JPH0469947B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an electrophotographic photoreceptor, and more specifically, in an electrophotographic photoreceptor in which a charge generation layer and a charge transport layer are provided on a conductive support, the following general charge transport layer is used as the charge transport layer. formula(), [In the formula, R is hydrogen, a lower alkyl group, a lower alkoxy group, and Ar is a group

[Formula] (where R ₁ and R ₂ represent a lower alkyl group, phenyl group or benzyl group, and R ₄ represents a lower alkyl group)
or group

[Conventional technology]

In recent years, inorganic photoconductive substances that are widely known as electrophotographic photosensitive materials include selenium and cadmium sulfide, and organic photoconductive substances such as poly-N-vinylcarbazole, Various substances including polyvinylanthracene have been proposed. Among these, poly-N-vinylcarbazole is
Although it is possible to form a film by itself, it has the drawbacks of low flexibility and poor durability as an electrophotographic photoreceptor. Therefore, it has been proposed to use plasticizers to increase flexibility, but while plasticizers improve flexibility, they have the disadvantage of reducing electrophotographic properties such as sensitivity and residual potential. It will appear. On the other hand, in addition to electrophotographic methods that use these materials, methods are gaining popularity in which the two functions of photoconductive materials, namely the generation of charge carriers and the transport of the generated charges, are performed using separate organic compounds. (For example, "Recording Materials Manual," Chapter 2, Photosensitive Materials, published by Triceps Publishing).
This method is known to yield high sensitivity because a wide range of compounds can be selected that are optimal for each of the two functions of charge carrier generation and charge transport. In this method, it is necessary to sequentially stack a compound that generates a charge, ie, a charge generating substance, and a compound that transports the generated charge, ie, a charge transport substance, on the conductive support. In many cases, the compounds used in the charge transport layer are low-molecular organic compounds and do not have film-forming ability. Therefore, a film must be formed using a polymer binder such as polyester resin, polyvinyl chloride resin, methacrylic resin, or polycarbonate resin. In order to rapidly transport the charge carriers generated in the charge generation layer, the charge transport layer must be uniform. Here, the solubility of the charge transport substance in the binder becomes a problem. For those with low solubility, they are dispersed in a binder as fine powder, but in this case it is difficult to obtain a uniform film, and even if dissolved, crystals may precipitate over time. This often significantly reduces electrophotographic performance. In addition, when a conventional electrophotographic photoreceptor having a functionally separated type photosensitive layer is repeatedly used in an electrophotographic process, the ability to recover the original charging characteristics decreases, shortening the life of the photoreceptor. have. In other words, if the practical processes of electrophotography, such as charging, dark decay, light decay, and cleaning, are repeated many times, one or two of the following problems may occur: surface charge fluctuations after charging, a decrease in charge retention ability, and an increase in residual potential. The above-mentioned optical fatigue phenomenon occurs and significantly deteriorates the performance of electrophotography, posing a serious problem in practical use. Recently, in order to solve the above problem, research has been carried out using indoline compounds as photoreceptors, and the results are published, for example, in JP-A-58-166354 and JP-A-60-
No. 143352 and JP-A-59-62861. [Problems to be solved by the invention] However, the indoline compounds reported above are still not fully satisfactory. Therefore, they have excellent solubility in polymer binders, high sensitivity, and low residual potential. There has been a demand for an indoline compound for electrophotographic photoreceptors that has low optical fatigue and excellent durability even after repeated use in an electrophotographic process. [Means for Solving the Problems] In order to solve the above problems, the present inventors conducted extensive research focusing on N-aminoindoline derivatives as charge transport materials, and found that certain indoline derivatives are suitable for electrophotography. The present inventors have discovered that the present invention satisfies the various requirements for the invention and have completed the present invention. That is, the present invention uses the N-amino-2,3,3-trimethylindoline derivative represented by the formula (), which has good solubility in a polymeric binder and excellent electrophotographic properties, for charge transporting. The object of the present invention is to provide an electrophotographic photoreceptor containing the present invention as a substance. The N-amino-2,3,3-trimethylindoline derivative () of the present invention can be obtained by, for example, obtaining free hydrazine () from 4-substituted phenylhydrazine hydrochloride according to the following reaction formula, and converting this hydrazine into methyl isopropyl ketone ( ) in benzene and azeotropic dehydration to give hydrazone (), which was then refluxed in acetic acid and cyclized to give substituted 2,3,3-trimethylindolenine (), which was purified with hydrogen in alcohol. This indoline was reduced with sodium boronate to obtain indoline (), which was further reacted with sodium nitrite in acetic acid to nitrosate, and then reduced with Vitride (Hani Chemical Co., Ltd.) to obtain N-
