction before reacting with the compound represented by.

Examples of the present invention are shown below.

Examples 1 to 3 α-type metal-free phthalocyanine (BASF ■ trade name Hel
1 part by weight of iogen Blue 7560) and silicone resin (Shin-Etsu Chemical Co., Ltd. trade name, KR255)6.
7 parts by weight was made into a solution of 5 parts by weight using tetrahydrofuran as a solvent, and a ball mill (Nippon Kagaku Togyo Co., Ltd. 3) was prepared.
The mixture was kneaded for 5 hours using a small-sized bot mill. The obtained pigment dispersion was applied onto a sialuminum plate (conductor) using an applicator and dried at 90° C. for 40 minutes to form a charge generation layer with a thickness of 1 μm.

Next, 1 part by weight of the oxazole derivative shown in Table 1 below and a polyester resin (Toyobo ■ trade name).

2.4 parts by weight of Vylon 200) and 0.6 parts by weight of styrene resin (manufactured by Esso i, Picotex 100) were made into a 27% by weight solution using tetrahydrofuran as a solvent, and applied onto the charge generation layer using an applicator. 4 at 90℃ after coating
After drying for 0 minutes, a charge transport layer having a thickness of 3017 μm was formed to obtain an electrophotographic photoreceptor.

Regarding the electrophotographic photoreceptor produced in this way.

Electrostatic recording paper testing device (Kawaguchi Electric ■Product name 5P-428)
The electrophotographic properties were measured using In this case, negative 5KV
Charging is performed by corona discharge for 10 seconds (the initial potential is the surface potential immediately after charging for 10 seconds), and after being left in a dark place for 30 seconds (the surface potential at this time is expressed as Vso, Vso/■ .×100 is the dark decay (chi)),
Expose one surface to 2 lux using a tungsten lamp, record the attenuation of the surface potential and the time, and calculate N'm.
Time t (seconds) and illuminance (lux) until O becomes 1/2
Sensitivity is the product of (Half exposure amount Eso * Lux seconds)
expressed. These results are shown in Table 1 below.

Examples 4 to 6 1 part by weight of β-type copper phthalocyanine (manufactured by Dainippon Ink Co., Ltd., Cyanine Blue LC) and silicone resin (Shin-Etsu Chemical Co., Ltd.)
6.7 parts by weight of (trade name, l1255) was made into a 5% by weight solution using tetrahydrofuran as a solvent.
The resulting dispersion was applied and dried in the same manner as in Examples 1 to 3 to form a charge generation layer with a thickness of 1 μm.

Next, the oxazole derivative type 1 moving part and polyester resin (Toyobo ■ trade name) shown in the second group below.

A 27% by weight solution of 2.4 parts by weight of Vylon 200) and 0.6 parts by weight of styrene resin (manufactured by Esso, Picotex 100) in tetrahydrofuran as a solvent was applied onto the charge generation layer using an applicator. 4 at 90℃
It was dried for 0 minutes to form a charge transport layer with a thickness of 15 μm, thereby obtaining an electrophotographic photoreceptor.

The characteristics of the electrophotographic photoreceptor thus prepared were measured in the same manner as in Examples 1 to 3, and the results are shown in Table 2.

Margins below 10-21- Note that the above compounds (V), (■ and (capital)) were produced as follows.

Production Example 1 (Production of 4-dimethylamino/-2'-fluorobenzoin) 14.99 of dimethylaminobenzaldehyde, 12.49 of 2-fluorobenzaldehyde and 8.0 g of potassium cyanide were dissolved in 150 ml of a 50% titanol solution. It was heated under reflux for 30 minutes. After heating under reflux, it was allowed to cool and the precipitated pale yellow crystals were filtered and dried at 80°C. The crystals were recrystallized with 500 ml of methanol to give a melting point of 168-170°C.
4-dimethylamino-2'-fluorobenzoin (yield 45%) was obtained.

Production Example 2 [Production of 4-dibutetrabylaminobenzonitrile] A-'
7,762 g and 100 g of "-propyl phosphate were heated under reflux for 2 hours and then allowed to cool. When the solution temperature fell to 55-60°C, a sodium hydroxide aqueous solution (56.3 g/
225 m/ was added and heated under reflux for 1 hour. Immediately after heating and refluxing, the reaction solution 22- was transferred to an x-1 beaker and left to stand. The reaction solution was separated into two layers, the upper layer was yellow and the lower layer was a white solid. The white solid was extracted three times with 100ml of ether, and the upper layer and extract were dried over anhydrous sodium sulfate. After distilling off the ether,
The same volume of acetic anhydride was added and left overnight. Add a hydrochloric acid aqueous solution (45 ml!/67, 5 ml) to the reaction solution and leave to cool.
When a 25% sodium hydroxide solution was added, the mixture was separated into an oil layer and an aqueous layer. The water layer is 100m1 of ether! The extract was extracted three times and dried together with the oil layer over anhydrous sodium sulfate. Distillation under reduced pressure (b, pxao~140℃/
Dipropylaniline (yield 69%) was obtained.