It is prepared by obtaining amino-2,3,3-trimethylindoline () and condensing it with an aromatic aldehyde (). (In the formula, R and Ar are the same as above) N- represented by the general formula () obtained in this way
All amino-2,3,3-trimethylindoline derivatives exhibit extremely excellent properties as organic photoconductors. Particularly when used as a charge transport material in an electrophotographic photoreceptor, it has excellent solubility in a polymer binder, and can provide a photoreceptor with high sensitivity and excellent durability. N-amino-2 represented by the general formula (),
Representative examples of 3,3-trimethylindoline derivatives are illustrated below. Next, a basic method for producing the electrophotographic photoreceptor of the present invention using the above-mentioned N-amino-2,3,3-trimethylindoline derivative () will be explained. The mode of use is not limited. A photoreceptor containing an indoline derivative (2) of the present invention includes a charge generation layer 3 mainly composed of a charge generation substance 2 and an indoline derivative (2) uniformly contained on a conductive support 1 shown in FIG. It has a photosensitive layer 5 made of a charge transport layer 4. Here, indonline derivative () is used as a charge transport substance,
A charge transport layer 4 is formed together with the binder. The light transmitted through the charge transport layer 4 reaches the charge generation substance 2 dispersed in the charge generation layer 3, and the charge generation substance 2 generates charges necessary for light attenuation. The charge transport layer 4 receives this charge injection and transports it. Here, it is a necessary condition that the absorption wavelength regions of the charge generating substance 2 and the indoline derivative (2) do not overlap each other, mainly in the visible region. This is because in order to efficiently generate charge carriers in the charge generation material 2, it is necessary to transmit light to the surface of the charge generation material. The indoline derivative () of the present invention has almost no absorption in the visible region, and is characterized in that it works particularly effectively as a charge transport material when combined with a charge transport material that generally absorbs light in the visible region and generates charge. . To produce the photoreceptor shown in FIG. 1, the charge generating substance 2 is vacuum-deposited on the conductive support 1, or fine particles of the charge generating substance 2 are deposited in a suitable solvent in which a binder is dissolved as necessary. After coating and drying the dispersion obtained by dispersing the indoline derivative in It is obtained by coating and drying a solution containing the agent.
Application can be done using conventional means, such as a doctor blade or Meyer bar. The thickness of the charge generation layer 3 is 5μ or less, preferably 2μ
The thickness of the charge transport layer 4 is 3 to 50 μm, preferably 5 to 20 μm. Further, the compound of the present invention () is blended in the charge transport layer 4 in an amount of 10 to 90% by weight, preferably 30 to 90% by weight. As the conductive support 1, a metal plate or foil made of aluminum or the like, a plastic film coated with a metal such as aluminum, or paper treated with electrical conductivity is used. As the binder, polyester resin, polyvinyl chloride resin, acrylic resin, methacrylic resin, polystyrene resin, polycarbonate resin, etc. are used, and among them, polycarbonate resin is preferred. As the charge generating substance 2, for example, inorganic materials such as selenium and cadmium sulfide, and CI pigment blue 25 (color index CI21180), CI
Pigment Red 41 (CI21200), CI Assisted Red 52 (CI45100), CI Basic Red (CI45210)
Azo pigments such as CI Pigment Blue 16
Phthalocyanine pigments such as (CI74100); Indigo pigments such as CI Butt Brown 5 (CI73410) and CI Butt Dyed (CI73030); Argo Scarlet R (manufactured by Bayer), Indance Scarlet R (manufactured by Bayer), etc. peryene pigments, and even chlorodiane blue, i.e. 4,
4'-[(3,3'-dichloro-4,4'-biphenylylene)bis(azo)]-bis-3-hydroxy-2-
naphthanilide, methylsquarium i.e. 2,
4-bis-(2-methyl-4-dimethyl-4-dimethylaminophenyl)-1,3-cyclobutadienediylium-1,3-diolate, hydroxysquarium i.e. 2,4-bis-(2-hydroxy -4-dimethylaminophenyl)-1,
Organic pigments such as 3-cyclobutadienediilium-1,3-diolate are used. [Example] Next, the present invention will be explained in detail using synthesis examples and examples. Synthesis Example 1 Synthesis of 2,3,3-trimethylindoline ((in the formula, R=H): 6.6 g of sodium borohydride was mixed with 200 g of methanol
ml, and 27 g of 2,3,3-trimethylindolenine ((in the formula, R=H) was added dropwise over 1 hour. The reaction temperature rose from room temperature to reflux temperature.
After the dropwise addition, the mixture was refluxed for 4 hours and checked using GC, which showed that 33% remained unreacted. sodium borohydride
After adding 2.3 g and reacting for 1 hour, 13% remained unreacted, so 2.6 g of sodium borohydride was further added and the reaction was continued for 1 hour before being terminated. The mixture was decomposed with 100 ml of 50% acetic acid water under cooling with ice water, neutralized with an aqueous solution of caustic soda, water was added, extracted with benzene, dried over anhydrous sodium carbonate, concentrated, and distilled. 22 g (theoretical yield: 80.4%) of the target compound having a boiling point of 88° C./4 mmHg was obtained. 400MHz NMR of this stuff
The spectrum (CDCl ₃ ) is as follows. δppm: 1.03 (3H, S), 1.16 (3H, d, J = 6.5
Hz), 1.27 (3H, S), 3.50 (1H, q, J = 6.5
Hz), 3.70 (1H, broad S), 6.59-6.61 (1H,
m), 6.71-6.75 (1H, m), 6.98-7.03 (2H,
m) Synthesis Example 2 Synthesis of 1-amino-2,3,3-trimethylindoline (() in the formula, R=H): Add 20 g of the compound obtained in Synthesis Example 1 above to 200 ml of acetic acid, and add nitrous acid at room temperature. 9 g of soda was added little by little over 30 minutes. Thereafter, the mixture was allowed to react for 4 hours, and after confirming disappearance of the raw material compound by TLC, the mixture was poured into water. Extraction with benzene, drying over magnesium sulfate, and concentration yielded 23.6 g of oil. Dissolve this oil in 200ml of benzene and use Vitride 36
This was added dropwise to g. The reaction temperature rose from room temperature to 60°C. After stirring for 4 hours,
Disappearance of the nitroso compound was confirmed by TLC. After pouring into a caustic soda aqueous solution and stirring for 30 minutes,
The layers were separated, and the aqueous layer was extracted with benzene. The benzene solution was dried over anhydrous sodium carbonate, concentrated, and then distilled to obtain 10.6 g (theoretical yield: 48.6%) of the target compound having a boiling point of 100° C./1 mmHg. 400MHz NMR of this stuff
The spectrum (CDCl ₃ ) is as follows. δppm: 1.02 (3H, S), 1.26 (3H, d, J = 6.5
Hz), 1.29 (3H, S), 2.79 (1H, q, J = 6.5
Hz), 3.39 (2H, broad S), 6.82-6.86 (2H,
m), 7.04-7.06 (1H, m), 7.13-7.17 (1H,
m) Synthesis Example 3 Synthesis of 4'-diethylaminobenzylidene-1-amino-2,3,3-trimethylindoline (Exemplary Compound-4) 1.77 g of diethylaminobenzaldehyde and 1.8 g of the compound obtained in Synthesis Example 2 were added to 20 ml of ethanol.
3 drops of acetic acid were added, and the mixture was stirred under reflux for 4 hours. After the reaction was completed, the solvent was distilled off under reduced pressure, and then
Applied to silica gel chromatography (solvent benzene),
3.2 g of oil was obtained. Add this with ethanol 2
The crystals were recrystallized several times to obtain 2.06 g of crystals (theoretical yield: 61.5%) with a melting point of 90 to 91°C. The IR spectrum (KBr) of this product is shown in Figure 2. Also of this
The 400MHz NMR spectrum ( _CDCl3 ) is as follows. δppm: 1.14 (3H, d, J = 6.4Hz), 1.19 (6H,
t, J = 7.1Hz), 1.27 (3H, S), 1.31 (3H,
S), 3.39 (4H, q, J = 7.1Hz), 3.99 (1H,
q, J = 6.4Hz), 6.68 (2H, d, J = 8.9Hz),
6.77~6.81 (1H, m), 7.05~7.07 (2H, m),
7.13-7.17 (1H, m), 7.56 (2H, d, J = 8.9
Hz), 7.62 (1H, S) Synthesis example 4 N'-ethyl-3'-carbazolylmethylidene-1
-Synthesis of amino-2,3,3-trimethylindonline (Exemplary compound-16): 2.23 g of N-ethyl-3-formylcarbazole
Then, 1.8 g of the compound obtained in Synthesis Example 2 was added to Synthesis Example 3.
The reaction and purification were carried out in the same manner as above to obtain 2.5 g of crystals (theoretical yield: 65.6%) with a melting point of 135°C. of this
The IR spectrum (KBr) is shown in Figure 3. The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.20 (3H, d, J = 6.4Hz), 1.30 (3H,
S), 1.36 (3H, S), 1.43 (3H, t, J = 7.2
Hz), 4.12 (1H, q, J = 6.4Hz), 4.36 (2H,
q, J=7.2Hz), 6.84 (1H, dd, J=3.0, 5.5
Hz), 7.09 (1H, d, J = 7.2Hz), 7.20-7.26
(3H, m), 7.38-7.40 (2H, m), 7.44-7.48
(1H, m) 7.82 (1H, S), 7.91 (1H, dd, J=
1.6, 8.6Hz), 8.14 (1H, d, J = 7.7Hz), 8.35
(1H, d, J = 1.4Hz) Synthesis Example 5 Synthesis of 4'-diphenylaminobenzylidene-1-amino-2,3,3-trimethylindoline (Example Compound-19): 2.73 g of diphenylaminobenzaldehyde and the above 1.8g of the compound obtained in Synthesis Example 2 was reacted and purified in the same manner as in Synthesis Example 3 to obtain crystals with a melting point of 123-4℃.