Next, N,N-dimethylformamide 549 was kept at 20° C. or lower, and phosphorus oxychloride 44.59 was added dropwise over 30 minutes.

The dipropylaniline obtained above was added dropwise over 1 hour. After the dropwise addition was completed, the mixture was heated and stirred at 90 to 95°C for 2 hours. Thereafter, one reaction solution was added to ice water and neutralized with saturated sodium acetate solution. It was extracted five times with 100 ml of ether and dried over anhydrous sodium sulfate.

After distilling off the ether, vacuum distillation (b, 1) 155-163
'C/3 mmHg) L, dipropylaminobenzaldehyde (yield: 46 cm) was obtained.

This dipropylaminobenzaldehyde 11.69
5-chitanol 23mI! A hydroxyamine hydrochloride aqueous solution (4.7 g/5.7 ml) was added thereto and stirred for 20 minutes. An aqueous sodium hydroxide solution (3.4 g/4.5 rnl) was added to the reaction mixture, and the mixture was left at room temperature for 2 hours and 30 minutes. Add ice 29B and CO! After purging with gas, it was left in a refrigerator overnight. The precipitated white crystals were suction filtered, washed with water, and then dried.

12.4 parts of acetic anhydride was added to the obtained compound, and the mixture was heated under reflux for 20 minutes. Thereafter, the reaction solution was added to 35 ml of cold water and neutralized with sodium hydroxide solution. Ether 4omI!
The extract was dried with anhydrous sulfuric acid and IJum. Ether distillation Takashi vacuum distillation (b, p180℃/4m
mHg) to obtain 4-dipropylaminobenzonitrile (yield 79%). When this was left to stand, it crystallized to become yellow crystals with a melting point of 39-41°C.

Production Example 3 [Production of 4-dimethylaminobenzonitrile] Production Example 2
Diethylaminobenzaldehyde synthesized according to the procedure of 29.89. Hydroxyamine hydrochloride 15.99. 259 m/s of sodium formate and 333 m/s of formic acid were heated under reflux for 1 hour. The reaction solution was 800ml of water! When the mixture was added dropwise with stirring, pale green crystals were precipitated. The mixture was filtered and dried, and recrystallized from acetone to obtain 4-dimethylaminobenzonitrile (yield: 509K) having a melting point of 67 to 69°C.

Production Example 4 [Production of 4-diethylaminobenzonitrile] Production Example 2
25 g of diethylaminobenzaldehyde synthesized according to the procedure of 10.59 g of hydroxyamine hydrochloride. 16.59 m/s of sodium formate and 220 m/s of formic acid were heated under reflux for 1 hour. Add the reaction solution to 400ml of water! When added to the solution with stirring, white crystals precipitated. The product was filtered, dried, and recrystallized from water-acetone to obtain 4-diethylaminobenzonitrile (yield: 50°C) with a melting point of 25-66°C to 67°C.

Production Example 5 [Production of compound] Maintain concentrated sulfuric acid 359 at 60°C in a dark place, and add Production Example 1 to it.
A mixture of 2.4 g of 4-dimethylamino-2'-fluorobenzoin obtained in Example 2 and 2.1 g of 4-dipropylaminobenzonitrile obtained in Production Example 2 was added and stirred for 1 hour. The reaction solution was 900ml of water! When added to the solution, a yellow-green precipitate was deposited.

When the filtrate was made alkaline with 3N sodium hydroxide solution, pale yellow crystals were precipitated. This was suction filtered and air-dried. Recrystallized from methanol to give 1.73g of pale yellow solid.
(yield: 43 cm). This pale yellow solid is 92-(4-dimethylaminophenyl)-4-(
It was confirmed that it was 4-dimethylaminophenyl)-5-(2-fluorophenyl)-1,3-oxazole (compound ①).

(1) Melting point; 134-135°C (2) Elemental analysis value: C story Hs*N*OF26- CHN calculated value (profitability 76.15 7.00 9.19 actual value (
%) 76.07 7.11 9.15 Production Example 6 [Production of compound fVI)] Concentrated sulfuric acid 359 was kept at 60°C in a dark place, and Production Example 1 was added to it.
A mixture of 2.492 g of 4-dimethylamino-2'-fluorobenzoin obtained in Production Example 3 and 1.5 g of 4-dimethylaminobenzonitrile obtained in Production Example 3 was added and stirred for 30 minutes. When the reaction solution was added to water ooOm/, a yellow-green precipitate was deposited. When the filtered solution was made alkaline with 3N sodium hydroxide solution, pale yellow crystals were precipitated. This was suction filtered and air-dried. Recrystallization from methanol gave a pale yellow solid 1.56 (yield 44%). This pale yellow solid has the following analysis results!
It was confirmed that it was +2-(4-dimethylaminophenyl)-4=(4-dimethylaminophenyl)-5-(2-fluorophenyl)-1,3 oxazole (chemical formula i17■).