1.86 g (theoretical yield 43.1%) was obtained. IR of this thing
The spectrum (KBr) is shown in Figure 4. The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.14 (3H, d, J = 6.4Hz), 1.26 (3H,
S), 1.35 (3H, S), 4.07 (1H, q, J = 6.4
Hz), 6.81~6.8.2 (1H, m), 7.00~7.16 (11H,
m), 7.23-7.27 (4H, m), 7.51 (1H, S),
7.55 (2H, d, J = 8.7Hz) Synthesis Example 6 Synthesis of 4'-dibenzylamino-2'-methylbenzylidene-1-amino-2,3,3-trimethylindoline (Exemplary Compound-22): 4' -3.15 g of dibenzylamino-2-methylbenzaldehyde and the compound obtained in Synthesis Example 2 above
1.76 g was reacted and purified in the same manner as in Synthesis Example 3 to obtain 4.16 g of crystals (theoretical yield: 88%) with a melting point of 59°C. The IR spectrum (KBr) of this product is shown in Figure 5. The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.13 (3H, d, J = 6.4Hz), 1.27 (3H,
S), 1.31 (3H, S), 4.00 (1H, q, J = 6.4
Hz), 4.15 (4H, S), 6.56 (1H, d, J = 2.6
Hz), 6.65 (1H, dd, J=2.6, 8.7Hz), 6.79
(1H, d, J=7.3Hz), 7.02~7.06 (2H, m),
7.11~7.13 (1H, m), 7.21~7.26 (6H, m),
7.30-7.34 (4H, m), 7.71 (1H, d, J = 8.7
Hz), 7.78 (1H, S) Synthesis Example 7 Synthesis of methyl isopropyl ketone tolylhydrazone ((in the formula, R = methyl): Under a nitrogen stream, 37.4 g (0.307 mol) of 4-methylphenylhydrazine was placed in a reaction flask, Methyl isopropyl ketone 52.76g (0.64mol), special grade benzene
Add 153ml and 2 drops of acetic acid, react at 73~85℃ for 4.5 hours, and then distill under reduced pressure to obtain a boiling point of 95~103℃/
55 g (theoretical yield: 94.4%) of the target compound was obtained at 0.37 mmHg. The 6th IR spectrum (KBr) of this
Shown in the figure. Synthesis Example 8 Synthesis of 2,3,3,5-tetramethylindolenine ((in the formula), R=methyl): Tolylhydrazone of methyl isopropyl ketone
55 g was dissolved in 550 ml of acetic acid (special grade) and reacted for 3 hours under reflux at 117° C. under a nitrogen stream. After confirming the disappearance of hydrazone with GC,
Acetic acid was collected under reduced pressure. Remaining 5% baking soda water 1000ml
ml and extracted with 300 ml of benzene. The benzene layer was washed with water three times, dried with soda carbonate, and concentrated to obtain 47.5 g of oil. The product was rectified under reduced pressure to obtain 41.1 g (theoretical yield: 82%) of the target compound having a boiling point of 85° C./4 mmHg. 400MHz of this stuff
The NMR spectrum (CDCl ₃ ) is as follows. δppm: 1.27 (6H, S), 2.25 (3H, S), 2.38 (3H,
S), 7.08 (1H, S), 7.10 (1H, d, J = 7.6
Hz), 7.41 (1H, d, J = 7.6Hz) Synthesis Example 9 Synthesis of 2,3,3,5-tetramethylindoline ((in the formula), R = methyl) Add 270 ml of special grade methanol and potassium hydroxide to a reaction flask. (Granular) Dissolve 2 grains, NaBH ₄ 27.5
g was dissolved, and 42.4 g of 2,3,3,5-tetramethylindolenine was added dropwise at room temperature over 40 minutes. After stirring overnight at room temperature, for 2 hours, 54-64
The mixture was heated and stirred at ℃. After confirming that unreacted substances have disappeared,
Cooled. A mixture of 64 ml of acetic acid and 64 ml of water was added dropwise at 25°C, and the mixture was stirred at 54-64°C for 2 hours. After cooling, this was poured into ice water containing 46 g of sodium hydroxide, and extracted with benzene. The benzene solution was filtered through Celite, washed with water, dried, and concentrated to give 34 g.
of oil was obtained. This oil is distilled under reduced pressure and has a boiling point of 90℃/3mm.