(1) Melting point; 172 to 173°C (2) Elemental analysis value: Calculated value (q6) 74.79 6.03 10.47 Actual value (chi) 74.53 6.04 10.47 Production Example 7 [Production of compound (material)] Concentrated sulfuric acid 329 was maintained at 60°C in a dark place, and Production Example 1 was added to it.
2.29 g of 4-diethylamino-2'-fluorobe/zoin obtained in Example 4 and 4-diethylaminophenyl obtained in Production Example 4 were stirred for 1 hour. The reaction solution was 800ml of water! When added to the solution, a yellow-green precipitate was deposited. When the filtered solution was made alkaline with 3N sodium hydroxide solution, pale yellow crystals were precipitated. This was suction filtered and air-dried. Recrystallization from methanol gave a pale yellow solid of 1.399 g (yield: 40 g). According to the analysis results below, this pale yellow solid is 2-(4-diethylaminophenyl)-4-(4-dimethylaminophenyl)-
It was confirmed that it was 5-(2-fluorophenyl)-1,3-oxazole (compound X).

(1) Melting point: 102-105°C (2) Elemental analysis value: Calculated value (Chill 75.35 6.51 9.77 Actual value (Chill 75.25 6.53 9.72 conducted) Examples 1-3
The oxazole derivative ((V) used in

(Vl) and (capital)] and 2-(4-diethylaminophenyl)-4-(4-dimethylaminophenyl)-5-(2-chlorophenyl)-1,3- as a conventionally used oxazole derivative for comparison. A test of the stability of oxazole (II) against ultraviolet irradiation was conducted as follows.

Nitrogen gas was bubbled through an acetonitrile solution prepared by separately dissolving the compounds CVil, (capital) and (III) at a concentration of 2 x 10-'mat/l for 1 hour, and then nitrogen gas was bubbled through the solution. Irradiate with a 150W high-pressure mercury lamp. Samples are taken at 5 minute intervals after the start of irradiation, diluted at a constant rate with an acetonitrile solution, and then changes in the absorption spectrum are examined using an ultraviolet spectrophotometer.

Compounds used for comparison (ml = 2 after 5 minutes of mercury lamp irradiation)
9- is the initial absorption spectrum (λmax = 363.on
mg=4.8X l O' I! /mo/-cm, 3
Absorption spectrum different from 10nm 5holder (λmax=37Q, Q nm258, Onm,
245. Onm). The latter absorption spectrum is due to 2-(4-diethylaminophenyl)-6-dimethylaminone enanthro(9,1O-d)oxazole produced by decomposition of the compound (full).

The decomposition rate of Compound (1) used for comparison was determined from the absorbance measurement at 258.9 nm, which appears due to the decomposition of the absorption spectrum at each time point, using the Lambert-Beer O method to determine the concentration of decomposed products produced.

Between the charge carrier chambers used in the electrophotographic photoreceptor of the present invention, (
V) and (2) show that even after 60 minutes of irradiation, the initial state (D
X vector (V: λmaX = 363.0 nm
tt=40gXI O'l! /mol! @cm, 31
0. Onm 5holder: ■:λmax+w
359. Onm g =4.5X 10'l/mat
@ ni H, 31 (l Q nm 5holder:
■: λmax-363, Onm s =4.5
X 10'1 Anol・an, 310. Onm 5
holder) and absorption spectrum pattern is 30
- No change. The decomposition rate of these compounds is determined by the absorbance at 310.0 nm of the absorption spectrum at each time (Asla
o) and the absorbance of λmax (Aλmax) (Asl
o, o/Aλmax).

Figure 1 shows the time-dependent changes in the photodecomposition rate of acetonitrile solutions of compounds (V), (VIA, (capital) and ([1) by irradiation with high-pressure mercury lamps.
Curve 2 shows the decomposition rate of compound (■).

Curve 3 shows the decomposition rate of compound (to) and curve 4 shows the decomposition rate of compound (II).

As is clear from the above, the electrophotographic photoreceptor according to the present invention is stable against ultraviolet irradiation and has good electrophotographic properties.

[Brief explanation of drawings]

Figure 1 shows the relationship between the compounds (■l, (4) and (Iff+
This is the change over time in the decomposition rate of an acetonyl solution when irradiated with a high-pressure mercury lamp. Explanation of symbols 1... Curve 2 showing the decomposition rate of the oxazole-induced fallow used in Example 1... Curve 3 showing the decomposition rate of the oxazole derivative (■) used in Example 2... Curve 4 showing the decomposition rate of the oxazole derivative (4) used...Curve showing the decomposition rate of the oxazole derivative (I[Il) used for comparison

Claims (1)

[Claims] 1. An electron compound containing an oxazole derivative represented by the general formula (,1) (wherein R1+RIR4 and R4 represent an alkyl group, and may be the same or different) Photographic photoreceptor. 2. The electrophotographic photoreceptor according to claim 1, which comprises a charge-generating substance and a charge-transporting substance on a conductive support, and the charge-transporting substance is an oxazole derivative represented by the above general formula m. 3. The electrophotographic photoreceptor according to claim 2, wherein the charge generating material and the charge transporting material are each contained in separate layers.