32.1 g of the target Hg compound (theoretical yield 78.5%) was obtained. The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.02 (3H, S), 1.17 (3H, d, J = 6.5
Hz), 1.26 (3H, S), 2.26 (3H, S), 3.48 (1H,
q, J=6.5Hz), 3.62 (1H, broad S), 6.53
(1H, d, J = 7.7Hz), 6.81-6.85 (2H, m) Synthesis example 10 Synthesis of 1-amino-2,3,3,5-tetramethylindoline ((in the formula, R = methyl): Add 2,3,3,5-tetramethylindoline to 200ml of acetic acid and add 10.5g of sodium nitrite at room temperature.
was added little by little, and stirring was continued at room temperature for 4 hours. After the reaction was completed, the mixture was poured into water and extracted with benzene. The Bengen layer was washed with water, sodium bicarbonate, water, and dried. This benzene solution was added dropwise to 66.5 g of vitride while stirring in a nitrogen stream (room temperature to 60°C). After that, stir for 4 hours and add caustic soda.
It was poured into 11g/500ml of water and hydrolyzed. After separation,
Extract the aqueous layer with benzene, wash the benzene layer with water,
After drying, it was concentrated to obtain 24 g of the target compound. Recrystallized from ligroin, white needle-like crystals with a melting point of 67℃
15.7g (theoretical yield 63.4%) was obtained. of this
The 400MHz NMR spectrum ( _CDCl3 ) is as follows. δppm: 1.01 (3H, S), 1.24 (3H, d, J = 6.5
Hz), 1.27 (3H, S), 2.28 (3H, S), 2.72 (1H,
q, J = 6.5 = Hz), 3.30 (2H, broad S), 6.73
(1H, d, J=7.8Hz), 6.86 (1H, S) Synthesis example 11 N'-ethyl-3'-carbazolylmethylidene-1
-Synthesis of amino-2,3,3,5-tetramethylindoline (Exemplary compound-17) 1.9 g of 1-amino-2,3,3,5-tetramethylindoline and N-ethylcarbazole-3-
2.23 g of carbaldehyde was added to 20 ml of ethanol, 2 drops of acetic acid were added, and the mixture was stirred under reflux for 2 hours.
Thereafter, it was cooled to room temperature and the formed crystals were filtered and collected. This was recrystallized from acetonitrile,
3.44 g (theoretical yield: 87.1%) of crystals with a melting point of 169°C were obtained. The IR spectrum (KBr) of this product is shown in Figure 7. The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.19 (3H, d, J = 6.4Hz), 1.29 (3H,
S), 1.33 (3H, S), 1.41 (3H, t, J = 7.2
Hz), 2.31 (3H, S), 4.08 (1H, q, J = 6.4
Hz), 4.32 (2H, q, J = 7.2Hz), 6.90 (1H,
S), 7.01 (1H, d, J = 7.9Hz), 7.11 (1H,
d, J = 7.9Hz), 7.23 (1H, t, J = 7.9Hz),
7.35-7.38 (2H, m), 7.45 (1H, dd, J=7.1,
8.2Hz), 7.79 (1H, S), 7.90 (1H, dd, J=
8.5, 1.5Hz), 8.12 (1H, d, J = 7.8Hz), 8.33
(1H, d, J = 1.5Hz) Synthesis Example 12 Synthesis of 4'-diphenylaminobenzylidene-1-amino-2,3,3,5-tetramethylindoline (Exemplary Compound-20): 1-Amino-2 , 1.9 g of 3,3,5-tetramethylindoline and 2.73 g of p-diphenylaminobenzaldehyde were treated in the same manner as in Synthesis Example 11,
4.0 g (theoretical yield: 90%) of crystals with a melting point of 150°C was obtained.
The IR spectrum (KBr) of this product is shown in Figure 8. The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.13 (3H, d, J = 6.3Hz), 1.25 (3H,
S), 1.32 (3H, S), 2.29 (3H, S), 4.04 (1H,
q, J = 6.3Hz), 6.88 (1H, S), 6.97-7.11
(10H, m), 7.22-7.26 (4H, m), 7.48 (1H,
S), 7.54 (2H, d, J = 8.7Hz) Synthesis Example 13 Synthesis of 4'-diethylaminobenzylidene-1-amino-2,3,3,5-tetramethylindoline (Exemplary Compound-5): 1-Amino 1.9 g of -2,3,3,5-tetramethylindoline and 1.77 g of p-diethylaminobenzaldehyde were added to 20 ml of ethanol, 2 drops of acetic acid were added, and the mixture was stirred under reflux for 4 hours. After that, the crystals formed by cooling were filtered and 3.43g (theoretical yield 98
%) of crystals were obtained. This was recrystallized from ethanol-ethyl acetate, and 3 g of crystals with a melting point of 171-2°C were obtained.
(Theoretical yield: 86%). The IR spectrum (KBr) of this product is shown in FIG. Also of this
The 400MHz NMR spectrum ( _CDCl3 ) is as follows. δppm: 1.12 (3H, d, J = 6.4Hz), 1.16 (6H,
t, J=7.1Hz), 1.25 (3H, S), 1.28 (3H,
S), 2.28 (3H, S), 3.36 (4H, q, J = 7.1
Hz), 3.94 (1H, q, J = 6.4Hz), 6.66 (2H,
d, J=8.9Hz), 6.86 (1H, S), 6.92-6.94
(2H, m), 7.54 (2H, d, J=8.9Hz), 7.59
(1H,S) Synthesis Example 14 Synthesis of 4'-dibenzylamino-2'-methylbenzylidene-1-amino-2,3,3,5-tetramethylindoline (Exemplary Compound-23): 1-Amino-2 , 0.95 g of 3,3,5-tetramethylindoline and 1.57 g of 4-dibenzylamino-2-methylbenzaldehyde were reacted and purified in the same manner as in Synthesis Example 3 to give 2.1 g of crystals with a melting point of °C (theoretical yield 86%). ) was obtained. The IR spectrum (KBr) of this product is shown in FIG. 400M of this stuff
The Hz NMR spectrum (CDCl ₃ ) is as follows. δppm: 1.12 (3H, d, J = 6.5Hz), 1.26 (3H,
S), 1.29 (3H, S), 2.28 (3H, S), 2.39 (3H,
S), 3.96 (1H, q, J = 6.5Hz), 4.15 (4H,
S), 6.55 (1H, d, J = 2.6Hz), 6.64 (1H,
dd, J=2.6, 8.7Hz), 6.86 (1H, S), 6.93
(2H, S), 7.22-7.26 (6H, m), 7.30-7.34
(4H, m) Synthesis Example 15 Methyl isopropyl ketone-p-methoxyphenylhydrazone ((in the formula, R = methoxy)
Synthesis: p-methoxyphenylhydrazone hydrochloride 150g
was neutralized with caustic soda to give hydrazine, and recrystallized from benzene to obtain 126.7 g (wet). To this hydrazine, 147g of methyl isopropyl ketone,
Add 441ml of special grade benzene and 0.5ml of acetic acid, and reflux.
Stirred for 4.5 hours. After the reaction is complete, the benzene is collected and distilled to obtain the target compound with a boiling point of 128-132℃/Hg.
105.1 g (theoretical yield 59.3%) was obtained. of this
The 400MHz NMR spectrum ( _CDCl3 ) is as follows. δppm: 1.11 (6H, d, J = 6.9Hz), 1.54 (3H,
S), 2.54 (1H, q, J = 6.9Hz), 3.75 (3H,
S), 6.55 (1H, broad S), 6.81-6.84 (2H,
m), 6.98-7.02 (2H, m) Synthesis Example 16 Synthesis of 2,3,3-trimethyl-5-methoxyindolenine ((in the formula), R = methoxy): 105.1 g of hydrazone obtained in Synthesis Example 15 above acetic acid
The mixture was added to 950 ml and stirred for 3 hours under reflux at 110-119°C. After collecting acetic acid, add benzene and wash with water. The benzene layer was dried, concentrated, and distilled under reduced pressure to obtain 81.0 g (theoretical yield: 84.0%) of the title indolenine having a boiling point of 114-6°C/3 mmHg and a melting point of 55°C. The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.27 (6H, S), 2.23 (3H, S), 3.81 (3H,
S), 6.80-6.84 (2H, m), 7.42 (1H, d, J
= 8.3Hz) Synthesis Example 17 Synthesis of 2,3,3-trimethyl-5-methoxyindoline ((in the formula), R = methoxy): Dissolve two granular caustic potash in 220ml of special grade methanol, and add NaBH ₄ 21.0 Dissolve g at 10℃
34 g of indolenine obtained in Synthesis Example 16 was added as a solid at 10 to 15° C. over 30 minutes. at room temperature
After reacting for 15 hours, acetic acid-water (1:1) solution
95.4 ml was added dropwise over 30 minutes while keeping the temperature below 20 degrees. The mixture was reacted for 30 minutes while raising the temperature to 45 degrees, and after cooling, it was decomposed with water containing 36 g of caustic soda. Then, extract with benzene, wash the benzene layer with water, dry and distill under reduced pressure to obtain a boiling point of 115-7℃/3.
30.3 g of indoline (88.2% theoretical yield) of mmHg was obtained. The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.02 (3H, S), 1.17 (3H, d, J = 6.5
Hz), 1.26 (3H, S), 3.48 (1H, q, J = 6.5
Hz), 3.64 (1H, broad S), 3.74 (3H, S),
6.54-6.60 (2H, m), 6.65 (1H, S) Synthesis example 18 1-amino-2,3,3-trimethyl-5-methoxyindoline ((in the formula, R = methoxy)
Synthesis: 19.1 g of 2,3,3-trimethyl-5-methoxyindoline was added to 200 ml of acetic acid, and 9 g of sodium nitrite was added little by little while stirring. After stirring at room temperature for 3 hours, the mixture was poured into water, extracted with benzene, washed with water, and dried. This benzene solution was added dropwise to 57.8 g of vitride under a nitrogen stream while stirring and keeping the temperature below 60 degrees. After stirring for 4 hours, pour 8 g of caustic soda into 200 ml of water.
Hydrolyzed. Thereafter, it was extracted with benzene, washed with water, dried, and concentrated to obtain 17.3 g of a crude product. This was recrystallized from petroleum ether to obtain 9.92 g of methoxyindoline (theoretical yield: 48.1%) with a melting point of 55°C.
The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.01 (3H, S), 1.24 (3H, d, J = 6.5
Hz), 1.27 (3H, S), 2.69 (1H, q, J = 6.5
Hz), 3.37 (2H, broad S), 3.75 (3H, S),
6.66-6.71 (2H, m), 6.76 (1H, d, J = 8.4
Hz) Synthesis Example 19 Synthesis of 4'-diethylaminobenzylidene-1-1amino-2,3,3-trimethyl-5-methoxyindoline (Exemplary Compound-6) 1-Amino-2,3,3-trimethyl-5- 1.44 g of methoxyindoline and 1.24 g of p-diethylaminobenzaldehyde were added to 20 ml of ethanol, 3 drops of acetic acid were added, and the mixture was stirred under reflux for 4 hours.
Thereafter, it was cooled and the crystals formed were filtered and collected.
This was recrystallized from acetonitrile and had a melting point of 143.
2.37 g of crystals (theoretical yield 92.7%) were obtained. The IR spectrum (KBr) of this product is shown in FIG. The 400MHz NMR spectrum (C ₆ H ₆ ) of this product is as follows. δppm: 0.909 (6H, t, J = 7.1Hz), 0.949 (3H,
d, J=6.3Hz), 1.10 (3H, S), 1.13 (3H,
S), 3.00 (4H, q, J = 7.1Hz), 3.46 (3H,
S), 3.75 (1H, q, J = 6.3Hz), 6.63 (2H,
d, J = 8.9Hz), 6.77 (1H, dd, J = 2.4, 8.4
Hz), 6.81 (1H, d, J = 2.4Hz), 7.36 (1H,
d, J=8.4Hz), 7.67 (1H, S), 7.80 (2H,
d, J=8.9Hz) Synthesis example 20 N'-ethyl-3'-carbazolylmethylidene-1
-Synthesis of amino-2,3,3-trimethyl-5-methoxyindoline (Exemplary compound-18) 2.27 g of 1-amino-2,3,3-trimethyl-5-methoxyindoline and N-ethylcarbazole-3-carbo 2.45 g of aldehyde was treated in the same manner as in Synthesis Example 19, and 2.76 g of crystals with a melting point of 164-5°C were obtained.
(Theoretical yield: 61.1%). The IR spectrum (KBr) of this product is shown in FIG. The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.20 (3H, d, J = 6.4Hz), 1.30 (3H,
S), 1.33 (3H, S), 1.89 (3H, t, J = 7.2
Hz), 3.79 (3H, S), 4.06 (1H, q, J = 6.4
Hz), 4.34 (2H, q, J = 7.2Hz), 6.71 (1H,
d, J=2.5Hz), 6.76 (1H, dd, J=2.5, 8.4
Hz), 7.11 (1H, d, J = 8.4Hz), 7.23 (1H,
dd, 7.1, 8.6Hz), 7.37-7.40 (1H, m), 7.46
(1H, dd, J=7.1, 8.1Hz), 7.81 (1H, S),
7.89 (1H, d, J = 8.6Hz), 8.13 (1H, d, J
= 8.6Hz), 8.34 (1H, d, J = 1.4Hz) Synthesis example 21 4'-dibenzylamino-2'-methylbenzylidene-1-1amino-2,3,3-trimethyl-
Synthesis of 5-methoxyindoline (exemplary compound-
24) Synthesis Example 3: 1.03 g of 1-amino-2,3,3-trimethyl-5-methoxyindoline and 1.57 g of 4-dibenzylamino-2-methylbenzaldehyde.
The reaction and purification were carried out in the same manner as above, and crystals with a melting point of 56℃ were obtained.
2.0 g (80% theoretical yield) was obtained. The IR spectrum (KBr) of this product is shown in FIG. The 400MHz NMR spectrum (CDCl ₃ ) of this product is as follows. δppm: 1.13 (3H, d, J = 6.4Hz), 1.27 (3H,
S), 1.28 (3H, S), 2.39 (3H, S), 3.76 (3H,
S), 3.94 (1H, S), 4.65 (4H, S), 6.55 (1H,
d, J=2.2Hz), 6.64 (1H, dd, J=2.2, 8.8
Hz), 6.69 (2H, d, J = 7.9Hz), 6.93 (1H,
d, J=7.9Hz), 7.23~7.26 (6H, m), 7.30~
7.35 (4H, m), 7.70 (1H, d, J = 8.8Hz),
7.80 (1H, S) Example 1 Chlordian Blue 0.2 as a charge generating substance
g was mixed with 4 g of dichloroethane solution containing 5% polycarbonate resin ("Iupilon E-2000" manufactured by Mitsubishi Gas Chemical Co., Ltd.), and dichloroethane 20
ml was added, and then ground to 1 μm or less using a vibrating mill to prepare a dispersion of charge carrier-generating pigment. This was applied onto a polyethylene terephthalate (PET) film coated with aluminum using a Mayer bar and dried at 45°C to form a charge carrier generation layer with a thickness of approximately 1 μm. On this charge carrier generation layer, a charge transport layer coating solution was applied, which was prepared by dissolving 5% by weight of the charge transporting materials of Synthesis Examples 3 and 13 of the present invention in a 5% by weight solution of polycarbonate (Iupilon E-2000) in dichloroethane. Using a doctor blade, apply to a dry film thickness of approximately 15μ,
It was dried at 45-60°C for 4 hours. Fluctuations in surface potential of the thus obtained electrophotographic photoreceptor films (Products 1 and 2 of the present invention) were measured using an electrostatic copying paper tester (Model SP-428; manufactured by Kawaguchi Denki Seisakusho). The photoreceptor was charged by performing -6KV corona discharge for 5 seconds, the surface potential V ₀ (unit - volt) was measured, and after holding this in a dark place for 5 seconds, it was exposed to light with an illuminance of 5 lux using a tungsten lamp. The exposure amount required to attenuate the surface potential to 1/2 and 1/6, that is, the half-decreasing exposure amount E1/2 (lux-second) and E1/6 (lux-second), and the illumination intensity of 5 lux. The surface potential V _R20 (volts) after irradiation with light for 20 seconds was determined. Subsequently, 10,000 lux light is irradiated for 3 seconds to eliminate residual charges, and one cycle is completed. This was repeated 200 times, and the same measurement was performed on the 200th time. For comparison, a photoreceptor (comparative product 1) was prepared in the same manner except that the following comparative compound-1 was used instead of the compound of Synthesis Example 3.
Fluctuations in surface potential were measured using These results are shown in Table-1. Comparative compound-1

[Table] Example 2 A photoreceptor was prepared in the same manner as in Example 1, except that Exemplary Compounds 16, 17, and 18 and Comparative Compound 2 below were used, and changes in surface potential were measured. The results are shown in Table-2. Comparative compound-2

[Table] Example 3 A photoreceptor was prepared in the same manner as in Example 1 except that exemplified compounds 19, 20, 22, 23, and 24 were used, and variations in surface potential were measured. Table the results.
Shown in 3.

[Table] Example 4 A photoreceptor was prepared in the same manner as in Example 1 except that exemplified compounds 4 and 6 and comparative compound 1 were used, and phthalocyanine was used instead of chlordian blue. The fluctuations were measured. The results are shown in Table-4.

[Table] Example 5 Exemplary compounds-16, 17, 18, 19, 20, 22, 23 and
A photoreceptor was produced in the same manner as in Example 11 except that No. 24 was used, and the fluctuation in surface potential was measured. The results are shown in Table-5.

【table】

〔Effect of the invention〕

The electrophotographic photoreceptor using the N-amino-2,3,3-trimethylindoline derivative of the present invention has high sensitivity, low residual potential, little optical fatigue even after repeated use, and excellent durability. Therefore, it has the properties most required in the field of electrophotographic processes and is industrially advantageous.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the electrophotographic photoreceptor of the present invention. Figures 2 to 5 are drawings showing the IR spectra of Exemplary Compounds 4, 16, 19 and 22, respectively. FIG. 6 is a drawing showing the IR spectrum of methyl isopropyl ketone tolyl hydrazone. Figures 7 to 13 show exemplary compounds 17, 20, 5, 23, 6, 18, and 24, respectively.
It is a drawing showing an IR spectrum.

Claims (1)

[Claims] 1. In an electrophotographic photoreceptor in which a charge generation layer and a charge transport layer are provided on a conductive support, the charge transport layer has the following general formula (), [In the formula, R is hydrogen, a lower alkyl group, or a lower alkoxy group, and Ar is a group [Formula] (where, R ₁ and R ₂ are a lower alkyl group, phenyl group, or benzyl group, and R ₄ is a lower alkyl group. )
or a group [formula] (wherein R ₃ represents a lower alkyl group)] Photographic photoreceptor.